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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 3/11/2026 has been entered.
Claim Objections
Claim 7 is objected to because of the following informalities:
On the third line, the limitation, “at least two said primary port opening..”, lack antecedent basis because the primary port opening was not previously recited.
On the fourth line, the limitation, “maximum number of said air primary openings…”, lack antecedent basis because the air primary openings were not previously recited. For purpose of examination, the air primary openings are examined to be the previously recited primary port openings.
On the last line, the limitation, “the primary air port openings…”, lack antecedent basis because they were not previously recited. For purpose of examination, the primary air port openings are examined to be the previously recited primary port openings.
Appropriate correction is required.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 7, 8, 42 is/are rejected under 35 U.S.C. 102a1 as being anticipated by MacCallum (US 20070215023 A1).
Regarding claim 7, MacCallum discloses a chemical recovery boiler rectangular in plan-form (para. 76) draining smelt (“smelt spouts”, see e.g., Figs. 1, 3, 4, 20) from one spout wall (para. 86) with no significant primary combustion air port opening area (there is no area of the wall containing the “principal jets”, i.e., openings for combustion air) on the wall opposite the spout wall in which with at least two said primary port opening (primary port opening is examined to be the same as the primary combustion air port opening) (each wall has 3, 5, or 7 jets as shown by Figs. 6, 12, 13; the opening(s) that produce a single one of said jets is considered a port opening) on each of two walls adjacent to said spout wall (the smelt spout can be located on a single wall, e.g., front or rear wall, whereas the principal jets can be on the adjacent side walls) (paras. 67, 194; see also Figs. 20 and 22 and para. 86), with the maximum number of said air primary openings (note: the air primary opening is examined to mean the same as the previously recited primary port opening) on each of said walls adjacent to said spout wall no more than seven plus N where N = (D - W)/S rounded down to the next whole where W is the distance from the centerline of one wall to the centerline of the opposite wall, D is the dimension of the boiler perpendicular to W and S equals the spacing of the primary air port openings (the primary air port openings is examined to be the same as the primary combustion air port opening) (N can be as low as zero since the plan-form dimension could be a square; see Figs. 6, 12, 13).
Regarding claim 8, MacCallum discloses the chemical recovery boiler of Claim 7 in which all said primary air port openings (the primary air port openings is examined to be the primary port openings recited in claim 7) on a first one of the two walls adjacent to said spout wall are directly opposite said primary air port openings on the one of the two adjacent walls opposing said first wall plus or minus three tube pitches (see Figs. 6, 12, 13).
Regarding claim 42, MacCallum discloses the chemical recovery boiler of claim 7 further comprising one or more additional spouts for draining smelt on at least one wall other than the spout wall (para. 86).
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) 9-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over MacCallum (US 20070215023 A1) in view of Katsui (US 20050039647 A1).
Regarding claim 9, MacCallum discloses wherein a jet of combustion air emanates from each of said primary air port openings (the primary air port openings is examined to be the primary port openings recited in claim 7) toward the interior of the boiler EXCEPT the volumetric flow and/or mass flow and/or velocity are controlled automatically and independently for each said air port openings (the air port openings is examined to be the primary port openings recited in claim 7).
However, Katsui teaches a furnace wherein a jet of combustion air emanates from each primary port (22a-c) toward the interior of the furnace and the volumetric flow and/or mass flow and/or velocity are controlled automatically and independently for each air port openings (para. 58).
It would have been obvious to a person skilled in the art at the time of effective filing of the application to modify MacCallum wherein the volumetric flow and/or mass flow and/or velocity are controlled automatically and independently for each said primary air port openings. The motivation to combine to provide extra controllability of the combustion conditions (e.g., flow patterns) inside the boiler (see MacCallum, e.g., paras. 4, 29-43, and throughout discussing the importance of flow patterns inside the boiler).
Regarding claim 10, MacCallum discloses/suggests the chemical recovery boiler of Claim 9 in which the volumetric flow and/or mass flow and/or velocity of at least one first said primary port opening is adjusted to be at least 25% (not explicitly stated but highly suggested, see comment below) greater or lesser than the volumetric flow and/or mass flow and/or velocity of at least one second said primary port opening opposite the first said primary port opening plus or minus three tube pitches creating a strong jet/weak jet relationship between said air port openings (the air port openings is examined to be the primary port openings recited in claim 7) (see Fig. 13b and para. 195) (see also optimization comment below).
