WO2015028770A1

WO2015028770A1 - Method and apparatus for back-flow prevention

Info

Publication number: WO2015028770A1
Application number: PCT/GB2014/000329
Authority: WO
Inventors: Michael Haigh; David Broadbent
Original assignee: Michael Haigh; David Broadbent
Priority date: 2013-08-24
Filing date: 2014-08-26
Publication date: 2015-03-05
Also published as: GB2532656B; GB201603140D0; GB2532656A

Abstract

The invention relates to a method and apparatus for flood prevention, particularly floods caused by back flow of water through a water closet. The invention provides for provision of a sealant (1) which is flowable and expansible in wet or humid conditions, ie in water (2 ) in a wc bowl (3), the sealant being delivered to an outlet passageway (4) where the sealant (1) expands for obturating fluid flow, in this case water, back through the passageway (4) into and through the wc bowl to form a flood. The sealant (1) comprises a mixture of a clay-like sodium bentonite and sand. The sealant (1) is in a flexible container such as a nylon bag (5) which has through passageways to provide for contact of the bentonite with water in the wc bowl. Sodium bentonite swells to many times its dry size, for example 15-18 times its dry size on contact with water, forming a strong water-proof seal. The bag (5) is housed in a bag of dissolvable material such as polyvinyl alcohol (=PVA).

Description

METHOD AND APPARATUS FOR BACK-FLOW PREVENTION

The invention relates to a method and apparatus for flood prevention, and particularly for obturating flow of a fluid, particularly for flood prevention in lavatories.

The problem of flooding is an increasing one with the effect of climate change around the world. Domestic flooding is of particular concern, but commercial properties are under similar threat which insurance companies are struggling to underwrite. Accidental chemical or fuel spills are also a major concern to the environment. Road traffic accidents for example often result in spilled fluids which find their way into drains and contaminate the local water. Fire brigade call- outs to fires on industrial sites and even farms often result in similar problems with chemicals or effluent washed down into surface drains.

As regards property, there are various routes of entry for flood water into say a house, for example doors, air bricks, cat flaps and lavatories, all of which require specific protection. Flood surge coming up through a ground floor lavatory is particularly unpleasant and will, by itself , often render a property uninhabitable for a long period of time.

The difficulty in reliably preventing flood ingress through a lavatory is generally related to the variation in internal dimensions of lavatories, both new and already fitted in existing buildings. Creating a seal that would work effectively on more than one make or type of lavatory has therefore been practically impossible hitherto.

It is an object of the invention to seek to mitigate these disadvantages.

According to a first aspect of the invention there is provided a method for obturating flow of a fluid through a passageway, comprising the steps of providing a sealant which is flowable and expansible in wet or humid conditions, and delivering the sealant to a passageway containing fluid whereby it can expand for obturating fluid flow.

According to a second aspect of the invention there is provided apparatus for obturating flow of liquid, comprising a clay material sealant which is flowable and which is adapted to expand on contact with liquid. A method and apparatus embodying the invention are hereinafter described, by way of example, with reference to the accompanying drawings.

Fig.l shows schematically a vertical cross-section through a lavatory or wc bowl with apparatus embodying the invention in place in an outlet passageway for water to exit in normal conditions from the wc;

Fig.2 shows schematically a further embodiment of apparatus embodying the invention in place in an outlet passageway for water to exit in normal conditions from the wc;

Fig.3 shows schematically a vertical cross-section through a lavatory or wc bowl with a device embodying the invention in place at an outlet passageway for water to exit , in normal conditions, from the wc; and

Fig.4 shows to an enlarged scale a schematic side elevational view of a hand-held device embodying the invention.

Referring to Fig.l of the drawings, there is shown a sealant 1 which is flowable and expansible in wet or humid conditions, ie in water 2 in a wc bowl 3, the sealant being delivered to an outlet passageway 4 where the sealant 1 expands for obturating fluid flow, in this case water, back through the passageway 4 into and through the wc bowl to form a flood.

The sealant 1 in the embodiment comprises a mixture of a clay-like material, in the embodiment sodium bentonite, and sand. Sodium bentonite is a natural material which swells to many times its dry size, for example 15-18 times its dry size on contact with water, forming a strong water-proof seal.

The sand assists in enhancing flow of the sodium bentonite.

The sealant 1 in the form of the sodium bentonite and sand mixture is in the embodiment contained in a flexible container 5 which has through paths in its boundary wall. In the embodiment the container is in the form of a mesh or reticulated fabric, which may be of natural or artificial material ,for example nylon. The size of the through paths is large enough to allow passage of water 2 into the container and hence to contact the mixture therein, but small enough to prevent particles of sealant mixture leaking out of the container 5.

In use, a paste forming material such as a starch, in the embodiment modified potato starch powder 6, is added to the water 2 and the sealant is delivered into the water and up to mouth 7 of the outlet passageway 4. Water passes through the wall of the container 5 and contacts the sealant 1, the sodium bentonite constituent causing the sealant to swell and expand sufficiently completely to fill and block the mouth 7 of the outlet passageway 4. During this process the starch powder 6 forms a paste which adheres to the wall of the container 5 and wall of the passageway 4 to form a barrier to passage of water between the container 5 and wc 3.

An independent elongate member 8 as shown in Fig.l is used as a tamper to force the sealant in its container 5 into the mouth 7, see arrow "A" in Fig.l, there being a disc 9 at ,on or adjacent the distal end of the member 8 to spread the force being applied to the container 5 while it is being pushed into place in the mouth 7.

In another embodiment, Fig.2, the bentonite and sand mixture in container 5 is inside another container or bag 5a. The bag or container 5a in the embodiment encloses or substantially enclose the container 5, the container 5a being in the form of a PVA (polyvinyl alcohol) material which is biodegradable, environmentally friendly and non-toxic.

The PVA bag or container 5a acts as an additional sealing medium. As shown in Fig.2, the PVA bag or container 5a suitably encloses the container 5.The bag or container 5a may as shown be suitably shaped to enable it to be located accurately in the mouth 7 of the outlet passageway 4. Thus as shown the bag or container 5a may be tapered in a direction in use into the outlet passageway 4 , for example the bag or container 5 a may be of conical configuration.

The PVA dissolves completely in 30 seconds to one minute, so facilitating virtual instantaneous expansion of the bentonite sealant.

In use, upon immersion in water 2 in the wc, the bag 5a dissolves or melts allowing water to pass through the wall of the container 5 to contact the sealant 1 , the sodium bentonite constituent of which swells and expands sufficiently to completely fill and block the mouth 7 of the outlet passageway 4. During this process the dissolving PVA material of the bag or container 5a forms an adhesive gelatinous layer which adheres to the wall of the container 5 and smooth, usually porcelain, wall of the outlet passageway 4 to form an additional barrier to passage of water between the container 5 and wc 3.

The independent hand-held device 8 (Fig.l) may be used as before to tamp or to force the sealant in its container 5, 5a into the mouth 7, there being as before a convex device 9 at, on or adjacent the distal end of the member 8 to spread the force being applied to the container 5,5a while it is being pushed into place in the mouth 4.

Referring now to Figs. 3 and 4, in which like parts in Figs 1 and 2 are referred to by like reference numerals, there is shown a further embodiment 108 of device used to force the sealant in its container 5 or 5,5a into the mouth 7 of the outlet passageway 4. The device 108 carries a convex device 117 at, on or adjacent the distal end of the device 108 to spread the force being applied to the container 5, or 5,5a while it is being pushed into the mouth 7 of the outlet passageway 4.

The device 108 has an elongate member 109 normally urged to a rest position by biasing means in the form of a coil spring 1 lO.There is a shoulder 111 carried by the elongate member 109. A lever member 112 is pivotably mounted adjacent one end on a pivot pin 113 carried by a body 114 of the device 108, the one end of the lever member 112 being in the form of a nose which bears on the shoulder 11 l.The body 114 also has two spaced apart, substantially parallel arms 115 with aligned through holes 116 through which the elongate member 109 passes and which guide it during movement from the rest to a pressure exerting position and vice versa, as shown by arrow' X'. (Fig.4).

The elongate member 109 terminates at its distal end in the member 117 having a convex surface which serves to spread the load on the article, in the embodiment the container 5 or 5,5a and sealant 1.

The body 114 also carries a member in the form of an upwardly, as considered in use, open hook-like member 117a which in use engages under a cross member or strut 118 which is removably mounted in the wc bowl, in the embodiment under a rim 3a (Fig.l) of the bowl.

The device 108 has a fixed hand- grippable member 119 and a turned -over or bent free end 120 to prevent the member 109 from falling out of or otherwise exiting the body 114, should it be tilted. There is a stop 121 mounted under spring pressure to engage the hook-like member 117a positively under the strut 118.

In use the sealant 1 in the container 5 or 5,5 a is placed at the outlet of the wc bowl. It is urged into the outlet as it expands by offering up the device 108 to the sealant after mounting the strut 118 in place, engaging the hook-like member 117a under it and grasping the lever 112 and member 119, squeezing them together manually and so urging the member 109 downwardly as viewed in Fig.3 so as engage the container 5, or 5,5a via the member 117 and force the container 5 and the sealant 1 firmly into the outlet so as to obviate back-flow and hence flooding from the wc.

In a modification, not shown, the device 108 is replaced by an independent spring-loaded strut device such as a telescopic device which can be extended under hand-pressure at the proximal end to extend a part of the device such as an inner telescopic part bearing at its distal end a plate or the like for engaging and pressing the sealant in its container 5 or 5,5a into the outlet, similar to the member 8, 9 of Fig.l.

The container 5 and sealant 1 described with reference to the drawings are used to obdurate the passageway 4 against back-flow of water into any design or make of wc during a flood situation. When danger of a flood has passed, the now expanded sealant 1 and its container 5 are removed from the mouth 7 and discarded. The additional sealant material paste 6, 6a adhered to the wall of the wc 3 is simply flushed away when the wc is next flushed.

It will be understood that though preferred, the use of the sand referred to in the embodiments is optional. When used, it enhances the flow or "malleability" of the sodium bentonite. Stated in another way, the sand assists in the shaping of the sealant 1 to conform to the configuration of the mouth 7 of the outlet passageway 4 in order to provide in the embodiments a firm and positive seal against back flow of water into the wc and from there into a dwelling, for example.

It will be understood that the PV A material referred to in the embodiments is polyvinyl alcohol.

It will also be understood that sodium bentonite referred to in the embodiments expands when wet, absorbing several times its dry mass as described above to provide a self-sealing barrier to passage of water into the wc and from there into a dwelling ,for example, so as to mitigate or obviate unwanted flooding.

Claims

1. A method for obturating flow of a fluid through a passageway, comprising the steps of providing a sealant which is flowable and expansible in wet or humid conditions, and delivering the sealant to a passageway containing fluid whereby it can expand for obturating fluid flow.

2. A method according to Claim 1 , comprising the step of providing as sealant an

expansible clay material for obturating fluid flow.

3. A method according to Claim 2, the step of providing the clay material comprising providing sodium bentonite.

4. A method according to Claim 2 or Claim 3, comprising providing the clay material with a material for enhancing flow.

5. A method according to Claim 4, the step of providing the flow enhancing material comprising adding sand to the clay material.

6. A method according to any preceding Claim, comprising the step of providing the sealant within a flexible container permeable to water.

7. A method according to Claim 6, comprising providing the flexible container as a flexible bag.

8. A method according to Claim 7, comprising providing the bag as a mesh or lattice material.

9. A method according to Claim 8, comprising the step of providing externally of the sealant, a material adapted to provide an additional sealing material between the sealant and the passageway.

10. A method according to Claim 9, the additional sealing material being adapted to form a paste on contact with the liquid.

11. A method according to Claim 9, the step of providing the said material comprising providing a starch.

12. A method according to Claim 11, comprising providing a modified potato starch.

13. A method according to Claim 12, comprising providing a modified potato starch powder incorporating a fungicide.

14. A method according to Claim 9, the said material comprising a PVA material

between the sealant and passageway.

15. A method according to any preceding Claim, comprising the step of forcing the sealant into at least a mouth of the passageway whereby to position it firmly thereat.

16. Apparatus for obturating flow of liquid, comprising a clay material sealant which is capable of expanding on contact with liquid.

17. Apparatus according to Claim 16, which is also flowable.

18. Apparatus according to Claim 17, comprising a sand mixed with the clay material sealant whereby to enhance flow thereof.

19. Apparatus according to any of Claims 16 to 18, the clay sealant comprising sodium bentonite.

20. Apparatus according to any of Claims 16 to 19, comprising a flexible container for the sealant which is permeable to liquid.

21. Apparatus according to Claim 20, the container comprising a mesh or lattice.

22. Apparatus according to any of Claims 16 to 21, comprising a further flexible container housing the first-mentioned container.

23. Apparatus according to Claim 22, the further flexible container comprising a polyvinyl alcohol material.

24. Apparatus according to any of Claims 16 to 23, comprising means to force the sealant into a mouth of the passageway.

25. Apparatus according to Claim 24, the said means comprising an elongate push member.

26. Apparatus according to Claim 25, the elongate push member being telescopic.

27. Apparatus according to Claim 25, the elongate push member comprising part of a hand- grippable lever operated device.

28. A water closet whenever back flow of liquid through an outlet thereof is obviated using a method according to any one of Claims 1 to 15 or using apparatus according to any one of Claims 16 to 27.