Multi-stage centrifugal compressor
AssigneeCaterpillar Tractor Co.
InventorJesse O. Wiggins
Life of this patent
Estimating the term…
Abstract
A centrifugal air compressor (11) has an annular air flow path (14) of progressively increasing diameter and progressively diminishing cross-sectional area in which a plurality of internal compression-diffusion stages (30) are provided. The stages of progressively greater diameter are defined by rows (29) of impeller (12) blades which are alternated with rows (32) of stator blades along the air flow path (14) and each such blade row (29, 32) has a diffusion factor below about 0.55 and a de Haller number above about 0.70. The multi-staged construction combines higher isentropic efficiency with reduced size and may be used as a component of a gas turbine engine (18) or a turbocharger (57) or for other purposes requiring gas compression.
Claims8
In a centrifugal compressor (11) having relatively rotatable inner (12) and outer (13) elements defining an annular flow path (14) therebetween, said flow path (14) including a substantially axially directed flow inlet end (16) and a flow outlet end (17) of greater diameter and a curved portion (20) between said flow inlet end (16) and said flow outlet end (17) that becomes progressively more radially directed as it approaches said flow outlet end (17), a series of compression-diffusion stages (30) in said flow path (14), each of said stages (30) including at least one of a series of compressor blade rows (29) and at least one of a series of diffuser blade rows (32), said compressor blade rows (29) being connected to one of said inner (12) and outer (13) elements and said diffuser blade rows (32) being alternated with said compressor blade rows (29) along said flow path (14) and being connected to the other of said inner (12) and outer (13) elements, each of said blade rows (29,32) having an inlet side (35i) and an outlet side (35o) located further along the flow path (14) than the inlet side (35i) the improvement comprising:
- each blade row of all said compressor and diffuser blade rows of said compression-diffusion stages (30) being located in said curved portion (20) of said flow path (14) having a mean radius increase between the inlet side (35i) thereof and the outlet side (35o) thereof which is in the range of from about 2% to about 15%.
A centrifugal compressor (11) comprising:
- an annular stator (13),
- an impeller (12) positioned for rotation in said stator (13) and being radially spaced therefrom by an annular air flow path (14) which has an air inlet end (16) and an air outlet end (17) of larger diameter and which has a curved portion (20) of progressively increasing outward curvature which extends from said air inlet end (16) to said air outlet end (17),
- a series of compressor blade rows (29) located in said curved portion (20) of said flow path (14) and being connected to said impeller (12) and a series of diffuser blade rows (32) located in said curved portion of said flow path and being connected to said stator (13), said diffuser blade rows (32) being alternated with said compressor blade rows (29) along said flow path (14), each of said compressor blade rows (29) in conjunction with an adjacent one of said diffuser blade rows (32) constituting one of a series of compression-diffusion stages (30) in said curved portion of said flow path (14), and
- each of said blade rows (29,32) of all of said compression-diffusion stages (30) having blade means (28,31) for providing a calculated design point diffusion factor below about 0.55 and a de Haller number greater than about 0.70, and (32) having a mean radius which increases in the range of from about 2% to about 15% between the inlet side (35i) and the outlet side (35o) thereof.
Dependencies are inferred from the claim text.