Prosecution Insights
Last updated: April 19, 2026
Application No. 18/461,878

THERMOSYPHON REBOILER MODIFICATION

Non-Final OA §103
Filed
Sep 06, 2023
Examiner
RUPPERT, ERIC S
Art Unit
3763
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Saudi Arabian Oil Company
OA Round
1 (Non-Final)
59%
Grant Probability
Moderate
1-2
OA Rounds
2y 10m
To Grant
83%
With Interview

Examiner Intelligence

Grants 59% of resolved cases
59%
Career Allow Rate
437 granted / 739 resolved
-10.9% vs TC avg
Strong +24% interview lift
Without
With
+24.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
55 currently pending
Career history
794
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
48.5%
+8.5% vs TC avg
§102
21.1%
-18.9% vs TC avg
§112
27.3%
-12.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 739 resolved cases

Office Action

§103
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Election/Restrictions Claims 8-16 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 2/23/2026. Applicant’s election without traverse of Species A and Sub-species ii in the reply filed on 2/23/2026 is acknowledged. It is noted while Applicant indicates claims 1-20 read on the elected species, claims 8-16 are directed to the unelected Species B in which tube inserts are engraved and inserted into tubes of a reboiler. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. Claim(s) 1-2, 5-6, 17-18, 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Master (US20110083619A1) in view of Creighton (US3213525A). Regarding claim 1, Master teaches a method (see Fig. 1-3) comprising: providing a groove pattern (surface 40 with helical ribs 44) an inner surface of a thermosyphon reboiler (¶[0016]), wherein the thermosyphon reboiler comprises a first side (tube side of Fig. 1) configured to receive a liquid (via liquid inlet 16) and a second side (shell side of Fig. 1) configured to receive a heating fluid (via 12 & heating medium…remains in a liquid state - ¶[0015]), wherein the thermosyphon reboiler is configured to transfer heat from the heating fluid at the second side to the liquid at the first side to boil the liquid at the first side (boiling - ¶[0022-0023]), wherein providing a pattern the inner surface of the thermosyphon reboiler comprises providing a pattern (see pattern of helical ribs 44) across at least a portion of an inner surface of the first side of the thermosyphon reboiler, wherein the pattern has a specified depth that increases a heat transfer surface area of the first side of the thermosyphon reboiler; and preventing, by the provided pattern, film boiling from occurring at the inner surface of the first side of the thermosyphon reboiler (preventing…film boiling, abstract, claim 13). Master is silent to wherein the groove pattern is provided by engraving Creighton teaches the groove pattern is provided by engraving (forming said groove with a cutting tool – Col. 8, line 40-45). Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Master to include the engraving of Creighton, in order to provide a consistent and uniform groove manufacturing (Col. 2, lines 50-60). Regarding claim 2, Master teaches the limitations of claim 1, and Master further teaches the first side of the thermosyphon reboiler is tubular (24) and defines a first longitudinal axis, wherein engraving the pattern (44) comprises forming the pattern as a helix defining a second longitudinal axis, wherein the first longitudinal axis of the first side and the second longitudinal axis of the helix are coaxial. Regarding claim 17, Master teaches a method (see Fig. 1-3) comprising: providing an inner surface (40 with 44) of a thermosyphon reboiler (¶[0016]), wherein the thermosyphon reboiler comprises a first side and a second side (see tube and shell side of Fig. 1), wherein providing the inner surface of the thermosyphon reboiler comprises providing groove pattern (44) across at least a portion of an inner surface of the second side of the thermosyphon reboiler, wherein the pattern has a specified depth (depth of ribs 44) that increases a heat transfer surface area of the second side of the thermosyphon reboiler; flowing a heating fluid (via 12 & heating medium…remains in a liquid state - ¶[0015]) to the first side of the thermosyphon reboiler; flowing a liquid (via liquid inlet 16) to the second side of the thermosyphon reboiler; in response to flowing the heating fluid to the first side and the liquid to the second side, transferring heat from the heating fluid at the first side to the liquid at the second side, thereby boiling (boiling - ¶[0022-0023]) the liquid at the second side; and while boiling the liquid at the second side, preventing, by the groove pattern, film boiling (preventing…film boiling, abstract, claim 13) from occurring at the inner surface of the second side of the thermosyphon reboiler. Master is silent to wherein the groove pattern is provided by engraving. Creighton teaches the groove pattern is provided by engraving (forming said groove with a cutting tool – Col. 8, line 40-45). Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Master to include the engraving of Creighton, in order to provide a consistent and uniform groove manufacturing (Col. 2, lines 50-60). Regarding 18, Master teaches the limitations of claim 17, and Master further teaches the second side of the thermosyphon reboiler is tubular (tubes 24) and defines a first longitudinal axis (axis thereof), and the pattern (44) is formed as a helix defining a second longitudinal axis (axis thereof). Regarding 5-6/20, Master teaches the limitations of claim 2/17, and Master further teaches wherein the helix has a pitch, and a ratio of the pitch of the helix to the specified depth of the pattern is in a range of from about 3:1 to about 10:1, wherein the pitch of the helix varies along the second longitudinal axis (see pitch at 46 and 50, Fig. 3B & ¶[0021], which results in a ratio of 3.3:1 to 10:1 using 0.5 mm & 6 and 2 fins per cm). Claim(s) 3-4 and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Master (US20110083619A1) in view of Creighton (US3213525A) and Wang (CN105202961A). Regarding claims 3-4 and 19, Master teaches the limitations of claim 2/18, and Master does not teach the specified depth of the pattern is in a range of from about 0.05 millimeters (mm) to about 0.3 mm, wherein the specified depth of the pattern varies along the second longitudinal axis. Wang teaches the specified depth of the pattern is in a range of from about 0.05 millimeters (mm) to about 0.3 mm, wherein the specified depth of the pattern varies along the second longitudinal axis (see range, 0.15-0.35 mm, which varies between the first and second section – Page 2). Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Master to include the pattern dimensions and varying depth as taught by Wang, in order to improve heat exchange (Page 3). Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Master (US20110083619A1) in view of Creighton (US3213525A) and Koch (US3088494A). Regarding claim 7, Master teaches the limitations of claim 1, and Master does not teach the first side of the thermosyphon reboiler is tubular and defines a first longitudinal axis, the pattern has a form of a double helix defining a second longitudinal axis, and the first longitudinal axis of the first side and the second longitudinal axis of the double helix are coaxial. Koch teaches the first side of the thermosyphon reboiler is tubular and defines a first longitudinal axis, the pattern has a form of a double helix defining a second longitudinal axis, and the first longitudinal axis of the first side and the second longitudinal axis of the double helix are coaxial (“pair of parallel continuous helical grooves” – Col. 3, lines 35-45 & Fig. 2). Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Master to include a double helix configuration as taught by Koch, as it has been held obvious to provide a simple substitution of one known element for another to obtain predictable results (see MPEP 2143). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to ERIC S RUPPERT whose telephone number is (571)272-9911. The examiner can normally be reached Monday - Friday 8 am - 4 pm. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Len Tran can be reached at 571-272-1184. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /ERIC S RUPPERT/Primary Examiner, Art Unit 3763
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Prosecution Timeline

Sep 06, 2023
Application Filed
Feb 25, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
59%
Grant Probability
83%
With Interview (+24.1%)
2y 10m
Median Time to Grant
Low
PTA Risk
Based on 739 resolved cases by this examiner. Grant probability derived from career allow rate.

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