Abstract:
An apparatus and method for cleaning containers using water within the container and a submersible pump exhibiting a nozzle. Air may be injected into the pumped water to increase its pressure as it exists the nozzle.

Description:
FIELD OF THE INVENTION 
     The invention is in the field of jetter cleaning of containers. 
     BACKGROUND OF THE INVENTION 
     Water jetters are used to clean containers, such as sewer pipes, tanks, and ponds. Powerful triplex pumps are used in such applications to create jets of cleaning water, but triplex pumps are sensitive to debris intake and must normally be located outside of the container. For example, use of triplex pumps in sewer cleaning requires use of expensive clean water, such as potable hydrant water. Thus, present sewer cleaning often wastes much potable water. 
     The instant invention solves a long-existing need for a water jetter for use within containers, having submersible capability, using debris-laden waste water to jet, and generating pressure equal to or greater than that of triplex pumps. Its use of waste water instead of potable water saves money, preserves an important natural resource, and is friendly to the environment. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention employs a submersible pump to jet water through a nozzle. Venturi air or pressurized air may be used to enhance the pressure of the jetted water. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an embodiment of the invention. 
         FIG. 2  is a top view of an embodiment of the invention. 
         FIG. 3  is a side view of an embodiment of the invention. 
         FIG. 4  is a back view of an embodiment of the invention. 
         FIG. 5  is second perspective view of an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the Figures, a jetter assembly  1  comprises a removable skid cage  3 , a hydraulic motor  5 , a submersible centrifugal pump  7 , and a nozzle assembly  9 . The hydraulic motor  5  is driven by hydraulic fluid, received through hydraulic fluid intake  6 , from a hydraulic pump (not shown). The hydraulic motor, in turn, rotates an impeller (not shown) within the submersible centrifugal pump  7 . When submersed in water, the rotating propeller of the centrifugal pump  7  draws water (not shown), into water intake  11  and into the pump  7 , from where it is pumped, at a pressure such as 300 psi and at a volume such as 2000 gpm, through water conduits  13  into nozzle assembly  9  and out nozzles  23 . 
     Air at ambient pressure may be drawn into water conduits  13  via air intakes  15  and air conduits  17 . The air enters the water conduits  13  at injection points  21 . Injection tubes  19  within water conduits  13  are a continuation of air conduits  17 . At ambient air pressure, the air is drawn into the conduits  13  by the venturi effect, as pumped water flows through the water conduits  13 . 
     Air also may be pressurized to a pressure greater than the water pressure created by the pump  7 , such as 2000 psi. The pressurized air may be injected into air intake  15  by a pressurized air supply (not shown) through air conduits  17  and injection tubes  19 . The pressurized air is released into water conduits  13  through air tubes  19  that enter water conduits  13  at injection points  21 . 
     The injection of air into water conduits  13  substantially increases the pressure of the water as it flows past the air tubes  19 . Ambient pressure air is suitable, but higher air pressure increases still further the pressure of the water. The pressure-enhanced water is further driven into nozzle assembly  9 , from where the pressure-enhanced water, mixed with the air, is ejected through nozzles  23 . 
     The vertical angle of attack of the nozzle assembly  9  may be adjusted by lifting or lowering the nozzle assembly  9  by generally rotating the assembly within the skid cage  3  about an axis proximal the water intake  11 . A range of adjustment is generally indicated by arrows  25 . 
     To use the jetter assembly  1  in the cleaning of a sewer pipe containing flowing waste water, the assembly  1  is connected by hose to a surface supply of pressurized hydraulic fluid and lowered into a manhole. A second hose with ambient or pressurized air may be added. The assembly  1  is oriented with the nozzles downstream the flow of water in the sewer pipe. The jetter assembly  1  is then activated by the hydraulic fluid, driving the centrifuge pump  7 . Sewer water entering the water intake  11  is ejected from nozzles  23 , driving the jetter assembly  1  a suitable distance upstream from the force of the ejected water. Venturi or pressurized air may be injected to increase the ejected water pressure. Upon reaching the suitable distance, the activated jetter assembly is slowly retracted through the pipe toward the manhole by the pressurized air hose, pressurized hydraulic fluid hose, or other tether between the jetter assembly  1  and the surface above the manhole. As the jetter assembly  1  is refracted, water ejected by nozzles  23  lifts and pushes solids in the sewer pipe downstream and toward the manhole, creating a slurry that can be removed by a submersible pump located in the pipe at approximately the manhole, such as reflected in U.S. Pat. No. 5,336,333. 
     In sewer pipe and other applications in which the water drawn into the water intake  11  may contain significant, large solids, a screen (not shown) may be placed over water intake  11  to minimize solids intake. Also, solids accumulating in nozzle assembly  9  may be removed by removing the cap  27  of clean-out port  29  and cleaning within the nozzle assembly  9 . 
     “Containers” means any container that may be accessed, including without limitation pipes, tanks, and ponds. With the benefit of this disclosure, one of ordinary skill will understand that the air injection may be configured in a variety of ways, including structure and location variations, suitable for enhancing the pressure of water pressurized by a submersible pump. “Submersible pump” means any pump that operates submerged in water, including without limitation impeller pumps and disk pumps. “Nozzle” means any passageway configured to clean the inside of a container with jetted water. 
     With the benefit of this disclosure, one of ordinary skill will appreciate that many embodiments of the invention may be employed within the scope of the claims for a variety of applications.