Six main points teach you how to choose a vibrating screen

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Vibrating screen is an important screening equipment in mining equipment. After the material is screened by the vibrating screen, the specifications are clearer and the quality is higher, so its work efficiency affects the benefit of the entire production line. Therefore, it is also very important to choose a suitable vibrating machine, but some novice users may not know how to choose a vibrating screen. Below, the editor of Hiside will summarize a few selection points to teach you how to choose the right one.

Choose according to material characteristics

Each material that needs to be screened has its own unique properties, so choose a vibrating screen suitable for screening the material according to the different properties of the material. These attributes include: density, shape, temperature, viscosity, particle size, mobility, particle size distribution, corrosiveness, etc. According to your different materials, you need to choose different vibrating screens. If you are not sure about this, you can ask the manufacturer’s technicians to help you.

Arc vibrating screen

Choose according to the processing volume

1. When the required processing capacity is small, some light linear vibrating screens are cheaper and meet the demand; when the required processing capacity is large, a steel frame is required to ensure the quality. The steel frame of the mine linear vibrating screen can meet the requirements.

2. According to the size of the vibrating screen and the rated processing capacity, select a vibrating motor or a vibrating exciter of appropriate power.

3. Choose different sieve plate angles according to the nature of the material and the processing capacity requirements.

Choose according to the structure of the screen machine

When selecting a vibrating screen, the screen area and number of layers, the shape, size and area rate of the screen hole, as well as the motion mode of the vibrating screen, the vibration frequency and amplitude and other factors should also be considered when selecting the vibrating screen. The screening efficiency of the vibrating screen is related to the movement form of the screen surface, so the screening efficiency of the fixed screen is low, and the screening efficiency of the moving screen is relatively high. For the moving screen, the vibration of particles on the screen surface close to the vertical screen hole direction has a high vibration frequency and a better screening effect; if the particles slide in the direction of the screen surface, the screening effect is relatively poor.

Banana screen

Choose according to the purpose of screening

According to different screening purposes, different types of vibrating screens need to be selected, such as: materials need to be pre-screened, generally linear vibrating screens; for grading and screening of crushed materials, large-scale vibrating screens, probability screens, etc.; for materials For de-intermediation and dewatering, it is better to choose a dewatering vibrating screen.

According to the production site selection

According to the customer’s production site, choose the right size vibrating screen. Technicians need to measure the site on the spot and need to ensure that the linear vibrating screen can be placed in the production line. The more basic is the length, width, and height of the vibrating screen, and the measured values ​​must be accurate, otherwise the vibrating screen produced cannot be placed on the site. The vibration motor and exciter can be placed in different places (bottom or both sides) according to the actual site conditions. In this regard, we must choose a good manufacturer, because to ensure the power of Zhenyuan, Hiside Heavy Industry has rich experience and a large number of talents in the technical department, so it is worth choosing. The excitation force produced by bad manufacturers may not meet the amplitude requirements, which affects production. In addition to the length, width, and height, different shapes of inlet and outlet must be designed according to the production line, such as round and square.

Oother selection elements

1. Easy to repair. Try to choose a model that is easy to maintain under the same conditions. Mine vibrating screens are basically open-air operations, and the processed materials are all mineral materials. The harsh production environment is likely to cause large and small failures in the screen. The easy-to-repair screen can effectively save maintenance time and cost.

2. Parts. All parts and components of the selected models should be standardized and serialized. In this way, when replacing damaged parts, it can be directly replaced without modification and debugging.

3. Security. The selected mine vibrating screen model must ensure the safety of production. Safety in production is more important than Mount Tai, and you must not use unqualified models and accessories to save purchase costs or maintenance costs.

The above is an introduction on how to choose a vibrating screen. The vibrating screen is one of the indispensable equipment in the mining production line. The correct choice can help increase productivity. It can be selected according to the characteristics of the material, such as shape, particle size, density, etc.; Selection of processing capacity; selection according to the structure of the screen, such as screen area, number of layers, etc.; selection according to six aspects such as the selection of screening purposes.

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

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The linear vibrating screen gets its name because the material’s motion trajectory is straight. It uses the exciting force as the source of vibration to throw up the material on the screen while the material moves forward in a straight line. After the material passes through the screen, the material is separated from the inlet. It is the oversieve and undersieve, which are then discharged from the discharge port respectively. The vibrating force of the vibrating screen is the source of throwing up the material, so it needs to have a certain vibration force, so what should I do if the vibrating force of the linear vibrating screen is light?

