Insulation material for refractory
The role of insulating materials is to minimize heat losses from the high temperature reactors. These materials have low thermal conductivity while their heat capacity depends on the bulk density and specific heat. Insulating materials are porous in structure; excessive heat affects all insulating materials. Choice of insulating materials would depend upon its effectiveness to resist heat conductivity and upon temperature. High alumina with thermal conductivity 0.029 kcal m℃, and silica with thermal conductivity 0.042 kcal m℃ etc are amongst others, used as insulating materials.
Ceramic fibres are important insulating materials and are produced from molten silica, titania, Zirconia etc in the form of wool, short fibres and long fibres. They have excellent insulation efficiency. They are long weight.
Calcium Silicate: Used in industrial process plant piping where high service temperature and compressive strength are needed. Temperature ranges varies from 40 °C to 950 °C.
Glass mineral wool: These are available in flexible forms, rigid slabs and preformed pipe work sections. Good for thermal and acoustic insulation for heating and chilling system pipelines. Temperature range of application is –10 to 500 °C.
Thermocol: These are mainly used as cold insulation for piping and cold storage construction
Expanded nitrile rubber: This is a flexible material that forms a closed cell integral vapour barrier. Originally developed for condensation control in refrigeration pipe work and chilled water lines ,now-a-days also used for ducting insulation for air conditioning.
Rock mineral wool: This is available in a range of forms from light weight rolled products to heavy rigid slabs including preformed pipe sections. In addition to good thermal insulation properties, it can also provide acoustic insulation and is fire retardant