| 摘要 |
PURPOSE:To prevent concentrated usage on specific burners by selecting order in such a manner that in an automatic controlling device of a boiler as heading, the number of times for ignition and extinction operations is memorized and the burners having the least number of operation times are selected primarily. CONSTITUTION:A counter 1 adds up the number of ignition and extinction of burners for each burner A-D on the basis of action signals from limit switches for open and closed valves of burners. Among burners A-D, burners having the least number of usage are selected by a comparator 2 for number of usage and logic 1 to that burners is transmitted and to other burners logic 0 is transmitted. When the number of usage is same, the order depends on predetermined order. On the other hand, a commanding transmitter 4 for increasing and reducing the number of burners outputs commands for increasing and reducing in response to required conditions. By this, a logic circuit 3 outputs action commands to burners having the least number of operations selected by the comparator for the number of usage. By this constitution, concentrated usage on specific burners is prevented. |
