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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 10/3/2025 has been entered.
Claim Objections
Claim 17 is objected to because of the following informalities:
Claim 17 appears to have a typographical error in line 18. The examiner respectfully suggests replacing “iv)” with -- iii) --. Appropriate correction is required.
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) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 16 recites “a high-pressure urea synthesis loop” in line 5. It is unclear whether or not this limitation is the same structure recited in line 2. The examiner has interpreted the claim to mean that it is the same structure.
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.
Claims 1-9 and 11-15 are rejected under 35 U.S.C. 103 as being unpatentable over Applicant’s Admitted Prior Art as disclosed in the Specification (“AAPA”) in view of U.S. Patent 6,615,658 issued to (“Snelling”) and “Fiber Optica Strain and Temperature Sensing: Overview of Principles” by Engelbrecht (“Engelbrecht”).
As for claim 1, AAPA discloses a method for measuring a liquid level of a fluid contained in a pressure vessel that is a piece of equipment of a high pressure urea synthesis loop, or a reactor for synthesis of melamine (Specification: page 1, line 9 - page 2, line 9).
Although AAPA discloses the need to measure a liquid level in a pressure vessel (Specification: page 1, lines 9-14), AAPA does not disclose that the method comprises providing a thermometric well inside the pressure vessel, wherein the thermometric well extends vertically in the pressure vessel.
However, Snelling discloses a method for measuring a liquid level of a fluid, the method comprising i) providing a thermometric well (Fig. 4) inside a pressure vessel (22b), wherein the thermometric well extends vertically in the pressure vessel (see Fig. 4). Snelling discloses that the thermometric well senses the level of liquid inside the pressure vessel (Abstract)
Snelling and AAPA disclose each element claimed, although not necessarily in a single prior art reference, with the only difference between the claimed invention and the prior art being the lack of actual combination of the elements in a single prior art reference. One of ordinary skill in the art could have combined the thermometric well of Snelling with the pressure vessel of AAPA by placing the thermometric well inside the vessel as suggested by Fig. 4 of Snelling, and that in combination, the pressure vessel and thermometric well merely perform the same functions as each does separately. Therefore, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to modify the method and pressure vessel of AAPA by including the step of providing a thermometric well as disclosed by Snelling to achieve the predictable result of providing a structure to measure the liquid level inside the pressure vessel.
AAPA as modified by Snelling discloses a method for measuring a liquid level of a fluid contained in a pressure vessel that is a piece of equipment of a high pressure urea synthesis loop, or a reactor for synthesis of melamine (AAPA: Specification: page 1, line 9 - page 2, line 9), the method comprising:
i) providing a thermometric well (Snelling: Fig. 4) inside the pressure vessel (AAPA: page 1, lines 9-14 and Snelling: 22b) that is a piece of equipment of a high pressure urea synthesis loop, or a reactor for synthesis of melamine (AAPA: Specification: page 1, line 9 - page 2, line 9), wherein the thermometric well extends vertically in the pressure vessel (Snelling: see Fig. 4), wherein said thermometric well (Snelling: Fig. 4) has an inner surface which is not in contact with the fluid (Snelling: see Fig. 4) and is separated from the fluid by a side wall (Snelling: 55) of the thermometric well;
ii) heating said inner surface of the thermometric well (Snelling: col. 6, lines 49-56);
iii) detecting the temperature of at least one detection point of said inner surface (Snelling: col. 7, lines 39-47);
iv) estimating a position of the liquid level based on the difference between at least one reference temperature and the actual temperature detected at step iii) (Snelling: col. 7, lines 49-63).
AAPA as modified by Snelling does not disclose that, in step iii), the temperature is detected continuously by an optical fiber distributed temperature sensing (DTS) system. Instead, Snelling discloses that temperature is detected using electronic sensors (Snelling: col. 7, lines 39-47).
However, Engelbrecht discloses that temperature can be detected continuously (see the section “Distributed Sensing by Light Scattering” on page 257) by an optical fiber distributed temperature sensing (DTS) system (Abstract).
It would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the optical fiber distributed temperature sensing (DTS) system of Engelbrecht for the electronic sensors of Snelling because fiber-optic sensors offer distinctive advantages compared to electronic sensors or sensors with electrical connection leads (Engelbrecht: Introduction).
As for claim 2, AAPA as modified by Snelling and Engelbrecht discloses that the step ii) of heating the inner surface of the thermometric well includes heating the inner surface to a target temperature greater than a temperature of a medium contained in the pressure vessel (Snelling: col. 4, lines 14-46).
