JP2020183818A - Curtain burner and heat-treatment facility - Google Patents

Abstract

To reduce the pressure difference of combustible gas in a gas pipe of a curtain burner and reduce the variability of the flame height of the curtain burner.SOLUTION: There is included a gas pipe 21 having a gas discharge part that discharges combustible gas. The gas discharge part has an inner pipe 30 connected to a combustible gas supply source, and an outer pipe 40 that covers the perimeter of the inner pipe 30. The inner pipe 30 has a first gas outlet 31, and the outer pipe 40 constitutes a curtain burner 20 so as to have a plurality of second gas discharge ports 41 formed at intervals along the longitudinal direction of the gas discharge part.SELECTED DRAWING: Figure 7

Description

The present invention relates to a curtain burner and a heat treatment facility.

For example, gas carburizing treatment is known as a surface hardening treatment method for automobile parts and other mechanical parts. The gas carburizing treatment is performed by a gas carburizing facility equipped with a treatment chamber such as a carburizing chamber or a quenching chamber, and the product to be treated is subjected to a predetermined heat treatment such as heating, carburizing or quenching in a treatment chamber filled with a predetermined atmosphere. Will be done. For example, in the carburizing chamber, the carburizing treatment of the product to be treated is performed in an atmosphere controlled so that the carbon potential is within a predetermined numerical range.

The gas carburizing facility is provided with a door for separating the internal space and the external space of the processing chamber so that the processing chamber is maintained in a predetermined atmosphere during the heat treatment of the object to be treated. This door is opened when the heat-treated product to be treated is carried out of the processing chamber, or when the heat-treated product to be treated is carried into the treatment chamber. When the door is opened, outside air flows into the treatment room and the atmosphere in the treatment room flows out. However, if the atmosphere in the treatment room changes significantly here, the carburizing quality of the product to be treated is not preferable. It can have an impact. For example, when outside air flows into the carburizing chamber, the oxygen gas in the outside air reacts with the carburizing gas in the carburizing chamber, which lowers the carbon potential and may not guarantee the desired carburizing quality. Such a problem may occur not only in the gas carburizing equipment but also in other atmospheric heat treatment equipment that fills the processing chamber with a predetermined atmosphere and heat-treats the product to be treated.

For this reason, in conventional heat treatment equipment, a curtain burner is generally provided near the opening of the processing chamber, which is the carry-out port or carry-in port of the product to be treated. By covering the opening of the treatment chamber with a band-shaped flame, the curtain burner can suppress the inflow of outside air into the treatment chamber and the outflow of the atmosphere in the treatment chamber. For example, the oxygen gas in the outside air that is about to flow into the treatment chamber is consumed by the combustion reaction of the curtain burner, so that the change in the atmosphere in the treatment chamber can be suppressed. As a technique relating to a curtain burner, Patent Document 1 discloses that a curtain burner is provided on the exit side of an oil tank chamber in a continuous gas carburizing facility. Further, Patent Document 2 discloses that a curtain burner is provided below the entrance / exit of the atmospheric heat treatment furnace.

Japanese Unexamined Patent Publication No. 2008-208420 Japanese Unexamined Patent Publication No. 2004-053053

The curtain burner includes gas pipes having a plurality of gas discharge ports for discharging gas, and the gas discharge ports are formed at intervals along the longitudinal direction of the gas pipes. When such a curtain burner is activated, the combustible gas flowing inside the gas pipe is discharged from each gas discharge port to the outside of the gas pipe, and the discharged combustible gas ignites to generate a band-shaped flame. To.

By the way, in the gas pipe, the pressure of the combustible gas is attenuated by the pipe resistance as the distance from the source of the combustible gas increases. Therefore, there is a difference in the pressure of the combustible gas in the gas pipe between the gas discharge port located near the combustible gas supply source and the gas discharge port located away from the combustible gas supply source. As the pressure of the combustible gas in the gas pipe increases, the amount of combustible gas discharged from the gas discharge port increases and the height of the generated flame also increases. Therefore, when there is a pressure difference of the combustible gas in the gas pipe, , The height of the flame varies depending on the position of the gas discharge port.

In order to block the atmosphere with the curtain burner, it is necessary to cover the entire opening of the treatment chamber with the generated band-shaped flame. Therefore, if the height of the flame varies as described above, the height of the flame It is necessary to increase the amount of combustible gas supplied so that the opening can be sufficiently covered even in a portion where the height is relatively low. However, if the amount of combustible gas supplied is increased based on the portion where the height of the flame is low, the height of the flame is high in the portion where the height is already sufficient to cover the opening of the treatment chamber. Will be even higher. Since the flame located higher than the upper end of the opening of the treatment chamber does not contribute to blocking the atmosphere, continuing the operation in such a state means consuming extra combustible gas, which saves energy. Not preferable from the viewpoint.

The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the pressure difference of combustible gas in the gas pipe of the curtain burner and to suppress the variation in the height of the flame of the curtain burner.

One aspect of the present invention for solving the above problems is a curtain burner for covering an opening of a processing chamber of a heat treatment facility, the gas pipe having a gas discharge portion for discharging combustible gas, and the gas discharge portion. The inner pipe has an inner pipe connected to a combustible gas supply source and an outer pipe covering the periphery of the inner pipe, the inner pipe has a first gas discharge port, and the outer pipe has the gas. It is characterized by having a plurality of second gas discharge ports formed at intervals along the longitudinal direction of the pipe in the discharge portion.

One aspect of the present invention from another viewpoint is a heat treatment facility for heat-treating a product to be treated, which is provided in a treatment chamber having an opening through which the product to be treated passes and in the vicinity of the opening. The curtain burner is provided, and the second gas discharge port of the curtain burner is characterized in that it faces the opening side in a front view of the opening.

The pressure difference of the combustible gas in the gas pipe of the curtain burner can be reduced, and the variation in the flame height of the curtain burner can be suppressed.

It is a figure which shows a part of the gas carburizing equipment provided with the curtain burner which concerns on one Embodiment of this invention. It is the figure which looked at the oil tank from the outlet side of the product to be treated. It is the figure which looked at the gas pipe of the curtain burner from the top. It is the figure which looked at the gas pipe of a curtain burner from the bottom. It is the figure which looked at the gas pipe of the curtain burner excluding the outer pipe from the top. It is the figure which looked at the gas pipe of the curtain burner excluding the outer pipe from the bottom. It is a figure which shows the AA cross section in FIG. It is a figure which showed typically the flow of combustible gas in a gas pipe. It is a figure which shows the structural example of a gas pipe. It is a figure which shows the structural example of a gas pipe. It is a figure which shows the structural example of a gas pipe. It is the figure which looked at the gas pipe of the curtain burner excluding the outer pipe which concerns on another Embodiment from the bottom. It is a figure which shows the BB cross section in FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals to omit duplicate description.

FIG. 1 is a diagram showing a part of a gas carburizing facility 1 which is an example of a heat treatment facility. In FIG. 1, only the periphery of the carburizing chamber 10 which is an example of the treatment chamber and the oil tank 11 which is an example of another treatment chamber is shown. The gas carburizing equipment 1 of the present embodiment is a so-called continuous treatment type heat treatment equipment, and the carburized and hardened products W to be heat-treated are continuously subjected to carburizing and quenching treatment. In the figure, the X direction is the longitudinal direction of the gas carburizing facility 1, the Y direction is the width direction of the gas carburizing facility 1, and the Z direction is the height direction of the gas carburizing facility 1. In the gas carburizing facility 1 of the present embodiment, the product W to be processed is transported from left to right in FIG.

