Abstract: There is described a method for controlling an exhaust system having at least two fans, a plenum chamber interconnecting the at least two fans, and a bypass air damper in the plenum chamber to allow bypass air to flow therethrough, the method comprising: monitoring pressure in the plenum chamber of the system; detecting a variation of the pressure beyond a predetermined range; and regulating operation of the exhaust system in response to the pressure variation in order to return the pressure to within the predetermined range.

Abstract: An inline centrifugal wheel has a back plate and a hub extending from the back plate. A front plate has a diameter greater than the back plate and is inclined to extend downwardly from a central aperture to its outer perimeter. Blades extend between the back and front plate and have an outer edge extending between the outer edges of the front and back plate. The blades extend tangentially to the central aperture of the front plate.

Abstract: A damper support mechanism to reinforce a plurality of damper blades which are actuated together. When the blades are in a closed position, actuating brackets attached to each damper blade and a vertical bar are used to support the blades and preventing them from bending or breaking. The vertical bar is fixedly held in a stop mechanism located at the top or bottom of the vent opening.

Abstract: A nozzle stack and windband for an exhaust fan that has a nozzle stack with two side apertures for exhaust. Arranged around the periphery of a central aperture in the conical nozzle stack are two side apertures. The nozzle stack fits over the fan outlet. A nozzle stack may extend upwardly from a central aperture. Exhaust exiting the two side apertures induces a flow, especially when the windband encircles the nozzle.

Abstract: An inline centrifugal wheel has a back plate and a hub extending from the back plate. A front plate has a diameter greater than the back plate and is inclined to extend downwardly from a central aperture to its outer perimeter. Blades extend between the back and front plate and have an outer edge extending between the outer edges of the front and back plate. The blades extend tangentially to the central aperture of the front plate.

Abstract: End caps are attached to the end of each blade of a damper. When in the closed position, the end caps seal the space between the blade and frame. Sealing fins may extend from the end cap to further enhance the sealing capability. The end caps are easily replaced if worn and effectively prevent air from flowing between the frame and end of the blades.

Abstract: There is described a method for controlling an exhaust system having at least two fans, a plenum chamber interconnecting the at least two fans, and a bypass air damper in the plenum chamber to allow bypass air to flow therethrough, the method comprising: monitoring pressure in the plenum chamber of the system; detecting a variation of the pressure beyond a predetermined range; and regulating operation of the exhaust system in response to the pressure variation in order to return the pressure to within the predetermined range.

Abstract: A nozzle for an exhaust fan that has a primary, central aperture for exhaust. Arranged around the periphery of the central aperture is a plurality of side apertures. The nozzle fits over the fan outlet. A stack may extend upwardly from the central aperture. Exhaust exiting the side apertures induces a flow of ambient air, especially when a windband encircles the nozzle. The ambient air increases the volume of exhaust exiting the windband.

Abstract: The present invention provides for a cleaning apparatus for a vertical exhaust pipe in an exhaust system, the cleaning apparatus comprising a cleaning liquid source, an enclosure receiving a cleaning liquid from the cleaning liquid source, and a fluid communication between the enclosure and an inner surface of the exhaust pipe so that the cleaning liquid supplied to the enclosure by the cleaning liquid source is gravity fed into the exhaust pipe through the fluid communication, thereby creating a cleaning liquid film flowing down along at least part of the inner surface of the exhaust pipe, whereby the cleaning liquid film washes the at least part of the inner surface of the exhaust pipe. The cleaning apparatus is thus efficient, has a low risk of failure and is easily accessible for maintenance. A method for cleaning a vertical exhaust pipe in an exhaust system is also provided.

Abstract: There is described a method for controlling an exhaust system having at least two fans, a plenum chamber interconnecting the at least two fans, and a bypass air damper in the plenum chamber to allow bypass air to flow therethrough, the method comprising: monitoring pressure in the plenum chamber of the system; detecting a variation of the pressure beyond a predetermined range; and regulating operation of the exhaust system in response to the pressure variation in order to return the pressure to within the predetermined range.

Abstract: A fan assembly comprising a casing having an inlet and an outlet for fluid circulation through the casing, and a closeable opening to allow access to an interior of the casing. A rotor induces fluid circulation in the casing. A motor is connected to the rotor so as to actuate the rotor. A carriage supports the motor and the rotor, the carriage being operatively mounted to a track so as to be displaceable between an operating position of the fan assembly, in which the rotor is positioned in the casing for inducing fluid circulation in the casing, and a maintenance position of the fan assembly, in which the rotor is out of the casing for maintenance, wherein the rotor is displaced between the operating position and the maintenance position through the closeable opening.

