Abstract:
A container for receiving and holding effluent water containing oil/grease to be removed has sectional covers. A main sectional cover supports a partially immersed rotatable disk; a drive on the main sectional cover rotates the disk; a trough on the main sectional cover straddles the disk; and a blade on the trough scrapes a side of the disk, to direct oil and grease from the disk along the scraper blade along the trough for collection in a storage container. Efficiencies of construction of the sectional covers, disk and a sensor probe are disclosed.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates to a low cost assembly for the removal and recovery of oil, grease and solid wastes found in drains or effluent discharge of restaurants, food processing, or like facilities, industrial plants, maintenance facilities, or other circumstances involving mixtures of oil, grease and solid waste material to be recovered or removed. This application has subject matter similar to the disclosure of U.S. patent application Ser. No. 10/161,814, filed Jun. 4, 2002, the entire disclosure of which is hereby incorporated herein by reference.  
         [0002]     Oil, grease and solid waste contaminant removal or recovery systems are well known in the prior art. Over the past thirty years there has been a steady move towards requiring food handling facilities to have systems for servicing kitchen grease and solid waste bearing water flows. Sewer system lines can become clogged from the oil and grease waste materials (hereinafter referred to as “oil/grease”) put into the sewer system from food handling facilities. This has led more and more sewer authorities to implement fats, oils and grease control programs. These programs regulate food handling facilities and the manner in which they process oil, grease and solid waste material. The object of many of these programs is to ensure that food handling facilities remove as much of the oil and grease as possible from the effluent flow, thereby releasing only grey water to the sewer system.  
         [0003]     One method recognized in the prior art of accomplishing such removal is the use of a container including one or more rotating disks formed of a plastic or like applicable material to which oil and grease contaminants are attracted. Typically, the rotation of the disk is in an at least partially immersed condition, which allows the oil to cling to one or both sides of the disk so that contaminants are removed from the body of water upon rotation of the disk. Scrapers are typically used to force the oil contaminants from the opposite sides of the disk and channel such contaminants to a collection or disposal storage unit.  
         [0004]     U.S. Pat. No. 5,133,881 to Miller et al. is representative of such oil and grease removal systems containing one or more rotating disks. The Miller et al. patent discloses an oil/grease removal assembly which removes such contaminants from the surface of the body of water and includes a rotatable disk made of plastic or other material to which such oil contaminants have an affinity so they adhere to the disk. The disk is disposed in cooperative relation to an elongated trough having scraper blades for engaging the opposite sides of the disk for the removal of the oil contaminants therefrom with the trough disposed and structured to direct such oil contaminants away from the disk and the body of water via the trough to a storage container. The disclosure of this patent, issued to B. Glenn Miller and William C. Batten and assigned to Thermaco, Inc. in Asheboro, N.C., is hereby incorporated herein by reference.  
         [0005]     The existing devices may be difficult to service and are very often permanently installed at facility sites. Because many of the parts are coated with oil and grease, servicing can be messy and time consuming. In addition, these systems tend to be expensive and represent a significant capital investment. Accordingly, there is a need in the art for an apparatus for separation of oil, grease and solid waste from wastewater which is simple in design, low in cost and capable of being serviced easily in the field because of the availability of low cost replaceable parts which are easily installed and do not require extensive and costly repair.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention fulfills one or more of these needs in the art by providing a modular oil/grease removal assembly including a container for receiving and holding effluent water containing oil/grease to be removed from the effluent water and having sectional covers. A main sectional cover supports a rotatable disk in a partially immersed position within the body of effluent water and in contact with the oil/grease. A drive is mounted on the main sectional cover in driving engagement to provide rotation of the disk when the drive is engaged. A trough is mounted on the main sectional cover in engaging relation to opposite sides of the rotatable disk, and a scraper blade is mounted on the trough so that the scraper blade extends from the trough into sliding engagement with a side of the disk. The disk, scraper blade and trough are cooperatively disposed and structured to direct oil and grease from the disk along the scraper blade along the trough for collection in a storage container.  
         [0007]     In one embodiment the main sectional cover supports an electrical resistance heater that extends downwardly into the container so as to have an operable portion of the heater at least partially immersed within the body of effluent water to cause the oil/grease to be in liquid form. The main sectional cover may also support electrical controls for selectively operating the drive and the heater. A first shield preferably covers the rotating disk, trough and scraper blade, and a second shield covers the electrical controls. The first shield may be provided with vent holes to permit the escape of vapors so as to reduce vapor condensation within the first shield. The first shield may have hinged portion covering at least portions of the rotating disk, trough and scraper blade, so that the hinged portion can be opened for access to clean and/or service the rotating disk, trough and scraper blade.  
