Safety operation rules for high frequency dewatering vibrating screen

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The normal operation of the equipment can only be ensured by operating the vibrating screen in accordance with the correct safety regulations during the use of the vibrating screen. Today, the vibrating screen manufacturer will introduce to you the safety operation regulations of the high-frequency dewatering vibrating screen that we need to abide by!

Precautions for the installation of high-frequency dewatering vibrating screen

Linear vibrating screen

(1) When the vibration exciter is installed and repaired, it shall not be beaten hard or have a different phenomenon, and ensure that the original bearing is used and shall not be interchanged.

(2) The thickness and quantity of the eccentric block or counterweight plate attached to the eccentric block must be the same, and the radial clearance of the bearing should be C3 grade.

(3) The connection between the universal joint and the vibration exciters on both sides must be concentric, the eccentric blocks on both sides are in the free plumb position, and the universal joint connecting bolts can pass through smoothly; if there is any deviation during installation, check the universal joint Whether the joints at both ends of the section are concentric, do not swing the eccentric block angle for installation.

(4) The vibrating screen should be installed with springs with the same stiffness. The spring stiffness on both sides of the feeding end and the discharging end should be as consistent as possible, and the allowable height difference does not exceed 3mm.

(5) Both sides of the support seat of the rubber spring of the vibrating screen should be in the same horizontal plane, and the error is between 2-4mm to ensure that the materials on the screen surface advance evenly.

(6) When using electric welding to install or disassemble parts, the ground wire must be directly fixed on the welded workpiece and as close as possible to the welding point, and the welding current must not pass through any bearings or joints.

(7) In principle, welding should not be performed on the side plate. Depending on the current environment, if connecting components are required, the side plate should be drilled and then connected with bolts.

(8) The universal joint must be concentric, and a protective device must be installed to prevent it from breaking and falling and hurting people.

Precautions for the use of high frequency vibrating screen

High frequency dehydration vibrating screen

1. Understand equipment related knowledge

The operator should ensure that the operator understands the scope of use and technical performance parameters of the equipment; has sufficient understanding and mastery of the structure, principle and common sense of maintenance of the equipment; familiar with the process flow and equipment control of the system; keep in mind the high-frequency vibrating screen Safe operating procedures.

2. Check before operation

(1) The area around the equipment should be checked to ensure that no personnel are left behind to avoid personal injury when the machine is turned on.

(2) Check whether the feeding, discharging chute and under-sieve chute are unblocked.

(3) Check whether the sieve plate and bead bolts are loose, as well as the wear of the sieve plate.

(4) Check whether the V-belt and flexible sheet are in good condition, whether the tightness is appropriate, and whether there is damage. If there is damage, it should be replaced in time.

(5) Check the connection between the universal joint and the connecting bolts of the transition pressure plate, and whether the rubber spring is damaged.

(6) Follow the sequence of the process system to ensure that the empty screen is started and all safety equipment is in a safe and operable state.

(7) The vibrating screen must be started under no load, and the material can be fed after the amplitude is stable.

3. Observation during operation

(1) Observe the distribution of materials on the screen, and make appropriate adjustments if necessary to ensure uniform distribution of materials on the screen.

(2) Observe whether the vibration frequency and amplitude of the vibrating screen are abnormal, and whether the operation is stable.

(3) Check the temperature of the motor, vibration exciter and transmission bearing seat.

(4) Observe whether there are abnormal noises such as collisions and knocks during the operation of the vibrating screen. If it is found, it must be stopped in time.

(5) Check the vibration damping of the rubber spring.

(6) Under normal operating conditions, the bearing temperature should not exceed 45 degrees.

4. Parking precautions

(1) The amplitude of over-resonance of the vibrating screen during startup and shutdown is 5 times of normal, and it should not exceed 8 times.

(2) In any case, as long as an accident occurs, the equipment should be stopped first before contacting the centralized control room and relevant positions.

(3) Under normal circumstances, the sequence of the process system should be followed, and the vibrating screen should be stopped under no load, and must not be stopped with materials.

(4) Pay attention to the large-amplitude swing when parking to ensure the safety of the equipment, and remember to abide by the safety operation rules of the high-frequency vibrating screen.

