Vibrating screen is usedVibratorIt works due to reciprocating rotary vibration generated by excitation.The upper rotating weight of the vibrator makesSieve surfaceThe plane whirling vibration is generated, while the downward rotating heavy hammer makes the screen surface produce conical whirling vibration, and the combined effect makes the screen surface produce compound whirling vibration.Its vibration track is a complex spatial curve.The curve is projected as a circle on the horizontal plane and an ellipse on the vertical plane.Adjust the upper and lower rotating weightsExciting force, can be changedamplitude。The space for adjusting the upper and lower weightsphase angle, you can change the curve shape of the movement track of the screen surface and change the movement track of the material on the screen surface.
Chinese name
Vibration sieve
Foreign name
vibrating screen
Advantages
High efficiency, light weight, screening dry materials
Category
Mine vibrating screen, fine vibrating screen, screen shaft type
Principle
VibratorReciprocating rotary vibration caused by excitation
It is a kind of filtering mechanical separation equipment used for mud solid phase treatment, consisting of screen and vibrator.The thickness of the screen is expressed in mesh. Generally, the coarse screen is below 50 mesh, and the fine screen is above 80 mesh.The vibrator is an eccentric wheel, which rotates under the drive of the motor to make the screen frame vibrate.Due to the vibration of the screen frame, the coarse solid particles will stay on the screen surface when the mud flows to the screen surface, and will be discharged from one end along the slope. The fine solid particles and mud liquid will flow to the mud pit through the screen hole together.
type
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YK round vibrating screen
Main types of vibrating screen: advantages and disadvantages of the product: high efficiency, light weight, complete and diversified series, multiple levels, and dry material screening can meet the demand.This machine is not suitable for materials with high moisture and adhesion. Vibration during operation makes materials adhere to the screen surface more tightly, causing material congestion or forced shutdown.Due to the limitation of working principle, this model consumes relatively high energy, especially under the condition of large output.In addition, the working noise and dust are heavy.
classification
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VibrationScreening equipmentIt can be divided into:Mine vibrating screen，Light fine vibrating screen，Experimental vibrating screen machine
Experimental vibrating screen: flapping screen, top impact vibrating screen, standard inspection screen, electric vibrating screen, etc. Please refer to the experimental equipment
According to the material running track of vibrating screen, it can be divided into:
Divided by linear motion track:Linear vibrating screen(The material moves forward in a straight line on the screen surface)
Divided by circular motion track:Circular vibrating screen(The material moves in a circle on the screen surface) Structure and advantages
According to the reciprocating motion track, fine screening machine (the material moves forward on the screen surface in a reciprocating manner)
Vibrating screen is mainly divided into linear vibrating screen, circular vibrating screen and high-frequency vibrating screen.Vibrating screen can be divided into single shaft vibrating screen and double shaft vibrating screen according to the type of vibrator.Single shaft vibrating screen uses single unbalanced weight excitation to make screen box vibrate and screen surface incline,Sieve boxThe motion track of is generally circular or elliptical.Double shaft vibrating screenIt is excited by the double unbalanced weight of synchronous opposite rotation, the screen surface is horizontal or gently inclined, and the motion track of the screen box is a straight line.Vibrating screen includes inertial vibrating screenEccentric vibrating screen, self centering vibrating screen andelectromagnetismVibrating screen, etc.[1]
Linear vibrating screen
Vibrating screen is a screening machine widely used in coal and other industries, which is used for classification, washing, dehydration and media removal of materials.Among them, linear vibrating screen has been widely used because of its high production efficiency, good classification effect, convenient maintenance and other advantages.In the working process, the dynamic performance of vibrating screen directly affects the screening efficiency and service life.The vibrating screen uses the vibration of the vibrating motor as the vibration source to make the material be thrown up on the screen mesh and move forward in a straight line at the same time. The material enters the feed inlet of the screen evenly from the feeder. Through the multi-layer screen mesh, several specifications of materials above the screen and under the screen are generated and discharged from their respective outlets.Linear vibrating screen (linear screen) has the advantages of stability, reliability, low consumption, low noise, long service life, stable vibration mode, high screening efficiency, etc. It is an efficient new screening equipment, widely used in mines, coalsmelt, building materials, refractory materials, light industry, chemical industry and other industries.[2]
Circular vibrating screen
Circular vibrating screen
Circular vibrating screen(Circular vibrating screen) is a new type of vibrating screen with multiple layers and high efficiency.Circular vibrating screen adopts cylindrical eccentric shaft vibrator and eccentric block to adjust amplitude. The material screen has a long flowing line, many screening specifications, reliable structure, strong exciting force, high screening efficiency, low vibration noise, solid and durable, convenient maintenance, safe use and other characteristics. Circular vibrating screen is widely used inmine、building material、traffic, energychemical industryAnd other industries.High manganese steel woven screen, perforated screen plate and rubber screen plate can be used according to material products and user requirements,Sieve plateThere are single-layer and double-layer sieve plates, and all kinds of sieve plates can meet the different requirements of screening effect.This series of round vibrating screen is seat mounted.Sieve surfacedip angleThe adjustment of can be realized by changing the position and height of the spring support.[3]
Elliptical sieve
TES
The elliptical screen is a vibrating screen with elliptical motion track, which has the advantages of high efficiency, high screening accuracy, wide range of applications, etc.Compared with the ordinary sieving machine of the same specification, it has larger processing capacity and higher screening efficiency.It is suitable for screening of solvent and cold sinter in metallurgical industry, ore classification in mining industry, classification, dehydration and disintermediation in coal industry.It is an ideal substitute for existing large-scale vibrating screen and imported products from abroad.TES three-axis elliptical vibrating screen is widely used for screening of quarries and gravel materials, and also for grading of products in coal preparation, mineral processing, building materials, construction, power and chemical industries.
Screening principle: the power is transmitted from the motor to the driving shaft of the vibration exciter and the gear vibrator (speed ratio is 1) through the V-belt, so that the three shafts can rotate at the same speed to generate the excitation force. The vibration exciter is connected with the high-strength bolt of the screen box to generate elliptical movement.The material moves elliptically with the screen machine at high speed on the screen surface, quickly layering, sieving and moving forward, and finally completing the classification of the material.
The obvious advantages of TES series three-axis elliptical screen
The three-axis drive can make the screen machine produce ideal elliptical movement, which has the advantages of both circular and linear vibrating screens. The elliptical track and amplitude can be adjusted, and the vibration track can be selected according to the actual material conditions, which is more advantageous for materials difficult to screen;
The three-axis drive forces synchronous vibration, which can make the screen machine obtain a stable working state, especially favorable for screening with large processing capacity;
The three-axis drive improves the stress state of the screen frame, reduces the load of a single bearing, forces the side plates evenly, reduces the stress concentration points, improves the stress conditions of the screen frame, improves the reliability and life of the screen machine, and lays a theoretical foundation for the large-scale screen machine.
Due to its horizontal installation, the unit height is effectively reduced, which can well meet the needs of large and medium-sized mobile screening units.
Thin oil lubrication of bearing can effectively reduce bearing temperature and improve service life;
With the same screening area, the output of elliptical vibrating screen can be increased by 1.3-2 times.[4]
Thin oil vibrating screen
Vibration sieve
The thin oil vibrating screen has large processing capacity and high screening efficiency;The vibrator adopts bearing thin oil lubrication and external block eccentric structure.It has the characteristics of large exciting force, small bearing load, low temperature and low noise (bearing temperature rise is less than 35 °);The vibrator is assembled and disassembled as a whole, easy to maintain and replace, which greatly shortens the maintenance cycle (only 1-2 hours are needed to replace the vibrator);The side plate of the screen machine adopts the whole plate cold working, no welding, high strength and long service life.The connection between the cross beam and the side plate is connected by the torsional shear high-strength bolts, without welding, and the cross beam is easy to replace;The rubber spring is used for vibration reduction of the screen machine. Compared with the metal spring, it has the advantages of low noise, long service life, stable passing through the common vibration area, and low dynamic load of each fulcrum of the screen machine;Flexible coupling is used to connect the motor and vibration exciter, which has the advantages of long service life and small impact on the motor.
This series of sievers is widely used for grading operations in coal, metallurgy, hydropower, mining, building materials, chemicals, power, transportation, ports and other industries.[5]
Operation inspection
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YK vibrating screen
Before leaving the factory, the equipment shall be assembled by precision collection and no-load test run, and can leave the factory only after all indicators are checked to be qualified. Therefore, after the equipment is shipped to the use site, the user shall check whether the parts of the whole machine are complete and whether the technical documents are flawed according to the packing list and the delivery list of the complete set of equipment.After the equipment arrives at the site, it shall not be directly placed on the ground, but shall be stably placed on flat sleepers, and the distance from the ground shall not be less than 250mm.If it is stored in the open air, it shall be covered with tarpaulin to prevent rain erosion.High frequency vibrating screen
High frequency vibrating screen is called high frequency screen for short. High frequency vibrating screen (high frequency screen) is composed of vibrator, pulp distributor, screen frame, frame, suspension spring, screen mesh and other parts.
High frequency vibrating screen (high frequency screen) has high efficiency, small amplitude and high screening frequency.The principle of high-frequency vibrating screen is different from that of ordinary screening equipment. Because high-frequency vibrating screen (high-frequency screen) uses high frequency, on the one hand, it destroys the tension on the pulp surface and the high-speed oscillation of fine materials on the screen surface, accelerates the large density useful minerals and separation, and increases the probability of materials smaller than the separated particle size contacting the screen hole.
