Vibrating screens are commonly used in a variety of industries, including mining, mineral processing, food processing, and aggregate production. They are used to separate materials based on size, density, and other properties, and are considered to be a highly efficient and cost-effective method of material separation.

There are several types of vibrating screens, each designed to handle specific material separation and sizing requirements. Some of the most common types of vibrating screens include:

Linear Vibrating Screen: A linear vibrating screen uses a vibrating motor to generate a linear motion along the length of the screen. It is used for separation of dry materials such as crushed coal, sand, gravel, and minerals.

Circular Vibrating Screen: A circular vibrating screen uses a circular motion and is used for separation of wet or moist materials such as coal, sand, gravel, and minerals.

Elliptical Vibrating Screen: An elliptical vibrating screen uses an elliptical motion and is used for separation of fine materials such as ceramic raw materials, minerals, and chemicals.

High-Frequency Vibrating Screen: A high-frequency vibrating screen uses a high-frequency vibration to separate fine materials such as minerals, sand, and gravel.

Multi-Deck Vibrating Screen: A multi-deck vibrating screen is used to separate materials into multiple fractions of different sizes. It is commonly used in minerals processing and aggregate production.

Trommel Screen: A trommel screen uses a rotating drum to separate materials. It is commonly used for the separation of dry materials such as coal, sand, gravel, and minerals.

A vibrating screen operation involves using a machine to separate materials into different sizes based on their particle size. The machine consists of a screen deck, vibration mechanism, and a frame. The screen deck is made of mesh or perforated plates and is placed over a frame. The vibration mechanism, which can be either an electric motor or a vibrating generator, creates a linear or circular vibration that causes the material to move along the screen deck. The material is separated into different sizes as it moves along the deck, with larger particles falling through the larger openings and smaller particles being held back by the smaller openings.

The operation of a vibrating screen typically involves adjusting the amplitude, frequency, and direction of the vibration, as well as adjusting the angle and height of the screen deck. These adjustments help to optimize the performance of the screen and improve the efficiency of the separation process. The material to be separated is fed into the machine from the top, and the separated fractions are collected at the bottom of the machine.

Each type of vibrating screen is designed for specific material separation and sizing requirements, and the choice of the most suitable type of vibrating screen depends on the specific requirements of the application.

The process in which the broken material is divided into different particle sizes through one or several layers of sieve surface is called sieving. The vibrating screen is a vibrating screen that uses the relative movement between the bulk material and the screen surface to make some particles pass through the screen holes, and divide sand, gravel, crushed stone and other materials into different grades according to the particle size.

The vibrating screen screening process is generally continuous. After the screening raw materials are fed to the vibrating screen machine (referred to as the sieve), the materials smaller than the sieve size pass through the sieve, which is called the under-sieve product; the material larger than the sieve size passes through the sieve. Continuous discharge on the surface is called over-sieve product.

Vibrating screen machinery is a necessary auxiliary equipment in mine crushing and sand making production lines, and its selection has an important impact on the particle size and grading of the final product.

Factors to be considered in vibrating screen selection:

The characteristics of the sieved material (the content of the size of the material under the sieve, the content of the size of the difficult-to-sieve particles, the content of moisture and clay in the material, the shape of the material, the specific gravity of the material, etc.);

The structure of the vibrating screen (screen area, number of screen layers, size and shape of the screen hole, area ratio of the screen hole, motion mode of the vibrating screen, amplitude and frequency, etc.);

Requirements of beneficiation process (processing capacity, screening efficiency, screening method, vibrating screen inclination), etc.

In addition to considering the above effects, the following basic principles should also be observed:

(1) After determining the sieving area, the width of the sieve surface should be at least 2.5 to 3 times the size of the largest piece of material to prevent the sieve from being blocked by large pieces of material.

(2) In order for the sieve to be in a good working condition, the ratio of the length to the width of the sieve should be selected within the range of 2 to 3.

(3) Reasonable screen material and structure suitable for working conditions should be selected.

(4) Determination of sieve hole size. For fine sieves, curved sieves, and linear vibrating screens for fine particle screening, the sieve size is 2 to 2.2 times the separation particle size, and the maximum is not more than 3 times; for vibrating screens, For screening medium-grained materials, the sieve size is 1.2 times the separation size; for coarse-grained materials, the sieve size is 1.05 of the separation size; for probability sieves, the sieve size is generally the actual separation size 2 to 2.5 times the particle size.

(5) Determine whether to use double-layer or multi-layer sieves. When the particle size range of the material to be screened is wide, when the double-layer screen is used as a single-layer screen, the processing capacity of the vibrating screen can be improved, and the lower screen can be protected, so that the service life of the lower screen can be extended. The selection of the mesh size of the upper screen of the double-layer screen should generally be determined according to the characteristics of the ore feed particle size, and the material particle size equivalent to 55-65% of the original feed amount can be considered as the screen hole according to the underscreen amount of the upper screen. size.

