Serial type dry gas sealing device, application of serial type dry gas sealing device to light dydrocarbon pump and application method of serial type dry gas sealing device on light dydrocarbon pump

The invention discloses a serial type dry gas sealing device, application of the serial type dry gas sealing device to a light dydrocarbon pump and an application method of the serial type dry gas sealing device on the light dydrocarbon pump. The serial type dry gas sealing device comprises a mechanical sealing mechanism and a dry gas sealing mechanism which are arranged between a pump shaft and a shaft sleeve in a serial connection manner. The mechanical sealing mechanism is arranged close to the medium side, and the dry gas sealing mechanism is arranged close to the atmospheric side. According to the application of the serial type dry gas sealing device to the light dydrocarbon pump, the serial type dry gas sealing device is mainly applied to storage and transportation of C4 or C5 hydrocarbon substances. The application method of the serial type dry gas sealing device on the light dydrocarbon pump comprises the sealing assembling step, the sealing flushing step and the sealing achieving step. By means of the serial type dry gas sealing device, the sealing effect has dual guarantees, a large number of C4 or C5 hydrocarbon substances can be effectively prevented from leaking into the atmosphere through the application of the serial type dry gas sealing device to the light dydrocarbon pump, and zero leakage of conveying media in a C4 or C5 pump room can be achieved. According to the application method of the serial type dry gas sealing device, safe and stable running of the pump can be achieved, and the safe sealing and the sealing effect can be guaranteed under the state that the pump is started and normally runs.