GB2483917A

GB2483917A - Liquid drainage receptacle comprising level sensors and pump means

Info

Publication number: GB2483917A
Application number: GB1016142.0A
Authority: GB
Inventors: Mark Bushdyhan
Original assignee: FABRICON PREC Ltd
Current assignee: FABRICON PREC Ltd
Priority date: 2010-09-24
Filing date: 2010-09-24
Publication date: 2012-03-28
Anticipated expiration: 2030-09-24
Also published as: GB2483917B; GB201016142D0

Abstract

The invention relates to a liquid drainage receptacle 11 e.g. a trap for a shower tray for use with a drainage pump (not shown) comprising a receptacle body having a liquid inlet 13 and a liquid outlet 14, and a sensing means 20. The sensing means is associated with the receptacle body and senses the liquid level and activates the drainage pump when a liquid level threshold is reached. The sensor deactivates the drainage pump when the liquid level drops below the threshold liquid level. The sensing means may comprise liquid conductive sensors 21, 22 & 23. The system may also reduce the pumping noise and energy consumption required. Later embodiments also disclose a liquid drainage system and a method comprising said liquid drainage receptacle and drainage pump.

Description

Liquid Drainage Receptacle The present invention relates to a liquid drainage receptacle, especially for use with a drainage pump, to a drainage system comprising a liquid drainage receptacle and a drainage pump, and to a method of controlling the pumping action of a drainage pump.

In the installation of a wet room or other showering facility in a home or public building, gravity drainage of the waste water from an associated "trap" (or other liquid drainage receptacle), may not always be an option, i.e. drainage of the waste water from the liquid drainage receptacle under the influence of gravity only may not be possible. This may be for a number of reasons, such as, the inability to, or the undesirability of, creating a suitably large void in the floor below the wet room or other showering facility to accommodate a gravity-drainage trap, which, because of its function, must be of a certain minimum depth. The inability andfor undesirability for creation of such a suitably large void is a particular problem in apartment blocks and other multi-storey * buildings.

* ***** * * In such circumstances, pumped drainage is an/the alternative option available, i:e. the ** s.*S * provision of a drainage pump to evacuate the waste water from a suitably small trap is:> 20 (i.e. having a much reduced depth as compared to a gravity-drainage trap), which does ":4 not require the creation of a large void in the floor below the wet room or shower facility (although a small, minimally-invasive void may sometimes be required). Typically the drainage pumps used are of the diaphragm-type, which usually means that both waste water and air is evacuated from the trap, and which in turn often leads to a most undesirable "gulping" noise from the trap during its evacuation.

A number of solutions have been proposed to reduce the "gulping" noise that emanates from a pumped-drainage trap during waste water evacuation, for example by provision of a two-speed drainage pump having a high-speed selling (for high-volume evacuation) and a low-speed selling (for low-volume evacuation).

Another solution aims to automatically adjust the pump speed in relation to the flow rate of the waste water itself. A number of variants exist for achieving this aim, including (i) matching the flow rate of a shower unit providing the water via a dedicated flow switch that has to be installed into the plumbing pipe-work before the shower unit and the shower head delivering the water, (ii) matching the flow rate of the drainage pump to a purpose-emitted signal from a certain type of shower unit, and, (iii) matching the flow rate of the drainage pump to a shower unit by directly electrically connecting the shower unit to the electrical circuitry of the pump.

Each of these known solutions suffers from one or more problems however, which the S.....

* present inventor has sought to overcome. The problems include: the requirement for * *. St. * installation of one or more flow switches and/or flow sensors directly into the plumbing *..: pipe-work, the requirement for specifically commissioning a drainage pump/shower unit *t Ste.

* combination to enable matching of the pump rate with the water flow rate, and, the f' 20 need for a purpose-designed shower unit, all of which add cost, complexity and/or time *ttttS.

* . to the installation of a wet room or other showenng facility.

