tips to maximize crushing efficiency - pit & quarry : pit & quarry
To apply what this means to your crusher, operations produce the exact sizes in the reduction process that their market demands. In the past, quarries produced a range of single-size aggregate products up to 40 mm in size.
In practice, many jaw crushers are not fed to their designed capacity. This is because the subsequent processing plant does not have sufficient capacity to handle the volume of material that would be produced if the jaw crusher was working to capacity.
If you seek fewer fines, trickle feeding material into the jaw crusher could achieve this. But this would have an adverse effect on particle shape, and it also reduces throughput capacity, hindering the crushers efficiency.
Ideally, the feed rate should not be switched from choke to non-choke, as this can cause problems downstream at the secondary processing plant. In practice, many jaw crushers are fed in this intermittent fashion due to gaps in the delivery of feed material from the quarry.
The reduction ratio is then calculated by comparing the input feed size passing 80 percent versus the discharge size that passes 80 percent. The finer the closed-side setting, the greater the proportion of fines produced.
The closed-side setting of a jaw crusher helps determine the nip angle within a chamber, typically 19 to 23 degrees. Too large of an angle causes boiling in the crushing chamber. This is where the jaw plates cannot grip onto the rock, and it keeps slipping up and down, avoiding being crushed. The nip angle gets flatter as the machine is set tighter.
The settings on a jaw crusher are designed to produce material ideal for secondary crushing. The best particle shape is typically found in material that is about the same size as the closed-side setting.
Smaller sizes will contain a higher proportion of elongated particles because they have passed through the crusher without being touched. Larger sizes may also contain a higher proportion of elongated particles because they are further from the closed-side setting. This can cause bridging issues in downstream machines.
It is critical that a cone-type crusher be choke fed to produce the best product shape and quality. It is not as important in a jaw, as material is not generally stockpiled after the jaw. Because the cone is part of the secondary and tertiary stations, particle shape assisted by a choke-fed chamber is important because finished products are created in these stages.
Choke feeding is important for cone crushers because it maintains a good particle shape by facilitating an inter-particle crushing action. Trickle feeding is not the best option because it increases the proportion of flaky material in the crusher product, hindering its efficiency.
It is a good rule to maintain about 10 to 15 percent of material finer than the closed-side setting in the feed to assist crushing action. More than 10 to 15 percent will likely cause ring bounce due to the pressures in the chamber.
Its important to find the right liner for the feed gradation and desired product. If the liner is too large, feed material will drop too far in the chamber before being crushed. Too fine of a liner will prevent material from entering the chamber at all.
Monitoring the crushing force as registered through the load on the crusher motors, as well as the pressure on the hydraulic mantle adjustment mechanism, will give forewarning of crusher packing problems before they affect your efficiency.
Try to match the closed-side setting of the crusher to the top size of the product to be produced. If closing the circuit at 1 in. to produce a 1-in.-minus product, set the crusher at or near 1 in. or slightly below.
The initial impact is responsible for more than 60 percent of the crushing action, with the remainder made up of impact against an adjustable breaker bar and a small amount of inter-particle collision.
This is why it is vitally important that the feed arrangement to an impact crusher ensures an even distribution of feed material across the full width of the rotor. This will allow for even distribution of energy into the feed material and uniform wear patterns, ensuring consistent product gradation and power consumption.
Slower rotor speeds can be used as a means of reducing fines but may result in a product with more oversize or return than is desired. Slower rotor speeds are preferable as a means of minimizing the wear on crusher components, as well as for achieving less fines production and optimal product size.
The product grading from an impact crusher will change throughout the life of the wear parts, particularly the impact hammers or blow bars. As the profile of the hammer changes with increased wear, the product grading becomes coarser. Many modern impact crusher installations have a variable speed drive arrangement that allows an increase in the rotor speed to compensate for wear on the impact hammers.
In many impact crushers, a third curtain or crushing chamber can be added to increase reduction in every pass through the machine. This can be important in finer product applications where the third chamber can provide the desired output gradation. A third chamber that increases the reduction will also increase the power needs and, normally, the wear cost.
One tip to consider: Decreasing the gap between the hammers and impact curtain increases particle retention in the chamber. This increases the size reduction ratio, but it also reduces efficiency throughput capacity and increases fines production.
Follow the steps outlined in this article to achieve the best crushing efficiency for jaw, cone, gyratory and impact crushers and to ultimately increase profits and reduce fines production. By taking these steps, youre reducing the amount fines produced and adding dollars to your pocket.
rock crushing rule of thumb
Gyratory crusher: feed diameter 0.75 to 1.5m; reduction ratio 5:1 to 10:1, usually 8:1; capacity 140 to 1000 kg/s; Mohs hardness <9. More suitable for slabby feeds than jaw crusher. [reduction by compression].
reducing top size with minimum fines - crushing, screening & conveying - metallurgist & mineral processing engineer
We are producing crushed dolomite with a top size of 3mm using a HSI crusher and want to reduce the top size to 1mm while not substantially increasing the -300 micron fines. Current raw feed is 19mm stone.
My biggest concern is that just changing the screens to 1mm will cause a lot more fines to be produced, while we already want to reduce them if possible. I know my ideal situation is asking for a bit much, but any information about either which crushers will perform better or how I can change the current setup to decrease my top size and fines would be greatly appreciated.
I am unsure exactly what the current throughput is but I expect it is around 60 t/h. We are also not running at capacity, so we could increase running hours to ensure we meet the demand, so longer run time could be acceptable.
Sorry I realize I did not mention it in my question: We already producing on the limit of the fines our client finds acceptable. So reducing the top size would put the fines fraction past specification. We want to switch the feed of a ball mill over to the fines removed (the -300 microns), but if there is too large of an increase in the fines produced we will exceed the ball mill capacity.
If you already have an existing oversize protection screen on your vibrating screen you should have a fairly good idea of what your oversize fraction is. To reduce fines simply increase the mill feed rate, returning oversize will help but you may also need to increase the new feed rate (or increase size of mill feed by increasing the feed rate to the VSI)
You may try to screen out at 1 mm and +1mm may be recirculated back to crusher with lower capacity crusher as its runing now and with longer operating hours if its possible. For trial run start with different capacity at 1 mm dry screening to optimise the pant capacity. If required another crusher may be required after necessary studies.
If you want to buy a material between 1 mm and 300 microns,It is appropriate to use a high-pressure roller crusher, at least the fine grinding may be the end result.You must leave the gap between the rolls open at 800 micronsYou can buy the product between the grinding scale.
Yes! That seems like a very good solution to use a roller crusher, it will decrease the top size and reduce the fines. I will look into doing some tests to see if our dolomite is not too flaky. I haven't worked with a roller crusher before, how much more maintenance and operating costs does it have relative to other crushers like a VSI?
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how to control the discharge size in crushing stone and sand? | fote machinery
Sand and stone crushing equipment can crush large size stones into stones or sand with different particle sizes to meet the different requirements of sand and stone materials for construction, railway, highway, and other projects.
Crusher is the common equipment of sand and stone industry that is often used to break large stones, and it has a lot of different types and specifications with different discharge sizes. Understanding the specifications of finished materials can provide necessary reference for users to select equipment.
The main objectives of particle size control are: firstly, to make the configuration and operation of the crushing machinery layer reasonable, secondly, to reduce the proportion of needle-like and flake aggregate in finished products, thirdly, to adjust the proportion of each particle size of the finished aggregate.
In the case of smooth operation of the crusher, the particle size of the sand and stone should be controlled and the acicular and flaky particles should be reduced. The acicular particles are those whose length of the stone particles is larger than 2.4 times the average particle size of the grade to which the particles belong.
And flaky particles are those whose thickness is less than 0.4 times of the average particle size (mean particle size refers to the average particle size of the upper and lower limit of the particle size). Well, how can we control the discharge sizes to produce the high-quality stones with different particle sizes of 5-10 mm gravel, 10-20 mm (1/4 to 1/2 inch) gravel, and 15-25 mm (1/2 to 3/4 inch) gravel that we need? This article explains it in detail.
According to the crusher discharging particle size for preliminary control, there are many different types of crushers, each type of working principle is different, and the discharging control mode is also different.
The finished product of sand and stone production line includes not only the stone with smaller particle size, but also the stone with larger one. Sand and stone production is divided into crushing, screening, sand-making and other chains.
