Effect of powder inhibitors on ignition sensitivity evolution of wood-plastic mixed dust: Based on thermal decomposition behavior and deflagration residues

The ignition temperature (IT) of the dust cloud is one of the main parameters of combustible dust deflagration risk assessment. Since the previous research focuses on the IT of single dust, in order to reduce the deflagration risk of mixed dust, the effects of dust concentration and dispersed pressure on the IT of wood plastic mixed dust and the inhibition effects of different powder inhibitors were investigated through experiments. The thermal decomposition behavior of the mixed dust was studied by comprehensive thermal analysis, and the surface characteristics of the deflagration products were analyzed by FTIR spectra, thus revealing the inhibition mechanisms of inhibitors on ignition sensitivity of mixed dust. The results showed that the best ignition conditions for wood-plastic mixed dust were 300 g/m(3) and 15 kPa. Ammonium polyphosphate (APP) and aerosil had significant inhibition effects on the ignition sensitivity of wood-plastic mixed dust, and the inhibition effect was better with the increase of inerting ratio. Their inhibition mechanisms are different, and the inhibition effect of APP is better. It was worth noting that APP can promote the initial decomposition of wood-plastic mixed dust, resulting in accelerated dehydration and carbonization rate of mixed dust and improved thermal stability. (C) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.

Automated summary

The ignition temperature of combustible dust is an important parameter for assessing the risk of dust deflagration. This study investigated the effects of dust concentration and dispersed pressure on the ignition temperature of wood plastic mixed dust, as well as the inhibition effects of different powder inhibitors. The study also analyzed the thermal decomposition behavior of the mixed dust and the surface characteristics of the deflagration products, revealing the inhibition mechanisms of the inhibitors. The results showed that ammonium polyphosphate and aerosil had significant inhibition effects on the ignition sensitivity of wood plastic mixed dust, with ammonium polyphosphate exhibiting a better inhibition effect.