Abstract
Most of combustible dusts present both fire and explosion hazard. Explosion may occur at certain concentrations of dust mixed with air and in the presence of an ignition source. The threat posed by this real danger was confirmed by the events that took place in economic units such as: feed factories, wood products, textile industry, steel, etc. Among the parameters of explosiveness of combustible dust, which can cause an explosion, we mention: maximum explosion pressure, lower explosion limit, explosive index, minimum ignition energy, electrical resistivity of dust, minimum ignition temperature of dust layer and cloud, particle size and concentration of dust in suspension. The current paper presents the results of determinations of combustible wood dust concentrations, performed at an important economic unit, manufacturing veneer and wood panels, at a dusting ventilation installation composed of fan, cyclone and textile filter. These determinations were made in the pipe connecting the fan and the bag filter, to assess possible danger of explosion in the pipe, by relating the measured concentration to the lower explosion limit (concentration of wood dust).
Highlights
Dust explosion has different characteristics compared to gas explosion, and can be, in some cases, much more devastating
Results of measurements performed After performing 3 determinations of total wood dust concentrations in 3 phases, with the ISOSTACK BASIC SAMPLER device, in pipe connecting the cyclone and the installation fan, the results shown in table no.1 were obtained
Analysing data shown in table no. 1 the following resulted: - none of the concentration of wood dust determined in the pipe exceeded the lower limit of explosiveness, of 20 g/m3, all having values much lower than the mentioned limit. - the average of the 9 concentration measurements was 0.070323 mg/m3
Summary
Dust explosion has different characteristics compared to gas explosion, and can be, in some cases, much more devastating. The requirement to prevent explosions can be expressed as follows: the probability of an ignition source occurring at the same time as an explosive atmosphere to be minimal [1] It follows that, specific requirements are set for protective equipment and systems for specific areas of use. Specific requirements are set for protective equipment and systems for specific areas of use For applying this principle, Ex hazardous non-mining areas are classified into regions depending on probability and duration of the explosive atmosphere (regions 0, 1 and 2 for gases and 20, 21, 22 for combustible dusts in the air), and the equipment is divided into categories according to the level of protection provided, by avoiding sources of initiation during normal operation, during foreseeable failures or during rare failures. According to the ATEx Directives, the responsibility for risk assessment and taking appropriate protection measures to ensure an acceptable level of safety lies with both equipment manufacturers and their users
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
