types of vibrating screens | introduction and difference

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.

Working principle 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. Read More

vibrating screen working principle

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.

back to basics: choosing a screen : pit & quarry

back to basics: choosing a screen : pit & quarry

Screens are used throughout the aggregate processing flow to separate and size material prior to and following crushing stages. While most producers are aware of the overall process, following is refresher on the types and effects of screen angles and motion.

At the primary stage, large scalping screens remove fine material before the feed enters the primary crusher, helping to protect the crushers wear parts from abrasive stone or sand material that has already been sized. Without scalping, the primary crushers liners wear down faster, requiring more frequent changes and maintenance downtime.

Following the primary crushing stage, screens with two or three decks and different opening sizes are used to separate the aggregate material into different size categories with conveyors transporting the sized material for further crushing or for stockpiling as a saleable product. Usually this screening is accomplished through dry screens. Wet screens may help to remove debris from material before stockpiling, as clean stone is often required for concrete and asphalt specifications.

Depending on the process stage, the material to be screened is fed to the screen either from a loading device such as a wheel loader (intermittent feed) or from a hopper or conveyor (continuous feed). The screen box vibrates via shafts with counterweights or exciters, causing the material bed to vibrate, as well.

Through the vibration, larger particles work their way up to the top of the material bed, while the smaller particles make contact with the screening surface. This effect is called stratification. If the particles are smaller than the openings in the screen surface, they will fall through. If they are larger than the screen openings, the particles will be retained on the surface and eventually carried off of the screen. This is called the probability of separation.

Horizontal screens operate at 0 degrees, but may be adjustable to about 10 degrees in either direction, functioning at a lower overall height than inclined screens. They may have two or three shafts located within the screen boxs center of gravity, with timing gears and counterweights designed to provide either an oval or a linear motion.

Or they may provide linear motion via out-of-balance motors or geared exciters, within which eccentric weights are mounted onto both ends of a shaft located above the screen boxs center of gravity to provide vibratory motion. Horizontal screens provide high g-forces to vibrate and move the material down the length of the screen.

Horizontal screens typically offer better efficiency (accurate particle sizing) than inclined screens because the material is retained on the screen longer, with a slower travel rate to the end of the screen. This allows more properly sized material to fall through the screen openings. In a stationary plant setup, they are more often seen as tertiary (third stage) and/or finishing screens. Horizontal screens are also often specified for portable plants because of their low profile.

Inclined screens generally operate at angles ranging from 10 degrees to 35 degrees in one direction, and vibrate in a circular motion, offering better production capacity (processing rate) over horizontal screens because gravity helps move the material down the screen. Single or dual shafts with up to four bearings, located within the screen boxs center of gravity, provide the circular motion via weight elements mounted on the shafts flywheel. Inclined screens do not exert the same g-forces as horizontal screens.

Inclined screens can command a lower initial capital expenditure than horizontal screens because they typically are built with just one or two shafts; their frames do not have to be as robust as those of horizontal screens; and they do not require a higher-horsepower motor. Efficiency is not as high as it is with horizontal screens, however. Inclined screens are usually seen in stationary plants, and can be specified for just about any processing stage.

Circular-motion screens provide a high travel rate because they also are inclined screens. They generally accept a continuous feed very well. Screens using circular motion are best suited for larger material, as finer material tends to blind on this style of screen. Also, wet, sticky material does not screen well with this type of screen, unless water spray is also used.

Linear-motion horizontal screens typically generate less blinding and pegging of material on screen media because their straight-line motion, with high g-forces, can both dislodge material and also convey it forward across the screen. This motion can be more effective than circular- or elliptical-motion screens, resulting in a high-efficiency screen that also operates at a fairly high speed.

The operator is able to better control the material travel rate across the screen, further improving screening efficiency. Linear-motion screens also benefit producers through a lower installed cost because they require less headroom than circular or elliptical motion screens.

Elliptical-motion horizontal screens may offer some combined benefits of efficiency from linear-motion screens and the tumbling effect generated by inclined circular-motion screens. They also work to speed material travel rate at the feed end, while slowing it at the discharge end. However, this type of screen does not exert the high g-forces that linear-motion screens do.

Formulas exist to help select screens based on many factors, including tonnage of feed, screening area and desired efficiency. There are enough variables involved in the formula that it is best to work with manufacturers who understand the complete parameters of the application. It is important that the manufacturer knows the feed method, size, gradation, moisture content and rate. Existing equipment and mounting structure, total plant production needs and efficiency requirements are also part of the equation. Manufacturers can help to specify not only the best screen unit for the application, but also the best screen media choice.

xinhai horizontal and inclined vibrating screen for screening ore particle - xinhai

xinhai horizontal and inclined vibrating screen for screening ore particle - xinhai

Xinhaivibrating screenis divided into horizontal and inclined vibrating screen according to the angle between the machine and land. Vibrating screen is used to prescreening and check screening cooperating with crushing process in mineral processing.

Xinhailinear vibrating screenis belong to horizontal vibrating screen with linear movement direction. The same movement orbit of each point on screen is good for the screening. In metal processing, linear vibrating screen is used to compose a closed circle with grinding machine.

vibrating screen types - blog

vibrating screen types - blog

Inclined screens are the most basic type of screen, fixed to an inclined frame at an angle of between 15 and 30. The entire body of the screen vibrates on helical springs circularly with the same characteristics and material flow is supplied by gravitational acceleration.

The slope of the inclined screen is fixed, although the stroke can be adjusted to the required level. The general working stroke of an inclined screen is between 8 and 12 mm, and design of inclined screens permits changes to this stroke through the addition or removal of additional eccentric masses on the exciter.

The exciters of inclined screens are generally driven by an external electric motor that transmits the power via a belt and pulley mechanism. Vibromotor applications are not preferred for inclined screens due to their fixed condition working principle.

Inclined screens are generally designed with multi deck arrangements, which allows material to be classified the between 25 grade types. Additionally, these screens are generally fitted with an impact area directly before the screening section begins that breaks up the material and causes any long pieces to lie flat during screening.

Inclined screens are comprised of eight basic components, being the side walls, decks, screening media, exciter, electric motor, motor console, spring and spring supports. The most critical factor in inclined screens is their weld-free design. All of the parts mentioned here are assembled with bolt and nut connections to prevent the cracking and failure to the screen body associated with welding.

A horizontal screen is a non-conventional design that has unique properties that differentiate it from other types of conventional screen. Its most obvious advantage is its working angle. While conventional screens work at an angle of between 15 and 30, horizontal screens work in parallel to the ground, or at a slight incline of between 0 and 5 degrees.

Horizontal screens are equipped with triple drive mechanisms that produce an elliptical vibration motion at the required stroke and slope. As mentioned at the exciter mechanism section above, the triple drive mechanism combines the linear and circular vibration types in elliptic vibration. In this way, the advantages of both vibration types are combined in a horizontal screen, so that while the material is being transporting horizontally at a determined velocity through the linear vibration motion, plunging is prevented due to the circular vibration characteristic of the elliptical motion.

The stroke of horizontal screens may be adjusted in a range of 1420mm, although they generally operate with a stroke of between 16 and 18 mm and with a 750 rpm rotational speed. The material flow rate in the screening media varies between 0.2 m/s and 0.25 m/s. The mass flow rate depends on the differences of the phase angle between the eccentric masses.

The triple drive mechanism is driven by an electric motor, with power transmitted by a belt and pulley mechanism. There is a possibility that the belt may come away itself during operation as a result of the high stroke working conditions associated with horizontal screens. A new belt stretching mechanism has been designed to overcome this problem, and all the power transmitting mechanisms in horizontal screens have been equipped with belt stretching mechanisms.

