CENTRIFUGAL COMPRESSOR AND DIFFUSER FOR THE CENTRIFUGAL COMPRESSOR

Title:

CENTRIFUGAL COMPRESSOR AND DIFFUSER FOR THE CENTRIFUGAL COMPRESSOR

Document Type and Number:

WIPO Patent Application WO/1997/033092

Kind Code:

A1

Abstract:

In a multi-stage centrifugal compressor having a plurality of impellers fitted to one shaft or in a single-stage centrifugal compressor, a vaned diffuser having a plurality of vanes is disposed on the downstream side of the impellers, and a vaneless diffuser part is disposed on the downstream side of the vaned diffuser. The vaned diffuser is the one that has a small solidity, and the meridian section of two wall surfaces forming the vaneless diffuser part is such that the height of their flow path decreases gradually towards the downstream side. The ratio between the heights of the flow paths at the inlet and the outlet of the vaneless diffuser is from 0.3 to 0.6. A second vaned diffuser having several vanes may be disposed in place of this vaneless diffuser. In this case, too, the two wall surfaces that form the second vaned diffuser form a shape which becomes smaller towards the downstream side. In either case, the efficiency of the compressor is improved by the vaned diffuser, and since the flow path is contracted on the downstream side of the vaned diffuser, stall of rotation which is liable to occur in the impeller having a low specific rate is avoided.

Inventors:

KOBAYASHI HIROMI (JP)
NISHIDA HIDEO (JP)
TAKAHASHI KAZUKI (JP)
EINO TAKASHI (JP)

Application Number:

PCT/JP1996/000541

Publication Date:

September 12, 1997

Filing Date:

March 06, 1996

Export Citation:

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Assignee:

HITACHI LTD (JP)
KOBAYASHI HIROMI (JP)
NISHIDA HIDEO (JP)
TAKAHASHI KAZUKI (JP)
EINO TAKASHI (JP)

International Classes:

F04D29/44; (IPC1-7): F04D29/44

Foreign References:

JPH05133397A	1993-05-28
JPH0520597B2	1993-03-19

Other References: