阅读说明：本技术 一种可改变粗糙度的人工加糙管及其制造和再加工方法 (Artificial roughening pipe with changeable roughness and its making and reprocessing method ) 是由 陈少庆 徐位欣 王勤香 万柳明 李欢 赵梦涛 于 2020-11-18 设计创作，主要内容包括：本发明公开了一种可改变粗糙度的人工加糙管及其制造和再加工方法,属于流体力学设备领域。本发明的人工加糙管结构形式,能够通过调整弹簧式电阻丝的线径以及节距,方便地改变普通管道内部的粗糙度,以适应于不同水力学试验的对于管内粗糙度的调节要求。同时,本发明提供的此类人工加糙管的制造工艺,能够实现弹簧式电阻丝与圆管之间双侧腊焊点的稳定加固,在保证两者强度的情况下最大化简化工艺流程,无需特殊加工设备,能够大大降低成本。而且,由于采用腊焊点作为固定形式,本发明可以通过对弹簧式电阻丝进行通电加热,进而熔化腊焊点,以便于重新加工人工加糙管,改变其粗糙度,实现重复利用。(The invention discloses a manual roughening pipe with changeable roughness and a manufacturing and reprocessing method thereof, belonging to the field of fluid mechanics equipment. The manual roughening pipe structure form can conveniently change the roughness of the interior of a common pipe by adjusting the wire diameter and the pitch of the spring type resistance wire so as to meet the requirements of different hydraulics tests on the adjustment of the roughness in the pipe. Meanwhile, the manufacturing process of the artificial roughened pipe provided by the invention can realize the stable reinforcement of wax welding spots on two sides between the spring type resistance wire and the circular pipe, maximally simplify the process flow under the condition of ensuring the strength of the spring type resistance wire and the circular pipe, does not need special processing equipment, and can greatly reduce the cost. Moreover, as the wax welding points are adopted as a fixed form, the spring type resistance wire can be electrified and heated to further melt the wax welding points, so that the manual roughening tube can be conveniently reworked, the roughness of the tube can be changed, and the repeated utilization can be realized.)

1. A manual roughening pipe with changeable roughness is characterized by comprising a circular pipe with a smooth inner wall and a spring-type resistance wire coaxially assembled inside the circular pipe; the outer diameter of the spring-type resistance wire is equal to or slightly smaller than the inner diameter of the circular tube, the linear section of the spring-type resistance wire is circular, two ends of the spring-type resistance wire are respectively provided with an outer contact point, and the spring-type resistance wire has axial telescopic freedom degree in a free state; the spring-type resistance wire and the internal corner formed by the inner wall of the round tube are fixed by filling the molten and then solidified wax, and the spring-type resistance wire can generate heat and melt the solidified wax in the power-on state.

2. The artificial roughening pipe as claimed in claim 1, wherein the spring type resistance wire is iron-chromium-aluminum alloy wire or nickel-chromium alloy wire.

3. The roughness-changeable artificial roughening pipe as claimed in claim 1, wherein said circular pipe is made of heat-resistant material.

4. The roughness-altering artificial roughening tube as set forth in claim 3 wherein said circular tube is formed of glass.

5. A method for manufacturing the artificial roughened pipe with changeable roughness as claimed in any one of claims 1 to 4, wherein the steps are as follows:

s1: the end parts of the two ends of the spring type resistance wire are respectively detachably connected with a metal wire;

s2: the spring-type resistance wire connected with the lead is coaxially assembled inside the circular tube, the pitch of the spring-type resistance wire is stretched to a target value, and then the two ends of the spring-type resistance wire are temporarily fixed by using a clamp;

s3: keeping a round tube provided with a spring type resistance wire upright on the tray, wherein a lead at the top of the round tube extends out of the top of the round tube, and a lead at the bottom of the round tube extends out of the space between the bottom of the round tube and the tray and is stretched to the outside of the tray; then filling wax powder into the circular tube gradually until the inner cavity of the circular tube is completely filled with the wax powder;

s4: lifting the circular tube filled with the wax powder from the tray in an upright state to separate an opening at the bottom of the circular tube from the tray and keep the circular tube suspended;

s5: applying vibration to the outer wall of the circular tube by using a vibrator to enable the wax powder filled in the inner part of the circular tube to gradually fall off from the bottom opening, and reserving the wax powder in an upward internal corner formed by the spring-type resistance wire and the inner wall of the circular tube until all the other wax powder except the internal corner in the circular tube falls off;

s6: keeping the posture of the circular tube unchanged, respectively connecting metal leads at two ends of the spring-type resistance wire to the positive electrode and the negative electrode of an external power supply, completely melting the wax powder in the internal corner by electrifying and heating the spring-type resistance wire, then disconnecting the spring-type resistance wire from the external power supply, and cooling and solidifying the melted wax again to finish the fixation of the internal corner at one side of the spring-type resistance wire;

s7: the cooled round pipe is inverted by 180 degrees and is erected on a tray, so that the inner corner of the side, which is not filled with the wax, faces upwards;

s8: filling the wax powder into the inner part of the round pipe gradually again until the inner cavity of the round pipe is completely filled with the wax powder, and repeating S4-S5 to ensure that the upward internal corner is filled with the wax powder;

