Abstract:
The present invention generally provides a modular apparatus for storing and maintaining variable amounts of concrete slurry, and methods for assembling, utilizing and cleaning the apparatus. The modular nature of the apparatus permits a slurry manufacturer to create and store different volumes of slurry without resorting to multiple storage containers. It further permits a slurry manufacturer to clean the storage container on a regular basis without the expensive and time-consuming process of vertically inserting personnel and equipment through the open top of the container. Embodiments of the invention include a water jacket for use in maintaining the temperature of the slurry in the container.

Description:
[0001]     This application claims the benefit of U.S. Provisional Application No. 60/752,252, filed on Dec. 19, 2005, which is incorporated herein by this reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to apparatus and methods for storing concrete slurry and maintaining it in an agitated state, and more particularly, to modular apparatus and methods of maintaining agitated slurry at a pre-defined and constant temperature.  
         [0004]     2. Description of the Prior Art  
         [0005]     The concrete slurry used in the construction industry generally comprises a mixture of water, cementation materials and sand fines. The slurry is generally ordered in advance, pre-mixed at an off-site concrete batch plant to particular specifications, and then delivered to the job site in trucks with large rotatable drums that continuously agitate the slurry until it is ready to be used. The unused slurry is returned to the plant, where it may be recycled, reclaimed or stored until it is needed again.  
         [0006]     Throughout this entire process, and until it is poured, the slurry must be maintained in an agitated condition. Failure to do so will cause the slurry to harden prematurely, and become useless. As such, most slurry manufacturers use specially designed slurry containers to continuously agitate the unused or returned slurry.  
         [0007]     Traditional slurry containers include a cylindrical upright drum with an agitator extending downward into the slurry mixture. A significant shortcoming of such a container is that it cannot be expanded to accommodate different volume requirements. As such, if the volume of slurry exceeds the capacity of a single container, the excess volume must be stored in additional, separate containers.  
         [0008]     Separate storage creates numerous problems in maintaining a consistent quality in a single batch of slurry. Because the slurry must be mixed and maintained in separate containers, minute differences in the ingredients, water-mix ratios, temperatures, consistencies, or even locations, may result in different slurry qualities—which may dilute or contaminate the entire batch, and cause unanticipated effects on architectural stress points or defects in the concrete, or things as simple as color mis-matches.  
         [0009]     Purchasing a separate, larger container is an expensive and wasteful alternative, since the larger container cannot effectively mix smaller volumes of slurry.  
         [0010]     A second significant shortcoming of the traditional slurry container is that it, is difficult to clean. Regular cleaning is essential in avoiding contamination of the slurry.  
         [0011]     However, the only means of cleaning a traditional slurry container is through the open top end of the container—which often necessitates manual cleaning.  
         [0012]     A third significant shortcoming of the traditional slurry container is that it does not effectively regulate the slurry temperature. Heat affects the quality of the concrete, in that the slurry will solidify faster as more heat is applied. However, too much heat will result in weak or substandard concrete. The mere creation of the slurry, and its subsequent constant agitation, generates heat. Additional sources of heat include the warmer summer months and geographic climates.  
         [0013]     Various inventions have been developed to address one or more of these problems. For example, U.S. Pat. No. 3,930,462 discloses a slurry tank having a crude water jacket along two sides and the bottom of a tank for regulating slurry temperature. However, there is no temperature control for the remaining sides of the tank, making it difficult to attain consistent temperature regulation. U.S. Patent Application No. 2003/0002384 discloses a portable concrete batch plant for onsite mixing of slurry having a slurry mixing component with a heat exchanger and hot water system. However, the exchanger and system control the temperature of the water used in creating the slurry in the first place; there is no separate system for use in maintaining the temperature of the slurry once created.  
         [0014]     In addition, neither of the above inventions is able to store variable volumes of slurry. The capacity of the &#39;462 invention is limited to the physical dimensions of the container, with excess volumes requiring additional containers. Though the &#39;384 invention is arguably capable of mixing a large volume of slurry, that slurry must be used immediately—the invention&#39;s ability to store slurry is limited to the capacity of the storage component, which must be small enough for the invention to remain portable. Finally, neither of the above inventions are any easier to clean than a traditional slurry container, since both of them still must be cleaned through their respective open tops.  
