Abstract:
A portable waste disposal system for cementuous slurry comprises a collapsible wire cage, a waterproof containment bag inside the wire cage and a filtration bag inside the waterproof containment bag. The system enables the cementuous slurry generated during the plastering of a swimming pool and pumped from inside a swimming pool to a location adjacent the pool be disposed of quickly and safely. The liquid generated during the process may be neutralized and left on site, thereby avoiding transport of such liquid.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of the filing of U.S. provisional Patent Application Ser. No. 60/812,761 filed Jun. 12, 2006 entitled “Disposal System for Waste Generated During Plastering of Swimming Pool”, which is fully incorporated by reference herein. 
     
     FIELD OF THE INVENTION 
       [0002]    This invention relates generally to the disposal of waste generated during the plastering of a swimming pool. 
       BACKGROUND OF THE INVENTION 
       [0003]    Thousands of swimming pools are built in the United States each day. Typically, a four inch concrete shell is laid and covered with a bond coat to seal the initial concrete shell. A concrete slurry made of Portland cement, aggregate and water is then mixed together and sprayed onto the sealed surface of the pool. 
         [0004]    Workers using trowels then smooth the surface. After a predetermined time period, the surface of the pool is then pressure washed to expose the aggregate, often in the form of colored rock. During this pressure washing, a cementuous slurry or waste is generated which must be removed from inside the pool. This is commonly accomplished using a pump which pumps the cementuous slurry or waste to a location adjacent the pool, where it is allowed to harden before being removed. 
         [0005]    Swimming pool construction, both residential and commercial, generates 20-25 percent of waste cementuous slurry during the plastering phase of construction. There are several methods of handling this waste cementuous slurry at the present. There are vacuum trucks that suck the waste slurry up and transport it to a sanitary landfill. A major problem with this method of disposal is the cost of the equipment, but more importantly, the cement has to be chemically treated to retard the set time so the truck can get to the landfill before the cement sets. There have been multiple instances where the cement sets up in the truck, causing major cleanup cost. 
         [0006]    Another method of disposal currently being used is to build a wood shell consisting of four wooden walls 17 inches high. The length of the shell is generally 8 feet and the width is generally 4 feet. This shell is lined with a 6-10 mil plastic sheet or liner forming waterproof bottom and sides. The slurry is pumped from the pool during the plastering stage and allowed to set overnight to allow the cement to settle to the floor of the container (wooden shell and plastic liner). Fluid remains in the bag above the settled cement. The next day, a crew will come in and cut the plastic liner at the cement/water interface to drain the water off. The crew will then break the cement bed with hammers and haul the cement away. 
         [0007]    There are several major problems with this methodology. First, the slurry is allowed to set overnight, which allows pets and children access to the slurry. The pH of the slurry water is 11.5-12.5, which makes it extremely basic in nature. 
         [0008]    This fluid having such a high pH may cause injury such as permanent eye damage if allowed to contact the human eye. It is also now illegal in at least several western U.S. states to discharge fluid down a drain or onto a street at this pH range. Such fluid immediately may kill any grass or vegetation it contacts. Attempts to neutralize the fluid have generally been unsatisfactory because the cement has to be separated from the aqueous phase for neutralizing. The current box method does not allow for that separation. 
         [0009]    Therefore, there is a need for a waste disposal system which may quickly and safely dispose of the cementuous slurry waste generated during the plastering of a swimming pool. 
       SUMMARY OF THE INVENTION 
       [0010]    The waste disposal system of the present invention comprises a bag support in the form of a collapsible wire cage movable between an erected condition or position and a collapsed condition or position, a waterproof containment bag adapted to be received within the erected cage and a filtration bag adapted to be received inside the waterproof containment bag. The system may further comprise a polymeric flocculating agent and a muriatic acid or any other acidic material. 
         [0011]    The waterproof containment bag is a two ply bag having a bottom and four sides of the same dimensions. This waterproof containment bag may have outer dimensions which are approximately the same as the inside dimensions of the erected cage. In one embodiment, the inner ply of the waterproof containment bag is made of non-woven polypropylene and is waterproof. The outer ply is made of woven polypropylene. However, other materials may be used. The inner and outer plies may be sewn or otherwise secured together. 
