Presentation of HASLE Refractories A/S
Insulation and Heat Loss
www.hasle-refractories.com
hasle@hasle-refractories.com
Insulation
High-temperature processes require a considerable amount of energy. Often the energy consumption
for high-temperature processes is used only partially for the actual technical process and 30 to 40%
energy escapes through the walls into the atmosphere. To optimize the energy used and to prevent its
escape into the ambience, special materials called insulating refractories are necessary.
The function of insulating refractory is to reduce the rate of heat flow (heat loss) through the walls of
kiln/furnaces. Insulation is effected by providing a layer of material having low heat conductivity, which
means heat does not readily pass through them.
The choice of an insulating material must be based on its ability to resist heat conductivity, on the
highest temperature it will withstand and method to install it.
Insulating materials may be classified into the following groups:
1. Insulation Castable/Gunning
2. Insulation Bricks
3. Calcium Silicate Board
4. Ceramic Fiber
Insualation
Type of Insulation
1. Insulating Castables
Insulating castables are different from other castables in the way that the main component of the
castable is made from products with high porosity, or through the heating up/curing forming highly
porous structures.
Insualation
Type of Insulation
1. Insulating Castables
Advantages:
An insulating castable is very suitable to fill up the space between a strong hot face refractory lining
and a fibre insulation. The castable flows into all corners and cracks, and leaves no cavity. Besides, it
is easy and uncomplicated to handle.
Disadvantages:
Insulating castables usually have low refractoriness, low temperature application limits and low
mechanical strength, and they are therefore rarely applied as primary lining. In addition, they are not
resistant to slag and other chemical attack.
Insualation
Type of Insulation
2. Insulating Bricks
Insulating bricks differ from other bricks by greater porosity and thereby lower crushing strengths. The
advantage of an insulating brick is that it can be used both as primary lining and back lining.
3. Calcium Silicate
Calcium Silicate is an insulation material molded by reacting calcium silicate powder with high pressure
heat, and mixing it with inorganic fiber. It is easy and fast for installation.
Insualation
Type of Insulation
4. Ceramic Fibre
It can be spun or blown into bulk, air-laid into a blanket, folded into modules, converted into papers,
boards, and shapes, die-cut into gaskets, twisted into yarns, woven into rope and cloth, and blended
into liquid binders for mastics and cements.
They are used in areas where good insulating properties are needed - for packing and for expansion
joints. If there is no mechanical wear, ceramic fibre can be used as the only refractory material in
contact with the process - e.g. in kilns for heat treatment of metal, glass etc.
Heat Transfer
Sample:
Shape:
Hot Face Temperature:
Ambient Temperature:
Type of Out Side Surface:
Convektion Cold Face:
Square
1,000 Degree C.
30 Degree C.
Absolute Black Surface.
Natural
They install Castable+Insulating Castable+Calciumsilicate Board and would like to know approximated
temperature outside?
Heat Transfer
Sample:
Estimate for temperature and energy potential.
Castable D59A
Insulating Castable BS1200
Calciumsilicate Board
Thickness (mm).
Energy (MJ/m2)
95
109
50
254
218
178
4
400
Temp (Degree C)
1,000
932
760
109
Heat transfer 1,123 W/m2
D59A
BS1200
Cal
1,000 C
30 C
1,000 C
932 C
760 C 109 C
D59A 95mm. + BS1200 109mm. + Cal 50mm.
Heat transfer 1,123 W/m2
Heat Transfer
We fix total lining thickness 254mm. and we can design refractories lining:
D59A
BS1200
Cal
95mm.
109mm.
50mm.
D59A
95mm.
1,000 C
Cal
BHI1200
109mm.
50mm.
1,000 C
932 C
1,000 C
Heat transfer 1,123 W/m2
95mm.
109mm.
50mm.
951 C
30 C
614 C 91 C
1,000 C
Heat transfer 779 W/m2
BS1200
95mm.
Fiber
30 C
760 C 109 C
D59A
BS1200
1,000 C
30 C
1,000 C
D59A
159mm.
BHI1200
95mm.
159mm.
1,000 C
30 C
1,000 C
837 C
Heat transfer 2,648 W/m2
177 C
738 C 115 C
Heat transfer 1,218 W/m2
D59A
1,000 C
926 C
30 C
1,000 C
925 C
Heat transfer 1,235 W/m2
116 C
Heat Transfer
Sample:
Shape:
Hot Face Temperature:
Ambient Temperature:
Type of Out Side Surface:
Convektion Cold Face:
Square
1,300 Degree C.
30 Degree C.
Absolute Black Surface.
Natural
They install Castable+Insulating Castable+Calciumsilicate Board and total thickness is 250mm.
Heat Transfer
We fix total lining thickness 250mm. and we can design refractories lining:
D59A
BS1200
Cal
100mm.
100mm.
50mm.
1,300 C
D59A
Cal
100mm.
150mm.
1,300 C
30 C
1,300 C
1,197 C
30 C
981 C 136 C
1,300 C
Heat transfer 1,674 W/m2
1,250 C
Heat transfer 809 W/m2
D59A
200mm.
Cal
50mm.
1,300 C
30 C
1,000 C
1,067 C
Heat transfer 1,889 W/m2
146 C
93 C
QUESTIONS?
THANK YOU
Acid Dew Point:
Waste containing acidic components form combustion products which are corrosive when combined
with water. Methyl Chloride contains chlorine, which forms HCl. When cooled to 120 - 150oF, the water
vapor / HCl mixture in the flue gas condenses. Corrosion of refractory or vessel shell material results.
Sulfur compounds burn to form SO2 and SO3 (usually 3 to 10% ends up as SO3). The SO3 combines
with water vapor when flue gas cools to the dew point temperature - often between 200 and 400o F,
condensing to form H2SO4. Dewpoint problems often occur at the furnace shell when the
refractory/rainshield system allow a low shell temperature.
Refractory linings are relatively porous. Flue gas components penetrate to the steel shell. If the shell
temperature is below the acid dewpoint of the gas, condensation will occur