DETAILED ACTION
Status of Claims
Claims 13-16 and 18-23 are pending and presented for examination on the merits. Claim 13 is currently amended. Claims 20-23 are new.
Status of Previous Claim Rejections Under 35 USC § 112
The previous rejections of claims 13-16, 18, and 19 under 35 U.S.C. § 112(b) are withdrawn in view of the amendment to claim 13.
The previous rejection of claim 17 under 35 U.S.C. § 112(b) is moot in view of the canceled status of the claim.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 13, 14, 16, and 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over US 5,431,709 (A) to Winchester et al. (“Winchester”) in view of US 2,855,293 (A) to Savard et al. (“Savard”) and further in view of US 2001/0043639 (A1) to Shver (“Shver”).
Regarding claim 13, Winchester is directed to the injection of inert and/or reactive gases (process gases) into a bath of molten metal by means of a submerged tuyere (method for treating molten metals and/or slags in metallurgical baths). Col. 1, lines 6-8. The injection includes a step of using an injector to introducing fuel gas and oxygen into solid steel scrap, molten pig iron, molten steel, molten oxides, solid non-ferrous metal scrap, or molten non-ferrous metals (introducing a process gas into a melt bath). Col. 2, lines 25-33.
The tuyere is designed and the gas velocity is increased such that there is a supersonic jet with fully expanded Mach numbers between 1.1 and 3 (accelerating the process gas to supersonic speed and introducing the process gas by at least one supersonic nozzle with supersonic speed). Col. 3, lines 3-18, 48-51. The tuyere is in contact with the molten metal (introducing the process gas below a melt bath surface into a liquid phase of a molten metal and/or into a slag and/or into a region of a phase boundary between molten metal and slag). FIG. 2; col. 3, lines 44-47; col. 6, lines 17-22.
The pressure ratios of fuel gas and oxygen are run at high enough of a value to create under-expanded supersonic gas jet in the molten metal or oxide at the end of the tuyere, and the static pressure inside the jet and at the tuyere exit is greater than the static pressure of the molten metal or oxide (operating at least one supersonic nozzle outside its gas-dynamic design point). Col. 3, lines 34-47.
Winchester does not teach that the fuel gas and oxygen (process gas) is introduced at several locations of the melt bath using a plurality of supersonic nozzles. However, Winchester teaches that the tuyere is installed in a refining vessel as shown in any of the U.S. patents cited therein. Winchester cites, for example, US 2,855,293. Col. 1, lines 15-25.
US 2,855,293 to Savard et al. is directed to a method of high-pressure oxygen gas injection to treat molten metal. Col. 1, lines 15-17. In the process, concentrated oxygen is injected below the surface of the melt. Col. 2, lines 3-7; col. 3, lines 9-12. Intimate contact is achieved through the use of high pressure and small cross-section of injected stream or streams. Col. 2, lines 28-31. Several jets can be used (process gas introduced at several locations below a melt bath using a plurality of nozzles). Col. 2, lines 31-34; col. 3, lines 33-36; FIG. 6. The treatment results in better efficiency and performance with a deeper bath, permitting more metal to be treated per batch for a vessel of a definite diameter. Col. 4, lines 43-47. Injecting from the bottom ensures reaction throughout the depth of the whole bath. Col. 6, lines 31-48.
It would have been obvious to one of ordinary skill in the art to have used multiple nozzles of Winchester, as suggested by Savard, when treating a bath of molten metal because the use of several jets would increase the volume of melt available to react or get in contact with the gas, thereby ensuring that the whole melt, as opposed to only a limited portion, is treated.
Savard discloses a flow-high pressure regulator as part of the treating vessel. Col. 4, lines 54-59; FIG. 1. A pressured gauge leads to a high-pressure globe valve that permits the oxygen pressure to be controlled at any desirable level and which permits pressure alteration by simply turning the valve handle. Col. 4, lines 59-66. Savard does not expressly disclose using this regulator to control a plurality of nozzles (e.g., FIG. 6) individually, subjecting individual nozzles to volume flows and/or pressure changes.