s9: keeping the posture of the circular tube unchanged, respectively connecting metal leads at two ends of the spring type resistance wire to the positive electrode and the negative electrode of an external power supply, and preheating the spring type resistance wire to the temperature close to the wax melting point but slightly lower than the wax melting point; then the spring-type resistance wire is electrified and heated intermittently by controlling an external power supply, the temperature of the wire body of the spring-type resistance wire is kept to fluctuate back and forth between the temperature higher than the wax melting point and the temperature lower than the wax melting point, the wax powder in the upward internal corner is gradually and completely melted after a plurality of power-on and power-off reciprocating cycles, and the wax blocks in the downward internal corner are still adhered in the internal corner;

s10: gradually cooling the circular tube to ensure that the internal corners at both sides of the spring type resistance wire are fixed by the melted and re-solidified wax blocks;

s11: and (5) taking down the metal leads on the two sides of the spring type resistance wire and the clamps at the two ends of the spring type resistance wire to finish the manufacture of the manual roughening pipe.

6. The manufacturing method of claim 5, wherein in S2 and S7, the wax powder is filled into the circular tube layer by layer and is filled by applying high frequency vibration to the circular tube.

7. The method according to claim 5, wherein the frequency of the S4 and the S7 high frequency vibrations is 50 to 150 Hz.

8. The method according to claim 5, wherein the preheating temperature at S8 is 5-10 ℃ lower than the wax melting point.

9. The manufacturing method according to claim 5, wherein after the manual roughening of the tube is completed, the spring-type resistance wire is ground by a file toward the inner side of the axis of the round tube to remove burrs.

10. A method for reprocessing the artificial roughened pipe with changeable roughness according to any one of claims 1 to 4, comprising the steps of:

s1: integrally heating the manual roughening pipe to melt wax blocks in the manual roughening pipe into liquid, taking out the spring type resistance wire in the manual roughening pipe, and cleaning wax attached to the wire body of the spring type resistance wire;

s2: after the artificially roughened pipe is cooled, carrying out wall-adhering scraping operation on the inner wall of the circular pipe by using a scraper, removing residual wax on the inner wall of the circular pipe, and keeping the inner wall of the circular pipe smooth;

s3: according to the designed wire diameter of the manual roughening pipe, taking a spring type resistance wire which meets the wire diameter, and detachably connecting a metal wire at the end parts of two ends respectively;

s4: the spring-type resistance wire connected with the lead is coaxially assembled inside the circular tube, the pitch of the spring-type resistance wire is stretched to a new target value, and then the two ends of the spring-type resistance wire are temporarily fixed by using a clamp;

s5: keeping a round tube provided with a spring type resistance wire upright on the tray, wherein a lead at the top of the round tube extends out of the top of the round tube, and a lead at the bottom of the round tube extends out of the space between the bottom of the round tube and the tray and is stretched to the outside of the tray; then filling wax powder into the circular tube gradually until the inner cavity of the circular tube is completely filled with the wax powder;

s6: lifting the circular tube filled with the wax powder from the tray in an upright state to separate an opening at the bottom of the circular tube from the tray and keep the circular tube suspended;

s7: applying vibration to the outer wall of the circular tube by using a vibrator to enable the wax powder filled in the inner part of the circular tube to gradually fall off from the bottom opening, and reserving the wax powder in an upward internal corner formed by the spring-type resistance wire and the inner wall of the circular tube until all the other wax powder except the internal corner in the circular tube falls off;

s8: keeping the posture of the circular tube unchanged, respectively connecting metal leads at two ends of the spring-type resistance wire to the positive electrode and the negative electrode of an external power supply, completely melting the wax powder in the internal corner by electrifying and heating the spring-type resistance wire, then disconnecting the spring-type resistance wire from the external power supply, and cooling and solidifying the melted wax again to finish the fixation of the internal corner at one side of the spring-type resistance wire;

s9: the cooled round pipe is inverted by 180 degrees and is erected on a tray, so that the inner corner of the side, which is not filled with the wax, faces upwards;

s10: filling the wax powder into the inner part of the round pipe gradually again until the inner cavity of the round pipe is completely filled with the wax powder, and repeating S6-S7 to ensure that the upward internal corner is filled with the wax powder;

s11: keeping the posture of the circular tube unchanged, respectively connecting metal leads at two ends of the spring type resistance wire to the positive electrode and the negative electrode of an external power supply, and preheating the spring type resistance wire to the temperature close to the wax melting point but slightly lower than the wax melting point; then the spring-type resistance wire is electrified and heated intermittently by controlling an external power supply, the temperature of the wire body of the spring-type resistance wire is kept to fluctuate back and forth between the temperature higher than the wax melting point and the temperature lower than the wax melting point, the wax powder in the upward internal corner is gradually and completely melted after a plurality of power-on and power-off reciprocating cycles, and the wax blocks in the downward internal corner are still adhered in the internal corner;

s12: gradually cooling the circular tube to ensure that the internal corners at both sides of the spring type resistance wire are fixed by the melted and re-solidified wax blocks;

s13: and (4) taking down the metal leads on the two sides of the spring-type resistance wire and the clamps at the two ends of the spring-type resistance wire, finishing reprocessing of the manual roughening pipe, and obtaining the manual roughening pipe with new roughness.

Technical Field

The invention belongs to the field of fluid mechanics equipment, and particularly relates to a manual roughening pipe with changeable roughness and a manufacturing and reprocessing method thereof.

