Sage Journals: Discover world-class research

Abstract

This paper deals with a rotary positive-displacement machine with built-in compression, the study of which is usually neglected in courses on fluid machinery for mechanical engineering students. First, the working principles of the claw rotor compressor are presented; then basic thermodynamic considerations, leading to the formulation of volumetric efficiency, are reported. The volumetric efficiency of the compressor is reviewed as a function dependent on filling and leakages, leading to the definition of the delivery efficiency. Considering the filling efficiency alone, formulated according to a thermodynamic analysis of the closed system, it is possible to determine the limit pressure ratio that causes no flow from the compressor. The ideal work is also formulated and a comparison with the sliding vane compressor is made. Some considerations that deprive the compressor of its ideality are advanced in order to avoid misleading conclusions.

Keywords

claw rotor compressor thermodynamics filling efficiency ideal work

Get full access to this article

View all access options for this article.

References

Catalano

L. A.

Napolitano

, Elements of Fluid Operating Machines, (Pitagora, 1998; in Italian).

Ferrari

, Hydraulic and Thermal Machines, (Esculapio, 2007).

Cherkassky

V. M.

, Pumps, Fans, Compressors, (Mir Publishers, 1985).

Bloch

H. P.

Hoefner

J. J.

, Reciprocating Compressors: Operation and Maintenance, (Elsevier Gulf, 1996).

Ritchie

J. B.

Patterson

, ‘Geometry and leakage aspects of involute rotors for the Roots blower’, Proc Institution of Mechanical Engineers, 183(pt. 1, no. 36) (1968–69), 707–721.

Litvin

F. L.

Fuentes

, Gear Geometry and Applied Theory (Cambridge University Press, Cambridge, 2004).

Patterson

Ritchie

J. B.

, ‘Roots blower performance’, Int. J. Mechanical Science, 11 (1969), 575–593.

Driver

R. W.

, ‘Expression for the maximum efficiency of compression of a Roots air compressor’, Proc. Institution Mechanical Engineers, Part A: Power and Process Engineering, 200(2) (1986), 101–104.

Stone

C. R.

, ‘The efficiency of Roots compressors and compressors with fixed internal compression’, Proc. Institution Mechanical Engineers, Part A: Power and Process Engineering, 202(3) (1988), 199–205.

10.

Wycliffe

, Rotary Positive Displacement Fluid Machines, GB patent no. 2088957 (1982).

11.

Wycliffe

, Mechanical Pumps, US patent no. 4504201 (1985).

12.

Wycliffe

, ‘Mechanical high vacuum pumps with an oil free swept volume’, J. Vacuum Science Technology A: Vacuum, Surfaces, and Films, 5(4) (1987), 2608–2611.

13.

Ioffe

I. V.

Koss

V. A.

Gray

Livesey

R. G.

, ‘Modeling of a multistage claw rotor vacuum pump’, J. Vacuum Science Technology A: Vacuum, Surfaces, and Films, 13(3) (1995), 536–539.

14.

Peng

Xing

Shu

, ‘Thermodynamic analysis of the rotary tooth compressor’, Proc. Institution Mechanical Engineers, Part A: Journal of Power and Energy, 216(4) (2002), 321–327.

15.

Hsieh

C. F.

Hwang

Y. W.

Fong

Z. H.

, ‘Study on the tooth profile for the screw claw-type pump’, Mechanism and Machine Theory, 43(7) (2008), 812–828.

16.

Brown

R. N.

, Compressors: Selection and Sizing, (Elsevier Gulf, 1997).

17.

Troup

A. P.

Dennis

N. T. M.

, ‘Six years of dry pumping – a review of experience and issues’, J. Vacuum Science Technology A: Vacuum, Surfaces, and Films, 9(3) (1991), 2048–2052.

Adding the Teaching of Claw Rotor Compressors to Fluid Machinery Courses

Abstract

Keywords

Get full access to this article

References