magnetite circular vibrating screen in chile

vibrating screen - mineral processing

vibrating screen - mineral processing

Separate crushed materials and gravel into different sizes through large screens or industrial screens. As part of the crushing operation, coarse screens called grizzly bears or oxen are used to separate too large or too small materials from raw materials.Screens have static, horizontal and cylindrical screens, but today, most factories use inclined vibrating screens. The screening equipment determines the clear and reliable material separation, which provides the basis for the subsequent mineral processing.

Main parts of high frequency vibrating screen are mainframe, screen, electric vibrators, electric motor, rub spring and coupler.The screening decks are capable of single to triple decks, greatly improve the screening efficiency and capacity. Besides, providing a thin and loose bed of particles, which as well as do a good effect on the screen.Sieving is one of the oldest and most widely used physical size separation methods and is widely used in industry. In the continuous screening process, high frequency and low amplitude features lead to the vertical elliptical movement, the particles that fall from the feed hopper and reach the surface of the screen are sorted under the action of gravity. Oversized particles rebound along the screen, and most undersized particles pass through the holes.

High frequency vibrating screen is the most important screening machine mainly used in the beneficiation industry. They are used to separate materials containing solids and crushed ores with a particle size of less than 200 m. Wetting or drying materials can be sieved.Unlike the ordinary vibrating screen, the frequency of high-frequency screening is controlled by an electromagnetic vibrator installed above the surface of the screen and directly connected to the surface of the screen, and the vibration frequency is adjustable.High-frequency vibrating screens are usually operated at an angle of inclination, traditionally varying between 0 and 25 degrees, up to 45 degrees. In addition, it should operate at a low stroke with a frequency range of 1500-7200 RPM. Before using a high-frequency screen, it is usually necessary to pretreat the feed, because the holes in the screen are easily blocked.

The limitation of the high frequency vibrating screen is that the fine screen is very fragile and easily blocked. As time goes by, the separation efficiency will decrease and the screen needs to be replaced.

Circular vibrating screenThe multi-layer vibrating screen is specially designed for screening stones in quarries. It can also be used to classify products in coal preparation, mineral processing, building material production, power and chemical industries.The main advantages of the circular vibrating screen are as follows.(1) By adjusting the excitation force, the flow rate can be changed easily and steadily.(2) The circular vibrating screen has stable vibration, reliable operation and long service life.(3) Simple structure and reliable operation. The relatively light weight and small volume make maintenance easier.(4) The closed structure of the screen effectively prevents dust pollution.(5) Low noise intensity and small power consumption are generated during the operation of the vibrating screen.High frequency vibrating screen(1) Light, durable structure. The compact high-power vibration exciter is used as the drive. No belt or other accessories are required. The screen is very light but durable.(2) Adjustable flow rate. The screening capacity can be adjusted with ease because the stroke can be varied by adjusting the unbalanced weight with the most suited number of poles.(3) Screening capacity can be easily adjusted by adjusting the stroke, frequency, etc.(4) Stable performance. The high power of vibration makes screen run stable, even when screening adhesive materials.(5) Accurate screening. According to the specific materials and flow rate, single-layer to triple-layer deck-type groove can be designed according to the screening requirements to achieve accurate and efficient screening.(6) Simple start, stop. Press the controller button to easily control the start or stop of screening.

In the beneficiation line of various ores, the high-frequency sieve plays a vital role. The high-frequency sieve sifts out the coarse particles and sends them back to the crusher for crushing. At the same time, the fine-grained materials are discharged in time to avoid excessive crushing caused by re-grinding.The sieved materials can enter the next stage of beneficiation process. The use of high-frequency sieve can not only meet the requirements of mineral fineness, but also achieve smaller particle size separation, thereby reducing the capacity and overall energy consumption required in the crushing stage. Therefore, the grade of the final product is improved, and a better recovery rate and screening efficiency are provided.

circular vibrating screen vs linear screen - mineral processing

circular vibrating screen vs linear screen - mineral processing

There are many types of vibrating screens, which can be divided into circular vibrating screens and linear screens according to the movement trajectory of materials. These two types are commonly used screening equipment. A few days ago, a customer left a message asking about the difference between them and wanted to know how to choose. Here we will make a comparison from 9 points to help customers quickly distinguish between circular vibrating screen and linear screen.