         [0008]     In one embodiment, a unitary shield covers the rotating disk, trough scraper blade, and the electrical controls. If a single shield is used, preferably, the shield has a partition to separate the rotating disk and trough scraper blade from the electrical controls. The shield may include front and rear sections meeting to form a barrel for a hinge for covers for the rotating disk, trough scraper blade and electrical controls.  
         [0009]     The electrical control may include a timer connected to the drive to control the start and stop operation of the drive to permit a selected duty cycle to remove grease at times when grease is likely to be present, and the second shield may have a hinged portion covering a control for the timer, permitting access to the timer without removal of the entire second shield.  
         [0010]     The main sectional cover typically has two pair of opposite sides with one pair of opposite sides adapted to engage the container for support of the main sectional cover by the container and the other pair of opposite sides adapted to engage additional sectional covers. The sides adapted to engage additional sections preferably have a flange extending downwardly and laterally so as to be positioned under a portion of an additional section, with a further downard extension to provide rigidity. The additional sectional cover is typically substantially rectangular with two opposite sides adapted to engage the container for support of the additional sectional cover by the container and one of the two other opposite sides adapted to engage and seal to the main section. The container typically has an inwardly turned upper flange, a gasket on the flange, and clasps to hold the sectional covers to the flange and seal the covers to the flange by compression of the gasket.  
         [0011]     The additional sectional cover may have four sides with three sides adapted to engage the container for support of the additional sectional cover by the container and the fourth side has an upper protrusion that has a lower surface with a gasket so the upper protrusion engages and seals to an upper surface of the flange of the main sectional cover that extends downwardly and laterally and a downward ear that engages the further downward extension of the main section.  
         [0012]     Alternatively, the protrusion may be downward. In another alternative, a pseudo hinge allows optional joining of sections.  
         [0013]     The container typically has an inlet end, an outlet end and left and right sides, looking in the direction from the inlet to the outlet ends, and the sectional covers have first and second mounting edges so that they can be mounted to the container with a first mounting edge on the left and a second mounting edge on the right or the second mounting edge on the left and the first mounting edge on the right.  
         [0014]     In one embodiment there are two or more main sectional covers and one or more additional sectional covers between the main sectional covers having opposite sides to engage the main sections. The opposite sides of the additional sectional cover each having upper and lower protrusions spaced by a spacer of dimension so the upper protrusion engages an upper surface of the flange of the main sectional cover that extends downwardly and laterally and the lower protrusion engages the further downward extension. The upper protrusion may have a lower surface with a gasket to seal with the flange of the main sectional cover that extends downwardly and laterally.  
         [0015]     The apparatus may include an additional sectional cover, with the sectional covers configured to provide a hinged but severable relationship between the sectional covers.  
         [0016]     In one embodiment, the additional sectional cover has four sides with three sides adapted to engage the container for support of the additional sectional cover by the container. The fourth side has a lower protrusion and a gasket so the lower protrusion of the additional section abuts the further downward extension of the main sectional cover and the gasket engages and seals to the main sectional cover.  
         [0017]     In one embodiment the disk includes two disk sheets separately formed and subsequently joined together. The two sheets preferably are identical and each include a flat oleophilic surface and a surface having a plurality of spaced peripheral lugs. The lugs of each sheet are preferably odd in number so that upon turning the oleophilic surfaces away from one another and joining the two sheets, the lugs of the opposing sheets may be interleaved to form a periphery for the disk with gaps between the lugs. The sheets may be joined by means selected from the group consisting of screwing, bolting, ultrasonic welding, vibration welding, other welding and adhering. The sheets may have bosses on the same side as the lugs and the sheets are joined at the bosses. The sheets are preferably injection molded plastic. A suitable plastic is polypropylene. The drive may be a sprocket with flattened teeth to engage the lugs. The sheets preferably have central hole with a surrounding rim to form a bearing for an axle extending through the central hole.  