Comment: the relative velocities of opposing primary ports is a matter of routine optimization. See MPEP 2144.05. MacCallum discloses that the ratio of the velocities of the opposing primary ports can be adjusted to a range at or near the claimed range (paras. 31, 195) (see para. 139 where the ports can be the same size; therefore, the degree of penetration of air into the boiler interior is directly related to the velocities of air emanating from the opposing ports). MacCallum further discloses that the relative velocities affect the flow stability within the boiler (para. 144), which may affect boiler operations (para. 145) and gas mixing (para. 185).
Regarding claim 11, MacCallum discloses the chemical recovery boiler of Claim 10 in which said strong jet/weak jet relationship between said primary air port openings is periodically in time and automatically reversed (they reverse between a small jet and large jet). Paragraph 30 appears to disclose where the airflow pattern can be controlled to be fully-opposed, partly-opposed, partially-interlaced, or fully-interlaced. This means that the jets can be controlled to have one of the configurations shown in Figs. 12, 13 at different times, i.e., they can periodically change in time to have a different strong jet/weak jet relationship.
Note: even if MacCallum did not disclose this feature, it would have been obvious to include this feature so that the boiler can have the different air configurations shown in MacCallum.
Regarding claim 12, MacCallum discloses the chemical recovery boiler of Claim 11 in which said strong jet/weak jet relationship alternates sequentially from primary port opening to primary port opening along a first wall of the boiler (para. 31), said first wall adjacent to the spout wall (the spout can be on any wall, such as a front or back wall, and the primary ports can be on the side walls) (paras. 67, 86, 194).
Regarding claim 13, MacCallum discloses the chemical recovery boiler of Claim 12 in which the number of said primary port openings on a first of said walls adjacent to said spout wall is even and the number of said primary port openings on the second of said walls adjacent to said spout wall is odd (see Fig. 13a).
Regarding claim 14, MacCallum discloses the chemical recovery boiler of Claim 13 in which the said primary port openings on said first wall are interlaced with said primary ports on said second wall such that said primary port openings on said first wall are centered plus or minus three tube pitches between said primary port openings on said second wall (see Fig. 13a).
Claim(s) 41-52 is/are rejected under 35 U.S.C. 103 as being unpatentable over MacCallum (US 20070215023 A1)
Regarding claim 41, MacCallum fails to disclose the chemical recovery boiler of claim 7 in which S is between 3 feet and 7 feet. However, if the only distinction between the claimed invention and the prior art is size, then it is not a patentable distinction. See MPEP 2144.04(IV)(A).
Regarding claim 42, MacCallum discloses the chemical recovery boiler of claim 7, except wherein the distance from the spout wall to the closest primary air port opening on each of two walls adjacent to said spout wall is 0.75*S. However, the claimed distance is a matter of optimization that can be found through routine optimization. See MPEP 2144.05.
In this case, MacCallum discloses where the distance from the spout wall to the closest primary port on each of two walls adjacent to said spout wall is more or less S (“The primary air introduced…”; see para. 30 and Figs. 6, 12, 13). Moreover, the precise distance affects the flow distribution of upward flowing flue gas, which would affect the fouling of the heating surfaces in the boiler (para. 113). For example, if the primary ports adjacent the sprout wall were spaced farther from the sprout wall, then there would be less upward flow of flue gas in the region adjacent the sprout wall (see Fig. 6). Also, the precise distance would also affect the mixing of the combustion air with the combustibles (paras. 120, 156) because it would affect the flow distribution.
Regarding claim 43, MacCallum discloses the chemical recovery boiler of claim 42, except wherein the distance from the spout wall to the closest primary port opening on each of two walls adjacent to said spout wall is greater than 2.25 feet. However, the claimed distance is a matter of optimization that can be found through routine optimization. See MPEP 2144.05.
In this case, the claimed distance would depend on the width of the walls of the boiler. If the number of primary ports per wall is held constant, and the width of the boiler walls increase, then the distance from the spout wall to the closest primary port on each of two walls adjacent to said spout wall should also increase, assuming equal spacing of the primary ports along the wall adjacent the sprout wall.
Regarding claim 44, MacCallum discloses the chemical recovery boiler of claim 7, except wherein the primary air port openings has an area of greater than 37.5 square inches. However, the claimed distance is a matter of optimization that can be found through routine optimization. See MPEP 2144.05.
In this case, the area of the primary port (total area of the smaller jet opening areas) would affect the volumetric air flow out of the primary port, and the volumetric air flow would affect combustion efficiency and the amount of emissions produced (para. 120). For example, if everything is kept constant except the area of the primary air port opening is enlarged, then more air can be delivered to the combustion zone.
Regarding claim 45, MacCallum discloses the chemical recovery boiler of claim 7, except wherein each of the primary air port openings has a height of greater than 15 inches or a width greater than 2 inches. However, the claimed distance is a matter of optimization that can be found through routine optimization. See MPEP 2144.05.
In this case, the height and width affect the primary air port opening area (total area of the smaller jet opening areas), and the area affects the volumetric air flow. See rejection of claim 44 discussing how the volumetric air flow would affect combustion efficiency and emissions.
Regarding claim 46, MacCallum discloses the chemical recovery boiler of claim 7 in which the primary air port opening on the two walls adjacent to the spout wall provide more than 80 percent of the total primary air port opening area (Fig. 6 shows that the primary air ports/jets are on only two opposite walls, and as explained in the rejection of claim 7, the spout wall can be adjacent the walls containing the primary air ports)
Regarding claim 47, MacCallum discloses the chemical recovery boiler of claim 46 in which the primary air ports on two walls adjacent to the spout wall provide more than 90 percent of the primary air port opening area (see rejection of claim 46).
Regarding claim 48, MacCallum discloses the chemical recovery boiler of claim 47 in which the primary air port openings on two walls adjacent to the spout wall provide more than 95 percent of the primary air port opening area (see rejection of claim 46).
Regarding claim 49, MacCallum discloses the chemical recovery boiler of claim 7 in which the primary air port openings (scavenging jet) on the spout wall comprise between 3 and 8 port openings (see Comment 1 below) in proximity (i.e., in the boiler, near the bottom) to each spout (Scavenging jet blow primary air at the char, as shown in Fig. 3, to keep the char away from the spout) (abstract).
Comment 1. MacCallum states that each scavenging jet can comprise several jets, i.e., ports (para. 134). The precise number is a matter of optimization that can be found through routine optimization. Having more ports means that more air can be blown at the char to keep it away from the spout.
Regarding claim 50, MacCallum discloses the chemical recovery boiler of claim 49 in which the only primary air port openings (scavenging jets) on the spout wall are those in proximity (i.e., in the boiler, near the bottom) to each spout to maintain the char bed sufficiently clear of the spouts to allow the smelt flowing freely to the spouts (All the remaining primary air is delivering to the scavenging jets; see abstract).
Regarding claim 51, MacCallum discloses the chemical recovery boiler of claim 7 in which the chemical recovery boiler is a retrofit of an existing chemical recovery boiler that included primary air port openings on the spout wall and on the wall opposite the spout wall, and in which the retrofit included removing primary air port openings from the wall opposite the spout wall and increasing the area of primary air port openings on the walls adjacent the spout walls.
The claim is a product-by-process claim limitation. Even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process. See MPEP 2113. In this case, the claimed invention is the same or substantially the same as the one disclosed by MacCallum.
Regarding claim 52, MacCallum discloses the chemical recovery boiler of claim 51 in which the area of the primary air port openings on the walls adjacent to the spout wall have a total area within plus or minus 20% of the total area of the primary air ports prior to the retrofit and the total number of air port openings is decreased. The claim is a product-by-process claim limitation. See discussion for the rejection of claim 51.
Allowable Subject Matter
Claims 15-22 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Response to Arguments
Please see the rejections regarding how the terms “port” and “periodically” are defined.
Conclusion
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/JASON LAU/Primary Examiner, Art Unit 3762