Abstract:
A compact, portable, easily installed, self-contained, negative pressure odor control vessel for odor control possessing oxidizing properties, as well as counter-vailing and absorption properties.

Description:
CROSS REFERENCES TO CO-PENDING APPLICATIONS  
       [0001]    This patent application is a continuation-in-part of Ser. No. 08/468,969 entitled “Odor Control Vessel” filed on Jun. 06, 1995, by the same inventors. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention is for an environmental scrubber, and more particularly pertains to an odor control vessel used for control of sulfides, mercaptans and other malodorous compounds generated in waste water collection and treatment systems and selected industrial processes.  
           [0004]    2. Description of the Prior Art  
           [0005]    Various odor control schemes are presently available; however, each includes one or more disadvantage. Spray atomization devices will only control odors which are directly contacted by a spray. Equipment and chemical costs for spray atomization devices are costly and somewhat inefficient. Activated carbon scrubbers will only absorb odors and have a short life. Hazardous waste problems are also associated with spent carbon. Bio-filters can create hazardous waste in spent media, and have relatively low removal efficiency. The use of deodorant blocks has also been incorporated, but was found to be very ineffective. Chemical additions were also used, but they prove to be very expensive and most are corrosive in nature. Oxidizing agents include chlorine, (chlorine/caustic) sodium and calcium hypochlorite, potassium permanganate and hydrogen peroxide. All are effective, but non-specific. Thus, they react with non-malodorous organic compounds which increases the cost of their use. As a group, these products generally pose safety problems—toxicity, the production of toxic by-products, inherent corrosive and explosive characteristics. Temperature and pH influence the effectiveness of most. Chlorine dioxide is an exception. Unwanted reaction with nitrogen-based compounds can not occur, it is much safer to handle and does not form chlorinated by-products. Clearly, what is needed is an effective and efficient reasonably priced and environmentally friendly odor scrubbing or control device, such as for large-scale applications.  
         SUMMARY OF THE INVENTION  
         [0006]    The general purpose of the present invention is an odor control vessel.  
           [0007]    According to one embodiment of the present invention, there is provided an odor control vessel, including a compartmentized vessel including an oxidizing chamber, a polishing chamber and a sealed fan chamber. Malodorous air is drawn through an air diffuser and through an oxidizing chamber containing oxidizing media, such as, but not limited to, diatomaceous earth, and then through a diffuser plate leading to the polishing chamber containing polishing media, such as, but not limited to, diatomaceous earth, for final scrubbing of the malodorous air. A fan, which creates a negative pressure in the space from which air is being drawn, then exhausts scrubbed air to the atmosphere. The odor control vessel is constructed for ready accessibility of the interior of the odor control vessel in order to facilitate rapid change-out of scrubbing materials in the oxidizing chamber and the polishing chamber. The odor control vessel offers economic, effective and broad malodor control to address and abate community and employee odor complaints in municipal waste water treatment or other industrial processes. The odor control vessel is placed in or adjacent to a lift station, grit room, headworks, desludge chamber, press room or other enclosed point sources from which foul air is fan drawn for scrubbing in the oxidizing and polishing chamber and vented to the atmosphere.  
           [0008]    One significant aspect and feature of the present invention is an odor control vessel incorporating the combination of oxidation, absorption and countervailing technologies to control odors.  
           [0009]    Another significant aspect and feature of the present invention is the utilization of scrubbing media which can be recycled.  
           [0010]    Still another significant aspect and feature of the present invention is an odor control device which utilizes a fan which is the only moving part.  
           [0011]    An additional significant aspect and feature of the present invention is an odor control vessel, the interior of which is easily and readily accessible for renewal and/or changeout of scrubbing media.  
           [0012]    A further significant aspect and feature of the present invention is an oxidizing media which releases chlorine dioxide.  
