Celeroton converters allow for the monitoring of the operating status of a turbo compressor. Hence, the pumping of the compressor and potentially resulting system damage can be avoided.
If the mass flow (or volume flow) of a turbo compressor drops below its permitted minimum value, the pressure ratio cannot be maintained anymore, which results in a cyclical increase and decrease of the mass flow and the pressure ratio. This unfavourable operating status is called pumping. Pressure surges, which occur during pumping, can damage the compressor and the whole system in the long run. Therefore, this operating status should be implicitly avoided.
The minimal mass flow, which is necessary for a secure operation, is dependent on the pressure ratio and is depicted in the compressor performance map as the surge line. The area on the left hand side of the surge line cannot be covered by the compressor without special measures (grey marked area in subsequent chart).
CT-17-700 compressor performance map with surge line and prohibited operating range (grey).
With the use of turbo compressors and converters from Celeroton, you have the possibility to detect the shortfall of the surge line and to avoid any corresponding system damage. If the turbo compressor is run close to the surge line, the converter will generate an appropriate warning. The user can display this warning via the interface of the converter (CAN, RS232/485 or digital/analogue outputs) and can subsequently perform a suitable countermeasure. Nevertheless, if there is pumping during operation of the turbo compressor, the converter will immediately recognise it and display a corresponding error message. In case of failure, the converter will automatically initiate a countermeasure, which returns the compressor in a safe and stable operating status. This countermeasure can be configured by the user. Options are an automatic reduction of the speed or a command to switch-on a side air-valve via the interface of the converter.