JPS5853696B2 - Heat treatment furnace for upset tubes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat treatment furnace for upset pipes, such as oil country tubular goods, which have thick-walled upset parts for connection at both ends, and in which the heating of the upset part is almost equal to the heating of the pipe body part. A system that allows for accurate positioning (centering) of the upset tube in the heat treatment furnace so that the process can be completed in the same amount of time and also to ensure that the upset section passes through the upset section heating means. It is.

Generally, when an upset tube is heated in a heat treatment furnace while being sequentially transferred in a direction perpendicular to its longitudinal direction,
Since the length of the furnace required for heating is determined by the time required to heat the upset section, the heating time of the tubular section becomes too long and the amount of scale generated increases.

Moreover, increasing the length of the furnace due to the upset portion, which accounts for only a few percent of the weight of the tube body portion, increases equipment costs and fuel consumption.

Therefore, conventionally, only the upset section is preheated outside the heat treatment furnace, and then the upset tube is inserted into the heat treatment furnace, and the heating of the upset section is completed in approximately the same time as the heating time of the tube body. However, as a preheating means for the upset section, for example, a heating device using a burner or an induction heating device is used, which makes the equipment even larger and more complex, and increases equipment costs and running costs. However, there were drawbacks such as an increase in the total time required for heat treatment.

Therefore, in order to eliminate such conventional drawbacks, the present applicant first applied heat treatment to the upset part over a predetermined range along the transfer path of the upset part in the heating zone of a heat treatment furnace having a heating zone and a soaking zone. We have proposed a heat treatment furnace that is equipped with a heating means that directly blows high-temperature atmospheric gas inside the furnace, and thereby completes heating of the upset part in approximately the same time as the heating time of the tube body part.

This heat treatment furnace will be explained with reference to FIGS. 1 and 2.

1 and 2, 1 is a heat treatment furnace for upset tubes, and on one side wall of this heat treatment furnace 1, an upset tube 2 transported from outside the furnace 1 is installed. A charging port 1a is provided for inputting the material.

3 is a vertical roller conveyor for charging the amplifier set tube 2 into the furnace 1 from outside the furnace 1, and the upset tube 2 charged into the furnace 1 by the vertical roller conveyor 3 is A cross-feeding conveyance device 4 consisting of a fixed skid 4a and a movable skid 4b provided in the furnace 1 sequentially transports the materials in a direction perpendicular to the longitudinal direction.

Inside the furnace 1, there is a heating burner rotor 5 provided on the rear wall of the furnace 1.
A required high-temperature atmosphere is created by the hot air from above, and the amplifier set tubes 2 that are being sequentially transferred by the transverse conveying device 4 are heated.

In the upset tube 2 in a high-temperature atmosphere, the tube section 2a is heated faster than the upset section 2b, so the upset section 2b is heated at approximately the same time as the heating time of the tube section 2a.
After the heating of the upset part 2b is completed, the upset part 2b is arranged over a predetermined range along the transfer path of the upset part 2b.
a nozzle 6 that blows high-temperature atmospheric gas to b; a suction blower 7 that sucks high-temperature atmospheric gas in the furnace 1;
A heating means consisting of a duct 8 for supplying high-temperature atmospheric gas from the discharge side of the suction blower 7 to each nozzle 6 is provided.

Note that some upset tubes 2 to be heat treated have a maximum length of 9,700 mm and a minimum length of 9,100 mm, and the difference in length is 600 mm, so the nozzle 6 is Even if the width of the ejection range of the high-temperature atmospheric gas is set to, for example, 500 mm, and the upset tubes 2 have different lengths, the upset portions 2b at both ends of the upset pipes 2 may be sufficiently located within the ejection range. It is supposed to be heated.

By the way, since the upset tubes 2 to be heat treated have different lengths as mentioned above, when charging the upset tubes 2 into the furnace 1 from outside the furnace 1 using the vertical roller conveyor 3, It is necessary to accurately insert the upset tube 2 into a predetermined position in the furnace 1 depending on its length.

The charging position of this upset tube 2 with respect to the furnace 1 (
If the centering (centering) is not performed accurately, the amplifier set section 2b will be out of the ejection range of the high-temperature atmospheric gas in the nozzle 6, and the upset section 2b will not be able to be heated to a predetermined temperature. unable to achieve the goal.

The centering means of the present invention for accurately positioning (centering) the charging of the upset tube 2 in the furnace 1 is installed in the heat treatment furnace equipped with the heating means for the upset section 2b described above. It is something.

An example of implementation of the centering means is shown below in FIG.
This will be explained based on FIG.

