Abstract:
A liquids collection unit is provided for the collection of liquids, including spent grease in food preparation establishments. The unit includes a housing that surrounds a tank. Coupled to the tank are a suction hose and a motor, which creates a vacuum in the tank to draw liquid into the tank when the hose is disposed in liquid. The suction motor of the device is disposed on a detachable plate on the tank. Sensors located within the tank monitor the liquid level of the liquid in the tank. A down-tube from the detachable plate terminates in a dimpled protuberance in the bottom of the tank. A heating element disposed near the bottom of the tank provides for the circulation of liquids in the tank during periods when the liquids are being stored.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates in general to the field of recycling systems and more particularly to a system and method for the collection and storage of liquids, including liquid waste products, such as spent grease produced by food preparation establishments. In the commercial food preparation industry, issues relating to the generation, handling, and disposal of spent cooking grease are matters implicating critical environmental regulations, employee safety concerns, and cost considerations. Every restaurant, cafeteria, and commercial kitchen generates some amount of spent cooking grease and, therefore, must face these issues. 
     A common view of managing spent grease is to dispose of it as any other waste material. Oftentimes, this solution includes the practice of simply running the material down waste drainage pipes or disposing of the grease in common garbage dumpsters. Today, significant restrictions mandate a radical departure from such practices. Federal authorities, armed with the Clean Water Act, and most local authorities, empowered with similar legislation, have imposed strict requirements regulating the dumping of untreated waste materials. To comply with federal and local environmental laws, restaurants may turn to publicly owned waste treatment facilities that dispose of spent grease for a fee. As an alternative, restaurants may turn to local garbage disposal companies that manage dumpsters. Restaurants and other food preparation establishments frequently pay additional fees to these garbage disposal firms for the disposal of spent grease. As another alternative, restaurants may use contractors that are in the business of collecting and disposing of only spent grease. 
     Another factor governing the food preparation industry&#39;s handling of spent grease is the recognition that spent grease in high volumes is a valuable commodity and may be sold to recyclers who, in turn, sell to brokers for use in products such as feed additives. The market price that recyclers are willing to pay for spent grease fluctuates, as with any commodity. During periods of high demand, a restaurant may demand up to five cents per gallon from a recycler. During periods of low demand, there is little incentive for a recycler to pick up and resell the commodity, especially from restaurants that produce low volumes of the product. A recycler may even refuse to pick up spent grease at a restaurant unless the recycler is paid for its pickup and disposal service. 
     Faced with regulatory requirements and the economic effect of grease as a commodity, many restaurant establishments find it more advantageous to enlist the services of recyclers that specialize in collecting and selling spent grease. At the same time, many recyclers facing low grease prices are forced to improve their business practices in order to realize narrow profit margins in the business of recycling spent grease. 
     During periods of low demand for the commodity of spent grease, such as the present time, recyclers are able to make only modest capital investments. Recyclers seek to minimize the operational cost of collecting and processing spent grease while simultaneously increasing the volume of spent grease processed. To state the challenge facing recyclers in a different way, on each service trip that a recycler makes to a restaurant for pickup of spent grease, the volume of grease picked up must be sufficiently high, to justify the cost of the pickup and processing. Therefore, where volume is a determining economic factor in the recycling business, advancements in the collecting and recycling of the commodity become critical to recyclers. 
     Presently, recyclers that provide recycling services to restaurants typically request that a restaurant begin the process by manually removing spent grease from vats of frying appliances and by storing the spent grease in barrels typically located behind the restaurant. It is not uncommon for thieves to steal these barrels during periods when spent grease commands a high price. Other recyclers provide a restaurant with a portable vacuum machine that collects spent grease from frying appliances and stores the grease until such time that the recycler arrives for pickup. The use of these common portable vacuum machines has revealed numerous operational and safety pitfalls. 
     The most bothersome operational pitfall of current portable vacuums relates to serviceability. Current portable vacuums typically embody a design that requires the entire machine to be removed from a restaurant and to be disassembled when repair service is necessary. Removal of the machine disrupts and delays normal business operations in the restaurant. Further, the removal of a machine for repair generates additional labor and transportation costs to the recycler and may diminish the already slim profit margins of the recycler. Therefore, a need has arisen for a method of servicing portable liquid collection units without having to remove the whole machine from the restaurant and without having to disassemble the machine for every repair. 
