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 .
Priority
Acknowledgment is made of applicant’s claim for foreign priority (NL2023243, filed on 31 May 2019) under 35 U.S.C. 119 (a)-(d). The certified copy has been filed.
Claim Objections
Claim 6 objected to because of the following informalities:
The phrase “the plurality of circulation evaporator effects” should be corrected to read “the plurality of forced circulation evaporator effects” for consistency with Claim 1.
Appropriate correction is required.
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
Determining the scope and contents of the prior art.
Ascertaining the differences between the prior art and the claims at issue.
Resolving the level of ordinary skill in the pertinent art.
Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-3, 6-16 are rejected under 35 U.S.C. 103 as being unpatentable over VALLESPIN et al (NPL: Fluidized Bed Heat Exchangers for the Evaporation of Waste Waters: Design Advantages and Operational Experiences, 2017, hereinafter VALLESPIN).
Regarding Claim 1, VALLESPIN discloses an evaporation process for water containing dissolved solids that is used for water recovery, solids recovery, or liquid waste volume reduction in several industries, notes that such evaporators are often affected by severe fouling which negatively affects their operation, and presents fluidized bed heat exchangers as a solution to the fouling problem (abstract, Pg. 293).
In the alcohol and bio-ethanol industry, the bottom product of distillation, vinasse or stillage, is evaporated in multiple-stage evaporation trains. The recovered condensate is reused in the production facility, and the concentrated product is further dried for biomass recovery. Vinasse contains organic components such as sugars and proteins together with inorganic salts. A similar process is applied in the pulp industry, where black liquor from Kraft digesters, containing organic lignin and inorganic chemicals such as sodium hydroxide and sodium sulfide, is evaporated in multiple-stage trains before being used as fuel in burners for steam production, and combustion of the concentrated black liquor yields ash containing recoverable chemical components from the pulp digestion process (Pg. 293, Col. 1).
In these evaporation systems, the self-cleaning fluidized bed heat exchanger operates by circulating cleaning particles with the fouling liquid through the tubes of a vertical shell and tube heat exchanger. The upward flow fluidizes the particles and scours deposits from the internal tube surfaces at an early stage. At the outlet, the particles are separated from the liquid and returned via a downcomer to the inlet channel so that the cleaning cycle repeats continuously.
This operating principle is illustrated in Figure 1 (Pg. 294, Col. 1). It is reasonably interpreted that this self-cleaning fluidized bed heat exchanger represents the heat-exchanger portion of a self-cleaning forced circulation evaporator effect.
To regulate the amount of particles entering the inlet channel, a portion of the inlet flow entrains particles from the downcomer into the inlet channel. The cleaning action depends on particle quantity, size, material, and fluid velocity. The cleaning particles may be cut metal wire, glass beads, or ceramic beads with diameters of about 1 to 4 mm, and the material is selected to be corrosion resistant to the operating medium (Pg. 294, Col. 1).
Fluidized bed heat exchangers can serve as forced circulation evaporators by integrating a fluidized bed heat exchanger with a downstream flash vessel. To keep the fluidized bed stable, back pressure is applied to suppress boiling inside the heat exchanger. The outlet liquid passes through an orifice into a flash vessel at lower pressure, where liquid and vapor separate. Most of the liquid is recirculated to the heat exchanger, and a small fraction is discharged to control solids concentration in the recirculation loop, as illustrated in Figure 2 (Pg. 294, Col. 2).
The forced circulation evaporator with a fluidized bed heat exchanger can be integrated into various evaporation configurations, including MVRs, thermocompressors, and multiple-effect evaporator trains (Pg. 294, Col. 2).
