KR20240078352A - Heating furnace - Google Patents

Abstract

The switching cycle of gas suction from the heat treatment space of the main body to the gas line and gas ejection from the gas line to the heat treatment space is lengthened.
The heating furnace 100 has a heat treatment space 11 for heat treatment of the object 1, a main body portion 10 including a heating portion disposed in the heat treatment space 11, and a heat treatment space 11 for heat treatment. It has a gas supply unit for supplying necessary gas to the heat treatment space 11 of the main body 10, and a gas line 31 connected to the heat treatment space 11 of the main body 10, and supplies gas from the heat treatment space 11. A suction blowing portion (30) for repeatedly sucking gas into the line (31) and blowing the gas drawn into the gas line (31) into the heat treatment space (11), and provided inside the gas line (31). It includes a recuperative heat exchanger 40 for performing heat exchange between the gas sucked from the heat treatment space 11 and the gas ejected into the heat treatment space 11. The gas line 31 is configured so that gas is not supplied from outside the heat treatment space 11.

Description

Heating furnace {HEATING FURNACE}

The present invention relates to a heating furnace.

A heating furnace is known in which gas is supplied into a furnace and heat treatment of an object to be processed is performed.

As one of such heating furnaces, Patent Document 1 discloses a heating furnace in which gas in the furnace is introduced into the circulation path outside the furnace by a circulation fan and the gas introduced in the circulation path outside the furnace is returned to the furnace. there is. The circulation path outside the furnace is provided with a heat storage body for heat exchange with the gas and a flow path switching device. As the flow of gas flowing in the circulation path outside the furnace is periodically switched by the flow path switching device, the gas introduced from inside the furnace to the circulation path outside the furnace undergoes heat exchange with the heat storage body and becomes low temperature, and the gas returned into the furnace is transferred to the heat storage body. Heat exchange takes place and the temperature becomes high, and then it is ejected into the furnace. It is said that with such a configuration, the heating furnace described in Patent Document 1 can supply a strong circulating flow into the furnace at high temperature.

Japanese Patent Publication No. 9-178112

As described above, in the heating furnace described in Patent Document 1, heat storage and heat dissipation are alternately performed with a heat storage body provided in the circulation path outside the furnace, so in relation to the heat exchange characteristics, gas suction and gas ejection are performed for about 5 to 10 seconds. There is a need to switch to shorter cycles. For this reason, the lifespan of the flow path switching device for switching the flow of gas suction and ejection is shortened.

The present invention solves the above problems and aims to provide a heating furnace capable of lengthening the switching cycle of gas suction from the heat treatment space of the main body to the gas line and gas ejection from the gas line to the heat treatment space.

The heating furnace of the present invention

A main body portion having a heat treatment space for heat treating an object to be treated and including a heating portion disposed in the heat treatment space;

a gas supply unit that supplies gas necessary for heat treatment to the heat treatment space of the main body;

a suction blowing portion having a gas line connected to the heat treatment space of the main body portion, and repeatedly sucking gas from the heat treatment space into the gas line and blowing the gas sucked into the gas line into the heat treatment space; ,

It is provided inside the gas line and includes a recuperative heat exchanger for heat exchange between gas sucked from the heat treatment space and gas ejected into the heat treatment space,

The gas line is characterized in that it is configured so that gas is not supplied from outside the heat treatment space.

According to the heating furnace of the present invention, since the suction ejection portion includes a recuperative heat exchanger, it is possible to lengthen the switching cycle of suction of gas from the heat treatment space to the gas line and ejection of gas from the gas line to the heat treatment space. . In other words, since the heat exchanger is a configuration in which heat exchange is performed between the high-temperature gas sucked from the heat treatment space and the low-temperature gas ejected into the heat treatment space, it is like a heat storage body to repeat heat storage and heat dissipation without changing the gas flow path. It can prevent the temperature from rising or continuing to fall rapidly. For this reason, it is possible to lengthen the switching cycle between suction of gas from the heat treatment space to the gas line and ejection of gas from the gas line to the heat treatment space.

1 is a cross-sectional view schematically showing the configuration of a heating furnace in the first embodiment.
FIG. 2 is a cross-sectional view schematically showing the configuration of the heating furnace shown in FIG. 1 when cut along line II-II.
Figure 3 is a perspective view schematically showing the configuration of a cooler using a compact heat exchanger.
Figure 4 is a perspective view schematically showing the configuration of a heat exchanger.
Figure 5(a) is a diagram for explaining the operation of sucking gas into the first extension part of the gas line from the heat treatment space in the heating furnace in the first embodiment and ejecting the gas through the second extension part, (b) ) is a diagram for explaining the operation of sucking gas into the second extension part of the gas line from the heat treatment space and ejecting the gas through the first extension part.
Fig. 6 is a cross-sectional view schematically showing the configuration of a heating furnace in the second embodiment.
Figure 7(a) is a diagram for explaining the operation of sucking gas into the first extension part of the gas line and ejecting the gas through the second extension part in the heating furnace in the second embodiment, and (b) is a diagram for explaining the operation of gas This is a diagram to explain the operation of sucking gas into the second extension part of the line and ejecting the gas through the first extension part.
Fig. 8 is a cross-sectional view schematically showing the configuration of a heating furnace in the third embodiment.
FIG. 9 is a diagram schematically showing the configuration of the heating furnace shown in FIG. 8 when viewed from the direction of arrow Y1.
Fig. 10 is a cross-sectional view schematically showing the configuration of a heating furnace in the fourth embodiment.
Figure 11 is a diagram showing the relationship between the unit vector along the direction of gas ejected from the heat exchanger into the heat treatment space and the unit normal vector extending toward the side on which the object to be processed is mounted with respect to the mounting surface of the plate on which the object to be processed is mounted. .
Fig. 12 is a cross-sectional view schematically showing the configuration of a heating furnace in the fifth embodiment.
Figure 13 is a diagram showing the relationship between the rotation speed of the fan in a driven state and the rotation speed of the fan in a non-driving state. (a) is the rotation speed when the duty ratio is set to 60% when the fan is driven by PWM control. , and (b) shows the number of rotations when the duty ratio is set to 70%.
Fig. 14 is a cross-sectional view schematically showing the configuration of a heating furnace in the sixth embodiment.
FIG. 15 is a diagram showing the rotation speed, etc. when the control unit controls the drive of the fan in the driven state so that the rotation speed measured by the rotation speed measuring unit matches the reference rotation speed.
Fig. 16 is a cross-sectional view schematically showing the configuration of a heating furnace in the seventh embodiment.

Embodiments of the present invention are shown below, and the features of the present invention are explained in detail.

<First embodiment>

Fig. 1 is a cross-sectional view schematically showing the configuration of the heating furnace 100 in the first embodiment. FIG. 2 is a cross-sectional view schematically showing the configuration of the heating furnace 100 shown in FIG. 1 when cut along line II-II. However, in Figure 2, the driving roller 13, which will be described later, is omitted.

Here, the heating furnace 100 is described as a roller hearth furnace. A roller hearth furnace is a continuous heating furnace in which a plurality of drive rollers 13 are arranged at regular intervals along the direction of movement within the furnace, and the object to be treated (1) is conveyed on the drive rollers 13. FIG. 1 shows a cut surface when the heating furnace 100 is cut from a plane perpendicular to the conveyance direction of the object 1 to be treated. However, the heating furnace 100 is not limited to a roller hearth furnace, and may be another type of heating furnace such as a batch heating furnace.

The heating furnace 100 includes a main body portion 10, a gas supply portion 20, a suction ejection portion 30, and a heat exchanger 40.

The main body 10 has a heat treatment space 11 for heat treating the object 1 and includes a heating unit 12 disposed within the heat treatment space 11. There are no particular restrictions on the shape or size of the main body 10. The heating unit 12 is a heater capable of heating up to about 1300°C, for example. In this embodiment, the driving roller 13 is disposed in the heat treatment space 11, and the object 1 is disposed between the driving roller 13 and the heating unit 12. In contrast, the heating unit 12 is disposed on the opposite side to the driving roller 13, that is, above the object to be treated 1. However, the location of the heating unit 12 is not limited to a position on the opposite side of the object 1 from the driving roller 13.

In this embodiment, as shown in FIG. 1, the main body 10 includes four furnace walls: a first side wall 10a, a second side wall 10b, a furnace bottom wall 10c, and a ceiling wall 10d. I'm doing it. The first side wall 10a, the second side wall 10b, the furnace bottom wall 10c, and the ceiling wall 10d each face each other in a direction perpendicular to the conveyance direction of the object 1. Additionally, as shown in FIG. 2, both ends of the object to be treated 1 in the transport direction are open and connected to a discharge inlet through which the object to be treated 1 enters and exits. The furnace wall of the main body 10 including the first side wall 10a, the second side wall 10b, the furnace bottom wall 10c, and the ceiling wall 10d is made of, for example, an insulating material.

