JP2014119216A - Temperature control method of heating device and heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature control method of a heating device and the heating device capable of quickly raising temperature of material to be heated while preventing dew condensation of moisture in combustion gas on the surface of the material to be heated.SOLUTION: A temperature control method of a heating device comprising a burner 2 which supplies combustion gas E into a furnace and heats metallic material 5 to be heated charged into a furnace and a furnace temperature setting means 7c which can adjust furnace temperature to a predetermined preset temperature by adjusting a combustion amount of the burner 2 includes: preliminarily temperature raising treatment in which a setting temperature of the furnace temperature setting means 7c is set as a high setting temperature of higher than a predetermined heating treatment temperature when performing heating treatment of the material 5 to be heated, upon the charging of the material 5 to be heated into the furnace, and the furnace temperature is made to be the high setting temperature; and set temperature restoring treatment in which the set temperature of the furnace temperature setting means is set as the heating treatment temperature, after the charging of the material 5 to be heated into the furnace and the furnace temperature is made to be the heating treatment temperature.

Description

  The present invention provides a burner for supplying a combustion gas into a furnace and heating a metal object to be heated, and adjusting the combustion amount of the burner to bring the furnace temperature to a predetermined set temperature. The present invention relates to a temperature control method and a heating device of a heating device provided with an adjustable furnace temperature setting means.

  As a conventional heating device, for example, Patent Document 1 discloses a burner that supplies a combustion gas into a furnace and heats a metal object to be heated, and a fuel supply amount and air supply to the burner. The combustion air ratio corresponding to the excess ratio of the combustion air to the fuel supplied to the burner by adjusting the amount can be adjusted to a predetermined combustion air ratio, and the furnace temperature is adjusted to the steady temperature by adjusting the burner combustion amount. A heating device that adjusts to the above is disclosed.

  In the heating apparatus disclosed in Patent Document 1, after burning a metal object to be heated at room temperature into a furnace at room temperature, combustion of the burner is started, and the object to be heated put into the furnace is supplied from the burner. The temperature is raised by contact with the gas. In order to prevent moisture in the fuel gas from condensing on the surface of the object to be heated at a low temperature and preventing oxidation of the surface of the object to be heated due to the dew condensation in the initial stage of raising the temperature of the object to be heated. The combustion air ratio of the burner is increased to lower the dew point of the combustion gas supplied into the furnace.

Japanese Patent No. 3927259

  However, in the technology disclosed in Patent Document 1, as described above, the supply of the burner combustion gas into the furnace is started after the room-temperature object to be heated is put into the room-temperature furnace. In order to prevent moisture contained in the condensation, the combustion air ratio of the burner is described in, for example, claim 1 of this Patent Document 1 so that the dew point of the combustion gas of the burner is lowered to around normal temperature. Thus, it is necessary to raise the combustion air ratio to 4.7 or more. In this way, if the combustion air ratio is significantly increased, the burner combustion may become unstable, and the temperature of the combustion gas generated by the burner combustion decreases, so that the object to be heated can be quickly removed. The problem that the temperature cannot be raised occurs.

  The present invention has been made paying attention to this point, and its purpose is to quickly raise the temperature of the heated object while suppressing the dew condensation on the surface of the heated object of moisture in the combustion gas. It is in the point which provides the temperature control method of a heating apparatus which can be performed, and a heating apparatus.

In order to achieve this object, the temperature control method of the heating device according to the present invention is as follows:
A burner that supplies combustion gas into the furnace to heat the metal object to be heated and that is capable of adjusting the furnace temperature to a predetermined set temperature by adjusting the amount of combustion of the burner A temperature control method for a heating device including an internal temperature setting means, the first characteristic configuration is
When the object to be heated is put into the furnace, the set temperature of the furnace temperature setting means is set to a high set temperature higher than a predetermined heat treatment temperature when the object to be heated is heated. , A preliminary heating process in which the furnace temperature is the high set temperature;
A set temperature return process in which the set temperature of the furnace temperature setting means is set to the heat treatment temperature after the material to be heated is put into the furnace, and the furnace temperature is set as the heat treatment temperature. In the point.

