JPH0133916Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention relates to a heating machine for preheating a metal tube when coating the inner surface of the metal tube.

<Conventional technology> In recent years, plastic coated pipes have been widely used in oil and gas pipelines, etc.
Heat-recoverable tubes and heat-recoverable sheets are often used to protect the joints of these steel pipes, and in order to install them, the steel pipes at the joints are preheated to 50-60°C or higher, and then the tube or sheet is heated. and tightly adheres it to the steel pipe.

On the other hand, oil and gas excavations tend to move to cold regions, and it is not easy to preheat steel pipes when processing heat-recoverable materials in such cold regions.

In addition, the temperature of objects flowing through pipelines is increasing, and the heat-resistant properties of the coating materials that protect pipelines are also increasing, so the preheating temperature of steel pipes is also increasing as the heat resistance of the coating material improves. There is.

Previously, several had gas burners were used to heat the steel pipe from the outer periphery.

<Problem that the invention aims to solve> Conventionally, heating the outer periphery of a steel pipe was done manually using several hand gas burners, but this not only required a lot of labor and time, but also was difficult to heat uniformly. .

This invention aims to solve the above problems.

<Means for Solving the Problems> This invention heats a metal tube from the inside, and has a plurality of gas burners arranged radially outward in a frame that can be moved inside the metal tube.

<Function> Multiple gas burners arranged radially outward heat the entire inner circumference of the tube simultaneously without being affected by outside temperature, so it can be heated quickly and evenly.

<Example> As shown in the accompanying drawings, a required number of burner support wheels 3 are supported by a ring-shaped frame body 1 by a connecting piece 2.

A plurality of gas burners 4 are arranged and fixed on the support ring 3 in an outward radial manner, and the gas supply pipes 5 of each burner are converged and connected to a gas cylinder as appropriate.

Further, supporting legs 6 whose lengths can be adjusted and fixed are provided radially on the frames 1, 1, and a rolling wheel 7 is provided at the tip of the supporting legs.

The gas burners may be arranged in one or several rows, and the angle at which they are attached can be changed as desired, such as radially, or inclined in the circumferential direction or toward the center, as well as the number of burners installed and arrayed.

This invention, which consists of the above structure, is a steel pipe a
and the support leg 6 so that the burner support ring 3 is approximately concentric.
The length of is adjusted and fixed, the gas burner 4 is moved to the steel pipe joint part a, and the burner 4 is ignited to heat the steel pipe a from the inner surface.

<Effect of the invention> When the inner surface of the steel pipe is heated with a large number of burners 4 in this way, the entire inner circumference of the steel pipe is heated almost evenly,
Since the heating surface is not exposed to the outside air, it can be heated quickly and efficiently, and can be heated in a short time with a small number of hands.

According to the experimental results, a heating machine with 12 gas burners arranged in two rows was used on a 1400 steel pipe to reduce the outside temperature.
When the temperature was 10°C, the temperature could be raised to 150°C in just 3 minutes.

In addition, since the supporting legs 6 can be adjusted in length or shortened, they can be used in common depending on the size of the pipe diameter.

Note that it is also possible to configure the support ring as a gas passage and supply gas to each burner from this gas passage.

[Brief explanation of the drawing]

The drawings show an embodiment of this invention; FIG. 1 is a longitudinal sectional front view, and FIG. 2 is a side view taken along the line A--A in FIG. 1. a... Steel pipe, 1... Frame, 4... Gas burner.

Claims (1)

[Claims for Utility Model Registration] (1) A metal tube inner surface heating machine characterized by having a required number of gas burners radially installed on a frame to which a plurality of radial supporting legs are attached so that the device can move within the metal tube. (2) The metal tube inner surface heating machine according to claim 1, which is a registered utility model and has a plurality of supporting legs each having a rolling wheel at the tip thereof, the length of which is adjustable.