This application claims priority to U.S. Provisional Application Ser. No. 61/030,274, filed Feb. 21, 2008, entitled "Holding Tank Heating System," the disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE DISCLOSURE
1. Field of the Invention
The present invention relates generally to heating systems for sewage holding tanks. Particularly, the present invention relates to heating systems for portable toilet satellite stations or above ground sewage holding tanks. More particularly, the present invention relates to a heating system for a portable toilet satellite station holding tank that warms the holding tank and the inside area of a portable toilet satellite station to additionally warm users.
2. Description of the Related Art
A portable toilet, also known as a port-a-potty, is a modern, portable, self-contained outhouse typically manufactured of molded plastic often used as a temporary toilet for construction sites, parks, outdoor events and the like where no sanitation facilities exist.
Typical portable toilets are large enough for a single occupant. They are held upright by a base and the weight of the liquid in the holding tank at the bottom but are usually also secured to the ground to prevent high winds from blowing them over. Some portable toilets include both a seated toilet and a urinal and possibly a sink. Most include lockable doors, ventilation near the top, and a stovepipe vent for the holding tank.
The collection of sewage in the holding tank must be kept in generally liquid form in order to efficiently and hygienically remove the sewage from the holding tank for disposal. A vacuum truck sucks the sewage out from the holding tank and then the sewage is transported to be disposed of. Keeping sewage at a temperature above freezing can be particularly challenging in areas where the temperature outside is below freezing.
One known method of preventing liquid in the holding tank from freezing is adding salt brine to the tank. Salt brine is a mixture of salt and a mixing agent such as water. Using salt brine is labor intensive because of the need to store enough salt and to mix the brine in effective proportions. It also requires that the disposal trucks used to transport the raw sewage from the portable toilet be washed down daily such that the salt is washed off so it will not corrode the components of the truck that come in contact with the salt brine solution, usually the pump and tank.
A second known method of preventing liquid in the holding tank from freezing is to add methanol to the holding tank. Methanol is a petroleum product which has anti-freeze characteristics. Being a petroleum product, the cost of methanol is increasing daily. In addition, it is an explosive liquid that must be carefully mixed. If the portable toilet owner is dumping the raw sewage in a rural environment, methanol has a negative effect on environmental quality and may be considered a pollutant. The disposing of any methanol, wherever, has a negative environmental effect, as city sewage plants cannot remove this pollutant in their refining processes.
Adding traditional anti-freeze to the tank is a third method of preventing holding tank freezing. Traditional anti-freeze is also expensive and is often cost prohibited. In addition, this method requires extra effort to dispose of legally.
Government regulations often additionally require that in the workplace, often at construction sites, portable toilets be heated. To heat the portable toilets, many employers rely on known portable space heaters; however, these are easily removed from the portable toilet and therefore, the space heaters are often missing for various reasons. This provides for a time consuming and costly responsibility of continuing to maintain government regulatory standards.
The present invention overcomes problems associated with the related art.
SUMMARY OF THE INVENTION
The present invention relates to a portable toilet satellite station including an enclosure having a front wall, rear wall, side walls and a roof, the enclosure further having an interior at least partially defined by including the front wall, rear wall, side walls and the roof. The portable toilet satellite station preferably further includes a door in the front wall and a toilet located within the enclosure. In some preferred embodiments, the portable toilet satellite station additionally includes a sink that drains into the holding tank. The sink's source of water can be a water tank located above the sink.
The toilet includes a holding tank preferably having a vent leading outside of the enclosure to vent gases produced by sewage stored in the holding tank. To generally prevent freezing of the sewage within the holding tank and water within the water tank, the portable toilet includes a heating system, such that the holding tank can be heated. In the most preferred embodiments, the heating system further includes an interior vent that at least partially directs heated air produced by the heating element into the interior of the enclosure.
In some preferred embodiments, the heating element is an electric coil heater placed within a heater pipe. An example of a suitable electric coil heating element is disclosed in U.S. Pat. No. 6,869,533 (Norgaard).
These and various other advantages and features of novelty which characterize the present invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages and objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, in which corresponding reference numerals and letters indicate corresponding parts of the various embodiments throughout the several views, and in which the various embodiments generally differ only in the manner described and/or shown, but otherwise include corresponding parts;
FIG. 1 is a perspective view of a portable toilet satellite station 10 of the present invention;
FIG. 2 is a partially exploded and partial cutaway view of the portable toilet satellite station 10 of FIG. 1 illustrating an interior area 24 and the preferred configuration and installation of a heater system 40;
FIG. 3 is a partial, cutaway view of the heater system 40 of FIG. 2;
FIG. 4 is a partial cutaway schematic view of an alternate embodiment of the present invention illustrating an above-ground holding tank system 100 having a heating system 140, preferably, generally similar to the heater system 40 of FIGS. 2-3; and
FIG. 5 is a cross-sectional view of the heater pipe 42 of FIG. 3 as viewed along line 5-5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a preferred portable toilet satellite station 10. The portable toilet satellite station 10 includes an enclosure 12 having a front wall 14 having a door (not shown), rear wall 18, side walls 20a, 20b and a roof 22. The enclosure 10 further includes an inside area 24 at least partially defined by the front wall 14, rear wall 18, side walls 20a, 20b and the roof 22. The inside area 24 is generally the area in which a user would move about when using the satellite station 10. Within the inside area 24, a toilet 26 and, optionally, a urinal (not shown) are located. The toilet 26 and urinal are interconnected to a holding tank 28 having a tank interior 30 in which sewage (not shown) is stored until it can be disposed. In preferred embodiments, the holding tank 28 contains a deodorizing liquid (not shown) as is commonly used. The preferred holding tank 28 is vented with a vent pipe 32 extending upwardly from the holding tank 28 and then outside of the enclosure 12.