Although VALLESPIN does not explicitly disclose selecting the first forced circulation evaporator effect, but less than all forced circulation evaporator effects, for the self-cleaning configuration in a multiple-effect evaporator train, the selection of which evaporator effect receives the self-cleaning configuration is a routine process-design choice. In view of VALLESPIN’s disclosure that the self-cleaning forced circulation evaporator can be implemented in multiple-effect evaporator trains, that the cleaning particles remove deposits at an early stage of fouling formation, and that fouling control depends on operating conditions such as concentration and temperature, a person having ordinary skill in the art would have selected the first forced circulation evaporator effect, but less than all forced circulation evaporator effects, for the self-cleaning configuration to provide fouling control when the waste water stream first enters the series while avoiding unnecessary installation of the self-cleaning configuration in every effect (Pg. 293–294).
Regarding Claim 2, VALLESPIN makes obvious the multi-effect evaporation process for the evaporation of a waste water stream of Claim 1. VALLESPIN discloses that the combination of high mineral concentration and high temperatures causes minerals to precipitate as a scaling layer on the heat exchanger walls (Pg. 293, Col. 2), and a self-cleaning fluidized bed heat exchanger in which the waste water stream and cleaning particles are passed together through the tubes of a shell and tube heat exchanger in a forced circulation evaporator so that fouling deposits are removed at an early stage and the cleaning cycle repeats continuously (Pg. 294, Col. 1).
In a multi-effect evaporator train, working temperature and concentration conditions vary from effect to effect. In view of VALLESPIN’s teaching that fouling depends on operating conditions including temperature and concentration, a person having ordinary skill in the art would have selected an effect based on the temperature profile of the multi-effect evaporator train, including the effect having the highest or lowest working temperature relative to the other effects, for installation of the same self-cleaning configuration based on fouling control and process-design considerations.
Regarding Claim 3, VALLESPIN makes obvious the multi-effect evaporation process for the evaporation of a waste water stream of Claim 1. VALLESPIN discloses that fouling tendency increases with concentration level, that the combination of high mineral concentration and high temperature causes precipitated minerals to crystallize as a scaling layer on the heat exchanger walls, and that a self-cleaning fluidized bed heat exchanger passes the waste water stream and cleaning particles together through the tubes of a shell and tube heat exchanger in a forced circulation evaporator so that fouling deposits are removed at an early stage and the cleaning cycle repeats continuously (Pg. 293, Col. 2; Pg. 294, Col. 1). In the examples, the same configuration maintains non-fouling performance at concentrations as high as about 400,000 mg/L (Pg. 296, Col. 2).
In a multi-effect evaporator train, the concentration of dissolved inorganic and organic materials in the waste water stream is a process condition that varies across the effects as water is evaporated. In view of VALLESPIN’s teaching that fouling tendency increases with concentration level and that the self-cleaning fluidized bed heat exchanger maintains non-fouling performance under high-concentration conditions, a person having ordinary skill in the art would have selected the effect having the highest concentration of the mixture in the waste water stream for installation of the same self-cleaning configuration to address expected fouling.
Regarding Claim 6, VALLESPIN makes obvious the multi-effect evaporation process for the evaporation of a waste water stream of Claim 1. VALLESPIN discloses a self-cleaning fluidized bed heat exchanger in which a fouling liquid and cleaning particles are circulated together through the tubes of a forced circulation evaporator, where the upward flow fluidizes the particles and creates a scouring effect on the tube walls to remove deposits at an early stage of fouling formation. The cleaning cycle repeats continuously, and the forced circulation evaporator with the fluidized bed heat exchanger can be integrated into multiple-effect evaporator trains (Pg. 294, Col. 1–2).
Regarding Claim 7, VALLESPIN makes obvious the multi-effect evaporation process for the evaporation of a waste water stream of Claim 1. VALLESPIN discloses waste water evaporation applications involving vinasse or stillage from alcohol and bio-ethanol production and produced water from hydrocarbon extraction, which are industrial waste waters containing organic materials subject to high-temperature evaporation in the disclosed evaporator systems (Pg. 293–296).
Regarding Claim 8, VALLESPIN makes obvious the multi-effect evaporation process for the evaporation of a waste water stream of Claim 1. VALLESPIN discloses evaporation of highly contaminated industrial waste waters, including vinasse from a shochu distillery and produced water from oil and gas production, which contain dissolved organic and inorganic materials and cause severe fouling in evaporators (Pg. 293–296).
