JPH0525739Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a heating furnace for steel pipes for automatically forming lining coatings such as plastic on the inner and outer surfaces of steel pipes.

[Prior art and its problems] When forming a lining coating on a steel pipe, the steel pipe (tube) placed horizontally is erected vertically using an appender, then suspended vertically from a monorail and immersed in a treatment tank. , a device configured to be placed horizontally again using an appender is known (Special Publication No. 1983).
-50142). However, in the case of this device, there is a problem in that productivity is very low because it takes time to hold the steel pipe in the appender and release it, and it also takes time to set it up or lay it down.

Furthermore, a layout of a plastic lining coating factory in which processing steps are arranged in a straight line is known (Japanese Patent Laid-Open No. 56-58561). but,
This factory layout has the disadvantage that the factory equipment becomes very long because the processing steps are in a straight line.

[Purpose of the invention] The purpose of the invention is to improve productivity and to minimize the length of factory equipment in a steel pipe heating furnace.

[Structure of the invention] The structure of the heating furnace for steel pipes according to the invention is as follows.

A linear pre-heating furnace 2, a lining tank 6 following this pre-heating furnace 2, a C-shaped post-heating furnace 3 following this lining tank 6, these pre-heating furnace 2, lining tank 6, and post-heating. The conveyor 11 is an endless type in which pipe holders 13 are attached downwardly at regular intervals. An upward slope section 15 is formed, and a downward slope section 16 is formed on the outlet side of the post-heating furnace 3, and further below this upward slope section 15 is a guide frame 7.
is arranged horizontally, and the carrier 1 is placed on this guide frame 7.
A steel pipe leveling device 9 is disposed horizontally below the downwardly sloped portion 16 of the conveyor 11.
A heating furnace for steel pipes, characterized in that a spiral shaft 10 is attached to the spiral shaft 10 which is inclined in a direction away from the carrier 11 and rotates in synchronization with the traveling of the carrier 11.

[Function] The function of the above-mentioned heating furnace will be explained. The steel pipe to be lined is placed on the conveyor 11 on the guide frame 7.
The pool is laid out so that it is perpendicular to the direction of travel. This steel pipe is the holder 13 of the carrier 11.
When the end of the steel pipe is suspended, the end side is gradually lifted up on the upward slope section 15 of the conveying body 11, and the opposite end of the steel pipe is brought into contact with the inclined guide 8 of the guide frame 7 while moving toward the conveying body 11 side. , the suspension holder 13 is suspended vertically, enters the preheating furnace 2, and preheating treatment is performed while passing through there.

After the preheating treatment, the steel pipe is then transferred to the lining tank 6.
Here, it is immersed in a lining tank 6 using a lifting device, for example, to be coated (lining film), and then enters a post-heating furnace 3, where it is post-heated while passing through there.

The lower end of the steel pipe coming out of the post-heating furnace 3 is externally engaged with the spiral of the spiral shaft 10 and is fed in a direction away from the carrier 11, and a downward slope portion 16 is formed in the carrier 11. Therefore, the steel pipe is gradually laid down from vertical to horizontal. In this state, the steel pipe is removed from the holder 13 and temporarily pooled on the steel pipe leveling device 9.

[Example] The figure shows an example of the present invention, in which 1 is a lining heating section, 2 is a vertical flat pre-heating furnace, 3 is a vertical flat post-heating furnace, and the post-heating furnace 3 is a flat surface. It consists of a C-shape. 4 is a gas burner, and this gas burner 4 produces high-temperature hot air, and this high-temperature hot air is circulated through the pre-heating furnace 2 and the post-heating furnace 3 by a hot air circulation fan 5 to maintain the inside of the furnace at a high temperature. In the example, the temperature on the pre-heating furnace 2 side is 300°C, and the temperature on the post-heating furnace 3 side is 200°C.

Reference numeral 6 designates a deep-bottomed lining tank located between the pre-heating furnace 2 and the post-heating furnace 3. The lining tank 6 is filled with molten plastic, and the steel pipe a is moved by a lifting device 7a. Lining tank 6
immersed inside.

In front of the inlet 2a of the preheating furnace 2, 7 is a guide frame having a horizontal inclined guide 8 that approaches the inlet 2a of the preheating furnace 2, and on this guide frame 7 is a steel pipe a waiting to be lined. It is pooled in a lying position.

Reference numeral 9 denotes a steel pipe horizontal device having a horizontal spiral shaft 10 that is inclined so as to gradually move away from the rear of the outlet 3b of the post-heating furnace 3.

