PORTABLE COMPOSTING TOILET SYSTEM
A portable composting toilet system has a compartmentalized receptacle for receiving human waste, a gray-water circulation subsystem for circulating gray water formed by mixing water with waste through the compartmentalized receptacle to promote mixing of the waste to thereby accelerate digestion of the waste, and an air-circulation subsystem for emitting air bubbles into a sludge formed at a bottom of the compartmentalized receptacle to break up the sludge to thereby accelerate digestion of the waste. The air circulation subsystem can include an air-driven pump that causes the gray water to circulate while allowing feeding pressurized air to diffuser loops in each compartment to create sludge-breaking bubbles. This portable composting toilet system so efficiently decomposes waste that the maintenance costs of hauling residual sludge to the surface (when the toilet is used underground in a mine) is significantly lower than for conventional toilets, thus providing substantial cost savings to mine operators.
The present invention relates in general to toilets and, more particularly, to portable composting toilets.
BACKGROUND OF THE INVENTIONPortable outhouses, such as those commonly used at construction sites and in underground mines, hold only a limited amount of water and thus must be emptied frequently. In the context of an underground mine, odor and waste disposal pose serious problems. Hauling waste to the surface for disposal is both expensive and time-consuming.
Portable composting toilets utilize a holding tank to store and process human waste. (“Composting” means the microbial decomposition of organic matter.) Typically, these portable composting toilets use a chemical or biological digester to accelerate the biological decomposition of the human waste in order to reduce both the amount of sludge that has to be hauled to the surface and the frequency with which the toilet has to be emptied.
However, current composting toilets suffer from a number of shortcomings. One such shortcoming is that conventional portable composting systems require daily maintenance because the composting material must be “flipped”, usually by a manually operated drum on a daily basis, in order to maintain efficient bacterial breakdown of the human waste.
Furthermore, these portable outhouses are typically constructed of plastic which has a propensity to develop surface micro-cracks which become repositories for waste matter. Using disinfectants to clean the toilet has the unfortunate side-effect of destroying or at least substantially diminishing the biological breakdown process. Even attempting to cleanse these portable outhouses with water is problematic because water tends to dilute the bacterial digester, thus reducing the efficacy of the biological breakdown, and furthermore adds weight to the sludge that has to be periodically hauled to the surface. Thus, cleaning of these portable composting toilets usually requires manual scrubbing with special cleaners, which is labor-intensive.
Accordingly, an improved portable composting toilet that overcame one or more of the shortcomings of the prior art would be highly desirable.
SUMMARY OF THE INVENTIONIn general, a portable composting toilet has a compartmentalized receptacle for receiving and circulating human waste mixed with water and a biological digesting product to accelerate bio-degradation (composting) of the waste. The portable composting toilet receives human waste into one portion of its compartmentalized receptacle, mixes the waste with water to form gray water while the sludge settles to the bottom of the receptacle. The portable composting toilet uses a gray water-circulation subsystem to circulate the gray water (containing waste or partially dissolved waste) to continually turn and circulate the gray water and waste, thus greatly expediting the composting of the human waste. The portable composting toilet also utilizes an air-circulation subsystem that not only drives the water-circulation subsystem but also emits air bubbles from diffuser loops in each compartment of the compartmentalized receptacle in order to break up the sludge that collects at the bottom of the compartments of the compartmentalized receptacle, thereby further expediting the bio-degradation of the human waste. Accordingly, the frequency with which the portable composting toilet requires emptying and the total mass of composted waste that has to be hauled to the surface (when used underground in a mine) is substantially reduced, resulting in substantial cost savings for the mining company.
In other words, the present invention entails a portable composting toilet system for receiving and processing human waste. The toilet system comprises a housing having an opening disposed above a compartmentalized receptacle for receiving human waste, the compartmentalized receptacle further receiving water and a digesting product to biologically digest the waste. The toilet system has a gray water circulation subsystem for circulating gray water formed by mixing water with waste through the compartmentalized receptacle to promote mixing of the waste to thereby accelerate digestion of the waste. The toilet system also has an air circulation subsystem for emitting air bubbles into a sludge formed at a bottom of the compartmentalized receptacle to break up the sludge to thereby accelerate digestion of the waste.
Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:
It will be noted that throughout the appended drawings, like features are identified by like reference numerals. It should also be noted that the figures are not necessarily drawn to scale.
