GB2424718A

GB2424718A - Flash flood flow control chamber

Info

Publication number: GB2424718A
Application number: GB0605428A
Authority: GB
Inventors: Stuart Edward Alan Ramella
Original assignee: Polypipe Building Products Ltd
Current assignee: Polypipe Building Products Ltd
Priority date: 2005-03-30
Filing date: 2006-03-16
Publication date: 2006-10-04
Anticipated expiration: 2026-03-16
Also published as: GB0605428D0; GB2424718B

Abstract

A chamber 1 for controlling flow of liquid in a flow handling system such as a storm water drain. The chamber comprises inlet 2, outlet 3 and connector 4 for connection to a surcharge device e.g. storage tank. The chamber is partitioned by weir 10 to provide inlet sub-chamber 8 containing the inlet and connector and outlet sub-chamber 9 having the outlet. A restrictor orifice 11 connects the sub-chambers. The inlet is higher than the outlet and the same height as the connector. With light rain water passes from the inlet through the orifice to the outlet. In flash flood conditions the capacity of the orifice is exceeded and water diverts to the surcharge device to return through the orifice to the outlet when input falls. If the surcharge device is filled water spills over the partition to outlet to prevent backflow. Sediment catching walls may be provided.

Description

LIQUID FLOW CONTROL

The invention relates to liquid flow control, particularly of rainwater, melting snow or ice, or floodwater, and is further particularly directed to a chamber for controlling flow of a liquid in a liquid flow handling system, and to a system incorporating same.

Rainwater from buildings, car parks and the like is usually channelled into a collection system leading to a waterway or drain such as a storm water drain.

However, in conditions of excess surface water from for example flooding or "flash" flooding owing to a sudden downpour, the system cannot cope, with the result that water backs up and causes flooding of land, roads, buildings etc., all of which is inconvenient, potentially dangerous, and expensive.

Systems have been provided to check the flow, but they usually rely on expensive and complicated structures to function.

It is an object of the invention to seek to mitigate this disadvantage.

According to the invention there is provided a chamber for controlling flow of a liquid in a liquid flow handling system, comprising an inlet for liquid, an outlet for liquid, a connector for connection to a surcharge device and restrictor and overflow means of the chamber for controlling flow of liquid through the chamber over a range of flow conditions.

The said means may comprise a member interiorly of the chamber. This is a relatively simple yet effective solution as the restrictor and overflow means can be provided by or in a single element.

The member may be planar and upstanding whereby to provide two chamber parts interiorly of the chamber. This provides for effective flow control, particularly when the member may be upstanding from a base of the chamber to a position below the top (in use) of the chamber whereby to provide a weir.

The upper edge of the member may be higher than the inlet, outlet and connector. This promotes flow control.

The restrictor means may comprise an orifice, suitably drilled through the member. This again provides controlled flow, particularly as the orifice may be smaller in diameter than the outlet, which for ease of construction may both be circular, suitably coaxial.

The chamber may comprise a body made of plastic, and the said means may also comprise plastics for example in the form of a polymer sheet.

The base may comprise a polymer sheet, suitably welded to the body, for ease of construction.

Suitably the body may comprise a corrugated pipe, for example as sold under the RTM "RIDGIDRAIN".

The inlet, outlet and connector may comprise sockets penetrating a boundary wall of the pipe. Such sockets may be welded in place, to provide a liquid-proof structure.

The chamber may comprise a first chamber part adapted to provide a trap for collecting debris entering the chamber via an inlet thereto, an overflow to a second chamber part which is adapted for connection by a connector to a surcharge device, and the restrictor and overflow means may comprise a restrictor for passage of liquid to an outlet, and an overflow means from the second chamber part for controlling flow of liquid through the chamber over a range of flow conditions.

There may be two first chamber parts, each of which may have a liquid inlet thereto.

This provides a relatively simple yet efficient construction, particularly when the two first chamber parts may be defined by substantially parallel planar members extending across the interior of the chamber.

Suitably, the planar members may each comprise a substantially L-shaped member.

Each planar member may comprise a substantially upright member interiorly of the chamber.

A lower limb of each L-shaped member may have an upper, in use, free edge comprising a weir adapted to provide a respective overflow.

The two L-shaped planar members may be connected by a wall adapted to provide the second chamber part and the overflow means therefrom.

The wall may be substantially orthogonal to the two L-shaped planar members, and suitably maybe of substantially the same height as the higher of the limbs of the respective L-shaped members.

The restrictor may comprise an orifice plate means in the wall.

