Abstract:
A method and apparatus is disclosed for eliminating the bagging of paint spray booth sludge, and instead, centrifuging the collected sludge, re-watered if need be for transport, into a high solids content sludge and water for holding the sludge in suspension upstream of the centrifuge and apparatus for accomplishing the same.

Description:
DISCLOSURE 
       [0001]    This application is a United States Non-Provisional patent application claiming the benefit and priority of Provisional patent application, Ser. No. 61/000,712, filed on Oct. 26, 2007 and relates to a method and apparatus for paint sludge consolidation and more particularly to an improved method and apparatus utilizing centrifugal consolidation adapted to replace a gravitational bag consolidator. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    It is known to collect the overspray from paint spray booths by causing the overspray to agglomerate into a sludge which is directed to and collected in a generally water filled tank and either floats or is treated to float. The water may include certain known chemicals to facilitate agglomeration. This floating agglomerated sludge is then removed from the surface of the water in the tank by some type of skimmer or surface rake. The material collected by the rake is usually very wet and is sent into a bag and permitted to drain for a period of time to reduce the moisture content. Even so the moisture content stays quite high and the bagged sludge is still a considerable mess and must be physically removed and disposed of. This system requires continued use of bags and is inconvenient in use. 
       SUMMARY OF THE INVENTION 
       [0003]    The disadvantage of the above bag type consolidator has been overcome by the improved method and apparatus of the present invention for consolidating paint spray booth sludge. The method and apparatus of the present invention comprises the steps and means for receiving the agglomerated sludge raked off of the water tank, or otherwise collected, and then, if need be, re-watering the sludge to transport the same, then centrifuging the sludge and water to separate the sludge from the water, using the separated water to facilitate the transportation, centrifuging the sludge to a high solids matter say a 40% or above, and preferably to a solids state of 45% or 50% or greater, and returning the separated water upstream to keep system or even the source of sludge clean, keeping any sludge from accumulating thereon so that all or at least almost all such sludge is removed by the centrifuge, for cleaner and more economical disposal. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  is a schematic for a first embodiment of method and apparatus of the present invention. 
           [0005]      FIG. 2  is a further improvement of second embodiment of the method and apparatus of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0006]    Referring to  FIG. 1 , a prior art sludge collection system  10  is shown in conjunction with the present invention  50 . 
         [0007]    The prior art device  10  includes a tank  12 , to which paint overspray or sludge collected in paint spray booths, upstream and not shown, is sent, indicated by the arrow  14 . The sludge is generally conditioned to float in tank  12 . The sludge is removed from the top of the tank  12  by a skimming or raking mechanism  16  and discharged into the chute  18 , wherein the device of the prior art, it was allowed to fall into and collected in a bag  20 . The wet sludge in the bag  20  drains through openings in the fabric thereof and eventually is disposed of and a new bag put in place. Excess water is returned from the upper portion of tank  12  to the spray booth paint overspray sludge collection system, as indicated at  22 . 
         [0008]    In the present invention and in the  FIG. 1  embodiment, the above described system is modified to provide a diverter baffle or bypass  52  and opening  54  in the sidewall of the chute  18 . The bypass includes a chute extension  56 , which discharges the wet sludge indicated by the arrow  58 , formerly collected in the bag, to a collector tank  60 . 
         [0009]    For purposes of ensuring transportation of the sludge  58  that falls into the tank  60 , more water may be added if needed, from the city water supply, indicated by  62  through two pipes  64  or  66 . One of the passages or pipes  64  is filled with an automatic solenoid fill valve  68  (controlled by water level detecting means  71 ) and the other pipe  66  with a manual fill valve  70 . The tank  60  is also provided with the level control system  71 , which could be on the order of a float valve. Any excess water in the tank can be sent to a drain  72  and drain pan  74  if need be. As sludge is removed from the system by the centrifuge additional water may be needed to keep up the water level. Should any additional water be needed, it could be provided by the system and pipes  64  or  66 . 
         [0010]    The sludge to be de-watered and accompanying transporting water is withdrawn from the tank  60 , through a valved  81  pipe  82  by a pump  84 . The pump  84  discharges this water sludge mixture through a valved  90  pipe  92 , into a centrifuge  100 . 
         [0011]    The relatively dry centrifuged sludge indicated by the arrow  102 A drops into a hopper or basket  102 , while the water cleaned by the centrifuge flows through a pipe  104 , via valve  106  into a recovery tank  108 . The tank  108  has a level mechanism  110  which is used to control a pump  112  in the pipe  114 . The pump  112  sends the recovered clean liquid back into the tank  60  to keep the sludge dropped into that tank in suspension and to prevent it from collecting therein. Thus, the tank  60  and generally the entire system  50  is clean running and self cleaning and needs little or no maintenance. 
         [0012]    Referring to  FIG. 2  a simplified and less complicated embodiment of the method and apparatus of the present invention as shown, and where similar the same reference numerals are used for the prior art portions and primed reference numerals are used for the new elements. 
         [0013]    This embodiment  10 ′ includes the tank  12 ′ which is similar to the tank  12  of  FIG. 1 , except the chute  18  and raking mechanism  16  are not used and/or removed to make the system simpler and easier to maintain. Now the sludge from pipe  14  is sent into the tank  12 ′ and generally kept in suspension with the centrifugal return flow from the pump  112 ′, in pipe  114 ′. The suspended sludge is drawn out of the tank  12 ′ via the pipe  82 ′ and pump  84 ′ and supplied to the centrifuge  100 ′ to separate the sludge  102 A′ and the return water supplied to the pump  112 ′. A level control  71 ′ similar to the level control  71  of  FIG. 1  can be provided. If need be make up water can be supplied from the source  62 ′, via pipes  64 ′ or  66 ′, through solenoid fill valve  68 ′ or a manual fill valve  70 ′, to the tank  12 ′, in a manner similar to that for  62 ,  64 ,  66 ,  68  and  70  for the tank  60  of  FIG. 1 . 
         [0014]    In operation the embodiments of  FIGS. 1 and 2  are similar in that the sludge is collected from tank  12  or  12 ′, sent to a centrifuge  100  or  100 ′ separating the sludge  102 A or  102 A′ and returning the water via pump  112  or  112 ′ to the tank  60  or  12 ′ to keep the sludge in suspension so it can be pulled out via pipe  82  or  82 ′ by the pump  84  or  84 ′ and sent to the centrifuge  100  or  100 ′. 
         [0015]    The present invention, thus, eliminates the prior bagging process and use and consumption of bags for the same while producing a much dryer, more compacted sludge which can be more easily and cleanly disposed of. 
         [0016]    With respect to sizing some of the components, they are matched to the booth or booths serviced. For example, see U.S. Pat. No. 6,682,654, inventor Steve E. Telchuk, issued Jan. 27, 2004 entitled “Sludge Recovery Apparatus and Method” and U.S. Pat. No. 6,979,399, inventor Steve E. Telchuk, issued Dec. 27, 2005 entitled “Sludge Recovery Apparatus and Method” which are incorporated herein by reference herein by reference. 
         [0017]    While several embodiments were shown it is understood that equivalent steps and elements to those in the following claims are within the scope of the invention.