NZ334012A - Dry toilet including a bag and a filter to hold back solid waste - Google Patents

Abstract

A non-flushing toilet system comprising a container and a resilient filter bag (1). The bag (1) has sides (2), a filter (3) along with a convergent drain base (4) leading to an outlet (5). In use the filter (3) allows liquid waste to pass through, but holds back solid waste, the liquid waste passing through the outlet (5). A cap (6) may be provided as a squeeze fit over the outlet (5) where the outlet (5) may need to be closed during transportation for disposal after use.

Description

Patents Form # J) NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION AFTER PROVISIONAL # DATED TITLE • 334012 3 February 1999 Disposable dry toilet I, Lautofa Samuel IULI Address. Unit 6, 5 Kitchener Road, Mt Albert 1003, Auckland, New Zealand Nationality A New Zealand citizen do hereby declare the invention for which I pray that a patent may be granted to me and the method by which it is to be performed, to be particularly described in and by the following statement pros iwp fee code 1050 INTELLECTUAL PROPERTY OFFICE | OF NZ 1 5 FEB 2000 RECEIVED lCe*) ;A Dry Toilet ;TECHNICAL FIELD OF THE INVENTION ;This invention relates to a dry toilet and in particular a dry toilet that separates dry waste from liquid waste In this specification "dry" means that no flushing water is used with the toilet. ;5 ;BACKGROUND ART ;There are advantages in using a dry toilet in that there is a substantial saving in flushing water which is used to carry the sewage to a discharge outfall or treatment plant and which must itself be discharged. However dry toilets themselves have the disadvantage that the sewage must be 10 disposed of and the mixed wet and dry nature of sewage makes this difficult. There is a need to provide an effective solution to this difficulty. ;OBJECT ;It is an object of the present invention to provide a bag for a toilet and/or a toilet and/or a 15 method of disposing of waste which will go at least some way towards meeting the foregoing requirements or which will at least provide the public with a useful choice. ;F267qCap 2000 CW/|q ;-2- ;DISCLOSURE OF THE INVENTION ;Accordingly in one aspect the invention consists in a toilet comprising a bag formed of water impervious material, and having side walls and a bottom part, an outlet associated with the bottom part, and a filter separating the bottom part from the outlet, the filter holding back solid waste but allowing liquid wastes to pass through the filter to the outlet to be discharged from the bag through the outlet in use. ;Preferably the bags are of sufficient strength to be reusable. ;Preferably the filter comprises a first layer of filter material positioned on a weight bearing member. ;Preferably the filter material comprises two layers, the first layer being formed of recycled paper with cratered perforations, and the second being formed of water permeable tissue. ;Preferably the weight bearing member is placed on a spacer member. ;Preferably the weight bearing member and the spacer member are corrugated. ;Preferably corrugations in the weight bearing member and the corrugations in the spacer member are positioned substantially at right angles. ;F267qCap 2000 CW/jq ;• • ■ * -3- In a further aspect the invention consists in a toilet comprising a container, a bag according to any one of the preceding paragraphs within the container, retaining means to retain the bag in use in an open condition m the container, a seat means providing entry to the bag when in the container, and an outlet from the container in a lower part thereof, so that in use liquids passing 5 from the outlet in the bag pass through the outlet from the container.

Preferably the bottom floor of the container is sloped towards the outlet Preferably the bottom floor of the container has radial corrugations about the outlet.

In a still further aspect the invention consists in a method of disposing of waste comprising the steps of providing a toilet according to any one of the preceding paragraphs, after some use of the toilet closing the bag, removing the bag from the toilet and delivering the bag to a collection centre Preferably the bag is emptied at the collection centre.

Preferably the bag is cleaned at the collection centre, and a new filter is installed Preferably the bag is distributed for re-use.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without F267qCap 2000 CW/|q departing from the scope of the invention as defined in the appended claims. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

