An ejector includes a nozzle, a body including a refrigerant suction port and a pressure increasing portion, a passage forming member inserted into the nozzle, and an actuation device moving the passage forming member. A nozzle passage includes a smallest passage cross-sectional area portion, a convergent portion, and a divergent portion. The passage forming member includes a tip portion which changes the passage cross-sectional area at the smallest passage cross-sectional area portion when the actuation device moves the passage forming member. A positive displacement amount is defined as an amount of a displacement of the passage forming member when the passage forming member is moved so as to increase the passage cross-sectional area at the smallest passage cross-sectional area portion. The tip portion has a shape in which an increase rate of the smallest passage cross-sectional area portion is increased according to an increase of the positive displacement amount.

An ejector includes a nozzle, a body including a refrigerant suction port and a pressure increasing portion, a passage forming member inserted into the nozzle, and an actuation device moving the passage forming member. A nozzle passage includes a smallest passage cross-sectional area portion, a convergent portion, and a divergent portion. The passage forming member includes a tip portion which changes the passage cross-sectional area at the smallest passage cross-sectional area portion when the actuation device moves the passage forming member. A positive displacement amount is defined as an amount of a displacement of the passage forming member when the passage forming member is moved so as to increase the passage cross-sectional area at the smallest passage cross-sectional area portion. The tip portion has a shape in which an increase rate of the smallest passage cross-sectional area portion is increased according to an increase of the positive displacement amount.

An ejector includes a nozzle having a fluid passage circular in cross section. The fluid passage includes a throat portion smallest in cross-sectional area, a divergent portion that becomes larger in cross-sectional area toward a downstream side from the throat portion, and an ejection port that is provided at a downstream end of the divergent portion. A passage wall surface of the divergent portion includes a recess portion that is recessed from within outward in a radial direction of the passage wall surface. The recess portion is located adjacent to the ejection port, and the recess portion extends continuously in a circumferential direction of the passage wall surface to enclose the fluid passage and have an annular shape. Accordingly, noise due to an expansion wave of the ejected fluid can be reduced.

An ejector includes a nozzle having a fluid passage circular in cross section. The fluid passage includes a throat portion smallest in cross-sectional area, a divergent portion that becomes larger in cross-sectional area toward a downstream side from the throat portion, and an ejection port that is provided at a downstream end of the divergent portion. A passage wall surface of the divergent portion includes a recess portion that is recessed from within outward in a radial direction of the passage wall surface. The recess portion is located adjacent to the ejection port, and the recess portion extends continuously in a circumferential direction of the passage wall surface to enclose the fluid passage and have an annular shape. Accordingly, noise due to an expansion wave of the ejected fluid can be reduced.

A device for determining a concentration of at least one gas in a sample gas flow by infrared absorption spectroscopy. The device includes an infrared radiation source which emits a radiation which is conducted through an analysis cell, a feed line, the sample gas flow which is conducted into and out of the analysis cell via the feed line, a detector which measures an absorption spectrum arising in the analysis cell, a suction jet pump which includes a propellant gas connection, and a propellant gas line which extends to the propellant gas connection of the suction jet pump. The suction jet pump is arranged downstream of the analysis cell and feeds the sample gas flow through the analysis cell via the feed line. The propellant gas line includes a regulating valve which regulates a propellant pressure in the propellant gas line.

A device for determining a concentration of at least one gas in a sample gas flow by infrared absorption spectroscopy. The device includes an infrared radiation source which emits a radiation which is conducted through an analysis cell, a feed line, the sample gas flow which is conducted into and out of the analysis cell via the feed line, a detector which measures an absorption spectrum arising in the analysis cell, a suction jet pump which includes a propellant gas connection, and a propellant gas line which extends to the propellant gas connection of the suction jet pump. The suction jet pump is arranged downstream of the analysis cell and feeds the sample gas flow through the analysis cell via the feed line. The propellant gas line includes a regulating valve which regulates a propellant pressure in the propellant gas line.

A bleed system including a jet pump system configured to provide a supply gas comprising at least one of a higher pressure gas, a lower pressure gas, or a mixture of the higher pressure gas and the lower pressure gas. A needle body defines a throat region between a nozzle wall and the needle body. The needle body is configured to cause a gap between a rear needle surface of the needle body and the nozzle wall to decrease as the rear needle surface extends toward the throat region. The jet pump system is configured to discharge the higher pressure gas through the throat region and mix the higher pressure gas and the lower pressure gas in a mixing portion of an exhaust portion.