Abstract:
The present invention consist of an improved and very compact hand held pool debris removal system using a hydrodynamic water circulation device capable of producing significant water flow through a conduit. Such water flow is then used to lift and convey debris from bodies of water such as fountains, ponds and swimming pools. The device operates by creating a high speed water jet curtain using an external source of energy by means of pressurized water, which impinges on an steady body of water transforming the energy provided by the external water source into a strong flow capable of lifting and conveying light and heavy debris from the floor of bodies of water and forcing these debris into a fine mesh filter for retention and later disposal.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The art of removing debris or materials from the bottom of bodies of water is quite old. The obvious answer to the problem has been to utilize a suctioning device that creates a large and strong stream of water which can be directed to the areas where the debris is deposited. Then the debris is transferred to a filter or dumped out of the body of water with the water stream. Based on these premises the ideal bottom of pool debris removing device is one with sufficient water speed to carry or lift heavy debris such as rocks, pebbles or sand, and with enough water flow to allow a large entry area for oversize debris such as leaves, pine cones, branches etc. Unfortunately, residential pool owners cannot afford the cost and maintenance of a perfect system, therefore, part of the removal is done with nets for large debris and water suctioning means for smaller debris. Among the suctioning means for retrieving small size debris, the most widespread are those attached to a hose which is connected to the pool water return system. These systems are quite effective but limited to pools with medium to large water pumps and filtration systems. Another popular system are the so called cleaning robots. These robots use the positive pressure water circulation system to create a jet water induction system inside the robot. Then the water stream mixed with small debris is deposited in a very permeable reservoir inside the robot housing. These robots randomly navigate the bottom of the pool and a low velocity and flow is sufficient to remove light and semi-buoyant debris since it operates for a large period of time. Same as the suction hose, these robots need to operate with water circulation systems found only in medium to large size pools. 
         [0002]    There is another category of bottom of pool cleaners which are hand held and use an external source of pressurized water such as a water spout to create a water induction system by punctual water jets. This later class is used on low cost pools and spas. They operate similar to the aforementioned robots, using a water stream inductor to create the stream of water used to move the bottom deposited debris into a very permeable filter. Since these water inducing pool cleaners need to rely on a limited water flow and pressure provided by a residential water spout, the size of the inductor inlet is limited. Due to this limitation some of these debris removers are dedicated to remove large semi-buoyant debris, but not heavy debris. On the other hand, if they are designed to remove heavy debris, they are fitted with a small water stream inlet which takes a lot of time and strokes. The lately also limits the size of debris to be removed and often gets clogged. Typically small pools are outfitted with fractional horsepower water circulation systems not suitable to use water suction hose or cleaning robots systems, leaving them with the only alternative of hand held devices such as nets or externally powered water circulation systems. Therefore, there is a need for an effective and affordable bottom of the pool debris removal system for those using fractional horsepower circulation systems mainly found in above ground pools. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0003]    The limitations and disadvantages associated with the prior art are overcame by the present invention of a hand held simple, inexpensive and effective submersible debris removal system that can be used for any type of water body requiring debris and foreign solids removal. The hand held debris removal device object of the present invention is very compact, powerful and effective due to the fluid dynamics principles utilized to maximize the energy provided by residential water flow rates and pressure, and convert that energy in a water displacement system that is efficiently utilized to convey a substantial velocity to a mass of steady water through a small conduit. In that manner the hand-held pool cleaning device object of the present invention uses the velocity created by a conical high speed water jet curtain to accelerate the steady water at speeds capable of effectively dragging debris, sand, small rocks from the bottom of bodies of water such as pools, spas, ponds and aquariums and creating sufficient pressure to convey the water through a fine mesh filtration system leaving the debris deposited into a retrievable and reusable container. Unlike the portable water jet powered devices in prior art, the device object of the present invention is capable of using micro-porosity media or paper filters similar to those used on high end pool filtration systems; the main enabler is the higher level of water pressure inside the filtration media capable of overcoming the permeability resistance. 
