Columnar air moving devices, systems and methods

Air moving device includes a housing, an impeller in the housing for generating a downward air flow, and vanes in the housing in close proximity to and a selected distance below the impeller to straighten the air flow. The device produces an air flow that substantially remains in a column over a substantial distance. The method includes producing an air flow that substantially remains in a column over a substantial distance and directing the air flow from the ceiling towards the floor to provide temperature destratification of the air in an enclosed space. The method also includes directing warm air from the ceiling to the floor and storing heat in the floor, apparatus on the floor and ground under the floor. The stored heat is released when the ceiling is cooler than the floor.

TECHNICAL FIELD

The present invention relates to heating, ventilating and air conditioning air spaces, and more particularly to systems, devices and methods for moving air in a columnar pattern with minimal lateral dispersion that are particularly suitable for penetrating air spaces and air temperature de-stratification.

BACKGROUND ART

The rise of warmer air and the sinking of colder air creates significant variation in air temperatures between the ceiling and floor of buildings with conventional heating, ventilation and air conditioning systems. Such air temperature stratification is particularly problematic in large spaces with high ceilings such as warehouses, gymnasiums, offices, auditoriums, hangers, commercial buildings, and even residences with cathedral ceilings, and can significantly decrease heating and air conditioning costs. Further, both low and high ceiling rooms can have stagnant or dead air. For standard ceiling heights with duct outlets in the ceiling there is a sharp rise in ceiling temperatures when the heat comes on.

One proposed solution to air temperature stratification is a ceiling fan. Ceiling fans are relatively large rotary fans, with a plurality of blades, mounted near the ceiling. The blades of a ceiling fan have a flat or airfoil shape. The blades have a lift component that pushes air upwards or downwards, depending on the direction of rotation, and a drag component that pushes the air tangentially. The drag component causes tangential or centrifugal flow so that the air being pushed diverges or spreads out. Conventional ceiling fans are generally ineffective as an air de-stratification device in relatively high ceiling rooms because the air pushed by conventional ceiling fans is not maintained in a columnar pattern from the ceiling to the floor, and often disperses or diffuses well above the floor.

Another proposed solution to air temperature stratification is a fan connected to a vertical tube that extends substantially from the ceiling to the floor. The fan may be mounted near the ceiling, near the floor or in between. This type of device may push cooler air up from the floor to the ceiling or warmer air down from the ceiling to the floor. Such devices, when located away from the walls in an open space in a building, interfere with floorspace use and are not aesthetically pleasing. When confined to locations only along the walls of an open space, such devices may not effectively circulate air near the center of the open space. Examples of fans connected to vertical tubes are disclosed in U.S. Pat. No. 3,827,342 to Hughes, and U.S. Pat. No. 3,973,479 to Whiteley.

A device that provides a column of air that has little or no diffusion from the ceiling the floor, without a vertical tube, can effectively provide air de-stratification. U.S. Pat. Nos. 4,473,000 and 4,662,912 to Perkins disclose a device having a housing, with a rotating impeller having blades in the top of the housing and a plurality of interspersed small and large, vertically extending, radial stationary vanes spaced below the impeller in the housing. The device disclosed by Perkins is intended to direct the air in a more clearly defined pattern and reduce dispersion. Perkins, however, does not disclose the importance of a specific, relatively small gap between the impeller blades and the stationary vanes, and the device illustrated creates a vortex and turbulence due to a large gap and centrifugal air flow bouncing off the inner walls of the housing between the blades and vanes. Perkins also discloses a tapering vane section. The tapering vane section increases velocity of the exiting air stream.

A device with a rotary fan that minimizes the rotary component of the air flow while maximizing the axial air flow quantity and velocity can provide a column of air that flows from a high ceiling to a floor in a columnar pattern with minimal lateral dispersion that does not require a physical transporting tube. Such a device should reduce the energy loss by minimizing the rotary component of the air flow, and therefore minimizes turbulence. Such a device should minimize back pressure, since a pressure drop at the outlet of the device will cause expansion, velocity loss and lateral dispersion. The device should have minimum noise and low electric power requirements.

