Abstract:
An extracting blower that removes liquid and solid contaminants from supply air, and provides high velocity air for cooling equipment, personnel and/or structures. The blower uses air velocity and the centrifugal force of a rotating fan to separate the contaminants into a rear partitioned chamber of the fan housing and out a rear scavenging air exhaust, while blowing clean air out the main air blower.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U. S. Provisional Application No. 60/131,918, filed Apr.30, 1999. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to extracting blowers. Specifically, this invention relates to extracting blowers that intake atmospheric air including liquid and solid particles and that separate the liquid and solid particles from the atmospheric air thereby generating clean air. 
     2. Description of the Related Art 
     Blowers for cooling and ventilation are well known in the industry. However, environmental air contaminants, such as airborne dust, water and other liquid vapors, and other light matter create a problem for blowers and their use. The contaminants become trapped in the blower itself, creating a build-up or sludge, which diminishes the effectiveness and useful life of the blower. Of greater significance, blowers that are unable to clean the air from these contaminants will pass them through and blow them on the area being cooled. Often, this area includes equipment that is sensitive to such contaminants, such as electrical equipment, rotating equipment and other structures and machines. It would therefore be a useful improvement on industrial blowers to include an improved design to remove such contaminants. 
     Prior art includes several designs for blowers that scrub blown air. However, many of these blowers rely on gravity to assist in the separation of the contaminants from the air, and therefore are only effective in removing larger contaminant particles. Other blowers use a complex system of baffles, filters, secondary pressure pumps or fully enclosed housings, which are difficult to maintain, clean and operate. It would therefore be a useful improvement to blower fans for the design to remove dust and liquid contaminants from the intake air while using relatively few moving parts and having convenient internal access for case in maintenance and operation. 
     BRIEF SUMMARY OF THE INVENTION 
     Air blowers are used in a variety of industries to provide cooling air to personnel, structures and equipment. Oftentimes, the air supply for these air blowers is contaminated with solids (e.g., dirt, grease, metallic and non-metallic dust) and/or liquids (e.g., water, organic and inorganic chemical vapors). These contaminants in the air being blown can damage equipment by compromising electrical circuits, reducing the efficiency of rotating equipment and decreasing the life of the equipment due to increased friction, corrosion and abrasion between moving parts. 
     Accordingly, the objectives of this invention are to provide, inter alia, an air blower that: 
     mechanically removes solid and liquid contaminants from a local air supply; 
     provides clean and dry forced air of sufficient velocity, quantity and pressure for cooling purposes; and 
     has a low maintenance requirement due to simple design and minimal moving parts. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of the extracting blower, not including the fan. 
     FIG. 2 is a cross-sectional view taken along line  3 — 3  of FIG. 1, including one embodiment of the fan and including the annular baffle. 
     FIG. 3 is a cross-sectional view taken along line  3 — 3  of FIG. 1, including a preferred embodiment of the fan. 
     FIG. 4 is a cross-sectional view taken along line  4 — 4  of FIG.  2 . 
     FIG. 5 is a cross-sectional view taken along line  5 — 5  of FIG.  2 . 
     FIG. 6 is a cross-sectional view of a fan wiper shown in FIG.  3 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The Extracting Blower is generally shown in FIGS. 1-6 as  10 . Extracting blower  10  generally comprises a fan  20  that rotates within housing  100 . As depicted in FIG. 2, housing  100  is divided into a front chamber  102  and a rear chamber  104 . Fan  20  includes a conical shaped back plate  26  and a plurality of fan blades  28  extending therefrom. Back plate  26  has a back plate front side  31 . Fan blades  28  extend partially within front chamber  102  and partially within rear chamber  104 . Back plate  26  constitutes a barrier between front chamber  102  and rear chamber  104  while permitting a degree of fluid communication between front chamber  102  and rear chamber  104 . 
     In short, air including liquids and solids (hereinafter referred to as “Dirty Air”) enters housing  100  through air intake opening  108  and hits rotating fan  20 . The liquids and solids of the Dirty Air strike the back plate  26 , and due to the centrifugal force generated by the rotating fan  20 , migrate outward along the back plate  26  together with a small regulated amount of air. Fan  20  and housing  100  are constructed so that only such migrating liquids, solids, and small regulated amount of air pass into rear chamber  104  and out of rear chamber  104  through a rear chamber contaminant exhaust outlet  120 . The remainder of the air does not pass into rear chamber  104  and is instead forced out of front chamber  102  through a front chamber clean air outlet  118 . Thus, the liquid and solid particles are separated from the Dirty Air, and air excluding at least some of the liquid and solid particles (hereinafter referred to as “Clean Air”) flows through front chamber clean air outlet  118 . 