Advantages of vibrating screen
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Vibration sieve
It is mainly composed of screen box, vibration exciter, suspension (or support) device and motor.The motor drives the main shaft of the vibration exciter to rotate through the V-belt. Due to the centrifugal inertia force of the unbalanced weight on the vibration exciter, the screen box is vibrated.Different amplitudes can be obtained by changing the eccentric weight of the exciter.
Vibration sieveMain advantages of:
1. Due to the strong vibration of the screen box, the phenomenon of material blocking the screen hole is reduced, and the screen has higher screening efficiency and productivity.
2. Simple structure and convenient removal and replacement of screen surface.
3. The electricity consumed for screening each ton of material is less.
Mechanical structure
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Vibrating screen generally consists of vibratorSieve box, support or suspension devicetransmissionAnd other parts.
Vibrator
Single shaft vibrating screen andDouble shaft vibrating screenThere are generally two types of vibrators according to the configuration of eccentric weight
Type.The configuration mode of eccentric weight is block eccentric type.
Sieve box
The screen box consists of screen frameSieve surfaceAnd its pressing device.The screen frame is composed of side plates and beams.The screen frame must be rigid enough.
Supporting device
There are two kinds of supporting devices for vibrating screen: hanging type and pedestal type.Seat type installation is relatively simple, and the installation height is low. Generally, it should be preferred.The supporting device of vibrating screen is mainly composed ofElastic elementComposition, commonly used areCoil spring, plate spring andRubber spring。
transmission
The vibrating screen usually adopts a V-belt transmission device. The vibrating screen has a simple structure and can be selected arbitrarilyVibratorBut the belt is easy to slip during operation, which may lead to screen hole blockage.Vibrating screen is also usedcoupling Direct drive.The coupling can maintain the stable rotation number of the vibrator and has a long service life, but it is difficult to adjust the rotation number of the vibrator.
working principle
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Screening is the process of dividing a group of broken materials with different particle sizes into several different levels by repeatedly passing through a single-layer or multi-layer screen surface with uniform holes.The particles larger than the screen hole remain on the screen surface, which is called the material above the screen surface. The particles smaller than the screen hole penetrate the screen hole, which is called the material below the screen surface.The actual screening process is: after a large number of broken materials with different particle sizes and mixed sizes enter the screen surface, only a part of the particles contact the screen surface. Due to the vibration of the screen box, the material layer on the screen is loose, which further enlarges the existing gap of large particles. Small particles take the opportunity to pass through the gap and transfer to the lower layer or conveyor.Due to the small gap between small particles, large particles can not pass through, so the original disorderly arrangement of particles has been separated, that is, stratified according to particle size, forming the arrangement rule of small particles at the bottom and coarse particles at the top.The fine particles that reach the screen surface, and those smaller than the screen holes penetrate the screen, finally realizing the separation of coarse and fine particles, and completing the screening process.However, there is no sufficient separation. Generally, a part of the undersize material remains in the undersize material during screening.When fine particles pass through the screen, although the particles are smaller than the screen holes, their difficulty in passing through the screen is different. For particles with similar size of materials and screen holes, it is more difficult to pass through the screen, and it is more difficult to pass through the particle gap at the lower layer of the screen surface.
Working characteristics
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① The block eccentricity is used as the exciting force, which is strong.
② . The screen crossbeam and screen box adopt high-strength bolts, which is simple in structure and convenient in maintenance;
Vibration sieve
③ Tire coupling is used for flexible connection and smooth operation;
④ The structure of small amplitude, high frequency and large inclination angle is adopted, which makes the machine have high screening efficiency, maximum processing, long service life, low power consumption and low noise.
according toScreening machineThe structure and working principle of the machine can be roughly divided into the following categories:
1、Roller screenThe working surface is composed of rolling shafts arranged horizontally.
2. The working surface of roller screen is composed of rolling shafts arranged horizontally.The working part of the fixed screen is fixed, and the materials are screened by sliding along the working face.Fixed grid screen is one of the most widely used screens in concentrators. It is generally used for pre screening before coarse crushing or intermediate crushing.The utility model has the advantages of simple structure and convenient manufacture.It does not consume power and can directly unload ore onto the screen surface.The main disadvantages are low productivity and screening efficiency, which are generally 50-60%.
3. The plane motion screen body is oscillating or vibrating in a plane.According to its plane motion track, it can be divided into linear motion, circular motion, elliptical motion and complex motion.Shaking screens and vibrating screens belong to this category.
Scope of application
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The scope of application of vibrating screen is very wide, which involves almost every aspect of life. Various types of vibrating screens are needed in processing and manufacturing.
Vibrating screen is mainly used in mining, coal, smelting, building materials, refractory, light industry, chemical industry, medicine, food and other industries.
Vibrating screen is most widely used in concentratorTransmission mechanismIt can also be divided into the following types: eccentric vibrating screen, inertial vibrating screen, self centering vibrating screenResonance sieve。
instructions
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1. The design of the sieve machine is exquisite and easy to assemble, and one person can operate the sieve machine.
2. Compared with other types of screening equipment, it has a larger screening area and high efficiency of processing capacity.