There are no restrictions on the type of object 1 subject to heat treatment, for example, an unfired ceramic body for manufacturing chip-shaped ceramic electronic components such as a multilayer ceramic capacitor. In this embodiment, the plate 2 on which the plurality of objects 1 are mounted is configured to be conveyed on the driving roller 13. The plate 2 is made of ceramic, for example.

The gas supply unit 20 supplies gas necessary for heat treatment to the heat treatment space 11 of the main body 10. The main body 10 is provided with a gas supply port 14, and the gas required for heat treatment is supplied to the heat treatment space 11 through the gas supply port 14 by the gas supply portion 20.

Meanwhile, the main body 10 is provided with a gas outlet 15 for discharging unnecessary gas so that the pressure in the heat treatment space 11 is maintained constant.

The suction blowing part 30 has a gas line 31 connected to the heat treatment space 11 of the main body 10, and suction of gas from the heat treatment space 11 to the gas line 31 and the gas line ( The gas sucked into 31) is repeatedly ejected into the heat treatment space 11. In this specification, "the suction of gas from the heat treatment space 11 to the gas line 31 and the ejection of the gas drawn into the gas line 31 into the heat treatment space 11 are repeated," as described later. This means that the flow of gas sucked into the gas line 31 and the gas ejected from the gas line 31 are alternately switched to cause suction and ejection of gas.

The gas line 31 is configured so that gas is not supplied from outside the heat treatment space 11. That is, the gas sucked from the heat treatment space 11 into the gas line 31 is blown out into the heat treatment space 11 as is without any other gas or air being mixed in. Accordingly, the gas sucked into the gas line 31 by the suction blowing portion 30 and blown out into the heat treatment space 11 is a gas that has the same composition as the gas in the heat treatment space 11.

The gas line 31 in this embodiment includes a first extension portion 31a connected to the first heat exchange passage 41 of the heat exchanger 40, which will be described later, and a second heat exchange passage 42 of the heat exchanger 40. ) and a second extension part 31b connected to it, and a connection part 31c connecting the first extension part 31a and the second extension part 31b. In this embodiment, as shown in FIG. 2, the first extension portion 31a and the second extension portion 31b each extend in a direction away from the main body 10, and the connecting portion 31c extends from the first side wall 10a. ) extends in a direction parallel to the

In this embodiment, the first extension part 31a, the second extension part 31b, and the connection part 31c are all located at the same height. That is, the gas line 31 is provided so that gas flows in the horizontal direction.

The suction blowing portion 30 in this embodiment includes a first fan 32a disposed on the first extension portion 31a of the gas line 31, and a first fan disposed on the second extension portion 31b ( It includes a second fan 32b for flowing gas in a direction opposite to the flow of gas driven by 32a). The first fan 32a and the second fan 32b may have any structure as long as they can blow air. In the following description, the first fan 32a and the second fan 32b may be collectively referred to as the fan 32. In addition, although not shown, the suction blowing unit 30 includes a control unit for controlling the driving of the first fan 32a and the second fan 32b.

The first fan 32a is arranged so that gas flows from the first extension portion 31a of the gas line 31 to the connection portion 31c when driven. That is, when the first fan 32a is driven, gas is drawn from the heat treatment space 11 to the first extension 31a of the gas line 31 through the heat exchanger 40. At this time, the second fan 32b is in a non-driving state. The gas sucked from the heat treatment space 11 to the first extension part 31a of the gas line 31 passes through the connection part 31c and the second extension part 31b, and flows through the heat exchanger 40 into the heat treatment space ( 11) is ejected.

The second fan 32b is arranged so that gas flows from the second extension portion 31b of the gas line 31 to the connection portion 31c when driven. That is, when the second fan 32b is driven, gas is drawn from the heat treatment space 11 to the second extension portion 31b of the gas line 31 through the heat exchanger 40. At this time, the first fan 32a is in a non-driving state. The gas sucked from the heat treatment space 11 to the second extension part 31b of the gas line 31 passes through the connection part 31c and the first extension part 31a, and flows through the heat exchanger 40 into the heat treatment space ( 11) is ejected.

Meanwhile, the first fan 32a is arranged so that gas flows from the first extension 31a of the gas line 31 to the heat treatment space 11 when driven, and the second fan 32b is installed therein. It may be arranged so that gas flows from the second extension portion 31b of the gas line 31 to the heat treatment space 11 during driving. In that case, when the first fan 32a is driven, gas is drawn from the heat treatment space 11 through the heat exchanger 40 to the second extension part 31b of the gas line 31, and the first extension part 31a ) and the gas is ejected through the heat exchanger 40 and into the heat treatment space 11. In addition, when the second fan 32b is driven, gas is drawn from the heat treatment space 11 through the heat exchanger 40 to the first extension 31a of the gas line 31, and the second extension 31b And the gas is ejected into the heat treatment space 11 through the heat exchanger 40.

The heating furnace 100 in this embodiment is disposed in the gas line 31 and includes a cooler 33 for cooling the gas drawn from the heat treatment space 11 and passing through a heat exchanger 40 to be described later. there is. The cooler 33 includes a first cooler 33a disposed on the first extension portion 31a of the gas line 31, and a second cooler 33b disposed on the second extension portion 31b of the gas line 31. ) is included. The first cooler 33a is disposed in a position on the upstream side of the first fan 32a in the first extension portion 31a when the first fan 32a is driven. The second cooler 33b is disposed in the second extension portion 31b at a position upstream of the second fan 32b when the second fan 32b is driven. Meanwhile, the upstream side of the first fan 32a refers to the upstream side of the direction in which gas flows when the first fan 32a is driven, and in FIG. 2, the heat exchanger 40 is connected to the first fan 32a. This is the location on the near side. Likewise, the upstream side of the second fan 32b means the upstream side of the direction in which gas flows when the second fan 32b is driven, and in FIG. 2, the heat exchanger 40 is connected to the second fan 32b. This is the location on the near side.

The first cooler 33a cools the gas drawn from the heat treatment space 11 through the heat exchanger 40 to the first extension 31a of the gas line 31. As an example, the gas sucked from the heat treatment space 11 to the first extension portion 31a of the gas line 31 is cooled to about 100° C. by the heat exchanger 40 and then cooled to about 100° C. by the first cooler 33a. Cooled below 50℃. Such a configuration can prevent high-temperature gas from flowing into the first fan 32a and causing thermal damage.

The second cooler 33b is drawn from the heat treatment space 11 to the second extension portion 31b of the gas line 31 and cools the gas that has passed through the heat exchanger 40. As an example, the gas drawn from the heat treatment space 11 to the second extension portion 31b of the gas line 31 is cooled to about 100° C. by the heat exchanger 40. The gas cooled by the heat exchanger 40 is further cooled to 50° C. or lower by the second cooler 33b. As a result, it is possible to prevent high-temperature gas from flowing into the second fan 32b and causing thermal damage.

Additionally, by providing the first cooler 33a and the second cooler 33b, the temperature distribution of the heat exchanger 40 can be maintained in an balanced state. That is, when the first cooler 33a and the second cooler 33b are not provided, gas is sucked from the heat treatment space 11 into the gas line 31, and gas is drawn from the gas line 31 into the heat treatment space 11. The temperature of the heat exchanger 40 increases in the process of repeating the ejection of gas into. In that case, there is a possibility that the temperature of the gas cooled by the heat exchanger 40 greatly exceeds 100°C.

However, since the heating furnace 100 in the present embodiment is provided with the first cooler 33a and the second cooler 33b, the temperature rise of the heat exchanger 40 as described above is suppressed, and the heat exchanger 40 It is possible to prevent the temperature of the gas passing through from greatly exceeding 100°C.

As will be described later, the first cooler 33a and the second cooler 33b are disposed on the extension portion that serves as the gas suction flow path among the first extension portion 31a and the second extension portion 31b of the gas line 31. The cooling function of the cooler 32 is configured to be turned on, and the cooling function of the cooler 32 disposed in the extension portion serving as the gas ejection flow path is turned off.

As the first cooler 33a and the second cooler 33b, for example, it is possible to use a known heat exchanger. Figure 3 is a perspective view schematically showing the configuration of the cooler 33 (the first cooler 33a and the second cooler 33b) using a compact heat exchanger, which is one of the heat exchangers. As shown in FIG. 3, the cooler 33 has a structure in which gas passages F1 through which high-temperature gas flows and refrigerant passages F2 through which refrigerant flows are alternately stacked. With such a structure, the gas flowing through the gas flow path F1 can be effectively cooled. The gas flow path F1 and the refrigerant flow path F2 are configured to be oriented perpendicular to each other. A plurality of fins are provided in the gas flow path F1 and the refrigerant flow path F2, and heat exchange is performed between the gas flowing in the gas flow path F1 and the refrigerant flowing in the refrigerant flow path F2.

Meanwhile, Figure 3 shows a configuration in which the gas flow path F1 and the refrigerant flow path F2 are each provided in two layers, but the number of stacks of the gas flow path F1 and the refrigerant flow path F2 is not limited to two.

The cooling function of the first cooler 33a will be described. A refrigerant for cooling the gas flowing through the gas flow path F1 flows in the refrigerant flow path F2. The refrigerant is, for example, cold air. For example, a cooling fan is provided on the upstream side of the refrigerant flow path F2 to allow cool air to flow through the refrigerant flow path F2. Gas that has passed through the heat exchanger 40 flows through the gas flow path F1.

As an example, assume that gas at about 100°C, which is sucked from the heat treatment space 11 and passed through the heat exchanger 40, flows into the gas flow path F1 of the first cooler 33a at a flow rate of 30 L/min. When cold air with an air volume of 30 to 120 L/min is flowed as a refrigerant through the refrigerant flow path F2 of the first cooler 33a, the gas flowing through the gas flow path F1 is cooled to about 50°C. The same applies to the second cooler 33b.

Meanwhile, the first cooler (33a) and the second cooler (33b) can be any that can cool gas, and have a heat exchange structure in which gas flow paths (F1) through which gas flows and refrigerant flow paths (F2 through refrigerant) are alternately stacked. It is not limited to period. Additionally, if the gas is sufficiently cooled by the heat exchanger 40, the cooler 33 can be omitted.

The heat exchanger 40 is provided inside the gas line 31 and is a recuperative heat exchanger for performing heat exchange between the gas sucked from the heat treatment space 11 and the gas ejected into the heat treatment space 11. The heat exchanger 40 includes a first heat exchange passage 41 through which one of the gas sucked from the heat treatment space 11 and the gas ejected into the heat treatment space 11 flows, and a second heat exchange passage through which the other gas flows. We have (42).

Figure 4 is a perspective view schematically showing the configuration of the heat exchanger 40. As shown in FIG. 4 , the heat exchanger 40 has a structure in which first heat exchange passages 41 and second heat exchange passages 42 are alternately stacked. The first heat exchange flow path 41 and the second heat exchange flow path 42 are configured to be oriented parallel to each other. Meanwhile, Figure 4 shows a configuration in which the first heat exchange flow path 41 and the second heat exchange flow path 42 are each provided in two layers, but the number of stacks of the first heat exchange flow path 41 and the second heat exchange flow path 42 is 2. It is not limited.

The heat exchanger 40 is provided in a portion of the gas line 31 located inside the main body 10, specifically, in an area penetrating the main body 10. In the examples shown in FIGS. 1 and 2 , the heat exchanger 40 is provided in an area inside the gas line 31 penetrating the first side wall 10a of the main body 10. However, the heat exchanger 40 may be provided on the second side wall 10b of the main body 10, and as described later, the heat exchanger 40 may be provided on the first side wall 10a and the second side wall 10b of the main body 10. It may be provided on each side. Since the heat exchanger 40 is provided in the part of the gas line 31 located inside the main body 10, the temperature of the gas passing through the heat exchanger 40 and ejected into the heat treatment space 11 is adjusted. , it can be set to a temperature closer to the temperature inside the furnace.

Meanwhile, in FIGS. 1 and 2, the heat exchanger 40 is provided in the entire area penetrating the main body 10 of the gas line 31, but is installed only in a part of the area penetrating the main body 10. It may be provided. Additionally, the heat exchanger 40 may be provided in such a way that it is pushed out from an area inside the gas line 31 penetrating the main body 10 to an area outside the main body 10.

1 and 2, a recuperative heat exchanger 40 for performing heat exchange between the gas sucked from the heat treatment space 11 and the gas ejected into the heat treatment space 11 is connected to the gas line 31. By being provided at a portion located inside the main body portion 10, the gas line 31 can be connected to the heat treatment space 11 at one location. With such a configuration, the freedom of installation of the gas line 31 is improved compared to a configuration in which the gas line 31 is connected to the heat treatment space 11 at two locations.

The first heat exchange flow path 41 of the heat exchanger 40 is connected to the first extension part 31a of the gas line 31, and the second heat exchange flow path 42 is connected to the second extension part of the gas line 31. It is connected to (31b). The heat exchanger 40 is provided with a plurality of first heat exchange passages 41 in a layered form, and all of the first heat exchange passages 41 are connected to the first extension portion 31a. In addition, the heat exchanger 40 is provided with a plurality of second heat exchange passages 42 in a layered form, and all of the second heat exchange passages 42 are connected to the second extension portion 31b.

As shown in FIG. 4, a portion of the partition wall 43 blocking the first heat exchange passage 41 and the second heat exchange passage 42 of the heat exchanger 40 is exposed within the heat treatment space 11 of the main body portion 10. It is done. With such a configuration, interference between the flow of gas ejected from the heat exchanger 40 into the heat treatment space 11 and the flow of gas drawn into the heat exchanger 40 from the heat treatment space 11 can be suppressed. there is. In Figure 4, the gas is ejected from the first heat exchange passage 41 of the heat exchanger 40 into the heat treatment space 11, and the gas is sucked into the second heat exchange passage 42 from the heat treatment space 11. The flow is indicated by an arrow.

That is, in a configuration in which a portion of the partition wall 43 is not exposed within the heat treatment space 11, the gas ejected from the heat exchanger 40 into the heat treatment space 11 affects the flow of gas sucked from the heat treatment space 11. It becomes difficult to go straight. For example, when gas is ejected from the first heat exchange passage 41 of the heat exchanger 40 into the heat treatment space 11 and the gas is drawn into the second heat exchange passage 42 from the heat treatment space 11, the first heat exchange passage 42 A flow occurs in which part of the gas ejected from the heat exchange passage 41 is immediately drawn into the second heat exchange passage 42.

However, as shown in FIG. 4, a portion of the partition wall 43 blocking the first heat exchange flow path 41 and the second heat exchange flow path 42 is exposed within the heat treatment space 11 of the main body portion 10, thereby 2 Gas is drawn into the heat exchange passage 42 not only from the straight direction of the gas, but also from the side of the partition wall 43 exposed within the heat treatment space 11. As a result, a part of the gas ejected from the first heat exchange flow path 41 is suppressed from flowing into the second heat exchange flow path 42, so the gas ejected into the heat treatment space 11 tends to proceed straight. The same applies to the case where gas is sucked into the first heat exchange passage 41 and gas is ejected from the second heat exchange passage 42.

The inventor conducted a simulation, and found that the length L1 of the part of the partition wall 43 exposed in the heat treatment space 11 is 1/2 or more of the dimension W1 in the width direction of the heat exchanger 40, as described above. It was found that interference between the flow of blowing gas and the flow of suction gas could be effectively suppressed. For example, when the width direction dimension W1 of the heat exchanger 40 is 30 mm, the length L1 of the portion of the partition wall 43 exposed within the heat treatment space 11 is set to 15 mm or more. desirable.

In addition, since a part of the partition wall 43 is exposed within the heat treatment space 11, heat exchange for the gas blowing into the heat treatment space 11 progresses in the area where the partition wall 43 is exposed within the heat treatment space 11. , gas with a temperature closer to the temperature in the heat treatment space 11 can be ejected toward the object 1 to be treated.

Here, the dimension W1 in the width direction of the heat exchanger 40 is 30 mm, the height H1 of the first heat exchange passage 41 and the second heat exchange passage 42 is 1.5 mm, and the thickness D1 of the partition wall 43 is 1.5 mm. ) is 1 mm, the length (L1) of which part of the partition wall (43) is exposed in the heat treatment space (11) is 15 mm, and the length (L2) of the first heat exchange flow path (41) and the second heat exchange flow path (42) is 15 mm. 200 mm, the first heat exchange flow path 41 and the second heat exchange flow path 42 are each 7 layers, and when the temperature of the heat treatment space 11 is 1200°C, the heat exchanger 40 is ejected into the heat treatment space 11. The temperature of the gas and the temperature of the gas sucked from the heat treatment space 11 and discharged from the heat exchanger 40 to the first extension part 31a or the second extension part 31b of the gas line 31 were confirmed. Here, the air volume of the gas flowing through the gas line 31 was changed to 15 L/min, 30 L/min, and 45 L/min, and the temperature of the above-mentioned gas was confirmed. The confirmed results are shown in Table 1. In Table 1, “ejection gas temperature” is the temperature of the gas ejected from the heat exchanger 40 into the heat treatment space 11, and “emission gas temperature” is the temperature of the gas sucked from the heat treatment space 11 and discharged from the heat exchanger 40 into the gas line. This is the temperature of the gas discharged from the first extension part (31a) or the second extension part (31b) of (31).

As shown in Table 1, when the wind volume of the gas flowing through the gas line 31 is 15 L/min, the temperature of the gas ejected from the heat exchanger 40 into the heat treatment space 11 is 1169 ° C. The temperature of the gas discharged from the first extension part 31a or the second extension part 31b of the gas line 31 was 81°C. In addition, when the wind volume of the gas flowing through the gas line 31 is 30 L/min, the temperature of the gas ejected from the heat exchanger 40 into the heat treatment space 11 is 1140°C, and the gas line 31 from the heat exchanger 40 is 1140°C. ) The temperature of the gas discharged from the first extension part 31a or the second extension part 31b was 110°C. On the other hand, when the wind volume of the gas flowing through the gas line 31 is 45 L/min, the temperature of the gas ejected from the heat exchanger 40 into the heat treatment space 11 is 1112 ° C. ) The temperature of the gas discharged from the first extension part 31a or the second extension part 31b was 138°C.

