The importance of controlling pollution in the industrial sector is equal to that in the household sector. One of the ways of doing this right is a draft controller. They modulate the boiler outlet damper in order to maintain a constant pressure in the combustion chamber, where they come into utilization. Any boiler that will be operated at a negative draft requires to have a draft control system. A precise draft control - "gap" pid draft control and firing rate feed forward assure stable draft even during load changes. This is especially important for outlet draft control on boilers with induced flue gas recirculation (fgr) nox reduction. The draft cutoff switch is required for a positive pressure and hence, the controller is configured with the draft cutoff switches white wire on terminal 9, the blue wire on terminal 10, the red wire on terminal 11, and the air switch connected to the bottom draft cutoff port. These pollution control devices do not work without the signal from the actuator and it has a small clock hand on the display, which rotates when everything is working.