         [0018]     The assembly may include a sensor module mounted to the main sectional cover. The sensor module includes a probe extending downwardly within the body of effluent water to a depth normally below the oil/grease. A sensor in the probe provides electrical indications as to whether the sensor is in proximity to oil/grease or water. An alarm on the sensor module to provide a human-recognizable indication if the sensor senses that the probe is in proximity to oil/grease rather than the normally-present water. The sensor and alarm are typically electrical and are powered by a low voltage power supply to the sensor module separate from power to the drive that rotates the disk. An electrical alarm output from the sensor module may be provided to enable electrical connection to a remote monitoring apparatus to signal alarm conditions to the remote monitoring apparatus, such as a SCADA monitoring apparatus. The probe is preferably a watertight cylindrical shaft, and the sensor is positioned at a distal end of the cylindrical shaft and held in place at the distal end by a spacer. The sensor module may also include a ready light indicating proper operation.  
         [0019]     In one embodiment the container has an inlet end and a solids removal module positioned at the inlet end. The solids removal module may be a strainer. Alternatively, the solids removal module may include a hopper having an eductor at a lower portion of the hopper, a water inlet to the eductor to make a jet of water to remove contents of the hopper in proximity to the eductor and an outlet from the eductor to an outlet of the container. The hopper preferably includes a lower portion laterally offset from the eductor, so that excess solids do not block jet action of the eductor.  
         [0020]     The invention may also be considered as a method of assembly of a modular oil/grease removal assembly including installing a container for receiving and holding effluent water containing oil/grease to be removed from the effluent water and having sectional covers; mounting a main sectional cover supporting a rotatable disk for partial immersion within effluent water in the container and in contact with the oil/grease, a drive in driving engagement to provide rotation of the disk when the drive is engaged; a trough mounted on the main sectional cover in engaging relation to opposite sides of the rotatable disk; a scraper blade mounted on the trough so that the scraper blade extends from the trough into sliding engagement with a side of the disk. The disk, scraper blade and trough are cooperatively disposed and structured to direct oil and grease from the disk along the scraper blade along the trough for collection in a storage container. An electrical resistance heater may be included that extends downwardly into the container so as to have an operable portion of the heater at least partially immersed within the body of effluent water to cause the oil/grease to be in liquid form. Electrical controls for selectively operating the drive and the heater may also be on the main sectional cover. The method includes mounting additional sectional covers to cover the container, and installing a first shield to cover the rotating disk, trough and scraper blade and a second shield to cover the electrical controls.  
         [0021]     The method may also be considered as including installing a container for receiving and holding effluent water containing oil/grease to be removed from the effluent water and having sectional covers. The method includes mounting a main sectional cover that has two pair of opposite sides with one pair of opposite sides adapted to engage the container for support of the main sectional cover by the container and the other pair of opposite sides having flanges extending downwardly and laterally with a further extension downwardly to provide rigidity and that supports a rotatable disk for partial immersion within effluent water in the container and in contact with the oil/grease, a drive in driving engagement to provide rotation of the disk when the drive is engaged, a trough mounted on the main sectional cover in engaging relation to opposite sides of the rotatable disk, a scraper blade mounted on the trough so that the scraper blade extends from the trough into sliding engagement with a side of the disk. The disk, scraper blade and trough are cooperatively disposed and structured to direct oil and grease from the disk along the scraper blade along the trough for collection in a storage container. An electrical resistance heater extends downwardly into the container so as to have an operable portion of the heater at least partially immersed position within the body of effluent water to cause the oil/grease to be in liquid form. Electrical controls for selectively operate the drive and the heater. The method includes mounting additional sectional covers that have four sides with two opposite sides engaging the container for support of the additional sectional cover by the container and one of two opposite sides engaging the main sectional cover.  
         [0022]     When the container has an inwardly turned upper flange, and a gasket on the flange, this method of assembly may include engaging clasps to hold the sectional covers to the flange and seal the covers to the flange by compression of the gasket.  
         [0023]     The method may include installing two or more main sectional covers and one or more additional sectional covers between the main sections, the opposite sides of the additional sectional cover each having upper and lower protrusions spaced by a spacer by engaging the upper protrusion on an upper surface of the flange of the main sectional cover that extends downwardly and laterally and engaging the lower protrusion with the further downward extension. If the upper protrusion has a lower surface with a gasket the method may include sealing the upper protrusion with the flange of the main sectional cover that extends laterally and downwardly.  
