DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statements (IDS) submitted on 10/07/2024, 05/12/2025, and 01/22/2026 are being considered by the examiner.
Claim Objections
Claims 15 and 19 are objected to because of the following informalities:
Regarding claims 15 and 19: “comprises as” should read “comprises”.Appropriate correction is required.
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 of this title, 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.
Claims 1-7, 10-13, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over H2OOP (“Tube Leak Detectors in Power Plants” - https://h2oop.com/tube-leak-detection-in-power-plants/ - July 7th 2021 snapshot retrieved via wayback machine is attached to the instant Office action) in view of Desrochers et al. (US 20070137318 A1).Regarding claim 1:H2OOP teaches a method for monitoring a state of water- or steam-conducting tubes of at least one heat exchanger, said at least one heat exchanger being arranged in an exhaust gas flow of a heat recovery steam generator (e.g., paragraph immediately before FIG. 3), comprising:
detecting a presence of steam within the exhaust gas flow automatically using a sensor that measure a measured quantity representing a moisture content of the exhaust gas flow and/or using an optical detection system, and triggering an alarm based on a detection of the presence of steam(First paragraph after FIG.2 – “Installing a humidity sensor after the boiler will also be able to pick up a tube leak because the leak is in the form of steam. The added moisture content to the process gas is picked up by the sensor alerting the plant of a leak.”)
H2OOP, as snapshotted by the wayback machine, fails to explicitly teach:
sensors(I.e., more than one sensor. The examiner notes that this explicitly shown in FIG. 3 of the regular web page, which shows three sensors, each at a stack and disclosed as also being able to be located at the stack or the economizer outlet. However, the wayback machine snapshot does not show FIG. 3. The examiner relies on Desrochers as teaching incorporating multiple sensors into a single area.)Desrochers teaches:
multiple humidity sensors spread across the duct/conveyance structure cross section (e.g., [0071]-[0072]; FIGS. 7-8; it is noted that Desrochers is only relied upon for duplication of humidity sensors)
Therefore it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a plurality of sensors, as taught by Desrochers, in the method of H2OOP, to increase accuracy and/or reliability.
Regarding claim 2:H2OOP and Desrochers teach all the limitations of claim 1, as mentioned above.H2OOP also teaches:
wherein the sensors are moisture sensors(First paragraph after FIG. 2. The plural of sensor is met upon combination, as set forth in the claim 1 rejection above.)
Regarding claim 3:H2OOP and Desrochers teach all the limitations of claim 2, as mentioned above.H2OOP teaches or renders obvious:
wherein the measured values measured by the sensors are compared with at least one stored limit value, and the alarm is triggered if at least one of the measured values exceeds the limit value
H2OOP teaches that “[h]umidity measurements also have to use all process data including load, ambient conditions, duct burner operation and power augmentation to establish base humidity levels when there are no leaks present.” This teaches or renders prima facie obvious a stored limit value as the established “base humidity levels when there are no leaks present”. It is noted that H2OOP also teaches “[i]nstalling a humidity sensor after the boiler will also be able to pick up a tube leak because the leak is in the form of steam. The added moisture content to the process gas is picked up by the sensor alerting the plant of a leak.” Thus, there must be a level above which the alert is triggered. To compare, it must be stored in some form. The plural “sensors” is met upon combination with Desrochers, as set forth in the claim 1 rejection above.
Regarding claim 4:H2OOP and Desrochers teach all the limitations of claim 2, as mentioned above.As combined in the claim 1 rejection above, Desrochers teaches:
wherein the sensors measure the measured quantity at measurement points which are arranged in distributed fashion over a cross section of the exhaust gas flow (e.g., [0071]-[0072]; FIGS. 7-8)
Regarding claim 5:H2OOP and Desrochers teach all the limitations of claim 4, as mentioned above.As combined in the claim 1 rejection above, Desrochers teaches:
wherein the measurement points are arranged in a style of a grid in uniformly distributed fashion over the cross section of the exhaust gas flow (e.g., [0071]-[0072]; FIGS. 7-8)
Regarding claim 6:H2OOP and Desrochers teach all the limitations of claim 4, as mentioned above.H2OOP also teaches:
wherein the measurement points are positioned downstream of the last heat exchanger through which the exhaust gas flow flows(“The sensors are installed after the Heat Recovery Steam Generation (HRSG) system, typically at the economizer outlet or at the stack.”)