Sandstone aggregate quality control is mainly based on sandstone aggregate particle size and gradation requirements, and adopts the advanced and mature crushing equipment and vibrating screen, to ensure that the production of sand and stone aggregate is in line with the standards and regulations of grading quality.
In the sand and stone aggregate market, stones or sand the customers need to have a certain standard particle size, for example: gravel is divided into 5-10 mm, 10-20 mm, 16-31.5 mm, sand is divided into coarse sand (average particle size of 0.5 mm or more), medium sand (average particle size of 0.35-0.5 mm), fine sand (average particle size of 0.25-0.35 mm).
However, the materials are mixed with particles in various sizes, which cannot meet the demand. Therefore, most of the crushing process is equipped with a vibrating screen, which is used to classify the discharge materials and screen out the stones or sand of various specifications that they need. If the requirements are not met, they can return to the crusher to continue crushing.
Those materials whose size are less than the 3/4 size of the sieve hole of the particles can easily cross the sieve hole, known as easy-to-sieve particles. Particles larger than 3/4 of the sieve hole are difficult to pass through the sieve hole, known as difficult-to-sieve particles. Particles whose particle size is 1-1.5 times of the size of the sieve hole are called stoppers.
Therefore, the screening containing a large number of fine grade materials can increase the method of auxiliary screening of larger size in sieve hole to discharge the coarse size products in advance.
In general, single layer vibrating screen can screen out two kinds of materials, double-layers vibrating screen can screen out three kinds of materials, three-layers vibrating screen can screen out four kinds of materials, and five-layers vibrating screen can screen out six kinds. Users can make reasonable choices according to their needs for finished stones and sand and suggestions from equipment manufacturers.
Usually the circular vibrating screen is used to assist the crusher in the crushing production line. In the whole process, customers can adjust each device according to their own needs to adjust the material size. Through our analysis, do you have a general understanding of how to control the particle size in your sand and stone production?
We hope to help you to buy a suitable crusher and to operate your machines smoothly. Now many equipment manufacturers are designing production lines for customers. If you are new to this industry, you can listen to the suggestions of equipment manufacturers because they have professional knowledge and rich experience to help you solve problems.
As a leading mining machinery manufacturer and exporter in China, we are always here to provide you with high quality products and better services. Welcome to contact us through one of the following ways or visit our company and factories.
Based on the high quality and complete after-sales service, our products have been exported to more than 120 countries and regions. Fote Machinery has been the choice of more than 200,000 customers.
12 tips to maximize cone crusher productivity - metso outotec
In order to gain a consistent aggregate quality, quantity and uniformity and achieve a balanced circuit, employees should operate cone crusher at a consistent closed side discharge setting. It will result in less production and more over-sized aggregate, if the crusher is operated at a wider-than-optimum setting, even if done only temporarily. In addition, over-sized product almost always causes issues in the circuit flow.
An example regarding the effect that crusher setting has on the product gradation is as follows, if the target crusher setting is 3/8 in. (10mm) yet the setting is not checked and it wears open to 1/2 in. (13mm), then the end result is a 15 percent decrease in the minus 3/8-in. (10mm) material size. There is a significant decrease in cone crusher productivity. If crushers are not being operated at consistent close side settings, many aggregate producers lose some of their revenue and the size of the amount could really surprise them. Therefore, it is good to check the crushers setting on a per shift basis.
The product will have an inconsistent shape and the production rate will be inconsistent, if the crusher is being operated at different cavity levels during the shift. When operating at a low cavity level, also known as half cavity, the product gradation will be much coarser. This level makes the product particles flatter and more elongated. A proper choke-fed cavity level should be pursued as it will increase crusher throughput tonnage and result in a more cubical product especially with tertiary (short head) crushers that make the most of the producers salable products.
Try not to trickle feed a cone crusher. In addition to causing poor cone crusher productivity and product shape, trickle feeding has an impact on bearing alignment within said crusher. A crusher should be operated above 40% but below 100% rated horsepower in order to maximize cone crusher productivity and to have a proper loaded bearing alignment. An optimal power range is to operate between 75%-95%. Operating a crusher above 110% rated power can cause premature crusher failure.
Try to direct the incoming feed material so that it is distributed vertically into the center of the crusher. This will ensure that all sides of the crushing cavity remain evenly filled. If the feed is directed somewhere else other than the center, it will cause over-sized product, more flat and elongated product particles and a low crusher throughput tonnage.
In this situation, the operator will typically tighten the crusher setting in an attempt to produce a smaller product size, which can cause an over-load in the form of adjustment ring movement on the side that is heavily loaded. Over time, in this condition the adjustment ring can become tilted on the main frame and it can cause a bigger loss in productivity. With correct feed distribution, maximum crusher capacity, more consistent product uniformity, significant reduction of the adjustment ring action, minimum pressure on the bearings, reduction in energy consumption and even wear of the liner can be reached.
The feed material entering the crushing cavity should not be segregated but should be well mixed and homogenous. The feed can become segregated when bigger stones are directed to one side and smaller ones to the opposite side of the crushing cavity. In this case, the smaller stones will have a higher bulk density which can cause a condition called packing or pancaking.
Packing makes the adjustment ring move on the side of the crusher where smaller stones are, and this movement forces the operator to open the crusher setting. Opening the crusher setting eliminates the over-load condition but it will cause oversized product because of the setting increase. Also, if the feed becomes segregated and if the adjustment ring is jumping or bumping, the ring can become tilted which leads to even a larger loss in cone crushers productivity.
Surge loading has a bad effect on the production of any crusher. Surge piles or feed hoppers along with variable speed feeding devices can be used to provide a better and more consistent feed control to the crusher. This makes it possible for the operator to run the crusher at a very consistent and stable cavity level. Cone crusher productivity can be easily increased by a minimum of 10 % by having better feed control. It can be achieved by using surge piles, hoppers and variable speed feeding devices such as belt conveyors or vibrating pan feeders.
Regarding the volume limit, each crushing cavity has a volumetric limit that determines maximum throughput and a choke-fed crusher is operating at its volumetric limit. The volume limit is exceeded when feed material overflows the top of the crusher.
As for the horsepower limit, each crusher has been designed to operate at a maximum power draw, and power draw will increase as the feed rate increases and as the feed material is crushed finer. The horsepower limit has been exceeded when the crusher draws more power than it is rated for.
Lastly, we must not forget about the crushing force limit of the crusher and as with the horsepower limit, crushing forces being applied between the mantle and bowl liner increase as the feed rate increases and as the feed material is crushed finer. The crushing force limit of the crusher has been crossed when the adjustment ring jumps, bumps, bounces, wiggles or moves on top of the main frame.
An ideal operational condition would exist when the crusher is operating at its volumetric limit while still being slightly below both the horsepower limit and crushing force limit. Operating any crusher outside of its designed parameters with either excessive power draw or with excessive crushing force results in a very serious crusher over-load. These over-loads create something known as fatigue damage which is permanent, irreversible and cumulative. Without a doubt, frequent over-loads will shorten the life cycle of any cone crusher.
If you find the crusher operating in a crushing force over-load condition (ring movement) or a power over-load condition (excessive power), open the crusher setting slightly, but try to stay choke fed. The benefit of staying choke fed is that there will still be rock-on-rock crushing and grinding taking place in the crushing cavity. This helps to maintain good cubical product shape even though the setting is slightly larger than optimum.
The other option of course would be to decrease the feed rate to the crusher. The disadvantage of this option is that product shape would typically suffer. Most common reasons for adjustment ring movement or excessive power draw are tramp events, poor feed distribution, segregation of the feed, too many fines in the feed, high moisture content, wrong mantle and bowl liner being used. It is also possible that the operator is simply trying to operate at an unrealistically small closed side setting.
The crusher will slow down and the belts will slip when proper drive belt tension is not maintained. This will cause unbelievably high power peaks at a very low crusher throughput tonnage. Improper or neglected drive maintenance will result in a high-horsepower consumption at a low crusher throughput tonnage. This inefficient use of connected horsepower will cause a higher than normal energy cost per ton of material crushed.
A speed sensor can be used to monitor the crusher countershaft speed and will send a warning signal of a slowing crusher to the PLC or it could be wired to simply turn on a warning lamp. When a warning is detected, the maintenance department can be dispatched to re-tighten the drive belts. When a speed sensor is used, drive belt life is extended, and proper production levels can be maintained.
