Ferrous sulfide cleaning device

Abstract

The invention relates to a ferrous sulfide cleaning device, and belongs to the technical field of petrochemical engineering treatment equipment. The iron ion online monitor is used for monitoring the content of iron ions in the passivator cleaning solution in real time; the PH detector is used for monitoring the PH value of the passivator cleaning liquid in real time, and the passivator liquid supply system is used for injecting a passivator into the dissolving tank; the water supply system is used for injecting industrial water into the dissolving tank; the circulating cleaning system is used for cleaning the to-be-cleaned equipment; the PLC control system is used for accurately controlling automatic proportioning and filling of industrial water and passivator cleaning liquid and automatically judging whether passivating and cleaning are qualified or not, and the distribution box is used for supplying power to an electricity load. The problems that manual matching control of industrial water and passivating agent liquid is not accurate, time consumed by manual cleaning of equipment is too long, whether passivating cleaning is qualified or not cannot be judged by analyzing the iron ion content and the PH value on line, and manual labor investment is large are solved.

Description

Technical Field

[0001] The present invention relates to a device for cleaning ferrous sulfide, belonging to the technical field of petrochemical processing equipment. Background Art

[0002] Ferrous sulfide is the product of the corrosion of sulfur and its sulfides in oil products with iron and its oxides. The sulfur in these oil products mainly comes from crude oil, and some also comes from additives in the crude oil processing process. Active sulfur has high corrosion activity and can directly react with metals to cause metal corrosion, such as elemental sulfur, hydrogen sulfide (H2S), and mercaptan (R-SH); inactive sulfur refers to those sulfides that usually cannot directly react with metals, such as thioether (R-S-R'), disulfide (RS-S-R'), cyclic sulfide, alkyl sulfoxide, thiophene, etc. However, in the catalytic cracking reaction during the crude oil refining process, these so-called inactive sulfur organic sulfides will decompose to form active sulfur such as S and H2S, and these active sulfur will react with iron or iron compounds under different conditions to form ferrous sulfide or other sulfides of iron.

[0003] First, at high temperatures (350 - 400 °C), sulfur can directly react with metals to form ferrous sulfide, and H2S can start to react with Fe at 200 °C. Some mercaptans contained in crude oil can also directly react with iron at high temperatures (above 200 °C) to produce ferrous sulfide corrosion products.

[0004] Second, at high temperatures, H2S can decompose, and the elemental sulfur produced has high activity and reacts extremely strongly with Fe.

[0005] Third, in the flue gas pipeline of the catalytic cracking unit, when SO2 and CO coexist at high temperature parts (400 - 600 °C): SO2 + 2CO → 2CO2 + S; S + Fe → FeS.

[0006] Fourth, the chlorides contained in crude oil produce HCl during the hydrogenation process and high-temperature hydrolysis process, which synergistically acts with H2S in the crude oil.

[0007] Fifth, the corrosion when naphthenic acid coexists with H2S at high temperature. The FeS protective film formed by H2S corrosion on the metal surface during the refining process of sulfur-containing crude oil forms oil-soluble Fe(RCOO)2 under the action of naphthenic acid, making the metal surface bare and shiny. At the same time, the secondary product H2S formed can also participate in the corrosion process at high temperatures and play a role in replenishing and regenerating.

[0008] Sixth, ferrous sulfide is generated by atmospheric corrosion reaction. Since the device has been shut down for a long time and the internal components of the equipment have been exposed to the air for a long time, atmospheric corrosion will occur and rust will be generated. Since rust is not easy to be completely removed, it will react with hydrogen sulfide during the production process to generate ferrous sulfide. This reaction is relatively easy to proceed. Due to the long-term shutdown, the devices with poor anti-corrosion are more likely to generate ferrous sulfide.

[0009] In the oil refining process, due to the combined effects of electrochemical corrosion, chemical corrosion, microbial corrosion and oxidation corrosion, the opportunity for the generation of ferrous sulfide always exists. The higher the sulfur content of the oil product, the greater the probability of generating ferrous sulfide. In the initial stage of the oil product processing, the generated ferrous sulfide tightly covers the surface of the equipment and has a certain protective effect on the equipment. However, due to the combined effects of various corrosion systems and the erosion of gas-liquid phase fluids, the dense ferrous sulfide will peel off and settle at the bottom of the tray, liquid receiving tank, packing, etc. with the flow of the oil product. Some ferrous sulfide still adheres to the surface of the equipment, and heavy components such as oil residue, coke powder and coke asphalt are also likely to deposit in the above areas and wrap the ferrous sulfide. During the shutdown process treatment of the device, such as steam purging and water washing, these deposits are very difficult to be removed. When the equipment is opened and exposed to air, ferrous sulfide will spontaneously combust, releasing a large amount of heat rapidly, and at the same time will ignite the organic substances such as oil residue and coke powder wrapped. In the petrochemical industry, cases of tower burning and explosion caused by the spontaneous combustion of ferrous sulfide are not uncommon. This has always been a major problem for oil refining enterprises at home and abroad.

