The invention relates to drying fans, including for water damage restoration and other applications.
In the water damage restoration industry, fans are used for drying a water damaged structure, including carpeting, furniture, framework, etc. If water can be evaporated quickly, damage can be minimized. The fans move air over the water damaged surfaces at high velocity. The two types of fans typically used are axial propeller type fans and centrifugal squirrel cage type fans. The present invention is directed to improvements in axial fans because of their lower electrical current requirements.
The corner between a wall and a floor is the most difficult area to dry and takes the longest time to dry. The present invention addresses and solves this problem with an axial flow fan. The invention has particularly desirable application to water damage restoration, though may be used in other applications therebeyond.
The present invention focuses the drying air toward the problem area of the room. In the preferred embodiment, this is accomplished by a desirably shaped exhaust duct downstream of the axial fan blades, which exhaust duct both: a) provides expansion of the airflow where desired; and b) directs the airflow where desired. In one particularly desirable embodiment, the exhaust duct geometry directs expansion of air into a problem area such as a corner by allowing the air to expand predominantly only in one direction chosen to be the direction of the most difficult to dry location in the room.
In one aspect, a downwardly sloping ramp is provided in the exhaust duct. The ramp is located at a downstream location spaced from the axial fan blades as far as possible, and the ramp pitch is minimized, due to the inability of the axial fan blades to produce static pressure. Without static pressure, if one attempts to expand the air too quickly, the result is a dramatic loss of velocity. The length of the duct downstream of the blades must be optimized. Too long of a length is a waste of material, whereas too short of a length will not provide desirably directed airflow.
In the preferred embodiment, the length of the duct upstream of the axial fan blades is minimized, to allow the blades to be supplied or “fed” with as much air as they can possibly move, and to avoid starving the blades for supply air. An intake cowling is provided and enhances this supply air.
In further embodiments, the axial fan blades are moved as close as possible to the wall and/or floor. This is desirable so that intake air does not have to change direction and accelerate before becoming exhaust air, or only has to undergo minimal directional change. The air moving through the fan stays close to the wall and/or floor in order to dry the wall and/or floor, particularly at the corner. Keeping the blades close to the wall and to the floor also eliminates the need for large radiused round cowling sections at the wall and/or the floor because the wall and floor upstream of the intake acts as a section of intake “duct”. This “duct” helps the air to establish an axial direction of flow, and hence aids in supplying the blades with intake air. This intake air also aids in structure drying. In further embodiments, the remaining cowling sides opposite the wall and the floor may have maximized radii in order to aid air supply, with the limiting factor being exterior housing dimensions. In preferred embodiments, all exterior housing surfaces are shaped for portability and storable stackability.
Further desirable aspects include stator vanes removing downstream rotation from the air and transferring same into useful axial air velocity. In another aspect, stand mounting pads are provided with threaded inserts, allowing the operator to mount the fan quickly on a stand and pointed in a desired direction. In another aspect, motor mounting pads are provided, allowing for rigid assembly of the motor to the fan housing. In another aspect, desirable electrical component location is provided, allowing the operator to quickly and easily access and use the controls without bending over, and to quickly and easily access and use the controls in each of a first fan orientation providing a counterclockwise drying flow pattern around a room, and a second fan orientation providing a clockwise drying flow pattern around a room. In another aspect, a handle is offset to one side so that the operator does not have to carry the fan farther away from his/her body. The handle is also parallel to a flat side of the fan such that the operator does not have to twist his/her arm when carrying it nor have obstruction to the natural motion of his/her legs when walking. The handle is located close to the center of gravity, and when held, the fan hangs close to vertical and does not interfere with walking. In a further aspect, interlocking nubs are provided, allowing multiple fans to be stacked on one another. In another aspect, a cord wrap is provided, storing the cord within the circumscribing cuboid, keeping the cord out of the way during storage and transfer. In another aspect, variable height legs are provided, establishing a selectable pointed airflow angle, and allowing for air circulation below the fan.