Background

In fluid mechanics, the coefficient of roughness, which directly changes the state of motion of the fluid in the pipe, is generally used to comprehensively reflect the coefficient of the wall facing the flow retardation. In general, the viscous bottom layer is larger than the asperity height, and one phenomenon in which the in-path resistance coefficient is related only to the Reynolds number is called hydrodynamic smoothing; the phenomenon that the roughness height is much larger than the thickness of the adhesive bottom layer and the resistance coefficient is changed only according to the roughness degree is called hydraulic roughness. The flow velocity of the fluid in the round pipe is influenced by the disturbance of the pipe wall and is distributed in a U shape on the cross section. The influence range of the circular pipe wall on the fluid state of fluid in the pipe changes along with the change of the pipe wall roughness, the larger the relative roughness of the pipe wall of the circular pipe is, the larger the range of disturbed fluid in the pipe is, namely, the smaller the range of laminar flow in the pipe is.

In the hydraulic test, the flowing state of water flow under different pipe wall roughness is usually tested, so that pipelines with different pipe wall roughness need to be designed. Such pipes that have a specific increased roughness over conventional pipes are generally referred to as artificially roughened pipes. In the prior art, the manual roughening pipe can be processed in a 3D printing or cavity pouring mode, and the inner wall of the existing pipeline can also be roughened, but the processing modes are complex in process and high in cost. And when the pipe is processed based on the existing pipe, the roughness has certain limitation, and the large-range change of the roughness cannot be realized.

In addition, the roughness of the existing manual roughening pipe is fixed after the pipe body is machined and formed, and cannot be changed by secondary machining. Therefore, how to design a new rough pipe and a simple and low-cost processing method is a technical problem to be solved urgently at present.

Disclosure of Invention

The present invention is directed to solving the problems of the prior art and to providing a manually roughened tube with a variable roughness and methods of making and reworking the same.

The invention adopts the following specific technical scheme:

the invention provides a manual roughening pipe with changeable roughness, which comprises a circular pipe with a smooth inner wall and a spring type resistance wire coaxially assembled inside the circular pipe; the outer diameter of the spring-type resistance wire is equal to or slightly smaller than the inner diameter of the circular tube, the linear section of the spring-type resistance wire is circular, two ends of the spring-type resistance wire are respectively provided with an outer contact point, and the spring-type resistance wire has axial telescopic freedom degree in a free state; the spring-type resistance wire and the internal corner formed by the inner wall of the round tube are fixed by filling the molten and then solidified wax, and the spring-type resistance wire can generate heat and melt the solidified wax in the power-on state.

Preferably, the spring-type resistance wire is an iron-chromium-aluminum alloy wire or a nickel-chromium alloy wire.

Preferably, the material of the circular tube is a heat-resistant material.

Preferably, the material of the round tube is glass.

In a second aspect, the present invention provides a method for manufacturing an artificially roughened pipe with a modified roughness as defined in any one of the first aspects, comprising the steps of:

s1: the end parts of the two ends of the spring type resistance wire are respectively detachably connected with a metal wire;

s2: the spring-type resistance wire connected with the lead is coaxially assembled inside the circular tube, the pitch of the spring-type resistance wire is stretched to a target value, and then the two ends of the spring-type resistance wire are temporarily fixed by using a clamp;

s3: keeping a round tube provided with a spring type resistance wire upright on the tray, wherein a lead at the top of the round tube extends out of the top of the round tube, and a lead at the bottom of the round tube extends out of the space between the bottom of the round tube and the tray and is stretched to the outside of the tray; then filling wax powder into the circular tube gradually until the inner cavity of the circular tube is completely filled with the wax powder;

s4: lifting the circular tube filled with the wax powder from the tray in an upright state to separate an opening at the bottom of the circular tube from the tray and keep the circular tube suspended;

s5: applying vibration to the outer wall of the circular tube by using a vibrator to enable the wax powder filled in the inner part of the circular tube to gradually fall off from the bottom opening, and reserving the wax powder in an upward internal corner formed by the spring-type resistance wire and the inner wall of the circular tube until all the other wax powder except the internal corner in the circular tube falls off;

s6: keeping the posture of the circular tube unchanged, respectively connecting metal leads at two ends of the spring-type resistance wire to the positive electrode and the negative electrode of an external power supply, completely melting the wax powder in the internal corner by electrifying and heating the spring-type resistance wire, then disconnecting the spring-type resistance wire from the external power supply, and cooling and solidifying the melted wax again to finish the fixation of the internal corner at one side of the spring-type resistance wire;

s7: the cooled round pipe is inverted by 180 degrees and is erected on a tray, so that the inner corner of the side, which is not filled with the wax, faces upwards;

s8: filling the wax powder into the inner part of the round pipe gradually again until the inner cavity of the round pipe is completely filled with the wax powder, and repeating S4-S5 to ensure that the upward internal corner is filled with the wax powder;

s9: keeping the posture of the circular tube unchanged, respectively connecting metal leads at two ends of the spring type resistance wire to the positive electrode and the negative electrode of an external power supply, and preheating the spring type resistance wire to the temperature close to the wax melting point but slightly lower than the wax melting point; then the spring-type resistance wire is electrified and heated intermittently by controlling an external power supply, the temperature of the wire body of the spring-type resistance wire is kept to fluctuate back and forth between the temperature higher than the wax melting point and the temperature lower than the wax melting point, the wax powder in the upward internal corner is gradually and completely melted after a plurality of power-on and power-off reciprocating cycles, and the wax blocks in the downward internal corner are still adhered in the internal corner;

s10: gradually cooling the circular tube to ensure that the internal corners at both sides of the spring type resistance wire are fixed by the melted and re-solidified wax blocks;

s11: and (5) taking down the metal leads on the two sides of the spring type resistance wire and the clamps at the two ends of the spring type resistance wire to finish the manufacture of the manual roughening pipe.

