WO2000045690A1 - Disposable dry toilet - Google Patents

Abstract

The invention comprises a toilet formed of water impervious material, having side walls and a bottom part. An outlet (5) is associated with the bottom part, and a filter is provided separting the bottom part from the outlet (5). The filter holds back solid waste but allows liquid wastes to pass through the filter to the outlet (5) to be discharged from the bag (1) through the outlet (5) in use. Generally the toilet includes a bag (1) formed of flexible water impervious material which is held in a rigid container (10).

Description

DISPOSABLE 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.

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

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

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.

6 DISCLOSURE OF THE INVENTION

Accordingly in one aspect the invention consists in a toilet being 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 toilet comprises a bag formed of flexible water impervious material.

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.

T ule 26 Preferably corrugations in the weight bearing member and the corrugations in the spacer

member are positioned substantially at right angles.

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 in 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

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.

SUBSTITUE SHEET (Rule 26) 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

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,

SUBSTITUE SHEET (Rule 26) Figure 1 1 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,

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

ule 26 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.

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

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 1 1 and preferably a wall or ring 12 into which the outlet 5 from

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.

SUBSTITUE SHEET (Rule 26) 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

the cylinder to a floor or ground surface. A floor drain would then be provided for liquid

overflows.

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

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

radial ribs such as 25 about a central aperture 26 from which extends the outlet 5.

SUBSTITUE SHEET Rule 26 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

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.

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

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 lower cost the preferred material may well be a material such as polypropylene or a lacquered or

STITUE ET Rule 26 painted steel may be a better and cheaper alternative. Figure 10 shows in slightly modified form

the funnel 26 provided to the outlet at 1 1 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

may be secured to a ground surface by suitable fixing devices indicated diagrammatically at 42

at Figure 9.

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 1 1 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.

SUBSTITUE SHEET (Rule 26) 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 drain base will

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

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

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

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.

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

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.

SUBSTITUE SHEET (Rule 26 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.

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

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.

SUBSTITUE SHEET (Rule 26) 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

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 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

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

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.

SUBSTITUE SHEET Rule 26 Referring now to the embodiment in Figure 20: the toilet construction is mounted on a platform

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.

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.

In the construction of Figure 21 the construction of Figure 2 is revised by providing a "push up -

gravity down plug^" 1 10. The plug can be made in two parts so that for example, a lower part 1 10 has a stem 1 12 which can be passed through the aperture at 5. The lower end of the plug

provides a widened base 1 13. A widened head 1 14 is engageable onto the stem 112. The

construction is such that once the parts 1 12 and 1 14 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 1 15 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 1 15 seals about the

SUBSTITUE SHEET (Rule 26) 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

wanning 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.

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

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.

SUBSTITUE SHEET (Rule 26) 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 trialing could be made in place such as remote holiday camp sites until the system is

acceptable to a substantial part of the population.

SUBSTITUE SHEET Rule 26)

Claims

CLAIMS:

1 . A toilet 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 wherein the toilet includes a bag formed of flexible water

impervious material.

3. A toilet as claimed in claim 2 wherein the bags are of sufficient strength to be reusable.

4. A toilet as claimed in either one of claims 2 and 3 wherein the filter comprises a first layer

of filter material positioned on a weight bearing member.

5. A toilet as claimed in claim 4 wherein 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.

6. A toilet as claimed in either claim 4 or claim 5 wherein the weight bearing member is

placed on a spacer member.

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

SUBSTITUE SHEET (Rule 26)

8. A toilet as claimed in either claim 6 or claim 7 wherein the spacer member is corrugated.

9. A toilet as claimed in claim 8 wherein the corrugations in the weight bearing member and

5 the corrugations in the spacer member are positioned substantially at right angles.

10. A toilet comprising a container, a bag according to any one of claims 2 to 9 within 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 in the container, and an outlet from the

[ 0 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.

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

the outlet.

15

12. A toilet as claimed in either one of claims 10 and 1 1 wherein the bottom floor of the

container has radial corrugations about the outlet.

1 3. A toilet substantially as herein described with reference to the accompanying drawings.

0

SUBSTITUE SHEET (Rule 26)

14. A method of disposing of waste comprising the steps of providing a toilet according to any^¬

one of claims 2 to 13 after some use of the toilet closing the bag, removing the bag from the

toilet and delivering the bag to a collection centre.

15. A method as claimed in claim 14 wherein the bag is emptied at the collection centre.

16. A method as claimed in claim 15 wherein the bag is cleaned at the collection centre and a

new filter is installed.

17. A method as claimed in either one of claims 14 to 16 wherein the bag is distributed for re¬

use.

18. A method as claimed in claim 14 and substantially as herein described with reference to the accompanying drawings.

SUBSTITUE SHEET (Rule 26)