     Another operational drawback of current portable vacuum units is that there is not a method for effectively heating during storage mode, when the grease is stored in the unit prior to pickup by the recycler. Know portable vacuum units may employ heating systems that are unreliable or that heat the grease to unnecessarily high temperatures, far above the temperature necessary to prevent the grease from coagulating. Another problem of heating the grease tank to an excessively high temperature is that doing so poses safety risks to operators, increases the energy cost to restaurants, and subjects the machines to excessive wear and tear. 
     Another common operational pitfall of known portable vacuum units concerns safety. In normal restaurant operations, many accidents are related to the exposure of restaurant personnel to hot grease and spilled grease. Many restaurant injuries are related to grease handling. Common problems occur, for example, when restaurant workers (1) spill hot grease, having temperatures as high as 350° F., on themselves while transferring grease from vats of frying appliances to storage barrels; (2) spill grease onto the floor, causing employees to slip and fall; or (3) spill grease onto the ground in the parking lot, causing customers of the restaurant to slip and fall. The effects of these problems raise significant safety concerns for restaurants and further add to the cost of insurance and workers&#39; compensation coverage. 
     SUMMARY OF THE INVENTION 
     A portable liquids collection unit is provided that performs the functions of collecting, storing, and disposing of spent grease generated by restaurant establishments. The device includes a tank capable of storing a large quantity of spent grease, a vacuum motor to draw in grease, and a selection of components to monitor and control the liquid level and temperature inside the tank. The vacuum motor creates vacuum pressure in the tank, causing the suction of liquids into the tank when a suction hose from the tank is disposed in a liquid reservoir. The portable unit includes a detachable plate mounted on the top surface of the tank. Attached to the detachable plate are the suction motor and other components of the units that may require service from time to time. The serviceable components of the device are thus coupled to a detachable plate. A down-tube coupled to the plate terminates in a dimple formed in the tank. The dimple acts as a reservoir and a collection point for drawing fluid out of the tank. A heating pad or plate is disposed a distance in the tank and a distance above the bottom surface of the tank. 
     One advantage of the invention described herein is a portable liquids collection unit. For a heavy device that may hold hot materials, ease in moving the device is a highly desirable attribute for restaurant establishments and recyclers. Furthermore, by its design, which incorporates backup thermostats and a large heating pad conducive to high-convection currents, the device prevents coagulation of grease and requires less heat to maintain grease at desired temperature. The protruding dimple of the bottom surface of the tank provides an effective collection point for drawing liquids out of the tank. 
     Another advantage is that the invention utilizes operations that make it safer for all workers, including those at restaurant establishments and recyclers. The device uses vacuum pressure and a service wand to draw grease into an enclosed tank, providing a safe way for workers at restaurant establishments to capture spent grease. Moreover, the device prevents grease from flowing out of the tank and limits the volume of grease that could spill onto the floors on which workers may slip. 
     Another advantage is that the invention reduces the costs to recyclers in the business of collecting and disposing of spent grease The unit includes a detachable plate on which major components of the device are mounted, enabling the device to be serviced by removing only the minimum number of components and without removing the entire device from the establishment. Removal of the entire device from the food preparation establishment each time servicing was necessary would interfere with normal business operations of the restaurant and generate additional labor and transportation costs to the recycler. 
     Other advantages of the present invention will be apparent to those of ordinary skill in the art in view of the following specification, claims, and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein: 
     FIG. 1 is a depiction of the portable vacuum unit described herein; 
     FIG. 2 is a cross-section of a side view of the device, displaying the internal tank, connections thereto, and other components described herein; 
     FIG. 3 is a plan view of a selection of components mounted on a bolted plate on top of the internal tank and covered by the hinged lid described herein; and 
     FIG. 4 is a cross-section of the device taken along line  4 — 4  of FIG.  2 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The portable vacuum and storage device and method of use described herein concerns the collection and disposal of liquids. Food preparation establishments, including restaurants, need to dispose of spent grease, and recyclers are in the business of collecting, cleaning, and selling spent grease. The invention described herein is intended to fulfill the needs of both restaurant establishments and recyclers in the management of spent grease. 
