Rotary ram-in compressor

Abstract

A rotary ram-in compressor for use in gas turbine engines and the like, having a plurality of vanes attached to discs, with the opposing parts of each two adjacent vanes defining a feeding channel in-between. In operation, working gases are rammed through the feeding channels, followed by positive displacement of the rammed-in gases to a receiver wherein pressurized gases collect. The pressurized gases are actively swept from the receiver by either a successive rotary ram-in compressor or a successive rotary ram compressor.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a positive displacement compressor and, more particularly, to a rotary positive displacement compressor convenient for use in gas turbine engines and the like. DESCRIPTION OF PRIOR ART [0002] Rotary compressors are well known devices, used in several fields to develop a pressure gradient between two points across a stream of working gases. Two main types of rotary compressors are in use, dynamic compressors, i.e., centrifugal flowing, axial flowing, and the combined types, and positive displacement compressors. In dynamic compressors the working gases are accelerated followed by its deceleration within diverging passages, wherein part of its kinetic energy is converted into static pressure rise. In positive displacement compressors the pressure is increased by reducing the specific volume of the gases during their passage through the compressor. [0003] Dynamic Compressors are widely in use in gas turbine and steam engine...

AI Technical Summary

Benefits of technology

[0004] The present invention provides a rotary positive displacement compressor having no rubbing parts within, which allows its use in the applications wherein relatively high operating rotational speeds are needed.

[0009] In a preferred embodiment, a rotary ram compressor is used for active sweeping of gases from the compressor's receiver, as the static pressure rise developed within its diverging channels prevents excess flow of pressurized gases from the receiver through its channels, regardless of the pressure level developed within the receiver, with the density and the pressure level of the gases within the receiver being dependant on the ratio between the volumetric rate with which gases are fed to the receiver by the compressor (which depends on the number of its feeding channels, and their dimensions and velocity) and the volumetric rate with which gases are swept from the receiver by the rotary ram compressor (which depends on the number of its channels, the dimensions of its channels' inlets, and their velocity).

[0010] In another preferred embodiment, a successive rotary ram-in compressor is used for active sweeping of gases from the compressor's receiver, as the static pressure rise developed within the receiver of the second rotary ram-in compressor prevents excess flow of gases from the receiver of the first rotary ram-in compressor through the feeding channels of the second rotary ram-in compressor, with the density and the pressure level of the gases within the receiver of the first rotary ram-in compressor being dependant on the ratio between the volumetric rate with which gases are fed to the receiver and the volumetric rate with which gases are swept from it.

[0013] The velocity of the feeding channels of the ram-in compressor is kept below the speed of sound, to avoid the formation of shock waves, which if formed will interfere with the free ingestion of gases by the feeding channels, and thus, the maximum allowable pressure level within the receiver will be around double that of the pressure of gases at the compressor's inlet (at which the speed of back flow of the pressurized gases from the receiver to the feeding channels will be almost equivalent to the speed of sound), with most of the provided pressure rise within the receiver being due to increased density of the working gases.

Problems solved by technology

On the contrary, conventional types of positive displacement compressors are not convenient for use in gas turbine engines, and the like, as the friction between the rubbing parts within them limits their practically useful range of operating rotational speeds.

Images