As shown in FIGS. 1 and 3, the upset portions 2b at both ends are located on the conveyance line outside the furnace 1 in the vertical conveyor 3 of the upset tube 2 within the ejection range of the high-temperature atmospheric gas at the nozzle 6. For example, the minimum length L of the amplifier set tube 2 that is sufficiently positioned and heated is 910 mm.
0 mm), the upset tube 2
Photoelectric detectors 9 and 10 are provided which are shielded from light by.

Further, the photoelectric detector 11 is provided at a distance of 1 □ from the photoelectric detector 9, which is equal to the maximum length L of the amplifier set tube 2 (for example, 9700 mm).

In the process of transferring the upset tube 2 from the transverse conveyance device 12 on the previous process side to the vertical roller conveyor 3 and conveying it to the furnace 1 side, the upset tube 2 is detected by the photoelectric detector 11. The trailing edge of 2 is detected.

At the same time as the rear end of the amplifier set tube 2 is detected, the number of pulses from the pulse transmitter 13 connected to a roller at an arbitrary position on the vertical roller conveyor 3 is automatically counted.

At the same time that the tip of the upset tube 2 is detected by the photoelectric detector 9, counting of the number of pulses from the pulse transmitter 13 is stopped, and counting from the photoelectric detector 11 is stopped according to the counted number of pulses. The moving distance 13 of the rear end of the amplifier set tube 2 up to the point in time is automatically calculated.

Next, by the calculation signal corresponding to the moving distance 13,
A reversible electric motor 14 is driven and controlled, and this reversible electric motor 140
Due to the rotation, the upset tube positioning end stopper 17, which is provided to penetrate into the furnace 1 from the outside of the other side wall of the furnace 1, reaches its maximum length via a moving mechanism consisting of a pinion 15 and a rank 16, for example. The upset tube 20 (9700 mm) is moved to a position equivalent to 1/2 of the moving distance 13 with respect to the predetermined positioning portion, so that the amplifier set portions 2b at both ends of the upset tube 2 having different lengths L are moved to the high temperature This arrangement allows accurate charging positioning (centering) of the upset tube 2 with respect to the furnace 1 so that the upset tube 2 is located within the ejection range of atmospheric gas.

When the tip of the amplifier set tube 2 hits the end stopper 17, a detection signal from an impact detector 18, such as a load cell, provided on the end stopper 17 side causes the transverse transport in the furnace 1. The device 4 is driven to sequentially transport the upset tubes 2 within the furnace 1.

Note that the length L of the upset tube 2 is the same as that of the photoelectric detector 9.
, 10, the rear end will be detected by the photoelectric detector 10 before the leading end is detected by the photoelectric detector 9. The driving of the vertical roller conveyor 3 is stopped in response to the signal, and the upset tube 2 on the vertical roller conveyor 3 is removed from the vertical roller conveyor 3 by an arbitrary displacement device.

Further, the length L of the amplifier set tube 2 is the same as that of the photoelectric detector 9,
If the distance between 11 and 12 is longer than 12, the front end will be detected by the photoelectric detector 9 before the rear end is detected by the photoelectric detector 11, so the detection signal from the photoelectric detector 9 will cause the vertical The drive of the feeding roller conveyor 3 is stopped, and the upset tube 2 is removed from the vertical feeding roller conveyor 3 in the same manner as described above.

As described above, according to the present invention, the upset tube to be heat treated can be accurately centered in the heat treatment furnace, so even if the upset tubes have different lengths within a predetermined range, The upset parts at both ends can be reliably passed through the upset part heating means in the heat treatment furnace, so that the heating completion time of the amplifier set part and the heating completion time of the tube body part can be matched with high accuracy. I can do it.

[Brief explanation of the drawing]

The drawings show an example of the implementation of the present invention, in which Fig. 1 is an internal plan view of an amplifier set tube heat treatment furnace including centering means, Fig. 2 is a sectional view taken along line A-A in Fig. 1,
FIG. 3 is an explanatory diagram of the centering means.

Claims (1)

[Claims] 1. In a heat treatment furnace that heat-treats amplifier set tubes that are vertically fed and charged into the furnace from outside the furnace in a direction perpendicular to the longitudinal direction thereof, the amplifier set tubes are arranged over a predetermined range along the transfer path of the upset section, It consists of a nozzle that blows high-temperature atmospheric gas to the upset part, a suction flon that sucks high-temperature atmospheric gas in the furnace, and a duct that supplies high-temperature atmospheric gas from the discharge side of the suction blower to the nozzle. A heating means, an upset tube length measuring device for measuring the length of the upset tube charged into the furnace, and an end stopper for positioning the upset tube that advances or retreats in response to length measurement data from the length measuring device. A heat treatment furnace for amplifier set tubes, characterized in that it is equipped with a centering means consisting of: