Custom Analysis

Dust Explosion

Low Explosion Limit (Blower-type)

Dust Explosion

This test determines whether a powder is explosive or not.
After dispersing powders in a case by compressed air, the powder ignitability is determined by electric sparks. Under a certain concentration, powders do not explode. That concentration is the low explosion limit and the risk of dust explosion is judged from this value.

0 < concentration ≦40 High risk
40 < concentration ≦100 Medium risk
100 < concentration Low risk
(※It does not mean there is no risk)

Explosion Limit Oxygen Concentration

This test determines at what oxygen concentration the risk of explosion goes away If a powder is explosive.
Oxygen concentration is adjusted by adding nitrogen gas to compressed air. Test method is the same to the above.
With the most powders, when the oxygen concentration is under 12-13%dust explosion does not occur. However, some metal powders and fine organic powders may explode at several % of oxygen concentration.

Minimum Ignition Energy

This test determines how easy a powder ignites by changing electric spark energy. Test method is the same to the above.
Risk of ignition influenced by static electricity is determined by ignition energy.
0mJ < ignition energy ≦10mJ High risk
10mJ < ignition energy ≦100mJ Medium risk
100mJ ≦ ignition energy Low risk

Max Explosion Pressure / Pressure Rise Rate

This test is to evaluate intensity of powder ignition and to estimate emission area of explosion emission outlet. 20~30L spheric dust explosion tester is used. Intensity of explosion is shown in Kst value and classified as follows. Class 0 Kst = 0 Non explosion Class 1 0 < Kst ≦ 200 Low-intensity explosion Class 2 200 < Kst ≦ 300 High-intensity explosion Class 3 300 < Kst Extremely high-intensity explosion