Patent Application
20080179228
This invention relates to apparatus for the treatment of wastewater resulting from cleaning of, for example, buildings, vehicles and machinery by reducing the volume of wastewater required for disposal by an efficient water evaporation utilizing a waste oil burner as a heat source.
As explained in my U.S. Pat. No. 6,887,344, No. 5,582,680, and No. 6,200,428, the entire disclosures of which are incorporated by reference into this application, good manufacturing processes, concern for the environment, and changes in environmental practices and regulations all have created additional needs in handling waste fluids after manufacturing and cleaning operations, especially in disposing of water based mixtures containing pollutants such as greases, oils, soaps, heavy metals, road film and carcinogens. Whereas in the past it was acceptable merely to dump such waste liquids in the ground or in sewer systems, current good practices and environmental laws and regulations now severely discourage and/or prohibit such practices. Although very laudable in intent, the result can be very costly, especially to businesses who must use substantial quantities of water in their operations, as for example to clean buildings, vehicles and other machines, which will result in wastewater containing greases, oils, minute metallic and other particles, and detergents. Additionally, there are many wastewater sources for which mass reduction by evaporation is useful.
Each of the aforementioned patents describes and claims an apparatus operated on the evaporation principle and which is relatively inexpensive to manufacture, simple and safe to operate, and relatively more efficient in the active removal of non-volatile fluids and contaminants from wastewater. What is needed is an improvement to such apparatus that is compact and useful in the myriad operations that produce wastewater, such as in the treatment and reduction of wash and rinse water resulting from the cleaning and or mopping of buildings, vehicles and machinery, including especially the large amounts of wastewater generated by cleaning large areas of high trafficked floors in commercial and industrial facilities using power scrubbing equipment.
The waste left after water has been removed from a waste stream may comprise a dry powder of solids in certain cases or, potentially, a waste oil. Such a waste oil may come from petroleum products in the wastewater or many businesses may have waste oil from other sources. While this oil is considered a waste, the oil may still be used as an energy source, such as by burning the waste oil as a fuel source in a heating apparatus. It would be a benefit to a business to use this waste as a fuel source; however, waste oil tends to leave a significant residue when combusting with numerous contaminants. Cleaning the equipment that burns waste oil is needed to extend the life of the equipment.
Thus, an apparatus that is compact and easily moved within a facility, and uses an environmentally safe heat transfer fluid and an optional disposable liner to contain the wastes remaining after evaporation is needed. Further, a waste oil heating system that provides heat to a wastewater evaporator to utilize an energy source that may otherwise be wasted is needed.
In accordance with this invention, there is provided a novel wastewater treatment apparatus that treats wastewater containing, as impurities and pollutants, various non-volatile (at water boiling points) fluids such as greases, oils, carcinogens and detergents, by vaporizing the water using a waste oil heating system and a heat transferring mineral oil by which heat transfer is effected.
An advantage of the present invention is that the apparatus offers significant savings in labor, reduction of contamination risk, and energy savings. Further, the invention provides an easily cleaned waste oil heating system that allows an increased use of resources as the waste oil may come from the wastewater stream treated by the apparatus or other sources.
The present invention is disclosed with reference to the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. The examples set out herein illustrate several embodiments of the invention but should not be construed as limiting the scope of the invention in any manner.
Referring to
Fluid receiving vessel 20 as shown includes side walls, a V-shaped bottom wall and at least a partially open top. Similarly to my previous U.S. Pat. No. 6,887,344, fluid vessel 20 in turn is supported by heating vessel 18 by outwardly extending (e.g., 4 inch) flanges 24 at the top of all four sides sitting atop similar, inwardly extending flanges 26 at the top of all four sides of heating vessel 18. As thus shown in
Within heating chamber 16 and below vessel 20 as shown in
The heat tubes 29a,b are preferably straight tubes because burning waste oil will tend to leave a significant amount of residue in the tubes. Straight tubes can be easily cleaned on a regular basis. To facilitate this, waste oil burners 30a,b are at least partly supported by a door 70 in the external jacket 14 that may be removed or swung open to expose the open ends of the heat tubes 29a,b so that they may be cleaned. Further, since waste oil may have various contaminants that may be unknown depending on the source of the waste oil, it may be necessary to filter or scrub the exhaust. In this regard, removable filters or a scrubber system may be placed in communication with the flue pipe 37 or the output of the heat tubes 29a,b.
