| 摘要 |
PURPOSE:To make it possible to prevent trouble of a pump caused by corrosive gas and reacted products by controlling the opening of a control valve for a gas leading hole in such a way that the difference of the pressure between flowing seals with the pressure in a gear chamber is set to be usually at a predetermined positive pressure. CONSTITUTION:A gas leading hole 39 is provided between the first floating seal 23-a and the second floating seal 23-b, being capable of floating toward a rotor side. The pressure P1 between the floating seals 23-a and 23-b and the pressure P2 in a gear chamber 18 are converted into electric signals proportional to the pressure P1 and P2 and led to a controller 44. Further, to the gas leading hole 39, a seal gas leading piping 42 having a control valve 43 is connected. The opening of the control valve 43 is controlled by the controller 44 so as to control the flow rate of the seal gas in such a way that P1-P2 is usually set at a predetermined positive pressure. Thus, the condition of P1>P2 can be set, even when gas generating corrosive gas and reacted products is used, it is possible to perfectly perform the shaft seal of the gear chamber 18 on a discharge side which is under the severe condition.
|