         [0012]    The filtration bag is generally smaller than the waterproof containment bag and fits therein. The filtration bag has a top having an opening, a bottom and four sides of the same dimensions. The filtration bag is two-ply having an inner ply and an outer ply. In one embodiment, the outer ply may be made entirely of woven polypropylene and have a perforated upper section and a non-perforated waterproof lower section. The inner ply of the filtration bag may have an upper and lower section sewn or otherwise secured together. The upper section of the inner ply may be made of a 50-micron filtration cloth which allows fluid to pass therethrough as long as the particles are less than 50 microns in diameter and the lower section of the inner play may be made of woven polypropylene which is waterproof. 
         [0013]    In accordance with the practice of this invention, cementuous slurry is pumped inside the filtration bag where a flocculating agent is added to the slurry to accelerate the separation of the concrete and fluid and expedite the hardening of the concrete. The fluid is filtered by the filtration bag through a 50 micron filter media inner ply lining the upper portion of the filtration bag. The filtered fluid the passes into the containment bag where an acidic neutralizer is added to lower the pH of the fluid to a neutral or close to neutral condition. 
         [0014]    The primary advantage of this invention is that it enables waste cement slurry created during the course of plastering a swimming pool to be quickly and inexpensively separated into its cement and liquid components and then safely disposed without any danger to persons, pets or the environment. 
         [0015]    These and other advantages of the invention will be more readily apparent from the following description of the drawings, in which: 
     
     
       DESCRIPTION OF THE INVENTION 
         [0016]      FIG. 1  is an exploded perspective view of one embodiment of a collapsible wire cage, containment bag and filtration bag of the present invention; 
           [0017]      FIG. 2  is a perspective view of the collapsible wire cage of  FIG. 1  in a fully erected condition; 
           [0018]      FIG. 3  is an enlarged perspective view of a front corner of the collapsible wire cage of  FIG. 2  illustrating the locking mechanism for holding the wire cage in an erected condition; 
           [0019]      FIGS. 4A ,  4 B and  4 C are top plan views of the locking mechanism of  FIG. 3  illustrating the locking mechanism in locked condition, in partially unlocked condition, and fully unlocked conditions, respectively; 
           [0020]      FIG. 5  is a perspective view of the collapsible wire cage of  FIG. 2  in a partially collapsed condition; 
           [0021]      FIG. 6  is a perspective view of the wire cage of  FIG. 2  in a fully collapsed condition; 
           [0022]      FIG. 7  is a perspective view of the top portion of the erected wire cage of  FIG. 2  having a containment bag and filtration bag located within the wire cage; 
           [0023]      FIG. 8  is a perspective view of a filtration bag constructed in accordance with the present invention; 
           [0024]      FIG. 9  is a bottom plan view of the filtration bag of  FIG. 8 ; 
           [0025]      FIG. 10  is a side elevational view of the filtration bag of  FIG. 8 ; 
           [0026]      FIG. 11  is a bottom plan view of the containment bag of  FIG. 1 ; and 
           [0027]      FIG. 12  is a diagrammatic view through the center of the waste disposal system of  FIG. 1  when the system is partially assembled. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    With reference to the drawings and, particularly to  FIG. 1 , it will be seen that the waste disposal system  5  utilizes a collapsible wire cage or bag support  10 , a containment bag  26  and a filtration bag  28  for separating cementuous slurry  51  pumped into the filtration bag  28  through a collar  30  of the bag. See  FIG. 12 . As explained more fully hereinafter, the cementuous slurry  51  pumped into the filtration bag  28  is separated into its cement and water components,  6 ,  8 , respectively, the water or fluid component  8  removed from the filtration bag  28  and passed into the containment bag  26  where it is collected preparatory to disposal after having the pH content of the fluid lowered to a neutral or nearly neutral condition. 