As for claim 3, AAPA as modified by Snelling and Engelbrecht discloses that in the step iv), the at least one reference temperature includes an expected temperature of at least one detection point (Snelling: col. 8, lines 5-19).
As for claim 4, AAPA as modified by Snelling and Engelbrecht discloses that, in the step iv), the at least one reference temperature includes a temperature previously detected at said at least one detection point (Snelling: col. 8, lines 5-19 and col. 8, lines 35-51).
As for claim 5, AAPA as modified by Snelling and Engelbrecht discloses that, in the step iv), the at least one reference temperature includes a temperature of the fluid contained in the pressure vessel (Snelling: col. 8, lines 20-34).
As for claim 6, AAPA as modified by Snelling and Engelbrecht discloses that the step iii) includes detecting the temperature of at least two detection points of said inner surface at different elevation (Snelling: col. 7, line 64 - col. 8, lines 4).
As for claim 7, AAPA as modified by Snelling and Engelbrecht discloses that the step iv) includes:
determining a thermal profile of the inner surface of the thermometric well (Snelling: col. 7, line 64 - col. 8, line 4), based on the temperature detected at said detection points, and the position of the liquid level is estimated on the basis of said thermal profile (Snelling: col. 7, lines 59-63).
As for claim 8, AAPA as modified by Snelling and Engelbrecht discloses that step iv) includes:
measuring a temperature at several detection points on the inner surface, the detection points being at different elevations (Snelling: col. 7, lines 39-47);
detecting a singular pair of consecutive detection points (Snelling: col. 7, lines 48-58) wherein the difference temperature between said detection points is greater than the difference of temperature of other pairs of consecutive detection points (Snelling: col. 4, lines 39-57);
assuming that the liquid level is located between the detection points of said singular pair (Snelling: col. 7, lines 59-63).
As for claim 9, AAPA as modified by Snelling and Engelbrecht discloses that the step iii) is performed by detecting the temperature at only one detection point (Snelling: col. 6, lines 57-59) and is repeated over time (Snelling: col. 8, lines 35-39), and the step iv) includes that the liquid level is assumed to have crossed the detection point when a change of temperature greater than a reference threshold is detected (Snelling: col. 8, lines 39-51).
As for claim 11, AAPA as modified by Snelling and Engelbrecht discloses that at least one of temperature and pressure of the fluid contained in the pressure vessel is greater than a critical value (Baharuddin: the temperature and pressure have values such that water is contained in the vessel; paragraph [0023]).
As for claim 12, AAPA discloses a system for measuring a liquid level of a fluid in a pressure vessel (AAPA: Page 1, lines 9-14) that is a piece of equipment of a high pressure urea synthesis loop (AAPA: Specification: page 1, line 9 - page 2, line 9), or a reactor for synthesis of melamine (AAPA: Specification: page 1, line 9 - page 2, line 9).
Although AAPA discloses the need to measure a liquid level in a pressure vessel (Specification: page 1, lines 9-14), AAPA does not disclose a thermometric well which extends vertically in the pressure vessel.
However, Snelling discloses a thermometric well (Snelling: Fig. 4) which extends vertically in a pressure vessel (Snelling: see Fig. 4), wherein the thermometric well has an inner surface which is not in contact with a fluid (Snelling: see Fig. 4), being sealedly separated from the inside of the pressure vessel where the fluid is contained (Snelling: sealed by 30; col. 7, lines 13-15), wherein the thermometric well includes at least one heater (Snelling: col. 6, lines 21-24) arranged to heat said inner surface to a target temperature.
Snelling and AAPA disclose each element claimed, although not necessarily in a single prior art reference, with the only difference between the claimed invention and the prior art being the lack of actual combination of the elements in a single prior art reference. One of ordinary skill in the art could have combined the thermometric well of Snelling with the pressure vessel of AAPA by placing the thermometric well inside the vessel as suggested by Fig. 4 of Snelling, and that in combination, the pressure vessel and thermometric well merely perform the same functions as each does separately. Therefore, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to modify the system and pressure vessel of AAPA by providing a thermometric well as disclosed by Snelling to achieve the predictable result of providing a structure to measure the liquid level inside the pressure vessel.
AAPA as modified by Snelling discloses that, to measure the liquid level around the thermometric well, the system is configured to:
a) heat, via the at least one heater, said inner surface of the thermometric well (Snelling: col. 6, lines 49-56);
b) detect the temperature of at least one detection point of said inner surface (Snelling: col. 7, lines 39-47); and
c) estimate a position of the liquid level based on the difference between at least one reference temperature and the actual temperature detected at step b) (Snelling: col. 7, lines 49-63).
