This invention relates generally to the field of wastewater systems and in particular to a passive collector of fats, oils and grease of the type that is typically associated with a wastewater drainage system for a food service establishment. Most particularly this invention relates to a grease trap or collector which is used to collect such fats, oil and grease from a sink or drain from a commercial kitchen or the like to prevent the same from being discharged directly into a municipal wastewater system.
Grease traps or interceptors are well known and used extensively to collect fats, oil and grease (“F/O/G”) from the wastewater discharge streams from commercial food service establishments such as kitchens and restaurants. In many jurisdictions there are by-laws or other local rules which require the owners or operators to use such devices to prevent the F/O/G from being freely discharged and then fouling the downstream wastewater system.
Typically in the past these grease interceptor devices have taken the form of steel containers or vessels which are positioned in the wastewater effluent stream downstream of the food preparation areas. Often they are large volume containers which are sunk into the floor with removable lids at or slightly above grade. They are typically immovable and plumbed into place. Water from the sinks or dishwashers flows, by gravity, into and then out of the devices, and is then carried away by the wastewater or sewer system. Baffles and the like are positioned inside of the container to trap the floating F/O/G within the container to prevent it from entering into the sewer system. However, even with a large container, over time the FOG builds up and then the grease interceptor needs to be emptied.
Typically such devices are built with a removable lid so that the floating F/O/G can be periodically removed from the top of the container. There are several methods used to empty the F/O/G from the container. In some small volume devices an employee may be asked to remove the top of the container and then bail out the F/O/G into a ladle or bucket and then dump the removed material into a dumpster or other solid waste container. In other cases a service will be used to bring a pump out truck to pump out the F/O/G from the container, once the lid is taken off. In this case a long hose is threaded from the truck to the container and the F/O/G is sucked out through the hose. Various other means of emptying the container also exist.
However, in all cases when the lid is taken off the smell is very strong and noxious. The smell can penetrate clothing, foul the air and typically will be located deep within the kitchen. Nasty smells within the kitchen can be very off putting for customers of the food service establishment, as well as the employees. Therefore the F/O/G removal operation is often scheduled for late at night or early in the morning when the facility is otherwise closed. However in some cases the food service facility may be open 24 hours per day making this scheduling more difficult. Furthermore, in some applications such as a shopping mall food court, the grease interceptor may be located at such a distance from an outside wall that it can be difficult to stretch the suction hose from the truck to the interceptor. What is desired is a way to accomplish the removal of the F/O/G without exposing the employees and customers to the foul smells associated with the accumulated F/O/G while improving the cost effectiveness and convenience of the F/O/G collection process.
Accordingly the present invention provides a grease interceptor system which includes a grease trap that comprises a portable light weight container body, which can be easily connected and disconnected to the wastewater system for pick up and removal, without the need for the container to be opened during this removal step. The present invention provides for an above grade mounting for the container body of the grease interceptor in between opposed inflow and outflow portions of the wastewater drain pipes. The body includes inflow and outflow openings which are sized and positioned to be connectable to the drain pipes. The drain pipes are provided with shut off valves to permit the drain pipes to be closed when the grease interceptor is disconnected from the drain pipes. There is also provided easy to use pipe couplings to fluidly connect to the container body of the grease interceptor to the drain pipes.
In one embodiment the present invention provides a method whereby a container body which is full of trapped F/O/G may be removed by means of a hand cart placed under the bottom of the grease interceptor container body. Plugs, such as screw thread caps, or valves are provided to permit the inflow and outflow openings of the full grease container to be sealed for transport once the container body is disconnected from the inflow and outflow lines. Means are provided on the body of the grease interceptor to temporarily displace the connecting elements laterally as the body is placed into or pulled out of position between the drain pipes, to protect the seals, o-rings and coupler stems that are present on the container body to provide the hydraulic connection to the wastewater drain.
Thus according to the present invention a replaceable grease interceptor can be removably secured in place in a wastewater line to collect F/O/G. When full, a service is called and a clean, empty unit is wheeled into the kitchen on a hand cart. The wastewater flow line valves are shut both upstream and downstream of the container body and the couplers are disconnected. Then the full unit can be moved slightly, in a direction generally perpendicular to the axis of the pipe connections, by placing the hand cart under the unit and levering it up and pulling it out slightly, to permit closure members, such as the plugs, stoppers, caps or other sealing means to be threaded, or otherwise secured in place to seal the pipe openings in the body. Then the full unit can be fully removed from between the inlet and outlet drain pipes. It will be noted that this initial movement of the container body can be accomplished without tilting the body side to side thus reducing the chances of causing a spill out of the pipe coupler openings, before the drain plugs are secured in the openings. Once the full unit is removed from between the upstanding pipes the clean unit can be placed in position.
The clean unit is positioned between the drain pipes and coupled to the drains. Once this is done the valves upstream and downstream on the wastewater lines can be re-opened to permit the water to drain through the unit whereby fresh F/O/G will be captured. The full unit can be wheeled away to a truck or the like for eventual disposal at a land fill site or the like or for recycling as appropriate. In this way the F/O/G remains substantially enclosed as the container is moved through the kitchen and then out through the commercial establishment and the bad smell is greatly reduced if not eliminated. A single service truck can be provided with multiple replacement containers and can follow a route to service many separate commercial restaurants by pulling the full units and replacing them with empty units as needed. Over time the route can be timed to co-ordinate with the frequency of the haul away need of the establishment.
Thus according to a first aspect the present invention provides a grease trap system for wastewater systems, said grease trap system comprising:
a ground engaging frame into which a replaceable container body may be inserted,
an inlet pipe connector with shut off valve on an inlet side of said frame;
an outlet pipe connector with a shut off valve on an outlet side of said frame;
a grease interceptor comprising a replaceable container body including means to trap fats, oils and grease within said replaceable container body and further being sized and shaped to be positioned within said frame and connected to said inlet and outlet pipe connectors, said container body including inlet and outlet slide couplers through opposed walls of said body, said inlet and outlet slide couplers having associated connecting means to sealingly fluidly connect said inlet and outlet connectors to said container body, said inlet and outlet slide couplers being further configured to be sealed for transport of said container body by a closure member;
wherein said slide couplers laterally displace away from said inlet and outlet connectors when said container body is being replaced.
According to another aspect the present invention provides a method of collecting grease from a wastewater stream comprising the steps of:
positioning a replaceable container body between a pair of inlet and outlet connectors mounted on a frame, wherein said connectors are connected to a wastewater drain and fluidly connecting inlet and outlet slide couplers on said body to said connectors so wastewater flows through said container body;
capturing fats, oils and grease in said container body over time;
shutting inflow and outflow pipe valves to stop the flow of wastewater through said body;
displacing one or both of said inlet and outlet pipe connections and said inlet and outlet couplers laterally to permit said container to be removed from between said connectors without interference at said connectors;
sealing inlet and outlet slide couplers on said container to ready said container body for transport; and
transporting said sealed container to a remote location to be emptied and cleaned.
Reference will now be made to preferred embodiments of the invention by way of example only to the following illustrative figures in which:
a is a close up view of a section through an orientation tab on the frame of the present invention;
The threaded pipe end 20 is sized and shaped to engage with and seal with a slide coupler 22 mounted in an inlet sleeve 24 of the container 11. The slide coupler 22 defines an inlet opening 26 in an upstream side 28 of the container body 11. The slide coupler 22 is comprised of an internally threaded collar 30 rotatably mounted on an outside stem portion 32, in a channel 34. The channel is formed by shoulders 33, 35 (
The container body 11 is preferably made from molded plastic and sized and shaped to hold a reasonable amount of liquid inside. Plastic has the advantage of being reasonably light weight, easy to clean and inexpensive to manufacture, but the present invention comprehends that other materials may also be used without departing from the scope of the invention. The container body 11 includes a removable top or lid 50, which can be secured to the container body 11 in a liquid tight manner, such as through the use of fasteners clips and seals or the like as is known in the art. Most preferable the container body 11 includes the usual baffles and grease separating structures (not shown) within to allow the container body 11 to trap grease oil and the like over time as wastewater flows through the body 11. As will be understood wastewater will enter through an upstream side 28 and then exit the container body 11 through a downstream side 52 and then be carried away by an outlet drain pipe 54.
As well as the inlet pipe connector 12 there is provided an outlet pipe connector 60 on the frame 16 on the downstream side 52 of the container body 11. As can now be better understood the frame holds both the inlet and outlet connectors in the correct position to accommodate a container 11 there-between and so greatly helps in installing the connectors in the correct position when they are first plumbed into the wastewater drain pipe. The outlet pipe connector 60 is preferably the same as the inlet pipe connector 12 previously described, only in reverse. There is an outlet sleeve 62 which most preferably is at a height relative to the inlet sleeve 24 that allows the wastewater flowing into the container body 11 to the flow out of the container 11 by gravity drainage with the F/O/G trapped inside.
Located within the outlet sleeve 62 is an outlet slide coupler 64 which is comprised of an internal stem portion 66 and an external stem portion 68. Again these may be joined together by threads, solvent welding or the like. The internal stem portion 66 includes a stop lip 70, and a pair of o-ring seals 72, 74 located within channels 76, 78 respectively to seal against an inside surface of the outlet sleeve 62. The external stem portion 68 includes a receiving channel 80 in which an internally threaded collar 82 is rotatably received. Once again the slide coupler 64 may move back and forth within the outlet sleeve 62, by means of the difference in distance between the internal side of the collar 82 and the end of the sleeve 62.
Downstream of the outlet slide coupler 64 is the outlet pipe connector 60. As with the inlet pipe connector 12 the outlet pipe connector 60 includes an externally threaded tube which forms an outlet pipe 86 onto which the threaded collar 82, may be secured. Again an o-ring seal 88 may be used to seal the slide coupler 64 to the outlet pipe 86. Also the outlet pipe connector 60 includes a manually operable shut off valve 90 to shut off the water flow through the pipe 86 when the valve is shut.
As shown in
Turning to
It will be appreciated by those skilled in the art that although threaded engagements are shown between the slide couplers 22, 68 and the connectors 12, 60 and have been found to work well, other types of connection can also be used, such as a bayonet type mount or the like. All that is required is for the components to be manually coupled together in a manner that permits them to be easily connected and disconnected as and when required, preferably without the need for any tools or the like. As well, although there is reference to the sealing ring 21 being placed on the threaded pipe end 20 of the connector it will be understood that the sealing ring could also be placed on the other component as a matter of design choice without departing from the spirit of the present invention.
Most preferably the external ends of the slide couplers will be displaced away from the connectors (i.e. towards the container 11) when disconnected as described above. This will allow the container 11 to be lifted up, for example, on a lift cart or dolly with lifting forks 51 and moved back from between the pipes. Ideally the present invention allows the lifting and movement of the container to occur in a plane perpendicular to the plane of the pipes. This avoids a problem of the prior art where the lifting of one end of the container, while the other end was still partially engaged with the pipes might lead to tipping the container and accidental spilling before the container is fully disengaged from the pipe connections.
In
The frame 16 can now be understood in better detail. The frame 16 is shown from behind in
Having now described the various components of the invention the operation of the invention can now be more clearly understood. First a clean container is put into place between a pair of connectors as described above. The container will sit up slightly on supports that are positioned in such a way to permit conventional lift truck, or dolly forks, to be inserted under the container 11 to easily manipulate it when full. Various forms of lift truck are available so the present invention comprehends various forms of supports positioned and configured for the type of forks to be used. According to the present invention therefore the supports are positioned under the container to allow easy access for lifting forks under the container and to center the lifting to avoid tilting the container, which is important as explained below.
Then both on both sides the wastewater drain pipes, inlet and outlet, are coupled to the container 11 by extending the slide couplers out of the containers until they are sealed with the connectors. Then the valves are opened and wastewater is allowed to flow into and then out of the grease trap in the usual hydraulic gravity feed fashion. Over time grease and oil will collect and at a certain point it will be necessary to empty the container 11. In this case a service is called. The service will bring a fresh clean and empty container body to the site. They will then shut off the flow of wastewater through the pipes by turning off or closing the inlet and outlet valves. Next they will position a dolly under the full container and get ready to lift the same. Then they will unscrew the threaded sleeves, the action of which moves the slide couplers in towards the container 11 and then gently lift the container 11 up with the dolly, and back slightly, without tiling it so much that it spills. At this point it is only necessary to move the container 11 enough to provide access to the slide couplers to screw in a drain plug on either side of the container. The next step is to continue to guide the container from out between the inlet and outlet connectors and the frame 16 until the full container is clear. Since it is now sealed it will not be emitting any odours. Once the full container is out of the way, the fresh clean container can be positioned on the frame 16 between the threaded pipe ends and fluidly connected to the upstream and downstream pipes by means of the collar connectors. The next step is to open the valves to get the wastewater flowing again through the empty container body. Then the full container, which is sealed by reason of the plugs, is taken out to a waiting truck for transport. In this sealed state it can be easily wheeled out of the food service establishment without offending any staff or patrons.
Now that the container is sealed and moveable it may be taken to a remote site, by truck for example to be emptied and cleaned. Alternatively, the restaurant staff may disconnect and remove the unit and take it to their grease collection bin usually located behind the restaurant where they will remove the grease manually. Then it can simply be reinstalled in place. A preferred form of cleaning includes using water such as a hose or pressure sprayer to clean out the container of any solids collected in the container. The plastic will easily wash clean. By providing a removable top or cover it will make the container easier to clean and empty and the container top need not be opened until the container is at a disposal site such as a land fill disposal site. Thus the bad odours that are emitted will not be in close proximity to the food service areas.