"Fines in the crusher feed" is defined as material entering the top of the crusher which is already equal to or smaller than the crusher's closed-side discharge setting. As a rule of thumb, the maximum number of fines in the crusher feed should not exceed 25 percent for secondary crushers or 10 percent for tertiary crushers. When there is an excessive quantity of fines in the feed, it is typically the result of a vibrating screen problem. This problem could be because the screen is insufficient in size or a screen which is properly sized but is inefficient in operation.
Re-crushing and re-handling product size material due to vibrating screen, inefficiencies due to the way the screen is originally set up or due to improper vibrating screen maintenance will lead to an excessive quantity of fines in the crusher feed. This in-turn will lead to inefficient use of connected crusher horsepower and a higher energy cost per ton of material crushed.
Three feet, or one meter, is the maximum distance from which the feed material should fall from into the top of a small to mid-size cone crusher. When the feed material drops from a much greater distance than it should, the stones tend to slam into the V shaped crushing cavity with such velocity that it subjects the crusher to shock loads and extremely high stress levels. This situation is called high-velocity wedging. High-velocity wedging can result in power over-loads or force over-loads, or both. This action puts undue stress and strain on the crusher components and results in increased maintenance repair costs and poor crusher productivity.
Also, controlling the speed of the material that reaches the crusher is very important. When the material falls from a high height, some material can pass through the open side of the crushing chamber and others only crush in the end of the chamber, reducing the efficiency and causing adjustment ring movement, resulting in severe damages in the bronze liner on the main frame seating surface and the main frame pin bushings. Additionally, it can result in premature damage of the tramp release cylinders. In order to avoid those problems, the feeding material speed should be reduced, with steps in the chutes or stone box, reducing the fall height.
A vibrating screen positioned before the crusher is used to remove the fines or sticky material from the feed stream before it reaches the crushing chamber. This will help to avoid the packing or pancaking of the feed material within the crushing chamber, which also causes the jumping or bumping of the adjustment ring and inefficient operation. Keep in mind that the vibratingscreen needs to be sufficient in size and efficient in operation for it to work successfully.
the common questions of cone crusher and corresponding solutions | hxjq
Crushing machine is the most widely used equipment in the mining industry, and it is divided into several types according to different applications. The cone crusher is one of the most common ones and often used as the secondary crushing machine in the whole stone crushing process.
During the operation of the cone crusher, the operator often encounters a variety of problems. This article will list the common problems of the cone crusher and our professional engineers will give the most appropriate solutions, hoping it can help you.
Poor oil quality will reduce the viscosity of the oil film, causing the oil film to rupture in the process of breaking the spindle bushing, causing the copper sleeve to burn out. Therefore, it should be checked and replaced in time.
When the oil tubing is blocked or the oil pump's capacity is reduced, it is easy to cause the copper bush to be oil-free and the oil film cannot be formed until the copper sleeve is burnt. Therefore, the pipeline and the oil pump should be inspected regularly to ensure sufficient oil.
If the materials are mixed with iron, iron will increase the instantaneous load of the crusher, causing the oil film to rupture and burning the copper bush. Therefore, the metal detector on the feeding machine should maintain a sensitive and reliable state.
The gap between the spindle and its bushing should be kept between 1.0 and 1.2 mm. If it is too large or too small, the copper bushing will be burnt. Therefore, the gap between the spindle bushing and the spindle should be carefully checked during the replacement of new bushings.
The deformation of the spindle will cause a significant reduction in the cooperation between the spindle and the spindle bushing, especially after the crusher is running hot, causing the copper sleeve to burn. Therefore, the spindle status needs to be checked regularly.
Generally, the gap between the locking ring and the adjusting ring of the newly installed crusher is 12.5 mm. Therefore, according to the wear condition of the adjusting ring and the locking ring thread, the gap between the two can be appropriately increased to increase the locking force.
Different types of cone crushers have different maximum feeding sizes. Once the size of materials exceeds the maximum feeding range, the crushing load will increase and the locking force will be relatively insufficient, causing the adjustment ring to vibrate and adversely affect the product size. Therefore, the feed size needs to be strictly controlled.
Due to the improper or unreasonable position of the crusher feeding chamber, the feeding center and the crusher center seriously deviate, resulting in an unbalanced crushing force of the crusher, which makes the adjusting ring has a large force on one side.
The locking ring and the adjusting ring are combined by four bolts. Due to there is mixed with iron in material or the feeding size is overlarge, causing the locking bolt of crusher overload and brake, and the adjusting ring vibrates. Therefore, under this condition, the locking bolts should be replaced and the gap between the locking ring and adjusting ring should be set in the correct position.
The short type cone crusher with the longest parallel band can crush materials to a relatively fine size. And generally, it is used in the fine crushing process; while standard type cone crusher can crush materials to a relatively coarse size, but it has a high output and usually used in the middle crushing process.
During the crushing process, the worn condition of the sealing ring between the shaft frame and the mainframe should be checked. After a long term of use, this part of cone crusher may be worn and the original flexibility of the sealing ring would be reduced.
The reason for the oil leakage may also be that the oil cannot be quickly discharged from the equipment, especially when the oil temperature is low. Therefore, in the production, it should be checked whether there is any dirt in the main oil drain hose or pipe. Otherwise, the accumulation of dirt will hinder the flow of oil, which will cause the cone crusher to leak oil.
If the oil return hole of the U-shape tile of the cone crusher is too small, the lubricating oil will be leaked, and the amount of oil returned is small, which cant satisfy the well-lubrication of gears. In this case, it is necessary to appropriately increase the oil return hole of the U-shape tile to ensure the oil return amount, and fundamentally solve the problem of ole leakage and poor lubrication of the bevel gear.
The lubricating oil enters the lower part of the main shaft from the inlet pipe and is rubbed by the lubricating friction disc. If the working pressure of the cone crusher lubrication system is improper, the oil will be ejected from the shaft gap, causing the lubricating oil to leak downward along the outer circumference of the sealing cylinder.
If the gap between the inner wall of the base oil sump and the counterweight oil baffle ring plate is too small, the lubricating oil between them will easily form an oil seal under the action of tension during the working process of the cone crusher. Under the pressure of the air pressure, the oil seal will continuously overflow from the dust seal along the inner wall of the mainframe.
The design of the sealing structure is related to the effect of the sealing and the life of the sealing ring. The sealing effect of the sealing ring depends on the size of the mounting groove. The sealing ring installation groove is too deep and the compression of the sealing ring is insufficient of which will make a bad sealing effect.
Install the sealing ring correctly to ensure that the equipment is well sealed. Do not install the sealing ring with an angled tool to prevent scratching from the rings and avoid stretching it to deformation. Lubricate the sealing ring properly for installation.
Therefore, we should prohibit the temperature rise of the lubricating oil by increasing the heat dissipation area of the fuel tank to improve the heat dissipation effect of the fuel tank. If necessary, a cooler can be added to reduce the temperature of the lubricating oil.
The author hopes that the above questions and corresponding answers can help you. If you have any other questions about the cone crusher, please fill out the message form on the right or send us an email, our engineers will give you the first reply.
jaw crusher - an overview | sciencedirect topics
The mechanism of movement of rocks down the crusher chamber determines the capacity of jaw crushers. The movement can be visualised as a succession of wedges (jaw angles) that reduce the size of particles progressively by compression until the smaller particles pass through the crusher in a continuous procession. The capacity of a jaw crusher per unit time will therefore depend on the time taken for a particle to be crushed and dropped through each successive wedge until they are discharged through the bottom. The frequency of opening and closing of the jaws, therefore, exerts a significant action on capacity.
Following the above concepts, several workers, such as Hersam . Gaudin , Taggart , Rose and English , Lynch , Broman , have attempted to establish mathematical models determining the capacity.
Although it is not truly applicable to hard rocks, for soft rocks it is reasonably acceptable . This expression, therefore, is of limited use. The expressions derived by others are more appropriate and therefore are discussed and summarised here.
Rose and English  determined the capacity of a jaw crusher by considering the time taken and the distance travelled by the particles between the two plates after being subjected to repeat crushing forces between the jaws. Therefore, dry particles wedged between level A and level B (Figure4.4) would leave the crusher at the next reverse movement of the jaw. The maximum size of particle dropping out of the crusher (dMAX) will be determined by the maximum distance set at the bottom between the two plates (LMAX). The rate at which the crushed particles pass between the jaws would depend on the frequency of reversal of the moving jaw.