         [0029]    With reference now to  FIG. 2 , there is illustrated the collapsible wire cage  10  in an erected condition. In  FIG. 6 , this cage  10  is shown in a fully collapsed condition, and in  FIG. 5 , the cage  10  is shown in a partially collapsed condition. As best illustrated in  FIG. 5 , the wire cage  10  comprises a welded wire grid base or bottom panel  12  having front and rear border rods or wires pivotally connected by helical lacing wires  20  to a welded wire front panel  18  and a rear panel  14 , respectively. Each of the front panel  18  and rear panel  14  also comprises a welded wire grid. The rear panel  14  has edgemost border rods or wires helically laced to edgemost border rods or wires of side panels  16 ,  17  such that the side panels  16 ,  17  may be pivoted relative to the back or rear panel  14 . As may be seen most clearly in  FIG. 5 , when the wire cage  10  is collapsed, the front panel  18  is pivoted downwardly into contact with the top surface of the bottom panel  12 . The side panels  16 ,  17  are pivoted inwardly one atop the other, and onto the back panel  14 , then pivoted onto the top of the collapsed front and side panels to create a fully collapsed cage, as illustrated in  FIG. 6 . Other methods of collapsing the wire cage  10  may be used as desired. 
         [0030]    In the illustrated embodiment, there are feet  40  attached to the underside of the bottom panel  12  at the four corners of the panel  12 . These feet  40  may be welded or otherwise secured to the underside of the bottom panel  12  and, in turn, may be secured to a conventional wooden pallet or the bed of a truck for transportation from one site to another. 
         [0031]    With reference now to  FIGS. 2 and 3 , it will be seen that there are four locking mechanisms  22  on each side of the front panel  18  which function to help maintain the cage  10  in its erected condition. These locking mechanisms  22  cooperate with loops  24  on the front edges  42  of the side panels  16  and  17  to secure the cage  10  in an erected condition. With particular reference to  FIGS. 3 and 5 , it will be seen that each of the loops  24  comprises a U-shaped section of wire having horizontal legs  44  welded to horizontal bars  46  of the side panels  16  and  17  and a loop portion  43  joining the horizontal legs  44 . The loop portion  43  of each of these loops  24  extends forwardly from the front edge  42  of a side panel  16 ,  17  such that a locking pin  50  in cooperation with securement brackets  52  on the front side of the front panel  18  may secure the front panel  18  to the side panel  16 ,  17  in an erected condition of the cage  10 . Each securement bracket  52  comprises a pair of spaced vertical legs  54  welded to vertical wires  60  of the front panel  18 . The upper ends of each of these legs  54  terminate in U-shaped loops  55  which are connected through a cross bar  56 , also welded to the front side of the vertical wires  60  of the front panel  18 . When the locking pin  50  is inserted through the loops  55  of the securement bracket  52  and passed through a loop  24  of one of the side panels  16 ,  17 , the front panel  18  is locked to the side panel. With reference to  FIGS. 3 and 4A ,  4 B and  4 C, it will be seen that each locking pin  50  terminates at its inner end in a generally hook-shaped loop  58  which, when rotated counterclockwise, as viewed in  FIG. 3 , may be disengaged from one of the vertical wires  60  of the front panel  18  and moved into a position in which the locking pin  50  may be moved inwardly toward the center of the front panel to disengage the free end of the pin from the locking loop  24  of the side panel. See  FIG. 4C . Thereby, the front panel  18  with the locking pins  50  disengaged from the locking loops  24  be lowered to the position illustrated in  FIG. 5  to collapse the cage  10 . 
         [0032]    With four such locking mechanisms  22  on each side of the front panel  18 , it will be seen that the front panel  18  is easily secured to the side panels  16 ,  17  in the erected condition of the cage  10 . Preferably, the front panel  18  is divided into two sections  18   a,    18   b  intermediately of its height, which sections have laterally extending border rods or wires connected via a helical lacing wire  64  so as to enable those two sections  18   a,    18   b  to pivot one relative to the other. Thereby, the upper half or section  18   b  of the front panel  18  may be unlocked and pivoted downwardly relative to the lower half or section  18 a of the front panel  18  for purposes of enabling collected water in the containment bag  26  to more easily be emptied from the containment bag  26 , as explained more fully hereinafter. 
