RU2213904C2 - Welded high-pressure bottle - Google Patents

Abstract

FIELD: mechanical engineering; pressure vessels. SUBSTANCE: proposed welded high-pressure bottle contains shell with central part wall thickness reduced to designed section and thickened end faces for welding, lower and upper bottom plates and support shoe in bottom part. At least one of bottom plates is furnished with filling-and-discharge union. Support shoe in made in form of lower thickened end face of shell playing the part of reinforcing belt of girth weld of lower welded-in bottom plate. Lower end face of shell is furnished with closed slot formed on its inner surface and playing the part of position lock when fitting lower welded-in bottom plate inside shell. EFFECT: facilitated production of bottle, increased strength and convenience in operation. 1 dwg

Description

 The present invention relates to mechanical engineering and can be used in the manufacture of high-pressure cylinders for the transportation and storage of liquids and gases, including gas cylinders for gas welding equipment and mobile vehicles, cylinders with air-oxygen mixtures for personal respiratory protection, etc.

Given the high requirements for reliability and safety in the operation of gas cylinders, at present they are mainly made monolithic without welding or with limited use only for welding the blind bottom of the cylinder (see GOST 949-73 "Steel cylinders of small and medium capacity for gases on P _p ≤20 MPa (200 kgf / cm ² ); The industry catalog of the MFM of the USSR, "Pipes and tube products. Small and medium-sized cylinders" M., 1985, p. 14 and 27; RF Patent 1838712, MKI F 17 C 1 / 00; B 21 D 22/18 "Cylinder"). Monolithic thick-walled cylinders of low strength carbon and low-alloy steels with sufficiently high plastic properties have high reliability, but they have a large mass and limit the ability to effectively use heavy cylinders in automobile transport and in portable means of gas welding and medical equipment, oxygen-insulating gas masks, etc.

 Relief of high-pressure cylinders can be achieved through the use of high-strength metal materials and the search for new design and technological solutions.

 Known high-pressure cylinder (see. A. S. the USSR 313024, 1971), consisting of an inner cylindrical shell with bottoms and a fitting and an outer reinforcing braid of high-strength wire. The disadvantage of such a cylinder is the technological complexity of creating a braid from a high-strength wire, a small effect in reducing the mass and the impossibility of a significant increase in gas pressure, and an increase in its volume can be realized only by increasing the volume of the cylinder.

 Another known high-pressure cylinder for compressed and liquefied gases (see RF patent 2022201, 1994), including the outer and inner shells with a bottom, placed one in the other so that the bottom of one shell, mainly the inner one, forms the bottom of the cylinder, the bottom part of the outer one is the neck, while the mating surfaces of the shells are formed in such a way that the interference between them is maximized in the part adjacent to the neck of the cylinder and successively decreases in each section to the bottom of the cylinder, while the walls the shells are made decreasing from the bottom to the edge, and the edge of the outer shell bends around the bottom of the inner shell. The structural drawback of such a cylinder is the difficulty of manufacturing the outer and inner shells with a variable wall thickness, the limited possibility of using high-strength metal structural materials having reduced technological ductility, and their hardening heat treatment, because The envelope formation of the bottom part of the inner shell is performed at one of the final stages in the assembly of the balloon. In addition, the design of the cylinder does not adequately seal the outer and inner shells with each other.

 Also known is a high-pressure welded balloon (application FRG 2323844, publ. 1981), the body of which consists of an upper and lower cup, which are tightly pressed against each other and connected by a weld. The disadvantage of this cylinder is the lower strength of the welded joint, because the weld does not have sufficient reinforcement over the cross section.

 A well-known welded high-pressure cylinder (see Instruction 1006-72 "Manufacture, thermal and thermomechanical processing of containers from titanium alloys", VIAM, 1972, p.4-5) containing a shell and two bottoms, one of which is made fitting and at the ends of the shell and bottoms thickened sections are formed along which welding is performed, which ensures a decrease in the mass of the cylinder due to the thinned sections and a decrease in the level of stresses in the weld zone along the thickened edges under hydrostatic loading by internal pressure of a gas or liquid medium.

 The disadvantage of this cylinder is the technological complexity of the formation of thinning on the Central part of the cylindrical shell by mechanical processing or rotational extrusion, requiring the preliminary formation of allowances on the end parts of the shell for mounting the shell on the mandrel during thinning.

 As the closest prototype, a welded high pressure cylinder was selected (see RF patent 2145398, MKI F 17 C 1/00, publ. 02/27/2000), containing a shell with welded seams with a calculated wall thickness and thickened end edges, lower and upper bottoms, at least one of which is equipped with a filling and consumable fitting, and a support shoe in the bottom.

 The prototype also has the disadvantages of analogues.

 The aim of the present invention is to develop the design of a welded high-pressure cylinder, providing the possibility of using high-strength metal structural materials while simplifying the technology and increasing the efficiency of its production, ease of use.