The distance, h, between A and B is equal to the distance the particle would fall during half a cycle of the crusher eccentric, provided the cycle frequency allows sufficient time for the particle to do so. If is the number of cycles per minute, then the time for one complete cycle is [60/] seconds and the time for half a cycle is [60/2]. Thus, h, the greatest distance through which the fragments would fall freely during this period, will be
Then for a fragmented particle to fall a distance h in the crusher, the frequency must be less than that given by Equation (4.10). The distance h can be expressed in terms of LMIN and LMAX, provided the angle between the jaws, , is known. From Figure4.4, it can be seen that
Rose and English  observed that with increasing frequency of the toggle movement the production increased up to a certain value but decreased with a further increase in frequency. During comparatively slower jaw movements and frequency, Rose and English derived the capacity, QS, as
Equation (4.12) indicates that the capacity, QS, is directly proportional to frequency. At faster movement of the jaws where the particle cannot fall the complete distance, h, during the half cycle, QF was found to be inversely proportional to frequency and could be expressed by the relation
The relationship between the frequency of operation and capacity of the jaw crusher can be seen in Figure4.5. This figure is plotted for values of LT=0.228m, W=1.2m, LMIN=0.10m, R=10, G=1 and the value of varied between 50 and 300rpm.
It should be noted that while considering the volume rates, no consideration was made to the change of bulk density of the material or the fractional voidage. However, during the crushing operation the bulk density of the ore changes as it passes down the crusher. The extent of the change depends on
PK is considered a size distribution function and is related to capacity by some function (PK). As the particles decrease in size, while being repeatedly crushed between the jaws, the amount of material discharged for a given set increases. Rose and English related this to the set opening and the mean size of the particles that were discharged. Defining this relation as it can be written as
The capacity is then dependant on some function which may be written as (). Equations (4.16) and (4.17) must, therefore, be incorporated into the capacity equation. Expressing capacity as mass of crusher product produced per unit time, capacity can be written as
The bulk density of the packing will depend on the particle size distribution. The relation between PK and (PK) and and () is shown in Figure4.6. It is based on a maximum possible bulk density of 40%.
As the closed set size must be less than the feed size, () may be taken as equal to 1 for all practical purposes. The maximum capacity of production can be theoretically achieved at the critical speed of oscillation of the moving jaw. The method of determining the critical speed and maximum capacity is described in Section4.2.3
The capacity of a jaw crusher is given by the amount of crushed material passing the discharge opening per unit time. This is dependent on the area of the discharge opening, the properties of the rock, moisture, crusher throw, speed, nip angle, method of feeding and the amount of size reduction.
In order to calculate the capacity of crushers, Taggart  considered the size reduction, R80, as the reduction ratio of the 80% passing size of the feed, F80, and product, P80. This may be written as
Hersam  showed that at a fixed set and throw, a decrease in feed size reduced the reduction ratio and increased the tonnage capacity. A fraction of the crusher feed is usually smaller than the minimum crusher opening at the discharge end (undersize) and, therefore, passes through the crusher without any size reduction. Thus, as the feed size decreases, the amount actually crushed becomes significantly less than the total feed. The crusher feed rate can increase to maintain the same crushing rate. Taggart expressed the relationship between crusher capacity and reduction ratio in terms of a reduction ton or tonne, QR defined as
The reduction tonnage term is dependent on the properties of the material crushed so that for a given reduction ratio, the crusher capacity will vary for different materials. Taggart attempted to compensate for this by introducing the comparative reduction tonne, QRC, which is related to the reduction tonne by the expression
The comparative reduction tonne is a standard for comparison and applies for the crushing conditions of uniform full capacity feeding of dry thick bedded medium-hard limestone where K=1. The factor K is determined for different conditions and is a function of the material crushability (kC), moisture content (kM) and crusher feeding conditions (kF). K is expressed as
To evaluate K, the relative crushability factor, kC, of common rocks was considered and is given in Table4.2. In the table, the crushability of limestone is considered standard and taken as equal to 1.
The moisture factor, kM, has little effect on primary crushing capacities in jaw crushers and could be neglected. However when clay is present or the moisture content is high (up to 6%) sticking of fine ores on the operating faces of the jaws is promoted and will reduce the production rate. The moisture effect is more marked during secondary crushing, where a higher proportion of fines are present in the feed.
The feed factor kF, applies to the manner in which the crusher is fed, for example, manually fed intermittently or continuously by a conveyor belt system. In the latter case, the rate of feeding is more uniform. The following values for factor kF are generally accepted:
The reduction ratio of the operation is estimated from screen analysis of the feed and product. Where a screen analysis is not available, a rough estimate can be obtained if the relation between the cumulative mass percent passing (or retained) for different size fractions is assumed to be linear (Figure4.7).
Figure4.7 is a linear plot of the scalped and unscalped ores. The superimposed data points of a crusher product indicate the fair assumption of a linear representation. In the figure, a is the cumulative size distribution of the unscalped feed ore (assumed linear) and b is the cumulative size distribution of the scalped ore. xS is the aperture of the scalping screen and d1 and d2 are the corresponding sizes of the scalped and unscalped feed at x cumulative mass percentage. Taking x equal to 20% (as we are required to estimate 80% that is passing through), it can be seen by simple geometry that the ratio of the 80% passing size of the scalped feed to the 80% passing size of the unscalped feed is given by
Run of mine granite is passed through a grizzly (45.7cm) prior to crushing. The ore is to be broken down in a jaw crusher to pass through a 11.5cm screen. The undersize is scalped before feeding to the jaw crusher. Assuming the maximum feed rate is maintained at 30t/h and the shapes of feed and product are the same and the crusher set is 10cm, estimate the size of jaw crusher required and the production rate.
Substituting values, assuming cubic-shaped particles where the shape factor=1.7, we haveF80=0.81.745.7+0.210=64.15cmandP80=0.81.711.5=15.64cmR80=64.1515.64=4.10HenceQRC=22.744.100.64=145.4t/h
For a jaw crusher the thickness of the largest particle should not normally exceed 8085% of the gape. Assuming in this case the largest particle to be crushed is 85% of the gape, then the gape of the crusher should be=45.7/0.85=53.6cm and for a shape factor of 1.7, the width should be=45.7 1.7=78cm.
From the data given by Taggart (Figure4.8), a crusher of gape 53.6cm would have a comparative reduction tonnage of 436 t/h. The corresponding crushing capacity would beQT=4360.644.10=68.1t/hand is thus capable of handling the desired capacity of 22.74 t/h.
To determine the capacity of jaw and gyratory crushers, Broman  divided the crusher chamber into different sections and determined the volume of each section in terms of the angle that the moving jaw subtended with the vertical. Broman suggested that the capacity per stroke crushed in each section would be a function of the top surface and the height of the section. Referring to Figure4.9, if is the angle of nip between the crusher jaws and LT and LMAX are the throw and open side setting, respectively, then
Michaelson  expressed the jaw crusher capacity in terms of the gravity flow of a theoretical ribbon of rock through the open set of the crusher times a constant, k. For a rock of SG 2.65, Michaelsons equation is given as
For a set of crusher sizes and set openings, the calculations obtained from the work of Rose and English and others can be compared with data from equipment manufacturers. Figure4.10 shows a plot of the results. Assuming a value of SC of 1.0, the calculations show an overestimation of the capacity recommended by the manufacturers. As Rose and English pointed out, the calculation of throughput is very dependent on the value of SC for the ore being crushed. The diagram also indicates that the calculations drop to within the installed plant data for values of SC below 1.0. Most other calculation methods tend to estimate higher throughputs than the manufacturers recommend; hence, the crusher manufacturers should always be consulted.
The Values Used in the Calculation were 2.6 SG, (PK)=0.65, ()=1.0 and SC=0.51.0 (R&E); k=0.4 (Hersam); k=0.3 (Michaelson); k=1.5 (Broman) and =275rpm. The Max and Min Lines Represent the Crushers Nominal Operating Capacity Range.
Jaw crushers are heavy-duty machines and hence must be robustly constructed. The main frame is often made from cast iron or steel, connected with tie-bolts. It is commonly made in sections so that it can be transported underground for installation. Modern jaw crushers may have a main frame of welded mild steel plate.