         [0015]     It is therefore desirable to provide apparatus with expandable capacity to accommodate different volumes of slurry, and methods of use. It is further desirable to provide apparatus and methods including components to effectively regulate the slurry temperature. It is further desirable that the temperature be efficiently regulated regardless of the slurry volume, without exposing any portion of the slurry to temperature extremes or otherwise affecting the quality of the concrete. Finally, it is desirable to provide methods and apparatus for easily cleaning a slurry tank on a regular basis.  
       SUMMARY OF THE INVENTION  
       [0016]     The present invention provides a modular apparatus for storing variable amounts of concrete slurry, and methods of use. One embodiment includes one or more base panels attached together to form a base panel assembly or foundation, and a plurality of upwardly extending side panels attached to the perimeter of the foundation. The foundation and side panels form a slurry container having a closed bottom and sides. The dimensions and shape of the container may be altered according to the slurry manufacturer&#39;s needs, simply by adding or removing the appropriate number of base and side panels.  
         [0017]     The modular nature of the present invention provides an easy means of cleaning the slurry container. Rather than vertically inserting cleaning personnel and equipment, the slurry manufacturer may simply remove one or more side panels or end walls in order to access the interior for cleaning and maintenance purposes. This permits the manufacturer to utilize a wider range of cleaning equipment, including the use of a skid steer (Bobcat®) or other front loading excavator for removal of residual concrete during periodic cleaning. The removable panels also allow the modular invention to be expanded by adding additional base and wall panels at any such opening, resulting in a larger enclosure made up of multiple modules attached to each other.  
         [0018]     The present invention further allows a slurry manufacturer to regulate the temperature of the slurry in the tank via the introduction of temperature regulating fluids through a modular water jacket. The modular water jacket is constructed from a second set of side panels erected around the existing side panels, with a space between the exterior and interior panel sets defining the water jacket itself. The flow of heated or cooled fluids through the water jacket regulates the temperature of the slurry in the tank.  
         [0019]     Some embodiments of the water jacket of the present invention include a series of channels to control the flow of the temperature regulating fluids. These channels may be formed by the support structures attached to each side panel, and/or by various flow openings within said support structures. These channels provide a more uniform distribution of fluid through the water jacket providing more thorough heating or cooling of the slurry, preventing the disproportionate heating or cooling of different areas within the water jacket and adjacent slurry.  
         [0020]     It is therefore an object of the present invention to provide a modular slurry tank that may be expanded or contracted in order to change its slurry holding capacity according to the needs of the user.  
         [0021]     It is therefore an object of the present invention to provide a modular slurry tank that allows for future growth of the slurry tank by adding additional side and bottom panels.  
         [0022]     It is another object of the present invention to provide methods and apparatus for effectively regulating the temperature of the slurry in the tank without diluting, or otherwise negatively affecting, the quality of the slurry.  
         [0023]     It is another object of the present invention to provide a temperature regulating mechanism capable of accommodating different dimensions of the tank, and changes in those dimensions.  
         [0024]     It is another object of the present invention to provide a slurry tank that is easy and inexpensive to clean on a regular basis.  
         [0025]     Additional objects of the invention will be apparent from the detailed description and the claims herein. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]      FIG. 1  is a side perspective view of an embodiment of the invention.  
         [0027]      FIG. 2  is a top plan view of the embodiment of  FIG. 1 .  
         [0028]      FIG. 3  is a cross sectional side view along line  3 - 3  of  FIG. 1 .  
         [0029]      FIG. 4  is a cross sectional top view along line  4 - 4  of  FIG. 1 .  
         [0030]      FIG. 5  is a cross sectional end view along line  5 - 5  of  FIG. 1 .  
         [0031]      FIG. 6  is a perspective view of an embodiment of the invention showing a side wall having been removed.  
         [0032]      FIG. 7  is a side perspective and partially cut away view of an embodiment of a panel of a water jacket of the present invention.  
         [0033]      FIG. 8  is a side view of an embodiment of the present invention, illustrating expandability (modularity) in phantom lines. 
     
    
     DETAILED DESCRIPTION  
       [0034]     Referring to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, and referring particularly to the exemplary embodiment of  FIG. 1 , it is seen that the present invention includes a slurry container generally having one or more base panels  10  forming a foundation, and a plurality of upwardly extending side panels  20 .  
