What are the classifications of vibrating screening machines ？

1. Fixed sieve
The working part is fixed and stationary, and the material is screened by sliding along the working surface. Fixed grid screen is a commonly used type in mineral processing plants, usually used for pre screening before coarse or medium crushing. It has a simple structure and is easy to manufacture. It does not consume power and can directly unload the ore onto the screen surface. The main drawbacks are low productivity and screening efficiency, usually only 50-60%.
There are two types of fixed screens: grid screen and strip screen.
The grid screen is installed on the upper part of the coarse ore bin to ensure the appropriate feeding block size of the coarse crusher. The large blocks on the grid screen need to be crushed using a hammer or other methods to pass the screen. Fixed mesh screens are generally installed horizontally.
The bar screen is mainly used for pre screening before coarse and medium crushing, and is generally installed in an inclined manner. The inclination angle should be such that the material can automatically slide down the screen surface, which means the inclination angle should be greater than the friction angle between the material and the screen surface. When screening ore, the inclination angle is generally between 40 ° -50 °. For bulk ore, the inclination angle can be slightly reduced, while for viscous ore, the inclination angle should be slightly increased.
The mesh size of the strip sieve is approximately 1.1-1.2 times the required particle size below the sieve, and generally the mesh size is not less than 50mm.
The width of the bar screen depends on the width of the feeding port of the feeder, conveyor, and crusher; And it should be greater than 2.5 times the maximum block size in the ore feed.
2. Roller screen
The working surface is composed of horizontally arranged rolling shafts with plates on them, and fine materials pass through the gaps between the rollers or plates. Large pieces of material are moved towards one end by a roller belt and discharged from the end. Mineral processing plants generally rarely use this type of sieve.
The screen surface of a roller screen is composed of many parallel arranged roller shafts on which screen plates are staggered. The roller shafts rotate through sprocket or gear transmission, and their rotation direction is the same as the direction of material flow. In order to loosen the material layer on the sieve and facilitate the screening, the shape of the sieve disc can be eccentric or irregular. To prevent materials from getting stuck on the sieve shaft, a safety device is installed. The roller screen is all seat type, with left and right transmission options, as well as those with and without takeaway wheels. The takeaway wheels can be moved on the steel rail. Roller screen is a relatively outdated screening equipment with a complex and bulky structure, which is being phased out. Metal mines are often replaced by heavy-duty vibrating screens, but some old users such as the coal department are still accustomed to using this equipment.
Working principle: Due to the screen shaft being arranged at different working angles, the speed is faster when the material runs at a higher working angle position; When the material is running at a lower working angle, the speed is smoother. The materials running at the same speed of two types of wood start to move axially when they meet at a certain position on the screen surface, so that the materials are evenly distributed on the screen surface, achieving the goal of improving screening efficiency.

3. Cylindrical sieve
The working part is cylindrical, and the entire sieve rotates around the axis of the cylinder. The axis is generally installed at a small inclination angle. Materials are fed in from one end of the cylinder, fine grade materials pass through the sieve holes on the cylindrical working surface, and coarse materials are discharged from the other end of the cylinder. The rotational speed of the cylindrical screen is very low, the operation is stable, and the power balance is good. However, its sieve holes are prone to clogging, screening efficiency is low, working area is small, and productivity is low. Mineral processing plants rarely use it as screening equipment.
Cylindrical sieve
Purpose of cylindrical screen: The cylindrical screen can be widely used for screening dry powder or granular materials in industries such as metallurgy, building materials, chemicals, grains, pharmaceuticals, abrasives, and fertilizers. It is particularly suitable for dry production of machine sand and can also be used for screening wet granular materials.
Characteristics of cylindrical sieve:
(1) The net output of screen drying and cleaning is strong, non blocking, and screening efficiency.
(2) The material composition under the screen ratio is flexible, and the screen size can be adjusted to achieve the expected ratio. Red Star Machinery Equipment specializes in manufacturing various machine types and polyhedral structure wheel screening to meet different needs.
(3) Screening ability, with a wide range of screening capabilities.
(4) Easy to operate, easy to adjust, and easy to maintain.
(5) Closed, with minimal pollution and a good environment.
(6) No vibration, noise, long service life.
Mineral processing equipment - cylindrical screen, and to provide you with first-class solutions and after-sales technical support for mineral processing processes. We would like to learn more about mineral processing equipment. In the production process of pulp and paper using cylindrical screen, high concentration pulps, high concentration cleaning agents, and coarse filters are used to eliminate pulp debris before canceling the pulp and reducing the burden of reflux filtration devices.
4. Planar motion screen
The body oscillates or vibrates within a plane. According to its planar motion trajectory, it can be further divided into linear motion, circular motion, elliptical motion, and complex motion. Shaker screens and vibrating screens belong to this category.
The shaking screen is driven by a crank connecting rod mechanism. The electric motor drives the eccentric shaft to rotate through a belt and pulley, and uses a connecting rod to make the body move back and forth in a certain direction. The movement direction of the machine body is perpendicular to the centerline of the support or suspension rod. Due to the swinging motion of the machine body, the material on the screen surface moves towards the discharge end at a certain speed, and the material is screened simultaneously.
Compared with the above-mentioned sieves, the shaking sieve has higher productivity and screening efficiency. Its disadvantage is poor power balance. Nowadays, it is rarely used in mineral processing plants and has been replaced by more reasonable vibrating screens.
Vibration screens are most commonly used in mineral processing plants, and can be divided into the following types according to their transmission mechanisms: eccentric vibration screens, inertial vibration screens, self centering vibration screens, and resonance screens.