Housing 52 is a plastic molded member, preferably polyethylene, preferably formed by rotational molding or blow molding, having an upstream inlet section 54 and a downstream outlet section 56, with an outer perimeter parting line 58 and an inner perimeter parting line 60 therebetween. Upstream section 54 provides an intake cowling receiving intake air as shown at arrow 38, and section 56 provides an exhaust cowling discharging exhaust air as shown at arrow 39. The inlet side of the housing is protectively covered by a grate 62, and the outlet side of the housing is protectively covered by a grate 64. Exhaust cowling 56 has a tapered ramp 66,
Exhaust cowling 56 has a downstream end 68 having an outlet face 70 lying in a plane preferably perpendicular or transverse to the rotational axis 30 of the fan hub. In other embodiments, axis 30 may be positioned at the noted compound cone angle within the noted cone, though the disclosed embodiment is preferred for easier manufacture, with face 70 perpendicular to axis 30, and the angle of axis 30 and axial flow direction 38, 39 being varied relative to wall 24 and/or floor 26 by variable height legs 162, 164, 166, 168, to be described. Outlet face 70 has a noncircular shape of variable radius from axis 30. Outlet face 70 is defined by an inner perimeter 72 and an outer perimeter 74 at downstream end 68 of exhaust cowling 56. At least one and preferably both of the noted perimeters have a noncircular shape of variable radius. Each of perimeters 72, 74 has a perimeter corner at room corner 22, namely an inner perimeter corner 76 at room corner 22, and an outer perimeter corner 78 at room corner 22. Outer perimeter 74 has straight sides 80 and 82 meeting at outer perimeter corner 78. Side 80 extends along wall 24. Side 82 extends along floor 26. Inner perimeter 72 has straight sides 84 and 86 meeting at inner perimeter corner 76. Side 84 extends generally parallel to wall 24. Side 86 extends generally parallel to floor 26. The flat sides and the noted extensions along the wall and floor, in combination with the fan inlet side configuration, to be described, minimizes the spacing to the wall and floor and also minimizes the directional change for the air flow, which maximizes air velocity at surfaces 26 and 24, and thus volumetric air flow capacity. This results in a fan better suited for and more efficiently capable of drying either or both of surfaces 24 and 26 than prior fans.
Inner and outer perimeters 72 and 74 of outlet face 70 are radially spaced by a varying radial thickness therebetween. The varying radial thickness is at a minimum at wall 24 and floor 26, as shown at minimum radial thickness 88 and 90, respectively. Outlet face 70 has first, second, third and fourth segments 92, 94, 96, 98. First segment 92 is at room corner 22. Third segment 96 is diagonally opposite first segment 92 along a first diagonal line 100,
Outlet face 70 has first, second, third and fourth inner perimeter segments 104, 106, 108, 110. First inner perimeter segment 104 is at room corner 22. Third inner perimeter segment 108 is diagonally opposite first inner perimeter segment 104 along diagonal line 100. Second and fourth inner perimeter segments 106 and 110 are diagonally opposite each other along diagonal line 102. Outlet face 70 has a first inner perimeter diameter along diagonal line 100, and a second inner perimeter diameter along diagonal line 102, wherein the noted first inner perimeter diameter is greater than the noted second inner perimeter diameter. Outlet face 70 has an inner perimeter with a varying diameter thereacross. In the preferred embodiment, the varying diameter is at a maximum along diagonal line 100, and is at a minimum along diagonal line 102. Other embodiments may have other diameter relationships.
Intake cowling 54 has an upstream end 112 having an inlet face 114 lying in a plane preferably perpendicular or transverse to rotational axis 30 of the fan hub and of noncircular shape of variable radius from rotational axis 30. Inlet face 114 is defined by an inner perimeter 116 and an outer perimeter 118 at upstream end 112 of intake cowling 54. At least one and preferably both of perimeters 116 and 118 have the noted noncircular shape of variable radius. Outer perimeter 118 has an outer perimeter corner 120 at room corner 22. Outer perimeter 118 has first and second straight sides 122 and 124 meeting at outer perimeter corner 120. Side 122 extends along wall 24. Side 124 extends along floor 26. Inner and outer perimeters 116 and 118 are radially spaced by a varying radial thickness therebetween. The noted varying radial thickness is at a minimum at wall 24 and at floor 26 as respectively shown at 126 and 128, and is at a maximum at outer perimeter corner 120 as shown at 130, diagonally opposite quadrant 96.