Furthermore, the drainage pumps used often have on-off cycles that are of fixed length, and which include on-off countdown periods within their cycles, meaning that such pumps are not able to respond or react quickly enough to the presence or absence of waste water in a trap. As a result, a pumped-drainage trap may exhibit an initial drainage lag (leading to an initial build-up of waste water before the drainage pump is activated) and may thereafter continue to be pumped even when all of the waste water has already been evacuated. Such unnecessary operation of the drainage pump is undoubtedly energy inefficient, and thus poses another problem that the present inventor has sought to overcome.

It would therefore be desirable to provide an improved liquid drainage receptacle (e.g. a trap), especially for use with a drainage pump, to provide an improved drainage system comprising such a liquid drainage receptacle and drainage pump, and to provide a method of controlling the pumping action of a drainage pump, all of which do not suffer from the problems observed with known prior art solutions.

Accordingly, the present invention provides in a first aspect a liquid drainage receptacle, for use with a drainage pump, comprising: a receptacle body having a liquid inlet and a liquid outlet, and sensing means associated with the receptacle body for sensing the liquid level in the *.* 0 * receptacle body and for activating the drainage pump when a threshold liquid level is * **. ** * reached and subsequently deactivating, preferably immediately deactivating, the *:*. drainage pump when the liquid level drops below the threshold liquid level.

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A liquid drainage receptacle according to the invention solves many of the problems encountered with prior art drainage solutions, including removal of the need to have one or more flow switches and/or flow sensors installed (possibly as a retro-fit option) directly into the plumbing pipe-work, removal of the need to have the drainage pump/shower unit combination specifically commissioned by a suitably skilled person to enable matching of the pump rate with the water flow rate, and, removal of the need to purchase a purpose-designed shower unit. Thus use of a liquid drainage receptacle according to the invention can reduce the cost, complexity and/or time taken to install a wet room or other showering facility.

Furthermore, use of a liquid drainage receptacle according to the invention with a drainage pump provides an energy efficient method of drainage, with which neither an initial drainage lag nor unnecessary post-evacuation pumping of the receptacle occur.

The drainage pump for use with the liquid drainage receptacle of the invention may be a diaphragm-type pump, however other types of pump such as a peristaltic pump, an impeller pump, or the like, may alternatively be used.

Preferably, the liquid outlet is in the form of an aperture in the receptacle body which opens into an upwardly-bending pipe section. Further preferably the upwardly-bending pipe section extends into a horizontally-bending pipe section. Together these two bending pipe sections may be described as forming a sigmoid" shape, or a swan's * neck"-type elbow pipe section. In addition to changing orientation, the cross-sectional * area of the pipe section(s) may change, preferably in a gradual manner from a wider cross-sectional area to a narrower cross-sectional area, so as to funnel the waste liquid S.....

* away from the receptacle body. When installed beneath a wet room or the floor of a .: 20 showering facility, the pipe section(s) may be connected to conventional drainage pipe 0*0060 * . work in a usual manner.

Advantageously, the sensing means may comprise a first liquid-level sensor for detecting the presence of liquid in the receptacle and a second liquid-level sensor for detecting excess liquid in the receptacle for drainage. Typically both the first and second liquid-level sensors may be located on a printed circuit board. A suitable location may be provided for the printed circuit board (or the like) on the receptacle body, and a suitable water-resistant adhesive may be used to temporarily or permanently adhere the printed circuit board (or the like) to the receptacle body and/or to provide a protective, water-tight seal over the printed circuit board (or the like).

Examples of suitable water-resistant adhesives include potting compounds, which may be thermosetting plastics, such as a polyurethane potting compound, a silicone potting compound, an epoxy resin potting compound, or the like.

Further preferably the second liquid-level sensor may be separated from the first liquid-level sensor by a pre-determined distance. Said distance thus contributes to the definition of a volume of liquid in the receptacle body and thereby delimits a threshold liquid level against which the sensing means will activate and deactivate the drainage pump. Preferably, activation of the drainage pump may be facilitated by the conductive property of the liquid (e.g. water) when in contact with both the first and second liquid-level sensors, thereby enabling completion of an electrical circuit detectable by, e.g. the printed circuit board. Correspondingly, deactivation of the drainage pump may be

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* facilitated when said electrical circuit is broken, as the liquid level drops below the * 0**IS * threshold liquid level. 0S S * S. * 55

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*5 St St * Preferably the first liquid-level sensor may be located adjacent to the liquid outlet, so as i.:' 20 to assist its function of detecting the presence of liquid in the receptacle. The second liquid-level sensor is therefore preferably remotely located from the liquid outlet for detecting a threshold liquid level, i.e. excess liquid in the receptacle for drainage.

