HTPZ-8 The free swelling index tester consists of a programmable microcomputer temperature controller and a swelling index electric furnace. It is used to determine the swelling index of bituminous coal in crucibles in accordance with the requirements of the national standard “GB/T5448-2014 Determination of Swelling Index of Bituminous Coal in Crucibles – Electric Heating Method”, so as to judge the caking property of coal.

Place the coal sample in a self-expanding crucible and heat it to (820±5)℃ according to the specified procedure. Compare the obtained coke block with a set of numbered standard coke block side profile diagrams, and take the closest coke type number as the crucible swelling number. This method is applicable to coal, coking departments and scientific research institutions. The instrument uses resistance wires as heating elements and aluminosilicate fiber cotton as thermal insulation materials, featuring fast heating rate and low energy consumption. It is equipped with a coke measuring observation tube, which can directly compare the obtained coke block with a set of numbered standard coke block side profiles.

Technical Parameters:
power：Not more than 1000W；
Temperature measurement range：Room temperature ~ 999℃, Accuracy: Class 0.5, Resolution: 1℃, Thermocouple: Armored nickel-chromium K-type thermocouple;
Time measurement range：0～999min(99min59s) ； 
Timing accuracy: ±30s/24h, resolution: 1min;
Heating requirements: Meet the requirements of the national standard GB/T5448-2014;
power supply：220（1±10%）V   50Hz
Dimensions: Stove: diameter 225mm, height: 260mm, weight: 10kg;
Controller: 350 (length) × 300 (width) × 150 (height) mm, Weight: 4kg

Meet the standards：GB/T5448-2014和ASTM D 720

Device configuration：

1 controller, 1 furnace body, 2 thermocouples, 5 crucibles, 2 electric furnace wires, 1 electric furnace plate, 1 connecting wire, 1 crucible tongs, 1 quartz thermostatic dish, 1 focal observation tube.