circular motion vibrating screen
IFE circular motion vibrating screens are used for screening of granoulos bulk material and are robust in design and build. The screen frame consists of both side panels and cross beams being bolted and glued to the panels carrying the screen deck substructure. The excitation is made with in-house manufactured IFE unbalanced shaft or with a single IFE unbalanced motor. IFE circular motion vibrating screens can be equipped with all different kinds of screen mats available on the market. IFE circular motion vibrating screens are best suitable for long-living and economical operation.
The IFE unbalanced shaft is a well-established and reliable drive for circular motion vibrating screens. The working torque can amount to 19000 kgcm, depending on type. Bearing lifetimes of up to 80.000 hours of operation can be achieved due to the optimized design of the first-class roller bearings and combined oil bath lubrication. These shafts are highly reliable. The speed of the unbalanced shaft can be controlled either with a V-belt or infinitely variable using a frequency converter, resulting in a variable adjustment of the amplitude.
Many accessories are available for all IFE screens, such as sprinkler systems, vibration sensors, screen panel cleaning mechanism or additional wear plates. Decades of experience allow IFE to achieve best results for your applications.Of course, all screening machines can be combined easily and perfectly with other machines from IFE and altogether present the ultimate solution.
Vibramech vibrating screens are custom designed for client needs and cover a vast range of sizes and unique process applications. Our screen design makes use of Finite Element Method and Strain Gauge Analysis to prove structural integrity. Our vibrating screens also feature wear protection and commonality of components to minimise spare parts inventories.
Horizontal screens are designed for wet or dry applications, ideal for smaller aperture sizing, de-sliming or dense medium recovery. Available in single-, double- and triple-deck configurations.
Vibrator motor-driven dewatering screens are designed for dewatering applications. They feature high G-forces with a dual-sloped screening deck for superior water removal.
Inclined screens, typically installed at a 15 or 19 deck angle, are combined with an optimised drive configuration. They are designed for large aperture screening or heavy-duty scalping applications.
Liwell screens are for difficult screening applications where sticky material is screened at small aperture sizes without process water. We are the exclusive sub-Saharan African distributor.
Vibramech screens are equipped with vibrator motor, geared exciter or oscillator drives, and are available in single-, double- or triple-deck configuration. The range of screening media includes polyurethane panels, rubber panels, wedge wire panels or woven wire panels. Screen isolation is achieved using rubber buffers, coil springs or Rosta mount isolators, and screens can be supplied with sub-frames if additional isolation is required.
Our flexibility in design provides customers the freedom to optimise their plant infrastructure without the standard screen geometric constraints, and enables screens to be retrofitted to existing infrastructure.
Other features include:
Over 500 units of Vibramech vibrating equipment are supplied and commissioned worldwide each year.
Complete the enquiry form to see how Vibramech vibrating screens will optimise your screening processes.
Vibramech has vibrating equipment installed throughout Africa and internationally, including Australia, Canada, China, India, USA and South America, Philippines, Russia and United Kingdom. This has resulted in an installed base of over 8000 pieces of Vibramech vibrating mineral processing equipment worldwide.
Vibramech supplies vibrating equipment primarily to the mining and mineral processing industries across the globe and has extensive experience in gold, diamond, coal, iron ore, manganese, platinum, chrome, nickel, uranium, copper, mineral sands and aggregate operations.
Vibramech has more than four decades of mineral processing experience and vibrating equipment design, enabling us to deliver screens, feeders, grease tables and drives best suited to our customers requirements.
Our customers plant infrastructures can be freely designed without standard geometric constraints because of Vibramechs design flexibility. This also means that equipment can be retrofitted to an existing infrastructure without major alterations to underpans, chutes and support steelwork.
More than 8000 pieces of equipment worldwide have been supplied by Vibramech. Our footprint extends throughout Africa and other regions including Russia, Kazakhstan, China, Canada, USA, South America, Australia, India, United Kingdom and the Philippines
Vibramech supplies vibrating equipment primarily to the mining and mineral processing industries across the globe and has extensive experience in gold, diamond, coal, iron ore, manganese, platinum, chrome, nickel, uranium, copper, mineral sands and aggregate operations.
vibrating screen working principle
When the smaller rock has to be classified a vibrating screen will be used.The simplest Vibrating Screen Working Principle can be explained using the single deck screen and put it onto an inclined frame. The frame is mounted on springs. The vibration is generated from an unbalanced flywheel. A very erratic motion is developed when this wheel is rotated. You will find these simple screens in smaller operations and rock quarries where sizing isnt as critical. As the performance of this type of screen isnt good enough to meet the requirements of most mining operations two variations of this screen have been developed.
