Mag drive pumps with external flushing did replace pumps with double mechanical seals
Picture: MUNSCH heavy-duty Mag Drive Pump series CM with external barrier fluid
At a production site for crop science chemicals mag drive pumps with external flushing did replace most of the pumps with double mechanical seals even though, fluids were more than challenging in most cases. Today this solution is well trusted and has become a standard so-lution even to other factories on site. A way to imitate?
The idea to place a centrifugal mag drive pump back to where it once failed (i.e. because sticky impurities blocked the mag drive’s lubrication) resulted from a careful consideration of eco-nomical and operational needs. The reason was that a pump with mechanical seals, a well- proven standard with critical fluids, requires a set of instrumentation and controls as well as the knowledge to start and operate the system safely.
Because the fluids pumped in crop science often require high environmental and other safety standards, a cheap solution is definitely barred.
Here, the German chemical pump specialists MUNSCH introduced a simple yet safe alternative:
A ½‘’ pipe, attached to the mag drives standard flushing connections, and filled with a clean liquid provides for a sufficient cooling and lubrication of the mag drive unit and plain bearings. The plain bearing’s design prevents the clean liquid from leaving the area and protects the mag drive unit from contamination by the pumped fluid.
The amount of barrier liquid is enough to operate the pump within its limits up to a pump speed of 3’000 rpm. The liquid level receives visual checks by means of a sight glass once per week and an occasional re-fill even less often.
The barrier system works without pressure and hermetically sealed by valves. The pump does not need any additional monitoring and controls. In fact, all pumps installed run successfully with this simple configuration.
The amount of pumps being safely operated at a large integrated chemical site in Germany provides the necessary safety for this solution and offers an alternative way for future inter-ventions to other operators running mag drive pumps with contaminated fluids.
Source & Picture: MUNSCH Chemie-Pumpen GmbH