Dilution stack sampling apparatus

摘要

Dilution stack sampling apparatus, for analyzing gaseous components of a gas stream from a stack containing particulate material of varying size therein. A passageway has a first end communicating at an angle with the probe intermediate its ends to receive a sample of gas and to change its flow direction to inertially remove most of the particulate material. An eductor connected to the second end of the passageway mixes dilution air with the sample of gas to provide a diluted sample. A filter upstream of the second end of the passageway removes remaining particulate material from the sample of gas which is not the inertially separated. Instrument air can be provided in a back-flow direction at the upstream side of the filter to periodically remove particulate material from the filter. The diluted sample and the dilution gas are supplied to gas analyzer, and the mass flow rate of the dilution gas and diluted gas are measured. The amount of the dilution gas and the dilution sample are compared in the gas analyzer to determine the ratio of each measured gas in the sample to the total gas sample.