The present invention relates to a device (1, 30) for the recirculation of an at least partially gaseous composition containing hydrogen, wherein the device (1, 30) is a dry rotary pump comprising a first rotating shaft (13) and a second rotating shaft (14) driving respectively a first piston with claws (8) and a second piston with claws (9) in rotation in a pumping chamber (2) comprising an inlet orifice (11) and an outlet orifice (10) for the gaseous composition, the first rotating shaft (13) and the second rotating shaft (14) being configured to be driven in rotation by a drive system (17,18) situated in a gear chamber (4), wherein the device (1, 30) comprises a first pair of seals (19) and a second pair of seals (20), each comprising a first shaft seal (19a, 20a) and a second shaft seal (19b, 20b), the first pair of seals (19) being provided around the first rotating shaft (13) and the second pair of seals (20) being provided around the second rotating shaft (14) between the pumping chamber (2) and the gear chamber (4), wherein the device (1, 30) comprises a pressure equalization chamber (25) which is in fluid connection with a gap (24) present between the first shaft seal (19a, 20a) and the second shaft seal (19b, 20b) of the first and of the second pair of seals (19, 20) to regulate the pressure in the gap (24), wherein the gear chamber (4) is in fluid connection with the gap (24), and wherein the pumping chamber (2) is in fluid connection with the first shaft seal (19a) of the first pair of seals (19) and with the first shaft seal (20a) of the second pair of seals (20) by means of a pulsation attenuation chamber (22). The present invention also relates to a fuel cell system (40, 50, 60, 70, 80, 90) comprising a device for recirculation according to the present invention.

The subject invention pertains to a method and apparatus for an orientation independent compressor. The subject compressor can be part of a vapor compression cycle system, and can use one or more of a variety of working fluids, including, but not limited to, refrigerants such as r-134a, r-22, CO.sub.2, and NH.sub.3. Embodiments of the compressor can utilize positive displacement apparatus to compress the vapor. In a specific embodiment, the compressor can incorporate an oil-lubricated rotary lobed type positive displacement compressor. In a further specific embodiment, the working fluid vapor can be a refrigerant, such as r-134a, incorporating entrained oil, such as miscible lubricating oils. An example of such a miscible lubricating oil that can be used is polyester (POE) oil.

A dry rotary pump for recirculating an at least partially gaseous composition containing hydrogen. The dry rotary pump comprising a first rotating shaft and a second rotating shaft. The first rotating shaft and the second rotating shaft are driven in rotation by a drive system in a gear chamber. The dry rotary pump comprises a first pair of seals and a second pair of seals, each comprising a first shaft seal and a second shaft seal. The dry rotary pump comprises a pressure equalization chamber in fluid connection with a gap between the first shaft seal and the second shaft seal to regulate pressure in the gap. The gear chamber is in fluid connection with the gap, and the pumping chamber is in fluid connection with the first shaft seal and the first shaft seal by a pulsation attenuation chamber.

Devices, systems, and methods, include an oxygen delivery device that includes an oxygen delivery module, at least one sensor to detect patient breathing, and a controller configured to control the oxygen delivery module to cause the oxygen delivery module to deliver oxygen to the patient based on data from the at least one sensor such that in response to a determination, based on data from the at least one sensor, that no breathing is detected for a first pre-determined period of time, the controller causes the oxygen delivery module to deliver oxygen to the patient in continuous flow mode, and in response to a determination, based on additional data from the at least one sensor, that breathing is detected for a second period of time, the controller causes the oxygen delivery module to deliver oxygen to the patient in a pulse flow mode.

An oxygen delivery device includes an oxygen delivery module configured to deliver a pulse including greater than 100 mL of concentrated oxygen, and a controller configured to control the oxygen delivery module to cause the oxygen delivery module to deliver the pulse including greater than the 100 mL of the concentrated oxygen within approximately first 60% of a patient's inspiratory period. A device includes an oxygen delivery module, a piezoelectric valve coupled to an output of the oxygen delivery module to receive the concentrated oxygen, a driver to electrically actuate the piezoelectric valve, and a controller to control the driver to cause controllable actuation of the piezoelectric valve by the driver to cause controllable opening of the valve to enable oxygen flow to be directed for inhalation by a patient via the piezoelectric valve.

Disclosed are devices, systems, and methods, including an oxygen delivery device that includes an oxygen delivery module to produce at least concentrated oxygen, and a gas moving device to deliver air to the oxygen delivery module. The gas moving device includes at least one piston rotatable inside a first chamber defined in a housing, the rotational movement of the at least one piston inside the first chamber resulting in varying pressure generated in a first portion of the first chamber, and a vane member rigidly coupled to the at least one piston, the vane member being configured to move inside a vane chamber defined in the housing, the piston and the vane rigidly coupled to the piston define the first portion of the first chamber and a second portion of the first chamber.