[0010] With the progress of domestic oil refining technology and the improvement of management level, the device is developing in the direction of long cycle. However, there is always a contradiction between the inferiorization of crude oil quality and the long cycle. Due to the combined effects of both aspects, it has become a necessary process to remove the dirt accumulated in the equipment during the shutdown stage of the device. This can not only eliminate the unsafe factors when the equipment is opened (such as the spontaneous combustion of ferrous sulfide damaging the equipment), but also create a good maintenance environment (such as removing malodorous substances such as hydrogen sulfide), and can also restore the original function of the equipment (such as removing crystal scale and heavy oil dirt).

[0011] Generally, refineries have a procedure for clearing oil before a unit shutdown for maintenance, including steam purging, water flushing, etc. However, due to the lack of a systematic chemical cleaning procedure, only light components can often be removed, while heavy oil scale, FeS, etc. cannot be removed. The sludge, slurry, residual oil, and coke in the system cannot be completely removed either. Moreover, there are dead corners left by steam purging and water flushing, failing to meet the safety procedure standards. Therefore, it is very necessary to remove harmful substances such as ferrous sulfide and hydrogen sulfide on refining equipment and pipelines before maintenance. However, current industrial cleaning equipment is mainly manually operated, not only with a high labor intensity but also low efficiency. First of all, the cleaning equipment operated manually requires a large amount of manpower and time. For large industrial equipment, it may require several people or even dozens of people to operate, and the cleaning process may take several hours or even several days, which increases the cost of industrial production to a certain extent.

[0012] Secondly, traditional cleaning equipment often cannot achieve an accurate ratio of industrial water to passivating agent solution. During the cleaning process, it is necessary to adjust the ratio of industrial water to passivating agent solution according to various factors such as different working environments, the material of the equipment, its usage status, the type and quantity of other compound impurities accumulated, etc., in order to achieve the best cleaning effect. In addition, due to the inaccurate estimation of the amount of passivating agent by manual calculation and the incomplete consideration of various factors, it is often difficult to achieve an accurate ratio. A high proportion of the passivating agent increases the cleaning cost, while a low proportion affects the cleaning effect.

[0013] Therefore, there are many problems with existing cleaning equipment, such as the inability to achieve an accurate ratio of industrial water to passivating agent solution and the inability to adjust according to different working environments and requirements. These problems limit the effectiveness and application scope of cleaning equipment, bringing many troubles to industrial production. How to solve these problems and improve the automation, accuracy, and flexibility of cleaning equipment is an important direction for the development of current industrial cleaning equipment technology.

[0014] During the cleaning process, the ratio of industrial water to passivating agent solution is an important factor affecting the cleaning effect. In order to achieve an ideal cleaning effect, it is necessary to quantitatively control the passivating agent. For example, by online monitoring the iron ion content and pH value in the cleaning solution to adjust the passivating agent in real time, so as to achieve the best cleaning effect. However, existing cleaning equipment requires manual sampling of the circulating cleaning solution at regular intervals and sending it to a laboratory for chemical analysis and detection of various parameter indicators of the circulating cleaning solution. This not only takes time and effort but also affects the accuracy of the test results of the circulating cleaning solution.

[0015] In the prior art, the patent application number is CN201310114860.3, and the invention name is "A Ferrous Sulfide Passivator and Its Preparation Method". It is a passivator with a fast reaction speed, high efficiency, non-toxic and harmless, and can be directly discharged to the sewage treatment plant. This passivator is made of Tween 80, citric acid, sodium dodecyl sulfate, potassium permanganate, and secondary deionized water.

[0016] Chinese invention patent application, publication number: CN 113617766 A, invention name: "Double Horizontal Pump Mechanical Cleaning Device, Process and Layout System for Storage Tanks". The cleaning device mainly consists of a vacuum suction tank, a gas-liquid separation tank, a horizontal centrifugal pump, a heat exchanger, an automatic control system, and related instrument pipe fittings, etc.