BRIEF DESCRIPTION OF THE DRAWINGS One preferred form of the invention will now be described with reference to the accompanying drawings in which, Figure 1 is a side elevation of one preferred form of toilet according to the invention, Figure 2 is an enlargement of the circled part in Figure 1, Figure 3 is a cross-section through the filter placed in a bag within the container of Figure 1, Figure 4 is a cross-section as in Figure 3 but substantially at right angles to the construction in Figure 3, Figure 5 is a plan view of a drain base for use in a bag used in the container of Figure 1. Figure 6 is a cross-sectional view of the drain base of Figure 5, Figure 7 is a plan view of the top of a toilet formed in the container of Figure 1, Figure 8 is a side elevation of the top of Figure 7, Figure 9 is a side elevation of a container and top according to one preferred form of the invention, Figure 10 is an enlargement of the circle part in Figure 9, Figure 11 and Figure 12 are front elevations and plan views of a simplified construction according to the invention, Figures 13, 14 and 15 show a toilet construction according to one preferred form of the invention where no service facilities are provided, Figure 16 is a representation of an aerator for use in the invention, F267qCap 2000 CW/|q Figure 17 shows various additions that can be made to the basic invention, Figure 18 is a side elevation of a further alternative construction, Figure 19 is a plan view of the construction of Figure 18, Figure 20 shows a further alternative, and Figure 21 shows an alternative to the construction in Figure 20.

BEST MODE FOR CARRYING OUT THE INVENTION Referring to the drawings, the invention provides a bag 1 which has sides 2. A filter 3 is provided along with a convergent drain base 4 leading to an outlet 5. A cap 6 may be provided as a squeeze fit over the outlet 5 in circumstances where the outlet 5 may need to be closed such as for example during transportation after use. In other embodiments toilet tissue or some other such material could be used to close the outlet 5. The bag fits into a container 10 which will be described further hereinafter The bag must have sufficient strength to prevent rupturing particularly when lifted from the bin 10 and during any transportation It is also desirable that the inner surfaces of the bag at least have a low friction coating which could be provided for example a polyflurotetroethylene coating such as that sold by reference to the brand name TEFLON. The bag 1 has the function of containment of waste solids, transportation of the waste solids and incorporation of a filter and base 3 and 4. It is also desirable to provide a tie for example a polythene tie (not shown) so that the top of the bag can be closed. Other closure devices could be provided The containment bags could be multicoloured for example with identifying logos and are desirably recyclable F267qCap 2000 CW/iq • -6- i i At a recycling station the bags could be emptied and cleaned for example by steam cleaning and hosing down A new filter tie and cap could then be provided. Consumers of course could empty the contents of the bag into a composting device instead of using contracted collection Compost bins could be provided for those consumers. Even if emptied it is desirable that the 5 empty bag is collected, cleaned and recycled. It is desirable that the recycling and cleaning take place otherwise the filter and egress may clog up and in particular replacement of the filter may not occur at the desired times.

The container 10 has an outlet 11 and preferably a wall or ring 12 into which the outlet 5 from 10 the bag 1 to at least some extent extends.

A flared receptor, for example in the form of a shallow funnel can be installed into the floor conduit or inside the container This is preferable when compared to sloping the inside of the container or the floor and allows waste liquid to be correctly discharged even if the waste liquid outlet is not fully in alignment The inwardly facing walls 13 of the rim 12 preferably slope inwardly downwardly in use The container could be simply a steel (or other material) cylinder with brackets provided to fix 20 the cylinder to a floor or ground surface. A floor drain would then be provided for liquid overflows f267qCap 2000 CW/|q Referring now to Figure 3 and 4 the filter 3 is desirably provided as follows. Two filter layers may be provided for example a top filter layer 20 which may be formed of cratered or apertured perforated recycled paper and a second filter layer 21 formed, for example, of permeable tissue The filter layers 20 and 21 on a bottom layer 22 which is desirably provided with concentric 5 ridges 23 on the under side and a drain base 24 which is also desirably ribbed as shown in Figure 3 by the provision of ribs such as ribs 25. The ribs 25 and the ribs 23 desirably are substantially at right angles to each other so that the ribs 25 substantially radiate from a central point where the outlet 25 is positioned and the ribs 23 may be for example substantially concentric.

Alternatively, layers 20, 22 and 23 could be incorporated as one, and the layer 21 (the permeable tissue) placed on top The drain base 24 may be, for example, vacuum formed from a plastics material providing the 15 radial ribs such as 25 about a central aperture 26 from which extends the outlet 5.

The drain base 24 supports the weight of the filter on the apices 27 of the corrugations 25 and provides drain off from the filter from the valleys 28 formed between the corrugated peaks 25 and provides aeration under the filter. The valleys 28 preferably extend downwardly inwardly 20 so that with gravity and the capillary action of liquid is directed to the central outlet 5. This liquid then passes into a funnel 26 formed by the rim 12 previously described. A peripheral rim 29 of the convergent drain base 24 supports the corrugations and provides ballast alignment, elevates the outlet 5 and provides a sealing edge between the bag 1 and the base member 24.

