A maintenance process for anode protection device of concentrated sulfuric acid pipeline

Abstract

The present invention develops a maintenance process for an anode protection device for a concentrated sulfuric acid pipeline. By arranging a fixed bed, a connecting rod, an electrode pressure rod and a fixed rod are used to cooperate to complete a maintenance and disassembly section process, and an electrode pressure block is used to complete a maintenance and installation section process, so that the upper casing can be replaced without shutting down the system and draining the concentrated sulfuric acid, thereby greatly improving the maintenance efficiency, effectively reducing the maintenance cost and energy consumption, and eliminating the operation risk and the risk of concentrated sulfuric acid leakage pollution. After the anode protection device for the concentrated sulfuric acid pipeline is repaired and installed, the fixed bed is retained until it is disassembled after a power-on test run is successful, which greatly facilitates the re-maintenance work after an unsuccessful power-on test run.

Description

Technical Field

[0001] The invention relates to the technical field of concentrated sulfuric acid storage and transportation equipment protection, in particular to a maintenance process for an anode protection device of a concentrated sulfuric acid pipeline. Background Art

[0002] Anodic protection technology has been used for more than 60 years since its first industrial application in 1958. It has developed into a new material corrosion protection technology. Ordinary 1Cr18Ni9Ti, 304, 304L, 316, 316L and other stainless steels are equipped with anodic protection technology and applied to the use of high-temperature concentrated sulfuric acid delivery pipelines.

[0003] Anodic protection device for concentrated sulfuric acid pipeline Figure 1 As shown, there is a bulge 4 in the middle of the electrode 3, the electrode 3 portion below the bulge 4 is wrapped by the lower sleeve 6 and in contact with concentrated sulfuric acid, the lower sleeve 6 has a groove at the top to accommodate the bulge 4, the electrode 3 portion above the bulge 4 is wrapped by the upper sleeve 5, and then the upper sleeve 5 is fastened with a double-layer gland 8, and then the double-layer gland 8 is fixed to the base 7 by bolts, and the base 7 is fixed to the shell 9. After installation, the terminal 2 at the top of the electrode 3 is connected to the wire, and finally the electrode cover 1 is installed. When the double-layer gland 8 is connected to the base 7 by bolts, the upper sleeve 5 applies pressure to the bulge 4, so that the upper sleeve-bulge-lower sleeve forms a sealed structure, which effectively prevents the leakage of concentrated sulfuric acid.

[0004] The above-mentioned concentrated sulfuric acid pipeline anode protection device and the cathodes distributed in dots on the shell form a complete protection device. Its working principle is to use the shell in contact with concentrated sulfuric acid as the anode, set a certain number of cathodes on the shell surface, and form a current loop of anode-sulfuric acid-cathode. A certain current is applied to the concentrated sulfuric acid pipeline to generate anodic polarization. Through the passivation potential, the shell enters the stable passivation zone and maintains its potential in the passivation potential area. The passivation film formed in the stable passivation zone reduces the corrosion of the pipeline in concentrated sulfuric acid.

[0005] Among them, the material of the upper casing and the lower casing is mainly polytetrafluoroethylene. When the upper casing is installed, the force of the double-layer pressure cover is concentrated on the upper casing, and the force-bearing area is small, which is easy to be damaged. At the same time, the upper casing is in a high-temperature concentrated sulfuric acid environment for a long time and is very easy to age. In order to prevent acid seepage, the upper casing is also easily damaged when the double-layer pressure cover is adjusted, which makes the upper casing most vulnerable to damage and requires frequent maintenance and replacement.

[0006] Once the upper casing is damaged or the insulation of the upper casing is destroyed, resulting in an electrode short circuit, the potential on the shell deviates from the passivation potential area, which not only fails to protect the shell, but also accelerates the corrosion of the shell.

[0007] In the prior art, the maintenance process of the concentrated sulfuric acid pipeline anode protection device is: the concentrated sulfuric acid is drained after the system is shut down, then the concentrated sulfuric acid pipeline anode protection device is completely disassembled, the upper casing is replaced, and finally the concentrated sulfuric acid pipeline anode protection device is reinstalled. This maintenance process system has a long downtime, high maintenance cost, high energy consumption, and in the process of draining the concentrated sulfuric acid, there are operational risks, and the concentrated sulfuric acid partially leaks to cause pollution and other problems.

