Filter Canister Flow Distribution Visualization Experiments
DEFENCE RESEARCH ESTABLISHMENT OTTAWA (ONTARIO)
Pagination or Media Count:
A colorimetric method of visualizing the airflow distribution inside a charcoal filter canister was developed. The aim of the experiments carried out with this method was to ensure the adequacy of a new plastic canister design. The method uses silica gel of the same size as the charcoal used in the canister, coated with an acidbase dye which changes colour from yellow to a dark blue in the presence of a base. A mixture of air and diethyl amine is passed through the canister, and its reaction with the dye causes it to turn blue immediately. A cross section of the silica gel bed shows the transition between the reacted dye and non-reacted dye. The interface line gives an indication of airflow distribution inside the charcoal bed. The contrast obtained between the dyes original colour and the reacted colour was found to be dependent on the appropriate relative humidity preconditioning of the canister.
- Fluid Mechanics