Horizontal screens have brought many advantages to screening operations, although there are some disadvantages, the most critical being the complexity of the triple drive mechanism. In fact, triple drive mechanisms have a sufficiently robust design to overcome any condition, however maintenance procedures are not short, although the robustness of the design means that frequent maintenance is unnecessary.

Banana or multi-slope screens are capable of achieving exceptional throughput per screening area. These screens have high capacity, low bed depth and high velocity, and may include any number of deck slopes, from two to as many as six, varying from 45 through to horizontal on the final slope.

Banana screens are excited by a vibromotor located on the top of the screen. As mentioned, the exciter section of banana screens has a segmented deck structure, causing the linear motion created by the vibromotor to accelerate the material differently at each deck surface due to the geometry of the screen, ensuring effective screen operation is achieved.

The feed section (highly inclined) of a banana screen permits high velocity material flow, which serves for the quick removal of fine material. Midway along the banana screen, the resultant thinner bed stratifies quickly, and the remaining fine material (below the cut point) is screened out more effectively than would be possible with a slower and thicker bed. The lower screen slope (see diagram) slows the material down, allowing more efficient screening of near size material at this point. The advantage of this is the quicker stratification provided due to the high velocity imparted by the banana screen shape.

The various slopes may also incorporate deck media with different apertures to meet the particular processing requirements. The screens are commonly designed to fit modular rubber or polyurethane deck panels, although woven wire or punched plates may also be used, depending on requirements.

De-watering screens have been designed to allow the drainage of slurry material water and to reduce the moisture rate of the material. These systems comprise a vibromotor pair, a vibromotor console, screening media and a screen body. The screen surface is slightly inclined (between 0 and 5) to facilitate drainage and the working speed is between 10001500 RPM.

The counter-rotated vibromotors create a linear vibration that causes the screen body to shake together with slurry material. The water from the slurry materials is drained under the effect of vibration and flows through bottom side of the screening surface as the material moves forward. In this way, a pool of water forms in the valley as sand builds up on the inclined surface. The uphill slope of the screen along with a discharge weir creates a deep bed that acts as a filter medium, allowing the retention of material much finer than the screen openings.

Different to dry material screens, dewatering screens work at G-forces in excess of 5g, ensuring a perfect drainage operation. Generally operating within a range of 5g and 6g this pre-condition is necessary for a good dewatering operation.

The fabricated vibromotor console frame, as a vital component in vibration transmission, is stress relived due to the high G-force working conditions. The screen side plate and the vibromotor side plates of the console must be machined to exacting tolerances to ensure a precise fit, and consequently, a long operating life. The steel frame should be constructed with bolted connections to avoid the cracking associated with weld failures.

Due to the wet and corrosive environment of the dewatering screen, rubber springs should be used on the support legs to absorb the live frame vibrating loads, which will extend screen life and maintenance periods.

High-frequency screens are engineered to provide higher production capacities and more efficient sizing than conventional screens. High-frequency screens operate with aggressive vibration applied directly to the screen, which allows for the highest capacity in the market for the removal of fine material, as well as chip sizing, dry-manufactured sand and more.1

Different to other type screens, the vibromotors of high-frequency screens are mounted on each deck instead of on the screen body. Aggressive vibration is applied within a range of 36005000 RPM directly to the screen media, allowing for higher capacity and more efficient sizing when compared with conventional screens. Under the effect of high-frequency vibration, a smaller bed depth is obtained, which allows for stratification and greater screening efficiency.

The high-frequency and low-amplitude operation ensure a faster material travel speed without loss of screening efficiency. This combination of high frequency and know amplitude is ideal for fine material screening, in which coarse material particles are lifted higher while the finer particles stay closer to screen, and as a result, the probability of separation is increased with high-frequency screens.