In addition, heating chamber 16 is substantially filled (e.g., about one half the depth of chamber 16) with a non-toxic, heat transfer liquid mineral oil 32 such as PARATHERM NF Heat Transfer Fluid supplied by Paratherm Corporation of Conshocken, Pa., to evenly distribute to vessel 20 the heat transferred from the heat tubes 29a,b and causing the wastewater contained in the fluid vessel to boil and evaporate while enabling the contaminates in the wastewater to settle in vessel 20 in concentrated form for later disposal. Also, as shown in
As described in my previous U.S. Pat. No. 6,887,344, the wastewater is delivered to vessel 20 by an inlet 34 connected by a pipeline or flexible hose 35 and self priming pump means 36 to a suitable supply tank, such as tank 12, as shown in
At the rear of vessel 20 is an access pipe 46 extending through both jacket 14 and vessel 18 and opening into vessel 20 to enable the insertion of a hose to pump out any contaminate-concentrated water remaining in the apparatus for suitable disposal. Pipe 46 (
Similarly to my previous U.S. Pat. No. 6,887,344, power to operate apparatus 10 is supplied to the control panel 28 mounted at the side of jacket 14 as shown, with the electrical power delivered through a suitable 3-prong plug from any 110 volt receptacle. The control features may include those described in my patent, U.S. Pat. No. 5,582,680, but may also simply comprise a “dead man” switch 52 to power supply pump 36 only while switch 52 is actively held in its closed position by the operator, an optional combined start-stop 24-hour timer control 54 to start and shut off the electrical power at selectable times, and a “HI-LO” switch 56 to select alternative high and low heat settings of, for example, 350° F. and 150° F., respectively.
Further as shown, apparatus 10 is supported by suitable legs 59, which preferably are adjustable in height and may include lockable casters for easy movement.
As described in my previous U.S. Pat. No. 6,887,344, the removable wastewater supply tank 12 (e.g., about 24 inches wide and 4 inches high) preferably extends beyond apparatus 10 (e.g., 10 inches at each end) to enable a direct fill from the drain of a power scrubber and is mounted on casters 60 to enable the tank 12 to be moved out from under apparatus 10. The top wall 62 of tank 12 includes an access opening through which wastewater is dumped into a removable filter tray 65 placed in tank 12, and supply pump 36 which is mounted on a bracket detachable from top wall 62 (to enable pump 36 to be used with other wastewater supply means) connected by the flexible, detachable hose 35 to inlet 34. The example size of tank 12 is sufficient to hold wastewater from a 50-gallon power scrubber. The power cord 57 (
Pump 36 may alternatively be mounted directly on the back wall of jacket 14. If desired, or if necessary because of local environmental regulations, the evaporating discharge pipe 40 can be connected to a conventional water condenser coil (not shown) to collect distilled water for reclaiming and reuse as washwater.
In operation, the apparatus is first filled with wastewater generated by a floor scrubber or the like, either by hand or through supply tank 12 by holding pump switch 52 closed until vessel 20 is filled to an appropriate level. The preferred heating level is then set on HI-LO switch 56 and the timer control 54 is then set both to close the heating circuit for the selected time and to actuate blower fan 42 causing the wastewater to reach its boiling temperature, evaporate the water and expel the water vapor from the apparatus. When the water is substantially evaporated, the remaining waste is then removed from vessel 20 through pipe 46 or cover 44.
Referring now to
Liner 75 is fabricated so as to prevent the through-passage of water and waste, the sides and bottom of liner 75 conforming in its outer shape to the contours of the fluid receiving vessel 20 of the wastewater treating apparatus. Liner 75 has at least one closeable opening 76 at its top to admit unprocessed wastewater from any source and vent evaporating water during operation to reduce the nonvolatile contaminates to their dry state. Liner 75 is formed of sufficient material at its top to be capable of being sealed shut and removed from fluid receiving vessel 10 and disposed, for example by incineration, along with the residue. The closure may consist of draw string 78 as shown or other suitable means such as adhesive tape.
If the temperature difference between the heat tubes and the oil exceeds certain limits, the efficiency of the heat transfer from heat tubes to oil is reduced, due in part to radiative and conductive cooling through the external walls of the heating chamber containing the oil and the heat tubes, and due in part to variations in convective behavior of the oil at different temperature ranges and viscosities. Consequently, a means is described whereby the relative differences between the oil temperature, the heating vessel temperature, and the ambient temperature may be held within such limits as will promote a maximally efficient transfer of heat to the oil and energy savings. This means is similar to the means described in my previous U.S. Pat. No. 6,887,344 and contributes to the useful life of the heat tubes and the heat transfer fluid.