DISCLOSURE OF THE INVENTION

An air moving device which has a housing with an air inlet and an air outlet spaced from the inlet. A rotary impeller with a plurality of blades is mounted in the housing at the air inlet end and produces air flow with an axial component and a rotary component. A plurality of spaced, longitudinally extending, radial air guide vanes in the housing downstream of the impeller are in close proximity to the impeller blades to minimize the rotary component and change the air flow to a laminar and axial flow in the housing that exits the outlet end in a columnar pattern with minimal lateral dispersion. A method of moving air includes producing an air flow through a housing, and directing the air flow through the housing in a laminar and axial flow and exits an outlet so as to produce a columnar pattern with minimal lateral dispersion. The method also includes directing warm air from near the ceiling toward the floor, allowing the heat from the warm air to be stored in the floor, articles on the floor and the earth under the floor. The method includes directing air in a generally horizontal direction to allow penetration of an air space in a container, trailer truck or a room to promote flushing of that air space and circulation thereof. The device and method are particularly suitable for high efficiency, low power usage, air temperature de-stratification, and to improve air quality and circulation.

DETAILED DESCRIPTION OF THE INVENTION

Referring now toFIGS. 1 to 9, there is shown an air moving device12having an elongated outer housing13, an electric rotary fan14in the housing for producing air flow in the housing and a plurality of longitudinally extending, outer radial vanes15and an inner housing hub16opposite the vanes in the housing downstream of the fan for directing air flow in the housing.

The housing13has a circular cross section, and an open first end17and an open second end18spaced from the first end17. In the illustrated embodiment, a detachable, axially outwardly convex cowling19forms the first end17and provides an air inlet21with a diameter slightly smaller than the outer diameter of the cowling19.

The housing13has a first section25extending from the cowling19to an interior shelf26. A generally C-shaped hanger23mounts at opposite ends24to opposite sides of the housing13at the upper end of the first section25, for mounting the air moving device12to a support. The first section25, when viewed from the side, has a curved, slightly radially outwardly convex shape that conforms to the curvature of the cowling19. The shelf26extends radially inwardly to join with the upstream end of a second section27. The second section27tapers inwardly and extends axially from the shelf26to the second end18along a smooth curve that goes from radially outwardly convex near the shelf26to radially outwardly concave near the second end18. The second end18forms an air outlet28that has a smaller diameter than the air inlet21. A plurality of circumferentially spaced external fins29extend from the shelf26to the second section27to provide the appearance of a smooth curve from the air inlet21to the air outlet28when the housing13is viewed from the side.

The fan14includes an impeller31having a cylindrical, inner impeller hub32, with an electric motor34therein, and a plurality of rigidly mounted, circumferentially spaced blades33extending radially from the impeller hub32. In the illustrated embodiment the impeller31has three equally spaced blades33and rotates about an axis in a counter-clockwise direction when viewed from above. Each blade33, in side view, extends from an upstream edge35, downwardly and leftwardly to a downstream edge36with each blade33being slightly concave, in an airfoil or wing shape, downwardly to propel air rightwardly as shown by the arrow. Each blade33then inclines at a selected angle to the axis of rotation of the impeller. Each blade33shown extends axially and radially toward the outlet or second end18to direct air axially with a rotary component. If the motor34runs in the opposite direction, the incline of the blades33would be reversed. The fan14includes a stationary cylindrical mounting ring38that extends around the blades33, with the impeller hub32being rotably mounted relative to the mounting ring38. The mounting ring38has spaced, protruding upstream and downstream rims40and41. The fan14mounts in the housing13between the cowling19and the shelf26.

Each of the vanes15is identical and includes upstream portion43and a downstream portion44. The upstream portion43is carried in a stator46. The stator46has a cylindrical stator hub47with a diameter substantially equal to the diameter of the impeller hub32. The upstream portions43of the vanes15are mounted in a circumferentially spaced arrangement around the stator hub47, and extend longitudinally along and radially from the stator hub47. Each upstream portion43has an upstream end48and a downstream end49. A support body50includes a cylindrical stator ring52that extends around the upstream portions43and connects to the outer ends of the upstream portions43of the vanes15near the upstream ends48. The support body50also includes a protruding stator rim53that is substantially planar with the upstream ends48of the upstream portions43of the vanes15, and that connects to the stator ring52and extends radially outwardly therefrom.

The housing13has an inner surface and the inner housing hub16has an outer surface concentric with a spaced from the housing inner surface to define an air flow passage through the housing. The inner housing hub16includes the fan hub32, stator hub portion47and downstream hub portion57, each having an outer surface and arranged end to end along the center of the housing and opposite and spaced from the housing inner surface to define the air flow passage. In particular, these outer surfaces shown are cylindrical and substantially the same diameter for a substantial portion of the passage and as the housing13converges the downstream hub portion57converges to generally follow the curvature of the inside surface of the housing.

The stator46nests in and is separable from the housing13with the stator rim53between the shelf26of the housing13and the downstream rim41of the mounting ring38of the fan14, and with a gap55having a selected size between the downstream edge36of the blades33of the impeller31and the upstream ends49of the upstream portions43of the vanes15. If the gap55is too large, turbulence will be generated in the air flow between the impeller31and the vanes15, reducing the velocity of the air flow. If the gap55is too small, fluid shear stress will generate noise. The size of the gap55is generally selected as no greater than a maximum selected dimension to avoid turbulence and no less than a selected minimum dimension to avoid noise, and more particularly selected as small as possible without generating noise.

The selected size of the gap55is generally proportional to the diameter of the impeller31and may further be affected by the speed of the impeller31. The following are examples: For an impeller31with a diameter of 6.00″, at 1800 rpm, the maximum size of the gap55should be 1.25″ and the minimum gap should be 0.2″. For an impeller31with a diameter of 8.5″, at 1400 rpm, the maximum size of the gap55should be 1.25″, and the minimum gap should be 0.2″ but could be 0.020 for lower rpm's as the size of the gap is rpm dependent. Generally, the maximum size of the gap55should be less than one half the diameter of the impeller31.

In the illustrated embodiment, eight equally spaced upstream portions43of the vanes15are provided, and when viewed from the side, the upstream portions43of the vanes15extend straight upwardly from the downstream ends49and then curve leftwardly near the upstream ends48. The upstream portion43of each curved vane portion is inclined at an angle opposite the incline of the blade33that extends axially and radially inward toward the outlet or second end28to assist in converting the rotary component of the air flow into laminar and axial flow in the housing.

Straight upstream portions43A of the vanes15may also be used, as shown inFIG. 7, and other numbers of vanes15may be used. Further, if the motor34runs in the opposite direction, the incline of the curvature near the upstream ends48would be reversed.

The downstream portions44of the vanes15attach at an inner end to a downstream inner housing hub portion57, are circumferentially spaced and extend radially outwardly from the housing hub portion57to the housing13. The housing hub portion57and the downstream portions44of the vanes15extend axially from the stator46to or near the air outlet28. The housing hub portion57has a circular cross section, has a diameter substantially equal to the diameter of the stator housing hub portion47at the upstream end adjacent to the stator housing hub portion47, and tapers downstream to a point58near the air outlet28. This hub portion may be characterized as torpedo shaped. In the illustrated embodiment there are four downstream portions44of the vanes15circumferentially spaced at 90 degrees, with each downstream portion44being aligned with an upstream portion43of a vane15. Other numbers of downstream portions44of the vanes15can be used.

