(1). Reception of raw materials:
Reception of bulk raw materials If transported by bulk trucks or trains, dump trucks are used to weigh the raw materials on a floor scale and unload the raw materials to the unloading pit.
(2) Crushing of raw materials:
The process of feed crushing is based on the required particle size, feed variety, and other conditions. According to the number of crushing of raw materials, it can be divided into the primary crushing process, cyclic crushing process, or secondary crushing process. According to the combination form with the batching process, it can be divided into the batching first and then the crushing process and the crushing and then the batching process.
1. One-time crushing process: It is the simplest, most commonly used, and most primitive crushing process. Whether it is a single raw material or a mixed raw material, it can be crushed once. According to the number of crushers used, it can be divided into single crushing and parallel crushing. For crushing, most small-scale feed processing plants use single-machine crushing, and medium-sized feed processing plants use two or more grinders in parallel. The disadvantage is that the particle size is uneven and the power consumption is high.
2. There are three types of secondary crushing process, namely single-cycle crushing process, stage crushing process, and tissue crushing process. 3. Ingredients first and then crushing process. According to the design of the feed formula, the ingredients are mixed and mixed, and then enter the crusher for crushing.
4. Crushing first and then batching process This process first crushes the powder to be powdered, enters the batching bin respectively, and then batches and mixes.
(3) Batching process:
Currently, the commonly used process flow includes manual adding batching, volumetric batching, batching with one bin, batching with multiple bins, batching with multiple bins, batching with multiple bins, and batching with multiple bins.
(4) The mixing process:
Can be divided into batch mixing and continuous mixing. Batch mixing is to mix various mixing components together according to the ratio of the formula and send them to the “batch mixer” that works periodically. Batch-to-ground mixing. This mixing method is more convenient to change the formula, and there is less mutual mixing between each batch. It is a commonly used mixing process at present. The opening and closing operations are more frequent, so most of them adopt automatic program control. The continuous mixing process is to continuously measure various feed components simultaneously and separately, and mix them in proportion to form a stream containing various components. When this stream enters the continuous mixer, it is continuously mixed to form a uniform stream. The advantage of this process is that it can be carried out continuously, and it is easy to connect with continuous operations such as pulverization and granulation. It does not need to be operated frequently during production. However, when changing the formula, the adjustment of the flow rate is more troublesome and continuous. There are more material residues in the conveying and continuous mixing equipment, so the problem of mixing between the two batches of feed is more serious.
(5) Granulation process:
1. Quenching and tempering: Quenching and tempering is the most important link in the granulation process. The quality of quenching and tempering directly determines the quality of pellet feed. The purpose of tempering is to adjust the mixed dry powder material into a powdered feed with certain moisture and humidity which is multiple to granulation. At present, the feed mills in our country complete the tempering process by adding steam.
2. Granulation: (1) Ring die granulation: the uniformly tempered material is first removed by the guard magnet, and then evenly distributed between the pressing and mixing and the pressing die so that the material enters the extrusion from the pressing area of the feeding area The area is clamped into the die hole by the pressing roller to continuously squeeze and split to form a columnar feed. As the press die rotates, the cutter fixed on the outside of the press die is cut into pellet-like feed. (2) The materials after flat mold granulation and mixing enter the granulation system, and the rotating distributor located on the upper part of the granulation system evenly spreads the materials on the surface of the pressure mold, and then the materials are pressed into the mold hole by the rotating pressure mixing and removed from the mold hole. The bottom is pressed out, granulationod-shaped feed coming out of the die hole is cut into the required length by the cutting roller.
3. Cooling During the granulation process, the high temperature, and high humidity steam are introduced and the material is squeezed to generate a lot of heat so that when the pellet feed comes out of the granulator, the water content reaches 16%-18%, and the temperature is as high as 75%. ℃ -85 ℃. Under this condition, pellet feed is easy to deform and break, and it will also cause adhesion and mildew during storage. The moisture must be reduced to below 14%, and the temperature must be lowered to below 8 ℃ higher than the air temperature. It needs to be cooled.
4. Crushing. In order to save power, increase output and improve quality in the production process of pelletizer, the materials are often first made into pellets of a certain size, and then crushed into qualified pellets according to the particle size during livestock and poultry feeding. product.
5. Screening: After the poet feed is processed by the crushing process, some unqualified materials such as powder agglomerates will be produced. Therefore, the crushed pellet feed needs to be sieved into neat and uniform products.