Design Guidelines for High Performance Industrial Furnaces - High Temperature Air Combustion: From Energy Conservation to Pollution Reduction - page 318

Heat pattern

Treating temperature

Temperature at
the discharging

Room
temperature

Period of heating
and soaking

Period of cooling

FIGURE 5.75 Heat pattern of heat treatment furnace.

C F = heat content at heat-treating temperature

C room = heat content at room temperature

M = mass of heating materials

2. Heating metal fittings in furnace H MF
H MF = M MF ( C F - C exit )

C F = heat content at heat-treating temperature

C exit = heat content at temperature of discharging point

M MF = mass of metal fittings

3. Heating furnace wall H WL

H WL = C INS M INS ( T F - T exit )

T F = average temperature of wall at treating

T exit = average temperature of discharging point

C INS = specific heat of insulator

M INS = mass of insulator

4. Emission heat capacity from furnace wall H emis

H emis = qA ∆ t

q = unit emission heat

A = surface area of furnace

t = time of heating and soaking

5. Heating atmosphere gas H circ

= ∑

H η ∆ T t

circ j

j