Brick Insulation

Insulating Brick ASTM classifies insulating firebrick under C155 by group. The group number corresponds to the service temperature divided by 100 (Table 13). For example, group 16 corresponds to a test temperature of ca 1600°F (871°C). 

Table 13. ASTM C155 Insulating Brick Classification ...

When heavier refractories are required because of operating conditions, insulating brick is installed next to the shell and firebrick is installed to protect the insulating brick. Industrial experience in many fields of application has demonstrated that such a hning will success-billy withstand the abrasive conditions for many years without replacement. Most serious refractory wear occurs with coarse particles at high gas velocities and is usually most pronounced near the operating level of the fluidized bed. 

Insulating brick Varies 30-75 Varies Poor 65-85 Higt Poor Excellent Poor Poor... 

A furnace is constructed with 0.20 m of firebrick, 0.10 m of insulating brick, and 0.20 m of building brick. The inside temperature is 1200 K and the outside temperature is 330 K. If the thermal conductivities are as shown in Figure 9.7. estimate the heat loss per unit area and the temperature at the junction of the firebrick... 

Hence the temperature at the firebrick-insulating brick interface = (1200 — 137) — 1063 K. 

The heat loss through a firebrick furnace wall 0.2 in thick is to be reduced by addition of a layer of insulating brick to the outside. What is the thickness of insulating brick necessary to reduce the heat loss to 400 W/m2 The inside furnace wall temperature, is 1573 K. the ambient air adjacent to the furnace exterior is at 293 K and the natural convection heat transfer coefficient at the exterior surface is given by h S.OAT11 23 W/in2 K, where AT is the temperature difference between the surface and the ambient air,... 

Thermal conductivity of firebrick = 1.5 W/m K Thermal conductivity of insulating brick — 0.4 W/m K... 

Insulated dye developers, 19 285-286 Insulated gate bipolar transistors (IGBTs), silicon carbide in, 22 539—540 Insulating brick, ASTM classifications and specifications for, 21 508, 509t Insulating castables, classification of, 21 510t... 

Horizontal tube supports are made of refractory steel to withstand the high temperatures. Hangers for vertical tubes make for a less expensive construction per unit of tube surface. Furnaces are lined with shaped light weight refractory brick 5-8 in. thick. A 1 in. layer of insulating brick is placed between the lining and the metal shell. 

Clay fuses at from 2800 tit 3200T. tl53fi to 1760 0 the uppet limit being for flint clay and the lower for the plastic form which, due to its cc-mcming qualities, is especially valuable in fire-brick manufacture, Red brick is not suitable for refractory service, nor is insulating brick. There are several fire-clay furnace cements on the market that arc adaptable to monolithic lining. The standard sire of fire-brick and insulating brick is 9 inches by 4i inches by 2i inches 122.9 by 11.4 by 6.4 centimeters). 

We distinguish two kinds of insulation materials fibre materials and insulation bricks. I received information on this subject from the American firm BNZ Materials Inc. and its Dutch subsidiary INSULCON. They manufacture insulation bricks which are called Marinite. 

Insulation materials contain more air and have an lower apparent density than ordinary refractory materials. In the case of insulation bricks the desired porosity is obtained by making use of additives which produce gases when heated (e.g. calcium carbonate), or of porous raw materials. In figure 11.3. 2 the effect of the appplication of insulation bricks is represented. 

The objective of this theory is to insulate the combustible substrate (fuel) from attaining igniting temperature. The mastic becomes the thermal barrier for conductivity of heat of fire. It can accomplish this in two ways through rapid conductivity of the heat away from the fire, as illustrated by the wire gauze over the Bunsen burner, through very slow thermal conductivity as exemplified by a fire-insulating brick. 

If Ti K and T2 K are the temperatures at the firebrick/insulating brick and the insulating brick/building brick junctions respectively, then in equation 9.12, for conduction through the firebrick ... 

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