JPH0960734A - Recovery device for leaked gas in dry gas seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent environmental pollusion, and concurrently, contribute to resource saving by recovering process gas leaked out of the primary seal of a dry gas seal. SOLUTION: A cushion tank 3 holding equilibrium in pressure is provided for a small compressor 2 and its suction side in a gas leak line 1 for process gas leaked out of the primary seal of a dry gas seal, and process gas boosted in pressure by the small compressor 2 is returned to a process gas line so as to be recovered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recovering process gas leaked from a dry gas seal of a turbomachine or the like.

[0002]

2. Description of the Related Art An example of a conventional dry gas seal for a turbomachine is shown in FIG. The process gas used for the primary seal of the dry gas seal 10 is sent to the inner seal chamber 23 through the filter 21 and the pressure control valve 22. The seal pressure of the inner seal chamber 23 is regulated by the pressure control valve 22 so as to be slightly higher than the pressure inside the housing 24.

A portion of the process gas entering the inner seal chamber 23 passes through the labyrinth 25 into the housing 24 and the remainder exits the outer seal chamber 27 through the primary seal 26. Most of the process gas entering the outer seal chamber 27 is the orifice 28.
It is depressurized at and sent to the flare or released to the atmosphere, but partly passes through the secondary seal 31 into the chamber 30.

In order to prevent the process gas that has entered the chamber 30 from leaking to the outside of the machine, an inert gas such as nitrogen is supplied into the chamber 30 through the purge line 29.
It is released into the atmosphere along with the leaked process gas.

[0005]

However, when environmental pollution and resource saving have been promoted recently, there remains a problem in that expensive process gas that leads to ozone layer depletion is not recovered.

[0006]

The present invention has been invented to solve the above-mentioned problems, and the gist of the first invention is that the process gas leaked from the primary seal of the dry gas seal is In a dry gas seal, characterized in that a leak gas line is provided with a small compressor and a cushion tank for maintaining pressure equilibrium on its suction side, and the process gas boosted by the small compressor is returned to the process gas line and recovered. It is in the leak gas recovery device.

The gist of the second aspect of the invention is to provide a small compressor and a cushion tank for maintaining pressure balance on the suction side of the small gas compressor in the leak gas line of the process gas leaked from the primary seal of the dry gas seal. The purpose is to recover the liquid by condensing and liquefying the process gas whose pressure has been increased by the compressor.

[0008]

DETAILED DESCRIPTION OF THE INVENTION One embodiment of the present invention is shown in FIG. A small compressor 2 of reciprocating type or diaphragm type is provided in the leak gas line 1 for guiding the process gas leaked from the primary seal of the dry gas seal, and a cushion for maintaining pressure balance is provided on the suction side of the small compressor 2. Tank 3 is installed.

The leaked gas whose pressure is increased by the small compressor 2 is supplied to the process line 4 and recovered. Further, a condenser 6 is provided in a line 5 branched from the process line 4, in which the leak gas is condensed and liquefied by exchanging heat with the cooling liquid supplied through the cooling liquid lines 7 and 8 and recovered in this state. You can also

However, when the small compressor 2 is operated, pulsation occurs on the suction side thereof, and if the dry gas seal becomes negative pressure, it may be damaged. Even if the dry gas seal does not become negative pressure, the pulsation is controlled by the dry gas seal. May disturb
Since the cushion tank 3 is arranged on the suction side of the compact compressor 2, the cushion tank 3 can prevent pulsation of the leak gas line 1 and maintain a positive pressure.

[0011]

According to the recovery device of the present invention, since an expensive process gas that may destroy the atmospheric ozone layer can be recovered, it is possible to prevent environmental pollution and contribute to resource saving.

Further, since the cushion tank is provided on the suction side of the small compressor, it is possible to prevent the pulsation accompanying the operation of the small compressor from acting on the dry gas seal, which facilitates the control of the dry seal and It is possible to prevent damage.

[Brief description of drawings]

FIG. 1 is a system diagram showing a recovery device according to an embodiment of the present invention.

FIG. 2 is a system diagram of a conventional dry seal.

[Explanation of symbols]

 1 Leakage gas line 2 Small compressor 3 Cushion tank 6 Condenser

Claims (2)

[Claims] 1. A small compressor and a cushion tank for maintaining pressure equilibrium on its suction side are provided in the leak gas line of the process gas leaked from the primary seal of the dry gas seal, and the process gas boosted by the small compressor is supplied. A leak gas recovery device for a dry gas seal, which is returned to the process gas line for recovery. 2. A small compressor and a cushion tank for maintaining pressure equilibrium on the suction side are provided in the leak gas line of the process gas leaked from the primary seal of the dry gas seal, and the process gas boosted by the small compressor is provided. A leak gas recovery device for a dry gas seal, characterized by condensing and liquefying with a condenser.