Prosecution Insights
Last updated: July 17, 2026
Application No. 18/486,719

APPARATUS AND METHOD FOR FLUID MIXING

Non-Final OA §102§103§112
Filed
Oct 13, 2023
Examiner
BHATIA, ANSHU
Art Unit
1774
Tech Center
1700 — Chemical & Materials Engineering
Assignee
V-Stax, L.L.C.
OA Round
1 (Non-Final)
84%
Grant Probability
Favorable
1-2
OA Rounds
0m
Est. Remaining
99%
With Interview

Examiner Intelligence

Grants 84% — above average
84%
Career Allowance Rate
803 granted / 953 resolved
+19.3% vs TC avg
Strong +17% interview lift
Without
With
+17.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
43 currently pending
Career history
983
Total Applications
across all art units

Statute-Specific Performance

§101
0.8%
-39.2% vs TC avg
§103
72.4%
+32.4% vs TC avg
§102
10.4%
-29.6% vs TC avg
§112
11.3%
-28.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 953 resolved cases

Office Action

§102 §103 §112
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 The remarks regarding the restriction requirement have been considered and are persuasive. Therefore, the restriction requirement is withdrawn. Claim Objections Claim 15 is objected to. Regarding claim 15, it is suggested that the claim be amended to “The apparatus of claim 9, further comprising one or more intermediate swirling plates located between the swirling device and the parabolic scalloped, dish-shaped device.” in order to enhance the clarity of the claim. Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claim 16 is rejected under 35 U.S.C. 112 (b) for being indefinite. It is not clear what “ligament size or length” means. The term ligament does not appear in the specification. Correction/clarification is required. Claims 17-19 are rejected under 35 U.S.C. 112 (b) for being indefinite since they depend on claim 16 and do not overcome the claim 16 rejection under 35 U.S.C. 112 (b). Claim Rejections - 35 USC § 102 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. 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. Claims 16, 17, 18, 19, 20, 21, are rejected under 35 U.S.C. 102 (a)(1) as being anticipated by Brown (U.S. Publication 2014/0334250). Regarding claim 16, Brown teaches a method of mixing a second fluid into a first fluid with a high degree of surface contact between the first and second fluids (paragraph 30 teaches fluid to fluid mixing which is considered inherently requiring a high degree of surface contact between the fluids), wherein the first fluid is a liquid (paragraph 30 teaches the fluids may include liquids), and wherein the method comprises: flowing the first fluid into a mixing apparatus in a laminar condition (paragraph 32 teaches laminar flow conditions); causing the second fluid to full surface contact the first fluid (paragraph 32 teaches effective distributive mixing which is considered reading on full surface contact between the two fluids); subsequently, rotatably shearing material within a mixture of the first and second fluids (paragraph 52 teaches rotor 11 and shear stressing the material being mixed); and performing shear rotation with variable timing to provide a programmable and precise laminar ligament size or length (paragraph 32 and shear stressing the material being mixed using ). Regarding claim 17, Brown teaches wherein the second fluid is an inoculant or reactant for treating the first fluid (paragraph 31 teaches waste treatment which is considered inherently requiring a material for treating a fluid). Regarding claim 18, Brown teaches wherein the second fluid is introduced into the first fluid by an assembly of aerodynamic swirling vanes (rotor 11 mixes the fluids by rotating which creates an aerodynamic swirling, vanes are considered the shape of the annular steps items 20). Regarding claim 19, Brown teaches wherein the second fluid includes a pressurized gas and at least one other fluid (paragraph 30 teaches fluids and gasses, the gas would inherently have to be pressurized to be transported to the stirrer), and the second fluid is introduced into the first fluid by a multi-physics fluid delivery device (rotor 11 and heating/cooling taught in paragraph 28 is considered reading on a multi-physics fluid delivery device). Regarding claim 20, Brown teaches an apparatus for mixing a second fluid into a first fluid (Figure 1, the materials being worked upon are considered intended use, however paragraph 30 teaches liquids), wherein the first fluid is a liquid (paragraph 30 teaches the fluids may be liquids), and wherein the apparatus comprises: an inlet for flowing the first fluid into the apparatus in a laminar condition (paragraph 27 teaches multiple inlets, paragraph 32 teaches laminar flow conditions between cavities, however the flow rate is considered intended use); flow passages for causing the second fluid to come into contact with the first fluid (paragraph 8 teaches cavities defining flow passages, paragraph 30 teaches liquids in single or multiple streams); and a rotatable shearing device for shearing material within a mixture of the first and second fluids (paragraph 10 teaches rotating mixing parts that subject material to be mixed to intensive shear stresses, figure 1 item 11 rotor is considered reading on the rotatable shearing device). Regarding claim 21, Brown teaches wherein the shearing device includes a variable speed () rotatable scissor (paragraph 90 of the specification defines a scissor as a rotor stator configuration, Brown figure 1 and paragraph 46 teaches an inner rotor 11 and an outer stator 12) for shearing the material within the mixture of the first and second fluids to a programmed size or length (the size or length of the material being worked upon is considered intended use). Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. 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. Claims 1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 14, and 22 is rejected under 35 U.S.C. 103 as being unpatentable over Brown (U.S. Publication 2014/0334250) in view of Holl (U.S. Publication 2005/0053532). Regarding claim 1, Brown teaches a method of mixing a second fluid into a first fluid with a high degree of surface contact between the first and second fluids (paragraph 30 teaches fluid to fluid mixing which is considered inherently requiring a high degree of surface contact between the fluids), wherein the first fluid is a liquid (paragraph 30 teaches the fluids may include liquids), and wherein the method comprises: flowing the first fluid into a mixing apparatus in a laminar condition (paragraph 32 teaches laminar flow conditions); a swirling device for swirling the first fluid within the mixing apparatus (rotor 11 mixes the fluids by rotating which creates a swirling motion); causing the second fluid to contact the first fluid (paragraph 32 teaches effective distributive mixing which is considered reading on full surface contact between the two fluids). Regarding claim 1, Brown is silent to subsequently, causing a mixture of the first and second fluids to flow through a parabolic scalloped flow-focusing, dish-shaped device exiting into a venturi containing a venturi regulator, such that the first and second fluids are further mixed. Regarding claim 1, Holl teaches a rotor/stator (paragraph 4) comprising a flow-focusing dish shaped device (item 18, disc portion is considered reading on a flow focusing dish shaped device) venturi containing a venturi regulator such that the first and second fluids are further mixed (paragraph 39 teaches a venturi, the outward curved surface is considered reading on the venturi regulator). Regarding claim 1, it would have been obvious to one of ordinary skill in the art prior to the effective filling date of the claimed invention to modify the rotor/stator mixer of Brown with the dish and venturi configuration of Holl in order to increase the degree of mixing (see Holl paragraph 39). Regarding claim 1, absent any unexpected results it would have been obvious to one of ordinary skill in the art prior to the effective filling date of the claimed invention to modify the shape of the dish in order to obtain the desired flow rate since it is well settled that it is an obvious matter of design choice to change the general shape or size of a known element in the absence of a disclosed non-obvious advantage associated with the change. Gardner vs. TEC Systems Inc., 725 F.2d 1338, 1349-50 (Fed. Cir. 1984); In re Kuhle, 526 F.2d 553, 555 (CCPA 1975); In re Dailey, 357 F.2d 669, 672 (CCPA 1966). Regarding claim 2, Brown teaches wherein the first fluid is a bulk fluid (paragraph 30 teaches fluids, paragraph 31 teaches bulk chemicals). Regarding claim 3, Brown teaches wherein the second fluid is an inoculant or reactant for treating the first fluid (paragraph 31 teaches reacting, which would inherently require a reactant for treating a fluid, the fluid taught in paragraph 30). Regarding claim 4, Brown teaches using multiple fluids (paragraph 30) for various applications (paragraph 31). Regarding claim 4, Brown is silent to the amounts of each fluid. Regarding claim 4, Absent any unexpected results, it would have been obvious to one of ordinary skill in the art prior to the effective filling date of the claimed invention to modify the amount of each fluid to produce the desired product since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). Regarding claim 5, Brown teaches wherein the mixing apparatus is located within a fluid delivery system (paragraph 30 teaches fluids, paragraph 31 teaches dispersive and distributive mixing operations which is considered reading on a fluid delivery system). Regarding claim 6, Brown teaches wherein the swirling of the first fluid is performed by radially arrayed aerodynamic vanes (paragraph 13 teaches projections and an angled surface which is considered reading on aerodynamic vanes). Regarding claim 8, Brown teaches wherein the second fluid flows through openings at the leading or trailing edges of the vanes (paragraph 30 teaches fluids, paragraph 13 teaches angled surfaces/projections, the fluids would inherently have to pass through the cavities formed by the rotor on either edge of the rotor in order to mix and reach the outlet item 17). Regarding claim 9, Brown teaches an apparatus for mixing a second fluid into a first fluid with a high degree of surface contact between the first and second fluids (paragraph 30 teaches fluid to fluid mixing which is considered inherently requiring a high degree of surface contact between the fluids), wherein the first fluid is a liquid (paragraph 30 teaches the fluids may include liquids), and wherein the method comprises: flowing the first fluid into a mixing apparatus in a laminar condition (paragraph 32 teaches laminar flow conditions); an inlet for flowing