JP2013036100A - Control device and method of gas furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the high-accuracy heat treatment of a member to be heated, in a control device and a method of a gas furnace.SOLUTION: The gas furnace 11 is constituted by arranging a plurality of burners 21 at a furnace wall, there are arranged temperature detectors 41, 42 and 43 for directly detecting temperatures of a thin-thickness cylinder W1, an intermediate part W2 and a heavy-thickness bottom W3 of the member W to be heated which is supported into the furnace, and a control device 47 adjusts outputs of the plurality of burners 21 on the basis of actual temperatures of the member W to be heated which are detected by the temperature detectors 41, 42 and 43 so that the actual temperatures become target temperatures.

Description

  The present invention relates to a control apparatus and method for a batch type gas furnace that performs various heat treatments on a member to be heated.

  A batch-type gas furnace is generally provided with a temperature detector that detects the atmospheric temperature in the furnace, and the control device controls the combustion state of the burner so that the temperature in the furnace detected by this temperature detector becomes the target temperature. I have control. As such a conventional gas furnace control device, for example, there is one described in Patent Documents 1-3 below.

  Patent Document 1 discloses that constant air-fuel ratio combustion is performed at the maximum fuel injection amount of each burner using combustion air preheated by a combustion air preheating device provided independently to each of a plurality of burners. I have to. Moreover, what was described in patent document 2 compares the temperature of each heating zone detected by a plurality of temperature detectors with a preset temperature set value, and opens the valve opening of a control valve for fuel flow control. Is controlling. Moreover, what was described in patent document 3 sets the furnace temperature of each zone from the initial temperature of a to-be-heated material, and the furnace temperature which the thermocouple detected, and controls a heating burner.

Japanese Patent Publication No. 03-043553 Japanese Patent Publication No. 60-032696 JP-A-62-054024

  In the conventional batch-type gas furnace described above, the temperature in the furnace is detected, and the burner combustion state, that is, the burner ON / OFF and the fuel supply amount so that the temperature in the furnace becomes the target temperature. Is controlling. However, when heat-treating the member to be heated, what is important is not the temperature in the furnace (atmosphere temperature) but the temperature of the member to be heated. Therefore, it is difficult to heat a member to be heated with high accuracy in a conventional batch type gas furnace.

  The present invention solves the above-described problems, and an object of the present invention is to provide a gas furnace control device and method that enables highly accurate heat treatment of a member to be heated.

  In order to achieve the above object, a gas furnace control apparatus according to the present invention includes a temperature detector that directly detects the temperature of a heated member supported in a furnace in a gas furnace in which a plurality of burners are provided on a furnace wall. And a burner controller that adjusts the outputs of the plurality of burners based on the detection result of the temperature detector.

  Therefore, the temperature detector directly detects the temperature of the heated member, and the burner control unit adjusts the output of the plurality of burners based on the temperature of the heated member detected by the temperature detector. It is possible to adjust the actual temperature of the material, and even with a deformed material to be heated with a mixture of thick and thin parts, optimal heating control according to the type of heat treatment is possible, and high accuracy of the heated member Heat treatment can be performed.

  In the gas furnace control device of the present invention, the burner control unit adjusts the number of burners to be activated based on the detection result of the temperature detector.

  Therefore, the burner control unit adjusts the number of burners to be activated based on the temperature of the heated member detected by the temperature detector, so that adjustment of the fuel amount, air amount, etc. in all the burners becomes unnecessary, and the burner control unit is activated. It is only necessary to adjust the fuel amount and air amount of the burner, and the control can be simplified.

  In the gas furnace control device of the present invention, the temperature detector is fixed to at least the thick part and the thin part of the heated member, and the burner control part is based on the temperature of the thick part and the thin part. And adjusting the outputs of the plurality of burners.

  Therefore, since the heat transfer time is different between the thick part and the thin part in the heated member, the temperature rise is delayed in the thick part compared to the thin part. Since the temperature is detected separately and the burner control unit adjusts the output of the burner according to each temperature, it is possible to perform an optimum heat treatment adapted to the shape of the member to be heated.

