Study On Explosion Characteristics And Preventive Measures Of Lens Dust Of Thermosetting Resin

In the process of industrial production,dust explosion accidents occur from time to time.Thermosetting resin lens dust is a kind of combustible dust.In the background of lens production becoming larger and larger,the risk of dust explosion cannot be ignored.In order to grasp the explosion characteristics of thermosetting resin lens dust and the protective measures,and provide guidance of safety control to enterprises,the author has had field investigation of the resin lens production process,and taken the experiment test,numerical simulation,the theoretical research,also made application to a lens factory,the main contents are as follows:(1)Experimental study on explosion characteristics of thermosetting resin lens dust.Using CR-39 and MR resin as raw materials,the minimum ignition energy(MIE),minimum ignition temperature of dust cloud(MITC),minimum ignition temperature of dust layer(MITL),lower limit of explosion(LEL)and maximum explosion pressure(Pmax)of dust cloud were studied by hartmann tube,g-g furnace,hot plate furnace and 20L spherical explosion tank,etc.By changing the dust concentration,the relation curve between the dust concentration and the maximum explosion pressure and the rise rate of explosion pressure was obtained.The experimental results provide a basis for the formulation of dust explosion protection measures.(2)Using the software of ANSYS Workbench,the stress and deformation of dust collector during dust explosion are simulated and analyzed.By changing the wall thickness of the dust collector,the relationship curve between the wall thickness and stress and deformation is obtained.The results show that for the dust collector made of Q235-B material,the wall thickness of 3mm is a reasonable thickness to ensure that the stress of the dust collector is within the yield strength.When the dust concentration in the dustcollector is 500g/m~3,the stress of the dust collector caused by explosion is the maximum.When the dust concentration in the dust collector is controlled at 60g/m~3,the maximum stress of the dust collector is below the allowable stress,which is safe and reliable.(3)According to the risk engineering principle,the dust explosion accident protection measures is put forward.Covering measures to reduce the probability of accidents and to reduce the severity of accidents from four aspects:improving explosive environment,controlling ignition source,structural explosion protection and organizational management measures.(4)Application in a thermosetting resin lens production enterprises for example.Based on the theory of dust explosion pentagon,this paper analyzes the specific causes of three dust explosion accidents,and adopts a series of protective measures,including changing the grinding process to improve the dust particle size,installing spark detector extinguisher in the dust removal pipe to suppress the explosion,adopting dust collector with sufficient anti-explosion ability,and wet dust removal.The dust concentration in the field after improvement was detected by dust tester,which was much better and the effectiveness of the measures was verified finally.