Quantitative Risk Assessment Of Grain Dust Explosion

Grain industry is of frequent occurrence of dust explosion. On the background of Qinhuangdao Lihua starch factory major dust explosion accidents, through the experiment the formation of dust cloud was simulated. The risk of grain dust explosion accidents was evaluated quantificationally, in order to provide theoretical guidance for preventing such accidents and strengthening the safety management.At first, A simulation experimental system of dust cloud formation and simple concentration test device of dust cloud were built independently. The experimental system of dust cloud formation consists of air supply device, raising dust device, concentration test device, dynamic data collection and analysis device. By changing the pressure, nozzle diameter and injection direction, thickness of the dust accumulation and so on, the weight of raised dust was tested. Through the self-designed concentration test device to observe the change of the concentration of dust cloud in one position under different parameters, the preliminary rule of formation of corn starch dust cloud was studied. Through the experiment, the quality of raising dust in the vertical direction is more than horizontal direction under the condition of changing direction of injection, and in the experimental range there exist the critical velocity. When the direction is vertical, the critical speed is 1.94 m/s. The quality of raising dust under this speed is heavier, so it is easy to form dust cloud.Then the risk of grain production and operation environment is evaluated quantificationally with the catastrophe progression method. Firstly, the general target was decomposed according to the mechanism of corn starch explosion and risk factors of dust explosion, and the influence factors of the dust cloud formation in the process of evaluation were considered. The results show that the risk level of area of corn starch dust explosion is class 5, very dangerous, which reappears Lihua starch factory dust explosion accidents. It shows that this evaluation method is feasible. At last, based on the evaluation results the improvement measures for preventing the occurrence of dust explosion is putting forward. Thesis research results have certain application reference value for the prevention and control of such accidents.