  In the control apparatus for a gas furnace according to the present invention, the plurality of burners are classified into a group corresponding to a thick portion of the heated member and a group corresponding to a thin portion of the heated member, and the burner control portion Is characterized in that the number of burners activated in each group is adjusted based on the detection result of the temperature detector.

  Therefore, the burner control unit adjusts the number of burners to be activated in each group based on the temperature of the thick part and the thin part, so that the optimum heat treatment adapted to the shape of the heated member can be achieved with simple control. It can be performed.

  In the gas furnace control device of the present invention, the group corresponding to the thick portion in the heated member is characterized in that a larger number of the burners are sorted than the group corresponding to the thin portion.

  Therefore, although the temperature rise of the thick part in the heated member is delayed, the temperature of the thick part greatly exceeds the target temperature when heat is applied suddenly, so the heated member is heated by a large number of burners. Thus, it is possible to perform optimum heating adapted to the thick part.

  In the control device for a gas furnace according to the present invention, the burner control unit outputs the outputs of the plurality of burners so as to achieve a first temperature increase rate with respect to the member to be heated up to a predetermined first heating temperature set in advance. When the first heating temperature is reached, the outputs of the plurality of burners are adjusted so that the second heating rate is lower than the first heating rate.

  Therefore, the optimum heat treatment can be performed without giving a sudden temperature change to the member to be heated.

  In the gas furnace control method according to the present invention, in the gas furnace in which a plurality of burners are provided on the furnace wall, the temperature of the member to be heated supported in the furnace is directly detected, and the plurality of the above-described plural furnaces are detected based on the detection result. The output of the burner is adjusted.

  Therefore, the actual temperature of the member to be heated can be adjusted, optimal heating control according to the type of heat treatment can be performed, and heat treatment of the member to be heated can be performed with high accuracy.

  In the gas furnace control method of the present invention, the plurality of burners are classified into a group corresponding to the thick portion of the heated member and a group corresponding to the thin portion, and the thickness based on the temperature of the thick portion. The number of burners activated in the group corresponding to the thick part is adjusted while the number of burners activated in the group corresponding to the thick part is adjusted based on the temperature of the thin part.

  Therefore, the temperature detector detects the temperature of the thick part and the thin part separately and adjusts the number of burners activated in each group according to each temperature. Optimal heat treatment suitable for

  In the method for controlling a gas furnace according to the present invention, depending on the shape of the member to be heated, the change of the burner or the change of the burner ignition order or the change of the group organization or the group sorted before the heat treatment or during the heat treatment operation. It is characterized by increasing or decreasing.

  Therefore, the optimum heat treatment adapted to the shape of the member to be heated can be performed with a simple setting.

  According to the gas furnace control apparatus and method of the present invention, a temperature detector that directly detects the temperature of a heated member in the furnace, and a burner control that adjusts the outputs of a plurality of burners based on the detection results of the temperature detector Since the portion is provided, the actual temperature of the member to be heated can be adjusted, regenerative heating control according to the type of heat treatment can be performed, and the member to be heated can be subjected to highly accurate heat treatment.

FIG. 1 is a schematic configuration diagram showing a gas furnace control apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the inside of the gas furnace of the present embodiment. FIG. 3 is a graph showing the target temperature of the actual temperature in the gas furnace of the present embodiment. FIG. 4 is a graph for explaining the actual temperature control method in the gas furnace of the present embodiment. FIG. 5 is a graph showing a temperature change in the gas furnace of this example.

  Exemplary embodiments of a gas furnace control device and method according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included.

  FIG. 1 is a schematic configuration diagram illustrating a control apparatus for a gas furnace according to an embodiment of the present invention, FIG. 2 is a cross-sectional view illustrating the inside of the gas furnace according to the present embodiment, and FIG. 3 is a gas furnace according to the present embodiment. FIG. 4 is a graph for explaining the actual temperature control method in the gas furnace of this embodiment, and FIG. 5 is a graph showing the temperature change in the gas furnace of this embodiment. .