[0017] Chinese invention patent, announcement number: CN102908888B, invention name: "Ferrous Sulfide and Hydrogen Sulfide Gas Cleaning and Passivation Device, Method and Application". It is a ferrous sulfide and hydrogen sulfide gas cleaning and passivation device, which includes: a liquid preparation tank truck, a passivation cleaning agent supply device, and a water supply device. The passivation cleaning agent supply device and the water supply device are connected to the liquid preparation tank of the liquid preparation tank truck through pipelines, and are used to provide passivation cleaning agent and water to the liquid preparation tank of the liquid preparation tank truck.

[0018] Chinese invention patent application, publication number: CN 107472732 A, invention name: "Liquid Hazardous Chemicals Skid-mounted Cleaning Device and Method". The invention provides a liquid hazardous chemicals skid-mounted cleaning device and method. This liquid hazardous chemicals skid-mounted cleaning device includes a tank body, a barrier layer, a polymer explosion-proof material, a first pump, a second pump, a water tank, a cleaning liquid, and a filter. Among them, the barrier layer is arranged in the tank body, and the tank body is divided into an upper space and a lower space by the barrier layer. The upper space is filled with a polymer explosion-proof material. A plurality of through holes are formed on the barrier layer. The tank body also includes a cleaning liquid filling port and a liquid extraction port. The cleaning liquid filling port is arranged on the circumferential side wall or the top of the lower space, and the liquid extraction port is arranged on the bottom wall of the lower space or the bottom of the circumferential side wall. The outlet of the water tank is connected to the cleaning liquid filling port through the first pump, and the liquid extraction port is sequentially connected to the water return port of the water tank through the filter and the second pump.

[0019] Chinese utility model patent, announcement number: CN 202984223 U, invention name: "Vehicle-mounted Mobile Storage Tank Cleaning Device". It is a vehicle-mounted mobile storage tank cleaning device, which consists of: a mobile trailer with a carriage. The carriage is equipped with an integrated clean water tank and a sewage tank. The clean water tank is connected to a cleaning pump, and the cleaning pump is connected to a tank washer. The sewage tank is connected to a mobile sewage pump. Both the sewage tank and the clean water tank are connected to an oil-water separator.

[0020] Chinese Utility Model Patent, Publication No.: CN 215103048 U, Invention Title: A Sulfurized Ferrous Passivation Operation Device for Large-Diameter Towers, including a fixed plate body, on the upper surface of which a passivator mixing tank and a waste liquid recovery tank are fixed. The passivator mixing tank is provided with a passivator stock solution tank and a water inlet pipe connected to its upper end. A water pump is arranged on the upper surface of the passivator mixing tank, and the water delivery end of the water pump is provided with a drain pipe connected to the upper feed port of the tower body.

[0021] Chinese Utility Model Patent, Announcement No.: CN 216024185 U, Invention Title: A Liquid Mixing Tank, including a skid-mounted base and a tank body, a PLC control cabinet, and a pressurizing pump arranged on the skid-mounted base. A rotating spray device is arranged in the tank body, and the rotating spray device is connected to the tank body through a lifting device. The feed end and the discharge end of the pressurizing pump are respectively connected with a discharge pipe and a circulation pipe. The discharge pipe is communicated with the tank body, and the circulation pipe is in pipeline communication with the rotating spray device.

[0022] Chinese Utility Model Patent, Announcement No.: CN 212143812 U, Invention Title: An Oil Tank Cleaning System, the cleaning device of which includes a booster pump and a cleaning nozzle. The cleaning nozzle can be inserted into the oil tank and can be lifted and rotated 360° relative to the oil tank to perform spray cleaning on the inner wall of the oil tank.

[0023] The main features of the cleaning devices listed in the above patents are vehicle-mounted and manual cleaning devices, and they do not have an online iron ion detection function and cannot automatically judge on-site whether the passivation cleaning is qualified based on the pH value, temperature, and iron ion content. It is necessary to take samples for analysis regularly manually, which is time-consuming and laborious. Summary of the Invention

[0024] In order to solve the problems of inaccurate manual ratio control of industrial water and passivator liquid, excessive time consumption of manual cleaning equipment, inability to analyze iron ion content and pH value online, inability to judge on-site whether the passivation cleaning is qualified, and large investment in manual labor, the present invention provides a sulfurized ferrous cleaning device.

