Research On Explosion Characteristics Of Stearic Acid Dust And Explosion Suppression Technology

Stearic acid,has great hazard of fire&explosion,is wildly used in industrial production.However,the descriptions of experimental and theoretical research on stearic acid dust are lacking.Therefore,it is important to study stearic acid dust explosion and mechanism of dust explosion suppression can support the stearic acid dust explosion suppression with theory.This paper selects 20L explosion sphere to study the explosive characteristics of stearic acid dust.Firstly,the lower explosion limit,the maximum explosion pressure and the maximum explosion pressure rising rate were obtained with dust at different concentrations and particle sizes.In addition,the effects of the inhibitors were verified by dust explosion test of mixtures containing stearic acid dust and DAP/MAP.Finally,the mechanisms of two inhibitors and stearic acid dust were analyzed by using thermogravimetric analysis(TGA)based on the theory of combustion dynamics and thermodynamics and dust explosion.(1)The experimental results show that the particle sizes of 120～150μm,75～120μm,58～75μm,≤58μm stearic acid dust explosion limits are 20～30g/m3,20～30g/m3,10～20g/m3,10～20g/m3 respectively.(2)With the increasing of stearic acid dust particle sizes,the dust explosion severity and explosive sensitivity of stearic acid also be increased.Particularly,stearic acid dust presented a critical diameter(i.e.,58μm),where the explosion pressure has been significantly enhanced.(3)The maximum explosion pressure and its rising rate increased first and then decreased with the increase of dust concentration,and the combustion time decreased all the time.The explosion energy release and combustion rate of dust cloud increased with dust concentration at a certain range.(4)For sample four with particle size smaller than 58μm,the maximum explosion pressure of 1.12MPa and the maximum explosion pressure rising rate of 142.00MPa/s were obtained at the dust concentration 500g/m3,indicating the highest explosion sensitivity and severity degree of stearic acid dust.(5)The results indicate that mixtures of inhibitors obtain good results,while DAP perform better than MAP.Meantime,the efficiency of dust inhibitors improved by increasing concentration,while inhibitors presented a critical concentration(i.e.,50%),which the inhibitor has the best efficiency.(6)The experimental results show that MAP provides the highest thermal stability but the lowest rate of heat absorption of the mixtures.DAP exhibits a lower thermal stability in comparison to MAP,but exhibits a remarkable rate of energy absorption during its decomposition reaction.