Linear vibrating screen is an important equipment in coal preparation, mineral processing, building materials, electric power and chemical industries, and various faults often occur in daily use, which affect the use. For example, vibrating screens often encounter the problem of screen clogging when sieving materials. Today, the editor summarizes the reasons for the blockage of the linear vibrating screen, and solves the problem of blockage through corresponding methods.

Causes of blockage of vibrating screen

The processing capacity of the vibrating screen is positively correlated with the effective opening rate of the screen. The larger the effective opening rate, the better the penetration of the material and the greater the processing capacity of the vibrating screen. In actual production applications, there are two factors that cause the effective opening rate of the vibrating screen to decrease (ie, the screen is blocked): one is the proximity effect, which refers to the formation of particles with the same diameter as the screen being embedded in the mesh. Clogging; there is also the accumulation effect, which is mostly caused by the stickiness of materials or the blocking of the screen caused by accumulation and agglomeration caused by electrostatic mutual adsorption. Therefore, to ensure the throughput, the cleanliness of the screen mesh must be maintained. There are generally two main reasons for the blockage of the vibrating screen: the first material and the second screen. Specifically, the reasons for the blockage of the vibrating screen can be summarized as follows:

1. The density of the material is high, and the selection of the screen is inappropriate;
2. The material to be screened is wet;
3. The material to be screened has static electricity or is easy to stick;
4. The screened materials are lighter;
5. The screen wire has a large diameter and is not easy to blank;
6. The bottom of the screen lacks a net cleaning device (rubber bouncing ball), also known as a clear tennis ball;
7. The woven screen wire is too thick;
8. Spherical particles or materials with multiple contact points to the sieve holes;
9. There are more flaky particles;
10. Thicker screens, such as rubber screens, have unreasonable hole shape design, which does not reach the upper and lower sizes, which causes the particles to get stuck. Because most of the material particles that need to be screened are irregular, the causes of blockage are also diverse.

The solution to the blockage of the vibrating screen

In order to effectively prevent the blockage of the linear vibrating screen, measures should be taken to address the reasons for the blockage of the screen:
1. Analyze and judge the materials to be screened, and select the appropriate screen. If the screen is blocked, the first thing to consider is whether the particle size of the screened material is appropriate, and more importantly, the characteristics of the screened material. If it is viscous, it will easily stick to the screen and cause the screening efficiency to drop. You can properly adjust the amplitude of the vibrating screen to see the effect.
2. In addition, the poor self-cleaning ability of the screen may also cause the mesh to be blocked. At this time, if the vibrating screen permits, a ball support plate can be installed, which uses the principle of a bouncing ball to make the screen Clean up.
3. When sieving materials with fine particles, high moisture content and mud content, the materials are easy to bond, and when the moisture content is greater than 5%, they need to be dried, dehydrated and then screened. If the moisture content is greater than 8%, wet screening is required. .
4. For materials with more flake particles, pay attention to adjusting the crushing method of the materials and the particle size matching of different crushing processes.
5. The vibrating screen is equipped with different numbers of rubber bouncy balls under different meshes.
6. Reasonable adjustment of the tension of the vibrating screen is an effective way to reduce the hole blocking of the screen. The reasonable tension makes the screen and the supporting beam produce a slight secondary vibration, thereby effectively reducing the phenomenon of hole blocking. Occurrence, this can better make the screen work properly. The specific method is: the tension hook is made into a constant tension mechanism, that is, a spring is installed on the tension bolt, so that the phenomenon of blocking the holes of the vibrating screen can be avoided, and the screening effect can be improved, so that the vibrating screen can be screened. higher efficiency.

The linear vibrating screen uses a vibrating motor as the source of vibration, so that the material is thrown up on the screen while moving forward in a straight line. The material enters the inlet of the screening machine evenly from the feeder, and generates data through the multi-layer screen. The oversieve and undersieve of various specifications are discharged from their respective outlets. It has low energy consumption, high output, simple structure, easy maintenance, fully enclosed structure, no dust spillage, automatic discharge, and is more suitable for assembly line operations. So do you know what are the sieving methods of the linear vibrating screen? Let me explain it to you next. In the sieving process of materials, the powder sample is passed through a series of standard sieves with different sieve holes, separated into several particle grades, and weighed separately. The particle size distribution expressed as a mass percentage is called the sieve analysis method. That is, sieve analysis, the purpose of which is to determine the particle size composition of the material. There are three common screening methods; these three screening methods can roughly meet the screening requirements of users for different materials. The linear vibrating sieve analysis method can be divided into several types, such as dry sieving, wet sieving, hand sieving, dry and wet mixing, mechanical sieving, air jet sieving, acoustic sieving, panning sieving and self-organizing sieving. And so on, the results of sieve analysis often use frequency distribution and cumulative distribution to express the particle size distribution. There are many methods mentioned above, it depends on which material the user screens, so as to choose the appropriate screening method, but the more commonly used are the first three, let’s take a look together next.

