A throttle valve for a centrifugal compressor includes a body having a central passage and one or more diverter flow paths. The central passage is formed by an inner surface of the body, each diverter flow path has an inlet and an outlet, and the one or more diverter flow paths are configured to induce a swirl within a fluid flow through the central passage while a portion of the fluid flow passes through the one or more diverter flow paths. The throttle valve also includes at least one blade disposed within the central passage. The at least one blade is configured to direct the portion of the fluid flow to the inlets of the one or more diverter flow paths while the at least one blade is in a partially open position.

First and second towers may discharge air. An airflow guide or converter may change a direction of the air discharged from the first tower and the second tower by moving a gate inside and outside of at least one of the first or second towers so as to block discharged air flowing forward and selectively facilitate an upward air flow. The airflow converter may include a guide motor to provide a driving force, the gate, which may reciprocate between the inside and the outside of the first and/or second towers; and a board guider connected to the gate to transmit a driving force of the guide motor to the gate as a linear motion force.

A centrifugal compressor includes: an impeller provided in a housing; a throttling portion provided in front of the impeller in the housing; an actuator rod connected to an actuator and including a plate portion including a plane at its end; and a connecting portion connected to the throttling portion and including a pair of projections facing each other across the plate portion in an axial direction of the actuator rod.

First and second towers may discharge air. An airflow guide or converter may change a direction of the air discharged from the first tower and the second tower by moving a gate inside and outside of at least one of the first or second towers so as to block discharged air flowing forward and selectively facilitate an upward air flow. The airflow converter may include a guide motor to provide a driving force, the gate, which may reciprocate between the inside and the outside of the first and/or second towers; and a board guider connected to the gate to transmit a driving force of the guide motor to the gate as a linear motion force.

A blower assembly for advancing the flow of air in an air flow device at a selected one of a plurality of air flow rates. The blower assembly includes a blower housing defining a body thereof and a wall of the blower housing moveably secured to the body, a blower wheel rotatably mounted to the blower housing and a motor for rotating the blower wheel at a selected one of a plurality of rotational speeds. The blower assembly further includes a motion device secured to the body and to the wall. The motion device moves the wall relative to the body to a selected one of a plurality of distinct wall positions. The motor rotates the blower wheel at a selected one of a plurality of rotational speeds. A controller calculates an optimum wall position and rotational speed to provide for minimal energy usage rate.

A draft inducer blower assembly includes a blower having a fan, a dilution air intake passage, an exhaust gas intake passage, and a discharge passage. The blower is configured to operatively connect to a heater system in a manner to facilitate flow of combustion air into a combustion chamber and to draw dilution air into the blower and to mix the dilution air with the exhaust gases and to facilitate flow of the mixed air and exhaust gases through the vent. The dilution air intake passage is positionable in at least a low flow configuration and a high flow configuration. The dilution air intake passage is more restrictive of intake of dilution air in the low flow configuration than in the high flow configuration.

A blower is disclosed. The blower of the present disclosure comprises: a fan for producing air flow; a lower body providing an inner space in which the fan is installed, and having an intake hole through which air passes; an upper body placed on the lower body to form a flow passage which communicates with the inner space of the lower body, and having a space which is formed to pass through the upper body in the forward and backward direction, wherein the upper body includes a slit which is formed through the upper body and through which air flowing through the flow passage of the upper body is discharged to the space, and the slit comprises: a rear slit adjacent to the rear end of the upper body; and a front slit adjacent to the front end of the upper body.

Centrifugal compressors can incorporate a side stream flow of intermediate pressure vapor between stages of that compressor. The side stream flow can be controlled by a side stream injection port controlled by a capacity control valve that has a curved surface facing a flow of refrigerant from the first stage to the second stage. The capacity control valve can allow or obstruct flow through the side stream injection port. The capacity control valve can extend and retract in a direction substantially perpendicular to the direction of flow from the first stage impeller to the second stage impeller. The side stream injection port and the capacity control valve can be ring-shaped. The side stream injection port and the capacity control valve can allow at least some of the side stream to be introduced on a side of the capacity control valve opposite the curved surface.

A blower assembly for a powered air-purifying respirator (PAPR) assembly includes: a lower housing; an upper housing connected to the lower housing, such that the upper housing and the lower housing collectively define a first interior cavity; a filter configured to filter ambient air drawn into the blower assembly; and a fan. The upper housing and the filter define a pathway for a flow of air into the first interior cavity. The fan is positioned in the first interior cavity such that, when the fan is activated, ambient air is drawn into the blower assembly and travels along the pathway into the first interior cavity for subsequent delivery out of the blower assembly. The lower housing defines an outlet port for directing breathable air out of the blower assembly for delivery to a user (e.g., via a breathing tube interconnecting a headpiece and the outlet port).

The invention relates to a module, comprising:—at least one, preferably only one, tangential turbomachine (28-1; 28-2) comprising a bladed wheel (32-1; 32-2) and a motor (33-1; 33-2) for rotationally driving the bladed wheel (32-1; 32-2),—a frame (30-1; 30-2) forming an opening (60-1; 60-2), preferably only one opening,—a shut-off means (62-1; 62-2) designed to selectively shut off the opening (60-1; 60-2), the shut-off means (62-1; 62-2) having at least two regions which, in contact in a position of the shut-off means (62-1; 62-2) in which the opening (60-1; 60-2) is left free, are at a distance apart in a position in which they shut off the opening (60-1; 60-2).