Abstract:
An apparatus and method for reclaiming uncured concrete are disclosed. The apparatus includes a hopper with water inlet for introducing water to the hopper. The outlet of the hopper is connected to a separator that is suitably connected to the hopper to receive material therefrom. A screen is positioned in the separator to separate material flowing therethrough. The separator has two outlets for removing material from the separator.

Description:
RELATED PRIORITY DATE APPLICATION  
       [0001]    This application claims the benefit under 35 U.S.C. 119(e) of the U.S. provisional application No. 60/262546 filed on Jan. 17, 2001. 
     
    
     
       TECHNICAL FIELD OF THE INVENTION  
         [0002]    The present invention relates to solid/liquid separation, and, more particularly, to an apparatus and a method for reclaiming uncured concrete. Still more particularly, the present invention discloses a method and an apparatus for separating cement slurry, sand, and gravel from mixed concrete for future use.  
         BACKGROUND OF THE INVENTION  
         [0003]    The wide use of concrete for the construction of roads, buildings and the like is well known. In most building operations utilizing concrete, there is always left over a significant amount of unused, uncured concrete. That concrete is not easily disposable and presents a serious environmental problem. Furthermore, the unused concrete is an economic waste. In order to solve the disposal problem and to reduce the economic waste, methods have been developed to reclaim the concrete for further usage in the preparation of new concrete. Those methods utilize pits which are dug in the ground to recover the concrete material through gravity separation. One difficulty with the use of those pits is that they are fixed and cannot be transported to different locations as the need arises. Still, another disadvantage is the water used in those methods presented disposal problems.  
           [0004]    According to the present, an apparatus and a method for reclaiming unused, uncured concrete utilizing portable, above ground equipment that are capable of recovering rock, sand and light cement material for future use. The water being used to assist in the separation is recycled and the need for disposing that water in large quantities is eliminated.  
           [0005]    These and other advantages of the present invention will become apparent from the following description and drawings.  
         SUMMARY OF THE INVENTION  
         [0006]    A concrete reclaimer and a method for separating cement slurry, sand, and gravel from mixed concrete for future use are disclosed. The concrete reclaimer includes a hopper, a pump, a separator, a sand tank and four water holding tanks, connected in series. The pump is mounted at the bottom of the hopper for pumping material from the hopper to the separator via a hose which is removably connected to the pump. The hopper and the separator are connected to a water distribution manifold by hoses for receiving water recirculated from the four water holding tanks.  
           [0007]    The hopper includes a hopper holding tank with an upper edge at a height which is suitable for receiving discharge of waste, uncured concrete from a concrete mixer truck. Several manifolds provide water to the interior portion of the holding tank, the hopper lower water supply and pump cooling nozzles.  
           [0008]    The separator is supported above the sand tank by four adjustable legs and has a bottom discharge opening for flowing material from the separator to the sand tank. A chute is attached to the separator for removing material therefrom. A rotatable screen wheel is mounted on the interior of the separator and is driven by a drive mechanism mounted on the outside wall of the separator.  
           [0009]    The sand tank is followed by four tanks connected in series with each tank receiving overflow material from the previous tank. Discharge assemblies at the bottoms of each of the four tanks are connected to a hose connected to a water pump that recirculates water and solid material.  
           [0010]    In operation, a concrete mixer truck carrying unused, uncured concrete positions its discharge chute over the hopper. The water recirculation pump is activated to begin pumping water to the hopper and the separator. The water is injected through two separate inlets into the upper and lower portions of the hopper. The concrete from the truck and any washed material from the truck concrete container is then discharged into the hopper where is it contacted by the water to create a diluted concrete slurry which is pumped by the pump to the upper portion of the separator. Therein, the water is sprayed through sprayers. The slurry flows by gravity inside the separator. When the slurry reaches the rotating screen wheel rock material of larger diameter is screened out from the slurry and is centrifugally directed to a discharge outlet from the separator. The remaining material comprising cement, sand and water slurry flows by gravity to the bottom of the separator and exits therefrom through its open end to fall by gravity to the sand tank where most of the sand settles. The effluent from the sand tank flows to the fist water holding tank. Overflow from the first tank flows to the second tank, overflow from the second tank flows to the third tank and overflow from the third tank flows to the fourth tank. Water is continuously removed from the bottom of the four tanks to the water pump that recirculates the water. In the process described, the rock is separated from the concrete slurry in the separator, the sand is separated from the water/cement slurry in the sand tank and cement light material is separated from the water in the four water tanks. The separated rock, sand and light cement material are thus recovered for future use. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings wherein:  
