The machinery used in Rendering process are called rendering machinery. The rendering machinery used in rendering process for edible and inedible products are different from each other. In edible rendering processes, machines are used basically for meat processing operations and they produce lard or edible tallow for use in food products.
Edible rendering is generally carried out in a non-stop process at low temperature. Machines are used for chopping the edible fat materials finely and for heating them with or without added steam. Machines are used for fat trimmings from meat cuts. Carrying out two or more stages of centrifugal separation is very important. Depending on the original materials, the solids may be used in food products, pet foods, etc.
Most edible rendering is done by machines at the meat packing or processing companies. An alternative process by the machines cooks slaughterhouse offal to produce a thick lumpy stew. Materials that are not suitable for human food for aesthetic or sanitary reasons are the feedstocks for inedible rendering processes.
Much of the inedible raw material is rendered using the dry method in the machines. This may be a batch or a continuous process. Here, the material is heated in a steam jacketed vessel to ward off the moisture. Simultaneously fat from the fat cells is released. The material is first ground, then heated to release the fat and drive off the moisture. Then it is percolated to drain off the free fat, and then more fat is pressed out of the solids.
This machinery process at this stage are called cracklings or dry-rendered tankage. The cracklings are further ground to make meat and bone meal. A variation on a dry process involves finely chopping the material, liquidizing it with hot fat, and then evaporating the mixture in one or more evaporator stages.
Each process requires specific machinery actions. Centrifugal and evaporating equipments are used in the following stages.Gustavus Swift, Nelson Morris, and Lucius Darling were among the early pioneers of the U.S. rendering industry.
Rendering