1. Reasons for the light vibration of the linear vibrating screen

High frequency dehydration vibrating screen

1. The power supply cannot operate normally

For the linear vibrating screen, the screen cleaning device is also the second power source to provide the vibrating force. Once the transducer is overheated or the power supply fails to operate normally, the vibrating force of the vibrating screen can be reduced. The inspection standard is that the normal temperature of the transducer is 60°C during operation. If the temperature is found to be abnormal, it should be shut down for maintenance, mainly due to material residues. Therefore, the contact part of the transducer and the screen should be cleaned before the screen is operated.

2. Vibration motor failure

The vibrating motor is the main power source of the vibrating screen. Once the motor fails, the vibration force will decrease. So what are the problems with the motor? The lack of oil in the motor will affect its operation, and once the lubricating oil consumption is severe, the friction of the motor components will increase and the vibration force will be reduced. Therefore, it is necessary to check the fuel consumption of the motor regularly, and immediately stop and add lubricating oil once it is found.

3. Design and production issues

At the beginning of the design of the vibrating screen, if there is no detailed communication, and the model is selected without understanding the characteristics of the material and the required output, the vibrating screen designed and produced will easily appear inconsistent with the requirements, and the vibration force will be too light and fail to meet the production requirements. The problem. Therefore, when we purchase vibrating screening equipment, we should also provide detailed material characteristics and required output, so that the vibrating screen manufacturer can also suggest suitable models for you according to the detailed parameters.

Second, the solution to the light vibration of the linear vibrating screen

1. Adjust the exciting force

First, adjust the excitation force to adjust the angle of the eccentric block. There are eccentric blocks at both ends of the motor, and this eccentric block has a certain angle. The excitation is different for different angles. The angle is smaller, the excitation force is smaller, and the angle is larger. , The excitation force is larger, at this time, you can adjust the angle of the eccentric block according to your own needs, and you can also change the movement trajectory and residence time of the material on the screen. In order to adapt the screening machine to the required separation state of various materials, such as various changes in the distribution of materials, output per hour, screening efficiency, penetration rate, etc., the angle of the eccentric block is adjusted to the ideal state.

2. Adjust the angle and gauge

To adjust the angle of the vibrating screen, you need to open the adjustment hole of the bottom barrel. Loosen the fixing bolts of the lower eccentric block. Screen the material trajectory according to the required. Adjust the phase angle of the upper and lower weights in the opposite direction of the discharge port. Then put a small amount of material on the screen surface, make the screen machine run, and check the movement trajectory of the screen surface material. If the processing parameters have reached the effect, stop the machine and tighten the fixing bolts, and the adjustment is over.

3. Adjust the weight of the eccentric block

The weight adjustment of the eccentric block can be equipped with additional weights on the upper and lower weights. The main function is to increase the exciting force output by the screen machine. According to the number of layers of the screen machine and the specific gravity of the material to increase or decrease the exciting force, increase or decrease the additional weight. Then test the machine to observe the weight, and wait until the screening machine reaches the screening effect. Sometimes due to the influence of the specific gravity of the material, the humidity, the tilt angle and other parameters, it is impossible to adjust the stagger angle one-time successfully, so Users are requested to have sufficient patience to make adjustments so that the screen machine can play its due efficiency.

3. Measures to prevent the vibration of the linear vibrating screen from being light

1. Feeding at a constant speed

When using the vibrating screen, some users find that there are a lot of objects on the screen and they feel that the machine can’t move. At this time, the reason is that there are more materials. When the material can be fed, the material is fed at a constant speed, so that the material is at a relatively uniform speed when the material is unloaded. Will not press the machine to reduce the exciting force.

The exciting force of the vibrating screen itself originates from the vibrating motor itself, so at the moment of its operation, the motor itself will have a high temperature rise, and it is precisely because of the existence of this cooperation gap that the shaft of the vibrating motor will expand after the temperature rises. The shaft after expansion happens to work closely with the bearing, and the rod reaches the normal operating condition. If it is not maintained, the excitation force may not be reached. Therefore, the motor needs to be maintained and maintained regularly.

The above is the answer to what to do if the vibration force of the linear vibrating screen is light. First of all, we must know that the reason for the light vibration force may be caused by the power supply failure, motor failure and design and production problems. Secondly, we want to solve this problem. It can be solved by adjusting the excitation force, the angle gauge, and the weight of the eccentric block. If you want to prevent it, you need to maintain the motor and feed evenly.

