Abstract:
A pair of high speed blowers are pivotally mounted in a vertical plane on a movable frame structure. Each blower has blades turning in an opposite direction from the other blower. The blowers are locked in place at an angle of 10 to 60 degrees with respect to each other so that air emanating from the blowers impinge on each other downstream from the blowers. The air impingement creates a triangular type expanding air stream pattern downstream from the impingement area.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a forced air flow ventilation system. More specifically, it refers to the employment of two or more blowers mounted on a frame having an air flow pattern such that the air from separate blowers turning in different directions impinge upon each other at varying angles to produce a wide fan pattern of air. 
     Typically, prior art fans or blowers are mounted to expel blown air directly in front of the blower. In U.S. Pat. No. 5,370,576 a pair of truck cab blowers are mounted one above the other to force outside air into the truck cab. Fan housing cover plates are pivoted to either an open or closed position. Air flow adjustment members  74  and  76  are rotated to independently adjust the air discharge direction. There is no suggestion for rotating the air flow adjustment members so that the air flow from separate blowers impinge upon each other. In U.S. Pat. No. 5,643,082, a series of blowers or fans are installed in a building wall in separate frames. Each blower emits an air stream into the building directly from the front of the blower. There is no air flow from adjacent blowers that impinge upon each other. 
     The air flow pattern from separate blowers is limited by the size of the blower and the position of the blower with respect to its target. A system is needed which will extend the flow pattern to a wider area from a given number of blowers. 
     SUMMARY OF THE INVENTION 
     The present invention provides a system for expanding the flow pattern of a pair of blowers so that a greater area is affected by the impingement of the blower air streams. Therefore, the air flow area covered by the two impinging air streams is greater than the sum of the air streams for the two blowers acting independently, side by side. 
     A pair of blowers are pivotally mounted one above the other in a vertical frame structure. The fan blades in one blower turn clockwise and the fan blades in the other blower turn counterclockwise. The blowers have a protective grate in front of multiple blades, but no other structure impedes the flow of air from each blower. The blowers are locked in place at an angle of 10 to 60 degrees with respect to each other so that air emanating from the blowers impinge on each other at a point spaced from the front of the blowers. This impingement creates a fan-like pattern that expands outwardly and downstream from the impingement point. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which: 
     FIG. 1 is a front perspective view of a movable frame structure on which is mounted two blowers. 
     FIG. 2 is a back perspective view of a single blower locked within the movable frame structure of FIG.  1 . 
     FIG. 3 is a diagrammatic view of an air stream fan-like pattern produced from impinging air streams from a pair of blowers. 
     FIG. 4 is a diagrammatic view of an air stream fan-like pattern produced from an impinging air stream as in FIG. 3, but with a different angle position of the blowers. 
     FIG. 5 is a front perspective view of an expanded frame structure for mounting blowers. 
     FIG. 6 is an exploded view of the frame elements for the blower mounting structure. 
     FIG. 7 is an exploded view of the bottom frame elements for the blower mounting structure. 
     FIG. 8 is perspective view of another bottom frame element for the blower mounting structure. 
     FIG. 9 is a side view of a blower locked within its frame structure, but with an alternate locking mechanism as compared to FIG.  2 . 
     FIG. 10 is a side view of a blower as in FIG. 9 with the blower adjusted to a different angle. 
    
    
     DETAILED DESCRIPTION 
     Throughout the following detailed description, the same reference numerals refer to the same elements in all figures. 
     The movable frame structure  10  of FIGS. 1 and 2 has a first blower  12  and a second blower  14  pivotally mounted therein. A motor  16  powers each blower having seven fan blades  18 . More or less fan blades can be employed. One blower has blades  18  turning clockwise and the other counterclockwise. A flange  20  extension on a blower support  19  retains the blower  12  in a first position. Pin  21  inserted into holes on a side plate  23  cause the blower to point downward at one of two different angles. Likewise, a corresponding side plate  25  with pin  21  inserted can angle blower  14  upwardly as shown in FIG.  3 . Each blower is mounted within an integral cage structure  24 . The cage structures  24  are composed of tubular elements  56  and  58  having a hollow interior portion  26  for receiving connector elements  28  as shown in FIG.  6 . Each connector element  28  has through bores  30  for alignment with bore  32  in a lower cage structure element  56  and to bores  34  in an upper cage structure element  58 . Through bolts  36  held in place by nuts  38  provide a connection with element  28  between top  58  and bottom  58  cage structure. 
