Analysis of the production process of extrusion granulator

1. Storage, metering, mixing. The raw materials are transported by the bucket elevator and belt to the storage bin. The number of silos, the complexity of the metering and mixing techniques, is related to the number of components in the product formulation. During production, the batch mixing operation is generally used. The raw materials of each component in the formula are weighed in the weighing chamber. After the formula is required, all of them are mixed into the batch mixer, and a balance bin is installed in the system. Other devices operate continuously. Trace elements can also be added to the mixer. In order to ensure uniform particle distribution, a high-intensity mixer is used. After the mixed material and the return material are lifted by the bucket elevator, the mixed material is mixed with the return material in the double-shaft paddle mixer, and the returned material is the unqualified particles after being crushed and sieved, and the ratio of the recycled material to the new material is about 35: 65.

2. extrusion. The mixed raw material is extruded through a roll extruder, the principle of which is to form the material by extrusion. The mixture is added to the gap between the two rotating rollers by a vertical screw feeder. During the extrusion process, the pressure of the material is gradually increased. When the gap between the two axes is small, the material is affected. Press zui big, then gradually reduce until 0.

3. Broken, graded. The plates formed in the roller extruder are further broken and classified to obtain the desired particle size. The crushed raw materials are divided into super large particles, product particles and fine particles on a multi-stage sieve. The fine particles on the zui low sieve are recycled to the mixer and then extruded. The oversized particles that are retained in the upper layer of the multi-stage sieve need to be further broken. After crushing, return to the sieve.

4. Polishing and trimming. Under normal circumstances, the Zui final product needs one to two steps of polishing and finishing. The irregularly shaped particles are rounded at the corners and the like by a round drum. The fine powder produced during the polishing process is circulated by sieving (a screen). When trimming, it is generally necessary to add an anti-caking agent.

If it is a large-particle material for producing a single product, the process of weighing, metering, raw material pulverization, mixing, etc. is omitted, and the process is simpler, so that the investment of the large-scale extrusion granulator is further reduced.