Device for removing oxide skin inside and outside end of stainless steel coil pipe

Abstract

The utility model relates to the technical field of stainless steel coil pipes for water heaters, in particular to a device for removing oxide skin inside and outside the end of a stainless steel coil pipe. In order to solve the problem that many defects exist in the traditional method for removing the inner and outer oxide skin of the end of the stainless steel coil pipe, the novel device for removing the inner and outer oxide skin of the end of the stainless steel coil pipe comprises a voltage-stabilizing direct-current power supply, a neutral salt electrolytic tank and a rinsing and draining tank, four first insulation supporting rod sets are supported at the pool opening end of the neutral salt electrolytic pool, a conductive hollow hanging basket is fixedly hung between every two first insulation supporting rods, the two conductive hollow hanging baskets are distributed in a left-right mode, protruding columns are arranged at the bottoms of the two conductive hollow hanging baskets, and the stainless steel coil pipe is electrically connected with the positive electrode of a voltage-stabilizing direct-current power source. And the two conductive hollow hanging baskets are electrically connected with the negative electrode of the voltage-stabilizing direct-current power supply. The stainless steel coil pipe inner and outer oxide skin removing device can remove inner and outer oxide skin of the two ends of a stainless steel coil pipe at a time, and production efficiency is greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of stainless steel coils for condensing wall-mounted boiler water heaters, in particular to a device for removing oxide scales inside and outside the ends of the stainless steel coils. Background Art

[0002] At present, the heat exchange unit used in household condensing wall-mounted boiler water heaters is mainly a stainless steel coil made of spirally wound stainless steel pipes. The two ends of the stainless steel coil are distributed one after the other in the axial direction and are respectively located on the left rear and right front sides of the stainless steel coil. In actual use, since the exhaust temperature of the stainless steel coil is lower than the dew point temperature, the water vapor in the flue gas condenses on the surface of the stainless steel coil, further causing the acidic gases in the flue gas, such as CO2, NO, NO2, SO2, SO3, Cl - 、F - They dissolve in condensed water to form an acidic mixed solution of carbonic acid, nitric acid, sulfuric acid, hydrochloric acid, and hydrofluoric acid, which causes corrosion of the heat exchange surface and reduces the service life of the water heater. In addition, when the condensed water dries, the acid concentration will increase and the corrosiveness will be stronger.

[0003] Modern ferritic stainless steels (such as SUS443, SUS444, and SUS445J1 / J2) are the ideal replacement for traditional 304 / 316 heat exchanger tubes in household condensing gas water heaters due to their relatively high thermal conductivity and pitting resistance equivalent value (PREN), excellent crevice corrosion resistance, lack of stress corrosion tendency in Cl environments, and stable price (unaffected by nickel price fluctuations). However, during the production and processing of stainless steel coils, solution annealing is required to restore the material's corrosion resistance and mechanical properties. This heat treatment can easily form a complex oxide scale on the coil surface, which is tightly bonded to the substrate. This scale not only affects the appearance but also significantly degrades the corrosion resistance of the coil ends. It is well known that stainless steel's pitting resistance is achieved through the formation of a uniform and dense Cr2O3 passive film on the surface. Therefore, removing the scale and restoring the passive film is crucial to fully realize the advantages of modern ferritic stainless steel and improve the heat transfer efficiency and service life of stainless steel coils.

[0004] Traditional processes for removing scale from the interior and exterior of stainless steel coil ends include sandblasting, grinding with a grinding wheel or flap wheel, and HNO3 / HF pickling. The first two not only pollute the environment with dust and noise, and are harmful to humans, but also increase surface stress and roughness (impeding the repair of the passive film), reducing corrosion resistance, and are not suitable for removing scale from the interior of stainless steel coil ends. HNO3 / HF pickling is toxic, polluting, complex, and adds significant additional costs. Summary of the Invention

[0005] In order to solve the above-mentioned defects of the traditional method for removing the internal and external oxide scales of the stainless steel coil end, the utility model provides a new device for removing the internal and external oxide scales of the stainless steel coil end.

[0006] The utility model is realized by adopting the following technical solutions:

[0007] A device for removing oxide scales inside and outside the end of a stainless steel coil comprises a voltage-stabilized DC power supply, a neutral salt electrolysis cell containing a neutral salt electrolyte during use, and a rinsing and draining cell containing deionized water during use.

[0008] The cell mouth end of the neutral salt electrolysis cell is supported by two groups of first insulating support rod groups arranged side by side in front and back, and each group of first insulating support rod groups is composed of two first insulating support rods arranged side by side in the front and back and arranged in the left and right directions. A conductive hollow hanging basket with its opening facing upward and immersed in the neutral salt electrolyte is suspended between the two first insulating support rods of each group of first insulating support rods. The two conductive hollow hanging baskets are distributed left and right. The bottoms of the two conductive hollow hanging baskets are provided with raised columns whose diameters are smaller than the inner diameters of the two ends of the stainless steel coil and are arranged upward. The layout positions of the two conductive hollow hanging baskets and the two raised columns are respectively adapted to the two ends of the stainless steel coil whose axial directions are arranged in the front and back directions and whose two ends are arranged vertically when in use, to ensure that the two ends of the stainless steel coil can be respectively sheathed on the two raised columns and do not contact the raised columns. The stainless steel coil is electrically connected to the positive pole of the stabilized DC power supply, and the two conductive hollow hanging baskets are electrically connected to the negative pole of the stabilized DC power supply.

[0009] A variable frequency ultrasonic vibration plate is provided in the rinsing and draining tank, and two groups of second insulating support rods arranged front and back are provided at the mouth of the rinsing and draining tank. Each group of second insulating support rods consists of two second insulating support rods arranged side by side front and back. The two groups of second insulating support rods are respectively used to support the two ends of the stainless steel coil and the distance between the two second insulating support rods in each group of second insulating support rods is used for the two ends of the stainless steel coil to extend from there and be immersed in the rinsing and draining tank.

[0010] When in use, follow the steps below: 1) Place the two conductive hollow hanging baskets at the corresponding positions of the two groups of first insulating support rods respectively; 2) Arrange the axial direction of the stainless steel coil along the front-to-back direction and its two ends are arranged vertically and then supported on the two groups of first insulating support rods. At the same time, ensure that the two ends of the stainless steel coil can be respectively sheathed on the two raised columns without contacting the raised columns and that the two ends of the stainless steel coil are immersed in the neutral salt electrolytic rust removal and passivation solution (in specific implementation, in order to quickly locate the position of the stainless steel coil and ensure that the two ends of the stainless steel coil can be respectively sheathed on the two raised columns without contacting the raised columns, this can be achieved by marking the two groups of first insulating support rods, that is, the stainless steel coil is placed according to the marked marks each time); 3) Connect the stainless steel coil to the positive pole of the regulated DC power supply. Both conductive hollow hanging baskets are electrically connected to the negative pole of the stabilized DC power supply. When ready, the stabilized DC power supply is turned on to perform neutral salt electrolysis on the two ends of the stainless steel coil; 4) After the neutral salt electrolysis is completed, the stabilized DC power supply is turned off, the stainless steel coil is removed, and the stainless steel coil is then supported between the two sets of second insulating rods so that the axial direction of the stainless steel coil is arranged along the front-to-back direction and the two ends are arranged vertically, so that the two ends of the stainless steel coil can be immersed in the rinsing and draining tank; 5) The variable frequency ultrasonic array plate is turned on and the two ends of the stainless steel coil are treated for 3 to 5 minutes; 6) The stainless steel coil is removed and placed between the two sets of second insulating support rods with the two ends arranged horizontally to drain the moisture from the two ends of the stainless steel coil, thereby completing the removal of the oxide scale inside and outside the ends of the stainless steel coil.

[0011] Furthermore, the neutral salt electrolysis tank and the rinsing and draining tank are both cubic in shape, arranged side by side on the left and right, and the height and length in the front-to-back direction of the two are the same, and the four first insulating support rods and the four second insulating support rods are respectively connected one by one, and the structure is specific, standardized, and easy to manufacture.

[0012] Furthermore, the device also includes a lower cavity, which is located at the lower part of the neutral salt electrolytic cell and the rinsing and draining cell. An inspection port is provided on the side of the lower cavity. An electrolyte supply tank and a sedimentation separation tank are provided in the lower cavity. An outlet is provided at the bottom of the neutral salt electrolytic cell. The inlet of the sedimentation separation tank is connected to the outlet of the neutral salt electrolytic cell through a sedimentation pipe. A sedimentation valve is provided on the sedimentation pipe. The outlet of the sedimentation separation tank is connected to the inlet of the electrolyte supply tank through a supply pump. The sedimentation separation tank uses negative pressure filtration to filter the neutral salt electrolyte received in the neutral salt electrolytic cell. The electrolyte supply tank receives the neutral salt electrolyte filtered from the sedimentation separation tank. The outlet of the electrolyte supply tank is connected to the inlet of the neutral salt electrolytic cell through a replenishment pump. The electrolyte supply tank replenishes fresh neutral salt electrolyte in time according to the concentration change of the neutral salt electrolyte in the neutral electrolytic cell. At the same time, the electrolyte supply tank can also reconfigure and store neutral salt electrolyte.

