The Cylinder Exhaust Vacuum System

The applications of pneumatic actuators have been extending widely in many fields as the most important executive elements. However, after the pneumatic actuator finished a stroke, the compressed air in the original working chamber is exhausted directly into the atmosphere without any use, and the exhausted-air has the capacity for work yet. If some of the air can be reclaimed for reutilization, which has momentous significance and economic value for the energy-saving system. In this paper, a new method on exhaust energy saving is proposed to solve the problem.An original exhausted-air reclaiming technical method has been presented, that is to say, compressed air energy is transformed into vacuum energy through the vacuum ejector, which is storaged in the vacuum tank for reutilization in order to realize the aim to save energy.The main contents in this dissertation are summarized as follows:(1) In order to analyze the vacuum system performance, a constitution form of the vacuum system has been studied, and then the corresponding mathematical model of the system has been built up, this established the theoretical foundation for experiment by simulation.(2) Some experiments are done on vacuum generator system to study the vacuum system performance, and the rules of additive vacuum ejector affecting on pressure in chamber and on the piston's movement characteristic are acquired.(3) In order to study the matching relationship between compressed air consumption and vacuum ejector, the theoretical analysis has been done on vacuum generator process, and the theoretical matching relation expression between working parameters and flowing area. It provides a theoretical basis for optimizing the performance of vacuum generator system.(4) The evaluation method of the exhausted-air reclaiming efficiency is given in order to analyze the reclaiming effect of the system, and the analysis show that the exhausted-air reclaiming efficiency is relative to the initial vacuum of the vacuum tank, etc. With the vacuum of the vacuum tank going up, the system's efficiency declines gradually.Take following patterns for instance: When the supply pressure is 0.5MPa, the type of vacuum ejector is ZH15D, the cylinder diameter is 32mm. If the initial vacuum of the vacuum tank is zero, the system's efficiency will be higher than 70%; if the initial vacuum of the vacuum tank is 37kPa; the system's efficiency is going to be about 16%.The results prove that the vacuum generator system not only have obvious energy-saving effect, but also have good application prospects.