[0008] Moreover, after the concentrated sulfuric acid pipeline anode protection device is repaired and installed, it is necessary to power on and test run it so that the potential on the shell is in the passive potential area. If the power-on test run fails at one time, the system needs to be shut down again, the concentrated sulfuric acid needs to be drained and re-inspected. Summary of the invention

[0009] The present invention develops a maintenance process for an anode protection device for a concentrated sulfuric acid pipeline. By arranging a fixed bed, a connecting rod, an electrode pressure rod and a fixed rod are used to cooperate to complete a maintenance and disassembly section process, and an electrode pressure block is used to complete a maintenance and installation section process, so that the upper casing can be replaced without shutting down the system and draining the concentrated sulfuric acid, thereby greatly improving the maintenance efficiency, effectively reducing the maintenance cost and energy consumption, and eliminating the operation risk and the risk of concentrated sulfuric acid leakage pollution. After the anode protection device for the concentrated sulfuric acid pipeline is repaired and installed, the fixed bed is retained until it is disassembled after a power-on test run is successful, which greatly facilitates the re-maintenance work after an unsuccessful power-on test run.

[0010] A maintenance process for an anode protection device of a concentrated sulfuric acid pipeline, the maintenance process is specifically as follows:

[0011] 1. Installation of fixed bed 12

[0012] (1) The anode protection device of the concentrated sulfuric acid pipeline is powered off and the electrode cover 1 and terminal 2 are removed;

[0013] (2) The bottom of the fixed bed 12 is fixedly connected to the fixing device, and the fixed bed 12 is fixed to the housing 9 through the fixing device; the upper end of the fixed bed 12 is provided with an adjustment groove 13 and a first through hole 14 from top to bottom, and the upper end of the fixed bed 12 is provided with an external thread;

[0014] (3) Fixed beds 12 are symmetrically installed on both sides of the concentrated sulfuric acid pipeline anode protection device;

[0015] 2. Maintenance and disassembly section

[0016] (4) A groove is provided at the bottom of the connecting rod 15, and the connecting rod 15 is connected to a threaded pair formed at the top of the electrode 3 through the groove;

[0017] (5) Then, the electrode pressing rod 16 is passed through the adjustment groove 13, and the electrode pressing rod 16 is pressed on the top of the connecting rod 15, and then the first adjusting nut 17 is screwed into the upper end of the fixed bed 12 until the electrode 3 is pressed tightly;

[0018] (6) The surface of the fixing rod 18 is provided with an external thread. The fixing rod 18 is passed through the first through hole 14 until it abuts against the connecting rod 15, and then the fixing rod 18 is fixed to the fixed bed 12 through the second adjusting nut 19;

[0019] (7) Disassemble the double-layer gland 8 and move the double-layer gland 8 and the upper sleeve 5 upward;

[0020] 3. Maintenance and installation section

[0021] (8) The electrode pressing block 20 is composed of two separate parts, each of which is composed of a locking portion 21 and a pressing portion 22. The locking portion 21 is provided with a second through hole 23. The electrode pressing block 20 is placed on the electrode 3 from the side and then pressed down until the pressing portion 22 abuts against the bulging portion 4, and then the locking portion 21 is fixed on the base 7.

[0022] (9) Disassemble the electrode pressing rod 16 and the fixing rod 18, and then take out the double-layer pressing cover 8 and the upper sleeve 5;

[0023] (10) Replace the upper sleeve 5, and then reinstall the double-layer gland 8 and the upper sleeve 5;

[0024] (11) Reinstall the electrode pressing rod 16 and the fixing rod 18 according to steps (5) and (6);

[0025] (12) Disassemble the electrode pressing block 20, then reset the double-layer pressing cover 8 and the upper sleeve 5, and finally fix the double-layer pressing cover 8;

[0026] (13) The electrode pressing rod 16 and the fixing rod 18 are disassembled again, and the electrode cover 1 and the terminal 2 are restored to their original positions, thus completing the replacement of the upper sleeve 5.

[0027] Furthermore, after the repaired concentrated sulfuric acid pipeline anode protection device is successfully powered on for trial operation, the fixing device and the fixed bed 12 are disassembled.

[0028] Furthermore, the fixing device is a clamp 11.

[0029] Furthermore, when the clamp 11 is fixed on the shell 9, a soft cushion 10 is arranged in the middle.

[0030] Furthermore, the material of the soft pad 10 is rubber.

