If the material wants to be screened, it must pass through the screen on the linear vibrating screen. When using the screen, a very critical factor is the tension of the screen, which is related to the screening effect of the material and the linear vibrating screen. production efficiency. Because the insufficient tension of the screen mesh will bring many influences, what are the influences of the insufficient tension of the linear vibrating screen mesh? How to solve it?

Influence of insufficient tension of linear vibrating screen mesh

1. Lead to material retention

Insufficient tension of the screen mesh of the linear vibrating screen will lead to the retention of materials, thereby preventing the forward movement of the material layer, which may lead to the accumulation of materials, or even block the screen mesh, affecting the production efficiency of the vibrating screen. Therefore, it is necessary to increase the tension of the vibrating screen to flatten the screen surface, thereby increasing the service life of the vibrating screen, and at the same time contributing to the power and productivity of the vibration. Part of the screening will concentrate on the force for a long time, which will easily cause the screening to break, and screen the materials that should not be screened, which will affect the screening effect.

2. Serious stress concentration

If the screen tension of the linear vibrating screen is large, the stress concentration will be serious. If the screen tension is loose, it is easy to produce secondary vibration, and the screen will be damaged prematurely under the action of alternating stress, which will increase the production cost.

3. Affect the sieve penetration area

The bending deformation of the screen mesh of the linear vibrating screen affects the effective sieving area of ​​the sieve hole, so that the material that should have passed through the sieve fails to pass through the sieve, resulting in a decrease in the screening efficiency. Therefore, it is necessary to strengthen the tension of the screen mesh of the linear vibrating screen, so that the entire screen mesh is evenly stressed and its service life is prolonged. Now let’s talk about the solution to the insufficient tension of the screen mesh.

The solution to the insufficient tension of the linear vibrating screen

1. Increasing the tension force can also reduce the bending deformation of the screen, but it will increase the stress on the screen. By applying tension, the screen can withstand a certain degree of prestress, which is conducive to improving the flatness of the screen, but it should be less than the safety allowable value.

2. Add the number of brackets. This can reduce the tortuous deformation of the sieve, but when the number of supports reaches the value, the effect of the addition on the deformation of the sieve is not so obvious. Additionally, as the number of supports increases, the stress on the screen becomes more uniform and the stress concentration decreases.

3. Increasing the tension force and reducing the support spacing can reduce the bending deformation of the screen and improve the flatness of the screen surface.

Adjustment method of mesh tension of linear vibrating screen

1. Adjustment of the tension of the circular screen

(1) Tension and fixation of the mother and daughter buckle: the method is to use the mother and daughter buckle to fix the screen on the mesh frame, and then tighten it to achieve the effect of tension and fixation. This method has high tension, long service life of the screen, and easy replacement, but it is prone to problems of material leakage and material running;

(2) Adhesive tensioning and fixing: This form is a new method of tensioning and fixing of screen meshes in recent years. The fixing method is to apply a layer of special glue on the mesh frame, and use it after the application is completed. The mesh installation tool evenly spreads the screen mesh on the mesh frame, so as to realize the tension and fixation of the mesh mesh. In this method, the mesh wire is uniformly stressed, and the screen frame and the screen box are in close contact without material leakage and material leakage. However, this method requires tooling and personnel to stick the mesh, and it is inconvenient to replace the mesh;

(3) U-groove tensioning and fixing: This form is a commonly used tensioning and fixing method and is suitable for various types of vibrating screens. The fixing method is to directly use bolts to fix the screen on the mesh frame, which is simple in structure and convenient in installation, but troublesome in disassembly.

2. Adjustment of the tension of the square screen

(1) Tension and fixation by hook plate method: For woven screen mesh or screen plate with thickness less than 6mm, the end of screen mesh or screen plate can be bent into a hook shape: if the diameter of screen wire is small, use thin steel plate and rubber pad to fix it. The edge of the screen mesh is wrapped, and then becomes a hook shape, and then fixed with hooks and bolts; the left and right hooks are tensioned, and the front and rear hooks are tensioned;

(2) Tensioning and fixing of wooden wedges: The punching screen plate and the slit screen surface can be fixed on the vibrating screen frame with wooden wedges. On the two side walls of the screen box, two long angle steels are symmetrically welded, and a section of short angle steel is welded at a certain distance above it, and each of the long angle steels forms an inclination angle. The sieve surface is supported between the two angle steels and pressed with wooden wedges and wooden bars. The wooden wedge expands when it encounters water, which can press the screen surface very tightly. This method is simple and reliable, and the replacement of the screen surface is simple and convenient. This method is mostly used for heavy-duty screens such as mining vibrating screens;

(3) Bolt tensioning and fixing: This form is mainly used in light linear vibrating screens. The tensioning and fixing of the screen mesh of this series of sieves can be achieved by pressing wooden or steel strips and fixing them with bolts. Tight and fixed. It should be noted here that the mesh frame equipped with the wood bar pressing and the steel bar pressing is corresponding, and the price of the wood frame mesh frame will be lower than that of the metal mesh frame. We should pay attention to this when purchasing.

