Vacuum Generators

Vacuum generators operate according to the Venturi principle. Compressed air flows from the pressure supply port into the ejector and constriction in the nozzle increases the flow of air to supersonic speed. After exiting the nozzle, air expands and flows through the nozzle into the outlet port (or silencer). A vacuum is created in the chamber between the venturi and receiver nozzles which causes air to be drawn in from the vacuum port. Vacuumed air and exhaust air both leave from the outlet. Only unlubricated compressed air is used since lubricated can suck in dust and dirt impairing the suction performance. There are two basic kinds of vacuum generators: ejectors and vacuum units. Ejectors can be further categorised into three types. Basic ejectors are air-tight workpieces while compact ejectors possess an air-saving regulation which means vacuum generation is only switched on once the value falls below a preset minimum. Finally, there are ejector modules. By contrast, vacuum units include an ejector, monitoring and control, which turns off automatically and are considered stand-alone devices. All types of vacuum generators are predominantly found in industry for robot applications, sheet metal processing and feeder applications. They are widespread in the automobile industry too.