Radiant tube replacement method and radiant tube replacement cart

Abstract

To provide a method for replacing a radiant tube and a carriage for replacing radiant tube capable of efficiently carrying out a maintenance work of a heating furnace.SOLUTION: A method for replacing a radiant tube comprises: a first step for positioning a first carriage with a holding part that does not hold the radiant tube on a frame deck and positioning a second carriage with the holding part that holds a new radiant tube on the frame deck; a second step for moving the first carriage so that the first carriage locates at a replacement position of the frame deck that faces a used radiant tube; a third step for allowing the holding part of the first carriage to hold the used radiant tube; a fourth step for retracting the first carriage from the replacement position; a fifth step for moving the second carriage so that the second carriage locates at the replacement position; and a sixth step for mounting a new radiant tube which the holding part of the second carriage holds to a furnace body.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a radiant tube replacement method and a radiant tube replacement carriage. [Background technology]

[0002] Inside a heating furnace (such as a continuous annealing furnace), many furnace internal parts (such as radiant tubes and rollers) are arranged. During regular maintenance of a heating furnace, in addition to replacing used furnace internal parts with new ones, work such as repairing and improving the heating furnace is also carried out, and these works are carried out using an overhead crane installed in the heating furnace building.

[0003] Radiant tubes are generally located at an elevation of approximately 5 to 20 meters above ground level. Therefore, replacing a radiant tube requires the use of an overhead crane, which takes time. Furthermore, during maintenance, multiple radiant tubes typically need to be replaced, so the limited number of overhead cranes available can be monopolized by the radiant tube replacement work, potentially interfering with other work.

[0004] Patent Document 1 discloses a method for replacing radiant tubes in which an exchange device, which is an integrated unit consisting of an exchange carriage with a holder for holding the radiant tubes and rails for moving the exchange carriage, is transported between the ground and a structural deck by an overhead crane. In this case, when the radiant tubes are attached or detached from the furnace body, the radiant tubes are held by the holder of the exchange carriage, eliminating the need for an overhead crane, and therefore the overhead crane's occupation time for the radiant tube replacement work is reduced. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 4-194506 Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the replacement method of Patent Document 1, the overhead crane is occupied during the following work, all of which is performed during the heating furnace maintenance period. Therefore, with the replacement method of Patent Document 1, the overhead crane still needs to be used during the heating furnace maintenance period. (1) When transporting an empty exchange device to accommodate used radiant tubes from the ground to the structural deck. (2) When transporting the replacement device holding the used radiant tube from the structural deck to the ground. (3) When removing the used radiant tube from the replacement device and installing a new radiant tube into the replacement device. (4) When transporting the replacement device holding the new radiant tube from the ground to the structural deck. (5) When a new radiant tube is attached to the furnace body and the empty replacement unit is transported from the structural deck to the ground.

[0007] Therefore, the present disclosure describes a radiant tube replacement method and a radiant tube replacement cart that enable efficient maintenance work on heating furnaces. [Means for solving the problem]

[0008] Example 1. One example of a method for replacing radiant tubes is a method for replacing used radiant tubes attached to the furnace body of a heating furnace with new radiant tubes using a plurality of bogies including a first bogie and a second bogie, each of which has a running section configured to be able to run on the structural deck of the heating furnace, and a holding section mounted on the running section and configured to be able to hold a radiant tube. An example of a method for replacing radiant tubes includes a first step of placing a first cart on the structural deck whose holding part does not hold a radiant tube, and placing a second cart on the structural deck whose holding part holds a new radiant tube; a second step of moving the first cart on the structural deck so that the first cart is positioned at an exchange position on the structural deck facing the used radiant tube after the first step; a third step of holding the used radiant tube in the holding part of the first cart after the second step; a fourth step of moving the first cart from the exchange position on the structural deck after the third step; a fifth step of moving the second cart on the structural deck so that the second cart is positioned at the exchange position after the fourth step; and a sixth step of attaching the new radiant tube held by the holding part of the second cart to the furnace body after the fifth step. In this case, when replacing a radiant tube, an empty cart (first cart) that can travel on the structural deck and a cart (second cart) that can travel on the structural deck and holds a new radiant tube are already positioned on the structural deck. Therefore, there is no need to use the furnace's overhead crane during the process from removing the used radiant tube from the furnace body to installing the new radiant tube in the furnace body. Therefore, the time the overhead crane is occupied during the radiant tube replacement work is extremely short. As a result, it is possible to carry out maintenance work on the heating furnace efficiently.

[0009] Example 2: The method of Example 1 may further include a seventh step, prior to the first step, of transporting the first and second carriages from the ground to the structural deck using an overhead crane while the heating furnace is in operation, and an eighth step, after the sixth step, of transporting the first and second carriages from the structural deck to the ground using an overhead crane while the heating furnace is in operation. In this case, the work of transporting the first and second carriages between the ground and the structural deck using the overhead crane is performed while the heating furnace is in operation, i.e., while the heating furnace is not undergoing maintenance. In other words, the overhead crane is not used for replacing the radiant tubes during maintenance work on the heating furnace. This makes it possible to perform maintenance work on the heating furnace extremely efficiently.

[0010] Example 3: In the method of Example 1 or Example 2, the third step may include holding a used radiant tube in the holding portion of the first bogie while the first bogie is fixed to the structural deck, and the sixth step may include attaching a new radiant tube held by the holding portion of the second bogie to the furnace body while the second bogie is fixed to the structural deck. In this case, the bogie delivers and receives the radiant tube while positioned. This makes it easier to replace the radiant tube. Furthermore, there is no concern that the bogie will lose balance and tilt during the radiant tube replacement process.

[0011] Example 4: In any of the methods of Examples 1 to 3, after the fifth step and before the sixth step, the distance to a base portion provided in the heating furnace is measured by a measuring unit, and the pushing amount of the new radiant tube is determined based on the measured distance. WorkThe sixth step may include pushing the new radiant tube from the second carriage into the furnace based on the pushing amount, thereby placing the protrusion at the tip of the radiant tube on the base. In this case, the extremely simple technique of measuring the distance with the measuring unit makes it possible to easily place the new radiant tube in the appropriate position within the furnace, without requiring an operator to enter the furnace and check the position of the tip (protrusion) of the radiant tube.

[0012] Example 5: In any of the methods of Examples 1 to 4, the holding portion may include a base portion and a connecting portion configured to detachably connect the base portion to the proximal end of the radiant tube via a pin. In this case, the radiant tube can be held in the holding portion by the extremely simple technique of inserting and removing the pin.