The number of the blades33may be 2, 3, 4, 5, 6, 7 or 8. The number of the vanes15may be 2, 3, 4, 5, 6, 7 or 8. The number of vanes15should be different from the number of blades33. If the number of vanes15and blades33are the same, added noise is generated due to harmonics.

The air moving device12discharges air at a high velocity in a generally axial flow having a columnar pattern with minimal lateral dispersion after exiting the air outlet28. The cowling19extends along a curve toward the inside to reduce turbulence and noise for air flow entering the air inlet21. The impeller hub32, the stator hub47and the housing hub57form the inner housing hub16. The taper of the housing hub57generally follows the taper of the housing13so that the cross sectional area for air flow decreases about 10% to 35% through the air moving device12to avoid back pressure and at the same time increase air flow velocity. In the embodiment shown the air flow decreases about 22%.

The vanes15convert the rotary component of the air flow from the impeller31into laminar and axial air flow in the housing. The leftward curve of the upstream ends48of the upstream portions43of the vanes15, in the illustrated embodiment, reduces the energy loss in the conversion of the rotary component of the air flow from the impeller31into laminar and axial air flow in the housing. The small gap55between the impeller31and vanes15prevents the generation of turbulence in the air flow in the gap55. The taper of the housing13in combination with the taper of the housing hub57to the point58allows the air flow to exit the air outlet28in a continuous, uninterrupted columnar pattern with minimal dispersion, with no center hole or gap at a linear speed greater than would be imparted by a fan alone. The inside surface of the housing13is a substantially smooth uninterrupted surface to minimize turbulence and energy loss.

The hanger23is mounted to rotate and lock relative to the housing13, so that when the hanger23is attached to an overhead support such as ceiling, the air flow from the air moving device12may be directed vertically or aimed at any selected angle from the vertical as shown inFIG. 8. As shown inFIGS. 1 and 9, the first section25of the housing13includes mounting tabs91on opposite sides on the upper edge of the first section25. Each mounting tab91includes a round, outwardly directed mounting face92, and a housing aperture93that extends inwardly through the center of the mounting tab91. A pair of outwardly projecting housing ridges94extend radially on the mounting face92on opposite sides of the housing aperture93.

Each end24of the hanger23has a round, inwardly facing hanger end face96, similar in size to the mounting face92on the housing13. A hanger end aperture97extends through the center of the hanger end face96. A plurality of spaced, radially extending grooves98, sized to receive the housing ridges94, are provided on each hanger end face96. Bolt100extends through the hanger end aperture97and threads into an internally threaded cylindrical insert101, rigidly affixed in housing aperture93. The angle of the housing13is chosen by selecting a pair of opposed grooves97on each hanger end24to receive the housing ridges94. The pivotal arrangement enables the housing to move to a selected angle and is lockable at the selected angle to direct air flow at the selected angle.

FIG. 10shows an air moving device12mounted to the ceiling62of a room63shown as being closed sided with opposed side walls. Warm air near the ceiling62is pulled into the air moving device12. The warm air exits the air moving device12in a column64that extends to the floor65. When the column64reaches the floor65, the warm air from the ceiling pushes the colder air at the floor65outward towards the opposed side walls66and upward towards the ceiling62. When the column64reaches the floor65, the warm air from the ceiling will also transfer heat into the floor65, so that heat is stored in the floor65. The stored heat is released when the ceiling is cooler than the floor. The heat may also be stored in articles on the floor and earth under the floor. The air moving device12destratifies the air in a room63without requiring the imperforate physical tube of many prior known devices. The air moving device12destratifies the air in a room63with the warmer air from the ceiling62minimally dispersing before reaching the floor65, unlike many other prior known devices. The air moving device12will also remove dead air anywhere in the room. It is understood that the air moving device12may also be mounted horizontally in a container, trailer truck or room as is describe hereafter.

