Patent EA-002070-B1 (EA)
Title: Analyzer for continuously measuring h2s contained in a gas and device including same for regulating the air flow rate injected into an h2s sulphur oxidation reactor
Inventor: SAVIN-PONCET SABINE
IPC: G01N33/00
Filed: 1999-05-10
Abstract: 1. An analyser for continuous measuring hydrogen sulfide content in a gas sample having H2S, comprising: a pipe (5) for gas sampling and injecting the sample into the analyser' a compressor module (10) having an inlet orifice (9) and a recirculating orifice (11) said recirculating orifice is extended by a conduit (12) for circulating said compressed sample' a system of diluting the gas sample after compression comprising an air supply conduit (14) branch-mounted on the conduit (12) for circulating the compressed gas sample and equipped with a valve(16) with a regulating opening and an electrochemical detector (21) for measuring the hydrogen sulfide content mounted in the conduit (12) for circulating the compressed gas sample downstream the air supply conduit (14) and for delivering a signal (22) proportional to the the hydrogen sulfide concentration in the sample, characterized in that the system of diluting the gas sample after compression further comprises a primary indicator and/or controlling flowmeter (13) mounted in the conduit (12) for circulating the compressed gas sample upstream the air supply conduit (14), a secondary regulating flowmeter (17) mounted in the air supply conduit (14) upstream the valve(16) and controlling the valve opening, and a regulating module (18) connected to each of said primary and secondary flowmeters and operating the secondary flowmeter according to the first; a drying module (2), comprising an inlet (3) and an outlet (4) is connected to the pipe (5) for sampling and injecting the sample and connected by the outlet (4) via a pipe (8) to the inlet orifice (9) of the compressor module (10). 2. The analyser according to claim 1, characterized in that the pipe (5) for gas sampling and injecting the sample is connected to the inlet of the drying module (2) for drying a sample and has a primary filter at the end away from the inlet. 3. The analyser according to claim 1, characterized in that the end of said pipe (5) is provided with a fine filter on the same side as the drying module (2). 4. The analyser according any of the preceding claims, characterized in that the pipe (5) for gas sampling and injecting the sample is surrounded with a jacket equipped with means for maintaining the temperature, in particular by electrical heating or circulating of a heating fluid. 5. The analyser according any of the preceding claims, characterized in that the drying module (2) for drying a gas sample consists of a dryer with a semi-permeable membrane. 6. The analyser according any of the preceding claims, characterized in that the compressor module (10) is a membrane compressor. 7. The analyser according any of the preceding claims, characterized in that the primary flowmeter (13) mounted in the conduit (12) for controlling compressed sample in the compressor and the secondary flowmeter (17) mounted in the air supply conduit (14) are mass flowmeters. 8. The analyser according claim 7, characterized in that the regulating module (18), connected to the primary flowmeter to the secondary flowmeter, is a module, regulating mass. 9. A device for controlling the air flow injected into an oxygenation reactor (30) for converting hydrogen sulfide having an inlet (31) and an outlet (32), said inlet is equipped with the first (34) and the second (35) conduits for feeding in the reactor gas to be treated and air correspondingly, said outlet is equipped with a discharge conduit (36) to evacuate effluent gases resulted after oxidation, said controlling device is a type which comprises a unit (i) of predicted calculation provided with a predicting computer (37) receiving a signal (38) from a flowmeter (39) an a signal (40) from the first analyser of the hydrogen sulfide content said instruments are mounted on the primary conduit (34) at the inlet to the oxidation reactor and generating from said signals a signal (42) representing the air flow corresponding an amount of air proportional to hydrogen sulfide content entering the oxidation reactor (30), a unit of counter reaction comprising a correcting computer which receives a signal (22) produced by the secondary analyser of the oxidation content (1) mounted on the exit conduit (36) from the oxidation reactor and generating from said signal a signal (44) representing a correcting air flow to bring hydrogen sulfide content, present in the effluent passing through said exit conduit, back to a predetermined value, and a (iii) flow regulator (45) receiving signals (42, 44) generated by the predicting computer and by the correcting computer (43), and a signal (46) produced by a flowmeter (47) mounted on the air inlet conduit (35) at the inlet to the oxidation reactor, and applying a valve (48) with regulating opening mounted on said air inlet conduit (35) downstream the flowmeter (47), a controlling signal (49) for regulating opening of said valve, said controlling signal is a resultant from the signals generated by the predicting and correcting computers, characterized in that at least the analyser of the hydrogen sulfide content (1) mounted on the outlet conduit (36) of the oxidation reactor (30) and connected to the correcting reactor (43) is an analyser according to one of claims 1 to 8. 10. The device according to claim 9, characterized in that the predicting computer (37) applies a coefficient of proportionality between the molar quantity of oxygen and the molar quantity of hydrogen sulfide being within the range from 0,5 to 10, more preferably from 0,5 to 4. 11. The device according to claim 9 or 10, characterized in that the predicting computer (37) applies the coefficient of proportionality between the molar quantity of oxygen and the molar quantity of hydrogen sulfide, which increase gradually in the course of oxidation. 12. The device according to claims 9 to 11, characterized in that the analyser (41) of the oxidation content mounted on the primary conduit (34) at the input to the oxidation reactor (30), is also an analyser according to one of claims 1 to 8. 13. The device according to any of claims 9 to 12, characterized in that the hydrogen sulfide gas conduit (34) feeding said gas to the oxidation reactor is a conduit of outgoing products from a reactor of hydrogeneration and/or hydrolysis in which the residual gas from the sulfur reactor is treated to convert sulfur-containing compounds to hydrogen sulfide and that the flowmeter (39) connected to the predicting computer (37) is mounted on the conduit for feeding outgoing gases from the sulfur reactor to the reactor of hydrogeneration and/or hydrolysis.