Regarding claim 7:H2OOP and Desrochers teach all the limitations of claim 4, as mentioned above.H2OOP also teaches:
wherein in the event of detecting the alarm, a position of a leak is calculated on a basis of a comparison of the measured values ascertained at different measurement points, and the calculated position is output
The phrase “in the event of detecting the alarm” makes the remaining limitations contingent. Under BRI if the alert is sent but not yet read or processed (i.e., the alarm is not yet detected), the contingent limitations are not required. The examiner notes that claim 7 is additionally rejected in view of Zander below.
Regarding claim 10:H2OOP and Desrochers teach all the limitations of claim 1, as mentioned above.As combined in the claim 1 rejection above, H2OOP and Desrochers teach:
a heat recovery steam generator comprising: an exhaust gas channel, in which at least one heat exchanger comprising water- or steam-conducting tubes is arranged, sensors and/or an optical detection system designed to detect the presence of steam in an exhaust gas guided through the exhaust gas channel provided within the exhaust gas channel, and a controller data-connected to the sensors and/or to the optical detection system and configured to carry out the method as claimed in claim 1 (see claim 1 rejection above; see H2OOP, sections below FIG. 2; see Desrochers – [0056]-[0057] however, the examiner also takes the stance that the claimed “controller” is merely using generic computer components to carry out claim steps, which is well-known in the art as well as interpretable as mere automation)
Regarding claim 11:H2OOP and Desrochers teach all the limitations of claim 10, as mentioned above.H2OOP also teaches:
wherein the sensors are moisture sensors(First paragraph after FIG. 2. The plural of sensor is met upon combination, as set forth in the claim 1 rejection above.)
Regarding claim 12:H2OOP and Desrochers teach all the limitations of claim 10, as mentioned above.Desrochers teaches:
a holding grid accommodating the sensors provided over a cross section of the exhaust gas channel (“exhaust gas” is also met upon combination with H2OOP), and positioned at regular intervals on the holding grid (e.g., [0071]-[0072]; FIGS. 7-8)
It would have been obvious to incorporate the holding grid of Desrochers in the device of H2OOP to hold the sensors in an appropriate and stable configuration to sample a larger area of the duct/channel.
Regarding claim 13:H2OOP and Desrochers teach all the limitations of claim 12, as mentioned above.As combined in the claim 1 rejection above H2OOP and Desrochers teach:
wherein the holding grid is arranged downstream of the last heat exchanger (H2OOP teaches that the moisture/steam sensing is done “at the economizer outlet or at the stack” which are each locations that are downstream of the last heat exchanger)
Regarding claim 16:H2OOP and Desrochers teach all the limitations of claim 6, as mentioned above.As combined in the claim 1 rejection above H2OOP and Desrochers teach:
wherein the measurement points are positioned exclusively downstream of the last heat exchanger through which the exhaust gas flow flows (H2OOP teaches that the moisture/steam sensing is done “at the economizer outlet or at the stack” which are each locations that are downstream of the last heat exchanger)
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over H2OOP (“Tube Leak Detectors in Power Plants” - https://h2oop.com/tube-leak-detection-in-power-plants/ - July 7th 2021 snapshot retrieved via wayback machine is attached to the instant Office action) in view of Desrochers et al. (US 20070137318 A1) and further in view of Zander et al. (US 6659166 B1).Regarding claim 7:H2OOP and Desrochers teach all the limitations of claim 4, as mentioned above.In an alternative interpretation, H2OOP fails to teach:
wherein in the event of detecting the alarm, a position of a leak is calculated on a basis of a comparison of the measured values ascertained at different measurement points, and the calculated position is outputZander teaches:
a position of a leak is calculated on a basis of a comparison of the measured values ascertained at different measurement points, and the calculated position is output (e.g., Col. 2, Lines 47-52; Col. 8, Lines 11-13)
Therefore it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the position / location determination of Zander in the method of H2OOP to: allow for monitoring multiple heat exchangers and determination of which one has the leak if a leak is detected; and/or for faster leak locating and repair. The examiner notes that this may be done by sampling from different points or by placing additional sensors at differing locations that allow for the aforementioned leak location determination.