Precautions for maintenance of high frequency vibrating screen

(1) After replacing the drive belt, it is necessary to re-check whether the outer end faces of the two pulleys are on the same level.

(2) After the overhaul is completed or the electrical components are replaced, the steering must be checked to ensure the safe use and operation of the vibrating screen.

(3) After the equipment is overhauled, the vibration exciter must be turned by hand, and the main shaft should rotate flexibly without friction and jamming.

(4) Regularly check the connection parts of each bolt, which must be firm and reliable, and all bolts must not have any looseness.

(5) Regularly check the wear and tear of the sieve plate.

(6) Check the side plates and beams of the vibrating screen once a month.

(7) Regularly check the rubber spring, V-belt, flexible connecting piece and universal joint.

(8) Lubricate each lubricating point and replace the lubricating oil according to the equipment requirements.

(9) Overhaul the vibrating screen once a year, remove all the vibrating screens for cleaning and oil change, carry out a single careful inspection of the bearings, and replace them if necessary.

The above is a very detailed introduction to the safety operation rules of high-frequency vibrating screen, mainly about the operation rules of installation, use, maintenance and other aspects. We can make a relevant understanding. At the same time, if you encounter any problems in operation, you can contact us

Introduction of Calculation and Measurement Method of Vibrating Screen Screening Efficiency

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When using a vibrating screen, the screen has two important process indicators: one is the processing capacity, which is a quantitative indicator that indicates the screening work. Another is the screening efficiency, which is a quality indicator that indicates the screening work. Among the products on the sieve, the more the number of fine grades that do not pass through the sieve holes, the worse the sieving effect is. In order to quantitatively evaluate the completeness of sieving, the index of sieving efficiency should be used.

Screening efficiency of vibrating screen: It is an indicator of the working quality of the screen, indicating the degree of screening operation and the quality of screening products. It is usually expressed as a percentage by the ratio of the weight of the undersize product obtained during sieving to the weight of the fractions smaller than the sieve size contained in the raw material.

Because it is difficult to weigh the product of the screening operation in actual production. However, it is possible to perform sieving analysis on each product of the screening operation, thereby measuring the percentage of fine fraction weight of the sieve size through which the ore feeding, the under-screen product and the over-screen product pass through the screening operation. How to calculate the screening efficiency of vibrating screen?

Arc vibrating screen

The screening efficiency can be calculated by the lower ore screen: E=β(α-θ)/α(β-θ)*100%.

α——The content of the particle size smaller than the sieve size in the raw material;

β——The content of the particle size smaller than the sieve size in the product under the sieve;

θ——The content of particles smaller than the sieve size in the product on the sieve.

Example: a vibrating screen with a sieve hole of 15 mm, after sampling and sieving analysis, it is known that the 15-0 mm particle size accounts for 50% of the sieved materials, and the product on the sieve contains 8% of the particle size, and the sieving efficiency is calculated. how many?

α (content of the raw material smaller than the size of the sieve size) = 50%, θ (the content of the product on the sieve smaller than the size of the sieve size) = 8%

So: E=100(α-θ)/α ore screen (100-θ)*100%=100(50-8)/50(100-8)*100% =91.3%

High frequency dehydration vibrating screen

Because the screening efficiency of vibrating screen is affected by many factors, it depends on what material to be processed, the composition of the material, the purpose of screening and the moisture content and viscosity of the material.

Determination method of sieving efficiency

Take samples every 15-20 minutes in the material flow entering the sieve and the material flow on the sieve. Sampling should be carried out continuously for 2-4 hours. The average sample obtained is sieved in the inspection sieve. The sieve hole of the inspection sieve is consistent with the The mesh size of the sieve used in production is the same. The percentage content α and θ of the grades smaller than the sieve size in the raw material and the product on the sieve are respectively calculated, and the sieving efficiency can be calculated by substituting them into the formula.

If there is no inspection sieve with the same size as the sieve, you can use a set of sieves for sieving analysis, draw the results into a sieve analysis curve, and then calculate the percentage content of this grade from the sieve analysis curve. a and theta.