         [0035]     Each base panel  10  may be provided with one or more attachment devices  11  along the edges of the base panel  10  for interengagement with other base panels  10  or side panels  20 . Although the illustrated embodiment is depicted in a generally rectangular form, it is to be appreciated that base panel(s)  10  may be of any shape or dimension including without limitation, pentagonal, hexagonal, octagonal, round, oval, etc. The attachment mechanisms  11  may be any number of devices for securing one object to another, including, but not limited to bolts, hooks, latches, male-female joints, teeth, etc., or combinations thereof. The attachment mechanisms  11  of each base panel  10  may be interlocked with the corresponding attachment mechanism  11  of another base panel  10 , or with a similar attachment mechanism  21  of a side panel  20 .  
         [0036]     Each side panel  20  also includes one or more attachment mechanisms  21  along one or more edges of the side panel  20  for engagement with base panels  10  and/or other side panels  20 . The attachment devices  21  may be interlocked with the corresponding attachment mechanism  21  of another side panel  20 , or with the attachment mechanism  11  of a base panel  10 . Although the illustrated embodiment is depicted in a generally rectangular form, it is to be appreciated that side/end panel(s)  20  may be of any shape or dimension including without limitation, rectangular, square, etc., and may have any suitable cross sectional shape including L-shaped, T-shaped, arcuate, or combinations thereof.  
         [0037]     In several embodiments, side panels  20  also include reinforced support structures  22  as shown in  FIG. 3 . The support structures  22  may be affixed to one or both faces of each side panel  20 , or even embedded within the side panels  20  as shown in  FIG. 7 .  
         [0038]     The above described attachment mechanisms  11 ,  21  allow a slurry manufacturer to interlock any two or more panels via their edges (either two base panels, a base panel and a side panel, two side panels, side/end panel(s), or any combination of a plurality of panels). When interlocked, the panels form a tight seal along the edge of the junction sufficient to prevent the outflow of liquids. The combination of any number of base panels  10  permits the expansion of the present invention&#39;s horizontal dimensions (foundation) to accommodate different volumes of slurry, and to form irregular shapes to accommodate space restrictions imposed by the environment. The connectivity between the base panels  10  and side panels  20  allows the side panels  20  to fully enclose the perimeter defined by the base panels  10  assembly (foundation), regardless of the particular dimensions of the base  20  panels themselves.  
         [0039]     In some embodiments, one or more support members  33  are provided, generally in pairs, for attachment to the tops of side panels  20 . Support beams  30  are attached to the support members  33 , ordinarily located on opposite pairs of side panels  20 . Support members  33  provide reinforcement between adjacent side panels  20 , and provide a cross support for the enclosure through beam  30  to ensure that the side panels  20  do not collapse or deform under the pressure of the contained slurry. Agitator assemblies  31  may be mounted upon one or more of the support beams  30 , each assembly  31  including a shaft  34  and blades  35  used to agitate the slurry contained within the present invention. In some embodiments, additional support members  28  are provided at the tops of side panels  20 , with cross beams  29  provided between them to further reinforce panels  20 .  
         [0040]     In some embodiments of the present invention, a modular water jacket is provided for maintaining the temperature of the concrete slurry in the container. In these embodiments, side panels  20  are provided with dual walls defining a space  40  therebetween as more fully illustrated in  FIGS. 3 and 7 . The space  40  may be filled with a temperature regulating fluid, such as water, which is injected through an inlet  24  provided on the exterior of a side panel  20 , and removed through a separate outlet  25 . The fluid is circulated either via the injection pressure or separate pumping mechanism(s)  27 . It is to be appreciated that multiple side panels  20  having dual walls with inlets  24  and outlets  25  may be provided, and that the outlet  25  from one side panel may be connected to the inlet  24  of an adjacent side panel via a piping structure  26 , such that the fluid may be circulated from one side panel  20  to another. It is also to be appreciated that not all side panels  20  need be included in the circulation of fluid, although this is preferred so as to maintain uniform temperature regulation. Temperature regulating units such as heaters or coolants, may be utilized to maintain a desired fluid temperature, which, in turn, affects the temperature of the slurry in the container. Additional insulating panels or liners may also be employed, particularly on the exterior wall, to maintain the temperature inside. An exemplary hot temperature for the fluid is around 165 degrees F., and an exemplary cold temperature is around 37 degrees F., it being understood that any suitable temperature above, or below this range may be used depending upon the air temperature, the starting temperature of the slurry, and the desired temperature for the slurry.  