Further advantageously the sensing means may comprise a third liquid-level sensor for alternatively detecting excess liquid in the receptacle for drainage. Thus it may be possible to switch between the second liquid-level sensor (detecting a threshold liquid level) and the third liquid-level sensor (detecting an alternatively higher or lower threshold liquid level) by incorporating appropriate circuitry into the sensing means.

Each of the first, second and third liquid-level sensors may be liquid-conductive sensors, i.e. sensors that react to the presence of a conductive liquid, e.g. water (which typically has a conductivity in the range of from 0.0005 to 0.05 siemens per metre (Sm 1)) Advantageously, the sensing means may further comprise an additional sensor in the form of a temperature sensor, which may be used as a back-up sensor to ensure activation of the drainage pump regardless of whether the liquid to be drained is conductive or non-conductive. Such a temperature sensor may be a positive temperature coefficient (PTC) sensor, which experiences an increase in electrical resistance when its temperature is raised (e.g. on contact with a liquid) and conversely an increase in electrical conductivity when its temperature is dropped (e.g. on contact

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* with a liquid).

* 5S505 * * The receptacle body may be provided with a lid in which the liquid inlet is provided.

*5** *J * Such a lid may be temporarily fixed (e.g. screwed or bolted) to the receptacle body or it I:'> 20 may be permanently fixed (e.g. ultrasonically bonded, welded, etc. as appropriate to the material from which both the receptacle body and lid are made).

Beneficially, the liquid inlet may be in the form of a threaded aperture in the lid into which a fixing means, for affixing the receptacle to an appropriate under-surface of a wet room or shower facility, is screwable, usually by means of a complementary thread.

Both the receptacle body (including any liquid outlet pipe sections) and any associated lid may be made from a plastics material, preferably a mouldable plastics material, such as high density polyethylene (HDPE), polypropylene (PP), acrylonitrile butadiene styrene (ABS), polyphenylene oxide (P0), and the like.

According to a second aspect of the present invention there is provided a drainage system comprising a liquid drainage receptacle as hereinbefore described and a drainage pump, wherein, in use, liquid enters the receptacle body via the liquid inlet, the liquid level rises until a threshold liquid level is reached, the sensing means senses that the threshold liquid level has been reached and subsequently activates the drainage pump to pump liquid from the receptacle body via the liquid outlet until the liquid level drops below, preferably just below, the threshold liquid level, upon which the sensing means deactivates the drainage pump, such that the liquid outlet remains submerged.

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*S,* S. * Of course, the sequence of events described above will typically form a single cycle of * *** St * a continuous drainage regime that is followed as liquid continues to enter the receptacle body, until such time as the flow of liquid into the receptacle is stopped, and *t as St * the liquid level conclusively drops below the threshold liquid level (yet the liquid outlet remains submerged).

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Use of a liquid drainage receptacle according to the invention in this manner solves many of the problems encountered with prior art drainage solutions, including removal of the need to have one or more flow switches and/or flow sensors installed (possibly as a retro-fit option) directly into the plumbing pipe-work, removal of the need to have the drainage pump/shower unit combination specifically commissioned by a suitably skilled person to enable matching of the pump rate with the water flow rate, and, removal of the need to purchase a purpose-designed shower unit. Thus use of a liquid drainage receptacle according to the invention in this manner can reduce the cost, complexity and/or time taken to install a wet room or other showering facility.

It is therefore within the scope of the present invention to use a liquid drainage receptacle as hereinbefore described with a drainage pump, and/or a system comprising the same, to reduce the noise that may otherwise be associated with the pumping action of the pump.

Furthermore, use of a liquid drainage receptacle according to the invention in this manner with a drainage pump provides an energy efficient method of drainage, with which neither an initial drainage tag nor unnecessary post-evacuation pumping of the receptacle occur.