Shver is drawn to an apparatus that introduces a high velocity oxidizing gas (process gas) into a furnace for metal melting, refining, and processing. Abstract; para. [0003]. A plurality of burner/lances (plurality of nozzles) are embedded in the walls of the furnace and used to deliver flows of oxidizing gas. Para. [0039], [0041]-[0046]. A flow controller is used to control the flows of oxidizing gas and fuel to the burner/lances by means of flow control actuators and sensors. Para. [0050]. The flow controller is a programmable device that has a program for independently controlling the burner function for each burner/lance, controlling at least the oxidizing gas/fuel ratio and its thermal output (controlling the plurality of nozzles individually). Para. [0050]. Control also includes the total amount of oxygen supplied and flow rates of the oxidizing gas (subjecting individual nozzles to volume flows and/or pressure changes of the process gas). Para. [0067]-[0070]. These controls efficiently adjust the oxidizing gas in individual reaction zones. Para. [0069], [0070].
It would have been obvious to one of ordinary skill in the art to have implemented individual control mechanisms for each nozzle of Winchester, as modified by Savard, because independent control would permit the user to customize and tailor each region of the melt in accordance with the needs of the reaction in that specific area, thereby improving efficiency and reducing material/energy waste.
Regarding claim 14, Savard shows introduction of gas from the bottom or the side. Col. 2, lines 64-72; col. 3, lines 1-35; col. 4, lines 12-32, 75; col. 5, line 1; FIGS. 2, 4, 5, and 6. For at least one injector at the bottom and at the side, the injectors would be at different heights relative to the melt bath surface. It would have been obvious to one of ordinary skill in the art to have placed injectors at various locations and heights of the vessel because it would maximize the regions of the melt exposed to the gas.
Regarding claim 16, Winchester teaches that the static pressure inside the jet and at the tuyere exit is greater than the static pressure of the molten metal or oxide (at least one of the plurality of supersonic nozzles is operated outside its gas-dynamic design point, the gas-dynamic point selected such that a gas pressure of the process gas at an outlet cross-section of the supersonic nozzle corresponds to an ambient pressure within the molten metal). Col. 2, lines 64-66; col. 3, lines 34-40, 64-68.
Regarding claim 18, Winchester teaches that the tuyere is in contact with the molten metal. FIG. 2; col. 3, lines 44-47; col. 6, lines 17-22. Because the tuyere is in touch with the molten metal, it follows that the fuel gas and oxygen are introduced into the vessel vertically from below and/or laterally. This is illustrated in FIG. 2, which shows the molten metal (52) above the tuyere (gas bubbles are introduced from below).
Savard also shows introduction of gas from the bottom (FIG. 2) or the side (FIG. 5). Col. 4, lines 26-32, 75; col. 5, line 1.
Regarding claim 19, Winchester teaches that the tuyere is encased in refractory brick that is set into the wall of the converter vessel or furnace containing the metal or oxide (using a metallurgical vessel having a nozzle passing through a wall and/or bottom of the metallurgical vessel). Col. 2, lines 50-52; col. 6, lines 14-16; FIGS. 1 and 2.
Savard also shows the injector embedded within the wall of the vessel (using a metallurgical vessel having a plurality of nozzles passing through a wall and/or bottom of the metallurgical vessel). Col. 2, lines 64-72; col. 3, lines 1-35; col. 4, lines 12-32; FIGS. 2, 4, 5, and 6.
Regarding claim 20, Winchester discloses that the fuel gas and oxygen are run at high enough pressure ratios to create an under-expanded supersonic gas jet in the molten metal or oxide at the end of the tuyere (operating at least one of the plurality of supersonic nozzles outside its gas-dynamic design point such that the process gas under-expands in the molten metal). Col. 3, lines 34-40.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Winchester in view of Savard and Shver, as applied to claim 13 above, and further in view of US 3,938,743 to Miller (“Miller”).
Regarding claim 15, Winchester teaches that the diameters and lengths of the tubes used in the tuyere are selected to create supersonic jets with fully expanded Mach numbers between 1.1 and 3 (col. 3, lines 48-51), but does not teach a nozzle having a convergent part and a divergent part.
Miller is directed to tuyeres of metallurgical or refining vessels. Abstract. The tuyere creates a supersonic velocity in a gas flowing therethrough. Col. 2, lines 1-6. The structure includes an axially aligned venturi member having a converging portion, a restricted neck portion, and a divergent portion at the injection end of the nozzle. Col. 2, lines 6-20, 32-36; col. 3, lines 26-28, 47-51. The venturi member and portions 22, 23, and 24 are designed for a particular velocity, such as Mach 2, utilizing well known nozzle design parameters. Col. 3, lines 52-54; FIGS. 1 and 3.