Note that when the content of the under-sieve particle size in the raw material exceeds 50%, there are many difficult-to-sieve particles, and the material has a lot of viscous mud and high water content, try to avoid using double-layer sieves as single-layer sieves.

(6) Determine the effective working area of the sieve. The sieving area calculated according to the requirements of the production process is the effective area of the sieve, and the specification of the sieve is the nominal area of the sieve. For vibrating screens used for screening medium-sized materials, the effective sieving area should be 0.8 to 0.85 of the nominal area of the sieve. times. Of course, this is closely related to the opening ratio of the sieve holes on the sieve surface.

(7) For materials above 200mm, heavy-duty vibrating screens are mostly used; for materials above 10mm, circular motion screens are mostly used; linear vibrating screens and high-frequency vibrating screens are mostly used for desliming, dehydration and classification.

(8) When conditions permit, seat screens should be preferred to facilitate inspection and maintenance. When the hanging screen must be selected, the lifting height should be reduced as much as possible to reduce the swing range of the vibrating screen and facilitate production operations.

In short, when choosing a vibrating screen, you should not only consider one reason, but fully consider various factors to ensure that you choose the equipment that suits your working conditions.

The vibrating screen is a screening equipment capable of grading, dehydration, desliming, de-intermediation, and sorting. The vibration of the sieve body is used to loosen, stratify, and pass through the sieve to achieve the purpose of material separation. The screening effect of the vibrating screen not only has a great impact on the value of the product, but also has a direct impact on the efficiency of the next operation.

In daily production, vibrating screens will encounter various problems, such as bearing heating, parts wear, breakage, and screen hole blockage, wear, etc. These are the main reasons that affect the screening efficiency. Therefore, in order to improve efficiency, Solving these common problems is key to providing security for follow-up operations.

Vibrating screen bearing heating

In general, during the test run and normal operation of the vibrating screen, the bearing temperature should be kept in the range of 35~60°C. If the temperature exceeds this value, cooling treatment is required. The main reasons for the high bearing temperature are as follows:

1. The bearing radial clearance is too small

The radial clearance of the vibrating screen bearing is too small, which will cause the bearing to wear and heat up, mainly because the bearing carries a large load, the frequency is high, and the load is constantly changing.
Solution: It is recommended that the bearing adopt large clearance. If it is a bearing with ordinary clearance, the outer ring of the bearing can be ground to form a large clearance.

2. The bearing cover is too tight

There needs to be a certain gap between the gland of the vibrating screen and the outer ring of the bearing, so as to ensure the normal heat dissipation and certain axial movement of the bearing.
Solution: If the top of the bearing gland is too tight, it can be adjusted through the gasket between the end cover and the bearing seat, and it can be adjusted to a suitable gap.

3. Too much or too little bearing oil, oil pollution or inconsistent oil quality

The lubrication system can ensure the normal operation of the vibrating screen bearings, prevent the intrusion of foreign matter and sealing effect, and can also eliminate frictional heat, reduce friction and wear, and prevent the bearing from overheating. quality.

Solution: According to the requirements of the equipment, oil should be added to the bearing box regularly to avoid too much or too little oil. If there is a problem with the oil quality, it is necessary to clean, replace the oil and seal in time.

Vibrating screen parts are worn or broken

Some parts of the vibrating screen may be severely worn or even broken after long-term operation. The common worn and broken parts include spring springs, bearings, pipe beams, beams and screen frames.

1. The spring is worn or broken

The spring should be an important part of the vibrating screen for shock absorption and noise reduction. If the spring is worn or broken, it will not only generate a lot of noise, but also cause disorder on the screen.

Solution: The spring should be replaced in time to prevent production accidents.

2. Bearing wear or fracture

The bearing is an important part of the vibrating screen of the vibrating screen. There are many reasons for the bearing to wear or break. Once the wear is serious or broken, it can only be replaced by parking.

3. Pipe beam fracture

Generally, during dehydration or de-mediation, the water scouring force is relatively strong, and water will leak from the gap between the screens to scour the pipe beam. If the wall of the pipe beam is too thin, the pipe beam is easy to break at the scoured place.

Solution: It is suggested that you can prepare with both hands. First, when selecting a vibrating screen, you should choose the same type of thick-walled pipe beam, or a larger model of pipe beam to increase the thickness of the pipe beam wall; The joints of each sieve plate of the screen are provided with horizontal and vertical beading to reduce water leakage from the gap.

Note: If the fracture of the pipe beam is not serious, in order not to affect the production, repair welding can be carried out on the pipe beam to continue to use. When repairing welding, the weld seam must follow the longitudinal direction of the pipe beam, and absolutely no transverse weld seam is allowed, otherwise the pipe beam will Easier to break from transverse welds.