  In the gas furnace control apparatus of the present embodiment, as shown in FIGS. 1 and 2, the gas furnace 11 is a batch system, and four side wall portions 11b are formed around the bottom portion 11a. A horizontal ceiling part 11c is fixed to the upper part of the side wall part 11b. The shape of the gas furnace 11 is not limited to this quadrangle, and may be a dome shape with a curved ceiling. In the gas furnace 11, the member to be heated W is supported by two mounts 12 in the center of the bottom 11 a. This heated member W has a bottomed cylindrical shape, and is composed of a thin cylindrical portion W1 and a thick bottom portion W3.

  In the gas furnace 11, a plurality (22 in this embodiment) of burners 21 are provided on opposing side wall portions (furnace walls) 11b. Eleven burners 21 are arranged at almost equal intervals on each side wall portion 11b, and eleven burners 21 provided on each side wall portion 11b are arranged to face each other. The burner 21 is provided with an automatic flow rate adjustment valve 22, and the ON / OFF and the output can be adjusted by adjusting the opening degree. Here, the burners 21-1 to 21-22 will be described with reference to the 22 burners 21, and the automatic flow control valves 22-1 to 22 to 22 automatic flow control valves 22 will be described. A description will be given with reference to −22. The shape of the gas furnace 11 is not limited to this shape, and the attachment position of the burner 21 is not limited to the side wall portion 11b but may be the bottom portion 11a or the ceiling portion 11c.

  In each of the burners 21-1 to 21-22, a gas supply line 31 is connected to the automatic flow rate adjusting valves 22-1 to 22-22, and the gas supply line 31 is connected to a gas supply source 32. ing. The gas supply line 31 is provided with a gas supply pump 33 and an opening / closing valve 34. Each of the burners 21-1 to 21-22 is connected to an air supply line 35 with respect to the automatic flow control valves 22-1 to 22-22. The air supply line 35 is connected to an air supply source 36. Has been. The air supply line 35 is provided with an air supply pump 37 and an opening / closing valve 38.

  In this embodiment, each of the burners 21-1 to 21-22 includes a first group corresponding to the thin cylindrical portion W1 of the member to be heated W, and an intermediate portion W2 between the thin cylindrical portion W1 and the thick bottom portion W3. And a third group corresponding to the thick bottom W3. Here, burner 21-1, 21-3, 21-12, 21-13, 21-14 as the first group, burner 21-16, 21-17 as the second group, burner 21-10 as the third group, 21-11, 21-18, 21-20, 21-21, 21-22 are assigned. The grouping of the burners 21 is such that an optimum group is set based on past experimental data, and is not limited to this sorting.

  The gas furnace 11 is provided with temperature detectors 41, 42, and 43 that directly detect the temperature of the heated member W. The first temperature detector 41 is fixed so as to be in close contact with the thin cylindrical portion W1 of the heated member W by welding, and detects the substantial temperature of the cylindrical portion W1. The second temperature detector 42 is fixed so as to be in close contact with the intermediate portion W2 between the thin cylindrical portion W1 and the thick bottom portion W3 of the heated member W, and detects the actual temperature of the intermediate portion W2. To do. The third temperature detector 43 is fixed so as to be in close contact with the thick bottom portion W3 of the heated member W by welding, and detects the substantial temperature of the bottom portion W3.

  Further, the gas furnace 11 is provided with temperature detectors 44, 45, and 46 for detecting the internal atmospheric temperature. The fourth temperature detector 44 is disposed on the ceiling portion 11c in the vicinity of the thin cylindrical portion W1 of the heated member W, and detects the ambient temperature in the vicinity of the cylindrical portion W1. The fifth temperature detector 45 is disposed on the ceiling portion 11c in the vicinity of the intermediate portion W2 between the thin cylindrical portion W1 and the thick bottom portion W3 of the heated member W, and the ambient temperature in the vicinity of the intermediate portion W2 is determined. To detect. The sixth temperature detector 46 is disposed on the ceiling portion 11c in the vicinity of the thick bottom portion W3 of the heated member W, and detects the ambient temperature in the vicinity of the bottom portion W3.

