Prosecution Insights
Last updated: April 19, 2026
Application No. 17/753,156

ENERGY RECOVERY FROM CONTACT DRYERS

Non-Final OA §103
Filed
Feb 22, 2022
Examiner
LAU, JASON
Art Unit
3762
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Cargill Incorporated
OA Round
3 (Non-Final)
53%
Grant Probability
Moderate
3-4
OA Rounds
3y 4m
To Grant
68%
With Interview

Examiner Intelligence

Grants 53% of resolved cases
53%
Career Allow Rate
470 granted / 880 resolved
-16.6% vs TC avg
Moderate +14% lift
Without
With
+14.3%
Interview Lift
resolved cases with interview
Typical timeline
3y 4m
Avg Prosecution
61 currently pending
Career history
941
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
64.5%
+24.5% vs TC avg
§102
18.8%
-21.2% vs TC avg
§112
15.0%
-25.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 880 resolved cases

Office Action

§103
DETAILED ACTION Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 8/5/2025 has been entered. Claim Interpretation The following is a quotation of 35 U.S.C. 112(f): (f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph: An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked. As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph: (A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function; (B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and (C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function. Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function. Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function. Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. 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. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. Claim(s) 1, 4, 6-8, 20 are rejected under 35 U.S.C. 103 as being obvious over Janicki (US 10800667 B1) in view of Tsangaris (US 20080210089 A1), and Zhang (CN 201962163 U), and as evidenced by Stone (US 20190023592 A1). Regarding claim 1, Janicki discloses an installation (Fig. 4) suitable for drying a water-containing food or feed composition of solid matter comprising (see Background section): (i) one or more contact dryer (349) for drying said food or feed composition of solid matter (303) using the heat of vaporisation from acidic process vapours (319) (col. 7, lines 30-32 and col. 8, line 62-col. 9, line 9) [note: the dryer is capable of using acidic vapors since it can handle a wide range of waste streams, such as streams from mining (see Background), and these streams can be acidic, as evidenced by para. 3 of Stone], the one or more contact dryer(s) comprising a process vapour outlet (top of dryer 349) and a process vapour inlet (321); (ii) a vapour compressor (317) for compressing the process vapours to increase the temperature and pressure of said acidic process vapours, comprising a process vapour inlet and a process vapour outlet (Fig. 4); (iii) one or more purifying apparatus(es) (315) arranged to receive the acidic process vapours; (iv) a first connecting means (Fig. 4: exhaust line between the dryer 349 and the filter 315) for transferring the acidic process vapours from said one or more contact dryer(s) to one or more purifying apparatus(es) (315); (v) a second connecting means (Fig. 4: line carrying filtered slurry 316 to the compressor) for transferring purified vapours from said one or more purifying apparatus(es) to the vapour compressor; and (vi) a third connecting means connecting the vapour compressor (317) to the one or more contact dryer(s) (349) (Fig. 4). Janicki fails to disclose: where the purifying apparatus is a wet scrubber configured to neutralise acidity of the of the acidic process vapours prior to directing purified vapours to the vapour compressor; and wherein surfaces of the installation configured to come in contact with the acidic process vapours are made from a stainless steel titanium alloy Tsangaris teaches a gas conditioning system, comprising a wet scrubber configured to neutralise acidity of the of the acidic process vapours (alkaline solution in wet scrubber neutralizes acids) (paras. 17, 145). It would have been obvious to a person skilled in the art at the time of effective filing of the application to modify Janicki wherein the purifying apparatus further comprises a wet scrubber configured to neutralise acidity of the of the acidic process vapours, in order to purify the gases. The filter (Janicki, 315) would remove some of the particulates, especially the larger particulates (see Tsangaris; col. 27, lines 44-47), and the wet scrubber would remove the smaller particulates and the acidic vapors (Tsangaris, para. 17). As explained above, Janicki discloses a system that can handle a wide range of waste streams, such as streams from mining (see Background), and these streams can be acidic, as evidenced by para. 3 of Stone. If the acidic vapors are not removed, then corrosion of the interior surfaces of the system may occur. With the modification, a wet scrubber can be placed downstream the dryer (Janicki, 349), e.g., downstream the filter system (Janicki, 315) and upstream the compressor (Janicki, 317). A person skilled in the art would have been motivated to place the wet scrubber in this location, so that the contaminated vapors do not foul and/or corrode the compressor (Janicki, 317) and the dryer (Janicki, 349). Zhang teaches wherein surfaces of the waste water recycling installation are made from a stainless steel titanium alloy (e.g., 321 stainless steel), in order to protect against corrosion, including corrosion due to acids (para. 31). It would have been obvious to a person skilled in the art at the time of effective filing of the application to modify Janicki wherein surfaces of the installation configured to come in contact with the acidic process vapours are made from a