[0025] To achieve the above object, the technical solution of the present application is a ferrous sulfide cleaning device, which includes a dissolution tank, an iron ion on-line monitor, a pH detector, a distribution box, a passivator liquid supply system, a water supply system, a circulating cleaning system, and a PLC control system in a box body; among them, the iron ion on-line monitor is used to monitor the iron ion content in the passivator cleaning liquid in real time; the pH detector is used to monitor the pH value in the passivator cleaning liquid in real time, the passivator liquid supply system is used to inject passivator liquid into the dissolution tank; the water supply system is used to inject industrial water into the dissolution tank; the circulating cleaning system is used to clean the equipment to be cleaned; the PLC control system is used to accurately control the automatic proportioning and filling of industrial water and passivator liquid, and automatically judge whether the passivation cleaning is qualified, and the distribution box is used to supply power to the electrical load.

[0026] Further, the dissolution tank is provided with a water inlet, and a safety valve and a vent solenoid valve are also installed at the top of the dissolution tank. A drain pipe is installed at the bottom of the dissolution tank, and a drain valve is provided on the drain pipe. The water supply system includes a water inlet pipe connected to the water inlet and a pneumatic regulating ball valve and an electromagnetic flowmeter A on the water inlet pipe.

[0027] Further, a magnetic flap level gauge B is provided on the side of the dissolution tank, a ball valve D is installed between both ends of the magnetic flap level gauge B and the dissolution tank, and a sampling valve, an instrument valve and a pressure gauge are also installed on the dissolution tank.

[0028] Further, the passivator liquid supply system includes an electric pump A, an electromagnetic flowmeter B, and a first pneumatic V-ball valve. The passivator liquid supply system provides passivator liquid through a passivator solution barrel. An electric pump A, an electromagnetic flowmeter B, and a first pneumatic V-ball valve are sequentially installed on the pipeline between the passivator solution barrel and the dissolution tank.

[0029] Further, a pneumatic diaphragm pump, a buffer tank and a ball valve A are also provided on the pipeline between the passivator solution barrel and the electric pump A. A breathing valve and a breathing port are provided at the top of the buffer tank, and a magnetic flap level gauge A is also installed on the side of the buffer tank. A ball valve B is also provided between both ends of the magnetic flap level gauge A and the buffer tank, and a first solenoid valve is also provided between the pneumatic diaphragm pump and the magnetic flap level gauge A.

[0030] Further, a ball valve E is also provided at the bottom of the buffer tank.

[0031] Further, a check valve A is also installed on the pipeline between the first pneumatic V-ball valve and the dissolution tank.

[0032] Further, the circulating cleaning system includes a ball valve C, an electric pump B, a second pneumatic V-ball valve, an integrated thermal resistor, and a filter A. The ball valve C, the electric pump B, and the second pneumatic V-ball valve are sequentially installed on the circulating liquid outlet pipeline from the outlet end of the dissolution tank to the equipment to be cleaned; the integrated thermal resistor and the filter A are sequentially installed on the circulating liquid outlet pipeline from the equipment to be cleaned to the inlet end of the dissolution tank.

[0033] Further, the circulating cleaning system further includes a return pipeline. One end of the return pipeline is connected to the dissolution tank, and the other end is connected between the electric pump B and the second pneumatic V-ball valve. A wafer check valve is also installed on the return pipeline.

[0034] Further, a check valve B is also provided on the circulating liquid outlet pipeline between the equipment to be cleaned and the second pneumatic V-ball valve.

[0035] Further, the PH detectors are respectively installed at the inlet end and the outlet end of the dissolution tank. The iron ion on-line monitor is installed on the circulating liquid outlet pipeline between the inlet end of the dissolution tank and the PH detector. A sampling valve is also installed on the circulating liquid outlet pipeline between the iron ion on-line monitor and the PH detector.

[0036] Further, the filter A and the filter B are in parallel, and wafer butterfly valves are also installed at both ends of the filter A and the filter B.

[0037] Further, a glass window is also provided on the circulating liquid outlet pipeline between the integrated thermal resistor and the equipment to be cleaned. The glass window is located outside the box and is used to directly observe the liquid in the pipeline.

[0038] Further, instrument valves and pressure gauges are provided on the pipeline between the electromagnetic flowmeter B and the electric pump A and on the circulating liquid outlet pipeline between the electric pump B and the second pneumatic V-ball valve.

[0039] Further, the PLC control system is electrically connected to the electromagnetic flowmeter A, the electromagnetic flowmeter B, the iron ion on-line monitor, the PH detector, the integrated thermal resistor, the magnetic flap level gauge A, the magnetic flap level gauge B, the first solenoid valve, and the vent solenoid valve through signal lines, and can collect signals, store data, and control the operation of each component. The PLC control system has a historical data query function and can view the historical data curves of the ferrous sulfide content, PH value, temperature, liquid level, industrial water flow, passivator liquid flow, and total flow by time period. The total flow = industrial water flow + passivator liquid flow, and it also has safety interlock and alarm functions.

