RU2338955C1 - High-pressure vessel (versions) - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: high-pressure vessel incorporates shell. The open faces of the said shell elements are in an overlapping or abutting contact between themselves, the about joint areas being additionally fitted with, at least, one coupling overlapping ring. The overlapping contact between the aforesaid elements or between the said elements and the overlapping ring is ensured by a sealing adhesion layer, the size of overlapping of all aforesaid elements is calculated by the formula as follows, i.e. L≥p×D/(4×σ), where p is the designed vessel destruction pressure, D is the maximum vessel diameter in the area of the adhesion joint, σ is the designed polymerised adhesive layer shear strength, the load-bearing enclosure featuring a double overlapping of the aforesaid joints coming over to the vessel bottom.

EFFECT: simple high-pressure vessel design, ease of manufacture, higher assembly efficiency and lower production costs.

4 cl, 8 dwg

Description

The invention relates to the production of high-pressure cylinders, which can be used to store compressed and liquefied gases in fire extinguishing systems, breathing apparatus, etc.

A well-known container for compressed and liquefied gases, including the outer and inner shells with a neck and a bottom, respectively, placed one in the other with an interference fit, using, if necessary, a coating, sealant or adhesive in their place of contact [Description of the invention to the patent of the Russian Federation No. 2022201 of 18.05 .1992, IPC ⁵ F17С 1/00, publ. 10/30/1994].

The design of the container and the method of its manufacture are characterized by increased complexity, which, in combination with the usual characteristics of the finished product, is not economically feasible.

A known design of a metal high-pressure cylinder, including a body and bottoms connected with a neck with a thread, the tightness of the threaded connection is ensured by a special method of assembly, namely, the assembly in the plastic state of the metal of one of the connection details [Description of the invention to the patent of the Russian Federation No. 2178861 from 04/19/2000, IPC ⁷ F17C 1/00, publ. 01/27/2002, bull. Number 3].

In the manufacture of the container, a threaded connection is used, including two different types of thread - one typical (for example, standard), and the other a special one, taking into account linear deformations that occur during the heating of an adjacent part to a plastic state. This requires special preparation of production and special equipment.

A high-pressure cylinder is known, containing two half-cylinders with bottoms, connected along the thickened edges by means of a thread with a nipple sleeve and sealed by fusion of the edges or the introduction of adhesive components, while the outer surface of the cylinder along the generatrix of the cylinder is reinforced with a layer made of glass or carbon fibers [Description inventions to the patent of the Russian Federation No. 2168083 dated 04/04/1996, IPC ⁷ F16J 12/00, F17C 1/00, publ. 10/30/1994].

The use of several independent technological transitions (joining with thread and sealing with adhesive components), each of which is potentially self-sufficient, makes the production technology of a well-known balloon unreasonably complicated.

Known combined high-pressure cylinder, consisting of bonded shells made of composite material and bottoms connected to the shell using tape threads and provided with annular grooves in which the ends of the shell are clamped and O-rings made of elastic material are installed [Description of the invention to the patent of the Russian Federation No. 21118745 from 01/23/1997, IPC ⁶ F17С 1/06, F17С 1/16, F17J 12/00, publ. 09/10/1998].

This cylinder has the same disadvantages as the previous one, with the only difference that the sealing of the used threaded connection is provided by a ring of elastic material placed in a special annular groove.

Known high-pressure gas cylinder containing a power shell made of composite material, for example from "Kevlar", an integrated sealing shell made of metal with bottoms and flanges [Description of the invention to the patent of the Russian Federation No. 2118356 from 10.11.2000, IPC ⁷ F17C 1/06, F17C 1 / 16, publ. 08.27.2000]. For gluing the elements of the cylinder are used adhesives based on leukonates, and the strength of the connection is ensured by welding.

The welding joint actually duplicates the glue, which makes the design of the container and the manufacturing process of its manufacture quite complicated.

Also known is a metal-plastic high-pressure cylinder, including an external power plastic shell and an internal thin-walled steel liner containing a middle cylindrical part and two bottoms connected by welding [Description of the invention to the patent of the Russian Federation No. 2289062 from 04/12/2005, IPC ⁸ F17C 1/00, B21D 51/24, publ. 12/10/2006]. The structural advantages of this cylinder are provided by the fact that the bottom of the liner is made in one piece with the fitting and the peripheral annular section for connection with the middle cylindrical part, which makes this bottom very reliable.

The use of welding to connect thin-walled parts of a known balloon greatly complicates the manufacturing process.