In the majority of cases, the types of screen decks that you will be operating will be either the horizontal screen or the inclined vibrating screen. The names of these screens do not reflect the angle that the screens are on, they reflect the direction of the motion that is creating the vibration.
An eccentric shaft is used in the inclined vibrating screen. There is an advantage of using this method of vibration generation over the unbalanced flywheel method first mentioned. The vibration of an unbalanced flywheel is very violent. This causes mechanical failure and structural damage to occur. The four-bearing system greatly reduces this problem. Why these screens are vibrated is to ensure that the ore comes into contact will the screen. By vibrating the screen the rock will be bounced around on top of it. This means, that by the time that the rock has traveled the length of the screen, it will have had the opportunity of hitting the screen mesh at just the right angle to be able to penetrate through it. If the rock is small enough it will be removed from the circuit. The large rock will, of course, be taken to the next stage in the process.
Depending upon the tonnage and the size of the feed, there may be two sets of screens for each machine.
The reason for using two decks is to increase the surface area that the ore has to come into contact with. The top deck will have bigger holes in the grid of the screen. The size of the ore that it will be removed will be larger than that on the bottom. Only the small rock that is able to pass through the bottom screen will be removed from the circuit. In most cases the large rock that was on top of each screen will be mixed back together again.
The main cause of mechanical failure in screen decks is vibration. Even the frame, body, and bearings are affected by this. The larger the screen the bigger the effect. The vibration will crystallize the molecular structure of the metal causing what is known as METAL FATIGUE to develop. The first sign that an operator has indicated that the fatigue in the body of the screen deck is almost at a critical stage in its development are the hairline cracks that will appear around the vibrations point of origin. The bearings on the bigger screens have to be watched closer than most as they tend to fail suddenly. This is due to the vibration as well.
In plant design, it is usual to install a screen ahead of the secondary crusher to bypass any ore which has already been crushed small enough, and so to relieve it of unnecessary work. Very close screening is not required and some sort of moving bar or ring grizzly can well be used, but the modern method is to employ for the purpose a heavy-duty vibrating screen of the Hummer type which has no external moving parts to wear out ; the vibrator is totally enclosed and the only part subjected to wear is the surface of the screen.
The Hummer Screen, illustrated in Fig. 6, is the machine usually employed for the work, being designed for heavy and rough duty. It consists of a fixed frame, set on the slope, across which is tightly stretched a woven-wire screen composed of large diameter wires, or rods, of a special, hard-wearing alloy. A metal strip, bent over to the required angle, is fitted along the length of each side of the screen so that it can be secured to the frame at the correct tension by means of spring-loaded hook bolts. A vibrating mechanism attached to the middle of the screen imparts rapid vibrations of small amplitude to its surface, making the ore, which enters at the top, pass down it in an even mobile stream. The spring-loaded bolts, which can be seen in section in Fig. 7, movewith a hinge action, allowing unrestricted movement of the entire screening surface without transmitting the vibrations to the frame.
One, two, or three vibrators, depending on the length of the screen, are mounted across the frame and are connected through their armatures with a steel strip securely fixed down the middle of the screen. The powerful Type 50 Vibrator, used for heavy work, is shown in Fig. 7. The movement of the armature is directly controlled by the solenoid coil, which is connected by an external cable with a supply of 15-cycle single-phase alternating current ; this produces the alternating field in the coil that causes the up-and-down movement of the armature at the rate of thirty vibrations per second. At the end of every return stroke it hits a striking block and imparts to the screen a jerk which throws the larger pieces of ore to the top of the bed and gives the fine particles a better chance of passing through the meshes during the rest of the cycle. The motion can be regulated by spiral springs controlled by a handwheel, thus enabling the intensity of the vibrations to be adjusted within close limits. No lubrication is required either for the vibrating mechanism or for any other part of the screen, and the 15-cycle alternating current is usually supplied by a special motor-generator set placed somewhere where dust cannot reach it.
The Type 70 Screen is usually made 4 ft. wide and from 5 to 10 ft. in length. For the rough work described above it can be relied upon to give a capacity of 4 to 5 tons per square foot when screening to about in. and set at a slope of 25 to 30 degrees to the horizontal. The Type 50 Vibrator requires about 2 h.p. for its operation.
The determination of screen capacity is a very complex subject. There is a lot of theory on the subject that has been developed over many years of the manufacture of screens and much study of the results of their use. However, it is still necessary to test the results of a new installation to be reasonably certain of the screen capacity.
