Crushing refers to the process of changing the physical properties of the material through mechanical force, destroying its internal cohesion, and turning the large bulk material into fine particles with smaller volume and meeting the production particle size requirements. The crushing process is an important link in the feed processing process, and the degree of crushing is directly related to the subsequent processing procedures of feed products and the quality of feed products. Hammer feed crusher is a kind of impact crushing equipment, which has the characteristics of high versatility, small footprint, good crushing quality, fast no-load start, flexible transmission connection, weak temperature sensitivity to feed, high productivity and convenient use and maintenance, etc., and has been widely used in the feed processing industry at home and abroad.
1 structure
The base is the installation foundation of the pulverizer, which is generally a steel plate welded structure, which is used to support and connect the rotor and other components of the pulverizer. The base requires good rigidity and firmness, so as to achieve the purpose of reducing vibration and increasing reliability and extending service life.
The rotor is the main moving part of the whole crusher, mainly composed of spindle, bearing, bearing seat, hammer plate, pin shaft, hammer and other parts, because the speed of its movement is very high, so it is required to carry out dynamic balance calibration before use. The rotor is the core component of the pulverizer, and it is also one of the rotary transmission components, which forms a crushing chamber with the sieve to crush the material and screen it, and each part of the rotor can produce vibration and noise during the working process. The rotor assembly and the motor are connected by a coupling and rotate at high speed, and the material is crushed by colliding with the material during the rotation process. Among them, the hammer is one of the worn workpieces due to high-speed rotation during work, so it is required to have a certain hardness, strength and wear resistance. In addition, the material, structure and arrangement of the hammer have an impact on the crushing efficiency of the material, so it is generally heat treated before use, so as to enhance its strength and wear resistance. In addition, the arrangement of the hammer also has an impact on the efficiency of the crusher, and there are generally 4 kinds of arrangement, namely symmetrical arrangement, spiral arrangement, symmetrical staggered arrangement and staggered arrangement.
The sieve disc is also one of the parts in the shredder that is prone to wear, which is able to control the particle size of the crushed product. The sieve piece is fixed on the machine body through the operation door pressing window to form a closed crushing chamber, and the material will be screened out from the sieve hole after crushing to meet the crushing requirements. The particle size of the material after crushing is controlled by the size of the sieve hole, that is, the pore size of the sieve should be determined according to the crushing particle size.
The lower part of the operating door is equipped with rollers, which can be moved to the other side after opening, and the screen is pressed by a special pressing mechanism, which is generally opened when the hammer or screen is replaced.
The upper part of the casing has a feeding port, the lower part is connected with the base, and the sieve plate is installed on both sides, and the crushing chamber is formed with the base for crushing materials. Feed guide mechanism. Depending on the direction of rotation of the rotor, the material is guided into the grinding chamber from the right or left.
2 classification
Hammer feed crusher has a variety of classification methods, according to the different layout positions of the rotor shaft of the crusher, it is usually divided into vertical and horizontal two, and the commonly used is the horizontal hammer crusher. In recent years, China has produced a vertical shaft hammer crusher, which has great advantages, and the existing horizontal hammer crusher is very likely to be replaced by it. According to the different directions of the material entering the crushing chamber, it is generally divided into three types: tangential feeding, radial feeding and axial feeding. According to the variation of some parts, there are also some special types, such as non-sieving mill and droplet grinder.
Among them, the water drop mill is a deformation of the axial feed mill, because the shape of the grinding chamber is like a water droplet, and the shape of its sieve is a drop shape, so that the material circulation layer is destroyed, which not only reduces energy consumption, but also improves the crushing efficiency. According to the different structure of the sieve, the droplet crusher can be divided into part of the tooth plate type and the full drop screen type, the former has a screen wrapping angle of only 270 degrees, so the top of the crushing chamber needs to install a tooth plate, which can prolong the service life of the sieve, but the screening efficiency is lower than the latter. In the case of small power of the motor, tangential feeding and axial feeding feed grinders can be selected, which are generally used in small and medium-sized feed crushing production links, because its power is small, and the rotor speed is low, and it is generally not suitable for processing feed materials that are difficult to process; The radial feeding feed crusher is mostly suitable for large and medium-sized hammer feed grinders, and the engine power is large and the productivity is high.