Commercial warewashers and three-compartment sinks are widely used nationally and internationally. The equipment is used by many different industries including the food service, medical, and laboratory industries. The use of water by commercial warewashers and three-compartment sinks is for washing, rinsing, and sanitizing kitchen and dining wares. The amount of water used in this process varies with the type, model, and method of sanitation. On average, the commercial warewashers use as much as 100 to 300 gallons of potable water per hour. The three-compartment tanks use, on average, 840 gallons of water per day. The heat energy consumption is notable. The first step in both low and high temp warewashing is to heat the fill water entering the machine from ground temperature to 120°-140° F. (49°-60° C.). Although chemical machines do not require additional water heating, they do require added chemicals to sanitize. With high temp machines, the power wash tank and/or power rinse tank(s) water is internally heated from 150° F. (66° C.) to 175° F. (79° C.) by heating units in the warewasher. Additionally, on high temp machines, there is an additional independent piece of equipment commonly referred to as a hot water booster heater to heat additional incoming potable water from 180°-195° F. (82°-91° C.) for the final rinse. This is just one example. Heat energy is consumed heating water in other scullery operations. The greywater produced by the warewashers, three-compartment sinks and other sources may be reused. Prior attempts to reuse the greywater have failed to make a material impact. The current practice is to dispose of the greywater down the drain. The costs associated with the greywater include the cost of the water, heat energy, detergent, other chemicals and disposal. Effectively reusing greywater including the variety of resources in the greywater would result in huge savings and have a definite environmental impact.
The International Plumbing Code, 2006, paragraph 701.7 reads, “Wastewater when discharged into the building drainage system shall be at a temperature not higher than 140° F. (60° C.). When higher temperatures exist, approved cooling methods shall be provided.” Most commercial warewashers implement a three-step process. If water at or above 140 degrees Fahrenheit is drained from equipment with steamers and warewashers, a drain-water-tempering kit must be installed in the equipment to ensure the water does not soften the plastic piping. The problem with the current method of tempering is that it uses potable water to cool the greywater to the appropriate temperature. This is an additional waste of potable water, and heat energy. The heat in the sanitation greywater could be captured and reused. The greywater from the sanitation cycle could be reused. Reusing these resources would provide huge savings and conservation. Currently, no system exists that functions well enough to make a widespread impact.
Warewashers and three-compartment sinks are not the only sources of greywater in commercial food service facilities.
The first scullery step in most restaurants and food service establishments is to scrap the kitchen and dining wares. The scraps may go into a garbage can, sink basket, scrap accumulator, garbage disposer, pulper, dehydrator, digester and in some cases by way of a scrapping trough. Scrapping troughs vary in widths and lengths and operate optimally with high flow rates of recirculated water and allow two-hand scrapping. Scrapping troughs with disposers incorporated in them typically have to be plumbed with additional potable water lines introduced for flushing from the opposite end of the trough from the disposer due to the inability of a disposer to recirculate water. This water is typically not recirculated or reused causing a facility to suffer increased water usage and sewage expense. The ideal temperature for water in the scraping system is 105-115° F. (40-46° C.). Currently, potable water is used and heated in commercial warewashers for the scraping process and then disposed of. This is a waste of water because potable water is not necessary for scrapping. If 105-115° F. (40-46° C.) greywater could be utilized in these systems there would be considerable savings and conservation.
A commercial warewasher not only uses water in the scrapping, washing, and sanitation cycles, there are other hidden water costs. There is the water used with chemical dispensers, water from other equipment commonly found on commercial dish machines, such as cold water tempering options commonly found on the drains to temper drain water, and on un-heated scrap tanks receiving spent final rinse water to heat these tanks, and water used to wash the inside of the dish machines during routine cleaning. A commercial operation could save millions of gallons of water by capturing and reusing all of the drain water from a commercial warewasher.
One reason scullery greywater is not currently being reused from commercial warewashers, three-compartment sinks, scrapers and other water consuming apparatuses is that commercial facilities are unique in design and manner of use. Greywater reusing mechanisms have been attempted in scullery operations, but failed for lack of efficiency, resilience, scalability, and/or configurability, such that an effective universal solution has not been achieved. Often the attempted solutions are designed to fit with one brand, type, or model of kitchen apparatus. They are not self-contained or amenable to the needs of the facility design.
The present invention provides a new approach to decreasing water usage, energy consumption and chemical use and sewage expense in commercial scullery operations by reusing the drain water and/or recovering the heat energy from a scullery operation, thereby reducing operation costs. The invention, however, is not limited to scullery operations, it could be applied to other operations that produce greywater and could benefit from reusing water and resources. Scullery operations is used interchangeably with commercial kitchen operations.
The invention may be used to a particular advantage in the context of a scullery operation by reusing the drain water and/or heat energy from a commercial warewasher and/or three-compartment sink and reusing it to operate a disposer, pulper, scrap accumulator, scrap collector, or scrap trough, thereby reducing the amount of potable water and heat energy used by the amount needed to operate the disposal, pulper, scrap accumulator or scrap trough, thereby reducing operations costs and meeting mandates to reduce water usage.
An embodiment of the invention is specifically designed to accommodate all sizes of dish machines from the smallest to the largest, regardless of manufacturer. The invention is further designed to pass through all unused drain water during operation (via pumping and overflow system) or during non-use (via overflow system only) without overflowing onto the floor. The invention truly has a flow-through design.
In one embodiment of the invention the drain water receiver has the pumping capacity to pump more water than a given warewasher can consume on a per-minute and/or per-hour basis. Commercial warewasher water “consumption” is based on NSF Standard 3 testing criteria. NSF consumption ratings measure the final rinse water used for sanitization only. Further, the drain water receiver's pumping capacity exceeds the volume of final rinse water consumed on a continual operating basis. In addition, the drain water receiver's pumping systems is designed to handle the extra fill and make-up fill water dish machines commonly use during operation but is not published or advertised to the customers and is not recognized in the NSF testing per se. Pumping capacity and overflow capacity of the invention is primary to holding capacity.
A manifestation of the invention comprises a receiving tank that is scalable in dimensions and its component parts (as described subsequently) are configurable to fit in a wide variety of commercial settings, one or more inlet ports on the receiving tank are configurable to receive drain water from a warewasher or other system, preferably the drain water is gravity fed to the receiving tank, one or more overflow ports on the receiving tank being at a height lower than the inlet ports, that function in conjunction with the inlet port to prevent overflow or back up into a warewasher or other system, at least one pump configured to optimally transfer the drain water out of the receiving tank for reuse, an intake system allowing the pump to operate at minimal water levels, a sensor for powering the pump in response to the water level in the receiving tank, controls may be implemented to receive data from the sensors for operation of the pump at a remote location, a system may be implemented to prolong the life of the pump by maintaining continuous operation of the pump whether or not there is demand for the greywater, a filtering system may comprise a primary screened box to pre-screen drain water entering the inlet port and a secondary screened box situated to prevent particulate matter from clogging the pump, the drain water receiver may function to temper drain water that is over 140° F., at least one heat exchanger may be configured to capture or release energy from the drain water if there is a need for this function, a baffled system to prevent sloshing.
A principal object of the invention is to provide higher efficiency, maximum operational reliability, lower operating costs, and reduce wastewater for scullery operations or other analogous operations.
Other objects will become apparent from the following description, in which reference is made to the accompanying drawings.
The invention as illustrated can receive drain water through inlet port 3 from a warewasher (not shown) or other greywater producer and store the drain water in the receiving tank 2 for transfer to another source requiring grey water or heat energy or both. For example, the greywater may be used for a scrapping trough (not shown), which feed into a garbage disposer, pulper, scraper accumulator or other device (none of which are shown) for reuse. Reusing the water and heat energy conserves water, heat energy, and reduces the total output to the sewer lines. This results in a huge savings per year in a large commercial kitchen and substantial savings in any other commercial kitchens. This is illustrative of one manner in which the invention may be implemented. It being understood that the drain water receiver 1 can be used with many types of greywater generating systems/devices for reuse in many different ways, not just in the commercial kitchen setting. The terms drain water and greywater are used interchangeably. One purpose of the invention is to facilitate the reuse of greywater. Greywater from commercial kitchens is often referred to as drain water. The drain water receiver addresses the unique capacity and adaptation issues relevant to commercial kitchens, which vary in size and design.
The drain water receiver 1, as illustrated comprises a receiving tank 2 that is configurable and scalable to uniquely fit in a wide variety of commercial kitchens or other settings and functions to transfer greywater to another source for reuse. The component parts of the drain water receiver 1, as illustrated and described below are configurable to accommodate many different design requirements. While it is preferable to scale and configure the drain water receiver to have a low-profile such that it fits underneath a greywater generating system/device, it could be configured and scaled to fit above it, next to it or in a remote location. These configurations, however, would likely be less useful. The receiving tank 1, in its preferred form is a unibody structure made of fabricated heavy-gauge stainless steel body. The receiving tank 2 can be flexible in size to accommodate catchment capacity, flow requirements, pump rates or to configure to a system. The receiving tank 2 could conceivable be constructed with a framed structure or other type of structure or from a variety of materials as long as it maintains its function of effectively receiving and holding drain water.
While receiving drain water by gravity feed is preferred, the receiving tank 2 could receive it by other means. The drain water, for example, could be delivered into the receiving tank 2 by pump or manually. The drain water is received through an inlet port 3 mounted to the receiving tank 2. In
As viewed in
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The pump 7 is configured to optimally transfer the drain water out of the receiving tank 2 for reuse. As viewed in
The pump 7 draws the grey water from the receiving tank 2 via the intake system 8. The pump 7 is configured to vertically couple with the intake system 8 that allows the pump 7 to operate at minimal water levels. The base of the receiving tank 2 may be sloped, such that there is a flat spot along the midline of the receiving tank 2 base. This allows that drain water to gravity feed to a low spot in receiving tank 2 base. The pump 7 is configured to allow the lowest possible pump face 21 mounting location. As shown in
The liquid level sensing device 9 is mounted to the interior of the receiving tank 2 to sense the water level. The liquid level sensing device 9 communicates with the pump 7 to power on and off the pump 7 at certain water levels. It is preferred that the liquid level sensing device 9 communicates with the pump 7 to power off when the water level is too low and pump cavitation is probable and to power on when the water is at a minimum level where cavitation will not occur. The liquid level sensing devices 10 and 11 may additionally be mounted to the interior of the receiving tank. These additional sensors are used to communicate with certain greywater generating devices/systems to provide a high water and low water data set to indicate the bandwidth of greywater available in the receiving tank 2.
The receiving tank 2 in its preferred form is sloped such that the all of the water in the receiving tank 2 gravity flows to the lowest point of the receiving tank base 22. The intake system 8 and the drain port 6 are located at the lowest points in the receiving tank 2 for optimal flow of drain water out of the receiving tank 2. This allows the pump 7 to operated effectively at low water levels. Where the receiving tank 2 is sloped, the liquid level sensing devices 9, 10, and 11 may be mounted near the lowest point of the receiving tank base 22 for optimal sensing. Using multiple liquid level sensing devices, though not necessary, allows monitoring the variety of water levels in the receiving tank 2 and certain greywater receiving devices to function optimally in response to the water level data.
It is known that pumps have shorter lifespans when turned on and off frequently. For optimal pump life a system may be implement to prevent frequent powering on and off of the pump 7. A bypass system may be implemented to prolong the life of the pump. As shown in
The pump 7 may be turned on and off manually. In the preferred embodiment, the pump is monitored and operated via an external control system 25, as shown in
Often drain water contains solid particles large enough to clog the pump 7. If the drain water receiver 1, as illustrated is used in an environment where the incoming drain water contains solid particles, the drain water receiver 1 must contain a filtering system. A filtering system is necessary for use in a commercial kitchen setting, because the grey water contains food and other solid particles. As shown in
The drain water receiver 1 may be used to capture and transfer heat energy. In scullery operations the drain water receiver 1 may be used to temper drain water entering the receiving tank 2. There are a variety of methods for tempering drain water that is 140° F. (60° C.) or higher when utilizing a drain water receiver 1 for this function. The drain water may be mixed with cooler drain water that is also entering the receiving tank 2. A heat exchanger (not shown) may be used with the drain water receiver 1 to capture heat energy for use elsewhere. These examples of tempering drain water are illustrative and not exhaustive. Heat exchangers (not shown) may also be used to capture cold energy from the drain water in the receiving tank 2. The function of capturing and transferring heat energy is an optional feature of the drain water receiver 1.
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The operation of the drain water receiver 1, is best illustrated in
In step 102, the water is optionally stored in the receiving tank 2.
In step 103, as the water flows to the lowest point in the tank situated near the pump 7 and along the midline of the receiving tank, it flows through additional baffling/support 26 to reduce sloshing. This step is designed to protect the water level sensors 9, 10, or 11. A reduction in water turbulence or sloshing could conceivably be accomplished by other means.
In step 104, when the water entering the tank has reached a level where the water level is too high, excess water is gravity fed out of overflow port 4. If the water continues to rise regardless of step 104, or when step 104 is not implemented, step 105 will occur naturally. In step 105, the excess water gravity feeds through the overflow port 5. In steps, 104 and 105 the overflow water may be disposed of down the drain. Though two overflow ports are not necessary, this is a preferred method of operation.
In step 106, water gravity flows into the intake system 8 and is transferred by the pump 7 out of the receiving tank 2 based on the water level. Prior to entering the intake system 8, the water may be filtered by the secondary screened box 14. If there is no external demand for grey water, the pump may continue to operate feeding water in a circular path through a three-way acting valve 12, or in the alternative, through a return line 27, though not necessary, the longevity of the pump 7 depends on this step. The water level sensors 10 and 11 may be used in step 106 for acquiring information about the water level and providing data to a receiving device for optimal operation.
In step 107, grey water is pumped by pump 7 to another source. The pump may be activated in a number of ways including but not limited to manually, remotely by bluetooth, radio, WiFi, hardwired controls or any other means capable of signalling the pump to activate.
As an alternative to step 107, step 109 is implemented, the water level sensor 9, signals to the pump 7 to power on and off based on the water level in the receiving tank 2. In the alternative, the water level sensor 9 may signal a ready to operator indicator, such that the operator knows when to power pump 7 on and off.
In step 110, the water in the receiving tank 2 is disposed of via drain port 6 for inspection, cleaning and maintenance of the drainwater receiver 1.
In step 111, where the invention contains doors 16, they are removed for inspection, cleaning and maintenance of the drainwater receiver 1.
In step 112, heat energy is captured and transferred in an out of the drain water contained in the receiving tank 2 by submersible heat exchange coils or other means for transferring heat energy.