JP7249274B2 - Furnace with discharge nozzle plate for distributing gas through the furnace and method of operating the same - Google Patents

Description

[Related Application]
This application claims priority to U.S. patent application Ser. The entirety of US patent application Ser. No. 15/345,553 is incorporated herein by reference.

Oxidation furnaces are commonly used to produce carbon fibers from precursors such as acrylic, pitch or cellulose fibers. One common processing method involves drawing fiber segments of the precursor material continuously through one or more oxidation furnaces.

Each of the oxidation furnaces has a respective oxidation chamber in which oxidation of the fiber segments takes place. Each fiber segment is drawn into the first oxidation furnace as a carbon fiber precursor, then made multiple passes through each oxidation furnace before exiting the final oxidation furnace as an oxidized fiber segment. be able to. A roll stand and tensioners are used to pull the fiber segments through the oxidation chamber of the furnace. Each oxidation furnace heats the segments by a circulating flow of hot air to a temperature approaching approximately 300°C.

One example of such a furnace is the Despatch Carbon Fiber Oxidation Furnace available from Despatch Industries of Minneapolis, Minnesota. A description of such a furnace can be found in commonly assigned US Pat. The furnace described in U.S. Pat. No. 6,200,000 is a "center-to-ends" oxidation furnace. In a center-to-end oxidation furnace, hot air is supplied to the oxidation chamber of the furnace from the center of the chamber and flows toward the ends of the chamber.

Such center-to-end oxidation furnaces typically include a central feed structure located in the center of the chamber. The central feed structure includes a plurality of feed plenums stacked together. Gaps are provided between the stacked feed plenums to allow fiber segments to pass between the plenums. Each plenum includes a duct structure that receives heated air through one or both of its ends. Each plenum has a series of holes formed in each of the opposing sidewalls of the corresponding ductwork. These series of holes are also referred to herein as "nozzles." Each plenum is configured to receive heated air and direct a flow of heated gas out of a nozzle in generally horizontal and parallel streams of heated gas toward opposite ends of the oxidation chamber.

Such nozzles are typically formed in a pair of relatively thin metal sheets that form the sidewalls of the plenum structure. These metal sheets are also referred to herein as "nozzle sheets". 1 and 2 show part of an example of a conventional nozzle sheet 100 in which nozzles 102 are formed.

Nozzle sheet 100 is typically less than 1/4 inch thick and made from aluminum or similar material suitable for use in furnaces. Nozzles 102 are typically formed in each nozzle sheet 100 by perforating the sheet.

Given that such a nozzle sheet is relatively thin and there are a large number of nozzles in this sheet, to reinforce the thin nozzle sheet, the air leaving the nozzles also leaves the nozzles in a more uniform and parallel stream. A sheet of hex honeycomb material is commonly laminated to the outer surface of each nozzle sheet to help control the angular direction of the air leaving the nozzles. 3 shows a portion of the hex honeycomb material sheet 104 and FIG. 4 shows the hex honeycomb material 104 disposed on the outer surface of the nozzle sheet 100 shown in FIGS.

However, it can be difficult to precisely align the openings in the hex material sheet with the corresponding nozzles in the thin nozzle sheet. Any misalignment between the openings in the hex material and the nozzles in the nozzle sheet can lead to the air leaving the nozzles leaving the nozzles in a less uniform and less parallel stream. Also, adding two sheets of hex material to each plenum increases the cost of manufacturing and assembling each plenum.

U.S. Patent No. 4,515,561

The present invention has a heating system for heating gas, a substrate heating space in which a plurality of substrates can be arranged at different heights, and a side wall in which a plurality of passages are formed. a plenum that guides from the passageway into the substrate heating space;
each of the plurality of passages formed in the plenum having a respective tapered cross-sectional shape, a respective inlet opening, and a respective outlet opening, each of the plurality of passages defining the inlet opening; and the outlet opening, the plenum tapers from a gas entry point at the top of the plenum to the bottom of the plenum, and the sidewall has a substantially uniform volume. adapted to discharge said heated gas from said plurality of passages in said furnace.