Very coarse materials are usually screened using an inclined screen called a grizzly screen. Grizzlies are characterized by parallel steel bars or rails set at a fixed distance apart and installed in line with the flow of the material. The gap between the grizzly bars is usually greater than 50 mm, and can be as large as 300 mm, with a feed size of up to 1 m. Vibrating grizzlies are usually inclined at an angle of around 20 and have a circular or linear throw mechanism.

The bars are typically made from wear-resistant manganese steel and are usually tapered to create gaps that become wider towards the discharge end of the screen to prevent material from wedging between the bars. Grizzly screens generally used as a feeder prior to the crusher to supply the flow of correct-sized material through the crusher.

Designed to convey material while separating fines, Vibrating Feeders utilize smooth, controlled feed rates to maximize capacity. The grizzly bars are tapered to self-relieve, and feature adjustable spacing for bypass sizing. The feeder construction includes a heavy-duty deck plate with optional AR plate liners, while the heavy-duty spring suspension withstands loading impact and assists vibration.

MEKA inclined screens provide screening efficiency that is high quality and dependable. Our screens come in various sizes starting from 2 m (22 sqft) up to 16 m (172 sqft) and are equipped with up to four decks that can be supplied with different types of meshes.

MEKA Horizontal Screens are a combination of quality, reliability, and performance; providing a long service life while operating under the most demanding applications. The screens elliptical motion is combined with high acceleration, thereby bringing more power into play than in traditional screens.

horizontal, inclined, vibrating & linear screens | moore watson ltd

horizontal, inclined, vibrating & linear screens | moore watson ltd

Hypro-Screen IVS Series is a heavy duty, robust machine enabling efficient screening with high output and accurate sizing. It provides constant amplitude, which enhances the performance and efficiency of the screen, ensuring optimum reliability and low operating costs. A wide range of screens are available in static or mobile units. This single shaft four bearing screen offers positive vibration, and ensures rapid spread and stratification of the product. The Hypro-Screens can be mounted horizontally at either 12 or 20. The direction of the shaft can be reversed according to the angle and inclination of the duty. This versatility makes the range suitable for handling rock, gravel, coal or such without major adjustments or alterations. The integral electric motor Vee belt drive, which can be arranged on either side of the screen, eliminates the need for additional structure. The inner frame is of a welded steel construction with suitably braced sides bored to accommodate the inner bearing housings and bolted to the side panels. International standard, heavy duty, double-row, self-aligning bearings are fitted to housings on either side of the inner frame and by plummer block on the underframe. All bearings are sealed against dust and moisture by carefully machined labyrinths. Grease nipples are provided for lubrication purposes.

vibrating inclined and horizontal screens | polygonmach | asphalt - concrete - crusher

vibrating inclined and horizontal screens | polygonmach | asphalt - concrete - crusher

POLYGONMACH vibrating screen has become the highly preferred screening equipment for screening all types of materials due to its durable and simple design. The modular structure allows users to easily replace spare parts and easily perform maintenance activities.

POLYGONMACH vibrating screen can be produced as "drive from the top" or "drive from the center" version. The screen material can be made of steel or polyurethane according to the hardness level of the material to be screened.

Polygon Machinery was established in the year 2019 with a motto to build a space for asphalt concrete machineries. Polygon Machinery is responsible for manufacturing industrial plants and machineries for asphalt concrete. The company has been founded by people who are having more than 15 years of experience in construction, road, and mining machinery and plants. The machineries manufactured at Polygon Machinery are used for the construction of roads, parking lots, airports, and the core of the embankment dams

xinhai horizontal and inclined vibrating screen for screening ore particle-xinhai

xinhai horizontal and inclined vibrating screen for screening ore particle-xinhai

Xinhai mineral processing equipment mainly include: grinding equipment, flotation equipment, dewatering equipment, magnetic separation equipment, and so on. Some of the equipment is Xinhai independent research and development, and has been awarded national patent. View details

Gold CIP Production Line adsorbs gold from cyaniding pulp by active carbon including 7 steps: leaching pulp preparation, cyaniding leaching, carbon adsorption, gold loaded carbon desorption, pregnant solution electrodeposit, carbon acid regeneration, leaching pulp. View details

Xinhaivibrating screenis divided into horizontal and inclined vibrating screen according to the angle between the machine and land. Vibrating screen is used to prescreening and check screening cooperating with crushing process in mineral processing.