That is, if the wind volume of the gas flowing through the gas line 31 is 30 L/min or less, the temperature of the gas ejected into the heat treatment space 11 is 1140°C or more, and the gap with the gas temperature in the heat treatment space 11 is 60°C or less. It becomes. That is, the temperature of the gas ejected from the heat exchanger 40 into the heat treatment space 11 is close to the temperature inside the furnace.

Additionally, if the wind volume of the gas flowing through the gas line 31 is 30 L/min or less, the temperature of the gas sucked from the heat treatment space 11 and discharged through the heat exchanger 40 is 110°C or less. In this case, it becomes easy to lower the temperature of the gas using the cooler 33 to 60°C or lower, which is the heat resistance temperature of the fan 32.

Therefore, under the above-mentioned conditions, it is preferable that the gas flow rate flowing through the gas line 31 is 30 L/min or less.

Here, the suction of gas from the heat treatment space 11 by the suction blowing portion 30 to the gas line 31 and the operation of blowing gas from the gas line 31 into the heat treatment space 11 will be explained.

As shown in FIG. 5(a), when the first fan 32a is driven and the second fan 32b is in a non-driving state, the gas in the heat treatment space 11 of the main body 10 flows into the heat exchanger 40. ) is drawn into the first heat exchange passage 41. The gas temperature in the heat treatment space 11 is assumed to be, for example, about 1200°C.

At this time, the cooling function of the first cooler 33a disposed in the first extension portion 31a, which serves as the gas suction passage, is turned on, and the cooling function of the first cooler 33a disposed in the second extension portion 31b, which serves as the gas discharge passage, is turned on. The cooling function of the second cooler 33b is turned off.

The gas drawn into the first heat exchange passage 41 of the heat exchanger 40 undergoes heat exchange with the gas flowing through the second heat exchange passage 42, and the temperature drops to around 100°C. The gas that has passed through the first heat exchange passage 41 of the heat exchanger 40 is introduced into the first extension portion 31a of the gas line 31 and passes through the gas passage F1 of the first cooler 33a, thereby producing 50 Cooled to a temperature below ℃. The gas that has passed through the first cooler (33a) flows into the second extension portion (31b) through the connection portion (31c) of the gas line (31) and is introduced into the second heat exchange passage (42) of the heat exchanger (40). . At this time, since the cooling function of the second cooler 33b is turned off, it is possible to prevent the gas introduced into the second heat exchange passage 42 from being cooled more than necessary.

The gas introduced into the second heat exchange passage 42 of the heat exchanger 40 undergoes heat exchange with the gas flowing through the first heat exchange passage 41, and reaches a temperature of about 1150° C., which is close to the temperature within the heat treatment space 11. heated to a temperature The gas that has passed through the second heat exchange passage 42 is ejected into the heat treatment space 11 and reaches the surfaces of the plurality of objects 1 on the plate 2.

In Figure 5(a), gas is sucked from the heat treatment space 11 into the first heat exchange passage 41 of the heat exchanger 40, and the first extension portion 31a of the gas line 31, the connection portion 31c, and The direction of the gas flow when the gas is ejected from the second heat exchange passage 42 of the heat exchanger 40 into the heat treatment space 11 after passing through the second extension portion 31b is indicated by an arrow.

Subsequently, as shown in FIG. 5(b), when the second fan 32b is driven and the first fan 32a is in a non-driving state, the gas in the heat treatment space 11 of the main body 10 performs heat exchange. It is drawn into the second heat exchange passage 42 of the machine 40. At this time, the cooling function of the second cooler (33b) disposed in the second extension portion (31b) that serves as the gas suction passage is turned on, and the second cooler (33b) disposed in the first extension portion (31a) that serves as the gas discharge passage is turned on. The cooling function of the first cooler 33a is turned off. The gas drawn into the second heat exchange passage 42 of the heat exchanger 40 undergoes heat exchange with the gas flowing through the first heat exchange passage 41, and the temperature drops to around 100°C.

The gas that has passed through the second heat exchange passage 42 of the heat exchanger 40 is introduced into the second extension portion 31b of the gas line 31 and passes through the gas passage F1 of the second cooler 33b, Cooled to a temperature below 50℃. The gas that has passed through the second cooler (33b) flows into the first extension portion (31a) through the connection portion (31c) of the gas line (31) and is introduced into the first heat exchange passage (41) of the heat exchanger (40). . At this time, the cooling function of the first cooler 33a is turned off, so the gas introduced into the first heat exchange passage 41 can be prevented from being cooled more than necessary.

The gas introduced into the first heat exchange passage 41 of the heat exchanger 40 undergoes heat exchange with the gas flowing through the second heat exchange passage 42, and reaches a temperature of about 1150° C., which is close to the temperature within the heat treatment space 11. heated to a temperature The gas that has passed through the first heat exchange passage 41 is ejected into the heat treatment space 11 and reaches the surfaces of the plurality of objects 1 on the plate 2.

In Figure 5(b), gas is sucked from the heat treatment space 11 into the second heat exchange passage 42 of the heat exchanger 40, and the second extension portion 31b of the gas line 31, the connection portion 31c, and The direction of the gas flow when the gas is ejected from the first heat exchange passage 41 of the heat exchanger 40 into the heat treatment space 11 after passing through the first extension portion 31a is indicated by an arrow.

Here, the operation of suction and jetting of gas by driving the first fan 32a described above and the operation of suction and jetting of gas by driving the second fan 32b are each defined as “one cycle.”

By repeating the above-described cycle, that is, driving the first fan 32a and driving the second fan 32b at regular intervals, the first heat exchange flow path 41 and the second heat exchange flow path 42 of the heat exchanger 40 An operation of sucking the gas in the heat treatment space 11 from one of the flow paths and ejecting the gas into the heat treatment space 11 from the other flow path, and sucking the gas in the heat treatment space 11 from the other flow path. , the operation of ejecting gas from one flow path into the heat treatment space 11 can be repeatedly performed.

According to the heating furnace 100 in this embodiment, it is possible to lengthen the above-mentioned cycle switching by including the recuperative heat exchanger 40. In other words, the heat exchanger 40 is configured to perform heat exchange between the high-temperature gas sucked from the heat treatment space 11 and the low-temperature gas ejected into the heat treatment space 11, so heat storage and heat storage are achieved even without changing the gas flow path. Like a heat storage body for repeated heat dissipation, it is possible to suppress the temperature from rapidly rising or continuously falling. For this reason, it is possible to lengthen the switching cycle of gas suction from the heat treatment space 11 to the gas line 31 and gas ejection from the gas line 31 to the heat treatment space 11.

In the heating furnace 100 in the present embodiment, for reasons described later, the suction blowing portion 30 suctions gas from the heat treatment space 11 to the first extension portion 31a of the gas line 31 and performs heat treatment. Suction of gas from the space 11 to the second extension portion 31b of the gas line 31 is performed at intervals of 10 seconds or more and 10 minutes or less.

The ratio of the driving time of the first fan 32a and the driving time of the second fan 32b is 1:1. However, the ratio of the driving time can be adjusted within the range of, for example, 0.4:0.6 to 0.6:0.4. That is, the driving time of the first fan 32a and the second fan 32b can be adjusted to a ratio of 40% to 60% of the total operating time for suction and ejection of gas, respectively.

Here, the heating furnace 100 in this embodiment includes a recuperative heat exchanger 40 for performing heat exchange between the gas sucked from the heat treatment space 11 and the gas ejected into the heat treatment space 11. . Therefore, from the viewpoint of heat exchange characteristics, there is no need to switch the gas flow in the first heat exchange passage 41 and the second heat exchange passage 42 of the heat exchanger 40, and continuous operation is possible. However, if the flow of gas is not switched, the gas is cooled by the cooler 33 with the cooling function turned on, causing water vapor contained in the gas to condense, increasing the number of condensation adhering to the surface.

For this reason, in the heating furnace 100 in this embodiment, the flow of gas sucked from the heat treatment space 11 into the gas line 31 and the flow of gas ejected from the gas line 31 into the heat treatment space 11 are separated. It is configured to switch by the suction ejection unit (30). This gas flow can be switched depending on the occurrence of condensation in the cooler 33. Therefore, switching between the driving of the first fan 32a and the driving of the second fan 32b can be performed every time of 10 seconds or more and 10 minutes or less. For this reason, the lifespan of the first fan 32a and the second fan 32b can be increased compared to the configuration in which the above switching is performed in a short time.

Here, when the object to be treated 1 is an unfired ceramic element for manufacturing ceramic electronic components such as a multilayer ceramic capacitor, the binder is removed or various reactions are performed through heat treatment. The binder is, for example, carbon. For example, the binder in the ceramic body undergoes thermal decomposition at a temperature around 150℃ and is almost completely removed until the temperature ultimately exceeds 1000℃, but it remains inside even at temperatures exceeding 600℃. It is expected that the remaining components will be quickly removed. For example, it is known that when the temperature in the furnace reaches the maximum temperature while the binder is incompletely removed, structural defects or quality deterioration of the manufactured ceramic electronic components occur. Therefore, it is important to quickly remove the binder.