To sum up, the low efficiency of vibrating screen is affected by many factors. If the screen is worn, or the quality of the screen surface is not high, particles larger than the screen size will enter the product under the screen. If the screening efficiency increases abnormally and sharply, it is possible that the screen is severely worn, or the screen surface quality is not good. High, the sieve size does not meet the quality requirements, resulting in too many particles larger than the sieve size.

How to prevent the vibrating screen from rusting?

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In the mining sand and gravel industry, vibrating screens are often used to screen materials. Generally, the production in this industry is in an open-air environment, so sometimes bad weather is encountered. The main screening object in the vibrating screen, the screen, is sometimes inevitably affected by rain, etc., which will cause the screen to rust. However, the rust of the vibrating screen will not only affect the production efficiency of the vibrating screen, but also It affects the production efficiency of the entire machine-made sand production line, so when rust occurs, it must be dealt with in time.

How to prevent the vibrating screen from rusting

High frequency dehydration vibrating screen

1. Select high-quality equipment

Choose a vibrating screen equipment with good material quality, and the quality of its accessories is also good, and it is not easy to rust. Therefore, high-quality screen material can largely avoid the occurrence of rust.

2. Cover the protective layer

Set a protective layer on the screen of the vibrating screen, for example, apply vaseline, oil, paint, etc. on the screen, or use hot-dip, electroplating, sputtering and other methods to coat the screen with corrosion-resistant metal, usually forming an oxide film, isolating The air will corrode the screen, and then do a good job of rust prevention and reduce the rust of the screen. Because the rust of the screen is mainly due to the chemical reaction between its surface and the moisture in the air, so in order to do a good job in the anti-rust work of the screen, the screen of the vibrating screen must be isolated from the air.

Linear vibrating screen

3. Pay attention to cleaning the screen

Do a good job of cleaning the vibrating screen to ensure the screening effect of the screen. Do a good job of removing dirt and grease. The surface of the vibrating screen will adhere to grease or dirt after a period of use. If it is not cleaned in time, it will also cause the screen to rust. Therefore, after using the vibrating screen, the impurities on the screen should be cleaned in time. . It can be washed with soap, warm water or weak detergent. If there is oil stain, it can be scrubbed with a soft cloth and then washed with detergent.

If there is rust on the surface of the vibrating screen, it can be cleaned with rust-removing acid such as nitric acid and other rust-removing items; if a rainbow pattern appears, it can be cleaned with warm water mixed with neutral detergent.

4. Pay attention to the placement of the equipment

Pay attention to the placement of the vibrating screen equipment. The equipment should be placed in a dry and cool place to avoid direct contact with moisture. The reason why the vibrating screen is easy to rust is because of the open-air production method used. In order to fundamentally solve the problem of rusting of the vibrating screen, closed production can be used, or the vibrating screen can be placed in a relatively clean and dry environment, which can Reduce the contact between the vibrating screen and the moisture in the air, solve the rust problem of the screen, and also reduce the dust pollution problem of the vibrating screen.

The screen is an important part of the vibrating screen. The screen will be in direct contact with the material. If the screen is rusted, it will affect the screening efficiency of the vibrating screen. Therefore, it is necessary to take certain measures to prevent the screen from rusting. , which can also ensure that the vibrating screen equipment plays a better screening role.

What are the precautions for daily maintenance of linear vibrating screen?

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Linear vibrating screen is a kind of vibrating screen, which is widely used in many industries. The equipment is simple to use and has good effect, so it is favored by many users. Although the linear vibrating screen is easy to use, it still needs our careful maintenance during use.

Usually, the linear vibrating screens we see are driven by dual vibration motors. When the two vibration motors are synchronized and counter-rotated, the exciting force generated by the eccentric block cancels each other in the direction parallel to the motor axis, and when the vertical vibration The direction of the motor shaft is stacked as 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. In the process of use, the equipment needs frequent maintenance. During the maintenance, the following points need our attention.

Linear Vibrating Screen

1. In the early stage of operation, check the bolts at least once a day to prevent loosening.

2. When it is used again after being left for a long time, the insulation resistance should be measured, which should be greater than 0.5 megohm for the measurement of a 500-volt megger.

3. The vibrating screen and the screen carrier are equipped with special damping rubber, so as to achieve the longest service life. The rubber strip should be properly located between the two, and the damaged damping rubber strip should be replaced.