         [0004]    To better understand the advantages of the device of the present invention over the prior art, it is necessary to understand the hydrodynamic theory behind it. If we simplify the complex fluid dynamic calculations involved on water jets behavior, and the Boyle&#39;s equation for conservation of energy on gasses, we could establish that water jets have certain energy expressed in a momentum which is directly proportional to the liquid mass and the speed. To transmit that energy to a steady body of water, there must be an exchange of momentum between the water jet and the steady mass of water. If we discard the slippage and the friction loses, and assumed a high degree of mixing, the momentum of the supply source and the induced current, should remain the same by the law of conservation of energy. Utilizing a modified version of Boyle&#39;s equation, we will learn that: 
         [0000]    
       
      
       V 
       2 
       *P 
       2 
       =V 
       1 
       *P 
       1 
       *f*e  
      
     
         [0000]    Where V 1  is the volume of water supplied to the inductor, P 1  is the supply water pressure at the inductor inlet, V2 is the induced stream volume, P 2  is the induced stream pressure, “f” is the friction factor inside the inductor and “e” is the efficiency factor or fraction of the hydraulic momentum transmission between the high speed water jet curtain and the steady body of water. 
         [0005]    Therefore, the total flow rate of water through the inductor (V 2 *P 2 ) is highly dependent on the water supply flow and pressure. But even more dependent on the magnitude of the friction losses and the efficiency of hydraulic energy conversion between the high speed water jet curtain and the steady body of water. Here is where the present invention departs from the prior art devices. The “f” and “e” factors are much smaller in punctual water jets induction systems due to higher pressure loses and poor inter-mixing of the high speed water jet particles with the steady stream due to the limited contact area of the high speed single point jet with the steady fluid surface area around the jet. To improve that mixing ratio, many have tried multiple jets, but then friction losses start consuming the available energy and reducing the efficiency due to the increase of friction on the contact area at the nozzles. Since the energy available to produce a substantial induction over a stream of water is restricted to the flow and pressure available at residential water spouts, that energy transformation must be as efficient as possible to obtain the desired water speed and pressure required for lifting and filtering small and heavy debris. Of course most of the pressure at the exit of the water induction system is in the form of what is called velocity pressure. According to Bernoulli&#39;s laws a water stream total pressure is the addition of the Static Pressure and The dynamic Pressure. In order to maximize that pressure it is necessary to limit the flow of the total induced stream to practical values which are proportional to the available flow and pressure of the pressurized water supply in a ratio of about 5:1. The skilled in the art who is knowledgeable of the principles of fluid-dynamics on water jets, will understand how the high pressure water jet curtain used in the present invention is capable of achieving a greater contact surface between the high speed particles of water and the steady particles of the resting fluid, therefore more available energy is utilized to accelerate the steady water stream. Secondly, the pressure losses around an uninterrupted peripheral nozzle are significantly smaller than a large number of smaller single source jets, therefore allowing more energy to be utilized to transfer momentum to the induced water stream. Based on experimental data and as is expected, the nozzle gap, direction and area reduction design are very sensitive to a point where small variations from the ideal state will render the device ineffective. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, which are not true to scale, and which, together with the detailed description below, are incorporated in and form part of the specification, serve to illustrate further various embodiments and to explain various principles and advantages according to the present invention. Advantages of embodiments of the present invention will be apparent from the following detailed description of exemplary embodiments thereof, which should be considered in conjunction with the accompanying drawings in which: 
           [0007]      FIGS. 1   a,    1   b,    1   c,  and  1   d  describe prior art devices using single point water jets to create water motion. 
           [0008]      FIG. 2 a    is a basic illustration of the high speed water jet generator showing its internal configuration and principle of operation. 
           [0009]      FIG. 2 b    is a sectional view of the high velocity water jet curtain generator as constructed by the preferred method. 
           [0010]      FIG. 3 a    is a perspective view of the device object of the present invention. In this view the device is configured with a high permeability debris catcher. 