Suitably, the orifice plate means may comprise a tubular stub element mounted in the wall and a restnctor plate mounted transversely to the stub element.

The tubular stub element and the restrictor plate may be initially separate elements which are adapted for connection together whereby to form the restrictor.

The tubular stub element and restrictor plate may be secured together by screw means.

This provides a relatively simple yet efficient construction.

The two L-shaped members and the wall may comprise an integral unit.

The chamber may comprise a substantially upright tubular member in which the integral unit is mounted.

The upright tubular member may suitably comprise a plastic right cylindrical member.

The inlets and outlets may comprise tubular members penetrating the wall of the cylindrical member.

According to a further aspect, there is provided a liquid flow handling system, including a chamber as hereinbefore defined, suitably for handling water flow.

Embodiments of a chamber embodying the invention are hereinafter described, by way of example, with reference to the accompanying drawings.

Fig. 1 is a plan view of a first embodiment of a chamber according to the invention; Fig. 2 is a sectional view of the chamber on line A-A of Fig. 1; Fig. 3 is a sectional view of the chamber on line B-B of Fig. 1; Fig. 4 is a perspective view of a second embodiment of the chamber according to the invention; Fig. 5 is, to a reduced scale to that of Fig. 4, a plan view of the chamber of Fig. 4; Fig. 6 is an elevational view of the chamber of Figs. 4 and 5; and Fig. 7 is an enlarged exploded view of a restrictor of the chamber of Figs. 4 to 6.

Referring firstly to the first embodiment shown in Figs. 1 to 3 of the drawings, there is shown a chamber I for controlling flow of a liquid in a liquid flow handling system, comprising an inlet 2 for liquid, an outlet 3 for liquid, and a connector 4 for connection to a surcharge device, and restrictor and overflow means 5 of the chamber I for controlling flow of liquid through the chamber 1 over a range of flow conditions.

The chamber 1 has a body 6 made of plastic, for example a corrugated plastic pipe the base of which is closed off by a polymer sheet 7 secured as by welding to the base (in use) of the body 6 to provide a leak-proof chamber 1. Likewise, the inlet 2, outlet 3 and connector 4 are each provided by a cylindrical plastic socket penetrating a boundary wall of the body 6 and welded thereto to provide leak-proof connections.

The inlet 2 is higher, as shown, than the outlet 3, whilst being at substantially the same level as the connector 4, which is connected by piping to a tank (not shown) usually underground, (as is the chamber I) to which surcharge water is passed during say flash- flood conditions.

Interiorly of the chamber 1 is the means 5 in the form of a planar member which is secured as by welding to the base 7 and the boundary wall of the body 6 to provide interiorly of the chamber 1, two chamber parts 8, 9 one of which 8 houses the inlet 2 and connector 4, and the other 9 of which houses the outlet 3. The planar member 5 terminates at a free edge 10 below the top (in use) of the chamber 1, thereby providing a weir 5. The top edge 10 is above the level of the inlet 2 and connector 4.

The planar member or weir 5 also has a through orifice 11 in the form of a hole therethrough. In the embodiment, the hole 11 is circular and drilled through the member at a level below the level of the inlet 2 and connector 4. The outlet 3 is circular and, in the embodiment, of larger diameter than the orifice 11, the orifice 11, and outlet 3 being substantially coaxial.

In use, the chamber 1 is mounted underground in say a manhole. The inlet 2 is coimected to a rainwater collection array such as drains, guttering etc. The outlet 3 is connected to a discharge network say to a stormwater drain or water course. The connector 4 is connected to an underground tank (not shown) such as that marketed under the trade mark POLYSTORIvI In normal conditions, water flows through the inlet 2 to the chamber part 8. It fills up that part to the level of the through orifice 11, through which it flows in a controlled maimer to the chamber part 9. When the level of water reaches the outlet 3, it can flow away through the outlet 3. The orifice 11 thus acts as a flow restrictor or vortex flow device.

If flow conditions are such that the inflow rate exceeds the rate at which water can flow through the orifice or restrictor 11 to the outlet 3, the level of water in the chamber part 8 rises until it reaches the connector 4. It flows therethrough to the tank, which thus acts as a back up or holding tank for the surcharge which can be caused by a flash flood. The excess water thus does not back up into the inlet 2 in a reverse flow, so obviating flooding.

If however the tank becomes full, or there is an extreme surcharge, the water continues to rise in the chamber part 8 until it reaches the level of the free edge 10 of the weir 5. It spills over the top edge 10 of the weir 5 into the chamber part 9 and thence directly to the outlet 3, and on to the storm drain or water course.