DETAILED DESCRIPTIONIn general, and as will elaborated below in greater detail,
Housing
The housing 200 as shown in
In one embodiment, as shown in
As shown particularly in
As depicted in
As further illustrated in
As shown in
As further shown in
Referring back to
Compartmentalized Receptacle
The compartmentalized receptacle 300 (as best shown in
Optionally, the second compartment and the third compartment are divided by a wall 340 having a downwardly-angled deflector shield 342 to prevent waste from back-splashing a user of the toilet system. The wall 340 has an opening directly above the deflector shield through which the gray water overflows to rinse the deflector shield 342. As will be appreciated, this gray water sluicing over the deflector shield 342 is not clean water, but is nonetheless relatively cleaner gray water than the other gray water in the tub (or receptacle).
The three-chamber version of the compartmentalized receptacle 300 can be made by inserting a small tub 350 inside a larger tub 360. In other words, the first, second and third compartments can be formed by inserting the small tub 350 within the larger tub 360 whereby the small tub 350 fits flush against one side 362 of the larger tub 360 but defines a passageway 364 along an opposite side 366 of the larger tub to permit gray water and waste to be drawn back into the first compartment 310 from the third compartment 330. This passageway 364 is preferably a triangular channel formed by the beveled underside of the smaller tub.
In another embodiment, the compartmentalized receptacle 300 can have a fourth compartment for ultraviolet-light sterilization of the waste. This fourth compartment can also be used for chlorination. As will be appreciated by those of ordinary skill in the art of composting toilets, the toilet system can be modified to have a fifth chamber, a sixth chamber, or effectively any number of chambers to provide progressive washing-out of the gray water.
In yet another embodiment, the compartmentalized receptacle 300 could be constructed with only two compartments, a front compartment for directly receiving human waste and a rear compartment for housing a pump for circulating gray water mixed with waste into the front compartment, the front and rear compartments being in fluid communication to permit gray water and waste to be drawn back into the rear compartment. In other words, this two-chamber (two-bay) version would eliminate the central chamber (or middle bay).
Gray Water Circulation Subsystem
The gray water circulation subsystem 400, as noted above, is designed to circulate gray water (i.e. dirty water containing dissolved or partially dissolved waste, including waste particles and debris, toilet paper, etc.) through the various chambers or compartments of the compartmentalized receptacle 300. This continual circulation and mixing accelerates bio-degradation and composting of the waste.
The gray water circulation subsystem 400 uses a pump 450 that receives air pressure from a pressurized air source. In the main implementation of this technology, pressurized air is fed into an air-distribution system having an air manifold that diverts (or “bleeds off”) a portion of the airflow from the air circulation subsystem 500 in order to initially prime the pump 450 and then to power the pump 450 that, in turn, drives the gray water circulation subsystem 400. Further details about the air-circulation subsystem and air-distribution unit will be provided in the subsequent section.
As shown in
As further depicted in
To prime the pump 450, pressurized air from the pressurized air source is injected into the tubular pump body via the air inlet causing pressurization of the inside of the tubular pump body. As the pump is submersed, and the top of the elbow (or U-shaped spout) is exposed to the atmosphere, the air pressure differential between the top and bottom of the pump will push the water upwardly because the air pressure at the top of the pump (being at atmospheric pressure) is less than the air pressure at the bottom (being pressurized to above atmospheric pressure). This pressure differential thus causes the gray water to be displaced upwardly through the U-shaped spout or elbow and into the second compartment. As noted in the preceding paragraph, once the pressure differential is established (after the pump has been primed), the gray water will circulate continuously.
The gray water fills up in the second compartment, and is “cleaned” somewhat relative to the gray water in the first compartment, and then overflows into the third compartment by flowing through the opening in the wall between the second and third compartments. In flowing through the opening in the wall between the second and third compartments, the “cleaner” gray water flows over the deflector shield, thus rinsing and cleaning the deflector shield. (It bears underscoring that expressions such as “relatively clean”, “cleaner” and “cleaning” are to be construed within the context of gray water; in other words, all of the gray water contained in the toilet is dirty or gray, but the water is gradually cleaned as it is processed). As the gray water circulates, waste particles and debris eventually settle or sediment from the water and form a sludge at the bottom of the receptacle. The gray water (and especially the top portion thereof) thus becomes gradually cleaner in time as the waste sediments or settles from the water. As gray water is transferred to adjacent compartments, it thus gradually becomes cleaner, thus providing a mechanism to rinse the deflector and to effectively flush the system.