AAPA as modified by Snelling does not disclose that, in b), the temperature is detected continuously by an optical fiber distributed temperature sensing (DTS) system. Instead, Snelling discloses that temperature is detected using electronic sensors (Snelling: col. 7, lines 39-47).
However, Engelbrecht discloses that temperature can be detected continuously (see the section “Distributed Sensing by Light Scattering” on page 257) by an optical fiber distributed temperature sensing (DTS) system (Abstract).
It would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the optical fiber distributed temperature sensing (DTS) system of Engelbrecht for the electronic sensors of Snelling because fiber-optic sensors offer distinctive advantages compared to electronic sensors or sensors with electrical connection leads (Engelbrecht: Introduction).
As for claim 13, AAPA as modified by Snelling and Engelbrecht discloses that said pressure vessel is a chemical reactor (AAPA: Specification: page 1, line 9 - page 2, line 9).
As for claims 14 and 15, AAPA as modified by Snelling and Engelbrecht discloses that the piece of equipment of the high-pressure urea synthesis loop is selected from among a reactor, a stripper, and a condenser (AAPA: Specification: page 1, lines 9-11).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Applicant’s Admitted Prior Art as disclosed in the Specification (“AAPA”) in view of U.S. Patent 6,615,658 issued to (“Snelling”) as applied to claim 1, further in view of U.S. Patent 4,603,580 issued to Waring (“Waring”) and “Fiber Optica Strain and Temperature Sensing: Overview of Principles” by Engelbrecht (“Engelbrecht”).
As for claim 10, AAPA as modified by Snelling and Engelbrecht discloses the method according to claim 1 above (see the rejection of claim 1).
AAPA as modified by Snelling and Engelbrecht does not explicitly disclose that the step iii) is performed by means of an electric resistance installed in the thermometric well. Instead, Snelling discloses that the step iii) is performed by a heater of undisclosed structure in order to determine a liquid level (Snelling: col. 6, lines 49-56 and col. 7, lines 59-63).
However, Waring discloses an electric resistance (32) installed in a thermometric well (14; Fig. 1). Waring discloses that the electric resistance is a heater used to heat an interior of a thermometric well in order to determine a liquid level (col. 3, lines 38-65).
Because Snelling and Waring both disclose heaters used to determine a liquid level, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to substitute the heater of Waring for the heater of Snelling in order to achieve the predictable result of providing a heater that can be used to determine a liquid level.
Claims 16 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Applicant’s Admitted Prior Art as disclosed in the Specification (“AAPA”) in view of U.S. Patent 6,615,658 issued to (“Snelling”).
As for claim 16, AAPA discloses a method for measuring a liquid level of a fluid contained in a pressure vessel that is a piece of equipment of a high pressure urea synthesis loop, or a reactor for synthesis of melamine (Specification: page 1, line 9 - page 2, line 9).
Although AAPA discloses the need to measure a liquid level in a pressure vessel (Specification: page 1, lines 9-14), AAPA does not disclose that the method comprises providing a thermometric well inside the pressure vessel, wherein the thermometric well extends vertically in the pressure vessel.
However, Snelling discloses a method for measuring a liquid level of a fluid, the method comprising i) providing a thermometric well (Fig. 4) inside a pressure vessel (22b), wherein the thermometric well extends vertically in the pressure vessel (see Fig. 4). Snelling discloses that the thermometric well senses the level of liquid inside the pressure vessel (Abstract)
Snelling and AAPA disclose each element claimed, although not necessarily in a single prior art reference, with the only difference between the claimed invention and the prior art being the lack of actual combination of the elements in a single prior art reference. One of ordinary skill in the art could have combined the thermometric well of Snelling with the pressure vessel of AAPA by placing the thermometric well inside the vessel as suggested by Fig. 4 of Snelling, and that in combination, the pressure vessel and thermometric well merely perform the same functions as each does separately. Therefore, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to modify the method and pressure vessel of AAPA by including the step of providing a thermometric well as disclosed by Snelling to achieve the predictable result of providing a structure to measure the liquid level inside the pressure vessel.
