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.

An interstage throttle for a centrifugal compressor includes a flow guide plate, a throttle ring, a drive ring, and linkage assemblies. The flow guide plate includes guide vanes that form channels that direct working fluid in between stages of the compressor. The linkage assemblies connect the drive ring to the throttle ring such that rotation of the drive ring moves the throttle ring in an axial direction. Teeth of the throttle ring partially block the channels when the throttle ring is in an extended position. A method of operating a centrifugal compressor includes directing the working fluid discharged from the first stage to a second stage via channels in a interstage throttle. A centrifugal compressor includes a first stage with a first impeller, a second stage with a second impeller, and an interstage throttle fluidly connecting the first stage to the second stage.

Turbomachines such as air dynamometers are disclosed that include a radial outflow compressor and gas collector. In some examples, the gas collector is designed as a separate component that is coupled to the machine, such as coupled to a frame. In some examples, the collector and frame are intentionally spaced and coupled at discrete points to minimize the transfer of mechanical and thermal energy therebetween. Aspects of the present disclosure also include turbomachines that include at least one impeller bypass flow path for the direct transfer of air between ambient and a location in the collector downstream of the impeller blades. In some examples, such flowpath(s) may allow for the inflow of external ambient air into the collector.

A technique is provided that can further reduce power at the time of “unload operation control” in a gas compressor that generates a compressed gas at a set pressure by constant-speed control. The gas compressor includes a compressor main unit, a drive source, an intake throttle valve, a gas release valve, rotation speed converting means, a pressure detecting device that detects a discharge pressure, and a controller that, the relationship between an upper-limit pressure H and a lower-limit pressure L being H>L, carries out opening the intake throttle valve and closing the gas release valve and operating the drive source at a full-load rotation speed until the discharge pressure reaches the upper-limit pressure H. The controller carries out at least one of closing the intake throttle valve and opening the gas release valve to reduce the discharge pressure to within a predetermined range when the discharge pressure reaches the upper-limit pressure H. The controller carries out switching to load operation when the discharge pressure drops to the lower-limit pressure L. In the gas compressor, the controller outputs a command of a lower rotation speed than the full-load rotation speed to the rotation speed converting means when the discharge pressure rises and reaches the upper-limit pressure H. The controller outputs a command of the full-load rotation speed to the rotation speed converting means when the discharge pressure drops and reaches the lower-limit pressure L.

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 includes a centrifugal fan and a partition wall disposed in a suction space in the centrifugal fan. The partition wall has a base portion extending along a fan central axis to partition the suction space into a first space for a first fluid and a second space for a second fluid. The partition wall has an enlarged portion connected to an end of the base portion on another side of the fan central axis. The enlarged portion covers a part of a fan boss. A clearance passage is defined between the enlarged portion and the fan boss and has a first space side opening and a second space side opening. The enlarged portion is biased in the suction space to the second space such that a pressure at the second space side opening is less than a pressure at the first space side opening.

A centrifugal compressor includes: a housing including an intake flow path; a compressor impeller disposed in the intake flow path; an accommodation chamber formed upstream of the compressor impeller in the housing; a movable member disposed in the accommodation chamber and configured to be movable between a retracted position where the movable member is retracted from the intake flow path and a protruding position where the movable member protrudes from the accommodation chamber into the intake flow path, the protruding position being located closer to the intake flow path with respect to the retracted position, and a contacting portion and a non-contacting portion provided on an accommodation chamber opposing surface of the accommodation chamber, the accommodation chamber opposing surface being positioned upstream of the movable member, the contacting portion being contactable with the movable member, the non-contacting portion being non-contactable with the movable member.

Described is a blower system. The blower system includes one or more blowers. Each blower has an intake for providing air into an air chamber which houses an impeller. A gate covers each intake. Each gate is movable between a closed position in which it is pulled against the intake and an open position in which the gate is lifted off of the intake. A controller system is included that is operable for causing the gates to move from the closed to the open position when a vehicle is present or approaching and cause the gates to return to the closed position when no vehicle is present or leaving.

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.

An interstage throttle for a centrifugal compressor includes a flow guide plate, a throttle ring, a drive ring, and linkage assemblies. The flow guide plate includes guide vanes that form channels that direct working fluid in between stages of the compressor. The linkage assemblies connect the drive ring to the throttle ring such that rotation of the drive ring moves the throttle ring in an axial direction. Teeth of the throttle ring partially block the channels when the throttle ring is in an extended position. A method of operating a centrifugal compressor includes directing the working fluid discharged from the first stage to a second stage via channels in a interstage throttle. A centrifugal compressor includes a first stage with a first impeller, a second stage with a second impeller, and an interstage throttle fluidly connecting the first stage to the second stage.