           [0011]      FIG. 3 b    represents a cross sectional view of  FIG. 3 a    showing the internal configuration. 
           [0012]      FIG. 4 a    is a perspective view of an alternate configuration for the device object of the present invention, where a micro-porosity standard water paper filter is attached to collect small size debris, dirt, and dead algae particles. Also this figure shows the use of a thin brush as nozzle-floor separator. 
           [0013]      FIG. 4 b    is a sectional view of  FIG. 4 a    showing internal configuration. 
           [0014]      FIG. 5  represents the main body of the present invention with the threaded interface so the high velocity water curtain generator could be adjusted to various conditions to obtain maximum performance. 
           [0015]      FIG. 6  is a cross sectional view of a typical pool robot using the water induction system object of the present invention. 
           [0016]      FIG. 7  is a perspective view of the pool cleaner object of the present invention where a garden hose is directly connected to the water curtain generator body, while the unit is held by a pole attached to the same body. 
           [0017]      FIG. 8  is a perspective view of the hand held bottom of pool cleaning device object of the present invention showing a hollow pole with garden hose fitting attached to the end of it. 
           [0018]      FIG. 9  is a section view for a telescopic water conduit or pole. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    Detailed embodiments of the present invention are disclosed herein; The portable pool debris removal system object of the present invention is configured using the same basic elements of similar prior art pertaining to hand held portable pool cleaners: A pole, a water inductor, a collection bag and a pick up nozzle. The main difference separating the present invention from similar prior art devices is the novel water induction system utilized and the type of filtration media that could be utilized as a result of a higher outlet water pressure. As we will learn in the foregoing description, the water induction system consisting of a high speed water jet curtain coupled with an efficient pick-up nozzle and a very fine mesh debris collection reservoir can provide features not achieved by prior art devices of the same class shown by  FIGS. 1   a,    1   b,    1   c  and  1   d.    
         [0020]    To better describe the invention it is necessary first illustrate the hydrodynamic high speed jet curtain generator behind this novel pool debris removal device.  FIG. 2 a    shows a cross sectional view for a simplified high speed water jet curtain generator and  FIG. 2 b    shows a manufactured version of such high speed jet curtain generator. The generator body  100  is basically a tubular structure surrounded by a high pressure chamber  105 . The generator body  100  has an inlet tube  101  and an outlet tube  102 . The inlet tube  101  includes the generator body inlet port  103  and the outlet tube includes the generator body outlet port  104 . The inlet tube  101  and the outlet tube  102  are delimited by a peripheral discharge nozzle  108 . The peripheral discharge nozzle has a discharge outlet  119  in fluid communication within the internal walls  110  and  111  of the generator body  100 , and an inlet area  109  in fluid communication with the high pressure chamber  105 . The peripheral discharge nozzle  108  is delimited by a pair of walls  118 . These walls  118  form a progressively reducing cavity around the inlet tube  101  and the outlet tube  102  which is designed to effectively transform the potential energy from the pressurized water in the high pressure chamber  105  into kinetic energy at the nozzle discharge area  119  with minimal friction losses and maximum efficiency. The nozzle  108  walls  118  are compound curved surfaces extending from the discharge area to the inlet area. In a simplified manner they are like concentric conical surfaces with different inclination. Since the main function of the peripheral discharge nozzle is to progressively transform pressure energy into velocity energy, the nozzle discharge area  119  is substantially smaller than the nozzle inlet area  109 . The high pressure chamber  105  surrounds the generator inlet tube  101  and the outlet tube  102 , and includes a high pressure chamber inlet  107 . When high pressure water is introduced into the high pressure chamber  105 , the water is forced to circulate evenly through the discharge nozzle  108 . At the nozzle discharge area  119  the inlet water stream has reached the maximum velocity and it is discharged into the mixing chamber  106  as a thin high speed curtain of water  114  pointing towards the outlet port  104 . The high speed jet curtain  114  impinges into the steady body of water and drags the steady water body  112  from the inlet port  103  into the mixing chamber  106  and progressively mixes with the stream entering the generator body  100 . As the high speed jet curtain of water  114  leaves the nozzle discharge outlet  119 , in the three dimensional space forms a conical stream of high speed water. The inner wall of the conical stream of water starts mixing with the surrounding steady water at the mixing chamber  106 . As the two streams enter in contact, the steady water stream  112  starts gaining momentum, while the high speed jet curtain  114  starts loosing speed at the area of contact. This interaction cause the high speed jet curtain to start progressively diminishing the speed till there is a uniform water stream having a momentum equivalent to the energy diffused from the high speed jet curtain  114 . After the mixing is complete an accelerated water stream  113  exits the generator body through the outlet port  104 . 
         [0021]      FIG. 2 a    illustrates the speed magnitude of the circulating water with variable shade density. Since water is an uncompressible fluid, the main design driver for the system is to conserve energy which is done by minimizing friction losses where possible, and applying hydrodynamic principles for conservation of momentum. The inlet tube  101  inside diameter is slightly smaller than the outlet tube  102  inside diameter. This difference allows the nozzle discharge outlet  109  to discharge the high speed water jet curtain  114  in the intended natural direction with the least interruption and losses while avoiding the Coanda&#39;s effect which in this application will reduce by friction the water jet curtain speed. The outlet diameter is maintained constant in order to maintain the mixed stream velocity at its peak to create maximum pressure velocity for a given maximum water flow through the inductor. If we relate to the equation of conservation of momentum to the device, the water flow times the speed of the water curtain, must be equal to the water flow times the speed at the outlet of the inductor, indicating that due to the limited amount of water supply and pressure, the cross sectional area of the inductor conduit must be limited to maintain the desired water flow and consequentially the speed. Such described principles were validated using fully functional prototypes and it was found that utilizing not more than  5  times the ratio water out/pressurized water in, the size of the conduit was reasonably within the range to gather and convey most of the typical bottom of the pool debris. Of course, the mixed water stream velocity and velocity pressure could have greater values as the ratio of total water circulation flow (GPM) to pressurized water flow is less than 5. As the skilled in the art may rationalize, this will substantially reduce the available opening for debris to pass through. 
         [0022]    To configure the required elements in a way that provides the required functionality, facilitate manufacturing and lower cost it is best to use the plastic injection molding process to create the parts, which drives the specific parts design. Of course it is understood that subtle changes could be made on the design without departing from the basic philosophy and spirit of the invention. As such,  FIG. 2 b    describes the same high velocity water jet curtain generator or water flow inductor as shown in  FIG. 2   a,  as constructed in the preferred manufacturing process. In this configuration, the water flow inductor is comprised of a main housing  121 , which replaces the basic generator body  100  described by  FIG. 2   a.  The housing  121  is comprised of two plastic molded parts fused together. Of course, the skilled in the art is aware that the two parts can also be joined together by any other methods including fasteners, retaining clips, etc. One piece is the inlet module  122  and the other piece is the outlet module  123 . These modules contain the necessary elements that when fused together all the basic elements and geometry described by  FIG. 2 a    are maintained. After joined together these modules form the housing  121  which contains the high pressure chamber  105 , the high pressure chamber inlet  107 , the discharge nozzle  108  and all other features shown by the basic generator body shown by  FIG. 2 a   . Since the nozzle outlet width has to be precisely controlled by concentricity and distance, the joining halves may contain spacing elements around the nozzle walls  118  (not shown) to assure the proper spacing for the nozzle discharge area  119 . During prototype testing it was determined that the width of the nozzle discharge area  119  was in the order of 0.030 in. for the available water flow and pressure from a residential water faucet, reason why manufacturing precision is required to replicate model parameters without affecting performance. As part of an alternate embodiment, this nozzle discharge area  119  opening could be adjusted within a limited range to accommodate certain conditions. The housing  121  may also contain structures  129  to attach a holding pole  130  to the pool cleaner assembly  116  as shown by  FIG. 7 . 