In summary, the influence of insufficient tension of the linear vibrating screen mesh is that insufficient tension will lead to the retention of materials, affect the movement of materials, lead to accumulation, and also affect the screening area of ​​the screen holes, reducing the screening efficiency of the vibrating screen; lead to serious stress concentration. It can be solved by adding the number of supports. In addition, we added the adjustment method of the screen tension. Different types of screens and vibrating screens have different adjustment methods. We need to pay attention when adjusting.

As an important screening equipment, vibrating screen is now more and more widely used in various industries. For different industries, the vibrating screen has different model size, screening accuracy and output. For example, in the mining industry, the general vibrating screen equipment model is relatively large. How to improve the screening accuracy of the vibrating screen in the screening work of different materials, let’s take a look at it in detail.

Reasons for the low screening accuracy of vibrating screen

1. The mesh of the screen is blocked

Solution: increase the anti-clogging device; develop the habit of cleaning the screen of the vibrating screen frequently, and reduce the load of the vibrating screen.

2. The material has high moisture and viscosity

Solution: put it into the vibrating screen after proper drying; change the inclination of the screen box.

3. Uneven feeding on the screen surface of the vibrating screen

Solution: increase the material flow divider; adjust the feeding amount of the vibrating screen appropriately.

4. The material layer on the screen surface of the vibrating screen is too thick

Solution: increase the material flow divider to control the feeding amount; tighten the screen and tighten the transmission belt. Let’s talk about how to improve the screening accuracy of the vibrating screen.

Measures to improve the screening accuracy of vibrating screen

1. Adjust the vibration frequency

Adjust the vibration frequency of the vibrating screen. In the operation of the equipment, if you want to achieve higher screening accuracy, you can adjust the vibration frequency to achieve the purpose of improving the screening accuracy. The higher the vibration frequency of the vibrating screen, the faster the moving speed of the material on the screen surface, and the higher the jumping height of the material on the screen surface, which is more conducive to the penetration of small particle materials.

2. Using two vibrating screens

Two vibrating screens are used to screen the materials. At this time, one vibrating screen is used for primary screening, and the other is used for fine screening, which can effectively improve the screening accuracy. However, the screening accuracy can be guaranteed by this method, but the equipment capital investment is relatively large, and the processing capacity is relatively small. Usually, when the screening accuracy can meet the needs of users, it is generally considered to use a rotary vibrating screen and a vibrating screen for screening.

3. Extend the screening time

Extend the screening time of the vibrating screen. This type of screening method is mainly used when the material is difficult to screen. By prolonging the screening time of the material on the screen surface, the longer the movement time of the material on the screen surface, the smaller particles of material passing through the screen holes. The higher the probability, the better the screening accuracy of materials can be improved. However, some improvements need to be made to the vibrating screen at this time. The common method is to install a gate on the frame of the vibrating screen and the discharge port, so that if you want to improve the screening accuracy, you can close the gate to allow more material on the screen surface. Staying for a certain time can effectively improve the screening accuracy.

4. Reduce the amount of feed

We all know that if the vibrating screen wants to achieve better screening accuracy, it usually needs to feed uniformly. The main reason is that the feeding amount is too large and the material layer of the material is too thick, so that the material on the screen surface of the vibrating screen is prone to accumulation, which is not conducive to the material passing through the screen. Similarly, for the vibrating screen, a uniform feeding method is also adopted, so as to ensure that the material is adequately screened on the screen surface, which is conducive to improving the screening accuracy. A better way is to use a vibrating feeder and other equipment to evenly feed the material , to ensure the continuity and uniformity of the material flow.

5. Add a cleaning device

In the production process, a cleaning device is added to the vibrating screen. If the cleaning device is well selected or used correctly, the screening degree of the vibrating screen can be effectively improved. The bouncing ball is a common component of vibrating screen cleaning. The bouncing ball is generally used for materials with good fluidity or slightly blocking the net. The bouncing ball is affected by the vibration force of the vibrating screen and hits the net with the material to achieve the net cleaning effect. If this kind of cleaning device does not work well for special fine powder. Especially fine materials need to use ultrasonic device. The ultrasonic device is especially used for the screening of fine materials, and the application of ultrasonic waves to the vibrating screen can effectively improve the screening accuracy. The brush is generally used with two ultrasonic waves or bouncing balls for two-layer net cleaning.

