JP6909998B2 - Gas phase heating method and vapor phase heating device - Google Patents

Description

The present invention relates to a vapor phase heating method and a vapor phase heating apparatus that heat an object to be heated by utilizing the latent heat of condensation of the vapor of the thermal transfer liquid.

In recent years, in various heat treatment devices in the assembly manufacturing process of various industrial products or home appliances, or in the device manufacturing process of various electronic parts, various batteries, or substrates on which electronic parts are mounted, which are constituent parts of those products. The shape of the object to be treated is complicated. For example, even in a substrate on which electronic components are mounted, solder is applied in a state where the holding force is weak as the electronic components are placed by applying solder paste not only to the flat substrate but also to the part of the three-dimensional substrate other than the horizontal plane. Heat treatment is performed to melt and join the paste. In addition, the heat capacity of the object to be heated tends to increase due to the three-dimensional structure. Here, the various heat treatment devices are, for example, a drying furnace, a curing furnace, a reflow furnace used for soldering in a mounting process of electronic components, and the like.

In these heating steps of the object to be heated, if there is a variation in temperature rise at each location of the object to be heated due to non-uniform heating capacity, all parts are desired in order to obtain the desired time required for the heating step. It is necessary to further hold the desired time from the state where the temperature has risen to a temperature, and in order to hold the portion where the temperature rises slowly for the desired time, the portion where the temperature rises quickly is exposed to more heat than necessary. Therefore, in the case of an object to be heated, which is particularly affected by heat, there is a concern that the quality of the object to be heated may be affected. Further, in the case of a heating process using heat transfer due to collision of hot air, when the heat capacity of the object to be heated is large, the collision rate of hot air with the object to be heated is increased in order to obtain a desired rate of temperature rise. The heat transfer coefficient can be increased.

However, for example, when it is necessary to apply a solder paste to a portion of a three-dimensional substrate other than the horizontal surface and heat-treat the electronic components in a state where the holding force is weak, the solder is melted and then cooled. By colliding hot air at high speed before the solidification of the solder is completed, there is a high possibility that the components will peel off from the substrate.

Therefore, as a method of efficiently heating the object to be heated by utilizing the high heat transfer coefficient while avoiding the peeling of parts due to the collision of hot air even for a substrate with a large heat capacity, the latent heat of condensation contained in the vapor of the heat transfer liquid is used. A heating method using a steam heating furnace is known. Since the steam used in such a steam heating furnace has a larger specific gravity than air, the air and steam are relatively easily separated into two phases, but the object to be heated is carried in / out into the steam heating furnace. In addition, since the steam heating furnace is usually provided with an inlet / outlet, the steam easily flows out of the furnace, and the steam of the valuable heat transfer liquid is lost without being recovered.

As a countermeasure for this, the following methods are generally known.

(1) An opening for carrying in and out the object to be heated is provided above the interface where the air in the steam heating furnace and the steam of the heat transfer liquid are separated by the difference in their specific gravities, and is covered from this opening. A method of loading and unloading a heated material into a steam heating furnace.

(2) A double shutter or the like is provided at the entrance / exit of the steam heating furnace for carrying in and out the object to be heated to form a closed space for temporarily shielding the steam heating furnace and the external space, and the object to be heated is provided. A method of separating the steam heating furnace from the external space when carrying in and out.

(3) A method in which a relatively long tunnel is provided at the entrance and exit of a steam heating furnace, and a condenser for condensing the steam of the heat transfer liquid by a cooling unit or the like is attached in the middle of the tunnel to condense and recover the steam flowing out into the tunnel.

However, in the case of the method (1), in order to heat the object to be heated, the object to be heated is lowered to a height at which the object to be heated is immersed in the steam of the thermal transfer liquid with respect to the horizontal plane in which the object to be heated is carried into the steam heating furnace. The mechanism for transporting is complicated due to the need to move to, and the steam of the heat transfer liquid in the steam heating furnace is agitated during the loading of the object to be heated and the descent immersion of the steam into the phase. Air may be mixed with the steam of the heat transfer liquid, and the heating capacity itself due to the latent heat of condensation of the steam of the heat transfer liquid may decrease.

In the case of method (2), especially on the outlet side of the steam heating furnace, heat transfer occurs when the shutter on the steam heating furnace side of the closed space is temporarily opened in order to transfer the object to be heated to the closed space on the outlet side. The liquid vapor is also introduced into the closed space together with the object to be heated, closes the shutter on the steam heating furnace side of the closed space, and temporarily releases the shutter on the external space side of the closed space to carry the object to be heated to the external space. It is not possible to prevent a part of the vapor of the thermal transfer liquid from flowing out to the external space as the object to be heated is carried out to the external space.