The limitation “wherein said waste water stream at the start of the process has a chemical oxygen demand (COD) in the range of 5,000 mg/L to 100,000 mg/L” defines an initial property of the waste water stream rather than a process step. VALLESPIN applies the same self-cleaning forced circulation evaporation process to highly contaminated industrial waste waters, and selecting an industrial waste water feed having an initial COD within the claimed range would not change the recited evaporation steps or the self-cleaning forced circulation evaporator configuration.
Regarding Claim 9, VALLESPIN makes obvious the multi-effect evaporation process for the evaporation of a waste water stream of Claim 1. VALLESPIN discloses that a fluidized bed heat exchanger was installed in a shochu distillery’s forced circulation evaporator to evaporate vinasse and prevent scaling from inorganic compounds such as CaSO₄, MgSO₄, and Na₂SO₄ present in the waste water stream (Pg. 294, Col. 2).
Regarding Claim 10, VALLESPIN makes obvious the multi-effect evaporation process for the evaporation of a waste water stream of Claim 1. Regarding the limitation “a second waste water stream from a dyestuff production process,” this limitation identifies the source of the waste water material being worked upon and does not add a further evaporation step, operating condition, or self-cleaning evaporator configuration. Applying VALLESPIN’s process to waste water that includes dyestuff-production waste water would merely involve selecting another industrial waste water feed for the same known process (Pg. 293–296; In re Otto, 312 F.2d 937 (CCPA 1963); In re Young, 75 F.2d 996 (CCPA 1935)).
Regarding Claim 11, VALLESPIN makes obvious the multi-effect evaporation process for the evaporation of a waste water stream of Claim 1. VALLESPIN discloses cleaning particles including cut metal wire, glass beads, and ceramic beads having diameters of about 1 to 4 mm, and the shochu distillery example uses metal wire particles having a size of 2 mm. VALLESPIN also discloses that parts in the tube side and the particles were SS 304, which corresponds to stainless steel particles and falls within the claimed size range of 1 to 5 mm (Pg. 294, Col. 1; Pg. 295, Table 2; Pg. 295, Col. 2).
Regarding Claim 12, VALLESPIN makes obvious the multi-effect evaporation process for the evaporation of a waste water stream of Claim 1. VALLESPIN discloses that the heated waste water and cleaning particles leaving the self-cleaning fluidized bed heat exchanger enter an outlet channel and separator, where the particles disengage from the liquid and are returned to the inlet channel through a downcomer pipe, thereby yielding a heated liquid stream and a concentrated cleaning particle stream in the recirculation loop (Pg. 294, Col. 1).
Regarding Claim 13, VALLESPIN makes obvious the multi-effect evaporation process for the evaporation of a waste water stream of Claim 1. VALLESPIN discloses that the heated waste water stream and cleaning particles exiting the self-cleaning fluidized bed heat exchanger enter an outlet channel and separator, where the particles disengage from the liquid and are returned to the inlet channel through a downcomer pipe, thereby yielding a heated liquid stream and a concentrated particle stream. The heated liquid stream is passed through an orifice into a flash vessel at lower pressure, where liquid and vapor are separated, with most liquid recirculated to the heat exchanger and a smaller fraction discharged to control solids concentration. The forced circulation evaporator with the fluidized bed heat exchanger can be integrated into multiple-effect evaporator trains (Pg. 294, Col. 1–2).
Regarding Claim 14, VALLESPIN makes obvious the multi-effect evaporation process for the evaporation of a waste water stream of Claim 1. VALLESPIN discloses that, in the shochu distillery case, the system handles a feed flow of 2 m³/h and a recirculation flow of 180 ± 10 m³/h with a tube flow velocity of 0.65 m/s, which reads upon the claimed flow velocity of about 0.5 to about 0.7 m/s (Table 2, Pg. 295).
