Patent Application
20090077729
Waterless toilets effecting the safe and complete treatment of human toilet wastes amongst other forms of organic waste have been around ever since the digging of the first outhouse. Various steps can be seen in the evolution of waterless toilets, including compartmentalization of wastes (digging a hole), elaborating that hole to a tank (septic tanks), bringing that tank above ground (above ground in-vessel toilets), ending in several evolutionary branches—those toilets that burn the waste (incinerating toilets), those toilets that send the waste elsewhere (flush-to-sewer or flush-to-collection toilets), and those toilets that break down the waste amongst a high-lignin organic matter matrix (composting toilets).
In U.S. Pat. No. 7,103,926 by Rasberry, Rasberry's simple patented design of the portable latrine brought the vessel out of the ground. Though seemingly simple, the removal of the interface between the vessel for human wastes and the soil and groundwater allowed for control of the flow of pathogens vectored by urine into the environment.
Lejgren, in the U.S. Pat. No. 6,260,216, captures the idea of an above ground receiving vessel for human waste, and adds a sliding grid for winnowing down of the introduced solids. This element of motion has been emulated in a series of composting toilets, mostly unpatented. All of these planar methods of agitation are prone to failure through jamming; more importantly, they do not allow the conservation of a relatively inert abrasive and absorptive medium like sawdust to be used in the technology.
These two ideas of the above ground vessel and the agitating element were elsewhere elaborated in U.S. Pat. No. 5,345,620 by Sundberg, who changes the vessel into a rotating drum, providing a way to conserve the inert organic matter. Three failings with this design are the tremendous amount of torque necessary to rotate a barrel full of wet organic matter, incomplete aeration of the middle of the mass leading to odiferous anaerobic breakdown, and the inability to apply uniform heat across the surface area of the vessel exterior.
Naturally, continued evolution and improvement in the moving parts of a waterless toilet is required to maximize organic matter breakdown, liquid fraction evaporation, and pathogen kill, leading to this patent application.
The above-mentioned, and many other, toilet patents over a century have led to the evolution of the present utility design for which a patent is requested. That is, a composting toilet box containing an above-ground vessel, to the exterior of which heat is applied, containing an independently rotating discontinuous helical auger, allowing for the conservation of the relatively inert sawdust abrasive medium, or even an inorganic matrix such as porous plastic beads. All these features serve to optimize the complete breakdown of introduced organic matter through physical abrasion, dewatering, evaporation of the water content, support of a benign biodegrading aerobic microflora whose provenance is the sawdust and whose function is to biodegrader the organic waste, and finally thermal kill of animal pathogens. Further components include electronics control of these various elements, and an insulated layer between the composting vessel and the external box.
Broadly speaking, all composting toilets encourage the breakdown of organic wastes, principally human faeces. Some drain off the liquid portion, some attempt to evaporate it with a dryer mechanism. Using the remarkable properties of sawdust, including high water holding capacity, immense surface area, resistance to complete saturation, and physical abrasive properties, the discontinuous helical auger can be used to effect complete physical breakdown, evaporation of water, and kill of animal pathogens if maintained in the correct heat environment. The discontinuous helical auger acts to turn the mass of sawdust over such that the upper horizontal planar surface of the sawdust mass is not disturbed, obviating the mounding of sawdust to either end or the middle. The sawdust and auger are contained within a heated vessel that allows for ingress of toilet and other organic wastes (e.g. food waste, diseased dead birds) such that that matter is drawn extremely slowly first toward the middle and finally to the other end, where all that remain are inorganic elements and other traces. An air fan removes vapor-laden air and vents it to the outside. Odor is minimized owing to the shape of the auger not allowing for anaerobic pockets of sawdust leading to anaerobic reactions leading to smell. Physical breakdown is achieved through the abrasion of the sawdust powered by the auger blade, and simply the auger blade itself powered under very high gear reduction.
In the drawings, which form part of this specification:
In the idealized cross-sectional side view of the waterless Biodegrader biotoilet, a person sits upon a toilet seat 6 atop a toilet hole 5 leading to a stainless steel vessel 3 suspended by brackets 32 to hold a sawdust matrix mass A heated by electric heaters 31. A transverse axle 10 supports spokes 13 with optional spoke supports 12, 12A that in turn support the discontinuous helical blade 11, 11A that turns under the power of a geared engine box 9. The toilet room floor 2 can be a floating floor if the height of the toilet unit is too high, and the entire box airspace A2 above the sawdust mass is actively vented out a vent pipe 7. Spent sawdust is removed through an access hatch 8 set into the box 4 when refreshing of sawdust required. Sweeper flanges such as 15 work to scrape any solids away from the ends of the machine, avoiding anaerobic pockets.
Modifications in the attachment of spokes, detection devices within the auger, the use of two augers in tandem, and the length and diameter of the auger will simply change the turning potential of the auger, so long as the strength and dimensions of the stainless steel remains in relative proportion. Materials other than stainless steel such as carbon fibre can be envisioned but would require extensive testing for tensile strength and long-term resistance to chemical breakdown. Higher quality welding is particularly necessary in the auger itself.
Although the most widespread use of this biodegrader machine incorporating the helical auger would be as a toilet, the same technology can also be used to sanitarily process food waste, manure from other animals, and finally diseased dead animals the pathogens in which must be deactivated prior to disposal.