The weir 5 acts as a fail-safe overflow device, which obviates back flow through the inlet 2, so avoiding flooding.

When the extreme conditions pass, the water held in the tank can flow back into the chamber, the level in the chamber part 8 falls, and normal flow through the restrictor orifice 11 is resumed, until the next set of extreme conditions arise.

Referring now to the second embodiment shown in Figs. 4 to 7 of the drawings, there is shown a chamber 101 for controlling flow of a liquid in a liquid flow handling system, comprising a first chamber part 102 (of which there are two in the embodiment shown and described by Figs. 4 to 7) adapted to provide a trap for collecting debris 103 entering the chamber 101 via an inlet thereto 104, an overflow 105 to a second chamber part 106 which is adapted for connection by a connector 107 to a surcharge device (not shown) and by a restrictor 108 for passage of liquid to an outlet 109, and an overflow means 110 from the second chamber part 106 for controlling flow of liquid through the chamber 101 over a range of flow conditions.

The chamber 101 is in the embodiment a right cylindrical tubular plastic chamber which is closed off at the bottom by a plastic sheet ill, suitably attached in a leak-proof maimer by suitable securing means such as by adhesive.

The two first chamber parts 102 are defined by L-shaped planar members 112 also of plastic and which extend across the chamber 101 in chordal planes, being secured in leak-proof manner as by welding to the interior surface of the boundary wall or body of the tubular plastic chamber.

The inlets 104 for liquid are in the form of tubes penetrating the wall of the chamber 101 to allow passage of liquid to the first chamber parts 102.

The connector 107 is in the form of a tube which penetrates the wall of the chamber 101 to allow liquid to pass from the second chamber part 106 to a storage means such as a tank (not shown) marketed under the trade mark POLYSTORM.

The outlet 109 from the chamber 101 is in the form of a tube which penetrates the boundary wall and allows liquid to pass from the chamber 101 from a third chamber part 113 to further processing.

The two planar members 112 are connected by a transverse wall 114 which is positioned at a transition between the limbs of the L-shaped members 112, and which is of equal height to the height of the higher limb of the L-shaped planar members 112.

The restrictor 108 allows passage of liquid from the second 106 to the third chamber part 113 and comprises an orifice plate 115. The plate 115 itself has an orifice through an end cap 117 which is screw-engaged to a tubular plastic stub 118 which penetrates the wall 114. The orifice 116 is smaller in diameter than the diameter of the connector 107 and is coaxial, or slightly offset coaxially, therewith. The orifice 116 promotes controlled flow of liquid from the second 106 to the third chamber part 113, as will be described, acting as a flow restrictor or vortex flow device.

In use, the chamber 101 is mounted underground in say a manhole.

The inlets 104 are connected to a rainwater collection array such as drains, guttering, etc. The outlet 109 is connected to a discharge network, say to a stormwater drain, or water course. The connector 107 is connected to an underground reservoir or tank, such as is marketed under the trade mark POLYSTORJyI as hereinbefore described.

In use, in normal conditions, water flows through the respective inlets 104 and falls into the respective first chamber parts 102. These act as silt traps, and any silt, debris or the like detritus 103 falls to the bottom of the first chamber parts 102 where it is collected.

The water level rises in the first chamber parts 102 until it reaches the level of the upper (as viewed) free edges 105 of the respective lower limbs of the L-shaped members 112.

These edges 105 act as weirs over which the water flows to pass into the second chamber part 106, which begins to fill. When the water reaches the level of the orifice plate 108, 115, 116 it passes therethrough, and thus through the wall 114, to the third chamber part 113. This fills to the level of the outlet 109, when the water flows away from the chamber 101 for further processing via a stormwater drain or water course.

If the third chamber part 113, which acts as a storage chamber, becomes full, water flow backs up into the reservoir or tank through the connector 107. The reservoir or tank thus act as back-up or holding tank for excess water, which can be caused for example by a flash flood or storm The excess water does not back up into the inlets 104 in a reverse flow, so obviating flooding.

If however the reservoir or tank becomes full and the stormwater volume is excessive for the orifice plate 108, 115, 116 to cope with, the water level rises in the second chamber part 106 and spills or overflows into the third chamber part 113 over the free top edge 110 of the wall 114 which acts as a weir. The orifice plate or flow control device 108 is thus bypassed using the overflow weir to the outlet 109.

