經典型真空產生器產品結構

CLASSIC PUMPS MULTI-STAGE PUMPS:PRINCIPLE OF OPERATION

MULTI-EJECTOR

Larger capacity vacuum pumps are created by placing identical nozzle sets in a parallel configuration, either in the same body or in a stacking module. Additional vacuum flow capacity is attained but maximum vacuum level is not affected since that is determined by the nozzle series. This method provides a specific repeatable increment of capacity increase that is very handy when sizing a pump for an application since the basic shape of the performance curve doesn't change. Vacuum flow and air consumption is increased in proportion to the number of nozzle sets, and system evacuation time is decreased proportionately.

HIGH FLOW MODE

An air supply to the pump is turned on and high-pressure air flows thru the first nozzle, generating a vacuum flow when it passes into the second nozzle. As air is evacuated from the system,induced air flows into the vacuum port and is drawn into the first stage ejector (gap between first and second nozzles) and combines with the compressed air flow from the first nozzle before passing into the second stage ejector (gap between second and third nozzle). The powerful combind airflow induces a high vacuum flow rate thru the second stage ejector until the increasing vacuum level causes the flap check valve to close. The valve closing point is dependent on nozzle series (A, E, L, M, ML, or X) and the operating air pressure. For example at 87 psi the flap valve will close at 11" Hg for an ML-series pump and at 18'' Hg for an E-series pump. This closing is evident by the change in slope of the performance curve.