[0013] Example 6: In any of the methods of Examples 1 to 4, the holding unit may include a base unit, a first connecting unit configured to detachably connect the upper base end of the radiant tube to the base unit via a first pin, and a second connecting unit configured to detachably connect the lower base end of the radiant tube to the base unit via a second pin. The first connecting unit may be rotatable about a first through-hole provided in the base unit when the first pin is inserted through the first through-hole. The second connecting unit may be movable along the extension direction of a second through-hole provided in the base unit and extending in an arc shape centered on the first through-hole when the second pin is inserted through the second through-hole. Radiant tubes deteriorate over time with use and deform, causing them to sag downward. Therefore, when a used radiant tube is pulled straight out of the furnace body horizontally, the deformed portion may interfere with the furnace wall. However, according to Example 6, when the radiant tube is held in the holder, the radiant tube can rotate around the first pin along the extension direction of the second through hole. Therefore, if the used radiant tube is deformed, the deformed portion can be displaced upward by rotating the radiant tube around the first pin. Therefore, by pulling the used radiant tube out of the furnace body in this state, even a used radiant tube that is significantly deformed can be easily pulled out horizontally from the furnace body.

[0014] Example 7: In any of the methods of Examples 1 to 6, the holding unit is mounted on the traveling unit so as to be movable forward and backward relative to the traveling unit, and the third step includes advancing the holding unit of the first carriage so that the holding unit approaches the furnace body, removing the used radiant tube from the furnace body while the used radiant tube is held by the holding unit of the first carriage, and retracting the holding unit of the first carriage so that the holding unit of the first carriage moves away from the furnace body, in this order; and the sixth step may include advancing the holding unit of the second carriage so that the holding unit of the second carriage approaches the furnace body, attaching a new radiant tube held by the holding unit of the second carriage to the furnace body, and retracting the holding unit of the second carriage so that the holding unit of the second carriage moves away from the furnace body, in this order. In this case, by moving the holding unit forward and backward relative to the traveling unit, the radiant tube held by the holding unit can be easily moved from the carriage to the heating furnace or from the heating furnace to the carriage. This makes it easier to replace the radiant tube.

[0015] Example 8. In the method of Example 7, the carriage is configured to suspend and hold the radiant tube, and further comprises a suspension unit mounted on the running section so as to be movable forward and backward relative to the running section, and in the first step, instead of the holding section of the second carriage, the suspension unit of the second carriage suspends and holds a new radiant tube, and in the third step, the holding section of the first carriage advances so that the holding section approaches the furnace body, and while the used radiant tube is held by the holding section of the first carriage, the used radiant tube is removed from the furnace body, and the holding section of the first carriage retreats so that the holding section moves away from the furnace body, and after the used radiant tube is suspended and held by the suspension unit of the first carriage, the used radiant tube is removed by the holding section of the first carriage. and a sixth step may include advancing the second carriage's suspension unit so that it approaches the furnace body, releasing the suspension of the new radiant tube by the suspension unit of the second carriage after the new radiant tube is held by the second carriage's holding unit, advancing the second carriage's holding unit so that it approaches the furnace body, attaching the new radiant tube held by the second carriage's holding unit to the furnace body, and retracting the second carriage's holding unit so that it moves away from the furnace body. Note that some heating furnaces have limited space on their structural decks, necessitating the use of small carriages. The holding unit mounted on the running unit cannot move forward or backward beyond the size of the small bogie (the size of the running unit), so there are restrictions on the holding position of the radiant tube relative to the small bogie. Therefore, if the radiant tube is held by the holding unit of the small bogie, there is a concern that the radiant tube may protrude from the small bogie or the weight of the radiant tube may cause the small bogie to float up.However, according to Example 8, when receiving used radiant tubes removed from the furnace body and when attaching new radiant tubes to the furnace body, the radiant tubes are held by the holding section, while at other times the radiant tubes are suspended by the hanging section. In this way, by transferring the radiant tubes between the holding section and the hanging section, the position of the radiant tube suspended by the hanging section relative to the small cart can be adjusted. Therefore, even when a small cart is used, the radiant tubes can be moved forward and backward beyond the size of the small cart (the length of the running section), for example, and the constraints on the radiant tube's holding position relative to the small cart are relaxed. Therefore, the radiant tubes can be moved stably using the small cart.

[0016] Example 9. Another example of a method for replacing radiant tubes is a method for replacing a first used radiant tube attached to the furnace body of a heating furnace with a first new radiant tube, and replacing a second used radiant tube attached to the furnace body of the heating furnace with a second new radiant tube, using a plurality of carriages including a first carriage, a second carriage, and a third carriage, each of which has a running section configured to be able to run on the structural deck of the heating furnace, and a holding section mounted on the running section and configured to be able to hold a radiant tube.Another example of a radiant tube replacement method includes a first step of placing a first bogie on the structural deck whose holding unit is not holding a radiant tube, placing a second bogie on the structural deck whose holding unit is holding a first new radiant tube, and placing a third bogie on the structural deck whose holding unit is holding a second new radiant tube; a second step of moving the first bogie on the structural deck so that the first bogie is positioned at a first replacement position on the structural deck facing the first used radiant tube; a third step of holding the first used radiant tube on the holding unit of the first bogie after the second step; a fourth step of moving the first bogie from the first replacement position on the structural deck after the third step; a fifth step of moving the second bogie on the structural deck so that the second bogie is positioned at the first replacement position after the fourth step; a sixth step of attaching the first new radiant tube held by the holding portion of the second carriage to the furnace body after the sixth step; a seventh step of retracting the second carriage from the first replacement position on the structural deck after the sixth step; an eighth step of moving the second carriage on the structural deck so that the second carriage is positioned at a second replacement position on the structural deck facing the second used radiant tube after the seventh step; This example includes a ninth step of holding the used radiant tube in the holding portion of the second bogie, a tenth step of moving the second bogie from the second replacement position on the structural deck after the ninth step, an eleventh step of moving the third bogie on the structural deck so that the third bogie is positioned at the second replacement position after the tenth step, and a twelfth step of attaching the second new radiant tube held by the holding portion of the third bogie to the furnace body after the eleventh step. In this case, the same effects as in Example 1 can be obtained. In addition, by simply preparing one more bogie than the number of radiant tubes to be replaced, the used radiant tubes can be sequentially replaced with new radiant tubes.In other words, by attaching a first new radiant tube to the heating furnace and having an empty second cart hold a second used radiant tube, it is possible to perform radiant tube replacement work extremely efficiently using a minimum number of carts.