Abstract: The high velocity and high dilution exhaust system uses a centrifugal fan provided with a tapered nozzle. The nozzle compresses the airstream exiting the fan to increase back pressure and velocity. The air flow from the fan enters a stack having a venturi further increasing the velocity and decreasing the pressure. The decrease in pressure causes a suction, allowing the introduction of ambient air to mix with and dilute the output of the fan. The total discharge from the exhaust stack has a high velocity resulting in a plume height and effective height of the exhaust before dispersion occurs.

Abstract: The high velocity and high dilution exhaust system uses a centrifugal fan provided with a tapered nozzle. The nozzle compresses the airstream exiting the fan to increase back pressure and velocity. The air flow from the fan enters a stack having a venturi further increasing the velocity and decreasing the pressure. The decrease in pressure causes a suction, allowing the introduction of ambient air to mix with and dilute the output of the fan. The total discharge from the exhaust stack has a high velocity resulting in a plume height and effective height of the exhaust before dispersion occurs.

Abstract: An axial fan assembly comprises a rotating shaft adapted to be actuated in rotation and axial fan assembly sections. Each assembly section has one rotor, the rotor including a hub rotatably engaged with the shaft and a plurality of blades radially extending from the hub; and one stator in proximity and downstream of each rotor. The stator includes an inner ring rotationally receiving the shaft. A plurality of vanes radially are connected the inner ring, such that a swirl of a flow of air produced by the rotor is reduced when the flow of air goes through the stator. An end-to-end configuration is provided between the axial fan assembly sections so as to increase a static pressure at the outlet of the axial fan assembly.

Abstract: A fan assembly comprising a casing having an inlet and an outlet for fluid circulation through the casing, and a closeable opening to allow access to an interior of the casing. A rotor induces fluid circulation in the casing. A motor is connected to the rotor so as to actuate the rotor. A carriage supports the motor and the rotor, the carriage being operatively mounted to a track so as to be displaceable between an operating position of the fan assembly, in which the rotor is positioned in the casing for inducing fluid circulation in the casing, and a maintenance position of the fan assembly, in which the rotor is out of the casing for maintenance, wherein the rotor is displaced between the operating position and the maintenance position through the closeable opening.

Abstract: The present invention provides for a cleaning apparatus for a vertical exhaust pipe in an exhaust system, the cleaning apparatus comprising a cleaning liquid source, an enclosure receiving a cleaning liquid from the cleaning liquid source, and a fluid communication between the enclosure and an inner surface of the exhaust pipe so that the cleaning liquid supplied to the enclosure by the cleaning liquid source is gravity fed into the exhaust pipe through the fluid communication, thereby creating a cleaning liquid film flowing down along at least part of the inner surface of the exhaust pipe, whereby the cleaning liquid film washes the at least part of the inner surface of the exhaust pipe. The cleaning apparatus is thus efficient, has a low risk of failure and is easily accessible for maintenance. A method for cleaning a vertical exhaust pipe in an exhaust system is also provided.

Abstract: The high velocity and high dilution exhaust system uses a centrifugal fan provided with a tapered nozzle. The nozzle compresses the airstream exiting the fan to increase back pressure and velocity. The air flow from the fan enters a stack having a venturi further increasing the velocity and decreasing the pressure. The decrease in pressure causes a suction, allowing the introduction of ambient air to mix with and dilute the output of the fan. The total discharge from the exhaust stack has a high velocity resulting in a plume height. and effective height of the exhaust before dispersion occurs.

Abstract: The high velocity and high dilution exhaust system uses a centrifugal fan provided with a tapered nozzle. The nozzle compresses the airstream exiting the fan to increase back pressure and velocity. The air flow from the fan enters a stack having a venturi further increasing the velocity and decreasing the pressure. The decrease in pressure causes a suction, allowing the introduction of ambient air to mix with and dilute the output of the fan. The total discharge from the exhaust stack has a high velocity resulting in a plume height and effective height of the exhaust before dispersion occurs.

Abstract: An exhaust fan to be mounted on a roof and for exhausting spent gases from a building, including a centrifugal fan scroll casing with a centrifugal fan impeller mounted on an axle within the casing and having an axis of rotation at right angles to the side members of the scroll casing. A bifurcated stack including two generally parallel passageways is connected to the scroll casing so that the stack is upright and communicates with the outlet port of the scroll casing. A ring defining an annulus may be provided at the outlet end of the stack to induce ambient air to mix with the spent air exhausting from the bifurcated tubular member.