| 摘要 |
PURPOSE:To enable variation of a combustion output without increasing the working frequency of a solenoid valve, by a method wherein according to a command from a pulse controller, combustion of a burner or its group is periodically brought, in a given order, into an ON and an OFF-state, and the length of combustion duration between ON and OFF of combustion of a burner is regulated. CONSTITUTION:A combustion time controller 9 regulates the set times of holding timers 10a-10e according to an output signal from o PID regulator 7. The holding timers 10a-10e are started upon receipt of a pulse signal from a pulse controller 8, and with solenoid valves 3a-3e, 4a-4e opened, fuel and air are fed to burners 1a-1e for combustion. The combustion is continued until the set times of the holding timers 10a-10e, set by a combustion time controller 9, are completed, and when the set time elapses, the solenoid valves 3a-3e, 4a-4e are closed to stop combustion of the burners 1a-1e, respectively. This constitution enables a combustion output to be varied in a wide range without increasing the working frequency of each solenoid valve. |
