Cesana-AG

Minimum Ignition Energy Apparatus MIKE 3

1992 - 2016 manufactured by Adolf Kuhner AG, Birsfelden, Switzerland

Apparatus for determining the minimum ignition energy of dust/air-mixtures

For an assessment of the hazard situation in dust-processing installations, knowledge of the minimum ignition energy is indispensable. This value can possibly determine the extent and hence the cost of protective measures.
The minimum ignition energy (MIE) is the lowest energy value of a high-voltage capacitor discharge required to ignite the most ignitable dust/air mixture.
This characteristic can be determined according to international standards:

EN 13821: Determination of minimum ignition energy of dust/air mixtures
ASTM E2019: Standard Test Method for Minimum Ignition Energy of a Dust Cloud in Air
EC 61241-2-3: replaced by ISO/IEC 80079-20-2:2016
ISO/IEC 80079-20-2:2016: Explosive atmospheres. Material characteristics. Combustible dusts test methods

Operation

A modified Hartmann tube made of glass with a volume of 1.2 liter is used as the explosion vessel. The dust dispersion system at the base of the tube is of the "mushroom-shaped" type around which the sample is loosely scattered. A blast of compressed air at 7 bar is used to disperse the dust in the glass cylinder where it is ignited by a spark between two electrodes.

Measurement Range

Experiments have shown that dust/air mixtures can easily have MIE values less than 10 mJ. The measurement range of the MIKE 3 has thus been extended to lower energy values. The high-voltage component has been specially designed for the low ignition energies. Thanks to pneumatically actuated high-voltage switches, the parasitic capacitances have been reduced by an order of magnitude. Energy range: 1mJ ... 1000mJ