         [0012]    [0012]Figure 1A is schematic top view of the preferred embodiment of the apparatus of the present invention;  
         [0013]    [0013]Figure 1B is a schematic rear view of the embodiment of FIG. 1A.;  
         [0014]    [0014]FIG. 2A is a schematic top view of a section of the apparatus of FIG. 1A;  
         [0015]    [0015]FIG. 2B is a schematic side view of the apparatus of FIG. 2A;  
         [0016]    [0016]FIG. 2C is a schematic bottom view of the apparatus of FIG. 2A;  
         [0017]    [0017]FIG. 3 is a partly elevational, partly schematic view of a section of the apparatus of FIG. 2A;  
         [0018]    [0018]FIG. 4 is a partly elevational, partly schematic view of another section of the apparatus of FIG. 2A;  
         [0019]    [0019]FIG. 5 is a partly elevational, partly schematic view of another section of the apparatus of FIG. 2A;  
         [0020]    [0020]FIG. 6 is a partly elevational, partly schematic view of another section of the apparatus of FIG. 2A;  
         [0021]    [0021]FIG. 7 is a partly elevational, partly schematic view of another section of the apparatus of FIG. 2A;  
         [0022]    [0022]FIG. 8 is a schematic side view of another section of the apparatus of FIG. 1A;  
         [0023]    [0023]FIG. 9 is a schematic side view of a section of the apparatus of FIG. 8;  
         [0024]    [0024]FIG. 10 is a schematic side view of another section of the apparatus of FIG. 1A;  
         [0025]    [0025]FIG. 11A is a schematic top view of a section of the apparatus of FIG. 8;  
         [0026]    [0026]FIG. 11B is schematic side view of the apparatus of FIG. 11A;  
         [0027]    [0027]FIG. 12A is a schematic front view of a section of the apparatus of FIG. 8;  
         [0028]    [0028]FIG. 12B is schematic side view of the apparatus of FIG. 12A;  
         [0029]    [0029]FIG. 13A is a schematic front view of a section of the apparatus of FIG. 8;  
         [0030]    [0030]FIG. 13B is schematic top view of the apparatus of FIG. 13A;  
         [0031]    [0031]FIG. 14A is a schematic top view of a section of the apparatus of FIG. 8;  
         [0032]    [0032]FIG. 14B is a schematic side view of the apparatus of FIG. 14A;  
         [0033]    [0033]FIG. 14C is a schematic, perspective, side view of the apparatus of FIG. 14A;  
         [0034]    [0034]FIG. 15A is a schematic front view of a section of the apparatus of FIG. 8;  
         [0035]    [0035]FIG. 15B is a schematic back view of the apparatus of FIG. 15A;  
         [0036]    [0036]FIG. 16A is a schematic, perspective side view of a section of the apparatus of FIG. 8;  
         [0037]    [0037]FIG. 16B is a schematic bottom view of the apparatus of FIG. 16A;  
         [0038]    [0038]FIG. 17 is an elevational view of a section of the apparatus of FIG. 1A;  
         [0039]    [0039]FIG. 18 is an elevational view of a section of the apparatus of FIG. 1A;  
         [0040]    [0040]FIG. 19A is an elevational view of a section of the apparatus of FIG. 1A;  
         [0041]    [0041]FIG. 19B is a front elevational view of the apparatus of FIG. 19A;  
         [0042]    [0042]FIG. 20A is a schematic side view of an alternative embodiment of a hopper to be used in the apparatus of the present invention;  
         [0043]    [0043]FIG. 20B is schematic opposite side view of the apparatus of FIG. 20A;  
         [0044]    [0044]FIG. 20C is a schematic front view of the apparatus of FIG. 20A;  
         [0045]    [0045]FIG. 20D is a schematic rear view of the apparatus of FIG. 20A;  
         [0046]    [0046]FIG. 20E is a schematic top view of the apparatus of FIG. 20A; and  
         [0047]    [0047]FIG. 20F is a schematic bottom view of the apparatus of FIG. 20B;  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0048]    According to the present invention, an apparatus and a method are disclosed for separating cement slurry, sand, and gravel from mixed concrete for future use. Referring now to FIGS. 1A and 1B, there is shown a concrete reclaimer  10  in accordance with the present invention. Concrete reclaimer  10  includes a hopper  20 , a pump  22 , a separator  24 , a sand tank  26  and water holding tanks  36   a,    36   b,    36   c  and  36   d,  connected in series.  
         [0049]    Pump  22  is mounted at the bottom of hopper  20  for pumping material from hopper  20  to separator  24  via a hose  21  which is removably connected to pump  22  by quick connect/disconnect couplings. Pump  22  is attached to discharge pump connection  44 . In a typical application, discharge pump  22  is rated at ten horsepower with a four inch discharge port and has the ability to pass three and one half inch solids and pump water at six hundred fifty gallons per minute at fifteen feet of head.  