A general rule of thumb for good screening is that: The bed depth of material at the discharge end of a screen should never be over four times the size opening in the screen surface for material weighing 100 pounds per cubic foot or three times for material weighing 50 pounds per cubic foot. The feed end depth can be greater, particularly if the feed contains a large percentage of fines. Other interrelated factors are:
Vibration is produced on inclined screens by circular motion in a plane perpendicular to the screen with one-eighth to -in. amplitude at 700-1000 cycles per minute. The vibration lifts the material producing stratification. And with the screen on an incline, the material will cascade down the slope, introducing the probability that the particles will either pass through the screen openings or over their surface.
Screen capacity is dependent on the type, available area, and cleanliness of the screen and screenability of the aggregate. Belowis a general guide for determining screen capacity. The values may be used for dried aggregate where blinding (plugged screen openings), moisture build-up or other screening problems will not be encountered. In this table it is assumed that approximately 25% of the screen load is retained, for example, if the capacity of a screen is 100 tons/hr (tph) the approximate load on the screen would be 133 tph.
It is possible to not have enough material on a screen for it to be effective. For very small feed rates, the efficiency of a screen increases with increasing tonnage on the screen. The bed of oversize material on top of the marginal particlesstratification prevents them from bouncing around excessively, increases their number of attempts to get through the screen, and helps push them through. However, beyond an optimum point increasing tonnage on the screen causes a rather rapid decrease in the efficiency of the screen to serve its purpose.
Two common methods for calculating screen efficiency depend on whether the desired product is overs or throughs from the screen deck. If the oversize is considered to be the product, the screen operation should remove as much as possible of the undersize material. In that case, screen performance is based on the efficiency of undersize removal. When the throughs are considered to be the product, the operation should recover as much of the undersize material as possible. In that case, screen performance is based on the efficiency of undersize recovery.
These efficiency determinations necessitate taking a sample of the feed to the screen deck and one of the material that passes over the deck, that is, does not pass through it. These samples are subjected to sieve analysis tests to find the gradation of the materials. The results of these tests lead to the efficiencies. The equations for the screen efficiencies are as follows:
In both cases the amount of undersize material, which is included in the material that goes over the screen is relatively small. In Case 1 the undersize going over the screen is 19 10 = 9 tph, whereas in Case 2 the undersize going over is 55 50 = 5 tph. That would suggest that the efficiency of the screen in removing undersize material is nearly the same. However, it is the proportion of undersize material that is in the material going over the screen, that is, not passed through the screen, that determines the efficiency of the screen.
In the first cases the product is the oversize material fed to the screen and passed over it. And screen efficiency is based on how well the undersize material is removed from the overs. In other cases the undersize material fed to the screen, that is, the throughs, is considered the product. And the efficiency is dependent on how much of the undersize material is recovered in the throughs. This screen efficiency is determined by the Equation B above.An example using the case 1 situation for the throughs as the product gives a new case to consider for screen efficiency.
Generally, manufacturers of screening units of one, two, or three decks specify the many dimensions that may be of concern to the user, including the total headroom required for screen angles of 10-25 from the horizontal. Very few manufacturers show in their screen specifications the capacity to expect in tph per square foot of screen area. If they do indicate capacities for different screen openings, the bases are that the feed be granular free-flowing material with a unit weight of 100 lb/cu ft. Also the screen cloth will have 50% or more open area, 25% of total feed passing over the deck, 40% is half size, and screen efficiency is 90%. And all of those stipulations are for a one-deck unit with the deck at an 18 to 20 slope.
As was discussed with screen efficiencies, there will be some overs on the first passes that will contain undersize material but will not go through the screen. This material will continue recirculating until it passes through the screen. This is called the circulating load. By definition, circulating load equals the total feed to the crusher system with screens minus the new feed to the crusher. It is stated as a percentage of the new feed to the crusher. The equation for circulating load percentage is:
To help understand this determination and the equation use, take the example of 200 tph original or new material to the crusher. Assume 100% screen efficiency and 30% oversize in the crusher input. For the successive cycles of the circulating load:
The values for the circulating load percentages can be tabulated for various typical screen efficiencies and percents of oversize in the crusher product from one to 99%. This will expedite the determination for the circulating load in a closed Circuit crusher and screening system.
Among the key factors that have to be taken into account in determining the screen area required is the deck correction. A top deck should have a capacity as determined by trial and testing of the product output, but the capacity of each succeeding lower deck will be reduced by 10% because of the lower amount of oversize for stratification on the following decks. For example, the third deck would be 80% as effective as the top deck. Wash water or spray will increase the effectiveness of the screens with openings of less than 1 in. in size. In fact, a deck with water spray on 3/16 in. openings will be more than three times as effective as the same size without the water spray.
