Design of Anti-clogging Screen Panel of Graded Banana Screen

September.30,2021

The function of the coal grading banana screen is to divide the mine rough coal into different grades. In order to improve the processing capacity and screening efficiency of the banana sieve, vibration is often applied to the sieve machine through a vibration exciter. The banana screen is mainly composed of a screen box, a beam and an excitation system. The main working part of the sieve machine is the sieve surface. The sieve surface of the banana sieve is mainly composed of 3 rows of sieve plates with openings of 50mm and 2 rows of sieve plates with openings of 300mm. The shape of the sieve of 50mm includes capsule shape and round, which are distributed in a diamond shape. The shape of the sieve of 300mm is round, and the opening rate is about 30%.

Since the inclination angle of the 5-row sieve surface of the banana screen gradually decreases from the feeding end to the discharging end, the inclination angle of the 300mm sieve opening near the discharging end is very small, and the screen machine does not have obvious ejection effect on the material, and the shape is very irregular. Difficult to sieve particles (300～450mm) can easily block the sieve holes. In addition, the opening rate of the 300mm sieve is low, and the normal production will be seriously affected after the blockage occurs.

Changing the inclination angle of the screen machine or the inclination angle of the screen surface is an effective way to avoid clogging. However, changing the inclination angle of the screen requires changing the support height of the screen, which is not only difficult to construct, but also affects normal production. Changing the inclination angle of the screen surface requires changing the structure of the screen machine, which is not only difficult to operate, but also has an adverse effect on the performance of the screen machine.

It is precisely when some easy-to-think solutions are inconvenient to implement, the author creatively proposes to replace a new type of screen surface with a punched screen plate with an opening of 300mm. This screen surface must meet three conditions: one is not easy to be blocked; the other is a high opening rate; and the third is that it is easy to manufacture and maintain. The bar screen that can meet these 3 conditions is selected among many screen surface forms. The first plan proposed is to replace the bar screen with a sieve plate with an opening of 300mm, and fix the bar screen on the beam of the banana screen, vibrate together with the screen machine, and maintain a certain inclination; the second The plan is to replace the 300mm sieve plate with a bar screen, but the bar screen is not in contact with the screen machine, and the distance between each other is greater than the maximum amplitude of the screen machine in resonance; the third plan is in the second plan On the basis, in order to further increase the transport capacity of large pieces of material on the small inclination bar screen, all the bars are replaced with screws, which rotate at a certain angular velocity; the fourth plan is based on the third plan A further improvement is that there is no contact between the screen surface and the screen machine, the bars and the screws are arranged at intervals, the bars are fixed, and the screw rotates at a certain angular velocity.

LZZG banana screen has outstanding characteristics such as large production capacity, good process indicators, novel structural design, stable performance, high reliability, small maintenance, and easy adjustment. It is an ideal model for desilting, dewatering and de-intermediation of products in coal preparation plants.