4. Broken beam

The fracture of the crossbeam is mostly due to the long working time at the critical frequency, the looseness of a large number of high-strength bolts fastening the side plate, which seriously deforms the spring, and the difference in height between the left and right causes the crossbeam to break; it may also be that the weight error of the eccentric block is too large, causing Structural damage caused the beam to break.

Solution: Stop to replace the damaged structural parts and beams and tighten the bolts; adjust the quality of the eccentric block.

5. The screen frame is broken

The fracture of the screen frame is generally caused by the shaking of the vibrating screen frame of the vibrating screen.

Solution: The side plate can be thickened, or the side plate near the exciter can be partially thickened (or add additional plates) to enhance the rigidity of the entire screen frame.

Vibrating screen holes are clogged or worn

1. The sieve hole is blocked

Generally, the clogging of the vibrating screen hole is mostly due to the high mud content and water content in the incoming material, which makes the material stick to the sieve hole and block the sieve hole.

Solution: Firstly, clean the sieve holes, and then properly adjust the water spray volume and the inclination angle of the sieve surface.

2. Screen wear

When the vibrating screen is used for a long time, the screen holes will be severely worn and the screening effect will be affected.

Solution: If the wear of the screen hole is not serious, it can be repaired in time. If the wear of the screen hole is serious, it can be considered to replace the screen.

The above are the common problems of vibrating screens, and they are also the key problems that seriously affect the screening operation. When solving these problems, in addition to finding and solving problems in time, attention should also be paid to the purchase and selection of vibrating screens, so as to effectively improve the operating efficiency of the vibrating screen.

The linear vibrating screen is driven by double exciters. When the two exciters are rotated synchronously and in opposite directions, the exciting forces generated by the eccentric blocks cancel each other in the direction parallel to the motor axis, and in the direction perpendicular to the motor axis The stack is a resultant force, so the motion trajectory of the screen machine is a straight line.

The two motor shafts have an inclination angle relative to the screen surface. Under the combined force of the exciting force and the self-gravity of the material, the material is thrown up on the screen surface and moves forward in a straight line, so as to achieve the purpose of screening and grading the material. Can be used to automate operations in the assembly line. It has the characteristics of low energy consumption, high efficiency, simple structure, easy maintenance, and fully enclosed structure without dust spillage. The highest sieving mesh number is 400 meshes, which can screen out 7 kinds of materials with different particle sizes.

Working principle: The multi-layer powder linear vibrating screen is driven by double vibration motors, and works by the principle of vibration motor excitation. When the two motors rotate synchronously and in opposite directions, the vibration force generated by the eccentric block cancels each other out in the direction parallel to the axis of the motor. Under the combined action of the vibration force and the self-gravity of the material, the material is thrown on the screen surface. Jumping and moving forward in a straight line to reasonably match the screen to achieve the purpose of screening.

Usually, the linear vibrating screen produced is delivered as a complete machine, so the user basically does not need to consider the assembly of the linear screen equipment. After the equipment is installed, it is self-assembled; sometimes the linear screen user has an irreparable failure in the box and needs to replace the box, or disassemble the equipment when repairing the equipment or moving the equipment over a long distance, which also involves the problem of self-assembly.

Linear vibrating screen is mainly composed of screen box, screen frame, screen mesh, vibration motor, motor pedestal, vibration damping spring, bracket and so on.

1. Screen box: It is welded by several kinds of steel plates with different thicknesses. It has certain strength and rigidity and is the main component of the screen machine.

2. Screen frame: made of pine or wood with less deformation, it is mainly used to keep the screen flat and achieve normal screening.

3. Screen: There are several kinds of screens such as low carbon steel, brass, bronze, stainless steel wire.

4. Motor pedestal: When installing the vibration motor, the connecting screws must be tightened before use, especially three days before the trial of the new screen machine, it must be repeatedly tightened to avoid loosening and causing accidents.

5. Vibration damping spring: prevent the vibration from being transmitted to the ground, and support the full weight of the screen box at the same time. When installing, the spring must be perpendicular to the ground.

6. Bracket: It consists of four pillars and two channel steels, which support the screen box. When installing, the pillars must be perpendicular to the ground, and the channel steels below the two pillars should be parallel to each other.

Installation method of linear vibrating screen

1. Nail mesh: the screen layer on the screen frame, the trawl layer, and mark the mark with a marker to facilitate remembering the position; remove the layer with a hammer or a flat-blade screwdriver; use a rectangular object to raise the two ends of the screen frame (bricks). , square wood, square tube, etc.). The middle of the screen frame naturally sags to form a bow. The screen is 3-5 cm longer than the screen frame. After the screen is cut, one end is nailed to the screen frame with large-headed shoe spikes. The screen is aligned with the outer end of the screen frame, and the shoe spikes are spaced 10-12 cm apart. Then go to the other end and pull the screen tight, and nail the screen to the screen frame in the same way.

