Suitability of ignition source “exploding wire” for determination of dust explosion characteristics in the 20-L-sphere

• Comparative study of alternative igniter for dust explosion testing in 20-L-sphere.
• Comparison of explosion characteristics of 5 different dusts determined with pyrotechnical igniter and exploding wire.
• Comparison of flame propagation, max. flame volume, shape of flame and burning time for both ignition sources.
• Measurement of ignition energy of pyrotechnical igniter and exploding wire.

Several safety characteristics of dusts are determined in the 20-L-sphere (also known as SIWEK Chamber) according to international standards. Dust cloud ignition is carried out using pyrotechnical igniters. Due to various disadvantages of such igniters the need for alternative ignition sources arises again and again. An alternative could be an ignition source which is known as “exploding wire” or “fuse wire”. The paper presents test results of a comparative study between both ignition sources for the determination of the safety characteristics “Maximum Explosion Pressure” and “Maximum Rate of Explosion Pressure Rise” of five selected dusts in the 20-L-sphere. In addition to that the ignition mechanisms of both ignition sources were analyzed by high speed camera recordings and the ignition energy was determined with electric and calorimetric recordings. The paper shows results of measurements of the ignition energy of both ignition sources as well as sequences of the flame propagation.