Moreover, the heating device according to the present invention for achieving this object is as follows:
A burner that supplies combustion gas into the furnace to heat the metal object to be heated and that is capable of adjusting the furnace temperature to a predetermined set temperature by adjusting the amount of combustion of the burner A heating device provided with an internal temperature setting means and an operation control means for controlling the operation, the first characteristic configuration is:
The operation control means is
When the object to be heated is put into the furnace, the set temperature of the furnace temperature setting means is set to a high set temperature higher than a predetermined heat treatment temperature when the object to be heated is heated. , A preliminary heating process in which the furnace temperature is the high set temperature;
After the material to be heated is put into the furnace, the set temperature of the furnace temperature setting means is set to the heat treatment temperature, and the set temperature return process is performed using the furnace temperature as the heat treatment temperature. There is in point to do.

According to the first characteristic configuration of the heating device and the temperature control method thereof, the temperature in the furnace is higher than a predetermined heat treatment temperature when performing the heat treatment of the object to be heated when the object to be heated is put into the furnace. Because the temperature is adjusted to a high temperature, the temperature of the furnace is adjusted to a predetermined heat treatment temperature, and the heated object is quickly put in the furnace in a high temperature atmosphere than when the heated object is charged into the furnace. The temperature can be raised. Accordingly, it is possible to prevent condensation of moisture in the combustion gas on the surface of the object to be heated even in the process of raising the temperature of the object to be heated put in the furnace.
Further, since the furnace temperature is adjusted to the heat treatment temperature after the object to be heated is put into the furnace, the object to be heated put into the furnace can be heated at the heat treatment temperature.

  Furthermore, according to this characteristic configuration, since the furnace temperature at the time of charging the object to be heated is a high set temperature, for example, when the furnace temperature at the time of charging the object to be heated is normal temperature Thus, it is not necessary to adjust the combustion air ratio of the burner to a high level in order to prevent condensation, and the combustion gas temperature of the burner is kept high by making the combustion air ratio of the burner close to the theoretical air ratio. Therefore, it is possible to quickly raise the temperature of the object to be heated and prevent the moisture in the combustion gas from condensing on the surface of the object to be heated.

In addition to the first characteristic configuration of the temperature control method of the heating device, the second characteristic configuration of the temperature control method of the heating device according to the present invention,
The heating device is provided with an air ratio setting means capable of setting a combustion air ratio of the burner,
When the object to be heated is introduced into the furnace, the air ratio setting means causes the combustion air ratio of the burner to be higher than a predetermined heat treatment air ratio when heat-treating the object to be heated. It is in the point including the air ratio raise process set to.

  According to the second characteristic configuration of the temperature control method of the heating device, a predetermined heat treatment air ratio in which the combustion air ratio of the burner is set to an air ratio close to the theoretical air ratio when the object to be heated is put into the furnace. As a slightly higher set air ratio (for example, about 1.4 to 3.0), the dew point of the combustion gas supplied into the furnace is lowered by combustion of the burner, and the surface of the heated object of moisture in the combustion gas It is possible to further suppress dew condensation on the surface.

The third characteristic configuration of the temperature control method of the heating device according to the present invention is in addition to any of the first or second characteristic configuration of the temperature control method of the heating device,
In the set temperature recovery process, when the elapsed time from when the object to be heated is put into the furnace reaches a predetermined set elapsed time, the set temperature of the furnace temperature setting means is set to the heat treatment temperature. There is a point to set.

  According to the third characteristic configuration of the temperature control method of the heating device, the temperature of the combustion gas in the furnace even when the furnace temperature is lowered from the high set temperature to the heat treatment temperature as the elapsed time from the charging time. Is determined in advance as the set elapsed time, and when the elapsed time from the time of charging becomes the set elapsed time in the set temperature recovery process, the furnace temperature setting means Since the set temperature is changed from the high set temperature to the heat treatment temperature, the moisture at the surface of the object to be heated is prevented from dew condensation on the surface of the object to be heated while the heat treatment temperature is set to the object to be heated. Can be migrated.

The fourth characteristic configuration of the temperature control method of the heating apparatus according to the present invention is in addition to any of the first to second characteristic configurations of the temperature control method of the heating apparatus,
In the set temperature return processing, when the surface temperature of the object to be heated becomes higher than the dew point of the combustion gas, the set temperature of the furnace temperature setting means is set to the heat processing temperature.