         [0050]    Hopper  20  and separator  24  are connected to a water distribution manifold  33  by a hose  27  and a hose  31 , respectively, fitted with quick connect/disconnect couplings for receiving water recirculated from tanks  36   a,    36   b,    36   c  and  36   d,  as hereinafter described. Supply tee  43  connects hose  27  to hopper  20 .  
         [0051]    Separator  24  has a bottom discharge opening for flowing material from the bottom of separator  24  to tank  26  below. Separator is supported above tank  26  by four adjustable leg assemblies  25 . A chute  23  is attached to separator  24  for removing material therefrom. A hatch  45  on separator  24  provides access to the interior of separator  24 . A drive mechanism  29  is mounted on the outside wall of separator  24 . Drive mechanism  29  is covered by cover  30 .  
         [0052]    Three pipes  28  connect tank  26  to tank  36   a  for flowing overflow material from tank  26  to tank  36   a.  Three pipes  39   a  connect tank  36   a  to tank  36   b  for flowing overflow material from tank  36   a  to tank  36   b;  three pipes  39   b  connect tank  36   b  to tank  36   c  for flowing overflow material from tank  36   b  to tank  36   c;  and three pipes  39   c  connect tank  36   c  to tank  36   d  for flowing overflow material from tank  36   c  to tank  36   i.  The inlets of pipes  39   a,    39   b  and  39   c  are mounted about one foot bellow the mouths of tanks  36   a,    36   b  and  36   c,  respectively, to allow for the collection of twelve inches of rain in case of a heavy rainfall.  
         [0053]    Discharge assemblies  37   a,    37   b,    37   c  and  38  at the bottoms of tanks  36   a,    36   b,    36   c  and  36   d,  respectively, are connected to hose  35  comprised of hose portions  35   a,    35   b,    35   c  and  35   d  for flowing material by gravity from tanks  36   a,    36   b,    36   c  and  36   d  to hose  35 . Hose portion  35   a  is connected to a pump  34  that discharges material to manifold  33  which is connected to hoses  27  and  31  and a utility hose (not shown). Pump  34  is rated at five horsepower with a three inch inlet and a three inch discharge and has the ability to pass 3/8 inch solids and pump water at four hundred gallons per minute at ten feet of head.  
         [0054]    Referring now to FIGS. 2A, 2B and  2 C, hopper  20  includes a hopper holding tank  100  having an upper cylindrical portion  80 , a bottom dish  82  and a lower reduced diameter cylindrical portion  84 , all seam welded together. Upper cylindrical portion  80  is preferably formed by welding in series a rolled channel, a rolled flat bar and another rolled channel. The upper edge of holding tank  100  is at a height which is suitable for receiving discharge of waste, uncured concrete from a concrete mixer truck.  
         [0055]    Forward water manifolds  101   a  and  101   b  and rear water manifolds  103   a  and  103   b  provide water to the interior portion of holding tank  100 . They also provide water to the hopper lower water supply and pump cooling nozzles  102   a,    102   b,    102   c  and  102   d.  Forward water manifolds  101   a  and  101   b  include ports with valves  108   a  and  108   b,  respectively, to supply water to mixer trucks for mixer drum wash out and for filling water tanks. Forward water manifold  101 a is connected to rear water manifold  103   a  via a hose  104   a  and manifold  101   b  is connected to rear water manifold  103   b  by a hose  104   b.  Rear water supply manifolds  103   a  and  103   b  are connected to a supply tee  43  using hoses  105   a  and  105   b,  respectively. Hopper lower water supply and pump cooling nozzle  102   a  is connected to forward water manifold  101   a  via a hose  106   a,  nozzle  102   b  is connected to manifold  103   a  via a hose  106   b,  nozzle  102   c  is connected to manifold  103   b  via a hose  106   c  and nozzle  102   d  is connected to manifold  101   b  via a hose  106   d.  Hopper lower water supply and pump cooling nozzles  102   a,    102   b,    102   c  and  102   d  provide water to lower portion of hopper holding tank  100  and cooling water for discharge pump  22 . Forward water manifolds  101   a  and  101   b,  rear water manifolds  103   a  and  103   b,  hopper lower water supply and pump cooling nozzles  102   a,    102   b,    102   c  and  102   d,  and water supply tee  43  are all assembled using standard plumbing components. Water supply tee  43  is connected to a pump (not shown) supplying concrete waste water under pressure to hopper  20  at 15 to 20 PSI and at a volume of 250 to 300 gallons per minute.  
         [0056]    The threaded end of a discharge pump connection  44  is inserted through a port (not shown) in the lower part of hopper holding tank  100 . A flange (not shown) is threaded on to discharge pump connection  44 . The flange is bolted to the discharge port of the hopper discharge pump. Discharge pump connection  44  is seam welded into the port in the lower part of hopper holding tank  100 .  