4. When the rotation direction of the motor does not meet the requirements, adjust the phase sequence of the power supply.

Linear vibrating screen

5. After accumulative running for 1500 hours, the bearing should be checked, and if there is serious damage, it should be replaced immediately.

6. The lead angle of the tension plate of the linear vibrating screen can be adjusted. To install the screen, the lead angle bolts should be loosened so that the upper and lower screens can be moved and placed properly. The first tensioning screws and bolts tighten the plate and give slight pressure to drive the lead angle. , until the screen to the screen, firmly tighten the screw direction angle.

7. When replacing the weaving net, it should be ensured that the gap between the side plate of the screen box and the screen is equal to the first tightening and flattening, and the tension is maintained evenly with the tensioning plate, and the tension is checked. If the contact is insufficient, tight or uneven, it is a big cause of premature screen damage.

8. When disassembling the vibrating screen, it should be disassembled carefully from the outside to the inside to avoid artificial damage to the parts. In particular, to eliminate the balance wheel, it must be removed. The removed parts must be cleaned one by one, and carefully inspected. If any damage is found, it should be repaired or replaced in time.

The above are some precautions for the daily maintenance of the linear vibrating screen. In the maintenance process, correct methods must be taken to avoid the occurrence of problems.

What should I do if the linear vibrating screen fails?

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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 high sieving mesh number is 400 meshes, which can screen out 7 kinds of materials with different particle sizes. In the daily use of the linear vibrating screen, it is inevitable that some damage will not occur. The following vibrating screen manufacturers will introduce the common faults and solutions of the linear vibrating screen in detail.

Linear vibrating screen

1. Pipe beam fracture

If the wall of the tube beam is too thin, it may cause fracture. In this case, the same type of thick-walled tube or a larger type of tube beam should be used. But it should not be too large or too thick, because this will increase the vibration quality of the sieve and bring about many problems; the connection of each sieve plate of the dehydration and de-intermediation screen must have horizontal and vertical layers. If there is no vertical layer, water The pipe beam will leak from the gap between the screens and the pipe beam will be easily broken at the flushing place; the wider the screen, the easier the pipe beam will be broken.

2. Beam fracture

The fracture of the beam is mostly due to the long working time at the critical frequency, the relaxation of a large number of high-strength bolts that fasten the side plates, the severe deformation of the spring, and the difference between the left and right heights. The beam is broken. At this time, the damaged structural parts and beams should be replaced, the bolts should be tightened, and the quality of the eccentric block should be adjusted.

3. The screen frame is broken

The screen frame is prone to breakage due to trembling. The best way to solve this problem is to thicken the side plate, or add an additional plate to the local area of the side plate near the exciter to enhance the rigidity of the entire screen frame.

Arc vibrating screen

4. The discharge port is broken

Since the vibrating screen is generally made of non-standard products, the size required by different customers is different, and some require the discharge port to be extended forward or downward, so that the discharge port will be broken relatively slightly more. If it is the initial design, the plate thickness or ribs can be strengthened. In case of accidental breakage, the material quality can be checked.

In addition, check whether the parameters of the vibrating screen are correct. In addition, in the feeding process, it is necessary to avoid excessive feeding of the vibrating screen at one time, and the screen can be basically used completely. The outlet of the vibrating screen is discharged, and the excessive weight backlog will also cause the breakage of the discharge port of the vibrating screen.

If the linear vibrating screen fails, you can refer to the above methods to solve it, but if your problem has not been solved, please contact the manufacturer in time for after-sales service, and ask professionals to repair it in time, so as not to reduce your work efficiency.

For more details about the common problems of linear vibrating screen, please click to visit:

What should I do if the vibration force of the linear vibrating screen is light? Causes and solutions

What are the reasons for the mixing of the linear vibrating screen? Causes and solutions

Influence and adjustment method of insufficient tension of linear vibrating screen mesh

 

The working principle and working process of high frequency dewatering vibrating screen

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Nowadays, the coal slime content in the products of the coal industry increases and contains a lot of water, which brings certain difficulties to the dehydration of coal slime. In the past, the investment in the water treatment of coal slime was relatively large, which was not conducive to the control of production costs, but now the high-frequency dewatering vibrating screen is used, which has the characteristics of large processing capacity and simple process system, which can well dewater the coal slime. High-frequency dewatering screen is a kind of vibrating screen with high frequency and high vibration intensity as the main features. It is suitable for wet separation and solid-liquid separation of fine-grained materials. The vibrating screen manufacturer summarized the working principle of the high-frequency dewatering vibrating screen and introduced the high-frequency dewatering vibrating screen in detail.