The jaws are usually constructed from cast steel and fitted with replaceable liners, made from manganese steel, or Ni-hard, a Ni-Cr alloyed cast iron. Apart from reducing wear, hard liners are essential to minimize crushing energy consumption by reducing the deformation of the surface at each contact point. The jaw plates are bolted in sections for simple removal or periodic reversal to equalize wear. Cheek plates are fitted to the sides of the crushing chamber to protect the main frame from wear. These are also made from hard alloy steel and have similar lives to the jaw plates. The jaw plates may be smooth, but are often corrugated, the latter being preferred for hard, abrasive ores. Patterns on the working surface of the crushing members also influence capacity, especially at small settings. The corrugated profile is claimed to perform compound crushing by compression, tension, and shearing. Conventional smooth crushing plates tend to perform crushing by compression only, though irregular particles under compression loading might still break in tension. Since rocks are around 10 times weaker in tension than compression, power consumption and wear costs should be lower with corrugated profiles. Regardless, some type of pattern is desirable for the jaw plate surface in a jaw crusher, partly to reduce the risk of undesired large flakes easily slipping through the straight opening, and partly to reduce the contact surface when crushing flaky blocks. In several installations, a slight wave shape has proved successful. The angle between the jaws is usually less than 26, as the use of a larger angle causes particle to slip (i.e., not be nipped), which reduces capacity and increases wear.
In order to overcome problems of choking near the discharge of the crusher, which is possible if fines are present in the feed, curved plates are sometimes used. The lower end of the swing jaw is concave, whereas the opposite lower half of the fixed jaw is convex. This allows a more gradual reduction in size as the material nears the exit, minimizing the chance of packing. Less wear is also reported on the jaw plates, since the material is distributed over a larger area.
The speed of jaw crushers varies inversely with the size, and usually lies in the range of 100350rpm. The main criterion in determining the optimum speed is that particles must be given sufficient time to move down the crusher throat into a new position before being nipped again.
The throw (maximum amplitude of swing of the jaw) is determined by the type of material being crushed and is usually adjusted by changing the eccentric. It varies from 1 to 7cm depending on the machine size, and is highest for tough, plastic material and lowest for hard, brittle ore. The greater the throw the less danger of choking, as material is removed more quickly. This is offset by the fact that a large throw tends to produce more fines, which inhibits arrested crushing. Large throws also impart higher working stresses to the machine.
In all crushers, provision must be made for avoiding damage that could result from uncrushable material entering the chamber. Many jaw crushers are protected from such tramp material (often metal objects) by a weak line of rivets on one of the toggle plates, although automatic trip-out devices are now common. Certain designs incorporate automatic overload protection based on hydraulic cylinders between the fixed jaw and the frame. In the event of excessive pressure caused by an overload, the jaw is allowed to open, normal gap conditions being reasserted after clearance of the blockage. This allows a full crusher to be started under load (Anon., 1981). The use of guard magnets to remove tramp metal ahead of the crusher is also common (Chapters 2 and 13Chapter 2Chapter 13).
Jaw crushers are supplied in sizes up to 1,600mm (gape)1,900mm (width). For coarse crushing application (closed set~300mm), capacities range up to ca. 1,200th1. However, Lewis et al. (1976) estimated that the economic advantage of using a jaw crusher over a gyratory diminishes at crushing rates above 545th1, and above 725th1 jaw crushers cannot compete.
In hardening and martempering conditions austenitic manganese steel was free from carbides both at the grain boundaries and in the grains. Hence, the crusher jaws produced with austenitic manganese in these conditions eradicated brittle failure experienced in locally produced crusher jaws.
Hardening followed by tempering precipitated carbide at the grain boundaries and in the grains instead of reducing the residual stress associated with hardening. The volume fraction of these carbides, however, increased with tempering temperature.
In martempering conditions austenitic manganese steel had better plastic flows due to a decrease in overall thermal gradient and reduction in residual stresses associated with heat-treatment operations. This gave a better combination of hardness and toughness than austenitic manganese steel in hardening conditions used for the production of imported crusher jaws.
Srikanth  used a jaw crusher to create37m coal dust particles. Coal samples were obtained from coal mines in addition to some samples from the same source as Thakur's samples. They used a Microtrac Standard Range Analyzer (SRA) and Small Particle Analyser (SPA), which measured projected area (and hence diameter) using laser scattering and diffraction, respectively. The data were combined and plotted on a RosinRammler graph (discussed in Chapter 8). Their main findings were as follows:
Higher rank coals produced more total dust (<15m) and respirable dust (<7m). Semianthracite coal produced 3.7 times more total dust and 4.2 times more respirable dust compared with high-volatile bituminous coal.
The RosinRammler graph distribution parameter, n, was also rank dependent. The value for n was 0.68, 0.84, 0.90, and 0.95 for semianthracite, low-volatile coal, high-volatile bituminous coal, and subbituminous coals, respectively. This is similar to findings by Thakur (refer to Chapter 8 in the book).
A material is crushed in a Blake jaw crusher such that the average size of particle is reduced from 50 mm to 10 mm with the consumption of energy of 13.0 kW/(kg/s). What would be the consumption of energy needed to crush the same material of average size 75 mm to an average size of 25 mm:
The size range involved by be considered as that for coarse crushing and, because Kick's law more closely relates the energy required to effect elastic deformation before fracture occurs, this would be taken as given the more reliable result.
In an investigation by the U.S. Bureau of Mines(14), in which a drop weight type of crusher was used, it was found that the increase in surface was directly proportional to the input of energy and that the rate of application of the load was an important factor.
This conclusion was substantiated in a more recent investigation of the power consumption in a size reduction process which is reported in three papers by Kwong et al.(15), Adams et al.(16) and Johnson etal.(17). A sample of material was crushed by placing it in a cavity in a steel mortar, placing a steel plunger over the sample and dropping a steel ball of known weight on the plunger over the sample from a measured height. Any bouncing of the ball was prevented by three soft aluminium cushion wires under the mortar, and these wires were calibrated so that the energy absorbed by the system could be determined from their deformation. Losses in the plunger and ball were assumed to be proportional to the energy absorbed by the wires, and the energy actually used for size reduction was then obtained as the difference between the energy of the ball on striking the plunger and the energy absorbed. Surfaces were measured by a water or air permeability method or by gas adsorption. The latter method gave a value approximately double that obtained from the former indicating that, in these experiments, the internal surface was approximately the same as the external surface. The experimental results showed that, provided the new surface did not exceed about 40 m2/kg, the new surface produced was directly proportional to the energy input. For a given energy input the new surface produced was independent of:
Between 30 and 50 per cent of the energy of the ball on impact was absorbed by the material, although no indication was obtained of how this was utilised. An extension of the range of the experiments, in which up to 120 m2 of new surface was produced per kilogram of material, showed that the linear relationship between energy and new surface no longer held rigidly. In further tests in which the crushing was effected slowly, using a hydraulic press, it was found, however, that the linear relationship still held for the larger increases in surface.
In order to determine the efficiency of the surface production process, tests were carried out with sodium chloride and it was found that 90 J was required to produce 1 m2 of new surface. As the theoretical value of the surface energy of sodium chloride is only 0.08 J/m2, the efficiency of the process is about 0.1 per cent. Zeleny and Piret(18) have reported calorimetric studies on the crushing of glass and quartz. It was found that a fairly constant energy was required of 77 J/m2 of new surface created, compared with a surface-energy value of less than 5 J/m2. In some cases over 50 per cent of the energy supplied was used to produce plastic deformation of the steel crusher surfaces.
The apparent efficiency of the size reduction operation depends on the type of equipment used. Thus, for instance, a ball mill is rather less efficient than a drop weight type of crusher because of the ineffective collisions that take place in the ball mill.
Further work(5) on the crushing of quartz showed that more surface was created per unit of energy with single particles than with a collection of particles. This appears to be attributable to the fact that the crushing strength of apparently identical particles may vary by a factor as large as 20, and it is necessary to provide a sufficient energy concentration to crush the strongest particle. Some recent developments, including research and mathematical modelling, are described by Prasher(6).
The main sources of RA are either from construction and ready mixed concrete sites, demolition sites or from roads. The demolition sites produce a heterogeneous material, whereas ready mixed concrete or prefabricated concrete plants produce a more homogeneous material. RAs are mainly produced in fixed crushing plant around big cities where CDWs are available. However, for roads and to reduce transportation cost, mobile crushing installations are used.