[0013] Furthermore, each conductive hollow hanging basket is a square barrel-shaped stainless steel hanging basket with its opening facing upward. The four corners of the top of each conductive hollow hanging basket are respectively provided with four metal hanging ears for hanging on the first insulating support rod. The four metal hanging ears of each conductive hollow hanging basket are electrically connected to the negative pole of the power supply unit, which facilitates the electrical connection between the conductive hollow hanging basket and the negative pole of the power supply unit, thereby making the conductive hollow hanging basket negatively charged.

[0014] Furthermore, the lower cavity is also provided with a power control cabinet, the power supply unit is located in the power control cabinet and the power control cabinet can adjust the current provided by the power supply unit, so as to facilitate the adjustment of the current according to the degree of oxidation of the stainless steel coil end.

[0015] The beneficial effects of the present invention are as follows: the present invention can remove the inner and outer oxide scales of the two ends of the stainless steel tube coil at one time, which not only ensures the uniformity of the surface color of the stainless steel coil, but also makes the surface of the stainless steel coil reach a "passivated" state, ensuring the heat exchange efficiency, greatly improving the production efficiency, reducing the processing cost, and at the same time does not pollute the environment and does not affect the health of workers. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings herein are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present utility model, and together with the description, are used to explain the principles of the present utility model.

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0019] Figure 2 This is a schematic diagram of the electrical connection between the power control cabinet and the conductive hollow hanging basket.

[0020] In the figure: 1-neutral salt electrolysis cell, 2-rinsing and draining cell, 3-first insulating support rod, 4-conductive hollow hanging basket, 5-raised column, 6-frequency ultrasonic vibration plate, 7-second insulating support rod, 8-electrolyte supply tank, 9-precipitation and separation tank, 10-power control cabinet. DETAILED DESCRIPTION

[0021] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features therein can be combined with each other.

[0022] In the description, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance. It should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, removable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms based on specific circumstances.

[0023] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0024] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0025] like Figure 1 and Figure 2 As shown, a device for removing oxide scale inside and outside the end of a stainless steel coil comprises a stabilized DC power supply, a neutral salt electrolytic cell 1 containing a neutral salt electrolyte when in use, and a rinsing and draining cell 2 containing deionized water when in use;

[0026] The cell mouth end of the neutral salt electrolysis cell 1 is supported by two groups of first insulating support rod groups arranged side by side in front and back, and each group of first insulating support rod groups is composed of two first insulating support rods arranged side by side in the front and back and arranged in the left and right directions. A conductive hollow hanging basket 4 with its opening facing upward and immersed in the neutral salt electrolyte is suspended between the two first insulating support rods 3 of each group of first insulating support rods. The two conductive hollow hanging baskets 4 are distributed left and right, and the bottoms of the two conductive hollow hanging baskets 4 are provided with raised columns 5 whose diameters are smaller than the inner diameters of the two ends of the stainless steel coil and are arranged upward. The layout positions of the two conductive hollow hanging baskets 4 and the two raised columns 5 are respectively adapted to the two ends of the stainless steel coil whose axial directions are arranged in the front and back directions and whose two ends are arranged vertically when in use, ensuring that the two ends of the stainless steel coil can be respectively sheathed on the two raised columns 5 and do not contact the raised columns 5. The stainless steel coil is electrically connected to the positive pole of the stabilized DC power supply, and the two conductive hollow hanging baskets 4 are both electrically connected to the negative pole of the stabilized DC power supply;

[0027] A variable frequency ultrasonic vibration plate 6 is provided in the rinsing and draining tank 2, and two groups of second insulating support rod groups arranged front and back are provided at the pool mouth of the rinsing and draining tank 2. Each group of second insulating support rod groups is composed of two second insulating support rods arranged side by side front and back. The two groups of second insulating support rod groups are respectively used to support the two ends of the stainless steel coil and the distance between the two second insulating support rods 7 of each group of second insulating support rod groups is used for the two ends of the stainless steel coil to extend from there and be immersed in the rinsing and draining tank 2.

