RU197731U1 - DEVICE FOR WINDING METAL PIPES IN A COIL - Google Patents

Abstract

The utility model relates to the field of mechanical engineering and, in particular, to devices for the mechanical processing of pipes by pressure and can be used for winding heat transfer pipes for nuclear power plants, gas, oil and chemical industries, namely, coil heat exchangers of the BREST-OD-300 project and evaporators for separation of liquefied gases into the coil with the set. A device for winding heat-exchange metal pipes into a coil comprises three single-strand guide rollers mounted on central shafts in a housing mounted on a rotary faceplate, two of which are made with the possibility of contacting the lower part of the heat-exchange metal pipe, and the upper one-strand guide roller is made with the possibility contacting the top of the heat transfer tube. In front of the rollers at a height equal to the diameter of the roller, a bracket is installed with a welded section of the guide tube, inside which a removable sleeve of polymer material is pressed in. The upper one-strand guide roller is a clamping one, which creates a compressive moment of forces on the pipe equal to 270-290 Nm, by means of two bolts located below the shaft of the upper one-strand guide roller and the upper adjusting eye bolt with two springs located on the above-mentioned eye bolt above and below the shaft of the upper single-strand guide roller. The upper one-strand guide roller is folded to the left with respect to the movement of the heat-exchange metal pipe. The ratio of the inner diameter of the removable polymer sleeve and the nominal diameter of the winding pipe is 1.12: 1.15. The result is improved quality. As the material of the replaceable sleeve, a polymer material with a sliding friction coefficient of not higher than 0.2 is used. As a result of using this device, high-quality products are obtained - without internal compressive and tensile stresses and macro-deviations of the coil geometry, which is confirmed by visual measuring control hydraulic and pneumatic tests. 3 s.p. f-ly, 2 ill.

Description

The utility model relates to the field of mechanical engineering and, in particular, to devices for the mechanical processing of pipes by pressure and can be used in the winding of heat transfer pipes for nuclear power plants, the gas, oil and chemical industries, namely the heat exchanger coils of the BREST-OD-300 project and evaporators for separation of liquefied gases into a coil with specified parameters (diameter and winding pitch).

In the designs of nuclear power plants, densely packed heat exchangers are widely used, where the main problem is the low uniformity and density of the winding.

Known devices for bending pipes and special pipe bending machines with a fixed mandrel of a spoon-shaped form or dies (Handbook of cold stamping. Edited by Romanovsky, ed. Sixth. - L .: Engineering, 1979, pp. 76-77, Fig. 74a, b , c, d).

The main disadvantage of the known devices and devices for bending pipes is that when bent, defects in the cross section of the pipe are formed, such as: ovality, thinning (thickening) of the pipe wall, waviness (corrugation) on the inner contour of the bent pipe sections. According to the rules for the arrangement and safe operation of equipment and pipelines of the PNAE G-7-008-89 nuclear power plants (as amended on 08/14/2006) on the details of pipelines of group B, ovality should not exceed 8%, thinning (thickening) of the pipe wall should satisfy the requirements of the drawings and technical specifications for the product, the waviness (corrugations) on the inner contour of the bent pipe sections should not exceed the norms established by the drawings and technical specifications for the product.

The relevance of the proposed device for winding metal pipes into the coil is caused by the practice of operation, namely, that all known devices of the device and installation for bending metal pipes and, especially, the winding of metal pipes into coils have a clear drawback, namely, when bending or winding metal, especially thin-walled pipes or pipes of easily deformable metals and alloys, the pipe deforms in general and, most importantly, the deformation of the cross section.

The closest in technical essence to the claimed solution is a device for winding metal pipes into a coil, which is equipped with three grooved rollers located on a rotary platform, with two rollers located at the bottom, and the upper one-strand guide roller placed above in relation to the winding pipe (photo 1 , prospectus of JSC Atomenergomash, p. 16, photo “Heat exchanger“ twisted ”with spiral-curved pipes”; photo 2, dated 11.02.2019).

The main disadvantage of this device is that the winding of pipes on a lathe occurs with a deviation from the radius of curvature and with the formation of folds on the inner surface of the pipe, which leads to marriage and loss of quality of the wound pipe.

The technical problem of the proposed utility model is the implementation of the possibility of high-quality winding of metal pipes into a coil with specified parameters by eliminating the deformation of their cross section.

This problem is solved due to the fact that the device for winding metal pipes into a coil includes three single-strand guide rollers mounted on central shafts in diameter mounted on a rotary faceplate, two of which are in contact with the lower part of the heat exchanger tube, and the upper one-strand guide roller in contact with the upper part of the heat transfer pipe, in front of the rollers at a height equal to the diameter of the roller, a bracket is installed with a welded section of the guide pipe, inside of which a removable sleeve of polymer material is pressed, the upper one-strand guide roller is clamping, creating a compressive moment of forces on the pipe equal to 270 -290 Nm, by means of two bolts located below the shaft of the upper one-armed guide roller and the upper adjusting eye bolt with two springs located on the said eye-bolt above and below the shaft of the upper one-armed guide roller, the upper one-armed The second guide roller is folded to the left with respect to the movement of the heat exchange tube.

The ratio of the inner diameter of the removable polymer sleeve and the nominal diameter of the winding pipe is 1.12: 1.15.

The length of the guide tube is three nominal diameters of the heat exchanger pipe.

As the material of the replaceable sleeve, a polymer material with a sliding friction coefficient of not higher than 0.2 is used.

This configuration of the location of the length of the guide tube and the force of the pinch roller sets the direction of movement of the heat transfer pipe when passing through the guide tube. When eliminating the curvature of the heat exchanger pipe, the lateral deformation of the heat exchanger pipe and the deflection of the pipe turns during winding are minimized, thereby ensuring the possibility of tight high-quality winding of metal pipes into the coil.