In method (3), the vapor of the thermal transfer liquid is cooled once, liquefied, and then recovered, so that the latent heat of vaporization required for heating to vaporize the thermal transfer liquid is cooled and taken away as it is. In addition to a large loss of energy, depending on the cooling temperature of the steam, the saturated vapor pressure of the thermal transfer fluid cannot completely vaporize the vapor of the thermal transition fluid, and a part of the vapor completely flows out into the atmosphere. Cannot be prevented.

For these problems, for example, the method of Patent Document 1 is known. FIG. 10 is an explanatory view of the conventional vapor phase soldering apparatus of Patent Document 1. The configuration disclosed in Patent Document 1 is the following configuration. FIG. 10 is a side view, and the left half of the steam heating furnace 35 is shown in a vertical cross section. The liquid 40 is a heat transfer liquid for generating vapor 31 by heating. The exhaust port 32 is a nozzle for discharging the gas in the steam heating furnace 35 to the outside of the furnace. The doorway 33 is a doorway end that serves as a boundary between the inside and outside of the furnace. The conveyor 34 is a conveyor for carrying the object to be processed into the steam heating furnace 35. The tunnel 36 serves as a passage for carrying in and out the object to be processed, and also serves as a passage for air flow, which will be described later. The tunnel 37 is an extension of the tunnel 36, and serves as a passage for carrying in the object to be heated. The tunnel 38 is located on the boundary between the tunnel 36 and the tunnel 37, is a tunnel that branches from the tunnel 36 and extends diagonally upward from the upper part of the tunnels 26 and 27, and is an air flow passage passing through the tunnel 36. It becomes. The discharge port 39 is a nozzle that discharges this air flow.

As an operation, when the liquid 40 is heated to generate the steam 31, the steam 31 rises to a certain height inside the steam heating furnace 35, and the air-steam interface 41 is formed between the liquid 40 and the upper air phase. can. On the other hand, some steam flows out of the furnace through the entrance 33 and the tunnel 37. Here, if an air flow having a momentum exceeding the momentum of the outflow steam is created in the tunnel 36, this airflow passes through the tunnel 38 and is discharged from the discharge port 39, so that the steam 31 that has flowed out into the tunnel 37 It is pushed back by this air flow and can be prevented from flowing out of the furnace.

In order to create a uniform air flow in the flow direction in the tunnel 36, the length of the tunnel 36 may be three times or more the height of the tunnel. The tunnel 38 extends diagonally upward toward the steam heating furnace 35 in order to guide the air passing through the tunnel 36 to the upper part as smoothly as possible. This is because if a vortex is generated at the boundary between the tunnel 36 and the tunnel 38, the steam in the tunnel 37 is taken in. The reason why the airflow is guided to the upper part is that the steam 31 has a large specific gravity to the air and therefore is collected in the lower part, that is, in the tunnel 37.

In order to contain the steam in the tunnel 37, more preferably, the kinetic energy of the air passing through the tunnel 36 is made larger than the kinetic energy of the steam flowing out from the entrance / exit 33 of the tunnel 37. That is, assuming that the specific gravity of steam to air is α, the average flow velocity of outflow steam is Vl, and the flow velocity of air is V2, it is desirable that V2> V1 × √α holds.

In the tunnel 37, if the pressure at the upper part of the steam heating furnace 35 is made smaller than the pressure inside the tunnel 38 so that the air side and the steam side are equalized at the inlet / outlet 33, the steam blowing pressure becomes smaller. An oblique interface of steam is created, and the amount of steam outflow is significantly reduced.

If both the tunnel 36 and the tunnel 37 are slightly inclined so as to descend toward the steam heating furnace 35, the condensate naturally returns to the steam heating furnace 35, which is convenient.

Japanese Unexamined Patent Publication No. 60-108163

In such a configuration of Patent Document 1, in the case of a device in which the steam heating furnace is composed of only one zone alone, as described above, the steam of the heat transfer liquid is steam-heated by taking in the airflow from the outside and controlling the airflow. The operation of confining in the furnace is possible.

However, when it is necessary to form a more complicated temperature profile, not only one zone but also a steam heating furnace or a heating furnace using a heating means other than the heating method utilizing the latent heat of condensation of steam is connected. The equipment to be used is required, and in that case, a special mechanism for preventing the outflow of steam is required in a narrow space between a plurality of adjacent steam heating furnaces or the heating furnaces, and the total length is long in a continuous furnace. It has a problem of becoming.

The present invention solves the above-mentioned conventional problems, and is continuously configured by connecting a plurality of heating furnaces including a steam heating furnace that heats an object to be heated by utilizing the latent heat of condensation of the steam of the heat transfer liquid. In the gas phase heating method and equipment of the furnace, a special mechanism for preventing the outflow of steam is not required, and the pressure difference of the steam of the heat transfer liquid between the adjacent steam heating furnace and the heating furnace can be reduced. It is an object of the present invention to provide a vapor-phase heating method and a vapor-phase heating apparatus capable of performing the same.