Intake cowling 54 has an inner profile having a contoured intake surface 140,
Housing 52 has an inner profile further preferably having a blade location zone surface 152, preferably upstream of parting line 60, though such zone may be at parting line 60 or downstream thereof. The fan blades are shown schematically in the drawings, and have an axial span between a leading blade edge 35,
Upstream end 142 of contoured intake surface 140 defines a first cross sectional flow area. Downstream end 144 of contoured intake surface 140 defines a second cross sectional flow area. Upstream end 148 of contoured exhaust surface 146 defines a third cross sectional flow area. Downstream end 150 of contoured exhaust surface 146 defines a fourth cross sectional flow area. The noted first cross sectional flow area is greater than the noted second cross sectional flow area and greater than the noted third cross sectional flow area. Contoured exhaust surface 146 includes a ramp portion providing the noted tapered ramp 66 leading diagonally downwardly to room corner 22.
A front pair of legs 162, 164,
Housing 52 has first, second, third and fourth outer corners 170, 172, 174 and 176. First outer corner 170 is at room corner 22. Third outer corner 174 is diagonally opposite first outer corner 170 along diagonal line 100. Second and fourth outer corners 172 and 176 are diagonally opposite each other along diagonal line 102 perpendicular to diagonal line 100. Handle 178 on housing 52 is along diagonal line 100 and radially outboard of third outer corner 174. The housing has a leg 180 extending radially outwardly from fourth outer corner 176 along diagonal line 102 and engaging floor 26 to further support housing 52 on the floor. The handle is offset to one side, e.g., towards the inlet or the outlet, so that the operator does not have to carry the fan farther away from his/her body. The handle is also parallel to the flat inlet and outlet sides of the fan so that the operator does not have to twist his/her arm when carrying it nor have obstruction to the natural motion of his/her legs. The handle is also located as close to the center of gravity as possible of the fan, so that when held the fan hangs as close to vertical as possible and does not interfere with walking.
Stator vanes 44, 46, 48, 50 support motor 42 in the housing and have an inner radial end at the motor and an outer radial end at the housing. The stator vanes extend radially between the housing and the motor and also extend axially and block airflow rotation about axis 30 and instead direct such airflow axially. The housing has an inner profile having a plurality of shoulder stand-offs such as 182,
Further in the preferred embodiment, electrical controls for the fan are provided at an easily accessible location along the outer perimeter of the shroud housing as shown at 184, including a switch such as 186 and one or more outlet plugs such as 188, for providing electrical power to further downstream fans which may be connected in series or parallel. The location of the electrical component controls allows the operator to quickly and easily use the controls without bending over to the floor.
The inlet and outlet faces of the housing have a plurality of interlocking mating nubs and recesses such as 190, 192, 194, 196, 198, 200, etc. allowing vertical stacking of the fans (with axis 30 extending vertically), facilitating transport and/or storage. Leg 180 has recessed ends 202 and 204 providing a cord wrap for winding and storing the electrical cord within the entire fan's circumscribing cuboid, including during the noted stacking, thus keeping the cord out of the way during transfer and storage.
The housing has stand mounting pads 206 and 208 with threaded inserts 210 and 212 allowing the operator to mount the fan quickly on a stand and to point airflow 38, 39 along a desired direction.
External surfaces of the fan housing have a draft towards central parting line 58. This facilitates demolding of the plastic part. This also facilitates proper alignment of the fan to the wall. The draft angle of the external surfaces of the housing makes it easy for the operator to line up the axis of rotation of the fan at an angle to the wall.
The fan orientation shown in
It is recognized that various equivalents, alternatives and modifications are possible within the scope of the appended claims.
This application claims the benefit of and priority from Provisional U.S. Patent Application No. 60/550,012, filed Mar. 4, 2004. Reference is also made to commonly owned co-pending U.S. patent application Ser. No. 11/068,341, filed on even date herewith, incorporated herein by reference.
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