  The control device (burner control unit) 47 inputs the actual temperature of the cylindrical portion W1, the actual temperature of the intermediate portion W2, and the actual temperature of the bottom portion W3 of the heated member W detected by the temperature detectors 41, 42, and 43. At the same time, the ambient temperature in the vicinity of the cylindrical portion W1, the ambient temperature in the vicinity of the intermediate portion W2, and the ambient temperature in the vicinity of the bottom portion W3 of the heated member W detected by the temperature detectors 44, 45, and 46 are input.

  And the control apparatus 47 adjusts the automatic flow control valves 22-1 to 22-22 based on each substantial temperature in the cylindrical part W1, the intermediate | middle part W2, and the bottom part W3 in the to-be-heated member W, or the atmospheric temperature of the vicinity. Thus, the outputs of the plurality of burners 21-1 to 21-22 can be adjusted.

  Moreover, the control apparatus 47 can adjust the output of the whole burners 21-1 to 21-22 by performing ON / OFF and opening degree adjustment of the automatic flow control valves 22-1 to 22-22. Specifically, the control device 47 operates the automatic flow control valves 22-1 to 22-22 based on the actual temperatures at the cylindrical portion W1, the intermediate portion W2, and the bottom portion W3 of the heated member W, and starts the burner. The number of 21-1 to 22-22 is adjusted.

  That is, burners 21-1, 21-3, 21-12, 21-13, and 21-14 are assigned as the first group corresponding to the thin cylindrical portion W1 in the heated member W, and correspond to the intermediate portion W2. Burners 21-16, 21-17 are assigned as the second group, and burners 21-10, 21-11, 21-18, 21-20, 21-21 are assigned as the third group corresponding to the thick bottom portion W3. , 21-22 are assigned. Therefore, in the burners 21 other than the 13 burners 21, the corresponding automatic flow rate adjustment valve 22 is OFF (opening degree 0).

  And the control apparatus 47 of the burners 21-1, 21-3, 21-12, 21-13, and 21-14 assigned to the 1st group based on the substantial temperature in the cylindrical part W1 in the to-be-heated member W. By turning ON / OFF, the number of burners 21 to be activated is adjusted. Similarly, the control device 47 turns on / off the burners 21-16 and 21-17 assigned to the second group based on the actual temperature in the intermediate portion W2 of the heated member W, thereby starting the burner. Adjust the number of 21. Similarly, the control apparatus 47 is based on the substance temperature in the bottom part W3 in the to-be-heated member W, The burner 21-10, 21-11, 21-18, 21-20, 21-21 allocated to the 3rd group. The number of burners 21 to be activated is adjusted by turning ON / OFF 21-22.

  The first group of burners 21-3 and 21-14 are preferably set such that the opening degree is 70% when the base 12 is placed on because the gantry 12 is disposed on the front surface.

  Here, the specific control by the control apparatus 47 when heat-treating the to-be-heated member W in the gas furnace 11 is demonstrated. Examples of the heat treatment of the heated member W include stress removal and quenching of the welded portion, and as shown in FIG. 3, the target of the heated member W depends on the type of heat treatment, the size and shape of the heated member W, and the like. The actual temperature is set, and the control device 47 controls the outputs of the plurality of burners 21 so that the actual temperature of the heated member W becomes the target actual temperature.

