January, 2023 | Haiside

What should be paid attention to when installing a linear vibrating screen

2023-01-30/in News /by admin

Linear vibrating screen is a multifunctional screening and grading machine. It is widely used in mining, coal, smelting, motor installation process, building materials, refractory materials, light industry, chemical industry and other industries. It has the advantages of large output and high precision. About linear vibrating screen how much do you know about the installation?

What should be paid attention to when installing the linear vibrating screen?

Install the vibrating motor of the linear vibrating screen, the connecting screws must be tightened before use, especially three days before the trial of the new screen machine, it must be tightened repeatedly to avoid loosening and causing accidents; vibration damping spring: prevent vibration from being transmitted to the ground, and at the same time support the screen box The full weight, when installed, the spring must be perpendicular to the ground; screen frame: made of pine or wood with less deformation, mainly used to keep the screen flat and achieve normal screening;

Screen: There are several kinds of screens such as low carbon steel, brass, bronze, stainless steel wire, etc.; Bracket: It is composed of four pillars and two channel steels, supporting the screen box. When installing, the pillars must be vertical to the ground. The channel steel should be parallel to each other; screen box: it is welded by several steel plates with different thicknesses, has certain strength and rigidity, and is the main component of the screen machine.

The linear vibrating screen motor should have reliable grounding. There is a grounding device inside the motor, and the lead end has a mark. It can also be grounded with strong bolts on the foot; the motor should be fastened on the installation surface, and the installation surface must be smooth and flat; the motor can be installed horizontally. ;Adjustment of excitation force; The motor lead wire adopts four-core rubber cable, and the lead wire cable is not allowed to have sharp bends when connected to the power supply, and it is reliably fixed with the vibrating body.

Installation steps and methods of linear vibrating screen

1. The linear vibrating screen should be checked before installation

(1) Whether the packaging is complete and undamaged, and whether it is damp;

(2) Whether the motor is deformed or damaged during transportation, whether the parts are complete, and whether the fasteners are loose or falling off;

(3) Whether the motor nameplate data meet the requirements;

(4) Use a 500V megohmmeter to check that the insulation resistance of the stator winding to the ground must not be less than 20 megohms, otherwise, the stator winding should be dried, and the temperature should be uniform during the drying process, and should not exceed 120°C;

(5) Check whether the lifting ring is tightened in place before lifting;

(6) The roughness of the contact surface between the vibration machine and the motor foot is not less than 6.3;

(7) Anchor bolts should adopt grade 8.8 strength and be locked with non-return nuts or spring washers to prevent loosening.

2. Installation and adjustment

(1) The motor should be fastened on the installation surface, and the installation surface must be smooth and flat.

(2) The motor can be installed horizontally.

(3) The lead wire of the motor adopts the four-core rubber cable YZ-500V. When connecting to the power supply, the lead wire cable is not allowed to have sharp bends, and it must be reliably fixed with the vibrating body.

(4) The motor should have a reliable grounding. There is a grounding device inside the motor, and the lead end has a mark. It can also be grounded with a solid bolt on the foot.

(5) Adjustment of excitation force.

3. Maintenance and maintenance

(1) During the operation of the vibration motor, attention must be paid to the lubrication of the bearings. Under normal working conditions, the accumulated running time is about 1600 hours, the bearing grease should be replaced and the bearing, bearing chamber and bearing gland should be cleaned.

(2) After the motor is out of use or stored for more than half a year, it should be disassembled for maintenance and replaced with lubricating grease.

(3) After the accumulative running time of the motor exceeds 5000 hours, the bearing should be checked, and if it is damaged, it should be replaced with a new one.

(4) After the motor has been parked for half a year or longer, the insulation resistance of the stator coil to the ground should be measured before use. When measuring with 500V megohm, the insulation resistance should not be less than 20 megohm. Users should be familiar with this manual before using the machine.

4. Precautions after installation of linear vibrating screen

Start and stop without load

Vibrating dewatering screens are generally used in complete sets of crushing and screening equipment or washing processes, requiring the screen to start and stop without load. Therefore, the principle of starting against the process flow and stopping along the process flow must be followed. Parking with materials is not allowed except for special reasons. When there is accumulated material on the screen surface, it must be removed before it can be started. The feeding can only be started after the operation is normal.

Operator training

You should understand the structure and simple working principle of each part of the equipment; before working, you should be ready to drive, check that the rotating parts are flexible and free of jamming, the screen is intact, all parts are not loose, and the bolts are fastened.

The above is the relevant introduction to the installation of the linear vibrating screen. During the installation, the user should strictly refer to it step by step to avoid unnecessary losses caused by problems. Of course, in addition to dismantling and repairing due to equipment failure, users should try to avoid dismantling the equipment. If they need to move the linear screen equipment, they should try to move the whole machine as much as possible.

What are the vibrating screen techniques?

2023-01-11/in News /by admin

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

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

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

Factors to be considered in vibrating screen selection:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Precautions for operation of main components of linear vibrating screen

2023-01-05/in News /by admin

Linear vibrating screen is generally composed of vibrator, screen box, support or suspension device, transmission device and other parts, and is mainly used in mining, coal, smelting, building materials and other industries. The working conditions of the linear vibrating screen are relatively harsh, and various failures often occur during operation. In response to these problems, the vibrating screen manufacturer gave us the following detailed explanations on the key points of operation and maintenance of the main components of the linear vibrating screen.

