RU1580711C - Method for manufacturing multilayer shells - Google Patents

Abstract

The invention relates to mechanical engineering, specifically to a method for manufacturing multilayer shells of vessels and high pressure pipelines and can be used in power engineering. chemical and other engineering industries. The purpose of the invention is to increase the strength of the shell in operation. The sheet is wound on a mandrel, while welding adjacent spoits to each other. The winding is performed with the tension of the sheet, the value of which is determined from the ratio

Description

The invention relates to mechanical engineering, and more particularly, to methods for manufacturing multilayer shells of vessels and pipelines of high pressure, and can be used in the energy, chemical, and other industries.

The purpose of the invention is to increase the strength of the shell in operation.

The method is carried out as follows.

The steel sheet is wound onto the liner and its end is welded to the adjacent layer. The following layers are wound with design tension, while adjacent layers are welded during the winding process, then the outer end of the finished shell sheet is welded to the adjacent layer. In order to increase the strength of the article, it is advisable to ensure the same stress in all layers of the shell at the working gas pressure. For this, it is necessary to create a preliminary stress in the layers when winding the sheet. The magnitude of the prestress can be determined as follows. The tangential stresses are distributed over the shell thickness according to the following relationship.

P

 ) 2 G2 - PG

(1 +

) P- 0)

GDO n - internal radiug. about & techki, m;

G2 - outer radius, shells, m;

g is the radius of the elementary layer, m;

P working pressure, Pz.

To satisfy the condition of equal stresses s of the layers of the finished product under working pressure, it is necessary to create a preliminary stress in the elementary layer equal to the difference of the tangential stresses with the tth and inner layers, i.e.:

(70) (st0) 1-0-0, (2)

where ((Tg) i is the tangential stress.

Substituting equation (i) into formula (2). After the transformations, we obtain an expression for determining the prestress in the layers

- / L

G2

G2

AND

(1--)

P

(3)

The prestressing of the layers can be created by tensioning the sheet during the winding process, and the tensile strength of the sheet is calculated from the expression obtained from formula (3)

P2 (1G1

) 5H

N

22

G2 - P

R,

(4)

5

0

5

0

5

0

5

0

where 6 is the thickness of the layer, m;

P is the average radius of the layer, m;

H - layer width, m.

Example. The casing of the cylinder with an inner diameter of 100 mm and a wall thickness of 4 mm for a working pressure of A P 42 MPa is made from a sheet of steel 07X16HN with a thickness of 0.5 mm and a width of 300 mm. The first layer is wound on a mandrel fixed in the spindle of the lathe, and the next layers on the previous ones with a preliminary tension determined by expression (1).

The calculation results are presented in the table.

The layer is pre-tensioned by winding with the main drive of the machine and brake pads pressed against the sheet by adjusting screws, the tension of the sheet is measured by means of a torque sensor mounted on the spindle. The layer-by-layer welding is carried out by a Quantum-12 quantum optical generator continuously simultaneously with winding.

This method makes it possible to increase the strength of the fabricated shell by 2-10% depending on the inner diameter and working pressure inside the finished product. Increasing the strength of the shell is achieved by creating in each layer a different amount of prestress in accordance with the different loading of these layers.

(56) U.S. Patent No. 2,663,324, CL.138-121.1953

USSR copyright certificate No. 246735, cl. B 23/31, 1967.

Pre-tensioning force by eating

1296

J2JЈ8 J 293637:

Claims (1)

The claims METHOD FOR MANUFACTURING MULTI-LAYERED SHELLS, mainly 5 working under internal pressure, at which the first layer is wound onto an op-; de N - tensile force, N; equal, and subsequent layers - on the previous-ri - the inner radius of the shell, m; with tension, the force of which is | the average radius of the i-ro layer, m; increase as winding, and each 10. roofing felts, Ina layer, m; the subsequent layer is joined by welding sc. length of the shell, m; previous, characterized in that, s, p. operating pressure during operation in order to increase the strength of the shell of the groove, Pa; operation, the effort of the tension during winding. the outer radius of the shell, each layer is determined from the ratio of 5