         [0057]    Hopper holding tank  100  is supported in an upright, stable position through the use of a plurality of hopper support legs  109  welded to the underside flange of the lowest rolled channel comprising the body of hopper holding tank  100  and welded to the inside of a hopper rolled base angle  107 .  
         [0058]    Referring now to FIG. 3, there are shown the details of hopper lower water supply and pump cooling nozzle  102   a.  Hose  106   a  connects hopper lower water supply and pump cooling nozzle  102   a  to forward water manifold  101   a  (not shown). Hose  106   a  is fitted onto a nipple  132  threaded on one side which in turn is connected to a threaded forty five degree elbow  133 . By means of a threaded nipple  134 , elbow  133  is connected to a threaded tee  135 . Threaded tee  135  is fitted with a threaded nipple  139  and a threaded nipple  142 . Threaded nipple  139  is inserted through a port (not shown) at the bottom of hopper holding tank  100 . The port is sealed by pipe nuts  136   a  and  136   b,  steel washers  137   a  and  137   b,  and rubber washers  138   a  and  138   b  installed on threaded nipple  139  on both sides of the wall of hopper holding tank  100 .  
         [0059]    Threaded nipple  142  is joined to a threaded nipple  144  by a threaded coupling  143   a.  Threaded nipple  144  is inserted through a port (not shown) located at the bottom of the dish section of hopper holding tank  100 . The port is sealed by pipe nuts  147   a  and  147   b,  steel washers  145   a  and  145   b,  and rubber washers  146   a  and  146   b  installed on threaded nipple  144  on both sides of the wall of hopper holding tank  100 . Threaded nipple  144  is attached to a threaded nipple  148  via a coupling  143   b  and threaded nipple  148  is attached to threaded ninety degree elbow  149 . Elbow  149  is threadingly connected an outlet  150 . Cooling water is discharged from outlet  150  onto discharge pump  22 . Similar connections are made to nozzles  102   b,    102   c  and  102   d.    
         [0060]    [0060]FIG. 4 depicts the details of forward water manifold  101   a.  Hose  106   a  is fitted with a nipple  161  threaded on one side only. The threaded end of nipple  161  is installed in a forty five degree elbow  162  containing a threaded nipple  163  fitted into a threaded port (not shown) in the bottom of a pipe  160 . Pipe  160  is connected to a utility hose threaded tee and valve assembly  172  to which hose  104   a  connecting to the rear water supply manifold (not shown) is attached by a threaded nipple (one side only)  173 . The threaded end of pipe  160  is fitted with a threaded cap  164 . The top threaded port (not shown) in pipe  160  is fitted with a threaded nipple  167  which extends through a port (not shown) located on the top part of bottom dish  82  of hopper holding tank  100 . The port is sealed by a pipe nut  168 , steel washers  169   a  and  169   b  and rubber washers  170   a  and  170   b  installed on threaded nipple  167  on both sides of the wall of bottom dish  82  of hopper holding tank  100  and a threaded ninety degree elbow  171 . A similar connection is made in manifold  101   b.    
         [0061]    [0061]FIG. 5 shows the details of rear water manifold  103 a. Similar details apply to rear water manifold  103   b.  Hose  106   b  to hopper lower water supply and pump cooling nozzle  102   b  (not shown) is fitted with a nipple  161   a  threaded on one side only. The threaded end of nipple  161   a  is installed in a forty five degree elbow  162   a  containing a threaded nipple  163   a  fitted into a threaded port (not shown) in the bottom of a pipe  173   a.  A hose  104   a  is attached to pipe  173   a.  A threaded ninety degree elbow  174   a  with a nipple threaded on one side (not shown) is attached to the other end of pipe  173   a.  The top threaded port (not shown) in pipe  173   a  is fitted with threaded nipple  167   a  which extends through a port (not shown) located on the top part of bottom dish  82  of hopper holding tank  100 . The port is sealed by a pipe nut  168   a,  steel washers  169   a  and  169   b  and rubber washers  170   a  and  170   b  installed on threaded nipple  167   a  on both sides of the wall of hopper holding tank  100  and a threaded ninety degree elbow  171   a.    
         [0062]    Discharge hopper water supply tee  43  is detailed in FIG. 6. Discharge hopper water supply hose  27  is connected to a threaded nipple  178  by a quick connect/disconnect coupling  179 . At the other end of threaded nipple  178  is installed a threaded tee  177 . Nipples  175   a  and  175   d,  threaded on one side only, are installed in each end of threaded ninety degree elbows  174   a  and  174   b,  respectively. Nipples  175   b  and  175   c,  threaded on one side only, are installed in threaded tee  177 . Threaded nipples  175   a  and  175   b  are connected together by a hose  176   a.  Threaded nipples  175   c  and  175   d  are connected together by a hose  176   b.  Elbow  174   a  is connected to rear water manifold  103   a  as shown in FIG. 5. Elbow  174   b  is connected to rear water manifold  103   b  (not shown).  