Working principle of high frequency dewatering vibrating screen

The working principle of the high-frequency dewatering vibrating screen is to use high-frequency vibration to destroy the surface tension of the pulp, and the fine-grained materials will vibrate at a high speed on the screen surface to accelerate the separation of large-density minerals, and increase the contact between the materials smaller than the separation-sized materials and the screen holes. Probability, double vibration motor or flange type vibration exciter, the two motors are driven outside to make self-synchronized rotation in opposite directions, so that the screen body performs periodic reciprocating motion along a straight line, and fine-grained materials can be quickly screened out through the screen holes , in order to achieve the purpose of screening and dehydration.

Because the high frequency screen adopts high frequency, on the one hand, it destroys the tension on the surface of the pulp and the high-speed oscillation of the fine-grained materials on the screen surface, accelerates the separation of the large-density useful minerals, and increases the contact between the materials smaller than the separation size and the sieve holes. probability. Therefore, better separation conditions are created, so that the materials smaller than the separation particle size, especially the particles with large specific gravity, together with the ore pulp, pass through the sieve holes to become the under-sieve product.

High frequency dehydration vibrating screen

Workflow of high frequency dewatering vibrating screen

1. Two vibration motors with the same parameters installed on the excitation beam symmetrically rotate in opposite directions when they are connected to electricity, and each generates an equal centrifugal force, and the components of the two forces in the vertical vibration direction cancel each other out in opposite directions;

2. The component forces in the parallel vibration direction are superimposed on each other to form a linear vibration force, and the linear vibration force continuously acts on the screen body in a reciprocating cycle, so that the screen body vibrates on the buffer spring;

3. At the same time, the buffer spring reduces the dynamic load of the screen body to the support foundation of the screen machine, and the screen body drives the screen surface to vibrate synchronously, and transmits the force to the material on the screen;

4. The impact material is thrown up on the screen surface to advance for dehydration, the material is continuously input from the feeding chute, and dehydrated through the screen surface, the under-screen material is discharged into the under-screen chute, and the over-screen material is discharged into the discharge chute.

Motion characteristics of high frequency dewatering vibrating screen

According to the needs of mechanical structure and process parameters, the vibrator of the high-frequency dewatering vibrating screen is arranged above the center of gravity of the screen box. This arrangement makes the motion trajectory of the screen machine ellipse at the feeding end, round in the middle, and ellipse at the discharging end. , so the motion trajectory of the high-frequency dewatering vibrating screen is ellipse-circle-ellipse.

Because of this unique motion feature, the long axis of the ellipse at the feed end of the high-frequency dewatering vibrating screen forms an acute angle with the angle between the screen and the long axis of the ellipse at the discharge end, and the angle between the long axis of the ellipse at the discharge end and the screen surface forms an obtuse angle. In this way, the moving speed of the material at the feeding end is greater than that at the discharging end, which ensures that the material can be loosened quickly at the feeding end of the screen, and the material layer is thinner, so that the fine-grained material is layered as soon as possible. The sieve, the water mucosa is broken and dehydrated; and the material speed at the discharge end is small, which can prolong the dehydration time of the material on the sieve surface, thereby improving the dehydration effect. This feature of the screen machine strengthens the dehydration effect.

Linear vibrating screen

Advantages of high frequency dewatering vibrating screen

1. Simple and compact structure, high rigidity, high strength and balanced force distribution;

2. The service life is long, and the overall service life of the vibrating screen equipment is as high as 5 years;

3. The screen can be made of wear-resistant polyurethane material, with long service life and high screening efficiency;

4. Low working noise, the noise is lower than 75 decibels, and the operation is stable;

5. Light weight, low power consumption, high vibration intensity (9-12mm), and high screening efficiency;

6. The variety is complete, which can fully meet the screening process requirements of different material characteristics and processing capacity;

7. The operation and maintenance of the screen machine is simple, cost-effective, sufficient spare parts, and timely and thoughtful service. Below we will introduce the maintenance of the dewatering vibrating screen.