Referring toFIG. 11, an air moving device12is fitted with an inlet grill68and an electric connector69for attachment to a light can70with a light bulb socket71at the upper end. The inlet grill68includes a plurality of circumferentially spaced grill fins72that attach to the first end17of the housing13. The grill fins72are separated by air intake slots73, and extend axially outwardly from the first end17and curve radially inwardly and are integral with a flat circular mounting plate74that is substantially parallel with the first end17. The electrical connector69has a tube76that is integral at one end with the center of the mounting plate74and extends axially therefrom, and a light bulb type, right hand thread externally threaded male end77attached to the other end of the shaft78. Grill68, plate74and tube76are shown as made of a one piece construction. Plate74has holes that received screws83or like fasteners to fasten plate74to ceiling62.

The shaft78telescopes in the tube76. The tube76has a pair of opposed keyways76A that receive keys78A on the shaft78which allow axial sliding movement of the shaft78in the tube76. A compression spring75fits in the tube and bears against the bottom of shaft78and top of plate74. Preferably the shaft78has a selected length relative to the length of the can70such that when the air moving device12is mounted in a can70in a ceiling62, the threaded male end77engages the socket71before the mounting plate74contacts the ceiling62and when the threaded male end77is screwed into the socket71, the mounting plate74bears against the ceiling62. The spring75is compressed between plate74and shaft78. Screws83fasten the plate to the ceiling62. Since the light can70may be open to air above the ceiling62, the mounting plate74is preferably sized to cover the open lower end of the can70, so that only air from below the ceiling62is drawn into the air moving device12. The air moving device12fitted with the inlet grill68and the electrical connector69can also be used with a ceiling light socket.

The air moving device12may include an intake grill79for preventing objects from entering the impeller31, as shown inFIG. 12. The intake grill79shown has a substantially hemispherical shape, and includes a plurality of circumferentially spaced grill fins80separated by intake slots81. The grill fins80extend axially outwardly and curve radially inwardly from the first end17of the housing13to a central point82spaced from the first end17. Other shapes of intake grills are suitable for the present invention.

FIG. 13shows an air moving device12with a misting nozzle84. The nozzle84extends through the point58of the housing hub57to spray water into the column of air exiting the air outlet28to cool the air through evaporation. The media exiting the nozzle84and being supplied through tube85can have other purposes such as a disinfectant or a fragrance or a blocking agent for distinctive needs. The nozzle84connects to a water line85, in the housing hub59that connects to a water source (not shown).

FIG. 14shows an air moving system86for use in buildings with very high ceilings, including an air moving device12, an upwardly extending, tube87(shown cut away) connected at a lower end to the air inlet21of the air moving device12, and a truncated upper air moving device88having an air outlet89connected to the upper end of the tube87. The housing of device88is called truncated because it may be shortened or cut off below the fins29. A conventional air moving device12may be used for device88. The tube87may be flexible and is preferably fire resistant. The air moving system86is mounted to a ceiling or like support with the air outlet28of the air moving device12spaced above the floor, preferably about 10 to 50 feet. The tube may be for example from 30 to 100 feet long. The upper air moving device88at the top of the system86has a higher air moving flow capacity than the air moving device12at the bottom of the cascading system86. By way of example, and not as a limitation, the upper air moving device88may have a capacity of 800 cfm and the air moving device12may have a capacity of 550 cfm.

FIGS. 15,15A,15B,15C,15D and16show the air moving device12mounted in an opening103in a ceiling104. A generally cylindrical can105mounts on and extends above the ceiling104, and has an open can bottom106, and a closed can top107. The can top107includes a semi-circular, downward opening, circumferentially extending channel108. A semi-circular fin111extends radially across the channel108to prevent swirling of the air before entering the air inlet21. Additional fins may be used. A grill and support assembly125mounts to the ceiling and extends and connects to the exterior of the housing of device12. A grill including spaced openings110between fins109to allow air to flow up from the room along the housing and past the cowling19into the inlet21. The grill and support assembly125includes an outer ring120fastened to the underside of the ceiling including the convexly curved grill fins109with air openings110between connected outer ring120and an inner ring121. Ring121has a spherical concave inner bearing surface122. A ring123has a spherical convexly curved exterior bearing surface124is mounted on and affixed to the housing with bearing surfaces122and124mating in a frictional fit to support the housing to be at a vertical position or tilted at an angle to the vertical axis and be held by friction at the vertical axis or a selected angle relative to the vertical axis to direct air flow as required.