FIG. 11 is a diagram showing part of an example of a conventional nozzle sheet; FIG. 2 is a cross-sectional view of the nozzle sheet shown in FIG. 1; FIG. 11 shows a portion of a hex honeycomb material sheet; Figure 4 shows the hex honeycomb material of Figure 3 positioned on the outer surface of the nozzle sheet shown in Figures 1 and 2; 1 is a perspective view of one exemplary embodiment of a furnace; FIG. Figure 6 is a perspective view of the furnace shown in Figure 5 with the top wall removed from the chamber of the furnace; Figure 6 is a cross-sectional plan view of the furnace shown in Figure 5; Figure 6 shows a detail of the central feed structure of the furnace shown in Figure 5; FIG. 4 is a cross-sectional plan view of one exemplary embodiment of a feed plenum; Figure 10 is a side view of one sidewall of the supply plenum shown in Figure 9; Figure 11 shows in more detail a portion of the side wall shown in Figure 10; Figure 12 is a cross-sectional view of a portion of the side wall shown in Figure 11; Figure 13 is a detailed view of one of the nozzles shown in Figure 12; FIG. 2 is a flow diagram of an exemplary embodiment of a method of heating fibers by contact with a heated gas; FIG. 12 illustrates one alternative tapered cross-sectional shape of the nozzle; FIG. 10 illustrates another example furnace that provides uniform airflow through the substrate heating space; FIG. 10 illustrates an example side wall and passageway;

5-7 illustrate one exemplary embodiment of an oxidation furnace 500 that can use the nozzle plate described below. However, it should be understood that the nozzle plate described below can be used in other oxidation furnaces.

The oxidation furnace 500 shown in FIGS. 5-7 is suitable for use in producing carbon fibers using oxidation processes of the type described above. For example, the exemplary embodiment of the oxidation furnace 500 shown in FIGS. 5-7 is used in oxidation processes using one or more furnaces (eg, in a stacked configuration), as known to those skilled in the art. be able to.

Those skilled in the art will appreciate that various conventional features used in oxidation furnaces have been omitted from the figures and the following description for the sake of brevity and clarity. Examples of such features include, but are not limited to, baffles, ducts, vanes, vents, etc. used to regulate gas flow within the furnace 500 to reduce unwanted process gas emissions to the ambient environment. Vestibules, exhaust features, and/or insulation, louvers, and other thermal features that improve the thermal efficiency of the furnace 500 may be included. It should be appreciated that the exemplary furnace 500 shown in FIGS. 5-7 can be provided with such features.

In the exemplary embodiment shown in Figures 5-7, the furnace 500 comprises a furnace chamber 502 in which oxidation of fiber segments takes place. In this exemplary embodiment, furnace chamber 502 is defined by a plurality of walls. The walls that define the oxidation chamber 502 are a top wall 504 , a bottom wall 506 , two side walls 508 , 510 along respective sides 512 , 514 of the chamber 502 , and at respective ends 520 , 522 of the chamber 502 . There are two end walls 516,518. A respective inlet for the fibers is formed in each of the end walls 516,518. Each inlet is formed by a plurality of slots extending between a first side 512 and a second side 514 of chamber 502 through which fiber segments heated by oxidation furnace 500 pass. pulled. These inlets and slots can be formed conventionally.

Furnace 500 also includes heating system 524 . Heating system 524 is used to supply heated gas into chamber 502 . In this exemplary embodiment, the gas used is ambient air.

Heating system 524 can be implemented in a variety of ways. 5-7, the heating system 524 includes at least one heater 526 (shown in FIG. 7), a blower 528 (shown in FIG. 7) that draws gas through the heater 526; and a motor 530 that powers the blower 528 . Each heater 526 can be implemented in various ways. For example, each heater 526 can be implemented using one or more heating elements. Also, each heater 526 can be implemented using an indirect gas heater, an electric heater, or a combination thereof. Each heater 526 can be implemented in other ways.

Heating system 524 can be controlled using, for example, one or more suitable controllers, such as proportional-integral-derivative (PID) controllers.

Furnace 500 includes feed structure 532 disposed within chamber 502 between ends 520 , 522 of chamber 502 . In the exemplary embodiment shown in FIGS. 5-7, the furnace 500 is a center-to-end oxidation furnace in which heated gas is supplied from the center of the oxidation chamber 502 towards the ends 520, 522 of the chamber 502. FIG. In this exemplary embodiment, feed structure 532 is positioned within chamber 502 at or near the center of chamber 502 between ends 502, 522, also referred to herein as "central feed structure" 532. is called

In the exemplary embodiment shown in FIGS. 5-7, central feed structure 532 includes a plurality of feed plenums 534 stacked together with gaps therebetween.