         [0024]     If the additional sectional cover has four sides with three sides adapted to engage the container for support of the additional sectional cover by the container and the fourth side has an upper or lower protrusion that has a lower surface with a gasket so the upper protrusion, the method may include engaging and sealing the upper protrusion to an upper surface of the flange of the main sectional cover that extends downwardly and laterally and engaging a downward ear of the additional sectional cover with the further downward extension of the main sectional cover.  
         [0025]     The invention may also be considered as a method of assembly of a modular oil/grease removal assembly for receiving and holding effluent water containing oil/grease to be removed from the effluent water including identifying an inlet source of effluent water and a downstream drain for grey water, installing a container having an inlet, an outlet and left and right sides looking in the direction from the inlet to the outlet ends, installing a main sectional cover that supports the functional apparatus to remove oil/grease from water and discharges oil/grease to one of the left and right sides of the container so that the discharge of oil/grease is convenient for servicing, and mounting additional sectional covers to completely cover the container. Such a method may also include refraining from mounting the main sectional cover from a structurally feasible mounting that would have the discharge of oil/grease be inconvenient for servicing.  
         [0026]     The invention also may be considered as a method of making a disk for a modular oil/grease removal assembly including forming two disk sheets separately and subsequently joining the two disk sheets together to form a disk. Preferably, the two sheets are made identical and each include a flat oleophilic surface and a surface having a plurality of spaced peripheral lugs. Especially when the lugs of each sheet are odd in number, the method includes turning the oleophilic surfaces away from one another, interleaving the lugs of the opposing sheets, and joining the two sheets to form a periphery for the disk with gaps between the lugs. The sheets may be joined by means selected from the group consisting of screwing, bolting, ultrasonic welding, vibration welding, other welding and adhering. If the sheets have bosses on the same side as the lugs, the method preferably includes joining the sheets at the bosses. Forming the sheets is preferably by injection molding plastic, particularly polypropylene. Forming preferably includes forming the sheets with a central hole with a surrounding rim to form a bearing and passing an axle through the central hole.  
         [0027]     The method may also include mounting a sensor module to the main sectional cover including a probe extending downwardly within the body of effluent water to a depth normally below the oil/grease. A sensor in the probe provides electrical indications as to whether the sensor is in proximity to oil/grease or water, and an alarm on the sensor module provides a human-recognizable indication if the sensor senses that the probe is in proximity to oil/grease rather than the normally-present water. Such a method preferably includes connecting a low voltage power supply to the sensor module separate from the power to the functional apparatus to remove oil/grease from water. It may also include connecting an electrical alarm output from the sensor module to a remote monitoring apparatus to signal alarm conditions to the remote monitoring apparatus, such as a SCADA monitoring apparatus.  
         [0028]     The method may also include positioning a solids removal module at the inlet end. The solids removal module may be a strainer. As an alternative, the solids removal module may be a hopper having an eductor at a lower portion of the hopper, and the method includes including connecting a water inlet to the eductor to be available to make a jet of water to remove contents of the hopper in proximity to the eductor and connecting an outlet from the eductor to an outlet of the container.  
         [0029]     The invention also may be considered as a method of modifying a modular oil/grease removal assembly including removing one or more of the sectional covers, removing an installed solids removal strainer, and installing a hopper having an eductor at a lower portion of the hopper, and including connecting a water inlet to the eductor to be available to make a jet of water to remove contents of the hopper in proximity to the eductor and connecting an outlet from the eductor to an outlet of the container.  
