GB2333165A

GB2333165A - Liquid draining apparatus

Info

Publication number: GB2333165A
Application number: GB9721009A
Authority: GB
Inventors: David Arthur Collier
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-10-04
Filing date: 1997-10-04
Publication date: 1999-07-14
Anticipated expiration: 2017-10-04
Also published as: GB9721009D0; GB2333165B

Abstract

This invention relates to apparatus for draining liquid from a reservoir for liquid. Drain apparatus is generally indicated at 10 and comprises a reservoir 11, having an outlet 12 and draining apparatus generally indicated at 13. The draining apparatus 13 comprises a float 20, which has a drain outlet 21, a rigid pipe 22 and a mounting 23. A vortex forming plate 32 is mounted to extend generally tangentially of the drain 21 and its position can be adjusted relative to the drain.

Description

Liquid Draining Apparatus This invention relates to apparatus for draining liquid from a reservoir for liquid.

There are many instances in which liquid reservoirs fill at a rate, which is faster than it is desirable to release liquid from the reservoir. Such a situation particularly arises in connection with liquid run-off, which may be in a fairly localised scale, for example a garage forecourt, or may be the run-off created by a large development of buildings and their infrastructure.

Where buildings are constructed on green field sites, it is now a frequent requirement that the site be served by a reservoir, which in effect replaces the green field as the buffer in the water cycle. Otherwise, if the drains were simply connected straight into a river, the flow of water during and immediately after rain, would be much greater that the river naturally handled prior to the construction of the buildings and flooding would be likely to occur.

It is desirable to allow such reservoirs to drain down at a constant rate, equivalent to the rate at which rain water would naturally have leeched into the river system, but traditional constant head devices are not acceptable, because it is usually necessary that such reservoirs empty or virtually empty so as to avoid the health risks that can arise from the presence of a substantially stagnant body of water near to an area of habitation. Various proposals have been made for suitable draining down devices and International Patent Application No. W094/05867 is not an untypical example. In this arrangement a float supports a vortex generator beneath the surface of liquid in a reservoir and that vortex generator is connected to an outlet by a flexible pipe. Such an arrangement can experience a number of problems, particularly due to air being induced by the vortex into the pipe, which will tend to cause the pipe, or part thereof, to float. The result is the pipe is effectively shortened, which can in turn cause the float to be tipped or overturned and the vortex to be interrupted. The head of water above the vortex generator is not maintained constant and so the outflow may be more or less that is desired.

A number of other proposals, such as shown in U.S.

Patent 3753496 include floats which support upwardly facing vortex drains. These are very vulnerable to becoming blocked by floating items, such as dead sheep.

From one aspect the invention consists in apparatus for drawing liquid from a reservoir of liquid, the reservoir having an outlet adjacent its bottom, the apparatus comprising a float, having a vortex-creating drain, for maintaining the drain at a pre-determined distance below the surface of the liquid and an outflow pipe for connecting the drain to the reservoir outlet characterised in that the apparatus further comprises a rigid tether pivotally connected to the float for causing the float to follow a pre-determined path as the liquid is drained whilst maintaining the float in a desired orientation.

It will be appreciated that the rigid tether serves to control the float whatever movement there is of the connecting pipe. However, preferably, the pipe is fixed relative to the tether or, in an even greater improvement, the pipe is rigid and constitutes the tether.

In that last case, the apparatus may include a mounting for pivotally connecting the pipe to the outlet. The mounting preferably mounts the pipe for pivoting about an axis passing through the outlet. Thus the mounting may be constituted by generally T-shaped termination and the end of one arm of that termination may be connectable to the outlet. Indeed each arm end may be connectable to an outlet, if flow requirement so dictate.

It is preferred that the float includes walls forming a barrier surrounding the drain. Such a barrier will significantly reduce the likelihood of flotsam blocking the drain.

The barrier may be dimensioned to extend above and/or below the drain, and may be impermeable to liquid.

Particularly conveniently it may be constructed so that any liquid passing to the drain must first pass under the barrier. This reduces the risk of floating rubbish being drawn into the drain and also allows a relatively small head to be used enabling the reservoir to be emptied substantially through the drain but, without risking the introduction of surface contaminants into the river system.