[0017] Example 10. An example of a radiant tube exchange carriage comprises a running section configured to be able to run on the structural deck of a heating furnace, a holding section configured to be able to hold a radiant tube, and a hanging section configured to suspend and hold the radiant tube. The holding section is mounted on the running section so that it can move forward and backward relative to the running section. The hanging section is mounted on the running section so that it can move forward and backward relative to the running section independently of the holding section. In this case, the same effects as in Examples 1 and 8 can be obtained. [Effects of the Invention]

[0018] The radiant tube replacement method and radiant tube replacement cart disclosed herein enable efficient maintenance work on heating furnaces. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a top view schematically showing an example of a heating furnace. [Figure 2] 2(a) is a cross-sectional view taken along line IIA-IIA in FIG. 1, and FIG. 2(b) is a cross-sectional view taken along line IIB-IIB in FIG. [Figure 3] FIG. 3 is a side view schematically illustrating an example of an exchange carriage. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 5 is a perspective view for explaining the connection state between the base portion and the connection portion. [Figure 6] FIG. 6 is a top view of a heating furnace for explaining an example of a radiant tube replacement process. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8]FIG. 8 is a top view of the heating furnace for explaining the process subsequent to that shown in FIG. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. [Figure 10] FIG. 10 is a cross-sectional view of the heating furnace and the exchange carriage for explaining the process subsequent to that shown in FIG. [Figure 11] FIG. 11 is a top view of the heating furnace for explaining the subsequent processing steps shown in FIG. [Figure 12] FIG. 12 is a top view of the heating furnace for explaining the subsequent processing steps shown in FIG. [Figure 13] FIG. 13 is a top view of a heating furnace for explaining another example of the radiant tube replacement process. [Figure 14] FIG. 14 is a top view of the heating furnace for explaining the process subsequent to that shown in FIG. [Figure 15] FIG. 15 is a top view of the heating furnace for explaining the process subsequent to that shown in FIG. [Figure 16] FIG. 16 is a top view of the heating furnace for explaining the process subsequent to that shown in FIG. [Figure 17] FIG. 17 is a top view of the heating furnace for explaining the process subsequent to that shown in FIG. [Figure 18] FIG. 18 is a top view of the heating furnace for explaining the process subsequent to that shown in FIG. [Figure 19] FIG. 19 is a side view schematically showing another example of the exchange carriage. [Figure 20] FIG. 20 is a cross-sectional view of the heating furnace and the exchange carriage for illustrating the process of removing a used radiant tube from the furnace body using the exchange carriage of FIG. [Figure 21] FIG. 21 is a cross-sectional view of the heating furnace and the exchange carriage for explaining the process subsequent to that shown in FIG. [Figure 22] FIG. 22 is a cross-sectional view of the heating furnace and the exchange carriage for explaining the process subsequent to that shown in FIG. [Figure 23]FIG. 23 is a cross-sectional view of a heating furnace and an exchange carriage for explaining the process of attaching a new radiant tube to the furnace body using the exchange carriage of FIG. [Figure 24] FIG. 24 is a cross-sectional view of the heating furnace and the exchange carriage for explaining the process subsequent to that shown in FIG. [Figure 25] FIG. 25 is a cross-sectional view of the heating furnace and the exchange carriage for explaining the process subsequent to that shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] In the following description, the same elements or elements having the same functions will be designated by the same reference numerals, and redundant explanations will be omitted. Note that in this specification, when referring to the top, bottom, right, and left of a figure, the directions of the reference numerals in the figure will be used as the reference.

[0021] [Heating furnace] First, the configuration of a heating furnace 1 will be described with reference to Figures 1 and 2. The heating furnace 1 is, for example, a continuous annealing furnace, and includes a furnace body 2, a plurality of (for example, several tens of) radiant tubes 3 arranged inside the furnace body 2, a structural deck 4, and a transport device (not shown).

[0022] Furnace body 2 includes a front wall 2a to which radiant tubes 3 are attached, a rear wall 2b positioned opposite front wall 2a, and a pedestal portion 2c provided on the surface of rear wall 2b so as to be located within furnace body 2. Front wall 2a has a plurality of openings 2d formed therein for attaching radiant tubes 3. Radiant tubes 3 may be attached to front wall 2a using fastening members such as bolts, or by welding or the like.

[0023] The radiant tube 3 is a tubular combustion chamber for heating a specific region inside the furnace body 2. The radiant tube 3 is located inside the furnace body 2, for example, at a height of about 5 m to about 20 m above the ground (above the floor). The weight of the radiant tube 3 may be, for example, about 400 kg to 600 kg. In the following, the used radiant tube 3 to be replaced will be referred to as "radiant tube 3U" (shown in black in the drawings), and the new radiant tube 3 to be used in place of the radiant tube 3U will be referred to as "radiant tube 3N" (shown in bold in the drawings).

[0024] As shown in Figure 2, the radiant tube 3 includes a main body 3a and base ends 3b and 3c. The main body 3a may be bent so as to extend in a vertical plane when the radiant tube 3 is attached to the furnace body 2. For example, the main body 3a may be bent in the shape of the letter "W." As the radiant tube 3 deteriorates with use, it deforms and sags downward, as shown in Figure 2(b).

[0025] A protrusion 3d is provided at the tip end of the main body 3a (the portion opposite to the base ends 3b and 3c). When the radiant tube 3 is attached to the furnace body 2, the protrusion 3d is placed on the base 2c.

[0026] Base end 3b (upper base end) may be located on the upper side when radiant tube 3 is attached to furnace body 2. Base end 3c (lower base end) may be located on the lower side when radiant tube 3 is attached to furnace body 2.

[0027] The structural deck 4 is provided outside the furnace body 2 and is configured as a space where workers can perform various maintenance work on the heating furnace 1, including replacing the radiant tubes 3. A structural deck 4 may be provided for each floor of the furnace body 2. The transport device is configured to transport items between the ground and the structural deck 4, or to suspend and hold items in the air, for various maintenance work on the heating furnace 1. The transport device may be, for example, an overhead crane provided on the ceiling of the building where the heating furnace 1 is located, a mobile crane, a chain block configured to be able to travel on beams provided in the building where the heating furnace 1 is located, or a forklift.

[0028] [Exchange trolley] Next, the configuration of the exchange bogie 10 (bogie) will be described with reference to Figures 3 to 5. The exchange bogie 10 is used for replacing the radiant tubes 3, and is transported between the ground and the structural deck 4 by an overhead crane. Note that, below, an empty exchange bogie 10 (first bogie) that does not have a radiant tube 3 mounted thereon may be referred to as the "exchange bogie 10A," and an exchange bogie 10 (second bogie) that has a radiant tube 3N mounted thereon may be referred to as the "exchange bogie 10B."

[0029] As shown in Figures 3 and 4, the exchange carriage 10 includes a running section 20 and a holding section 30. The running section 20 includes a car body 21, a plurality of wheels 22, a drive section 23, and a rail member 24. The car body 21 extends in a predetermined direction and has a substantially rectangular shape when viewed from above. The length of the car body 21 may be longer than the radiant tubes 3 or may be approximately the same as the length of the radiant tubes 3.

[0030] The plurality of wheels 22 are attached to the sides of the car body 21 so as to be rotatable relative to the car body 21. This allows the exchange cart 10 to move on the frame deck 4, for example, by an operator manually pushing or pulling the exchange cart 10.

[0031] The drive unit 23 is an actuator such as an electric motor, and is configured to drive at least one of the plurality of wheels 22. The drive unit 23 may be configured to assist an operator in pushing and pulling the exchange cart 10, or may be configured to drive the wheels 22 based on instructions from a controller (not shown). In the latter case, the operator can operate the exchange cart 10 remotely.