     
    
     BRIEF DESCRIPTION DRAWINGS  
       [0030]     The invention will be better understood by a reading of the Detailed Description of the Preferred Embodiments along with a review of the drawings, in which:  
         [0031]      FIG. 1  is a perspective view of an embodiment of the invention;  
         [0032]      FIG. 2  is a perspective view of the container with the shields removed;  
         [0033]      FIG. 3  is a perspective view of the container with one of the additional cover sections removed;  
         [0034]      FIG. 4  is an enlarged perspective view of the mating of an additional sectional cover with the main sectional cover;  
         [0035]      FIG. 4A  is a sectional view of two main sectional covers mated with a further additional sectional cover;  
         [0036]      FIG. 4B  is a view of an alternate embodiment of the additional sectional cover with a downward protrusion;  
         [0037]      FIG. 4C  is a perspective view of another embodiment for abutting the covers;  
         [0038]      FIG. 5  is a perspective view of the strainer basket being put in place;  
         [0039]      FIG. 6  is a side view of the main sectional cover with the sensor probe in place, partly broken away;  
         [0040]      FIG. 7  is a schematic side view of the sensor probe circuit;  
         [0041]      FIG. 8  is a perspective view of one half of an embodiment of the disk;  
         [0042]      FIG. 9  is a perspective schematic view of a hopper and eductor useful in connection with certain embodiments;  
         [0043]      FIG. 10  is a front perspective view of an alternate shield;  
         [0044]      FIG. 11  is a rear perspective view of the shield of  FIG. 10 ;  
         [0045]      FIG. 12  is an enlarged view of a portion of the shield of  FIG. 10 , partially disassembled;  
         [0046]      FIGS. 13 and 14  are similar perspective views of an alternate wiring arrangement for the apparatus; and  
         [0047]      FIG. 15  is a perspective view of a modified junction box usable with the apparatus for  FIG. 14 .  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0048]     In the following description, like reference characters designate like or corresponding parts throughout the several figures. It should be understood that the illustrations are for the purpose of describing preferred embodiments of the invention and are not intended to limit the invention thereto.  
         [0049]     As best seen in  FIG. 1 , the oil, grease and solid removal assembly  10  includes a container  12  with sectional covers  14   a ,  14   b , and  14   c . In a preferred embodiment as seen in  FIG. 1 , the sectional covers are separate plates, preferably stainless steel. The assembly  10  has at least one rotatable disk  16  (shown in  FIG. 2 ) supported by the center sectional cover  14   b .  FIG. 2  also depicts the gear drive motor  20  and the trough  22  which are attached to the center sectional cover  14   b . The container  12  also includes an inlet pipe  26  and an outlet pipe  28 . The effluent water with waste materials enters through the inlet pipe  26 , and after oil, grease and solid waste have been removed, the grey water exits out of the outlet pipe  28 . As seen in  FIG. 2 , the trough  22  has scraper blades  24 . The gear drive motor  20  supports and rotates the drive sprocket  38  which is cooperatively meshed with peripheral holes in the disk  16 .  
         [0050]     The basket support  34  is depicted in  FIG. 5 . The basket support  34  is constructed of rotomolded plastic and is designed to hold a strainer basket  54 . The basket support  34  is immediately downstream of the inlet pipe  26  and has a cutout to align with the inlet pipe  26 . Basket support openings  37  permits the effluent water with oil and grease to flow downstream of the basket support  34  after the solid waste material has been trapped in the strainer basket  54 .  
         [0051]     Referring to  FIG. 1 , the sectional covers  14   a ,  14   b  and  14   c  cover each of the sections of the oil, grease and solid waste removal assembly. In the preferred embodiment, a leading sectional cover  14   a  provides easy access to the strainer basket  54  within the basket support  34  and a downward stream sectional cover  14   c  is atop the outlet baffle (not shown) leading effluent from a low portion of the container  12  to the outlet  28 .  
         [0052]     The center sectional cover  14   b  is depicted in  FIGS. 3 and 4 . The center sectional cover  14   b  is constructed of stainless steel and includes a flange  13  extending downwardly and laterally and a further extension  15 , seen in  FIG. 4 . The rotatable disk  16  is constructed of oleophilic plastic or is at least covered with an oleophilic material. In one embodiment, the disk  16  has equally spaced indentations  17  on its outer circumferential edge. The sprocket  38  meshes with the holes  17  in the disk  16 . The disk  16  is rotated clockwise in the view of  FIG. 2  when the gear drive motor  20  rotates counter-clockwise.  
         [0053]     As best seen in  FIG. 2  the center sectional cover  14   b  supports the trough  22 , which is constructed of stainless steel. The trough  22  further includes elongated scraper blades  24  which are constructed of a flexible plastic or rubber material. As seen in  FIG. 3 , the center sectional cover  14   b  also supports the heating element  50  which is utilized to maintain a sufficiently warm water temperature to melt any grease contained in the grey water, permitting it to flow to and be removed by the rotating disk  16 . The heating element  50  seen in  FIG. 2  is a 300 watt heater with a quick reaction thermostat and is designed to run continuously. The timer  51  is connected to the gear drive motor  20  and controls the start and stop operation of the gear drive motor  16  and ultimately the rotation of the disk  16 . It permits a selected duty cycle to remove grease at times when grease is likely to be present.  