     Housing  100 , as previously disclosed, includes a front chamber  102  and a rear chamber  104 . In the preferred embodiment, housing  100  has a generally cylindrical shape and includes a front wall  106 , a rear wall  110 , and a side wall  114 . Front wall  106  and rear wall  110  generally correspond to the circular ends of the cylindrical shape, and side wall  114  generally corresponds to the height of the cylindrical shape. Alternatively, front wall  106  defines a partial convex shape. 
     Front wall  106  includes an air intake opening  108  through which Dirty Air flows into housing  100 . Preferably, air intake opening  108  is concentrically located on front wall  106 . Rear wall  110  includes a rotor drive shaft opening  112  through which the rotor drive shaft  22  of fan  20  extends into housing  100 . Preferably, rotor drive shaft opening  112  is concentrically located on rear wall  110 . 
     In its interior, housing  100  also includes a chamber partition  116  preferably fixedly attached to side wall  114 . In the preferred embodiment, chamber partition  116  is substantially parallel to rear wall  110 . Chamber partition  116  includes a partition opening  117 , which is generally circular in the preferred embodiment, through which the fan  20  extends. Preferably, partition opening  117  has an opening center concentrically located on chamber partition  116  and is also concentric with rotor drive shaft opening  112 . 
     In the preferred embodiment, front chamber  102  is defined by front wall  106 , side wall  114 , and chamber partition  116 . In the preferred embodiment, rear chamber  104  is defined by rear wall  110 , side wall  114 , and chamber partition  116 . 
     Front chamber  102  also includes a front chamber clean air outlet  118  which provides fluid communication between front chamber  102  and the exterior of housing  100 . Front chamber clean air outlet  118  preferably comprises a first passage  119  providing fluid communication between front chamber  102  and the exterior of housing  100 . 
     Rear chamber  104  also includes a rear chamber contaminant exhaust outlet  120  which provides fluid communication between rear chamber  104  and the exterior of housing  100 . Rear chamber contaminant exhaust outlet  120  preferably comprises a second passage  121  providing fluid communication between rear chamber  104  and the exterior of housing  100 . 
     In the embodiment shown in the Figures, housing  100  includes a tangential section  130 . Tangential section  130  continues the division of housing  100  between front chamber  102  and rear chamber  104 . Chamber partition  116  extends within tangential section  130  enabling such division within tangential section  130 . In one embodiment, front chamber clean air outlet  118  and rear chamber contaminant exhaust outlet  120  are located on tangential section  130 . It is understood, however, that extracting blower  10  does not require a tangential section  130  to function. Although not shown in the Figures, extracting blower  10  would be functional if side wall  114  was completely circular (not including tangential section  130 ) and front chamber clean air outlet  118  and rear chamber contaminant exhaust outlet  120  were located directly on side wall  114 . 
     Fan  20  includes a conical shaped back plate  26  and a plurality of fan blades  28  extending therefrom, as previously disclosed, as well as a rotor drive shaft  22 , which is aligned along fan axis  23 , which is generally perpendicular to rear wall  110 . Rotor drive shaft  22  extends through the rotor drive shaft opening  112  of rear wall  110  into rear chamber  104 . Exterior to housing  100 , rotor drive shaft  22  is functionally attached to a motor  200  which generates the rotation of rotor drive shaft  22 . Motor  200  may be an electric motor, an internal combustion engine, a steam engine, a gas turbine or any other mechanical device known in the field for producing rotational power through a rotor drive shaft. In the preferred embodiment, motor  200  is an electric motor. 
     Conical shaped back plate  26  is fixedly, and preferably concentrically, attached to rotor drive shaft  22 . In addition, back plate  26  is located within rear chamber  104  and is situated therein so that the reflex angle  34  defined by back plate  26  is proximate rear wall  110  and so that the obtuse angle  36  defined by back plate  26  is proximate chamber partition  116 . Obtuse angle  36  preferably measures between 140 and 160 degrees (70°-80° measured between fan axis  23  and back plate  26 ). Back plate  26  is rotatable about fan axis  23 , thus obtuse angle  36  can be described as the sum of acute angles  37 , defined between back plate  26  and fan axis  23 . In the preferred embodiment, obtuse angle  36  measures 150 degrees (75° measured between fan axis  23  and back plate  26 ). The outer cross-sectional diameter of back plate  26  is slightly larger than the cross-sectional diameter of the partition opening  117  of chamber partition  116  so that a portion of back plate  26  overhangs chamber partition  116 . 