The closest set of essential features claimed as inventions technical solutions is a composite high-pressure gas cylinder containing an internal thin-walled metal liner (sealed housing) and an external organoplastic shell around the entire surface of the liner, which is made welded, containing the middle cylindrical part (shell) and two bottom (also including shell elements, i.e. cylindrical parts open from the ends), connected to the middle part by means of underlays x rings [Description of the invention to the patent of the Russian Federation No. 2077682 from 04.29.1994, IPC ⁵ F17C 1/06, publ. 04/20/1997, bull. No. 11].

Compared with the previous technical solution, the welded joints of the thin-walled middle cylindrical part and two bottom ones are carried out using backing rings, which reduces the requirements for the technological modes of welding of the liner. Nevertheless, the production of such cylinders requires the organization of special jobs, the use of expensive welding equipment and the involvement of highly qualified specialists, in particular, to work on laser and electron beam welding installations, as well as their maintenance.

The problem solved by the first embodiment of the invention and the technical result achieved are to create a technologically advanced and fairly simple design of high-pressure cylinders, increase the productivity of their assembly and, accordingly, reduce production costs.

To solve the problem and achieve the claimed technical result in a known pressure vessel, including a sealed housing with bottoms, at least two shell elements, each of which has at least one open end, and a power shell of at least , one layer of reinforced plastic, the elements of the shells from the open ends are lapped together, while the lap contact of the shell elements is carried out using a sealing layer of adhesive composition and azovanie adhesive joints, and the value of the mutual overlap of the elements of the shells is calculated by the formula:

L≥p × D / (4 × σ),

where p is the estimated pressure of the destruction of the vessel;

D is the maximum diameter of the vessel body in the area of the adhesive joint;

σ is the calculated fracture stress of the polymerized adhesive layer by shear,

and the power shell is made with an overlap of adhesive lap joints and approaching the bottoms.

In addition, the part of at least one of the elements of the shell, providing an overlap connection, is made stepwise.

The foregoing for the first embodiment of the invention, the prior art applies to the second invention of the group.

The problem solved by the second embodiment of the invention and the technical result achieved also lie in creating a technologically advanced and fairly simple design of high-pressure cylinders, increasing the productivity of their assembly and, accordingly, reducing production costs.

To solve the problem and achieve the claimed technical result in a known pressure vessel, including a sealed housing with bottoms, at least two shell elements, each of which has at least one open end, and a power shell of at least , of one layer of reinforced plastic, the shell elements from the open ends contact end-to-end, and the joint zones are additionally equipped with at least one connecting lap ring, while the lap contact elements of shells and lap rings is carried out using a sealing layer of adhesive composition and the formation of an adhesive joint, and the value of mutual overlap for each element of the shell and lap ring is calculated by the formula:

L≥p × D / (4 × σ),

where p is the estimated pressure of the destruction of the vessel;

D is the maximum diameter of the vessel body in the area of the adhesive joint;

σ is the calculated fracture stress of the polymerized adhesive layer by shear,

and the power shell is made with an overlap of adhesive lap joints and approaching the bottoms.

In addition, parts of at least two end-to-end contacting shell elements at the junction with the lap ring are made stepwise.

It should be noted that the term "shell element" refers to the cylindrical part of any part of the sealed body of the pressure vessel, through which, in the case of the present invention, their one-piece connection is provided, with the exception of the lap ring - an additional technological part that provides the possibility of lap joint of two adjacent elements shells. Thus, the shell elements are present at the ends of both one bottom of the vessel body in the form of its cylindrical part, and on the other - in the case of the manufacture of a sealed case from two bottoms, one of which has a neck and the other is made deaf, and also, of course, with two ends of the shell itself - in the case of the manufacture of a sealed enclosure of two bottoms with a cylindrical shell or several cylindrical shells between them. Regardless of the design of the bottom and the presence of a neck in it, in order to be able to realize the claimed invention, it is necessary that its open part from the end be cylindrical, i.e. would contain a shell element.

The invention is illustrated by drawings, where

figure 1 shows a typical design of a pressure vessel;

figure 2-4 shows the design options of the pressure vessel;

figure 5-8 - possible options for connecting parts in a pressure vessel.

The pressure vessel includes a sealed housing 1 with bottoms 2 (and 2 '), at least two shell elements 3, 4 and 5, 6, each of which has at least one open end 7, 8 or 9, 10 and a power shell 11 of reinforced plastic or at least one of its layers. Depending on the type of connection of the elements of the shells, two characteristic variants of the design of the housing 1 can be distinguished.

For the first option, the elements of the shells 3 and 4 from the open ends 7 or 8 are in contact with each other overlap (see figures 1, 2, 5 and 6), while the lap contact of the elements of the shells 3 and 4 is carried out using a sealing layer of adhesive composition and the formation adhesive joints (not conventionally shown, but implied).

