SU1366269A1 - Method of producing multilayer high-pressure vessels - Google Patents

Abstract

The invention relates to the manufacture of multi-layer pressure vessels and may find application in the chemical, petrochemical and other industries. The aim of the invention is to increase the strength characteristics, durability and reliability and simplify the manufacturing technology of a multi-layer vessel. Dp this steel strip billet wound on the central shell of the vessel, the wall gradually in the process of winding the heating temperature. The central shell of the vessel is simultaneously cooled. Adjusts the intensity of heating band forecaster. This method ensures that the temperature is optimally distributed over the thickness of the multilayer wall of the product, which at the end of the winding process varies along the radius in a linear fashion. After winding is completed and the free end of the strip is fixed to the outer layer, the vessel is cooled to normal temperature. In this case, strains that are optimally distributed over the layers arise in the vessel wall, and upon subsequent loading of the vessel with the working pressure, the layers become uniformly loaded. 2 pe. SS (f С

Description

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The invention relates to the manufacture of multi-layer, rolled high pressure vessels and can be used in their manufacture for the chemical, petroleum refining, petrochemical and other industries.

The aim of the invention is to increase the strength, durability and reliability of multi-layered high pressure vessels and simplify their technology. manufacturing by creating a prestressed state with an optimal distribution of the initial stresses across the vessel layers and simplifying the manufacturing technology.

Figure 1 shows the implementation of the proposed method; Fig. 2 shows plots of circumferential stresses in the wall of a multilayer vessel.

The method is carried out as follows.

The central shell of 1 vessel with a length of 1500 mm with an outer diameter of 1260 mm and a thickness of 30 MM, made of low-alloyed structural steel, for example, steel 09G2S5, is put on drum 2 and installed between three rollers, one of which is 3 leading. , and the third 5 - supporting. Welding one end of a strip workpiece 6 with a width of 1500 mm and a thickness of 5 mm from low-alloy rolled steel, such as 10G2C1 steel, to the central shell. Then, the strip is wound onto the central shell, pressing the layer over the pressure roll 4.

In the process of winding, the strip blank 6 is heated evenly across the width in the zone of its supply to the drum 2 by means of a heating device 7. The heating temperature of the strip during the winding process will gradually increase to 200-250 ° C with the number of layers 40-50. At the same time, the central shell of the vessel 1 is cooled from the inside by passing coolant through the drum 2 through the channels 8 through the drum 2, thereby providing a heat input from the inner layers of the vessel. The intensity of cooling in the process of winding regulate, changing the flow rate of the coolant.

The heating temperature of the strip blanks in the process of winding

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and regulating the cooling rate of the central shell and the inner layers of the vessel, the result is an optimal temperature distribution across the thickness of the multilayer wall of the product: at the end of the winding process, the temperature changes along the radius according to a linear law, the average temperature gradient is K / mm.

After winding is completed, the free end of the strip blank is fixed by welding to the outer layer and the vessel is cooled to a normal temperature.

When cooled, the stresses in the vessel wall are optimally distributed over the layers, while in the inner layers the circumferential stresses compressively, in the external layers tensile stresses, the magnitude of the stresses change along the radius in such a way that upon subsequent loading of the vessel by the workers pressure layers are uniformly loaded. As a result, the intensity of the stress state of the vessel under operating conditions is significantly reduced compared to a vessel made in a known manner, which increases the strength characteristics, durability and reliability of the product and reduces its intensity.

 Figure 2 shows the graphs of circumferential stresses in the wall of a multi-layer rolled vessel made from a known method (curves 1) and this method (curves 2). The outer diameter of the vessel is D 2900 mm, the internal diameter is d 2400 mm, the wall thickness is h 250 mm. The dashed lines indicate the initial stresses, and the solid lines show the resulting stresses when the vessel is loaded with a working pressure of 48 MPa. The presented results were obtained by computer numerical experiment methods. At working pressure, the intensity of the resulting stresses in the vessel made by the proposed method is 1.5 times less as compared to c. a vessel manufactured in a known manner, which allows reducing the metal consumption of the product by 15%, reducing the vessel wall thickness to 210 mm. The durability of a structure with an optimal distribution of initial stresses under non-stationary loading conditions increases more than 3 times.

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Claims (2)

SUMMARY OF THE INVENTION A method for manufacturing multilayer pressure vessels, comprising winding a steel strip billet onto a central shell with securing its ends and creating a prestressed state in the structure, characterized in that, in order to increase strength characteristics, durability and reliability by creating a preliminary stress state with an optimal distribution of initial stresses over the layers of the vessel and simplify the technology of its manufacture, the strip blank is heated, gradually increasing the heating temperature during the winding process, the central shell is simultaneously cooled, and after the winding process is completed and the free end of the strip blank is fixed to the outer layer, the vessel is cooled to normal temperature. .1366269 2  / \ -_ / 1 / - \ l \ V. Ύ- 1200 ¹ £ 70 s' S g J / y / /4 10 Κλ / λι s' S S