Hope you are enjoying the posts and able to gain some insights from the blog.
Now for this week blog, I am touching on a more sensitive question, which people have asked me in almost all Electrostatic Hazard Seminars. "Can Non-Conductive Bag act as an ignition source?"
A non-conductive bag, being an insulator can act as a source of Brush Discharge which has approximate energy of up to 3-4 mJ associated with it. Depending on the type of flammable atmosphere, brush discharge from the non-conductive bag may/ may not act as an ignition source.
Based on the equivalent energy of brush discharges, it must be assumed that most potentially explosive gas/air mixtures, solvent vapor/air mixtures and hybrid mixtures (vapor/gas and dust with air) can be ignited by brush discharges.
Even though the MIE of certain dust is less than a few millijoules, no ignitions of dust clouds by brush discharges have ever been reported. On the basis of the present state of knowledge, therefore, brush discharges are very unlikely to ignite pure dust clouds containing no flammable gases or vapors.
It has to be remembered that if a non-conductive bag is used while charging of powder through manhole of a vessel containing solvent (which is, of course, a wrong practice), there is a possibility of ignition of a hybrid mixture of solvent vapor, dust, and air.
Apart from the issues of acting as a source of Electrostatic Discharge itself, charged surface of a non-conductive bag can always lead to the charging of isolated conductors (including operators) and other-plant items via Induction and these charged isolated conductors can in-turn become a source of discharge.
Also, as static charge generated on non-conductive bag accumulates, it leads to clinging of material to the bag. This not only increases the wastage but also increases the risk of dust cloud formation while folding of bags. Clinging to bags also increases the risk of bag shaking to remove the residual powder and henceforth the risk of electrostatic discharges.
It is always recommended to use dissipative bags with appropriate grounding.
Hope this clarifies the subject matter. Do share your comments and send your queries related to the subject.
For any topics you would like me to address in future, you can drop me an email on himanshuchichra@gmail.com.
Please do not forget to like, share and comment. Now you can also follow the blog via E-Mail without being concerned about any spams.
Now for this week blog, I am touching on a more sensitive question, which people have asked me in almost all Electrostatic Hazard Seminars. "Can Non-Conductive Bag act as an ignition source?"
A non-conductive bag, being an insulator can act as a source of Brush Discharge which has approximate energy of up to 3-4 mJ associated with it. Depending on the type of flammable atmosphere, brush discharge from the non-conductive bag may/ may not act as an ignition source.
Based on the equivalent energy of brush discharges, it must be assumed that most potentially explosive gas/air mixtures, solvent vapor/air mixtures and hybrid mixtures (vapor/gas and dust with air) can be ignited by brush discharges.
Even though the MIE of certain dust is less than a few millijoules, no ignitions of dust clouds by brush discharges have ever been reported. On the basis of the present state of knowledge, therefore, brush discharges are very unlikely to ignite pure dust clouds containing no flammable gases or vapors.
It has to be remembered that if a non-conductive bag is used while charging of powder through manhole of a vessel containing solvent (which is, of course, a wrong practice), there is a possibility of ignition of a hybrid mixture of solvent vapor, dust, and air.
Apart from the issues of acting as a source of Electrostatic Discharge itself, charged surface of a non-conductive bag can always lead to the charging of isolated conductors (including operators) and other-plant items via Induction and these charged isolated conductors can in-turn become a source of discharge.
Also, as static charge generated on non-conductive bag accumulates, it leads to clinging of material to the bag. This not only increases the wastage but also increases the risk of dust cloud formation while folding of bags. Clinging to bags also increases the risk of bag shaking to remove the residual powder and henceforth the risk of electrostatic discharges.
It is always recommended to use dissipative bags with appropriate grounding.
Hope this clarifies the subject matter. Do share your comments and send your queries related to the subject.
For any topics you would like me to address in future, you can drop me an email on himanshuchichra@gmail.com.
Please do not forget to like, share and comment. Now you can also follow the blog via E-Mail without being concerned about any spams.
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