3. The unique screen structure design makes it easy and fast to change the screen (only 3-5 minutes). In addition, this design
Various screens (nylon, special nylon, PP) are allowed.
4. The parent network fully supports the fine mesh, so the fine mesh can have a long life, reduce the use of fine mesh consumables, and reduce many costs by silting up the production process for a long time.
Function and principle:
The basic principle is to use the weight (unbalanced weight) installed at the upper and lower ends of the motor shaft to transform the rotating movement of the motor into a horizontal, vertical and inclined three-dimensional movement, and then convey this movement to the screen surface.If the phase angle of the upper and lower weights is changed, the travel direction of the raw materials can be changed.
Daily maintenance
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Before starting:
1. Check whether the coarse mesh and fine mesh are damaged
2. Whether each group of tie rings is locked 3.Check whether the V-ring of the rotary vibrating screen frame is damaged. If damaged, repair it in time to prevent material leakage.
2、 At startup:
1. Pay attention to whether there is abnormal noise and whether the current is stable
2. Whether the vibration is abnormal
3. After use: clean up after each use
Regular maintenance
Regularly check whether the coarse screen, fine screen and spring are fatigue and damaged, and whether the parts of the machine body are damaged due to vibration. The parts that need to be lubricated must be lubricated.Vibration: with the model, screen surface specification, screen surface layer number, screen hole size, feed particle size, processing capacity, motor power, vibration frequency and double amplitude data, people searching for vibrating screens can have a deeper understanding.
Standard Operating Procedures
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Vibration sieve
Inspection before running the vibrating screen: including equipment hygiene, complete, tight and intact connecting bolts at all parts, check whether the vibration exciter is intact, check whether the springs are damaged, missing, broken, etc., check whether the triangular belt is tensioned, whether the screen box is brokenSieve plateCheck whether there is damage. Check whether the screen plate is blocked by sundries. The screen surface should be flat and free of damage and looseness. Check whether the feeding and discharging chute is unblocked. Check whether the beam is open welded. Check whether the safety protection device is safe and reliable. Check whether the control box, communication and lighting are in good condition. Check whether the grounding protection is reliable. Check whether the control buttons are flexible and reliable.
When starting: after starting the shale shaker, stand beside the control box to monitor the start of the equipment and stop the machine immediately in case of any abnormality.After the startup is normal, patrol again to check whether the nozzle of each shale shaker is blocked or falling off, often observe the temperature and sound of the motor, often observe the sound of the vibratorSieveWhether the amplitude of four corners is consistent, whether there is coal leakage, whether the triangle belt is loose or falling off, and often observe the dehydration and disintermediation effect.Check whether the feeding and discharging conditions of the sieve are normal or not.
Shutdown: stop the machine after the materials on the screen are discharged.When stopping, observe whether the screen collides with other equipment when passing through the resonance point. When the following conditions are found, stop immediately.In case of endangering personal safety or equipment safety, when there are many sundries in the screen area and the blanking is not smooth, the screen mesh is broken in a large area, the chute under the screen is seriously blocked, the screen box is severely swinging and other abnormal conditions.The vibrating screen can be restarted after the problem is eliminated.
Main role
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With the further development of China's economic construction and scientific research, new vibrating screens will continue to appear, and their use in various sectors will also increase, and will play an increasingly important role.
In engineering application
In the past 30 years, Professor Wen Bangchun has popularized and applied the theoretical and application achievements to engineering practice.For example, largeExciterDeflection self synchronous vibrating screen, inertial resonance probability screen, new structure vibrating crusher, new structure vibrating cooler, etc., have been successfully applied in the industrial sector, and have achieved significant economic and social benefits. They have won more than 10 national invention awards, national science and technology progress awards, and provincial and ministerial awards.
Innovation of design theory and method
The more systematic dynamic design theory and method of vibrating screen machinery, especially the dynamic design theory and method of nonlinear vibrating screen machinery, as well as the comprehensive design method with dynamic optimization, intelligent optimization and visual optimization as the content, provide theoretical reference and basis for the design of high-quality such products, especially the research and development of new products.
Theoretical innovation of nonlinear dynamics
summaryWen BangchunThe professor's long-term systematic research and experiment on vibration and wave utilization technology and equipment working theory has created a theoretical basis for multiple branches of shale shaker utilization engineering (such as the application of vibration synchronization and control synchronization theory, the use of nonlinear vibration, the use of wave and wave energy, etc.).
Weight adjustment
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Since part of the work of the vibrating screen belongs to fine operation, problems of one kind or another cannot be avoided during operation. Sometimes when screening materials, the discharging situation is different. At this time, the material screening can be adjusted by adjusting the upper and lower weights to achieve better results.