6. Reduce the moisture content of materials

For materials that are difficult to screen, it is usually due to the fact that the material contains a large amount of water, or the material has a certain viscosity and other factors. These factors affect the screening accuracy and screening effect of the vibrating screen. If you want to achieve a better screening effect, take certain measures to dry the material before feeding, so that the material will not block the screen during the screening process. What we need to explain here is that the vibrating screen cannot be used for screening materials with a large water content.

Factors affecting the screening accuracy of vibrating screen

1. The size of the vibrating screen

The size of the vibrating screen is a factor that affects the screening accuracy. Different types of vibrating screens have different adaptability to the materials entering the screen, and the screening motions of materials on different types of vibrating screens are also different.

2. Feeding method

The factors affecting the screening accuracy are also the feeding method. The screening accuracy has a particularly important relationship with the quantitative feeding of the vibrating screen. The control of the feeding amount per unit time and the feeding amount during the running process of the vibrating screen is to determine the screening efficiency and screening. One of the important factors of accuracy. If the quantitative feeding cannot be controlled, the screening efficiency will generally be poor.

The above is the answer on how to improve the screening accuracy of the vibrating screen. First of all, we must clarify that the screening accuracy of the vibrating screen is not high because the screen mesh is blocked, the material moisture and viscosity are large, etc., and then take certain measures to improve the screening accuracy. For example, the vibration frequency of the vibrating screen is adjusted, and two vibrating screens are used to screen materials. In the actual production process, the vibrating screen can be adjusted appropriately according to the specific situation and production needs.

The vibrating screen relies on the vibration generated by the vibrating screen exciter to perform the screening work. For the vibrating screen that works in the workshop or outdoors, the working environment temperature also has certain requirements. If the temperature is too high, the vibrating screen will be affected. Damage, affecting the service life of the vibrating screen and delaying production.

Generally speaking, the working environment temperature of the vibrating screen does not exceed 40°C. If it exceeds 40°C, some cooling measures are required. How can the high temperature around the vibrating screen be reduced?

How to reduce the high temperature around the vibrating screen

1. Filling with coolant

When adding coolant to the vibrating screen, try to fill the same type of coolant as that in the water radiator. Do not fill tap water at will, unless it is for emergency treatment. When adding cooling water to the water radiator, be sure to wait for the water temperature to drop to about 70°C before proceeding; the “gradual water injection method” should be adopted to gradually reduce the temperature, instead of adding water too fast or too quickly, that is, let the engine idling while adding water , While filling slowly, the water flows in a long way to ensure the safety of operators and equipment.

2. Build a sunscreen

When working outdoors, the vibrating screening equipment should pay attention to building a sun screen or awning. Long-term exposure to the hot sun will not only make the machine easy to wear and aging, but also make the entire vibrating screening equipment too hot and unable to work normally, affecting the efficiency and quality of the screening, and severely will also cause the vibrating screen components such as: vibration The motor, etc. is damaged. For vibrating screening equipment working indoors or in kilns, attention should be paid to the adjustment of indoor temperature, as well as ventilation and air permeability.

3. Do a good job of lubrication

The lubrication work is aimed at the bearings of the vibrating screen. Lubrication plays an important role in the transmission of the vibrating screen and equipment maintenance. Lubrication can affect the performance, accuracy and life of the equipment. In the high temperature season, the lubrication time should be adjusted first. Compared with the spring and autumn, the time should be shortened by 0.5-1 times, and the oil quality should be observed. The temperature of the fat oil is easy to change. If the temperature rises, add oil appropriately. If the temperature is a little higher and then slowly falls, it proves that the lubrication is effective, and the lubrication is not enough due to insufficient oil inside the bearing, leading to an increase in temperature. If the temperature does not change or only rises after refueling, it proves that the bearing has worn out, or is severely short of oil, and even the oil inside is already dry.

The above is the answer to how to reduce the high temperature around the vibrating screen. We can add coolant, build a sun screen for the vibrating screen that works outdoors, and do a good job of lubricating the equipment. No matter indoors or outdoors, we must keep the vibrating screen in a good condition. Try to avoid the use of vibrating screen equipment in high temperature environment, if it can’t be avoided, it is necessary to have certain cooling measures for it.

Linear vibrating screens are generally used in the mining industry. In mines, the production environment is usually harsh. Therefore, we usually pay great attention to the operation and maintenance of the vibrating screen. If there is bad operation and maintenance, it will have a greater impact on the vibrating screen. , Which in turn affects the overall production efficiency. Especially for the operation and maintenance of several main components of the linear vibrating screen.