Claims 8-9, 14, and 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over H2OOP (“Tube Leak Detectors in Power Plants” - https://h2oop.com/tube-leak-detection-in-power-plants/ - July 7th 2021 snapshot retrieved via wayback machine is attached to the instant Office action) in view of Desrochers et al. (US 20070137318 A1) and further in view of Kakuta et al. (US 20240151641 A1).Regarding claim 8:H2OOP and Desrochers teach all the limitations of claim 1, as mentioned above.H2OOP fails to teach:
wherein the optical system comprises at least one video cameraKakuta teaches:
wherein the optical system comprises at least one video camera ([0062], [0077]-[0081], [0097], [0114], [0132])
Therefore it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the camera moisture detection of Kakuta as it is an art-recognized equivalent means for the detection of water vapor or steam.
The examiner notes that this claim is alternatively rejected under 35 U.S.C. 103 as being unpatentable over H2OOP (“Tube Leak Detectors in Power Plants” - https://h2oop.com/tube-leak-detection-in-power-plants/ - July 7th 2021 snapshot retrieved via wayback machine is attached to the instant Office action) in view of Kakuta et al. (US 20240151641 A1). The reasons for changing the moisture / steam / vapor sensing methodology is the same as above (art-recognized equivalent means).
Regarding claim 9:H2OOP and Desrochers teach all the limitations of claim 1, as mentioned above.H2OOP fails to teach:
wherein the optical detection system comprises at least one laserKakuta teaches:
wherein the optical detection system comprises at least one laser ([0062], [0077]-[0081], [0097], [0114], [0132])
Therefore it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the laser moisture detection of Kakuta as it is an art-recognized equivalent means for the detection of water vapor or steam.
The examiner notes that this claim is alternatively rejected under 35 U.S.C. 103 as being unpatentable over H2OOP (“Tube Leak Detectors in Power Plants” - https://h2oop.com/tube-leak-detection-in-power-plants/ - July 7th 2021 snapshot retrieved via wayback machine is attached to the instant Office action) in view of Kakuta et al. (US 20240151641 A1). The reasons for changing the moisture / steam / vapor sensing methodology is the same as above (art-recognized equivalent means). Also see sections 3.1 and 3.2 of Dennis et al. (“SAF WATER LEAK DETECTION BY THE MEASUREMENT”), cited in the conclusion section below.
Regarding claim 14:H2OOP and Desrochers teach all the limitations of claim 10, as mentioned above.H2OOP fails to teach:
wherein the optical detection system comprises at least one video camera and/or at least one laserKakuta teaches:
wherein the optical detection system comprises at least one video camera and/or at least one laser ([0062], [0077]-[0081], [0097], [0114], [0132])
Therefore it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the video camera or laser moisture detection of Kakuta as it is an art-recognized equivalent means for the detection of water vapor or steam.
The examiner notes that this claim is alternatively rejected under 35 U.S.C. 103 as being unpatentable over H2OOP (“Tube Leak Detectors in Power Plants” - https://h2oop.com/tube-leak-detection-in-power-plants/ - July 7th 2021 snapshot retrieved via wayback machine is attached to the instant Office action) in view of Kakuta et al. (US 20240151641 A1). The reasons for changing the moisture / steam / vapor sensing methodology is the same as above (art-recognized equivalent means). Also see sections 3.1 and 3.2 of Dennis et al. (“SAF WATER LEAK DETECTION BY THE MEASUREMENT”), cited in the conclusion section below.