The carburizing chamber 10 of the present embodiment has an opening (hereinafter, “transport port 10a”) through which the object W to be processed passes on the side wall, and an elevating door covering the transport port 10a on the outside of the carburizing chamber 10. 12 is provided. When the door 12 is opened, the product W to be processed is transported from the carburizing chamber 10 to the oil tank 11 through the transport port 10a of the carburizing chamber 10. The oil tank 11 has an opening (hereinafter referred to as “carry-out port 11a”) through which the object to be processed W passes on the side wall opposite to the carburizing chamber 10, and the oil tank 11 is an elevating type that covers the carry-out port 11a on the outside. Door 13 is provided. When the door 13 is opened, the product W to be processed is carried out from the oil tank 11 through the carry-out port 11a.

When the carburized product W is carburized by the gas carburizing facility 1 as in the present embodiment, the door 12 and the door 13 are closed, and each treatment chamber is filled with a predetermined atmosphere. For example, the inside of the carburizing chamber 10 is filled with an atmosphere in which the carbon potential satisfies a predetermined numerical range. Further, for example, the inside of the oil tank 11 is filled with a low oxygen atmosphere so that the product W to be treated is not oxidized.

The gas carburizing facility 1 of the present embodiment has a configuration in which the carburizing chamber 10 and the oil tank 11 are adjacent to each other, but the configuration of the gas carburizing facility 1 is not limited to that described in the present embodiment. The gas carburizing facility 1 has a configuration in which, for example, the product W to be treated, which has been carburized, is once carried out from the carburizing chamber 10 and transported to the oil tank 11 arranged at intervals with respect to the carburizing chamber 10. There may be. Further, the gas carburizing facility 1 is an example of a heat treatment facility, and the heat treatment facility is not particularly limited as long as it is a facility that performs heat treatment in a state where the treatment chamber has a predetermined atmosphere.

As shown in FIGS. 1 and 2, the gas carburizing facility 1 of the present embodiment includes a curtain burner 20 on the outside of the oil tank 11. The curtain burner 20 is arranged below the carry-out port 11a in the front view of the carry-out port 11a as shown in FIG. 2, and is provided so as to emit a flame upward in the Z direction. From the viewpoint of covering the carry-out port 11a of the oil tank 11, the curtain burner 20 is arranged above the carry-out port 11a in the front view of the carry-out port 11a, and is provided so as to emit a flame downward in the Z direction. You may. Further, the curtain burner 20 may be arranged on the side of the carry-out port 11a in a front view of the carry-out port 11a, for example, and may be provided so as to emit a flame toward the carry-out port 11a side. Further, the curtain burner 20 of the present embodiment is provided to block the atmosphere in the vicinity of the carry-out port 11a, but the curtain burner 20 is not limited to the carry-out port 11a, but is not limited to the carry-out port 11a, but is not limited to the carry-out port 11a. It is appropriately provided near the opening. That is, the installation position of the curtain burner 20 is not particularly limited as long as it is provided in the vicinity of the opening of the processing chamber and is provided so as to emit a flame on the opening side in the front view of the opening.

As shown in FIGS. 3 to 6, the curtain burner 20 has a gas pipe 21 through which combustible gas flows, and the gas discharge portion 21a of the gas pipe 21 where the combustible gas is discharged has a pipe structure. It has a double pipe structure. That is, the gas discharge portion 21a of the gas pipe 21 has an inner pipe 30 and an outer pipe 40 that covers the periphery of the inner pipe 30. The portion of the gas pipe 21 other than the gas discharge portion 21a has a single pipe structure, and the inner pipe 30 is exposed to the outside.

As shown in FIGS. 5 and 6, the inner pipe 30 of the present embodiment is formed in an L shape in a plan view, and is formed in a straight line in the gas discharge portion 21a. Of both ends 30a and 30b of the inner pipe 30, one end 30a is connected to a combustible gas supply source 50 which is a source of combustible gas such as a gas cylinder, and the other end 30b (what is the combustible gas supply source 50? The opposite end) has a closed shape that is not open. As shown in FIGS. 3 and 4, the outer pipe 40 has an end portion 40a on the combustible gas supply source 50 side joined to the inner pipe 30 without a gap, and the end opposite to the combustible gas supply source 50. The portion 40b has a closed shape that is not open. The phrase "the inner pipe 30 is connected to the combustible gas supply source 50" is not limited to the fact that the inner pipe 30 is directly connected to the combustible gas supply source 50, but indirectly via other pipes or the like. Also includes the state of being connected to the combustible gas supply source 50.

