DETAILED ACTION
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 6/2/2025 has been entered.
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.
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.
Claim(s) 11, 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Pryor (US 4319921 A) in view of Fluhrer (US 7442119 B2).
Regarding claim 11, Pryor discloses an automatic gas flow control system for an eductor recirculation system in a metal recycling furnace, said furnace having a delacquering chamber (Fig. 6, 21) and a heating chamber (Fig. 6, 20) separated from said delacquering chamber, said eductor recirculation system having an eductor with a gas mixing chamber (48), a gas suction port (58), a motive gas inlet opening (inlet for burner 61 or blower) into said mixing chamber (col. 7, lines 1-18), and a gas discharge port (70) exiting from said mixing chamber,
said gas suction port drawing exhaust gases from said delacquering chamber and directing said gases into said mixing chamber (col. 7, lines 1-8), said motive gas inlet injecting and directing motive gases into said mixing chamber in a direction away from said gas suction port (Fig. 6),
said delacquering chamber exhaust gases mixing with said motive gases in said mixing chamber to form an eductor gas mixture (Fig. 6), said gas discharge port directing said eductor gas mixture toward said furnace heating chamber.
Pryor fails to disclose:
said automatic gas flow control system comprising:
a. an electronic controller;
b. a light source positioned in said eductor recirculation system between said gas suction port and said motive gas inlet, said light source directing a predetermined intensity of light through at least a portion of said delacquering chamber exhaust gases in said eductor recirculation system;
c. an electro-optical sensor positioned in said eductor recirculation system between said gas suction port and said motive gas inlet, said sensor facing said light source, said sensor receiving at least a portion of said light from said light source directed through said exhaust gases, measuring the intensity of said at least a portion of said light generating an electronic signal indicative of said measured light intensity and communicating said signal to said electronic controller; and
c. a variable speed blower (note: Pryor discloses, in col. 7, lines 16-18, a blower located approximately where burner 61 is located, but it is not clear if it is a variable speed blower), said blower being operatively associated with said electronic controller and with said motive gas inlet, said blower controllably injecting motive gases through said motive gas inlet into said eductor mixing chamber, said electronic controller adjusting said blower speed in response to said electronic signal to controllably adjust the concentration of volatiles in said eductor.
Fluhrer teaches an automatic gas flow control system for a ventilation device comprising:
a. an electronic controller (control device/circuit; see abstract);
b. a light source (Fig. 1, light transmitter 22) positioned in the exhaust hood, said light source directing a predetermined intensity of light through at least a portion of the exhaust gases (cooking vapors; see abstract);
c. an electro-optical sensor (Fig. 1, receiver 24) positioned in said exhaust hood, said sensor facing said light source, said sensor receiving at least a portion of said light from said light source directed through said exhaust gases, measuring the intensity of said at least a portion of said light generating an electronic signal indicative of said measured light intensity and communicating said signal to said electronic controller (see abstract and col. 8, lines 18-33); and
c. a variable speed blower (Fig. 1, 20), said blower being operatively associated with said electronic controller, said electronic controller adjusting said blower speed in response to said electronic signal to controllably adjust the concentration of volatiles in said eductor (col. 8, lines 18-33).
Although Fluhrer does not teach placing the light source and electro-optical sensor between said gas suction port and said motive gas inlet of an eductor recirculation system, Fluhrer does teach placing the devices in an exhaust/vent hood where the cooking fumes rise and are vented upward. A person skilled in the art combining the teachings of Fluhrer with Pryor would be motivated to place the light source and sensor in the vertical ventilation duct (see Fig. 6 of Pryor disclosing a vertical ventilation duct connected to the gas suction port 58), upstream the blower (Pryor discloses, in col. 7, lines 16-18, a blower located proximate the motive gas inlet), and this location is between said gas suction port and said motive gas inlet.
Therefore, it would have been obvious to a person skilled in the art at the time of effective filing of the application to modify Pryor to include an automatic gas flow control system comprising: a. an electronic controller; b. a light source positioned in said eductor recirculation system between said gas suction port and said motive gas inlet, said light source directing a predetermined intensity of light through at least a portion of said delacquering chamber exhaust gases in said eductor recirculation system; c. an electro-optical sensor positioned in said eductor recirculation system between said gas suction port and said motive gas inlet, said sensor facing said light source, said sensor receiving at least a portion of said light from said light source directed through said exhaust gases, measuring the intensity of said at least a portion of said light generating an electronic signal indicative of said measured light intensity and communicating said signal to said electronic controller; and c. a variable speed blower, said blower being operatively associated with said electronic controller and with said motive gas inlet, said blower controllably injecting motive gases through said motive gas inlet into said eductor mixing chamber, said electronic controller adjusting said blower speed in response to said electronic signal to controllably adjust the concentration of volatiles in said eductor.