Moreover, it is within the scope of the present invention to use a liquid drainage

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*5S5 55 * * receptacle as hereinbefore described with a drainage pump, and/or system comprising S.....

* the same, to reduce the overall energy consumption of the pump from a level that would otherwise be observed when the pump is used with a non-inventive liquid drainage receptacle. Thus the invention provides an environmentally-friendly solution as compared to known drainage systems.

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***StS * p According to a third aspect of the present invention there is provided a method for controlling the pumping action of a drainage pump so as to reduce the energy consumed by the pump and/or to reduce the noise associated with the pumping action comprising: -providing a drainage pump; -providing a liquid drainage receptacle comprising a receptacle body having a liquid inlet and a liquid outlet, and sensing means associated with the receptacle body for sensing the liquid level in the receptacle body and for activating the drainage pump when a threshold liquid level is reached and subsequently deactivating the drainage pump when the liquid level drops below the threshold liquid level; and -connecting the drainage receptacle to the drainage pump.

Typically, the drainage receptacle may be physically connectable to the drainage pump, via the liquid outlet, for drainage of excess liquid in the receptacle. Furthermore, the drainage receptacle may be electrically connectable to the drainage pump, via the sensing means, to enable activation and deactivation of the pump.

For a better understanding, the present invention will now be more particularly described, by way of non-limiting example only, with reference to and as shown in the accompany schematic drawings (not to scale) in which: Si....

* Figure 1 is a perspective view of a liquid drainage receptacle according to the *io*is * * invention Figure 2 is a plan view of the liquid drainage receptacle shown in Figure 1; * 20 Figure 3 is an end elevation view of the liquid drainage receptacle shown in Figures 1 * *0 and2

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* St Figure 4 is a side elevation view of the liquid drainage receptacle shown in Figures 1, 2 and 3; Figure 5 is a cross sectional view taken along line A-A of Figure 4, and Figure 6 is a perspective view of a typical drainage system according to the invention.

In the figures, a liquid drainage receptacle 10 comprises a receptacle body 11 fitted with a lid 12, and having a liquid inlet 13 and a liquid outlet 14.

Receptacle body 11 is in the form of a hollow cylinder that is closed at one end, and has lid 12 fitted to the other end, for receipt of waste liquid, for example waste water, for drainage. Lid 12 may be either temporarily or permanently filled to receptacle body 11.

Liquid inlet 13 is provided in lid 12 in the form of a threaded aperture 15, into which a fixing means (not shown) is screwable (by means of a complementary thread).

Liquid outlet 14 is in the form of an aperture 16 in receptacle body 11 which opens into upwardly-bending pipe section 17. Said upwardly-bending pipe section 17 extends into a horizontally-bending pipe section 18, which is connectable to conventional plumbing pipe-work (not shown) in a usual manner via aperture 19. Together, upwardly-bending pipe section 17 and horizontally-bending pipe section 18 may be described as being

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* "sigmoid" in shape, or as forming a "swan's neck" form of elbow pipe joint. The cross-* **.*.

* S sectional area of the pipe sections 17,18 change in a gradual manner from a wider cross-sectional area in the region of aperture 16 to a narrower cross-sectional area in

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* * 20 the region of aperture 19, so as to funnel waste liquid (not shown) away from receptacle body 11.

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Each of receptacle body 11, lid 12, upwardly-bending pipe section 17 and horizontally-bending pipe section 18 may be made from the same material, typically a moulded plastics material, for example high density polyethylene (HDPE), polypropylene (PP), acrylonitrile butadiene styrene (ABS), polyphenylene oxide (P0), or the like.

Receptacle body Ills furthermore provided with sensing means 20 for sensing the liquid level in said body and for activating an associated drainage pump (not shown) when a threshold liquid level (T) is reached and subsequently deactivating said pump when the liquid level drops below the threshold liquid level.

Sensing means 20 comprises a first liquid-level sensor, in the form of a first liquid-conductive sensor 21, for detecting the presence of liquid in receptacle body 11, and a second liquid-level sensor, in the form of a second liquid-conductive sensor 22, for detecting excess liquid in receptacle body 11 for drainage. Sensing means 20 further comprises a third liquid-level sensor, in the form of a third liquid-conductive sensor 23, for alternatively detecting excess liquid in receptacle body 11 for drainage. As the name suggests, a liquid-conductive sensor will only sense and react to the presence of a conductive liquid (e.g. water), but not to the presence of a non-conductive liquid (e.g. a non-conducting oil).

First liquid-conductive sensor 21 is located adjacent to liquid outlet aperture 16, whilst **0** * both second liquid-conductive sensor 22 and third liquid-conductive sensor 23 are * S....

* separated from first liquid-conductive sensor 21 by a pre-determined distance, such that each of second liquid-conductive sensor 22 and third liquid-conductive sensor 23 -; --; 20 are remotely located from liquid outlet aperture 16, and indeed are located above said aperture 16. As is shown in the figures, particularly Figures 1, 4 and 5, the position of S.....

* second liquid-conductive sensor 22 corresponds to threshold liquid level (T), whilst the position of third liquid-conductive sensor 23 corresponds to alternative threshold liquid level (t). In both cases, the location of threshold liquid level (T,t) is such that liquid outlet 14 will remain submerged once the receptacle 10 is installed, connected to a drainage pump (not shown) and in use. A positive temperature coefficient (PIG) sensor (not shown) may be provided in sensing means 20, as a back-up sensor to ensure that the associate drainage pump (not shown) can be activated based on the temperature of the liquid to be drained and regardless of the conductivity of the liquid.

Such a PCT sensor may be located above the threshold liquid level (T,t).

Each of said first, second and third liquid-level sensors 21,22,23 are provided on printed circuit board 24, which itself is located in a suitably shaped hollow projection 25 provided on the outer surface of receptacle body 11, and which is electrically connectable to drainage pump circuitry (not shown) in a usual manner. Within projection 25, receptacle body 11 is provided with three small apertures (not shown) corresponding in location to each of first, second and third liquid-level sensors 21,22,23 on printed circuit board 24. Printed circuit board 24 is positioned within hollow projection 25 such that said first, second and third liquid-level sensors 21,22,23 project into the inside of receptacle body 11 (into which waste liquid is receivable). Printed circuit board 24 is fixed in position using a suitable water-resistant adhesive, for example a potling compound, such as a polyurethane potting compound, a silicone potting compound, an epoxy resin potting compound, or the like, (not shown), which is * also used to cover printed circuit board 24 once it is in position and to provide a water-* **.** :::: tight seal over it.

* 20 Liquid drainage receptacle 10 may be comprised in a drainage system along with a drainage pump (not shown), such that, in use, liquid (not shown) enters receptacle ****** * body 11 via liquid inlet 13, the liquid level rises until a threshold liquid level (T,t) is reached, sensing means 20 senses that the threshold liquid level (T,t) has been reached and subsequently activates the drainage pump to pump liquid from receptacle body 11 via liquid outlet 14 until the liquid level drops below the threshold liquid level (T,t), upon which sensing means 20 deactivates the drainage pump, such that liquid outlet 14 remains submerged.

Figure 6 illustrates a drainage system 30 according to the invention comprising a liquid drainage receptacle 10 (as hereinbefore described) and a drainage pump unit 31. The schematic of Figure 6 illustrates a typical shower enclosure comprising a shower tray 32 and a showering unit 33 comprising a shower head 34. Shower tray 32 is provided with a waste 35, beneath which liquid drainage receptacle 10 is fitted such that waste water from shower head 34 (or other source) can drain from shower tray 32 into receptacle 10 via liquid inlet 13.

Horizontally-bending pipe section 18 of receptacle 10 is fluidly connected to a waste pipe 36 for drainage of the waste water from shower tray 32, and sensing means 20 is electrically connected to drainage pump unit 31 via an electrical cable 37. Waste pipe 36 feeds into drainage pump unit 31, and to a drainage pump (not shown) therein, which is itself fluidly connected to an output waste pipe 38 for drainage of waste water into conventional plumbing pipework.

In use, waste water enters receptacle body 11 via the liquid inlet 13, the liquid level * S. S. * rises until a threshold liquid level is reached, sensing means 20 senses that the S.....