Summary of common problems and solutions for coal centrifuges

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Coal centrifuge is a machine that uses centrifugal force to separate liquid and solid particles or each component in a mixture of liquid and liquid. It is mainly used to separate the solid particles in the suspension from the liquid; or to separate the two incompatible liquid substances in the emulsion with different densities; it can also be used to remove the wet solid For liquids, special ultra-velocity tube separators can also separate gas mixtures of different densities; taking advantage of the different settling speeds of solid particles of different densities or particle sizes in liquids, some sedimentation centrifuges can also determine the density or size of solid particles. To classify. So in the process of use, how to maintain the coal centrifuge? Let us follow the coal centrifuge manufacturers to learn more about it!

Common problems of coal centrifuge

Reasons for the power supply and the motor not running:

1. The power cord is disconnected internally, and the plug and socket are in poor contact.

2. The speed regulator switch is out of order, the power supply is not turned on, or the connection wire is disconnected.

3. The brush is open, and the brush is stuck or severely worn out of contact with the commutator.

Maintenance method:

1. Check the power lead and replace the plug and socket with poor contact.

2. Open the bottom cover, check the speed regulator with a universal meter, repair the open circuit, and replace damaged parts, such as worn-out brushes.

 Reasons for the motor not reaching the rated speed:

1. The power supply voltage is too low, and the speed is obviously slowed down when the power supply voltage is below 190V.

2. The bearing is damaged and the rotation is not flexible, or the bearing is lack of oil and dirt, which causes the bearing to heat up and increase the friction resistance.

3. Poor contact between the two brushes.

Clean Coal Centrifuge

Maintenance method:

1. Find out the reason for the low power supply voltage, adjust the voltage to 220v with a power supply regulator, and when the voltage reaches normal, polish the rectifier with sandpaper to make the brush and the rectifier have good contact.

2. When the bearing is short of oil or dirty, it should be cleaned first and then refueled. It is acceptable to add butter or petroleum jelly. The lubrication amount is 1/3~3/2 of the bearing clearance. If the bearing is damaged, replace the bearing.

The vibration is large when rotating, the centrifuge jitters back and forth, and the noise is large. The causes:

1. The bearing or bearing sleeve on the motor is severely worn.

2. The upper end of the motor is mainly bent.

3. The load is unbalanced, the two test tubes are asymmetrical, the weight of the sleeve is different, there are more broken glass in the sleeve, and the centrifuge tube sleeve does not meet the requirements.

4. The rotor of the motor is not in the center of the magnetic field, that is, the space around it is inconsistent or the outer cover is deformed in the wrong position, friction and noise will occur.

5. The motor and the bottom screw are loose, the shaft is not vertical, and the machine feet are not flat.

6. The centrifuge fixing screws with damping springs are loose or the springs are broken.

Maintenance method:

1. Replace with new bearings or sleeves.

2. Remove the main shaft for straightening or replace the main shaft.

3. The test tube and the casing must be balanced and weighed at the same time. High-speed centrifugal balance is more important. The centrifuge tube sleeve cannot be changed at will.

Slime Centrifuge

Reasons for long-term shutdown or low-speed startup in cold weather:

1. Lubricant solidification.

2. Lubricating oil deteriorates and sticks.

Maintenance method:

1. After power on, it can be started with manual help, and it will return to normal after running at high speed for a period of time.
2. Clean the bearing and re-oil it.

Causes of damp and leakage:

1. The centrifuge is useless for a long time, the indoor humidity is high, and the moisture is eroded.

2. Insulation between the live part of the centrifuge and the casing of the machine is not good or the insulation performance of the insulator decreases after being damp.

Maintenance method:

1. The centrifuge that has not been used for a long time should be kept dry. Generally, it should be energized at least once a month and rotated for 15 minutes. If moisture is found, it can be rotated continuously for 2 hours to drive off the moisture in the machine.

2. When the cabinet is leaking, the contact point between the live wire and the cabinet should be found and replaced with a new one. The case must have a good grounding wire.

How does the vibrating screen work?

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Vibrating screens have been widely used in mining, metallurgy, coal, water conservancy, transportation, and chemical industries to complete various processes, such as screening, grading, washing, de-intermediation and dehydration of materials . As an intermediate link between mining and smelting, mineral processing efficiency not only directly affects mineral processing productivity, but also has a profound impact on the rational use of national resources.

The vibrating screen works by using the double-rotation vibration generated by the vibrator. The upper rotating weight of the vibrator makes the screen surface vibrate in plane, while the lower rotating weight makes the screen surface vibrate the cone surface. Its combined effect The effect is that the screen surface produces double-rotating vibration. Its vibration trajectory is a complicated spatial curve. The curve is projected as a circle on the horizontal plane, and projected as an ellipse on the vertical plane. The amplitude can be changed by adjusting the excitation force of the upper and lower rotating weights. Adjusting the spatial phase angle of the upper and lower weights can change the curve shape of the screen surface movement trajectory and change the movement trajectory of the material on the screen surface.