This goal is achieved by the fact that the known device of a welded high-pressure cylinder containing a shell with a wall thickness thinned to the calculated section δ _{calculation of the} central part and thickened end edges δ _r = 1.1-1.5 δ _calculation for welding, lower and upper bottoms with a fitting, at least in one of them, and a support shoe in the bottom part, while the role of the support shoe is played by the lower thickened end face of the shell, on the inner surface of which there is a closed groove or open groove providing a fixed floor ix when installed inside the lower shell are welded bottom. In this case, the thickened end face of the shell, which acts as a support shoe, simultaneously forms a banding belt on the welded ring of the lower welded bottom.

 In addition, the design of the upper bottom together with a fitting and a cylindrical part of the shell provides an additional increase in manufacturability and reduce the complexity in production.

 The authors are not aware of technical solutions with the characteristics indicated in the claims aimed at achieving the same goal as in the object claimed as an invention, therefore, the proposed technical solution meets the criterion of "significant differences".

The invention is illustrated by drawings (figures 1 and 2), which show the device of a high-pressure cylinder and its elements:
Figure 1. Welded high pressure tank
1 - cylindrical shell; 2 - upper bottom; 3 - filling consumable fitting; 4 - lower bottom; 5 - weld seam fitting with the upper bottom; 6 - weld of the upper bottom with a shell; 8 - closed groove, fixing the installation position of the lower welded concave bottom; 7 - lower thickened end face of the shell - supporting shoe; 9 - a weld of a shell with a lower welded bottom installed in a closed groove; d _nap is the diameter of the outer calculated part of the shell; δ _calc - _calculated wall thickness of the thinned part of the shell; δ _t is the thickness of the thickened wall of the shell in the weld zone; d _prot - the diameter of the grooves for installing the lower bottom; D _g - overall outer diameter; N _g - overall height.

 FIG. 2. An example of execution of the upper bottom together with the fitting and the shell of the cylinder and with the installation of the lower welded convex-concave bottom in an open groove on the inner surface of the lower thickened end of the shell - the support shoe.

Pressure vessel (1 and 2) comprises a cylindrical shell (1) with thinned to the calculated thickness δ _calc thickened wall and δ _t ends, the upper bottom (2) with filling-consumable bushing (3) and a lower bottom (4), connected by welds (5, 6, 9). In this case, the lower thickened end face of the shell acts as the support shoe (7) of the cylinder and the retaining band of the ring weld (9) of the lower welded bottom with the shell.

 Welded high pressure cylinder (figures 1 and 2) works as follows.

 Compressed gas (or liquid) under pressure from the compressor enters through the filling nozzle (3) into the internal cavity of the cylinder formed by the cylindrical shell (1) and the upper (2) and lower (4) bottoms.

где σ^τ - максимальные тангенциальные напряжения, кгс/см²;
Р - избыточное внутреннее гидростатическое давление, кгс/см²;
d_нар- максимальный наружный диаметр баллона, см;
δ_расч - минимальная толщина стенки баллона, см.Moreover, in accordance with the theory of resistance of materials under hydrostatic loading of the shell by internal pressure, a biaxial stress state arises in its walls with maximum tensile stresses in the tangential direction, determined by the formula / 1 /:

where σ ^τ - the maximum tangential stress, kgf / cm ² ;
P - excess internal hydrostatic pressure, kgf / cm ² ;
d _nar - the maximum outer diameter of the cylinder, cm;
δ _calculation - the minimum wall thickness of the cylinder, see

To ensure the calculated level of strength and reliability of the container, taking into account a safety factor of 2.6, the thickness of the shells of the thickened end edges δ _{t of the} shell (1) and the bottoms (2) that are mated with respect to the design shell thickness is set to δ _t = (1, 1-1.5) × δ _calculation (since the strength of the welded joints is lower than the strength of the base metal σ _st ≤0.9σ _main , which eliminates the possibility of residual plastic deformation in the area of thickened edges adjacent to the weld (6), and in the weld (6) when loading the cylinder with internal by pressing to the calculated values during operation, while the lower thickened end face of the shell acts as a support shoe and a retaining band of the annular weld seam (9) of the lower weld bottom (4), and a closed groove or open groove (diameter d _prot ) formed on its inner surface, perform the role of fixing position of the installation of the lower welded bottom inside the shell.

 Thus, the proposed welded high pressure cylinder provides, due to changes in design, the creation of lightweight high pressure cylinders while simplifying the technology, reducing labor intensity and increasing economic performance, as well as increasing operating efficiency.

 Based on the foregoing, the present invention in comparison with the prototype provides a positive effect and has the criterion of "positive effect".

 Using the proposed technical solution does not require additional re-equipment of enterprises.

 The first industrial testing of the proposed technical solution will be carried out at JSC "Ural Plant of Technical Gases" (Ekaterinburg).

Claims (1)

 The device is a welded high pressure cylinder containing a shell with a wall thickness of the central part thinned to the design section and thickened ends for welding, lower and upper bottoms, at least one of which is equipped with a filling and consumable fitting, and a support shoe in the bottom, characterized in that the support shoe is made in the form of a lower thickened end of the shell, which acts as a banding belt of the ring weld of the lower welded bottom, and the lower end of the shell is provided with a closed groove, formed m on its inner surface and playing the role of a fixer for the installation position of the lower welded bottom inside the shell.