         [0033]    Although four locking mechanisms  22  are shown on each side of the front panel  18 , it will be understood by those skilled in the art that any number of locking mechanisms of any known configuration or type may be used in accordance with the present invention. 
         [0034]    As shown in  FIGS. 11 and 12  one embodiment of the waterproof containment bag  26  is a two ply bag having a bottom  70  and four sides  72  of the same dimensions. The bottom  70  and each side  72  is two ply. As shown in  FIG. 12 , this waterproof containment bag  26  comprises a waterproof inner ply or liner  25  of non-woven polypropylene approximately 6 to 10 millimeters in thickness and an outer ply  27  primarily for strength made of woven polypropylene of a thickness of approximately six millimeters. The inner and outer plies  25 ,  27  are preferably sewn together along their upper edges (indicated by numeral  29 ) but may be joined in any desired manner. The plies  25 ,  27  may be other desired materials of any desired thickness. 
         [0035]    As shown in  FIGS. 1 and 11 , two lifting straps  74 ,  76  are secured to the waterproof containment bag  26  on the outside thereof. Each lifting strap  74 ,  76  is formed into a lifting loop  74   a,    76   a  at the top of the waterproof containment bag  26 , extends down a corner or side of the waterproof containment bag  26  and up the opposite side or corner of the bag  26 . The lifting straps  74 ,  76  form an X pattern at the bottom of the waterproof containment bag  26  for strength, as shown in  FIG. 11 . The lifting straps  74 ,  76  are preferably made of polypropylene and designed to lift 4000 lbs of weight. This type of bag is known in the industry as a rhino bag. 
         [0036]    In one preferred embodiment, the waterproof containment bag  26  is 48 inches in length, 48 inches in width and 48 inches in height. However, any other size of waterproof containment bag may be used in accordance with the present invention. 
         [0037]    The second bag of the waste disposal system  5  is the filtration bag  28  which functions to separate the liquid waste  8  of the cementuous slurry  51  from the solid waste or concrete  6  (see  FIG. 12 ) created from the cementuous slurry. In one preferred embodiment, the filtration bag  28 , like the waterproof containment bag  26 , is a two ply bag. However, unlike the waterproof containment bag  26 , the filtration bag  28  is divided into a waterproof lower section  80  and a porous upper section  82 , such that water and any particle 50 microns or smaller may pass through the upper section  82  of the filtration bag  28  while cement and any particle 50 microns or larger remains in the filtration bag  28 . 
         [0038]    In one embodiment the filtration bag  28  is a two ply bag having a top  84  with an opening  86  surrounded by a neck  88 , a bottom  89  and four sides  96  of the same dimensions. The opening  86 , in one embodiment, has a diameter of approximately  12  inches. As shown in  FIG. 12 , the lower section  80  of the filtration bag  28  has an inner ply  31  and an outer ply  39  while the upper section  82  of the filtration bag  28  has an inner ply  33  and an outer ply  37 . 
         [0039]    The inner ply or liner  29  of the filtration bag  28  comprises a lower section  31  approximately 24 inches in height of waterproof non-woven polypropylene and an upper section  33  twelve inches in height of 50 micron filter cloth sewn or otherwise secured around the lower edge to the upper edge of the lower section  31  of the inner ply  29 . Other size filtration cloths may be used in the upper section  33  of the inner ply of the filtration bag  28  if desired and the lower section  31  of the inner ply  29  of the filtration bag  28  may be made of any other suitable waterproof or leakproof material. 
         [0040]    The outer ply  35  of the filtration bag  28  comprises an upper section  37  which is perforated as by cuts or slits  90  to allow the particles 50 microns or smaller which have passed through the filtration cloth of the upper section  31  of the inner ply  29  of the filtration bag  28  to pass through the outer ply  35  of the upper section  37  of the filtration bag  28 . The lower section  39  of the outer ply  35  of the filtration bag  28  is waterproof and constructed primarily for strength. Both sections  37 ,  39  of the outer ply  35  of the filtration bag  28  are preferably made of non-woven polypropylene but may be made of any suitable material. The inner and outer plies  29 ,  35  of the filtration bag  28  are sewn together along their upper edges but may be joined in any desired manner. 
