1 Scope
This national standard specifies the principia of insulation design, structure option, insulating layer thickness calculation and material application as well as construction and acceptance check of industrial furnace.
This standard is applicable to the industrial furnaces used in the technical processes related to fusion, heat, heat treatment, sinter, firing, and so on.
This standard is not applicable to the inner lining of furnaces or parts with special purposes related to melting of metal, watercraft, nuclear energy and boiler., and so on.
2 Informative References
The following standards contain provisions which, through reference in this text, constitute provisions of this standard. At time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below:
Technical Guides for Evaluating the Rationality of Heat Usage in Industrial Enterprise GB/T 3486-93
Definitions and Terms of Thermal Insulating Materials GB/T 4132-84
Standard for Checking and Evaluating the Quality of Brickwork in Industrial Furnaces GB J50 309-92
Specifications for Construction and Acceptance of Industrial Equipment and Pipeline Heat Insulation GB J 126-89
Code for Construction and Acceptance of Industrial Furnaces Building GB J 211-87
3 Terms
This national standard adopts the following terms:
3.1 thermal insulation
In order to reduce the heat abstraction around the industrial furnace and its smoke exhaust and heat recovery system and ameliorate operational condition, it is adopted the measure of adding heat resistance and decreasing outside surface temperature.
3.2 lining
The inner lining of furnace stack (includes furnace arch, furnace wall, and furnace bottom) and its smoke exhaust and heat reclamation facilities which is built in flameproof heat insulator and used for industrial furnace.
3.3 refractory lining, insulation, outer protecting
Generality, the parts along the thickness direction of lining is composed in different materials; inside, the layer closes to high temperature is refractory, its outside is insulation. According to the demand, the insulation may be composed in different materials occasionally, it may be provided with two or more layers; at times, the insulation doubles as refractory lining.The steel plate of external application of insulation or other strong material protection is outer protecting.
3.4 Interface temperature
It is the temperature at the borderline between different materials which used in bricking-up at the time of operating furnace.
3.5 The other terms in this standard shall be in according with the requirements of GB/T 4132.
4.Insulation design and structure selection.
4.1 It is suitable to combine with the thermal insulation material at the time of choosing refractory to act as the working layer of bricking-up for industrial furnace.
4.2 For the industrial furnace, it is suitable to take thermal insulation material as the insulation for bricking-up at the time of giving priority to reduce heat elimination in surrounding environment; it is suitable to take the thermal insulation material as the working layer for bricking-up at the time of giving priority to reduce heat accumulation of bricking-up.
4.3 For the industrial furnace and its smoke exhaust and heat reclamation facilities, it is suitable to adopt different materials for the refractory lining and insulation of the bricking-ups in each part according to the different working temperature, and refractory coating in differ construction methods. After keeping warmth, the outside surface temperature of furnace stack is request not to exceed the temperature value specified in Table A6 of Appendix A in GB/T 3486. See Appendix A in this standard. (Standard appendix).4.4 Generality, the insulation of furnace stack shall be prescinded from supporting external force. It is suitable to adopt the measures of stratified support or hanging and reduce its influence of dead weight if the insulation dead weight exceeds the load that materials is able to support when furnace wall is working in over-high temperature. The parts of bottom of straight wall, back of skew brick and other stress section shall adopt the materials with enough strength and relevant service temperature.
4.5 It is suitable to adopt proper refractory and build for the door, orifice, hole and joint of high temperature furnace stack, its insulation is request not to reveal.
4.6 For the insulation exterior of furnace wall and parts where needs to keep the fastness and rigor for bricking-up, it is suitable to set steel shell and necessary steel structure, or other outer protecting.
