There are many kinds of feed mills. How to purchase a good feed mill properly? The following describes the principle of selection. 1. When selecting a type, the first consideration should be the type of raw material that the pulverizer purchased is to crush. For crushing grain feeds, hammer mills with top feed can be selected; for crushing bran wheat feeds, claw mills can be selected; if good versatility is required, such as crushing grains, Considering both pie and straw, a tangential feed hammer mill can be selected; shellfish and other mineral feeds can be crushed, and shellless screen mills can be used; for pretreatment of premixed feed, the size of the product is required to be crushed. Fine and can be adjusted according to need, should use a special non-screen crusher. 2. The general crusher's specifications and nameplates contain the rated capacity (kg/h) of the crusher. However, several points should be noted: (1) The rated production capacity contained is generally based on comminuted corn, the moisture content is stored in safe moisture (approximately 13%) and the φ1.2mm aperture sieve is under the condition of the output of the stage, because corn is Commonly used grain feeds, sieves with a diameter of 1.2 mm in diameter are the smallest sieves commonly used, and at this time the production capacity is small, which takes into account the more general and difficult conditions in production. (2) The production capacity of the selected crusher is slightly greater than the actual production capacity, and the continuous production and supply of the feed will not be affected when the production capacity of the crusher is reduced due to hammer wear and air leakage from the air duct. 3, crusher energy consumption is very large, when buying, can not but consider energy conservation. According to the standards of relevant departments, when the hammer mill uses φ1.2mm mesh sieves for comminution of corn, the output per kilowatt hour should not be less than 48 kilograms. At present, the power production of the domestic hammer mill has greatly exceeded the above regulations, and the quality has reached 70-75 kg/kWh. 4, the power of the grinder. Both the machine instructions and the nameplate contain the kilowatts of power of the motor for the crusher. It often shows not a fixed number but a certain range. For example, 9FQ-20 type crusher, supporting power is 7.5-11kw; 9FQ-60 crusher, supporting power is 30-40kw. There are two reasons for this. First, there is a big difference in the power required when the raw materials are crushed. For example, under the same working conditions, the power used to crush the sorghum is twice as large as that of the crushed corn. The second reason is that the load of the crusher has a great influence on the use of different screen holes. Some people think that when the 9FQ-60 crusher uses a φ1.2mm mesh screen, the motor capacity should be 40kw. For a φ2mm mesh screen, a 30kw motor can be used, and a φ3mm mesh is a 22kw motor. Otherwise it will cause some degree of waste. The hammer mill can be calculated using the following empirical formula. 1v=6.4 - 10.5Q(kw) Where: 1v - supporting power (Kw) Q - crusher rated productivity (T/h) 6.4 - 10.5 is coefficient, coarse crushing takes small value, fine Shred large values. 5, should consider the crusher discharge method. There are three ways to smash the finished product through the discharge device: self-weight blanking, negative pressure suction and mechanical transport. Small stand-alone use more self-heavy materials to simplify the structure. Most of the medium-sized pulverizers have a negative pressure suction device. The advantage is that the moisture of the finished product can be sucked, the humidity in the finished product is reduced, the storage efficiency is improved, the crushing efficiency is improved by 10-15%, and the dusting degree of the crushing room is reduced. The mechanism conveyor is mostly used for crushers with a table top production greater than 2.5T. 6, grinder dust and noise. The dust and noise in feed processing mainly comes from the crusher. The two environmental sanitation indicators should be fully considered when selecting a type. If it is necessary to use a grinder with high noise and dust, noise and dust prevention measures should be taken to improve the working environment and to facilitate the health of operators.