           [0013]    Having thus described embodiments of the present invention, it is the principal object of the present invention to provide an odor control vessel.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    Other objects of the present invention and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof and wherein:  
         [0015]    [0015]FIG. 1 illustrates an isometric view of an odor control vessel, the present invention;  
         [0016]    [0016]FIG. 2 illustrates an exploded view of the odor control vessel; and,  
         [0017]    [0017]FIG. 3 illustrates a cross sectional side view of the odor control vessel.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]    [0018]FIG. 1 illustrates an isometric view of an odor control vessel  10 , the present invention, for removal of hydrogen sulfide and other pungent, foul or otherwise offensive odors and smells from an enclosed area. Visibly illustrated components include a cylindrically shaped vessel  12  of plastic or other suitable material. A foul air intake tube  14  passes through a hole  15  at the bottom region of the vessel  12 , and a clean air exhaust tube  16  passes through a hole  17  the upper region of the vessel  12 . A vented cover  18  with a handle  20  aligns over and about the upper edge of the vessel  12 . The odor control vessel  10  divides into an oxidizing chamber  22  located in the lower region of the vessel  12 , a polishing chamber  24  located in the upper mid-region of the vessel  12  and a fan chamber  26  located in the upper region of the vessel  12 .  
         [0019]    [0019]FIG. 2 illustrates an exploded view of the non-chemical components of the odor control vessel  10  where all numerals correspond to those elements previously described. A one-piece molded air diffuser  28  includes intersecting open bottom manifold members  30  and  32  aligned and contiguous with a circular disk  34 . The circular disk  34  aligns to the bottom  36  of the vessel  12  to fully form the remaining portion of the manifold members  30  and  32 . End  32   a  of manifold  32  plumbs to the inner end of the foul air intake tube  14  as illustrated in FIG. 3. A plurality of vent holes  38   a - 38   n  are located along the upper curved areas of the intersecting manifold members  30  and  32 . An alternate air diffuser  40  having intersecting tubular manifold members  42 ,  44 ,  46  and  48  is illustrated to the left of air diffuser  28 . The alternate air diffuser  40  can be interchanged with the one-piece molded air diffuser  28 . A circular flexible plastic screen  50 , having slits  52   a - 52   d , divides the screen  50  into pie shaped segments  54   a - 54   d , and aligns over and about the intersecting manifold members  30  and  32  of air diffuser  28  to prevent entry of oxidizing media, such as stabilized oxidizing media  56  of FIG. 3, into the vent holes  38   a - 38   n . The oxidizing media will be further described in FIG. 3. Slits  52   a - 52   d  allow the pie shaped segments  54   a - 54   d  to deform and to conform to the general shape of the intersecting manifold members  30  and  32  to effect an effective screen seal of the vents  38   a - 38   n . A plurality of supports  58   a - 58   d  secure appropriately about the interior wall  60  of the vessel  12  and at the upper region of the oxidizing chamber  22  to support a middle air diffuser plate  62  which includes a plurality of diffuser holes  64   a - 64   n  of any suitable size. The holes can be covered with an optional polymer mesh or screen. The middle air diffuser plate  62  separates oxidizing chamber  22  from the polishing chamber  24 , as illustrated in FIG. 3. A plurality of wedge shaped supports  66   a - 66   d  secure appropriately about the interior wall  60  of the vessel  12  and at the upper region of the polishing chamber  24  to support the disk shaped blower chamber fan support member  68 . The wedge shape of the supports  66   a - 66   d  allows for easier tipping insertion or removal of the diffuser plate  62  due to the less restrictive geometry of the wedge shaped support members  66   a - 66   d . A fan  70  mounts to the fan support member  68 . As illustrated in FIG. 3, the intake  73  of fan  70  aligns to a hole  72  in the fan support member  68 . A plate  74 , having a plurality of orifices, covers the bottom of the hole  72  to prevent entry of polishing media  76  into the fan  70 . A flexible rubber coupling hose  78  secures over the output  80  of the fan  70  by a clamp  82 . A pipe member  84 , having a threaded outboard end, secures in the other end of the flexible rubber coupling hose  78  by a clamp  86 . The threaded end of pipe member  84  screwingly engages the interior of the clean air exhaust  16 . Decoupling of the fan  70  and fan support member  68  for replacement of treated media is readily accomplished by loosening clamp  86  and unscrewing the pipe member  84  from the interior threads of the pipe member  84 . The fan  70  and fan support member  68 , in addition to the diffuser plate  62 , are then removed for media renewal. An electric fan speed control  88  connects to the fan motor  90  and includes cord  92 .  
       MODE OF OPERATION  
       [0020]    [0020]FIG. 3, a cross sectional side view of the odor control vessel  10 , best illustrates the mode of operation where all numerals correspond to those elements previously described. A seal  94  aligns about the inner surface  60  of the vessel  12  to effect a seal between the fan support member  68  and the inner surface  60 . Seal  94  effectively seals the fan chamber  26  from the chemically treated oxidizing media  56  in the oxidizing chamber  22  and the polishing media  76  in the polishing chamber  24 . Air flow through the odor control vessel  10  is indicated by arrows starting at the foul air intake tube  14  which pass through the air diffuser  28 , oxidizing media  56  in the oxidizing chamber  22 , diffuser plate  62 , polishing media  76  in the polishing chamber  24 , perforated plate  74 , fan  72 , fan output  80 , coupling hose  78 , pipe member  84 , and finally through the clean air exhaust  16  where the scrubbed air is vented to the atmosphere. The forced air fan is optional, and air flow can be passive or natural, therefore not requiring a fan. The use of a controlled release chlorine dioxide oxidizing media  56 , such as, but not limited to, Persnickety Ox Pellets, Appendix A, available from Syneco Systems, Inc. in St. Louis Park, Minn., in conjunction with polishing chamber media  76 , such as, but not limited to, Countervailant™ impregnated diatomaceous earth, provides for safe, extremely effective broad spectrum malodor control. Referenced percentages of W/V available, chlorine dioxide can range from 4.5% to 11.5% and a cubic foot of the media can range from 2.48 to 6.34 pounds of chlorine dioxide.  
         [0021]    The polishing media  76  releases Countervailant™ chemistry. The oxidizing chamber media  56  releases chlorine dioxide which is impregnated into diatomaceous earth which is amorphous silica containing less than 1% of crystalline silica. The exact size, shape and density of medias  56  and  76  is determined by the needs of the specific odor control vessel  10 . These needs include a controlled and determined surface area exposed relative to the residence time of malodorous air in each chamber.  
         [0022]    The size, shape and density of the medias  56  and  76  is also determined by the size of the containment chamber, such as oxidizing chamber  22  and polishing chamber  24 . The dimensions requirements of medias  56  and  76 , for purposes of illustration and example, change with the sizes of oxidizing chamber  22  and the polishing chamber  24 . Larger sized oxidizing and polishing chambers  22  and  24 , respectively, require large sized oxidizing chamber media  56  and polishing chamber  76 , and smaller sized units require smaller sized oxidizing chamber media  56  and polishing chamber  76 . The crushing effect to lower layers of media  56  and  76  in larger chambers  22  and  24  require larger sized media  56  and  76  to resist such effects, smaller sized units may use smaller sized media  56  and  76  because the crushing effect is less, and smaller sized media optimizes available surface area exposed to the malodorous air being drawing through it.  
         [0023]    The chlorine dioxide-releasing oxidizing chamber media  56  incorporated in the oxidizing chamber  22  provides for an extremely powerful oxidizing agent. For example, one pound of chlorine dioxide is equivalent in oxidation power to 3.8 pounds of potassium permanganate. Because chlorine dioxide reacts selectively and primarily with only the most offensive odor producing compounds (hydrogen sulfide [H 2 S], organic sulfurs, organic amines, petroleum distillates), the odor control vessel  10  system will normally provide a much longer service life than other devices, such as activated carbon. Similarly, chlorine dioxide will remain intact longer than chlorine, hypochlorite, peroxide and permanganate. Unwanted reactions do not occur. Power is not needlessly spent. Chlorine dioxide remains available and ready on demand.  
         [0024]    The polishing chamber  24  protects against the escape of malodors, such as ammonia, which cannot be oxidized by chlorine dioxide. The Countervailant™ treated media  76  in chamber  24  allows other barriers to be built against the escape of malodors which cannot be readily oxidized.  
         [0025]    Countervailant™ technology is highly specialized, complex and broadly useful chemistry. It is especially effective on non-oxidizable odors, such as ammonia, and incorporates neutralization technology, but expands considerably beyond it. Polymeric absorption is a facet which involves the building up malodor molecules via electrostatic attractions and Van der Waals forces so that they are not recognized as malodors. The process of esterification is also incorporated. Acids and alcohols react to form esters. These esters normally have a pleasant scent. Countervailant™ technology is effective in dealing with malodors in both liquid and gaseous phases.  
         [0026]    Appendix 1 recites an oxidizing air scrubber and is attached hereto as Appendix 1.  
         [0027]    Various modifications can be made to the present invention without departing from the apparent scope hereof.