Inhibition Effect of KHCO 3 and KH 2 PO 4 on Ethylene Explosion.

The explosion risk of ethylene (C 2 H 4 ) seriously hinders safe development of its production and processing. To reduce the harm caused by C 2 H 4 explosion, an experimental study was conducted to assess the explosion inhibition characteristics of KHCO 3 and KH 2 PO 4 powders. The experiments were conducted based on the explosion overpressure and flame propagation of the 6.5% C 2 H 4 -air mixture in a 5 L semi-closed explosion duct. Both the physical and chemical inhibition characteristics of the inhibitors were mechanistically assessed. The results showed that the 6.5% C 2 H 4 explosion pressure ( P ex ) decreases by increasing the concentration of KHCO 3 or KH 2 PO 4 powder. The inhibition effect of KHCO 3 powder on the C 2 H 4 system explosion pressure was better than that of the KH 2 PO 4 powder under similar concentration conditions. Both powders significantly affected the flame propagation of the C 2 H 4 explosion. Compared with KH 2 PO 4 powder, KHCO 3 powder had a better inhibition effect on the flame propagation speed, but its ability to reduce the flame luminance was less than KH 2 PO 4 powder. Finally, the inhibition mechanism(s) of KHCO 3 and KH 2 PO 4 powders were revealed based on the powders' thermal characteristics and gas-phase reaction.