[0031] Furthermore, the upper sleeve 5 is made of polytetrafluoroethylene.

[0032] Advantages of the present invention:

[0033] 1. The present invention sets a fixed bed, uses connecting rods, electrode pressure rods and fixed rods to complete the maintenance and disassembly process, and uses electrode pressure blocks to complete the maintenance and installation process, so as to achieve the effect of replacing the upper casing without shutting down the system and draining the concentrated sulfuric acid, which greatly improves the maintenance efficiency, effectively reduces the maintenance cost and energy consumption, and has no operation risk and concentrated sulfuric acid leakage pollution risk; after the concentrated sulfuric acid pipeline anode protection device is repaired and installed, the fixed bed is retained until the power-on test is successful and then disassembled, which greatly facilitates the re-maintenance work after the power-on test is unsuccessful;

[0034] 2. The process of the present invention is simple, the required equipment is simple, and it is easy to operate and easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic structural diagram of the anode protection device for concentrated sulfuric acid pipeline of the present invention;

[0036] Figure 2 This is a maintenance side view of the anode protection device for concentrated sulfuric acid pipeline of the present invention;

[0037] Figure 3 It is a side view of a fixed bed of the present invention;

[0038] Figure 4 This is a schematic diagram of the maintenance and disassembly section of the present invention;

[0039] Figure 5 This is a schematic diagram of the maintenance and installation section of the present invention;

[0040] Figure 6 The figure is a cross-sectional schematic diagram and a bottom view of the electrode compact of the present invention;

[0041] In the figure: 1-electrode cover, 2-terminal, 3-electrode, 4-bulging part, 5-upper sleeve, 6-lower sleeve, 7-base, 8-double-layer pressure cover, 9-shell, 10-cushion, 11-hoop, 12-fixed bed, 13-adjustment slot, 14-first through hole, 15-connecting rod, 16-electrode pressure rod, 17-first adjusting nut, 18-fixed rod, 19-second adjusting nut, 20-electrode pressure block, 21-locking part, 22-pressure part, 23-second through hole DETAILED DESCRIPTION

[0042] Example 1

[0043] A maintenance process for an anode protection device of a concentrated sulfuric acid pipeline, the maintenance process is specifically as follows:

[0044] 1. Installation of fixed bed 12

[0045] (1) The anode protection device of the concentrated sulfuric acid pipeline is powered off, and the electrode cover 1 and terminal 2 are removed;

[0046] (2) Figure 2 As shown, the bottom of the fixed bed 12 is fixedly connected to the clamp 11, and the fixed bed 12 is fixed to the shell 9 through the clamp 11. A rubber cushion 10 is arranged between the clamp 11 and the shell 9; Figure 3 As shown, the upper end of the fixed bed 12 is provided with an adjustment groove 13 and a first through hole 14 from top to bottom, and the upper end of the fixed bed 12 is provided with an external thread;

[0047] (3) Fixed beds 12 are symmetrically installed on both sides of the concentrated sulfuric acid pipeline anode protection device;

[0048] 2. Maintenance and disassembly section

[0049] (4) A groove is provided at the bottom of the connecting rod 15, and the connecting rod 15 is connected to a threaded pair formed at the top of the electrode 3 through the groove;

[0050] (5) Then, the electrode pressing rod 16 is passed through the adjustment groove 13, and the electrode pressing rod 16 is pressed on the top of the connecting rod 15, and then the first adjusting nut 17 is screwed into the upper end of the fixed bed 12 until the electrode 3 is pressed tightly;

[0051] (6) The surface of the fixing rod 18 is provided with an external thread. The fixing rod 18 is passed through the first through hole 14 until it contacts the connecting rod 15, and then the fixing rod 18 is fixed to the fixed bed 12 through the second adjusting nut 19. The structure after installation is shown in FIG. Figure 4 ;

[0052] (7) Disassemble the double-layer gland 8 and move the double-layer gland 8 and the upper sleeve 5 upward;

[0053] 3. Maintenance and installation section

[0054] (8) Figure 6 As shown, the electrode pressing block 20 is composed of two separate parts, each of which is composed of a locking portion 21 and a pressing portion 22, and a second through hole 23 is provided on the locking portion 21; the electrode pressing block 20 is sheathed around the electrode 3 from the side and then pressed down until the pressing portion 22 abuts against the bulging portion 4, and then the locking portion 21 is fixed on the base 7;

[0055] (9) Remove the electrode pressure rod 16 and the fixing rod 18, and then remove the double-layer pressure cover 8 and the upper sleeve 5; see Figure 5 ;

[0056] (10) Replace the upper sleeve 5, and then reinstall the double-layer gland 8 and the upper sleeve 5;

[0057] (11) Reinstall the electrode pressing rod 16 and the fixing rod 18 according to steps (5) and (6);

[0058] (12) Disassemble the electrode pressing block 20, then reset the double-layer pressing cover 8 and the upper sleeve 5, and finally fix the double-layer pressing cover 8;

[0059] (13) The electrode pressing rod 16 and the fixing rod 18 are disassembled again, and the electrode cover 1 and the terminal 2 are restored to their original positions, thus completing the replacement of the upper sleeve 5.

[0060] The material of the upper casing 5 is polytetrafluoroethylene; after the repaired concentrated sulfuric acid pipeline anode protection device is successfully powered on for trial operation, the clamp 11 and the fixed bed 12 are disassembled.

[0061] Since January 5, 2022, Jiangxi Copper Lead and Zinc Metals Co., Ltd. has used this maintenance process to replace 22 sets of concentrated sulfuric acid pipeline anode protection devices, which takes an average of only 2 hours, saving maintenance costs. During the maintenance period, there was no increase in energy consumption and no leakage of concentrated sulfuric acid.

[0062] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A maintenance process for an anode protection device for a concentrated sulfuric acid pipeline, characterized in that: The maintenance process is as follows:

1. Installation of fixed bed (1) Disconnect the power supply of the anode protection device of the concentrated sulfuric acid pipeline and remove the electrode cover and terminal; (2) The bottom of the fixed bed is fixedly connected to the fixing device, and the fixed bed is fixed to the shell through the fixing device; the upper end of the fixed bed is provided with an adjustment groove and a first through hole from top to bottom, and the upper end of the fixed bed is provided with an external thread; The fixing device is a clamp; (3) Fixed beds are installed symmetrically on both sides of the anode protection device for concentrated sulfuric acid pipelines; 2. Maintenance and disassembly section (4) A groove is provided at the bottom of the connecting rod, and the connecting rod is connected to a threaded pair formed at the top of the electrode through the groove; (5) Then pass the electrode pressure rod through the adjustment slot, press the electrode pressure rod on the top of the connecting rod, and then screw in the first adjustment nut from the upper end of the fixed bed until the electrode is tightened; (6) The surface of the fixing rod is provided with an external thread. The fixing rod is passed through the first through hole until it abuts against the connecting rod, and then the fixing rod is fixed to the fixed bed through the second adjusting nut; (7) Remove the double-layer gland and move the double-layer gland and the upper casing upwards; 3. Maintenance and installation section (8) The electrode pressing block is composed of two separate parts, each of which is composed of a locking part and a pressing part, and a second through hole is provided on the locking part; the electrode pressing block is put on the electrode from the side and then pressed down until the pressing part abuts against the bulging part, and then the locking part is fixed on the base; (9) Remove the electrode pressure rod and the fixing rod, and then take out the double-layer pressure cover and the upper sleeve; (10) Replace the upper casing, and then reinstall the double-layer gland and the upper casing; (11) Reinstall the electrode pressure rod and fixing rod according to steps (5) and (6); (12) Remove the electrode pressing block, then reset the double-layer pressing cover and the upper sleeve, and finally fix the double-layer pressing cover; (13) Remove the electrode pressure rod and fixing rod again, restore the electrode cover and terminal, and complete the replacement of the upper sleeve.

2. The maintenance process of the concentrated sulfuric acid pipeline anode protection device according to claim 1 is characterized in that: After the repaired concentrated sulfuric acid pipeline anode protection device is successfully powered on for trial operation, the fixing device and the fixed bed are dismantled.

3. The maintenance process of the concentrated sulfuric acid pipeline anode protection device according to claim 1 is characterized in that: When the clamp is fixed on the shell, a soft cushion is arranged in the middle.

4. The maintenance process of the concentrated sulfuric acid pipeline anode protection device according to claim 3 is characterized in that: The material of the soft pad is rubber.

5. The maintenance process of the concentrated sulfuric acid pipeline anode protection device according to claim 1 or 2, characterized in that: The material of the upper sleeve is polytetrafluoroethylene.

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