Method for analyzing a gas mixture

• US 4,994,158 A
• Filed: 05/20/1988
• Issued: 02/19/1991
• Est. Priority Date: 11/17/1983
• Status: Expired due to Fees

• Current Assignee: Oy Tampella AB
• Original Assignee: Oy Tampella AB
• Inventors: Helke, Risto J. A., Kiimalainen, Jorma
• Primary Examiner(s): Tung, T.
• Application Number:
  US07/196,548
• Time in Patent Office: 1,005 Days
• Field of Search: 204/1 T, 204/4 A, 204/409, 204/416-420, 204/153.1, 204/153.15, 73/23, 73/28, 73/23.2, 73/28.01, 422/88, 436/79
• US Class Current: 205/781.5
• CPC Class Codes: G01N 1/2247 Sampling from a flowing stream of gas
• CPC Class Codes: G01N 15/06 Investigating concentration of particle suspensions by weighing G01N5/00; investigating sedimentation of particle suspensions G01N15/04; investigating individual particles G01N15/10
• CPC Class Codes: G01N 2001/225 isokinetic, same flow rate for sample and bulk gas
• CPC Class Codes: G01N 2001/2285 Details of probe structures
• CPC Class Codes: G01N 27/4162 investigating the composition of gases, by the influence exerted on ionic conductivity in a liquid conductometry in general G01N27/06; amperometric gas sensors G01N27/404
• CPC Class Codes: G01N 33/0011 Sample conditioning in general G01N1/28

Abstract

The invention relates to a method for analyzing a gas mixture which contains a dust-like solid by separating and directing to analysis a certain quantity of the gas mixture along a sample-taking conduit, wherein a known quantity of liquid is mixed with the separated gas mixture in order to absorb the gas mixture into the liquid. The analysis is performed by analyzing the liquid which has absorbed the gas mixture. The liquid is mixed with the separated gas mixture which is being directed to analysis immediately after the gas mixture has been separated, and the separated gas mixture and the liquid are directed together along the sample-taking conduit to analysis.

Claims

1. A method for analyzing a gas mixture which contains a finely divided solid which comprises,

separating a predetermined quantity of said gas mixture from said gas mixture by introducing said predetermined quantity of said gas mixture into a first open end of a sample-taking conduit,

concurrently introducing a predetermined quantity of liquid in which said finely divided solid is dissolvable substantially at said first open end of said sample-taking conduit with said predetermined quantity of said gas mixture to form a mixture of said predetermined quantity of said gas mixture and said predetermined quantity of said liquid in which at least a portion of said finely divided solids become dissolved into said liquid and at least a portion of the dissolvable components of said gas mixture become absorbed into said liquid, said liquid being concurrently introduced into said sample-taking conduit in such a manner that plugs of said liquid are formed between which space is left for the gas,

passing said predetermined quantity of said gas mixture and said predetermined quantity of liquid through said sample-taking conduit for a time sufficient to enable substantially complete absorption of the absorbable components of said predetermined quantity of said gas mixture into said predetermined quantity of liquid,

the flowing predetermined quantity of liquid rinsing the walls of said conduit and preventing deposits of said finely divided solids on said conduit walls,

and withdrawing said predetermined quantity of liquid from a second open end of said sample-taking conduit and passing said predetermined quantity of liquid to an analysis zone to determine the absorbed constituent concentration of said predetermined quantity of liquid.

2. A method according to claim 1, further comprising the step of

providing means at said first open end for introducing said liquid such that said liquid forms a continuous film transverse to the gas flow.

3. A method according to claim 1, further comprising the step of providing a conduit in the shape of a slit which encircles the first open end through which the liquid is introduced into the sample-taking conduit.

4. A method according to claim 1, wherein the step of introducing said liquid is conducted such that said liquid forms a continuous film transverse to the gas flow.

5. A method according to claim 1, in which in order to mix a continuously determined flow volume of the separated gas mixture with liquid, said liquid has a predetermined flow volume and is fed continuously into the sample-taking conduit in order to carry out continuous analysis.

6. A method according to claim 1, in which a predetermined quantity of liquid is circulated for a predetermined time period by recycling analyzed liquid into the sample-taking conduit in order to analyze the gas mixture accumulation during said time period.

7. A method according to claim 1, in which solids which have not been dissolved in said liquid and gases which have not been absorbed into said liquid are separated from said liquid before passing said liquid to said analysis zone.

8. A method according to claim 1, further comprising the step of

recirculating said predetermined quantity of liquid at least once through the first open end and the sample-taking conduit after the step of withdrawing said predetermined quantity but before the step of passing said predetermined quantity to analysis.

9. A method according to claim 1, in which the liquid fed in is maintained at a substantially constant temperature.

10. A method according to claim 1 for the analysis of the concentration of glauber salt in the flue gases from a recovery boiler in which the liquid used is water and that the sodium concentration in the water is measured by means of a sodium-specific electrode.

11. A method according to claim 1, in which said predetermined quantity of liquid is introduced into said sample-taking conduit and mixed with the separated gas mixture by spraying it into said sample-taking conduit to form a film in a transverse direction in said sample-taking conduit.

12. A method according to claim 1, in which said predetermined quantity of said gas mixture is separated from said gas mixture isokinetically into said sample-taking conduit.

13. A method for analyzing a gas mixture in a stream flow, the gas mixture containing a finely divided solid, the method comprising the steps of:

separating a first predetermined quantity of the gas mixture from the stream flow by introducing the predetermined quantity into a first open end of a sample-taking conduit,

concurrently introducing a predetermined quantity of liquid substantially at the first open end of the sample-taking conduit to form a combined mixture of the gas mixture and the liquid, all of the liquid being received within the conduit, the liquid and the gas mixture being introduced into the conduit such that plugs of the liquid are formed, the gas mixture being received between the plugs of the liquid,

passing the combined mixture through the sample-taking conduit for a time sufficient to enable complete absorption of components of the gas mixture into the liquid,

rinsing the walls of the conduit with the plugs of liquid, and

withdrawing the predetermined quantity of liquid from a second open end of the sample-taking conduit and passing the predetermined quantity of liquid to apparatus for analyzing the liquid to determine the solid which has been absorbed into the liquid, based, in part, on the predetermined quantity of liquid and the rate of the stream flow.