     FIG.  1  and FIG. 2 depict an embodiment of the portable vacuum unit  10  of the present invention. The device  10  includes a stainless steel external housing  12  that includes a hinged lid  14  on the top surface of device unit  10 . Hinged lid  14  pivots open and covers a pump and a set of electrical components. Service hose  16  is attached to the device through opening  19  of housing  12 . Service hose  16  serves as a pickup tube to draw out grease from vats of kitchen fryers. Service hose  16  extends through stainless steel external housing  12  to attach to upper end of an internal tank  20 , which is shown. in FIG.  2 . Service hose  16  includes a high-temperature liner to accommodate the temperatures of the grease or other liquids sucked through the hose. Attached to the other end of service hose  16  is stainless steel service wand  22 . A handle  24 , made of synthetic rubber with low specific heat, is wrapped around wand  22 , allowing the steel wand to be held by operators when the rubber of the hose is hot. Service wand  22  includes a small cup  26  designed to catch hot grease that may run down the outside of service wand  22 . Cup  26 , positioned between service wand  22  and handle  24 , prevents grease from flowing down service wand  22  and onto hands of an operator of the portable vacuum unit. 
     As shown in FIG. 1, service hose  16  may be hung, pointing upward, at an orientation that does not allow liquid to drain from the hose. The end of service hose  16  is attached to tank  20  at a level  28  that is above the liquid level  30  of tank  20 . An advantage of this design is that it prevents liquid from backflowing from the tank, so that even if the service hose  16  were dropped to the floor during use and power to the vacuum pump motor were disconnected, the maximum amount of grease spilled from the unit would be only the contents remaining in the service hose. Vacuum unit  10  is mounted on rotatable wheels  32 , providing portability and easy maneuverability to the device. A retractable power cord  34  is connected to electrical components covered by hinged lid  14 . 
     FIG. 2 shows level switches  36  and  38  inside tank  20 . The level switches are coupled to circuits  40  of FIG.  3 . Level switch  38  and corresponding circuitry operate light indicator  42  on the front of the housing  12  of the device to indicate that the grease within internal tank  20  has risen to an intermediate level. In this embodiment, the intermediate level is set at 80% of the full level. The second level switch  36  and its corresponding circuitry operate to prevent operators from drawing grease through service hose  16  into the internal tank beyond the full level of the tank. When level switch  36  is activated, its circuitry cuts off power to pump motor  50 . When the full level of level switch  36  is reached, the power to the device is shut off, thereby preventing the operator from drawing additional fluid into the full tank. 
     Shown in FIG. 2 is a vacuum pump motor  50  positioned at the top of tank  20 . The size of tank  20  is typically 120 gallons. The large size of the tank provides restaurant establishments with extended periods of use before requiring the services of a recycler. In operation, vacuum pump motor  50  creates a negative pressure within tank  20 . The negative pressure created by vacuum pump motor  50  can draw grease through the service hose  16  into tank  20 . In the embodiment described herein, the vacuum pump motor  50  generates vacuum rated at 100 inches of water. 
     The vacuum pump motor  50  is mounted above and gasketed to the top surface of a detachable plate  44 , which is positioned on top of the internal tank  20  and .below hinged lid  14 . Plate  44  is fastened to the top of tank  20  by spring tension clips. Plate  44  also includes a plug  46 . Attached to plug  46  is a conduit  48  leading to the bottom of the tank. Conduit  48  is shown in FIG.  2 . The lower end of conduit  48  is connected to heating pad  52 . Built into the heating pad is heating cartridge  54 , which is shown in FIG.  4 . The heating pad serves to keep the grease in tank  20 :heated and to prevent the grease from coagulating. If the grease remains in a liquid form, it is more easily processed following storage. On the heating pad  52  and adjacent to the heating cartridge are double thermostats  56 . The double thermostat configuration  56  regulates the temperature of heating pad  52  and provides built-in backup capability. Each thermostat  56 , by itself, is capable of shutting off heater cartridge  54  and serves to back up each other to maintain desired temperature, which is typically around 120° to 140° F. Thermostats  56  are placed near the heater cartridges. 