1. Adjustment of the eccentric block of the exciter

1) The size of the exciting force is closely related to the movement of the screen machine. There are 8 adjustment holes between the main block and the counterweight block of the eccentric block,which are equally divided by 15°, so it can be adjusted according to 8 positions at different angles. After being adjusted to different positions, the centrifugal force changes, and the vibration amplitude of the screen machine is changed accordingly.

When adjusting, each vibrator needs to be adjusted synchronously. If the adjustment position is different, the exciting force generated is different, and the material on the screen surface will jump irregularly. Therefore, correct adjustments must be made, especially when the exciter is replaced. When using the vibrator, the position of the adjustment hole must be consistent.

2) Inspection after adjustment, it is required that the two symmetrical points on both sides of the screen have the same amplitude and direction. If there is a slight difference in the amplitude of the two sides of the screen machine, no more than 0.5mm is allowed, because the movement track of the material is related to the uniformity of the material on the screen surface, and it is necessary to adjust the distribution of the incoming material in time.

2. Coupling

The vibration exciters on both sides of the screen machine are connected by universal couplings. When replacing them, attention should be paid to the straightness of the joint surface of the universal couplings. The universal coupling has been dynamically balanced before leaving the factory, and the straightness of the coupling is directly related to the vibration amplitude of the screen machine.

When replacing, use the method of natural sagging of the eccentric block of the exciter, and then connect and fix the universal coupling with the coupling of the exciter. The difference in screw hole position is adjusted by adjusting the position of the spline. One thing to note is that the length dimension of the coupling and the length dimension of the spline should be selected reasonably to avoid insufficient coupling length or spline jamming.

3. Rubber buffer spring

Each rubber buffer spring can be used for about 15 to 20 months, and the size varies with the model of the screen machine. The temperature of the equipment cannot exceed 45°C when it is running. When replacing the rubber spring, attention should be paid to the elastic coefficient, that is, the height of the rubber spring at the inlet of the screen machine is similar to that of the outlet, so that the buffer rubber spring can be used reasonably and not easily damaged.

Also, when replacing the rubber springs, it should be noted that the rubber springs on the front and rear parallel lines should be replaced at the same time to avoid amplitude changes due to inconsistent aging of the rubber springs.

4. Support screen side

When a crack is found, it cannot be repaired simply by welding. Instead, it should be drilled and covered with a layer of steel plate, and fixed with screws. The main reason is that the stress and material of the screen side will change due to local heating during welding, making it more fragile.

5. Fastening of bolts

The connecting screws of each part are easy to loose due to long-term vibration, and must be inspected after the shutdown. The screws used should be high-strength bolts and high-strength locknuts, and should be coated with anti-loosening liquid. Anti-loosening disc springs should also be used for reinforcement for better results. In order to prevent the wear of the sieve plate bolts, polyurethane rubber sleeves can be used to cover the easy-wear parts of the bolts to avoid contact and wear with the material.

6. Screen support beam

The seamless steel pipe is used as the beam, and the dovetail groove slideway of the fixed screen plate is welded on it, and the round flanges welded at both ends are connected with the screen side by high-strength bolts. The beam needs to be annealed in the later stage of processing to eliminate internal stress and improve the strength of the beam and the screen. machine life. The crossbeam of the screen machine must be inspected after each shutdown, focusing on checking whether the support beam of the screen machine is severely worn and aged, and whether there is any damage such as cracks.

7. Sieve plate

The material of the sieve surface of the sieve plate used in the screen machine of some mineral processing plants is stainless steel 1Cr18Ni9Ti. Although the input cost is high, the use effect is better, especially in terms of abrasion resistance. At the entrance of the sieve machine, a blind sieve plate bonded with stainless steel and polyurethane is used, which has high strength.

The wavy and striped screens are used in raw material classification. The wavy screen has better penetration rate and is not easy to be blocked, but the disadvantage is that the screen bars are easily broken by large pieces of raw coal, so that large particles enter the next-level system. Repairs or replacements must be carried out promptly after each shutdown.

8. Additional facilities of the screening machine

1) The screening effect of the sieve machine is related to the thickness of the material on the screen surface and the distribution on the screen surface, so a material distribution plate that can adjust the angle can be installed at the feed port of the screen machine, according to the particle size of the raw coal and the feed material The amount of adjustment angle is used to adjust the uniformity of the material on the screen surface.

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

9. Screen lubrication

1) Lubrication of the exciter

Due to the high-speed rotation of the vibration exciter of the screen machine, axial deviation and torsion effect will occur during the operation, so the lubrication of the vibration exciter is particularly important for the maintenance of the screen machine. According to the running time, it is generally oiled once a week, and the amount of oil added is generally 300-600mL. Use 2# lithium base grease in winter and 3# lithium base grease in summer.

Since many equipments are still lubricated with calcium-based grease, you must pay attention to distinguishing when lubricating the exciter of the screen machine. The exciter cannot use calcium-based grease, otherwise the exciter will heat up and lock up during operation, resulting in accidents . Generally, the exciter is used for about three months, and the inside of the exciter is cleaned with an oil pump, and lubricating grease is added after cleaning.

2) Lubrication of the coupling

Since the coupling is splined, the vibration exciter produces shaft strings during operation, and the splines need to be well lubricated. Generally, oil is injected every 1200 hours of operation.

The above is a detailed explanation of the operation of the common components of the linear vibrating screen. Because of its high efficiency, low energy consumption, low noise, and stable work, the linear vibrating screen is widely used in the process of automatic operation of the assembly line. Because of the structure of double motors, the driving force is relatively large, the output is relatively high, and its screening efficiency is also relatively high, so the linear vibrating screen is the most efficient among all screening equipment, and its application is relatively wide.