Download Heating Methods - Clarkson University

Some Heating Methods
W.R. Wilcox, Clarkson University, November 2002
From Perry’s 7th edition, Turton, Bailie, Whiting, Shaeiwitz 1st edition, and the author’s experience. Maximum temperature
achievable depends on heat transfer method (radiant, conductive, convective) and materials involved. Values are very approximate.
Heating method
Example applications
Steam: Building heating
Low pressure proc stm
Medium pressure
High pressure
Fired: coal in air
methane in air
acetylene in air
hydrogen in oxygen
Electric resistance in air:
nichrome
platinum (expensive)
Kanthal (MoSi2?)
silicon carbide
Electrical resistance in inert
atmosphere: graphite
Induction
Room heating
Process stream heating
Process stream heating
Process stream heating
Metallurgical furnaces, steam generation
Home heating, process stream heating, steam generation
Welding
Working fused silica (“quartz”), i.e. pure SiO2
Lamps
Laser
Thermit reactions
Solar
Nuclear reactors
Geothermal
Home appliances (e.g. toasters, heaters), lab furnaces, furnaces requiring
special T profiles, e.g. for chemical vapor deposition and annealing in
the semiconductor chip industry, growth of crystals for night vision
sensors.
Very high temperature needed with good control, e.g. growth of all
silicon crystals used in chips & electronics.
Heating conductors rapidly or inside a cooler exterior, e.g. metal
processing and growth of crystals of YAG, sapphire, cubic zirconia,
silicon for sensors in digital cameras.
Rapid thermal annealing after ion implantation, localized heating.
Welding, drilling, surface melting.
e.g., Al + Fe2O3  Al2O3 + Fe (melt) for welding, manufacture of
cermets. (“Self-propagating High-temperature Synthesis, SHS”)
Commercial applications unknown
Substitute for other heating sources, e.g. for steam generation
Used in Iceland to generate steam for heating & electric power
Approx max
process T (oC)
120
150
170
240
1000
1000
1500
1500
Approx 1996
cost ($/GJ)
1000
1500
1300
1500
17
2200
2200
3.2
3.7
5.1
2.5
17
Efficiency low
except with
some steels
1600
Efficiency low
Depends on type
Efficiency low
2000
depends on
chemicals used
limited by container needs sunshine
limited by materials