In order to achieve the above object, the vapor phase heating method according to one aspect of the present invention is:
At least one steam heating furnace that heats the object to be heated by utilizing the latent heat of condensation of the steam of the heat transfer liquid, and at least one heating furnace or another steam heating furnace arranged in communication with the one steam heating furnace. in a continuous furnace and a furnace, a gas-phase heating method of heating the object to be heated,
Said heating furnace or said other steam heating furnace, via the communication unit always that pass communicating between said one steam heating furnace adjacent to the one steam heating furnace, the heating furnace the object to be heated Or, carry it into the other steam heating furnace or the one steam heating furnace, and carry it into the steam heating furnace.
In the steam cooling unit provided above the communicating portion of said one steam heating furnace, together with liquefied by cooling the vapor of the heat transfer liquid within said one steam heating furnace, wherein the pressure adjustment section By keeping the pressure in one steam heating furnace equal to the pressure in the heating furnace or the other steam heating furnace, the pressure in the continuous furnace is equalized and the carried-in object to be heated is heated. do.

In addition, in order to achieve the above object, the gas phase heating device according to another aspect of the present invention may be used.
At least one steam heating furnace that heats the object to be heated by utilizing the latent heat of condensation of the steam of the heat transfer liquid, and at least one heating furnace or another steam heating furnace arranged in communication with the one steam heating furnace. It is a gas phase heating device that is composed of a continuous furnace including a furnace and heats the object to be heated.
The one steam heating furnace
A communication unit that always communicates with the adjacent heating furnace or the other steam heating furnace so that the object to be heated can be carried in and out.
A steam cooling unit, which is arranged above the communication unit and cools and liquefies the steam of the heat transfer liquid in the one steam heating furnace.
And a pressure adjustment unit for adjusting the internal pressure of the steam heating furnace so as to hold the equivalent to the pressure in the furnace or other steam heating furnace.

As described above, according to the vapor phase heating method and the vapor phase heating apparatus according to the above aspect of the present invention, even in a continuous furnace in which a plurality of heating furnaces are connected at narrow intervals, a heat transfer liquid is used. The pressure inside the steam heating furnace, which heats the object to be heated by utilizing the latent heat of condensation of the steam, can be maintained at a constant pressure by the pressure adjusting unit. As a result, a special mechanism for preventing the outflow of steam is not required, and the movement of steam between the adjacent steam heating furnace and the heating furnace at the communication part of the transport part of the object to be heated is reduced to reduce the heat transfer. The pressure difference between the vapors of the liquid can be reduced.

Explanatory drawing of continuous furnace including gas-phase heating apparatus in embodiment of this invention Explanatory drawing of vapor-phase heating apparatus in embodiment of this invention Detailed explanatory view of the gas phase heating apparatus according to the embodiment of the present invention. Detailed explanatory view of the gas phase heating apparatus according to the embodiment of the present invention. Detailed explanatory view of the gas phase heating apparatus according to the embodiment of the present invention. Detailed explanatory view of the gas phase heating device of another aspect in the embodiment of the present invention. Explanatory drawing of vapor-phase heating apparatus in embodiment of this invention Explanatory drawing of temperature profile and gas phase heating device in the configuration of continuous transport of the object to be heated Explanatory drawing of temperature profile and gas phase heating device in the configuration of split transfer of the object to be heated Explanatory drawing seen from the direction which is 90 degrees different from the transport direction of the object to be heated of the steam heating furnace of the vapor phase heating apparatus in another embodiment of this invention. Explanatory drawing showing a conventional gas phase heating apparatus

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 is an explanatory diagram of a gas phase heating device according to an embodiment of the present invention. The gas phase heating device 50 is a continuous furnace including at least one steam heating furnace 4. The steam heating furnace 4 includes a communication unit 6 and an object cooling unit 8 to be heated.

As an example, the gas phase heating device 50 is configured by connecting a plurality of heating furnaces 5 in series. The gas phase heating device 50 includes at least one steam heating furnace 4 that heats the object to be heated 1 by giving latent heat of condensation of the steam 3 of the heat transfer liquid 2, and also of the heat transfer liquid 2 by hot air circulation or the like. A heating furnace 5 or the like by the heating means of the object 1 to be heated that does not use the steam 3 is connected. In the case of FIG. 1, the vapor phase heating device 50 sequentially includes the inlet portion 7, the steam heating furnace 4A, the heating furnace 5, the steam heating furnace 4, and the steam heating furnace 4 in the transport direction of the object to be heated 1. It is a continuous furnace provided with a heated object cooling unit 8 on the outlet side. The object to be heated 1 is transported by the transport unit 9 via the communication unit 6. An example of a thermal transfer liquid is an electrically insulating fluorine-based inert liquid.