Regarding claim 17:H2OOP, Desrochers, and Kakuta (or H2OOP and Kakuta) teach all the limitations of claim 8, as mentioned above.As combined in the claim 8 rejection above H2OOP and Kakuta teach:
wherein the video camera is directed at an inner surface of the heat recovery steam generator furnished with a predetermined pattern, and/or is positioned downstream of the last heat exchanger through which the exhaust gas flow flows(H2OOP teaches that the moisture/steam sensing is done “at the economizer outlet or at the stack” which are each locations that are downstream of the last heat exchanger.)
Regarding claim 18:H2OOP, Desrochers, and Kakuta (or H2OOP and Kakuta) teach all the limitations of claim 9, as mentioned above.As combined in the claim 9 rejection above H2OOP and Kakuta teach:
wherein the at least one laser is directed at an associated light detector arranged on an inner surface of the heat recovery steam generator, and/or wherein the at least one laser and the associated light detector are positioned downstream of the last heat exchanger through which the exhaust gas flow flows(H2OOP teaches that the moisture/steam sensing is done “at the economizer outlet or at the stack” which are each locations that are downstream of the last heat exchanger.)
Claims 15 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over H2OOP (“Tube Leak Detectors in Power Plants” - https://h2oop.com/tube-leak-detection-in-power-plants/ - July 7th 2021 snapshot retrieved via wayback machine is attached to the instant Office action) in view of Desrochers et al. (US 20070137318 A1) and further in view of Pandey et al. (US 20130176418 A1).Regarding claim 15:H2OOP and Desrochers teach all the limitations of claim 1, as mentioned above.H2OOP fails to explicitly teach:
wherein the heat exchanger comprises as a superheater, an evaporator, and a feedwater preheater when viewed in a downstream direction(although these are well-known HRSGs)Pandey teaches (FIG. 1):
wherein the heat exchanger comprises as a superheater (2), an evaporator (3), and a feedwater preheater (1) when viewed in a downstream direction
Therefore it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the HRSG structure of Pandey in the method of H2OOP as it is combining known elements to yield predictable results. H2OOP teaches a HRSG but is silent as to the specific components. Pandey teaches a well-known HRSG structure.
Regarding claim 19:H2OOP and Desrochers teach all the limitations of claim 10, as mentioned above.H2OOP fails to explicitly teach:
wherein the heat exchanger comprises as a superheater, an evaporator, and a feedwater preheater when viewed in a downstream direction(although these are well-known HRSGs)Pandey teaches (FIG. 1):
wherein the heat exchanger comprises as a superheater (2), an evaporator (3), and a feedwater preheater (1) when viewed in a downstream direction
Therefore it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the HRSG structure of Pandey in the device of H2OOP as it is combining known elements to yield predictable results. H2OOP teaches a HRSG but is silent as to the specific components. Pandey teaches a well-known HRSG structure.
Examiner’s Comment Regarding Potentially Allowable Subject Matter
The examiner recommends a claim that requires limitations similar to claims 7 and 15-16 with language that more clearly and exclusively sets forth the following concept that appears to be novel and non-obvious. A HRSG with multiple tube sets / heat exchangers (e.g., claim 15) that uses only data from a single set of multiple moisture sensors, all located in the same cross sectional plane, and the set being located exclusively downstream of the last heat exchanger to calculate a leak location based on pre-characterized plume behavior that is sensed by said set of moisture sensors. Ultimately, however, the specific claim language used is critical to ensuring that such a claim, under BRI, is not rejectable using prior art. The examiner is open to an interview to discuss such potential claim language.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure: Go et al. (“A Systematic Approach for Achieving Plant Performance Excellence”); and Dennis et al. (“SAF WATER LEAK DETECTION BY THE MEASUREMENT”).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Herbert Keith Roberts whose telephone number is (571)270-0428. The examiner can normally be reached 10a - 6p MT.
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, Peter Macchiarolo can be reached at (571) 272-2375. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/HERBERT K ROBERTS/Primary Examiner, Art Unit 2855
