Study On Air-cushion Fluid Field Of Air-cushion Belt Conveyor

With the development of port, coal, power, mining, grain, chemical and metallurgy, conveyors are wildly used in industry and play a more important role day by day. The key to the success of application of air-cushion belt conveyor is air-cushion technology, which is also an important foundation of air-cushion belt conveyor's development. It's more important to deep understand the air-cushion on air-cushion belt conveyor. At present, the researches on air-cushion groove-hole distribution model and prevent the belt running bias all over the world are still not enough, so this paper made a further research on fluid field of air-cushion belt conveyor.The development of air-cushion belt conveyor and research status in domestic and foreign are summarized in this paper. This paper introduced several theories of air-cushion fluid field such as radial headstream flow model nearby air hole, air-cushion cross direction gap flow model, air-cushion mathematical description and so on, and some factors which can cause the belt's running bias are also introduced in this paper. Experimental model was made of PVC and its 1 meter long. With the Laser Doppler Velocimetry (LDV) and U-shaped tube system, the air-cushion pressure distribution and air-cushion velocity vector distribution under experimental condition are detected. At the same time, the simulation is designed and its working conditions is the same as experiment biased on CFD software (FLUENT). The agreement between the results of numerical simulation and the date of experimental is carried out by the comparison analyses and it's good. In order to make up shortage of the study on air-hole distribution mode of equidistant air-holes with unequal diameter on the air-cushion belt conveyor, several groove-hole distribution modes are simulated. The pressure and velocity vector distribution are analyzed, the optimal parameters of air-hole distributing mode are obtained. In order to further improve the stability of air-cushion belt conveyor under the actual running condition, the establishment modes of balance groove-hole are studied under the condition of the optimal groove-hole distribution mode. The effects come from different establishment modes of balance groove-hole to air-cushion fluid field are analyzed and the optimal establishment mode of balance groove-hole is obtained. Through the analysis of the results, the main conclusions are as fellows:(1) In the simulation of groove air-hole distribution, the pressure connection area ranges from 77% to 82%, which area decides the carrying capacity of the air-cushion belt conveyor.(2) The same side of air-cushion's pressure distribution will increase if the locations of the balance groove-hole over cross the side row groove-hole, otherwise this side of air-cushion's pressure will decreases.(3) The pressure varies from 1800 to 2260 Pa and velocity ranges from 1.2 to 15.2 m/s in 90% area. The optimal balance groove-hole model's groove angle is 27°and its optimal direction angle is 24°lean to radial direction from horizon.A reference for a further study on air-cushion fluid field of air-cushion belt conveyor is provided from this paper. However, because the experimental seal techniques are not good enough and the limit of the belt's fixing condition, the facility's design and experimental methods need to be improved.