As the core equipment for polymer material polymerization and transportation processes, the melt gear pump typically operates under high-temperature and high-pressure conditions. Under these circumstances, the shaft sealing performance directly affects the stability of the equipment and production safety. Once the seal fails, it not only impacts continuous production but may also cause safety accidents. Therefore, selecting the appropriate type of shaft seal for different operating conditions is crucial.
Currently, the commonly used shaft sealing solutions for molten gear pumps mainly encompass six types. Packing seals are a relatively common configuration due to their simple structure and cost-effectiveness. Magnetic seals achieve stable operation and low wear through non-contact transmission, offering a longer service life. Lip seals combined with packing seals balance flexibility and reliability. Single-face or double-face mechanical seals offer superior sealing performance, achieving minimal or even zero leakage of the medium, making them suitable for situations with strict leakage requirements. For high-temperature conditions, spiral seals combined with external cooling perform excellently, while the combination of spiral seals + external cooling + packing further enhances the adaptability and reliability of the sealing system.
Overall, the selection of the sealing method needs to be systematically evaluated in combination with the characteristics of the medium, operating temperature, pressure, and operating environment in order to ensure the long-term stable and safe operation of the melt gear pump.