Operation and maintenance of linear vibrating screen exciter

The vibrating screen exciter is the main component of the linear vibrating screen, and its operation and maintenance are mainly the adjustment of the eccentric block.

1. The magnitude of the exciting force is closely related to the movement of the sieve machine. There are 8 adjustment holes between the main block and the counterweight of the eccentric block, which are equally divided by 15°, so they can be adjusted according to 8 positions at different angles. After adjusting to a different position, the centrifugal force changes, which in turn changes the amplitude of the screen.

2. When adjusting, each vibrating screen exciter needs to be adjusted synchronously. If the adjustment position is different, the exciting force generated will be different, and the material on the screen surface will jump irregularly. Therefore, correct adjustment must be made. Especially when replacing the exciter, the positions of the adjustment holes must be consistent.

3. Perform inspection after adjustment. The two symmetrical amplitudes and directions on both sides of the screen are required to be consistent. If the amplitude of the two sides of the screen is slightly different, no more than 0.5mm is allowed, because the movement trajectory of the material is related to the uniformity of the material on the screen, and it is necessary to adjust the feed distribution in time.

4. Due to the high-speed rotation of the vibrator of the screen machine, the axial deviation and torsion effect are generated during the operation, so the lubrication of the vibrator is particularly important for the maintenance of the screen machine. According to the operating time, the oil is generally injected once a week, and the amount of grease added is generally 300-600mL. Grease uses 2# lithium-based grease in winter and 3# lithium-based grease in summer.

Operation and maintenance of linear vibrating screen coupling

The exciters on both sides of the linear vibrating screen are connected by universal couplings. When replacing, pay attention to the flatness of the joint surface of the universal coupling. The universal coupling has been dynamically balanced before it leaves the factory, and the straightness of the coupling is directly related to the amplitude of the screen.

When replacing, the eccentric block of the vibration exciter is used to sag naturally, and then the universal coupling is connected and fixed with the coupling of the vibration exciter. The difference in the position of the screw hole is adjusted by adjusting the position of the spline. One thing to note is that the length of the coupling and the length of the spline should be selected reasonably to avoid insufficient coupling length or spline jamming.

For the coupling, because it is a spline connection, the vibration exciter generates a shaft string during operation, and the spline part needs to be well lubricated. Generally, oil is injected every 1200 hours of operation.

Operation and maintenance of spring of linear vibrating screen

Each rubber buffer spring of the linear vibrating screen can be used for about 15-20 months, and the size varies with the model of the screen machine. The temperature of the equipment should not exceed 45°C during operation. When replacing the rubber spring, pay attention to the coefficient of elasticity, that is, the height of the rubber spring at the entrance of the screen is similar, and the height of the outlet is similar, so that the buffer rubber spring can be used reasonably and it is not easy to damage. Also, when replacing the rubber springs, you should pay attention to the rubber springs on the front and rear parallel lines to be replaced at the same time to avoid changes in amplitude due to the inconsistent degree of aging of the rubber springs.

Operation and maintenance of the support screen frame of the linear vibrating screen

When cracks are found in the support screen frame of the linear vibrating screen, it cannot be simply repaired by welding. Instead, a layer of steel plate should be drilled and fixed with screws. The main reason is that the stress and material of the screen surface change due to local heating during welding. Make it more fragile.

Operation and maintenance of bolts of linear vibrating screen

The operation and maintenance of the linear vibrating screen bolt is mainly to tighten it. The connecting bolts of various parts are prone to loose due to long-term vibration. They must be inspected after shutdown. The bolts used should be high-strength bolts and high-strength locknuts, coated with anti-loosening fluid, and anti-loosing disc springs should be used for reinforcement. The effect is better. In order to prevent the wear of the screen bolts, polyurethane rubber sleeves can be used to cover the easily worn parts of the bolts to avoid contact and wear with the material.

Operation and maintenance of support beam of linear vibrating screen

The support beam of the linear vibrating screen adopts seamless steel pipe as the beam, on which the dovetail slide of the fixed screen plate is welded, and the welded round flanges at both ends are connected to the screen by high-strength bolts. The beam needs to be annealed in the later stage of processing to eliminate internal stress. Improve the strength of the beam and the service life of the screen. The beam of the screen machine must be inspected after each shutdown, focusing on checking whether the support beam of the screen machine is seriously worn and aged, whether there are cracks and other damages.