Xinhaivibrating screenis divided into horizontal and inclined vibrating screen according to the angle between the machine and land. Vibrating screen is used to prescreening and check screening cooperating with crushing process in mineral processing.

Xinhailinear vibrating screenis belong to horizontal vibrating screen with linear movement direction. The same movement orbit of each point on screen is good for the screening. In metal processing, linear vibrating screen is used to compose a closed circle with grinding machine.

Xinhailinear vibrating screenis belong to horizontal vibrating screen with linear movement direction. The same movement orbit of each point on screen is good for the screening. In metal processing, linear vibrating screen is used to compose a closed circle with grinding machine.

anthem inclined screen | superior industries

anthem inclined screen | superior industries

All that time it took to design and build postponed your ability to generate income. What if we told you we've got a library of pre-engineered plants ready to build, rapidly install and produce profit?

Superior replacement crusher parts are taken from the same warehouse used for our manufacturing operations. That means you get an equal part, with equal quality, thats designed exactly for your machine.

Unlike horizontal screens, which require high amounts of energy to move material, Anthem Inclined Screens take advantage of one of the cheapest, most abundant resources on earthgravity! Typically, this allows them to deliver at lower costs per ton than horizontals. Inclined screens operate at angles of 15 20 and with gravity rely on a circular motion to move material down the decks and through the media.They generally accept a continuous feed of material well. They require more headroom than horizontal screens and are usually found in stationary applications where clearance is not an issue.

We always have been and always will be a privately-owned company. That means we can add more employees to our customer service team without Wall Street breathing down our neck. Isnt that the way it should be?

vibrating screen types & working principle [how to choose] | m&c

vibrating screen types & working principle [how to choose] | m&c

According to different structure and use, vibrating screens usually be devided into many types by the vibrating screen manufacturers. Below wil introduce the top 10 vibrating screens, and how to choose the right vibratory screen?

linear vibrating screen is driven by double vibrating motors. When the two vibrating motors are rotating synchronously and reversely, the excitation force generated by the eccentric block offsets each other in the direction parallel to the axis of the motor, and overlaps into a resultant force in the direction perpendicular to the axis of the motor, so the motion track of the linear vibrating screen machine is a straight line.

Working Principle:The two motor axes of the linear vibrating screen have an angle of inclination in the vertical direction relative to the screen panel. Under the combined force of the exciting force and the self gravity of the material, the material is thrown on the screen surface to jump or move forward in a straight line. Through the multi-layer screen panels, a variety of specifications of materials are generated, and discharged from their respective outlets, so as to achieve screening and classification. linear vibrating screen is suitable for screening various dry powder or granular materials with particle size of 0.074-5mm, moisture content <7%, and no viscosity. The feed particle size is not more than 10 mm.

Circular vibrating screen is a new type of vibrating screen with multi-layer screen and high efficiency. According to the type of materials and the requirements of users, the high manganese steel woven screen, punched screen plate and rubber screen plate can be used. The circular vibrating screen is installed in the seat type. The adjustment of the screen surface angle can be realized by changing the position and height of the spring support.

Working Principle: The motion track of the screen box of the circular vibrating screen is circular. The circular vibrating screen uses the inertia exciter to produce vibration. The main shaft fixed on the screen box is driven by the motor to rotate at high speed, and the eccentric body installed on the main shaft rotates with it, generating centrifugal inertia force, so that the screen box that can freely vibrate will produce vibration similar to the circular track.

