In order to evaluate the flame-retardant capacity of KHCO₃ and ABC on the ignition of PMMA dust layer accumulation on hot surfaces, the ignition time and critical heating temperature of PMMA/KHCO₃ and PMMA/ABC dust layer were experimentally investigated. The thermal stability of the mixed dust, the condensed phase products and gas phase products of the mixed dust combustion were analyzed to reveal the flame-retardant mechanism. The ignition time of 30 μm PMMA was obviously longer than that of 5 μm PMMA, and the critical heating temperature was close to that of 5 μm PMMA. KHCO₃ and ABC could greatly extend the ignition time of the PMMA dust layer and increase the critical heating temperature of the dust layer. ABC was more effective than KHCO₃. The decomposition of KHCO₃ and ABC absorbed the heat and inhibits the pyrolysis of PMMA. The HPO₃ and P₂O₅ generated by the decomposition of ABC would cover the surface of PMMA aggregates or particles and act as a physical barrier. The main light combustible gas produced by PMMA pyrolysis were CO and C₂H₄. The CO₂ generated during the decomposition of KHCO₃ could dilute the combustible gas in the ambient to inhibit the combustion of PMMA.

为评价KHCO ₃和ABC对热表面堆积PMMA粉尘层点火的阻燃能力，对PMMA/KHCO ₃和PMMA/ABC粉尘层的点火时间和临界加热温度进行了实验研究。分析了混合粉尘、混合粉尘燃烧的凝聚相产物和气相产物的热稳定性，揭示了其阻燃机理。30 μm PMMA的点火时间明显长于5 μm PMMA，临界加热温度接近5 μm PMMA。KHCO ₃和ABC可以大大延长PMMA粉尘层的点火时间，提高粉尘层的临界加热温度。ABC 比 KHCO ₃更有效. KHCO ₃和ABC的分解吸收了热量并抑制了PMMA的热解。ABC 分解产生的 HPO ₃和 P ₂ O ₅将覆盖 PMMA 聚集体或颗粒的表面并充当物理屏障。PMMA热解产生的主要轻质可燃气体为CO和C ₂ H ₄。KHCO ₃分解过程中产生的CO ₂可以稀释环境中的可燃气体，抑制PMMA的燃烧。