The operation characteristics and the energy-saving based importance of water steam ejector was analyzed, the effect of the ejector in practical use was presented.

The vacuum system process of PET unit, the design of EG steam ejector shape and support, the selection of support spring and the main points in the ejector pipe design are introduced.

The property of steam ejector is analyzed. The optimize method of temperature curve and an algorithm of intelligent predictive pressure control are presented. The optimize control system is designed.