Regarding Claim 15, VALLESPIN makes obvious the multi-effect evaporation process for the evaporation of a waste water stream of Claim 1. VALLESPIN discloses that the cleaning performance of the self-cleaning fluidized bed heat exchanger depends on particle quantity, particle size, particle material, and fluid velocity, and that part of the inlet flow is used to entrain particles from the downcomer into the inlet channel to control the amount of particles entering the tubes (Pg. 294, Col. 1).
Although VALLESPIN does not explicitly disclose that the waste water stream with particles has a porosity in the range of 90 to 98%, the recited porosity reflects the void fraction of the fluidized bed operating regime already taught by VALLESPIN. A person having ordinary skill in the art would have adjusted particle quantity and fluid velocity to maintain particle movement through the tubes and avoid packing or clogging, thereby arriving at a high-porosity fluidized bed within the claimed range through routine optimization of known operating parameters. The claim does not show that the recited porosity range is critical or yields an unexpected result (In re Aller, 220 F.2d 454 (CCPA 1955)).
Regarding Claim 16, VALLESPIN makes obvious the multi-effect evaporation process for the evaporation of a waste water stream of Claim 1. VALLESPIN discloses that, in the shochu distillation case, the evaporator is heated with motive steam at a pressure of about 500 to 590 kPa (Table 1, Pg. 295).
Although VALLESPIN does not explicitly disclose heating the heat exchanger with steam having a temperature of about 110°C to about 160°C, the recited steam temperature reflects the saturated-steam condition corresponding to the disclosed motive-steam pressure. A person having ordinary skill in the art would have selected the steam temperature based on the disclosed steam pressure and the desired evaporator heating duty, thereby arriving at a steam temperature within the claimed range through routine optimization of known heating conditions. The claim does not show that the recited steam-temperature range is critical or yields an unexpected result (In re Aller, 220 F.2d 454 (CCPA 1955)).
Response to Arguments
Applicant’s arguments, see Remarks filed March 16, 2026, have been fully considered but are not persuasive. The rejection under 35 U.S.C. § 103 is updated and maintained.
Applicant’s reliance on Example 1 and FIG. 6 is not persuasive because, even if the reported results are accepted, the evidence is not commensurate in scope with amended Claim 1. Example 1 concerns a specific retrofit of a full-scale MEE plant treating a particular dyestuff waste water stream under particular operating conditions, while amended Claim 1 is not limited to that specific waste water composition, number of effects, operating conditions, retrofit history, or arrangement in which only the first effect is equipped with cleaning particles. In addition, the Specification describes operational facts affecting the reported results, including pre-retrofit cleaning, remaining fouling in the tubes, loosened fouling material clogging some tubes, and later inspection and cleaning, and presents the proposed downstream-fouling explanation only as “a possible explanation.” Accordingly, Example 1 and FIG. 6 do not establish unexpected results across the full scope of amended Claim 1.
Applicant’s reliance on CHALLA is not persuasive. CHALLA is not applied in the present rejection, and amended Claim 1 does not require the first forced circulation evaporator effect to be the most severely fouling effect. The rejection, as updated, does not rely on such a finding. Rather, the rejection is based on VALLESPIN’s disclosure of the known self-cleaning forced circulation evaporator configuration and its implementation in multiple-effect evaporator trains, with placement of the known configuration in the first effect, but less than all effects, being a routine process-design choice.
Applicant’s arguments with respect to Claim 10 are not persuasive. Upon further consideration, WATANABE is not necessary because the limitation “a second waste water stream from a dyestuff production process” identifies the source of the waste water material being worked upon and does not add a further evaporation step, operating condition, or self-cleaning evaporator configuration.
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 TAK L. CHIU whose telephone number is (703)756-1059. The examiner can normally be reached M-F: 9:00am - 6:00pm (CST).
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, PREM C. SINGH can be reached at (571)272-6381. 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.
/TAK L. CHIU/Examiner, Art Unit 1777
/KRISHNAN S MENON/Primary Examiner, Art Unit 1777
Prosecution Insights