1. Roller mill. It is a machine that uses a pair of cylindrical rollers for relative rotation to saw and grind the feed. It has the advantages of high productivity, low power, easy adjustment, etc. It is mostly used in the wheat flour milling industry. In the feed processing industry, it is generally used in the first process of secondary crushing operations.
2. Hammer type feed mill. It is a machine that uses high-speed rotating hammers to crush the feed. It has the characteristics of simple structure, strong versatility, high productivity and safe use. It is commonly used 9F-45, 9FQ-50 and 9FQ-50B.
3. Tooth claw type feed mill. It is a machine that uses high-speed rotating teeth to break feed. It has the advantages of small size, light weight, fine product size, and high working speed. Commonly used FFC-l5 type, FFC-23 type and FFC-45 type and so on.
When purchasing, select the model based on the number of items on the job day, and then select the specific product according to the manufacturing quality, sales price, and spare parts supply. When selecting, first perform an appearance inspection, and finally check whether the attachment, manual, and certificate are complete. At the same time pay attention to the following considerations:
(1) When selecting a type, first consider what kind of raw materials the crusher 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 (about 13%) and 1.2mm aperture sieves are subject to production at the time of the station. Because corn is a common grain feed, a sieve with a diameter of 1.2 mm in diameter is the smallest sieve commonly used. At this time, the production capacity is small, which takes into account the more common 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) The energy consumption of the crusher is very large. When purchasing, energy conservation must be considered. According to the standards of the relevant authorities, when the hammer mill uses crushed 1.2mm sieves for corn, the output per kilowatt 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 matching power of the crusher. 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 the 9FQ-60 crusher uses 1. When the sieve with 2mm mesh is used, the capacity of the motor should be 40kW. When using a sieve with 2mm mesh, 30kW motor can be used. For a 3mm sieve, the motor is 22kW. Otherwise it will cause some degree of waste. Hammer mill can be calculated using empirical formula 1V=6.4~10.5Q(kW). Where: 1V - supporting power (Kw); Q - crusher rated productivity (t / h); 6.4 ~ 10.5 for the coefficient, coarse crushing to take a small value, fine crushing to take large values.
(5) The crusher discharge method should be considered. 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 away, the humidity in the finished product is reduced, the storage efficiency is improved, the crushing efficiency is increased by 10% to 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) Pulverizer dust and noise. Dust and noise in feed processing mainly come from crushers. 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.
At the same time, we must take into account the following aspects when purchasing:
(1) Select according to crushed raw materials
For crushing grain feeds, hammer mills with top feed can be selected; for crushing bran wheat feeds, claw mills can be selected; if the versatility is good, the crushing of grains is mainly required. , And take into account the pie and the straw, optional tangential feed hammer mill; crushed shells and other mineral feed, can use the shell without sieve crusher; if used as a pre-mixed feed pre-processing, require product crushed size Fine and can be adjusted according to need, should use special non-screen crusher.
(2) Select according to production capacity
The crusher's rated capacity (kg/h) is contained in the manual and nameplate of the general crusher. However, several points should be noted: (1) The rated production capacity contained refers to the production in a specific state. For example, a cereal feed mill refers to the crushed raw material is corn, its moisture content is stored as safe moisture (about 13%), and the sieve aperture diameter is 1.2 mm. Because corn is a common grain feed, the 1.2 mm-diameter screen is the smallest screen commonly used. At this time, the production capacity is small, which takes into account the more common and difficult conditions in production. (2) The production capacity of the selected crusher should be slightly larger than the actual production capacity, otherwise it will increase the hammer wear, air leakage and other reasons leading to a decline in production capacity, affecting the continuous production and supply of feed.
(3) Select according to matching power
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 smashed sorghum is twice as powerful as the crushed corn. The second reason is that the load of the crusher has a great influence on the use of different screen holes. Therefore, when the 9FQ-60 crusher uses a sieve with 1.2 mm mesh, the motor capacity should be 40 kW; when using a sieve with a 2 mm mesh, a 30 kW motor can be used, and a 3 mm diameter sieve can be used. For a 22 kw motor, otherwise it will cause some waste.
(4) Select according to the layout
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, which has the advantage of absorbing the moisture of the finished product, lowering the humidity in the finished product, facilitating the storage, improving the crushing efficiency by 10-15%, and reducing the dust-generating degree of the crushing chamber.
(5) Select according to 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 a grinder with high noise and dust is chosen as a last resort, silencing and dust prevention measures should be taken to improve the working environment and benefit the health of operators.
(6) Select according to energy saving
According to the standards of the relevant authorities, when the hammer mill uses crushed 1.2 mm sieves for corn, the output per kilowatt should not be less than 48 kilograms. At present, the output per kilowatt-hour of the domestic hammer mill has greatly exceeded the above-mentioned regulations, and the quality has reached 70-75 kilograms per kilowatt-hour.