     The plurality of fan blades  28  are fixedly attached to back plate  26 , on the side of back plate  26  including obtuse angle  36 . Each fan blade  28  extends from back plate  26  within rear chamber  104  through the partition opening  117  of chamber partition  116  and into front chamber  102 . Each fan blade  28  includes an outer edge  30  adjacent chamber partition  116 . As shown in FIG. 2, chamber partition  116  and each fan blade  28  are constructed so that a first small gap  38  is defined between each fan blade outer edge  30  and chamber partition  116  (as the perpendicular distance therebetween). First small gap  38  is uniform throughout the entire circumference of partition opening  117 . After experimentation, it has been discovered that an acceptable size for first small gap  38  is ¼ inch, although other sizes (smaller or larger) would also function. 
     A second small gap  40  is defined between each fan blade  28  and the side of chamber partition  116  facing rear wall  110 . In one embodiment as shown in FIG. 2, each fan blade  28  includes a lip  32  on its outer edge  30  adjacent back plate  26 . Lip  32  defines a larger fan diameter within rear chamber  104  than the smaller fan diameter defined by fan edge  30  in front chamber  102 . Each lip  32  must be located within rear chamber  104  (between chamber partition  116  and back plate  26 ) and extends radially outward so that it overhangs chamber partition  116 . Second small gap  40  is in this embodiment defined between each lip  32  and chamber partition  116  (as the perpendicular distance therebetween). Second small gap  40  is preferably uniform throughout the circumference of chamber partition  116 . After experimentation, it has been discovered that an acceptable size for second small gap  40  is ¼ inch, although other sizes (smaller or larger) would also function. 
     Although the fan blades  28  shown in the FIG. 2 extend in a direction perpendicular to the back plate  26 , it is understood that the fan blades  28  could extend in any angular direction from back plate  26  and still be within the scope of this invention in all embodiments. In addition, although the fan blades  28  shown in the Figures extend in a linear radial direction from the center of back plate  26 , it is understood that the fan blades  28  could extend in any curved or arced radial direction from the center of back plate  26  and still be within the scope of this invention in all embodiments. Moreover, although the fan blades  28  shown in the Figures have a cross-sectional shape that is generally triangular (see FIGS.  2  and  3 ), it is understood that the fan blades  28  could be any cross-sectional shape and still be within the scope of this invention. 
     In the preferred embodiment shown in FIG. 3, fan blades  28  extend radially outward until outer edge  30  and lip  32  are radially equidistant from rotor drive shaft  22 . In the preferred embodiment, fan blade notch  217  in fan blades  28  afford fluid communication between front chamber  102  and rear chamber  104 , and are defined by first small gaps  238 , second small gaps  240  and third small gaps  239 . First small gap  238  is defined between each fan inner gap edge  43  and partition edge  113  (as the uniform perpendicular distance therebetween). After experimentation, it has been discovered that an acceptable size for first small gap  238  is ¼ inch, although other sizes (smaller or larger) would also function. Second small gap  240  is defined between fan rear gap edge  250  for each fan blade  28  and the chamber partition rear side  213 . Third small gap  239  is defined between fan front gap edge  255  for each fan blade  28  and the chamber partition front side  216 . 
     As depicted in FIG.  3  and FIG. 6, a wiper  29 , comprising a polygonal, preferably rectangular, cross section and attached to each fan blade  28 , is oriented normal to back plate  26  and on a bias to fan blade leading surface  128  of fan blade  28 . Wiper  29  is positioned from rear gap corner  35  to front blade corner  33 , such that wiper  29  does not interpose fan blade notch  217 , and extends aligned with blade front edge  41 . Wiper  29  has a preferred thickness in the range of ⅛ to ¼ inch and a preferred height of ½ inch, although smaller or larger heights are functional. As contaminants strike fan blade leading surface  128  and migrate toward fan blade outer edge  30 , they are assisted in their directional movement towards rear chamber  104  via back plate  26  by the channeling effect of wiper  29 . 
     In one embodiment as shown in FIG. 2, fan  20  also includes a front ring  42  attached to the end of each fan blade  28  distal back plate  26 . Front ring  42 , or like structures, are known in the art, and is preferably shaped so that its outer cross-sectional diameter is smaller than the cross-sectional diameter of the air intake opening  108  of front wall  110 . 
