Soft belt type electromagnetic induction heater

Abstract

The invention provides a soft belt type electromagnetic induction heater used for butt welding in pipeline engineering, which relates to the technical field of pipeline systems. The soft belt type electromagnetic induction heater comprises an induction heating ring. The invention is characterized in that high-temperature-resistance insulation fiber (7) and high-temperature flame-retardant cloth (8) are adopted to be covered outside a high-frequency soft cable (5) to be made into heating soft belts (1) in different specifications according to different diameters of steel pipes, both ends of the heating soft belts (1) are provided with purpose-made electric connectors (2) so that the high-frequency soft cable (5) forms a spiral wire heating ring, and the output current of a middle-frequencypower supply is communicated with both ends of the spiral wire for heating pipe openings. The invention has the advantages that the installation / dismounting operation of the soft belt type electromagnetic induction heater on / from the steel pipes is convenient, the use is safe and reliable, the problem of the existing middle-frequency induction heating technology in the large-caliber long oil transmission gas pipeline welding preheating construction is solved, and the requirement of high-efficiency welding construction of the engineering is met.

Description

technical field [0001] The invention is a soft belt type electromagnetic induction heater for butt welding in pipeline engineering. It relates to the technical field of piping systems. Background technique [0002] In the construction process of long-distance oil and gas pipelines, welding is a key link, and the quality of welding directly affects the service life and safety of products. In order to reduce welding residual stress and prevent weld cold cracks from occurring, before welding steel pipes made of high-strength and low-alloy materials, preheating the weld joint is an important process measure to ensure welding quality. [0003] At present, during the installation of long-distance oil and gas pipelines in the field, there are several ways to preheat the welded joints of steel pipes: [0004] (1) Flame heating: using liquefied petroleum gas, the flame generated by the ring heater directly heats the welding joint. This method is not only greatly affected by externa...

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Problems solved by technology

[0004] (1) Flame heating: using liquefied petroleum gas, the flame generated by the ring heater directly heats the welding joint. This method is not only greatly affected by external climate interference, but also has low preheating efficiency and uneven heating temperature. Coking occurs on the part, which affects the welding quality and work efficiency; in addition, it is necessary to configure and transport a large number of flammable liquefied gas cylinders, and follow the construction mobile operation, which increases the construction cost;

[0005] (2) Resistance heating: use rigid stainless steel soft belt material as pure resistance load, wrap the rigid stainless steel soft belt on the welding joint, convert electricity into heat energy, and conduct the heat energy to the surface of the steel pipe to gradually heat the metal at the welding joint; The electric heating method not only has low heating efficiency, but some heat is lost, and the heating temperature is not uniform inside and outside;

However, in the welding joint preheating of long-distance oil and gas pipeline construction in the field, due to the limitation of external construction conditions, different from the factory, special requirements are put forward for the heater, which cannot be fully satisfied at present.

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