the first fluid into the mixing apparatus in a laminar condition (paragraph 32 teaches laminar flow conditions, inlet item 16); a swirling device for swirling the first fluid within the mixing apparatus (rotor 11); flow passages within the swirling device for causing the second fluid to come into contact with the first fluid (paragraph 8 teaches cavities defining flow passages). Regarding claim 9, Brown is silent to a parabolic scalloped, dish-shaped device with a regulated venturi exit, downstream of the swirling device, for causing the first and second fluids to be further mixed. Regarding claim 9, Holl teaches a rotor/stator (paragraph 4) comprising a dish shaped device (item 18, disc portion is considered reading on a flow focusing dish shaped device) venturi containing a venturi regulator such that the first and second fluids are further mixed (paragraph 39 teaches a venturi, the outward curved surface is considered reading on the venturi regulator). Regarding claim 9, it would have been obvious to one of ordinary skill in the art prior to the effective filling date of the claimed invention to modify the rotor/stator mixer of Brown with the dish and venturi configuration of Holl in order to increase the degree of mixing (see Holl paragraph 39). Regarding claim 9, absent any unexpected results it would have been obvious to one of ordinary skill in the art prior to the effective filling date of the claimed invention to modify the shape of the dish in order to obtain the desired flow rate since it is well settled that it is an obvious matter of design choice to change the general shape or size of a known element in the absence of a disclosed non-obvious advantage associated with the change. Gardner vs. TEC Systems Inc., 725 F.2d 1338, 1349-50 (Fed. Cir. 1984); In re Kuhle, 526 F.2d 553, 555 (CCPA 1975); In re Dailey, 357 F.2d 669, 672 (CCPA 1966). Regarding claim 10, Brown teaches wherein the apparatus is configured to operate within a fluid delivery system (paragraph 30 teaches fluids, paragraph 31 teaches dispersive and distributive mixing operations which is considered reading on a fluid delivery system). Regarding claim 11, Brown teaches wherein the swirling device includes radially arrayed aerodynamic vanes (paragraph 13 teaches projections and an angled surface which is considered reading on aerodynamic vanes, figure cavities 44a-44d are arranged radially). Regarding claim 12, Brown teaches wherein the vanes have upstream surfaces, and openings in the upstream surfaces, for causing the second fluid to form films on the upstream surfaces of the vanes thus providing full surface area contact (paragraph 13 teaches an angled configuration which would inherently have an upstream surface, the materials being worked upon are considered intended use). Regarding claim 14, Brown teaches wherein the vanes include leading and trailing edges and openings for the second fluid at the leading or trailing edges (paragraph 13 teaches projections and an angled surface which would inherently have a trailing and leading edge, the material being worked upon is considered intended use). Brown is silent to the language of claim 22. Regarding claim 22, Holl teaches a rotor/stator (paragraph 4) further comprising a motor for rotating the scissor (item 34), the motor being located downstream of the flow passages for causing the second fluid to come into contact with the first fluid (item 34 is considered positioned downstream of inlets 64, the drive allows for materials to be mixed). Regarding claim 22, it would have been obvious to one of ordinary skill in the art prior to the effective filling date to modify the mixer of Brown with the motor of Holl in order to obtain the desired degree of mixing. Allowable Subject Matter Claims 7, 13, and 15 objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims (and if the claim 15 objection above is overcome). Regarding claim 7, the prior art does not teach or fairly suggest the method of mixing with the second fluid flows through openings in the upstream surface of the aerodynamic vanes to form a film on the vanes to promote mixing of the second fluid into the first fluid. Regarding claim 13, the prior art does not teach or fairly suggest an apparatus for mixing with the openings are spaced apart and diagonally aligned with a different line of flow of the first fluid across the upstream surfaces of the vanes. Regarding claim 15, the prior art does not teach or fairly suggest an apparatus for mixing with one or more intermediate swirling plates located between the swirling device and the parabolic scalloped, dish shaped device. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANSHU BHATIA whose telephone number is (571)270-7628. The examiner can normally be reached Monday - Friday 11 a.m. to 7:30 p.m.. 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. /ANSHU BHATIA/Primary Examiner, Art Unit 1774
Read full office action

Prosecution Timeline

Oct 13, 2023
Application Filed
May 13, 2026
Non-Final Rejection mailed — §102, §103, §112 (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

1-2
Expected OA Rounds
84%
Grant Probability
99%
With Interview (+17.0%)
2y 9m (~0m remaining)
Median Time to Grant
Low
PTA Risk
Based on 953 resolved cases by this examiner. Grant probability derived from career allowance rate.

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