in overview , the parts washing apparatus 10 of the present invention , illustrated in fig1 is comprised of a parts washing basin 12 , a solvent reservoir 14 upon which the parts washing basin 12 rests , a centrifugal filter assembly 16 mounted to the parts washing basin 12 below its drain 18 and inside the solvent reservoir 14 , and a solvent transfer means 20 to transport the solvent 26 from the solvent reservoir 14 to the parts washing basin 12 . attached to a mounting bracket 27 of the centrifugal filter assembly 16 , and descending from it , is a pump 22 that has its inlet 24 submerged in solvent 26 , and its outlet 28 connected to the solvent transfer means . the solvent 26 is contained in the solvent reservoir 14 . while the parts washing apparatus 10 is in use , the pump 22 pumps solvent 26 from the solvent reservoir 14 , through the solvent transfer means 20 , where it enters the parts washing basin 12 at a solvent inlet 30 . from the solvent inlet 30 , the solvent 26 flows over a part placed in the parts washing bin 12 or held under the inlet 30 . the solvent 26 is contaminated with foreign matter from the dirty part while the part is being washed . this contaminated solvent 26 flows from the parts washing basin 12 , through the drain 18 , into a spinning centrifugal filter receptacle 32 . the spinning action of the centrifugal filter receptacle 32 employs centrifugal force to drive the solvent through a disposable filter element 34 , after which the solvent 26 falls back into the solvent reservoir way , the recirculation of the solvent 26 in the parts washing apparatus 10 provides a continuous flow of filtered solvent to the parts washing basin 12 for the washing of dirty parts , while both drying and containing most the waste from the dirty part in the disposable filter element 34 . the preferred embodiment of the present invention will now be described . the parts washing basin 12 has a sink portion 36 with an attached flexible spout 38 acting as an inlet 30 for the solvent 26 and a drain 18 acting as a solvent outlet 39 . in some situations , it may be more convenient for the flexible spout 38 to have a connection for a flexible hose , or merely to have a flexible hose substituted for it . the sink portion 36 has a sink bottom wall 40 and a circumferential sink side wall 42 . for convenience of description and referring to fig3 the sink wall 42 has a front portion 44 generally nearest the user , a rear portion 46 generally away from the user , a right side portion 48 , a left side portion 50 , and a top edge portion 52 . the top edge portion 52 is blunted or rolled over 53 so as not to present any sharp edges to the user . the sink side wall portion 42 and the top edge portion 52 are usually formed integrally with the sink bottom 40 , but separate pieces may be attached to form the sink if easier or more cost effective . although the flash point of solvents used in parts washers is fairly high , it is still possible for the solvent to catch on fire . primarily for this reason , the rear edge 54 of a hood 56 is attached by hinges 58 to the rear portion 46 of the sink side wall 42 ( fig1 ). a support pin 60 is attached to an upper interior edge portion 62 of the hood 56 . a fusible link 64 is rotatably attached to the support pin 60 on the hood 56 and then to a support piston 66 , which is then rotatably attached to a pin 67 mounted on the left sink side wall 50 . the fusible link 64 is designed to melt during a solvent fire , which disengages the support piston 66 or bracket and allows the hood 56 to fall and cover the parts washing basin 12 . this contains the fire and deprives it of the oxygen need for combustion . it is preferred to use a piston for the support because the hood 56 is not only used for fire prevention . during normal use , the support piston 66 assists in smoothly lifting the hood 56 , and also preventing the hood 56 from suddenly slamming shut . of course , a hinged bracket of conventional design could be substituted for the piston . a work light 68 can be affixed to the hood 56 for the convenience of the user . the sink bottom wall 40 has an underside portion 70 located opposite the side that is contained in the sink portion 36 . attached to this sink underside portion 70 , surrounding the drain 18 , is a downwardly extending collar 72 . the collar 72 serves to position the parts washing basin 12 on the solvent reservoir 14 , to act as a splash guard for the solvent 26 while it is being centrifuged , and as mounting point for attachment of the centrifugal filter assembly 16 and pump 22 . the collar 72 has several laterally extending flanges 74 attached a couple of inches below the sink underside portion 70 . to assemble the parts washing apparatus 10 , the parts washing basin 12 is lowered from above the solvent reservoir 14 into it , inserting the collar 72 until the flanges 74 rest on the solvent reservoir 14 . the spacing between the underside 70 of the parts washing basin 12 and the flanges 74 forms an access portion 75 through which the transfer pipe 76 and any necessary electrical wiring ( not shown ) to drive the pump 22 and centrifugal filter assembly 16 are placed . in the preferred embodiment , the solvent reservoir 14 is an industry standard forty - five gallon steel drum . however , any convenient container could be used as long as it is capable of storing solvent in a safe manner and will support the parts washing basin at a comfortable height for the user . the centrifugal filter assembly 16 is best seen in fig2 . the centrifugal filter assembly 16 is mounted to the collar 72 with a mounting bracket 27 , so that a filter receptacle 32 is positioned directly below the drain 18 . the centrifugal filter assembly 16 is comprised of a filter receptacle 32 with an open top end 80 , a perforated circumferential side wall 82 , and a base 84 . the filter receptacle 32 is preferably made from stainless steel , although other solvent resistant metals and plastics may also be used . the filter receptacle base 84 has an interior upward facing imperforate portion 86 that is surrounded by the filter side wall 82 and an exterior downward facing portion 88 . attached to the downward facing portion is a circular mounting disk 89 that has a filter shaft 90 attached . if more convenient or economical in mass production , the circular mounting disk 89 can be omitted and the filter shaft 90 attached directly to the downward facing portion 88 . the centrifugal filter assembly 16 is attached to the collar 72 on the underside 70 of the parts washing basin 12 using the mounting bracket 27 illustrated in fig4 and 5 . the mounting bracket 27 is comprised of a longitudinal member 92 and a transverse member 94 that are attached to form a cross . a sealed motor 96 is mounted to one side the transverse member 94 with its shaft 98 extending through a hole 99 in the transverse member 94 ( fig2 ). the weight of the sealed motor 96 and the filter receptacle 32 are approximately equal so that their respective weights balance the transverse member 94 at its connection with the longitudinal member 92 . while it is desirable to have this balance to ease the attachment and removal of the mounting bracket 27 to the parts washing basin 12 , the balance of these parts is not necessary for the proper operation of the invention because the resiliency of the mounting bracket will properly position and support the centrifugal filter assembly 16 even though they may differ significantly in weight . a motor shaft pulley 100 is then attached near the end of the motor shaft 98 . on the opposite side of the transverse member 94 , a sealed bearing 104 is attached coaxial with another opening 105 . the filter shaft 90 is placed within the sealed bearing 104 located in the opening 105 in the transverse member 94 . a filter pulley 107 is attached to the end of the filter shaft 90 . the motor shaft pulley 100 and the filter shaft pulley 107 are interconnected with a belt 102 so that , when energized , the motor 96 will spin the filter receptacle 32 about an axis with a generally vertical orientation drawn outwardly from the interior cavity 109 of the filter receptacle 32 . of course , the size of the pulleys 100 , 107 and the rated speed of the motor 96 will control the rate of rotation of the filter receptacle 32 . the faster this rate of spin , the greater the centrifugal force that will be exerted on the solvent entering the filter receptacle . preferably , the filter receptacle will spin at approximately 450 to 500 revolutions per minute . at this rate of spin , the solvent is separated from the foreign waste materials without propelling the solvent upwardly toward drain 18 or unnecessarily atomizing it . since the filter receptacle 32 is positioned with the interior cavity 77 of the collar 72 , when the solvent 26 is forced through the filter element 34 and the perforated filter side wall 82 during operation of the parts washing apparatus 10 , the solvent will either drop directly into the solvent reservoir 14 or be deflected into the solvent reservoir 14 by the interior surface 73 of the collar 72 . returning to fig1 the pump 22 is removably attached by a pump extension 108 to the longitudinal member 92 through a hole which can be positioned anywhere on the longitudinal member 92 , as long as the pump mounting extension 108 does not interfere with either the belt 102 or the pulleys 100 , 105 . in fig5 the attachment of the mounting bracket 27 to the collar 72 is illustrated . a support member 110 is attached to either side of the longitudinal member 92 so that each of the support members 110 extends upwardly to a point where its upper end 111 is removably connected to a bracket 112 that has been attached to the collar 72 . it should be noted that slight modifications of the mounting bracket can be made by those skilled in the art to attach the centrifugal filter assembly 16 to many of the parts washers currently in use or on the market . these “ adapted ” mounting brackets are included with the remainder of the centrifugal filter assembly 16 , described above , as the primary components in a retrofit kit to transform existing parts washers into the present invention . secondary filter means 136 and tertiary filter means 148 are also preferably included with the retrofit kit , but can be deleted if already included on the existing parts washer . in the preferred embodiment , two design features enable the filter receptacle to more efficiently use centrifugal force to separate the solvent from the waste . the first modification helps retain the solvent inside the filter receptacle until centrifugal force draws it through the filter media and the perforated side walls . referring to fig2 this is done by slightly slanting the perforated side wall 82 in a frusto - conical configuration upwardly and inwardly from the base 84 to the open top end 80 . this upward and inward slant is preferably 12 to 14 degrees inwardly toward the vertical axis 106 . the second design feature employs a deflecting member 118 that has a top rounded center portion 119 and a downwardly extending skirt 121 that slants outwardly from the vertical axis 106 . the deflecting member 118 is attached to , or formed integrally from , the center 119 of the interior upward facing portion 86 of the base member 84 . the purpose of the deflecting member 118 is to direct the solvent outwardly toward the side wall 82 and away from the center 119 of the filter receptacle 32 where the centripetal acceleration approaches zero and the solvent is less likely to be affected by the corresponding centrifugal force . during normal use , a disposable filter element 34 is draped inside the filter receptacle 32 . referring to fig6 the upper open portion 126 of the disposable filter element 34 contains a securing means 127 that is folded over the open top portion 126 of the filter receptacle 32 . the securing means 127 , for instance , can be a string or elastic fiber that is sown into a channel 129 on the upper portion 126 of the disposable filter element 34 . the lower closed portion 128 of the filter element drapes over the deflecting member 118 . preferably , the disposable filter element 34 is approximately the same size as the interior 109 of the filter receptacle 32 , so that , when the filter receptacle 32 is spinning , the walls 130 of the disposable filter element 34 will cling to the filter side wall 82 . the disposable filter element 34 is preferably made from a fine mesh linen cloth , although other filter media would work , for instance , a heavy , permeable paper filter . the preferred embodiment of the invention presently uses a 100 micron mesh linen for its filter media . returning to fig3 the removable filter element 34 is accessed for service through a hatch 132 positioned above the filter receptacle 32 in the bottom portion of the sink 36 . as shown in fig3 the hatch 132 is circular and concentrically surrounds and includes the drain 18 . the hatch lies in a round opening in the sink bottom wall 40 that has a circumferential lip that is formed lower than the upper surface of the sink bottom wall 40 in order to contain the circular hatch 132 ( fig1 ). the hatch 132 can be secured to the sink 36 with one or more screws 138 or can just rest in the indentation 134 . a screen 142 usually covers the drain 18 and is particularly useful for keeping needed components of the part being washed from being flushed into the centrifugal filter assembly 16 . in fig3 the screen 142 is in the form of a disk that rests inside a circumferential indentation 143 ( fig1 ) that surrounds the drain 18 . fig2 shows another screen 144 that is formed into the shape of a cup and also rests in the circumferential indentation 143 that surrounding the drain 18 . the cup screen 144 has an upper lip portion 141 that is held in indentation 143 . it also has a bottom portion 145 with a contiguous circumferential side wall 147 that are both formed from a screen material that will retain relatively large pieces of foreign material that are washed from parts while passing the solvent and smaller foreign materials . depending on the preference of the user , the disk configuration screen 142 , the cup configuration screen 144 , both , or neither , can be placed in the drain 18 . together , the screens 142 , 144 , comprise the secondary filter assembly 136 . a tertiary filter assembly 148 used to polish the solvent before being introduced to the parts washing basin 12 can optionally be included . the tertiary filter assembly 148 is one of common design and comprises a filter housing 150 , a filter media 154 inside the filter housing , a filter cap 152 to seal the filter housing , an inlet 156 connected to the pump side 158 of the solvent transfer means 20 , and an outlet 160 connected to the spigot side 162 of the solvent transfer means 20 . the filter media usually takes the form of a filter cartridge comprised of a fan - folded permeable paper material , although many other filter media could be used . as mentioned above , existing parts washers can be adapted to the present invention by using a retrofit fit kit comprising a centrifugal filter assembly 16 with a mounting bracket 27 specially adapted to mount the centrifugal filter assembly 16 to the existing parts washer . the retrofit kit also preferably includes the secondary filter assembly 136 and the tertiary filter assembly 148 . an existing parts washer will typically have a parts washing basin 12 , a drain 18 , and a collar 72 that are similar to those illustrated in fig1 . as in the present invention , the centrifugal filter assembly 16 is mounted below the drain 18 of the existing parts washer by connecting bracket 112 either to the collar 72 or to the underside portion 70 of the parts washing basin 12 . generally , bracket 112 has two ends joined at an angle to each other with a first end 113 attached to the upper end 111 of the support member 110 and the second end having a hole to receive a mounting bolt extending from the existing parts washer . to mount the centrifugal filter assembly 10 to collar 72 , for instance , the second end of bracket 112 could be specifically configured to align with a hole drilled in collar 72 by the retrofit installer . bracket 112 is then bolted to collar 72 through these aligned holes . similarly , bracket 112 could be rotated ninety degrees so that the second end of the bracket is substantially parallel to the sink bottom 40 and aligned with a hole drilled by the installer in the sink bottom 40 . bracket 112 is then bolted to sink bottom 40 . a washer is placed around the mounting bolt passing through the sink bottom 40 and the bracket 112 to prevent solvent leakage through the hole . bracket 112 , therefore , can be thought of as an adapter for mounting the centrifugal filter assembly 10 to the existing parts washer . by altering its shape to conform to the existing parts washer and its length to properly position the centrifugal filter assembly 10 below drain 18 , almost any existing parts washer could retrofitted to the present invention . of course , bracket 112 could be omitted and the mounting bracket 27 could be specifically adapted for support member 110 to be attached to each type of existing parts washer . by altering the length of bracket 112 , support 110 , the transverse member 94 and the longitudinal member 92 , the centrifugal filter assembly can be properly positioned in almost all existing parts washers . in any case , the means of attachment preferably allows the centrifugal filter 10 assembly to be removed while replacing filter element 34 . the pump 22 on the existing parts washer can be left in place if it does not obstruct the installation of the centrifugal filter assembly 10 . otherwise , the pump 22 is removed and then suspended by pump mounting extension 108 from mounting bracket 27 , as is described above . the pump 22 and the motor 96 are electrically connected in parallel with the electrical wires passing through access 72 . to complete the retrofit , the secondary filter means 136 is placed in drain 18 and the tertiary filter is connected in series with the solvent transfer means 20 , in the same manner as is described above . the ease of maintenance of the parts washing apparatus 10 is one of the primary design benefits resulting from the teaching of this application . to clean the apparatus 10 , the user first removes the disk screen 142 and / or the cup screen 144 from the drain 18 . the user then removes the hatch 132 from the bottom portion of the sink portion 36 , exposing the filter receptacle 32 and the disposable filter media 34 . at this point , the user can dump the contents of the screens 142 , 144 into the disposable filter element 34 , or the user can do the same after the disposable filter element 34 is removed . if necessary , the securing means of the disposable filter element 34 is loosened and the disposable filter element 34 is lifted from the filter receptacle 32 . because of the centrifugal force placed on the disposable filter 34 element during its use , the disposable filter element 34 and its contents should be mostly free of solvent . the used disposable filter element 34 is then placed in a container to be processed by a solvent service provider . the disposable filter media in the tertiary filter 148 can also be removed at this time and placed in the reprocessing container . the user then replaces the disposable filter element from the tertiary filter 148 in the filter receptacle , re - installs the hatch 132 and replaces screens 142 , 144 . if the tertiary filter 148 has been serviced , a new disposable filter element is placed in the tertiary filter 148 and the cap 152 replaced . the entire service procedure on the parts washing apparatus 10 can be accomplished in a few minutes . the hazardous waste products removed from the system are all contained in the disposable filter element 34 and the disposable filter element of the tertiary filter assembly 148 . this relatively small volume of hazardous waste material is sealed in a small and light container that is mostly free of solvent and that can easily and safely be transported to a hazardous waste processing plant . the solvent 26 remains relatively free of contaminants and may be re - used for a much greater length of time than is now possible under the state of the art . while this invention has been described in terms of a preferred embodiment , it is contemplated that persons reading the preceding description and studying the drawing will realize various alterations , permutations and modifications thereof . it is therefore intended that the following appended claims be interpreted as including all such alterations and modifications as fall within the true spirit and scope of the present invention .