Gray water in the third compartment is drawn back by the pump 450 to the first compartment via the passageway 364 (e.g. the triangular channel along the bottom of the receptacle), thus completing the circulation cycle. Once the pump has been primed, the pump will continually circulate the gray water inside the toilet system as long as the pump's air pressure maintains the pressure differential needed to drive the water over the first wall into the second compartment. As will be appreciated, the passageway 364 (e.g. triangular channel) should be designed to be large enough to permit relatively unfettered passage of water-borne waste, toilet paper, etc.
As illustrated in
Air Circulation Subsystem
The air-circulation subsystem 500 can also be designed in different ways to accomplish the twin objectives of powering the gray water circulation subsystem and providing air bubbles to break up the sludge formed at the bottom of the compartmentalized receptacle 300. In the main embodiment, the air-circulation subsystem 500 has an air-distribution unit 505 such as the one shown by way of example in
As will be elaborated below, the diffuser loops 550 have a plurality of air holes 552 for diffusing pressurized air into the bottom of the compartmentalized receptacle 300 to create air bubbles for breaking up the sludge that forms at the bottom of the compartmentalized receptacle 300. By breaking up the sludge, these air bubbles accelerate the digestion and composting of the waste.
As shown in
As shown in
In addition to feeding pressurized air into the diffuser loops to create sludge-breaking air bubbles, the air-distribution unit 505 of the air-circulation subsystem 500 also drives the gray water circulation subsystem 400 by priming and pressurizing the pump 450. Priming and pressurization of the pump, as was described above in the preceding section, generates a pressure differential that draws water upwardly from a first compartment to overflow into a second, adjacent compartment, thereby driving the gray water circulation subsystem.
In the particular implementation shown in
The air manifold 540 shown in
As illustrated in
As shown in
Due to its water and air circulation subsystems, the portable composting toilet system 100 thus continually circulates, mixes and flushes the waste to expedite biodegradation and composting of the waste. The portable composting toilet system thus functions as a mini sewage treatment plant. As a result, the overall performance of this novel toilet system is superior to that of prior-art portable composting latrines. Specifically, this novel portable composting toilet system can effectively process human waste from 40 persons per days and requires removal of the resulting sludge only once during a 12-18 month period. The amount of manpower required for maintenance of this novel portable toilet system is much lower (about 29 hours/month) than that required for prior-art composting latrines (122 hours/month) or for portable outhouses (117 hours/month). In the context of underground mines where hauling waste to the surface is expensive, this dramatic improvement in portable composting technology could result in substantial cost-savings for mining companies.
It is obvious for those skilled in the art that as the technology develops the basic idea of the invention can be implemented in various ways. The invention and the embodiments thereof are thus not restricted to the examples described above, but they may vary within the scope of the claims.
Claims
1. A portable composting toilet system for receiving and processing human waste, the system comprising:
- a housing having an opening disposed above a compartmentalized receptacle for receiving human waste, the compartmentalized receptacle further receiving water and a digesting product to biologically digest the waste;
- a gray water circulation subsystem for circulating gray water formed by mixing water with waste through the compartmentalized receptacle to promote mixing of the waste to thereby accelerate digestion of the waste; and
- an air circulation subsystem for emitting air bubbles into a sludge formed at a bottom of the compartmentalized receptacle to break up the sludge to thereby accelerate digestion of the waste.
2. The toilet system as claimed in claim 1 wherein the compartmentalized receptacle comprises a first compartment for housing a pump for circulating the gray water, a second compartment adjacent to the first compartment into which the gray water flows for further mixing and digestion of waste, and a third compartment adjacent to the second compartment into which gray water flows, the third compartment being in fluid communication with the first compartment so that the gray water and waste can be drawn back into the first compartment, thereby circulating the gray water and waste for optimal biodegradation while also continually flushing the first, second and third compartments to enhance composting of the waste.
3. The toilet system as claimed in claim 1 wherein the air circulation subsystem comprises:
- an air inlet for receiving pressurized airflow from a pressurized air source; and
- an air manifold for dividing the pressurized airflow into a plurality of air conduits for delivering pressurized air to diffuser loops disposed in sludge at the bottom of the compartmentalized receptacle, the diffuser loops comprising air holes for diffusing pressurized air into the compartmentalized receptacle to create air bubbles for breaking up the sludge to accelerate digestion of the waste.