         [0063]    [0063]FIG. 7 depicts discharge pump hose connection  44 . A threaded nipple  382  is inserted through a port (not shown) in the lower section of hopper holding tank  100 . One end of threaded nipple  382  is attached to a threaded flange  384  mounted to discharge pump  22 . Threaded nipple  382  is seam welded in the port (not shown) through hopper holding tank  100 . Hose  21  is connected to the other end of threaded nipple  382  by a quick connect/disconnect coupling  383 .  
         [0064]    Referring now to FIG. 8 there is shown separator  24 . Separator  24  is supported by adjustable separator support legs  25  welded at ninety degree intervals on a separator cylinder  192 . Separator cylinder  192  contains a lower bearing support  183  welded inside separator cylinder  192 , A lower shaft bearing  184  is attached to bearing support  183 . A shaft slinger and screen wheel mounting plate  185  is welded to a screen wheel shaft  190 . Screen wheel shaft  190  together with screen wheel mounting plate  185  bolted to a screen wheel  186  rests on lower shaft bearing  184 . Above screen wheel  186  is located a gravel discharge port  187  in separator cylinder wall  192 . Screen wheel  186  is rotated by a screen wheel drive wheel  188  attached to a screen wheel drive mechanism  29 . An upper bearing support  194  bolted inside separator cylinder  192  holds an upper shaft bearing  195  and a rinse water supply pipe and spray manifold  191 . Hatch  45  is located on separator cylinder  192  adjacent to gravel discharge port  187 . A slurry discharge pipe  193  is inserted through a port (not shown) in the wall of separator cylinder  192 . A quick connect/disconnect coupling  197  is attached to the threaded end of slurry discharge pipe  193 . Slurry discharge hose  21  is connected to slurry discharge pipe  193  by coupling  197 . Water is provided to rinse water supply pipe and spray manifold  191  installed through a port (not shown) in the wall of separator cylinder  192  by hose  31 .  
         [0065]    The details of screen wheel  186 , mounting system and lower bearing support  183  and upper bearing support  194  are shown in FIG. 9. Lower bearing support  183  is centered and held in place by a lower bearing support rolled angle bottom centering shim  210 a and a lower bearing support rolled angle top centering shim  210   b  which, after placed in position, are both welded to lower bearing support  183  and separator cylinder  192 . A bearing mounting plate  214  is centered and welded on a lower bearing support hub (not shown) and welded to the lower bearing support spokes (not shown). Lower shaft bearing  184  is attached to bearing mounting plate  214  using four bolts and nuts  213 . A screen wheel shaft  190  with shaft slinger and screen wheel mounting plate  185  welded in place is inserted into lower shaft bearing  184 . Screen wheel mounting plate  218  (welded to screen wheel  186 ) is leveled inside separator cylinder  192  by four adjusting bolts  217  and held in place by four bolts and nuts  219  with shims  220 . Screen wheel  186  is surfaced with a circular screen  223  with a rolled flat bar (not shown) welded to the inside and outside perimeter of the round screen. Circular screen  223  is attached to screen wheel  186  by a plurality of nuts and mounting studs  221  welded to the top side of the rolled channel (not shown) comprising the perimeter of screen wheel  186 . A flexible gasket  228  is provided to seal between screen wheel  186  and separator cylinder  192 . A conical screen  224  is placed at the center of screen wheel  186  also with a rolled flat bar (not shown) welded to the inside and outside perimeter of conical screen. Conical screen  224  is attached to round screen  223  by nuts and mounting studs  222  welded to the top of the inside perimeter rolled flat bar of round screen  223 . Upper bearing support  194  is centered and held in place inside separator cylinder  192  by a plurality of shims  229  and bolts and nuts  231 . A bearing mounting plate  230  is welded to a upper bearing support hub (not shown) and to the upper bearing support spokes (not shown). Upper shaft bearing  195  is attached to the bearing mounting plate by four bolts and nuts  233 . Finally, a lifting eye  232  is welded to the top of screen wheel shaft  190 .  