The central feed structure 532 is shown in greater detail in FIG. A gap 536 (shown in FIG. 8) is provided between the stacked feed plenums 534 to allow fiber segments to pass between the plenums 534 .

More details regarding the supply plenum 534 are provided below in connection with the description of FIGS. 9-13.

Plenum 534 is in fluid communication at one or both of its ends with supply duct 538 (shown in FIGS. 6 and 7) for receiving heated gas from heating system 524 . In the exemplary embodiment shown in FIGS. 5-7, each plenum 534 is configured to receive heated air through one of its ends (although in other embodiments each plenum may It should be understood that the heated air is received through both parts).

The supply duct 538 may be suitably tapered or otherwise adjustable slotted or otherwise arranged to regulate the flow of the heated gas so that the velocity of the heated gas exiting the plenum 534 is substantially uniform. Functionality (not shown) may be provided.

Each furnace 500 also includes two return structures 540 within the oxidation chamber 502 . One return structure 540 is located near the first end wall 516 and another return structure 540 is located near the second end wall 518 . Each of the return structures 540 has a plurality of return channels, each stacked and positioned to generally correspond to the position of the corresponding plenum 534 of the central feed structure 532 . . A gap is provided between the return channels to allow fiber segments to pass between the return channels.

The return channel of each return structure 540 is configured to receive at least a portion of the gas directed to this return structure 540 from the central feed structure 532 . That is, each return structure 540 receives gas directed therefrom from one side of the plenum 534 in the central feed structure 532 .

A return duct 542 is used to establish fluid communication between each return structure 540 and the heating system 524 . In this manner, at least a portion of the heated gas received by return structure 540 is directed back toward heating system 524 to be heated and supplied to plenum 534 via supply duct 538 as described above.

In the exemplary embodiment shown in FIGS. 5-7, return duct 542 is located within the wall of chamber 502 . However, it should be understood that the return duct 542 can be implemented in other ways (eg, with at least a portion of the return duct 542 located outside the walls of the chamber 502).

In the exemplary embodiment described herein in connection with FIGS. 5-7, each of the plenums 534 are implemented as shown in FIGS. 9-13. Each plenum 534 is supplied with heating gas at a first end 900 of the plenum 534 . Heated gas is supplied from supply duct 538 .

Each plenum 534 is generally rectangular in cross-section and extends horizontally between and spaced apart sidewalls 508 , 510 of chamber 502 . As shown in FIG. 10, the sidewalls 904 of each plenum 534 are formed with passages 902 . These passageways 902 are also referred to herein as “nozzles” 902 . In this exemplary embodiment, each sidewall 904 of each plenum 534 is implemented with plates (referred to herein as "nozzle plates" 904) described in more detail below with respect to FIGS. also called).

The passageway formed in nozzle plate 904 for each nozzle 902 has an inlet opening 908 (FIGS. 12, 13) through which air supplied to plenum 534 enters and exits furnace 500 . has an outlet opening 910 (Figs. 12, 13) that discharges into the chamber 502 of the. Exit opening 910 of nozzle 902 faces respective ends 520 , 522 of chamber 502 .

Nozzles 902 extend across the width of plenum 534 . Nozzle 902 is constructed and arranged to direct the received flow of heated gas into ends 520 , 522 of oxidation chamber 502 in generally horizontal and parallel streams of heated gas. A stream of gas is directed alongside each fiber segment across that portion of the oxidation chamber 502 .

Each plenum 534 includes one or more baffles 906 positioned inside the plenum 534 between nozzle plates 904 of the plenum 534 . In this exemplary embodiment, baffle 906 is configured in a V-shape as shown in FIG. supplied. This V-shaped configuration of baffle 906 is generally designed to evenly direct the flow of the received heated gas out of nozzle 902 .

FIG. 10 shows nozzles 902 formed in one of the nozzle plates 904 of plenum 534 . In this exemplary embodiment, nozzles 502 are formed identically in both nozzle plates 904 (only one nozzle 902 of nozzle plates 904 is shown). FIG. 11 shows in more detail a portion of the nozzle plate 904 shown in FIG. FIG. 12 is a cross-sectional view of a portion of nozzle plate 904 shown in FIG. FIG. 13 is a detailed view of one of the nozzles 902 shown in FIG.