[0028] When in use, follow the steps below: 1) Place the two conductive hollow hanging baskets 4 at the corresponding positions of the two groups of first insulating support rods 3 respectively; 2) Arrange the axial direction of the stainless steel coil along the front-to-back direction and its two ends are arranged vertically and then supported on the two groups of first insulating support rods. At the same time, ensure that the two ends of the stainless steel coil can be respectively sheathed on the two raised columns 5 without contacting the raised columns 5 and that the two ends of the stainless steel coil are immersed in the neutral salt electrolytic rust removal and passivation solution (in specific implementation, in order to quickly locate the position of the stainless steel coil and ensure that the two ends of the stainless steel coil can be respectively sheathed on the two raised columns 5 without contacting the raised columns 5, this can be achieved by marking the two groups of first insulating support rods, that is, the stainless steel coil is placed according to the marked marks each time); 3) Connect the stainless steel coil to the positive pole of the regulated DC power supply. Both conductive hollow hanging baskets 4 are electrically connected to the negative pole of the stabilized DC power supply. When ready, turn on the stabilized DC power supply and perform neutral salt electrolysis on the two ends of the stainless steel coil; 4) After the neutral salt electrolysis is completed, turn off the stabilized DC power supply, take out the stainless steel coil, and then support the stainless steel coil between the two groups of second insulating support rods 1 so that the axial direction of the stainless steel coil is arranged along the front-to-back direction and its two ends are arranged vertically, so that the two ends of the stainless steel coil can be immersed in the rinsing and draining tank 2; 5) Turn on the variable frequency ultrasonic array plate and treat the two ends of the stainless steel coil for 3 to 5 minutes; 6) Take out the stainless steel coil, place the stainless steel coil between the two groups of second insulating support rods 7 with its two ends arranged horizontally, drain the moisture from the two ends of the stainless steel coil, and complete the removal of the oxide scale inside and outside the ends of the stainless steel coil.

[0029] During specific implementation, the neutral salt electrolysis cell 1 and the rinsing and draining cell 2 are both cube-shaped. The neutral salt electrolysis cell 1 and the rinsing and draining cell 2 are arranged side by side on the left and right, and the height and length of the two in the front-to-back direction are the same. The four first insulating support rods 3 and the four second insulating support rods 7 are respectively connected one by one, and the structure is specific, standardized, and easy to manufacture.

[0030] In specific implementation, the device also includes a lower cavity, which is located at the lower part of the neutral salt electrolytic cell 1 and the rinsing and draining tank 2. The side of the lower cavity is provided with an inspection port, and the lower cavity is provided with an electrolyte supply tank 8 and a sedimentation separation tank 9. The bottom of the neutral salt electrolytic cell 1 is provided with an outlet, and the inlet of the sedimentation separation tank 9 is connected to the outlet of the neutral salt electrolytic cell 1 through a sedimentation pipe. The sedimentation pipe is equipped with a sedimentation valve, and the outlet of the sedimentation separation tank 9 is connected to the inlet of the electrolyte supply tank 8 through a supply pump. The sedimentation separation tank 9 is connected to the inlet of the electrolyte supply tank 8 through a supply pump. Tank 9 uses negative pressure filtration to filter the neutral salt electrolyte in the received neutral salt electrolytic cell 1. The electrolyte supply tank 8 receives the neutral salt electrolyte filtered from the precipitation separation tank 9. The outlet of the electrolyte supply tank 8 is connected to the inlet of the neutral salt electrolytic cell 1 through a rehydration pump. The electrolyte supply tank 8 replenishes fresh neutral salt electrolyte in time according to the concentration change of the neutral salt electrolyte in the neutral electrolytic cell. At the same time, the electrolyte supply tank 8 can also reconfigure and store the neutral salt electrolyte.

[0031] In specific implementation, each conductive hollow hanging basket 4 is a square barrel-shaped stainless steel hanging basket with its opening upward. The four corners of the top of each conductive hollow hanging basket 4 are respectively provided with four metal hanging ears for hanging on the first insulating support rod 3. The four metal hanging ears of each conductive hollow hanging basket 4 are electrically connected to the negative pole of the power supply unit, which facilitates the electrical connection between the conductive hollow hanging basket 4 and the negative pole of the power supply unit, thereby realizing that the conductive hollow hanging basket 4 is negatively charged.

[0032] During specific implementation, the lower cavity is also provided with a power control cabinet 10. The power supply unit is located in the power control cabinet 10 and the power control cabinet 10 can adjust the current provided by the power supply unit, so as to facilitate the adjustment of the current according to the degree of oxidation of the stainless steel coil end.

