GB2324330A

GB2324330A - Apparatus for recycling waste water

Info

Publication number: GB2324330A
Application number: GB9707843A
Authority: GB
Inventors: Edward John Cowell; Philip Anthony Cowell
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-04-18
Filing date: 1997-04-18
Publication date: 1998-10-21
Also published as: GB9707843D0

Abstract

Apparatus for use in recycling waste water within a property comprises a pump unit comprising a self-priming pump (10), a filter unit (13), and means for conducting waste water from a primary-use facility such as a hand basin, a shower stall or a bath, to the pump via the filter unit, a header tank (15) having an overflow outlet (16) leading to a drain and means for conducting water from the pump to the header tank, and means for conducting water from the header tank to a second-use facility such as a water closet.

Description

APPARATUS FOR USE IN RECYCLING WATER This invention relates to apparatus for use in the recycling of water.

It is widely recognised that mains water of potable quality is an expensive commodity, and that its use in circumstances where it is not necessary represents a considerable waste of a valuable resource: it can also lead to severe inconvenience in times of water shortage.

It is an object of this invention to provide means which enables considerable savings to be made in the use of mains water.

According to the invention there is provided apparatus for use in recycling water which comprises a pump unit comprising a self-priming pump, a filter unit and means for conducting waste water from a primary-use facility to the pump via the filter unit, a header tank having an overflow outlet leading to a drain and means for conducting water from the pump to the header tank, and means for conducting water from the header tank to a second-use facility.

The second-use facility of the invention may take various forms, and it may be any facility where the use of clean, potable water is not mandatory, whether for reasons of health, hygiene or aesthetics. It may for example take the form of a garden or greenhouse watering system. However, it is presently envisaged that the greatest potential for saving water by employing the present invention is in embodiments where the second-use facility is a water closet, and the invention will be further described with that end use particularly in view.

., . .^ .

The apparatus of the invention will suitably be constructed so as to be adapted for use in the intended environment.

It may be used in domestic situations, in public conveniences, and in shops, offices, factories or elsewhere.

It is presently envisaged that the primary-use facility will be constituted by one or more of the following: a hand basin, a shower stall, a bath, though other sources of used water may be connected to the apparatus, for example washing machines, and the condenser units of domestic or commercial tumble dryers for clothes.

In use of the apparatus, used wash-water or other water from the primary-use facility will drain through the filter to prime the pump and will then be pumped to the header tank whence it may flow to charge the cistern of a water closet.

Thus the water closet may be flushed with water which has already been used in the establishment concerned with a consequent saving in the use of fresh water.

This is not to say that only used water will be used in the second-use facility. The extent to which non-fresh water will be used in the second-use facility will depend on the relative consumption of water as between the primary-use and second-use facilities. For this reason and to ensure that a cistern of a second-use facility is kept topped-up, it is preferred that the header tank of the apparatus be connected to a water supply via a demand valve. Such a demand valve may be constituted by a conventional ball valve arranged to ensure that the level of water in the header tank always remains above the level of the outlet to the second-use facility. Such water supply inlet may be arranged above the level of the header tank overflow outlet so as to avoid any risk of contamination of a mains supply.

For use in domestic situations, it is believed that a suitable capacity of the header tank for use in private homes will be about 100 to 150 litres. Typically, a wc cistern has a nominal capacity of about 10 litres, so this will allow (depending on the setting of the header tank's demand valve if present) say 8 to 12 flushes of the wc between occasions when the tank is fully charged, without the requirement for any topping up from a mains supply.

The tank will be periodically charged by waste from various possible sources. A bath may be filled with as much as 200 litres or even more, a personal shower may easily consume 50 litres, a wash basin typically has a capacity of 5 to 10 litres, and leaving a tap running whilst brushing one's teeth may result in the consumption of as much as 5 litres.

We do not promise that all waste water will be recycled, for example to a wc cistern, or that a second-use facility such as a wc cistern will only use recycled water.

Nevertheless, such a second-use facility will use recycled water when that is available, and waste water will be fed to what amounts to a buffer for local re-use.

It is no disadvantage that the header tank may on occasion be charged to overflowing by the pump. Indeed, this may well be advantageous for the following reasons. It is envisaged that much of the water to be re-used will have previously been used for personal washing. That water may therefore contain dirt, hair, whether body or head hair, or shaved hair, and it will usually contain skin flakes, skin oils and the reaction products of dirt, skin oils and soaps or detergents used for washing. Depending on the hardness or otherwise of the water, there may also be present scum due to the reaction with the washing agent of salts which are dissolved in a mains water supply . Such untreated waste water is passed to the pump via the filter where some of the suspended material will be removed. But it is anticipated that some solids may be present in the filtered water in the form of a floating scum. If the header tank is periodically filled to overflowing, surface water in the header tank will pass into the overflow and to a drain carrying with it a high proportion of any scum floating in the header tank with the result that there is a sort of self-cleaning effect with that tank. This may be promoted by dissolution of any scum in water which is loaded with detergent, for example such as are used in many commercially available brands of shampoo, shower gel or bubble bath preparation.

The size of the mesh of the filter used is of some importance for the best results. It is desirable to remove as high a proportion of solids as possible, thus implying a fine mesh, while at the same time allowing some such material to pass in order that the filter should not become clogged too quickly.

In the most preferred embodiments of the invention, a water treatment material is provided. Such material may be in the form of a block of any convenient shape. It is preferably located within the filter, and most preferably at a location at which it will be immersed in water during draining of a primary-use facility, while at other times it is clear of water. This will prevent too rapid dissolution of the treatment material while allowing treatment of water being drained. Such treatment material will suitably have a bacteriostatic or bacteriocidal effect on the treated water, for example due to the presence of chlorine ions which will also have a beneficial effect in breaking down any scum present. Such treatment material may also incorporate a dye, for example a blue dye, which will mask any turbidity of the treated water and have a useful cosmetic effect on the appearance of the treated water as well as providing a readily visible indication that the water is not of potable quality. As an alternative, or in addition, parts of the system which contain recycled water may be colour-coded or otherwise marked to indicate that the water they contain is not drinkable.

Such treatment material may suitably be fitted into a pocket provided for the purpose in the filter element. In such cases, in order that it may be replaced, and also in order that the filter may be cleaned periodically, it is desirable that the filter be located behind a removable cover. It is also desirable that such cover be transparent, so that the state of the filter may be checked periodically with the minimum of inconvenience.

The pump should be located at a low level where it may be fed by gravity with waste water from all the primary-use facilities to which it is connected: likewise, the header tank should be located at a level above all the second-use facilities which are to be supplied with the recycled water: the pump must plainly have sufficient power to lift used water to the header tank, but it should not be too powerful.

The typical requirement is thus about 5 metres water head for each storey of the building which the apparatus of the invention is to service. This requirement may be accommodated by providing different pump units for different types of building, or use may be made of a single pump whose (electric) drive motor has a plurality of different windings which are selectively switchable in order to vary its power.

The pump and filter are preferably housed in a common unit, and immediate connections to that unit may be by flexible conduits. It is desirable that valves be provided in the conduits leading to such a pump/filter unit so that such unit may be isolated for servicing or replacement.

The system of the invention may be installed in existing housing at low cost because much pre-laid pipework can be utilised, and it can be incorporated into new housing for little more than the cost of a pump and filter unit.

A preferred embodiment of the invention will now be described with reference to the accompanying diagrammatic drawing which illustrates an embodiment of the invention as it might be installed in a two storey building.

In the drawing, a building has a ground floor with a floor 1 and ceiling 2 and a first floor with a floor 3 and ceiling 4 above which is located a loft.

Lavatories having wc cisterns respectively 51 and 52 are located on the ground and first floors, and a wash basin 62 and bath 72 are also shown on the first floor.

The wash basin 62 and bath 72 being primary-use facilities are fed with water in the conventional way, but they are arranged to drain via pipework 8 to a sump 9 of a pump 10 arranged to be driven by an electric motor 12. The sump 9 contains a filter 13. The pump 10 is self-priming and on draining of used wash-water into the sump 9 it will arranged automatically to switch on in order to pump the used and filtered water via pipework 14 to a header tank 15 in the loft. the ehader tank 15 is provided with an overflow pipe 16 leading to a soil pipe 20 leading to a mains drain or cess tank. The header tank also has an outlet 17 connected to wc cisterns 52 and 51 as shown. The header tank 15 also contains a ball valve 18 controlling a mains water inlet 19 arranged to allow fresh mains water to enter the header tank 15 when the water level in that tank drops below the level of the outlet pipework 17.

The sump 9, pump 10, and motor 12 are suitably all parts of a common unitary construction, and they may all be contained within a cabinet 13 mounted below the level of the ground floor 1. Suitable pump units are commercially available for the circulation of water in domestic swimming pools.

Valves 7 are provided in the pipework 8, 14 in order to allow isolation of the cabinet 11 and its contents so that the pump unit may be taken out for replacement or servicing.

The sump 9 preferably has a transparent cover to allow inspection of the filter within the sump. The upper part of the filter is preferably formed with a pocket for the retention of a block of water treatment material which is thereby held above the level of any residual water within the sump which is insufficient to cause the pump to start.

The overflow outlet 16 of the header tank 15 should be of diameter the same as or greater than the inlet pipework 8, and they may suitably be of a standard diameter of 1M inches or about 40mm. The pipework 17 feeding the wc cisterns may be of a nominal M inch or 15mm diameter.

It will be appreciated that any other primary-use facility such as additional wash basins, shower stalls, washing machines and/or tumble dryers may be plumbed into the system to feed into the sump 9 so that water used thereby may be filtered for re-use.

Claims

1 Apparatus for use in recycling water within a property which apparatus comprises a pump unit comprising a selfpriming pump, a filter unit and means for conducting waste water from a primary-use facility to the pump via the filter unit, a header tank having an overflow outlet leading to a drain and means for conducting water from the pump to the header tank, and means for conducting water from the header tank to a second-use facility.

2 Apparatus according to claim 1, wherein the second-use facility is a water closet.

3 Apparatus according to claim 1, wherein the primary-use facility is constituted by one or more of the following: a hand basin, a shower stall and a bath.

4 Apparatus according to any preceding claim, wherein the header tank of the apparatus is connected to a water supply via a demand valve arranged to ensure that the level of water in the header tank always remains above the level of the outlet to the second-use facility.

5 Apparatus according to claim 4, wherein the water supply inlet is arranged above the level of the header tank overflow outlet so as to avoid any risk of contamination of a mains supply.

6 Apparatus according to any preceding claim, wherein a water treatment material is provided.

7 Apparatus according to claim 6, wherein the water treatment material is in the form of a block located within the filter.

8 Apparatus according to claim 7, wherein the block of water treatment material is sited at a location at which it will be immersed in water during draining of a primary-use facility, while at other times it is clear of water.

9 Apparatus according to any of claims 6 to 8, wherein the water treatment material has a bacteriostatic or bacteriocidal effect on the treated water and also incorporates a dye.

10 Apparatus according to any preceding claim, wherein the filter be located behind a removable cover.

11 Apparatus according to claim 10, wherein such cover is transparent.

12 Apparatus according to any preceding claim, wherein the pump and filter are housed in a common unit.