Maintenance of high frequency dewatering vibrating screen

1. Check whether the bolts of various parts are loose at any time, and whether the screen frame collides with the chute, etc.

2. The excitation current (amplitude) can be adjusted according to the ore properties and material requirements. In order to make the screen machine complete the task under the premise of high efficiency, the excitation current premise experiment can be done.

3. The electromagnetic exciter and the control box should be protected from water to avoid short circuit. Cover the exciter with a rubber sheet to prevent water and ore slurry from falling into it, forming a short circuit and blocking the air gap.

4. When the equipment is in normal operation, the ore feeding concentration of the sieve should be observed frequently, so that the concentration should be controlled at about 40%, so as to improve the classification efficiency.

5. When the slurry stream fed into the screen by the distribution bucket is too far, the position or angle of the screen frame should be adjusted in real time, so as not to affect the classification efficiency.

6. Because the screen has high classification efficiency, good dehydration function and high concentration of the amount on the screen, the slurry in the screen above the screen has poor mobility, so it should be equipped with a water pipe.

To sum up, the working principle of the high-frequency dewatering vibrating screen is to use high-frequency vibration to destroy the surface tension of the pulp, accelerate the separation of large-density minerals, and increase the probability of contact between the materials smaller than the separation size and the screen holes, and the fine-grained materials are sieved through the screen holes. point. When purchasing, we need to find a suitable vibrating screen model, because different models and specifications have different feeding rates, ranging from ten tons per hour to two hundred tons per hour, and we need to choose according to our own production needs.

 

Influence and adjustment method of insufficient tension of linear vibrating screen mesh

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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

Arc vibrating screen

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

High frequency dehydration 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

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.

What should I do if the vibrating screen runs out? The reason and treatment method of running pulp

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Mining vibrating screen can be used not only for powder materials, but also for the screening of liquid materials such as coal slime. However, unlike powder materials, powder materials are easy to accumulate, while liquid materials It is easy to flow out, which is the so-called slurry phenomenon. So what should I do if the vibrating screen runs out? At this time, it is necessary to analyze the reasons for the running pulp first, in order to better deal with it.

The reason why the vibrating screen runs out of pulp

High frequency dehydration vibrating screen

1. Influence of formation and mud

The influence of formation and mud is divided into the following two cases:

(1) When drilling into a loose sand-bearing layer or quicksand layer, the sand particles are easily stuck in the screen holes, resulting in the phenomenon of slurry running.

(2) Since the drugs added in the drilling fluid are not fully dissolved and stick on the screen, serious slurry running will occur at this time.

2. Unreasonable mesh number

The unreasonable mesh size of the selected screen will easily cause the slurry to run away. The processing capacity of each vibrating screen is 50L/s, because the conditions for the processing capacity test are according to the standard: 60 mesh screen is selected, and the test is carried out on the weighted mud with a specific gravity of 1.8, and the mud viscosity is the river with different particle sizes in the mud. sand. Due to the rapid drilling of the surface layer, a large amount of solid phase is generated and occupies the effective screen area, so the vibrating screen cannot use fine screen in the shallow well section.

3. Vibrating screen amplitude is too small

The vibration amplitude of the vibrating screen generally determines the processing capacity. If the amplitude is too small, it is easy to cause material accumulation, and it is easy to cause slurry running for coal slime slurry materials. Usually the vibration force of the vibrating screen is adjusted to 90% at the factory.

4. Uneven distribution of liquid flow in the screen frame

The uneven distribution of liquid flow in the screen frame is also the reason why the vibrating screen runs out of slurry. In the vibrating screen of the hook screen structure, the surface of the screen on both sides is lower than that in the middle, and the mud is easy to flow to both sides and escape.

5. The vibration motor turns incorrectly

If the vibration motor is turned inward by mistake, although the projection angle is also forward, the liquid flow has the force to push backward. At this time, the speed of the liquid flow moving forward is much slower, and it stays on the screen for a long time. It will cause the liquid flow to be unable to discharge, resulting in the phenomenon of running slurry.