There is no essential difference between the style and structure of the circular vibrating screen and the linear vibrating screen. The materials are screened through the vibration of the screen surface, but the difference in the vibration track will directly affect the screening purpose.

The motor drives the eccentric block of the vibration exciter to rotate at a high speed through the V-belt, which produces a large centrifugal inertial force, which stimulates the screen box to produce a circular motion with a certain amplitude. The material on the screen is affected by the impulse transmitted by the screen box on the inclined screen surface. A continuous throwing motion is produced, and the particles smaller than the sieve hole are passed through the sieve when the material meets the screen surface, thereby achieving classification.

Vibration motor is used 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 produces several specifications of screens through the multi-layer screen. The upper and lower objects are discharged from their respective outlets.

2. Vibration exciterThe circular vibrating screen is also called a single-shaft vibrating screen because the exciter is a shaft and uses an inertial motor to work. The linear vibrating screen is composed of two shafts and works on the principle of vibration motor excitation, so it is also called double Shaft vibrating screen.

3. Hole blocking phenomenonThe material of the circular vibrating screen moves in a parabolic circular trajectory on the screen surface, so that the material is dispersed as much as possible, thereby improving the bounce force of the material, and the material stuck in the screen hole can also jump out, reducing the hole blocking phenomenon.

5. Screen surface inclinationAccording to the particle size of the material, the circular vibrating screen can change the inclination of the screen surface, thereby changing the moving speed of the material along the screen surface and increasing the processing capacity of the screen machine. Generally speaking, the inclination angle of the screen surface of the linear vibrating screen in production is small.

6. MaterialUnder normal circumstances, the circular vibrating screen is made of thick plates, and the box is made of manganese steel to resist the impact of materials during the screening process. The materials for the production of linear vibrating screens are mainly light plates or stainless steel plates.

7. Applicable fieldsThe circular vibrating screen mainly screens materials with high specific gravity, large particles and high hardness, and is widely used in mining industries such as mines, coal, and quarries.

Linear screens mainly screen fine particles, light specific gravity, and low-hardness materials, mainly dry powder, fine granular or micro-powder materials, and are generally used in food, chemical, building materials, and pharmaceutical industries.

8. Processing capacityFor the circular vibrating screen, because the exciter is arranged above the center of gravity of the screen box, the elliptical long axis at both ends of the screen box is in a lower eight shape, and the upper end of the elliptical long axis at the feeding end faces the discharge direction, which is beneficial to the rapid material The upper end of the elliptical long axis of the discharge end is opposite to the discharge direction, which reduces the movement speed of the material, which is conducive to the penetration of difficult-to-screen materials, and the arc-shaped screen surface increases the effective area of the screen, thereby improving its Processing power.

In addition, for materials that are difficult to screen, the circular vibrating screen can turn the main shaft, so that the direction of vibration is opposite to the direction of movement of the material, and the moving speed of the material along the screen surface is reduced (when the screen surface inclination is the same as the spindle speed) to improve screening effectiveness.

In the field of mining and quarrying, circular vibrating screens are more widely used. In actual production, the choice of circular vibrating screen or linear vibrating screen mainly depends on the type of material handled by the user and the application field. The screening requirements are different, the selected equipment will be different.

vibrating screen types & working principle [how to choose] | m&c

vibrating screen types & working principle [how to choose] | m&c

According to different structure and use, vibrating screens usually be devided into many types by the vibrating screen manufacturers. Below wil introduce the top 10 vibrating screens, and how to choose the right vibratory screen?

linear vibrating screen is driven by double vibrating motors. When the two vibrating motors are rotating synchronously and reversely, the excitation force generated by the eccentric block offsets each other in the direction parallel to the axis of the motor, and overlaps into a resultant force in the direction perpendicular to the axis of the motor, so the motion track of the linear vibrating screen machine is a straight line.

Working Principle:The two motor axes of the linear vibrating screen have an angle of inclination in the vertical direction relative to the screen panel. Under the combined force of the exciting force and the self gravity of the material, the material is thrown on the screen surface to jump or move forward in a straight line. Through the multi-layer screen panels, a variety of specifications of materials are generated, and discharged from their respective outlets, so as to achieve screening and classification. linear vibrating screen is suitable for screening various dry powder or granular materials with particle size of 0.074-5mm, moisture content <7%, and no viscosity. The feed particle size is not more than 10 mm.

Circular vibrating screen is a new type of vibrating screen with multi-layer screen and high efficiency. According to the type of materials and the requirements of users, the high manganese steel woven screen, punched screen plate and rubber screen plate can be used. The circular vibrating screen is installed in the seat type. The adjustment of the screen surface angle can be realized by changing the position and height of the spring support.

Working Principle: The motion track of the screen box of the circular vibrating screen is circular. The circular vibrating screen uses the inertia exciter to produce vibration. The main shaft fixed on the screen box is driven by the motor to rotate at high speed, and the eccentric body installed on the main shaft rotates with it, generating centrifugal inertia force, so that the screen box that can freely vibrate will produce vibration similar to the circular track.

Circular vibrating screen is widely used in the materials classification of mining, building materials, transportation, energy, chemical industry and other industries because of its long flowing line and many screening specifications.

Elliptical vibrating screen is a vibrating screen with elliptical motion track (Elliptical Shale Shaker), which has the advantages of high efficiency, high screening accuracy and wide range of application. Compared with the ordinary sieve machine of the same specification, it has larger processing capacity and higher screening efficiency.

Triaxial elliptical vibrating screen is widely used for the screening operation of sand and stone materials in sand plant. It is the ideal screening equipment for all kinds of mines, quarries and mobile screening stations.

Working Principle: The power is transmitted from the motor to the main shaft of the exciter and the gear vibrator (speed ratio is 1) through the V-belt, so that the three shafts can rotate at the same speed and generate the exciting force. The exciter is connected with the high-strength bolts of the screen box, resulting in elliptical movement.

Materials on the screens do high-speed elliptical movement along with the screen machine, so as to achieve uickly separate, sift and move forward, and ultimately complete the classification of materials.

The working surface of the roller screen is composed of a series of rolling shafts that arranged horizontally, on which there are many screen plates. When working, the fine material passes through the gap between the roller or screen plate, large blocks of materials are driven by rollers, moving to the ends and discharging from the outlets. Roller screens are mostly used in the traditional coal industry.

Working Principle: For the rolling shafts are arranged according to different working angles, the speed of the material is faster when it runs in the position with higher working angle; the speed of the material is slower when it runs in the position with lower working angle.

When two kinds of materials running at different speeds converge at a certain position on the screen surface, they start to move axially, so that the materials are evenly distributed on the screen surface, and the screening efficiency is improved.

Rotary vibrating screen is mainly used for the classification of materials with high screening efficiency and fine screening accuracy. Fully closed structure, no flying powder, no leakage of liquid, no blocking of mesh, automatic discharge, no material storage in the machine, no dead angle of grid structure, increased screen area.

Any particle, powder and mucus can be screened within a certain range. Sieve to 500 mesh or 0.028mm, filter to 5 microns minimum. It can be used for classification, classification and filtration in food, chemical, metal, mining and other industries.

With the help of the heavy hammer installed at the upper and lower ends of the motor shaft, the rotary motion of the motor is transformed into a horizontal, vertical and inclined three-dimensional motion, which is then transmitted to the screen surface to make the material do an outward involute motion on the screen surface. Working Principle: After the rotary screen is started, the eccentric blocks of different phases at the upper and lower ends of the vibrating motor generate a composite inertia force, which forces the vibrating body of the rotary screen machine to rotate again and again, and the screen frame continuously moves to and fro under the action of the vibration force, and then drives the screen surface to vibrate periodically, so that the materials on the screen surface move in a positive and directional manner together with the screen box. Materials smaller than the screen meshes fall to the lower layer, and the materials larger than the screen meshes discharged from the discharge port.

High frequency vibrating screen is also called high frequency screen for short. High frequency vibrating screen (high frequency screen) is composed of exciter, pulp distributor, screen frame, supporting, suspension spring and screen, etc. High frequency vibrating screen is the most important screening machine in mineral processing industry, which is suitable for completely wet or dry raw materials.

Working Principle: Different from ordinary screening equipments, high frequency screen adopts high frequency, which destroys the tension on the pulp surface and makes the fine materials vibrate at high speed on the screen, accelerates the separation of useful minerals with large density (specific gravity), and increases the probability of contact between the materials with smaller than the separated particle size and the screen holes.