FIG. 2 is a detailed explanatory view of the gas phase heating device 50 according to the embodiment of the present invention. In the case of FIG. 2, before and after the steam heating furnace 4 in the carry-out direction (on the left side and the right side in FIG. 2), a heating furnace 5 by a heating means that does not use the steam 3 of the heat transfer liquid 2 by hot air circulation or the like is placed in the carry-out direction. It is arranged in communication with each other before and after.

The steam heating furnace 4 has a bathtub 4x that holds a predetermined amount of the heat transfer liquid 2 near the bottom surface. The bathtub 4x is provided with a heating source 10 such as an electric heater for heating the heat transfer liquid 2 to be held into steam 3.

The heating source 10 may be a throw-in type used by throwing the heat transfer liquid 2 into the bathtub 4x, or may be configured to heat the entire wall surface of the bathtub 4x or a part of the wall surface of the bathtub 4x. The heating capacity of the heating source 10 is such that at least the steam 3 of the heat transfer liquid 2 is cooled and liquefied by the inner wall surface of the steam heating furnace 4 or the transport portion 9 or the like to liquefy the heat transfer liquid 2. In addition, the heating capacity required to heat the object 1 to be heated and the heating capacity imparted to the heat transfer liquid 2 to form the amount of steam 3 required to heat the object to be heated 1 at a desired heating rate. A heating capacity larger than the total amount is required. As an example, the transport unit 9 is composed of a belt conveyor capable of transporting the object to be heated 1 through a continuous furnace.

The steam heating furnace 4 has a communication portion 6 that communicates with a heating furnace 5 arranged upstream or downstream of the steam heating furnace 4. The communication portion 6 is an opening required for carrying the object to be heated 1 from the upstream heating furnace 5 to the steam heating furnace 4 or carrying out the object to be heated 1 from the steam heating furnace 4 to the heating furnace 5 downstream. Therefore, it functions as an example of a carry-in / out section for passing the object 1 to be heated by the transport section 9 for carrying in / out the object 1 to be heated.

Here, in the case of such a configuration, normally, when the pressure in the steam heating furnace 4 becomes high due to volume expansion due to vaporization of the heat transfer liquid 2, the pressure in the heating furnace 5 before and after communicating through the communication portion 6 increases. When the pressure is lower than the atmospheric pressure, or at least the pressure in the steam heating furnace 4, the steam 3 in the steam heating furnace 4 flows out to the heating furnace 5 side through the communication portion 6. As a result, the steam 3 of the heat transfer liquid 2 flows out of the continuous furnace via the heating furnace 5 and the like. In order to avoid this, it is necessary to make the pressure in the heating furnace 5 equal to the pressure in the steam heating furnace 4, or conversely, make the pressure in the steam heating furnace 4 equal to the pressure in the heating furnace 5.

Therefore, a vapor phase heating method for making the pressure in the steam heating furnace 4 equal to the pressure in the adjacent heating furnaces 5 before and after will be described.

FIG. 3 is a cross-sectional view of the steam heating furnace 4 of FIG. 2 along lines III-III.

The first cooling communication unit 11 arranged above the transport unit 9 to which the object to be heated 1 is transported communicates with one end of the steam cooling unit 12, and the other end of the steam cooling unit 12 is the first. 2 Communicates with the pressure adjusting unit 19 via the cooling communication unit 13. The steam cooling unit 12 is configured so that a passage is formed such that the steam 3 entering from one end meanders toward the other end, and while the steam 3 meanders, heat is absorbed by the wall surface of the passage and cooled. The pressure adjusting unit 19 is composed of a cylinder and a piston as an example. In that case, the outer shell of the pressure adjusting unit 19 or the container 19a is a cylinder, and the piston acts as a moving body 18. The internal space of the pressure adjusting unit 19 is divided into two by the moving body 18. One of the first spaces 14A divided by the moving body 18 can communicate with the external space via the on-off valve 15 and the pressure adjusting unit 16. Further, in the internal space of the pressure adjusting unit 19, the other second space 14B divided into two by the moving body 18 communicates with the external space via the external space communicating portion 20 of the pressure adjusting unit 19.

The moving body 18 can be fixed to a predetermined position of the cylinder 19a by the moving body fixing portion 17 as needed.

Further, when the fixing of the moving body fixing portion 17 is released, the moving body 18 keeps the first space 14A and the second space 14B shielded along the wall surface of the cylinder 19a in the pressure adjusting portion 19. It is possible to move.

Here, the steam cooling unit 12 liquids all the vapors 3 introduced from the first cooling communication unit 11 among the vapors 3 of the heat transfer liquid 2 which is heated by the heating source 10 and vaporized by the latent heat of vaporization. It has a cooling capacity that can change its phase. The heat transfer liquid 2 cooled and liquefied by the steam cooling unit 12 can be reused by collecting it in the recovery unit 21 via a pipe 23 connected to the bottom surface of the steam cooling unit 12. Become. The heat transfer liquid 2 recovered by the recovery unit 21 is returned to the bathtub 4x of the heat transfer liquid 2 in the steam heating furnace 4 by the pump 22 as needed.

Before the object 1 to be heated is carried into the steam heating furnace 4, as a preparation for heating, the heat transfer liquid 2 is heated by the heating source 10 in the steam heating furnace 4, and the heat transfer liquid 2 is continuously steamed. The latent heat of vaporization to make it 3 is applied to form and increase the vapor phase of steam 3. At the beginning of the operation of the heating source 10, the temperature of each part in the steam heating furnace 4 is lower than the boiling point of the heat transfer liquid 2, so that the steam 3 of the heat transfer liquid 2 in contact with each part in the steam heating furnace 4 , Latent heat of condensation is applied to each place where the steam 3 comes into contact to liquefy the heat transfer liquid 2, and the liquefied heat transfer liquid 2 falls to the lower part of the steam heating furnace 4 by its own weight and is recovered in the bath of the heat transfer liquid 2. By repeating this process, each part in the steam heating furnace 4 is gradually heated by receiving the latent heat of condensation of the heat transfer liquid 2, and sequentially reaches the boiling point temperature of the heat transfer liquid 2. As a result, the interface between the atmospheric phase in the steam heating furnace 4 and the steam phase of the steam 3 of the heat transfer liquid 2 gradually moves upward and reaches the height of the communication portion 6.

Here, there is no problem when the specific gravity of the steam 3 of the heat transfer liquid 2 is lighter than that of the gas in the furnace, for example, the atmosphere, but when it is heavier than the atmosphere, the steam naturally flows out from the communication portion 6 due to its own weight. .. Therefore, with the on-off valve 15 released in advance, the pressure adjusting unit 16 adjusts the pressure in the steam heating furnace 4 so as to be equal to the atmospheric pressure or the pressure in the adjacent heating furnace 5. As a result, the steam 3 of the heat transfer liquid 2 exceeds the transport section 9 and reaches the height of the first cooling communication section 11 in the steam heating furnace 4.

FIG. 4 is a cross-sectional view taken along the line III-III of the steam heating furnace 4 of FIG. 2 as in FIG. 3, and is a preparation for carrying the object to be heated 1 into the continuous furnace and the steam heating furnace 4 to start production. Indicates the completed state.

The steam 3 of the heat transfer liquid 2 reaches the first cooling communication section 11 between the steam heating furnace 4 and the steam cooling section 12, and the steam cooling section 12 is made a negative pressure by the pressure adjusting section 16, so that the steam 3 becomes negative. , It is introduced into the steam cooling unit 12 via the first cooling communication unit 11, and the steam 3 of the heat transfer liquid 2 is cooled by the steam cooling unit 12 and liquefied. The steam cooling unit 12 is the steam 3 of the heat transfer liquid 2 that is heated by the heating source 10 and vaporized by the latent heat of vaporization as described above, and is introduced from the first cooling communication unit 11. Has the ability to change the phase of all to liquid. Therefore, the steam 3 is completely liquefied by the steam cooling unit 12 before reaching the second cooling communication unit 13. Here, the preparation for carrying in the object to be heated 1 is completed, the on-off valve 15 communicating with the pressure adjusting unit 16 is closed, and the first space 14A of the pressure adjusting unit 19 maintains the communication with the steam cooling unit 12. The external space is in a state of being shielded by the on-off valve 15 and the moving body 18.

Next, FIG. 5 is a cross-sectional view taken along the line III-III of the steam heating furnace 4 of FIG. 2, similarly to FIGS. 3 and 4. The fixing of the moving body 18 of the moving body fixing portion 17 is released in order to cope with a change in the amount of steam 3 due to the carry-in of the heated object 1 or the like due to the completion of the preparation for charging the object 1 to be heated. do.

This release may be performed manually or automatically.

In the case of manual operation, since the "negative pressure" controlled by the pressure adjusting unit 16 is constant at a predetermined value, it is difficult to detect any change point as a trigger for releasing the fixation. Manually unlock after the user decides that the preparation is complete.