The materiel for RA manufacturing does not differ from that of producing NA in quarries. However, it should be more robust to resist wear, and it handles large blocks of up to 1m. The main difference is that RAs need the elimination of contaminants such as wood, joint sealants, plastics, and steel which should be removed with blast of air for light materials and electro-magnets for steel. The materials are first separated from other undesired materials then treated by washing and air to take out contamination. The quality and grading of aggregates depend on the choice of the crusher type.
Jaw crusher: The material is crushed between a fixed jaw and a mobile jaw. The feed is subjected to repeated pressure as it passes downwards and is progressively reduced in size until it is small enough to pass out of the crushing chamber. This crusher produces less fines but the aggregates have a more elongated form.
Hammer (impact) crusher: The feed is fragmented by kinetic energy introduced by a rotating mass (the rotor) which projects the material against a fixed surface causing it to shatter causing further particle size reduction. This crusher produces more rounded shape.
However, the gyratory crusher is sensitive to jamming if it is fed with a sticky or moist product loaded with fines. This inconvenience is less sensitive with a single-effect jaw crusher because mutual sliding of grinding surfaces promotes the release of a product that adheres to surfaces.
The profile of active surfaces could be curved and studied as a function of the product in a way to allow for work performed at a constant volume and, as a result, a higher reduction ratio that could reach 20. Inversely, at a given reduction ratio, effective streamlining could increase the capacity by 30%.
The theoretical work of Rose and English  to determine the capacity of jaw crushers is also applicable to gyratory crushers. According to Rose and English, Equation (5.4) can be used to determine the capacity, Q, of gyratory crushers:
Capacities of gyratory crushers of different sizes and operation variables are published by various manufacturers. The suppliers have their own specifications which should be consulted. As a typical example, gyratory crusher capacities of some crushers are shown in Tables5.5 and 5.6.
About 100g heavy metal contaminated construction and demolition (C&D) waste is weighed and preliminarily crushed by a jaw crusher. Then the crushed C&D waste is mixed well and reduced by quartering twice. After that, the sample is dried at 100C for 1h. An electromagnetic crusher is used as a fine crushing for about 46min. Crushed sample is placed in a polypropylene screw-cap plastic bottles for storage.
Teflon crucibles used for digestion should be soaked in 1:1 nitric acid for 12h, wash with distilled water, and dry for later use. Volumetric flasks should be soaked in 1:1 nitric acid for 12h and washed with distilled water.
Before digestion, 0.10000.3000g of C&D waste powder is accurately weighed and evenly spread on the bottom of Teflon crucibles. Then they are placed in oven and dried for 2h at 120C together till constant weight. Aqua regia (18mL) (hydrochloric acid:nitric acid=3:1) is added, and 2mL 40% hydrofluoric acid is added 10min later. The crucibles with lids on are placed on an electric heating plate at 180C and heated till the solid waste is dissolved. Then, 30mL deionized water is added and the heating should be continuously maintained till the solution is vaporized to 23mL. Transfer the liquid to a 25mL plastic volumetric flask after it is cooled down, in which the volumetric flask should be washed with 1% nitric acid solution three times. Add deionized water to a certain volume and filter through 0.22m membrane. Place the solution at 4C for analysis.
Various types of rock fracture occur at different loading rates. For example, rock destruction by a boring machine, a jaw or cone crusher, and a grinding roll machine are within the extent of low loading rates, often called quasistatic loading condition. On the contrary, rock fracture in percussive drilling and blasting happens under high loading rates, usually named dynamic loading condition. This chapter presents loading rate effects on rock strengths, rock fracture toughness, rock fragmentation, energy partitioning, and energy efficiency. Finally, some of engineering applications of loading rate effects are discussed.
the 14 best ice crusher machines [ 2021 reviews ]
Ice crushers are useful appliances to have around the home. They save you the effort of having to crush ice manually when hosting a party, garnishing meals, or preparing cocktails. Using hands is unhygienic and is also wasteful as ice spills everywhere. Buying a manual or electric ice crusher is helpful in the kitchen and requires minimal effort.
Choosing the best ice crusher can be challenging. You have to consider the size, capacity, and portability of the device before making the purchase. To make things simple, weve compiled a list of the best ice crusher machines. Lets explore.
High-quality electric ice crushers feature stainless steel blades and can crush at least 6 pounds of ice per minute. Your family will be thrilled to hear you can make them colorful snow cones, and your friends will enjoy fresh cocktails out on the patio. Here are the best electric ice crushers available on the market:
The Waring Pro IC70 is a stainless steel large-capacity ice crusher that features a sturdy build. It also includes stainless steel blades and an industrial mechanism, making it ideal for commercial use. Moreover, this ice crusher comes with a small container that holds up to 12cups of freshly crushed ice. Also, it can crush up to 30lbs of ice per hour, making it ideal for restaurants. Its sleek design gives it an edge over other contenders.
Ideal for use in events and house parties, the Smartxchoices is an electric ice shaver with stainless steel blades and a heavy-duty iron case base. Moreover, this ice crusher features a powerful motor that helps crush 143lbs of ice in an hour. Plus, it rotates at 1680 runs per minute. If youre looking for an ice crusher that is easy and safe to use, we recommend choosing the Smartxchoices crusher machine. It includes a safety cover switch that helps prevent accidents. Besides that, it also features a water resistance shutoff switch to ensure safe operation.
If youre looking for the perfect kitchen assistant to crush ice for a bar or home use, the Yescom 300W Electric Ice Shaver can be your best friend. With the ability to crush ice at a 1450rpms (rate per minute), it can provide up to 143lbs of ice per hour. As a result, you can expect it to cater a high-demand for large amounts of ice. Additionally, this ice crusher boasts stainless steel shaving blades. These blades are safe to use and designed to stay sharp.
Yescom ensures to provide reliable and efficient service. You can buy this machine if youre looking for an ice crusher convenient to use. It also features a water-resistant cover on the shutoff switch to prevent accidents. Plus, the ice crushers power switch shuts off automatically if the hopper is opened to guarantee maximum user safety. Moreover, the anodized aluminum casing and hopper make the ice crusher easy to clean and resistant to rust. Besides that, it also features a heavy-cast rigid base to enhance stability and reduce noise.
This is a dual-blade electric ice crusher is best suited for use in bars, restaurants, food stores, clubs, and cafeterias. The machine features a heavy-duty, sturdy base designed to ensure stability and reduce vibration and noise. Moreover, it includes a waterproof switch designed to guarantee safe operation and peace of mind. The ice crusher stops working automatically after releasing the hopper handle to ensure safety. Besides that, it uses corrosion-resistant food-rate stainless-blades that remain sharp and safe to use. The machine also features a powerful motor that helps crush up to 143lbs of ice per hour.
Meet high demands of crushed ice in a short time once you purchase ZENY Ice Shaver Machine. Featuring a sturdy stainless steel construction, this machine is an ideal choice for a durable ice crusher. Besides that, this ice shaver comes with a highly efficient motor. Like other models on this list, the powerful motor enables it to produce 143lbs of ice per hour. That means you can meet the enormous demands of ice in less time. If youre looking for a model that requires minimal upkeep and is easy to operate, you can acquire the Zeny Ice Shaver Machine. Its smart operation design and food-grade stainless steel ensure convenient serving.
Designed for frosty drinks, cocktails, and deserts, Deni 6100 Ice Crusher is a durable machine featuring a stainless steel finish. Moreover, the crusher boasts rust-free stainless steel blades to enhance durability for long-term use. You can expect to have a convenient operation as it requires minimal upkeep. Besides that, the safety-enhanced lid makes this model a great choice when looking for easy-to-use models.
Reviewers report that this is an easy to use machine and can cut, grind, and chop ice in no time! This ice crusher also features a skid-free bottom and has a massive capacity of around 50 ounces. Moreover, the plastic used is BPA free and heavy-duty. The stainless-steel blade is rust free and durable. If you enjoy making slushy desserts, consider buying this manual ice grinder by Zalik.