As a result, high frequency screen results in a better separation conditions, which makes the materials that smaller than the separation size (especially with larger specific gravity), and pulp pass through the screen holes together to complete the screening. High-frequency vibrating screen is usually operated at an inclined angle 0-25, up to 45, and the operating frequency range is 1500-7200r/m.

Grizzly screen has simple and solid structure, no power consumption, no moving parts, low equipment cost and convenient maintenance, but the productivity is low, the screening efficiency is not high, generally 50% 60%, and the mesh is easy to be blocked.

Working Principle: Generally, the grizzly screen is placed in an inclined position, and the materials are dumped at the high end. Under the action of its own weight, it slides down the screen surface, and the particles smaller than the gap or hole on the screen surface pass through the screen to achieve classification.

Banana screen is mainly suitable for the classification of large and medium-sized materials with high content of fine particles, and it can also be used for dehydration, demineralization and desliming.

Working Principle: During operation, the motor is connected with the vibration exciter through the V-belt or soft connection. The motor drives the eccentric shaft to rotate to generate centrifugal inertia force, which forces the screen box to vibrate. After the materials fall into the screen from the feeding inlet, they move forward rapidly under the action of the vibration force, loosely and pass through the screen.The thickness of the material layer of banana screen from the feeding inlet to the discharging outlet is constant. The ratio of the material quantity to the flow speed on the screen of each section is stable, the material layer is high and uniform. The screening efficiency of banana screen is higher, which is 1-2 times higher than that of other screening machines with the same effective area.

Heavy inclined screen can be applied to the treatment of debris from quarry, mine and building demolition, the treatment of topsoil, the recycling of construction materials, the screening of gravel, and the screening of gravel and aggregates.

Working Principle: The screen box shaft is driven by the motor installed on the auxiliary frame through three V-belts, the auxiliary frame is rigidly connected with the machine underframe, and the screen box spring is used to support the screen box.Inclined screen usually adopts 2-4-layer screen panels, and is fixed on the inclined frame at an angle between 15 and 30. The material can be screened into 3-5 grades at the same time.

Horizontal screen has the advantages of both inclined screen and linear vibrating screen. horizontal screen has the features of good screen permeability, large processing capacity and small installation height.

The installation angle of common vibrating screen is 15-30, while the installation of horizontal screen is parallel to the ground, or slightly inclined 0-5. Horizontal screen is an ideal equipment for all kinds of mines, quarries and mobile screening stations.

Working Principle: Horizontal screen is designed with oval stroke. The advantage of this design is that it can change the oval big diameter length and angle of throwing material stroke to meet the best needs of vibrating screen. The oval stroke is easy to adjust by center gear, counterweight wheel and motor speed.

Different types of vibrating screens can be used for the same material to get different screening effects. The reasonable selection of vibrating screen is an effective way to improve vibration efficiency and maximize economic benefits. Generally, you need to consider the following 5 tips:

When choosing vibratory screen, the material characteristics should be taken into account, including the content of material particles under the screen, the content of difficult screen particles, material moisture, the shape and specific gravity of the material, and the content of clay.

Tips: Heavy vibrating screen is used for materials above 200mm; circular vibrating screen is used for materials above 10mm; linear vibrating screen and high frequency vibrating screen are used for desliming, dewatering and grading.

When selecting the vibratory screen, the screen areas, layer numbers, shape, size and area ratio of the screen holes, as well as the motion mode, vibration frequency and amplitude of the vibrating screen should also be considered.

Tips: In order to keep the screens under good working conditions, the ratio of screen length to width should be in the range of 2-3; when there is much viscous mud and high moisture in the material, double deck screens should be avoided as far as possible.

Vibratory screens need to be selected according to different screening purposes. If it is necessary to pre screen materials, circular vibrating screens are generally used; for the classification and screening of crushed materials, large vibrating screens and probability screens are selected; for the deionization and dehydration of materials, linear vibrating screens are better; if it is necessary to desliminate and clean up materials, probability screens are used.

When selecting the shale shakers, it also needs to be considered according to the processing capacity of the production line, screening method, screening efficiency and the tilt angle of the shale shakers.

Professional vibrating screen manufacturers could provide competitive vibrating screen price, diversity customized vibrating screen models, timely after-sales service, spare parts and can continue to provide services for customers whole production circle.

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