In general, since the flow of gas is effective in removing the binder, it is desirable to provide gas at a necessary and sufficient flow rate near the object 1 to be treated. By supplying gas at a necessary and sufficient flow rate to the vicinity of the object to be treated 1, the concentration of flying gas containing flying products from the inside of the object to be treated 1 is reduced in the vicinity of the object to be treated 1, and the Removal of flying products from the inside of the treated material 1 is promoted. Conversely, when the gas flow rate is low, it becomes difficult to remove flying products from the inside of the object 1 to be treated.

In the heating furnace 100 in this embodiment, gas is sucked from the heat treatment space 11 to the gas line 31 by the suction blowing portion 30, and the gas sucked into the gas line 31 is sucked into the heat treatment space ( By repeating the blowing to 11), gas at a necessary and sufficient flow rate can be supplied to the vicinity of the object 1 to be treated, without the need to introduce new gas into the gas line 31 from outside the furnace. Since the gas ejected from the gas line 31 into the heat treatment space 11 is a gas having the same composition as the gas in the heat treatment space 11, the object 1 at the position where the gas ejected from the gas line 31 touches It is possible to suppress the occurrence of reaction unevenness between the objects to be treated (1) at positions where the gas ejected from the gas line (31) does not reach.

<Second Embodiment>

Fig. 6 is a cross-sectional view schematically showing the configuration of the heating furnace 100A in the second embodiment. The cutting position in the cross-sectional view shown in FIG. 6 is the same as that in the cross-sectional view shown in FIG. 2. What makes the heating furnace 100A in the second embodiment different from the heating furnace 100 in the first embodiment is the configuration of the suction blowing portion 30.

In the heating furnace 100A in the second embodiment, the suction blowing part 30 has a third fan 32c and a fourth fan 32d in comparison with the configuration of the suction blowing part 30 in the first embodiment. Includes additional Like the first fan 32a and the second fan 32b, the third fan 32c and the fourth fan 32d may have any structure as long as they can blow air.

The third fan 32c is disposed on the first extension portion 31a of the gas line 31 and is a fan for flowing gas in a direction opposite to the flow of gas caused by driving the first fan 32a. As described above, the first fan 32a is arranged so that gas flows from the first extension portion 31a to the connection portion 31c when driven, and therefore, the third fan 32c allows gas to flow to the connection portion 31c when driven. ) is arranged to flow from the first extension portion 31a.

In this embodiment, the first fan 32a and the third fan 32c are arranged so that gas driven by one fan is directed to the other fan. As described above, since the first fan 32a is arranged so that gas flows from the first extension part 31a to the connection part 31c when driven, the third fan 32c is the first fan 32c of the gas line 31. It is provided in the extension part 31a at a position opposite to the first fan 32a and the first cooler 33a. With such an arrangement, gas driven by the first fan 32a flows toward the third fan 32c, and gas driven by the third fan 32c flows toward the first fan 32a.

The fourth fan 32d is disposed in the second extension portion 31b of the gas line 31 and is a fan for flowing gas in a direction opposite to the flow of gas caused by driving the second fan 32b. As described above, the second fan 32b is arranged so that gas flows from the second extension part 31b to the connection part 31c when driven, so the fourth fan 32d is designed to allow gas to flow to the connection part 31c when driven. ) is arranged to flow from the second extension portion 31b.

In this embodiment, the second fan 32b and the fourth fan 32d are arranged so that gas driven by one fan is directed to the other fan. As described above, the second fan 32b is arranged so that gas flows from the second extension part 31b to the connection part 31c when driven, so the fourth fan 32d is connected to the second fan 32d of the gas line 31. It is provided in the extension part 31b at a position opposite to the second cooler 33b in relation to the second fan 32b. With such an arrangement, gas driven by the second fan 32b flows toward the fourth fan 32d, and gas driven by the fourth fan 32d flows toward the second fan 32b. .

In this way, by providing two fans in which the gas flows in opposite directions in each of the first extension portion 31a and the second extension portion 31b of the gas line 31, the pressure loss generated by driving the fan is reduced. It becomes possible to distribute the load to two fans. This makes it possible to downsize the fan 32 provided in the gas line 31.

Here, the operation of suction and ejection of gas through the gas line 31 of the heating furnace 100A in the second embodiment will be described. When the gas in the heat treatment space 11 of the main body 10 is sucked into the first heat exchange passage 41 of the heat exchanger 40, as shown in FIG. 7(a), the first fan 32a and the fourth fan 32a The fan 32d is driven, and the second fan 32b and the third fan 32c are in a non-driving state. At this time, the cooling function of the first cooler 33a disposed in the first extension portion 31a, which serves as the gas suction passage, is turned on, and the cooling function of the first cooler 33a disposed in the second extension portion 31b, which serves as the gas discharge passage, is turned on. The cooling function of the second cooler 33b is turned off.

Conversely, when the gas in the heat treatment space 11 of the main body 10 is sucked into the second heat exchange passage 42 of the heat exchanger 40, as shown in FIG. 7(b), the second fan 32b and The third fan 32c is driven, and the first fan 32a and the fourth fan 32d are in a non-driving state. At this time, the cooling function of the first cooler 33a disposed in the first extension portion 31a, which serves as the gas outlet passage, is turned off, and the cooling function of the first cooler 33a disposed in the second extension portion 31b, which serves as the gas suction passage, is turned off. The cooling function of the second cooler 33b is turned on.

Here, it is also possible to reverse the arrangement of the first fan 32a and the third fan 32c. However, in the case of such an arrangement, the inventor's experiments showed that the pressure loss generated by the fan 32 in the non-driven state increases. Therefore, as in this embodiment, it is preferable that the gas driven by one of the first fan 32a and the third fan 32c is directed toward the other fan.

Likewise, it is possible to reverse the arrangement of the second fan 32b and the fourth fan 32d, but to reduce pressure loss, one of the second fan 32b and the fourth fan 32d is used as in this embodiment. It is preferable that the gas driven by the fan is arranged so that it is directed to the other fan.

<Third Embodiment>

In the heating furnace 100 in the first embodiment and the heating furnace 100A in the second embodiment, the gas line 31 includes a first extension portion 31a and a second extension portion ( 31b) and a connecting portion 31c.

On the other hand, in the heating furnace 100B in the third embodiment, the gas line 31 includes a portion extending in the horizontal direction and a portion extending in the vertical direction.

Meanwhile, here, similarly to the heating furnace 100A in the second embodiment, the suction blowing unit 30 includes not only the first fan 32a and the second fan 32b, but also the third fan 32c and the fourth fan ( It is explained as including 32d). However, the third fan 32c and the fourth fan 32d may be omitted.

Fig. 8 is a cross-sectional view schematically showing the configuration of the heating furnace 100B in the third embodiment. Like FIG. 1 , FIG. 8 shows a cut surface when the heating furnace 100B is cut from a plane perpendicular to the conveyance direction of the object 1 to be processed. FIG. 9 is a diagram schematically showing the configuration of the heating furnace 100B shown in FIG. 8 when viewed from the direction of arrow Y1.

The gas line 31 in this embodiment has a shape such that the gas line 31 shown in FIG. 6 is folded upward at a position between the first extension part 31a and the second extension part 31b. That is, the gas line 31 in this embodiment also includes the first extension part 31a, the second extension part 31b, and the connection part 31c, but the first extension part 31a and the second extension part 31c The shape of (31b) is different from the gas line 31 shown in FIG. 6.

The first extension portion 31a in this embodiment is connected to the first horizontal portion 31a1, which is a portion extending horizontally toward the outside of the main body 10, and the first horizontal portion 31a1, and is connected to the first horizontal portion 31a1 in the vertical direction. It has a first vertical portion 31a2, which is a portion extending to.

The second extension portion 31b in this embodiment is connected to the second horizontal portion 31b1, which is a portion extending horizontally toward the outside of the main body 10, and the second horizontal portion 31b1, and is connected to the second horizontal portion 31b1 in the vertical direction. It has a second vertical portion 31b2, which is a portion extending to.

The connection portion 31c extends in the horizontal direction and connects the first vertical portion 31a2 of the first extension portion 31a and the second vertical portion 31b2 of the second extension portion 31b.

As shown in FIG. 9, the first cooler 33a, the first fan 32a, and the third fan 32c are the vertically extending portions of the first extension portion 31a of the gas line 31. 1 It is arranged in the vertical part 31a2. The relative arrangement relationship of the first cooler 33a, the first fan 32a, and the third fan 32c is the same as that of the heating furnace 100A in the second embodiment.