In addition, the design of the reclining upper roller, equipped with an adjusting eyebolt with two springs, provides quick and accurate adjustment of the clamping force, as well as compensation for oscillations of the heat transfer pipe as it passes through the rollers, which eliminates the slightest pipe deformation when pulled in the device. This is especially true for thin-walled pipes and pipes made of easily deformable metals and alloys. This is due to the fact that a force of 270-290 Nm, which is rectifying with respect to the pipe, is created, and this does not create additional bending stresses on the heat transfer pipe, thereby ensuring the possibility of high-quality winding of metal pipes into the coil.

With the ratio of the inner diameter of the polymer insert and the winding pipe equal to 1.12: 1.15, it was experimentally established that the necessary minimum clearance is created for the heat exchange pipe to pass through the removable polymer sleeve, thereby ensuring the possibility of high-quality winding of metal pipes into the coil.

The length of the guide tube is three nominal diameters of the heat exchanger pipe, which is required for a smooth passage of the heat exchanger pipe without warping.

The use as a material of a removable roller sleeve of a polymer material with a sliding friction coefficient of not higher than 0.2 eliminates possible damage when the pipe moves along its entire outer surface.

As a result of the use of this device, high-quality products are obtained - without internal compressive and tensile stresses and macro-deviations of the coil geometry, which is confirmed by visual-measuring control, hydraulic and pneumatic tests.

The utility model is illustrated in the drawings of FIG. 1, FIG. 2 The device (Fig. 1) is mounted on the faceplate 4 for the possibility of adjusting the feed angle of the pipe 6. The device for guiding the heat exchange tubes has two lower guide rollers 2 and one upper single-strand guide roller 1, which simultaneously serves to create a pressing force on the pipe 6 with two bolts 3. The upper one-strand guide roller 1 is fixed from one end to the axis 8, while the other end is fixed using the upper adjusting eyebolt 9 with spring 10 and spring 11 (Fig. 2).

The guide sleeve 5 of the pipe 6 has a removable sleeve of polymer material 7 for the correct entry of the pipe 6 into the stream.

The device operates as follows:

The shaft 12, on which the upper single-strand guide roller 1 rotates, is tilted, turning around axis 8 to the left with respect to the direction of movement of the heat exchanger pipe. The pipe 6 is fed through a removable guide sleeve 5 into the stream between the rollers 1 and 2. The shaft 12 is rotated and the single-strand guide roller 1 is lowered onto the pipe 6. The calculation of the magnitude of the bending moment at which the plastic hinge in the pipe section (i.e., the stresses in the pipe reach the yield strength over the entire cross section of the pipe) the value of the bending moment in the considered pipe section is determined by the formula:

 Where

D is the outer diameter of the heat exchanger pipe;

d is the inner diameter of the heat exchanger pipe;

R _p0,2 - the average value of the yield strength of the material of the heat exchange pipe;

M = 6.84⋅10 ^-7 ⋅383⋅10 ⁶ = 262 Nm.

Under the assumption that the bending moment for the formation of a plastic hinge in the bent section of the pipe, taking into account hardening, will change in proportion to the increase in the maximum stress in the bent section of the pipe, the moment is determined by the formula:

M ₁ = М⋅σ _max / R _p0,2 = 262⋅396 / 383 = 271 Nm, where

σ _max - stresses in the pipe after it is flexible;

R _p0,2 - the average value of the yield strength of the material of the heat exchanger pipe.

Next, the pipe 6 is mounted on a winding heat exchanger. On the device for guiding the heat exchange pipes, the above-mentioned torque value is set by tightening the clamping bolts 3 with a torque wrench. Next, the torque value is precisely adjusted using the upper adjusting eyebolt 9 with spring 10. Then the pipe is wound into the coil due to the coordinated rotation of the spindle and the caliper stroke machine tool. As the material of a removable polymer sleeve, polystyrene or fluoroplast is used.

The coil winding process is repeated until the specified parameters are obtained.

Thus, the proposed device allows to obtain close-packed bundles of pipes with different diameters with the exception of their deformation and warpage, i.e. the quality of the products obtained is significantly improved.

The use of this utility model allows reducing the personnel per operator when winding pipes.

In addition, this device allows you to get coils from pipes up to 25 mm thick.

Claims (4)

1. Device for winding heat-exchange metal pipes into a coil containing three single-strand guide rollers mounted on central shafts in diameter mounted on a rotary faceplate, two of which are made with the possibility of contacting the lower part of the heat-exchange metal pipe, and the upper one-strand guide roller made with the possibility of contacting with the upper part of the heat-exchange metal pipe, characterized in that in front of the rollers at a height equal to the diameter of the roller, a bracket is installed with a welded section of the guide tube, inside of which a removable sleeve of polymer material is pressed in, the upper one-strand guide roller is a clamping one the compressive moment of forces on the pipe, equal to 270-290 Nm, by means of two bolts located below the shaft of the upper single-strand guide roller, and the upper adjusting eye bolt with two springs located on the said eye bolt above and below the shaft of the upper one-strand guide roller, the upper one-strand guide roller is made to swing to the left relative to the movement of the heat-exchange metal pipe. 2. The device according to p. 1, characterized in that the ratio of the inner diameter of the removable polymer sleeve and the nominal diameter of the winding pipe is 1.12: 1.15. 3. The device according to p. 1, characterized in that the length of the guide tube is equal to three nominal diameters of the heat transfer pipe. 4. The device according to p. 1, characterized in that the material of the removable sleeve is a polymer material with a sliding friction coefficient of not higher than 0.2.

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