drooping characteristic

linear characterisstic

rising characteristic

flat characteristic

2 cm

6 cm

8 cm

12 cm

from a metal wall from one medium to another

from heating an intermediate material and then heating the air from this material

by direct mixing ,

heat is transferred by bleeding some gases from furnace

water

dry steam

wet steam

super heated steam

100°C

above dew-point temperature of flue gases

below dew-point temperature of flue gases

less than wet bulb temperature of flue gases