  As shown in FIG. 1, in a state where the heated member W is supported by the two bases 12 in the gas furnace 11, the control device 47 performs three groups at time t <b> 1 as shown in FIG. 3. The 13 burners 21 assigned to are ignited in a preset order. That is, the control device 47 switches each automatic flow control valve 22 corresponding to the 13 burners 21 assigned to the three groups from OFF to ON. At this time, the controller 47 sets the first temperature increase rate (100 ° C./H) for the member W to be heated in the first temperature increase region A from 20 ° C. of normal temperature to 350 ° C. of the first heating temperature. The ignition timings of the 13 burners 21 are adjusted so that the actual temperature of the heated member W becomes the target actual temperature and the first temperature increase rate.

  The assignment state of the burners 21 in the three groups is shown in Table 1 below. As can be seen from Table 1, the firing order of the five burners 21 assigned to the first group is 3-12-13-1-14, and the firing order of the burners 21 assigned to the second group is 17-16, and the ignition order of the burners 21 assigned to the third group is 18-11-10-20-22-21. This Table 1 is displayed on the display so that an operator can visually recognize it. When the number of the burner 21 is lit, the burner 21 that has been ignited can be grasped, and the number of ignitions relative to the number of assigned parts can be grasped. Can do.

  As shown in FIG. 3, the control device 47 is configured so that any one of the substantial temperatures of the cylindrical portion W1, the intermediate portion W2, and the bottom portion W3 of the heated member W detected by the temperature detectors 41, 42, and 43 is the first heating temperature. When the temperature reaches 350 ° C., at time t 2, the second heating temperature region B from the first heating temperature of 350 ° C. to the second heating temperature of 610 ° C. is entered. A heating rate (50 ° C./H) is set. The controller 47 adjusts the ignition timing and extinguishing timing of the 13 burners 21 so that the actual temperature of the heated member W becomes the target actual temperature and the second temperature increase rate.

  In this case, the second temperature increase rate (50 ° C./H) in the second temperature increase region B is set lower than the first temperature increase rate (100 ° C./H) in the first temperature increase region A.

  When adjusting the output of each burner 21 in the first temperature rising area A and the second temperature rising area B, the control device 47 performs ignition and extinguishing individually in each group, thereby heating The actual temperature of the member W is adjusted. In this case, the control device 47 performs PID control based on the actual temperatures of the cylindrical portion W1, the intermediate portion W2, and the bottom portion W3 of the heated member W detected by the temperature detectors 41, 42, and 43.

For example, as shown in FIG. 4, the target actual temperature Tt of the heated member W is set, and the control device 47 detects the actual temperature T of the cylindrical portion W1 of the heated member W detected by the first temperature detector 41. ₁ to turn on / off each of the burners 21-1, 21-3, 21-12, 21-13, and 21-14 of the first group to adjust the heating temperature. That is, the cylindrical portion W1, since a thin, when the substantial temperature _{T 1} is raised to the target entity temperature Tt, OFF all burner 21-1,21-3,21-12,21-13,21-14 Even if it is hard to decrease the temperature. Therefore, the control device 47, when the substantial temperature T ₁ of the cylindrical portion W1 is decreased, started one burner 21, when the substantial temperature T ₁ of the cylindrical portion W1 from approaching the target entity temperature Tt is increased, all the burners 21 is stopped.

Further, the control unit 47, based on substantial temperature _{T 2} of the intermediate portion W2 of the heated member W by the second temperature detector 42 detects, ON / OFF of each burner 21-16,21-17 of the second group To adjust the heating temperature. That is, the intermediate portion W2 also because it is thin, the entity when the temperature _{T 2} is raised up to the target entity temperature Tt, the temperature hardly decreases even when OFF all burners 21-16,21-17. Therefore, the control unit 47, all the burners 21-16,21-17 stops when the substantial temperature _{T 2} of the intermediate portion W2 approaches the target entity temperature Tt, the entity of the intermediate portion W2 of exceeding the target entity temperature Tt When temperature _{T 2} is lowered, to start one of the burner 21.

