The concept of screening
Screening is a method of separating the particle group according to the particle size, specific gravity, electrification and magnetic properties. The equipment used for screening is screening equipment. Commonly used screens with different mesh sizes separate solid materials according to the required particle size. It is often used in conjunction with crushing, so that the particle size of the crushed materials can be nearly equal to ensure compliance with certain requirements or avoid excessive crushing. In all kinds of mining, construction, industry and other fields, the frequency of use of screening machinery is very high. The classification and application of various materials make the types of screening machines used vary.
Classification of screening equipment
Screening equipment can be roughly divided into the following categories according to the structure and working principle of the screening machine:
The working part is fixed, and the material is screened by sliding along the working surface. Fixed screens are widely used in concentrators, generally used for pre-screening before coarse or medium crushing. It has a simple structure and is convenient to manufacture. It does not consume power and can directly discharge the ore onto the screen surface. The main disadvantage is the low screening efficiency.
2.Plane motion screen:
The body swings or vibrates in a plane. According to its plane motion trajectory, it is divided into linear motion, circular motion, elliptical motion and complex motion. Both the shaking screen and the vibrating screen belong to the plane motion screen.
The working surface is composed of horizontally arranged rolling shafts, with plates on the shafts, and fine-grained materials pass through the gaps between the rolling shafts or plates. The bulk material is driven by the roller to move to one end and is discharged from the end. This sieve is used less.
The working part is cylindrical, and the entire screen rotates around the axis of the cylinder with a small inclination angle. The material is fed in from one end of the cylinder, the fine material passes through the sieve on the working surface of the cylinder, and the coarse material is discharged from the other end of the cylinder. The rotating speed of the cylindrical screen is low, the work is stable, and the power is well balanced. However, its screen holes are easy to be blocked, the screening efficiency is low, the productivity is low, the working area is small, and the concentrator is rarely used.
The crank connecting rod mechanism is used as the transmission part.The motor drives the eccentric shaft to rotate through the belt and pulley, and uses the connecting rod to make the body reciprocate in a certain direction. The movement direction of the machine body is perpendicular to the center line of the support rod or the suspension rod. Due to the swing 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.Its distortion and screening efficiency are relatively high. But the power balance is poor. It is currently rarely used.
Advantages of high frequency vibrating screen
1.High vibration frequency and low amplitude can effectively reduce the surface tension of the slurry, which is conducive to the separation and stratification of fine and heavy materials and speeds up the penetration of fine and heavy materials.
2.Using laminated screen, single-layer aperture increases, screen life increases, anti-blocking and anti-wear.
3.Multi-channel feeding, high screen surface utilization, large equipment processing capacity and low power consumption.
4.The rubber spring supports the screen frame, vibration isolation and sound absorption, low noise, small dynamic load of the equipment, and no concrete foundation.
5.The screen machine is designed with a new principle and is a new structure of high-efficiency screen surface vibrating screening machine.
6.The vibration exciter drives the screen surface to vibrate at high frequency through a transmission mechanism, and the screen box is stationary. The vibration system is designed to work in a near-resonant state. The whole machine is supported by vibration reduction, so that the ground does not bear dynamic load. The screen machine does not need to be made as a foundation. It can be installed directly on a solid and flat ground or an ordinary steel structure platform to work normally.
We are here to help you! If you close the chatbox, you will automatically receive a response from us via email. Please be sure to leave your contact details so that we can better assist