| 摘要 |
PURPOSE:To shut-off gas supply whenever gas volume approaches the lower limit of explosion or exceeds the same avoiding the explosion due to the combustion of the gas not yet consumed by a method wherein the volume of the gas passing through a gas supply line is measured while the volume of the gas to be supplied for the room is constantly calculated. CONSTITUTION:A processor circuit 11 comprises a memory circuit 12 individually memorizing the total flow rate per specified time interval measured by a gas flow rate meter 7, a damping coefficient set up circuit 13 setting up the damping coefficient of the gas concenration within respective time interval preliminarily calculated by the air volume and the ventilation frequency of a room 10, a calculation circuit 15 calculating the gas volume in the room 10 at this time, a set up circuit 14 setting up the explosion lower limit of the gas concentration in the room 10 and the decision circuit 16 transmitting signals to a shut off valve 6 after comparing the calculated value by the calculation circuit 15 with the set up value by the set up circuit 14. The explosion due to supplied gas may be avoided with the exception of a peculiar case by means of shutting-off the gas using this system whenever a gas volume approaches or exceeds the lower limit of explosion. |
