Abstract:
The present invention discloses an induced aeration device which utilizes a housing containing a plurality of slats having an air inlet on its bottom and an air outlet on its top. The housing contains a horizontally rotatable water distribution arm having horizontal water outlets directed in a reverse direction to that of rotation so that the distribution arm turns in response to the force created by the water outlet jets. A fan is disposed on top of the water distribution arm so that the fan turns with the water distribution arm. Further, the fan is effectively sized to induce the flow of air through the housing in sufficient quantity to aerate the influent water flow.

Description:
[0001]    This application benefit of Provisional Application Serial No. 60/223,297 filed on Aug. 7, 2000. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention generally relates to aeration devices and, more particularly, is concerned with an induced draft aeration device.  
           [0004]    2. Description of the Prior Art  
           [0005]    Induced draft aerators have long been used in treatment of water for the removal of volatile gasses and the oxidation of dissolved minerals commonly found in water. Common uses are for the removal of gasses such as carbon dioxide, hydrogen sulfide, and radon as well as the oxidation of iron and manganese for later removal by other treatment processes.  
           [0006]    An induced draft aerator operates by breaking water flow into small droplets that fall through the air to create a much greater contact area between the water and the air than normally occurs. This is accomplished by introducing the water into the top of a somewhat tall vessel containing many slats through which the water falls by gravity. Water splashing through the many levels of slats is broken into small droplets and is thereby aerated to allow volatile gasses to be released and to oxidize dissolved iron and manganese. A fan located at the top of the vessel draws or induces air from vents located near the bottom of the column up through the slats to provide a constant flow of fresh air around the water droplets. Air along with the removed gasses is exhausted through the fan.  
           [0007]    Previous designs utilize an electric motor to power a fan or blower. Problems that typically occur with this type of aerator are usually associated with the fan. Local power outages may cause the fan to not operate. Control system failure may not start the fan when required. Operator error may have the fan off line when it is needed. These and other potential problems that can cause the fan to not operate will result in less effective aeration and lower quality treated water.  
           [0008]    A search of the prior art has disclosed the following art:  
           [0009]    In U.S. Pat. No. 4,710,324 dated Dec. 1, 1987, Vesnaver disclosed a device for aerating water comprising (1) a fan within a pumping chamber for drawing air through an intake port and forcing air out an exhaust port therein, (2) a fan enabling means located outside the pumping chamber for moving the fan so that air is drawn through the intake port and out the exhaust port, (3) a means for insulating the pumping chamber from the heat created by the fan enabling means, and (4) a means for dispersing the air flowing out of the exhaust port and into water.  
           [0010]    In U.S. Pat. No. 4,796,319, dated Dec. 11, 1990, Eberhardt, et al., disclosed a portable water-driven fan for firefighting applications utilizing positive pressure ventilation. A unit including a water-powered turbine and a fan is constructed to be light in weight and compact and is capable of delivering a large volume of air sufficient for positive pressure ventilation. The unit is provided with a plurality of spray nozzles which enables the unit to deliver a water mist along with the air.  
           [0011]    In U.S. Pat. No. 4,907,654, dated Mar. 13, 1990, Eberhardt disclosed a fan system for use in firefighting applications employing positive pressure ventilation which includes a lightweight portable fan having a water-powered turbine as its driver. A flow control valve is operable to set the system to operate in a plurality of modes including a mode wherein an air stream and a water mist can be directed toward the fire.  
           [0012]    In U.S. Pat. No. 5,779,999, dated Jul. 14, 1998, Laslo disclosed a method for scrubbing flue gases utilizing a spray tower for removing acidic gases and particulate matter from flue gases produced by processing operations of the type carried out in utility and industrial facilities. The spray tower is equipped with a tank that serves as a reservoir for an alkaline slurry used to remove acidic gases and particulate matter from the flue gases. The slurry is pumped from the tank to spraying devices located within the tower. The spray tower further includes an internal structure that enables the slurry to be oxidized and gently agitated within a limited region of the tank and without the requirement for two separate aeration and agitation devices. As a result, the construction, operation and maintenance costs of the spray tower are significantly reduced as compared to prior art spray towers.  
           [0013]    In U.S. Pat. No. 5,378,267, dated Jan. 3, 1995, Bros, et al., disclosed a modular air stripper apparatus comprised of a plurality of stacked air stripping chambers.  
