Patent Application
20080232958
This invention relates to blowers for drying just-washed vehicles in an automatic or semi-automatic car wash.
It is common in automatic and semi-automatic car washes to use electric motor-driven blowers to remove rinse water from just washed vehicles. In a typical drive through car wash, the blowers are mounted in multiples near the exit. They may also be mounted on rollover gantries.
Dryer blowers can take various forms; for example, rows of cylindrical tubes may be connected to an air plenum to direct air toward the surfaces of a vehicle. As another example, an air plenum or housing may be connected by rigid or flexible structures having long narrow outlets to create an air blade effect which drives rinse water from the surfaces of the vehicle, typically pushing the water from the front to back of the vehicle as it passes a dryer station.
Another example of dryer blower structures is the so-called “volute” or spiral blower wherein a motor driven impeller is mounted in a spiral housing with an axial air inlet. Air is collected around the impeller and spun toward a generally tangential outlet. The cross-sectional area of the air channel may be increased toward the outlet by gradually increasing the radial dimension of the housing such that it is a maximum next to the outlet.
Such a blower can be used essentially as is by mounting the blower housing such that the outlet is directed toward the exterior surface of a just-washed vehicle. The blower may also be converted to a blade-type dryer blower by adding a transition structure to the housing outlet. It is well known, however, that frictional drag in the transition section causes energy losses in the air stream and lowers the efficiency of the overall dryer system.
In the broadest sense, the present invention is an improved volute or spiral blower housing which accommodates a motor driven impeller to admit air axially to the impeller and in which the spiral air channel has a substantially constant radial dimension but increases in cross-sectional area as it progresses toward an outlet by virtue of increasing width such that the housing defines an air channel which progresses from a minimum width to a maximum width adjacent a tangential outlet. The outlet opening is preferably long and narrow so as to create an air knife or air blade effect without the need for an add-on transition section which produces energy losses.
In one form hereinafter described, the volute portion of the housing is asymmetric; i.e., one end wall is substantially planar while the other end wall moves progressively farther and farther away from the planar end wall to effect the increase in cross-section of the volute. In this embodiment, the motor itself is preferably mounted substantially within the volute such that the housing appears to “swallow” the motor while at the same time allowing substantial air circulation for cooling purposes. A screened inlet is created in or adjacent the essentially planar end wall and a transition section of conical shape may be employed to draw air into the impeller.
In another embodiment, two of the asymmetric housing blowers may be mounted side by side as to create a double-width, long, narrow air outlet, which can be used to remove water along the entire vertical or lateral dimension of a vehicle, even a large vehicle such as a van or truck. The air intakes are on the opposite outside ends of the tandem arrangement.
In a still third embodiment, a substantially symmetrical volute housing is created wherein both of the end walls progressively flare out and away from one another to create the air channel of increasing cross-sectional area.
Referring to
The housing 16 has on one side an essentially planar end wall 18 and on the other side an end wall 20 defining an air channel which increases in width, i.e., in the direction parallel to the axis of rotation of the motor 12 as it progresses toward an outlet section 22 having a long, narrow outlet opening 24. Air is inlet to the impeller through a cone 28 which is supported by a screw-mounted spacer 26 also supporting a safety screen 30. Annular plates 32 and 34 are provided for structural support to receive the screws 35. The impeller 14 is of conventional design with backward curved blades 36 and is mounted for rotation on the motor shaft 38 as previously described. The motor 12 has a typical switch box 44 and is mounted on a support bracket 42, partially enclosed within but spaced from the interior surface 45 of the housing 16.
In operation, the motor 12 is energized to rotate the impeller 14 drawing air through the screening 30 and the conical section 28 into the impeller 14. Air is collected by the impeller and rotated along the air channel defined by the housing 16 toward the transition section 22 and the long, narrow outlet 24. In this case, the length-to-width aspect ratio of the outlet 24 is approximately 12:1. It is to be understood that this aspect ratio is illustrative rather than limiting in nature.
The horizontal beam carries blowers 58 and 60 with the axial air intakes on the opposite outside surfaces; the intake safety screen 78 is shown on the far left side of the tandem combination 58, 60 as shown in
Blowers 62 and 64 are mounted in tandem on the upright 48 with the air outlets 66 and 68 in side by side alignment to create a double length air blade, the dimensions of which can, by way of example, be up to about 90 inches.
On the other side, blowers 70 and 72 having outlet transition sections 74 and 76 respectively are mounted on the upright 50 to dry the opposite side of a vehicle passing between them. Transition sections such as that shown at 84 may be used in combination with all of the tandem mounted blowers 62, 64 and 70, 72 for aesthetic purposes as desired.
Referring now to
Purely by way of illustration, the motors 12 and 90 may be of a ten horsepower rating and rotate at 3600 rpm to produce an air flow of between about 5,000 and 6,000 cubic feet of air per minute. Although the invention is not limited to these figures, they have been found to represent a commercially viable design suitable for use in many automatic and semi-automatic carwash installations.
