Chemical Technology January 2016

PETROCHEMICALS PUMPS & V VES

Another partial flow between the rotor and the can absorbs the heat and flows back through the rear bearing and the hollow shaft. Logically, the pump section and the rotor space have to be connected. This design is out of the question for fluids with high temperatures or fluids containing particles which must not enter the rotor space. So the two spaces are separated from each other in the corresponding design variant. For fluids with a low boiling point, such as ammonia or light hydrocarbons, another variant with the code HP is available. With these fluids a few degrees difference in temperature can cause vaporisation. This variant has been specifically designed to maintain the pressure in the rotor space at the same high level as the pressure produced by the main hydraulic system. An integrated auxiliary hydrau- lic system circulates the coolant and lubricant in the rotor space. This securely prevents vaporisation of the fluid in the rotor space and mechanical seals. The fourth variant of the new type series is based on the same design. The HS variant has been developed for solids-laden fluids. “Generally, the can is relatively thin between the rotor and stator in order to keep energy losses to aminimum,” explains Dr Kastrup. “When handling solids- laden fluids, solid particles can wear through the sheet metal and enter the stator space.” The HS variant covers applications with ferritic particles in the fluid, which would accumulate in the magnetic field of the motor and result in wear at the motor. Other applications this model caters for

are fluids which form deposits or polymerise quickly. KSB has developed a special sealing concept and cooling liquid flow paths which make the fluid passage reliable as well as energy-optimised. Ecochem HP variant has an integrated auxiliary hydraulic system that circu- lates the coolant and lubricant in the rotor space.

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Chemical Technology • January 2016