Winchester teaches that the tuyere tubes can be any combination of length and diameter that creates a supersonic jet on the end of the tuyere for the desired flow and pressure ratio. Col. 3, lines 56-59. It would have been obvious to one of ordinary skill in the art to have incorporated the nozzle shape taught by Miller into the design of Winchester because it would meet the Winchester’s objective of attaining supersonic velocities of the gas being injected into the metal bath.
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Winchester in view of Savard and Shver, as applied to claim 13 above, and further in view of US 5,931,985 (A) to Schoeler et al. (“Schoeler”).
Regarding claim 22, Winchester, Savard, and Shver do not teach operating the nozzles in pulsating mode.
Schoeler discloses a process for blowing oxygen-containing gas on a metal melt in a metallurgical vessel. Abstract; col. 1, lines 5-12. The main oxygen flow in the lance/nozzles is caused to pulsate, its frequency is adapted such that an appreciable increase and a more intensive mixing of the individual media is effected (operating nozzle in pulsating mode to generate a pumping effect and intensive mixing). Abstract; col. 2, lines 14-18, 47-51; col. 3, lines 4-9.
It would have been obvious to one of ordinary skill in the art to have added a pulsing motion, as taught by Schoeler, to the nozzles of Winchester, as modified by Savard and Shver, because the vibrations would induce increase the intensity of the mixing action, encouraging increased contact among different regions of the melt.
Claim 23 is rejected under 35 U.S.C. 103 as being unpatentable over Winchester in view of Savard and Shver, as applied to claim 13 above, and further in view of US 3,330,645 (A) to de Moustier et al. (“de Moustier”).
Regarding claim 23, Winchester, Savard, and Shver do not teach the plurality of nozzles in a nozzle array in a replaceable cassette of a melting vessel holding the melt bath.
De Moustier is directed to the injection of fluids into hot molten metal, such as the injection of oxygen into molten iron in steelmaking operations. Col. 1, lines 13-15. The invention includes the novel type of tuyere bottom comprising a plurality of injectors that is readily adaptable as a replacement unit for a conventional tuyere bottom (nozzle array in a replaceable cassette of the melting vessel). Col. 1, lines 16-21, 38-42; col. 3, lines 25-29; FIG. 5.
It would have been obvious to one of ordinary in the art to have arranged the nozzles of Winchester in view of Savard and Shver in the manner disclosed by de Moustier because the integrated structure of de Moustier would facilitate the replacement of nozzles by simplifying (reducing) the number of parts, making removal and reinstallation faster and more efficient.
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over US 5,858,059 (A) to Abramovich et al. (“Abramovich”) in view of US 2008/0000325 (A1) to Mahoney et al. (“Mahoney”) and further in view of Shver.
Regarding claim 21, Abramovich discloses a method for injecting reactants, such as gases, liquids and solids, into a molten bath (method for treating molten metals and/or slags in metallurgical baths, injecting process gas into a melt bath). Col. 1, lines 50-54. Multiple injection locations are spaced at the bottom and sides of the reactor, the locations being tuyere blocks different and submerged beneath the molten bath (introducing process gas at several locations below a melt bath surface by a plurality of nozzles). Col. 2, lines 8-11, 22-27, 55-65; col. 4, lines 23-28; FIG. 2.
Feed streams, such as oxygen, are ejected from the tuyeres at a velocity between about 0.4 Mach and about 2.0 Mach (includes supersonic speeds, the process gas accelerated with supersonic speeds into a liquid phase of molten metal and/or slag and/or region of phase boundary between molten metal and slag). Col. 5, lines 40-43, 67; col. 6, lines 1-4.
Abramovich is silent regarding whether at least one nozzle can be operated outside its gas-dynamic design point such that the process gas over-expands in the molten metal.
Mahoney is drawn to a method of injecting oxygen into a melt within a metallurgical furnace, wherein a supersonic jet of oxygen is injected into a melt at a supersonic velocity using multiple nozzles. Abstract; para. [0001], [0023], [0027], [0049]. The nozzle is operated in an overexpanded state (operating at least one of a plurality of supersonic nozzles outside its gas-dynamic point such that the process gas overexpands in the molten metal). Para. [0032], [0060]; FIG. 4. An advantage of an overexpanded structured jet is that the combustion risk is reduced and the need to compress fuel above a threshold is eliminated. Para. [0063].
It would have been obvious to one of ordinary skill in the art to have designed and operated the nozzle of Abramovich in the manner taught by Mahoney because overexpansion of the process gas would decrease the potential for combustion and avoid the requirement to compress fuel above a pressure conventional with commercial fuel.
