Howdy Filippo,
Certainly some good questions and thoughts on your part in regard to the article, thanks for raising them. On the matter of his article, I agree with your thoughts on the things you brought up and in fact, in regard specifically to emptying the collector daily, I think it was a suggestion to the fearful minded. He seems to do that a lot in the article to err on the extreme side of safety. For years, I've emptied my collector when the bag (clear poly) is visibly about half full. Mainly because it becomes quite heavy after that point. That would amount to about once every 6 months.
I am by no means an expert or a scientist in regard to static charge and the explosiveness of concentrated dust (or not). Through many years of use of dust collection in both private and industry, I do know that I have never personally experienced any explosions or flash fires. I have however heard of them in grain mills but not in cabinet or furniture shops small or large. My experience covers over 3 and 1/2 decades and I know of some in here that have much more than me. I hope to hear (especially from those professionally or with longevity) who have experience and or factually supported knowledge in regard to this matter.
He cites the 10 references at the bottom of his article but I have not endeavored to investigate further due to very limited time on hand. Thus the reason for activating this discussion in which I hope to find many interested enough to participate and opine.
Here are the references he offered;
Quote:
References:
Boschung, P., Widmer A., Hilgner W., Luttgens, G., Maurer B.: An experimental contribution to the question of the existence of lightning-like discharge in dust clouds. Journal of Electrostatics, vol. 3, no. 4, Nov., pp. 303-310, 1977
Crowley, Joseph M. : Fundamentals of applied electrostatics. John Wiley & Sons, Inc., 1986
Economou, George: Electrostatic generation while tank washing and ignition of hazards of fuel air mixtures. Master Thesis in Navel Architecture and Marine Engineering, MIT, 1975
Glor, M.: Discharges and hazards associated with the handling of powders. Inst. of Physics Conf. Ser no 85, section 3, pp 207-216, 1988.
OSHA (1997): OSHA hazard information bulletins: Improper installation of wood dust collectors in the woodworking industry. Information date 19970502
OSHA (1996): OSHA hazard information bulletins: Fire and explosive hazards associated with the biosolids derived fuel (BDF) and waste water treatment plants. Information date 19960408
OSHA (1988): OSHA hazard information bulletins: Static electricity buildup in plastic pipe. Information date 19880903
Ptasinshi, L.: Identification of hazards caused by static electricity in dust chambers. Journal of Electrostatics, vol. 17, issue 3, pp. 313-320, 1985
Schwenzfeuer K., Glor M.: Tests to determine the ignition of dust by brush discharges. Journal of electrostatics, vol. 30, issue May, pp. 115-122, 1993
Thomas, G.O., G.L. Oakley: Studies of the sensitivity of explosive dusts to ignition by electric sparks. Propellant, Explosives, Pyrotechnics, No. 15, pp. 201-207, 1990.
Boschung, P., Widmer A., Hilgner W., Luttgens, G., Maurer B.: An experimental contribution to the question of the existence of lightning-like discharge in dust clouds. Journal of Electrostatics, vol. 3, no. 4, Nov., pp. 303-310, 1977
Crowley, Joseph M. : Fundamentals of applied electrostatics. John Wiley & Sons, Inc., 1986
Economou, George: Electrostatic generation while tank washing and ignition of hazards of fuel air mixtures. Master Thesis in Navel Architecture and Marine Engineering, MIT, 1975
Glor, M.: Discharges and hazards associated with the handling of powders. Inst. of Physics Conf. Ser no 85, section 3, pp 207-216, 1988.
OSHA (1997): OSHA hazard information bulletins: Improper installation of wood dust collectors in the woodworking industry. Information date 19970502
OSHA (1996): OSHA hazard information bulletins: Fire and explosive hazards associated with the biosolids derived fuel (BDF) and waste water treatment plants. Information date 19960408
OSHA (1988): OSHA hazard information bulletins: Static electricity buildup in plastic pipe. Information date 19880903
Ptasinshi, L.: Identification of hazards caused by static electricity in dust chambers. Journal of Electrostatics, vol. 17, issue 3, pp. 313-320, 1985
Schwenzfeuer K., Glor M.: Tests to determine the ignition of dust by brush discharges. Journal of electrostatics, vol. 30, issue May, pp. 115-122, 1993
Thomas, G.O., G.L. Oakley: Studies of the sensitivity of explosive dusts to ignition by electric sparks. Propellant, Explosives, Pyrotechnics, No. 15, pp. 201-207, 1990.
That ought ta do it! 