The buoyancy of the float is preferably adjustable to allow adjustment of the pre-determined distance.

Alternatively or additionally the location of the drain may be adjustable relative to the float to allow adjustment of the pre-determined distance.

A vortex-inducing formation may be disposed over or adjacent the drain. That formation may be in the form of a plate extending generally tangentially with respect of the drain and the location and shape of the formation may be adjustable.

One or more inserts may be provided which are insertable in the drain to alter the cross-section thereof.

This enables the flow through the drain to be adjusted simply depending on the characteristics which are desired.

The apparatus may further include valve means which are opened in response to the outflow pipe and/or the float attaining a pre-determined position for draining down the outflow pipe. In the case where the rigid pipe is the tether, the valve means may include a hole formed in the pipe or an extension thereof which aligns, in the desired position, with a drain hole.

From another aspect the invention consists in apparatus for draining a liquid from a reservoir of liquid, the reservoir having an outlet adjacent to its bottom, the apparatus comprising a float, having a vortex creating drain, for mounting the drain at a pre-determined distance below the surface of the liquid and an out-flow pipe for connecting the drain to the reservoir outlet characterised in that the apparatus further comprises the float including all forming a barrier surrounding the drain.

From a still further aspect the invention consists in apparatus for drawing a liquid from a reservoir of liquid, the reservoir having an outlet adjacent its bottom, a float, having a vortex-creating drain, for maintaining the drain at a pre-determined distance below the surface of the liquid and an out-flow pipe for connecting the drain to the reservoir outlet characterised in that the float is formed such that liquid passing through the drain is drawn from below the level of the drain.

From a still further aspect the invention consists in apparatus for draining a liquid from a reservoir of liquid, the reservoir having an outlet adjacent its bottom, the apparatus comprising a float, having a vortex creating drain, for maintaining the drain at a pre-determined distance below the surface of the liquid and an out-flow pipe for connecting the drain to the reservoir outlet characterised in that the buoyancy of the float is adjustable to allow adjustment of the pre-determined distance.

Additionally the invention consists in apparatus for draining a liquid from a reservoir of liquid, the reservoir having an outlet adjacent its bottom, the apparatus comprising a float, having a vortex-creating drain, for maintaining the drain at a pre-determined distance below the surface of the liquid and an out-flow pipe for connecting the drain to the reservoir outlet characterised in that the location of the drain is adjustable relative to the float to allow adjustment of the pre-determined distance.

The invention still further consists in apparatus for drawing a liquid from a reservoir of liquid, the reservoir having an outlet adjacent its bottom, the apparatus comprising a float, having a vortex-creating drain, for maintaining the drain at a pre-determined distance below the surface of the liquid and an out-flow pipe connecting the drain to the reservoir outlet characterised in that the apparatus further includes a vortex-inducing formation disposed over or adjacent the drain.

The invention may additionally consist in drain apparatus comprising apparatus for draining a liquid as defined above and a reservoir including an outlet.

It is particularly preferred that the reservoir is sized to sit in a larger reservoir in which case it may have screened inlets to further protect against flotsam and other debris.

Although the invention has been defined above it is to be understood that it includes any inventive combination of the features set out above or in the following description.

In particular it has been understood that the various inventive features identified above may be usefully utilised alone or in combination with other features.

The invention may be performed in various ways and a specific embodiment will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a plan view of drain apparatus incorporating apparatus for draining a liquid from a reservoir; Figure 2 is the section along the line AA in Figure 1; Figure 3 is an end elevation of the apparatus of Figure 1 viewed on the arrow B; and Figures 4a and b are sections along the line BB in Figure 3 showing a bleed down valve in its open and closed positions respectively.

Drain apparatus is generally indicated at 10 and comprises a reservoir 11, having an outlet 12, and draining apparatus generally indicated at 13. The reservoir 11 may be constituted by a large pond or the like, or it may be a relatively small rectangular metal box, as illustrated in the drawings, which is designed to sit within an existing pond or reservoir.

Taking the illustrated arrangement, the reservoir has a base 14, sidewalls 15 and 16, a closed end wall 17 and an open end wall 18, which itself may be closed by a net-like screen 19. If the reservoir 10 may, at times, be fully immersed then a screen (not shown) may be fitted over the top. In this way water may enter the reservoir 12, but large debris is excluded.