           [0014]    In U.S. Pat. No. 4,906,338, dated Mar. 6, 1990, DeLoach disclosed a method for removing the volatile constituents from gasoline and volatile organic chemicals from contaminated potable water when a fluid including a gasoline-water mixture and when contaminated potable water is introduced into a vertical tower which includes the steps of flowing the gasoline-water fluid and the water downward in a tower over and in contact with media trays stacked in courses in the tower. The media trays, either circular or square, fit closely within the tower inner wall, such trays are aluminum or molded plastic frames one-inch by one-inch angles on-eighth inch thick, with a plurality of one and one-half inch wide slats one-quarter of an inch thick on the top of the frame; the slats being spaced apart not less than one-half inch nor more than three-quarters of an inch. The stacked trays are so arranged in courses that the slats of trays of alternate courses, but the slats of intermediary trays are disposed at ninety degrees to the slats of trays in the alternate courses. A column of air flowing upward through the media trays entrains the volatile constituents released from the gasoline, and the volatile organic chemicals liberated from the water, when the fluid contacts the media in the tower. A structure for exhausting the air and entrained volatile constituents is provided, and a structure is provided for removing fluid from the bottom of the tower.  
           [0015]    While these aeration devices may be suitable for the purposes for which they were designed, they would not be as suitable for the purposes of the present invention, as hereinafter described.  
         SUMMARY OF THE PRESENT INVENTION  
         [0016]    The present invention discloses an induced aeration device which utilizes a housing containing a plurality of slats having an air inlet on its bottom and an air outlet on its top. The housing contains a horizontally rotatable water distribution arm having horizontal water outlets directed in a reverse direction to that of rotation so that the distribution arm turns in response to the force created by the water outlet-jets. A fan is disposed on top of the water distribution arm so that the fan turns with the water distribution arm. Further, the fan is effectively sized to induce the flow of air through the housing in sufficient quantity to aerate the influent water flow.  
           [0017]    Various advantages of the present invention follow: By eliminating the need for electricity, this aerator should offer lower installation and operation costs. By not relying on electricity, this design is not effected by power outages Additionally, no controls are required to start an electric blower when flow is present since the flow itself powers the blower. Since there are no controls or power switches, a source of potential operator error is also eliminated.  
           [0018]    The action of the spray jets provides significant aeration of the flow in addition to the aeration that occurs in the slats. The motion of the distribution arms to evenly distribute the flow over the slats replaces large perforated trays commonly found on existing designs. A larger fan area produces high airflow without the higher velocities present in most electric blowers. By minimizing high air velocities in the fan section, greater airflow can be utilized without blowing mist out of the top of the aerator. These factors together result in an induced draft aerator that is more efficient, easier and less expensive to install, maintain, and operate than designs currently available.  
           [0019]    An object of the present invention is to provide an induced draft water aerator that requires no electrical power or controls to operate. The key feature of this invention that distinguishes it from similar equipment currently available is that it utilizes the water itself to turn a mechanism that both distributes water within the aerator and provides airflow through the water to enhance aeration. This eliminates all problems associated with an electric motor that is normally used to induce airflow. It is unaffected by power outages or operator error. Furthermore, no control system is required to activate the fan whenever there is flow since the flow itself turns the fan. The large fan diameter provides a high airflow volume without problems associated with the high air velocities produced by smaller electric blowers. Additional benefits include lower installation and operational costs since no electrical or control systems are required.  
           [0020]    The foregoing and other objects and advantages will appear from the description to follow. In the description reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration, specific embodiments in which the invention may be practiced. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. In the accompanying drawings, like reference characters designate the same or similar parts throughout the several views.  
           [0021]    The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claim.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]    In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the accompanying drawings in which:  
         [0023]    [0023]FIG. 1 is an elevation view of the present invention showing the front of the aerator housing.  
         [0024]    [0024]FIG. 2 is an elevation view of the present invention showing the right side of the aerator housing.  
         [0025]    [0025]FIG. 3 is a cross section of the present invention showing the interior of the aerator.  
         [0026]    [0026]FIG. 4 is a plan view of the present invention showing a partial cut-away view.  
         [0027]    [0027]FIG. 5 is a side elevation view of the present invention showing the basic operating principle of the invention.  
         [0028]    [0028]FIG. 6 is a sectional view of the rotating mechanism showing the internal portions of the fan/spray jet assembly.  
     
    
     LIST OF REFERENCE NUMERALS  
       [0029]    With regard to reference numerals used, the following numbering is used throughout the drawings.  
         [0030]    [0030] 10  present invention  
         [0031]    [0031] 12  housing  
         [0032]    [0032] 14  water inlet  
         [0033]    [0033] 16  water outlet  
         [0034]    [0034] 18  air inlet  
         [0035]    [0035] 20  air outlet  
         [0036]    [0036] 22  access door  
         [0037]    [0037] 24  solid top  
         [0038]    [0038] 26  legs  
         [0039]    [0039] 28  fan/spray jet assembly  
         [0040]    [0040] 30  elbow  
         [0041]    [0041] 32  spray nozzles  
         [0042]    [0042] 34  distribution arm  
         [0043]    [0043] 36  central hub  
         [0044]    [0044] 38  fan  
         [0045]    [0045] 40  slats  
         [0046]    [0046] 41  slat coupling  
         [0047]    [0047] 42  slat support  
         [0048]    [0048] 44  support beam  
         [0049]    [0049] 46  drip edge  
         [0050]    [0050] 48  water  
         [0051]    [0051] 50  arrow  
         [0052]    [0052] 52  stationary visor  
         [0053]    [0053] 54  hole  
         [0054]    [0054] 56  upper sleeve bearing  
         [0055]    [0055] 58  lower sleeve bearing  
         [0056]    [0056] 60  weep holes  
         [0057]    [0057] 62  upper thrust bearing  
         [0058]    [0058] 64  lower trust bearing  
         [0059]    [0059] 68  nut  
         [0060]    [0060] 70  washer  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0061]    The following discussion describes in detail one embodiment of the invention and several variations of that embodiment. This discussion should not be construed, however, as limiting the invention to those particular embodiments. Practitioners skilled in the art will recognize numerous other embodiments as well. For a definition of the complete scope of the invention, the reader is directed to the appended claims.  
         [0062]    By way of general explanation, and as will be explained in detail hereinafter, the present invention is essentially an improvement over similar equipment that is currently available for the reduction in levels of soluble gasses and the oxidation of dissolved iron in water. The design and construction of this invention is similar to other designs with one major exception. This invention utilizes a blower that is turned by the flow of water coming into the unit instead of electric motors. The outward physical appearance of the unit differs slightly from other induced draft aerators due to a larger diameter fan on the top of the unit.  
         [0063]    Turning to FIG. 1, shown therein is a front view of the present invention  10  showing the front of the aerator housing  12 . It indicates the relative location of the raw water inlet pipe  14 , treated water outlet pipe  16 , screened air intake vents  18  and air outlet  20 , and access door  22 . Also shown are the solid top  24  and legs  26  of the housing.  
         [0064]    Turning to FIG. 2, shown therein is a side view of the present invention  10  showing the right side of the aerator housing  12 . This view shows the relative size of the screened air inlets  18  and outlets  20 . Other elements previously disclosed are also shown.  
         [0065]    Turning to FIG. 3, shown therein is a cross section of the present invention  10  showing the inner working parts of the aerator  10 . Raw water enters the aerator  10  through the inlet pipe  14  on the right side of the aerator and turns up at elbow  30  into the rotating fan/spray jet assembly  28 . Water exits the fan/spray jet assembly through multiple spray nozzles  32  located along distribution arm  34  extending from the rotatable central hub  36 . Thrust from these nozzles  32  cause the assembly  28  (see FIG. 4). The circular movement of the nozzles  32  evenly distributes the water over the slats  40  while the turning fan blades  38  attached to the same central hub  36  cause air to be pulled through the slats  40 . The water passes downwardly through the slats  40  and is collected in the bottom of the aerator housing  12  where it exits through the outlet pipe  16 . Also shown are the screened air inlet  18  and outlet  20 , slat structural support  42 , solid top  24 , support beam  44  for the fan/spray jet assembly and a drip edge  46 .  