Abramovich and Mahoney do not expressly disclose individual control of each supersonic nozzle, subjecting individual nozzles to volume flows and/or pressure changes.
Shver is drawn to an apparatus that introduces a high velocity oxidizing gas (process gas) into a furnace for metal melting, refining, and processing. Abstract; para. [0003]. A plurality of burner/lances (plurality of nozzles) are embedded in the walls of the furnace and used to deliver flows of oxidizing gas. Para. [0039], [0041]-[0046]. A flow controller is used to control the flows of oxidizing gas and fuel to the burner/lances by means of flow control actuators and sensors. Para. [0050]. The flow controller is a programmable device that has a program for independently controlling the burner function for each burner/lance, controlling at least the oxidizing gas/fuel ratio and its thermal output (controlling the plurality of nozzles individually). Para. [0050]. Control also includes the total amount of oxygen supplied and flow rates of the oxidizing gas (subjecting individual nozzles to volume flows and/or pressure changes of the process gas). Para. [0067]-[0070]. These controls efficiently adjust the oxidizing gas in individual reaction zones. Para. [0069], [0070].
It would have been obvious to one of ordinary skill in the art to have implemented individual control mechanisms for each nozzle of Abramovich, as modified by Mahoney, because independent control would permit the user to customize and tailor each region of the melt in accordance with the needs of the reaction in that specific area, thereby improving efficiency and reducing material/energy waste.
Response to Arguments
Applicant's arguments filed 10/27/2025 have been fully considered.
Applicant argues that Savard does not teach individual control of the injectors.
In response, the argument is moot in view of Shver, which teaches the use of a programmable flow controller that independently controls each burner/lance (para. [0050]). This includes control of the total amount of oxygen supplied and flow rates of the oxidizing gas (para. [0067]-[0070]). Given that these known controls permit the efficiently adjustment of gas in individual reaction zones (para. [0069], [0070]), one of ordinary skill in the art would have been motivated to have implemented a control mechanism for each nozzle because independent control permits one to customize and tailor each region of the melt in accordance with the needs of the reaction in that specific area.
Applicant argues that Savard discloses only subsonic injectors, whereas the claimed invention is directed to supersonic injectors.
In response, Savard does not teach or suggest that its injectors can only operate at subsonic speeds. This is supported by Winchester in which gas is accelerated to supersonic speeds and who explicitly refers to the tuyeres installed in refining vessel of any of the U.S. Patents listed therein (that includes Savard) as being capable of being used in their invention (col. 6, lines 17-21).
Additionally, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See MPEP 2145(IV), citing In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). Primary reference to Winchester teaches the use of a tuyere designed such that the gas travels at Mach numbers between 1.1 and 3 (supersonic speed) (col. 3, lines 3-18, 48-51). Savard is cited for the known implementation of multiple injection sites. Thus, the claim limitation directed to supersonic nozzles are addressed by other art of record.
Applicant argues that Savard discloses the positioning of the injectors in the alternative (bottom or side), whereas claim 14 requires bottom and side.
In response, although Savard illustrates nozzles in separate embodiments in the bottom of the vessel (FIGS. 2 and 4) and in the sides of the vessel (FIGS. 5 and 6), Savard also teaches that the use of several jets results in better efficiency and performance, especially in deeper baths, because more metal can be treated per batch (col. 2, lines 31-34; col. 3, lines 33-36; col. 4, lines 43-47; FIG. 6). This suggests the placement of the jets in multiple locations would be advantageous to reach as many sections of the bath. Thus, one of ordinary skill in the art would have been motivated to place injectors at various locations and heights of the vessel, such as at the bottom and at the sides of the vessel, because multiple jets would maximize the regions of the melt exposed to the gas. This rationale is consistent with Rationale (A) (combining prior art elements according to known methods to yield predictable results) at MPEP § 2143(I)(A).
Furthermore, it is prima facie obvious to combine equivalents known for the same purpose. See MPEP § 2144.06(I). In the present instance, placement of the nozzle at the side or bottom are equivalent in the sense that both locations perform the job of delivering gas to the melt. Therefore, combining the locations (bottom plus side) in one vessel would logically follow because they serve the same purpose.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 VANESSA T. LUK whose telephone number is (571)270-3587. The examiner can normally be reached Monday-Friday 9:30 AM - 4:30 PM ET.
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/VANESSA T. LUK/Primary Examiner, Art Unit 1733
February 11, 2026