         [0023]    In order to efficiently gather the debris deposited at the bottom of a pool, the inlet of the pool cleaning device assembly  116 , must be sufficiently wide to cover more surface area per sweep, and must contain bottom openings that allow sufficient water speed for picking up heavy debris. At the same time the opening must be large enough to prevent large size debris from blocking the inlets. Keeping those restrictions in mind, the flow generator  100 , or housing  121 , is coupled with a pickup nozzle  135  at the inlet port  103  as shown by  FIGS. 3 a      3   b,    4   a,  and  4   b.  The nozzle  135  is designed in a way that water flow and velocity are not compromised. The nozzle  135  contains side spacers to slide the unit over the pool floor  117 . These nozzle spacers  139  provide the required separation for the nozzle inlets  136  which maintains the water circulation between the nozzle inlet edge and the bottom of the pool at its maximum for optimal debris suctioning. Of course these nozzle spacers  139  are shown in  FIG. 3 b    as part of a one-piece nozzle for simplicity and low cost, but they may be replaced by any other elements that provide the same function such as wheels or stiff brushes. In an alternate embodiment, the nozzle is built with a moderately stiff brush  138  in the center as shown by  FIGS. 4 a    and  4   b.  The brush  138  provides the required nozzle edge separation and helps to remove debris stuck at the bottom of the pool. A debris retaining container  133  is typically attached to the housing outlet port  104 , allowing the passage of water but not the debris. This debris retaining container is easily detachable to dispose the collected debris. In prior art similar cleaners the debris catcher container is a very permeable net, where the high permeability is very necessary due to the low pressure levels of their water inducting system. This is the reason why prior art bottom pool cleaners with similar structure cannot collect small debris such as rocks, sand, dead algae, and the like. The necessary small mesh to retain small debris will create on these prior art devices a backpressure which will drastically reduce the circulation speed and flow which will render the device ineffective. 
         [0024]    Pool debris or solid contaminants are associated with the environment surrounding the pool, weather if it is indoor or outdoor, with vegetation or sand, with mud or rocks. This determines the kind of debris resting at the bottom of pools. When cleaning a pool with large debris a large and permeable reservoir is required for facilitate the job, on the other hand for small and heavy debris like rocks, sand, dead algae, and the like, small and close media reservoirs are the best choice. The hand-held cleaner object of the present invention is capable of using the typical low backpressure net for large debris, but also can be fitted with the typical paper filtration media used on high end pool filtration systems for retention of smaller debris without compromising the circulation velocity. This is possible thanks to the pressure velocity generated by the high speed water jet curtain  114  on the induced water flow. The alternate configuration described by  FIGS. 4 a    and  4   b,  show how the basic large debris catcher could be replaced by a paper filter cartridge  124 . The filter cartridge is held in place by a filter holder  126 , which is adjustable by means of a collar  127 . In the particular configuration as shown by  FIGS. 4 a    and  4   b,  the paper filter holder  126  completely covers the cartridge upper side flange  125 , to allow the use of standard paper filters cartridges. This method is only an illustrative example since many other configurations are possible for the utilization of low permeability filters. 
         [0025]    In another embodiment of the present invention shown by  FIG. 6 , the high efficiency water jet curtain generator is used on an automatic pool cleaner commonly called “robot”. These robots are driven by the pressurized water source from the pool pumping system, and collect the debris by inducing circulation under the frame of the robot separated from the bottom by wheels to allow water circulation and motion. The typical water induction system on these robots is by multi-jets and could be easily replaced by the high speed water jet curtain for added pickup power.  FIG. 6  shows a very simplified cross section of a robot where the water inductor  100  object of the present invention is fitted to provide an enhanced water circulation for picking up heavy debris. We can see the same elements afore described such as the high pressure chamber  105 , the inlet port  103 , the pressurized water source connection  107 , the outlet port  104 , the debris chamber  144  and water exit holes  143  that are permeable to water but not debris. As depicted by  FIG. 6 , a circulation channel or pickup nozzle is formed between the robot housing  141  bottom and the pool floor  117 . The water inductor  100  housing  121  is in this application configured in a way to adapt to the robot housing  141  configuration in order to facilitate manufacturing and reduce cost. The housing  121  is slightly different since the inlet tube  101  could be made as an integral part of the robot housing, while the outlet tube  100  is a separate component mechanically attached to the main robot assembly. 