Portable toilets are most commonly used outside. In colder climates, the deodorizing liquid and sewage within the tank interior can freeze, thus making it very difficult to dispose of and also indicating that the temperature within the enclosure is quite cold, uncomfortable for users and potentially in violation of government standards. The preferred portable toilet satellite station 10 includes a heating system 40 to selectively heat the holding tank 28 and generally prevent freezing of the liquid and sewage within the tank interior 30. In preferred embodiments, the heating system 40 includes a heater pipe 42 and generates heated air that is directed through the heater pipe 42 and into the tank interior 30 to warm the contents of the holding tank 28. In preferred embodiments, the heated air is also directed into the inside area 24 of the enclosure 12 by venting the heated air through a transverse aperture or interior vent 44 in the heater pipe 42. Preferred embodiments warm the contents of the tank interior 30 as well as warming the inside area 24 of the enclosure 12 to increase user comfort as is often required by government regulations. In addition, by heating the inside area 24 of the enclosure 12, a water holding tank 72 for a sink 74 will further be prevented from freezing.
A preferred heating system 40 is illustrated in FIGS. 2-3. The heater system 40 includes a heating element 50, in this embodiment, an electric heater coil 50, which can be inserted within the heater pipe 42. An example of a similar electric coil heating element is disclosed in U.S. Pat. No. 6,869,533 and U.S. application Ser. No. 11/951,894 (Norgaard), the disclosures of which are herein incorporated by reference. It is noted that this type of a heating element is preferred and other alternative heating elements and devices for producing heated air are considered within the scope of the invention.
The heater pipe 42 is then inserted into or otherwise operatively secured to an aperture 29 in the holding tank 28. The heating system 40 preferably further includes a blower assembly 44 having a motor 46A driving blower 46B located above the heating element 50 for directing and circulating warm or heated air down through the heater pipe 42 and into the holding tank 28 and, preferably, into the inside area 24 of the enclosure 12. In preferred embodiments, the heating system 40 produces about 50 cfm output warm air flow. For that purpose, the heater pipe 42 includes an air intake 43 above the blower 46B. Preferably, the air intake includes a screen or filter 48 and is arranged and configured such that tampering or insertion of objects into the heater pipe 42 proximate the blower 46B is difficult (see also, FIG. 5). Additional tampering prevention methods can include fastening the heater pipe 42 to at least one wall 18, 22a, 22b of the enclosure 12 with screws or rivets 5 to make removal of the heating pipe 42 difficult.
The heating system 40 preferably includes a temperature control unit 52 connected to the exterior of the heater pipe 42 with at least one retaining element 54. The temperature control unit 52 activates the heater element 50 and blower motor 46A. A removable cover 56 on the control unit 52 permits access to the wiring and controls for blower motor 46A and heating element 50. A temperature control thermostat (not shown) can be housed within the control unit 52, and may be adjusted to the desired temperature to be maintained within the holding tank 28 or inside area 24 so as to generally prevent freezing of the holding tank contents as well as to warm the inside area 24 of the enclosure 12.
The thermostatic control unit 52 could optionally further include a temperature sensor 58 located near the heated air output end 43 of the heating pipe 42 by output coupling 41 A. Operation of the heater element 50 and the blower assembly 44 may be regulated by the sensor 58 to achieve the desired temperature of warm air discharged through output coupling 41 A. Because many of the elements may be made of plastic material, such as the heater pipe 42, it is preferred to have the heat output sensor 58 to prevent overheating and resultant melting of such elements. In certain embodiments, this temperature is about 150 to about 160 degrees F.
The heating system 40 of the present invention is preferably powered by connecting an electric cord 80 extending out of the temperature control unit 52 to an extension cord 81 having access to a source of electricity (not shown). It will be understood that alternative sources of power such as battery, propane, sun or wind power, for example, are considered within the scope of this invention.
In preferred embodiments, the portable toilet satellite station 10 includes a sink system 70 for users to wash up. The sink system 70 can include a sink bowl 74 having a faucet 75. The sink system 70 further includes a water tank 72 interconnected to the faucet 75 and providing the source of water. Waste water drained from the sink bowl 74 is directed down into the holding tank 28 via a conduit or drainage pipe 76. As previously discussed, the heating system 40 of the present invention warms the water tank 72 by directing warm air into the inside area 24 of the enclosure 12 to ensure the water tank 72 does not freeze and the sink system 70 remains operable.
One alternate embodiment of the present invention is illustrated in FIG. 4. This embodiment is an above-ground holding tank system 100. The above-ground holding tank system 100 includes a restroom 112, in a trailer or the like, having a toilet 126 and a sink system 170. Waste is transferred from the toilet 126 and the sink system 170 to an above-ground tank 128 with respective pipes 129. In cold weather, the above-ground tank 128, just like the portable toilet holding tank 28, is susceptible to freezing. The preferred above-ground holding tank system 100 preferable includes an aperture 127 on the tank 128 through which a heating system 140 of the present invention can be secured. The heating system 140 directs warm air down towards and into the above-ground holding tank 128. The heating system 140 of FIG. 4 is preferably similar to the heating system 40 of FIG. 3. The heating system 140 preferably includes a goose-neck air intake section 143 for drawing in cold outside air to be warmed and directed into the above-ground holding tank 128. The warm air prevents sewage S within the above-ground tank 128 from freezing and can be vented through a roof vent 132.
Although the preferred embodiments of the present invention have been described herein, the above description is merely illustrative. Further modification of the invention herein disclosed will occur to those skilled in the respective arts and all such modifications are deemed to be within the scope of the invention as defined by the appended claims.