* threshold liquid level has been reached and subsequently activates the drainage pump to pump liquid from receptacle body 11 via liquid outlet 14 until the liquid level drops *S 5.55 * 20 below, preferably just below, the threshold liquid level, upon which the sensing means :.. 20 deactivates the drainage pump, such that liquid outlet 14 remains submerged.

* I 5S S *

Claims

CLAIMS: 1. A liquid drainage receptacle for use with a drainage pump comprising: a receptacle body having a liquid inlet and a liquid outlet, and sensing means associated with the receptacle body for sensing the liquid level in the receptacle body and for activating the drainage pump when a threshold liquid level is reached and subsequently deactivating the drainage pump when the liquid level drops below the threshold liquid level.

2. A drainage receptacle as claimed in claim I wherein the liquid outlet is in the form of an aperture in the receptacle body which opens into an upwardly-bending pipe section.

3. A drainage receptacle as claimed in claim 2 wherein the upwardly-bending pipe section extends into a horizontally-bending pipe section.* ***.* * 4. A drainage receptacle as claimed in any preceding claim wherein the sensing S.....* means comprises a first liquid-level sensor for detecting the presence of liquid in the receptacle and a second liquid-level sensor for detecting excess liquid in S..

* 20 the receptacle for drainage. * S. *0 0 I.. *

5. A drainage receptacle as claimed in claim 4 wherein the first liquid-level sensor is located adjacent to the liquid outlet.

6. A drainage receptacle as claimed in claim 4 or claim 5 wherein the second liquid-level sensor separated from the first liquid-level sensor by a pre-determined distance.

7. A drainage receptacle as claimed in any of claims 4, 5 or 6 wherein the second liquid-level sensor is remotely located from the liquid outlet.

8. A drainage receptacle as claimed in any of claims 4 to 7 wherein the sensing means comprises a third liquid-level sensor for alternatively detecting excess liquid in the receptacle for drainage.

9. A drainage receptacle as claimed in any preceding claim wherein the receptacle body is provided with a lid in which the liquid inlet is provided.

10. A drainage receptacle as claimed in claim g wherein the liquid inlet is in the form of a threaded aperture in the lid into which a fixing means is screwable.

11. A drainage system comprising a liquid drainage receptacle as claimed in claim 1 and a drainage pump, wherein, in use, liquid enters the receptacle body via the liquid inlet, the liquid level rises until a threshold liquid level is reached, the * ***** * sensing means senses that the threshold liquid level has been reached and * .***s * * subsequently activates the drainage pump to pump liquid from the receptacle body via the liquid outlet until the liquid level drops below the threshold liquid level, upon which the sensing means deactivates the drainage pump, such that * S. :.: * the liquid outlet remains submerged.

* ** *** * * 12. A method for controlling the pumping action of a drainage pump so as to reduce the energy consumed by the pump and/or to reduce the noise associated with the pumping action comprising: -providing a drainage pump; -providing a liquid drainage receptacle comprising a receptacle body having a liquid inlet and a liquid outlet, and sensing means associated with the receptacle body for sensing the liquid level in the receptacle body and for activating the drainage pump when a threshold liquid level is reached and subsequently deactivating the drainage pump when the liquid level drops below the threshold liquid level; and -connecting the drainage receptacle to the drainage pump.

13. A method according to claim 12 wherein the drainage receptacle is physically connected to the drainage pump, via the liquid outlet, for drainage of excess liquid in the drainage receptacle.

14. A method according to claim 12 or claim 13 wherein the drainage receptacle is electrically connected to the drainage pump, via the sensing means, to enable receptacle-activation and receptacle-deactivation of the pump.Sp.. sp.

* 15, Use of a drainage receptacle as claimed in claim I with a drainage pump to I.....reduce the noise associated with the pumping action of the pump.

II Sale * 20 16. Use of a drainage receptacle as claimed in claim I with a drainage pump to reduce the overall energy consumption of the pump.

S.. Sal * p 17. A drainage receptacle substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

18. A drainage system substantially as hereinbefore described with reference to and as shown in Figure 6 of the accompanying drawings.