The draining apparatus 13 comprises a float 20, which has a drain outlet 21, a rigid pipe 22 and a mounting 23.

The mounting 23, and hence the pipe 22, can pivot relative to the axis of the outlet 12 and the pipe is also pivotally connected to the drain 21 at 24.

As can be seen in Figure 2, when there is water in the reservoir 10, the float is supported by the water above the base 5 and floats in an orientation in which the drain 21 lies substantially horizontally. As the water drains out of the reservoir in the manner explained below, the float drops towards the lower position shown in Figure 2 following a path which is defined by the pipe 22, which acts as a rigid tether. This arrangement, in a particularly simple manner, prevents the problems with flexible pipes which were discussed above. Alternatively, the rigid pipe may be replaced by a rigid tether, in which case a flexible pipe may be attached to it and in some circumstances such an arrangement may be advantageous. Alternatively the pipe may be completely separate from the tether.

The float 21 is generally square in plan and has two opposed side walls 25a and 25b formed by buoyancy chambers 26 and 27, whilst the remaining walls 28 and 29 are simply plain. The buoyancy chamber 26 is cut away at 30 to allow for the pipe 22. It will be noted that all the side walls, 24, 25, 28 and 29 extend above and below the drain 21. They thus serve to protect the drain 21 from flotsam and require that the water that passes down the drain 21 is drawn into the central cavity 31, defined by the float, underneath the barriers constituted by the side walls 24, 25, 28 and 29.

This again reduces the risk of debris and hydro-carbon pollutants being passed through into the river system.

A vortex-forming plate 32 is mounted on the inner wall 33 of the buoyancy chamber 27 to extend generally tangentially of the drain 21. Such a plate creates a vortex into the drain, without the need for any suction or other mechanisms for changing the pressure within the pipe 21. It will be noted that the plate 32 is mounted by means of a stay 34, which can be adjusted on a track 35. This allows the angle of the plate to be adjusted and hence the strength of the vortex formed.

Further adjustments in the performance of the device can be achieved, by altering the head above the drain 21 either by adjusting the buoyancy of the float (for example by weighting the buoyancy chambers 26 and 27) or by adjusting the location of the plate 36 in which the drain 21 is formed. Additionally or alternatively, the dimensions of the throat of the drain 21 can be altered by means of inserts. It will thus be understood that the arrangement is such that the draining apparatus can be adjusted on site to suite the prevalent conditions.

When the reservoir 11 is substantially drained and the float is sitting on the base 14, water may still lie within the pipe 21. This can be removed by the arrangement shown in Figures 4a and b. Here it will be seen that the T-shaped termination mounting 23 engages in a sleeve 37 through which a hole 38, is bored so that the hole 38 lines up with a corresponding hole 39 in the mounting 23, when the float is sitting on a base 14, but is closed off in other positions of the float. In this way the pipe 21 can be drained down completely.

In countries where the reservoir 11 has to be completely dry, the float 20, or some other element of the apparatus 13, may cause a further outlet in the base 14 to be opened when the float 20 engages the base 14. As this water is likely to be highly contaminated with petrol and other hydro-carbons, it may be drained off to a separate tank from which it can be safely disposed. Alternatively the system in Figures 4a and b may suffice, when, as will be common for frost protection purposes, the outlet is in fact buried below ground level, in which case the hole 39 may bleed into a sump. The effective base 14 of the reservoir 11 will then be above the level of the outlet.