         [0054]     In the preferred embodiment, the oil, grease and solid removal assembly  10  is connected to drain from a sink or other device that discharges effluent water with waste materials to be separated. The water containing waste materials flows from the device&#39;s drain into the oil, grease and solid removal assembly  10  through the inlet pipe  26 . The effluent water flows into the basket support  34  containing a strainer basket  54  and the solid waste materials are trapped and removed from the effluent water. The effluent water containing oil and grease flows downstream from the basket support  34  through openings  37  into the center section. The center section cover  14   b  supports the oil and grease removal assembly. In the volume of the container  12  between the basket support  34  and the outlet baffle  46 , the effluent has time to reside, permitting oil and grease to rise to the top of the water. The grease is maintained in a liquid state by the heater  50 . When the gear drive motor  20  turns the drive sprocket  38 , the disk  16  is rotated in a clockwise direction by the counter clockwise rotation of the drive sprocket  38 . The disk  16  is positioned in the center cover  14   b , so that its lower portion is below the surface of the effluent water having the oil and grease which has floated to the surface. As the disk  16  rotates through the water, oil and grease are picked up on the sides of the disk  16 . As the disk  16  rotates, the scraper blades  24  which are attached to the trough  22  remove the oil and grease from the sides of the disk  16 . The oil and grease flows down the trough  22  to an oil and grease storage container (not shown). Once the oil and grease have been removed from the effluent water, the grey water flows downstream under the baffle outlet and exits the oil, grease and solid removal assembly  10  through the outlet pipe  28  into the sewage system.  
         [0055]     The oil, grease and solid removal assembly  10  is easy to maintain. The center section cover  14   b  containing the gear drive motor  20 , the drive sprocket  38 , the disk  16 , the trough  22  and the scraper blades  24  is a single, low cost unit. If there is a malfunction in any of the components of this unit, it is more cost effective to replace the entire unit than to repair the malfunctioning component. By stocking an extra unit at the facility site, virtually no down time in operation of the low cost oil, grease and solid removal assembly  10  would be experienced. In addition, because the center section cover  14  contains all of the oil and grease removal components, there is a greater flexibility in the installation process. The sectional cover  14   b  can be installed to have the trough  22  facing in opposite directions by placing the sectional cover one way or the opposite way, depending on the needs of the installation. The sectional covers  14   a  and  14   c  are preferably identical and either can be positioned over the strainer basket or the outlet baffle, depending on the selected orientation.  
         [0056]     The container  12  of the low-cost oil, grease and solid removal assembly  10  is constructed of a rotomolded plastic or welded stainless sheets. The container  12  is constructed with an inlet pipe  26  and the outlet pipe  28 . The sectional covers  14  can then be installed, although they may well be removed and reinstalled at the jobsite.  
         [0057]     Referring again to  FIG. 1 , the center sectional cover  14   b  is provided with a first shield  56  and a second shield  58 . The shields are molded plastic and are held in place over the trough component and electrical components, respectively. By using separate shields over the two operating components of the center sectional cover  14   b , humidity that is generated through the openings around the rotating disk is segregated from the electrical components shielded under the separate shield  58 . The two shields  56  an  58  are each provided with hinged components. A hinged component  60  lifts up to expose the rotating disk and trough, so that debris clogging the trough and scraper blades can be removed. The hinged cover  62  of the second shield  58  provides access to the timer  51  so that adjustments can be made to the timer setting.  
         [0058]      FIGS. 10-12  show an alternate shield embodiment. This embodiment still has two shields, but these are a front shield  156  and a rear shield  158 . A hinged component  160  lifts up to expose the rotating disk and trough, so that debris clogging the trough and scraper blades can be removed. The hinged cover  162  provides access to the timer  51  so that adjustments can be made to the timer setting. Each of the shields  156 ,  159  has internal partitions that separate the volume under the shield into left and right portions to keep humidity away from the electronics, as above. Preferably, the portion of the shield covering the disk has vents  157  to let humidity escape. The arrangement to join the front and rear shields and simultaneously make a hinge barrel for the hinging covers  160  and  162  is seen in  FIG. 12 . The front shield has upwardly open half-cylinders  164 , and the rear shield has downwardly open half-cylinders  166 . The half-cylinders are sized and shaped to form nearly complete cylinders when the rear shield and front shield are adjoined. Interposed between the half cylinders are short cylindrical bosses  168  formed on ears of the covers  160  and  162 . Edge guards  170  also help restrain the bosses to only rotary motion within the nearly complete cylinders.  