For the second option, the elements of the shells 5 and 6 from the open ends 9 or 10 are in contact with each other end-to-end (see Figs. 3, 4, 7 and 8), and the joint zones are additionally equipped with at least one lap joint ring 12, while lap contact of shell elements 5 and 6 and lap ring 12 is also carried out using a sealing layer of adhesive composition and the formation of an adhesive joint (also conditionally not shown, but implied).

The value of the mutual overlap L of the elements of the shells 3 and 4 or for each element of the shell 5 and 6 and lap ring 12 is calculated by the formula:

L≥p × D / (4 × σ),

where p is the estimated pressure of the destruction of the vessel;

D is the maximum diameter of the vessel body in the area of the adhesive joint;

σ is the calculated fracture stress of the polymerized adhesive layer by shear,

and the power shell 11 is made with an overlap of adhesive lap joints and approaching the bottoms 2.

The value of the overlapping L was determined from the condition that the fracture stress of the polymerized adhesive layer by shear σ equals the ratio of the shear force to the area of the sheared surface. In turn, the shear force is equal to the projection area of the bottom 2 or 2 ', multiplied by the design pressure r of the destruction of the vessel, and the area of the shifted surface is equal to the length of the corresponding circumference of the shell element 2, 4 or 5, 6 in the area of their connection to each other or their connection with lap ring 12, multiplied by the width of the polymerized adhesive layer (it is also the value of the mutual overlap L).

An adhesive composition (also known as a polymer composition) is, for example, anaerobic or some other adhesive manufactured by the domestic industry (for example, see the catalog [Anaerobic sealing compounds (sealants). Acrylic adhesives. FSUE "Research Institute of Polymers", Dzerzhinsk, 1999]), or its foreign analogues distributed under the trademark LOCTITE®, AGA, etc.

The design features of the housing 1 is that part of the elements of the shell 3 or 4 (see figure 5 or 6), providing lap joint, is made stepwise. Similarly, parts of two end-to-end contacting elements of shells 5 and 6 at the junction with lap ring 12 (see Fig. 7 or 8) are made stepwise. It should be noted that the step (distribution, crimping, calibration, exhaust, etc.) can be performed on the parts based on considerations of manufacturability, cylinder operating conditions, equipment capabilities, etc., for this reason only characteristic options are shown in the drawings stepped form of shell elements 3, 4 and 5, 6.

Potentially, the above features of the sealed housing 1 can be implemented simultaneously in one vessel, i.e. the open ends 7 and 8 of the shell elements 3 and 4 from the side of, for example, one bottom 2 can overlap each other, and the open ends of other, not shown shell elements (this can be a connection of the other bottom to the other end of the shell - not shown conditionally) can contact each other end-to-end, including the possibility of performing a cylindrical shell 13 made up by the same principle, which can conditionally be considered the right part of the housing 1 in the drawings (in addition to the fact that in other cases it can be elongated Whether the stretched bottom 2 ').

Conversely, the open ends 9 and 10 of the elements of the shells 5 and 6 of the bottom 2 can contact end-to-end, and the open ends of other, conditionally not shown elements of the shells can be lapped together. And so, in any combination.

Consider typical examples of the manufacture of pressure vessels, corresponding to both variants of the invention.

Initial data for design.

It is necessary to manufacture a vessel designed for an operating pressure of p = 15 MPa, the sealed metal case 1 of which is made of steel 10Kh18N10T (although the case 1 can be made of aluminum alloy, it can be non-metallic, for example, composite, etc.) with a minimum thickness walls 1 mm, with a maximum diameter D in the area of the connection of parts of the housing 1, equal to 150 mm The calculated fracture stress of the polymerized adhesive layer by shear is σ = 20 MPa. The accepted pressure for the destruction of the vessel - 36 MPa - is determined by multiplying the value of the working pressure by the standard coefficient k = 2.4, defined in PB 03576-03 ("Rules for the design and safe operation of vessels operating under pressure").

We calculate the value of the mutual overlap L of the elements of the shells 3 and 4 (or mutual overlap L for each element of the shell 5 and 6 and the lap ring 12):

L≥p × D / (4 × σ) = (36 × 150) / (4 × 20) = 67.5 mm.

For further design and use, the value of the mutual overlap L is taken equal to 70 mm.

Example 1. The cylinder includes two bottoms 2 and 2 ', for example, as shown in figure 1.

