Liquid supply apparatus

Abstract

 A liquid supply apparatus adapted to isolate a liquid supply source, e.g. an incoming water main, from equipment requiring such a supply. The liquid supply apparatus comprises a storage tank having a liquid inlet (13) and a liquid outlet (15), a valve means responsive to the level of liquid in the storage tank (8) and a safety overflow means, disposed below the level of the inlet (13). The valve means (11) controls the flow of liquid into the tank (8) and the safety overflow means, which comprises a weir (2) over which liquid may discharge from the tank (8), prevents the level of liquid in the storage tank (8) from rising above a pre-determined level.

Description

[0001] The present invention relates to liquid supply apparatus adapted to isolate a liquid supply source such as an incoming water main from equipment intended to utilise that supply source, so as to avoid any direct connection between the supply source and the equipment.

[0002] Water supply regulations in most countries prevent the connection of industrial or commerical equipment directly into the water main. This is to prevent the water supply from becoming contaminated by any chemicals or other impurities present in the equipment.

[0003] For example, in large commercial and industrial premises, cleaning fluids are dispensed from equipment which holds a range of concentrated chemical agents. These are diluted with water as they are dispensed. These chemical agents include those suitable for cleaning floors, tiles, bathrooms and general purpose applications. In such a system dilution is achieved by passing water under pressure over a venturi, which is attached to a unit containing the chemical agent. In some countries the regulations allow for any such equipment requiring water to be connected directly to the mains water supply, so long as a means is included in the system for backflow prevention. In other countries, including the U.K. and Germany, the regulations require that an air gap must be provided between the mains water supply and the equipment. According to U.K. regulations, this air gap must be at least 35mm.

[0004] The purpose of the liquid supply apparatus of the present invention is to provide no direct path, that is an air gap, between the mains water supply and any associated equipment.

[0005] Further, any equipment to be supplied with liquid may require that liquid be supplied at a predetermined pressure.

[0006] In order to supply liquid at pressure, the liquid storage tank has either to be mounted above the equipment, requiring the tank to be at a sufficient height, or a pump has to be connected to the outlet of the liquid storage tank so as to develop the required pressure. The operation of equipment requiring a liquid under any significant pressure using a gravity fed system can only be employed in buildings of sufficient height, and such a system would not allow the equipment and liquid supply apparatus to be located adjacent to one another. Therefore, it is a further aim of the present invention to provide an embodiment of apparatus for introducing an air gap between a liquid supply and any equipment requiring a supply of liquid, which is capable of providing liquid under pressure.

[0007] The present invention provides a liquid supply apparatus of the kind comprising a liquid storage tank; a liquid inlet and a liquid outlet for said storage tank; valve means responsive to the level of liquid in the storage tank for controlling flow of liquid into the tank from said liquid inlet; and safety overflow means disposed below the level of the inlet and adapted to prevent the level of liquid in the storage tank from rising above a predetermined level, wherein said safety overflow means comprises a weir over which liquid may discharge from said tank.

[0008] Preferably, the apparatus comprises a container which is divided into two sections by an internal dividing wall, wherein said storage tank comprises one of said sections, and said weir comprises said internal dividing wall; and an opening is defined in the other section to permit liquid passing over said weir to pass out of the container.

[0009] More preferably, a pump is housed in the other section of the container, and said pump has a pump inlet connected to the liquid outlet from the storage tank and a pump outlet extending out of the container.

[0010] An Embodiment of the present invention will now be described by way of example only, with reference to the accompanying drawing, which illustrates a side elevational view, in cross section, of the liquid supply apparatus of the present invention.

[0011] Referring to the drawing, the container 1 is constructed so as to define two sections 3, 4; these sections 3, 4 are separated by an internal weir 2 of U-shape. The first section 3, houses a pump 5 and the second section 4 comprises a liquid storage tank 8. The weir 2 extends substantially vertically from the base of the container 1 across the full width of the container and is of such a height so as to define a liquid storage tank 8 in the second section 4 of the desired capacity, in this embodiment 6.67 litres, within the container 1. The first section 3 defines that region in which the pump 5 and flow control means 9, 10 are positioned. An inlet 13 having a float valve 11 for controlling flow therethrough is positioned above the top edge 17 of the weir 2. In this embodiment the vertical distance 'A' between the inlet 13 and the top edge of the weir 2 is 35mm. The container 1 is rotationally moulded from a plastics material. The dimensions of the container are governed by the dimension of the pump 5 and the capacity of the liquid storage tank 8. The tank 8 must be of sufficient capacity to maintain a supply of water to the pump 5, and the pump 5 must be of sufficient capacity to produce the desired water pressure at outlet 15 of the container 1.