         [0041]    The filtration bag  28  has two lifting straps  92 ,  94 , each being formed into a lifting loop  92   a,    94   a  at the top of the filtration bag  28 . These straps  92 ,  94  each extend down the sides or corners of the waterproof containment bag  28  and form an X pattern at the bottom of the filtration bag  28 . See  FIG. 9 . The lifting straps  92 ,  94  are preferably made of polypropylene and designed to lift 3000 lbs of weight. This type of bag is also known in the industry as a rhino bag. In one preferred embodiment, the filtration bag  28  is 36 inches in length, 36 inches in width and 36 inches in height. However, another size or configuration of filtration bag may be used in accordance with the present invention. 
         [0042]    In use, one or more individuals erect the wire cage  10  from its collapsed condition ( FIG. 6 ) at a desired location, which is commonly adjacent the swimming pool being plastered. The waterproof containment bag  26  is placed inside the erected wire cage  10  with an upper portion  26   a  of the waterproof containment bag  26  being wrapped over the upper edge of the erected wire cage and located outside the erected cage  10 . If desired, this portion of the waterproof containment bag  26  may be secured to the erected wire cage  10  outside the cage. 
         [0043]    The filtration bag  28  is then placed inside the waterproof containment bag  26 , the neck  88  of the filtration bag  26  being adapted to be attached to the end of a hose to receive the cementuous slurry. The loops  92   a,    94   a  of the lifting straps  92 ,  94  of the filtration bag  28  are preferably secured to the erected wire cage  10  by bungee straps or other conventional fasteners. A fixed quantity of a polymeric flocculating agent  100  is introduced into the interior of the filtration bag  28  via opening  86 . See  FIG. 12 . A gallon is commonly used of a product sold under the trademark SLURRY MATE produced by Pebble Technology Incorporated of Scottsdale, Ariz. The purpose of the polymeric flocculating agent is to accelerate the separation of the cement  6  from the water or liquid  8 , thus allowing the liquid  8  to rise to the top of the cement  6  and filter through the upper section  82  of the filtration bag  28  and pass into and be collected in the waterproof containment bag  26 . The cement, i.e., any particles larger than  50  microns, remain in the lower section  80  of the filtration bag  28  and solidify. Once a certain amount of time has passed the filtration bag filled with cement may be removed from the waterproof containment bag. 
         [0044]    The next step in the process is to measure the pH of the filtered fluid waste which has been filtered and is now located in the waterproof containment bag  26 . The pH may be checked or measured with any pool pH test strip which is available at most pool supply stores or locations. If the pH reading is high, muriatic acid or any other acidic material  102  may be added to the fluid inside the waterproof containment bag  26 . Once the pH is in the range of 6.5-7.5 (neutral), one or more sides of the erected wire cage  10  may be lowered, thereby allowing the neutralized fluid  8  to flow out from inside the waterproof containment bag  26  onto the lawn or ground. Due to the neutral pH of such fluid, it is, in most places, lawful and safe to empty this fluid in such a manner. This avoids workers having to transport the fluid which may weigh as much as 4000 pounds. The remaining cement  6  is contained in the disposable filtration bag  28  and may be hoisted onto a delivery truck such as the same one which delivered the raw materials to the pool construction site. There is no overnight waiting for settling nor is there any chance for children or pets to get into the sealed bags. 
         [0045]    The embodiments of the invention shown and described are for illustrative purposes only. For example, any cage, although preferably a collapsible solid cage, may be substituted for the wire cage described hereinabove. While those skilled in the art may make various other changes to, or additional embodiments of, the invention, none of those changes/embodiments shall be deemed to depart from the spirit of the invention. Thus, all such changes/embodiments shall be embraced by the scope of the invention as defined in the claims. Accordingly, the invention is to be limited only by the scope of the following claims and their equivalents.