Abstract: A positive displacement, transverse flow, internally refluxing, rotary gas compressor which operates on a constant volume, variable mass, near-isothermal compression cycle. The compressor includes a pair of involutely lobed, intermeshed impellers that sweep gas from an intake port through the compressor housing to a discharge port in constant volume displacement cavities that are defined by the lobes of the impellers and the compressor housing walls. The cavities are effectively sealed against both the intake and discharge ports over upstream interior housing sidewall portions that extend from the intake port over an angle at least as great as the angle between adjacent lobes of the impellers. Downstream therefrom the interior housing sidewalls are spaced radially from the rotating impellers so as to allow limited reflux counterflow of discharge gas back into the advancing displacement cavities.

Abstract: A positive displacement, recirculating Root's type rotary compressor which operates on a constant volume, near isothermal cycle is disclosed. The compressor includes a pair of involutely lobed impellers and a discharge pressure reflux flow loop. The flow loop includes a discharge port, a flow distributor, an output port, and one or two pair of low impedance rectangular conduits terminating in linear nozzles that serve as reflux ports. Reflux flow through the nozzles is directed with impeller rotation. It isentropically expands into the constant volume displacement cavities so that the contained pressure approaches discharge level. The final pressure increase into discharge is gained through adiabatic compression at a low pressure ratio. The resulting process is inherently non-contaminating, as there are no valves and no contacting or rubbing parts in the flow stream. It can be applied wherever gases or vapors must be compressed.

Abstract: A positive displacement, recirculating Roots-type rotary gas compressor which operates on the basis of flow work compression is disclosed. The compressor includes a pair of large diameter recirculation conduits (30 and 32) which return compressed discharge gas to the compressor housing (16), where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers (12 and 14) and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize and accelerate gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, for example continuous pumping of natural gas in gas transmission facilities.

Abstract: A positive displacement, recirculating Roots-type rotary gas compressor which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits (24 and 26) which return compressed discharge gas to the compressor housing (14), where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers (10 and 12) and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor.

Abstract: A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor.