Canned-motor pump technology has multiple advantages
Hermetic-Pumpen
Canned-motor pump technology (photo) provides significant advantages and often constitutes a low-priced alternative to conventionally sealed pumps and magnetically coupled installations with external drive, since there are no long shafts or complex cooling and lubrication systems of mechanical seals. In conventionally sealed submersible pumps (that is, those equipped with mechanical seals), and also in magnetically coupled in-tank pumps, the motor is installed at the outside of the vessel. Depending on the immersion depth of the pump, this results in a correspondingly long shaft to connect the pump hydraulics to the drive motor. This kind of shaft is fixed, for example, using fluid-lubricated slide bearings, which are typically installed at distances of approximately 1.2–1.6 m. Statistically speaking, however, the probability of failures increases with each bearing. The installation of a submersible canned-motor pump provides a cost-efficient and reliable alternative. Thanks to the hermetically sealed design of the drive unit, which consists of the hydraulic and the motor, it can be completely immersed in the tank. Only the discharge pipe and the electrical connection are routed through the tank cover via the manhole plate out of the vessel. This company’s canned-motor pump also provides a monitoring concept that monitors the safe operation of the pump via installed sensors. In addition to operating temperature, liquid level and motor load, the specially developed MAP system can be integrated. It continuously monitors the position of the rotor and is therefore a reliable indicator for unintended operating states and wear. — Stand N21 — Hermetic-Pumpen GmbH, Gundelfingen, Germany