         [0066]    [0066]FIG. 10 sets forth the details of separator support leg  25 . A leg extension mount  258  is welded to the side of separator cylinder  192  opposite to the placement of lower bearing support  183  and lower bearing support rolled angle bottom centering shim  210   a  and lower bearing support rolled angle top centering shim  210   b.  A leg extension  253  with a vertical leg square tube  259  welded in place is inserted into leg extension mount  258 . A top leg extension stabilizing shim  254  and a side leg extension stabilizing shim  255  are placed between the inside wall of leg extension mount  258  and the outside wall of leg extension  253 . Leg extension  253  is held in leg extension mount  258  by a bolt  257  and a nut  256  welded to the top side of leg extension mount  258 . A vertical leg  245  is inserted inside vertical leg square tube  259  (welded to the end of leg extension  253 ). Vertical leg  245  is held in place by an upper side leg stabilizing shim  251 , an upper back leg stabilizing shim  252 , a lower side leg stabilizing shim  249 , and a lower back leg stabilizing shim  250 . Hardened bolts  247  hold vertical leg  245 , lower side leg stabilizing shim  249 , lower back leg stabilizing shim  250  and vertical leg keeper  248  in place. A plurality of leg height adjusting holes  246  are provided to adjust separator  24  to the proper height. The vertical leg height is further adjusted by a lower leg adjustment plate  240  with four welded adjusting studs  241 , an upper leg adjustment plate  244  welded to vertical leg  245  and held in place with three adjusting lock nuts  243   a,    243   b  and  243   c  for each adjusting stud  241 .  
         [0067]    [0067]FIGS. 11A and 11B show the details of screen wheel  186 , upper bearing support  194  and lower bearing support  183 , three pieces that are similarly constructed. The perimeter of screen wheel  186 , upper bearing support  194 , and lower bearing support  183  is comprised of a rolled channel wheel  270  with flanges inside. A hub  272  is centered inside rolled channel wheel  270  and a plurality of flat bar spokes  271  are welded to rolled channel wheel  270  and hub  272 . A mounting plate (plate  214  in the case of lower bearing support  183 , plate  218  in the case of screen wheel  186  and plate  230  in the case of upper bearing support  194 ) is centered over hub  272  and welded to hub  272  and flat bar spokes  271 . Four mounting holes  274  drilled in the mounting plates facilitate the attachment of upper shaft bearing  194 , lower shaft bearing  184  and screen wheel shaft  190 .  
         [0068]    Screen wheel drive system  29  is shown in FIGS. 12A and 12B. A gear box  301  and an electric motor  302  are bolted to a screen wheel drive system mounting plate  308 . Screen wheel drive wheel  188  is mounted on gear box  301 . Screen wheel drive wheel  188  is rotated by gear box  301  and electric motor  302  at a speed to rotate screen wheel  186  at approximately sixty revolutions per minute. Screen wheel drive wheel  188  is positioned in a port on the side of separator cylinder  192  to contact screen wheel  186 . Two mounting hinges  312  are welded to screen wheel drive system mounting plate  308  and separator cylinder  192 . Screen wheel drive wheel  188  is held against screen wheel  186  by two mounting studs  304   a  and  304   b  welded to separator cylinder  192  and inserted through two holes (not shown) in screen wheel drive system mounting plate  308 . A tensioning adjustment mechanism  313   a  around stud  304   a  consists, in sequence, of a steel washer  305   a,  a rubber washer  307   a,  a steel washer  314   a,  a tensioning spring  303 , a steel washer  315   a,  a rubber washer  316   a,  a steel washer  317   a  and a lock nut  306   a.  A similar tensioning adjustment mechanism  313   b  is provided around stud  304   b.  Mechanisms  313   a  and  313   b  are used to adjust the engagement between screen wheel drive wheel  188  and screen wheel  186 .  
         [0069]    [0069]FIGS. 13A and 13B depict screen wheel drive system cover  30 . A rolled cover  320  is of sufficient diameter to encompass screen wheel drive wheel  188  (not shown), gear box  301  (not shown), and electric motor  302  (not shown). A solid top cover  323  is welded to rolled cover  320 . A bottom cover (not shown) is of perforated metal and welded to rolled cover  320 . Two mounting hinges  322  are welded to rolled cover  320  and separator cylinder  192 . A mounting tab  324  is welded to rolled cover  320 . A mounting stud  321  is welded to separator cylinder  192  and inserted through a hole in mounting tab  324 . A nut (not shown) holds rolled cover  320  closed.  
         [0070]    Referring now to FIGS. 14A, 14B and  14 C, there is shown gravel discharge chute  23  mounted over gravel discharge port  187  (not shown) by two gravel discharge chute mounting tabs  331  welded to gravel discharge chute  23 . Two mounting studs (not shown) are welded to separator cylinder  192 . gravel discharge chute  23  is held in place by two lock nuts (not shown) threaded on the mounting studs.  
         [0071]    [0071]FIGS. 15A and 15B show the details of hatch  45 . Hatch  45  consists of a curved door section  340  cut out of separator cylinder  192  with curved flat bar sections  344   a  and  344   b  and straight flat bar sections  345  and  346  overlapped and welded to curved door section  340 . Hinges  343  are welded to flat bar section  345  and to the separator cylinder (not shown). Mounting slots  342  are cut into flat bar section  346 . Studs (not shown) are welded to the separator wall (not shown) to fit through the mounting slots to hold the separator access door closed by a nut and washer (not shown). A rubber gasket  341  is affixed to the back sides of curved flat bar sections  344   a  and  344   b  and straight flat bar sections  345  and  346 .  
