Field of Search:
4/1,10,12,18,39,40,78,115,118,29FF,227,228 210/167,169 204/149,151,269,301 21/54R,12R,DIG.2
Claims:
We claim
1. A combined toilet and sewage treatment apparatus comprising a bowl provided with a drainage aperture; a primary treatment chamber providing a first electrolyte reservoir, a secondary treatment chamber providing a second electrolyte reservoir; means for circulating electrolyte between said second reservoir and said bowl to flush said bowl, the electrolyte during circulation passing from said bowl through said drainage aperture to said first reservoir and from said first reservoir to said second reservoir when its level in said first reservoir reaches a predetermined level; and a pair of electrodes positioned in each of said first and second reservoirs so that when current is supplied to said electrodes, electrolysis of sewqge in the electrolyte in both said reservoirs occurs.
2. The apparatus of claim 1 further including means for evaporating fluid from the electrolytes and discharging the evaporated fluid to the exterior of the apparatus.
3. The apparatus of claim 1, wherein an ion permeable barrier is provided in said seond treatment chamber, said barrier being positioned between the two electrodes in said chamber and providing two discrete chambers between which ions can pass but which prevents the passage of visible electrolyte born paritcles, said ion permeable barrier extending to a height which is at least above the normal level of electrolyte in said second treatment chamber.
4. The apparatus of claim 1, wherein at least one of the electrodes in the secondary treatment chamber is plate-shaped and is located in a position parallel to a plane defined by the surface of the electrolyte in the secondary treatment chamber when such electrolyte is in its normal position.
5. The apparatus of claim 1, wherein a macerator is provided with said macerator being positioned in the apparatus so as to macerate all solids flowing from said bowl to said primary treatment chamber.
6. The apparatus of claim 1, wherein an ultraviolet light source is provided, it being positioned so as to direct ultraviolet rays into said secondary treatment chamber.
7. The apparatus according to claim 1, wherein all of said electrodes are of plate shape.
Description:
This invention relates to a combined toilet (head) and sewage treatment apparatus which,due to its compact size, is particularly suited for use in vehicles such as boats, aircraft and mobile homes.
BACKGROUND OF INVENTION
There continues to be a need for a compact and reliable toilet and sewage treatment apparatus which is capable of reliably functioning for an extended period of time through a substantial number of uses without discharging into the environment any material which might be considered a pollutant. The need for such a system is substantially increased as compared with only a few years ago, due to the widespread existence of prohibitions against the discharge of sewage from, for example, various types of craft such as aircraft and water-craft, and it is to be expected that this need will continue to increase as more and more restrictive legislation is passed throughout the world.
In the result, various systems have been proposed including that taught in U.S. Pat. No. 3,568,215.
SUMMARY OF INVENTION
The present invention constitutes an improvement on the apparatus disclosed in said patent in that the apparatus of the present invention, as compared with the prior art apparatus of said patent, is capable of being used for a much longer period of time and for many more uses than was the prior art apparatus, these improvements having been achieved through a number of discoveries resulting from substantial experimentation, these discoveries leading to modifications including, among others which will be discussed hereinafter, the provision of separate primary and secondary treatment chambers and the provision of an ion permeable barrier which has been found to maintain liquid stored in the secondary treatment chamber in a much clearer condition than without it, the advantage of this being that it is this liquid which is re-circulated for flushing purposes with each use of the toilet.
BRIEF DESCRIPTION OF DRAWINGS
In the attached drawings showing a preferred embodiment of the present invention,
FIGS. 1 and 2 are side and top views respectively of the preferred apparatus;
FIG. 3 is a vertical, partly sectioned view taken along the lines 3--3 of FIG. 2;
FIG. 4 is a horizontal, partly sectioned view taken along the line 4--4 of FIG. 1;
FIG. 5 is a vertical, partly sectioned view taken along the line 5--5 of FIG. 1; and
FIG. 6 is a schematic diagram of an electrical circuit which may be utilized to carry out a complete flushing and sewage treatment cycle of the apparatus.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, it will be seen that the apparatus includes a combined casing and secondary treatment chamber 1 to which is hingedly secured a seat 2, both of which can be molded from a suitable plastic.
Looking now at FIGS. 3 to 5, it will be seen that there is located under the seat 2 a bowl 3 which may be formed from a suitable plastic material and to which is hingedly secured a trap door 4, shown in its closed position in FIG. 3, and which is manually operable between its open and its closed position by flush handle 5 connected to the trap door 4 by rod 6 which extends horizontally through a side of the casing 1 to the trap door 4. The bowl may be designed to be readily removed from the casing 1.
As can best be seen in FIG. 3 there is located beneath the bowl 3 a removable splash pan 10 also normally of a plastic material and in the bottom of which there is integrally molded a depending, inverted frusto-conically shaped strainer 11 having a closed bottom end and being provided in its side wall with a plurality of vertically extending slots 12 each of which can be approximately one-eighth of an inch wide and each of which extends substantially the entire height of the side wall of the strainer.
Also mounted in the bottom of the splash pan 10 is a moisture proof light housing 13 within which is mounted an ultraviolet light source 14, the ultraviolet light source being helpful in breaking down and treating the sewage in the secondary treatment chamber and therefore requiring that it be located so as to direct ultraviolet rays into the secondary treatment chamber as shown diagrammatically in FIG. 3.
An electric motor 17, preferably of the moisture proof type, is mounted in a protected position just under the bowl 3 adjacent to the trap door 4, and with its drive shaft 18 directed vertically downward. To the lower end of shaft 18 is secured a form of impeller 19 which on rotation by the motor 17, functions as a macerator. During the flushing operation, this macerator breaks down the sewage particles to a size which is sufficiently small to pass through the slots 12 in the wall of the strainer 11.
Located immediately below the strainer 11 so as to receive all of its discharged effluent, is a rectangular, box-shaped primary sewage treatment chamber 24 whose shape can best be seen in FIGS. 3, 4 and 5. This primary treatment chamber 24 has an open top, a closed bottom, three side walls of equal height and a fourth side wall 25 of lesser height than the other three so that the overflow from the primary chamber 24 into the secondary treatment chamber 1 is mainly in only one direction as apparent from FIG. 3.
As shown in FIG. 4, the primary treatment chamber 24 is provided at each of its ends with electrodes 27 and 28 of a rectangular plate shape and only slightly smaller in size than the ends of the primary treatment chamber. The electrodes can be formed from a number of known materials. Suitable electrodes are available from the National Graphite Company in Welland, Ontario, as grade number AT-SR.
Located within the secondary chamber 1 are a pair of electrodes 30 and 31 which may be formed of the same material as those above. Electrode 30, which will normally be the positive electrode, substantially fills the portion of the bottom of the secondary treatment chamber 1 not occupied by the primary treatment chamber, this electrode 30 being of a rectangular plate shape and slightly spaced from the bottom of the treatment chamber as well as from its sides, and side wall 25 of the primary treatment chamber 24. The other electrode 31, which will normally be the negative electrode, is also of a rectangular plate shape but is located in an upright position as best shown in FIGS. 3 and 4, it being located between a side wall of the primary treatment chamber and a side wall of the secondary treatment chamber and being spaced from both side walls although located closer to that of the secondary treatment chamber to provide a space between it and a side wall of the primary treatment chamber for an ion permeable barrier 33 which is secured within the secondary treatment chamber and located between the two electrodes 30 and 31. The ion permeable barrier 33 may be formed from among others a material such as styrofoam, a plastic membrane, a non-glazed ceramic material, asbestos cloth or parchment paper. Its presence has been found to maintain the liquid being treated in the secondary treatment chamber clearer than would otherwise be the case without such a barrier and the resultant electrodialysis which occurs instead of the normal electrolytic action which occurs without such a barrier.
There is also provided within the casing 1 a flushing mechanism which includes a flush pump 40 driven by a flush pump motor 41, the flush pump being arranged as shown and so as to be capable of circulating liquid from the secondary treatment chamber up through intake pipe 42 and out of an aperture 43 in the side wall of the bowl 3 as best shown in FIG. 3 following which it flows from the bowl, through the strainer 11, into the primary treatment chamber 25 and eventually back to the secondary treatment chamber 1.
Before the first use of the appartus both chambers are charged with an aqueous NaCl (sodium chloride) electrolyte in an amount of 3 lbs. of the salt to 3 gals of water.
To flush the toilet after use, an electrical push button 50 on the end of the handle 5 is depressed and the handle moved to manually open the trap door 4. As seen in FIG. 6, the depressed push button switch completes a circuit from the negative line of a 12 V D.C. supply to a relay coil 51 causing it to be energized. This closes normally open contact 52 completing the circuit to the flush pump and macerator motors 17 and 41 and interrupting the normally "on" circuit to the electrodes 27, 28, 30 and 31 and UV source 14. When the bowl is cleared, the switch 50 is released, this de-enerigzes the relay coil opening the circuit to the pump motor 41 and macerator motor 17 and permits the relay switch to return to its normal position as shown, completing the circuit to the electrodes and ultraviolet light. This circuit is normally timed, in this embodiment by a manually normally operable timer 54 although the circuit can be arranged so that the timer is automatically turned on when the push button switch 50 is released.
Accordingly, to begin the processing cycle, the timer 54 is set for the required time, normally one-half an hour. The current then flows through the normally closed relay contacts to the electrodes an ultraviolet light source. If the toilet is flushed at any time when the processing cycle is in operation the push button switch energizes the relay, opening the electrode and light circuit, and closing the pump and macerator circuit. The reason for switching from one circuit to the other is to limit the amount of current required at any one time. This feature, while optional does permit the use of a lower capacity power supply than would otherwise be required.
Normally, an exhaust fan (not shown) will be arranged so as to draw air through the secondary treatment chamber 1, the air entering the chamber through an air inlet 68 located in one side wall of the chamber and being exhausted from this chamber through the exit 69 in the opposite side wall of the treatment chamber 1 as shown in FIG. 5.
Of course, it will be appreciated that while the flushing operation, that is the operation of the flush pump motor 41 and the macerator motor 17 continues for as long as the push button switch 50 is depressed the electrodes and UV light source are kept energized for 30 minutes or as otherwise required.
It will be found possible to utilize the apparatus for a substantial number of uses and for an extended period of time without any further attention in that the level of the electrolyte will be kept under control through evaporation cuased by electrolysis and also, normally by the flow of air (as shown by arrows in FIG. 5) drawn through the secondary treatment chamber as described above. However, after a substantial number of uses it will be necessary to disassemble the apparatus by removing the bowl 3 and the splash pan 10 and clean out the primary and secondary treatment chambers which will at that time contain some solid sediment. The apparatus can then be re-assembled and put back into use and the sediment can be readily discarded in that there will be only a very small amount by volume.
It will be obvious to those skilled in the art that the apparatus as described above is capable of functioning with its parts arranged otherwise than as described. For example, the bowl and optionally the splash pan could be located at a position remote from the treatment chambers and interconnected with them through a duct for the effluent and a feed pipe for the flushing liquid. Also, the flush pump could be located in a position outside of the treatment chamber and could be combined with an arrangement permitting the flushing out of the treatment chambers to remove the collected sediment wihtout having to completely disassemble the apparatus. Appropriate drains could be provided for this purpose. Also, the ion permeable barrier, when used, could be located in other positions, it being necessary only that it be so located as to function as a barrier to the flow of visible electrolyte born particles between the electrodes 30 and 31. However, if the barrier is not used, which is possible, the flushing electrolyte will be relatively dirty looking. The splash pan, macerator and UV light source can be omitted but only with a significant loss in the efficiency of the unit.