Preferably, in S2 and S7, the wax powder is filled into the circular tube layer by layer and is filled by applying high frequency vibration to the circular tube.

Preferably, the frequency of the vibration in S4 and the high-frequency vibration in S7 is 50 to 150 Hz.

Preferably, in the step S8, the preheating end point temperature is 5-10 ℃ lower than the wax melting point.

Preferably, after the manual roughening pipe is machined, the spring-type resistance wire is polished towards the inner side of the axis of the circular pipe by a file so as to remove burrs.

In a third aspect, the present invention provides a method for reprocessing a manually roughened pipe with a changeable roughness, as defined in any one of the first aspects, comprising the steps of:

s1: integrally heating the manual roughening pipe to melt wax blocks in the manual roughening pipe into liquid, taking out the spring type resistance wire in the manual roughening pipe, and cleaning wax attached to the wire body of the spring type resistance wire;

s2: after the artificially roughened pipe is cooled, carrying out wall-adhering scraping operation on the inner wall of the circular pipe by using a scraper, removing residual wax on the inner wall of the circular pipe, and keeping the inner wall of the circular pipe smooth;

s3: according to the designed wire diameter of the manual roughening pipe, taking a spring type resistance wire which meets the wire diameter, and detachably connecting a metal wire at the end parts of two ends respectively;

s4: the spring-type resistance wire connected with the lead is coaxially assembled inside the circular tube, the pitch of the spring-type resistance wire is stretched to a new target value, and then the two ends of the spring-type resistance wire are temporarily fixed by using a clamp;

s5: keeping a round tube provided with a spring type resistance wire upright on the tray, wherein a lead at the top of the round tube extends out of the top of the round tube, and a lead at the bottom of the round tube extends out of the space between the bottom of the round tube and the tray and is stretched to the outside of the tray; then filling wax powder into the circular tube gradually until the inner cavity of the circular tube is completely filled with the wax powder;

s6: lifting the circular tube filled with the wax powder from the tray in an upright state to separate an opening at the bottom of the circular tube from the tray and keep the circular tube suspended;

s7: applying vibration to the outer wall of the circular tube by using a vibrator to enable the wax powder filled in the inner part of the circular tube to gradually fall off from the bottom opening, and reserving the wax powder in an upward internal corner formed by the spring-type resistance wire and the inner wall of the circular tube until all the other wax powder except the internal corner in the circular tube falls off;

s8: keeping the posture of the circular tube unchanged, respectively connecting metal leads at two ends of the spring-type resistance wire to the positive electrode and the negative electrode of an external power supply, completely melting the wax powder in the internal corner by electrifying and heating the spring-type resistance wire, then disconnecting the spring-type resistance wire from the external power supply, and cooling and solidifying the melted wax again to finish the fixation of the internal corner at one side of the spring-type resistance wire;

s9: the cooled round pipe is inverted by 180 degrees and is erected on a tray, so that the inner corner of the side, which is not filled with the wax, faces upwards;

s10: filling the wax powder into the inner part of the round pipe gradually again until the inner cavity of the round pipe is completely filled with the wax powder, and repeating S6-S7 to ensure that the upward internal corner is filled with the wax powder;

s11: keeping the posture of the circular tube unchanged, respectively connecting metal leads at two ends of the spring type resistance wire to the positive electrode and the negative electrode of an external power supply, and preheating the spring type resistance wire to the temperature close to the wax melting point but slightly lower than the wax melting point; then the spring-type resistance wire is electrified and heated intermittently by controlling an external power supply, the temperature of the wire body of the spring-type resistance wire is kept to fluctuate back and forth between the temperature higher than the wax melting point and the temperature lower than the wax melting point, the wax powder in the upward internal corner is gradually and completely melted after a plurality of power-on and power-off reciprocating cycles, and the wax blocks in the downward internal corner are still adhered in the internal corner;

s12: gradually cooling the circular tube to ensure that the internal corners at both sides of the spring type resistance wire are fixed by the melted and re-solidified wax blocks;

s13: and (4) taking down the metal leads on the two sides of the spring-type resistance wire and the clamps at the two ends of the spring-type resistance wire, finishing reprocessing of the manual roughening pipe, and obtaining the manual roughening pipe with new roughness.

Compared with the prior art, the invention has the following beneficial effects:

the manual roughening pipe structure form can conveniently change the roughness of the interior of a common pipe by adjusting the wire diameter and the pitch of the spring type resistance wire so as to meet the requirements of different hydraulics tests on the adjustment of the roughness in the pipe. Meanwhile, the manufacturing process of the artificial roughened pipe provided by the invention can realize the stable reinforcement of wax welding spots on two sides between the spring type resistance wire and the circular pipe, maximally simplify the process flow under the condition of ensuring the strength of the spring type resistance wire and the circular pipe, does not need special processing equipment, and can greatly reduce the cost. Moreover, as the wax welding points are adopted as a fixed form, the spring type resistance wire can be electrified and heated to further melt the wax welding points, so that the manual roughening tube can be conveniently reworked, the roughness of the tube can be changed, and the repeated utilization can be realized.

Drawings

FIG. 1 is an exploded view of a manufactured artificially rough pipe;

FIG. 2 is a schematic view of a first state of the process of manufacturing a manually roughened pipe;

FIG. 3 is a schematic view of a second state of the process for making artificially roughened pipe;

FIG. 4 is a schematic view of a third state of the manufacturing process of the artificially roughened pipe;

FIG. 5 is a schematic view of a fourth state of the process of manufacturing a artificially roughened pipe;

FIG. 6 is a schematic view showing a fifth state in the process of manufacturing the artificially rough pipe;

FIG. 7 is a schematic view of a sixth condition in the manufacture of artificially roughened pipe;

FIG. 8 is a schematic view of a seventh condition in the manufacture of an artificially roughened pipe;

FIG. 9 is an eighth state view of a manufactured artificially rough pipe;

the reference numbers in the figures are: spring resistance wire 1, pipe 2, tray 3, wax powder 4, vibrator 5, wax solder joint 6, metal wire 7, external power supply 8.

Detailed Description

The invention will be further elucidated and described with reference to the drawings and the detailed description. The technical features of the embodiments of the present invention can be combined correspondingly without mutual conflict.

In a preferred embodiment of the invention, a novel structural form of the manual roughening pipe is provided, and the novel structural form of the manual roughening pipe is different from the conventional manual roughening pipe which is formed by integrally forming or subsequent etching and the like. Therefore, the spring-type resistance wire 1 can be tightly attached to the inner wall of the circular tube 2, the two sides of the spring-type resistance wire and the circular tube 2 can form internal corners, and the internal corners at the two sides are filled with melted and then solidified wax (the wax in the invention is paraffin, the melting point is 50-80 ℃), so that the spring-type resistance wire 1 and the circular tube 2 can be fixed. The specific outer diameter of the spring-type resistance wire 1 is optimized according to the actual situation, and the aim is to ensure that the spring-type resistance wire 1 can be attached to the inner wall of the circular tube 2 as much as possible under the condition that the spring-type resistance wire 1 can smoothly enter the circular tube 2, so that an overlarge gap is avoided. In the embodiment, the spring-type resistance wire 1 with the outer diameter equal to the inner diameter of the circular tube 2 is selected to ensure that the spring-type resistance wire and the circular tube have enough friction force to prevent the spring-type resistance wire from falling off in a subsequent vertical state.

The spring-type resistance wire 1 has axial elasticity, and has axial expansion freedom degree in a free state, so that during manufacturing, the pitch (namely the distance between two adjacent circles of springs) can be adjusted according to design requirements to change the roughness in the pipe. However, it should be noted that, since the spring-type resistance wire 1 is stretched, its outer diameter is reduced, so that it can only adjust the pitch within a certain range, and it is not suitable for over-stretching. When the adjusting range can not meet the requirements, the spring type resistance wire 1 with the pitch meeting the requirements in a free state can be selected. The spring-type resistance wire 1 can be an iron-chromium-aluminum alloy wire or a nickel-chromium alloy wire. The two ends of the spring-type resistance wire 1 are respectively provided with an external contact point for connecting a lead, and the external contact point is not too large to avoid influencing the water flow form. In this embodiment, the outer contact point is a ring body formed by bending the end of the resistance wire, and the external lead directly hooks the ring body to realize electrical connection.

The invention adopts the elastic spring type resistance wire 1 and the wax powder as raw materials, so that the artificially roughened tube can be repeatedly processed and reproduced, and the internal roughness of the artificially roughened tube can be adjusted as required. The principle is that external contact points at two ends of the spring type resistance wire 1 are connected with a power supply through a lead, then the spring type resistance wire is heated in a power-on state, and solidified wax is melted, so that the fixing effect of wax welding points on the spring type resistance wire 1 is eliminated. Therefore, the spring type resistance wire 1 can be taken out again to replace models with other thicknesses or the pitch of the spring type resistance wire can be adjusted.

Under the structure form of the manual roughening pipe, the roughness in the pipe can be flexibly adjusted through the pitch and the wire diameter of the spring type resistance wire 1, and the subsequent processing and manufacturing method cannot be changed through the adjustment, so that the automation degree and the convenience of the integral manufacturing can be greatly improved. Since the structure is of a completely new form, the manufacturing process flow of the artificially roughened pipe will be described in detail below.

In the invention, the manufacturing method of the artificial roughened pipe with changeable roughness comprises the following steps:

s1: firstly, the end parts of the two ends of the spring type resistance wire 1 are respectively detachably connected with a metal wire 7, and the metal wire 7 and the spring type resistance wire 1 can be bound or clamped and fixed so as to be convenient to detach.

S2: the spring-type resistance wire 1, the round tube 2 and the tray 3 which are connected with the metal lead 7 are taken, and then the spring-type resistance wire 1 and the round tube 2 are vertically arranged above the tray 3, as shown in figure 1. The spring-type resistance wire 1 is coaxially assembled inside the circular tube 2, and then stretched to a target value according to a designed pitch, and then the two ends of the spring-type resistance wire 1 are temporarily fixed by using a clamp, and at the moment, the longitudinal section inside the tube is shown in fig. 2. The temporarily fixed clamp can be an external clamping jaw or a cross rod erected at the end part of the circular tube 2, and the end part of the spring type resistance wire 1 can be bound on the cross rod for temporary fixation. Therefore, the spring-type resistance wire 1 can be tightly attached to the inner wall of the circular tube 2, and both sides of the spring-type resistance wire and the circular tube 2 can form internal corners. For convenience of description, the internal corners at two sides of the spring-type resistance wire 1 are respectively called an upward internal corner and a downward internal corner.

