GB1340918A - Sampling apparatus for analyzing gas - Google Patents

Abstract

1340918 Gas sampling for analysis NIPPON STEEL CORP 8 April 1971 9059/71 Heading G1B [ Also in Division B1] Apparatus for obtaining gas samples from a furnace or converter for analysis comprises a sampling tube mounted in a cooling cylinder 1 and an annular ceramic filter 16 at the tip of the apparatus, with means for blowing a gas, e.g. an inert gas such as nitrogen, over the filter 16 to blow away dust deposited thereon, and a mounting arrangement for the filter and sampling tube which absorbs thermal expansion. In Fig. 1, the sample gas is drawn through an inlet 14, the filter 16, and a pipe 8 to an analyser (not shown). The filter is mounted between a recess 19 of the cylinder 1 and a holder tube 2 which is urged axially by a compression spring 6. After a sample has been obtained, a cleaning gas is blown across the filter via an inlet 13, a chamber 15, and the bore of tube 2. Simultaneously a scraper 18 comprising brushes or dished metal discs is reciprocated within the filter by a doubleacting piston/cylinder 5, 4. In Fig. 2, the sample gas is drawn through the filter 16, holes 28 in a tube 27, the tube 27, and an outlet 9. In a modification, 27 may be a solid bar, the gas passing along an annular space 21 around the bar. The filter is mounted between the end of the cylinder 1' and a Keeper 23 on the end of the tube or bar 27, the other end of which is urged axially by a compression spring 6. A hood 26 extends over the filter. The cylinder 1' comprises coaxial inner and outer cooling jackets. Cleaning gas for the filter is supplied via a line 13 to a gallery 15 and nozzles 25. In Fig. 4, the oxygen supply to a lance 30 of a steel converter 29 is controlled in accordance with the CO and CO 2 content of the converter exhaust gas to obtain a predetermined carbon content in the steel bath. A sampler 32, 33 supplies gas samples to a CO and CO 2 analyser 34. A flowmeter 35 with a detector 37 measures the total gas flow from the converter. The outputs of the analyser 34 and flowmeter 35 are combined in a multiplier 36 the output of which feeds a controller 38 for the oxygen supply valve 39.