Coal banana screen screen and fastening method screen surface is the main part of the screen. The basic requirements for the screen surface are: sufficient strength, maximum effective area (the ratio of the total area of the screen to the entire screen surface area), the screen is not easy to plug, and the chance to meet the screen in the movement of the material is more. The former requirements affect the reliability and service life of the screen surface, and the latter three requirements are related to the working effect of the screen. Commonly used screen surface screen plate, screen mesh, slit screen plate and mesh silk cloth four. The first two are mainly used in classification and screening; The latter two are used in dehydration, desliming and desliming media. The correct selection of screen surface, can improve the screening effect and the reliability of the work, so as to play the application ability of the screen. In order to ensure the reliability of the work of the screen surface, the method of fixing the screen surface also has a great impact, which is particularly prominent on the screen surface made of metal wire or metal strips. Because if the fixed screen more relaxed: sieve vibration, screen mesh will produce local shaking, so that the total deflection of the screen wire production office, serious to lead to the fracture of the screen wire. Usually steel wire can only withstand 1~2 million times of repeated bending, assuming that the frequency of bending deformation of steel wire is equal to the frequency of vibration of the screen box due to fixed relaxation, the steel wire as long as the work 2000min, can reach the fatigue limit. A bar screen surface A bar surface is composed of shafts or bars arranged in parallel and tightened with each other. The size of the screen is determined by the width of the gap between the bars. Bar screens are usually assembled at the work site from local materials, so the bar section shapes may be varied. The bar screen surface for screening bulk materials is sometimes composed of welded metal beams on which replaceable manganese steel plates are installed to prevent wear. coal banana screens are sometimes provided with screens consisting of steel bars inserted on special supports. The bearing comprises a metal tube and a covering sleeve made of special rubber. Flange the support to the edge of the screen frame. On the side of the bracket are two rows of holes, and the steel bars that make up the screen are inserted into these holes.
Two, plate screen surface screen plate is a solid screen surface, mainly used in the screening of large materials. According to the experience of the general concentrator, the sieve plate should be used for the classification of the large block of more than 25mm, so that the life of the screen surface is longer and the screening efficiency is not affected. The opening rate of the screen is generally about 40%. The material of sieve plate is generally A3 and 16Mn, 16MnCr steel plate, steel plate thickness is commonly used 6mm, according to the different work strips can be properly thickened or thinned. The processing of sieve plate can be done by drilling or punching. The commonly used shape of the sieve is round, and in some cases it is also rectangular. When the rectangular screen is used, the long side should be consistent with the direction of material movement, and the processing method can only be punched. In order to avoid the blockage of the screen, the screen can be processed into an enlarged cone at the bottom, so that the screen gradually expands from the inlet to the outlet of the particle, which is conducive to the material through the screen. For perforated sieve plates, this expanded punching process can occur naturally. Under normal circumstances, punching is easier than drilling, so when conditions are available, punching method should be used. Circular sieves are almost always arranged in a diamond shape in order to make the sieve plate strong enough and open as much as possible.
Three, the outstanding advantages of Coal banana screen woven screen mesh is that the opening rate is large, up to 70% of the total screen area, but compared with the screen plate, the fastness is poor, the service life is short, so it is generally only used in the classification of fine particle size. It is often used in coal preparation plants for coal ash grade with particle size less than 13mm. The most commonly used material of screen is low carbon steel, it is only suitable for wear less material. A0 steel is used in many factories in our country, and sometimes lead wire sieve. High carbon steel or alloy steel can be used if the material has greater wear. The screen made of stainless steel and 65M steel wire, although the price is higher, but the service life can be extended several times, so it is economically advantageous in general. Most of the mesh holes are square, generally woven. The disadvantage of woven screen is that the surface is not smooth, hinder the relative movement of the material on the screen surface, the thicker the sieve, the more significant the problem. To overcome this shortcoming, a corrugated screen wire can be used. In order to reduce the connection of the screen protrusion, the screen can be flattened here, so as to reduce the resistance of the material along the screen surface, but also to extend the life of the screen. The use of special splint on both sides of the screen frame from the transverse pull tight, and then use bolts to fix the splint on the screen box. In order to make the screening material can be evenly distributed on the screen surface, often the sieve hair into an arch. Screen tension can improve its service life, so the work should often pay attention to its tightness.
Four, non-metallic screen surface
Rubber screen has the advantages of wear resistance, light weight and low noise, and has achieved good results in practical application. The rubber screen surface can be manufactured directly from rubber. The screen can be square, round or sewn, or it can have a heart made of steel bar, and the steel bar is coated with rubber. Rubber screen surface self-cleaning effect is the best, foreign countries have higher opening rate of products, for higher moisture materials, should be the ideal screen surface, but at present domestic products have the opening rate of the problem, and the sieve is more than 13mm.
(2) amino ester and polyurethane glue screen plate ammonia and polyurethane are new high-quality wear-resistant materials, suitable for the manufacture of screen surface. On the outside of the steel sieve plate covered with ammonia Taforga type 2 screen surface and reinforced with steel wire layer Tafortai type ammonia screen surface, has been popularized in the production, has good wear resistance, low noise, can be stored in the open air, etc.
