On equipping the unit with new multistage pumps the utmost value was set on an economical and energy saving operation, as well as on a long life cycle of the machines. Therefore multistage pumps with a max. speed of 1500 rpm have been chosen.

All pumps are equipped with an infinitely variable speed control by means of frequency converters, so that the performance of the pumps can be adjusted to the current consumption over the complete capacity range from approx. 40 to roughly 800 m3/h. The correct sizing of the pumps is made in such way, that the operating point of the machines always lie within the optimal efficiency on every demand. Through installation of an equally speed controlled jockey pump this is also guaranteed when the demands (night consumption) are very low.

The equipment of all pumps (incl. standby machine) with separate frequency converters not only helps to save electrial energy, due to the abolition of star-delta-relays resp. bypass-configurations, but also prevents water hammer during the switch-on and switch-off of the particular machines.

The present flow measurement is used for recording the consumption as well as for the increase of the discarge pressure, which is depending on capacity. Thus it is possible to compensate the pressure losses in the pipeline, which are depending on consumption, and therefore guarantee constant pressure levels in the town centre, no matter how much water is consumed.

The pressure regulation takes place via PI-controller and pressure transmitter. There are two of these appliances, as well as the automatic sequence control, due to reasons of safety. If one control unit has a malfunction the system automatically switches to the other one. (Source: Vogel Pumpen / 25 July, 2002)

Information & Contact:

Pumpenfabrik Ernst Vogel GmbH
Ernst Vogel-Strasse 2
A - 2000 Stockerau
phone +43 2266 604-0
fax +43 2266 65311