The motivation to combine is to provide optimal control over the furnace to accomplish the stated purpose in Pryor:
(24) The furnace of the invention has a number of advantageous features. Like the recycling furnace of U.S. Pat. No. 4,055,334, it utilizes the heat content of the exhaust gases from the scrap metal in the melting operation by combining the exhaust gases with the burner fuel from the main burner port(s). Also, the charge contaminants are pulled from the furnace sidewell through circulating passage 48 and the secondary burner ports 68 and 69 and are consumed as furnace fuel, thus obviating the necessity for a costly after-burner and additional fuel for incineration. However, unlike the recycling system of U.S. Pat. No. 4,055,334, the present furnace achieves an efficient utilization of the heat energy of the exhaust gases without recirculating these gases over the charge before exhausting them from the furnace.
The present invention provides a uniquely designed reverberatory melting furnace for aluminum scrap which has an enclosed sidewell, with suitable access doors in the sidewell for charging scrap and working the metal. Aluminum scrap cannot be melted in an open sidewell without some pollution control equipment which conventionally is an expensive bag house collection system. The enclosed sidewell of the invention obviates the need for this expensive arrangement. It constitutes a simple but effective containing chamber for the smoke and fumes resulting from the scrap melting process. The smoke and fumes flow from the sidewell to the furnace's enclosed main hearth via the enclosed circulating passage. Because it is completely enclosed, the furnace can be operated without excessive air infiltration by suitably regulating the air admitted through the sidewell doors, and the air or oxygen supplied by the furnace's burner(s) or other devices such as an eductor nozzle, fan, etc. Through its careful control of the amount of air or oxygen passing into the furnace, the present invention avoids to a great extent burning or oxidation of the metal.
Col. 9, lines 20-57
As discussed above, and elsewhere in Pryor, it is important that the right amount of recirculated heat, gases, and air, are brought into the furnace to achieve the efficient burning or oxidation of the metal. For example, it is unwise to control the variable blower to operate at high speeds at the start or end of the oxidation process if not enough heat or fumes are produced; therefore, having an automatic control system, as taught by Fluhrer, for measuring the concentration of fumes and adjusting the circulation of heat and gases, would avoid this problem.
Regarding claim 19, Pryor discloses wherein said furnace further comprises an eductor vacuum hood (Fig. 6: vertical duct above the inlet 58 and/or extension 60), said hood being positioned above said delacquering chamber to collect exhaust gases and volatiles from said delacquering chamber, said gas suction port drawing said delacquering chamber exhaust gases through said hood from said delacquering chamber (Fig. 6).
Claim(s) 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Pryor (US 4319921 A) in view of Fluhrer (US 7442119 B2), as applied to claim 11, and further in view of Yukio (US 3137781 A).
Regarding claim 12, Pryor fails to disclose a vacuum pump, said vacuum pump directing motive gases from said furnace into said blower. However, Yukio teaches a metal heating furnace (system shown in Fig. 2) comprising a vacuum pump (8) (col. 8, lines 30-32), said vacuum pump directing motive gases (Fig. 2, X) from said furnace (inlet duct for gas X of said furnace) into said blower (9) (the vacuum pump 8 creates a negative pressure in the chamber where gases X and Y mix, just upstream the opening 11, which would result in a negative pressure at the outlet (12) of the blower 9; the resulting negative pressure in outlet 12 would help draw gas X into the blower 9).
It would have been obvious to a person skilled in the art at the time of effective filing of the application to modify Pryor to include a vacuum pump, said vacuum pump directing motive gases from said furnace into said blower (a suitable placement for the vacuum pump would be in recirculation duct 48 of the eductor of Pryor). The motivation to combine is to assist the blower in circulating the gases through the eductor. The result would be improved performance of the eductor, especially during times of high demand when recirculating flow through the eductor needs to be high.
Response to Arguments
Applicant’s arguments regarding Hsi and Liu, and regarding improper hindsight, are moot since they do not apply to any of the present rejections.
Regarding the definition of a scrap dryer/delacquering kiln/decoating kiln provided by the Clean Air Act, it appears that the chamber (21) in Pryor is reasonably construed to be a delacquering chamber because it functions to vaporize oil and paints from the aluminum scrap during the melting of the aluminum scrap. The oil and paints start would start vaporizing before the aluminum scrap begins to melt because the oil and paints vaporize at temperatures much lower than the melting point of the aluminum. The Examiner also acknowledges that the chamber (21) can be construed to be a melt chamber, but a melt chamber and delacquering chamber are not mutually exclusive.
Conclusion
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/JASON LAU/Primary Examiner, Art Unit 3762