The method of dealing with the slurry running of the vibrating screen

Linear vibrating screen

1. Experiment with different meshes

First, try several screens with different mesh numbers to see which one is more suitable, so as to solve the phenomenon of slurry running. Secondly, it should be used after the drug is fully dissolved, or a larger mesh screen should be used.

2. Different screen meshes are used in sections

In the early stage of the use of vibrating screen drilling, a screen with a larger mesh should be used, and as the drilling depth deepens, a screen with a finer mesh should be gradually used.

3. Check the vibrating screen amplitude

The larger the vibration amplitude is, the larger the processing capacity is; the vibration force is adjusted to 90% at the factory. If the slurry is running, the angle of the inner and outer eccentric blocks can be aligned, and the vibration force is 100%. (At this time, the treatment volume of the mud is only increased by about 15%)

4. Check the flow distribution

That is, to check whether the liquid flow spreads on the screen frame reasonably, the mud should enter the screen frame from the middle. At the same time, two solutions can be adopted. One is to adjust the front spring seat to properly raise the angle of the front of the screen box; the other is to adjust the front spring seat. Adjust the position of the turning plate of the elongated tank to control the distribution of liquid flow.

5. Check the vibration motor steering

First remove the shield of the vibrator, check whether the rotation direction of the eccentric hammers of the two motors can both rotate to the outside, and secondly, if the rotation is wrong, please exchange any two phase wires in the incoming power supply of the electric control box. The two motors rotate inward), although they can also sweep out the cuttings, but the speed is slow; in the wrong method (two motors rotate in the same direction), the vibration force is not very large, and neither sand nor mud is disposed at all.

The above is the answer to how to do the slurry running of the vibrating screen. First of all, we analyze the reasons for the slurry running. It is mainly affected by formation and mud. For example, the added drug is not fully dissolved and sticks on the screen; the selected screen mesh is unreasonable, and it is easy to cause slurry to run; the vibration screen amplitude is too small, etc. Then it should be solved according to the specific reasons, such as using different screens in sections.

How to improve the screening accuracy of vibrating screen? Reasons for low accuracy

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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

Linear 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

Arc 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

High frequency dehydration 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 advantages and disadvantages of commonly used sieve plates for vibrating screens and selection principles

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There are many types of vibrating screens and a wide range of applications. No matter what kind of screening equipment, the screen is an indispensable part. The sieve plate separates materials of different sizes under the action of vibration force through materials of different shapes and sizes, and material sizes, to achieve the purpose of classification.

However, the sieve plate is in direct contact with the material and will suffer a certain amount of wear from the material. Therefore, the sieve plate should have sufficient strength, high open rate and not easy to block holes.

The advantages and disadvantages of commonly used sieve plates for vibrating screens

High frequency dehydration vibrating screen

1. Polyurethane screen

The all-urethane sieve plate is welded by a flat steel frame. The frame tooling is a design difficulty. It is a new type of fine selection product. In recent years, it has gradually replaced the stainless steel sieve plate. The all-polyurethane screen is mainly suitable for grading, dewatering, screening and other places such as coal mines, iron ore, copper mines, gold mines, etc. It is a necessary part of the vibrating screen. Because the sieve plate is used under very harsh conditions, it requires corrosion resistance, abrasion resistance, and aging resistance, so the size of the sieve slot should be small enough during use.

Advantages: polyurethane has high wear resistance, high elasticity, sound absorption, shock absorption, not easy to run rough, good wear resistance, long service life, high screening quality, strong self-cleaning ability, good screen penetration performance, noise reduction, and improved operating environment. Wide application range, etc.

Disadvantages: The product dimensions are not flexible and the production cost is high.

Selection principle: dehydration, de-intermediation and de-sliming of various linear vibrating screens.

2. Woven mesh screen

The woven mesh sieve plate is woven with metal wires with bent buckles, and the shape of the sieve holes is square or rectangular. The woven mesh screen has two types: coarse holes and fine holes. Coarse-hole woven screens are made of low-carbon structural steel wire, spring steel wire and stainless steel wire. Fine mesh woven nets are generally made of low-carbon steel, brass, tin, tin-copper and stainless steel, etc., and are woven with a special weaving machine.