         [0066]    Turning to FIG. 4, shown therein is a rotating mechanism plan view of the present invention showing the housing  12  and the basic operating principle of the invention. Water  48  passes from a center hub  36  through distribution arms  34  to nozzles  32  pointed tangential to the direction of rotation shown by arrows  50  of the assembly  28 . The thrust of the water jets  32  causes torque which results in movement of the fan blades  38  attached to the common hub  36 . The pitch of the fan blades  38  causes air to be drawn up through the slats and ejected through the air outlet as previously discussed.  
         [0067]    Turning to FIG. 5, shown therein is a side view of the rotating mechanism of the present invention showing a side view of the operation of a water nozzle or jet  32  spraying water  48  onto the slats  40  below. Slats  40  can be configured in a number of ways as would be done in the standard manner by one skilled in the art. The slats  40  shown consist of perforated PVC pipe with couplings  41  on each end. When stacked, the couplings  41  provide spaces between the pipe slats  40  for air and water flow. The use of perforated pipe provides additional surface area for the water  48  to be dispersed for more efficient aeration. The nozzles  32  are directed angularly downwardly towards the PVC slats  40  to minimize the amount of water spray that enters the fan  38  unit above. Other elements previously disclosed are also shown.  
         [0068]    Turning to FIG. 6, shown therein is a view of the rotating mechanism section showing the internal working parts of the fan/sprayjet assembly  28 . Water enters the stationary riser  52  through the base elbow. Holes or perforations  54  in the stationary riser  52  allow the water to flow to the spray nozzles  32  through the distribution arms  34  that are part of the rotating assembly along with the fan  38  above. Lateral support for the rotating hub  36  is provided by upper  56  and lower  58  sleeve-type bearings above and below the perforated zone  54  of the stationary riser  52 . Weep holes  60  in the rotating hub  36  are provided to release water that passes by the water lubricated upper sleeve bearing  56 . Water leakage past the sleeve bearings  56  is expected and considered inconsequential. Vertical thrust is carried by the upper  62  and lower  64  thrust bearings located at the top of the assembly  28 . The primary thrust load is the result of the weight of the rotating mechanism and the water in the distribution arms. The weep hole configuration keeps the thrust bearings out of the water flow. The entire rotating assembly  28  can be lifted from the stationary riser  52  by the removal of the single retaining nut  68  with washer  70 . The weight of the entire assembly is carried by a support beam  44  that is attached on each end to the walls and frame of the aerator structure. The base elbow  30  is also shown. It should be clear that water entering the assembly from an outside source causes the assembly  28  to rotate. This rotation both causes airflow through the aerator and distributes the flow evenly across the aeration slats  40 .  
         [0069]    The present invention may be constructed of aluminum, stainless steel, coated carbon steel, or fiberglass. Stainless steel could be used to construct the fan/spray jet assembly where additional strength is required to handle the forces of water impact. Slats shown are fabricated from PVC pipe. Other slat arrangements using PVC or other materials should be equally effective. The outer housing and structural components could be welded and could feature hinged access doors or removable panels to allow access and removal of all internal parts.  
         [0070]    Summarizing the operation of the present invention, it should be clear that induced draft aerators operate by splashing a flow of water on the physical surfaces within the aerator into many small droplets. This greatly increases the area of the water in contact with air to allow volatile gasses to be released into the air and to provide oxygen for the oxidation of dissolved iron. Water flows into the side of the aerator and into the distribution arms of the rotating fan/spray jet assembly. Thrust from the water passing through nozzles on the distribution arms causes rotation of the fan/spray jet assembly. The moving distribution arms evenly distribute the flow over the aeration slats below. Water cascades through the slats to the bottom of the aerator where it collects and flows by gravity through outlet piping. Fresh air drawn into the aerator by the motion of the fan passes through screened air intake vents near the bottom of the aerator. The air moves upward around the slats to the fan. Airflow from the fan is exhausted through the screened outlet at the top of the aerator. The majority of the aeration occurs during the time the water cascades through the slats. However, significant aeration also occurs as the water is sprayed onto the slats from the nozzles.  
         [0071]    It will be clear to one skilled in the art that the present invention could be adapted to be used in other industrial applications, e.g., for use in a cooling tower for reducing the temperature of the process water passing therethrough.  
         [0072]    What is claimed to be new and desired to be protected by Letters Patent is set forth in the appended claims: