Pumps according to this special design conveying water-like media can handle a dry run on suction side for up to 10 minutes. The increase of the isolation shell surface temperature is relatively slight.
The RTZ Design also provides the following benefits for customers in comparison to standard design:
- Through the application of a non-metallic containment shell, the hydraulic efficiency increases since eddy current losses do not occur in the containment shell.
- Since eddy-current losses do not occur, a separate flush flow to cool the isolation shell can be eliminated.
Typical Application RTZ Design:
- Tank emptying in tank farms
- Batch-Process
Design Solution
In normal operation, a dedicated flush flow lubricates and cools the pump’s bearings. Even in case of a flow interruption on suction side, the lubrication and cooling of the bearings is guaranteed by our RTZ Design providing a liquid reservoir inside the isolation shell.
The acceptable dry run time is limited by the allowed temperature increase of the isolation shell surface. It is being calculated with semi-empirical methods and considering the characteristics of the pumped liquid.