4. The toilet system as claimed in claim 1 wherein the air circulation subsystem comprises a pump primed by air pressure for generating a vacuum pressure to draw water upwardly from a first compartment to overflow into a second, adjacent compartment, thereby driving the gray water circulation subsystem.
5. The toilet system as claimed in claim 4 wherein the air circulation subsystem further comprises an air manifold disposed upstream of the pump for dividing pressurized airflow from a pressurized air source between the pump and three parallel diffuser loops, one diffuser loop being disposed in each of three separate compartments of the compartmentalized receptacle.
6. The toilet system as claimed in claim 5 wherein the air circulation subsystem further comprises:
- an air inlet mounted on the housing for connecting to an air hose that delivers pressurized air from the pressurized air source; and
- an air pressure regulator disposed downstream of the air inlet to regulate airflow.
7. The toilet system as claimed in claim 1 wherein the air-circulation subsystem comprises an air-distribution unit having an air inlet mounted on the housing, an air-pressure gauge mounted on the housing in proximity to the air inlet, an air regulator for regulating the airflow and an air manifold for dividing the airflow between an air-pressure-driven pump and a group of parallel diffuser loops.
8. The toilet system as claimed in claim 7 wherein each of the diffuser loops comprises a length of flexible tubing having a plurality of small holes therein through which bubbles are emitted, wherein ends of the flexible tubing are connected to a common T-joint that is also connected to an air hose through which air is delivered from the air manifold.
9. The toilet system as claimed in claim 8 wherein the flexible tubing is weighted down with at least one weight attached to the flexible tubing.
10. The toilet system as claimed in claim 2 wherein the second compartment and the third compartment are divided by a wall having a downwardly-angled deflector shield to prevent waste from back-splashing a user of the toilet system.
11. The toilet system as claimed in claim 10 wherein the wall comprises an opening above the deflector shield through which the gray water overflows to rinse the deflector shield.
12. The toilet system as claimed in claim 2 wherein the first, second and third compartments are formed by inserting a small tub within a larger tub whereby the small tub fits flush against one side of the larger tub but defines a passageway along an opposite side of the larger tub to permit gray water and waste to be drawn back into the first compartment from the third compartment.
13. The toilet system as claimed in claim 1 wherein the air-circulation subsystem comprises an air-distribution unit having an air inlet, an air pressure gauge downstream of the inlet, a T-joint downstream of the gauge for dividing airflow exiting the gauge, a first regulator downstream of the T-joint for regulating airflow into an air hose connected to a pump that drives the gray-water circulation subsystem and a second regulator downstream of the T-joint for regulating airflow into a plurality of parallel diffuser loops that emit air bubbles to break up sludge formed at a bottom of the compartmentalized receptacle.
14. The toilet system as claimed in claim 1 wherein the compartmentalized receptacle comprises only two compartments, a front compartment for directly receiving human waste and a rear compartment for housing a pump for circulating gray water mixed with waste into the front compartment, the front and rear compartments being in fluid communication to permit gray water and waste to be drawn back into the rear compartment.
15. The toilet system as claimed in claim 1 wherein the gray water circulation subsystem comprises a pump for being partially submerged in the gray water of a first compartment, the pump having a tubular pump body through which a perforated pipe passes to deliver gray water upwardly through a spout into a second compartment adjacent to the first compartment, the tubular pump body comprising an air intake port for delivering pressurized air into an annular gap between the tubular pump body and the perforated pipe.
16. The toilet system as claimed in claim 15 wherein the plurality of holes are arranged longitudinally along the perforated pipe.
17. The toilet system as claimed in claim 1 wherein the housing comprises a pair of externally mounted drainage valves that act as an inlet and an outlet for washing out the compartmentalized receptacle.
18. The toilet system as claimed in claim 1 wherein the housing comprises a detachable privacy enclosure to which may be secured a staircase structure having a plurality of steps.
19. The toilet system as claimed in claim 1 wherein the housing comprises a base having parallel, spaced-apart flat surfaces to permit safe handling by a forklift.
20. The toilet system as claimed in claim 1 wherein the housing comprises an access hatch for enabling access to an air pressure regulator for regulating pressure in the air-circulation subsystem and for periodically adding a biological enzyme digester and an anti-foaming agent to the gray water.
Type: Application
Filed: Jun 13, 2007
Publication Date: Dec 18, 2008
Applicant: Paul Villgren, Inc. (Sudbury)
Inventor: Paul J. Villgren (Sudbury)
Application Number: 11/762,496
International Classification: A47K 11/02 (20060101);