Passive acoustics process to monitor feed injection lines of a catalytic cracker (law077)

• US 5,652,145 A
• Filed: 12/22/1995
• Issued: 07/29/1997
• Est. Priority Date: 12/22/1995
• Status: Expired due to Fees

• Current Assignee: Exxon Research and Engineering Company (Exxon Mobil Corporation)
• Original Assignee: Exxon Research and Engineering Company (Exxon Mobil Corporation)
• Inventors: Cody, George D., Elzinga, E. R. Jr., Baker, Charles L. Jr.
• Primary Examiner(s): SNAY, JEFFREY R
• Application Number:
  US08/577,657
• Time in Patent Office: 585 Days
• Field of Search: 436/34, 436/37, 436/55, 422/105, 422/62, 73/579, 73/602
• US Class Current: 436/34
• CPC Class Codes: B01J 2208/00088 Flow rate measurement
• CPC Class Codes: B01J 8/001 Controlling catalytic processes B01J8/1809 takes precedence
• CPC Class Codes: B01J 8/1809 Controlling processes
• CPC Class Codes: B01J 8/26 with two or more fluidised beds, e.g. reactor and regeneration installations
• CPC Class Codes: C10G 11/187 Controlling or regulating
• CPC Class Codes: G01P 13/00 Indicating or recording presence, absence, or direction, of movement electric switches H01H; counting moving objects G06M7/00
• CPC Class Codes: G01P 15/00 Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
• CPC Class Codes: Y10T 436/12 Condition responsive control

Abstract

The present invention is a method for non-intrusively monitoring the chemical and physical processes associated with gas generation in the feed riser of a cat-cracker and the correlation of those changes in these processes to changes in the output product produced the cat-cracker. The method includes the steps of measuring RMS accelerations along a feed riser at one or more positions, determining the initial RMS acceleration at each of these positions when the unit is operating at its desired performance, comparing the measured FRP to the reference FRP when said reactor is operating at its desired performance and determining the reference FRP, and determining the change in the FRP.

Claims

1. A method for the monitoring of output of a catalytic reactor comprising:

(a) measuring wall vibrations along a feed riser at more than two positions, (b) determining RMS acceleration at each of said positions and generating a feed riser profile therefrom, (c) comparing said feed riser profile to a pre-determined initial feed riser profile obtained when said reactor is operating at the desired performance, to determine a change in reactor performance.

2. The method of claim 1 wherein said pre-determined feed riser profile was obtained from said reactor at an earlier time.

3. The method of claim 1 wherein said pre-determined feed riser profile was obtained from a similar reactor at an earlier time.

4. The method of claim 1 further comprising the step of changing the operating parameters of said reactor to bring it back to the initial feed riser profile.

5. The method of claim 1 wherein said operating parameters include feed temperature, gas injection, cat/oil ratio, gas superficial velocity, steam component of nozzles, feed nozzle injection pattern, coke composition on catalyst, and changes in catalyst.

6. The method of claim 5 wherein wall vibrations are measured at more than three positions and fit to a continuous function of position along the riser having four parameters.

7. The method of claim 5 wherein wall vibrations are measured at more than four positions and fit to a continuous function of position along the riser having five parameters.

8. The method of claim 5 wherein said continuous function is the sum of a Gaussian and a liner function raised to a power=3/2.

9. A method for monitoring the output of a catalytic reactor comprising:

(a) measuring wall vibrations along a feed riser at more than two positions,

(b) determining an initial RMS acceleration at each of said positions when said reactor is operating at the desired performance and generating an initial feed riser profile therefrom,

(c) determining a second RMS acceleration at each of said positions at a later time and generating a second feed riser profile therefrom,

(d) changing the operating parameters of said reactor so as to bring the second feed riser profile back to the initial feed riser profile.

10. The method of claim 9 wherein wall vibrations are measured at more than three positions and fit to a continuous function of position along the riser having four parameters.

11. The method of claim 9 wherein wall vibrations are measured at more than four positions and fit to a continuous function of position along the riser having five parameters.

12. The method of claim 11 wherein said continuous function is the sum of a Gaussian and a linear function raised to a power=3/2.