Coal roller screen is one of the important equipment of coal conveying system in coal-fired power plant. Inclined coal roller screen is in the original screen on the basis of self-developed screening equipment, after years of continuous improvement, the coal roller screen structure design is increasingly reasonable, screening efficiency is higher than other manufacturers of products, noise is lower than the national standard, no vibration no dust, not easy to block coal, it is easy to maintain, and has been used in many power plants at home and abroad, and the use effect is good.
Coal material from the human material mouth into the screen box, because the first 5 sieve shaft and the horizontal direction into 15° angle, so the coal material in its own gravity and screen rotation under the double action with a large speed down and screening, this process is coarse screening stage. Most of the material is screened at this stage and laid on the entire screen surface. When the material into the last 5 sieve shaft, because the last 5 sieve shaft and the horizontal direction into 5 angle, the basic level, the material forward speed is slow, this process is the fine screening stage, after this stage, less than 30mm particle size of the material is screened, more than 30mm particle size of the material through the discharge port is sent to the coal crusher further crushing. Coal roller screen is mainly composed of five parts: Front screen box, back screen box, lower screen box, screen shaft and coal baffle. All the shells are welded by various steel plates, wear-resistant lining plates are fixed on both sides of the box, this structure improves the service life of the equipment.
1) Screen shaft, screen pieces and other wearing parts are easy to replace. The screen is elliptical or plum shaped and staggered, which is conducive to the transportation of coal, and can reduce the possibility of forming a dead angle between the adjacent screen shaft to avoid blocking. It is suitable for bituminous coal, anthracite, lignite, coal gangue and other materials.
2) Each screen shaft is driven separately by the motor reducer, that is, each group of screen shaft is equipped with a set of driving devices; the reducer is connected with the coal roller screen by an elastic pin coupling; when any group of screen shaft fails, the material can be pushed by the previous screen shaft to move forward over the fault screen shaft without affecting the operation of the equipment. Each screen shaft rotates at the same speed in the same direction, and has overload capacity. Each rotating part rotates flexibly, without blocking phenomenon.
3) Screen shaft multi-angle reasonable arrangement. The screen shaft of the population section of the equipment has an angle of 15° with the horizontal direction, and the screen shaft of the exit section has an angle of 5° with the horizontal direction. This design makes the coal material enter the equipment first through the coarse screening stage, and then carry out the secondary fine screening stage, which effectively improves the screening efficiency and prevents the occurrence of coal blocking.
4) The wear-resistant lining plate is located on both sides of the equipment box, which can effectively avoid direct contact between the box and the material and improve the service life of the equipment; at the same time, the wear-resistant liner and the box are connected with bolts for easy replacement.
5) Electro-hydraulic) push rod switch baffle is located in the coal screen inside the entrance, coal roller screen maintenance, coal can directly into the lower belt, does not hinder the normal operation of the system. A coal baffle plate is arranged under the feeding port, and the baffle is in the position of state i when working; when the particle size of coal ≤ 30mm does not need screening or the equipment fails but the coal transmission line can not be stopped, the electric hydraulic rod can be started to convert the coal baffle to the position of state ii, so that the coal directly falls into the downstream transport belt. The material of the baffle is wear-resistant steel plate, which can make the coal evenly spread on the screen surface, and the screening effect is better.
6) The screen surface is all processed to improve the finish and prevent coal sticking; the sieve shaft is provided with a column "Shape cleaning plate (after heat treatment), which can remove the coal sticking on the side and root of the sieve sheet to prevent coal blocking.
7) The two ends of the screen shaft are covered with wear-resistant lining plates to solve the problem of large coal material stuck on both sides of the box and the screen sheet to ensure the normal operation of the equipment.
8) The end cover of the screen shaft is double sealed with rubber gasket and o-type felt ring to ensure that the box is tight and does not leak coal powder. The bearing seat adopts split structure, and the bearing is lubricated with calcium grease rather than thin oil, which is easy to maintain and repair. Bearing seal type is labyrinth type, there will be no oil leakage; bearing temperature rise is not more than 40℃, bearing temperature is not more than 70℃.
9) The whole machine is made of steel plate with a thickness greater than 10mm to ensure that the box and the base have sufficient stiffness. The welding surface is smooth and smooth, and there are no common defects such as pores, slag inclusion, welding nodules, cracks, etc. The main welding seam should be inspected.
10) Each screen shaft of the coal roller screen is provided with mechanical and electrical double protection, when the equipment is overloaded, the nylon safety pin of the coupling will be cut, and the reducer will play a mechanical protection. In addition, if the screen shaft is blocked, the motor current increases beyond the critical value will send an alarm signal, so as to play an electrical protection.
11) The coal roller screen is started in sequence, that is, the first screen shaft at the exit starts first, and then starts in ascending order, so that the equipment can be started with load when there is coal on the screen surface.
12) The screen shaft and screen have sufficient mechanical strength and stiffness to meet the load starting operation. The material of the screen is zg50mn2, with good wear resistance, the service life of the screen shaft is not less than 10a, and the service life of the screen is not less than 3a.
The above is some tips about coal roller screen selection, we are a professional crushing and screening and bulk material handling equipment suppliers, we have advanced tools and skilled workers and perfect after-sales service system to ensure our product quality.