Circular vibrating screen is widely used in the materials classification of mining, building materials, transportation, energy, chemical industry and other industries because of its long flowing line and many screening specifications.

Elliptical vibrating screen is a vibrating screen with elliptical motion track (Elliptical Shale Shaker), which has the advantages of high efficiency, high screening accuracy and wide range of application. Compared with the ordinary sieve machine of the same specification, it has larger processing capacity and higher screening efficiency.

Triaxial elliptical vibrating screen is widely used for the screening operation of sand and stone materials in sand plant. It is the ideal screening equipment for all kinds of mines, quarries and mobile screening stations.

Working Principle: The power is transmitted from the motor to the main shaft of the exciter and the gear vibrator (speed ratio is 1) through the V-belt, so that the three shafts can rotate at the same speed and generate the exciting force. The exciter is connected with the high-strength bolts of the screen box, resulting in elliptical movement.

Materials on the screens do high-speed elliptical movement along with the screen machine, so as to achieve uickly separate, sift and move forward, and ultimately complete the classification of materials.

The working surface of the roller screen is composed of a series of rolling shafts that arranged horizontally, on which there are many screen plates. When working, the fine material passes through the gap between the roller or screen plate, large blocks of materials are driven by rollers, moving to the ends and discharging from the outlets. Roller screens are mostly used in the traditional coal industry.

Working Principle: For the rolling shafts are arranged according to different working angles, the speed of the material is faster when it runs in the position with higher working angle; the speed of the material is slower when it runs in the position with lower working angle.

When two kinds of materials running at different speeds converge at a certain position on the screen surface, they start to move axially, so that the materials are evenly distributed on the screen surface, and the screening efficiency is improved.

Rotary vibrating screen is mainly used for the classification of materials with high screening efficiency and fine screening accuracy. Fully closed structure, no flying powder, no leakage of liquid, no blocking of mesh, automatic discharge, no material storage in the machine, no dead angle of grid structure, increased screen area.

Any particle, powder and mucus can be screened within a certain range. Sieve to 500 mesh or 0.028mm, filter to 5 microns minimum. It can be used for classification, classification and filtration in food, chemical, metal, mining and other industries.

With the help of the heavy hammer installed at the upper and lower ends of the motor shaft, the rotary motion of the motor is transformed into a horizontal, vertical and inclined three-dimensional motion, which is then transmitted to the screen surface to make the material do an outward involute motion on the screen surface. Working Principle: After the rotary screen is started, the eccentric blocks of different phases at the upper and lower ends of the vibrating motor generate a composite inertia force, which forces the vibrating body of the rotary screen machine to rotate again and again, and the screen frame continuously moves to and fro under the action of the vibration force, and then drives the screen surface to vibrate periodically, so that the materials on the screen surface move in a positive and directional manner together with the screen box. Materials smaller than the screen meshes fall to the lower layer, and the materials larger than the screen meshes discharged from the discharge port.

High frequency vibrating screen is also called high frequency screen for short. High frequency vibrating screen (high frequency screen) is composed of exciter, pulp distributor, screen frame, supporting, suspension spring and screen, etc. High frequency vibrating screen is the most important screening machine in mineral processing industry, which is suitable for completely wet or dry raw materials.

Working Principle: Different from ordinary screening equipments, high frequency screen adopts high frequency, which destroys the tension on the pulp surface and makes the fine materials vibrate at high speed on the screen, accelerates the separation of useful minerals with large density (specific gravity), and increases the probability of contact between the materials with smaller than the separated particle size and the screen holes.

As a result, high frequency screen results in a better separation conditions, which makes the materials that smaller than the separation size (especially with larger specific gravity), and pulp pass through the screen holes together to complete the screening. High-frequency vibrating screen is usually operated at an inclined angle 0-25, up to 45, and the operating frequency range is 1500-7200r/m.

Grizzly screen has simple and solid structure, no power consumption, no moving parts, low equipment cost and convenient maintenance, but the productivity is low, the screening efficiency is not high, generally 50% 60%, and the mesh is easy to be blocked.

