Prosecution Insights
Last updated: April 19, 2026
Application No. 18/024,464

TUBULAR REACTORS

Final Rejection §102§103
Filed
Mar 02, 2023
Examiner
SEIFU, LESSANEWORK T
Art Unit
1774
Tech Center
1700 — Chemical & Materials Engineering
Assignee
UNISA
OA Round
2 (Final)
79%
Grant Probability
Favorable
3-4
OA Rounds
2y 5m
To Grant
79%
With Interview

Examiner Intelligence

Grants 79% — above average
79%
Career Allow Rate
832 granted / 1049 resolved
+14.3% vs TC avg
Minimal +0% lift
Without
With
+0.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 5m
Avg Prosecution
35 currently pending
Career history
1084
Total Applications
across all art units

Statute-Specific Performance

§101
0.6%
-39.4% vs TC avg
§103
36.0%
-4.0% vs TC avg
§102
27.4%
-12.6% vs TC avg
§112
29.0%
-11.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1049 resolved cases

Office Action

§102 §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 . Claim Rejections - 35 USC § 102 The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claim 13 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by Dachs et al. (US 2006/0024222). Regarding claim 13, the reference Dachs et al. teaches a modified reactor tube (2) for use in a fixed bed tubular reactor, which includes a reactor tube (2) having a cylindrical internal reaction cavity (3), wherein the reactor tube includes catalyst particles (4) in the internal reaction cavity providing a catalyst bed (6) (see paras. [0025]; [0047]; Figs. 2a, 2b); and at least one reactor internal component (200) comprising a tubular insert (200) seated in the internal reaction cavity, the at least one reactor internal component (200) being located at an upstream section of the catalyst bed (6) in the reactor tube (2) (see paras. [0046]-[0050]; Fig. 2a), wherein the tubular insert (200) has: a tubular wall with an outer surface shaped and dimensioned to fit into the internal reaction cavity of the reactor tube (see paras. [0051]; [0054]; Figs. 2a, 2b); an inner passage of varied diameter which is operable to change a profile of the internal reaction cavity (see para. [0053]; Fig. 2a); two ends (202), a first end (202) operable to be positioned before a second end (202), relative to a direction of flow (G) in the fixed bed tubular reactor (2), such that the flow is from the first end (202) to the second end (202) (see para. [0053]; Fig. 2a); a neck portion (201) positioned between the two ends (202), defined where an inner diameter of the inner passage is the smallest, the neck portion (201) separating the tubular insert (200) into a funnel portion and a functional tube portion, the funnel portion being defined by a section of the tubular insert (200) between the first end (202) and the neck portion (201) and the functional tube portion being defined by a section of tubular insert (200) between the neck portion (201) and the second end (202) (i.e., the inner passage of the tubular insert 200 is provided in the shape of a venturi tube (see para. [0053]; Fig. 2a); wherein at the functional tube portion, the inner passage of the tubular insert (200) gradually increases in diameter in an axial direction, from the neck portion (201) to the second end (202) which changes a profile of the internal reaction cavity (3), and decreases a diameter of the internal reaction cavity (3) in at least a portion of the reactor tube (2) (see para. [0053]; Fig. 2a), wherein the at least one reactor internal component (200) stabilizes the temperature distribution profile of the reactor tube (2) when the fixed bed reactor is operational by distributing reactor heat over a longer axial distance (see paras. [0016]-[0018]; [0021]; [0025]; [0048]-[0050]; Figs. 2a, 2b). 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. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Dachs et al. (US 2006/0024222). Regarding claim 16, the claim depends from claim 13 such that the reasoning applied to claim 13 above is applied herein for the dependent portion of the claim. The reference Dachs et al. does not specifically disclose wherein the at least one reactor internal component (200) is located such that the neck (201) is positioned at the start of the catalyst bed (6). However, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to provide the at least one reactor internal component (200) within the internal reaction cavity (3) of Dachs et al. such that the neck portion (201) is positioned at the start of the catalyst bed (6), since the reference Dachs et al. teaches that the reactor internal component (200) can suitably be partially embedded in the catalyst bed (see para. [0025]; Fig. 2a). Response to Arguments Applicant's arguments filed on 28 October 2025 have been fully considered but they are not persuasive. In response to applicant's argument that the claimed tubular insert is employed for a different purpose than the purpose of Dachs et al. (see Remarks, page 6, lines 13-17), a recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. According to the teachings of Dachs et al. (see paras [0018]; [0021]; [0023]; [0025]; [0048]; Fig. 2a), the disclosed tubular insert structure 200 provides for improved temperature control within the reactor tube 2 by preventing hot spot 7 migration in the axial direction H towards an upstream end of a fixed bed filling 6 within the reaction tube 2. Thus, the tubular insert 200 taught by Dachs et al. can suitably be utilized for stabilizing the temperature distribution profile of a reactor tube as claimed by applicant. Applicant also argues that in the embodiment shown in Figure 2a of Dachs et al., the tubular insert 200 borders on the catalyst filing, and that there is no mention in the reference Dachs et al. that this specific insert can be positioned such that it is partially filled with catalyst particles (see Remarks, page 6, last paragraph). The examiner respectfully disagrees. Contrary to applicant assertion, the reference Dachs et al. does, in fact, teach that the disclosed tubular insert 200 can be inserted into the reaction tube 2 such that the tubular insert 200 is completely or partially embedded in a catalyst bed defined within the reaction tube (see para. [0025]). Applicant also argues that there is no teaching, suggestion, or motivation to arrive at the subject matter of claim 16, which specifies that that the at least one reactor internal component is located such that the neck is positioned at the start of the catalyst bed (see Remarks, page 8, lines 12-28). The examiner respectfully disagrees. According to the teachings of Dachs et al., the disclosed tubular insert 200 can be inserted into a reaction tube 2 such that the tubular insert 200 is completely or partially embedded in a catalyst bed defined within the reaction tube (see para. [0025]). Thus, the examiner maintains that it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to provide the at least one reactor internal component (200) within the internal reaction cavity (3) of Dachs et al. such that the neck portion (201) is positioned at the start of the catalyst bed (6), since the reference Dachs et al. teaches that the reactor internal component (200) can suitably be partially embedded in the catalyst bed (see para. [0025]; Fig. 2a). Conclusion THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to Lessanework T Seifu whose telephone number is (571)270-3153. The examiner can normally be reached M-T 9:00 am - 6:30 pm; F 9:00 am - 1:00 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, Claire Wang can be reached at 571-270-1051. 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. /LESSANEWORK SEIFU/Primary Examiner, Art Unit 1774
Read full office action

Prosecution Timeline

Mar 02, 2023
Application Filed
May 27, 2025
Non-Final Rejection — §102, §103
Oct 28, 2025
Response Filed
Jan 22, 2026
Final Rejection — §102, §103 (current)

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

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Prosecution Projections

3-4
Expected OA Rounds
79%
Grant Probability
79%
With Interview (+0.0%)
2y 5m
Median Time to Grant
Moderate
PTA Risk
Based on 1049 resolved cases by this examiner. Grant probability derived from career allow rate.

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