WO1989000682A1

WO1989000682A1 - Gas-tightness control system

Info

Publication number: WO1989000682A1
Application number: PCT/DK1988/000118
Authority: WO
Inventors: Erik Nielsen
Original assignee: DAN-TAET ODENSE AS
Current assignee: DAN-TAET ODENSE AS
Priority date: 1987-07-14
Filing date: 1988-07-12
Publication date: 1989-01-26
Anticipated expiration: 1990-01-14
Also published as: AU2080588A; DK367587D0

Abstract

In order to be able to control whether or not a gas installation is completely tight, a shut-off valve (3) is mounted in the service pipe (2) to a building (9) together with a volumenometer (4) and an electronic control unit (5). Moreover, gas detectors (8) can be mounted in the rooms (10) of the building. If gas should be present in a room (10), the gas detector (8) will send signals to the solenoid valve (3) via the control unit (5), upon which the gas supply is immediately cut off. A continuous control and thus surveillance of the installation can also be effected by periodic measurements of the gas consumption, and when this lies above the normal, by immediately cutting-off the gas, in that the ''consumption'' must be due to a leakage. In this way, the control system is independent of the presence of persons, and accidents as a result of an escape of gas can be prevented in a simple and secure manner.

Description

GAS-TIGHTNESS CONTROL SYSTEM

The invention relates to a gas-tightness control sys¬ tem for a singe-line gas installation in which gas under pressure is supplied to one or more tapping points.

The widespread use of gas has resulted in an increas¬ ed interest in the need for being able to control gas installations with the view to the greatest possible security.

An uncontrolled seepage or escape of gas will give rise to the risk of explosion or poisoning, and will thus be a permanent factor with which one must calcu¬ late.

For the control of gas installations in buildings, gas detectors mounted at central places are used, said detectors providing an acoustic alarm in the event of the presence of gas in the atmosphere around the detectors. The alarm thus warns those in the sur- roundings whenever there is gas in the atmosphere, after which the necessary steps can be taken to pre¬ vent accidents, such as turning off the supply of gas or ventilation etc.

This alarm, however, requires the presence of person¬ nel who can take the necessary actions, or that the alarm is connected to an exchange from which the nec¬ essary steps can be taken for the disconnection of the gas . This form of control is, however, both unsafe and troublesome for the users, either because the system- is dependent on the presence of persons during the. period of seepage, or that the necessary action must be taken immediately from a remotely-lying exchange.

It is the object of the invention to improve the security at gas installations, and this is achieved with a system which includes an electrically-driven shut-off valve introduced where the gas is conducted to the installation, plus a subsequent volumenometer with electrical signalling, and an electronic con¬ trol unit which can. supply pulses to the shut-off valve for the disconnection of the supply.

In a particularly simple and safe manner, there is achieved ^a means of contro^] for the safeguard of the tightness of a gas installation, in that one can con¬ tinuously control the supply.

One is thus able to arrange a measuring cycle of 24 hours, within which cycle there must not occur any consumption of gas during one or more periods of some minutes duration. If, in such a period, the volumeno- meter ascertains a "consumption", the unit provides a signal for the immediate disconnection of the gas supply by means of the valve. A seepage or leakage of gas is thus ascertained, and the gas is disconnected: before accidents occur hereby.

Where there" is a need for a minor consumption of gas, for example for the heating of a bimetal valve, the^*, control unit can be set to register an outflow which exceeds this permanent gas consumption. Finally, one can select the control period at any desired time at which there is not normally any con¬ sumption of gas.

By providing the system with detectors, as disclosed in claim 2 , a further safeguard against accidents is achieved, in that a seepage of gas will result in an immediate disconnection of the gas supply by blocking of the flow.

To safeguard the control system against undesired in¬ terference by disconnection of the gas detector, for example as a result of vandalism, it is expedient, as disclosed in claim 3, for any interference to result in immediate disconnection of the gas supply.

The invention will now be described in more detail with reference to the drawing, which shows an example of an embodiment for installation in a building.

In the drawing is shown the outline of a building 9, which is divided into various rooms 10.

The gas installation is a single-line pipeline which is connected to a mains supply 1 by means of a ser¬ vice pipe 2.

In the service pipe 2 there is introduced an elec¬ trically-driven motor or solenoid valve 3, a volumen- ometer 4 and a control unit 5.

The gas is fed through a supply pipe 6 to the indi¬ vidual places of consumption via an outlet valve 7. In the individual rooms 10 are erected one or more gas detectors 8 which are connected to the control unit 5 via electric wires 11. These detectors can be mounted in such a way that they break the current be¬ tween the detector and the control unit whenever gas is present in the air in the room, whereupon the con¬ trol unit sends a signal via the cable 12 to the motor-valve 3, which immediately disconnects the sup¬ ply of gas to the building 9.

This control system will thus continually ascertain whether a seepage exists as a result of a leakage in the installation.

The control unit 5 is arranged to monitor a measure¬ ment of the flow of gas through the meter 4 for a period of, for example, 15 minutes, in order to as.- certain whether the consumption og gas exceeds the amount which, for example, a pilot light or the like consumes. If a "consumption" is ascertained in "such a period of measurement, the solenoid valve 3 is ac¬ tivated, in that the reason for "the consumption" must lie in a leakage in the hidden installation, or the seepage is below that level at which the gas de- tector 8 registers an escape.

The control unit 5 can be set to effect a continuous surveillance of the installation by controlling- whether an extraordinary consumption arises during a period of, for example, 30 minutes in a measuring cycle of either 12 or 24 hours.

The time for this control is not determined before- * hand, but must merely be within this measuring cycle. If an extraordinary consumption arises during this control, the solenoid valve 3 is activated so that the supply of gas is immediately disconnected.

Claims

C L A I M S

1. Gas-tightness control system for a single-string' gas installation, in which gas under pressure is led to one or more tapping points, c h a r a c t e r ¬ i z e d in that the system comprises an electrically -driven shut-off valve (3) inserted where the gas is supplied to the installation, plus a subsequent vol¬ umenometer (4) with electrical signalling, and an electronic control unit (5) which can send pulses to the shut-off valve (3) for cutting-off the supply.

2. Gas-tightness control system according to claim

1, c h a r a c t e r i z e d in that it further comprises one or more gas detectors (8) which are connected to the control unit (5) which in the event of the presence of free gas around the detec¬ tor (8) sends pulses to the shut-off valve (3) for cutting-off the supply.

3. Gas-tightness control system according to claim

2, c h a r a c t e r i z e d in that the gas detec¬ tor (8) is connected to the control unit (5) in such a way that a breaking of the connection (11) results in pulses to the shut-off valve (3) for cutting-off the supply.