Reactor analysis system

• US 4,891,186 A
• Filed: 05/09/1988
• Issued: 01/02/1990
• Est. Priority Date: 05/20/1986
• Status: Expired due to Fees

• Current Assignee: Union Carbide Industrial Gases Inc.
• Original Assignee: Union Carbide Corporation (Dow, Inc.)
• Inventors: Wolfe, Thomas G., Francis, Arthur W. Jr., Roberge, Raymond P.
• Primary Examiner(s): Marcus, Michael S.
• Application Number:
  US07/193,196
• Time in Patent Office: 603 Days
• Field of Search: 422/62, 422/78, 422/70, 422/80, 422/81, 422/90, 436/103, 436/83, 436/115, 436/158, 436/55, 436/124
• US Class Current: 422/83
• CPC Class Codes: G01N 33/0032 using two or more different physical functioning modes
• CPC Class Codes: Y10T 436/12 Condition responsive control
• CPC Class Codes: Y10T 436/176921 As part of an elemental analysis
• CPC Class Codes: Y10T 436/19 Halogen containing

Abstract

Gas samples withdrawn from within a reactor vessel, as well as from the feed gas thereto, are passed to gas analyzers for particular components or impurities desired to be measured. The response time of the reactor analysis system employed is advantageously minimized by the elimination of dead gas space upon the closing of control valves and the provisions for rapid purging of the system or of individual gas analyzer feed lines.

Claims

1. An analysis system for monitoring a feed gas stream passing to and a gas present within a process reactor comprising:

(a) conduit means for continually withdrawing samples of a gas present within a reactor;

(b) conduit means for continually withdrawing samples from a feed gas stream passing to the reactor;

(c) a first valve means continually receiving samples from said conduit means containing samples of the gas present within the reactor and from said conduit means containing samples of the feed gas passing to the reactor, wherein said first valve means in a first position passes the sample of the gas present within the reactor downstream for analysis while discharging the sample of the feed gas from the system, and wherein said first valve means in a second position passes the sample of the feed gas stream downstream for analysis while discharging the sample of the gas present within the reactor;

(d) a main gas supply flow line for passing the gas sample to be analyzed from said first valve means to individual gas analyzer feedlines;

(e) a second gas sample valve means for tapping one or more individual samples of the gas sample to be analyzed from the main flow line, said second valve means being adapted for continuous straight through flow of the gas sample from said main flow line, said second valve means also being adapted to periodically tap the individual sample to be analyzed from said main flow line, with essentially no dead volume being created upon closing of said periodic tap means of said second valve means to discontinue the tapping of the gas sample for analysis;

(f) gas analyzer feed lines for withdrawing the individual gas samples from said second sample valve means for analysis;

(g) gas analyzer means for separately analyzing the individual gas samples present in said gas analyzer feed lines for a particular gas stream component;

(h) purge gas supply means adapted to pass purge gas to said gas analyzer feed lines for each individual gas sample for analysis; and

(i) control means in said gas analyzer feed lines for selecting either the individual samples of the gas to be analyzed or the purge gas to be passed to said gas analyzer means, whereby said system enables gas samples from the feed gas passing to the reactor and samples taken from the gas present within the reactor to be accurately monitored with rapid response time, the purge gas being available to rapidly and essentially completely purge said gas analyzer feed lines and said gas analyzer means between analyses, thus enabling accurate gas analysis to be carried out rapidly during the course of operation.

2. The analysis system of claim 1 and including purge control means adapted to enable either the gas sample to be analyzed or the purge gas to be passed through said main gas supply flow line.

3. The analysis system of claim 1 and including pump means for withdrawing the gas sample being discharged from said system after passage (to) through said first valve means (c).

4. The reactor analysis system of claim 1 in which said valve means (c) comprises a four way valve ball valve adapted for the constant flow of gas through two sample ports simultaneously.

5. The analysis system of claim 1 in which said gas analyzer means comprises means for separately analyzing an individual gas sample for oxygen and moisture.

6. The analysis system of claim 5 in which separate gas analyzer means are provided for measuring percent oxygen concentrations of from about 0.01 to 100% and for measuring parts per million oxygen, said control means being adapted to pass purge gas to said parts per million analyzer when the oxygen content of the gas sample to be analyzed exceeds a predetermined level, and to pass said individual gas sample from the gas sample to be analyzed thereto when the oxygen content is below said predetermined level.

7. The analysis system of claim 6 and including a catalytic oxidizer unit optionally operable in said gas analyzer feed line to said moisture analyzer, said unit being suitable for the conversion of hydrocarbons in oxygen to water and carbon dioxide, the increase in water concentration in said moisture analyzer constituting a measurement of the total concentration of hydrocarbons in the gas sample being analyzed.