         [0072]    [0072]FIGS. 16A and 16B set forth the details of rinse water supply pipe &amp; spray manifold  42 . A spray pipe manifold  351  is rolled into a circle with a weld tee  355  welded at each end of spray pipe manifold  351 . A weld nipple  356  (threaded on one end) is welded to weld tee  355 . Separator water supply hose  31  is connected to weld nipple  356  by a quick connect/disconnect coupling  350 . A plurality of holes (not shown) are drilled on the underside of spray pipe manifold  351  and a nipple threaded on one end  352  is inserted and welded in each hole. A threaded coupling  354  is attached to each nipple  352 . A fan spray jet  353  is then installed in each threaded coupling  354 . Nipple  352 , threaded coupling  354 , and fan spray jet  353  comprise spray assembly  357 .  
         [0073]    Referring now back to FIGS. 1A and 1B, sand holding tank  26  and water holding tanks  36   a,    36   b,    36   c  and  36   d  are waste industry standard roll on/roll off containers, each equipped with a water tight door. As stated previously, tank  36   a  overflows to tank  36   b,  tank  36   b  overflows to tank  36   c  and tank  36   a  overflows to tank  36   b  via pipes  39   a,    39   b  and  39   c,  respectively.,  
         [0074]    Referring now to FIG. 17, there are shown details of one of the three pipes  39   a  enabling water tank to overflow into tank  36   b.  Pipe  39   a  is located below the top of water tank  36   a  to allow for freeboard. A threaded nipple  64  (threaded one end only) is inserted in a port (not shown) cut in the wall of water tank  36   a.  The port is sealed by pipe nuts  60   a  and  60   b,  steel washers  61   a  and  61   b  and rubber washers  62   a  and  62   b  installed on threaded nipple  64  on both sides of the wall of water tank  36   a.  A threaded cap  65  is supplied as part of pipe  39   a  to provide for tank drainage. Similar assemblies are applicable for the remaining pipes that provide the overflow from one water tank to another, as previously described.  
         [0075]    [0075]FIG. 18 shows the details of water tank discharge assembly  37   a.  A threaded tee  73  is fitted with a threaded nipple  72   a  connected to a quick connect/disconnect coupling  71   a,  another threaded nipple  72   b  connected to a quick connect/disconnect coupling  71   b,  and a threaded nipple  72   c  connected to valve  75 . Valve  75  is fitted to a threaded nipple  76  inserted through a port (not shown) at the bottom of water tank  36   a.  This port is sealed by pipe nuts  77   a  and  77   b,  steel washers  78   a  and  78   b,  and rubber washers  79   a  and  79   b  installed on threaded nipple  76  on both sides of the wall of water tank  36   a.  Assemblies  37   b  and  37   c  are constructed similarly.  
         [0076]    [0076]FIGS. 19A and 19B show the details of water distribution manifold  33  connected to water supply pump  34  by a threaded nipple  52   j,  a threaded ninety degree elbow  51   a  and a threaded nipple  52   a.  Separator water supply hose  31  is attached to a threaded ninety degree elbow  51   b  by a quick connect/disconnect coupling  55   c,  a threaded nipple  52   i,  a valve  54   c,  and a threaded nipple  52   h.  A utility hose  39  is attached to a threaded tee  53   b  by a quick connect/disconnect coupling  55   b,  a threaded nipple  52   f,  a valve  54   b,  and a threaded nipple  52   e.  Discharge hopper water supply hose  27  is connected to a threaded tee  53   a  by a quick connect/disconnect coupling  55   a,  a threaded nipple  52   c,  a valve  54   a,  and a threaded nipple  52   b.  Threaded ninety degree elbow  51   b,  threaded tee  53   b,  and threaded tee  53   a  are connected together using threaded nipples  52   d  and  52   g.    
