Citation

Song SX, Cheng YF, Wang WT, Wang ZH, Zhang BB. J. Hazard. Mater. 2021; 416: e125783.

Copyright

(Copyright © 2021, Elsevier Publishing)

DOI

10.1016/j.jhazmat.2021.125783

PMID

unavailable

Abstract

In order to investigate the explosion process of calcium carbide (CaC(2)) dust in the acetylene (C(2)H(2)) atmosphere, the explosion characteristics of C(2)H(2) gas and C(2)H(2)/CaC(2) dust gas-solid two-phase mixture were studied using a 20-L spherical vessel, and the chemical composition of solid residues after explosion were also analyzed. Experimental results showed that the P(ex) values of C(2)H(2) gas explosion rose first and then remained stable with the increasing stoichiometric ratio values (φ) of C(2)H(2)/air, while the (dP/dt)(ex) values tended to increase at early stage and then decrease, the inflection point of (dP/dt)(ex) values was φ = 1.78. The explosion severity and risk of C(2)H(2) gas were enhanced by adding CaC(2) dust, and the optimum additive concentration of CaC(2) dust was 100 g/m(3). In the oxygen atmosphere, the C(2)H(2)/CaC(2) hybrid explosion was divided into two stages when the concentration of CaC(2) dust was over 300 g/m(3). The explosion risk of the first stage (Stage Ⅰ) was much more serious, while the explosion severity of the second stage (Stage Ⅱ) was much more fierce. The solid residues of hybrid explosion only contained CaO in the oxygen atmosphere, however, Ca(OH)(2) and CaO were detected in the solid residues in the air atmosphere, owing to the combustion heat of C(2)H(2) gas in oxygen was higher than that in air. The hydrolysis reaction time of CaC(2) particle with large particle size was prolonged, and the diffusion of solid product layer and surface chemical reaction both influenced the hydrolysis process according to the shrinking core model. Based on the explosion and chemical analysis experiments, the explosion mechanism of C(2)H(2)/CaC(2) dust gas-solid two-phase mixture was analyzed systematically.

Language: en

Keywords

C(2)H(2); CaC(2) dust; Explosion residue; Gas-solid two-phase; Shrinking core model