Abstract
The effects of flue gas temperature on dust measurement by the present JIS method were investigated in many facilities. For the test of dust collection part of type 1 combined with type 2 (the filter of type 2 is not heated), dust collection efficiency of type 1 (type 1/(typel + type 2)) greatly decreased as the flue gas temperature increased in boilers and glass melting furnaces. However, the slope of the regression line between dust concentration and flue gas temperature was different in the both facilities, it seems to be due to the composition of dust. Consequently, chemical composition of dust emitted from the above-mentioned two facilities was analysed. The composition of dust showed a clear difference between type 1 and type 2 at boilers. The concentrations of total carbon, sulfuric acid and metals of type 1 were 70%, 10% and 15%, respectively. On the other hand, the concentrations of total carbon, sulfuric acid and water of type 2 were 10%, 50% and 40%, respectively. In the case of glass melting furnace, there was no significant difference between type 1 and type 2 and sulfuric acidion was a major component.
Air dilution method and water-cooled method for dust measurement by type 2 were tested and they were compared with type 1 +type 2 method. As the result, there were no obvious differences between them.
From these results, dust concentration measured by the present JIS method (type 1) is dependent on flue gas temperature, so that it is necessary to use the dust sampling part scuh as type 1 combined with type 2.
