Insmart Hardgrove Grindability Tester
Heterogeneity in procured coal with varying percentages of combustible and non-combustible material brings another challenge to the coal consumer that is to continuously measure the resistance of coal to crushing. The measure of grindability can be obtained by using Hard Grove Grindability Index (HGI).
On popular demand from our customers Insmart has developed a compact coal grindability index determination unit. The unit is constructed in strict accordance with IS 4433 as well as ASTM D 409 and conforms to proposed procedures for the determination of the Hardgrove Grindability Index of coal and coke.
The Hardgrove Grindability Index value provides information for determining grinding power consumption and pulverizer capacities.
The HGI is worked out through a stepwise method:
- Digital cycle counter for setting the revolution of the machine and automatically stopping after desired revolution.
- A 50-gms sample of prepared coal that is uniform in size is placed within a bowl unit.
- The bowl unit undergoes a measured number of revolutions under a specified rotating load.
- Steel balls inside the bowl unit crush the coal sample.
- The coal fines are collected and the amount of coal lower than a specified size is noted and converted into a Hardgrove Grindability Index (HGI) value.
- Generally the resulting HGI Index values fall in between 30 (indicating higher opposition to pulverization) and 100 (indicating lesser resistance).
- The results allow users to formulate correct assessment of the power needed and resistance to grindability, factors that are important for optimizing plant processes.
- Accurate and precise computations obtained through Insmart HGI has helped customers in coal processing.