[0032] The rail member 24 is provided on the car body 21 so as to extend linearly along the longitudinal direction of the car body 21. The rail member 24 may have a substantially C-shaped cross section, as exemplified in FIG.

[0033] The holding portion 30 is mounted on the running portion 20 and is configured to be able to hold the radiant tube 3. The holding portion 30 includes a base portion 40 and two connecting portions 50.

[0034] The base portion 40 includes a base member 41, a pair of side walls 42, and a plurality of wheels 43. The pair of side walls 42 are provided on the base member 41. The pair of side walls 42 are, for example, plate-shaped, and are arranged to face each other in the width direction of the vehicle body 21.

[0035] 3 and 5, through holes 42a and 42b are provided in the side wall 42. The through hole 42a (first through hole) is located in the upper part of the side wall 42 and has a circular shape. The through hole 42b (second through hole) is located in the lower part of the side wall 42. When viewed from the opposing direction of the pair of side walls 42, the through hole 42b has an arc shape with the through hole 42a at its center. The length of the through hole 42b in the longitudinal direction (extension direction) may be, for example, approximately 10 cm to 20 cm.

[0036] The plurality of wheels 43 are attached to the sides of the base member 41 so as to be rotatable relative to the base member 41. The wheels 43 are configured to roll along the longitudinal direction of the rail member 24. Therefore, for example, when an operator manually pushes or pulls the base unit 40, the base unit 40 can move between one end and the other end of the rail member 24 along the longitudinal direction of the rail member 24. Note that the wheels 43 may be sandwiched between the rail member 24 from above and below, as illustrated in FIG. 4. In this case, rattles of the base unit 40 in the vertical and horizontal directions are suppressed by the rail member 24.

[0037] The two connecting parts 50 are configured to connect the radiant tube 3 and the base part 40. The two connecting parts 50 are detachably attached to the base part 40 (side wall 42) so as to be aligned vertically. Note that, below, the upper connecting part 50 may be referred to as "connecting part 50A" (first connecting part), and the lower connecting part 50 may be referred to as "connecting part 50B" (second connecting part).

[0038] 3 to 5, the connecting portion 50 includes a base member 51, an insert member 52, a pair of wall members 53, and a plurality of pins 54. The base member 51 is, for example, plate-shaped.

[0039] The insert member 52 is provided on the base member 51 so as to protrude from one of the main surfaces of the base member 51. The insert member 52 has, for example, a cylindrical shape that is smaller than the inner diameter of the radiant tube 3. The insert member 52 has a flange portion 52a that protrudes outward from its outer surface. The flange portion 52a is configured so that the base end 3b of the radiant tube 3 can be attached and detached using a fastener (e.g., a bolt, etc.) not shown. When the flange portion 52a is fixed to the base end 3b of the radiant tube 3, the insert member 52 is inserted into the base end 3b, thereby suppressing rattling of the radiant tube 3.

[0040] The pair of wall members 53 are provided on the base member 51 so as to protrude from the other main surface of the base member 51 (the main surface opposite to the surface on which the insertion member 52 is provided). The pair of wall members 53 are, for example, plate-shaped, and are arranged to face each other in the width direction of the vehicle body 21. The distance between the pair of wall members 53 may be set smaller than the distance between the pair of side walls 42. As shown in FIG. 5, the wall member 53 is provided with a through hole 53a.

[0041] As shown in FIGS. 3 to 5, the connecting portion 50A is detachably attached to the base portion 40 (side wall 42) via the pin 54 by inserting the pin 54 into the through holes 42a and 53a. At this time, the connecting portion 50A is rotatable about the pin 54 (through holes 42a and 53a). On the other hand, the connecting portion 50B is detachably attached to the base portion 40 (side wall 42) via the pin 54 by inserting the pin 54 into the through holes 42b and 53a. At this time, the connecting portion 50B is movable along the extension direction of the arc-shaped through hole 42b. A retaining member (not shown) may be further used to prevent the pin 54 from falling off.

[0042] [How to replace the radiant tube] Next, a method for replacing a radiant tube 3 when there is only one radiant tube 3 to be replaced will be described with reference to FIGS.

[0043] First, two exchange carriages 10A and 10B are prepared. A new radiant tube 3N is held in the holder 30 of the exchange carriage 10B in advance. That is, the base end 3b of the radiant tube 3N is fixed to the flange 52a of the connecting portion 50A, and the base end 3c of the radiant tube 3N is fixed to the flange 52a of the connecting portion 50B. These connecting portions 50A and 50B are then detachably attached to the base portion 40 via pins 54. At this time, the radiant tube 3N may be held on the exchange carriage 10B so that the entire radiant tube 3N is positioned on the exchange carriage 10B. For example, the radiant tube 3N may be held on the exchange carriage 10B so that the center of gravity of the radiant tube 3N and the center of gravity of the exchange carriage 10B are approximately aligned or close to each other in the horizontal direction. Alternatively, base ends 3b and 3c of radiant tube 3N may be fixed to connecting portions 50A and 50B attached to base portion 40 by pins 54, respectively.

[0044] Next, as shown in Fig. 1, the two replacement carriages 10A, 10B are hoisted from the ground onto the structural deck 4 by an overhead crane. The hoisting of the replacement carriages 10A, 10B by the overhead crane may be performed while the heating furnace 1 is in operation. In other words, the replacement carriages 10A, 10B may be hoisted from the ground onto the structural deck 4 by the overhead crane during a period when maintenance work other than the replacement of the radiant tubes 3 is not being performed.

[0045] Next, as shown in Figures 6 and 7, an operator pushes and pulls the replacement carriage 10A on the structure deck 4 to move the replacement carriage 10A to the replacement position for the radiant tube 3U. The replacement position here is a position where the replacement carriage 10A is in front of the radiant tube 3U to be replaced. After the replacement carriage 10A arrives at the replacement position, the replacement carriage 10A may be fixed to the structure deck 4 by a fixing device 5. One fixing method is to use, for example, an angle-shaped fixing device 5 to fasten the car body 21 to the fixing device 5 with a fastener (e.g., bolts, etc.) not shown, while fastening the structure deck 4 to the fixing device 5 with a fastener (e.g., bolts, etc.) not shown.

[0046] Next, as shown in Figures 6 and 7, the operator pushes the holding part 30 of the exchange cart 10A toward the furnace body 2, bringing the holding part 30 closer to the front wall 2a (advancing it forward). Next, the base end 3b of the radiant tube 3U is fixed to the flange part 52a of the connecting part 50A, and the base end 3c of the radiant tube 3U is fixed to the flange part 52a of the connecting part 50B. Next, the radiant tube 3U attached to the front wall 2a of the furnace body 2 is removed from the front wall 2a. This transfers the radiant tube 3U from the furnace body 2 to the holding part 30. In this state, as shown in Figure 8, the operator pushes the holding part 30 back (retracts it) so that the holding part 30 moves away from the front wall 2a of the furnace body 2, and pulls out the radiant tube 3U through the opening 2d in the front wall 2a. At this time, because the main body 3a of the radiant tube 3U is deformed, the deformed portion may catch on the lower edge of the opening 2d, making it impossible to pull the radiant tube 3U out horizontally. In such a case, as shown in FIG. 9, the radiant tube 3U and the connecting portions 50A, 50B may be rotated about the pin 54 (through holes 42a, 53a) to displace the deformed portion of the radiant tube 3U upward, and the radiant tube 3U may then be pulled out through the opening 2d in the front wall 2a. At this time, the deformed portion may rub against the lower edge of the opening 2d, allowing the radiant tube 3U to be pulled out through the opening 2d. In this way, the radiant tube 3U is held on the exchange cart 10A so that the entire radiant tube 3U is positioned above the exchange cart 10A, as shown in FIG. 10.

