Aerobic composting is a kind of manure treatment method, which has the advantage of high efficiency and environment protection. With the technology developing, the screening equipment for compost increasingly important. By analyzing the material motion and the screening process in the trommel, a series of quantitative and qualitative conclusions related to the structural parameters and process parameters of the trommel screen were obtained, based on these conclusions and combined with the characteristics and requirements of composting production process, calculated and designed the trommel screening machine. The trommel screen mainly deals with the composting products for livestock and poultry manure, which material bulk density of about 0.7t/m3, and the trommel screen has a processing capacity of 5t/h. Calculate the diameter, length and rotation speed of the trommel with mathematical model of trommel design, and designed the key components of the equipment, like stander and cover parts, support wheel and block wheel parts, feed and discharge port, etc. Use the finite element analysis software check and analyze the sprocket, and the final design parameters are determined. The discrete element method software is used to simulate and analyze the factors that affect the work efficiency of the trommel screen machine, and the original design parameters are optimized according to the test results.

The commonly compost screening equipment include vibrating screen, tumbler screen, roll screen, trommel screen and other devices. The material need to be handled include compost raw material and compost product. The characteristic of these material is that large viscosity and moisture content, corrosive, and the high content of organic matter in the material, more subdivided substances, rich fiber material. When the vibrating screen is used for compost production, due to its working characteristics, it is easy to produce larger dust. At the same time, the vibration of the screen deck is lead to the overall sealing of the screening equipment is not close easily. What’s more, leading to the leakage of dust, and if the material contains larger quality objects such as stones, bricks, it is easy to damage the screen deck. During the vibrating screen running, the frequency of screen blocking is higher, the wear fast, difficult to clean the screen mesh, large equipment maintenance, besides, it requires frequent downtime which affects the normal production of compost processing. Compared with other screening equipment during the same screening capacity, the initial investment of vibrating screen is lower, easy to maintenance, but high maintenance frequency leads to low maintenance cost advantage.
Trommel screen is a kind of screening equipment which is commonly used in composting production. Steady operation, low noise, the material has little impact to the screen mesh, the lifespan of trommel screens’ screen mesh is longer than vibrating screens’. The trommel screen has a strong ability to overturn the material, and it is also easy to produce dust in the working process. Through reasonable sealing design, it can effectively solve the problem of dust pollution. Compared with vibrating screen, under the same screening capacity, the initial investment of trommel screen is large, and due to its small screen mesh utilization rate, the floor area is larger than other common screening equipment of the same volume. The trommel screen can be used for the pre-treatment of compost materials and the further processing of compost products. Generally speaking, trommel screen is steady operation, low noise, small impact to screen mesh, long service life, it is suitable for handling the materials with complex component and high moisture content. It is a kind of screening equipment usually used for compost product.