The can105has an outwardly extending bottom flange140that fits against the underside of the ceiling104. The can105preferably has four circumferentially spaced bottom openings141at 90 degree intervals that are rectangular in shape and extend up the can wall a short distance from the bottom flange140. A clamping member142preferably made as a molded plastic body has a main body portion143above the ceiling104outside the can wall and an end flange portion144that fits inside the can opening142. The main body portion143has a U-shaped outer wall portion145and an inner hub portion146having an aperture147. The clamping member142inserts into the opening141via the open end of the can. A bolt fastener151extends through a hole in the flange, through a hole in the ceiling and threads into the aperture147in the main body portion to clamp the can105to the ceiling104.

As shown inFIG. 15Dthe grill and support assembly125is mounted to the ceiling104and can105by a bolt fastener149extending through an aperture in ring120, through the ceiling104and into a nut150in flange140in the can. Preferably there are four bolt fasteners149at 90 degree intervals midway between fasteners151above described. The ceiling104typically would be a plasterboard ceiling in which a suitable hole is cut. A variation ofFIG. 15would be to extend or form the peripheral of outer ring120into a flat panel having a dimension of 2 ft. by 2 ft. that would fit in and be held by a grid that holds a conventional ceiling panel.

Referring toFIG. 17, an air moving device is fitted with an inlet grill113, a light bulb style threaded male end114for threading into a light bulb socket, and a light bulb socket115. The inlet grill113includes a plurality of circumferentially spaced grill fins116that attach to the first end of the housing13. The grill fins116are separated by air intake slots117, and extend axially outwardly from the first end17and curve radially inwardly to a flat circular mounting plate118that is substantially parallel with and spaced axially from the first end17. Threaded male end114is mounted on and extends upwardly from the mounting plate118. The socket115is mounted inside the housing13in a downwardly opening fashion so that light from a bulb119threaded into the socket115is directed downwards.

Referring now toFIG. 18, there is shown a tent having an inclined top132extending down from an apex and connected at the lower end to a vertical side wall131and terminating above a floor133to provide a side opening134so that the tent is an open sided room. The air moving device12is mounted below the top apex and directs the air in the room downwardly in a columnar pattern to the floor and along the floor and then back with some air passing in and out the side openings134along the floor133. For wide tents, the air will pass up before it reaches the side walls.

The air moving device and system herein described has relatively low electrical power requirement. A typical fan motor is 35 watts at 1600 rpm for an impeller of 8.5″ that will effectively move the air from the ceiling to the floor in a room having a ceiling height of 30 ft. Another example is 75 watts with an impeller diameter 8.5″ at 2300 rpm in a room having a ceiling height of 70 ft.

Referring now toFIG. 19, there is shown a shipping container161having an air moving device12disposed horizontally in the lower left end. The device12directs the air horizontally along the bottom wall or floor, up the opposite side wall and across the top wall to exit an outlet duct162above and spaced from the device12of the air moving device. The device12will penetrate the air and promote flushing and circulation of the air space. The device12may be mounted to direct the air generally horizontally or up or down at an angle to the true horizontal. This arrangement may be provided in other air spaces such as a trailer truck, room or the like.

It is understood that the stator46and housing13could be made as a single unit. It is also understood that the housing13may be made in two sections as for example a tubular section of a selected length may be added to the end of a truncated devices as shown inFIG. 14.

Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made by way of example and that changes in details of structure may be made without departing from the spirit thereof.