[0047] Next, as shown in FIG. 11, the fixing device 5 is removed from the exchange cart 10A, and an operator pushes and pulls the exchange cart 10A on the structure deck 4 to move the exchange cart 10A holding the radiant tube 3U away from the exchange position. Next, an operator pushes and pulls the exchange cart 10B on the structure deck 4 to move the exchange cart 10B to the exchange position. The exchange position here is a position directly in front of the opening 2d in the front wall 2a from which the radiant tube 3U was removed. After the exchange cart 10B arrives at the exchange position, the exchange cart 10B may be fixed to the structure deck 4 by the fixing device 5, as in the case of the exchange cart 10A.

[0048] At this time, a measuring unit 6 (e.g., a laser distance measuring device) may be attached to the exchange carriage 10B to measure the distance to the base 2c, and the amount of pushing of the radiant tube 3N to be installed may be determined based on the measured distance. Incidentally, the radiant tube 3 expands and contracts due to heat as the heating furnace 1 operates. Therefore, the amount of pushing may be determined to be large enough so that the main body 3a of the radiant tube 3 does not come into contact with or fall off the base 2c even when the radiant tube 3 expands and contracts.

[0049] Next, as shown in FIG. 12, the operator pushes the holding part 30 of the exchange cart 10B toward the furnace body 2, moving the holding part 30 closer to the front wall 2a (advancing it forward) until the protruding part 3d of the radiant tube 3N is placed on the base part 2c. If the pushing amount has been determined, the holding part 30 is moved closer to the front wall 2a according to that pushing amount. Next, with the radiant tube 3N pushed through the opening 2d to a predetermined position in the furnace body 2, the radiant tube 3N is attached to the front wall 2a of the furnace body 2. Next, the base end 3b of the radiant tube 3N is removed from the flange part 52a of the connecting part 50A, and the base end 3c of the radiant tube 3N is removed from the flange part 52a of the connecting part 50B. This pushes the radiant tube 3N from the holding part 30 of the exchange cart 10B through the opening 2d in the front wall 2a into the furnace body 2 and attaches it to the furnace body 2.

[0050] Next, the worker pushes back (retracts) the holding part 30 of the replacement cart 10B so that the holding part 30 moves away from the front wall 2a of the furnace body 2. In this state, the fixing device 5 is removed from the replacement cart 10B, and the worker pushes and pulls the replacement cart 10B on the frame deck 4 to move the empty replacement cart 10B, which is not holding a radiant tube 3, away from the replacement position.

[0051] Next, the two replacement carriages 10A, 10B are suspended by a transport device (for example, an overhead crane) and lowered from the structural deck 4 to the ground. The transportation of the replacement carriages 10A, 10B to the ground by the overhead crane may be performed while the heating furnace 1 is in operation. In other words, the replacement carriages 10A, 10B may be lowered from the structural deck 4 to the ground by the overhead crane during a period when maintenance work other than the replacement of the radiant tubes 3 is not being performed.

[0052] [Effect] According to the above example, when replacing radiant tubes 3U and 3N, replacement carts 10A and 10B are already positioned on structural deck 4. Therefore, there is no need to use the overhead crane of heating furnace 1 during the process from removing radiant tube 3U from furnace body 2 to installing radiant tube 3N in furnace body 2. Therefore, the time the overhead crane is occupied during the replacement work of radiant tubes 3U and 3N is extremely short. As a result, maintenance work on heating furnace 1 can be carried out efficiently.

[0053] According to the above example, the work of transporting the exchange carriages 10A, 10B between the ground and the frame deck 4 by the overhead crane can be performed while the heating furnace 1 is in operation, i.e., during a period when the heating furnace 1 is not undergoing maintenance. In this case, maintenance work on the heating furnace 1 can be performed extremely efficiently.

[0054] According to the above example, when replacing radiant tubes 3U, 3N, exchange bogies 10A, 10B can be fixed to frame deck 4 by fasteners 5. In this case, exchange bogies 10A, 10B receive and deliver radiant tubes 3U, 3N while positioned. This makes it possible to more easily replace radiant tubes 3U, 3N. Furthermore, there is no risk of exchange bogies 10A, 10B losing balance and tilting during replacement of radiant tubes 3U, 3N.

[0055] According to the above example, when attaching radiant tube 3N to furnace body 2, the amount of pushing in of radiant tube 3N can be determined based on the distance to base portion 2c measured by measuring unit 6. In this case, the extremely simple method of measuring the distance using measuring unit 6 makes it possible to easily position radiant tube 3N in an appropriate position within heating furnace 1 without requiring an operator to enter heating furnace 1 and check the position of the tip end (protrusion 3d) of radiant tube 3N.

[0056] According to the above example, side wall 42 of base portion 40 and wall member 53 of connecting portions 50A, 50B can be detachably connected via pin 54. In this case, radiant tube 3 can be held in holding portion 30 by the extremely simple method of inserting and removing pin 54.

[0057] In the above example, connecting portion 50A can be rotated around pin 54 (through holes 42a, 53a), and connecting portion 50B can be moved along the extension direction of arc-shaped through hole 42b. In this case, even if radiant tube 3U is deformed, the deformed portion can be displaced upward by rotating radiant tube 3U, which is fixed to connecting portions 50A, 50B, around pin 54 (through holes 42a, 53a). Therefore, by pulling radiant tube 3U out of furnace body 2 in this state, even a significantly deformed radiant tube 3U can be easily pulled out horizontally from opening 2d.

[0058] According to the above example, the holding unit 30 can be mounted on the running unit 20 so that it can move forward and backward relative to the running unit 20. In this case, the radiant tube 3 held by the holding unit 30 can be easily moved from the exchange carriage 10 to the heating furnace 1, or from the heating furnace 1 to the exchange carriage 10. This makes it possible to more easily perform the replacement work of the radiant tube 3.

[0059] [Variations] The disclosure in this specification should be considered to be illustrative in all respects and not restrictive. Various omissions, substitutions, modifications, etc. may be made to the above examples without departing from the scope and spirit of the claims.