     FIGS. 7 and 8 show a connector  40  which engages a wheel mounting structure plate  42 . Bores  44  in plate  46  at the base of connector  40  are aligned to bores  48  in plate  42 . Bolts  50  attach the plates  42  and  46  together. Bolts  52  attach the bottom cage structure  56  to the connector  40 . Wheels  54  are used to move frame structure  10 . Brake  80  prevents further movement of frame structure  10 . 
     FIG. 5 shows an expanded frame structure  10   a  which could accommodate a third blower enclosed within cage structure  59 , or merely can be used to raise the blowers  12  and  14  to a higher level. 
     FIGS. 3 and 4 show the blowers  12  and  14  angled toward each other so that airstream  60  from blower  12  impinges on airstream  62  from blower  14  causing a fan-like pattern  64  of expanded air flow to be produced. 
     The impingement blowers  12  and  14  employed in this invention are driven by about a one h.p. motor  16 . The diameter of the blower front face  66  can vary from 10 inches to 42 inches. The following is a range of the air flow in cubic feet per minute (CFM) and feet per minute (FPM) for typical diameter blowers. 
     12 inch diameter blower: 
     5,000-9,000 CFM 
     3,000-6,000 FPM 
     24 inch diameter blower: 
     6,000-12,000 CFM 
     2,000-5,000 FPM 
     36 inch diameter blower: 
     8,000-20,000 CFM 
     800-2,500 FPM 
     The impingement angle between blowers  12  and  14  to obtain a maximum airflow  64  is 10 degrees to 60 degrees. 
     FIGS. 1 and 2 show adjustment of the blower angle and locking with pins  21  in the holes of side plate  23  or  25 . FIGS. 9 and 10 show an alternate means of adjustment of the blower angle and locking with a screw-down handle  68  positioned within slot  70 . The pivot point  22  remains the same for either adjustment means. A plate  72  bolted to the blower outer housing  74  supports rod  76  which rotates at pivot point  22 . 
     The wide air flow  64  generated by the impingement of flow  60  and  62  is carried out without the need for louvers or external duct work. Thus, there is an uninterrupted flow of air from each blower to the impingement site where the flow expands outwardly. 
     In the use of this invention, for example, two eighteen inch diameter high velocity blowers directed at each other at an angle of 30 degrees produces an air flow fan pattern of 40-50 feet in width from a distance 50 feet away from the blowers. The exact air flow air pattern will vary depending on the adjusted impingement angle between the blowers  12  and  14 . 
     By making the impingement angle adjustable it allows the user to make adjustments in pattern width and projected air velocity of the air pattern so an entire work area is in compliance with O.S.H.A. regulations. The use of this device replaces the costly and only partially effective workplace duct/vent configurations. Since the two blowers are mounted on a movable frame they are portable. Unlike the duct work which is typically permanent, the mobile impinging blowers of this invention offers the end user a much higher degree of flexibility when trying to address a workplace concerned with air movement. Also, unlike prior art duct work installations, the impinging air streams of this invention produce a wide uniform air flow that does not have any “dead spots” where air movement is absent. 
     Another application for the adjustable impinging blowers is evaporative cooling applications. The blowers  12  and  14  would work similar to an atomizing spray gun air cap but on a much larger scale. They could be adjustable to introduce a liquid stream of water into the intersection point of the air streams  60  and  62  and obtain superior atomization of the water which would aid in evaporative cooling applications as shown in U.S. Pat. No. 5,643,082, incorporated herein by reference. In fact, for super fine atomization of the liquid, the water could be first atomized by conventional methods such as primary air atomization or hydraulic (airless high pressure) atomization and then directed into the intersection point of air streams  60  and  62  from the blowers  12  and  14  respectively, where the water would go through secondary atomization reducing it to an even smaller droplet size and distributing the droplets evenly throughout the air pattern  64  produced by the two blower air streams  60  and  62 . Again, because the blowers are adjustable the evaporative cooling air pattern could be directed over a large area to cool it very effectively. The large flow rates of air produced by the blowers also could handle extremely high flow rates of water without sacrificing atomization quality. It is possible for the aforementioned type of system to be used effectively for the manufacturing of artificial snow. A large scale adjustable impinging blower system could be used with a high volume water supply to greatly speed up the manufacture and placement of artificial snow in an extremely large area. Present systems utilize single jet atomization orifices which take mm more time to cover an area since the pattern produced is circular and the volume of water handled is much lower. 
     A stop or brake  80  shown in FIG. 8 is used to prevent movement of the structure  10  when a fixed mode is desired. 
     Other equivalent elements can be substituted for the elements disclosed herein to produce the same results in the same way.