According to the 4th characteristic structure of the temperature control method of the said heating apparatus, when the surface temperature of the said to-be-heated material becomes higher than the dew point of the said combustion gas in setting temperature return processing, setting of the furnace temperature setting means Since the temperature is changed from the high set temperature to the heat treatment temperature, the process proceeds to the heat treatment at the heat treatment temperature of the heated object while preventing the condensation of moisture in the combustion gas on the surface of the heated object. be able to.
Moreover, if the set temperature of the furnace temperature setting means is changed from the high set temperature to the heat treatment temperature immediately when the surface temperature of the heated object becomes higher than the dew point of the combustion gas, the temperature of the heated object is increased. It is possible to prevent the heat treatment from being adversely affected by exceeding the heat treatment temperature, which is the temperature to be heat treated.

Schematic configuration diagram of the heating device The figure which shows the change of the furnace temperature in the heat processing of to-be-heated material Flow chart showing the procedure of heat treatment of the object to be heated

Embodiments of a temperature control method for a heating apparatus and a heating apparatus according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the heating device 20 includes a burner 2 that supplies a combustion gas E to the furnace of the heating furnace 1 and heats a metal object 5 that has been put into the furnace, and combustion of the burner 2. Furnace temperature setting means 7c capable of adjusting the furnace temperature by adjusting the amount, and operation control means 7a for controlling the operation of the heating device 20 are provided. The in-furnace temperature setting means 7c and the operation control means 7a are configured so as to function together with an air ratio setting means 7b to be described later when the control unit 7 comprising a computer executes a predetermined program.

  In the heating furnace 1, four burners 2 and a stirring fan 3 are provided on the upper plate 1 a, and the combustion gas E generated by the combustion of these burners 2 is circulated in the furnace by the stirring fan 3. It is configured. In addition, a door 6 that can be freely opened and closed is provided on the front surface of the heating furnace 1, and the door 6 is opened and closed so that an object to be heated 5 is charged into and taken out of the furnace. And in the furnace of the heating furnace 1, the partition plate 4 for preventing the flame of these burners 2 from touching the article to be heated 5 is provided, and the inside of the furnace of the heating furnace 1 is detected as the furnace temperature. A temperature sensor 15 is provided. The furnace temperature detected by the temperature sensor 15 is input to the control unit 7.

Each burner 2 is connected to a fuel gas supply path 11 for supplying the fuel gas F and an air supply path 13 for supplying the air A. The fuel gas supply path 11 supplies the fuel gas F to the burner 2. A fuel gas flow rate adjustment valve 10 capable of adjusting the flow rate is provided, while an air flow rate adjustment valve 12 capable of adjusting the supply flow rate of the air A to the burner 2 is provided in the air supply path 13.
The in-furnace temperature setting means 7c functioning by the control unit 7 controls the opening degree of the fuel gas flow rate adjusting valve 10 so that the in-furnace temperature detected by the temperature sensor 15 becomes a predetermined set temperature. The supply flow rate of the fuel gas F to the burner 2 is adjusted.

The air ratio setting means 7b functioning by the control unit 7 controls the opening degree of the air flow rate adjusting valve 12 based on the opening degree of the fuel gas flow rate adjusting valve 10 controlled by the furnace temperature setting means 7c. A combustion air ratio corresponding to the excess ratio of the air A to the fuel gas F supplied to the burner 2 is set to a predetermined combustion air ratio.
Further, the higher the combustion air ratio of the burner 2 is, the lower the dew point temperature of the combustion gas E becomes, and the moisture contained in the combustion gas E is less likely to condense.

Connected to the control unit 7 is an operation unit 9 for inputting a set temperature, which is a target temperature in the furnace temperature adjustment by the furnace temperature setting means 7c, and a display unit 8 for displaying the current furnace temperature. Has been.
In addition, the control unit 7 is provided with a timer or the like (not shown) for measuring the elapsed time after the heated object 5 is put into the furnace.

The heating device 20 configured as described above performs the predetermined temperature control method, thereby suppressing the condensation of moisture in the combustion gas E on the surface of the object to be heated 5 and quickly moving the object to be heated 5. It is configured so that the temperature can be raised. The configuration for executing the temperature control method will be described below.
The operation control means 7a sets the set temperature of the furnace temperature setting means 7c to a high temperature higher than a predetermined heat treatment temperature when the object to be heated 5 is heated when the object to be heated 5 is put into the furnace. After setting the temperature to a pre-heating process for setting the furnace temperature to a high set temperature, and setting the heated object 5 into the furnace, the set temperature of the furnace temperature setting means 7c is set to the heat treatment temperature. And a set temperature return process in which the furnace temperature is the heat treatment temperature. Here, the heat treatment temperature when performing the heat treatment of the article to be heated 5 is set to a temperature in the range of 150 ° C. to 350 ° C. when performing the heat treatment such as tempering of the article to be heated 5. . On the other hand, the high set temperature is a temperature that is 100 ° C. to 200 ° C. higher than the heat treatment temperature.