AAPA as modified by Snelling discloses a method for measuring a liquid level of a fluid contained in a pressure vessel that is a piece of equipment of a high pressure urea synthesis loop, or a reactor for synthesis of melamine (AAPA: Specification: page 1, line 9 - page 2, line 9), the method comprising:
i) providing a thermometric well (Snelling: Fig. 4) inside the pressure vessel (AAPA: page 1, lines 9-14 and Snelling: 22b) that is a piece of equipment of a high pressure urea synthesis loop, or a reactor for synthesis of melamine (AAPA: Specification: page 1, line 9 - page 2, line 9), wherein the thermometric well extends vertically in the pressure vessel (Snelling: see Fig. 4), wherein said thermometric well (Snelling: Fig. 4) has an inner surface which is not in contact with the fluid (Snelling: see Fig. 4) and is separated from the fluid by a side wall (Snelling: 55) of the thermometric well;
ii) heating said inner surface of the thermometric well (Snelling: col. 6, lines 49-56);
iii) detecting:
a) the temperature of the inner surface by a first thermocouple (Snelling: col. 7, lines 39-47 and col. 8, lines 20-34);
b) the temperature of the liquid with a second thermocouple arranged below an expected range of the liquid level (Snelling: col. 7, lines 39-47 and col. 8, lines 20-34); and
c) the temperature of a gaseous phase with a further thermocouple arranged above said expected range of the liquid level (Snelling: col. 7, lines 39-47 and col. 8, lines 20-34);
iv) estimating a position of the liquid level based on one or more of the detected temperatures at step iii) (Snelling: col. 7, lines 49-63 and col. 8, lines 20-34).
As for claim 17, AAPA discloses a system for measuring a liquid level of a fluid in a pressure vessel (AAPA: Page 1, lines 9-14) that is a piece of equipment of a high pressure urea synthesis loop (AAPA: Specification: page 1, line 9 - page 2, line 9), or a reactor for synthesis of melamine (AAPA: Specification: page 1, line 9 - page 2, line 9).
Although AAPA discloses the need to measure a liquid level in a pressure vessel (Specification: page 1, lines 9-14), AAPA does not disclose a thermometric well which extends vertically in the pressure vessel.
However, Snelling discloses a thermometric well (Snelling: Fig. 4) which extends vertically in a pressure vessel (Snelling: see Fig. 4), wherein the thermometric well has an inner surface which is not in contact with a fluid (Snelling: see Fig. 4), being sealedly separated from the inside of the pressure vessel where the fluid is contained (Snelling: sealed by 30; col. 7, lines 13-15), wherein the thermometric well includes at least one heater (Snelling: col. 6, lines 21-24) arranged to heat said inner surface to a target temperature.
Snelling and AAPA disclose each element claimed, although not necessarily in a single prior art reference, with the only difference between the claimed invention and the prior art being the lack of actual combination of the elements in a single prior art reference. One of ordinary skill in the art could have combined the thermometric well of Snelling with the pressure vessel of AAPA by placing the thermometric well inside the vessel as suggested by Fig. 4 of Snelling, and that in combination, the pressure vessel and thermometric well merely perform the same functions as each does separately. Therefore, it would have been obvious for one having ordinary skill in the art before the effective filing date of the present application to modify the system and pressure vessel of AAPA by providing a thermometric well as disclosed by Snelling to achieve the predictable result of providing a structure to measure the liquid level inside the pressure vessel.
AAPA as modified by Snelling discloses that, to measure the liquid level around the thermometric well, the system is configured to:
i) heat, via the at least one heater, said inner surface of the thermometric well (Snelling: col. 6, lines 49-56);
ii) detect:
a) the temperature of the inner surface with a first thermocouple (Snelling: col. 7, lines 39-47 and col. 8, lines 20-34);
b) the temperature of the liquid with a second thermocouple arranged below an expected range of the liquid level (Snelling: col. 7, lines 39-47 and col. 8, lines 20-34); and
c) the temperature of a gaseous phase with a further thermocouple arranged above said expected range of the liquid level (Snelling: col. 7, lines 39-47 and col. 8, lines 20-34);
iv) estimate a position of the liquid level based on one or more of the detected temperatures at step ii) (Snelling: col. 7, lines 49-63 and col. 8, lines 20-34).
Response to Arguments
Applicant’s arguments with respect to claims 1 and 12 have been considered but are moot in view of the new grounds of rejection.
Regarding claims 16 and 17, Applicant's arguments filed 10/03/2025 have been fully considered but they are not persuasive. On page 8 of the Remarks, Applicant argues that the prior art does not disclose temperature detections above and below an expected liquid level using at least three thermocouples. The examiner respectfully disagrees. Snelling discloses temperature detections above and below an expected liquid level using at least three thermocouples in col. 7, lines 39-63 and col. 8, lines 20-34.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JUSTIN N OLAMIT whose telephone number is (571)270-1969. The examiner can normally be reached M-F, 8 am - 5 pm (Pacific).
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/JUSTIN N OLAMIT/Primary Examiner, Art Unit 2853