| 摘要 |
The invention relates to gas-operated pressure oscillation generators of the diaphragm valve type, particularly pneumatically operated sound emitters used in cleaning inside spaces of furnaces, heat exchangers and similar apparatus, through which gas is flown such as hot flue gases or exhaust gases from chemical processes tending to form a dust deposit on the surfaces in the space. In such cleaning operations gas-carried pressure oscillations of sound or infrasound frequency are used for physically actuating the dust of the deposit. In such applications it is necessary to cool the interior of the pressure oscillation generator and to blow away dust particles in order not to jeopardize or impair the operation of the generator. According to the invention, a scavenging gas at substantially lower pressure than that of the operating gas is supplied to the interior of the pressure oscillation generator through one or more scavenging gas openings (16) in the seat (7) of the diaphragm valve, said openings being arranged adjacent the surface (10) of the seat engaged by the diaphragm (11). |
