Abstract:
A solvent filtration and recovery system for filtration and recovery of a solvent-based liquid used in dry cleaning includes filtration tank having filter chamber with motor-driven spin filters which are selectively operated. A valve and conduit arrangement allows the liquid from dry cleaning to enter the filter chamber for filtering and flows out as filtered liquid while the spin filters are not rotating. The arrangement allows initial at least partial draining of the solvent-based liquid in the filter chamber after such filtration procedure. A recovery tank is in communication with the filtration tank through a main drain. A motor drives the spin filters during a recovery procedure, in which centrifugal force caused by the rotating spin filters for a predetermined amount of time removes by-product from the spin filters, which is drained off from the filtration tank. A reservoir stores the solvent-based liquid and receives the liquid from both the recovery tank and the filtration tank. Operation is microprocessor implemented and controlled.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based on and claims the priority of U.S. Provisional Patent Application Ser. No. 60/759,710, entitled FILTRATION AND RECOVERY SYSTEM, of the present inventors Todd Sudholt and Daniel Sims, having a filing date of Jan. 18, 2006, which is incorporated herein in its entirety by reference. 
    
    
     FIELD 
     The present document relates to a filtration and recovery system for a solvent-based liquid. 
     SUMMARY 
     In an embodiment, a filtration and recovery system may comprise a filtration tank, the filtration tank defining a filter chamber in fluid flow communication with a first opening for the ingress of a solvent-based liquid and the egress of a by-product, a second opening for initial draining of the solvent-based liquid, and a third opening for the egress of the solvent-based liquid, the filtration tank having a plurality of filters for filtering the solvent-based liquid in a filtration procedure, the plurality of filters being adapted to accumulate the by-product during the filtration procedure, and a recovery tank in fluid flow communication with the filtration tank through a main drain in communication with the first opening and an auxiliary drain in communication with the second opening, the recovery tank including a front portion and a back portion defining a slanted surface, the slanted surface in communication with a filter portion having a secondary filter for filtering the by-product, wherein the filtration tank and the recovery tank establish a non-pressurized system for the movement of the by-product. 
     Additional features will be set forth in the description which follows or will become apparent to those skilled in the art upon examination of the drawings and detailed description which follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a simplified block diagram showing a filtration and recovery system; 
         FIG. 2  is a perspective view of the filtration and recovery system; 
         FIG. 3  is another perspective view of the filtration and recovery system; 
         FIG. 4  is a simplified partial cross-sectional side view of the filtration and recovery system; 
         FIG. 5  is a side view of a recovery tank of the filtration and recovery system; 
         FIG. 6  is a front view of the recovery tank; 
         FIG. 7  is a top view of the recovery tank; 
         FIG. 8  is a perspective view of the recovery tank shown in partial phantom lines; 
         FIG. 9  is a cross-sectional view of the recovery tank taken along line  9 - 9  of  FIG. 7  illustrating the direction of flow into a secondary filter disposed inside the recovery tank; and 
         FIG. 10  is flow chart illustrating the operation of the filtration and recovery system. 
     
    
    
     Corresponding reference characters indicate corresponding elements among the view of the drawings. 
     DETAILED DESCRIPTION 
     Referring to the drawings, an embodiment of filtration and recovery system is illustrated and generally indicated as  10  in  FIG. 1 . The filtration and recovery system  10  may include a filtration tank  12  for conducting a filtration procedure that filters a solvent-based liquid (not shown) used in a dry cleaning process  16 . In one embodiment, the dry cleaning process  16  may utilize a single dry cleaning machine (not shown) with the filtration and recovery system  10 , although in other embodiments the dry cleaning process  16  may include a plurality of dry cleaning machines. In another embodiment, the filtration and recovery system  10  may filter any type of solvent-based liquid used for other types of processes other than the dry cleaning process  16 . 
     The filtration tank  12  may be in fluid flow communication with a recovery tank  14  for recovering solvent-based liquid contained in a by-product that is produced in the filtration tank  12  during the filtration procedure as shall be discussed in greater detail below. In addition, the filtration tank  12  and recovery tank  14  are in fluid flow communication with a reservoir  18  that stores solvent-based liquid filtered during the filtration procedure or recovered from the by-product inside the recovery tank  14  during a recovery procedure as shall also be discussed in greater detail below. 
     As shown, the filtration and recovery system  10  may include a microprocessor  20  for controlling the filtration and recovery procedures. The microprocessor  20  may be operatively associated with a multi valve arrangement having a first valve  50 , second valve  52  and third valve  54  for controlling the flow of the solvent-based liquid as well as the flow of by-product during operation of the filtration and recovery system  10 . In one embodiment, first, second and third valves  50 ,  52  and  54  may be hydraulic or air pressure valves for permitting or preventing fluid flow communication. 
     Referring to  FIGS. 2-7 , filtration tank  12  may define a filter chamber  30  in communication with a first opening  42  adapted for the ingress of the solvent-based liquid into the filter chamber  30  during the filtration procedure as well as egress of by-product from the filter chamber  30  during the recovery procedure. The filter chamber  30  also communicates with a second opening  43  for allowing the solvent-based liquid to be initially drained during the recovery procedure. As shown, first opening  42  communicates with a conduit  88  that is engaged to a coupling  86 , such as a conventional Tee, that permits either the entry of solvent-based liquid used during the filtration procedure or the removal of by-product from the filter chamber  30  during the recovery procedure. The first valve  50  may communicate with the coupling  86  which is operable between an open position, wherein solvent-based liquid used during the dry cleaning process  16  is allowed to enter the filtration tank  12  and a closed position, wherein solvent-based liquid is prevented from entering the filtration tank  12 . 
     The coupling  86  may also communicate with a main drain  22  through second valve  52  that allows by-product to be removed from the filtration chamber  30  during the recovery procedure. Second valve  52  may be operable between an open position, wherein by-product may enter the main drain  22  for entry into the recovery tank  14  during the recovery procedure and a closed position, wherein the solvent-based liquid is prevented from entering the main drain  22  during the filtration procedure. 
     As shown, second opening  43  is in selective fluid flow communication with an auxiliary drain  24  through the third valve  54 . Third valve  54  is operable between an open position, wherein solvent-based liquid inside the filter chamber  30  can be initially drained during the first phase of the recovery procedure to a level where the second opening  43  communicates with the filter chamber  30 . 
     As further shown, a plurality of spin filters  26  are operatively disposed inside the filter chamber  30  for filtering the solvent-based liquid of by-product, such as dirt, grease, particulates, fibers and other materials that may become entrained in the solvent-based liquid during the dry cleaning process  16 . The plurality of spin filters  26  may be mounted on a hollow tubular member  38  which extends along the axis of the filtration tank  12  and defines a conduit  78  in communication with a third opening  45  for permitting solvent-based liquid to exit the filtration tank  12  after filtration and return to the reservoir  18 . In one embodiment, the hollow tubular member  38  defines a plurality of openings  76  in communication with a respective spin filter  26  mounted by a collar (not shown) such that solvent-based liquid that has been filtered by each spin filter  26  enters the conduit  78  of the tubular member  38  and exits third opening  45  for storage in the reservoir  18 . 
     As a result of this filtration procedure, by-product can accumulate on the spin filters  26  over time. The filtration tank  12  may include a motor  34  in operative engagement with one end of the tubular member  38  through a gear assembly  46  that rotates the mounted spin filters  26  in a spinning motion when directed by microprocessor  20 . This spinning motion dislodges and removes the by-product that has accumulated on the spin filters  26  due to the centrifugal force generated by the spinning motion of the spin filters  26 . The by-product then falls by force of gravity after removal from the spin filters  26  to the bottom portion of the filter chamber  30 . When first valve  50  is in the closed position and second valve  52  is in the open position during the recovery procedure, the by-product can be channeled through first opening  42  and into main drain  22  such that the by-product can enter the recovery tank  14  for the recovery of solvent-based liquid contained in the by-product. 
     Referring to  FIG. 4 , recovery tank  14  may define a recovery chamber  32  that includes an inlet  44  in communication with main drain  22  for the entry of by-product removed from the filtration tank  12  during the recovery procedure. In addition, the recovery tank  14  may define a back portion  66  and a front portion  68  in communication with an upper portion  60  and a lower portion  62 . The lower portion  62  may define a slanted surface  72  that slants downwardly from the back portion  66  to the front portion  68  such that the slanted surface  72  terminates at a filter portion  64  located below the front portion  68 . 
     In one embodiment, the slanted surface  72  may have a vertical drop of 6 inches from the front portion  68  to the back portion  66 , however it is contemplated that the slanted portion  72  may be set at any angle sufficient to permit by-product that enters inlet  44  to flow downwardly along slanted surface  72  by the force of gravity alone in a non-pressurized system during the recovery procedure. 
     As further shown, the upper portion  60  may define an overflow opening  56  in communication with a tubular member  94  adapted to permit the overflow of by-product inside the recovery chamber  32  to drain from the recovery tank  14  and into the reservoir  18 . In addition, the upper portion  60  may define a wash down opening  58  adapted to permit entry of a hose for washing down the recovery chamber  32  of residual by-product. 
     Referring to  FIG. 2 , the inlet  44  may communicate with the front portion  68  such that any by-product that enters inlet  44  from the main drain  22  is channeled downwardly by the force of gravity along the slanted portion  72  such that the by-product enters the filter portion  64 . The filter portion  62  may include a detachable secondary filter  28  adapted to filter the by-product such that solvent-based liquid contained in the by-product may be recovered and stored in reservoir  18 . In addition, a vent tube  90  may be provided that has an upper end  96  in communication with front portion  68  and a lower end  98  in communication with the filter portion  64 . The vent tube  90  is adapted to permit equalization of pressure between the front portion  68  and the filter portion  64  of the recovery chamber  32  during the recovery procedure. 
     In one embodiment, the detachable secondary filter  28  may be a filter basket made from a material adapted to permit solvent-based liquid to filter through while retaining residual by-product within the filter basket which may then be later removed from the filter portion  64  in order to dispose of the residual by-product. Referring to  FIG. 7 , the upper portion  60  of the recovery tank  14  may include a door  70  that permits access to the recovery chamber  32  so that the detachable secondary filter  28  may be removed as noted above. 
     The filtration tank  12  and recovery tank  14  may be engaged to a support  36  in order to provide a structural base for the filtration and recovery system  10 . As shown, the support  36  may have a pair of front legs  80  and a pair of back legs  82  for supporting the recovery tank  14 . The support  36  may further include a pair of upper legs  84  engaged to the recovery tank  14  which, in combination with the back legs  82 , support the filtration tank  12  such that the tank  12  is angled downwardly towards the rear legs  84  as illustrated in  FIG. 4 . This downward orientation of the filtration tank  12  permits the by-product to be evacuated by force of gravity alone from the bottom portion of the filter chamber  30  and into the recovery tank  14  through the main drain  22 . 
     Referring to  FIGS. 4 ,  8 - 10 , the method of operation for the filtration and recovery system  10  will be discussed in greater detail. As shown in  FIG. 10 , at step  100  the filtration procedure is initiated such that the microprocessor  20  places first valve  50  in an open position in order to permit solvent-based liquid used in the dry cleaning process  16  to enter the filtration tank  12  through first opening  42 , while second valve  52  and third valve  54  are placed in the closed position in order to prevent solvent-based liquid from entering the recovery tank  14 . During the filtration procedure solvent-based liquid from the dry cleaning process  16  flows into the filtration tank  12  through first opening  42 , as illustrated by flow A, and fills the filter chamber  30  such that solvent-based liquid enters and is filtered by the spin filters  26  and exits third opening  45 , as illustrated by flow B, such that filtered solvent-based liquid enters reservoir  18 . 
     After a predetermined period of time has expired, the filtration procedure is temporarily terminated by the microprocessor  20  and the recovery procedure may then be initiated by turning off the pump (not shown) that drives the solvent-based liquid from the dry cleaning machine(s) during the dry cleaning process  16  at step  102 . The microprocessor  20  at step  104  then places first valve  50  in the closed position in order to prevent any further solvent-based liquid from entering the filtration tank  12  as well as placing third valve  54  in the open position in order to allow the solvent-based liquid inside filter chamber  30  to be initially drained from the filtration tank  12 . 
     At step  106 , the solvent-based liquid is allowed to drain through the auxiliary drain  24  as illustrated by flow C and into the recovery tank  14  until the solvent-based liquid reaches the level of the second opening  43  inside the filter chamber  30 . Once the filtration tank  12  is sufficiently drained, the microprocessor  20  at step  108  engages the motor  34  with the gear assembly  46  such that the tubular member  38  is rotated in one direction in a centrifugal operation that removes by-product from the plurality of spin filters  26  for a predetermined amount of time. In one embodiment, the centrifugal operation is conducted for 15 seconds and then terminated for 15 seconds over a period of 3 minutes; however, other predetermined periods of time for cycling the centrifugal operation are contemplated. 
     This centrifugal operation agitates the spin filters  26  such that by-product is removed and allowed to accumulate at the bottom of the filter chamber  30 . In one embodiment, the centrifugal operation may rotate in one direction during one cycle and then rotate in the opposite direction in the next cycle in order to remove by-product from the spin filters  26 . 
     After the centrifugal operation is completed, at step  110  a rest period, for example 10-15 seconds, is conducted. At step  112 , the microprocessor  20  may then place second valve  52  in the open position, while first valve  50  remains in the closed position and third valve  54  remains in the open position. This valve arrangement permits the by-product accumulated along the bottom portion of the filter chamber  30  to be evacuated through the main drain  24  and into the recovery tank by force of gravity as illustrated by flow D. 
     At step  114 , the recovery procedure is initiated for recovery of solvent-based liquid from the by-product. During the recovery procedure, the by-product contacts the slanted portion  72  upon entering the recovery chamber  32  of the recovery tank  14  through the inlet  44  and is channeled toward the filter portion  64  in a gravity feed movement. As by-product is channeled towards the filter portion  64  the by-product enters the secondary filter  28  for filtration. During the recovery procedure, by-product accumulates in the secondary filter  28  inside the filter portion  64  so that any solvent-based liquid contained in the by-product is filtered through the secondary filter  28  and may exit through a filter outlet  92  located at the bottom of the filter portion  64  as illustrated by flow E. After exiting the filter outlet  92 , the solvent-based liquid is transported to the reservoir  18  for use in the dry cleaning process  16 . In one embodiment, by-product may be allowed to exit the filtration tank  12  and enter the recovery tank  14  for 30 seconds, although other times are contemplated. After the recovery procedure is completed, at step  116 , the microprocessor  20  places the second valve  52  and the third valve  54  in the closed position, while placing the first valve  50  in the open position in order to once again initiate the filtration procedure as noted above. 
     Once a sufficient amount of by-product has accumulated in the secondary filter  28 , secondary filter  28  with the accumulated by-product therein may be removed through the door  70  of the recovery tank  14 . The secondary filter  28  may then be inserted back into the filter portion  64  for further filtering of by-product from the filtration tank  12 . 
     It should be understood from the foregoing that, while particular embodiments have been illustrated and described, various modifications can be made thereto without departing from the spirit and scope of the invention as will be apparent to those skilled in the art. Such changes and modifications are within the scope and teaching of this invention as defined in the claims appended hereto.