         [0077]    Referring now back to FIGS. 1A and 1B and FIG. 2A, 2B and  2 C, in operation, a concrete mixer truck (not shown) carrying unused, uncured concrete positions its discharge chute over hopper  20 . Prior to discharging the concrete into hopper  20 , the system is turned on to activate the pumps and to begin the rotation of screen wheel  186 . Pump  34  is activated to begin pumping water to hopper  20  and separator  24  via hoses  27  and  31 , respectively. The water flows into hopper  20  through the nozzles previously described in detail into the upper portion of hopper  20  to create a water swirling action and into the lower portion of hopper  20  to further break up and dilute the uncured concrete and to cool discharge pump  22 . The concrete from the truck as well as any washed material from the truck concrete container is then discharged into hopper  20  where is it contacted by the water to create a diluted concrete slurry which is pumped by pump  22  to the upper portion of separator  24  through line  21 . Therein, the water is sprayed through sprayers described above with water being provided by hose  31 . The slurry flows by gravity inside separator  24 . When the slurry reaches rotating screen wheel  186  which has a circular screen  223  and conical screen  224  thereon, rock material larger than ¼ inches is screened out from the slurry and is centrifugally directed to port  187  for discharge from separator  24  through chute  23 . The remaining material comprising cement, sand and water slurry flows by gravity to the bottom of separator  24  and exits therefrom through its open end to fall by gravity to sand tank  26  where most of the sand settles. The effluent from tank  26  flows via pipes  28  to water holding tank  36   a.  Overflow from tank  36   a  flows to tank  36   b  through pipes  39   a.  Overflow from tank  36   b  flows to tank  36 c through pipes  39   b.  Overflow from tank  36   c  flows to tank  36   d  through pipes  39   c.  Water is continuously removed from the bottom of tanks  36   a,    36   b,    36   c  and  36   d  via discharge assemblies  37   a,    37   b,    37   c  and  38 , respectively, to hose  35  which is connected to pump  34 . Pump  34  discharges the water to manifold  33  which is connected to hoses  27  and  31  and a utility hose (not shown). The utility hose can be used to provide water for washing the truck concrete container, draining the water tanks and to perform any other utility tasks customary in the industry. In the process described, the rock is separated from the concrete slurry in separator  24 , the sand is separated from the water/cement slurry in tank  26  and cement light material is separated from the water in tanks  36   a,    36   b,    36   c  and  36   d.  The separated rock, sand and light cement material are thus recovered for future use.  
         [0078]    Hopper  20  and pump  34  are preferably used in connection with concrete reclaimer  10  when the material being handled is one inch sieve size or less. In the event the material being handled is larger, it is preferred that hopper  20  and pump  34  of concrete reclaimer  10  be replaced with a hopper  400  suitable for handling large and dense material such as river rock that will pass though a sieve size up to 1.5 inches. Referring now to FIGS. 20A, 20B,  20 C,  20 D,  20 E and  20 F, there is sown hopper  400  having a discharge chute  414 , shaped as ⅓ of a cone welded in a sloped disposition with the wide end elevated and the narrow end welded into the opening in a sump  458 . The upper edge of discharge chute  414  is at a height suitable for receiving discharge of waste, uncured concrete from a concrete mixer truck.  
         [0079]    Slurry water flows to water supply pump  410  via a water tank drain hose connection with on/off valve  442  or a sand container drain hose connection with on/off valve  444  and the water supply pump fill pipe  452  Hose  442  is only used to drain excess water from the sand container before removing sand.  
         [0080]    The slurry water is discharged from water supply pump  410  via a water supply pump discharge connection  454 . The slurry water flows through water supply pump discharge connection  454  into a utility hose connection  432  equipped with a utility hose valve  430 , a separator/batch plant water supply pipe  456 , and a discharge chute and sump water supply manifold  416 .  
         [0081]    The slurry water flowing through separator/batch plant water supply pipe  456  is supplied to separator  24  (shown in FIG. 1A) via the separator water supply hose connection. The flow of the slurry water to separator  24  is regulated via a separator water supply metering valve  426 . Alternatively, the slurry water flowing through separator/batch plant water supply pipe  456  is supplied for general batch plant use via a batch plant water supply hose connection with on/off valve  440 .  
         [0082]    The slurry water flowing through the discharge chute and sump water supply manifold is supplied to discharge chute upper water nozzles  412   a  and  412   b,  discharge chute lower water nozzles  418   a,    418   b,    418   c  and  418   d,  and sump water nozzles  420   a,    420   b,    420   c  and  420   d  via the water supply line to discharge chute upper water nozzles  446   a  and  446   b,  water supply line to discharge chute lower water nozzles  448   a,    448   b,    448   c  and  448   d,  and water supply line to sump water nozzles  450   a,    450   b,    450   c  and  450   d.  The slurry water flowing through the discharge chute and sump water supply manifold is metered using a hoper water supply metering valve  422 .  
         [0083]    The slurry water and the uncured concrete introduced into the discharge chute  414  flows down the chute to a slurry metering baffle  424 . At the bottom of the slurry metering baffle  424  where it is welded to the lower end of the discharge chute  414  is a hole having the same size diameter as the suction end of slurry discharge pump  434 . This hole regulates the flow of uncured concrete mixed with slurry water into the sump  458  so as not to overcome the pumping capacity of slurry discharge pump  434 . Slurry discharge pump  434  pumps the concrete slurry mixture to separator  24  via slurry discharge line valve  436  and slurry discharge line hose connection  438 .  
         [0084]    The system described herein is lightweight and portable whereby it can be easily transported in places where its use is the most efficient and economical. All of its components are above ground whereby it does not require digging pits or the like.  
         [0085]    While preferred embodiments of the invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit of the invention.