S3: the circular tube 2 assembled with the spring type resistance wire 1 is kept to stand on the tray 3, and the bottom opening of the circular tube 2 is flatly attached to the surface of the tray 3 so as to avoid wax powder leakage. The metal lead 7 at the top of the spring type resistance wire 1 extends out of the top of the circular tube 2, and the metal lead 7 at the bottom extends out of the tray 3 from the bottom of the circular tube 2 and the tray 3 and stretches to the outside of the tray 3 so as to be connected with an external power supply. Then, the inside of the circular tube 2 is gradually filled with the wax powder 4 until the inner cavity of the circular tube 2 is completely filled with the wax powder 4. In the filling process, the particle size of the wax powder is not too large, and the finest wax powder should be selected as much as possible. Simultaneously in order to guarantee that the reentrant corner department of spring resistance wire 1 and pipe 2 all can be filled up by the wax powder, the wax powder is filled layer by layer as far as possible, packs one deck wax powder promptly and vibrates pipe 2 back, is that this one deck wax powder fills up the inside cross section space that is full of whole pipe 2, then carries out the packing of next deck wax powder. Here, high frequency vibration may be applied to the circular tube 2 using a high frequency vibrator to sufficiently vibrate the dispersed wax powder. The final filling state of the wax powder is shown in fig. 3.

S4: on the basis of fig. 3, the round tube 2 filled with wax powder 4 is lifted from the tray 3 in an upright state, so that the bottom opening is separated from the tray 3 and is suspended, and the state shown in fig. 4 is formed.

S5: most of the wax powder in the circular tube 2 in the state of fig. 4 cannot automatically fall off under the action of self friction force, so that the vibrator 5 is required to apply high-frequency vibration to the outer wall of the circular tube 2, and the wax powder 4 filled in the circular tube 2 gradually falls off from the bottom opening and is stored in the tray 3. Because the upward reentrant corner that spring resistance wire 1 and 2 inner walls of pipe constitute, the wax powder can not drop because of the blockking of spring resistance wire 1 in this reentrant corner up, but wherein the reentrant corner that faces down and the wax powder in the inner chamber of spring resistance wire 1 all can drop automatically under the vibration. Therefore, in the continuous vibration process, the upward internal corner formed by the spring-type resistance wire 1 and the inner wall of the circular tube 2 retains the wax powder 4, as shown in fig. 5. When the remaining wax powder 4 in the round tube 2 except the upward position of the negative angle falls off, the vibration can be stopped.

S6: keeping the posture of the circular tube 2 unchanged in the state shown in fig. 5, and connecting the metal leads 7 at the two ends of the spring-type resistance wire 1 to the positive and negative electrodes of an external power supply 8 respectively, as shown in fig. 6. Through the electrification and the heating of the spring type resistance wire 1, the wax powder in the upward internal corner can be completely melted when the temperature is higher than the melting point of the wax powder. Of course, the melting process can be realized by heating the circular tube 2 in situ by external heating equipment, or by transferring the whole circular tube 2 into a high-temperature furnace for heating. However, the circular tube 2 can be prevented from being excessively processed at high temperature by the power-on heating mode, and damage or deformation of the circular tube can be reduced. In the heating process, after the wax powder 4 in the upward internal corner is completely melted, the external power supply 8 and the spring type resistance wire can be disconnected, the melted wax is cooled and solidified again to form wax blocks, and the upward internal corner in the spring type resistance wire 1 is fixed. At the moment, the state in the circular tube 2 is shown in fig. 7, and the spring-type resistance wire 1 and the circular tube 2 form a wax welding point 6 at the internal corner position.

The material of the circular tube 2 is a heat-resistant material, and ceramics, glass, stainless steel, copper, aluminum, or the like can be used. In this embodiment, glass is preferably used to facilitate observation of the melting state of the wax powder inside.

The fixation of the one-side wax welding of the spring type resistance wire 1 is completed in the steps, but in actual use, in order to avoid overlarge hydraulic disturbance caused by the internal corner on the other side, the internal corner on the other side needs to be fixed. However, since one side already has the wax welding 6, if the same heating method is used, the existing wax welding 6 will melt and fall off, so that the special way of performing the wax welding on the other side inside corner will be described below.

S7: the cooled tube 2 is inverted by 180 ° and is placed upright on the tray 3 with its wax-unfilled inside corner facing upwards and the existing wax welds 6 facing downwards.

S8: and filling the wax powder 4 into the circular tube 2 again gradually until the inner cavity of the circular tube 2 is completely filled with the wax powder 4, wherein the process can be continued by filling and vibrating in S3 layer by layer. And after the filling of the wax powder in the tube is finished, repeating S4-S5 to ensure that the upward internal corner is filled with the wax powder 4, wherein the concrete process is as follows:

the round tube 2 filled with the wax powder 4 is lifted from the tray 3 in an upright state, so that the bottom opening of the round tube is separated from the tray 3 and is kept suspended. Then, the vibrator 6 is used for applying vibration to the outer wall of the circular tube 2, so that the wax powder 4 filled in the circular tube 2 gradually falls off from the bottom opening, the upward inside corner formed by the spring-type resistance wire 1 and the inner wall of the circular tube 2 is reserved for the wax powder 4 until all the wax powder in the circular tube except the upward inside corner falls off, and a state shown in fig. 8 is formed.

S9: keeping the posture of the circular tube 2 unchanged, respectively connecting the metal leads 7 at the two ends of the spring-type resistance wire 1 to the positive electrode and the negative electrode of the external power supply 8 again, and preheating the spring-type resistance wire to the temperature close to the wax melting point but slightly lower than the wax melting point. Then through controlling the intermittent on-off of the external power supply, the spring type resistance wire is powered on intermittently to generate heat, the temperature of the wire body of the spring type resistance wire is kept to fluctuate back and forth between a temperature higher than a wax melting point and a temperature lower than the wax melting point, after a plurality of power-on and power-off reciprocating cycles, the wax powder in the upward internal corner can be gradually and completely melted, and the wax blocks in the downward internal corner are still adhered in the internal corner.

The step is a specific heating procedure of the invention, and the process adopted by the invention is preheating and intermittent electrified heating. Because the wax powder 4 at the inward-facing concave corner in the circular tube 2 is preheated to be close to the melting point, the wax powder can be gradually melted when the circular tube continues to receive heat, and although the wax welding point 6 at the downward-facing concave corner can also be partially melted, because the subsequent heating process is intermittent, the whole wax welding point 6 has a larger viscosity coefficient than the wax powder 4, and the wax powder is not easy to fall off integrally. For the wax welding point 6, when the spring type resistance wire 1 is electrified to generate heat, wax close to the wire body of the spring type resistance wire 1 is melted firstly, but the wax far away from the wire body still keeps a solid state or a solid-liquid state, so that the wax welding point 6 is prevented from falling off. Therefore, after the spring-type resistance wire 1 is powered off, the wax welding point 6 can be rapidly solidified again. Therefore, the spring type resistance wire 1 in the step is subjected to intermittent energization heating to be one of important control procedures, wherein intermittent period parameters are important, and specific optimization is needed to an optimal value, so that the heating value of the spring type resistance wire is enough to melt the wax powder at the upward internal corner of the part but not to melt and fall off the whole wax welding point 6 at the downward internal corner of the part when the spring type resistance wire is electrified.

In addition, in order to ensure the reliability of the solder joint 6 at the downward internal corner, the terminal temperature of the preheating in S8 is preferably 5 to 10 ℃ lower than the wax melting point and as close as possible to the wax melting point. Otherwise, the temperature is too far away from the wax melting point, so that subsequent intermittent heating is difficult to control. When the paraffin is selected, the type of the paraffin with high hardness and high melting point is selected as much as possible.

S10: when the wax powder 4 at the upward internal corner in the S9 is completely melted, the external power supply 8 can be switched off, the heating of the spring-type resistance wire 1 is stopped, and the spring-type resistance wire 1 is gradually cooled, so that the internal corners at two sides of the spring-type resistance wire 1 are fixed by the wax welding points 6 which are melted and then solidified, namely, as shown in FIG. 9.

S11: and finally, taking down the metal leads 4 at two sides of the spring type resistance wire 1 and the clamps at two ends of the spring type resistance wire 1 to finish the manufacture of the manual roughening pipe.

In the process of filling the wax powder 4 and the process of dropping the wax powder 4 in the present invention, the frequency of the high-frequency vibration should be optimized according to the test, and may be set to 50 to 150HZ in general. The purpose of frequency optimization in the filling process is to ensure that the wax powder is completely filled to the upward internal corner, so that the frequency can be set to be higher, and the purpose of frequency optimization in the falling process is to ensure that the wax powder at the upward internal corner cannot be vibrated out to fall off, so that the frequency is not too high.

In addition, during the processing of the manual roughening pipe, wax powder still possibly adheres to the wax welding point 6 at the downward internal corner of the spring resistance wire 1, or the wax powder flows downwards during the melting process at the internal corner, so that burrs are formed. Since these burrs cause abnormal hydraulic disturbance in the tube and are not favorable for accurately reflecting the influence of roughness on the water flow pattern, it is preferable that after the above-mentioned steps of S1 to S11 are completed, the spring-type resistance wire 1 is ground by a file toward the inner side of the axis of the circular tube 2 to remove these remaining burrs and keep the surface of the spring-type resistance wire 1 smooth.

Therefore, the structure form of the manual roughening pipe can conveniently change the roughness of the interior of a common pipe by adjusting the wire diameter and the pitch of the spring type resistance wire 1 so as to meet the requirements of different hydraulics tests on the adjustment of the roughness in the pipe. Meanwhile, the manufacturing process of the artificial roughened pipe provided by the invention can realize the stable reinforcement of wax welding spots on two sides between the spring type resistance wire 1 and the circular pipe 2, maximally simplify the process flow under the condition of ensuring the strength of the spring type resistance wire and the circular pipe, does not need special processing equipment, and can greatly reduce the cost.

Finally, because the elastic spring type resistance wire 1 and the wax powder are adopted as raw materials, the manual roughening pipe can be repeatedly processed and reproduced by remelting the wax welding spot 6, so that the internal roughness of the same round pipe 2 can be adjusted by reusing the same round pipe. The reprocessing method of the manual roughening pipe with changeable roughness comprises the following specific steps:

s1: firstly, the manual roughening pipe is integrally heated, so that wax blocks inside the manual roughening pipe are melted into liquid, then the spring type resistance wire 1 inside the manual roughening pipe is taken out, and the wax attached to the wire body of the spring type resistance wire is cleaned, so that the manual roughening pipe can be conveniently recycled.

S2: after the artificially roughened pipe is cooled, the inner wall of the circular pipe 2 is scraped against the wall by using a scraper, so that residual wax on the inner wall of the circular pipe 2 is removed, and the inner wall of the circular pipe is kept smooth.

After these two steps are completed, S1-S11 of the above manufacturing method can be repeated to obtain a new artificially roughened tube with a new roughness, as detailed below:

s3: according to the designed wire diameter value of a new manual roughening pipe, the spring type resistance wire 1 meeting the wire diameter is taken again, and the end parts of the two ends of the spring type resistance wire are respectively detachably connected with a metal wire 7. It should be noted that in this step, if the wire diameter of the spring-type resistance wire 1 is not changed, the spring-type resistance wire 1 cleaned again in S1 may be used without selecting other spring-type resistance wires 1, and if the wire diameter is changed, the spring-type resistance wire 1 needs to be selected again.

S4: the spring-type resistance wire 1 connected with the lead is coaxially assembled inside the circular tube 2, the pitch of the spring-type resistance wire 1 is stretched to a new target value, and then the two ends of the spring-type resistance wire 1 are temporarily fixed by using a clamp.

S5: keeping a round tube 2 assembled with a spring type resistance wire 1 upright on a tray 3, wherein a lead at the top of the round tube 2 extends out of the top of the round tube 2, and a lead at the bottom of the round tube 2 extends out of the tray 3 and is stretched to the outside of the tray 3; then, filling the wax powder 4 into the circular tube 2 gradually until the inner cavity of the circular tube 2 is completely filled with the wax powder 4;

s6: lifting the circular tube 2 filled with the wax powder 4 from the tray 3 in an upright state to enable the bottom opening to be separated from the tray 3 and keep hanging;

s7: the vibrator 5 is utilized to apply vibration to the outer wall of the circular tube 2, so that the wax powder 4 filled in the circular tube 2 gradually falls off from the bottom opening, and the wax powder 4 in the upward internal corner formed by the spring-type resistance wire 1 and the inner wall of the circular tube 2 is reserved until all the wax powder 4 in the circular tube 2 except the upward internal corner is completely fallen off;

s8: keeping the posture of the circular tube 2 unchanged, respectively connecting metal leads 7 at two ends of the spring-type resistance wire 1 to the positive electrode and the negative electrode of an external power supply 8, completely melting the wax powder 4 in the upward internal corner by electrifying and heating the spring-type resistance wire 1, then disconnecting the spring-type resistance wire 1 from the external power supply 8, cooling and solidifying the melted wax again, and fixing the internal corner at one side of the spring-type resistance wire 1;

s9: the cooled round tube 2 is inverted by 180 degrees and is erected on the tray 3, and the internal corner of the side which is not filled with the wax faces upwards;

s10: filling the wax powder 4 into the circular tube 2 gradually again until the inner cavity of the circular tube 2 is completely filled with the wax powder 4, and repeating S6-S7 to ensure that the upward internal corner of the circular tube is filled with the wax powder 4;

s11: keeping the posture of the circular tube 2 unchanged, respectively connecting metal leads 7 at two ends of the spring-type resistance wire 1 to the positive electrode and the negative electrode of an external power supply 8, and preheating the spring-type resistance wire 1 to a temperature close to the wax melting point but slightly lower than the wax melting point; then the spring-type resistance wire 1 is electrified and heated intermittently by controlling an external power supply 8, the temperature of the wire body of the spring-type resistance wire 1 is kept to fluctuate back and forth between a temperature higher than a wax melting point and a temperature lower than the wax melting point, the wax powder 4 in the upward internal corner is gradually and completely melted after a plurality of power-on and power-off reciprocating cycles, and the wax blocks in the downward internal corner are still adhered in the internal corner;

s12: gradually cooling the circular tube 2 to ensure that the internal corners at both sides of the spring type resistance wire 1 are fixed by the melted and re-solidified wax blocks;

s13: and (3) taking down the metal leads 7 at the two sides of the spring type resistance wire 1 and the clamps at the two ends of the spring type resistance wire 1, finishing reprocessing of the manual roughening pipe, and obtaining the new manual roughening pipe with the roughness.

The above S3 to S13 actually correspond to S1 to S11 in the foregoing manufacturing method, and therefore, the specific implementation process can be referred to S1 to S11 in the foregoing manufacturing method, which is not described again.

By the reprocessing method, the invention can conveniently utilize components in the original artificially roughened pipe to obtain the artificially roughened pipe with new roughness, thereby greatly reducing the use cost.

In addition, it should be noted that the relationship between the roughness in the manual roughening pipe and the wire diameter and the pitch of the spring type resistance wire can be determined in advance through experiments, and then can be conveniently determined through a table look-up method.

The above-described embodiments are merely preferred embodiments of the present invention, which should not be construed as limiting the invention. Various changes and modifications may be made by one of ordinary skill in the pertinent art without departing from the spirit and scope of the present invention. Therefore, the technical scheme obtained by adopting the mode of equivalent replacement or equivalent transformation is within the protection scope of the invention.