On the other hand, as an example of the case of automatic operation, the following configuration can be exemplified. At the initial stage of starting up the device, the pressure adjusting unit 16 continues to release the atmosphere in the first space 14A through the on-off valve 15 in order to make the inside of the first space 14A a predetermined negative pressure. Here, the ready state is a state in which the amount of steam sucked from the steam heating furnace 4 and the amount of liquefied by the steam cooling unit 12 are balanced and the volume of the space without the steam 3 does not fluctuate, that is, the movement. When releasing the fixation of the body fixing portion 17, the moving body 18 needs to be immobile, and at this time, the amount of gas passing through the pressure adjusting portion 16 becomes zero. If the pressure adjusting unit 16 or the like can detect the state in which the flow rate of the gas flowing through the pressure adjusting unit 16 becomes zero, the fixing can be automatically released by using this as a trigger.

By releasing the fixation of the moving body 18 fixed by the moving body fixing portion 17, the moving body 18 becomes the first space 14A and the second space 14B along the wall surface in the cylinder 19a of the pressure adjusting unit 19. Will move while shielding. At this time, the steam 3 of the heat transfer liquid 2 flows out to the adjacent heating furnace 5 or the like through the communication portion 6 of the transport portion 9 in response to the disturbance caused by carrying the object 1 to be heated into the steam heating furnace 4. It is necessary to keep the pressure in the steam heating furnace 4 in the ready state in order to prevent the above. In order to keep the pressure in the steam heating furnace 4 in the ready state, it is necessary to keep the pressure in the communicating steam cooling unit 12 constant. Further, for that purpose, it is necessary to keep the pressure of the first space 14A communicating with the steam cooling unit 12 constant. That is, it is necessary to maintain the pressure in the first space 14A when the moving body 18 is released from being fixed, that is, when the on-off valve 15 is closed. At this time, the pressure of the other second space 14B in contact with the moving body 18 is constant at the atmospheric pressure in the external space by the communication portion 20 for the external space. Therefore, in order for the pressure of the first space 14A not to fluctuate when the fixing of the moving body 18 is released, the volume of the first space 14A must not change, that is, the moving body 18 must not move, that is, it moves. It suffices if the force in the direction of gravity due to the weight of the body 18 can cancel the pressure difference between the atmospheric pressure, which is the pressure in the second space 14B, and the pressure in the first space 14A.

As a result, various disturbance factors of pressure fluctuation, for example, a change in the amount of steam 3 itself due to the introduction of the object to be heated 1 into the steam heating furnace 4, or a change in the amount of liquefaction and recovery of steam 3 in the steam cooling unit 12. Even if the pressure of the first space 14A tries to change due to the influence of such factors, the volume of the first space 14A automatically changes due to the vertical movement of the moving body 18 in the direction of gravity due to its own weight, and the pressure also automatically changes. Is held in. In other words, the moving body 18 slides in the cylinder 19a based on the pressure difference between the pressure in the steam heating furnace 4 and the pressure in the heating furnace 5 and the weight of the moving body 18, so that the moving body 18 slides in the steam heating furnace 4. The pressure is maintained equal to the pressure in the heating furnace 5.

At this time, the pressure in the steam heating furnace 4 via the second cooling communication unit 13, the steam cooling unit 12, and the first cooling communication unit 11 that communicate with each other is also maintained at a desired pressure. .. Therefore, in the continuous furnace, the pressure difference between the heating furnace 5 and the like connected before and after the steam heating furnace 4 and the steam heating furnace 4 does not occur, and the outflow of the steam 3 of the heat transfer liquid 2 can be prevented.

According to the above embodiment, even in a continuous furnace in which a plurality of heating furnaces 4 and 5 are connected at narrow intervals, the object 1 to be heated is heated by utilizing the latent heat of condensation of the steam 3 of the heat transfer liquid 2. It is possible to maintain the pressure inside the steam heating furnace 4 at a constant pressure. As a result, a special mechanism for preventing the outflow of steam becomes unnecessary, and the steam 3 moves between the adjacent steam heating furnace 4 and the heating furnace 5 in the communication portion 6 of the transport portion 9 of the object to be heated 1. Can be reduced to reduce the pressure difference of the vapor 3 of the thermal transfer liquid 2.

The present invention is not limited to the above embodiment, and can be implemented in various other aspects.

For example, FIG. 6 is a detailed explanatory view of a gas phase heating device according to another embodiment of the embodiment of the present invention. The same effect can be obtained by continuously applying a constant stress to the moving body 18 by an elastic body 24 such as a spring connected to the moving body 18 and the end 19b of the cylinder 19a with respect to the operation of the moving body 18. It is possible. Since the elastic force of the elastic body 24 changes depending on the degree of elongation, the movable range of the moving body 18 in this case is limited to a range in which the change in the elastic force of the elastic body 24 can be ignored. Further, when the elastic body 24 is used, the influence of the weight of the moving body 18 is small, so that the moving direction of the moving body 18 is not limited to the vertical direction.

Further, FIG. 7 is an explanatory diagram in the case where the steam heating furnace 4A for heating using the latent heat of condensation of the heat transfer liquid 2 is also connected to the upstream side adjacent to the steam heating furnace 4. As an example, when the steam heating furnace 4A on the upstream side uses a heat transfer liquid 2A having a boiling point different from that of the steam heating furnace 4, or as another example, the specifications of the heat transfer liquid 2A are the same, but heat. By controlling the amount of heat energy applied to the transfer liquid 2A, steam heating furnaces 4A having different concentrations of steam 3A in the heat transfer liquid 2A are arranged adjacent to each other. By communicating the steam cooling unit 12 and the pressure adjusting unit 19 having the configuration as shown in FIG. 3 for each of the steam heating furnace 4 and the steam heating furnace 4A, the pressure inside the furnace can be kept constant. There is no difference between the adjacent steam heating furnaces 4A and the steam heating furnace 4 due to the outflow or inflow of steam 3A of the heat transfer liquid 2A having different boiling points between adjacent furnace bodies, or the difference in the concentration of steam 3A. It is possible to reduce the movement of the vapor 3A in the communication portion 6 of the transport portion 9 of the object to be heated 1 and reduce the pressure difference of the vapor 3A of the thermal transfer liquid 2A.

Further, FIG. 8 is an explanatory diagram of a temperature profile in the gas phase heating apparatus according to the embodiment of the present invention, in the case of having a transport portion 9 in which the object to be heated 1 is continuously transported from the inlet to the outlet at the same speed. Is. Regarding the heating from the carry-in of the object to be heated 1, the object to be heated 1 is heated to a desired temperature by using the first steam heating furnace 4A as a preheating step, and in the next heating furnace 5, the preheating temperature is maintained by hot air circulation heating or the like. do. After that, in the second steam heating furnace 4, as the main heating step, the heat treatment is completed by further raising the temperature to a desired temperature, and the heated object 1 is cooled by the heated object cooling unit 8. , The temperature profile is completed. The steam cooling unit 12 and the pressure adjusting unit 19 having the configuration as shown in FIG. 3 are not shown.

Further, FIG. 9 shows that in the vapor phase heating apparatus according to the embodiment of the present invention, the transport portion 25 of the object to be heated 1 from the inlet to the outlet is transported separately for each steam heating furnace 4 and heating furnace 5. It is explanatory drawing of the temperature profile in the case of the configuration. By providing a transport unit 25 separated for each steam heating furnace 4 and heating furnace 5, the moving speed of the object to be heated 1 can be changed in each steam heating furnace 4 and heating furnace 5, and in some cases, the operation is stopped. It is also possible to hold the steam heating furnace 4 and the heating furnace 5 for a desired time. Therefore, it is possible to change the length of each heating step more than the temperature profile in the case of FIG. 8, and thereby, for example, when the temperature holding time in the heating furnace 5 is lengthened as in the temperature profile shown in FIG. Alternatively, although not shown, it is possible to create a more complicated temperature profile, such as being able to change the time after reaching the peak temperature in the steam heating furnace 4. Also here, the steam cooling unit 12 and the pressure adjusting unit 19 having the configuration as shown in FIG. 3 are not shown.

Further, in the steam heating furnace 4, the heating source 10 is arranged in the lower tub 4x inside the steam heating furnace 4, but the heating source 10 is not limited to such a configuration, and as shown in FIG. 10, the steam heating furnace 4 The steam generating part 4y is connected to the outside of the furnace via the connecting part 4z, the heat transfer liquid 2 is heated by the heating source 17y of the steam generating part 4y to generate the steam 3, and the generated steam 3 is passed through the connecting part 4z. It may be supplied to the steam heating furnace 4. Note that FIG. 10 is shown as an explanatory view viewed from a direction 90 degrees different from the transport direction of the object 1 to be heated in the steam heating furnace 4.

By appropriately combining any of the various embodiments or modifications, the effects of each can be achieved. Further, it is possible to combine the embodiments or the embodiments, or the embodiments and the embodiments, and also to combine the features in the different embodiments or the embodiments.

The vapor phase heating method and the vapor phase heating apparatus according to the above aspect of the present invention can adjust and equalize the concentration of the steam of the heat transfer liquid that transfers heat to the object to be heated. It is possible to adjust the heating rate, and when heating the object to be heated, there is no difference in heating capacity depending on the location and time, and even a three-dimensional object to be heated can be heated by uniform heat transfer. Is possible. Therefore, in the above aspect of the present invention, as a heating method and apparatus for uniformly heating a three-dimensional object to be heated, a drying furnace, a curing furnace, or a curing furnace in a manufacturing process of an industrial product or a home electric appliance or a manufacturing process of various electronic parts, or It can be applied to heat treatment methods and equipment that perform various heat treatments such as reflow furnaces.