     The placement of the thermostats near the heating cartridge enables the thermostats to efficiently regulate the temperature of the fluid in tank  20 . In the embodiment described herein, the double thermostats  56  are inches away from heating cartridge  54 . Heating pad  52  is mounted close to the bottom of, but not touching, tank  20 . In the embodiment herein, heating pad  52  is mounted inches from the bottom of tank  20 . This design permits heat to be distributed throughout of the, tank and requires less heat to maintain stored grease at desired temperature. Having a flat heating surface near the bottom of the tank also facilitates circulation of the stored grease. The heating pad  52  and the placement of heating pad  52  near, but not touching the bottom surface of tank  20  generates active convection currents, thereby aiding the circulation of the stored fluid in the tank and heating the liquid in the tank more efficiently and uniformly. The bottom of tank  20  is shaped with a steel dimple  58  the size of a coffee cup. Grease in tank  20  collects in protruding dimple  58 , where the grease is collected through a down-tube  60 . From the outside of the tank  20 , this dimple looks like a blister on the bottom surface of tank  20 . Down-tube  60  is positioned directly beneath a tank outlet cap  62 . Dimple  58  facilitates the collection of grease at a collection point in tank  20  that only down-tube  60  can reach. 
     FIG. 3 shows a selection of components mounted on plate  44 , which is mounted on the top of internal tank  20 . The main components comprise a vacuum pump motor  50 , a number of relays, plug  46  attached to conduit  48 , and cap  62  serving as a tank outlet for down-tube  60 . The plate  44  on which these components are mounted is detachable by removing a number of bolts  64 . Placing the motor  50  and the other serviceable components on detachable plate  44  improves the serviceability of unit  10 . This configuration enables service workers to remove only the plate  44  to perform most service or repairs on the unit. Removing only plate  44  eliminates the necessity of removing the entire machine from the restaurant establishment when repairs are necessary. When these main components need to be replaced, only bolts  64  and plate  44  must be removed before a replacement plate or individual components can be installed. Thus, if a tank is deemed to be out of service because of a mechanical or an electrical failure, it is likely that the cause of the problem can be found in one of the items coupled to plate  44 . The technician, upon visiting the food preparation establishment, can simply remove the existing plate  44 , install a new plate  44 , thereby allowing the restaurant to avoid serious disruption because of a faulty unit. 
     FIG. 4 shows a cross-section top view of the device. The internal tank  20  is covered by external housing  12 . Down-tube  60  is capped at its upper end and is coupled to detachable plate  44 , as shown in FIGS. 2 and 3. At its lower end, down-tube  60  terminates in a cavity formed by dimple  58 . Conduit  48  is attached to plug  46  of FIG. 2 at the upper end, which is attached to the detachable plate  44  of FIGS. 2 and 3. At its lower end, conduit  48  leads to heating pad  52 . 
     To operate the device, a restaurant operator wheels the portable device to the kitchen appliance having the vat of greased to be disposed. The operator turns on the power to the unit and dips service wand  22  into the vat of grease. Vacuum pump motor  50  establishes a vacuum in tank  20 , enabling the wand  22  to suck grease from the vat into tank  20 . When the tank level is filled to 80% of capacity, light  42  illuminates, indicating the level of fluid in the tank has reached an intermediate level. The operator may continue to draw grease into the tank until a full level is reached. When the full level is reached, power to vacuum pump motor  50  will be automatically terminated by circuitry  40  of FIG.  3 . After suctioning the grease from the vat, the operator returns the portable unit to a storage area. At a later time, additional liquids may be suctioned into the tank if the tank is not full. 
     After drawing product into the tank, operators may place the device in storage on standby mode, whereby heating pad  52  of FIGS. 2 and 4 at the bottom of the tank prevents grease from coagulating. Operators may use the device at a later time until the tank is full. At such time, a recycler would be called to remove collected grease from the device. As an alternative to a call-in procedure, a recycler could visit restaurant establishments for grease removal according to a prearranged schedule. To remove collected grease from the internal tank, the recycler removes tank outlet cap  62 , applies a vacuum to down-tube  60 , causing the grease to draw out of tank  20  through down-tube  60 . After the recycler removes the grease from tank  20 , the restaurant establishment may resume using the portable vacuum and storage device at any later time. The recycler typically recycles the collected grease and markets the recycled product. 
     Although the present invention has been described in terms of the collection of spent grease generated by restaurant establishments, it should be recognized that the unit described herein may be used for the collection of other liquids in other contexts. The present invention provides for the collection of liquid products in a manner that is efficient, convenient, and safe for employees and operators of the device and may be used in any context in which liquid products are to be collected by a portable unit. 
     Although the present disclosure has been described in detail, it should be understood that various changes, substitutions, and alterations can be made hereto without departing from the spirit and the scope of the invention as defined by the appended claims.