Presentation of HASLE Refractories A/S Insulation and Heat Loss

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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 Bricks3.Calcium Silicate Board4. 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 CastablesAdvantages:

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 TransferSample:  Shape: SquareHot Face Temperature: 1,000 Degree C.Ambient Temperature: 30 Degree C.Type of Out Side Surface: Absolute Black Surface.Convektion Cold Face: Natural

They install Castable+Insulating Castable+Calciumsilicate Board and would like to know approximated temperature outside?

Heat TransferSample: Estimate for temperature and energy potential. 

Thickness (mm). Energy (MJ/m2) Temp (Degree C)  1,000Castable D59A 95 218 932Insulating Castable BS1200 109 178 760Calciumsilicate Board 50 4 109  254 400

Heat transfer 1,123 W/m2

1,000 C

1,000 C 932 C 760 C 109 C

30 C

D59A BS1200 Cal

D59A 95mm. + BS1200 109mm. + Cal 50mm.Heat transfer 1,123 W/m2

Heat TransferWe fix total lining thickness 254mm. and we can design refractories lining:

Heat transfer 1,218 W/m2

1,000 C

1,000 C 926 C 738 C 115 C

30 C

D59A BS1200 Fiber

95mm. 109mm. 50mm.1,000 C

1,000 C 932 C 760 C 109 C

30 C

D59A BS1200 Cal

Heat transfer 1,123 W/m2 Heat transfer 779 W/m2

1,000 C

1,000 C 951 C 614 C 91 C

30 C

D59A BHI1200 Cal

Heat transfer 2,648 W/m2

1,000 C

1,000 C 837 C 177 C

30 C

D59A BS1200

Heat transfer 1,235 W/m2

1,000 C

1,000 C 925 C 116 C

30 C

D59A BHI1200

95mm. 109mm. 50mm. 95mm. 109mm. 50mm.

95mm. 159mm. 95mm. 159mm.

Heat TransferSample:  Shape: SquareHot Face Temperature: 1,300 Degree C.Ambient Temperature: 30 Degree C.Type of Out Side Surface: Absolute Black Surface.Convektion Cold Face: Natural

They install Castable+Insulating Castable+Calciumsilicate Board and total thickness is 250mm.

Heat TransferWe fix total lining thickness 250mm. and we can design refractories lining:

1,300 C

1,300 C 1,197 C 981 C 136 C

30 C

D59A BS1200 Cal

Heat transfer 1,674 W/m2

100mm. 100mm. 50mm.

1,300 C

1,000 C 1,067 C 146 C

30 C

D59A Cal

Heat transfer 1,889 W/m2

200mm. 50mm.

1,300 C

1,300 C 1,250 C 93 C

30 C

D59A Cal

Heat transfer 809 W/m2

100mm. 150mm.

 

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