[0012] The container 1 further includes an opening 12 in that part of the weir 2 defining the first section 3. This opening 12 is formed (e.g. routed out) in the lowermost part of the weir 2, such that any water passing into the first section 3 over the weir 2 will drain out of section 3. The dimension of the opening 12 is determined by the regulations laid down by the appropriate body such as the Water Research Council. Typically these regulations require that, in the event of any failure, the rate of flow of water through the opening 12 be greater than the rate of flow of water into the liquid storage tank 8 from the inlet 13.

[0013] The container 1 is designed so as to be pleasing on the eye, and the pipework is positioned to one side of the liquid supply apparatus, i.e. out of view. The container incorporates a lid 16. The float valve 11 is of a pivotting diaphragm type, and is designed to provide a full water pressure for 90% of its travel. It can be adjusted so as to control the level of water within the liquid storage tank 8. This level is set at a distance below the top 17 of the weir 2 so as to prevent any water passing into the first section 3 in normal use.

[0014] The pump 5 used in the liquid supply apparatus tank 8 is of a type suitable for building up a head of pressure. The outlet 7 of the pump 5 is connected by way of a non-return valve 9 to a pressure regulator 10. This pressure regulator 10 can be adjusted in the range from 25 to 55 p.s.i.

[0015] The outlet of the pressure regulator 10 is coupled to outlet 15 which passes through the wall of the container 1.

[0016] The preferred embodiment of the present invention provides a self-contained liquid supply apparatus tank assembly of one piece construction which can be used in any application requiring water under pressure not supplied directly from a mains water supply or in any application where a water under pressure is required that exceeds the mains water pressure.

[0017] Although a certain preferred embodiment has been shown and described, it should be understood that many changes and modifications may be made therein without departing from the scope of the appended claims.

Claims

1. Liquid supply apparatus of the kind comprising a liquid storage tank (8); a liquid inlet (13) and a liquid outlet (15) for said storage tank (8); valve means (11) responsive to the level of liquid in the storage tank (8) for controlling flow of liquid into the tank (8) from said liquid inlet (13); and safety overflow means disposed below the level of the inlet (13) and adapted to prevent the level of liquid in the storage tank (8) from rising above a predetermined level, wherein said safety overflow means comprises a weir (2) over which liquid may discharge from said tank (8).

2. Liquid supply apparatus as claimed in Claim 1, wherein the liquid inlet (13) is disposed in one wall of the storage tank (8).

3. Liquid supply apparatus as claimed in Claim 1 or Claim 2, wherein said valve means (11) is associated with said liquid inlet (13) and comprises a float valve responsive to the level of liquid in the storage tank (8).

4. Liquid supply apparatus as claimed in any of Claims 1 to 3, wherein said storage tank (8) has generally perpendicular walls, and one of said walls extends to a level below that of the others to form said weir (2).

5. Liquid supply apparatus as claimed in Claim 4, comprising a container (1) which is divided into two sections (3, 4) by an internal dividing wall, wherein said storage tank (8) comprises one of said sections (4), and said weir (2) comprises said internal dividing wall; and an opening (12) is defined in the other section (3) to permit liquid passing over said weir (2) to pass out of the container (1).

6. Liquid supply apparatus as claimed in Claim 5, wherein said container (1) is of one-piece moulded construction.

7. Liquid supply apparatus as claimed in Claim 5 or Claim 6, wherein a pump (5) is housed in the other section (3) of the container (1), and said pump (5) has a pump inlet (6) connected to the liquid outlet (15) from the storage tank (8) and a pump outlet (7) extending out of the container (1).

8. Liquid supply apparatus as claimed in Claim 7, wherein a non-return valve (9) is disposed in the pump outlet (7).

9. Liquid supply apparatus as claimed in Claim 7 or Claim 8, wherein a pressure regulator (10) is disposed in the pump outlet (7).

10. Apparatus for dispensing cleaning liquids, whenever connected to liquid supply apparatus as claimed in any preceding claim.

Drawing