Abstract: A centrifugal compressor is provided with means to centrifugally accelerate a gas stream and to simultaneously centrifugally accelerate a stream of dense small solid particles and discharging both streams into a vane free radial diffuser to form a composite flow in which kinetic energy from the particles is absorbed by the gas molecules while the heat of compression of the gas is absorbed by the solid particles, the composite flow then entering a centrifugal particle separator to give a clean high pressure gas for subsequent utilization.

Abstract: A diffuser having a dual-stage configuration with the diffusing element of the first stage aligned perpendicularly to the second stage. The diffuser vanes of the first stage are inclined at an angle to the direction of flow so that the flow field between the first stage and the second stage changes from the conditions before diffuser starting to the conditions after diffuser starting to produce an effect similar to the change in flow cross section of a variable throat area diffuser. The second stage of the diffuser has its wall configured similar to the contour of a two dimensional ramjet inlet diffuser.