It will be understood that the chamber hereinbefore described with reference to Figs. 4 to 7 the drawings, and a system incorporating it, provides a flow control device and silt removal in one integral simple yet efficient unit.

The chambers 1, 101 embodying the invention as shown in the drawings are thus part of a liquid flow control system, and provide a simple yet effective way of controlling liquid flow in extreme conditions such as flash flooding.

Claims

I. A chamber for controlling flow of a liquid in a liquid flow handling system, comprising an inlet for liquid, an outlet for liquid, a connector for connection to a surcharge device, and restrictor and overflow means of the chamber for controlling flow of liquid through the chamber over a range of flow conditions.
2. A chamber according to Claim 1, the said means comprising a member interiorly of the chamber.
3. A chamber according to Claim 2, the member being planar and upstanding whereby to provide two chamber parts interiorly of the chamber.
4. A chamber according to Claim 3, the member upstanding from a base of the chamber to a position below the top (in use) of the chamber whereby to provide a weir.
5. A chamber according to Claim 4, the upper edge of the member being higher than the inlet, outlet and connector.
6. A chamber according to any of Claims 3 to 5, the restrictor means comprising an orifice through the member.
7. A chamber according to Claim 6, the orifice being smaller in diameter than the outlet.
8. A chamber according to Claim 7, the orifice and the outlet being circular.
9. A chamber according to Claim 8, the orifice and outlet being coaxial.
10. A chamber according to any preceding claim, comprising a body made of plastic.
11. A chamber according to Claim 10, the said means comprising plastic.
12. A chamber according to Claim 10, the said means comprising a polymer sheet.
13. A chamber according to any of Claims 4 to 12, the base comprising a polymer sheet.
14. A chamber according to Claim 13, the base being welded to the body.
15. A chamber according to any of Claims 10 to 14, the body comprising a corrugated pipe.
16. A chamber according to Claim 15, the inlet, outlet and connector comprising sockets penetrating a boundary wall of the pipe.
17. A chamber according to Claim 1, comprising a first chamber part adapted to provide a trap for collecting debris entering the chamber via an inlet thereto, an overflow to a second chamber part which is adapted for connection by a connector to a surcharge device, the restrictor and overflow means comprising a restrictor for passage of liquid to an outlet, and an overflow means from the second chamber part for controlling flow of liquid through the chamber over a range of flow conditions.
18. A chamber according to Claim 17, comprising two first chamber parts, each having a liquid inlet thereto.
19. A chamber according to Claim 18, the two first chamber parts being defined by substantially parallel planar members extending across the interior of the chamber.
20. A chamber according to Claim 19, the planar members each comprising a substantially L-shaped member.
21. A chamber according to Claim 20, each planar member comprising a substantially upright member interiorly of the chamber.
22. A chamber according to Claim 21, a lower limb of each L-shaped member having an upper, in use, free edge comprising a weir adapted to provide a respective overflow.
23. A chamber according to Claim 22, the two L-shaped planar members being connected by a wall adapted to provide the second chamber part and the overflow means therefrom.
24. A chamber according to Claim 23, the wall being substantially orthogonal to the two h-shaped planar members.
25. A chamber according to Claim 24, the wall being of substantially the same height as the higher of the limbs of the respective L-shaped members.
26. A chamber according to Claim 25, the restrictor comprising an orifice plate means in the wall.
27. A chamber according to Claim 26, the orifice plate means comprising a tubular stub element mounted in the wall and a restrictor plate mounted transversely to the stub element.
28. A chamber according to Claim 27, the tubular stub element and the restrictor plate being initially separate elements which are adapted for connection together whereby to form the restrictor.
29. A chamber according to Claim 28, the tubular stub element and restrictor plate being secured together by screw means.
30. A chamber according to any of Claims 25 to 29, the two L-shaped members and the wall comprising an integral unit.
31. A chamber according to Claim 30, comprising a substantially upright tubular member in which the integral unit is mounted.
32. A chamber according to Claim 31, the upright tubular member comprising a plastic right cylindrical member.
33. A chamber according to Claim 32, the inlets and outlets comprising tubular members penetrating the wall of the cylindrical member.
34. A chamber for controlling flow of liquid in a liquid flow handling system, substantially as hereinbefore described with reference to the accompanying drawings.
35. A liquid flow handling system, including a chamber according to any preceding claim.
36. A system according to Claim 35, the liquid being water.
37. A liquid flow handling system, substantially as hereinbefore described with reference to the accompanying drawings.