Operation and maintenance of the linear vibrating screen sieve

The screen surface of the screen used in some concentrator screens is made of stainless steel. Although the investment cost is high, the use effect is better, especially in terms of abrasion resistance. The blind sieve plate bonded by stainless steel and polyurethane is used at the entrance of the sieve machine, which has higher strength. The wavy and striped screens are used in the classification of raw materials. The penetration rate of the wavy screens is better and not easy to be blocked, but the disadvantage is that the screen bars are easily broken by large pieces of raw coal, allowing large particles to enter the next-level system. It must be repaired or replaced in time after each shutdown.

Operation and maintenance of additional components of linear vibrating screen

1. The screening effect of the screen machine is related to the thickness of the material on the screen surface and the distribution on the screen surface. Therefore, a dividing plate with adjustable angle can be installed at the inlet of the screen machine, according to the particle size and feeding of the raw coal. The volume adjustment angle is used to adjust the uniformity of the screen surface material.

2. Install several water spray pipes above the screen surface of the sieve machine, and use the water pressure to increase the penetration rate and grading effect of the classification, and remove the impurities attached to the coal. The use of pressurized water on the deintermediation screen can improve the deintermediation effect and significantly reduce the media consumption.

The above is an introduction to the operation and maintenance of the main components of the linear vibrating screen, such as the adjustment of the eccentric block of the vibrating screen exciter. In addition, when lubricating the exciter, you must pay attention to distinguishing the grease. The exciter cannot use calcium-based grease. , Otherwise the exciter will heat up and lock up and cause an accident during operation. Generally, the exciter is used for about three months, and its interior is cleaned with an oil pump, and lubricating grease is refilled after cleaning.

When purchasing a vibrating screen, users will pay more attention to the cost performance, such as the screening effect, function, etc., whether the price is reasonable or not, they are more concerned about. Generally, vibrating screens are sometimes dedicated and can only screen one type of material. However, for current production, how to screen multiple materials with vibrating screens has become a trend, which means that one vibrating screen equipment can screen different forms Materials such as particle size and characteristics are screened.

How to screen a variety of materials with a vibrating screen

1. Change the vibrating screen amplitude

To realize the screening of a variety of materials by the vibrating screen, the amplitude of the vibrating screen can be changed according to the characteristics of the material. To make the vibrating screen achieve better screening results for materials with different properties, the amplitude of the vibrating screen needs to be adjusted accordingly , Because different materials have different shapes due to molecular structure, the requirements for amplitude are also different. For example, materials with relatively heavy specific gravity and good fluidity are suitable for screening with low amplitude, while materials with poor fluidity generally require high amplitude to achieve better screening results.

2. Replace the vibrating screen

The particle size of the material varies greatly according to the shape and type. Therefore, to realize the screening of a variety of materials by the vibrating screen, it is necessary to realize the variability of the mesh number of the screen. The simpler method is to purchase multiple screens of different meshes from the vibrating screen manufacturer or a nearby manufacturer, and manually replace the screens according to the needs to achieve screening of multiple materials.

It is worth noting that the screen is the part of the vibrating screen equipment directly in contact with the material, and it is an important guarantee for determining the accuracy of material screening and the output value. However, many users often find that the screen is broken. It is recommended that users should pay attention to the equipment operation: the oscillation force should not be too large, and should be within the equipment range, and the feeding amount should not be too large to prevent the screen from breaking. . In addition, the quality of the screen is affected by the choice of material, the thickness of the warp, and the placement of the warp and weft during weaving. Therefore, a good supplier should be selected when selecting related accessories.

3. Adjust the vibrating force of the vibrating screen

To screen a variety of materials, the other is to adjust the vibrating force of the vibrating screen according to the output requirements and the difficulty of the material through the screen. The adjustment of the vibrating force of the vibrating screen is mainly achieved by changing the angle of the upper and lower weights of the vibrating motor. The reason for changing the vibrating force is that the stickiness, water content, and specific gravity of the material are closely related to the sieving rate, and the output of two different materials on the same equipment is also quite different.

Therefore, when sieving materials that are difficult to pass through, it is necessary to increase the vibrating force to ensure a certain production efficiency, and when sieving materials with a higher sieving rate, the vibrating force can be reduced to reduce unnecessary energy. Waste. The size of the vibrating sieve force is not only related to the type of material, but also closely related to and proportional to the number of screen meshes.

The above is the answer and analysis of how the vibrating screen sieving a variety of materials. It is mainly possible to change the vibrating screen amplitude according to the characteristics of the material, replace the screen, and adjust the vibrating screen force according to the difficulty of sieving the material. It can be seen from these several methods that if you want to screen a variety of materials, the key lies in the diversified adjustment of the vibrating screen’s amplitude, screen, and excitation force to achieve the variability of these three parameters.