JPS5855215B2 - Tube heat treatment furnace - Google Patents

Description

[Detailed description of the invention] The present invention relates to a heat treatment furnace for pipe bodies such as cast iron pipes.

As a heat treatment for cast iron pipes, there is a method in which a desired ferrite structure is obtained by raising the pipe body to a certain temperature and then slowly cooling it at a predetermined cooling rate.

Conventionally, continuous furnaces are often used for this heat treatment, which heats and slowly cools the tube while transporting it inside the furnace, but this requires a fairly long distance and a large space to slowly cool the tube. .

Also, since the space was large, heat loss was also large.

On the other hand, fixed batch type furnaces have also been used, but they have been inefficient.

The present invention solves the above-mentioned problems and provides a heat treatment furnace that can perform processing efficiently in a small space and that can prevent the tube from becoming oval due to the high temperature during heat treatment. a lid that is removably installed on the tube support and forms a furnace chamber together with the tube support; and a lid that is disposed within the furnace chamber and supports the tube rotatably about its axis. A plurality of rollers for heating the tube body in the furnace chamber and a burner for heating the tube inside the furnace chamber are installed on a movable cart, and one embodiment thereof will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a tube support section placed on a movable cart 2, and 3 a lid detachably installed on the tube support section 1. The inner surface of the body 3 is composed of heat insulating materials 4 and 5, and these tube support parts 1
A furnace chamber 6 is formed by the lid body 3 and the lid body 3 .

Inside the tubular body support part 1, there are a set of three rollers consisting of one driving roller 7a and two idle rollers 7b and 7c; Two idle rollers 9a that are located above one set of rollers and support the tube body 8
.

A set of two rollers 9b are provided at appropriate intervals in the axial direction of the tube body 8.

These rollers 7a to 7c and 9a, 9b are arranged parallel to each other, and the idle roller 9a is the drive roller 7a.
, the idler roller 7b, and the tube body 8, and the idler roller 9
b is in contact with the driving roller 7a, the idling roller 7c, and the tube body 8, respectively.

The lid body 3 includes a burner 10 that mainly heats the tube body 8.
Burners 11 that mainly heat the idle roller 9b are installed at appropriate intervals in the axial direction of the tube body 8, and fuel tanks 12 and 13 that store fuel for these burners 10 and 11 are installed. installed.

Further, the lid body 3 includes cooling pipes 14a, 14b for cooling the inside of the furnace chamber 6, and cooling pipes 14a, 14b for cooling the inside of the furnace chamber 6.
Blower 15a and 15b are attached to supply cooling air to.

16a. 16b is a cover that covers the burners 10, 11 and the fuel tank 12.13.

Reference numeral 17 denotes a truck that moves on a rail 19 orthogonal to the rail 118, and a rail 20 that is flush with and parallel to the rail 18 is fixed onto the truck 17.

This cart 17 carries the movable cart 2 and moves, and the movable cart 2 moves on the rail 18 and moves on the rail 19 in a state where it is transferred onto the rail 20. The direction of movement of the heat treatment furnace consisting of the body support part 1, the lid body 3, etc. is changed by 90 degrees.

Note that the tube support portion 1 may be constructed integrally with the movable trolley 2.

As shown in FIG. 3, an exhaust hood 22 is attached to the upper end of the lid 3, and a damper 21 for opening/closing and adjusting the flow rate is installed inside the exhaust hood 22.
As shown in the figure, it is slidably fitted into an exhaust duct 23 disposed above the rail 18.

Combustion gas in the furnace chamber 6 caused by the burners 10 and 11 is exhausted to the outside via the exhaust hood 22, exhaust duct 23, and exhaust pipe 24.

Next, the operation will be explained.

When housing the tube body 8 in the furnace chamber 6, use a crane or the like to lift the lid body 3 as shown by the imaginary line in FIG.
are placed on the reversing rollers 9a and 9b, and then the lid 3 is lowered to cover the tube support 1.

After housing the tube body 8 in the furnace chamber 6 in this way, the burner 10
, 11, and rotates the drive roller 7a in the direction of the arrow.

As a result, the tube body 8 is rotated in the direction of arrow A and is heated to a predetermined temperature by the burner 10.

Although the temperature of the tubular body 8 increases due to the heating by the burner 10 and it becomes easily deformed, since the tubular body 8 is rotated about the tube axis as described above, the tubular body 8 is prevented from becoming oval.

