High-temperature pull-off device for heat exchange tube and tube plate joint
By designing a high-temperature pull-out device for heat exchange tube and tube sheet joints suitable for high-temperature tensile testing machines, the problems of unstable clamping and inaccurate data in existing technologies have been solved, enabling accurate pull-out force testing at high temperatures and supporting the formulation and revision of industry standards.
Patent Information
- Application Number
- CN202422710116.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-07
- Publication Date
- 2025-10-21
- Estimated Expiration
- 2034-11-07
AI Technical Summary
Existing technologies for testing the pull-out performance of heat exchanger tube and tube sheet joints under high temperature and high pressure suffer from problems such as insecure clamping, uncertain temperature, dangerous testing process, and inaccurate data. There is also a lack of mechanical performance evaluation standards and quality assurance technical specifications under high temperature conditions.
A high-temperature pull-out device was designed, comprising an upper clamp body, a central shaft, a manual nut, and locking jaws. The wedge structure and inclined surface design ensure secure clamping, and it is suitable for existing high-temperature tensile testing machines, enabling accurate testing of pull-out force at high temperatures.
It achieves reliable clamping of heat exchange tubes and tube sheet joints at high temperatures, ensuring the accuracy of test data, providing experimental data support for the formulation and revision of industry standards and technical specifications, and filling the technical gap in high-temperature pull-out force testing.
Smart Images
Figure CN223461388U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the technical field of metal material mechanical property detection, and particularly relates to a high-temperature pull-off device for heat exchange pipe and tube plate joint. BACKGROUND
[0002] The connection between the heat exchange pipe and the tube plate of the shell-and-tube heat exchanger often fails under high-temperature and high-pressure working conditions, causing huge economic losses to enterprises and even threatening the life safety of operating personnel. At present, relevant researchers have conducted a large number of studies on the high-temperature pull-off performance of the heat exchange pipe and the tube plate joint. The main purpose is to test the high-temperature pull-off force. One method is to horizontally bore one end of the heat exchange pipe of the heat exchange pipe and tube plate joint, then connect a pin shaft to a high-temperature tensile testing machine, and completely place the heat exchange pipe and tube plate joint in the heating furnace of the high-temperature tensile testing machine for heating. After heat preservation, the pull-off test is performed. This method is accurate in pull-off temperature, but the bored end of the heat exchange pipe becomes the weakest part of the heat exchange pipe. During the pull-off process, the heat exchange pipe is often broken at this part, and the pull-off data cannot be obtained. Another method is to weld a plunger inside one end of the heat exchange pipe of the heat exchange pipe and tube plate joint. After the heat exchange pipe and tube plate joint are heated to a specified temperature in a muffle furnace, they are clamped on a universal testing machine. A downward force is applied to the plunger welded inside one end of the heat exchange pipe to press off the heat exchange pipe and tube plate joint. This method cannot guarantee a certain temperature during the test. There are risks in the transfer and clamping process of the high-temperature heat exchange pipe and tube plate joint. Moreover, the heat exchange pipe and tube plate joint are also broken at the position of the welded plunger during the pressing-off process. Therefore, the high-temperature pull-off data obtained by this method is not accurate. Moreover, most of the current domestic relevant standards and specifications are normal-temperature pull-off force tests, or further test and numerical simulation combined method pull-off force test research. There is no clear evaluation standard for the mechanical properties of the tube head and tube plate joint under high-temperature conditions, and there is also a lack of corresponding quality assurance technical specifications in China. UTILITY MODEL CONTENTS
[0003] The utility model provides a kind of high-temperature pull-off device for heat exchange pipe and tube plate joint, and it is firm and reliable to be clamped, and the high-temperature pull-off force value tested is accurate, which can provide test data support for the revision of the standard and technical specification in this field.
[0004] The technical scheme adopted by the utility model is as follows:
[0005] A high-temperature pulling device for heat exchange pipe and tube plate joint, comprising an upper clamp screw head outside an upper clamp body, a central shaft inside the upper clamp body, both being an integral structure; an outer thread of a lower half of a hand nut being connected with the clamp body, an upper half of the hand nut being threadedly connected with an upper end of the central shaft or a lower part of the upper clamp screw head; the upper end of the central shaft being provided with a flat key, the flat key being connected with a key groove at a corresponding position inside the upper clamp body, a terminal end of the central shaft being fixedly connected with a central shaft disc, the central shaft disc being arranged in a jaw neck opened at an upper end of a locking jaw; an outer contour of the locking jaw being wedge-shapedly matched with a cavity structure inside the upper clamp body; a rotating handle being symmetrically and detachably arranged on the hand nut; a lower clamp screw head being arranged on a lower end surface of a lower clamp body, the lower clamp body having a cavity structure.
[0006] An inner side of the locking jaw is a slope, a bottom of the slope being provided with a through rectangular groove, and a pointed tooth being arranged on the slope.
[0007] A widest part of the upper clamp body is not greater than 100 mm.
[0008] The clamping device and the heat exchange pipe and tube plate joint are completely arranged in a heating furnace of a high-temperature tensile testing machine, and clamping is firm and reliable, the tested high-temperature pulling force value is accurate, the most core is that the high-temperature pulling clamping device is suitable for all existing high-temperature tensile testing machines, can fill the technical blank of the high-temperature pulling force test of the tube head and tube plate of the tube and shell heat exchanger in China, and can powerfully consolidate the technical foundation of the development of the tube and shell heat exchanger in the high-temperature field, and can provide a technical highlight for opening up the high-temperature pulling force inspection and detection work in the whole industry, establish the industry technical advantage, and provide test data support for the revision of the standards and technical specifications in the field. BRIEF DESCRIPTION OF DRAWINGS
[0009] Figure 1 is a structural schematic view of the utility model;
[0010] Figure 2 is a sectional view of the upper clamp body of the utility model;
[0011] Figure 3 is a left view of the upper clamp body of the utility model;
[0012] Figure 4 is a main view of the upper clamp body and the upper pull rod of the utility model;
[0013] Figure 5 is a bottom view of the locking jaw clamping the heat exchange pipe of the utility model;
[0014] Figure 6 is a left view of the locking jaw of the utility model. DETAILED DESCRIPTION
[0015] The utility model is further illustrated below in combination with the drawings and its implementation modes.
[0016] Refer to Figures 1-3 A high-temperature pulling device for the joint of a heat exchange pipe and a tube plate, comprising an upper clamp threaded head 1 located outside an upper clamp body 3, a central shaft 11 located inside the upper clamp body 3, both of which are integrated structures; the lower half of a hand nut 12 is connected with the outer thread of the clamp body, and the upper half of the hand nut 12 is connected with the upper end of the central shaft 11 in a threaded manner or with the lower part of the upper clamp threaded head 1 in a threaded manner; the upper end of the central shaft 11 is provided with a flat key, which is connected with a key groove 19 at the corresponding position inside the upper clamp body 3 in a matched manner, and the end of the central shaft 11 is fixedly connected with a central shaft disc 10, which is arranged in a jaw neck 4 opened at the upper end of a locking jaw 5; the outer contour of the locking jaw 5 is matched with the inner cavity structure of the upper clamp body 3; a rotating handle 2 is symmetrically and detachably installed on the upper part of the hand nut 12; a lower clamp threaded head 9 is installed on the lower end surface of a lower clamp body 7, which has a cavity structure.
[0017] Rotating the rotating handle 2 drives the upper clamp body 3 to move up and down, and then drives the central shaft 11 to drive the central shaft disc 10 to move up and down through the cooperation with the jaw neck 4, and drives the locking jaw 5 to move up and down. During the pulling process, the greater the downward pulling force applied is, the greater the horizontal component force applied to the heat exchange pipe 6 by the wedge-shaped upper clamp body 3 through the locking jaw 5 is, so that the heat exchange pipe 6 is firmly locked inside the locking jaw 5.
[0018] Refer to Figure 4 、 Figure 5 The inner side of the locking jaw 5 is a slope, the bottom of the slope is provided with a through rectangular groove 16, and a pointed tooth 18 is arranged on the slope, so that the heat exchange pipe is clamped more firmly.
[0019] The widest part of the upper clamp is the upper clamp body 3, and the size of the widest part of the upper clamp body 3 is not greater than 100 mm. It is ensured that the device is suitable for all existing high-temperature tensile testing machines.
[0020] The working process of the utility model is as follows:
[0021] (1) Clamping the sample: one end of the heat exchange pipe 6 is fitted with a plunger 17, and the end is placed in the locking jaw 5, the rotating handle 2 is rotated to lock the heat exchange pipe 6 in the locking jaw 5, the rotating handle 2 is unscrewed, the upper clamp and the sample are connected as a whole through the upper clamp threaded head 1 on the pull rod 14, then the lower clamp is connected on the lower pull rod through the lower clamp threaded head 9, the tube plate 8 is connected with the lower clamp together through the inner cavity of the lower clamp body 7, and finally the position of the tensile testing machine beam is adjusted to make the lower pull rod return to the initial position of the tensile test.
[0022] (2) Temperature rising: Put the upper clamp, sample and lower clamp as a whole into the inner cavity of the temperature rising furnace of the high temperature tensile testing machine, set the temperature to 500℃.
[0023] (3) Sample pulling-off: After 0.5h of heat preservation, apply displacement load at a speed of 3mm / min, and record the maximum force as the pulling-off force of the joint between the heat exchange tube and tube sheet.
[0024] (4) Sample dismounting: After cooling to 300℃, open the temperature rising furnace, connect the rotating handle 2 to the hand nut 12 through the internal thread 13, rotate the rotating handle 2 to move the locking jaw 5 upward, and take down the pulled-off heat exchange tube 6.
Claims
1. A high temperature puller for heat exchange tube to tube sheet joints, characterized by, The utility model discloses a clamp, which comprises an upper clamp threaded head (1) located outside an upper clamp body (3), a central shaft (11) located inside the upper clamp body (3), and the upper clamp threaded head (1) and the central shaft (11) are in an integrated structure; a lower half of a manual nut (12) is connected to the upper clamp body through external thread cooperation, and an upper half of the manual nut (12) is connected to an upper end of the central shaft (11) through thread cooperation or connected to a lower part of the upper clamp threaded head (1) through thread cooperation; a flat key is arranged on the upper end of the central shaft (11), the flat key is connected to a key groove (19) at a corresponding position in the upper clamp body (3) through cooperation, and a terminal end of the central shaft (11) is fixedly connected to a central shaft disc (10), the central shaft disc (10) is arranged in a jaw neck (4) at an upper end of a locking jaw (5); an outer contour of the locking jaw (5) is wedge-shapedly matched with a cavity structure in the upper clamp body (3); a rotating handle (2) is symmetrically and detachably arranged on the manual nut (12); a lower clamp threaded head (9) is arranged on a lower end surface of a lower clamp body (7), and the lower clamp body (7) has a cavity structure.
2. The high-temperature puller of a heat exchange tube-to-tubesheet joint according to claim 1, characterized in that, An inner side of the locking jaw (5) is a bevel, a rectangular groove (16) is arranged at a bottom of the bevel, and a pointed tooth (18) is arranged on the bevel.
3. The high-temperature puller of a heat exchange tube-to-tubesheet joint according to claim 1, characterized in that, A widest part of the upper clamp body (3) is not greater than 100 mm in size.