         [0059]     As seen in  FIG. 1 , the top sectional covers have edge mounted hooks  64 . Clasp components  66  are positioned on the container  12 , so that loops on the clasps can hold the hooks  64  down in compressive relation to the container  12 . As seen in  FIG. 3 , the container  12  has an inwardly turned upward flange  68  around the peripheral, capped by a gasket material  70  so that as the sectional covers  14   a ,  14   b ,  14   c  are held onto the container, a seal is formed to prevent the egress of vapors from the container  12 . The mounting of additional sectional covers is shown in  FIG. 4 . The main sectional cover  14   b  is provided with a downwardly and laterally extending flange  13  with a downward extension  15 . This downward extension provides longitudinal rigidity to the sectional cover  14   b.    
         [0060]     As seen in  FIG. 4 , the additional cover  14   c  is provided with an upwardly turned flange  72 . Once the main sectional cover  14   b  is in place, the additional sectional cover  14   c  can be mounted with the flange  72  overlying the downwardly and laterally extending flange  13 . A gasket on the underside of the edge of the additional sectional cover  14   c  forms a seal with the top of the laterally and downwardly extending flange  13 . These seals need not be perfect.  
         [0061]     As seen in  FIG. 4A , for larger volume installations, a larger container  12  can be used and multiple operative main sectional covers  14   b  can be put in place with an intermediate additional cover  120 , having opposite sides adapted to engage the main sectional covers  14   c . The opposite sides of the additional sectional cover  120  each have upper  122  and lower  124  protrusions spaced by a spacer  126  of a dimension, so that the upper protrusion  122  engages the upper surface of the flange  13  of the main sectional cover that extends downwardly and laterally, and the lower protrusion  124  engages the further downward extension  15  of the main sectional cover.  
         [0062]      FIG. 4B  shows an alternate embodiment of the additional cover  14   c  in which a downward protrusion or flange  72   a  is provided to abet the downward extension  15  of the main sectional cover. A gasket  73  provides the seal, which again need not be perfect.  
         [0063]      FIG. 4C  shows another alternative. In this embodiment, one of the sectional covers (the main sectional cover in this example) has slots  75 . Tabs  77  on the additional section are sized to fit into the slots to provide a hinged but severable relationship between the sections. The tabs and slots may be put on alternate ones of the sectional covers.  
         [0064]     Referring now to  FIG. 6 , a sensor module  80  is shown mounted to the main sectional cover  14   c . the sensor module  80  includes a probe  88  extending downwardly within the body of effluent water to a depth normally below the oil/grease. A sensor  90  within the probe provides electrical indications as to whether the sensor is in proximity to oil/grease or water. Since the sensor  90  that is at a depth that normally is immersed in water, if the oil/grease mat floating on the water becomes unduely thick, because of a malfunction of the unit, the sensor  90  will detect the change in the material in the proximity of the sensor. An alarm  86  on the sensor module provides a human recognizable indication if the sensor senses that the probe is in proximity to oil/grease rather than normally present water. The alarm  86  can be audible or a light, or other suitable alarm indicator. A suitable sensor as is a capacitive sensor such as a K-1 Series Sensor available from IFM Electronic gmbH of Essen, Germany. The sensor  90  is held at the distal end of the probe  88  by a spacer  92  such as a block of foam material. The electrical circuit within the sensor module  80  is powered by a low voltage source  94 . It is desirable that the electrical power source be separate from the power to the main separator unit, so that if the source of a malfunction is a failure of power to the entire assembly, it is less likely that the sensor probe will lose power. A remote monitoring output  96  can also be included in the sensor module and it is particularly desired to be of the type that provides connections to SCADA monitoring apparatuses. SCADA systems are well known facilities monitoring systems. A light  84  is provided on the sensor module  80  to show that it is operating.  
         [0065]     The electrical circuit of the sensor module is shown in  FIG. 7 .  