Reference numeral 11 denotes a steel pipe transport body consisting of an endless conveyor 12 that runs through the guide frame 7, the lining heating section 1, and the steel pipe leveling device 9, and holders 13 that are attached to the endless conveyor 12 at regular intervals. The carrier 11 is equipped with a preheating furnace 2.
In front of the inlet 2a, an upwardly sloped section 15 is formed that gradually rises in a straight line. A slope portion 16 that gradually descends is formed at the leveling device 9, and runs intermittently. 14 is a driving device for the conveyor 11.

Next, the operation of the heating furnace will be explained.
First, on the guide frame 7 side, the steel pipes a for lining are laid down in a pool, and the worker transports them one by one to the conveyor 11 (conveyor 12).
The end is suspended from the holder 13. The suspended steel pipe a is gradually pulled up as the carrier 11 travels, and stands vertically while its lower end is guided by the inclined guide 8. When the steel pipe a is erected, it enters the preheating furnace 2 from the inlet 2a, undergoes heat treatment there before lining, exits from the outlet 2b, and then reaches the lining tank 6. When it is above the lining tank 6, the lifting lift of the lifting device 7a transfers the steel pipe a, lowers the steel pipe a, immerses it in the lining tank 6, pulls it up again, and transfers it to the holder 13. During this time, the conveyor 11 is stopped. Steel pipe a suspended again on holder 13
enters the post-heating furnace 3 through the inlet 3a, undergoes post-heating treatment there, exits through the outlet 3b, reaches the steel pipe leveling device 9, and gradually begins to descend. Simultaneously with this lowering action, the lower end of the steel pipe a engages with a spiral shaft 10 that rotates in synchronization with the carrier 11, and the spiral shaft 10 applies feed, so that the steel pipe a gradually begins to lie down. Then, as the pipes eventually become nearly horizontal, the worker removes the steel pipes a from the holder 13, arranges them horizontally, and pools them.
In addition, in the lining tank 6 part, in the above embodiment, the steel pipe a is transferred to the lifting device 7a and immersed in the lining tank 6, but contrary to this, the lining tank 6 side is raised and the steel pipe a is Holder 13
Alternatively, the lining tank 6 may be allowed to stand still while being suspended, and the dipping operation may be performed by moving the lining tank 6 up and down.

[Effects of the invention] As described above, in the present invention, the steel pipe is suspended by the holder of the conveyor in the guide frame, gradually raised upright, passed through the preheating furnace for preheating treatment, and then automatically lined. The material is immersed in the tank, passed through the post-heating furnace again for post-heat treatment, and then gradually laid down in a steel pipe horizontal device to pool, resulting in the following effects.

a One worker only needs to suspend the steel pipe from the guide frame side to the carrier holder, and one worker only needs to remove the steel pipe from the steel pipe leveling device side. This improves work efficiency and requires only two workers.

(b) The steel pipe is gradually raised upright in the guide frame and gradually laid down in the steel pipe leveling device, and the immersion process in the lining tank is also automated, making it possible to line steel pipes that are longer than conventional methods, such as 5.5 mm.

c By forming the post-heating furnace into a C-shaped plane, the length of the entire heating furnace can be reduced by this amount.

Therefore, it is possible to efficiently utilize the factory site.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a heating furnace according to the present invention, FIG. 2 is a front view, and FIG. 3 is a sectional view taken along line A-A. 1... Heating section, 2... Pre-heating furnace, 3... Post-heating furnace, 4... Gas burner, 5... Hot air circulation fan,
6... Lining tank, 7a... Lifting device, 7...
Guide frame, 8... Inclined guide, 9... Steel pipe horizontal device, 10... Spiral shaft, 11... Transport body, 1
2... Endless conveyor, 13... Holder, 14
. . . Drive device, 15 . . . Up slope section, 16 . . . Down slope section.

Claims (1)

[Scope of Claim for Utility Model Registration] A linear preheating furnace 2, a lining tank 6 following this preheating furnace 2, a planar C-shaped postheating furnace 3 following this lining tank 6, and these preheating furnaces. 2 and a carrier 11 arranged to run through the lining tank 6 and the post-heating furnace 3, the carrier 11 is of an endless type with pipe holders 13 attached downward at regular intervals, and An upward slope section 15 is formed on the entrance side of the heating furnace 2, and a downward slope section 16 is formed on the exit side of the post-heating furnace 3, and further below this upward slope section 15, a guide frame 7 is formed.
is arranged horizontally, and the carrier 1 is placed on this guide frame 7.
A steel pipe leveling device 9 is installed horizontally below the downward slope portion 16 of the conveyor 11.
A heating furnace for steel pipes, characterized in that a spiral shaft 10 is attached to the spiral shaft 10, which is inclined in a direction away from the carrier 11 and rotates in synchronization with the traveling of the carrier 11.