GB2078342A - Expanding stopper and a ground water control system including such stoppers - Google Patents

Abstract

An expanding stopper (10) for controlling flow of liquid through a conduit (1) comprises an expandable bag (2) having elastic end portions (5) and (6), inlet and outlet means (7) for a fluid under pressure being hermetically connected through the upper part of the bag and adapted for connection to a distribution system (9) for the fluid, the inlet and outlet means being provided with connection means (8) for the attachment of the bag to a part of the conduit. The latter may form part of a ground water control system, such as a drainage or irrigation system. <IMAGE>

Description

SPECIFICATION Expanding stopper and a ground water control system including such stoppers The invention relates to an expanding stopper and a system for the adjustment of the ground water level including such stoppers, designed for central regulation of the drainage and of a drainage with regulated off-take.

Known stoppers are based on the mechanical principle of closing a drain pipe in an open shaft, which drain pipe is closed by inserting a slide gate, interrupting thus the off-take. Similar slide gates can be also provided in front of the off-take of the drain pipe, increasing thus by adjustment of the height of the gate the ground water level up to the overflow over the gate. Drawbacks of this regulation method are primarily in that the off-take from the drain pipe cannot be completely closed, the regulation has to be made in each shaft independently, requiring a large amount of labour and an equal adjustment of the required level in individual shafts cannot be obtained. This method can be used for a predomi nantly plane ground where the number of open shafts is small.This method is due to the amount of required labour and storage of man power not frequently used and usually no regulation is pro vided. In orderto reduce the required amount of labour automatic regulating devices for regulation of the ground water level have been provided, controll ing slide valves introduced in draining pipes in open shafts. These slide valves are operated by servomotors, controlled centrally by a control device. Draw backs of this method are the complexity, high investment costs, dependence on electric current and others. Due to their complexity these arrange ments are not reliable in operation. Another method of closing drain pipes is by means of flaps closing the drain pipe in open shafts, The opening is performed mechanically by pull rods. Drawbacks of this system are the same as at closing pipes by slide gates.

It is an object of this invention to provide efficient means for control of the ground water level, which could be controlled centrally and would require a minimum of attendance. An expanding stopper according to this invention comprises a bag having an upper part and a lower part, forming together a unit and provided on its ends with a resilient front portion and with a resilient rear portion, whereby an inlet and outlet means for a working medium, advantageously gas, is hermetically fixed to the upper part, which inlet and outlet means is provided with connecting means for fixing the regulating and closing bag to the pipe.

Stoppers according to this invention may be used in a drainage system in that it is inserted in the pipe or in a retaining body, whereby the inlets and outlets for an auxiliary medium, advantageously gas, of all the stoppers connected to a pressure distributing system for the auxiliary medium, situated along and/or within the pipe and connected to a control device situated advantageously in a structure on the surface.

A stopper according to this invention and a drainage system using said stoppers offer a number of advantages, the most significant being reduced investment costs, a speeding up of its introduction and reduction of labour for attendance. It enables application of easily obtainable and advantageous materials with longer life time. The arrangement operates very reliably both in case of closing and in regulating the passage of water through the drain pipe. It enables the advance of trash on the bottom of the drain pipe and causes no following wrong closure of the pipe, as is frequently the case e.g. with slide valve systems. The system allows central control of the stoppers in surface and underground shafts. This system can be also advantageous applied in a terrain with larger sloping.It utilizes also all advantages of regulating draining systems as for instance that water does not come in direct contact with surface parts of plants, reducing thus the possibility of spreading some plant deseases, it does not harm the soil structure, requirements for agrotechnical working of the soil are reduced, the water accumulated under the surface is utilized for cleaning drain pipes, working conditions are improved and it is also possible to use the invention for metering water in an infiltration ground.

One embodiment of an expanding stopper according to this invention for regulating the ground water level and a drainage system including such stoppers are diagrammatically shown in the accompanying drawings, in which: Figure 1 is side view of a stopper in a drain pipe, Figure 2 a front view of the stopper situated in a drain pipe, and Figure 3 a drainage system including such stoppers.

An expanding stopper according to this invention comprises a regulating and closing bag 2 having an upper part 3, which is substantially constantly in contact with the upper half of the internal wall of a pipe 1 in which the bag 2 is situated, and a lower part 4. The two parts 2 and 3 form together a unit and are at one end provided with an elastic front portion 5 and at the other with an elastic rear portion 6. An inlet and outlet for an auxiliary medium, advantageously gas, is firmly connected to the upper part 3, and passes through an opening in the upper part of the pipe 1 to which it is fixed by a connector 8, so that the whole stopper 10 is fixed to the upper part of the pipe 1. The inlet and outlet 7 for the auxiliary medium is connected to a distribution system 9 for this medium.The stopper 10 can also be used in a retaining structure 11, in which case it is situated in the pipe 1 (Figure 3) in an overflow body 12. The inlets and outlets 7 of all pressure regulating closures 10 are connected to the distribution system 9 for the auxiliary pressure medium, connected to a control device 13 situated advantageously in a surface structure.

If the soil humidity is excessive, water is taken off continuously and the drainage system is fully operational. In that case the stoppers 10 have their regulating and closing bags 2 drawn with both their upper and lower parts 3/4 constantly against the upper part of the internal wall of the pipe 1 due to deformations caused by the elastic front portion 5 and the elastic rear portion 6, which cooperate in drawing the lower part 4 against the upper part 3 and against the upper internal wall of the pipe 1, enabiing thus unrestricted passage of water past the stopper 10 in which case the function of the overflow 14, and possibly of the overflow body 12 of retaining structure 11 is eliminated. In that case the auxiliary pressure medium is discharged from the stopper 10.

If the soil humidity drops below the required soil humidity, loss of water has to be prevented and retarded and a retention space must be provided. In that case the auxiliary pressure medium is introduced at the individual stoppers 10 by the distributing system 9 for the auxiliary medium and is admitted into the regulating and closing bags 2. The auxiliary pressure medium inflates the regulating and closing bag 2 and finally both the upper part 3 and the lower part 4 are in full contact with the whole internal wall of the pipe 1. Thus passage of water past the stopper 10 is prevented. The water in the retaining structure 11 rises until it reaches the edge of the overflow 14 or the edge of the overflow body 12 of a retaining structure 11. The ground water level rises up to the horizontal edge of the overflow 14 or of the overflow body 12 of the retaining structure 11.

If the water level rises above the edge of the overflow 14 or of the overflow body 12 it overflows to the spillway of the overflow 14 into the pipe 1 downstream of stopper 10 and thus proceeds to the next retaining structure 11, or possibly to an off-take.

It is also possible to regulate the flow of water through the pipe and thereby the water level within the range between the level of the bottom of the pipe 1 and the edge of the overflow 14 or of the overflow body 12 by the stoppers 10 in that the pressure of the auxiliary pressure medium is adjusted by the pressure medium control device 13. The control device 13 can control, via the distributing system 9, the stoppers 10 simultaneously (if they are in series connection,) or individually (if they are in parallel connection). The auxiliary pressure medium, advantageously pressure gas, can be supplied to the regulating system from pressure tanks connected to the control device 13. As already mentioned, pressure gas or pressure liquid can be used for the control of the stoppers 10. The stoppers 10 for regulating the ground water level and their incorporation in a draining system can be used for irrigation.

Claims (7)

1. An expanding stopper for controlling flow of liquid through a conduit, the stopper comprising an expandable bag having an upper part and a lower part, forming together a unit, the ends of the bag being provided with an elastic front portion and an elastic rear portion, inlet and outlet means for a fluid under pressure being hermetically connected to the upper part of the bag and adapted for connection to a distributing system for the fluid, the inlet and outlet means being provided with connection means for the attachment of the bag to a part of the conduit.

2. An expanding stopper for controlling flow of liquid through a conduit constructed, arranged and adapted to operate substantially as herein described with reference to, and as shown in, Figures 1 and2 of the accompanying drawings.

3. A ground water control system including a: conduit and at least one expanding stopper accord- ing to Claim 1 or 2 arranged inside the conduit.

4. A system according to Claim 3 which is a drainage system.

5. A system according to Claim 4 including drain-pipes and overflow and/or retaining means and said expanding stoppers arranged in the pipes and/or the overflow and/or retaining means, the inlet and outlet means of each of the stoppers being connected to a distribution system for the fluid under pressure including connection piping for the fluid interconnecting the stoppers in series and/or in parallel.

6. A system according to Claim 5 wherein the connection piping for the fluid is arranged at least partly along or within the pipe.

7. A ground water control system constructed, arranged, and adapted to operate substantially as herein described with reference to and as shown in, Figure 3 of the accompanying drawings.