High frequency dehydration vibrating screen

Vibrating screen equipment can be divided into: mining vibrating screen, light fine vibrating screen, and experimental vibrating screen according to its weight.

Mine vibrating screens can be divided into: heavy-duty screens, self-centering vibrating screens, elliptical vibrating screens, dewatering screens, circular vibrating screens, banana screens, linear vibrating screens, etc.;

Light fine vibrating screen can be divided into: rotary vibrating screen, linear screen, straight row screen, ultrasonic vibrating screen, filter screen, etc.;

Experimental vibrating screen: flapping screen, top-strike vibrating screen, standard inspection screen, electric vibrating screen, etc.

According to the material running track of the vibrating screen, it can be divided into:

According to the linear motion trajectory: linear vibrating screen (the material moves forward on the screen surface in a straight line);

According to the circular motion trajectory: circular vibrating screen (materials move circularly on the screen surface);

According to the reciprocating motion trajectory: fine screening machine (materials reciprocate forward on the drying surface).

Arc vibrating screen

In recent years, although vibrating screening machinery has achieved unprecedented development, the theoretical framework of vibrating screens has been stable and becoming mature. Various types of vibrating screens have been introduced one after another, but vibrating screens with high screening efficiency and large output have always been vibrating. The new direction of sieve research and development.

The coal or ore mined in the mining field, or the crushed material, before the material is used or further processed, it needs to be divided into several grades of similar particle size or be dehydrated, de-intermediated, de-slimed, and sometimes a combination of several items. Yes. When performing the above work, there is always the problem of grading materials through the holes of the screen surface, and the grading of materials through the holes of the screen surface is called sieving. Through the research on the screening process of materials, it is found that the screening of materials can be divided into two stages:

1. Fine-grained materials smaller than the mesh size reach the screen surface through the material layer composed of coarse-grained materials;

2. The fine particle material passes through the sieve holes on the sieve surface to complete the sieve.

When the vibrating screen is working, the two motors synchronously and reversely rotate to make the exciter produce a reverse excitation force, forcing the screen body to drive the screen to move longitudinally, so that the material on it is periodically thrown forward for a range due to the excitation force. So as to complete the material screening operation. It is suitable for screening sand and gravel materials in quarries, and can also be used for product classification in coal preparation, mineral processing, building materials, electric power and chemical industries.

The working part of the vibrating screen is fixed, and the material is screened by sliding along the working surface. Fixed grid sieve is one of the most widely used in concentrators, generally used for pre-screening before coarse crushing or medium crushing. It has a simple structure and is convenient to manufacture. It does not consume power and can directly unload the ore onto the screen surface. The main disadvantages are low productivity and low screening efficiency, generally only 50-60%. The working surface of the vibrating screen is composed of horizontally arranged rolling shafts. There are plates on the shafts, and fine-grained materials pass through the gaps between the rollers or plates.

In order to smoothly complete the screening process of the material, the condition of relative movement between the material and the screen surface must be satisfied. Therefore, the screen box of the vibrating screen should have suitable movement characteristics, on the one hand, it can make the material on the screen surface become loose.

On the other hand, it can make the coarse particles blocked on the sieve holes escape, and keep the fine-grained materials smoothly through the sieve. In the actual production process, the actual screening process is: “After a large number of broken materials with different particle sizes and mixed coarse and fine particles enter the screen surface, only a part of the material contacts the screen surface. In this part of the material contacting the screen surface, It is not entirely a fine particle material smaller than the mesh size,
Most of the remaining fine particles smaller than the mesh size are distributed throughout the entire material layer.

Through the movement of the screen box, the material layer on the screen surface is loosened, so that the gap that exists between the large particles is further expanded, and the small particles take the opportunity to pass through the gap and transfer to the lower layer; at the same time, due to the small particles between the materials The gap is small, and large particles cannot pass through. Therefore, the position of large particles increases continuously during the movement. As a result, the original messy material particle group separates, that is, it is layered according to the particle size, forming an arrangement rule with small particles on the bottom and coarse particles on the top.

The fine particle material that reaches the screen surface, because its size is smaller than the sieve hole size, can smoothly penetrate the screen, and finally realize the separation of coarse and fine particle materials and complete the screening process.” However, sufficient separation is impossible. In time-sharing, there is generally a part of the fine particles remaining in the coarse particles on the sieve and cannot penetrate the sieve. Research shows that although the size of the fine particles is smaller than the sieve hole, the difficulty of their penetration is not the same. Compared with sieve holes, the smaller the particle size, the easier it is to penetrate the sieve, and vice versa, the more difficult it is.