Furthermore, the control unit 47 based on the bottom W3 ride substantial temperature _{T 3} of the heated member W to the third temperature detector 43 detects, each burner of the third group 21-10,21-11,21-18 , 21-20, 21-21, 21-22 are turned on and off to adjust the heating temperature. That is, the bottom W3, since a thick, entities although the temperature _{T 3} is not easily increased, when heated rapidly, since it exceeds the target entity temperature Tt, multiple burners 21-10,21-11, 21-18, 21-20, 21-21, 21-22 are gradually heated to approach the target actual temperature Tt. Therefore, the control unit 47, a burner 21 which is substantial temperature T ₃ of the bottom W3 starts to rise and 4, a burner 21 that the rate of increase in the substantial temperature T ₃ of the bottom W3 starts to decline as five, bottom W3 of the substantial temperature T ₃ of the burner 21 to start to decline is a seven, the target entity to substantial temperature T ₃ of the bottom W3 and the like again substantial temperature T ₃ of the bottom W3 to the burner 21 and six to start rising It approaches the temperature Tt.

  Thereafter, as shown in FIG. 3, the controller 47 determines that the actual temperatures at the cylindrical portion W1, the intermediate portion W2, and the bottom portion W3 of the heated member W detected by the temperature detectors 41, 42, and 43 are the second heating temperatures. When the temperature reaches 610 ° C., it enters the heating temperature maintaining region C that maintains the second heating temperature of 610 ° C. at time t3. Here, the second heating temperature 610 ° C. with respect to the member W to be heated is a predetermined deviation. The ignition timing and extinguishing timing of the 13 burners 21 are adjusted so as to maintain within (± 15 ° C.).

  Then, when the predetermined time (heat treatment time) in which the second heating temperature is set to 610 ° C. has elapsed, the control device 47 reduces the temperature from the second heating temperature to 610 ° C. at time t4. Since entering D, the temperature decreasing rate (50 ° C./H) for the member to be heated W is set here. The control device 47 adjusts the ignition timing and the extinguishing timing of the 13 burners 21 so that the actual temperature of the heated member W becomes the target actual temperature and the temperature decreasing speed.

  After that, when the temperature reaches a predetermined temperature, the control device 47 stops the 13 burners 21 at time t5. Then, in the second temperature drop region E, the control device 47 determines that the actual temperatures at the cylindrical portion W1, the intermediate portion W2, and the bottom portion W3 of the heated member W detected by the temperature detectors 41, 42, and 43 are the heating temperatures (first temperature). When the temperature is lowered to 350 ° C., which is the same as the one heating temperature, the door of the gas furnace 11 is opened at time t6.

  In addition, since the control apparatus 47 can control the automatic flow control valve 22 of the burner 21 in the areas A to D, it is currently assigned based on the detection results of the temperature detectors 41, 42, and 43. In each burner of the group, even before or during the start of heat treatment depending on the shape of the heated member W, change of burner assigned to each group, change of firing order, change of group organization, increase / decrease of group, etc. Is possible. Even if some of the burners 21 break down, various changes can be made. Furthermore, the output of all the burners 21 can be changed by changing the output of each burner 21 and adjusting the automatic flow rate adjusting valves 22-1 to 22-22.

In the present embodiment, the control device 47 includes 13 burners based on the actual temperatures of the cylindrical portion W1, the intermediate portion W2, and the bottom portion W3 of the heated member W detected by the temperature detectors 41, 42, and 43. Since the output is adjusted by adjusting the ignition timing and the fire extinguishing timing of 21, it is possible to appropriately adjust the actual temperature of the member W to be heated to the target actual temperature. That is, as shown in FIG. 5, in this embodiment, the target entity temperature Tt, is the substantial temperature T ₃ of the real temperatures T ₁ and the bottom W3 of the cylindrical portion W1 of heated member W, the target entity temperature Tt It is gradually approaching without greatly exceeding. On the other hand, the target entity temperature Tt, the ambient temperature T ₁₃ in the vicinity of the ambient temperature T ₁₁ and the bottom portion W3 in the vicinity of the cylindrical portion W1 of heated member W is approached gradually from greatly exceeds the target entity temperature Tt ing.