This unit is one of the best manual ice crushers on this list because it has a suction base that can make coarse and fine ice. Moreover, it comes with a 5-year warranty. Be careful to dry it well after each use as might rust otherwise. It also features a large production capacity and handles that can help it make coarse and fine ice. Plus, its body can hold up to 4 cups of ice at a time. Besides that, its easy to operate as you only need to fill the hopper with ice, remove the top, crank the handle, and you are ready.
The Innovee manual ice crusher is very sleek looking and attractive. It features a rust-proof zinc alloy construction for durability and long-term use. It also includes super sharp blades that make it easy to shave the ice. Moreover, it comes with a removable ice bucket equipped with non-slip legs, which ensure that it remains stable. Lastly, this device features a sturdy design and is constructed to be rust-proof.
The perfect manual ice crushers are used to create delicious and elegant platters, hors d oeuvres and cocktails. Luckily, the Lofami Ice Crusher is portable and lightweight so that you can take it to parties and festivals anywhere. It delivers simple and efficient operation, and all have to do is put ice in this crusher and crank the handle. After a few rotations, you start getting perfectly shaved ice in the bottom compartment.
It is designed using sharp stainless steel blades that cut ice very efficiently and in a short time without bending the blade. When you use Lofami ice crusher to cut snow, it provides firmness and stability on uneven surfaces because the crusher has a skid-proof base. Because its a hand-operated manual crusher, it doesnt require electricity and saves energy bills. Its the ideal ice crusher for shaved ice, slushies, snow cones, smoothies, frozen beverages, and more.
An excellent choice for use at home, parties, restaurants, or cafeterias is VIVOHOME Electric Ice Crusher. The machine uses food-grade stainless blades and a hopper. As a result, you get a durable ice crusher built to resist rust and corrosion. Another great feature of this unit is the dual blades. They provide a double shaving efficiency enabling you to shave large volumes of ice fast and efficiently.
The Vivohome commercial ice crusher runs at 1400rpms (rate per minute). Moreover, it can shave up to 440lbs of ice per hour. Apart from that, it features a 10mm thickened acrylic case. The housing can 4.4liters of shaved ice and prevents shaved ice from splashing everywhere. Because of the switch, you can be sure that it is safe to use. Furthermore, the crusher features two rows of heat vents. These vents dissipate heat fast and improve the cooling capacity, extending the life of the ice machine.
Whether you want to crush vegetables, fruits, or ice, you can trust the Flexzion Commercial Electric Ice Shaver. Featuring a stainless construction, this is one of the most popular ice crushers on the market. Its durable and remains operational after regular use. Moreover, this ice crusher boasts a stable base, sturdy casing, and a hopper. You can use it without fear because it ensures convenience and safety. Its a perfect choice for buyers and designed to crush large volumes of ice in less time. It has a fast-processing, energy-efficient motor designed to crush 440lbs of shaved ice in an hour. Best of all, it has dual stainless steel blades that help crush ice fast and properly.
Like other models, ROVSUN commercial crusher features a stainless steel body and is one of the best in its class. If youre looking for a durable industrial ice crusher, consider choosing this. You wont have to invest in a brand new ice maker every year. Besides that, it includes a high-efficiency motor that runs at 1400rpms and helps shave up to 440lbs of ice per hour. Thanks to the waterproof cover on the switch, this unit is safe to use. Better, it shuts off when the cover is exposed to protect you from injuring your fingers. Because of the razor-sharp dual stainless steel blades, this ice crusher is a great choice for an industrial machine.
Whether you want to prepare cocktails for a party, or snow cones and slushies for your restaurant, you can buy the WYZworks Stainless Steel Ice Shaver. Its a promise of quality performance and efficiency. The machine boasts an all-stainless steel body, making it easy to clean and durable. Furthermore, it has a switch shielded with a waterproof cover to ensure safety. Its an excellent choice for home and commercial use. The powerful motor enables you to have 440 lbs of shaved ice per hour. You also get an extra pair of replacement blades.
When you want to prepare a fresh and delicious drink quickly, a manual ice crusher can help you with little ice. Itll produce the perfect quantity of snow for your drink, and youll avoid producing ice that goes to waste. This useful device will make the summer cool and fun! However, if you decide to host a party at your home, it will be challenging to serve the food, prepare the cocktails and crush ice manually, all at the same time.
If you run a family business like a small caf, bar, or restaurant, an electric ice crusher is mandatory. Its the mainstay for most commercial businesses and can make up to 500 lbs of ice in an hour. Therefore, your small business and summer parties will be a total success! Your clients and your friends will rave about the refreshing cocktails.
If you want to find the best product, you must consider some features that will help you decide. Choosing the perfect brand for you depends on several factors. Firstly, you must focus on the ice crushers capacity to determine the amount of ice you require. You have to know the average number of customers you have, or the number of people invited to your party. Itll help you determine the ice crusher that suits your needs.
After that, look at the size and gauge whether it is portable or not. This way, you can take it everywhere you go, on all your camping trips or family picnics. You can also take it to family gatherings, birthday celebrations, graduation parties, and all your college reunions. If you only want an ice crusher to use at home, you dont need to buy one that crushes 30lbs. of ice per hour. This volume is more suitable for commercial use. Furthermore, an ice crusher that crushes a large amount of ice consumes excessive electricity.
In the case of living in a small apartment, you dont need a large ice crusher. You should choose a lightweight and compact device because its easier to store and carry around. Youre less likely to drop it because its heavy and hurt yourself. If you decide to buy one with unique features, itll come with a hefty price tag. Therefore, stick to the important features and verify your budget before buying one.
If you want to purchase an ice crusher, consider a powerful one with a reliable motor. Furthermore, it should have solid and sharp edges. That way, it can easily transform ice into snowflakes and shaved squares. This device shouldnt be heavy and difficult to move around the house. You dont want any hassle while carrying it to your backyard barbecue party. You can notice the force of ice pulverizing the blender by looking at the sides of the box. It may feature settings that can allow the blender to better crush the ice.
When purchasing an ice crusher machine, you want one to last for a while. If youve paid more than expected, durability should be a given. If you take care of the machine, clean it after use and maintain it, you will have a few more years. However, we recommend buying a high-quality stainless steel machine since the regular contact with water causes wear and tear.
Keep in mind all the features mentioned in this guide will help you go shopping for an ice crusher. If you buy the right one, your family gatherings and reunion parties with friends will be cooler. Everyone will rave about the cold cocktails, and the kids will enjoy the colorful ice cones. Make sure the machine is durable enough and consider cleaning it regularly to prolong its life
Also known as an ice shaver, it is an appliance that is used for crushing the ice efficiently. Its widely used as a commercial appliance that shaves large volumes of ice blocks in a few hours. However, small electric and manual crushers are also available for household use.
Large capacity crushers use rugged material like stainless steel so they can be roughly used for commercial purposes. Household or over-the-counter portable ice crushers come with a plastic body and an eye-catching look. The feed tube through which large ice blocks are fed to the machine is a wide-mouthed opening that also features a funnel for easy feeding. The most important part of the ice crusher is the steel blade. Commercial machines incorporate heavy-duty steel blades to facilitate the high-capacity ice crushing within few minutes. The container is another major component of the appliance and is used to store the crushed ice. Commercial machines have containers that can hold up to 12 glasses of crushed ice, but household ice crushers come with a smaller container.
The idea behind the working of an ice machine is to break large blocks of ice and crush them. Shaved ice is ideal for cocktails, soft drinks and juices. Its a staple for home bars, and other commercial establishments. Moreover, the working mechanism of these machines is quite simple. There are two types of ice crushers: manual and electric. Both of them work in different ways, but offer the same benefits.
Manual crusher comes with a handle that moves manually and crushes the ice through blades and an attached grinder. You can move the handle in a clockwise manner as its easier to pound ice this way. The biggest benefit of manual ice crusher is that the volume of ice fed in the machine can be controlled. Besides that, the machine cant jam due to overload. However, manual ice crushers are outdated models and replaced by electric machines.
Electric ice shavers are popular in modern bars and large commercial establishments. Though electric machine has the same purpose as the manual appliance, the advantage of an electric machine is that its less time-consuming. You can plug in, feed the ice, and switch on the ice machine; these are all the steps for making crushed ice fast. Once all the ice in the hopper is crushed, the machine stops automatically. Shaved ice collects in the container.
Bar and restaurant owners use shaved ice for drinks that contain spirits as the main ingredient. You can also use it for cocktails, making slushies and ice cones. Fountain soda machines also have crushed and shaved ice. If you want a slurry and thick cocktail, you can use shaved ice.