     In the embodiment of housing  100  including tangential section  130 , tangential section  130  is oriented so that it is tangential to the rotational direction of fan  20 . 
     In one embodiment as shown in FIG. 2, housing  100  also includes an annular baffle  140 . Annular baffle  140  is fixedly attached to the circumference of the air intake opening  108  and is constructed and oriented so that it directs air towards the interior of housing  100 , specifically, front chamber  102 . 
     In Operation 
     In operation, the motor  200  of extracting blower  10  is first activated. Activation of motor  200  induces drive means for rotation of rotor drive shaft  22  which in turn induces the rotation of fan  20 . The rotation of fan  20  creates a suction or negative pressure through air intake opening  108 , which prompts supply air (Dirty Air) surrounding the front exterior of housing  100  to enter housing  100  through air intake opening  108 . 
     As previously disclosed, Dirty Air encompasses air that includes liquid and solid particles, and Clean Air encompasses air excluding at least some of such liquid and solid particles. As is well known in the art, it is understood that the heaviest components of Dirty Air are the liquid and solid particles included therein. 
     The Dirty Air entering housing  100  through air intake opening  108  enters front chamber  102  at a relatively high velocity, which high velocity is generated by the suction and also by annular baffle  140  (in the embodiment including the same). Such high velocity partly ensures that the heavier liquid and solid particles of Dirty Air strike the back plate  26  of fan  20  whereas the lighter air particles of Dirty Air are substantially diverted from striking the back plate  26  of fan  20  by the rotational motion of the fan blades  28 . 
     The heavier liquid and solid particles of Dirty Air thus enter front chamber  102  at a high velocity and strike back plate  26 . The rotational motion of fan  20 , as is known in the art, circulates the air and generates a centrifugal force which forces elements radially outward from fan  20  and back plate  26 . Thus, the centrifugal force causes the heavier liquid and solid particles of Dirty Air, together with a limited and regulated amount of the lighter air particles, to migrate along back plate  26  in a direction radially outward from fan  20 . Ultimately and due to the existence of first small gap  38  as well as the location of back plate  26  within rear chamber  104 , the migrating heavier liquid and solid particles of Dirty Air (together with a limited and regulated amount of the lighter air particles) pass through second small gap  40  (or fan blade notch  217  in the preferred embodiment) and enter rear chamber  104 . 
     The lighter air particles of Dirty Air (or Clean Air) also enter front chamber  102  at a high velocity; however, due to their relatively lighter weight, are substantially diverted from striking back plate  26  by the rotational motion of the fan blades  28 . The rotating fan blades  28 , instead, direct the Clean Air tangentially outward within front chamber  102  and exhausts the Clean Air out of housing  100  through front chamber clean air outlet  118 . Clean Air exiting front chamber clean air outlet  118  is thus free of contaminants and can be used as a source for relatively clean cooling air. 
     The heavier liquid and solid particles of Dirty Air (together with a limited and regulated amount of the lighter air particles) that have now entered rear chamber  104  through second small gap  40  next exit rear chamber  104  through rear chamber contaminant exhaust outlet  120 . This egress is, at least in part, caused by the differential in pressure between the front chamber  102  and the rear chamber  104 . Due to, among other things, the rotation of fan  20 , the greater amount of Clean Air within front chamber  102 , and the small sizes of first small gap  38  and second small gap  40 , the pressure within front chamber  102  is substantially higher than the pressure within rear chamber  104 . This difference in pressure acts to exhaust any elements located within rear chamber  104  out through rear chamber contaminant exhaust outlet  120 . Thus, the heavier liquid and solid particles of Dirty Air (together with a limited and regulated amount of the lighter air particles) located within rear chamber  104  exit rear chamber  104  through rear chamber contaminant exhaust outlet  120 . Such elements exiting through rear chamber contaminant exhaust outlet  120  may be transmitted to a waste disposal site or used for other suitable purposes. 
     It is noted that the difference in pressure between front chamber  102  and rear chamber  104  can be controlled and adjusted by changing the dimensions of, among other elements, front chamber clean air outlet  118 , rear chamber contaminant exhaust outlet  120 , first small gap  38 , and second small gap  40 . It is also noted that the difference in pressure between front chamber  102  and rear chamber  104  is important in order to ensure that the heavier liquid and solid particles of Dirty Air (together with a limited and regulated amount of the lighter air particles) do migrate through second small gap  40  (or fan blade notch  217  in the preferred embodiment) and into rear chamber  104  instead of remaining within front chamber  102 . 
     The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.