1 Heated object 2 Thermal transfer liquid 2A Thermal transfer liquid 3 Steam 3A Steam 4 Steam heating furnace 4x Bathtub 4y Steam generator 4z Connection part 4A Steam heating furnace 5 Heating furnace 6 Communication part 7 Inlet part 8 Heated object cooling part 9 Transport Part 10 Heating source 11 1st cooling communication part 12 Steam cooling part 13 2nd cooling communication part 14A 1st space 14B 2nd space 15 On-off valve 16 Pressure adjustment part 17 Moving body fixing part 18 Moving body 19 Pressure adjusting part 19a Cylinder 19b End 20 External space communication part 21 Recovery part 22 Pump 23 Pipe 24 Elastic body 25 Transport part 31 Steam 32 Exhaust port 33 Doorway 34 Conveyor 35 Steam heating furnace 36 Tunnel 37 Tunnel 38 Tunnel 39 Discharge port 40 Liquid 41 Air- Vapor interface

Claims (8)

At least one steam heating furnace that heats the object to be heated by utilizing the latent heat of condensation of the steam of the heat transfer liquid, and at least one heating furnace or another steam heating furnace arranged in communication with the one steam heating furnace. in a continuous furnace and a furnace, a gas-phase heating method of heating the object to be heated,
Said heating furnace or said other steam heating furnace, via the communication unit always that pass communicating between said one steam heating furnace adjacent to the one steam heating furnace, the heating furnace the object to be heated Or, carry it into the other steam heating furnace or the one steam heating furnace, and carry it into the steam heating furnace.
In the steam cooling unit provided above the communicating portion of said one steam heating furnace, together with liquefied by cooling the vapor of the heat transfer liquid within said one steam heating furnace, wherein the pressure adjustment section By keeping the pressure in one steam heating furnace equal to the pressure in the heating furnace or the other steam heating furnace, the pressure in the continuous furnace is equalized and the carried-in object to be heated is heated. Steam-type heating method. The vapor phase heating method according to claim 1, wherein in the one steam heating furnace, the heat transfer liquid is heated in a bathtub below the steam heating furnace to generate the steam. The pressure adjusting unit is a space for adjusting the pressure by changing the volume of the space inside the cylinder , and the space for adjusting the pressure is a first space and a second space with a piston slidable by gravity in the cylinder. The first space communicates with the one steam heating furnace via the steam cooling unit, and the second space communicates with the external space in the one steam heating furnace. By sliding the piston in the cylinder based on the pressure difference between the pressure in the external space and the pressure in the external space and the weight of the piston, the pressure in the one steam heating furnace is reduced to the pressure in the heating furnace or the other. The vapor phase heating method according to claim 1 or 2, wherein the pressure is maintained at the same level as the pressure in the steam heating furnace. At least one steam heating furnace that heats the object to be heated by utilizing the latent heat of condensation of the steam of the heat transfer liquid, and at least one heating furnace or another steam heating furnace arranged in communication with the one steam heating furnace. It is a gas phase heating device that is composed of a continuous furnace including a furnace and heats the object to be heated.
The one steam heating furnace
A communication unit that always communicates with the adjacent heating furnace or the other steam heating furnace so that the object to be heated can be carried in and out.
A steam cooling unit, which is arranged above the communication unit and cools and liquefies the steam of the heat transfer liquid in the one steam heating furnace.
Vapor heating device and a pressure adjustment unit for adjusting the internal pressure of the steam heating furnace so as to hold the equivalent to the pressure in the furnace or other steam heating furnace. The vapor-phase heating apparatus according to claim 4, wherein the one steam heating furnace has a heating source for heating the heat transfer liquid in a bathtub below the steam heating furnace to generate steam. The vapor phase heating device according to claim 4 or 5, wherein the pressure adjusting unit includes a container having a space for adjusting the pressure by changing the volume. The space for adjusting the pressure is a space inside the cylinder, and the inside of the cylinder is divided into a first space and a second space by a piston slidable by gravity, and the first space is the steam cooling unit. communicates with the one of the steam furnace through said second space is communicated with the outer space, the pressure difference between the pressure of the pressure and the external space within the one steam heating furnace and the piston by the piston slides within the cylinder based on the weight, to hold the pressure in the one of the steam furnace equal to the pressure in the furnace or other steam heating furnace, to claim 6 The described vapor phase heating device. The space for adjusting the pressure is a space inside the cylinder, and the inside of the cylinder is divided into a first space and a second space by a piston slidable by gravity, and the first space is the steam cooling unit. The vapor-phase heating device according to claim 6, wherein an elastic body is stretched between the cylinder and the piston in the second space, which communicates with the one steam heating furnace via the above.

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