Moreover, Snow cones are also made with crushed ice. You can use packed crushed ice and pour liquor over it to make a sultry drink. Amaretto, vermouth, wine and Chambord and some other spirits use shaved ice to produce a unique flavor.
Youll see a metal bar at the bottom of the ice bin that needs to be lifted. If its not being pushed down, then your ice crusher will dispense whole ice. Once you remove the ice bin, you will see the metal bar at the bottom, which makes crushed ice. Check the behind the ice bin; there will be a small hole through which the metal rod passes. Here a plastic stirrup pulls at the lever and changes the bin to make cubes. You have to ensure that the metal bar doesnt go under the stirrup.
Most ice crushers dont feature any adjustments. If the ice crusher is dispensing large chunks of solid ice, you can remove the ice bucket and run it under hot water. This will ensure the defrosting of frozen fingers if present.
Youll most likely find a plastic access cover panel below the ice crusher motor that you have to remove. Open the freezer door and check under the dispenser area near the interior walls of the door. Locate a 4 inch x 6 inch white panel with two screws attached to it. Remove these screws allowing the white panel to come off easily. The motor is visibly mounted here attached by four screws. You can unscrew them to remove and replace the ice crusher motor.
rock dust can improve our soils | ecofarming daily
Over 100 years ago Julius Hensel wrote a book calledBread from Stones,which explained how crushed rock could improve soil fertility. His cause was taken up some nine decades later in the early 1980s by the late John Hamaker and Don Weaver. They asserted that impending climate change could be ameliorated by massive-scale soil remineralization combined with reforestation to provide a vegetative carbon dioxide sink. Their book,Survival of Civilization,was a landmark, while their warnings of climate instability have essentially come true.
Demineralization occurs rapidly on intensively farmed and tropical soils. Rock dust can reverse this process, restoring life to the soil by adding a myriad of minerals to feed microorganisms and, given enough organic matter, helping to rebuild topsoil rapidly.
Only with remineralization, said John Hamaker can the soils ecosystemobtain the nutrients they need to reproduce, lay down their bodies, and make the stable colloidal humus vital for plants, animals and humans to thrive on, as they once did before we demineralized the Earth.
Hamaker, whose book did more to promote soil remineralization than any other single initiative, died in July 1994. He had previously been accidentally sprayed with the toxic herbicide 2,4-D by a roadside spraying operation and suffered debilitating illness from that time on.
In his last year of life he wrote to Barry Oldfield, president of the Western Australian Men of the Trees group, advocating the use of moraine gravels (from glaciers, absent in Australia) and urging the recognition that a healthy soil breeds bacteria which can utilize all the atmospheric gases, including nitrogen and carbon dioxide, which then helps to stabilize climate change.
A newsletter devoted to the benefits of rock dust was launched in 1986 in the United States, and in 1994 was upgraded into a quarterly magazine. Remineralize the Earth was edited by Joanna Campe. Although the magazine has ceased publication, partly because of the perception that this subject has finally become much more accepted by the mainstream, many U.S. universities and some government agriculture departments are now doing their own research and taking action. Remineralize the Earth (RTE) continues its important work as an active non-profit rock dust advocate.
In the 1980s Phil Callahan brought our attention to the importance of paramagnetism to plant growth and showed how volcanic rock dusts can supply this energy to soils. Many people regard his claims as farfetched, but such is the fate of all new ideas.
The Boral scientists have taken a holistic approach, studying the effects of applying rock dusts to potting mix alone, and in combination with sweetpit (a limestone-based, diamagnetic soil preparation) and artificial fertilizers in varying amounts. The best impact on plant growth was when all three were applied together.
Trials have shown that rock dust improves soil pH, water retention capacity, microbial activity, root-to-shoot ratio, plant health generally, seed germination rates, and the humus complex, while it increases plant height and weight and reduces plant mortality. Rock dust makes a good replacement for sand in growing media, they found. Boral is now recognized as a world leader in scientific research into rock dusts as soil improvers.
It became apparent to researchers that a purely paramagnetic effect was at work here. It was verified by pot trials by the Men of the Trees group (MOTT) in Western Australia. One MOTT trial involved burying little plastic bags of rock dust in the plant pot. Amazingly, this was enough to enhance plant growth, despite no physical contact between plant roots and rock dust.
If soil hasnt the right nutrient mix to match the crop, then using any old rock dust may not help, and could even prove toxic to some degree. While basalt rock dust is a major source of trace elements, it lacks the essential macronutrients nitrogen, phosphorus and, to a lesser extent, potassium.
Boral suggests blending different types of rock dust, such as granites and river gravel, plus added minerals, to make up for any deficiency. While commercial enterprises do various rock dust mixes to broaden the spectrum of minerals, this still may not suit your soils individual requirements.
High iron levels can be a problem in some soils (which are often a red color), so a poorly selected basalt rock dust or lava scoria might add excess iron if not applied in careful measure. Iron is needed for photosynthesis, but too much can combine with aluminum to lock up phosphate and trace elements in acidic soil types. Ten to 50 parts per million of iron in fertile soils is considered sufficient.
Rock dust is also a great additive to acidic soils, as it can help increase soil pH, thus reducing acidity. Acidity in soils, whether natural or induced by chemical farming, tends to lock away nutrients such as calcium and phosphates from plants. Superphosphate is very acidifying, with triple-superphosphate the worse type and mono-super the least bad form. (Its better still to supply slow-release phosphate in the form of untreated rock phosphate that has been composted.)
Aluminum is also released when soils are acid and if this gets into our systems, free-radical damage can occur in our tissues. Aluminum toxicity is also linked to repetitive strain injury and Alzheimers disease, which are far more prevalent since aluminum cooking pans became popular after the war.
Most people apply lime to increase soil pH, but this can cause problems in itself. Student of Rudolf Steiner and biodynamics researcher Ehrenfried Pfeiffer warned that the use of lime can burn out the humus complex as it overstimulates soil and plant processes.
This was seen in Austrian trials which compared rock dust and lime added to soil and the subsequent changes in soil pH over 87 days. Within 24 hours the soil that had been limed had risen from a low pH 4 to an optimum of pH 7. Such a huge increase in the ion count is very stressful to plants. The pH scale is logarithmic, going from 1 to 14, the scale being actually 10 to 1014. Such a sharp pH rise meant an increased ion count from 100,000 to 100,000,000 ions! Plants can become sick with the shock of this rate of change.
After the 87 days the rock dusted soil also ended up with a pH of 7, but it was a very gradual rise spread over the time, which did not incur any plant stress at all. These are only a few of the many documented benefits of rock dust in agriculture.
At most quarries Ive visited I have been allowed to fill a few bags with rock dust free of charge enough for a household vegetable garden. If you buy tonnages, you might pay around $15 per ton still inexpensive. The big cost is in transportation. Get together with friends and neighbors and share a truckload for best economy.
Above the maximum rate there is a leveling off of effects, so its not worth overdoing it. Because the cost of transport and spreading of rock dust on acreage is not cheap, it is recommended to put more out at less frequent intervals to reduce such costs. That is, instead of spreading 2 to 4 tons per acre every two or three years, it is more economical to spread 4 tons per acre every five or so years. However, smaller amounts, even as little as a 1 to 2 tons/ha (1/2 to 1 ton to the acre) will bring good results, when applied more often.
Austrian farmers have found it beneficial to spread rock dust around the time of cutting the cover crop. They observe that the more aerobic environment created on the soil surface helps the green manure crop to rot down more easily.
If seeking only the paramagnetic values of rock to impart to soil, you can add it in chip form for a one-off application. Chips are cheaper to produce and will not erode away like the finer dust. By choosing material with higher paramagnetic values you can reduce quantities needed, making substantial savings on expensive transportation. If you obtain the usual finest screenings of 5 mm (one-quarter inch) dust you will have a range of particle sizes from powdery dust to small sharp pieces that give the paramagnetic antenna effect as advocated by Philip Callahan.
Warning:So much for the good news about using rock dusts there has to be a downside! Heres a word of warning: The fine particles are a hazard if breathed in, since siliceous dusts can be as dangerous as asbestos to the lungs. It is advisable to always wear dust masks whenever this could be a hazard. And cover your load or wet it down during transport or it may blow away!
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