It can now be appreciated that the present invention permits the replacement of full containers with empty containers without the need to expose the trapped fats oil and grease to the open air. Thus, by means of the dolly and the closure members or plugs, the present invention comprehends an easy, clean and smooth exchange of empty containers for full containers according to a service schedule that can be determined based on the usage and need of the food service establishment. Further the positioning of the inlet and outlet opening on opposite side walls of the device permits the initial lifting of the full container body to occur without tilting, ensuring that there is no spillage before the plugs can be put in place.
A second embodiment of an attachment assembly for connecting the container 11 to the fixed wastewater piping 15, 54 is shown in exploded view in
An outwardly extending sleeve 310 is formed on the container 11 onto which is surmounted an outer sleeve 312. A guide pin 314 is positioned on the sleeve 312 and is retained in a slot 316 of the upper plate 300. A similar guide pin 318 extends from the bottom of the sleeve 310 into a guide slot 320 of lower plate 302.
A slide coupling element 322 is slideably engaged in the outwardly extending sleeve 310. The slide coupling element 322 has two o-rings 390 and 392 mounted thereon. As in the previous embodiments the element 322 slides in and out relative to the sleeve 310 to seal and unseal with an end of the fixed wastewater piping. The slide coupling element 322 slides within an inner sleeve member 321 which seals against an inside of the container by means of gasket 319 and is secured in place by nut 317. The nut 317 also secures the outer sleeve 312 in place.
Adjacent to the other end of the assembly 308 is a wastewater piping shut off valve 324 having a handle 323 for opening and closing the shut off valve 324. The shut off valve 324 is attached to an end of the fixed wastewater pipe (not shown) such as 15, 54, and is permanently fixed at that location. The valve 324 can be opened and closed by pulling or pushing of the handle 323. As previously described the shut off valve 324 allows the pipes 15, 54 to be sealed during the replacement and removal of a full container with an empty one. On the container side of the valve 324 is located a sleeve 325 having upper and lower locking pins 326 which engage with locking arms 327 of the upper and lower pivoting locking plates 328 in a manner as described below. Because the locking pins 326 are located on the shut off valve, which is fixed in position, the locking pins 326 do not move during coupling and decoupling of the container to the fixed wastewater piping.
A further pair of pins 330 are provided extending from the sliding coupling element 322. The pivoting locking plates 328 have curved slots 336, which interact with pins 330 to extend and retract slide coupler 322, and a locking slot 338 which helps define the locking arm 327 to secure the slide coupler 322 into sealing engagement with shut off valve assembly 342 and in particular with the sleeve 325. It will be understood that similar slots and pins exist with respect to both the upper and lower plates 300 and 302, so that the slide coupler is secured in diametrically opposite positions about the pipe to ensure a good fit and seal. Also shown is pin 344 which extends into upper plate 300 and lower plate 302 through slots 346 which controls the movement of the pivoting locking plates 28 as described below.
Also shown in top plate 300 is angled slot 350 which carries a pin 352 attached to a container shut off valve 354. The actuation of the container shut off valve 354 is controlled by the movement of the pin 352 in the slot 350 as described below as well as the movement of the plates during the coupling or uncoupling steps. The slot 350 includes a bend as shown to accommodate the inward and outward motion of the slide coupler 322 during the coupling uncoupling steps as described below.
Having described the elements the operation of the present embodiment can now be understood.
As shown the top plate 300 and the bottom plate 302 are positioned to the left which has a number of effects. The first is that the pin 352 has carried the container shut off valve 354 to an open position. The second is that pivoting locking plate 328 has pivoted about the guide pin 314 to a position where the locking arm 327 has engaged fixed locking pin 326 to help draw the slide coupler 322 into sealing engagement with the sleeve 325. As well, the curved slot 336 has interacted with pin 330 to help draw the slide coupler out and into sealing engagement with the sleeve 325.
The following sequence is used to detach the assembly 308 from the valve 324 as shown in
While the foregoing description has been in respect of preferred embodiments of the invention it will be understood that many variations and alternations are possible without departing from the scope of the invention as defined by the appended claims. Some of these have been discussed above and others will be apparent to those skilled in the art. For example, although plastic is preferred for both the container and the pipes, these could be made from other materials that were light weight and flexible.
Number | Date | Country | Kind |
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2791444 | Sep 2012 | CA | national |