For efficient wet or dry screeningHi-capacity, 2-bearing design. Flywheel weights counterbalance eccentric shaft giving a true-circle motion to screen. Spring suspensions carry the weight. Bearings support only weight of shaft. Screen is free to float and follow positive screening motion without power-consuming friction losses. Saves up to 50% HP over4- bearing types. Sizes 1 x 2 to 6 x 14, single or double deck types, suspended or floor mounted units.Also Revolving (Trommel) Screens. For sizing, desliming or scrubbing. Sizes from 30 x 60 to 120.
TheVibrating Screen has rapidly come to the front as a leader in the sizing and dewatering of mining and industrial products. Its almost unlimited uses vary from the screening for size of crusher products to the accurate sizing of medicinal pellets. The Vibrating Screen is also used for wet sizing by operating the screen on an uphill slope, the lower end being under the surface of the liquid.
The main feature of the Vibrating Screen is the patented mechanism. In operation, the screen shaft rotates on two eccentrically mounted bearings, and this eccentric motion is transmitted into the screen body, causing a true circular throw motion, the radius of which is equivalent to the radius of eccentricity on the eccentric portion of the shaft. The simplicity of this construction allows the screen to be manufactured with a light weight but sturdy mechanism which is low in initial cost, low in maintenance and power costs, and yet has a high, positive capacity.
The Vibrating Screen is available in single and multiple deck units for floor mounting or suspension. The side panels are equipped with flanges containing precision punched bolt holes so that an additional deck may be added in the future by merely bolting the new deck either on the top or the bottom of the original deck. The advantage of this feature is that added capacity is gained without purchasing a separate mechanism, since the mechanisms originally furnished are designed for this feature. A positivemethod of maintaining proper screen tension is employed, the method depending on the wire diameter involved. Screen cloths are mounted on rubber covered camber bars, slightly arched for even distribution.
Standard screens are furnished with suspension rod or cable assemblies, or floor mounting brackets. Initial covering of standard steel screen cloth is included for separations down to 20 mesh. Suspension frame, fine mesh wire, and dust enclosure are furnished at a slight additional cost. Motor driven units include totally-enclosed, ball-bearing motors. The Vibrating Screen can be driven from either side. The driven sheave is included on units furnished without the drive.
The following table shows the many sizes available. Standard screens listed below are available in single and double deck units. The triple and quadruple deck units consist of double deck units with an additional deck or decks flanged to the original deck. Please consult our experienced staff of screening engineers for additional information and recommendations on your screening problems.
An extremely simple, positive method of imparting uniform vibration to the screen body. Using only two bearings and with no dead weight supported by them, the shaft is in effect floating on the two heavy-duty bearings.
The unit consists of the freely suspended screen body and a shaft assembly carried by the screen body. Near each end of the shaft, an eccentric portion is turned. The shaft is counterbalanced, by weighted fly-wheels, against the weight of the screen and loads that may be superimposed on it. When the shaft rotates, eccentric motion is transmitted from the eccentric portions, through the two bearings, to the screen frame.
The patented design of Dillon Vibrating Screens requires just two bearings instead of the four used in ordinary mechanical screens, resulting in simplicity of construction which cuts power cost in half for any screening job; reduces operating and maintenance costs.
With this simplified, lighter weight construction all power is put to useful work thus, the screen can operate at higher speeds when desired, giving greater screening capacity at lower power cost.
The sting of the positive, high speed vibration eliminates blinding of screen openings.
The sketches below demonstrate the four standard methods of fastening a screen cloth to the Dillon Screen. The choice of method is generally dependent on screen wire diameters. It is recommended that the following guide be followed:
Before Separation can take place we need to get the fine particles to the bottom of the pile next to the screen deck openings and the coarse particles to the top. Without this phenomenon, we would have all the big particles blocking the openings with the fines resting atop of them and never going through.
We need to state that 100% efficiency, that is, putting every undersize particle through and every oversize particle over, is impossible. If you put 95% of the undersize pieces through we in the screen business call that commercially perfect.
types of vibrating screens | introduction and difference
Vibrating screen is equipment for separating material sizes. There are many types of vibrating screens, such as horizontal screen, inclined screen, MD vibratory screen, rotary screen, vibratory screen, high-frequency screen, grizzly screen, dewatering screen, and other industrial screens. What is the difference between these types of vibrating screens?
Vibratory screen is a rectangular single-, double-, and multi-layer, high-efficiency new screening equipment. Vibrating screen can be divided into inclined and horizontal screen. At present, the screens range in width from 4-12 to 8-32. The screen size is usually set to 2.5 times its length and width. The width of the sieve determines the maximum carrying capacity of the sieve plate, and the length of the sieve determines the overall efficiency of the sieve plate. The vibrating screen is generally composed of a vibrator, a screen box, a supporting or hanging device, a transmission device, and others.
Horizontal screens are named because they are designed to be horizontal. The work direction of the screen is parallel to the ground or has a slope of 0 to 5. It is a triple-shaft screen, which uses for fixed and portable production lines. Compared with the inclined screen, it is more accurate and effective to determine the size and separate materials. This is because the material is retained on the screen for a longer period of time, which allowing sufficient time for the sized material to fall off the screen. The screen has the advantages of simple structure, reliable performance, large screening capacity, and economical use. Its low power consumption and low maintenance cost, it is the simplest and most practical screening equipment in the quarry crusher plant.
Vibrating inclined screen is the most popular types of vibrating screens. The screen fix to the tilted frame at an angle of 15 to 30 degrees. The inclined screen is usually designed in a multi-layer structure and can be classified into 2-5 grades. And the screen can be adjusted to provide overall performance and efficiency. We can adjust the slope, speed, and direction according to the application.
The inclined screen consists of eight basic components, namely side wall, platform, screening medium, actuator, motor, motor console, spring, and the spring bracket. The key factor of inclined screen equipment is its weldless design. All the 8 basic screen parts are assembled by bolt and nut connections to prevent screen cracking and failure due to welding.
MD vibrating screen is a compact, high capacity dry screen. It widely used in industries of dry sand, fertilizer, iron ore, wood chips, limestone, and others. It can screen more tons per hour. Compare with the traditional screening equipment, its processing capacity is bigger. Because of its excellent design, it takes up less space and reduces the size of the screen layer by layer. As a result, it can screen out products of many different sizes at the same time.
The trommel screen uses continuous rolling and lifting motions to screen and separate raw materials. These materials include municipal waste, recycling, industry, aggregates, and mining. This screen is a kind of machine which is widely used in separation technology. By the size of the particle size to control the screening. The barrel of the screen is generally divided into several sections which depending on the specific circumstances. The screen holes from small to large arrangements, each section on the same size as the screen hole. The screening equipment features: screen hole is not easy to plug. The screen cylinder can be closed, easy to close the dust collection. Adopt Special Screen Mesh, high screening efficiency, and long service life.
As the cylinder of the rotating sieve rotates, the raw material is lifted from the shelf until it is near the top of the cylinder. Then, the material falls, landing on other material at the bottom of the drum. This operation helps to break down the softer parts as well as separate the different types of materials. As the tumbling continues, smaller fractions are filtered through holes in the sieve plate. While the larger material continues along the length of the cylinder, finally discharging.
High-frequency screen with high efficiency, small amplitude, high screening frequency. It is effective equipment for screening and classification of fine-grained materials. It is widely used in screening and classification of iron ore, tin, tungsten, tantalum, and niobium. For the high-frequency screen, it is solely for the purpose of dehydration wet screening. Therefore, we hope to form a filtering layer on the screen surface as soon as possible, so as to block the passage of fine coal. Thus reducing the loss of solid materials in water and improving the recovery rate of solid. If the screen surface amplitude is too large, it will destroy the filter layer. Wet screening doesnt require large amplitudes.
High-frequency screen with high frequency can destroy the pulp surface tension and fine material in screen surface high-speed oscillation. This operation not only accelerates the density of useful minerals and segregation but also increases the probability of less than the size of the separation material in contact with the screen hole. Thus create a better separation condition which made the material smaller than the separation granularity. In particular, a large density of material and pulp together through the screen hole sieve out. It can provide higher capacity and more efficient dimensions than traditional screening devices.
Grizzly screen is universal screen equipment with special screen surface. Its biggest characteristic lies in its high screening efficiency, large relative processing capacity and not easy to plug holes. Especially suitable for high moisture, viscous material screening. It is widely used in the coal mine, chemical industry, metallurgy, electric power, building materials, and other industries that the medium-sized granular material classification. The advantages of the grizzly screens are a simple structure, convenient maintenance, high strength, impact resistance, wear resistance, low noise and so on.
Working principle: Grizzly screen is composed of many bars. Screen surface and horizontal composition of an angle. When screening ore dip angle is 40 ~ 45. When screening wet material dip angle increases 5 ~ 10. The material is fed through the upper end of the screen. The ore block larger than the size of the screen hole slides automatically along the screen surface. The ore block smaller than the size of the screen hole falls through the screen hole.
Dewatering screen is the main role of dewatering, desliming, desilting medium. It is used for sand washing plants, coal slime recovery in the coal preparation plants, tailings dry discharge in the mineral processing plants, etc. Therefore, it is also called sand dewatering screen, mine dewatering screen, slime dewatering screen, tailings dry drainage screen, high-frequency dewatering screen, etc.
The screen Mesh adopts super high molecular polyurethane material, impact resistance, corrosion resistance, wear resistance. The screen box is made of stainless steel. The screening machine is especially suitable for treating fine-grained minerals. It can also be used in combination with a cyclone. Dewatering efficiency is very high and widely used in tailings dry discharge, dewatering, and other operations.
Jiangxi Shicheng stone crusher manufacturer is a new and high-tech factory specialized in R&D and manufacturing crushing lines, beneficial equipment,sand-making machinery and grinding plants.
dewatering screens | eagle iron works
Typically, a Fine Material Washer will discharge material with a moisture content of around 20%. The addition of an Eagle Dewatering Screen can lower the moisture content to 7-10%. Stacking sand product until it is dry enough to be sold can take time and valuable space. The Eagle Dewatering Screen can be added to any brand of screw washer to drastically cut moisture content, leaving you with a drier product that you can sell sooner.
Featuring high-quality wear liners and heavy-duty urethane screen media, the Eagle Dewatering Screen is built to handle high G-forces. A divider deck is an optional feature that allows you to separate your product. Additionally, Eagle offers the ability to return fines back to a screw in a controlled measure to reduce your overall water footprint.
Slurry is fed onto a Dewatering Screen to achieve rapid drainage. As water quickly begins to drain, the sand builds up on the screen media surface. Counter-rotating motors create a motion that conveys solids to the discharge end of the screen as water drains through the screen media. The screen media, along with a discharge weir, creates a deep bed of sand that acts as filter medium, allowing retention of material much finer than the screen openings.
The Eagle Dewatering Screen is installed horizontally, as opposed to on an incline. Because this Dewatering Screen is specifically designed to be fed by a Fine Material Washer, the majority of water content has already been removed and no pool of water is being formed. This allows for a higher discharge point from the screen, so stacking conveyors fit better underneath the discharge end.
EIW, LLC has been providing aggregate beneficiation equipment of exceptional quality for over 145 years. EIW begins by engineering equipment for the defined needs of each customer. We provide support from point of sale throughout the life of the machine, including readily available replacement parts.
dewatering screens | mclanahan
Dewatering Screens have a wide variety of applications, including dewatering, desliming, degritting, rinsing, scrubbing, sizing and washing. They are designed to produce a consistent drip-free product and handlematerials such as sand, gravel, crushed aggregates, frac sand, industrial sands, mineral sands, hard rock, precious metals ore, coal, iron ore, salt and other granular materials.
Surface moisture as low as 7% has been achieved with McLanahanDewatering Screens; however, final moisture is dependent on surface area, surface morphology, and contact angle. Finer materials, such as those processed in fines recovery systems where the material is 100% passing 100 mesh (150 m), will dewater to a drip-free consistency, which conveys and stacks, but may have a surface moisture content of more than20%.
McLanahan Dewatering Screens are based on the original Velco Dewatering Screens that were developed for use in mineral processing plants in the mid-1970s and are now the predominant dewatering device for granular materials. McLanahan enhanced this design using a crossbeam structure that makes the machine more robust and easier to maintain. McLanahan Dewatering Screens are designed for minimal maintenance, with no cutting or welding required. They require little operator training when installed and produce minimal noise.
Another improvement from the original design, McLanahan engineered its screen media for heavy-duty applications. This media features longitudinal stringers for full-length support. Tight tolerance, full-length urethane-to-urethane engagement virtually eliminates the entry of the process material at screen section interfaces, preventing troublesome wear points that can occur when using pin-and-sleeve and multi-point supported media.
McLanahan pioneered the use of longitudinal dividers to allow as many as three products to be dewatered on one screen. Many applications feature a two-stream process, but McLanahan Dewatering Screens allow up to one fine stream and two coarse streams to be kept separate or blended to create specialty products.
