RU2078277C1 - Pipe unit with branch - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: cross-section of the bent portions of the unit is elliptic. The small axis of the ellipse is constant and equal to the initial diameter of a pipe line. The large axis of the ellipse is variable within the range of the angular co-ordinate from 0 deg to 90 deg. The axis is parallel to the radius of the bend to form pockets in the direction of the flow. EFFECT: enhanced reliability. 6 dwg, 1 tbl

Description

 The invention relates to the field of mechanical engineering and relates to the design of one-piece pipe connection with a branch or tee.

 Known node permanent connection of pipes (ed. St. N 1638430, class F 161 L 41/00, published in the bulletin N 12 03/30/91), used in branched pipelines experiencing the effects of vibration and bending loads. But its constructive use is not aimed at reducing the level of vibration, but at increasing the vibration strength of the structure by increasing its rigidity by creating sections of ovality with a certain length of these sections and location.

 The closest constructive decision, affecting the degree of deformation of the stream and adopted as a prototype, is a pipeline assembly with a branch (ed. St. N 1337604, class F 16 L 41/02, published in bulletin N 34 for 1987). The branch is made as a tee with input and two output sections. The axial lines are made curved along the inner and outer radius, due to which there is a decrease in the level of noise and vibration and the coefficient of hydraulic resistance by eliminating vortex formation. However, the design of this piping element is not hydraulically optimal. The fluid flow in this node will be accompanied by the formation of whirlpool zones, characterized by increased turbulence and, as a consequence, a sufficiently high wear rate, increased levels of vibroacoustic characteristics and hydraulic resistance. At the same time, in straight sections of pipelines, where the flow is stable and there are no whirlpool zones, all these characteristics are orders of magnitude lower.

 The objective of the invention is to increase the durability of pipeline elements (bends, tees), reducing their vibro-acoustic characteristics and hydraulic resistance.

The problem is achieved due to the fact that in the known node of the pipeline with a branch, for example in the form of a branch or a tee, containing curvature sections in the branch zone, a new set of cross sections of curvature sections in the form of an ellipse with a constant value of the small axis of the ellipse equal to the initial the diameter of the pipeline, and a large axis that varies in the range of the current angular coordinate from 0 to 90 ^o , located along the direction of the bend radius, with the formation of pockets in the direction of flow.

 The inventive design of the pipeline elements is the optimal form of the flowing part of the pipeline elements, providing a smooth continuous flow at various flow patterns (branch, tee). This leads to a significant decrease in the wear rate of pipelines, reducing their vibration, airborne noise and hydraulic resistance.

 In FIG. 1, 3 6 are a schematic representation of a piping assembly for various fluid flow variants; FIG. 2 sectional shapes of the channel surface in the branch zone.

The node of the pipeline is a main pipe 1 (Fig. 1) with a branch 2 at an angle of 90 ^o . In the area of one-piece connection there is a curvature section 3 with the formation of pockets 4, 5, retracted and protruding, respectively. The cross section of the curvature section 3 has the shape of an ellipse (Fig. 2) with a constant value of the minor axis 6, equal to the initial diameter of the pipeline d and changed by the major axis 7, located in the direction of the bending radius r ₂ .

(На чертеже угол погиба θ показан для примера 90^o).The change in the required values of the outer and inner radii r _NT and r _W occurs non-uniformly and depends on the die angle θ, the bend radius r _g , the pipe diameter d and the current angular coordinate v, i.e. r _nt , r _w = f (θ, r _g , d, Φ). The change in the values of r _NT and r _W for the angle of death θ = 90 ^° can be described by the following relationships

(In the drawing, the angle of death θ is shown for example 90 ^o ).

Due to this non-uniformity of changes in r _NT and r _{W, the} central axis XX of the section ellipses has an offset E relative to the ordinate:
E r _g r ₂ (r _NT r _W r _n + r _c ) / 2,
where r _in and r _n respectively the inner and outer radii of the standard channel;
r _rm required bending radius.

The pipeline may have a branch of type 2 tee. In the drawings of FIG. Figures 3 - 6 show tees with different variants of fluid flow (a, β, γ are the flow directions) and different locations of bending sections 3. The fluid flow in standard tees with the appendix attached at a 90 ^° angle is accompanied by the formation of whirlpool zones and significant flow turbulence. In the proposed designs of tees with hydraulically optimal shapes, the appendage (pipe g) is connected to the main pipeline smoothly without the formation of sharp angles, the shape of the main channel (pipes a and β is changed, which generally ensures continuity of flow for different schemes of tees and diameters from 32 to 1000 mm

The current values of the radii r _i will depend on the angle of the attached processes q, the radius of the junction of the process and the main pipe r ₂ , the diameters of the nozzles d _α , d _β , d _γ , the ratio of the diameters of the process and the main pipe d _γ / d _{α, β} for unequal tees and current angular coordinate v, i.e.

r _i = f (θ, r _g , d _α , d _β , d _γ , d _γ / d _{α, β} , Φ).
The cross sections of the nozzles in the area of the appendix attachment (in the bending zone) will have the shape of an ellipse with a variable major axis and a constant minor axis equal to the initial diameter of the pipeline. The proposed shape of the flow part allows to minimize vortex formation, as well as turbulence levels in the flow flowing through the tee.

 Examples of specific performance of the curvature sections (their sizes) are given in the table.

 The technical and economic effectiveness of the proposed solution is to reduce the intensity of wear of pipelines, reducing noise and vibration levels, their hydraulic resistance. The use of elements with improved operational characteristics in pipelines will increase the durability of pipelines, reduce the volume, time and cost of their repairs, ensure a higher level of habitability of the premises in which the pipelines are located.

 It is possible to use such pipeline elements in mechanical engineering, shipbuilding, in pipelines of thermal, hydraulic nuclear power plants, oil, gas, petrochemical industries, etc.

 The proposed elements of pipelines are made by casting or stamping without connecting elements.

Claims (1)

A pipeline assembly with a branch, for example in the form of a branch or tee, containing curvature sections in the branch zone, characterized in that the cross sections of the curvature sections have an ellipse shape with a constant value of the small axis of the ellipse equal to the initial diameter of the pipeline, varying in the range of the current angular coordinate from 0 to 90 ^{o the} major axis located along the direction of the radius of the bend, with the formation of pockets in the direction of flow.

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