stainless steel titanium alloy. The motivation to combine is to protect the surfaces against corrosion. Regarding claim 4, Janicki discloses the installation according to claim 1, wherein the installation is a stand-alone unit not connected to any other installation (the installation shown in Fig. 4 is a stand-alone unit). Regarding claim 6, Janicki discloses the installation according to claim 2 wherein the purifying apparatus further comprises a filter system (Fig. 4, 315). Regarding claim 7, Janicki discloses the installation according to claim 1, wherein the vapour compressor (317) is selected from one of: a screw compressor; a centrifugal compressor (col. 28, lines 62-64); a turbocompressor; a scroll compressor; or a piston compressor. Regarding claim 8, Janicki discloses the installation according to claim1, wherein the installation does not comprise a closed heat pump circuit (Fig. 4). Regarding claim 20, modified Janicki discloses the process according to claim 9, further comprising increasing the pH of the acidic process vapours in the one or more purifying apparatus(es) (the wet scrubber taught by Tsangaris uses an alkaline solution which raises the pH of the acidic process vapours). Claim(s) 2 is rejected under 35 U.S.C. 103 as being obvious over Janicki (US 10800667 B1) in view of Tsangaris (US 20080210089 A1), and Zhang (CN 201962163 U), as evidenced by Stone (US 20190023592 A1), as applied to claim 1, and further in view of Geng (CN 103822454 A). Regarding claim 2, Janicki fails to disclose a means for injecting fresh vapours into a third connecting means, which connects the vapour compressor to the one or more contact dryer(s). However, Geng teaches a solids dryer comprising: means (4) for injecting fresh vapours into a third connecting means (line), which connects the vapour compressor(6) to the one or more contact dryer(s) (3). It would have been obvious to a person skilled in the art at the time of effective filing of the application to modify Janicki to include a means for injecting fresh vapours into a third connecting means, which connects the vapour compressor to the one or more contact dryer(s). The motivation to combine is so that there is a heat source for the dryer at startup (see para. 39 of Geng). Claim(s) 9, 12 are rejected under 35 U.S.C. 103 as being obvious over Janicki (US 10800667 B1) in view of Zhang (CN 201962163 U), and as evidenced by Stone (US 20190023592 A1). Regarding claim 9, modified Janicki discloses (see rejection of claim 1 for citations) a process for drying a water-containing food or feed composition of solid matter (note: Janicki discloses in the Background section that his device can dry a wide range of feeds, and a feed is examined to be any solid material that is fed to Janicki’s device), comprising the following steps: (i) drying the composition of solid matter in a contact dryer, wherein the heat for drying the composition is generated from process vapours and optionally fresh vapours; (ii) transferring the process acidic vapours (see comment 1 below) from the contact dryer to one or more purifying apparatus(es) comprising a wet scrubber, to neutralize and reduce the level of any impurities/particles in the acidic process vapours in said purifying apparatus(es) before transferring the purified process vapours from said purifying apparatus(es) to a vapour compressor; (iii) compressing the purified process vapours in a vapour compressor; (iv) transferring the compressed process vapours into the contact dryer; (v) optionally injecting fresh vapours into a connecting means which connects the vapour compressor to the contact dryer; and (vi) recovering from the contact dryer a dried composition of solid matter, wherein surfaces of the installation configured to come in contact with the acidic process vapours are made from a stainless steel titanium alloy Comment 1. Janicki does not explicitly disclose that the process vapours are acidic; however, the process is for waste product streams, such as streams from mining, and waste streams from mining can be acidic (see para. 3 of Stone as evidentiary support). Regarding claim 12, Janicki discloses the process according to claim 9, wherein the process does not depend on or connect with any energy requirements unrelated to or outside of the process (the drying process of Janicki is not part of another process). Claim(s) 10, 11, 19 are rejected under 35 U.S.C. 103 as being unpatentable over Janicki (US 10800667 B1) in view of Zhang (CN 201962163 U) and Thomas (US 20180172348 A1), and as evidenced by Stone (US 20190023592 A1). Regarding claim 10, 11, 19, Janicki discloses the process according to claim 9 wherein the composition of solid matter to be dried is a wet slurry, but does not disclose a wet slurry selected from: stillage obtained during the production of starches and sweeteners from cereals, comprising corn or wheat; cereals, cereal grains, cereal endosperms, cereal germs, cereal bran or cereal derived products comprising cereal flakes, starches (native or modified), maltodextrins, or syrups, wherein the cereal can be corn or maize, rice, wild rice, wheat (comprising spelt, einkorn, emmer, durum and kamut), barley, sorghum, millet, oats, rye, triticale and mixtures thereof; distillers grains, comprising wet distillers grains (WDG) and dried distillers grains with solubles (DDGS), wherein the distillers grains are a cereal byproduct of the distillation process from beer breweries, distilleries and bioethanol plants, and wherein the cereal can be corn or maize, rice, wild rice, wheat comprising spelt, einkorn, emmer, durum and kamut; barley, sorghum, millet, oats, rye, triticale and mixtures thereof; fibrous material comprising fibres such as wood fibres comprising