[0060] (1) For example, multiple radiant tubes 3 may be replaced using multiple exchange carriages 10. Here, with reference to Figures 13 to 18, an example will be described in which three exchange carriages 10A, 10B, and 10C are used to replace two used radiant tubes 3U with new radiant tubes 3N. Note that, hereinafter, the two used radiant tubes 3 will be referred to as "radiant tube 3U1" and "radiant tube 3U2," and the two new radiant tubes 3N will be referred to as "radiant tube 3N1" and "radiant tube 3N2." Furthermore, explanations that overlap with those in the above examples will be omitted.

[0061] First, three replacement carriages 10A, 10B, and 10C are prepared, one more than the number of radiant tubes 3U1 and 3U2 to be replaced. A new radiant tube 3N1 is pre-held in the holding section 30 of replacement carriage 10B. A new radiant tube 3N2 is pre-held in the holding section 30 of replacement carriage 10C. Next, as shown in Figure 13, the three replacement carriages 10A, 10B, and 10C are hoisted from the ground onto the structural deck 4 using an overhead crane.

[0062] 14, an operator pushes and pulls the replacement carriage 10A on the frame deck 4 to move the replacement carriage 10A to the replacement position for the radiant tube 3U1. The replacement position here is a position where the replacement carriage 10A is in front of the radiant tube 3U1 to be replaced.

[0063] Next, the operator pushes the holding part 30 of the exchange cart 10A toward the furnace body 2, bringing the holding part 30 closer to the front wall 2a (advancing it forward). Next, the base end 3b of the radiant tube 3U1 is fixed to the flange part 52a of the connecting part 50A, and the base end 3c of the radiant tube 3U1 is fixed to the flange part 52a of the connecting part 50B. Next, the radiant tube 3U1 attached to the front wall 2a of the furnace body 2 is removed from the front wall 2a. This transfers the radiant tube 3U1 from the furnace body 2 to the holding part 30. In this state, the operator pushes the holding part 30 back (retracts it) so that the holding part 30 moves away from the front wall 2a of the furnace body 2, and pulls the radiant tube 3U1 out of the opening 2d in the front wall 2a. In this way, the radiant tube 3U1 is held by the exchange cart 10A so that the entire radiant tube 3U1 is positioned above the exchange cart 10A.

[0064] Next, as shown in Figure 15, the fixing device 5 is removed from the replacement carriage 10A, and an operator pushes or pulls the replacement carriage 10A on the structure deck 4 to move the replacement carriage 10A holding the radiant tube 3U1 away from the replacement position. Next, an operator pushes or pulls the replacement carriage 10B (second carriage) on the structure deck 4 to move the replacement carriage 10B to the replacement position. The replacement position here is a position directly in front of the opening 2d in the front wall 2a from which the radiant tube 3U1 has been removed.

[0065] Next, the operator pushes the holding part 30 toward the furnace body 2, moving the holding part 30 closer to the front wall 2a (advancing it forward) until the protruding part 3d of the radiant tube 3N1 rests on the base part 2c. Next, with the radiant tube 3N1 pushed through the opening 2d to a predetermined position in the furnace body 2, the radiant tube 3N1 is attached to the front wall 2a of the furnace body 2. Next, the base end 3b of the radiant tube 3N1 is removed from the flange part 52a of the connecting part 50A, and the base end 3c of the radiant tube 3N1 is removed from the flange part 52a of the connecting part 50B. This pushes the radiant tube 3N1 from the holding part 30 of the exchange cart 10B into the furnace body 2 through the opening 2d in the front wall 2a and attaches it to the furnace body 2.

[0066] 16, an operator pushes and pulls the replacement carriage 10B on the structural deck 4 to move it to the replacement position for the radiant tube 3U2. The replacement position here is a position where the replacement carriage 10B is in front of the radiant tube 3U2 to be replaced.

[0067] Next, the operator pushes the holding part 30 of the exchange cart 10B toward the furnace body 2, bringing the holding part 30 closer to the front wall 2a (advancing it forward). Next, the base end 3b of the radiant tube 3U2 is fixed to the flange part 52a of the connecting part 50A, and the base end 3c of the radiant tube 3U2 is fixed to the flange part 52a of the connecting part 50B. Next, the radiant tube 3U2 attached to the front wall 2a of the furnace body 2 is removed from the front wall 2a. This transfers the radiant tube 3U2 from the furnace body 2 to the holding part 30. In this state, the operator pushes the holding part 30 back (retracts it) so that the holding part 30 moves away from the front wall 2a of the furnace body 2, and pulls the radiant tube 3U2 out of the opening 2d in the front wall 2a. In this way, the radiant tube 3U2 is held by the exchange cart 10B so that the entire radiant tube 3U2 is positioned above the exchange cart 10B.

[0068] Next, as shown in Figure 17, the fixing device 5 is removed from the replacement carriage 10B, and an operator pushes or pulls the replacement carriage 10B on the structure deck 4 to move the replacement carriage 10B holding the radiant tube 3U2 away from the replacement position. Next, an operator pushes or pulls the replacement carriage 10C (third carriage) on the structure deck 4 to move the replacement carriage 10C to the replacement position. The replacement position here is a position directly in front of the opening 2d in the front wall 2a from which the radiant tube 3U2 has been removed.

[0069] Next, the operator pushes the holding part 30 of the exchange cart 10C toward the furnace body 2, moving the holding part 30 closer to the front wall 2a (advancing it forward) until the protruding part 3d of the radiant tube 3N2 is placed on the base part 2c. Next, with the radiant tube 3N2 pushed through the opening 2d to a predetermined position in the furnace body 2, the radiant tube 3N2 is attached to the front wall 2a of the furnace body 2. Next, the base end 3b of the radiant tube 3N2 is removed from the flange part 52a of the connecting part 50A, and the base end 3c of the radiant tube 3N2 is removed from the flange part 52a of the connecting part 50B. This pushes the radiant tube 3N2 from the holding part 30 of the exchange cart 10C into the furnace body 2 through the opening 2d in the front wall 2a and attaches it to the furnace body 2.

[0070] Next, a worker pushes back (retracts) the holding part 30 of the replacement cart 10C so that it moves away from the front wall 2a of the furnace body 2. In this state, the fixing device 5 is removed from the replacement cart 10C, and a worker pushes and pulls the replacement cart 10C on the structural deck 4 to move the empty replacement cart 10C, which is not holding a radiant tube 3, away from the replacement position, as shown in Figure 18. Next, the three replacement carts 10A, 10B, and 10C are hoisted by an overhead crane and lowered from the structural deck 4 to the ground.

[0071] As described above, by simply preparing a number of exchange carriages 10 that is one more than the number of radiant tubes 3U to be replaced, used radiant tubes 3U can be sequentially replaced with new radiant tubes 3N. In other words, by having radiant tubes 3U2 held on the empty exchange carriage 10B after radiant tubes 3N1 have been attached to the heating furnace 1, it is possible to perform the radiant tube 3 replacement work extremely efficiently using a minimum number of exchange carriages.