         [0041]     With respect to the flow of fluid through the space  40  of each side panel  20 , it is to be appreciated that structures  22  define one or more channels  42  between them, either in uniform or non-uniform positions with respect to one another. See  FIGS. 3 and 7 . In some embodiments, support structures  22  may be sized such that they do not fully extend from one end of panel  20  to the other, thereby defining one or more gaps through which fluid may flow. In other embodiments, one or more openings  43  may be provided in structures  22  to allow the flow of fluid to pass through, as shown in  FIG. 3 . Openings  43  may be located in the same positions on each structure  22 , but are preferably in different locations (e.g., at the top of one structure  22 , and at the bottom of an adjacent structure  22 ) in order to force the fluid to flow in a longer path for more uniform distribution in the space  40 . Flow openings  43  may have the same or different diameters. The channel(s)  42  and flow openings  43 , separately or together, preferably guide the flow of pressurized fluids to all parts of the water jacket spaces  40  to provide more thorough heating or cooling of the slurry, and prevent disproportionate heating or cooling of different areas within the water jacket and adjacent slurry. In the illustrate embodiment, structures  22  and openings  43  provide a serpentine channel  42  for the flow of fluids.  
         [0042]     It is to be appreciated that multiple, concentrically-located water jackets may be used if necessary. This permits the slurry manufacturer to heat or cool the inner portions of the slurry container, rather than merely the outside edges.  
         [0043]     In use, the slurry manufacturer determines desired dimensions for the slurry container based upon anticipated needs. The base of the slurry container is assembled by combining the necessary base panels  10 , and attaching them to one another via the interlocking attachment mechanisms  11 . The side panels  20  are attached around the perimeter of the base panels  10  assembly via the interlocking attachment mechanisms  11 ,  21 . Support members  33  and beams  30  are then attached to the top edges of opposing side panels  20 , and agitator assemblies  31  mounted thereon. Additional supports  28 ,  29  may also be installed. The slurry is then introduced into the slurry container and periodically (or continuously) agitated by the agitator assemblies  31  until it is ready to be disbursed.  
         [0044]     Should it be determined that the slurry container should be larger, one or more side (end) panels  20  may be removed creating an opening, and additional base panel(s)  10  attached to the existing base assembly at the opening. Then, additional side panels  20  may be attached around the perimeter of the new base panel(s)  10 , attaching to themselves and to the existing side panels  20 . This expands the capacity of the container to handle more slurry. It is to be appreciated that such expansion may be accomplished by the removal of any one or more side panels, and the addition of any one or more base panels and additional side panels to enclose the container. An exemplary expansion adding two base panels and associated side panels is illustrated in the phantom lines in  FIG. 10 . It is to be appreciated that the container may be reduced in size by performing the reverse of the operation above: removal of a section of side panels (and corresponding base panel(s)) and closing off the open end to form a smaller container tank. It is also to be appreciated that multiple containers of the present invention may be attached to each other using one or more common side walls, and/or that a container of the present invention may be divided into sections by inserting one or more side walls between existing side walls.  
         [0045]     If the temperature of the slurry is to be maintained at a certain level, side panels  20  may be of the water jacket type illustrated in  FIG. 7 , having dual walls defining a space  40  between them, with channel(s)  42  defined between supports  22 , and openings  43  in supports  22  for the flow of fluid through space  40 . A fluid pipe is attached to inlet  24  to introduce a temperature regulating fluid into the space  40  by means of one or more pumps  27 . This fluid exits through outlet  25 , which is connected to the inlet  24  of an adjacent panel, and so on, so that fluid is circulated throughout spaces  40  of each connected panel  20  of the water jacket. The fluid is pre-heated or pre-cooled as dictated by such things as the slurry type and temperature, weather conditions, etc. The fluid transfers the heat or coolness to the slurry in the container, and helps maintain the slurry at a suitable temperature for good quality under wide ranging conditions.  
         [0046]     Cleaning of the slurry container is a simple operation. One or more side panels  20  are removed from the container. This allows personnel and equipment to enter the container from the side for periodic cleaning maintenance. Since the avenue of entrance is through a side panel  20 , the slurry manufacturer is not limited to the vertical insertion of specialized cleaning equipment. Instead, the manufacturer may utilize any number of generic, non-specialized machines, such as a traditional skid steer or Bobcat®.  
         [0047]     It is to be understood that variations and modifications of the present invention may be made without departing from the scope thereof. It is also to be understood that the present invention is not to be limited by the specific embodiments disclosed herein, but only in accordance with the final claims when read in light of the foregoing specification.