The gas sucked from the heat treatment space 11 and flowing through the first extension portion 31a of the gas line 31 is cooled by the first cooler 33a with the cooling function turned on. When the temperature of the gas after cooling is below the dew point, water vapor contained in the gas condenses and adheres to the surface. In the heating furnace 100B in this embodiment, the first cooler 33a is disposed in the first vertical portion 31a2 of the gas line 31, so the condensation water adhering to the surface of the first cooler 33a is It can be dropped. Thereby, it is possible to prevent condensation water from remaining attached to the surface of the first cooler 33a.

As shown in FIG. 9, the second cooler 33b, the second fan 32b, and the fourth fan 32d are the vertically extending portions of the second extension portion 31b of the gas line 31. 2 It is arranged in the vertical part 31b2. The relative arrangement relationship of the second cooler 33b, the second fan 32b, and the fourth fan 32d is the same as that of the heating furnace 100A in the second embodiment.

The gas drawn from the heat treatment space 11 and flowing through the second extension portion 31b of the gas line 31 is cooled by the second cooler 33b with the cooling function turned on. When the temperature of the gas after cooling is below the dew point, water vapor contained in the gas condenses and adheres to the surface. In the heating furnace 100B in this embodiment, the second cooler 33b is disposed in the second vertical portion 31b2 of the gas line 31, so the condensation water adhering to the surface of the second cooler 33b is It can be dropped. Thereby, it is possible to prevent condensation water from remaining attached to the surface of the second cooler 33b.

The heating furnace 100B in this embodiment is disposed vertically below the cooler 33 inside the gas line 31, and further includes a vaporizer 34 for vaporizing water. The vaporizer 34 is a heat sink made of metal, such as aluminum, iron, or copper, or ceramic, and has fins. The surface of the heat sink may be porous. However, the vaporizer 34 can be anything that can vaporize water, and is not limited to a heat sink. In this embodiment, the vaporizer 34 includes a first vaporizer 34a and a second vaporizer 34b.

The first vaporizer 34a is located vertically below the first cooler 33a inside the gas line 31, and is disposed at a portion where the first horizontal portion 31a1 and the first vertical portion 31a2 are connected. The first vaporizer 34a is disposed to vaporize condensation water that forms on the surface of the first cooler 33a and then falls.

The second vaporizer 34b is located vertically below the second cooler 33b inside the gas line 31, and is disposed at a portion where the second horizontal portion 31b1 and the second vertical portion 31b2 are connected. The second vaporizer 34b is disposed to vaporize condensation water that forms on the surface of the second cooler 33b and then falls.

When the fan 32 is controlled to switch the suction and ejection of gas at predetermined times, the condensation water moves to the higher temperature side in the cooler 33 or falls downward along the switched gas flow. The condensation water that falls downward is vaporized in contact with the vaporizer 34, and flows back into the heat treatment space 11 of the main body 10 as water vapor.

In this way, according to the heating furnace 100B in the third embodiment, the gas line 31 includes a portion extending in the horizontal direction and a portion extending in the vertical direction, and the cooler 33 extends in the vertical direction. Since it is placed in the area where the cooler 33 is exposed, condensation water generated on the surface of the cooler 33 can be dropped. Thereby, it is possible to prevent condensation water from remaining attached to the surface of the cooler 33. Additionally, by arranging the cooler 33 in a portion extending in the vertical direction of the gas line 31, it becomes possible to reduce the exclusive area of the facility.

In addition, the heating furnace 100B in the third embodiment is disposed vertically below the cooler 33 inside the gas line 31 and includes a vaporizer 34 for vaporizing water, so the cooler 33 Condensation water that falls from the surface can be quickly vaporized. As a result, condensation water can be quickly refluxed into the heat treatment space 11 without allowing it to remain inside the gas line 31, and the composition of the gas ejected from the gas line 31 into the heat treatment space 11 and the heat treatment space ( 11) The difference in gas composition within the gas can be reduced.

On the other hand, if the condensation water that occurs and falls on the surface of the cooler 33 is vaporized inside the gas line 31, the vaporizer 34 can be omitted.

In addition, the first vertical portion 31a2 and the second vertical portion 31b2 do not necessarily need to extend in the vertical direction, and may be inclined with respect to the vertical direction. For example, the angle between the horizontal plane and the first vertical portion 31a2 and the angle between the horizontal plane and the second vertical portion 31b2 may be 60°.

<Fourth Embodiment>

In the heating furnace 100 in the first embodiment, gas is ejected from the heat exchanger 40 into the heat treatment space 11 in the horizontal direction. For this reason, the heat exchanger 40 is provided at a height as close as possible to the driving roller 13 on which the plate 2 is mounted so that the gas is ejected toward the plurality of objects 1 on the plate 2. It is desirable to be

However, although omitted in FIG. 1, a driving part such as a motor for driving the driving roller 13 is provided on the first side wall 10a of the main body 10 through which the gas line 31 passes. For this reason, if the heat exchanger 40 is placed at a height as close as possible to the driving roller 13, there is a possibility that the driving part of the driving roller 13 and the gas line 31 may interfere, so it is necessary to design need.

For this reason, in the heating furnace 100C in the fourth embodiment, the heat exchanger 40 is provided at a position away from the driving portion of the driving roller 13.

Fig. 10 is a cross-sectional view schematically showing the configuration of the heating furnace 100C in the fourth embodiment. Like FIG. 1 , FIG. 10 shows a cut surface when the heating furnace 100C is cut from a plane perpendicular to the conveyance direction of the to-be-processed object 1.

Compared to the heating furnace 100 in the first embodiment, the heat exchanger 40 in this embodiment is located at a higher position with respect to the driving roller 13, that is, at right angles to the conveyance surface of the driving roller 13. It is provided at a position away from the driving roller 13 in the height direction. With such an arrangement, interference between the driving part of the driving roller 13 and the gas line 31 can be suppressed.

In this embodiment, with respect to the surface on which the object to be treated (1) is mounted in the heat treatment space 11, a unit normal vector extending toward the side on which the object to be treated (1) is mounted, and a unit normal vector extending from the heat exchanger 40 to the heat treatment space 11 ) The heat exchanger 40 is arranged so that the inner product of the unit vector along the direction of flow of the gas ejected is negative. This point will be explained using FIG. 11.

Meanwhile, gas is ejected from the heat exchanger 40 along the direction in which the first heat exchange flow path 41 and the second heat exchange flow path 42 extend toward the tip, so that it flows from the heat exchanger 40 into the heat treatment space 11. The unit vector along the direction of movement of the ejected gas means the unit vector along the direction in which the first heat exchange flow path 41 and the second heat exchange flow path 42 extend toward the tip.

Figure 11 shows the unit vector (v) along the direction of flow of the gas ejected from the heat exchanger 40 into the heat treatment space 11 and the mounting surface 2a of the plate 2 on which the object 1 is mounted. This is a diagram showing the relationship between the unit normal vector (n) extending toward the side where the object to be processed (1) is mounted. The dot product (v·n) of the unit vector (v) and the unit normal vector (n) is negative. That is, the directions of the first heat exchange passage 41 and the second heat exchange passage 42 of the heat exchanger 40 are adjusted so that the gas is ejected diagonally downward from the heat exchanger 40.

According to the heating furnace 100C in the fourth embodiment, interference between the driving part of the driving roller 13 and the gas line 31 can be suppressed. In addition, since gas is injected from diagonally upwards to a plurality of objects 1 to be processed on the plate 2 within the heat treatment space 11, it becomes possible to inject gas to more objects 1 to be processed. As a result, the reaction to a larger number of objects 1 can be promoted, and the unevenness of the reaction for each object 1 can be further suppressed.

<Fifth Embodiment>

Fig. 12 is a cross-sectional view schematically showing the configuration of the heating furnace 100D in the fifth embodiment. The cutting position in the cross-sectional view shown in FIG. 12 is the same as that in the cross-sectional view shown in FIG. 2.

The heating furnace 100D in the fifth embodiment further includes a rotation speed measuring unit 50 compared to the configuration of the heating furnace 100 in the first embodiment. The rotation speed measuring unit 50 measures the rotation speed of the fan 32 in a non-driving state when one of the first fan 32a and the second fan 32b is in a driving state and the other is in a non-driving state. .

In the configuration in which the heat exchanger 40 is provided, the pressure loss in the gas line 31 is smaller than in the configuration in which a heat storage body for repeatedly storing and dissipating heat is provided, so the fan 32 disposed in the gas line 31 is relatively low. A fan with positive pressure characteristics can be used. When the fan 32, which has low static pressure characteristics, is in a non-driven state, it rotates with the gas flowing through the gas line 31 at a rotational speed according to the wind volume of the gas flowing through the gas line 31. For this reason, by measuring the rotation speed of the fan 32 in the non-driven state with the rotation speed measuring unit 50, it is possible to determine the wind volume of the gas flowing through the gas line 31.

13(a) and 13(b) are diagrams showing the relationship between the rotation speed of the fan 32 in a driven state and the rotation speed of the fan 32 in a non-driving state. The fan 32 in the driven state is one of the first fan 32a and the second fan 32b, and the fan 32 in the non-driving state is the other fan. Figure 13(a) shows the number of revolutions when the fan 32 is driven by PWM control with a duty ratio of 60%, and Figure 13(b) shows the number of revolutions when the duty ratio is 70%. It is showing. In FIG. 13, PCnt1 is the rotation speed of the first fan 32a, and PCnt2 is the rotation speed of the second fan 32b.

As shown in FIGS. 13(a) and 13(b), the rotation speed of the fan 32 in the non-driving state changes as the rotation speed of the fan 32 in the driven state increases or decreases. The temperature of the gas flowing through the gas line 31 is almost constant at about 30°C or higher and 50°C or lower, and the rotational speed of the non-driven fan 32 measured by the rotational speed measuring unit 50 is the rate of rotation of the fan 32 flowing through the gas line 31. It depends on the amount of gas.

Here, when the gas temperature in the heat treatment space 11 is changed, the gas flowing through the first heat exchange passage 41 and the second heat exchange passage 42 of the heat exchanger 40 increases as the temperature of the gas in the heat treatment space 11 increases. The temperature distribution increases and the pressure loss changes. In this case, even if the rotation speed of the fan 32 in the driven state is constant, the air volume of the gas flowing through the gas line 31 changes. For this reason, the wind volume of the gas flowing through the gas line 31 cannot be determined with high precision from the rotation speed of the fan 32 in the driven state.

However, in the heating furnace 100D in this embodiment, the rotation speed of the fan 32 in a non-driven state is measured by the rotation speed measurement unit 50, so that the wind volume of the gas flowing through the gas line 31 can be determined with high precision. there is. In addition, in order to determine the amount of gas flowing through the gas line 31, the fan 32 provided to flow gas into the gas line 31 can be used, so a separate device for measuring the amount of air is used. There is no need to prepare. As a result, the configuration of the heating furnace 100D that can determine the amount of gas flowing through the gas line 31 can be simplified.

On the other hand, it is also possible to set the heating furnace 100A in the second embodiment to a configuration in which the rotation speed measuring unit 50 is provided. In that case, the rotation speed measuring unit 50 has one set of the first fan 32a and the fourth fan 32d and the second fan 32b and the third fan 32c in the driving state. The rotation speed of at least one fan 32 of the set of fans 32 in the non-driving state is measured when the other set is in a non-driving state. In this case as well, the wind volume of the gas flowing through the gas line 31 can be determined with high precision based on the rotation speed of the fan 32 in the non-driven state measured by the rotation speed measuring unit 50.

<Sixth Embodiment>

Fig. 14 is a cross-sectional view schematically showing the configuration of the heating furnace 100E in the sixth embodiment. The cutting position in the cross-sectional view shown in FIG. 14 is the same as that in the cross-sectional view shown in FIG. 2. The heating furnace 100E in the sixth embodiment includes a rotation speed measuring unit 50 like the heating furnace 100D in the fifth embodiment, and is characterized by control by the control unit 35, which will be described later.

As shown in Fig. 14, the suction blowing unit 30 includes a control unit 35 for controlling the driving of the first fan 32a and the second fan 32b. In this embodiment, the control unit 35 controls the driving of the fan 32 in the driven state so that the rotation speed measured by the rotation speed measuring unit 50 matches the reference rotation speed. The standard rotation speed is set in advance to, for example, set the airflow rate of the gas flowing through the gas line 31 to a desired airflow rate. The control unit 35 matches the rotation speed measured by the rotation speed measurement unit 50 with the reference rotation speed, for example, through feedback control. The control unit 35 controls the operation of the fan 32 in the driven state so that the rotation speed measured by the rotation speed measuring unit 50 matches the reference rotation speed, thereby preventing foreign matter from attaching to the inside of the gas line 31. Even when the internal state of the gas line 31 changes, it is possible to control the air volume of the gas flowing through the gas line 31 to be the desired air volume.

FIG. 15 is a diagram showing the rotation speed, etc. when the control unit 35 controls the driving of the fan 32 in the driven state so that the rotation speed measured by the rotation speed measuring unit 50 matches the reference rotation speed. In Figure 15, PWM1 is the output signal of PWM control for controlling the fan 32 in the driving state in the first control state, iPCnt1 is the number of rotations of the fan 32 in the driving state in the first control state, and PWM2 is the output signal of PWM control for controlling the fan 32 in the driving state in the second control state, and iPCnt2 is the number of rotations of the fan 32 in the driving state in the second control state. In the first control state, the first fan 32a is in a driving state and the second fan 32b is in a non-driving state. In the second control state, the first fan 32a is in a non-driving state and the second fan 32b is in a driving state.

In the first control state and the second control state, the output of the PWM control of the fan 32 in the driven state was controlled so that the rotation speed of the fan 32 in the non-driven state measured by the rotation speed measuring unit 50 was 800 rpm. . As a result, as shown in FIG. 15, the rotation speed of the fan 32 in the non-driven state could be controlled to be almost constant at 800 rpm.

Meanwhile, in the above-described control example, the rotation speed of the fan 32 in the non-driving state was controlled to be 800 rpm, but the PWM control of the fan 32 in the driving state was greater than the wind speed at which the fan 32 in the non-driving state rotated stably. If the duty ratio is within 100%, it is possible to control the number of rotations at an arbitrary number.

On the other hand, even if the rotation speed measuring unit 50 is provided for the heating furnace 100A in the second embodiment, the same control can be performed. That is, the control unit 35 may control the driving of the fan 32 in the driven state so that the rotation speed measured by the rotation speed measuring unit 50 matches the reference rotation speed.

<Embodiment 7>

The heating furnace 100 in the first embodiment to the heating furnace 100E in the sixth embodiment each include one suction blowing portion 30. On the other hand, in the heating furnace 100F in the seventh embodiment, a plurality of suction blowing parts 30 are provided. By providing a plurality of suction blowing portions 30, it becomes possible to spray more gas to the object 1 to be treated. As a result, the reaction to a larger number of objects 1 can be promoted, and the unevenness of the reaction for each object 1 can be further suppressed.

Fig. 16 is a cross-sectional view schematically showing the configuration of the heating furnace 100F in the seventh embodiment. The cutting position in the cross-sectional view shown in FIG. 16 is the same as that in the cross-sectional view shown in FIG. 2.

In the example shown in FIG. 16, four suction jet portions 30 are provided. Specifically, two suction jet parts 30 are provided on the first side wall 10a of the main body 10, and two suction jet parts 30 are provided on the second side wall 10b facing the first side wall 10a. Part 30 is provided. However, the number of suction jet parts 30 is not limited to four, and all suction jet parts 30 may be provided on one side wall.

The present invention is not limited to the above embodiments, and various applications and modifications can be made within the scope of the present invention. For example, the characteristic configurations of the heating furnaces in each embodiment can be combined appropriately.

The shape of the main body 10 is not limited to the shape described in the above-described embodiment. For example, the shape of the main body 10 may be approximately spherical.

In each of the above-described embodiments, the suction blowing unit 30 includes a fan 32, and the fan 32 is driven to suction gas from the heat treatment space 11 to the gas line 31 and to the gas line ( The explanation was given by assuming that gas is ejected from 31) into the heat treatment space 11. However, the power source for suction and ejection of gas is not limited to the fan 32. For example, a piston may be placed in the gas line 31, and a movable part may reciprocate inside the piston cylinder to suction and eject gas.

The heating furnace in this application is as follows.

<1>. A main body portion having a heat treatment space for heat treating an object to be treated and including a heating portion disposed in the heat treatment space;

a gas supply unit that supplies gas necessary for heat treatment to the heat treatment space of the main body;

a suction blowing portion having a gas line connected to the heat treatment space of the main body portion, and repeatedly sucking gas from the heat treatment space into the gas line and blowing the gas sucked into the gas line into the heat treatment space; ,

It is provided inside the gas line and includes a recuperative heat exchanger for heat exchange between gas sucked from the heat treatment space and gas ejected into the heat treatment space,

A heating furnace, characterized in that the gas line is configured so that gas is not supplied from an outside source other than the heat treatment space.

<2>. According to paragraph 1,

The heating furnace, wherein the heat exchanger is provided in a portion of the gas line located inside the main body.

<3>. According to paragraph 2,

A heating furnace, characterized in that the heat exchanger is provided in an area penetrating the main body part of the interior of the gas line.

<4>. According to any one of claims 1 to 3,

The heat exchanger has a first heat exchange passage through which one of the gas sucked from the heat treatment space and the gas ejected into the heat treatment space flows, and a second heat exchange passage through which the other gas flows,

The gas line includes a first extension portion connected to the first heat exchange passage of the heat exchanger, a second extension portion connected to the second heat exchange passage of the heat exchanger, and the first extension portion and the second extension. A heating furnace characterized by having a connection part for connecting the parts.

<5>. According to clause 4,

A heating furnace, wherein a portion of a partition dividing the first heat exchange flow path and the second heat exchange flow path of the heat exchanger is exposed within the heat treatment space.

<6>. According to clause 4 or 5,

The suction blowing unit includes a first fan disposed in the first extension portion, and a second fan disposed in the second extension portion for flowing gas in a direction opposite to the flow of gas caused by driving the first fan. A heating furnace comprising:

<7>. According to clause 6,

The suction blowing unit includes a third fan disposed in the first extension portion and configured to flow gas in a direction opposite to the flow of gas caused by driving the first fan, and a third fan disposed in the second extension portion and configured to allow the second fan to flow. A heating furnace further comprising a fourth fan for flowing gas in a direction opposite to the flow of gas driven by .

<8>. In clause 7,

The first fan and the third fan are arranged so that gas driven by one fan is directed toward the other fan,

The second fan and the fourth fan are arranged so that gas driven by one fan is directed toward the other fan.

<9>. According to any one of claims 6 to 8,

It further includes a cooler disposed in the gas line and configured to cool the gas drawn from the heat treatment space and passing through the heat exchanger,

The cooler includes a first cooler disposed at a position upstream of the first fan when the first fan of the first extension part is driven, and the second cooler when the second fan of the second extension part is driven. A heating furnace comprising a second cooler disposed at a position upstream of the fan.

<10>. According to clause 9,

The cooling function of the first cooler and the second cooler is disposed in an extension part of the gas line that serves as a suction flow path for gas, and serves as an ejection flow path for gas. A heating furnace configured to turn off the cooling function of the cooler disposed in the extension portion.

<11>. According to claim 9 or 10,

The cooler is a heating furnace characterized in that it has a structure in which gas passages through which gas flows and refrigerant passages through which refrigerant flows are alternately stacked.

<12>. According to any one of claims 9 to 11,

The gas line includes a portion extending in a horizontal direction and a portion extending in a vertical direction,

A heating furnace, wherein the cooler is disposed in a portion extending in the vertical direction.

<13>. According to clause 12,

A heating furnace disposed vertically below the cooler inside the gas line and further comprising a vaporizer for vaporizing water.

<14>. According to any one of claims 4 to 13,

The suction blowing unit suctions gas from the heat treatment space to the first extension portion of the gas line and suctions gas from the heat treatment space to the second extension portion of the gas line every time of 10 seconds or more and 10 minutes or less. A heating furnace characterized by conversion.

<15>. According to claim 6, 9, 10, 11, 12 or 13,

A heating furnace, characterized in that it further comprises a rotation speed measuring unit that measures the rotation speed of the fan in a non-driving state when one of the first fan and the second fan is in a driving state and the other is in a non-driving state.

<16>. According to paragraph 7 or 8,

When one set of the sets of the first fan and the fourth fan and the set of the second fan and the third fan is in the driving state and the other set is in the non-driving state, the fan in the non-driving state A heating furnace, characterized in that it further includes a rotation speed measuring unit that measures the rotation speed of at least one fan in the set.

<17>. According to claim 15 or 16,

The suction blowing unit includes a control unit for controlling the operation of the first fan and the second fan,

The heating furnace, wherein the control unit controls the operation of the fan in a driven state so that the rotation speed measured by the rotation speed measuring unit matches the reference rotation speed.

<18>. According to any one of claims 1 to 17,

With respect to the surface on which the object to be treated is mounted in the heat treatment space, the inner product of a unit normal vector extending toward the side on which the object to be treated is mounted and a unit vector along the direction of flow of the gas ejected from the heat exchanger into the heat treatment space A heating furnace, characterized in that the heat exchanger is arranged to achieve this sound.

<19>. According to any one of claims 1 to 18,

A heating furnace, characterized in that a plurality of suction blowing parts are provided.

1: Object to be treated
10: main body
11: Heat treatment space
12: heating unit
13: Drive roller
14: Gas supply port
15: gas outlet
20: Gas supply unit
30: suction spout part
31: gas line
31a: first extension
31a1: first horizontal portion
31a2: first vertical part
31b: second extension
31b1: second horizontal portion
31b2: second vertical part
31c: connection part
32a: first fan
32b: second fan
32c: third fan
32d: 4th fan
33a: first cooler
33b: second cooler
34a: first vaporizer
34b: second vaporizer
35: control unit
40: heat exchanger
41: First heat exchange flow path
42: Second heat exchange flow path
43: Bulkhead
50: Rotation speed measuring unit
100, 100A, 100B, 100C, 100D, 100E, 100F: Heating furnace
F1: Gas flow path
F2: Refrigerant flow path

Claims (19)

A main body portion having a heat treatment space for performing heat treatment on an object to be treated and including a heating portion disposed in the heat treatment space;
a gas supply unit that supplies gas necessary for heat treatment to the heat treatment space of the main body;
a suction blowing portion having a gas line connected to the heat treatment space of the main body portion, and repeatedly sucking gas from the heat treatment space into the gas line and blowing the gas sucked into the gas line into the heat treatment space; ,
It is provided inside the gas line and includes a recuperative heat exchanger for heat exchange between gas sucked from the heat treatment space and gas ejected into the heat treatment space,
A heating furnace, characterized in that the gas line is configured so that gas is not supplied from an outside source other than the heat treatment space. According to paragraph 1,
The heating furnace, wherein the heat exchanger is provided in a portion of the gas line located inside the main body. According to paragraph 2,
A heating furnace, characterized in that the heat exchanger is provided in an area penetrating the main body part of the interior of the gas line. According to paragraph 1,
The heat exchanger has a first heat exchange passage through which one of the gas sucked from the heat treatment space and the gas ejected into the heat treatment space flows, and a second heat exchange passage through which the other gas flows,
The gas line includes a first extension portion connected to the first heat exchange passage of the heat exchanger, a second extension portion connected to the second heat exchange passage of the heat exchanger, and the first extension portion and the second extension. A heating furnace characterized by having a connection part for connecting the parts. According to clause 4,
A heating furnace, wherein a portion of a partition dividing the first heat exchange flow path and the second heat exchange flow path of the heat exchanger is exposed within the heat treatment space. According to clause 4,
The suction blowing unit includes a first fan disposed in the first extension portion, and a second fan disposed in the second extension portion for flowing gas in a direction opposite to the flow of gas caused by driving the first fan. A heating furnace comprising: According to clause 6,
The suction blowing unit includes a third fan disposed in the first extension portion and configured to flow gas in a direction opposite to the flow of gas caused by driving the first fan, and a third fan disposed in the second extension portion and configured to allow the second fan to flow. A heating furnace further comprising a fourth fan for flowing gas in a direction opposite to the flow of gas driven by . In clause 7,
The first fan and the third fan are arranged so that gas driven by one fan is directed toward the other fan,
The second fan and the fourth fan are arranged so that gas driven by one fan is directed toward the other fan. According to clause 6,
It further includes a cooler disposed in the gas line and configured to cool the gas drawn from the heat treatment space and passing through the heat exchanger,
The cooler includes a first cooler disposed at a position upstream of the first fan when the first fan of the first extension part is driven, and the second cooler when the second fan of the second extension part is driven. A heating furnace comprising a second cooler disposed at a position upstream of the fan. According to clause 9,
The first cooler and the second cooler are disposed in an extension part of the gas line that serves as a gas suction flow path, and the cooling function of the cooler is turned on, and the extension part serves as a gas ejection flow path. A heating furnace configured to turn off the cooling function of the cooler disposed in the extension portion. According to clause 9,
The cooler is a heating furnace characterized in that it has a structure in which gas passages through which gas flows and refrigerant passages through which refrigerant flows are alternately stacked. According to clause 9,
The gas line includes a portion extending in a horizontal direction and a portion extending in a vertical direction,
A heating furnace, wherein the cooler is disposed in a portion extending in the vertical direction. According to clause 12,
A heating furnace disposed vertically below the cooler inside the gas line and further comprising a vaporizer for vaporizing water. According to clause 4,
The suction blowing unit suctions gas from the heat treatment space to the first extension portion of the gas line and suctions gas from the heat treatment space to the second extension portion of the gas line every time of 10 seconds or more and 10 minutes or less. A heating furnace characterized by conversion. According to clause 6,
A heating furnace, characterized in that it further comprises a rotation speed measuring unit that measures the rotation speed of the fan in a non-driving state when one of the first fan and the second fan is in a driving state and the other is in a non-driving state. In clause 7,
When one set of the sets of the first fan and the fourth fan and the set of the second fan and the third fan is in the driving state and the other set is in the non-driving state, the fan in the non-driving state A heating furnace further comprising a rotation speed measuring unit that measures the rotation speed of at least one fan in the set. According to clause 15,
The suction blowing unit includes a control unit for controlling the operation of the first fan and the second fan,
The heating furnace, wherein the control unit controls the operation of the fan in a driven state so that the rotation speed measured by the rotation speed measuring unit matches the reference rotation speed. According to paragraph 1,
With respect to the surface on which the object to be treated is mounted in the heat treatment space, the inner product of a unit normal vector extending toward the side on which the object to be treated is mounted and a unit vector along the direction of flow of the gas ejected from the heat exchanger into the heat treatment space A heating furnace, characterized in that the heat exchanger is arranged to achieve this sound. According to any one of claims 1 to 18,
A heating furnace, characterized in that a plurality of suction blowing parts are provided.