Claims

Claims 1. Apparatus for drawing liquid from a reservoir of liquid, the reservoir having an outlet adjacent its bottom, the apparatus comprising a float, having a vortex-creating drain, for maintaining the drain at a predetermined distance below the surface of the liquid and an outflow pipe for connecting the drain to the reservoir outlet characterised in that the apparatus further comprises a rigid tether pivotally connectable to the float for causing the float to follow a predetermined path as the liquid is drained whilst maintaining the float in a desired orientation.
2. Apparatus as claimed in claim 1 wherein the pipe is fixed relative to the tether.
3. Apparatus as claimed in claim 1 or claim 2 wherein the pipe is rigid and constitutes the tether.
4.. Apparatus as claimed in any one of the preceding claims including a mounting for pivotally connecting the pipe to the outlet.
5. Apparatus as claimed in claim 4 wherein the mounting mounts the pipe for pivoting about an axis passing through the outlet.
6. Apparatus as claimed in claim 4 or claim 5 wherein the mounting is constituted by a generally T-shaped termination and the end of one arm is connected to the outlet.
7. Apparatus as claimed in claim 6 wherein each arm end is connectable to an outlet.
8. Apparatus as claimed in any one of the preceding claims 8. Apparatus as claimed in any one of the preceding claims wherein the float includes or forms a barrier surrounding the drain.
9. Apparatus as claimed in claim 8 wherein the barrier is dimensioned to extend above the liquid level.
10. Apparatus as claimed in claim 9 wherein the barrier extends below the drain.
11. Apparatus as claimed in any one claims 8 to 10 wherein the barrier is impermeable to liquid.
12. Apparatus as claimed in claim 11 wherein any liquid passing to the drain must first pass under the barrier.
13. Apparatus as claimed in any one of the preceding claims wherein the buoyancy of the float is adjustable to allow adjustment of the predetermined distance.
14. Apparatus as claimed in any one of claims 1 to 12 wherein the location of the drain is adjustable relative to the float to allow adjustment of the predetermined distance.
15. Apparatus as claimed in any one of the preceding claims including a vortex-inducing formation disposed over or adjacent the drain.
16. Apparatus as claimed in claim 15 wherein the formation is a plate extending generally tangentially with the respect to the drain.
17. Apparatus as claimed in claim 15 or claim 16 wherein the location or shape of the formation is adjustable.
18. Apparatus as claimed in any one of the preceding claims further including one or more inserts insertable in the drain to alter the cross-section thereof.
19. Apparatus as claimed in any of the preceding claims wherein including valve means which are opened in response to the outflow pipe and/or the float attaining a predetermined position for draining down the outflow pipe.
20. Apparatus for draining a liquid from a reservoir of liquid, the reservoir having an outlet adjacent its bottom, the apparatus comprising a float, having a vortex-creating drain, for maintaining the drain at a pre-determined distance below the surface of the liquid and an outflow pipe for connecting the drain to the reservoir outlet characterised in that the apparatus further comprises the float including or forming a barrier surrounding the drain.
21. Apparatus for draining a liquid from a reservoir of liquid, the reservoir having an outlet adjacent its bottom the apparatus comprising a float, having a vortex-creating drain, for maintaining the drain at a pre-determined distance below the surface of the liquid and an outflow pipe for connecting the drain to the reservoir outlet characterised in that the float is formed with that liquid passing through the drain is drawn from below the level of the drain.
22. Apparatus for draining a liquid from a reservoir of liquid, the reservoir having an outlet adjacent its bottom, a float, having a vortex-creating drain, for maintaining the drain at a pre-determined distance below the surface of the liquid and an outflow pipe for connecting the drain to the reservoir outlet characterised in that the buoyancy of the float is adjustable to allow adjustment of the pre
23. Apparatus for draining a liquid from a reservoir of liquid, the reservoir having an outlet adjacent its bottom, a float, having a vortex-creating drain, for maintaining the drain at a pre-determined distance below the surface of the liquid and an outflow pipe for connecting the drain to the reservoir outlet characterised in that the location of the drain is adjustable relative to the float to allow adjustment of the pre-determined distance.
24. Apparatus for draining a liquid from a reservoir of liquid, the reservoir having an outlet adjacent its bottom, a float, having a vortex-creating drain, for maintaining the drain at a pre-determined distance below the surface of the liquid and an outflow pipe for connecting the drain to the reservoir outlet characterised in that the apparatus further includes a vortex inducing formation disposed over or adjacent the drain.
25. Drain apparatus comprising apparatus for draining liquid as claimed in any one of the preceding claims and a reservoir including an outlet.
26. Drain apparatus as claimed in claim 25 wherein the reservoir is sized to sit in a large reservoir and has screened inlets.
27. Drain apparatus wherein the reservoir includes a valve which opens to an outlet in response to the float or tether being lowered to a pre-determined height.