FIG. 7 is a diagram showing a cross section of the gas discharge portion 21a perpendicular to the pipe longitudinal direction (Y direction in this embodiment). As shown in FIG. 7, the inner pipe 30 of the present embodiment has a circular cross section perpendicular to the pipe longitudinal direction in the gas discharge portion 21a. The inner pipe 30 has a first gas discharge port 31 for discharging the combustible gas introduced from the combustible gas supply source 50, and the first gas discharge port 31 discharges gas as shown in FIG. A plurality of portions 21a are formed along the longitudinal direction of the pipe. The first gas discharge ports 31 of the present embodiment are provided in a straight line at equal intervals along the longitudinal direction of the pipe in the gas discharge portion 21a, and each of the first gas discharge ports 31 is downward in the Z direction. It is suitable.

The outer pipe 40 of the present embodiment has a quadrangular cross-sectional shape perpendicular to the pipe longitudinal direction (Y direction in the present embodiment) of the gas discharge portion 21a. The outer pipe 40 has a second gas discharge port 41 for discharging combustible gas, and the second gas discharge port 41 is along the pipe longitudinal direction in the gas discharge portion 21a as shown in FIG. Multiple are formed. The second gas discharge ports 41 of the present embodiment are provided in two rows linearly at equal intervals along the longitudinal direction of the pipe, and each second gas discharge port 41 faces upward in the Z direction. Further, in the present embodiment, among the rows of the second gas discharge ports 41 existing in two rows, the position of the second gas discharge port 41 belonging to one row belongs to the position in the pipe longitudinal direction and belongs to the other row. The positions of the second gas discharge ports 41 in the longitudinal direction of the pipe are different from each other, and the arrangement of the second gas discharge ports 41 is a so-called staggered arrangement.

The curtain burner 20 of the present embodiment is configured as described above. In the curtain burner 20 provided with the gas discharge portion 21a having such an inner pipe 30 and an outer pipe 40 covering the periphery of the inner pipe 30, the combustible gas introduced into the inner pipe 30 from the combustible gas supply source 50 is emitted. , As shown in FIG. 8, first, the gas is discharged from the inside to the outside of the inner pipe 30 through the first gas discharge port 31 of the inner pipe 30. At this time, since the pressure of the combustible gas increases as it is closer to the combustible gas supply source 50 inside the inner pipe 30, the combustible gas discharged from the first gas discharge port 31 located closer to the combustible gas supply source 50. The amount of gas is high. Here, the combustible gas discharged from the inner pipe 30 flows into the space outside the inner pipe 30 and inside the outer pipe 40, and flows out of the gas pipe 21 through the second gas discharge port 41 of the outer pipe 40. Is discharged to. That is, in the curtain burner 20 of the present embodiment, the combustible gas discharged from the inner pipe 30 is not directly discharged to the outside of the gas pipe 21, but hits the inner surface of the outer pipe 40 and flows along the inner surface of the outer pipe 40. I will go. Due to the flow of the combustible gas in this way, even if there is a portion inside the inner pipe 30 where the pressure of the combustible gas is high, the combustible gas discharged from the portion diffuses in the outer pipe 40, and as a result, the outside The pressure difference of the combustible gas in the pipe 40 becomes small. As a result, the discharge amount of the combustible gas discharged from the gas discharge portion 21a becomes more uniform and the variation in the height of the flame becomes smaller than in the case where the gas pipe 21 has a single pipe structure.

