Test apparatus
1, an overview of the
1.1 the inspection device shall meet the specified conditions. The typical design of heating furnace is shown in appendix B of GB/ t5464-2010 "test methods for noncombustibility of building materials". Other heating furnace designs that meet the standards can also be adopted.
1.2 the device is a heating furnace system. The heating furnace system has a refractory pipe of electric heat coil, which is covered with an insulating layer. The cone-shaped air stabilizer is fixed at the bottom of the heating furnace, and the air hood is fixed at the top of the heating furnace.
1.3 the heating furnace is installed on the bracket and equipped with sample holder and sample holder insertion device
1.4 the thermocouple shall be arranged to measure the furnace temperature and wall temperature in accordance with the provisions of 4.4. If it is required to measure the surface temperature and center temperature of the sample, the additional thermocouple details are given in appendix C of GB/ t5464-2010. The contact thermocouple shall conform to the standards and shall measure the temperature in the furnace along its central axis.
2. Heating furnace, bracket and air cover
2.1 heating furnace tube shall be made of bauxite refractory with a specified density of (2800 + + 300kg/m3), height (150-100kg /m3)mm, inner diameter (75th-1mm)mm, wall thickness (10 + / 1mm)mm
2.2 the heating furnace tube shall be positioned at the center of a cylinder tube when it is made of heat insulation material with a thickness of 150mm and a top plate and a bottom plate with an inner concave edge so as to locate the heating furnace tube. The annular space between the heating furnace tube and the cylinder tube shall be filled with appropriate thermal insulation materials. For typical thermal insulation filling materials, please refer to appendix B of GB/ t5464-2010 "test methods for noncombustibility of building materials".
2.3 the bottom surface of the heating furnace is connected with an inverted conical air stabilizer with an opening at both ends, whose length is 500mm, and uniformly reduced from the top with an internal diameter of (75 + + 1)mm to the bottom with an internal diameter of (10 + + 0.5)mm. The air stabilizer is made of 1mm thick steel plate. Its inner surface should be smooth. The upper part of the air stabilizer adopts appropriate materials for external thermal insulation. For typical external thermal insulation materials, please refer to appendix GB/ t5464-2010 test method for non-combustibility of building materials B.
2.4 the air cover is made of the same material as the air stabilizer and installed on the top of the heating furnace. The inner surface of the junction with the heating furnace should be smooth. The exterior of the air shield shall be insulated with appropriate materials.
2.5 the combination of heating furnace, air stabilizer and air cover shall be installed on the stable horizontal support. The bracket has a base and airflow screen, which is used to reduce the airflow force at the bottom of the stabilizer. The airflow screen is 550mm high, and the bottom of the stabilizer is 250mm higher than the bottom of the bracket.