[0072] (2) For example, the replacement work of the radiant tubes 3 may be performed using an exchange carriage 10 illustrated in Fig. 19. In the exchange carriage 10 illustrated in Fig. 19, the length of the car body 21 may be slightly longer than the radiant tubes 3 or may be approximately the same as the length of the radiant tubes 3.

[0073] The exchange bogie 10 illustrated in FIG. 19 may further include a support unit 60 and one or more suspension units 70. The support unit 60 includes a plurality of support pillars 61 and an upper rail 62. The plurality of support pillars 61 are provided on the car body 21 so as to extend upward from the car body 21. The plurality of support pillars 61 are arranged so as to be aligned in the longitudinal direction of the car body 21. The upper rail 62 is supported at the tip ends of the plurality of support pillars 61. The upper rail 62 extends linearly along the longitudinal direction of the car body 21.

[0074] The suspending unit 70 includes a base 71 and a suspending device 72. The base 71 is attached to the upper rail 62 and is configured to be movable (slidable) along the upper rail 62. The suspending device 72 extends downward from the base 71. The suspending device 72 may be, for example, a chain block. The suspending device 72 is configured to suspend and hold the radiant tube 3 by being wrapped around the main body 3a of the radiant tube 3.

[0075] Next, with reference to Figures 20 to 22, the procedure for removing a used radiant tube 3U from the furnace body 2 using the exchange cart 10 illustrated in Figure 19 will be described. First, as shown in Figure 20, an operator pushes the holding part 30 of the exchange cart 10 toward the furnace body 2, moving the holding part 30 closer to the front wall 2a (advancing it forward). Next, the base end 3b of the radiant tube 3U is fixed to the flange part 52a of the connecting part 50A, and the base end 3c of the radiant tube 3U is fixed to the flange part 52a of the connecting part 50B. Next, the radiant tube 3U attached to the front wall 2a of the furnace body 2 is removed from the front wall 2a. This transfers the radiant tube 3U from the furnace body 2 to the holding part 30.

[0076] In this state, as shown in Figure 21, the worker pushes back (retracts) the holding part 30 so that the holding part 30 moves away from the front wall 2a of the furnace body 2, and pulls out the radiant tube 3U from the opening 2d in the front wall 2a. Here, because the exchange cart 10 exemplified in Figure 19 is relatively small, even if the holding part 30 moves to the end of the rail member 24, the tip of the radiant tube 3U may remain inside the heating furnace 1.

[0077] Next, as shown in Figure 21, a suspending device 72 is hooked onto the main body 3a of the radiant tube 3U. At this time, if the exchange cart 10 has only one suspending part 70, the suspending device 72 may be hooked near the center of gravity of the radiant tube 3U. If the exchange cart 10 has multiple suspending parts 70, the suspending device 72 may be hooked onto the radiant tube 3U so that the center of gravity of the radiant tube 3U is located between the two suspending parts 70.

[0078] Next, pin 54 is removed from through holes 42a, 42b, and 53a. This causes radiant tube 3U to be suspended and held by hanging part 70. In this state, as shown in FIG. 22, the worker completely pulls radiant tube 3U out of furnace body 2. At this time, radiant tube 3U moves along upper rail 62 via hanging part 70. In this way, radiant tube 3U is held on exchange cart 10 so that the entire radiant tube 3U is positioned above exchange cart 10.

[0079] 23 to 25, a procedure for attaching a new radiant tube 3N to the furnace body 2 using the exchange cart 10 illustrated in FIG. 19 will be described. First, as shown in FIG. 23, the base end 3b of the radiant tube 3N is fixed to the flange 52a of the connecting part 50A, and the base end 3c of the radiant tube 3N is fixed to the flange 52a of the connecting part 50B. In this manner, the radiant tube 3N with the connecting parts 50A and 50B attached is suspended and held by the suspending part 70. In this case, if the exchange cart 10 has only one suspending part 70, the suspending device 72 may be hooked near the center of gravity of the radiant tube 3N. In the case of an exchange cart 10 having multiple suspending parts 70, the suspending device 72 may be hooked to the radiant tube 3N so that the center of gravity of the radiant tube 3N is located between the two suspending parts 70. It should be noted that after radiant tube 3N is suspended and held by suspending portion 70, connecting portions 50A and 50B may be attached to radiant tube 3N.

[0080] Next, as shown in Figure 24, the worker pushes the radiant tube 3N toward the furnace body 2, bringing it closer to the front wall 2a (moving it forward). Next, the connecting parts 50A and 50B are attached to the base part 40 (side wall 42) via the pin 54. At this time, the tip of the radiant tube 3N can be positioned inside the heating furnace 1. Next, the hanging part 70 is removed from the radiant tube 3N.

[0081] Next, as shown in Figure 25, the operator pushes the holding part 30 toward the furnace body 2, moving the holding part 30 closer to the front wall 2a (advancing it forward) until the protruding part 3d of the radiant tube 3N rests on the base part 2c. Next, with the radiant tube 3N pushed through the opening 2d to a predetermined position in the furnace body 2, the radiant tube 3N is attached to the front wall 2a of the furnace body 2. Next, the base end 3b of the radiant tube 3N is removed from the flange part 52a of the connecting part 50A, and the base end 3c of the radiant tube 3N is removed from the flange part 52a of the connecting part 50B. This pushes the radiant tube 3N from the holding part 30 of the exchange cart 10 into the furnace body 2 through the opening 2d in the front wall 2a and attaches it to the furnace body 2.

[0082] As described above, when receiving a used radiant tube 3U removed from the furnace body 2 or when attaching a new radiant tube 3N to the furnace body 2, the holding unit 30 holds the radiant tubes 3U and 3N, while at other times the suspending unit 70 suspends and holds the radiant tubes 3U and 3N. In this way, by transferring the radiant tubes 3U and 3N between the holding unit 30 and the suspending unit 70, the positions of the radiant tubes 3U and 3N suspended and held by the suspending unit 70 relative to the exchange carriage 10 can be adjusted. Therefore, even when a small exchange carriage 10 is used, the radiant tubes 3U and 3N can move back and forth beyond the size of the small exchange carriage 10 (the length of the running unit 20), and the restrictions on the holding position of the radiant tubes 3U and 3N relative to the small exchange carriage 10 are relaxed. This allows the exchange carriage 10 to stably move the radiant tubes 3U and 3N. [Explanation of symbols]

[0083] 1...heating furnace, 2...furnace body, 2c...base portion, 3, 3U, 3N...radiant tube, 3b...base end portion (upper base end portion), 3c...base end portion (lower base end portion), 3d...protruding portion, 5...fixing device, 6...measuring portion, 10...exchange carriage (cart), 10A...exchange carriage (first carriage), 10B...exchange carriage (second carriage), 10C...exchange carriage (third carriage), 20...running portion, 30...holding portion, 40...base portion, 42...side wall, 42a...through hole (first through hole), 42b...through hole (second through hole), 50...connecting portion, 50A...connecting portion (first connecting portion), 50B...connecting portion (second connecting portion), 54...pin, 70...hanging portion.