First of all, we can adjust the additional weight of the vibrating motor. An additional weight is installed on one side of the upper and lower weights (upper and lower eccentric blocks), which can increase the exciting force of the vibrating screen. According to the specific gravity of the materials to be screened by the customer and the number of layers of the vibrating screen selected, the exciting force can be increased or decreased appropriately and the number of additional weights can be adjusted.Secondly, the phase angle of the upper and lower weights of the vibrating motor can be changed, thus changing the material in the vibrating screenscreen meshDwell time and motion trajectory on.
Moreover, the bottom cylinder of the vibrating screen can be opened to fix the lower heavy hammerBoltLoosen, and adjust the phase angle of the upper and lower weights in the opposite direction to the outlet of the vibrating screen according to the movement track of the materials screened by the vibrating screen.Then put some materials on the screen of the vibrating screen, let the vibrating screen run with power on, and watch the movement track of materials on the screen surface.If the separation efficiency, screening rate and handling capacity of the materials are also relatively uniform, stop the machine and tighten the fixing bolts.
Common faults
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1. Poor motor rotation
2. Abnormal sound
3. Raw materials cannot be discharged automatically
4. Fine mesh is easy to be damaged
5. Discharge frame outlet cracked
Daily maintenance:
1. Before starting: check whether the coarse mesh and fine mesh are damaged and whether each group of bundle rings are locked
YKR round vibrating screen
2. During startup: pay attention to whether there is abnormal noise, whether the power supply is stable, and whether there is abnormal vibration
3. After use: clean up after each use Regular maintenance:
(1) Regularly check whether the coarse and fine screens and springs are fatigue and damaged, and whether all parts of the machine body are damaged due to vibration.
(2) The motor must be supplemented with timelyLithium grease(ZL-3).Check the bearing after running for 1500 hours accumulatively, and replace it immediately if it is damaged.[6]
Maintenance plan
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Treatment of real screen wear with polymer materials
During the operation of shale shaker, parts are often worn and scratched due to the metal "hard to hard" matching relationship, such as the abrasion of the main shaft bearing position of shale shaker.After the above problems occur, the traditional solution for enterprises isRepair weldingorBrush platingPost machining repair, but both of them have certain disadvantages: the thermal stress generated by the high temperature of repair welding cannot be completely eliminated, there is no influence of the thermal stress of repair welding, and the repair thickness is not limited. At the same time, the metal materials of the product do not have the flexibility, which can absorb the impact and vibration of the equipment, avoid the possibility of re wear, and greatly extend the service life of equipment components,Save a lot of downtime for enterprises and create huge economic value.[6]
Application Need
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The pharmaceutical industry is closely related to people's health, so the country has very strict requirements on the pharmaceutical industry,
The pharmaceutical industry also has strict requirements on screening of materials. The most basic thing is that the vibrating screening equipment used in the pharmaceutical industry must beStainless steel 304The material is even 316, and the part contacting the material is not allowed to be contaminated by impurities, so the rubber accessories must also meet the food level health standard (silica gel), and the screening equipment required by the pharmaceutical industry must pass the GMP production standard.The use of vibrating screen in pharmacy has very strict requirements, which must meet the GMP production standards of the pharmaceutical industry, which is related to whether the drugs passing the screen will be contaminated.
In fact, as an uncomplicated screening machine, the so-called GMP standard means that in terms of material, 304 stainless steel must be used. In terms of rubber parts, pharmaceutical grade must be selected. The equipment must be polished inside and outside, free of black spots and burrs.[7]
Tips
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1. Check whether the attached safety splint is removed before starting.
JB-T 10460-2004 Banana shaped linear vibrating screen
influence factor
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Factors influencing screening of vibrating screen
The technical and economic indicators of screening process are screening efficiency and productivity. The former is the quality indicator, and the latter is the quantity indicator.There is a certain relationship between them and many other factors, which determine the screening results.The factors affecting the screening process can be divided into three categories:
Physical properties of screened materials
It includes the particle size composition, humidity, mud content and particle shape of the material itself.
When the content of fine particles is large, the productivity of the sieve is also large.When the material humidity is high, the screening efficiency will generally decrease.However, the larger the mesh size is, the smaller the impact of moisture is. Therefore, for wet materials with large moisture content, in order to improve the screening process, the method of enlarging the mesh size or wet screening can be adopted.The material with large mud content (when the mud content is greater than 8%) should be screened by wet screening or ore washing in advance.
Influence of screen surface structure parameters
Linear vibrating screenIs to make particles and screen surfaceVertical movementTherefore, the screening efficiency is high and the production capacity is large.The particles and screen surfacerelative motionMainly bar screen, plane vibrating screen, cylinder screen, etc. with parallel movement, their screening efficiency and production capacity are low.
For a certain material, the productivity and screening efficiency of the screen depend on the size of the screen hole.The productivity depends on the width of the screen surface, which has high productivity.The screening efficiency depends on the screen surface length, and the long screen surface has high screening efficiency.Generally, the length width ratio is 2.
The larger the effective sieve area (that is, the ratio of the mesh area to the area of the whole screen surface), the higher the productivity per unit area of the screen surface and the screening efficiency.
