Abstract:
An apparatus for harvesting algae from an open body of water includes a boat having a pair of spaced apart parallel flotation members and a deck disposed on and connected to the members. The spaced apart members define an area therebetween forming a process channel. A separating mechanism disposed on the boat separates the process channel into a plurality of process channel sections arranged in series. The process channel sections are disposed intermediate the flotation members. Each of the process channel sections include a deflector plate, a scum beach, a scum trough, and diffused air piping. The diffused air piping is in fluid communication with a dissolved air flotation system.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/903,481, filed on Nov. 13, 2013. The entire disclosure of the above application is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    This invention relates to water treatment by dissolved air floatation and, more particularly, harvesting algae from an open body of water utilizing dissolved air floatation technology. 
       BACKGROUND 
       [0003]    This section provides background information related to the present disclosure which is not necessarily prior art. 
         [0004]    Dissolved air flotation (DAF) is a water treatment process that clarifies wastewaters (or other waters) by the removal of suspended matter such as oil or solids. The removal is achieved by dissolving air in the water or wastewater under pressure and then releasing the air at atmospheric pressure in a flotation tank or basin. The released air forms tiny bubbles which adhere to the suspended matter causing the suspended matter to float to the surface of the water where it may then be removed by a skimming device. 
         [0005]    Dissolved air flotation is very widely used in treating the industrial wastewater effluents from oil refineries, petrochemical and chemical plants, natural gas processing plants, paper mills, general water treatment and similar industrial facilities. A very similar process known as induced gas flotation is also used for wastewater treatment. Froth flotation is commonly used in the processing of mineral ores. 
         [0006]    The feed water to the DAF float tank is often (but not always) dosed with a coagulant (such as ferric chloride or aluminum sulfate) to flocculate the suspended matter. 
         [0007]    A portion of the clarified effluent water leaving the DAF tank is pumped into a small pressure vessel (called the air drum) into which compressed air is also introduced. This results in saturating the pressurized effluent water with air. The air-saturated water stream is recycled to the front of the float tank and flows through a pressure reduction valve just as it enters the front of the float tank, which results in the air being released in the form of tiny bubbles. The bubbles adhere to the suspended matter, causing the suspended matter to float to the surface and form a froth layer which is then removed by a skimmer. The froth-free water exits the float tank as the clarified effluent from the DAF unit. 
         [0008]    Some DAF unit designs utilize parallel plate packing material, lamellas, to provide more separation surface and therefore to enhance the separation efficiency of the unit. 
         [0009]    DAF systems can be categorized as circular (more efficient) and rectangular (more residence time). The former type requires just 3 minutes; an example is a Wock-Oliver DAF system (www.wockoliver.com). The rectangular type requires 20 to 30 minutes; a typical example is a Syskill DAF system (www.syskill.com.au). One of the bigger advantages of the circular type is its spiral scoop. A typical DAF system is shown in the schematic diagram of  FIG. 13 . 
         [0010]    The DAF Corporation (www.dafcorp.com) FC Maximizer clarifier is designed and manufactured for harvesting algae. It is a hybrid DAF clarifier. Algae feeds on carbon dioxide and sun light. Algae&#39;s biomass once refined can be used for animal feed or its lipid oil for blended petroleum based fuels. The FC Maximizer clarifier is a cost-effective way to harvest algae. It can also feed algae. Part of the FC Maximizer clarifier system is the AMT air dissolving system. It can be used to nourish algae with a side stream of CO2 as a nutrient. This side stream of carbon dioxide with laden water and compressed air from this AMT is injected into the FC Maximizer clarifier as fine micron bubbles. These micron bubbles rise to the surface of the water in the tank at a rate 10″ to 12″ per minute. Hundreds of millions of all equal sized, fine micron bubbles entrap themselves in the suspended solids or algae bloom in the FC Maximizer tank. 
         [0011]    Parallel with this process, on the open tank top rim is a rotating stainless steel tank carriage that supports the fixed and rotating tank internal parts. A stainless steel, variable speed, two blade rotating scoop is attached to it. Again, this design gently dips and scoops up the dense fine float mat and discharges it into a holding tank. Clean carbon dioxide enriched nutrient water is discharged from the clarifier tank. This water can be piped back into different systems for a multitude of uses. 
         [0012]    The FC Maximizer clarifier is self-cleaning. It operates with minimal turbulence in a shallow round tank. The FC Maximizer clarifier will remove 98% of the algae bloom and lipid oil within the first two and a half minutes. The clarifier&#39;s wetted parts are all stainless steel. Sizes ranging from 20 gpm up to 9000 gpm are manufactured. 
         [0013]    However, the prior art does not directly remove algae from open bodies of water on an in-lake basis utilizing dissolved air floatation technology. 
       SUMMARY 
       [0014]    According to the present invention, the dissolved air floatation (DAF) equipment is mounted on a boat (catamaran or barge configuration) to remove microscopic algae directly from the water in lakes and ponds. One key element in the process is the utilization of DAF equipment. The lake water passes through a channel under the boat that allows for the processing of large volumes of water at low energy costs. 
         [0015]    The boat would collect both algae and phosphorus by using the dissolved air flotation (DAF) technology. DAF uses tiny bubbles to cause algae to float to the surface of the water. The algae then would be skimmed and stored on the harvesting boat. By weight, 3 percent of algae is phosphorous. Therefore, if 100 pounds of algae were removed, three pounds of phosphorus also would be taken out of the body of water. 
         [0016]    The collected algae would be conveyed to a storage facility for processing and/or transport. The algae can be used as a renewable biofuel in several forms. After processing of the algae for its biofuel value, the nutrient rich algal biomass can be used as a sellable, organic product. 
         [0017]    An apparatus for harvesting algae from an open body of water includes a boat having a pair of spaced apart parallel flotation members and a deck disposed on and connected to the members. The spaced apart members define an area therebetween forming a process channel. A separating mechanism disposed on the boat separates the process channel into a plurality of process channel sections arranged in series. The process channel sections are disposed intermediate the flotation members. Each of the process channel sections include a deflector plate, a scum beach, a scum trough, and diffused air piping. The diffused air piping is in fluid communication with a dissolved air flotation system. 
     
    
     
       DRAWINGS 
         [0018]    The above as well as other advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which: 
           [0019]      FIG. 1  is a top plan view of an algae harvesting boat according to the invention; 
           [0020]      FIG. 2  is structural framing plan for the boat shown in  FIG. 1 ; 
           [0021]      FIGS. 3A and 3B  are front and rear views of the boat shown in  FIG. 1 ; 
           [0022]      FIG. 4  is a side view of the boat shown in  FIG. 1 ; 
           [0023]      FIG. 5A  is a side elevational view of the boat shown in  FIG. 1 ; 
           [0024]      FIGS. 5B ,  5 C are perspective views of the boat shown in  FIG. 5 ; 
           [0025]      FIG. 6  is a front left perspective view of the boat shown in  FIG. 1 ; 
           [0026]      FIG. 7  is a top plan view of the process channel of the boat shown in  FIG. 1 ; 
           [0027]      FIG. 8  is an end elevational view of the process channel shown in  FIG. 7 ; 
           [0028]      FIG. 9  is a front left perspective view of the process channel shown in  FIG. 7 ; 
           [0029]      FIG. 10  is a front left perspective view of a boat of another aspect of the present disclosure; 
           [0030]      FIG. 11  is a front end elevational view of the boat of  FIG. 10 ; 
           [0031]      FIG. 12  is a rear end elevational view of the boat of  FIG. 10 ; and 
           [0032]      FIG. 13  is a diagram of a prior art dissolved air flotation system. 
       
    
    
     DESCRIPTION 
       [0033]    The following detailed description and appended drawings describe and illustrate various exemplary embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner. In respect of the methods disclosed, the steps presented are exemplary in nature, and thus, the order of the steps is not necessary or critical. 
         [0034]    Referring to  FIG. 1 , an algae harvesting boat includes two aluminum members which according to several aspects define pontoons  1  (having exemplary dimensions of 48″ diameter×40′ long) thereby providing flotation members supporting a non-skid deck on an aluminum frame  2 . A  48 ″ wide process channel  3  having multiple individual channel sections is defined by and positioned between the pontoons  1 . Mounted on the deck are a generator unit  4 , an electrical distribution panel  5 , a saturator  6 , a DAF pump  7 , a DAF air compressor  8 , a vacuum pump  9 , multiple algae storage tanks  10  individually receiving material from one of the multiple channel sections, 4″ butterfly valves  11  and oxygenation spray nozzles  12 . 
         [0035]    Referring to  FIG. 2 , the structural framing for the boat includes the two aluminum pontoons  1 , the aluminum structural beam framing  2 , and the 48″ wide process channel  3 . Welded deck framing  14  and aluminum channel framing  16  are also provided. 
         [0036]    Referring to  FIGS. 3A and 3B , front and rear views respectively of the boat include the two aluminum pontoons  1 , 24″ welded riser sections  18 , 12″ aluminum beam framing  20 , 12″ deck with integral framing  22 , a 42″ safety handrail  24 , a 48″ tall by 96″ wide trash guard  26  at an inlet of the process channel  3 , the generator unit  4 , the saturator  6 , the DAF pump  7 , the DAF air compressor  8 , the vacuum pump  9 , a submersible fountain pump  28 , the 4″ butterfly valves  11 , the algae storage tank  10 , the multiple oxygenation spray nozzles  12 . The trash guard  26  is positioned at the forward end of the process channel  3  and at least partially below a water level  30  to permit entrance of the water containing the algae, but to block large elements from entering the process channel  3 . 
         [0037]    Referring to  FIG. 4 , the boat includes the aluminum pontoons  1 , the 24″ welded riser sections  18 , the 12″ aluminum beam framing  20 , the 12″ deck with integral framing  22 , the 42″ safety handrail  24 , the vacuum pump  9 , the multiple 4″ butterfly valves  11 , the algae storage tanks  10 , and the oxygenation spray nozzles  12 . 
         [0038]    Referring to  FIGS. 5A-5C , side elevational and sectional views of the boat include the two aluminum pontoons  1 , the 24″ welded riser sections  18 , the 12″ aluminum beam framing  20 , the 12″ deck with integral framing  22 , the 42″ safety handrail  24 , the 48″ wide by 96″ long process channel sections  3   a,    3   b,    3   c,    3   d,  the trash guard  26 , the generator unit  4 , the electrical distribution panel  5 , the saturator  6 , the DAF pump  7 , the DAF air compressor  8 , the submersible fountain pump  28 , the oxygenation spray nozzles  12 , the vacuum pump  9 , the algae storage tanks  10 , and the water level  30 . 
         [0039]    Referring to  FIG. 6 , in a perspective view of the boat shown are the two aluminum pontoons  1 , the 24″ welded riser sections  18 , 12″ the aluminum beam framing  20 , the 12″ deck with integral framing  22 , the 42″ safety handrail  24 , the trash guard  26 , the generator unit  4 , the electrical distribution panel  5 , the saturator  6 , the DAF pump  7 , the DAF air compressor  8 , the 4″ butterfly valves  11 , the algae storage tanks  10 , and oxygenation spray nozzles  12 . 
         [0040]    Referring to  FIG. 7 , the process channel includes ½″ thick (48″×96″) solid vinyl sheeting  32 , a plurality of 2″ SCH80 piping supports  34 , a 1″ thick (48″×96″) solid vinyl baffle  36 , multiple sections of 1″ SCH80 diffused air piping  38 , multiple ½″ thick (24″×48″) deflector plates  40 , multiple ½″ thick (24″×48″) algae scum beaches  42 , and a 12″×12″×48″ solid vinyl scum trough  44 . 
         [0041]    Referring to  FIG. 8 , the process channel  3  includes the solid vinyl sheeting  32 , the piping supports  34 , the solid vinyl baffle  36 , the diffused air piping  38 , the deflector plates  40 , the algae scum beach  42 , and the solid vinyl scum trough  44 . 
         [0042]    Referring to  FIG. 9 , the process channel including the solid vinyl sheeting  32 , the 2″ SCH80 piping supports  34 , the solid vinyl baffle  36 , the diffused air piping  38 , the deflector plates  40 , the algae scum beach  42 , and the solid vinyl scum trough  44 . 
         [0043]    Referring to  FIGS. 10-12 , an algae harvesting boat  50  is modified from the algae harvesting boat of  FIG. 1  to include two rectangular-shaped aluminum members which according to several aspects define pontoons  52 ,  54  (having exemplary dimensions of 48″ wide×48″ high ×40′ long) which are used in place of the pontoons  1  of  FIG. 1 . The pontoons  52 ,  54  provide flat upper surfaces for attachment of the components of the system. Other components of algae harvesting boat  50  are substantially the same as the algae harvesting boat of  FIG. 1 . The pontoons  52 ,  54  provide flotation members supporting a non-skid deck on the aluminum frame  2 ′. The 48″ wide process channel  3 ′ having multiple individual channel sections is defined by and is positioned between the pontoons  52 ,  54 . Mounted on the deck are the generator unit  4 ′, the electrical distribution panel  5 ′, the saturator  6 ′, the DAF pump  7 ′, the DAF air compressor  8 ′, the vacuum pump  9 ′, multiple algae storage tanks  10 ′ individually receiving material from one of the multiple channel sections, the multiple 4″ butterfly valves  11 ′ and the multiple oxygenation spray nozzles  12 ′. The trash guard  26 ′ is similarly located at the forward end of the process channel  3 ′. 
         [0044]    With specific reference to  FIG. 12  the rectangular-shaped pontoons  53 ,  54  provide opposed, planar surfaces  56 ,  58  which are substantially parallel to each other. The surfaces  56 ,  58  define the inner flow and boundary surfaces of the process channel  3 ′ such that additional framing and components are not required to establish the boundary surfaces of the process channel  3 ′ which may be required with the round pontoons  1  of the embodiment of  FIG. 1 . The flat upward facing surfaces of the pontoons  52 ,  54  also provide for direct connection of the support structure of the aluminum frame  2 ′. 
         [0045]    In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope. 
         [0046]    Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
         [0047]    The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0048]    When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
         [0049]    Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
         [0050]    Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.