Working Principle: Generally, the grizzly screen is placed in an inclined position, and the materials are dumped at the high end. Under the action of its own weight, it slides down the screen surface, and the particles smaller than the gap or hole on the screen surface pass through the screen to achieve classification.

Banana screen is mainly suitable for the classification of large and medium-sized materials with high content of fine particles, and it can also be used for dehydration, demineralization and desliming.

Working Principle: During operation, the motor is connected with the vibration exciter through the V-belt or soft connection. The motor drives the eccentric shaft to rotate to generate centrifugal inertia force, which forces the screen box to vibrate. After the materials fall into the screen from the feeding inlet, they move forward rapidly under the action of the vibration force, loosely and pass through the screen.The thickness of the material layer of banana screen from the feeding inlet to the discharging outlet is constant. The ratio of the material quantity to the flow speed on the screen of each section is stable, the material layer is high and uniform. The screening efficiency of banana screen is higher, which is 1-2 times higher than that of other screening machines with the same effective area.

Heavy inclined screen can be applied to the treatment of debris from quarry, mine and building demolition, the treatment of topsoil, the recycling of construction materials, the screening of gravel, and the screening of gravel and aggregates.

Working Principle: The screen box shaft is driven by the motor installed on the auxiliary frame through three V-belts, the auxiliary frame is rigidly connected with the machine underframe, and the screen box spring is used to support the screen box.Inclined screen usually adopts 2-4-layer screen panels, and is fixed on the inclined frame at an angle between 15 and 30. The material can be screened into 3-5 grades at the same time.

Horizontal screen has the advantages of both inclined screen and linear vibrating screen. horizontal screen has the features of good screen permeability, large processing capacity and small installation height.

The installation angle of common vibrating screen is 15-30, while the installation of horizontal screen is parallel to the ground, or slightly inclined 0-5. Horizontal screen is an ideal equipment for all kinds of mines, quarries and mobile screening stations.

Working Principle: Horizontal screen is designed with oval stroke. The advantage of this design is that it can change the oval big diameter length and angle of throwing material stroke to meet the best needs of vibrating screen. The oval stroke is easy to adjust by center gear, counterweight wheel and motor speed.

Different types of vibrating screens can be used for the same material to get different screening effects. The reasonable selection of vibrating screen is an effective way to improve vibration efficiency and maximize economic benefits. Generally, you need to consider the following 5 tips:

When choosing vibratory screen, the material characteristics should be taken into account, including the content of material particles under the screen, the content of difficult screen particles, material moisture, the shape and specific gravity of the material, and the content of clay.

Tips: Heavy vibrating screen is used for materials above 200mm; circular vibrating screen is used for materials above 10mm; linear vibrating screen and high frequency vibrating screen are used for desliming, dewatering and grading.

When selecting the vibratory screen, the screen areas, layer numbers, shape, size and area ratio of the screen holes, as well as the motion mode, vibration frequency and amplitude of the vibrating screen should also be considered.

Tips: In order to keep the screens under good working conditions, the ratio of screen length to width should be in the range of 2-3; when there is much viscous mud and high moisture in the material, double deck screens should be avoided as far as possible.

Vibratory screens need to be selected according to different screening purposes. If it is necessary to pre screen materials, circular vibrating screens are generally used; for the classification and screening of crushed materials, large vibrating screens and probability screens are selected; for the deionization and dehydration of materials, linear vibrating screens are better; if it is necessary to desliminate and clean up materials, probability screens are used.

When selecting the shale shakers, it also needs to be considered according to the processing capacity of the production line, screening method, screening efficiency and the tilt angle of the shale shakers.

Professional vibrating screen manufacturers could provide competitive vibrating screen price, diversity customized vibrating screen models, timely after-sales service, spare parts and can continue to provide services for customers whole production circle.

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