On the other hand, the burner 10 heats not only the tubular body 8 but also the idling roller 9a to some extent, and the burner 11 heats the idling roller 9b.

Idling rollers 9a and 9b that are in direct contact with the tube body 8 in this way
is heated sufficiently, so that the tube body 8 is rotated by the idling rollers 9a and 9b.
It is possible to obtain a tube body 8 of excellent quality without being cooled by.

After a predetermined period of time has elapsed, the flame intensity of the burners 10 and 11 is weakened, and the tube body 8 is maintained at a predetermined temperature lower than 100 yen for a predetermined period of time.

After that, stop the operation of burners 10 and 11, and turn on blower 1.
5a and 15b are driven to pass cooling air into the cooling pipes 14a and 14b to slowly cool the tube body 8.

At this time, the drive roller 7a continues to operate and rotates the tubular body 8 in the direction of arrow A only occasionally.

Thus, after a predetermined period of time has elapsed, the heat treatment of the tubular body 8 is completed.

When transporting the tube 8 from the furnace chamber 6, the lid 3 is lifted up by a crane or the like, the tube 8 is taken out by an appropriate means, and then the lid 3 is placed over the tube support 1.

In this way, since the lid 3 is detachably provided on the tube support 1, the tube 8 can be easily carried into the furnace chamber 6 and taken out from the furnace chamber 6. can.

Furthermore, since the tube body 8 is heated while being rotated around its tube axis by the driving roller 7a, it is possible to prevent the tube body 8 from becoming oval.

Furthermore, as in this embodiment, if the drive roller 7a is not brought into direct contact with the tube body 8, but the idle rollers 9a and 9b are brought into direct contact with the tube body 8, the idle rollers 9a and 9b can be Since the tube body 8 is not cooled by the idle rollers 9a and 9b, the tube body 8 is of excellent quality.
can be obtained.

By the way, since the tube support part 1 is installed on the movable trolley 2, the rails 18 and the trolley 17 are appropriately arranged to constitute a circulation route for the movable trolley 2, and a plurality of movable trolleys 2 are arranged along this circulation route. In comparison with conventional continuous furnaces, the tubes 8 are carried into the furnace chamber 6, the tubes 8 are heat-treated, and the tubes 8 are taken out from the furnace chamber 6. The tube body 8 can be heat-treated in a small space and more efficiently than in conventional batch furnaces.

In this case, the combustion gas in the furnace chamber 6 caused by the burners 10 and 11 is exhausted to the outside through the exhaust hood 22, the exhaust duct 23, and the exhaust pipe 24, regardless of whether the mobile cart 2 is moving or stopped. .

In the above embodiment, a set of three rollers 7a, 7
Although an example has been described in which only one of b and 7c is used as a driving roller, two or all rollers may be used as driving rollers.

FIG. 4 shows another embodiment, in which the tube body 8 may be rotatably supported by the drive roller 25 and the idle roller 26.

In this case, heating the drive roller 25 to too high a temperature will have an adverse effect on the drive mechanism of the drive roller 25, so the burner 11 is not provided and only the burner 10 is provided.

As explained above, according to the heat treatment furnace according to the present invention, since the tube support part, the lid body, the roller, and the bar are installed on the movable trolley, the circulation path of the movable trolley is configured,
A plurality of movable carts are individually circulated along this circulation route, and during this time, the tubes are carried into the furnace chamber, heat-treated,
By carrying out the tube body from the furnace chamber, the tube body can be heat-treated in a smaller space compared to a conventional continuous furnace and more efficiently than a conventional batch type furnace.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal side view thereof, FIG. 2 is a side view of the state in which it moves on a rail, FIG. 3 is a longitudinal front view of an exhaust duct and an exhaust hood, and FIG. The figure is a longitudinal sectional side view of another embodiment. 1... Pipe body support part, 2... Moving trolley,
3... Lid body, 6... Furnace chamber, ? a, 25
...... Drive rollers, 7b, 7c, 9a, 9
b, 26"" idling roller, 10...burner,
12...Fuel tank.

Claims (1)

[Claims] 1 A tube support, a lid that is removably installed on the tube support and forms a furnace chamber together with the tube support, and a lid that is placed in the furnace chamber and that rotates the tube around its axis. A tubular body heat treatment furnace, characterized in that a plurality of rotatably supported rollers and a burner for heating the tubular body in the furnace chamber are installed on a moving carriage.