A system comprising a furnace, an impeller, and a controller. The impeller directs air into an environment through the furnace. The controller receives calls to heat the environment or circulate air in the environment. In response to receiving a call to heat the environment, the controller activates the furnace and the impeller such that the impeller draws a first amount of power and turns in a first direction causing air to be impelled from the impeller through the furnace into the environment. In response to receiving a call to circulate air in the environment, the controller activates the impeller such that the impeller draws a second amount of power and turns in a second direction causing air to be impelled from the impeller into the environment, wherein the second amount of power is less than the first amount of power and the second direction is opposite the first direction.

A pump assembly includes at least one rotatingly driven impeller (14) and at least one valve element (18) which is rotatable about a rotation axis (X) between at least two switching positions. The valve element (18) includes a first face side (22) which extends transversely to the rotation axis of the valve element. A suction opening (24), which is engaged with a suction port (26) of the impeller (14), is formed in this first face side in a central region. The first face side (22) includes a pressure surface which surrounds the suction opening (24) and is adjacent to a delivery chamber (28) which surrounds the impeller (14).

A pump assembly includes pump casing (2), an impeller (14) rotatably arranged in the pump casing, a two rotation directions (A, B) electrical drive motor connected to drive the impeller and a valve arrangement (28) arranged in the pump casing to switch a flow path downstream of the impeller between two exits (24, 26) of the pump casing, depending on a rotation direction of the impeller. The valve arrangement includes a first movable valve element (34) at a first exit (24) and a second movable valve element (36) at a second exit (26). The first valve element partly closes the first exit in a closed position and is movable into an opened position by flow in the first rotation direction and the second valve element partly closes the second exit in a closed position and is movable into an opened position by flow in the second rotation direction (B).

Since the pump chamber (32a), the valve chambers (33a and 33b), the discharge holes (33e and 33f), and the flow paths (34 and 35) are integrally provided to each other in the housing (30), in the case where these are formed of separate members, a step or the like that inhibits the flow of the cleaning liquid W is not formed in the flow path of the cleaning liquid W, so that the pressure loss of the cleaning liquid W can be reduced. In addition, since the valve chambers (33a and 33b) of the flow paths (34 and 35) extend to the discharge holes (33e and 33f), the cleaning liquid W flowing out of the flow paths (34 and 35) can be discharged at a portion closer to the central of the valve chambers (33a and 33b). As a result, the outlet portions of the flow paths (34 and 35) and the inlet portions of the discharge holes (33e and 33f) is brought closer to each other, and the turbulent of the cleaning liquid W in the valve chambers (33a and 33b) can be suppressed, thereby reducing the pressure loss.

Since the pump chamber (32a), the valve chambers (33a and 33b), the discharge holes (33e and 33f), and the flow paths (34 and 35) are integrally provided to each other in the housing (30), in the case where these are formed of separate members, a step or the like that inhibits the flow of the cleaning liquid W is not formed in the flow path of the cleaning liquid W, so that the pressure loss of the cleaning liquid W can be reduced. In addition, since the valve chambers (33a and 33b) of the flow paths (34 and 35) extend to the discharge holes (33e and 33f), the cleaning liquid W flowing out of the flow paths (34 and 35) can be discharged at a portion closer to the central of the valve chambers (33a and 33b). As a result, the outlet portions of the flow paths (34 and 35) and the inlet portions of the discharge holes (33e and 33f) is brought closer to each other, and the turbulent of the cleaning liquid W in the valve chambers (33a and 33b) can be suppressed, thereby reducing the pressure loss.

A positive-negative-rotation fan for a clothes dryer comprises multiple whole-size fan blades arranged on a periphery of an outer frame of the fan, and multiple half-size fan blades arranged on the periphery of the outer frame of the fan. The half-size fan blades and the whole-size fan blades have similar shapes, and the size of an edge of each half-size fan blade parallel to a radial direction of the fan is half of the size of a corresponding edge of the whole-size fan blade. The clothes dryer using the positive-negative-rotation fan can provide an even and great air volume and a great air intake pressure in a clockwise and counterclockwise alternating rotation process, and accordingly clothes are evenly dried and the drying time is short. By using a flow guide device, aggregated back-flows are not generated between the fan and an outlet of a volute.

A pump assembly is disclosed comprising, a pump including a pump housing having a fluid inlet. At least one fluid outlet extends from the pump housing. An impeller driven by a motor is mounted in the pump housing arranged to move a fluid from the fluid inlet to the at least one fluid outlet. A valve rotatably mounted between the impeller and the at least one fluid outlet selectively controls the flow of fluid through the at least one fluid outlet.

The invention discloses a water feeding pump or a fertilizer applying pump for a pump station of a fertilization and irrigation system. The water feeding pump (2) or the fertilizer applying pump (3) is a centrifugal pump. The centrifugal pump includes a volute and an impeller. The impeller includes a front disc (12), a rear disc (13), and main blades (14), and a plurality of back blades (18) distributed along a circumferential direction are disposed on a back surface of the rear disc, where an auxiliary rotating disc (11) is disposed between the impeller and a rear side wall of the volute, the auxiliary rotating disc is a rotating member and is driven by the back blades of the impeller to rotate.

An object of the present invention is to decrease a surging limit flow rate at a low flow rate time, by increasing the inflow velocity to the blade of the impeller wheel, by providing a resistive element that narrows in the radial direction a passage cross section of an air intake passage which communicates between a impeller wheel of a centrifugal compressor and an air intake opening. The centrifugal compressor includes: the compressor housing 9 having the air intake opening 13 opened in a rotary shaft direction, and the air intake passage 11; and the impeller wheel 7 for compressing the air flowing in from the air intake opening 13, inside the housing. The resistive elements 27 and 43 against the air intake flow are provided in either the inner peripheral wall 23 side portion or the center side portion of the air intake passage 11, so that, at the low flow rate time, a cross-sectional area of the air intake passage 11 is narrowed by the resistive elements 27 and 43 thereby increasing the inflow velocity to the blade 19 of the impeller wheel, and the intake air flow is biased to the hub side of the blade 19, and the intake air flow is biased to flow to the hub side or the shroud side of the blade 19.

A pump assembly is disclosed comprising, a pump including a pump housing having a fluid inlet. At least one fluid outlet extends from the pump housing. An impeller driven by a motor is mounted in the pump housing arranged to move a fluid from the fluid inlet to the at least one fluid outlet. A valve rotatably mounted between the impeller and the at least one fluid outlet selectively controls the flow of fluid through the at least one fluid outlet.