Posted 26 Aug 2013 (edited) I want to know the concept of the attached P&ID drawing. Please explain the concept of the P&ID drawing inside of the red box.(Boiler Control) Thanks for your help in advance. Edited 26 Aug 2013 by Tom749 Share this post Link to post Share on other sites
Posted 26 Aug 2013 Tom, Your question is not really easily answered in a chat topic in a forum. Might I suggest you locate a purchase a book called "The Control of Boilers", 2nd Edition or later, by Sam G. Dukelow. You will find this on Amazon or ISA websites. Also consider purchasing a reference book for understanding and reading of SAMA logic diagrams. Share this post Link to post Share on other sites
Posted 27 Aug 2013 HI, I'll take a stab at explaining the controls in the red box in a general way. 2 variable out puts from that controller, fuel and air. 2 inputs, O2 from the stack sensor, and looks like some mysterious "Fuel Demand" is the other This seems strange compared to what I'm used to. I am used to seeing boiler pressure as a controlling input to the fuel and air flow. Also I usually see a mechanical air damper controlling the air flow, not a motor speed controller. Anyhow, the whole concept of the red box is to control flow of fuel & air for combustion in the boiler, while maintaining the desired ratio. One variable flow control valve on the fuel line & one variable speed air fan. Of course the devil is in the details. That is my $0.02 BD Share this post Link to post Share on other sites