F267qCap 2000 CW/|q 8 - A top is provided for the container for example top 30 which may be formed of a suitable material such as steel which we believe will hold the weight of the user. Other materials such as polypropylene may be possible The top has an upper surface 31 and a downwardly depending 5 peripheral skirt 32 which fits over the container 3 An aperture 32 leading to the interior of the bag 1 is provided with a typical toilet seat arrangement 33 preferably mounted to the remainder of the top through a hinge at 34 A ventilation port 34 may be provided and the lid may be hingedly connected through hinge 35 to the remainder of the container 3.

A seat cover 36 again hingedly affixed for example to the lid through hinge point 34 may also be provided in substantially the known manner.

Referring now to Figures 9 and 10. The container bin can be constructed of any suitable material such as stainless steel, ceramics or composites thereof but for ease of manufacture and 15 lower cost the preferred material may well be a material such as polypropylene or a lacquered or painted steel may be a better and cheaper alternative. Figure 10 shows in slightly modified form the funnel 26 provided to the outlet at 11 which is shown in this embodiment as a downwardly depending tube 40 with an end cap 41. The end cap 41 can be arranged to allow discharge there from the tube 40 for example by leaving a suitable gap or otherwise as desired. The bin 20 may be secured to a ground surface by suitable fixing devices indicated diagrammatically at 42 at Figure 9 T267qCap 2000 CW/|q Where electronics are provided or intended to be provided a suitable electronics junction box 43 is provided at a suitable position such as again indicated in Figure 9.

In the construction of Figure 11 the containment bag 1 is placed over a rim 50 which is moulded onto a square or otherwise shaped base 51. The base 51 is supported over an opening at 52 into which the bag 1 is positioned. A base substantially as described above is provided in the bottom of the bag 1 so that liquid waste can drop to the ground below the bag 1 for example into a pit but solid waste can again be retained Stainless steel would be the preferred construction material for the base 51 and rim 50.

Referring to Figures 13 to 15 these show a construction wherein the bin 63 is somewhat taller for example about 200mm taller than the previously described construction. Again a lid 64 is provided and a sediment trap 65 is provided in the base of the bin 63. A converging drain base 66 is provided substantially as above described and a waste outlet 67 for liquids is provided.

Before use newspaper or small twigs or leaves such as pine needles must be placed over the concave sediment trap In use the waste water runs away (because of the reverse incline of the corrugations), from the centre catchment plateau to the perimeter draining holes (not shown). The waste water continues down the drain base 66 and is channelled away by waste liquid outlet 67 When the bin is full the top is removed, the bin is then balanced on its edge and rolled for example to a compost location, inverted to remove the contents and returned to its original location The drain base and sediment trap are desirably press moulded polypropylene because of the rugged use that the bin will suffer. Occasionally the sediment trap and dram base will T267qCap 2000 CW/|q ( I need cleaning. The drain bar should then be removed from the underside of the bin by opening any fasteners or withdrawing any screws or bolts and allowing the sediment trap to fall through the bin when the bin is inverted. This construction has advantages over pothole toilets in that the same location can be maintained and central composting can be achieved. There is also an 5 advantage over chemical toilets in that no chemicals are required and there is no toxic disposal of wastes In campsite locations a padlock (for lid and bin) can be provided. Wheels and push handles are another addition that could be used.

Figure 16 shows a waste solid aerator 70 in the form of a rod which can be used to stir and 10 distribute the contents of the bag. The rod can be made of PVC for example and hygiene can be maintained, for example, by placing an empty toilet roll former over the aerator when used. The formers if left in the waste material also help to aerate the waste.

In the construction of Figure 17 a toilet lid flexible retractor 80 is provided which ventilates the containment bag, that is to say, substitutes for the perforated toilet lid. Thus from a mesh grill wall opening to the outside ventilation pipe or ventilator dehumidifier the flexible hose 80 attachment can be hinged to the toilet brackets to extend over the toilet aperture Also a ventilator port flexible retractable conduit 81 can be provided which utilises a port just 20 behind the toilet aperture for ventilating the containment bag. The toilet lid does not have to be perforated so from a mesh grill wall opening to the outside, ventilation pipe 81, or ventilator/dehumidifier the flexihose attachment can extend to the ventilator port.

F267qCap 2000 CW/|q By providing suitable contacts 82 and 83 electronics can be provided and, for example, a flashing LED could be provided to be visible when a set weight of the containment bag is reached An alarm to show that no bag is in position could be combined with this Ideally the power source for the alarm units should be independent such as solar powered and it would also 5 be desirable to mark a full level on the inside of the containment bag.

The no bag alarm 84 is activated, for example, by providing a beeping alarm by the weight of the user if there is no containment bag over the rim. The alarm unit can be displayed next to the ventilator unit or if there is a flush tank provided a visual reminder sticker is also uncovered at the front of the rim when the containment bags is removed.

Once filtered waste liquid is passed through the outlet of the container care should be taken with disposal of that waste. It could be taken to the stormwater sump overflow, a sewage seepage filter block, soil catchment and dispersal, a dehumidifier facility or a pump gravity filtration. In the first of these waste water passes through, for example, a PVC pipe to a sump installed outside the premises Excess rain from the roof overflows and the contents can be diluted into the stormwater system. Alternatively the sump could be enclosed with a large PVC pipe for evaporation If a sewage seepage filter block is provided the solid state filter can be installed in the sewer pipe at the boundary line or where the tributary ends. Waste water builds up in the length of the sewer pipe and slowly discharges through the seepage filter as cleaned water.

F267qCap 2000 CW/|q It would be essential in such a construction that the filter was only provided in a line where it could be guaranteed that only liquid waste would arrive.

For soil catchment and dispersal waste water is discharged into buried irrigated hoses 5 throughout a users property, for example, it can be used for example, to water plants.

In a dehumidification facility the dehumidifiers can work directly through the ventilation port into the container bag or when waste water passes out of the bin into a holding tank.

In the event of a systems failure the waste liquid overflows to any of the reticulation options.

In a pump gravity filtration system all waste water including the kitchen, laundry and bathroom waste is centralised into a sediment tank. The water upon reaching a certain level activates pump drawing it up into a split tower. Gravity and capillary action forces the water through 15 filtration into the lower chamber That water can be used as desired. This reticulation method is particular suitable in lower rain fall areas Referring now to Figure 18, a hand pump dispenser 90 is provided along with a toilet roll dispenser 91 A rare port 92 is provided to allow an air exchange unit to be provided and a flat 20 bottle 93 is provided in the base of the construction.

An excess tray 94 is also provided to catch any moisture that may fall whilst the bottle 93 is being replaced. The bottle 93 is translucent and is positioned so that it is inclined with the rear F267qCap 2000 CW/|q end 95 being generally upper most. Waste liquid falls into the catchment area 96 and is channelled forward into the catchment hole 97. There is an embossed "full" indicator if desired at 98 These may take the form of extruded loop portions somewhat in the nature of a handle which fill before the bottle is full. This creates an air gap to minimise splashing when the bottle 5 93 is removed This construction is suitable as a personal toilet in, for example, rooms, bedsitters or at a camp sites where they could be for hire. Thus the liquid wastes can be collected and discharged from time to time as well as solid wastes.

Referring now to the embodiment in Figure 20; the toilet construction is mounted on a platform 10 100 and may be provided with movement devices such as wheels 101 or other devices such as gliders, rollers or the like Handles 102 allow the construction to be pushed and a support 103 is provided for the air exchange unit 104 which may also provide a retractable power supply cord 105.

Footrests 106 may optionally be provided along with a suitable braking system, for example, of known type The construction of Figure 20 therefore is suitable for example, for hospitals and invalid care homes The bottles can be disposed of with the container bags or recycled as garden wastes. 20 The advantage of this type of construction is that no toilet facilities are required and no plumbing requirements yet the device still controls waste disposal. r267qCap 2000 CW/|q In the construction of Figure 21 the construction of Figure 2 is revised by providing a "push up -gravity down plug" 110 The plug can be made in two parts so that for example, a lower part 110 has a stem 112 which can be passed through the aperture at 5. The lower end of the plug provides a widened base 113 A widened head 114 is engageable onto the stem 112. The 5 construction is such that once the parts 112 and 114 are inter-connected the plug can move up and down but not fully through the aperture in part 5. In the construction the head 114 has a lower face 115 which normally stands clear of the aperture at 5 because of the engagement of the broadened base 10 with walls of the rim 12. When the containment bag is lifted however the plug is forced downwardly by the weight of the contents so that the face 115 seals about the aperture at 5 preventing or at least substantially limiting passage of any, in particular liquid wastes, out through the aperture at 5 There is also an added procedure of shaking the bag to remove any lingering discharges and then it can be placed (the disposable bag) in a larger transport bag for its discreet removal from the user's premises.

Thus it can be seen that a system is provided which is able to reduce dumping of sewage into the ocean and onto land where it seeps through to the water table. The present system has affects on warming of the ocean, contamination of the food chain and alternately the quality of people's lives. It may be that such systems could be combined, for example, with a sewage tax The system would also be able to be combined with existing local body organic contract collections.

The systems also allows toilet and kitchen organics to be separated at source and household rubbish content to be further reduced in land fills. A reduced sewage capacity would be required for new and existing sewage systems r267qCap 2000 CW/|q It is believed that users would adopt the dry organic toilets rather than flushing systems with suitable promotion. Systems such as this would reduce the cost of developing, maintaining and upgrading sewage systems, guard against failure of those systems and also reduce discharge onto 5 the land or into oceans Users may still choose the flush system regardless of the environmental benefits of the dry organic toilet But this becomes a convenience in the literal sense and should be charged accordingly.

The invention also provides a number of choices of type.

I believe that the system described herein has benefits but it would need to be introduced with promotion as it is a systems devolution process rather than a meteoric demand for change. Initial tnaling could be made in place such as remote holiday camp sites until the system is acceptable to a substantial part of the population T267qCap 2000 CW/|q

Claims (17)

CLAIMS:

1. A toilet comprising a bag formed of water impervious material, and having side walls and a bottom part, an outlet associated with the bottom part, and a filter separating the bottom part from the outlet, the filter holding back solid waste but allowing liquid wastes to pass through the filter to the outlet to be discharged from the bag through the outlet in use.

2. A toilet as claimed in claim 1 wherem the bag is of sufficient strength to be reusable. i

3. A toilet as claimed in either one of claims 1 and 2 wherein the filter comprises a first layer of filter material positioned on a weight bearing member.

4. A toilet as claimed in claim 3 wherein the filter material composes two layers, the first layer being formed of recycled paper with cratered perforations, and the second being formed of water permeable tissue.

5. A toilet as claimed in either claim 3 or claim 4 wherein the weight bearing member is placed on a spacer member.

6. A toilet as claimed in claim 5 wherein the weight bearing member is corrugated.

7. A toilet as claimed in either claim 5 or claim 6 wherein the spacer member is corrugated. INTELLECTUAL PROP! RTY » OFFICE OF r - 9 AUG 2001 ^EOPflVEE) F267qCap 2000 CW/jq 0 " ' ^ -17 - %£

8. A toilet as claimed in claim 7 wherein the corrugations in the weight bearing member and the corrugations in the spacer member are positioned substantially at right angles.

9. A toilet comprising a container, a bag according to any one of the preceding claims within 5 the container, retaining means to retain the bag in use in an open condition in the container, a seat means providing entry to the bag when m the container, and an outlet from the container in a lower part thereof, so that in use liquids passing from the outlet in the bag ^ pass through the outlet from the container.

10 10. A toilet as claimed in claim 9 wherein the bottom floor of the container is sloped towards the outlet.

11. A toilet as claimed in either one of claims 9 and 10 wherein the bottom floor of the container has radial corrugations about the outlet. 15

| 12. A toilet substantially as herein described with reference to the accompanying drawings.

13. A method of disposing of waste comprising the steps of providing a toilet according to any one of the preceding claims after some use of the toilet closing the bag, removing the bag 20 from the toilet and delivering the bag to a collection centre.

14. A method as claimed in claim 13 wherein the bag is emptied at the collection centre. intellectual property office of n.z. ~ 9 AUG ?001 it F"^ - F267qCap 2000 CW/jq J 11 u ^ " H' 2 3

15. A method as claimed in claim 14 wherein the bag is cleaned at the collection centre and a new filter is installed.

16. A method as claimed in either one of claims 13 to 15 wherein the bag is distributed for reuse.

17. A method as claimed in claim 14 and substantially as herein described with reference to the accompanying drawings. 1/V /vJ PIPERS KNOV\ ES Attorney for Lautofa Samuel IULI