I was wondering if I could get some direction for calculating insulation thickness.
Problem -
I am installing a quench vessel which is rubber lined + bricked lined with an inlet and outlet flange for a hot corrosive application.
The rubber lining is extending over inlet flange face.
A 30" duct gets connected to the inlet flange. The duct carries gases that are about 600 deg F at draft pressures -2" WC
The rubber lining inside the vessel is protected by heat resistant bricks.
I am worried when the inlet duct gets connected, the rubber lining on flange face will get damaged due to high temperatures in the duct. Rubber will deteriorate at 250 F.
I really do not want to modify the 30" inlet duct (lot of work).
I want to insert a fiberfrax paper of right thickness so that rubber will not see the higher temperatures. Fiberfrax will act as gasket and insulation between the surface.
Can someone point to a calculation to figure of the insulation thickness?