The larger the mesh size, the greater the productivity per unit screen surface and the higher the screening efficiency.
Influence of production conditions
When the load of the sieve is large, the screening efficiency is low.To a large extent, the smoothness of the round vibrating screen depends on the size of the screen aperture and the total screening efficiency;The larger the screen hole is, the lower the screening efficiency is required, and the higher the productivity is.
The feed uniformity is of great significance to the screening process.
The inclination angle of the screen should be appropriate, which is generally determined through tests.Then there is the amplitude and vibration times of the screen, which is related to the structure and physical properties of the screen. In a certain range, increasing vibration can improve the screening index.[8]
Classification
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Spiral flash vibrating screen
The word "spiral flash" has probably been heard in the dryer industry.Yes, the spiral flash vibrating screen is deeply transformed on the basis of the dryer.Due to its large settling speed, it falls to the lower part of the drying chamber and repeats the above process.In the feed industry, it can be used to dry blood meal, meat and bone meal, fish meal, protein paste, dregs and other materials.
Rotary vane vibrating screen
We then share the rotary vane vibrating screen.The rotary vane vibrating screen sounds like a rotary vibrating screen, but in fact it is not.The rotary vane vibrating screen belongs to the downstream vibrating screen, and its working process is roughly as follows: the materials are put into the rotary drum through the feeding device, and the lifting plate installed in the drum lifts the materials to the top and falls down. When the materials fall down, they are broken by the high-speed rotating blades in the drum, and so on, moving all the way to the exit.At the same time, the hot air generated by the combustion furnace enters the cylinder to fully contact with the material, so that the material can be dried quickly, and then discharged through the conveyor at the discharge end.The rotary plate vibrating screen can be used for drying chicken, cattle, pig manure, forage, dregs, etc.[9]
practical application
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Vibration sieve
1. Screening: screening is to divide particles and powders into particle segments with different sizes.A single vibrating screen can be equipped with 4 layers of screens, which can continuously separate 2-5 particle sizes and control a narrow particle size range;
2. Screen out impurities: high-performance screen machine can quickly remove large particles or small particles with low percentage in the process of high flow treatment.The vibrating screen can quickly remove the insoluble solid substances in various slurries and discharge the slag continuously.
Learn about the production steps of silicon carbide powder:
(1) Take the silicon carbide raw material, crush it with a crusher, and screen it to the silicon carbide particles ≤ 5mm, then reshape it to the silicon carbide particles ≤ 2mm with a reshaping machine, and the elliptical particles account for more than 80%, and then pickle it to remove impurities and dry it;
(2) The above dried silicon carbide particles are crushed into silicon carbide powder with d50=9.5-11.5 μ m by a grinder. When crushing, the current of the grinder host is set to 65-75A, and the fan flow is set to 40-50m/min，The speed of the analyzer is 400-600 rpm;
(3) Then grade the silicon carbide powder with a vortex air classifier. When classifying, the fan flow of the vortex air classifier is 25-43m/min，The speed of the grading wheel is 2600-3300 rpm, and the finished product A with particle size ds94=6.5-5.5 μ m is separated from the grading port, and the semi-finished product with particle size ds94 ≤ 5.5 μ m is separated from the cyclone port;
(4) The semi-finished products separated from the swirling air inlet of the vortex air flow classifier are further classified by the impeller air flow classifier. During classification, the fan flow of the impeller air flow classifier is 25-10m/min，The speed of the grading wheel is 1300-1700 rpm. Finished product B with particle size of ds94=4.5-3.0 μ m is separated from the grading port, and the by-product is separated from the cyclone port.[10]
Development trend
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1. Development towards high efficiency and high yield: the modernization process of industry has led to the expansion of the scope of enterprises, the production ability of sand making equipment has been greatly improved, and it is matched with the high-efficiency and high-yield screening machine.
2. Development towards standardization, serialization and generalization: this is the way to facilitate planning, construct specialized production, ensure quality and reduce costs.According to the three different activity trajectories of vibrating screens, different screening essentials are accepted, and according to the special requirements of various industries in the people's economy, vibrating screening equipment in various situations has been formed, which has been widely used in industrial sectors.
3. The increase of vibration intensity: the vibration process of the screen machine is gradually strengthened, that is, the vibration parameters of the screen machine are improved to achieve greater speed and acceleration.
4. Development towards light weight, environmental protection and simplified layout: the old vibrating screen in the 1980s was inconvenient to change the screen. There were 48 pressing bolts on each layer. It took at least 4 hours to change a screen, and the powder with high mesh size was easy to leak out from the bolt.With the continuous improvement of the requirements of industrial departments on vibrating screens, the old vibrating screens will be gradually eliminated. In order to meet the requirements of industrial and chemical departments, the new vibrating screens should be developed in the direction of light weight, environmental protection and simplified layout.
