Kettle fire box
any suggestions on design/build of a fire box for a direct fired 15bbl kettle?
as always the all of your combined wisdom is greatly appreciatied.
Read the section in de Clerck's book on fireboxes. Use multiple exhaust outlets so hot gas has more contact area with kettle...in fact, do everything possible to increase contact area with hot gases. Insulate well. Have a port so you can see the burner flames, ideally including as they lick the kettle bottom. Install baffles so hot gas can't make a quick exit. Understand burner mfr's instructions. Use barometric dampers and thermometers on each exhaust. An exhaust gas analyzer is about $800 but is really cool. Design kettle skirt and/or brewhouse floor so as to minimalize washdown or boilover liquids getting under the kettle. Protect concrete floor under burner from heat damage. Install burner in such a way that it is finely adjustable for precise distance to kettle bottom, as well as easily removed for frequent jet maintenance.
Remember that each even tiny improvement you can make in efficiency will pay off in less fuel, less greenhouse gases, a better boil, and less time waiting for heating.
Hope something here is useful.