8. The analysis system of claim 5 and including means for analyzing the gas sample from said main flow line for the presence of HCl, and conduit means for supplying the gas sample in said main flow line to said HCl analysis means.

9. The analysis system of claim 8 and including sample by-pass means in said conduit means for supplying gas from said main flow line to said HCl analysis means.

10. The analysis system of claim 8 in which separate gas analyzer means are provided for measuring percent oxygen concentrations of from about 0.01 to 100% and for measuring parts per million oxygen, said control means being adapted to pass purge gas to said parts per million analyzer when the oxygen content of the gas sample to be analyzed exceeds a predetermined level, and to pass the gas sample thereto when said oxygen content is below the predetermined level.

11. The analysis system of claim 8 and including control means for switching from said individual gas sample to said purge gas in at least on of said individual gas analyzer feed lines if said HCl concentration is 10 ppm or greater.

12. The analysis system of claim 1 wherein said control means (i) for selecting either the gas sample or the purge gas to be passed to said analyzer comprises a third valve means placed in a line through which the gas sample passes on its way to said gas analyzer, whereby essentially no dead volume is created between said purge gas supply means and said gas sample feed line.

13. The analysis system of claim 1 and including pump means for the pumping of the gas sample to be analyzed through said main flow line.

14. The analysis system of claim 13 and including a forth valve means positioned between said first valve means and said pump means, said forth valve means comprising a control means for selecting either said gas sample to be analyzed or said purge gas to be passed to said main flow line.

15. An analysis system for monitoring a gas stream within a process comprising:

(a) conduit means for continually withdrawing gas samples from within said process;

(b) a main gas supply line for passing a gas sample to be analyzed to individual gas analyzer feed means;

(c) sample valve means for tapping one or more individual samples of the gas to be analyzed from said main flow line, said valve means being adapted for continuous straight-through flow of gas from said main flow line, said valve means also being adapted to periodically tap said individual sample to be analyzed from said main flow line, with essentially no dead volume being created upon closing of said valve means to discontinue the tapping of the gas sample for analysis;

(d) gas analyzer feed means for withdrawing individual gas samples from said sample valve means for analysis;

(e) gas analyzer means for separately analyzing the individual gas samples from said gas analyzer feed means for a particular gas stream component;

(f) purge gas supply means adapted to pass purge gas to each individual gas analyzer feed means;

(g) control means in said gas analyzer feed means for selecting either the individual gas samples of the gas to be analyzed or the purge gas to be passed to said gas analyzer means, whereby said system enables gas samples taken from within the process to be accurately monitored with a rapid response time, the purge gas being available to rapidly purge said gas analyzer feed means and said gas analyzer means between analyses, thus enabling accurate gas analysis to be carried out rapidly during the course of operation.

16. The analysis system of claim 15 and including purge control means adapted to enable either said gas sample to be analyzed or said purge gas to be passed through said main gas supply flow line.

17. The analysis system of claim 15 wherein said control means (g) for selecting either gas sample or purge gas to be passed to said analyzer comprises a second valve means placed in a line through which said gas sample passes on its way to said gas analyzer, whereby essentially no dead volume is created between said purge gas supply means and said sample feed line.

18. The analysis system of claim 15 in which said gas analyzer means comprises means for separately analyzing said individual gas samples for oxygen and moisture.

19. The analysis system of claim 18 in which separate gas analyzer means are provided for measuring percent oxygen concentrations of from about 0.01 to 100% and or measuring parts per million oxygen, said control means being adapted to pass purge gas to said parts per million analyzer when the oxygen content of said gas to be analyzed exceeds a predetermined level, and to pass individual gas sample from said gas to be analyzed thereto when said oxygen content is below said predetermined level.

20. The analysis system of claim 18 and including means for analyzing said gas sample from said main flow line for the presence of HCl, and conduit means for supplying gas in said main flow line to said HCl analysis means.

21. The analysis system of claim 20 in which separate gas analysis means are provided for measuring percent oxygen concentrations of from about 0.01 to 100%, and for measuring parts per million oxygen, said control means being adapted to pass purge gas to said parts per million analyzer when the oxygen content of said gas to be analyzed exceeds a predetermined level, and to pass individual gas sample from said gas to be analyzed thereto when said oxygen content is below said predetermined level.

22. The analysis system of claim 20 and including sample by-pass means in said conduit means for supplying gas from said main flow lines to said HCl analysis means.

23. The analysis system of claim 20 and including control means for switching from said individual sample of said gas to be analyzed to said purge gas in at least one of said gas analyzer feed means if said HCl concentration is 10 ppm or greater.