According to the National Bureau of Statistics, Feng Chaoyang, secretary-general of the Washing and Dressing Equipment Professional Committee in 2010, driven by the development of coal, iron ore, non-ferrous mine, steel, chemical industry, power generation, cement and other industries, the vibrating screen industry will still maintain strong demand.It is estimated that the total demand for vibrating screen will reach 9.23 billion yuan in 2010.[11]
Distribution of manufacturers
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According to the latest media survey, domestic enterprises engaged in the vibration machinery industry are mainly concentrated in Xinxiang and Hebi in Henan, Nantong and Xuzhou in Jiangsu, Anshan and Chaoyang in Liaoning, Shanghai, Tianjin, Tangshan in Hebei, and a few areas in Foshan, Hubei, Jinan in Shandong, and Shaoyang in Hunan.Henan Xinxiang has an absolute advantage in the field of vibration machinery production, R&D and manufacturing, which is mainly divided into light screening machinery and heavy vibration screening machinery.
Application of vibrating screen in paper industry:
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Preliminary separation of dry lime into slurry lime tank
Purpose: to ensure uniform particle size of materials entering the slurry lime pool;
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Papermaking filler (materials used by customers: slurry calcium carbonate and slurry titanium dioxide)
Objective: To improve the accuracy of paper filler;
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Papermaking white water -- medium:calcium carbonate, starch and trace other compounds
Filter the original papermaking white water to improve the quality of white water;
Recycle the white water of papermaking to remove the paper fiber in the white water;
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Papermaking coating
Purpose: surface treatment of base paper to achieve the desired effect;Scope of use:Coated paper, thermal paperCopper plate paperVarious special paper industries
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Wastewater recovery
Objective: To recover pulp from wastewater and reduce the cost of wastewater treatment up to standard;
Model establishment
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Establishment of vibrating screen box model
There are two methods to establish the finite element model of the screen box by using the finite element analysis ANSYS software. One is to directly use the ANSYS software to establish the solid model of the screen box, or to establish the solid model in the PRO/E software and then import it into ANSYS. This method takes a long time to model and calculate, and may not produce ideal results;The second method is to use the shell element and plate element in the ANSYS software to establish the finite element model of the screen box. This method has fast modeling, fast calculation and accurate results.According to the researchVibration sieveAccording to the design drawing, the side plate of the screen frame is divided into three parts, which are welded by steel plates with different thicknesses and the same materials. There are also stiffening beams with different cross section shapes on the side plate, as well as beams for connection. For the rolled edges of the side plate, we also treat them as stiffening beams. The stiffening beams are welded to the side plate, and the beams are connected to the side plate through flanges.Therefore, when modeling with shell element and plate element, it is necessary to pay attention to that, after the model is divided into element grids, at the junction of side plates with different thicknesses, as well as at the connection of side plates with beams and stiffening beams, the elements must have common nodes to transfer loads, otherwise, during the calculation process, plate elements and beam elements will be separated from each other,The result is inaccurate and the model establishment fails.
The side plate of the established vibrating screen is composed of dry surfaces. The boundary line between surfaces is the stiffening beam, and the intersection point of the boundary line of the surface is the connection point between the beam and the side plate. In this way, after the model is divided into the element grid, whether it is connected by welding or flange, it is represented by the common node in the model.
In addition, in the model of the side plate of the screen frame, because the quality and stiffness of the rivets and the stiffeners at the flange plate have little impact on the screen frame system, if it is established in the model, it will bring a lot of trouble to the division of the element grid. Many elements will be added invisibly, so it will be ignored.[12]
Reasons for bleeding
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There will be various problems during the use of shale shaker, among which the slurry leakage is mainly related to the factors of screened materials such as high solid content in drilling fluid, high mud viscosity, and cuttings dispersion through continuous analysis and summary;It is related to the self conditions of small vibrating force, high mesh number and small screen area of vibrating screen;It also has a lot to do with the direction and position of the liquid inlet of the shale shaker when it is installed on site. Some analysis can be made on these points.
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The screen mesh selected is unreasonable.The processing capacity of each shale shaker is 50L/s, which is because the processing capacity test condition is based on the national standard: select 60 mesh screen, weigh the mud with a specific gravity of 1.8, and the mud viscosity is that the mud contains river sand of different particle sizes.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 be used in the shallow well section.Therefore, the screen with larger holes should be used at the initial stage of drilling, and with the increase of drilling depth, the finer screen should be gradually used.
two
Formation and mud conditions affect the treatment capacity.On the other hand, when loose sand bearing strata or quicksand are drilled
three
Sand particles are easy to get stuck in the screen mesh hole, resulting in screen blockage.Therefore, several screens with different mesh sizes should be tested to reduce screen plugging.
four
Check whether the rotation direction of the motor is correct.First, remove the vibrator shield and check whether the eccentric blocks of the two motors rotate outward.Secondly, if the steering is wrong, please replace any two phase lines in the incoming power supply of the electric cabinet.Error mode 1 (two motors rotate inward), although it can also remove drilling cuttings outward, the speed is slow;Wrong mode 2 (two motors rotate in the same direction), the vibration force is very small, and there is basically no sand discharge or mud treatment.