When compared with the typical Fine Material Screw Washer, the final product will generally be at least 10% drier with a McLanahan Dewatering Screen. Because of the wide range of equipment within McLanahan, the Dewatering Screen can be combined to complement other process equipment, such as Screw Washers, Hydrocyclones and Separators. Certain types of washing processes (e.g. double wash) can benefit from a Screw Washer as a primary washing device supplemented by the Dewatering Screen for a drier product.
To dewater material effectively, slurry is fed onto a steep, downward inclined screen surface at the feed end of the Dewatering Screen to achieve rapid drainage. A pool of water begin forms in the valley as material builds up on the slightly upward inclined surface. Counter-rotating vibratory motors (or mechanical exciters on the largest of Dewatering Screens) create a linear motion at an angle to the screen surface that accelerates the solids upward and forward at 5 G. This, along with a generous stroke length, moves water through the countless openingsbetween the particles to promote droplet formation.
The abrupt reversal of motion detaches water from the material, and the water droplets pass through the screen media. The solids are conveyed up the screen by this linear motion. The uphill slope of the screen, along with a discharge weir, creates a deep bed that acts as a filter medium, allowing retention of material much finer than the screen openings.A thick bed of material promotes fine retention while allowing the water to migrate through.
Where cleaner materials are required, cross dams and spray bars can be included to assist with the washing process, liberating fines that pass through the media. Using a dilute feed and additional spray water, these screens can effect some limited sizing.
Dewatering Screens can beused to dewater -4 mesh (5 mm) particles of sand, coal, iron ore, salt, etc. They can also be used to dewaterfines in fines recovery circuits, typically +400 mesh (+38 m), as well as to rinse and dewater jig discharge nominally -2 (50 mm). Dewatering Screens can be used for limited efficiency fine sizing at or above 10 mesh (2 mm) to create differential products, for stone washing and rinsing <2 (-50 mm) aggregates prior to loadout, desliming, and for trash/organics dewatering/screening.
Some applications have experienced a moisture content as low as 7% with McLanahan Dewatering Screens, but final moisture content is dependent on both surface moisture and inherent moisture. When reporting moisture by weight (kg water/kg pulp), the specific gravity of the soilds also plays a factor, with higher specific gravity materials showing lower moisture contents.
If you remove all the water from the gaps between the particles, the only water left is that which is adsorbed as a thin film on the outside surface or as inherent moisture within the material itself (some brown coals can contain up to 20% inherent moisture). Therefore, the finer the materials being handled and the more irregular the surface, the higher the moisture content.
Certain materials are also more hydrophobic or hydrophilic,which also affects the residual water. It is also important to understand that a Dewatering Screens action is critical to creating droplet formation on the underside of the bed of material. This combination of amplitude and frequency was studied by the University of Karlsruhe, whichdeveloped recommendations for this action.
In the early days of Dewatering Screens, urethane pin and sleeve design media was common. Since then, parallel developments occurred, rated capacities increased (doubling in some cases) and more robust media designs came about. Today, pin and sleeve style designs are perfectly adequate and appropriate for sizing screen applications; however, with the heavy loads and aggressive action on Dewatering Screens, few media manufacturers can match the mechanical integrity required for the application.
McLanahan spent a long time researching and working on designs to match the need and the result is a longitudinal rail style system with urethane-to-urethane connections between the media and the stringers --this type of interface doesnt fail. The frequency of replacement of media in Dewatering Screens is such that no manufacturer or representative is going to lose much downstream revenue, but the end user always benefits from a better system.
Several factors need to be taken into consideration when designing a support structure for a Dewatering Screen, includingforces, natural frequencies andmultiple unit installations. McLanahan can provide design criteria and assistance; call our offices for support or contact us now.
As a quick guide, Dewatering Screens should never be underestimated in their ability to shake a structure with their mass and the 900 rpm and 10 mm amplitude. Multiple Dewatering Screen installations can be a challenge with harmonics; occasionally a beat will be experienced. In some cases, vibration transference through the ground can be experienced in other structures.
Good design practices include placing columns directly under the support points and substantial foundations to provide mass. Always allow 3 (75 mm) of clearance to other components in the direction of action (longitudinal to the screen) so no impact occurs when the vibratory motors or exciters go out of phase during shut down. Electric cables should always be supported/suspended from above directly to the junction box and neverdraped over vibrating components. McLanahans Dewatering Screen motors come with sealed junction boxes with long extended cablesto connect into the electrical circuit.
McLanahans personnel pioneered the use of deck-dividers to allow two or even three products to be dewatered at one time. Producing a fine product on one side and a coarse product on the other with the facility to blend is part of the standard offering from McLanahan. Process engineers will assist with the application to ensure all factors are considered. Extensive out-of-balance loading (one or more of the products not being fed for long periods of time) can decrease the lifespan of the equipment.