Advantages: light weight, high opening rate; and in the screening process, due to the elasticity of the metal wire, high-frequency vibration will cause the fine-grained materials stuck on the steel wire to fall off, thereby improving the screening efficiency. Suitable for screening of medium and fine-grained materials.

Disadvantages: shorter life span.

Arc vibrating screen

3. Stainless steel polyurethane composite screen

The stainless steel polyurethane composite sieve plate of this new technology is pressed into a wedge-shaped wire from stainless steel round wire, and is welded with the stainless steel convex support rib by the thermoplastic roller resistance welding process or the argon arc welding process. The frame is also vulcanized with polyurethane material, convex The support ribs replace the stainless steel convex wire part, and the process of welding the support ribs during assembly is also omitted. The outer frame is made according to the needs of users.

Advantages: high overall rigidity, low magnetism, sound absorption, shock absorption, not easy to run thick, easy to disassemble, especially suitable for the dehydration operation of heavy medium coal preparation plants.

Disadvantages: The production process is complex, the technology is relatively weak, and the quality is not easy to guarantee. In the drum resistance welding spin welding, the convex support ribs are easy to be welded, which affects the product quality and appearance, the production cost is high, and it is not easy to level, and the leveling effect is not satisfactory. . There are relatively few manufacturers with this process, and it is difficult to promote and apply it.

Selection principle: dehydration and de-intermediation of banana sieve.

4. Welded slotted screen

The welded seam sieve plate is a mature and old-fashioned sieve plate. It is mainly composed of stainless steel mesh sheets and stainless steel flat iron or carbon steel flat iron material frame assembly welding. The welding of stainless steel mesh sheets It is welded by a roller resistance welding machine, using rolled wedge screen strips and convex back strips of different cross-sections and the same cross-section, which are welded by resistance heat and current, which belongs to the contact resistance welding process.

Advantages: The working surface has high rigidity, narrow screen bars can be selected, high opening rate, flexible size change, and easy processing and forming.

Disadvantages: high noise, easy to run rough, not easy to disassemble, and poor surface abrasion resistance and anti-smashing performance during work.

Selection principle: dehydration, de-intermediation and de-sliming of various linear vibrating screens and slime curved screens.

5. Bar sieve plate

The bar screen is composed of a group of parallel steel bars with a certain cross-sectional shape. The bars are arranged in parallel, and the interval between the bars is the size of the mesh. The bar screen is generally used for fixed screens or heavy-duty vibrating screens, suitable for screening coarse-grained materials with a particle size greater than 50mm.

Linear vibrating screen

6. Polyurethane composite screen

Polyurethane composite sieve plate is a drum resistance welding machine that uses electrical current through the contact surface of the weldment joint and the adjacent area to generate the resistance heat energy to heat the welded metal to a local melting or high plastic state, and then use external force to weld it into a screen. The surface is assembled and processed to make it firm. On this basis, the frame is vulcanized with polyurethane material.

Advantages: Narrow screen can be selected, high opening rate, sound absorption, shock absorption, not easy to run thick, easy to disassemble and assemble.

Disadvantages: low screening rate, hole blocking, easy breakage of the screen, easy to wear, large particles of ore are easy to run out after wear, and the use value will be lost after wear or fracture, which indirectly causes high cost and inconvenient operation and maintenance. This kind of screen plate It can be produced by many domestic manufacturers in Taiyuan and Anhui, and it is easy to promote.

Selection principle: dehydration, de-intermediation and de-sliming of various linear vibrating screens and slime curved screens.

7. Punching sieve plate 

Punching screens are generally formed by punching round, square or rectangular screen holes on a steel plate with a thickness of 5-12mm. Compared with the round or square sieve plate, the rectangular sieve has a larger effective area, lighter weight, and higher productivity. It is suitable for processing materials with higher moisture content, but the separation accuracy of sieving is poor.

The above is an introduction to the advantages and disadvantages of commonly used sieve plates for vibrating screens. The sieve plate is an important working part of the vibrating screen to complete the process of screening materials. Different materials and different places should choose different sieve plates to achieve the ideal screening. Effect. Under the premise of meeting the production process indicators, choose the sieve plate that is suitable for your actual situation and cost-effective, so as to create greater economic benefits.