five
Check the amplitude of the vibrating screen.The larger the vibration amplitude, the larger the general handling capacity;The vibration force is adjusted to 90% when leaving the factory.In case of slurry running out, the angle of inner and outer eccentric blocks can be aligned, and the vibration force is 100%.(At this time, the mud treatment capacity is only increased by about 15%)
six
Check whether the liquid flow distribution on the screen frame is reasonable.For the vibrating screen with hook screen structure, the screen surface on both sides is lower than that in the middle
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It is easy to flow to both sides and lose. It should be ensured that the mud enters the screen frame from the middle.At this point, two options can be used.The first is to adjust the front spring seat and properly raise the angle of the front of the screen box;The second is to adjust the position of the flip plate of the extension slot to control the liquid flow distribution.
Routine maintenance
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Source network
1. It is recommended to make a support frame to hang the spare screen surface.
2. Check the pressing device of the screen frame every shift, and press it if it is loose.
3. Check the sealing strip frequently, and replace it in time in case of wear or defect.
4. The screen frame should be taken out frequently, and the screen surface should be checked regularly for damage or unevenness, and the screen hole should be checked for blockage.
5. Each shift shall check whether the connection of the feed box is loose. If the gap becomes larger, it will cause collision, which will break the equipment.
6. Although the vibrating screen does not need lubricating oil, it still needs to be overhauled once a year to replace the lining plate and trim the two screens.The vibration motor shall be disassembled for inspection, and the motor bearing shall be replaced with oil. If the bearing is damaged, it shall be replaced
7. Check the support device of the screen body every shift to see if the hollow rubber pad has obvious deformation or degumming. When the rubber pad is damaged or excessively flattened, replace two hollow rubber pads at the same time.
The daily maintenance of the vibrating screen includes the surface of the screen, especially the fastening of the screen surface. When the vibrating screen is loose, it should be fastened in time.The vibrating screen shall clean the screen surface regularly, repair, derust and paint the paint peeling parts of the vibrating screen in time, and apply industrial vaseline on the exposed processing surface to prevent rust.
Periodic inspection of vibrating screen:Periodic inspection of vibrating screen includes weekly inspection and monthly inspection.
Vibrating screen repair
1. The vibrating screen shall be repaired for problems found during regular inspection.The repair of vibrating screen includes timely adjustment of tension of triangle belt, replacement of new belt, replacement of worn screen surface and longitudinal spacer strip, replacement of damping spring, replacement of rolling bearing, transmission gear and seal, replacement of damaged bolts, repair of damage of screen frame components, etc.
2. The side plate and beam of the screen frame should avoid stress concentration, so the vibrating screen is not allowed to weld on these components.The vibrating screen should be replaced in time for cracks in the lower crossbeam. When cracks are found on the side plate, a 5mm hole should be drilled at the end of the crack in time, and then a stiffening plate should be added at the cracked part.The disassembly, repair and assembly of the vibration exciter shall be carried out by full-time personnel in a clean place.
3. After the shale shaker is disassembled, check the wear of the rolling bearing, check the gear tooth surface of the shale shaker, check the connection of each component, clean the lubrication circuit in the box of the shale shaker to make it smooth, remove the attachments on each joint surface, and replace all seals and other damaged parts of the shale shaker.[6]
Bearing damage prevention
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The vibrating screen is operated by using the compound rotary oscillation generated by the vibrator excitation.The upper rotating heavy hammer of the vibrator causes the screen surface to experience plane whirl oscillation, while the lower rotating heavy hammer causes the screen surface to experience cone reverse oscillation, and its combined action causes the screen surface to experience repeated oscillation.In normal operation, how to prevent the bearing of shale shaker from being damaged is discussed below:
When the eccentric blocks of the equipment fall off after a long time of use, or the size of the eccentric blocks is different, the symmetrical eccentric block layout of the linear shaker exciter will work at a high speed.It will cause abnormal equipment speed.At this moment, the eccentric block layout should be replaced in time to ensure that the two inclined blocks of the linear oscillating screen are of the same size and work in balance.When the rotating speed of the bearing of the linear oscillating screen is abnormal, it is easy to have conflicts and temperature rise.When the bearing of the linear oscillating screen is short of smooth oil or the increase of smooth oil does not meet the equipment demand, which causes the labyrinth sealing equipment of the oscillating screen to be blocked, the temperature rise of the bearing layout will exceed the regular scale value. At this moment, check the smooth system of the equipment in a timely manner to ensure that the smooth oil is clean enough. If the blocking appearance is found, install the bearing for thorough sanitation;If the seal ring is damaged or the bearing is cracked after wear, replace the seal ring and bearing in time, and adjust the rear weight of the linear oscillating screen from the beginning.[13]