  Further, the operation control means 7a is provided with a predetermined heat treatment when the heated air ratio of the burner 2 is heated by the air ratio setting means 7b when the heated object 5 is put into the furnace. It is configured to execute an air ratio increasing process for setting a set air ratio slightly higher than the air ratio. Here, the predetermined heat treatment air ratio is an air ratio in the range of 1.1 to 1.3 near the theoretical air ratio, and the set air ratio is a slightly higher combustion air ratio (for example, 1.. 4 to 3.0).

Further, the operation control means 7a is configured such that, in the set temperature return process in which the furnace temperature is set to the heat treatment temperature, the elapsed time from when the object to be heated 5 is put into the furnace measured by a timer When the time comes, the temperature set in the furnace temperature setting means 7c is set to the heat treatment temperature.
The operation unit 9 has a charging preparation button (not shown) for setting the set temperature to a high set temperature and instructing the operation control means 7a to set the combustion air ratio of the burner 2 to the set air ratio. And a charging completion button (not shown) for instructing the operation control means 7a to start measuring the elapsed time after the heated object 5 is charged into the furnace.
In addition, the display unit 8 has a charging preparation completion lamp (not shown) that is turned on when the furnace temperature is adjusted to a high set temperature and the combustion air ratio of the burner 2 is set to the set air ratio. Is provided.

  Next, details of the temperature control method executed by the heating device 20 adopting the above-described configuration will be described with reference to FIGS. FIG. 2 shows changes in the set temperature Ta, the furnace temperature Tb, and the surface temperature Tc of the heated object 5 from when the heated object 5 is put into the furnace, and FIG. 3 shows the heating device 20 for the heated object 5. The flow of the heat processing in is shown.

  As shown in FIG. 3, when starting the heat treatment of the article to be heated 5, the input preparation button of the operation unit 9 is pressed by the operator. As a result, the operation control means 7a receives the pressing signal of the input preparation button (# 101). When the pressing signal of the charging preparation button is received, the operation control means 7a sets the target set temperature to the high set temperature in the adjustment of the furnace temperature by the furnace temperature setting means 7c (# 102). As a result, the furnace temperature setting means 7c adjusts the opening degree of the fuel gas flow rate adjusting valve 10 and executes a preliminary temperature increase process for setting the furnace temperature to a high set temperature (# 103).

  When the furnace temperature is set to a high set temperature, the operation control means 7a determines the combustion air ratio of the burner 2 by the air ratio setting means 7b from a predetermined heat treatment air ratio when the object to be heated 5 is heated. Also, an air ratio increasing process for setting a slightly higher set air ratio is executed (# 104).

  When the combustion air ratio of the burner 2 is set to the set air ratio, the charging preparation completion lamp provided in the display unit 8 is turned on (# 105). When the charging preparation completion lamp is turned on, the worker 5 confirms that the lamp is turned on, and then the heated object 5 is put into the furnace and the charging completion button provided on the operation unit 9 is pressed. Then, the operation control means 7a receives the pressing signal of the closing completion button (# 106). Here, the time when the pressing signal of the insertion completion button can be received is the time t1 shown in FIG. As shown in FIG. 2, the furnace temperature Tb that has been adjusted to the high set temperature T1 is lowered by charging the article 5 to be heated into the furnace at time t1.

  Next, the control unit 7 measures the elapsed time from when the charging completion button is pressed as the elapsed time from when the object to be heated 5 is charged into the furnace. When this elapsed time reaches a predetermined set elapsed time (# 107), the operation control means 7a changes the set temperature of the furnace temperature setting means 7c to the heat treatment temperature (# 108). The time when the set temperature is changed to the heat treatment temperature is a time t2 shown in FIG. As shown in FIG. 2, the set temperature is changed from the high set temperature T1 to the heat treatment temperature T2 at time t2. Further, the elapsed time from the time t1 to the time t2 becomes a predetermined set elapsed time P.

  When the set temperature is changed to the heat treatment temperature, the furnace temperature setting means 7c performs a set temperature return process in which the furnace temperature is adjusted to the heat treatment temperature (# 109). When the furnace temperature is adjusted to the heat treatment temperature, the heat treatment at the heat treatment temperature is started (# 110). In FIG. 2, the time when the in-furnace temperature Tb is adjusted to the heat treatment temperature T2 is time t3. At this time t3, the surface temperature Tc of the article 5 to be heated is also adjusted to the heat treatment temperature T2.

  In the heat treatment (# 110), for example, the heat treatment period for heating at the heat treatment temperature is input and stored in advance from the operation unit 9, and the heating period from the time when the heat treatment temperature is set is the heating time. In the treatment period, the furnace temperature is gradually lowered to room temperature. And it is comprised so that a heat processing may be complete | finished when the furnace temperature falls to room temperature.

[Another embodiment]
(1) In the above embodiment, in the set temperature recovery process, the set temperature is set to the heat treatment temperature when the elapsed time from when the object 5 is put into the furnace reaches the predetermined set elapsed time. However, not limited to this, when the surface temperature of the article to be heated 5 becomes higher than the dew point of the combustion gas E, the set temperature of the furnace temperature setting means 7c may be set to the heat treatment temperature. Good. In this case, in order to obtain the dew point of the combustion gas E, a hygrometer for obtaining the humidity of the combustion gas E may be provided, but the dew point of the combustion gas E may be estimated from the combustion air ratio of the burner 2.

(2) In the above embodiment, the heat treatment (# 110 in FIG. 3) is started by adjusting the furnace temperature to the heat treatment temperature. You may comprise so that heat processing may be started by adjusting temperature to heat processing temperature. In this case, when detecting the surface temperature of the article 5 to be heated, a contact temperature sensor may be provided.

(3) In the said embodiment, although the control part 7 was comprised as a different body from the heating furnace 1, it is not restricted to this, The control part 7 may be provided in the heating furnace 1. FIG.

  As described above, there is provided a temperature control method and a heating device for a heating device capable of quickly raising the temperature of the heated object while preventing condensation of moisture in the combustion gas on the surface of the heated object. Can do.

2 Burner 5 Object to be heated 7a Operation control means 7b Air ratio setting means 7c In-furnace temperature setting means 20 Heating device E Combustion gas P Set elapsed time Ta Set temperature Tb In-furnace temperature Tc Surface temperature T1 High set temperature T2 Heat treatment temperature

Claims (5)

A burner that supplies combustion gas into the furnace to heat the metal object to be heated and that is capable of adjusting the furnace temperature to a predetermined set temperature by adjusting the amount of combustion of the burner A temperature control method for a heating device including an internal temperature setting means,
When the object to be heated is put into the furnace, the set temperature of the furnace temperature setting means is set to a high set temperature higher than a predetermined heat treatment temperature when the object to be heated is heated. , A preliminary heating process in which the furnace temperature is the high set temperature;
A set temperature return process in which the set temperature of the furnace temperature setting means is set to the heat treatment temperature after the material to be heated is put into the furnace, and the furnace temperature is set as the heat treatment temperature. Temperature control method for heating device. The heating device is provided with an air ratio setting means capable of setting a combustion air ratio of the burner,
When the object to be heated is introduced into the furnace, the air ratio setting means causes the combustion air ratio of the burner to be higher than a predetermined heat treatment air ratio when heat-treating the object to be heated. The temperature control method of the heating apparatus according to claim 1, further comprising an air ratio increase process set to the above.   In the set temperature recovery process, when the elapsed time from when the object to be heated is put into the furnace reaches a predetermined set elapsed time, the set temperature of the furnace temperature setting means is set to the heat treatment temperature. The temperature control method of the heating device according to claim 1 or 2, wherein the temperature control method is set.   3. The set temperature of the furnace temperature setting means is set to the heat treatment temperature when the surface temperature of the object to be heated becomes higher than the dew point of the combustion gas in the set temperature return processing. The temperature control method of the heating apparatus as described in 2. A burner that supplies combustion gas into the furnace to heat the metal object to be heated and that is capable of adjusting the furnace temperature to a predetermined set temperature by adjusting the amount of combustion of the burner A heating device comprising an internal temperature setting means and an operation control means for controlling operation,
The operation control means is
When the object to be heated is put into the furnace, the set temperature of the furnace temperature setting means is set to a high set temperature higher than a predetermined heat treatment temperature when the object to be heated is heated. , A preliminary heating process in which the furnace temperature is the high set temperature;
After the material to be heated is put into the furnace, the set temperature of the furnace temperature setting means is set to the heat treatment temperature, and the set temperature return process is performed using the furnace temperature as the heat treatment temperature. Heating device.

Images