The nozzles 902 may be formed in the nozzle plate 904 by, for example, drilling, machining, or using casting methods to produce the nozzle plate 904 with the passages for the nozzles 902 formed therein. can be done. Nozzles 902 can be formed in nozzle plate 904 in other ways.

As shown in FIG. 12, in this exemplary embodiment, nozzle plate 904 is much thicker than conventional perforated nozzle sheets. For example, nozzle plate 904 can have a thickness greater than 0.25 inches. Nozzle plate 904 may be made from aluminum or similar material suitable for use in a furnace.

Each nozzle 902 is also formed in nozzle plate 904 to have a circular opening (shown in FIG. 11) and a tapered cross-sectional shape (shown in FIGS. 12 and 13). The tapered cross-sectional shape of each nozzle 902 includes an inlet opening 908 that is larger than the corresponding outlet opening 910 of each nozzle 902 .

In the exemplary embodiment, the tapered cross-sectional shape of each nozzle 902 includes a tapered portion 912 that extends across at least a portion of the width of nozzle plate 904 from inlet opening 908 of nozzle 902 . Each nozzle 902 also has a straight portion 914 extending from the end of tapered portion 912 to the outlet opening 910 of that nozzle 904 .

The air supplied to each plenum 534 tends to travel parallel to the side walls 904 of the plenum 534 . However, the air interacts with baffle 906 as it passes through plenum 534 such that at least a portion of the air is directed into inlet opening 908 of each nozzle 902 as the air passes through plenum 534 . .

In the exemplary embodiment, tapered portion 912 of each nozzle 902 has a curved or chamfered edge 916 along inlet opening 908 . Curved or chamfered edges 916 help direct air flowing past nozzle 902 to enter nozzle 902 . The tapered portion 912 of each nozzle gradually redirects the air entering the nozzle 902, while the straight portion 914 of each nozzle 902 directs the air out of the exit opening 910 of the nozzle 902 in a uniform stream. to stabilize and condition the air.

Without a hex honeycomb material sheet as described above, the difficult task of precisely aligning the openings in each hex material sheet with the corresponding nozzles in the thin perforated nozzle sheet and the problems that such misalignment can cause. and can be avoided. Also, by not adding two sheets of hex honeycomb material to the plenums 534, the cost of manufacturing and assembling each plenum 534 can be reduced.

Additionally, the tapered cross-sectional shape of the nozzle 902 in combination with the thicker nozzle plate 904 allows the air leaving the nozzle 902 to leave the nozzle 902 in a more uniform and parallel stream of air without the use of a sheet of hex honeycomb material. help.

Moreover, by not using a perforated sheet, the same uniformity of the resulting airflow can be achieved with reduced static pressure.

Also, the absence of a sheet of hex honeycomb material eliminates the need to match the shape and configuration of the outlet openings 910 of the nozzles 902 to the openings of the hex honeycomb material stacked on the nozzle plate 904 .

FIG. 14 is a flow diagram of an exemplary embodiment of a method 1400 of heating fibers by contact with a heated gas. The embodiment of method 1400 shown in FIG. 14 is described herein as being implemented using the exemplary embodiments of oxidation furnace 500 and nozzle plate 904 described above in connection with FIGS. ing. However, it should be understood that other embodiments can be implemented in other ways.

The method 1400 includes supplying heated gas to a feed structure 532 disposed inside the furnace 500 and comprising a plurality of plenums 534 stacked on top of each other with gaps 536 therebetween (block 1402). In the exemplary embodiment, heated gas is supplied to each plenum 534 from heating system 528 via supply duct 538 .

The method 1400 includes directing at least a portion of the heated gas into the interior of the furnace 502 from a nozzle 902 having a tapered cross-sectional shape formed in at least one sidewall 904 of at least one of the plenums 534 ( Block 1404) is further included. The heated gas flows in generally horizontal parallel heated gas streams from the nozzle 902 toward the ends 520 , 522 of the oxidation chamber 502 alongside each fiber segment that traverses that portion of the oxidation chamber 502 .

In this exemplary embodiment, at least a portion of the heated gas is directed into the inlet opening 908 of the nozzle 902 and at least a portion of the heated gas is directed from the outlet opening 910 of the nozzle 902 into the interior of the furnace 500. be done. Also, in this example, at least a portion of the heated gas directed into the inlet opening 908 of the nozzle 902 is directed along a curved or chamfered edge 916 formed along the inlet opening 908 to the nozzle. It is directed into tapered portion 912 of 902 . Further, in this example, at least a portion of the heated gas directed into the interior of the furnace 500 from the outlet opening 910 of the nozzle 902 is directed into the straight section 914 of the nozzle 902 before being discharged into the interior of the furnace 500. .

The above-described embodiments are merely exemplary and are not intended to be limiting.

It should be appreciated that the tapered cross-sectional shape of nozzle 902 can be implemented in other ways. FIG. 15 shows one alternative tapered cross-sectional shape of nozzle 1502 that can be used in plenum 534 described above. Nozzle 1502 is substantially the same as nozzle 902 described above with respect to FIGS. 9-13, with the following differences.

In the exemplary embodiment, tapered portion 1512 of nozzle 1502 extends from inlet opening 1508 of nozzle 1502 to outlet opening 1510 of nozzle 1502 and does not include a straight portion. Also similar to the embodiments described above with respect to FIGS. 9-14, the tapered portion 1512 of each nozzle 1502 has a curved or chamfered edge 1516 along the inlet opening 1508 .

Other tapered cross-sectional shapes can be used.

In the exemplary embodiment described above, each plenum 534 is supplied with heating gas from one side. However, in other embodiments, the plenums in the central feed structure are supplied with gas from both sides.

Furthermore, in the exemplary embodiment described above, all nozzles have the same cross-sectional shape. However, this may not be the case in other embodiments, and the size and shape of the nozzles may vary from nozzle to nozzle within a given plenum and may vary from plenum within a given feed structure. be able to. Also, in the exemplary embodiment described above, each plenum is shown as having two sidewalls, both of which are formed with nozzles having tapered cross-sectional shapes as described above. However, this need not be the case (eg, only one of the sidewalls may be formed with a nozzle having a tapered cross-sectional shape as described above). Furthermore, in the exemplary embodiments described above, each plenum in the central feed structure has the same configuration and design. However, this need not be the case; instead, the one or more plenums included in the central feed structure are configured and/or designed differently than the one or more other plenums included in the central feed structure. can have

FIG. 16 shows another example furnace 1600 that provides uniform airflow through the substrate heating space 1602 . The example furnace 1600 of FIG. 16 uses nozzles similar or identical to those described above. Furnace 1600 can be closed or sealed against external air flow. Instead of heating carbon fibers as in the example furnace 500 of FIGS. 5-7, the example furnace 1600 heats and/or Airflow can be provided differently.

Furnace 1600 comprises a substrate heating space 1602 , a heating system 1604 and a plenum 1608 . Plenum 1608 includes sidewalls 1610 located between plenum 1608 and substrate heating space 1602 . Thus, sidewall 1610 is also the sidewall of substrate heating space 1602 . Sidewall 1610 has passages 1612 formed therein to allow heated gas 1606 to flow from plenum 1608 to substrate heating space 1602 . Plenum 1608 directs heated gas 1606 into substrate heating space 1602 from a plurality of passages 1612 . Each of the passages 1612 formed in the plenum 1608 has a respective tapered cross-sectional shape. Sidewalls 1610 and passageways 1612 distribute gas substantially uniformly through substrate heating space 1602 .

The heated gas 1606 can be directed over and/or impinged on one or more substrates 1616 within the substrate heating space 1602 . In the illustrated example, there are multiple levels of substrate 1616 within the substrate heating space, with heated gas 1606 flowing over substrate 1616 from sidewalls 1610 .

FIG. 17 shows example sidewalls 1610 and passageways 1612 . Examples of passageways 1612 are shaped as shown in FIGS. As shown in FIG. 17, passages 1612 are distributed in one or more repeating patterns across sidewall 1610 . One or more repeating patterns can include placement of passageways 1612 across sidewalls 1610 that optimize distribution of heated gas across the load area during substrate heating. As used herein, "optimal distribution" of heated gas means that substantially the same volume of air is spread over the surface on which it can act and/or that substantially the same amount of heat is dissipated by the device. Refers to being dissipated in a stream. In some examples, airflow volumes are considered substantially the same if the volumes are within ±15%. In some examples, two or more heat dissipation levels are substantially the same if the heat dissipation is within ±15%.

Returning to FIG. 16, the substrate heating space 1602 also has a return structure 1614 on the opposite side of the plenum 1608 . A return structure 1612 directs at least a portion of the heated gas 1606 out of the substrate heating space 1602 . A return structure 1614 directs at least a portion of the heated gas to the heating system.

11, 12, 13, and 15, each of the passageways 1612 in the side wall 1610 of this example has a respective inlet opening 908 and a respective outlet opening 910. As shown in FIG. One or more of passages 1612 can have a tapered portion 912 extending from inlet opening 908 . One or more of the passageways 1612 may also have curved or chamfered edges 916 along the entrance opening 908 . In some examples, one or more of the passages 1612 have a tapered portion 912 extending from the inlet opening 908 and a straight portion 914 extending from the end of the tapered portion 912 to the outlet opening 910. .

In some examples, the side wall 1610 can have a portion without passages, and this portion can be located between other portions that have passages. For example, the portion without the passageway 1612 can be located where the substrate 1616 is located (eg, vertically at the same height as the substrate 1616). Sidewall 1610 has a first portion having a first passageway 1612, a second portion having a second passageway 1612, and a second portion having no passageway 1612 between the first and second portions. 3 parts.

As shown in FIG. 16, the plenum 1608 tapers from the gas entry point 1618 of the plenum 1608 towards the opposite end of the plenum. Sidewall 1610 is configured to emit heated gas 1606 from passageway 1612 in a substantially uniform volume. In operation, the heating system 1604 of this example controls the static pressure of the plenum 1608 to provide a substantially uniform volumetric gas flow across the surface of the sidewall 1610 . In some examples, heating system 1604 maintains plenum 1608 (eg, via a fan) at a static pressure of at least 0.3 inches of water column across sidewall 1610 . In some other examples, heating system 1604 maintains plenum 1608 (eg, via a fan) at a static pressure of at least 0.5 inches of water column across sidewall 1610 .

In some examples, furnace 1600 is further provided with cooling coils or other gas cooling systems between return structure 1614 and heating system 1604 .

A number of embodiments have been described. It will, however, be understood that various changes can be made to the described embodiments without departing from the spirit and scope of the claimed invention.

Exemplary Embodiments Example 1 is a furnace for heating fibers, wherein the furnace is positioned within the furnace between a first end and a second end of the furnace with a gap therebetween. a feed structure comprising a plurality of plenums stacked on top of each other, the plenums in fluid communication with the heating system;
The at least one plenum has at least one sidewall with a plurality of passages formed therein, the at least one plenum configured to direct at least a portion of the heating gas from the plurality of passages into the interior of the furnace. and
Each of the plurality of passageways formed in the at least one plenum includes a furnace having a respective tapered cross-sectional shape.

Example 2 includes the furnace of Example 1, wherein each of the passageways formed in the at least one sidewall of the at least one plenum has a respective inlet opening and a respective outlet opening.

Example 3 includes the furnace of Example 2 in which, for at least one of the passages, each inlet opening is larger than each outlet opening.

Example 4 includes the furnace of Example 2 or Example 3 wherein at least one of the passages formed in said at least one sidewall of said at least one plenum tapers extending from a respective inlet opening. .

Example 5 includes the furnace of Example 4, wherein said at least one of the tapered passages further has curved or chamfered edges along respective inlet openings.

Example 6 is wherein at least one of the passages formed in said at least one sidewall of said at least one plenum includes tapered portions extending from respective inlet openings and respective outlets from ends of the tapered portions. The furnace of any of Examples 2-5 having a straight portion extending to the opening.

Example 7 includes the furnace of any of Examples 1-6, wherein no honeycomb material is disposed on the outer surface of the at least one plenum.

Example 8 includes the furnace of any of Examples 1-7 wherein the at least one sidewall has a thickness of at least 0.25 inch.

Example 9 is a method of heating fibers using a furnace, comprising:
supplying the heated gas to a feed structure disposed within the interior of the furnace and comprising a plurality of plenums stacked on top of each other with gaps therebetween;
directing at least a portion of the heated gas into the interior of the furnace through passages having a tapered cross-sectional shape formed in at least one sidewall of the at least one plenum;
including, including methods.

Example 10 shows that directing at least a portion of the heating gas from the passage into the interior of the furnace comprises:
directing at least a portion of the heated gas into an inlet opening of the passage;
directing at least a portion of the heated gas from the outlet opening of the passage into the interior of the furnace;
including the method of Example 9 comprising

Example 11 includes the method of Example 10 wherein, for at least one of said passages, each inlet opening is larger than each outlet opening.

Example 12 includes the method of Example 10 or Example 11, wherein at least one of the passageways has a taper extending from the respective inlet opening.

Example 13 shows that directing at least a portion of the heated gas into the inlet opening of the passageway directed at least a portion of the heated gas to a curved edge or chamfer formed along the inlet opening of the passageway. Including the method of any of Examples 10-12 including guiding along the edge.

Example 14 is the method of any of Examples 10-13, wherein directing at least a portion of the heated gas into an inlet opening of the passageway comprises directing at least a portion of the heated gas into a tapered portion of the passageway. including.

Example 15 shows that directing at least a portion of the heating gas from the exit opening of the passageway into the interior of the furnace comprises directing at least a portion of the heating gas along the straight line of the passageway prior to discharging the heating gas into the interior of the furnace. including the method of any of Examples 10-14 including navigating into the department.

Example 16 includes a furnace with a heating system that heats a gas, a substrate heating space, and a plenum with a sidewall having a plurality of passages formed therein. The plenum is configured to direct heating gas into the substrate heating space from a plurality of passages, each of the plurality of passages formed in the plenum having a respective tapered cross-sectional shape.

Example 17 includes the furnace of Example 16, wherein the substrate heating space has a return structure opposite the plenum that directs at least a portion of the heated gas out of the substrate heating space.

Example 18 includes the furnace of Example 17, wherein the return structure directs at least a portion of the heating gas to the heating system.

Example 19 includes the furnace of any of Examples 16-18, wherein the plurality of passages are distributed with one or more repeating patterns across the sidewalls.

Example 20 includes the furnace of Example 19, wherein one or more of the repeating patterns include an arrangement of passageways across the sidewalls that optimize distribution of heating gas over the loading area within the substrate heating space.

Example 21 has a sidewall having a first portion having a first of the passages and a second portion of the sidewall having a second of the passages, the sidewall having a second portion of the sidewall. The furnace of any of Examples 16-20 having a third portion between the first portion and the second portion of the side wall, the third portion of the side wall having no passages for directing the heating gas. include.

Example 22 includes the furnace of any of Examples 16-21, wherein each of the passageways formed in the side walls of the plenum has a respective inlet opening and a respective outlet opening.

Example 23 includes the furnace of Example 22 wherein at least one of the passageways formed in the side walls of the plenum tapers extending from the respective inlet opening.

Example 24 includes the furnace of Example 23, wherein at least one of the tapered passages further has curved or chamfered edges along the respective inlet openings.

Example 25 has at least one of the passages formed in the sidewalls of the plenum having a tapered section extending from the respective inlet opening and a straight section extending from one end of the tapered section to the respective outlet opening. including the furnace of any of Examples 22-24 having

Example 26 includes the furnace of any of Examples 16-25, wherein the plenum tapers from the gas entry point of the plenum toward the opposite end of the plenum.

Example 27 includes the furnace of Example 26, wherein the sidewalls are configured to release gas from the plurality of passages in substantially uniform volumes.

Example 28 includes the furnace of any of Examples 16-27, wherein the furnace further comprises an air circulation system configured to create a static pressure of at least 0.3 inches of water column across the opposite side wall of the substrate heating region. include.

Example 29 includes the furnace of any of Examples 16-27, wherein the furnace further comprises an air circulation system configured to create a static pressure of at least 0.5 inches of water column across the opposite side wall of the substrate heating region. include.

Example 30 is a method of heating a substrate in a furnace comprising:
supplying heated gas to a feed structure disposed within the furnace and comprising a plenum;
directing at least a portion of the heating gas into a substrate heating space within the furnace through passages having tapered cross-sectional shapes formed in the side walls of the plenum;
A method comprising:

Example 31 directs at least a portion of the heating gas into the substrate heating space through the passageway,
directing at least a portion of the heated gas into the inlet opening of the passage;
directing at least a portion of the heating gas from the outlet opening of the passage into the substrate heating space;
including the method of Example 30 comprising

Example 32 illustrates that directing at least a portion of the heating gas into the substrate heating space through the passageway comprises:
directing at least a portion of the heated gas into the inlet opening of the passage;
directing at least a portion of the heating gas from the outlet opening of the passage into the substrate heating space;
including the method of Example 31 comprising

Example 33 shows that directing at least a portion of the heated gas into the inlet opening of the passage directs at least a portion of the heated gas to a curved or chamfered edge formed along the inlet opening of the passage. including the method of example 31 including directing along.

Example 34 includes the method of Example 31, wherein directing at least a portion of the heated gas into the inlet opening of the passageway includes directing at least a portion of the heated gas into a tapered portion of the passageway.

Example 35 shows that directing at least a portion of the heated gas from the outlet opening of the passageway into the substrate heating space comprises directing at least a portion of the heated gas into a straight line of the passageway before discharging the heated gas into the substrate heating space. including the method of Example 31 including navigating into the department.

Example 36 includes the method of any of Examples 30-35, the method further comprising recycling at least a portion of the heated gas from the substrate heating space to the plenum via the return structure.

Example 37: Directing at least a portion of the heated gas into the substrate heating space through passages includes directing at least a portion of the heated gas into one or more repeating patterns of passages across the sidewalls. Including the method of any of Examples 30-36.

Example 38 is an example wherein directing at least a portion of the heating gas through the passageway into the substrate heating space comprises directing at least a portion of the heating gas through the passageway in a substantially uniform volume. including any of methods 30-37.

Although the method and/or system have been described with reference to certain specific embodiments, various modifications may be made by those skilled in the art without departing from the scope of the method and/or system. and that equivalents may be substituted. In addition, many modifications may be made to adapt a particular situation or material to the teachings of this disclosure without departing from its scope. Accordingly, the method and/or system are not limited to the particular implementations disclosed. Instead, the method and/or system includes all embodiments that fall within the scope of the appended claims both literally and under the doctrine of equivalents.

100 nozzle sheet 102 nozzle 104 hex honeycomb material sheet 500 oxidation furnace 502 chamber 504 top wall 506 bottom wall 508 side wall 510 side wall 512 first side 514 second side 516 first end wall 518 second end wall 520 end 522 end 524 heating system 526 heater 528 blower 530 motor 532 supply structure 534 supply plenum 536 gap 538 supply duct 540 return structure 542 duct 900 first end 902 nozzle 904 nozzle plate 906 baffle 908 inlet opening 910 outlet opening Section 912 Tapered Section 914 Straight Section 916 Chamfered Edge 1400 Method 1402 Block 1404 Block 1502 Nozzle 1508 Entrance Opening 1510 Exit Opening 1512 Tapered Section 1516 Beveled Edge 1600 Furnace 1602 Substrate Heating Space 1604 Heating System 1606 Plenum Heating Gas 1608 Side wall 1612 Passage 1614 Return structure 1616 Substrate 1618 Gas input point

Claims (7)

a heating system for heating the gas;
a substrate heating space in which a plurality of substrates can be arranged at different heights;
A plenum extending parallel to the height direction of the substrate heating space and having a side wall in which a plurality of passages are formed, wherein a heated gas flows from the plenum through the plurality of passages to heat the substrate. a plenum that guides into the space,
Each of the plurality of passages formed in the sidewall of the plenum has a respective inlet opening facing the plenum , a respective outlet opening facing the substrate heating space , the inlet opening and the outlet. a tapered portion formed between the opening and having a cross section that tapers from the inlet opening to the outlet opening ;
The plenum is formed in a tapered shape in which the cross section becomes narrower in the height direction of the substrate heating space from the gas input point at the upper end of the plenum toward the lower end of the plenum,
The furnace, wherein the sidewalls are adapted to release the heated gas from the plurality of passages in a uniform volume. 2. The furnace of claim 1, wherein the substrate heating space has a return structure opposite the plenum for directing at least a portion of the heated gas out of the substrate heating space. 3. The furnace of claim 2, wherein said return structure directs said at least a portion of said heated gas to said heating system. 2. The furnace of claim 1, wherein said plurality of passages are distributed with one or more repeating patterns across said sidewall. The sidewall has a first portion having a first one of the passages and a second portion of the sidewall having a second one of the passages, the sidewall comprising: between said first portion of and said second portion of said sidewall, said third portion of said sidewall having no passageway for directing said heated gas. Furnace according to claim 1. 2. The furnace of claim 1, wherein at least one of said tapered passages further comprises a curved or beveled edge along said respective inlet opening. 2. The at least one of said tapered passages formed in said side wall of said plenum having a straight portion extending from one end of said tapered portion to a respective outlet opening. Furnace.

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