1. Dry sieving method

The so-called dry sieving method, as the name implies, is to calculate the difference between the sum of the sieving balance and the bottom inventory of each sieving meter and the total dry mass m0 of the sample before sieving, as the loss during sieving, and calculate the loss rate. A certain weight of powder sample in the sieve is used to make the fine powder pass through the sieve with the help of mechanical vibration or manual tapping until the sieving is completed. The sieve residue of the powder sample is calculated according to the weight of the residue on the sieve and the weight of the sample. When determining the particle size distribution, dry sieving is generally used.

2. Wet sieve method

Put a certain weight of powder sample in the sieve and wash it for a certain period of time with a suitable dispersion water stream (with a certain water pressure), and then the sieving is complete. According to the weight of the sieve residue and the weight of the sample, the wet sieve method is used to obtain the sieve residue of the powder sample. If the sample contains more water and the particles have strong cohesiveness, wet sieving should be used (the accuracy is higher than that of dry sieving), especially for materials with finer particles. If it is allowed to mix with water, it is best to use wet sieving. . Because the wet method can prevent very fine particles from adhering to the sieve holes and blocking the sieve holes. In addition, the wet method is not affected by the material temperature and atmospheric humidity, and the wet method can also improve the operating conditions. Therefore, the wet method and the thousand method have been listed as the national standard method for the determination of the fineness of cement and raw materials.

3. Combined sieve analysis of wet and dry

Combined dry-wet sieve analysis is to combine the two methods and choose the best. When the material contains more water and mud, and the materials are bonded to each other, the combined dry-wet sieve analysis method should be used, and the results obtained by the sieve analysis are more accurate. . The specific method is to pour the sample into a fine-hole sieve and screen it in a basin containing water. Change the water in the basin every 1 to 2 minutes until the water in the basin is no longer turbid. The material on the sieve is dried and weighed, and the quality of the washed fine mud is calculated based on the difference between the weighed mass and the mass of the original sample.

The three screening methods mentioned above use simple equipment and easy operation, but the screening results are easily affected by the shape of the particles. The size of the particle size distribution is relatively coarse. When the lower limit of the test exceeds a certain value, the screening time will be reduced. Extending, it is easy to block the screen. Therefore, when screening, the particle size of the material should be adjusted as much as possible to avoid the material from blocking the screen.

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.

Choose according to processing capacity

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

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 relatively 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.

Choose according to the screening purpose

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.

other selection elements

1. Easy to repair. Try to choose models that are 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 and components. 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. Choosing a vibrating screen requires a lot of experience accumulation. Heside has been engaged in the development and production of vibrating screens for many years, and has solved various problems for customers. Therefore, if you buy a linear vibrating screen, you are welcome to choose Heside.

As a kind of mining machinery,the vibrating screen will inevitably produce various mechanical noises during operation.Of course,in addition to the normal mechanical noise,there are also some abnormal noises.How can the vibrating screen reduce noise?Here is a list of noise reduction methods for vibrating screens for your reference.

Solution to abnormal noise of vibrating screen

When the vibrating screen is in operation,once there is an abnormal sound,it should be shut down for inspection immediately to avoid damage to other parts of the screen,or even the production line is stopped.Generally,the inspection can be started from the following aspects:

1.The transportation support of the vibrating screen has not been removed,and the transportation support should be removed immediately.

2.If the ring bolt is not locked or the ring is not fully fitted,immediately tighten the nut or lock the copper nut,and hit the ring with a wooden hammer.

3.The foundation of the vibrating screen is uneven,so the foundation should be stabilized.A rubber plate on the base of the vibrating screen is better.

4.The vibrating screen spring is broken or dislocated,replace the spring or reset.

5.The vibrating screen body and the discharge port are in contact with hard objects,and the space between them is greater than 0.5 meters.

6.If the fastening bolts of the vibration motor are loose,immediately tighten the bolts of the vibration motor.

7.The connection of the feed port and the discharge port of the vibrating screen cannot be rigid connection,but flexible or cloth bag connection.

8.If the vibrating screen bearing is damaged,stop and replace it immediately.

9.If the vibrating screen beam is broken,it should be shut down immediately for maintenance and replacement.

Vibrating screen noise reduction measures

1.Replace the perforated steel screen with a polyurethane screen or rubber screen with small elastic modulus and low impact noise;

2.Use rubber springs instead of steel springs to reduce impact;install a soft sound insulation cover outside of the exciter;

3.Fasten all parts on the vibrating screen,especially the screen plate that needs to be replaced frequently,to avoid additional vibration caused by the loosening of individual parts;

4.Apply damping treatment between the inner and outer shells of the vibrating screen bearing.The rolling elements of the bearing can be made into hollow rolling elements or damping materials can be added to the hollow rolling elements,which can reduce the vibration of the bearing and reduce the noise of the bearing;

5.Rubber plates are added to the side plates of the screen box,the feeding port,the discharge port and the receiving chassis,which can effectively suppress the high-frequency vibration of the side plates of the vibrating screen and reduce the radiation noise;

6.Use flexible web gears instead of steel gears,and use rubber elastic bodies to transmit torque on the webs of the gears to absorb vibrations caused by gears meshing in and out.

Regarding how to reduce the noise of the vibrating screen,the above is the entire content for everyone.I hope it can be helpful to everyone.It should be noted that when dealing with the abnormal noise of the vibrating screen,it should be carried out in a shutdown state to avoid danger.