[0033] The above description is only a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions have been made with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents; and such modifications or replacements do not deviate from the essence of the corresponding technical solutions within the scope of the technical solutions of the embodiments, and they should all be covered by the scope of protection of the claims.

Claims

1. A device for removing the internal and external scale of the stainless steel coil end, characterized in that: It comprises a voltage-stabilized DC power supply, a neutral salt electrolytic cell (1) containing a neutral salt electrolyte when in use, and a rinsing and draining cell (2) containing deionized water when in use; The neutral salt electrolytic cell (1) is supported at the cell mouth by two groups of first insulating support rods arranged side by side in front and back, each group of first insulating support rods is composed of two first insulating support rods arranged side by side in front and back and arranged in the left and right directions in the axial direction, and a conductive hollow hanging basket (4) with its opening facing upward and immersed in the neutral salt electrolyte is suspended between the two first insulating support rods (3) of each group of first insulating support rods, the two conductive hollow hanging baskets (4) are distributed on the left and right, and the bottoms of the two conductive hollow hanging baskets (4) are provided with a diameter smaller than that of the stainless steel. The inner diameter of the two ends of the steel coil and the raised columns (5) arranged upward, the two conductive hollow hanging baskets (4) and the two raised columns (5) are respectively adapted to the two ends of the stainless steel coil whose axial direction is arranged in the front-to-back direction and whose two ends are arranged vertically when in use, ensuring that the two ends of the stainless steel coil can be respectively sheathed on the two raised columns (5) and do not contact the raised columns (5), the stainless steel coil is electrically connected to the positive pole of the stabilized DC power supply, and the two conductive hollow hanging baskets (4) are both electrically connected to the negative pole of the stabilized DC power supply; A variable frequency ultrasonic vibration plate (6) is provided in the rinsing and draining tank (2), and two groups of second insulating support rods arranged front to back are provided at the tank mouth of the rinsing and draining tank (2), each group of second insulating support rods is composed of two second insulating support rods arranged side by side front to back, and the two groups of second insulating support rods are used to support the two ends of the stainless steel coil respectively, and the distance between the two second insulating support rods (7) of each group of second insulating support rods is used for the two ends of the stainless steel coil to extend from there and be immersed in the rinsing and draining tank (2).

2. The device for removing the internal and external oxide scale of the stainless steel coil end according to claim 1, characterized in that: The neutral salt electrolysis cell (1) and the rinsing and draining cell (2) are both in the shape of a cube. The neutral salt electrolysis cell (1) and the rinsing and draining cell (2) are arranged side by side and have the same height and length in the front-to-back direction. The four first insulating support rods (3) and the four second insulating support rods (7) are respectively connected in a one-to-one correspondence.

3. The device for removing the internal and external oxide scale of the stainless steel coil end according to claim 2, characterized in that: The device further comprises a lower cavity, which is located at the lower part of the neutral salt electrolytic cell (1) and the rinsing and draining cell (2). An inspection port is provided on the side of the lower cavity. An electrolyte supply tank (8) and a sedimentation separation tank (9) are provided in the lower cavity. An outlet is provided at the bottom of the neutral salt electrolytic cell (1). The inlet of the sedimentation separation tank (9) is connected to the outlet of the neutral salt electrolytic cell (1) through a sedimentation pipe. A sedimentation valve is provided on the sedimentation pipe. The outlet of the sedimentation separation tank (9) is connected to the inlet of the electrolyte supply tank (8) through a supply pump. The outlet of the electrolyte supply tank (8) is connected to the inlet of the neutral salt electrolytic cell (1) through a liquid replenishment pump.

4. The device for removing the internal and external oxide scale of the stainless steel coil end according to claim 3, characterized in that: Each conductive hollow hanging basket (4) is a square barrel-shaped stainless steel hanging basket with an opening facing upwards. Four metal hanging ears for hanging on the first insulating support rod (3) are respectively provided at the four corners of the top of each conductive hollow hanging basket (4). The four metal hanging ears of each conductive hollow hanging basket (4) are electrically connected to the negative pole of the power supply unit.

5. The device for removing the internal and external oxide scale of the stainless steel coil end according to claim 4, characterized in that: The lower cavity is further provided with a power supply control cabinet (10), the power supply unit is located in the power supply control cabinet (10), and the power supply control cabinet (10) can adjust the magnitude of the current provided by the power supply unit.

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