Constant wide range temperature cycling causes many problems for most pumps. The ongoing expansion and contraction of dissimilar materials can cause premature wear and tear on parts and seals. To prevent the premature deterioration of critical components, Teikoku USA and Chempump offer canned motor pump solutions that maintain a constant temperature in the motor housing, unaffected by the temperature fluctuations of the process fluid. Here’s how it works:
Non-cooled BX-Type features the X High Temperature motor design used with the externally cooled circulation path to isolate the liquid in the motor section of the pump. The fluid in the motor section is circulated through the motor by an auxiliary impeller located on the rotor. It then exits the motor via an external circulation line, is cooled by the ambient temperature of the environment and then reenters the motor to lubricate the bearings and cool the motor. High temperature motor windings allow the motor to operate at higher temperatures. Once the pump reaches its equilibrium point, the motor temperature remains constant regardless of the process fluid temperature.
Because the fluid used in the motor section circulation is returned behind the pump impeller, BX style pumps are also ideal for constant high temperature, non-cooled service where system NPSHA is relatively low. In Heat Transfer Fluid circulation systems featuring condensate fed suction vessels, this is particularly beneficial. BX Type pumps, by design will offer the lowest NPSHR of any other sealless pump because the circulated fluid is never returned to the eye of the impeller. Teikoku USA and Chempump can fit the hydraulics with the lowest NPSHR to the BX motor to maximize NPSHA vs. NPSHR margin for longest possible operating life.