2. Equipment installation: Put the sieve support of the linear vibrating screen on the level ground. Note that the support should be placed upwards, not upside down. Take the spring base on the support as a reference, and the spring base should face upwards.

Put the spring on the spring coil of the outrigger and fix it well; lift the screen machine, align the spring coil of the screen machine with the corresponding spring, slowly lower the screen machine and put it down; install the vibration motor. Before use, the connecting screw must be tightened, especially three days before the trial of the new mesh screen machine, it must be tightened back and forth to avoid accidents caused by loosening; avoid vibration transmission to the ground and support the overall weight of the screen box. When installing, the spring must be perpendicular to the ground; lift the prepared linear vibrating screen box and place it on the spring stably. At this point, the linear vibrating screen box is installed.

Precautions:

1. The customer must remove the transport bracket during installation, otherwise it will affect the normal operation of the linear screen and even cause equipment damage.

2. Check the insulation resistance of the vibration motor winding to the ground. If it is less than 20MΩ, it must be dried before use.

3. On the screen body and the upper and lower spring seats of the machine base, the springs should be completely embedded in the spring seats to ensure the balance of the screen body. The vibration part of the screen machine should not have any rigid connection or contact with other objects outside the machine.

4. When starting the machine for the first time, pay attention to observe the running track of the material. If it is wrong, it can be reasonably adjusted to the correct running track according to the screened material.

In summary, this is the whole introduction of the installation method of the linear vibrating screen. Before installation, you must understand its working principle and installation instructions in detail. During the installation process, you must strictly follow the installation regulations, so as to truly improve the working efficiency of the linear vibrating screen.

The slope of the linear vibrating screen refers to the angle between the screen surface and the horizontal direction. This slope is related to the screening efficiency, because only if the slope is appropriate, the screening of the material can be more accurate. If the slope is too large, the material will be on the screen surface. The residence time will be short, although the discharge is easier, but the material is not carefully screened, if the slope is small, the material will stay on the screen surface for a long time, but the output per unit time will be low, so the slope of the linear vibrating screen is still To be within a reasonable range, what is the general slope of the linear vibrating screen?

What is the general slope of the linear vibrating screen

The slope of the linear vibrating screen is generally between 0-15°. If you want to screen special materials, you can increase the slope, but it does not exceed 25°. The material of the linear vibrating screen equipment moves in a straight line on the surface of the screen. Generally, the screen of the linear screen will have a certain inclination angle to promote the flow of the material on the screen. The angle between the screen and the horizontal plane is the slope of the linear vibrating screen. Appropriate slope screening effect is better, not only can the material classification be clear, but also can screen efficiency, but in actual production, the installation slope of the vibrating screen should be adjusted according to the specific properties of the processed materials and the different output requirements, but this The process should also be strictly in accordance with the implementation of the vibrating screen manufacturer.

The slope setting of the linear vibrating screen is related to the material to be screened. The linear vibrating screen is suitable for screening non-viscous dry powders and granules with a moisture content of less than 7%. When the moisture content of the material increases slightly, the linear vibrating screen can adjust the slope appropriately.

The influence of the slope of the linear vibrating screen

1. Affect the screening efficiency

The slope of the linear vibrating screen will directly affect the efficiency of the vibrating screen. If the slope is too large, the residence time of the material on the screen surface is short, and it is easy to discharge, but it will cause uneven screening of the material and affect the screening fineness.

2. Affect the screening output

The material of the linear vibrating screen equipment moves in a straight line on the surface of the screen. Generally, the screen of the linear screen will have a certain inclination angle to promote the flow of the material on the screen. Under normal circumstances, if the customer does not require the screening fineness and has requirements for the screening output, we can appropriately increase the slope of the linear vibrating screen to increase the jumping speed of the material on the screen surface and promote the material passing rate.

3. Affect material classification

The slope of the linear vibrating screen will affect the classification of materials. The screening principle of the linear vibrating screen is that the material is forced to move forward in a jumping motion, and the material is moved upward by the parabolic movement of the force driven by the screen machine. If the slope is too small, the jumping height of the material is low, the force of falling on the screen becomes smaller, and the classification of the material is not sufficient. Only the appropriate slope can make the classification of the material clear.

Regarding the question of the general slope of the linear vibrating screen, the above answers have been made. The general slope is between 0 and 15 degrees. If you want to screen special materials, you can increase the slope, but it does not exceed 25 degrees. Only the slope range is suitable and reasonable, which is very beneficial for material screening.