What is the thermal stability of coal
The thermal stability of coal refers to coal in high temperature combustion or gasification process on the stability degree of heat, which is coal under high temperature and keep its original size properties. Good thermal stability of the coal, to its original size. Combustion or gasification but not broken into small pieces in the combustion or gasification process, or broken less; and poor thermal stability in coal combustion or gasification process is rapidly split into small pieces or coal. This light is slagging in furnace, increasing resistance and bring out the material, reduce the combustion or gasification efficiency, heavy damage to the entire gasification process, and even cause shutdown accidents. Therefore, there are requirements of coal enough thermal stability.
(2) 6~13 mm 6~13 mm. Determination of coal level of coal 500 cubic centimeters, said its weight in preheating to heating muffle furnace 850 DEG C for 90 minutes, then remove the weighing and screening. The "6" mm, 3 mm,% total weight and number of char < 1 mm as the stability index KP6, KP3 and KP1 index show that the greater the value, the poor thermal stability.Thermal stability classification of coalGrade thermal stability KP6,%Good thermal stability is less than or equal to 30Thermal stability medium 30~45Poor thermal stability 45
A variety of industrial boilers and gasification furnace has different requirements on the particle size of coal, so the method of measuring the thermal stability of coal is also different:(1) 13~25 mm level determination of lump coal. The method is to put the coal sample to muffle furnace heat of 850 DEG C during the preheating 15 minutes, calculate the percentage of the total level of sieve char; to all levels of the cumulative percentage and screen level (1, 3, 6, 13 mm) to make 100 curve. S+13 scores greater than 13 mm level char as indicators of thermal stability and thermal stability, as a percentage of S-1 curve is less than 1 mm level char as auxiliary index.
