THE EFFECT OF STORAGE, HANDLING AND TRANSPORT TRAUMAS ON FILTER-MOUNTED DUSTS

摘要

The loss of material from dust-loaded filters was examined using five load ranges of four types of dust. Twelve replicate samples for each load range and dust type, a total of 240 samples, were collected on glass-fibre filters in the laboratory. Three of each group of 12 loaded filters were subjected to one of four levels of trauma: gentle shaking; dropping from table height; posting; or no trauma (control). The percentage weight loss was calculated for each sample. Weight loss from the control and shaken filters was low with a mean loss of 10.4% (SD = 15.4) and 5.2% (SD=11.8), respectively. Weight loss from the dropped and posted niters was much higher (mean losses of 68.2 and 54.4% with SDs of 18.8 and 27.9). The pattern of weight loss with increasing load varied with type of dust, being most marked for wood dust. The amount of loss following dropping or posting was also related to initial load. Three-way analysis of variance suggested strong interactions among dust type, load and trauma, with main effects for initial load and trauma being significantly related to percentage weight loss.