         [0066]     A further improvement in the apparatus can be an improved form of the disk  16 , partially seen in respect to  FIG. 8 .  FIG. 8  shows a disk sheet  100  having spaced peripheral lugs  102  and radially inwardly positioned bosses  104 . A central hole is formed in this sheet and has a surrounding rim  106 . Radially extending outward from the rim  106  are a plurality of ribs  108 . The lugs  102  are preferably formed in an odd number of themselves and are equally spaced around the periphery of the disk sheet  100 . Two of the sheets  100  are made identically and joined to make a complete disk. The side not shown in  FIG. 8  is flat and is provided with an oleophilic property. This property can be made by making the entire sheet  100  out of injection-molded plastic, preferably polypropylene. By taking the two sheets and putting them together lug side-to-lug side rotated by a suitable amount, an equally spaced even number of peripheral teeth are provided in the combined disk. The bosses  104  are provided equally spaced and permit alignment with holes  110  so that screws can be passed through the holes  110  into the aligned bosses  104  from both sides, forming a combined disk. The ribs  108  provide additional rigidity to the disk, and during the molding process ribs  108  permit the plastic to flow in the mold. The peripheral rim  106  provides a central bearing through which an axle may be passed, so that the disk can rotate smoothly on the axle. Providing the disk in this fashion provides a lower manufacturing cost than making a solid disk and machining peripheral holes. In one embodiment, 29 lugs are provided on each disk sheet, so that the combined sheets form a disk with 58 peripheral lugs. The two sheets can also be joined by ultrasonic or vibration welding, passing screws, rather than bolts into the bosses, or any other suitable method. With this embodiment, the lugs form generally axially oriented flat surfaces which engage the sprocket. Therefore it is desirable to have square teeth on the drive sprocket to engage the lugs as the drive motor drives the disk, to make solid contact.  
         [0067]     In a further embodiment, the strainer basket can be replaced with an eductor assembly  140 . A hopper  142  is positioned in place of a strainer basket and having a suitable overflow  144  for the grey water to exit the hopper  142 . The hopper  142  has a converging downward configuration terminating in a narrowed portion  146  offset laterally from an eductor  148  near the inlet end of the container. The eductor is offset laterally from the bottom of the hopper, preferably, so that as solids collect at the narrowed portion at the bottom of the hopper, they do not obstruct the eductor and inhibit its initiation of a jet. An inlet  150  to the eductor is provided with a water supply such as a municipal water supply (not shown). The water pressure from a narrowed inlet to an eductor outlet forms a venturi jet effect to draw the solids from the bottom  146  of the hopper through jet actuation. A tube  154  leads from the eductor to the outlet  28 , passing the solids downstream. Preferably the apparatus is made so that it can be equipped either with the strainer assembly or the eductor assembly. The eductor assembly can be retrofitted to an installed system by removing the strainer and installing the hopper  142  with installed eductor  148 , connecting a water supply and connecting the tube  154  to the outlet  28 . Eductors are known in this art as shown in U.S. Pat. No. 6,491,830 and have proven to be very effective in removing solids upstream of the oil/grease removal disk assembly. The entire disclosure of that patent is hereby incorporated herein by reference.  
         [0068]     Alternate power supply fittings can be seen in  FIGS. 13-15 .  FIGS. 13 and 14  show views of plug-in and hardwired arrangements respectively. A customer&#39;s choice of one version or another can be easily accommodated by using one or the other of plates  170  or  172  with the components as described herein when assembling the main sectional cover. Both plates are provided with covers  174  over possible future electrical or signaling connections. The plate  170  of the embodiment of  FIG. 13  is provided with a line cord  176 , enabling the apparatus to be plugged into a wall socket. The plate  170  is secured to the remainder of the shield by screws  178  passing through drilled and tapped holes  180 . The plate  172  of the embodiment of  FIG. 14  is provided with a recessed male plug  17 . At the stage seen in  FIG. 14 , the plate  172  is unsecured to the remainder of the shield, although it is also drilled and tapped with holes  180 . As seen in  FIG. 15 , a junction box  181  is provided with a protruding female plug  182  as well as a plate  186  that has holes  184  positioned to align with holes  180  when the plugs  178  and  182  are joined. At that stage, screws can be inserted through holes  184  and  186  to hold the plate and junction box to the shield, securing the electrical connection against a user disconnecting power to the system. Those screws also hold the plate  172  to the remainder of the shield. Of course, conduit and electrical wiring can be used in the junction box  181  in conventional fashion.  
         [0069]     Certain modifications and improvements will occur to those skilled in the art upon reading the foregoing description. It should be understood that all such modifications and improvements have been omitted for the sake of conciseness and readability, but are properly within the scope of the following claims.