groundwood, lacebark, thermomechanical pulp and bleached or unbleached kraft or sulfite pulps; vegetable fibres comprising bamboo, cotton, hemp, jute, flax, ramie, sisal, bagasse, banana and coconut fibres; dietary fibres comprising soluble fibres and insoluble fibres whether synthetic or natural or derived naturally or derived from nature and animal fibres; other foodstuffs and fat- or protein- or lipid- or dietary fibre-containing compositions; detergents in the form of washing powders and salt, mined or produced from seawater. However, Thomas teaches drying a grain consisting of wet distillers grain, slurry, sludge and mixtures thereof (claim 6), and foodstuffs (claim 8). It would have been obvious to a person skilled in the art at the time of effective filing of the application wherein the dryer of Janicki is used to dry distillers grains (e.g., wet distillers grains) and foodstuffs, so that the material can be efficiently and effectively dried. Claim(s) 18 are rejected under 35 U.S.C. 103 as being unpatentable over Janicki (US 10800667 B1) in view of Zhang (CN 201962163 U) and Tsangaris (US 20080210089 A1), and as evidenced by Stone (US 20190023592 A1). Regarding claim 18, Janicki suggests wherein compressing the purified process vapours in a vapour compressor comprises a one-stage process (Fig. 4 shows a one-stage for the compressor 317). Moreover, even if Janicki does not disclose or suggest a one-stage process, Tsangaris teaches the use of a one-stage compressor for compressing a gas (para. 169). The benefit of a one-stage processor is its reduced complexity and costs. Response to Arguments Re: Election Regarding claim 3, original claim 3 recited four different species of the contact dryer. Since Applicant has received an action on the merits for the originally presented invention (i.e., the contact drum dryer), this invention has been constructively elected by original presentation for prosecution on the merits. See MPEP 821.03. If a restriction were not permitted in this situation, then the claims could be constantly amended each time to shift the invention to a new embodiment, which would require a new examination. See MPEP 819. Regarding claims 21-25, the claims are directed to an invention that is independent and distinct from the invention originally claimed. Since applicant has received an action on the merits for the originally presented invention, claims 1, 2, 4, 6-12, 18-20 have been constructively elected by original presentation for prosecution on the merits. See MPEP 821.03. If a restriction were not permitted in this situation, then an applicant could continually add new sets of claims that are directed to inventions that are independent and distinct from the originally claimed invention. Re: 35 USC 103 Rejections Applicant asserts the following on pg. 11 of the Remarks: PNG media_image1.png 174 694 media_image1.png Greyscale Examiner’s response: The Examiner’s argument is that Janicki discloses a system that can handle a wide variety of waste streams, including waste streams from mining, which can be acidic as evidenced by Stone. Moreover, nothing in Janicki the precludes the system from handling acidic waste streams. Applicant asserts the following on pg. 11 of the Remarks: PNG media_image2.png 308 684 media_image2.png Greyscale Examiner’s response: The vapors are prevented from cooling so that they do not condense onto the filter bags of the filter (315) (col. 28, lines 3-5). The wet scrubber could be placed downstream of the steam filter assembly, thereby eliminating this concern. Applicant asserts the following on pg. 12 of the Remarks: PNG media_image3.png 82 676 media_image3.png Greyscale Examiner’s response: It would have been obvious to a person skilled in the art at the time of effective filing of the application to modify Janicki wherein the purifying apparatus further comprises a wet scrubber configured to neutralise acidity of the of the acidic process vapours, in order to purify the gases. The filter (Janicki, 315) would remove some of the particulates, especially the larger particulates (see Tsangaris; col. 27, lines 44-47), and the wet scrubber would remove the smaller particulates and the acidic vapors (Tsangaris, para. 17). Janicki discloses a system that can handle a wide range of waste streams, such as streams from mining (see Background), and these streams can be acidic, as evidenced by para. 3 of Stone. If the acidic vapors are not removed, then corrosion of the interior surfaces of the system may occur. Furthermore, a person skilled in the art would have been motivated to place the wet scrubber downstream the filter system (Janicki, 315) and upstream the compressor (Janicki, 317), so that the contaminated vapors do not foul and/or corrode the compressor (Janicki, 317) and the dryer (Janicki, 349). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to JASON LAU whose telephone number is (571)270-7644. The examiner can normally be reached Mon-Fri 8:00-5:00. 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, Michael Hoang can be reached on 571-272-6460. 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. /JASON LAU/Primary Examiner, Art Unit 3762
Read full office action

Prosecution Timeline

Feb 22, 2022
Application Filed
Jan 29, 2025
Non-Final Rejection — §103
Apr 18, 2025
Response Filed
May 04, 2025
Final Rejection — §103
Aug 05, 2025
Request for Continued Examination
Aug 08, 2025
Response after Non-Final Action
Oct 03, 2025
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

3-4
Expected OA Rounds
53%
Grant Probability
68%
With Interview (+14.3%)
3y 4m
Median Time to Grant
High
PTA Risk
Based on 880 resolved cases by this examiner. Grant probability derived from career allow rate.

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