| 摘要 |
<p>A method and apparatus for controlling combustion in a process heater (10) in which the flow of fuel (20) and oxidant are controlled pneumatically includes adjustable valve (82, 84) means to modify a signal to either an air flow control damper (50) or a fuel control valve (58) to maintain maximum thermal efficiency. Typically, a fuel control valve (58) and an air flow control valve (50) are pre-set, and then, in response to a signal according to the demands of the system, move in parallel. The ratio controller (82, 84) of this invention operates to allow an easy and efficient means of varying the ratio of fuel (20) to oxidant. </p> |