The smallest aperture on a Dewatering Screen is typically 50 mesh (0.3mm), so you will expect to see some of that size fraction and finer in the underflow of the screen. Not all of that fraction will pass through due to the very nature of caking style screens; fines are captured in the bed formed on top of the media. The usable fraction that does pass through the screen can be handled in several ways. The easiest is to recycle back to the device feeding the screen. In cases of greater flows, a dedicated scavenger circuit could be used.
Designed to produce a consistent, drip-free product that other types of equipment cannot provide, Dewatering Screens dewater, deslime, degrit, rinse, scrub and wash a variety of materials. McLanahan Dewatering Screens are designed for minimal maintenance, with no cutting or welding required. They require little operator training when installed along and produce minimal noise. With the highest capacities available in the industry, McLanahan Dewatering Screens can process up to 400 tph of coarse sand on a single machine.
sand processing equipment manufacturer-lzzg
As an innovative mining equipment manufacturing company, LZZG provides customers with professional equipment that meets their needs.
We have rich manufacturing experience, reasonable production line process configuration plan and perfect modern inspection system. In Longzhong, you can not only get high quality with guaranteed quality
Products, you can get customized and efficient configuration solutions.
At present, sand washing and sewage treatment systems, dry tailings discharge systems, and sand production lines have been spread across domestic provinces and many countries.
linear vibrating screen, sieve & separator manufacturer - gaofu
The Linear Vibrating Sieve has a particular effect on the screening and classification of powdery and grain materials. Linear vibrating screens are widely used in chemical, pharmaceutical, foodstuff, coherer, metallurgical and mining industries.
Metals, metallurgy and mining: aluminum powder, lead powder, copper powder, ore, alloy powder, electrode powder, manganese dioxide, electrolytic copper powder, electromagnetic materials, abrasive powder, refractory materials, kaolin, lime, alumina, heavy carbonic acid Calcium, quartz sand, metal powder industry, mining industry, etc.;
The linear vibrating screen is a general-purpose device. According to different industries, the implementation standards are different, such as: food grade, and pharmaceutical grade, so they can be customized accordingly.
Working principle of the vibrating separator: when two vibrating motors are vertically mounted on the screen body and do relative power, the eccentric blocks at the ends generated exciting forces, resulting in the lateral vibration forces which offset each other due to the relative operation of the motors. The longitudinal vibration force is passed to the entire screen box through the vibrating body to vibrate the screen surface, so that the material on the screen surface do jumping movement to the outlet direction, material smaller than the mesh hole will fall to the lower deck, and be discharged after continuous jumping. Because the screening process is reasonable, the materials after classification can obtain several different particle sizes of materials. In this way, the classification work is finished.
As a linear vibrating screen manufacturer, Gaofu companys products are not limited to one model. According to different industries and material characteristics, we have developed GFZX granule sifting machine, SZF straight sieve and other two models. Gaofu company can meet not only the standard needs of customers, but also tailor-made requirements for special customers. This is our advantage, because we have 38 years screening experience and more than 10,000 customer testimonials.
This vibrating separator has a simple structure and also easy operations. According to customers requirements and product characteristics, Gaofu can provide three kinds of screen frame: carbon steel screen frame, stainless steel screen frame or punching plate. No matter which one a customer chooses, Gaofu company can use strict manufacturing process to ensure the quality of products.
The linear vibrating screen can be adapted by the factory to meet special requirements regarding plant layout, performance and environmental constraints. Specify your particular requirements, or enquire us about the range of features, accessories, painting systems and materials of construction currently available.
vibrating screening machine manufacturer, supplier and exporter in india
Vibrating screening machine is designed for the use in sizing of minerals, ceramics, refractories and other powders. The principle on which the Jaykrishna multi-form grader operates is equally adaptable for the handling of many ceramic products.
The unit is more than Just a screen it is a precision tool for producing accurate grades, a not merely rough grouping of sizes. It is economical of power and space; screen life is long; upkeep low. Flexible in its adaptability to widely different materials and conditions, it is unyielding in the uniformity of grades produced. Multi-Deck vibrating screens are available in different models.
Jaykrishna Magnetics Pvt. Ltd. is the leading manufacturer and exporter of Magnetic and Vibratory Equipments in India. We are established since 1978. The unique and premium structural design imparts quality and elegance to our products. Our focus is on continuously improving our process, service and products to exceed the benchmarks set by our competitors and offer better products to you.