PROCEDURE AND APPARATUS FOR CONTINUOUS MEASUREMENT OF THE AMMONIA CONCENTRATION OF GASES IN THE PPM RANGE

A device for the continuous measurement of the ammonia concentration in gases in the ppm range includes a columnar absorption vessel (1) with a hemispherical bottom (4). The bottom of the column includes an overflow (3) and an outlet (5). The gas introduction pipe (7,8) empties above the bottom (4) and below a sieve bottom (6) arranged in the column (1). A packing material (10) rests on the sieve bottom (6), which packing (10) essentially fills the absorption column (1). A cooling part (11) extends from the absorption column (1). The cooling part (11) includes a cooling zone (15) and a gas collection space (16) above it with a closable connection piece (13). A pipe (14), which may include a serrated crown on each end, runs from the gas collecting space (16) downward in a cooled manner to the packing 10. The liquid absorption agent is introduced through a lateral connection piece (18) into the gas collection space (16). For the measurement of ammonia concentration, a certain volume flow of the gas to be measured is washed in a countercurrent flow with the absorption agent, and the NH3 content is determined in a part of the ammonia containing absorption agent. The volume flow rate of the absorption agent and of the gas from which NH3 has been removed is measured (the latter being dried), and the ammonia concentration is thereby calculated.