Therefore, according to the curtain burner 20 as in the present embodiment, when adjusting the height of the flame for covering the carry-out port 11a of the object W to be treated, the portion of the band-shaped flame having a low flame height. Even if the amount of combustible gas supplied is adjusted with reference to the above, the height of the flame in other parts will not be excessively high with respect to the carry-out port 11a. This makes it possible to reduce the consumption of combustible gas. In the present embodiment, the pipe structure of the gas pipe 21 is a double pipe structure, but if it is a multiple pipe structure, it is not limited to the double pipe structure. Further, the discharge pressure of combustible gas, the type of combustible gas, the size of the inner pipe 30 and the size of the outer pipe 40 are determined by the type of heat treatment, the size of the opening of the processing chamber of the product W to be treated, and the installation of the curtain burner 20. It is appropriately determined according to the position and the like.

Further, the shape of the inner pipe 30 and the shape of the outer pipe 40 of the gas pipe 21 are not particularly limited. For example, as shown in FIG. 9, the cross-sectional shape of the outer pipe 40 in the pipe longitudinal direction of the gas discharge portion 21a may be circular. Even in such a case, the pressure difference of the combustible gas in the outer pipe 40 can be reduced by once flowing the combustible gas discharged from the inner pipe 30 into the outer pipe 40.

From the viewpoint of reducing the pressure difference of combustible gas in the outer pipe 40, the gap between the outer surface of the inner pipe 30 and the inner surface of the outer pipe 40 in the cross section perpendicular to the pipe longitudinal direction of the gas discharge portion 21a is as shown in FIG. It is preferable that the inner surface shape of the outer pipe 40 is a polygonal shape so that a narrow space and a wide space are provided. Since the inner surface shape of the outer pipe 40 is polygonal, the gas flow is obstructed in the narrow space inside the outer pipe 40, and the gas temporarily stays in the other wide space. This makes it easier to equalize the gas pressure in a large space. On the other hand, when the cross-sectional shapes of the inner pipe 30 and the outer pipe 40 are both circular as shown in FIG. 9, the gap between the two is constant, so that the gas pressure is equalized as compared with the case of FIG. The effect is small. According to the pipe structure as shown in FIG. 8, a plurality of narrow spaces and wide spaces exist between the first gas discharge port 31 of the inner pipe 30 and the second gas discharge port 41 of the outer pipe 40. The pressure difference of the flammable gas in the outer pipe 40 can be made smaller than that of the pipe structure as shown in FIG. When the inner surface shape of the outer pipe 40 is a polygonal shape, the inner surface shape of the outer pipe 40 is not particularly limited as long as a narrow space and a narrow space can be formed between the inner pipe 30 and the outer pipe 40. The inner surface shape of the above is preferably triangular to octagonal, and more preferably quadrangular.

From the viewpoint of forming a narrow space and a wide space between the inner pipe 30 and the outer pipe 40, there is a gap between the inner pipe 30 and the outer pipe 40 in the cross section perpendicular to the pipe longitudinal direction of the gas discharge portion 21a. It does not have to be constant in the circumferential direction. For example, even if the cross-sectional shapes of the inner pipe 30 and the outer pipe 40 are both circular, if a protrusion is provided on the outer surface of the inner pipe 30 or a protrusion is provided on the inner surface of the outer pipe 40, the protrusion is provided. It is possible to form a narrow space and a wide space between the inner pipe 30 and the outer pipe 40. Further, for example, even with a combination of the inner pipe 30 having a circular cross section and the outer pipe 40 having an elliptical cross section, it is possible to form a narrow space and a wide space between the inner pipe 30 and the outer pipe 40.

The direction of the first gas discharge port 31 in the circumferential direction of the gas pipe 21 is not particularly limited. In the example shown in FIG. 7, the direction of the first gas discharge port 31 is a position rotated by 180 ° with respect to the direction of the second gas discharge port 41. For example, as shown in FIG. 10, the first gas discharge port 31 The direction of the gas discharge port 31 may be at a position rotated by 90 ° in the circumferential direction with respect to the direction of the second gas discharge port 41. Further, for example, as shown in FIG. 11, the direction of the first gas discharge port 31 and the direction of the second gas discharge port 41 in the circumferential direction of the gas pipe 21 may be the same as each other. Even with the curtain burner 20 having such a configuration, the pressure difference of the combustible gas in the longitudinal direction of the pipe is reduced as compared with the case where the combustible gas discharged from the inner pipe 30 is directly discharged to the outside of the gas pipe 21. be able to. From the viewpoint of reducing the pressure difference of the combustible gas in the outer pipe 40, the directions of the first gas discharge port 31 and the directions of the second gas discharge port 41 in the circumferential direction of the gas pipe 21 are different from each other. It is preferable to have. Further, the orientation of the first gas discharge port 31 and the direction of the second gas discharge port in the circumferential direction of the gas pipe 21 are preferably 90 ° to 180 ° different, and more preferably 120 ° or more. .. Further, from the viewpoint of further reducing the pressure difference of the combustible gas in the outer pipe 40, the directions of the first gas discharge port 31 and the second gas discharge port 41 in the circumferential direction of the gas pipe 21 are different from each other. At the same time, it is more preferable that the shape of the inner surface of the outer pipe in the cross section perpendicular to the pipe longitudinal direction of the gas discharge portion 21a is a polygonal shape.

The number and formation position of the first gas discharge port 31, the number and formation position of the second gas discharge port 41, and the like are not particularly limited. For example, as shown in FIG. 12, the first gas discharge ports 31 of the inner pipe 30 may be provided in two rows. In this case, when the number of rows of the first gas discharge port 31 is increased by one row, when looking at the cross section of the gas discharge portion 21a perpendicular to the pipe longitudinal direction as shown in FIG. 13, the first gas is compared with the case of FIG. The cross-sectional area of the discharge port 31 will increase. When paying attention to the cross-sectional area of the gas discharge port in this way, the second gas discharge port is calculated by (total cross-sectional area of the second gas discharge port 41 / total cross-sectional area of the first gas discharge port 31). The cross-sectional area ratio, which is the ratio of the total cross-sectional area of 41 to the total cross-sectional area of the first gas discharge port 31, is preferably 1.5 or less. When the cross-sectional area ratio is 1.5 or less, the combustible gas discharged from the inner pipe 30 is likely to diffuse in the outer pipe 40, and the pressure difference of the combustible gas in the outer pipe 40 can be further reduced. The total cross-sectional area of the first gas discharge port 31 is the total cross-sectional area of each of the plurality of first gas discharge ports 31, and the cross-sectional area of the first gas discharge port 31 is the first gas. It is measured with a cross section perpendicular to the longitudinal direction of the pipe in the gas discharge portion 21a cut so as to include the center of the hole of the discharge port 31. The total cross-sectional area of the second gas discharge port 41 is the total cross-sectional area of each of the plurality of second gas discharge ports 41, and the cross-sectional area of the second gas discharge port 41 is the second gas. It is measured in a cross section perpendicular to the longitudinal direction of the pipe in the gas discharge portion 21a cut so as to include the center of the hole of the discharge port 41.

Although an example of the embodiment of the present invention has been described above, the present invention is not limited to such an example. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the technical idea described in the claims, and of course, the technical scope of the present invention also includes them. It is understood that it belongs to.

A gas discharge simulation was carried out using a gas pipe having the structure shown in Table 1 below, and air with a temperature of 20 ° C. and a flow rate of 0.1 kg / sec was flowed through the gas pipe, and the pressure variation (maximum pressure and minimum pressure) in the gas pipe was performed. Difference) was measured.

The gas pipe of Comparative Example 1 has a single pipe structure, and the gas pipes of Examples 1 to 6 have a double pipe structure. The pipe structure of Example 1 has the same structure as that of FIG. 7, the pipe structure of Example 2 has the same structure as that of FIG. 9, and the pipe structure of Example 3 has the same structure as that of FIG. The pipe structure of FIG. 4 has the same structure as that of FIG. 10, and the pipe structure of Example 5 has the same structure as that of FIG. In the pipe structure of Example 6, the number of first gas discharge ports formed in the inner pipe is half the number of the pipe structure of Example 1. The "angle between the first gas discharge port and the second gas discharge port" in Table 1 is the direction of the first gas discharge port and the direction of the second gas discharge port in the circumferential direction of the gas pipe. It is a gas horn. Further, the pressure variation in the pipe structure of Examples 1 to 6 is calculated based on the pressure value in the space outside the inner pipe and inside the outer pipe.

As shown in Table 1, the pipe structures of Examples 1 to 6 can reduce the pressure variation with respect to the pipe structure of Comparative Example 1. Therefore, by forming the gas discharge portion of the curtain burner into a double pipe structure, the pressure difference in the gas pipe can be reduced, and the variation in the height of the generated flame can be suppressed.

According to the comparison between Example 1 and Example 2, in order to further reduce the pressure variation in the gas pipe, the inner surface shape of the outer pipe cross section is preferably a polygonal shape. Further, according to the comparison between Examples 1, 3 and 4, in order to further reduce the pressure variation in the gas pipe, the direction of the first gas discharge port and the second gas discharge port in the circumferential direction of the gas pipe It is preferable that the directions of the gas discharge ports are different from each other. Further, according to the comparison of Example 1, Example 5 and Example 6, in order to further reduce the pressure variation in the gas pipe, the cross-sectional area ratio of the second gas discharge port and the first gas discharge port is determined. , 1.5 or less is preferable.

The present invention can be used, for example, as a curtain burner on the outlet side of an oil tank of a gas carburizing facility.

1 Gas carburizing equipment 10 Coaling chamber 10a Transport port 11 Oil tank 11a Carrying out outlet 12 Door 13 Door 20 Curtain burner 21 Gas pipe 21a Gas discharge part 30 Inner pipe 30a Inner pipe end 30b Inner pipe end 31 First gas discharge Outlet 40 Outer pipe 40a Outer pipe end 40b Outer pipe end 41 Second gas discharge port 50 Combustible gas supply source W Processed product

Claims (6)

A curtain burner for covering the opening of the processing room of the heat treatment equipment.
Equipped with a gas pipe having a gas discharge part that discharges combustible gas,
The gas discharge part is
The inner pipe connected to the combustible gas supply source,
It has an outer tube that covers the periphery of the inner tube,
The inner pipe has a first gas discharge port and has a first gas discharge port.
The outer pipe is a curtain burner having a plurality of second gas discharge ports formed at intervals along the longitudinal direction of the gas discharge portion. The curtain burner according to claim 1, wherein the inner surface shape of the outer pipe in a cross section perpendicular to the pipe longitudinal direction of the gas discharge portion is a polygonal shape. The curtain burner according to claim 1 or 2, wherein the direction of the first gas discharge port and the direction of the second gas discharge port in the circumferential direction of the gas discharge portion are different from each other. The invention according to any one of claims 1 to 3, wherein the direction of the first gas discharge port and the direction of the second gas discharge port in the circumferential direction of the gas discharge portion are different by 90 ° to 180 °. Curtain burner. The ratio of the total cross-sectional area of the second gas discharge port to the total cross-sectional area of the first gas discharge port in the cross section perpendicular to the pipe longitudinal direction of the gas discharge portion (total cross-sectional area of the second gas discharge port). / The curtain burner according to any one of claims 1 to 4, wherein the total cross-sectional area of the first gas discharge port) is 1.5 or less. A heat treatment facility that heat-treats the product to be treated.
A processing chamber having an opening through which the object to be processed passes, and
The curtain burner according to any one of claims 1 to 5 provided in the vicinity of the opening.
A heat treatment facility in which the second gas discharge port of the curtain burner faces the opening side in a front view of the opening.

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