  As described above, in the gas furnace control apparatus according to the present embodiment, the gas furnace 11 is configured by providing a plurality of burners 21 on the furnace wall, and the temperature of the heated member W supported in the furnace is directly detected. Temperature detectors 41, 42, and 43, and a controller 47 that adjusts the outputs of the plurality of burners 21 based on the actual temperature of the heated member W detected by the temperature detectors 41, 42, and 43 are provided.

  Accordingly, each temperature detector 41, 42, 43 detects the actual temperature of the heated member W, and the control device 47 is based on the actual temperature of the heated member W detected by this temperature detector 41, 42, 43. Since the outputs of the plurality of burners 21 are adjusted, the actual temperature of the member to be heated W can be adjusted, regenerative heating control according to the type of heat treatment can be performed, and the heat treatment of the member to be heated W can be performed with high accuracy. It can be performed.

  Further, in the gas furnace control device of this embodiment, the control device 47 adjusts the number of burners 21 to be activated based on the detection results of the temperature detectors 41, 42, 43. Therefore, it is not necessary to adjust the fuel amount and the air amount in all the burners, and it is only necessary to adjust the fuel amount and the air amount of the burner to be activated, and the control can be simplified.

  Further, in the gas furnace control device of the present embodiment, the temperature detectors 41 and 43 are fixed to the thin cylindrical portion W1 and the thick bottom portion W3 of the heated member W, and the control device 47 includes the cylindrical portion W1. And the output of the some burner 21 is adjusted based on the temperature of bottom part W3. Accordingly, the cylindrical portion W1 and the bottom portion W3 of the heated member W have different heat transfer times, and therefore the temperature rise of the bottom portion W3 is delayed compared to the cylindrical portion W1, but the temperature detectors 41 and 43 are connected to the cylindrical portion W1. Since the actual temperature of the bottom part W3 is detected separately and the control device 47 adjusts the output of the burner 21 in accordance with each temperature, it is possible to perform an optimum heat treatment suitable for the shape of the heated member W. .

  Moreover, in the control apparatus of the gas furnace of a present Example, the some burner 21 is divided into the group corresponding to the cylindrical part W1 of the to-be-heated member W, the group corresponding to the intermediate part W2, and the group corresponding to the bottom part W3. The control device 47 adjusts the number of burners 21 activated in each group based on the detection results of the temperature detectors 41, 42, and 43. Therefore, the control device 47 adjusts the number of the burners 21 activated in each group based on the actual temperatures of the cylindrical portion W1, the intermediate portion W2, and the bottom portion W3. Optimal heat treatment suitable for the shape can be performed.

  Moreover, in the control apparatus of the gas furnace of a present Example, the group corresponding to the bottom part W3 in the to-be-heated member W sorts more burners 21 than the group corresponding to the cylindrical part W1. Accordingly, the temperature rise of the bottom W3 of the heated member W is delayed, but if the heat is applied suddenly, the substantial temperature of the bottom W3 greatly exceeds the target temperature, so the heated member W is slowly moved by the multiple burners 21. By heating, the optimum heating adapted to the bottom W3 can be performed.

  Further, in the gas furnace control device according to the present embodiment, the control device 47 includes a plurality of burners 21 so that the first heating rate is increased with respect to the heated member W up to a predetermined first heating temperature set in advance. The output is adjusted, and when the first heating temperature is reached, the outputs of the plurality of burners 21 are adjusted so that the second heating rate is lower than the first heating rate. Therefore, optimal heat treatment can be performed without applying a load to the heated member W.

  Moreover, the control method of the gas furnace of Example 1 detects the substantial temperature of the to-be-heated member W supported in the furnace, and adjusts the output of the some burner 21 based on this substantial temperature. In this case, the plurality of burners 21 are classified into a group corresponding to the thin cylindrical portion W1 and a group corresponding to the thick bottom portion W3 of the member to be heated W, and corresponding groups based on the actual temperature of the cylindrical portion W1. The number of burners 21 activated in the corresponding group is adjusted based on the actual temperature of the bottom W3.