To accomplish the foregoing, an alternate embodiment of the invention includes the incorporation of several thermally-activated sensors, two immersed in the oil in the heating vessel and not touching other surfaces or substances, another attached directly to the surface of the heating vessel, and the fourth located in the control box. The sensors are interconnected in the electrical circuit so that when the temperature differences between the sensors exceed a certain preset limit, the waste oil burners are turned off.
To control the heating circuit as described and as shown in
Thermally-activated sensors 80, 81, 82 and 83 are connected to a heating control circuit of any type that detects differences in temperature between two or more sensors and changes the state of a power-circuit switching means depending on the relationship between those differences and a set value, e.g.:
A suitable preset value may be about 30° F. such that the switching means is closed if the temperature differences are less than that amount and open if more than that amount. The waste oil burners 30a,b are actuated and deactuated through a circuit switching means as described above. When the starter button of apparatus 10 is first closed, the switching means is closed to activate the waste oil burners 30a,b to blow ignited waste oil through the heat tubes 29a,b, respectively, and raise the temperature of the heat transfer fluid 32 sufficiently to cause wastewater in vessel 20 to be evaporated. However, as the transfer fluid 32 is being heated, the temperature of the heat tubes 30a,b will continue to rise even faster and cause temperature gradients to occur within the transfer fluid 32.
The temperature probes 80, 81, 82, 83 are provided to limit the temperature differential. Consequently, when a difference in temperature between two of the thermally-activated sensors exceeds a set value, the heating circuit will deactivate the waste oil burners 30a,b until the temperature of the heat tubes 29a,b drops to a level at which the temperature differential is less than the set value. At that time, the differences in temperature between thermally-activated sensors does not exceed the set value and the waste oil burners 30a,b continue heating the heat transfer fluid 32. In a particular embodiment, the waste oil burners are actuated and deactuated individually so that the control circuit may run the waste oil burners individually to reduce a horizontal temperature differential if needed. This more energy efficient cycle continues until the heat transfer fluid 32 reaches and is maintained at its preset operating temperature to cause evaporation of the wastewater. The operation may continue by adding more wastewater as desired. When a sufficient amount of contaminants has been collected, the apparatus 10 preferably is operated until all of the remaining wastewater is evaporated leaving a residue that is free of water in the contaminants in liner 75 for disposal by an environmentally safe means.
In a more preferred embodiment shown in
The vessel 120 simplifies the construction and maintenance of the apparatus 110 because one may use a standard vessel that may be used with other wastewater treatment apparatus. While not shown in the figures, a jacket or similar structure as described in the previous embodiments may be used in the preferred embodiment. The vessel 120 is contained within the heating vessel 18 forming the heating chamber 16. The heat transfer fluid 32 is contained in the heating chamber 16 in contact with the outer surface of the heat tube 129 and the reentrant tubes 184.
The heat tube 129 and reentrant tubes 184 are best shown in
The preferred turbulators 133 are best shown in
The preferred placement of the turbulators 133 within the reentrant tubes 184 is so that the turbulator extends from the inlet 185a of the reentrant tube to the edge of the heating chamber 16 as shown in
The features and operation of the previous embodiments may be incorporated into the preferred embodiment as desired. For example, a liner similar to the liner 75 may be used in conjunction with the fluid vessel 120. In a further example, the supply tank 12 may be used with the preferred embodiment. In an even further example, a heating control circuit and thermocouples are used in the preferred embodiment.
From the description above, it should be clear that the present invention offers significant savings in labor, reduction of contamination risk, and energy savings. The use of waste oil as the fuel source in the heating portion of the apparatus allows an increased use of resources as the waste oil may come from the wastewater stream treated by the apparatus or other sources. This waste oil might normally be thrown away or incinerated; however, the configuration of the apparatus described above allows additional energy to be put to use from this waste. The use of a removable liner which may either be cleaned or disposed of substantially reduces the cleaning effort required for the apparatus. The use of the described temperature-difference control for the heating vessel reduces the waste of energy used in heating, and further adds to the useful life of the heat transfer fluid 32. It also may provide a degree of safety in case of heating vessel leakage or other abnormal condition.
It is to be understood that the aforementioned description is illustrative only and that changes can be made in the apparatus, in its components and their functions, without departing from the scope of the invention as defined in the following claims.
This application claims priority from U.S. Provisional Patent Application Ser. No. 60/887,222, filed Jan. 30, 2007, which is herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 60887222 | Jan 2007 | US |
| Child | 12022888 | US |