The bottom 2 with the neck is taken as less heavy, and an adhesive composition of 70 mm is applied to the inner surface of the lap portion 3 around the circumference. The prepared bottom 2 is put on the blind bottom 2 'by a value of 70 mm. In this case, the adhesive acts as a lubricant, making it easy to overcome the frictional force in the gap between the parts to be joined. Actually, the adhesive can first be applied to the blank bottom 2 '- it all depends on the specific conditions of production, technological capabilities, the habits of workers, established traditions, etc. After a technologically set time has elapsed, which is at least 20 minutes, at a temperature of at least 5 ° C, in the gap between the parts in the absence of atmospheric oxygen and with the assistance of metal ions, the composition polymerizes with the formation of an indispensable compound that carries a sealing function. The optimum aging conditions are 20-24 hours and a temperature of 20-22 ° C. During this time, complete adhesive polymerization occurs. Thus, reliable sealing of the connection and reliable fixation of parts 2 and 2 'relative to each other is achieved.

The resulting housing 1 is sent to the next technological operation - winding with fiber to obtain a power shell with mandatory overlap of the adhesive lap joint and approaching the bottoms 2 and 2 '.

After keeping the bottle, it is ready for further use as intended.

Example 2. Similar to example 1.

The difference lies in the fact that the bottoms are collected “dry”, and the anaerobic composition is applied to the joint zone, having previously rotated the housing 1 with the bottom 2 down.

A one-component, as a rule, liquid anaerobic composition due to mechanical displacement and due to capillary properties spreads in the gap between the parts, thereby filling the gap that is equal to the volume of the used liquid composition. If a part of the composition falls outside the established limits of the connection, for example, beyond the open end 8, then, due to the properties of anaerobic compounds, its excess will seep out (drain) without subsequent polymerization.

Example 3. The cylinder includes a bottom 2 with a neck, a cylindrical shell 13, a blind bottom 2 'and lap ring 12, for example, as shown in Fig.3.

A bottom 2 with a neck is taken and an adhesive composition of 70 mm is applied around the circumference of the lap section 5 and a lap ring 12 is put on, which has a width of 70 + 70 = 140 mm. After the technologically established time has elapsed, the composition polymerizes to form an integral connection of the shell element 5 and the lap ring 12.

Next, an anaerobic composition is also applied to the open inner surface of the lap ring 12 (by a value of 70 mm).

The prepared bottom 2 is put on a cylindrical shell 13. The open end 9 of the bottom 2 is in contact with the open end 10 of the shell 13 end-to-end by means of an overlap ring 12. The anaerobic composition is polymerized and the body 1 is sent for reinforcement with plastic.

Further, as in example 1.

Other examples of the implementation of the invention in the framework of the use of essential features in their various combinations are possible. In all cases, in the design of the pressure vessel, a thin-walled metal housing 1 ensures tightness, and the power shell 11 ensures the strength of the product.

Thus, the use of the invention allows you to create a variety of technological options for a fairly simple design of composite high-pressure cylinders, increase the productivity of their assembly and reduce production costs.

Claims (4)

1. The pressure vessel, comprising a sealed housing with bottoms, at least two shell elements, each of which has at least one open end, and a power shell of at least one layer of reinforced plastic, characterized in that the elements of the shells from the open ends are in contact with each other, while the lapping contact of the elements of the shells is carried out using a sealing layer of adhesive composition and the formation of an adhesive joint, and the size of the mutual overlap eleme nt shells is calculated by the formula: L≥p · D / (4 · σ), where p is the estimated pressure of the destruction of the vessel; D is the maximum diameter of the vessel body in the area of the adhesive joint; σ is the calculated fracture stress of the polymerized adhesive layer by shear, and the power shell is made with an overlap of adhesive lap joints and approaching the bottoms. 2. The vessel according to claim 1, characterized in that the part of at least one of the elements of the shell, providing lap joint, is made stepwise. 3. The pressure vessel, including a sealed housing with bottoms, at least two shell elements, each of which has at least one open end, and a power shell of at least one layer of reinforced plastic, characterized in that the elements of the shells from the open ends are in contact with each other, and the zones of the joints are additionally provided with at least one connecting lap ring, while the lap contact of the elements of the shell and the lap end is carried out using m of the sealing layer of the adhesive composition and the formation of an adhesive joint, and the mutual overlap for each element of the shell and lap ring is calculated by the formula: L≥p · D / (4 · σ), where p is the estimated pressure of the destruction of the vessel; D is the maximum diameter of the vessel body in the area of the adhesive joint; σ is the calculated fracture stress of the polymerized adhesive layer by shear, and the power shell is made with an overlap of adhesive lap joints and approaching the bottoms. 4. The vessel according to claim 1, characterized in that the parts of at least two end-to-end contacting elements of the shells at the junction with the lap ring are made stepwise.

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