  Therefore, the actual temperature of the member to be heated W can be adjusted, regenerative heating control according to the type of heat treatment can be performed, and heat treatment of the member to be heated W can be performed with high accuracy. In addition, since the number of burners 21 activated in each group is adjusted according to the actual temperatures of the cylindrical portion W1 and the bottom portion W3 of the heated member W, the optimum adjustment suitable for the shape of the heated member can be achieved with simple control. Heat treatment can be performed.

  Further, in the gas furnace control method according to the first embodiment, depending on the shape of the member to be heated W, the change of the burners 21 sorted into groups, the change of the burner ignition order, the change of the group organization before or during the start of the heat treatment It is possible to increase or decrease the group. Therefore, the optimum heat treatment adapted to the shape of the member to be heated can be performed with simple control.

  In the above-described embodiment, 22 burners 21 are provided in the gas furnace 11, but this number may be set as appropriate according to the size and shape of the gas furnace 11, the type of member to be heated, and the like. is there. Further, the number (13) of burners 21 to be used and the number of groups (3 groups) may be set as appropriate depending on the size and shape of the member to be heated.

11 Gas furnace 21, 21-1 to 21-22 Burner 22, 22-1 to 22-22 Automatic flow rate adjustment valve 41, 42, 43 Temperature detector 47 Control device (burner control unit)
W Heated member W1 Cylindrical part (thin part)
W2 Middle part W3 Bottom part (thick part)

Claims (9)

In a gas furnace in which a plurality of burners are provided on the furnace wall,
A temperature detector that directly detects the temperature of the heated member supported in the furnace;
A burner controller that adjusts the outputs of the plurality of burners based on the detection result of the temperature detector;
A control apparatus for a gas furnace, comprising:   2. The gas furnace control device according to claim 1, wherein the burner control unit adjusts the number of burners to be activated based on a detection result of the temperature detector. 3.   The temperature detector is fixed to at least the thick part and the thin part of the heated member, and the burner control unit adjusts the outputs of the plurality of burners based on the temperatures of the thick part and the thin part. The gas furnace control device according to claim 1 or 2, wherein the control device is a gas furnace.   The plurality of burners are classified into a group corresponding to the thick part of the heated member and a group corresponding to the thin part of the heated member, and the burner control unit determines the detection result of the temperature detector. 4. The gas furnace control device according to claim 3, wherein the number of burners activated in each group is adjusted based on the number of burners.   5. The gas furnace control device according to claim 4, wherein the group corresponding to the thick portion in the member to be heated has a larger number of the burners sorted than the group corresponding to the thin portion.   The burner control unit adjusts the outputs of the plurality of burners so as to achieve a first temperature increase rate for the member to be heated up to a predetermined first heating temperature set in advance, and when the first heating temperature is reached. 6. The gas furnace control device according to claim 1, wherein outputs of the plurality of burners are adjusted so that a second temperature increase rate is lower than a first temperature increase rate. In a gas furnace in which a plurality of burners are provided on the furnace wall,
Directly detecting the temperature of the heated member supported in the furnace, and adjusting the outputs of the plurality of burners based on the detection result;
A method for controlling a gas furnace.   The plurality of burners are sorted into a group corresponding to the thick part of the heated member and a group corresponding to the thin part, and activated in the group corresponding to the thick part based on the temperature of the thick part 8. The method of controlling a gas furnace according to claim 7, wherein the number of burners that are activated in a group corresponding to the thick portion is adjusted based on a temperature of the thin portion while adjusting the number of burners. 9. .   The shape of the member to be heated is configured to change the burner sorted into the group, change the burner ignition order, change the group organization, or increase / decrease the group before the heat treatment starts or during the heat treatment operation. Item 9. A gas furnace control method according to Item 8.

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