Claims

1. A method for replacing used radiant tubes attached to the furnace body of a heating furnace with new radiant tubes using a first cart and a second cart, each of which has a running section configured to be able to run on the structural deck of the heating furnace and a holding section mounted on the running section and configured to be able to hold radiant tubes, comprising: a first step of placing the first bogie, in which the holding unit does not hold a radiant tube, on the frame deck, and placing the second bogie, in which the holding unit holds the new radiant tube, on the frame deck; a second step of moving the first carriage on the frame deck after the first step so that the first carriage is positioned at an exchange position on the frame deck facing the used radiant tube; a third step of holding the used radiant tube in the holding portion of the first carriage after the second step; a fourth step of retracting the first carriage from the exchange position on the frame deck after the third step; a fifth step of moving the second carriage on the frame deck so that the second carriage is positioned at the exchange position after the fourth step; A radiant tube replacement method comprising, after the fifth step, a sixth step of attaching the new radiant tube held by the holding portion of the second carriage to the furnace body.

2. a seventh step of transporting the first cart and the second cart from the ground to the frame deck using an overhead crane during operation of the heating furnace, before the first step; 2. The method of claim 1, further comprising, after the sixth step, an eighth step of transporting the first car and the second car from the structural deck to ground level using the overhead crane while the heating furnace is in operation.

3. the third step includes holding the used radiant tube in the holding portion of the first bogie while the first bogie is fixed to the frame deck, 3. The method according to claim 1, wherein the sixth step includes attaching the new radiant tube held by the holding portion of the second bogie to the furnace body while the second bogie is fixed to the structural deck.

4. The method further includes a step of measuring a distance to a base provided in the heating furnace by a measuring unit after the fifth step and before the sixth step, and determining a pushing amount of the new radiant tube based on the measured distance, The method according to any one of claims 1 to 3, wherein the sixth step includes pushing the new radiant tube from the second carriage toward the inside of the heating furnace based on the pushing amount, thereby placing a protrusion provided at the tip of the radiant tube onto the base.

5. The holding portion is A base portion; The method according to any one of claims 1 to 4, further comprising a connecting portion configured to detachably connect the proximal end of the radiant tube and the base portion via a pin.

6. The holding portion is A base portion; a first connecting portion configured to detachably connect an upper base end portion of the radiant tube to the base portion via a first pin; a second connecting portion configured to detachably connect a lower base end portion of the radiant tube and the base portion via a second pin; the first connecting portion is rotatable around the first pin in a state in which the first pin is inserted into a first through-hole provided in the base portion, A method according to any one of claims 1 to 4, wherein the second connecting portion is movable along the extension direction of a second through hole provided in the base portion and extending in an arc shape centered on the first through hole, with the second pin inserted through the second through hole.

7. the holding unit is mounted on the traveling unit so as to be able to advance and retreat relative to the traveling unit, The third step includes: advancing the holding portion of the first carriage so that the holding portion approaches the furnace body; removing the used radiant tube from the furnace body while the used radiant tube is held by the holding portion of the first carriage; and retracting the holding portion of the first carriage so that the holding portion of the first carriage is separated from the furnace body, The sixth step comprises: advancing the holding portion of the second carriage so that the holding portion of the second carriage approaches the furnace body; Attaching the new radiant tube held by the holding portion of the second carriage to the furnace body; The method according to any one of claims 1 to 6, further comprising: retracting the holding portion of the second carriage so that the holding portion of the second carriage is away from the furnace body.

8. The carriage is configured to suspend and hold the radiant tube, and further includes a suspension unit mounted on the running unit so as to be movable forward and backward relative to the running unit, In the first step, the new radiant tube is suspended and held by the suspension portion of the second carriage instead of the holding portion of the second carriage, The third step includes: advancing the holding portion of the first carriage so that the holding portion approaches the furnace body; removing the used radiant tube from the furnace body while the used radiant tube is held by the holding portion of the first carriage; retracting the holding portion of the first carriage so that the holding portion of the first carriage is separated from the furnace body; After the used radiant tube is suspended and held by the suspension portion of the first carriage, the holding portion of the first carriage releases the holding portion of the used radiant tube; and retracting the suspension portion of the first carriage so that the suspension portion of the first carriage is separated from the furnace body, The sixth step comprises: advancing the suspension portion of the second carriage so that the suspension portion of the second carriage approaches the furnace body; After the new radiant tube is held by the holding portion of the second carriage, releasing the hanging holding of the new radiant tube by the hanging portion of the second carriage; advancing the holding portion of the second carriage so that the holding portion of the second carriage approaches the furnace body; Attaching the new radiant tube held by the holding portion of the second carriage to the furnace body; and retracting the holding portion of the second carriage so that the holding portion of the second carriage is away from the furnace body, in this order.

9. A method for replacing a first used radiant tube attached to the furnace body of a heating furnace with a first new radiant tube, and replacing a second used radiant tube attached to the furnace body of the heating furnace with a second new radiant tube, using a first cart, a second cart and a third cart, each of which has a running section configured to be able to run on the structural deck of the heating furnace, and a holding section mounted on the running section and configured to be able to hold a radiant tube, comprising: a first step of placing the first bogie, whose holding unit does not hold a radiant tube, on the frame deck, placing the second bogie, whose holding unit holds the first new radiant tube, on the frame deck, and placing the third bogie, whose holding unit holds the second new radiant tube, on the frame deck; a second step of moving the first carriage on the structural deck after the first step so that the first carriage is positioned at a first exchange position on the structural deck facing the first used radiant tube; a third step of holding the first used radiant tube in the holding portion of the first carriage after the second step; a fourth step of retracting the first carriage from the first exchange position on the frame deck after the third step; a fifth step of moving the second carriage on the frame deck after the fourth step so that the second carriage is positioned at the first exchange position; a sixth step of attaching the first new radiant tube held by the holding portion of the second carriage to the furnace body after the fifth step; a seventh step of retracting the second carriage from the first exchange position on the frame deck after the sixth step; an eighth step of, after the seventh step, moving the second carriage on the frame deck so that the second carriage is positioned at a second exchange position on the frame deck facing the second used radiant tube; a ninth step of holding the second used radiant tube in the holding portion of the second carriage after the eighth step; a tenth step of retracting the second carriage from the second exchange position on the frame deck after the ninth step; an eleventh step of, after the tenth step, moving the third carriage on the frame deck so that the third carriage is positioned at the second exchange position; A radiant tube replacement method comprising: after the eleventh step, a twelfth step of attaching the second new radiant tube held by the holding portion of the third carriage to the furnace body.

10. a traveling unit configured to be able to travel on a structural deck of the heating furnace; a holding portion configured to be able to hold a radiant tube; a hanging portion configured to hang and hold the radiant tube, the holding unit is mounted on the traveling unit so as to be able to advance and retreat relative to the traveling unit, A radiant tube exchange carriage in which the hanging section is mounted on the running section so as to be able to move forward and backward relative to the running section independently of the holding section.

Images