Several types of common vibrating screens？
Vibrating screen is a kind of screening machinery widely used in coal and other industries, used for grading, washing, dehydrating and disintermediating materials. Among them, the linear vibrating screen has been widely used for its advantages of high production efficiency, good classification effect and convenient maintenance. During the working process, the dynamic performance of the vibrating screen directly affects the screening efficiency and service life.
The vibrating screen uses vibration motor excitation as a source of vibration, so that the material is thrown up on the screen and moves forward linearly. The material enters the feed port of the screening machine uniformly from the feeder, and several specifications are produced through the multi-layer screen. The sieves and sieves are discharged from their respective outlets. Linear vibrating screen (linear screen) has the advantages of stability and reliability, low consumption, low noise, long life, stable vibration type, high screening efficiency, etc. It is a highly efficient new screening equipment, widely used in mining, coal, smelting, building materials , Refractories, light industry, chemical industry and other industries.
Round vibrating screen
Circular vibrating screen (circular vibrating screen) is a new type of vibrating screen with multiple layers and high efficiency for circular motion. The circular vibrating screen adopts a cylindrical eccentric shaft exciter and an eccentric block to adjust the amplitude. The material sieve has a long flowing line and many screening specifications. It has a reliable structure, strong vibration force, high screening efficiency, low vibration noise, strong durability, and maintenance. Convenient and safe to use, the round vibrating screen is widely used in product classification in mining, building materials, transportation, energy, chemical and other industries.
According to material products and user requirements, high manganese steel braided screen, punching screen and rubber screen can be used. There are two types of screen plates: single layer and double layer. All types of screen plates can meet different requirements of screening effect. This series of circular vibrating screens is seat-mounted. The inclination of the screen surface can be adjusted by changing the height of the spring support.
The elliptical sieve is a vibrating sieve with elliptical motion trajectory, which has the advantages of high efficiency, high screening accuracy and wide range of application. Compared with ordinary sieve machines of the same specifications, it has a larger processing capacity and a higher screening efficiency. It is suitable for the screening of solvents, cold sintered ore in the metallurgical industry, ore classification in the mining industry, classification in the coal industry, and dehydration and deintercalation operations. It is an ideal substitute for the existing large-scale vibrating screen and imported products from abroad. TES triaxial elliptical vibrating screen is widely used in quarrying, sand and gravel screening operations, and can also be used for coal grading, beneficiation, building materials, construction, power and chemical industries.
Screening principle: the power is transmitted from the motor to the active shaft and gear vibrator of the exciter through the V-belt (the speed ratio is 1), which realizes the three shafts rotating at the same speed and generates the exciting force. , Producing elliptical motion. With the high-speed elliptical movement of the sieve machine on the screen surface, the materials are quickly layered, sifted through, and forward, and the materials are finally classified.
Thin oil vibrating screen
The thin oil vibrating screen has large processing capacity and high screening efficiency; the vibrator adopts bearing thin oil lubrication and an external block eccentric structure. It has the characteristics of large excitation force, low bearing load, low temperature, and low noise (the bearing temperature rise is less than 35 °); the overall disassembly and assembly of the vibrator is convenient for maintenance and replacement, and the maintenance cycle is greatly shortened (replacement of the vibrator only takes 1 ～ 2 hours); the side plate of the screen machine adopts the whole plate cold work, no welding, high strength and long service life.
The connection between the beam and the side plate adopts torsional shear high-strength bolt connection, no welding, and the beam is easy to replace; the screen machine uses a rubber spring to reduce vibration, compared with the metal spring, with low noise, long life, stable over the common vibration area, each screen machine The fulcrum has a small dynamic load and other advantages; the motor and the vibrator are connected by a flexible coupling, which has the advantages of long service life and small impact on the motor.
The working part is fixed, and the material is screened by sliding the material along the working surface. Fixed grid sieves are one of the more widely used in mineral processing plants, and are generally used for pre-screening before coarse crushing or medium crushing. It is simple in structure and easy to manufacture. Without power consumption, the ore can be directly discharged onto the screen surface. The main disadvantage is low productivity and low screening efficiency, generally only 50-60%.
There are two types of fixed screens: grid screens and strip screens.
The grid screen is installed in the upper part of the coarse ore bin to ensure that the feed block size of the coarse crusher is appropriate. The large pieces on the screen of the grid screen need to be broken with a hand hammer or other methods to pass it through the screen. Fixed grid screens are generally installed horizontally.
The strip screen is mainly used for pre-screening before coarse crushing and middle crushing. It is generally installed at an angle. The size of the inclination angle should enable the material to automatically slide down the screen surface, that is, the inclination angle should be greater than the friction angle of the material against the screen surface. Generally, when the ore is sieved, the inclination angle is 40 ° -50 °. For large pieces of ore, the inclination angle can be slightly reduced, while for viscous ore, the inclination angle should be slightly increased.
The screen size of the strip screen is about 1.1-1.2 times the required particle size under the screen, and the general screen size is not less than 50 mm. The width of the bar sieve depends on the width of the feed opening of the feeder, conveyor and crusher;
The working surface is composed of horizontally arranged rolling shafts, with a plate on the shaft, and fine-grained materials pass through the gap between the rollers or the plates. The bulk material is driven by the roller to move to one end and is discharged from the end. Concentrators rarely use this kind of sieve.
The sieve surface of the roller sieve consists of a number of rollers arranged in parallel, on which the sieve discs are staggered, and the rollers are rotated by sprockets or gears. The direction of rotation is the same as the direction of material flow. In order to loosen the material layer on the sieve so as to penetrate the sieve, the shape of the sieve disc is eccentric and irregular. In order to prevent materials from jamming the screen shaft, a safety device is installed. Roller screens are all seat type, which are divided into left and right transmissions, and are divided into those with and without wheels. Those with wheels can move on the rails. Roller screen is a kind of old-fashioned sieving equipment which is relatively backward. The structure is complex and heavy. It is being eliminated. Metal mines are mostly replaced by heavy-duty vibrating screens. However, some old users such as the coal department are also accustomed to using this equipment.
Working principle: Since the sieve shafts are arranged at different working angles, the speed is faster when the material is running at a higher working angle; when the material is running at a lower working angle, the speed is slower. The materials of the two types of wood running at the same speed start to move axially when the screen surface meets at a certain position, so that the materials are evenly distributed on the screen surface, and the purpose of improving the screening efficiency is achieved.
Plane sports sieve
The body is oscillating or vibrating in a plane. According to its plane motion trajectory, it is divided into linear motion, circular motion, elliptical motion and complex motion. Shakers and shakers belong to this category.
The shaking screen uses the crank connecting rod mechanism as the transmission component. The motor drives the eccentric shaft to rotate through the belt and the pulley, and makes the body reciprocate in a certain direction by the connecting rod. The movement direction of the machine body is perpendicular to the center line of the support or suspension rod. Due to the swinging movement of the machine body, the material on the screen surface moves to the discharge end at a certain speed, and the material is screened at the same time.