         [0026]      FIG. 5  shows the main housing  121  configured in a way to adjust the high speed water jet nozzle  108  cross sectional area, and allow optimization of the flow for different pressurized water conditions. In the case of a robot which runs out of the pool pressurized pump water with pressures not exceeding 20 psi, then the nozzle could be opened to provide a more efficient setup for the given conditions. In this configuration the outlet tube  102  is threaded into the outlet module  123  to allow longitudinal displacement of the outlet tube  102  relative to the inlet tube  101 , therefore increasing or decreasing the high speed water jet nozzle walls  119  distance. By increasing or decreasing the nozzle walls  119  distance, the nozzle discharge area  119  is increased or decreased proportionally. For lower pressurized water supply pressures, increases on the nozzle discharge area  119  will maintain the necessary momentum and therefore optimized potential energy utilization. 
         [0027]    In the previous description it is obvious that the pressurized water supply source which is typically a residential water faucet could be connected directly to the body of the debris remover by a garden hose  120  as illustrated by  FIG. 7 . The garden hose is connected to the housing  121  by a hose fitting  127  in fluid communication with the high pressure chamber inlet  107 . The body of the garden hose  120  is constrained to the holding pole  130  by hooks  134 . In an alternate embodiment of the present invention shown by  FIG. 8 , the pressurized water source is attached to the end of the hollow holding pole  130  at the pole hose fitting  131  while the lower end of the pole  130  is attached to the housing  121  by the pole lower fitting  132  in fluid communication with the high pressure chamber inlet  107 . The holding pole  130  is hollow and also used as a conduit for pressurized water. For easy storage it is preferred that the holding pole is built in a telescopic manner with proper seals at the joints. This is shown by  FIG. 9 . The telescopic pole  130  has an internal pipe section  145 . This internal pipe section  145  slides into a pipe external section  146 . Both pipe sections are sealed in the interface with a seal  147 . At the end of the external pipe section  146  there are threads  148  to connect to the high pressure chamber inlet  107 . The opposite end is connected to a typical water hose fitting  131 . Another method to achieve the telescoping effect is an elastomeric hose inside the rigid sections of conduit which will extend as internal pressure increases. The pressurized water inside the hollow telescopic pole  130  will automatically extend the pole from its folded condition to its maximum length when in-use. 
         [0028]    Since the high speed water jet curtain nozzle discharge outlet  119  is very small when compared to typical water jet openings used on similar devices, the nozzle outlet  119  is vulnerable to blockage by contaminant particles mixed with the pressurized water supply, hampering the device performance. A small in-line screen filter is used to prevent these unwanted particles from reaching the water curtain nozzle. 
         [0029]    Many modifications and other embodiments of the invention set forth herein will come to mind to one skilled in the art having the benefit of the teaching presented in the foregoing description and associated drawings. While the above description contains many specificities, these should not be construe as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiments thereof. Many other variations are possible. Specific structural and functional details described are not to be interpreted as limiting, but merely as basis for the claims and as a representative basis for teaching to the skilled in the art the basic form of the invention and potential variations. 
         [0030]    Example many different configurations of inlet nozzles are possible, as well as many different ways to configure the filtration media structure and fixation system. Also modifications are possible for the tubular structure of the water inductor in which different close loop shapes or slightly interrupted loops could be utilized to apply the same principles and embodiments illustrated thereof.