[0040] Furthermore, the electromagnetic flowmeter B and the electric pump A are also electrically connected through a signal line. The electric pump A can automatically adjust the opening degree according to the signal of the electromagnetic flowmeter B through the PLC control system; the pneumatic regulating ball valve and the electromagnetic flowmeter A are electrically connected through a signal line, and the pneumatic regulating ball valve automatically adjusts the opening degree according to the signal of the electromagnetic flowmeter A through the PLC control system; the magnetic flap level gauge A and the first solenoid valve are electrically connected through a signal line, and the magnetic flap level gauge B and the second pneumatic V-ball valve are electrically connected through a signal line. The second pneumatic V-ball valve automatically adjusts the opening degree according to the signal of the magnetic flap level gauge B under the control of the PLC control system.

[0041] The present invention adopts the above technical solutions and can achieve the following technical effects:

[0042] (1) Compared with the existing sampling and external sending for chemical analysis of the passivator cleaning solution index, through the PLC control system, the iron ion online monitor and the pH detector, the iron ion content can be monitored in real time online and the pH value can be monitored online. According to the parameter changes, the degree of reaction between the passivator solution and iron sulfide can be automatically judged online, and whether the cleaning is qualified can be judged, so as to achieve the purpose of automatically detecting the cleaning effect.

[0043] (2) The present invention conducts automated operations and precise control of the ratio of industrial water to passivator solution through the PLC control system, greatly improving the cleaning efficiency, reducing errors in manual operations, and saving a large amount of time.

[0044] (3) Compared with the existing processes of manually preparing the passivator cleaning solution, monitoring the cleaning process, regularly sampling the circulating cleaning solution and sending it to the laboratory for chemical analysis, etc., the present invention greatly reduces the manpower requirement through an automated operation process and real-time online monitoring, thus saving labor costs. In addition, a sealed dissolution tank is used for the circulation of the passivator cleaning solution, reducing the contact between the passivator cleaning solution and the outdoor air, avoiding the harm of sulfur-containing gas inhalation by on-site cleaning personnel and reducing air pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic structural diagram of Embodiment 1 of the present invention;

[0046] Figure 2 It is a top view schematic diagram of Embodiment 1 of the present invention;

[0047] Figure 3 It is a front view schematic diagram of Embodiment 1 of the present invention;

[0048] Figure 4 It is a schematic diagram of the cleaning process of the reflux tank of the stripping tower T5101 of the present invention;

[0049] Figure 5This is a schematic diagram of the cleaning process for the debutanizer and the top reflux drum T1101 / V1108 system of the present invention.

[0050] Explanation of the numbers in the figure: 1. Pneumatic control ball valve; 2. Electromagnetic flowmeter A; 3. Safety valve; 4. Iron ion on-line monitor; 5. PH detector; 6. Wafer-type butterfly valve; 7. Filter A; 8. Sampling valve; 9. Integrated thermal resistor; 10. Check valve A; 11. First pneumatic V-ball valve; 12. Electromagnetic flowmeter B; 13. Instrument valve; 14. Pressure gauge; 15. Electric pump A; 16. Ball valve A; 17. Buffer tank; 18. Ball valve B; 19. Magnetic flap level gauge A; 20. Pneumatic diaphragm pump; 21. Dissolving tank; 22. Drain valve; 23. Ball valve C; 24. Electric pump B; 25. Second pneumatic V-ball valve; 26. Check valve B; 27. Wafer-type ball valve; 28. First solenoid valve; 29. Glass window; 30. Equipment to be cleaned; 31. Passivator solution barrel; 32. Box body; 34. Vent pipe; 35. Vent solenoid valve; 36. Breathing port; 37. Breathing valve; 38. Signal line; 39. PLC control system; 40. Ball valve E; 41. Water inlet pipe; 42. Drain pipe; 43. Circulating liquid outlet pipeline; 44. Return pipeline; 46. Distribution box; 47. Filter B; 49. Magnetic flap level gauge B; 50. Ball valve D. Detailed implementation mode

[0051] The present invention will be further described in detail below with reference to the drawings and specific embodiments: This is taken as an example to further describe the present application.

[0052] Embodiment 1:

[0053] As Figures 1 - 3 shown, this embodiment provides a ferrous sulfide cleaning device, including a dissolving tank 21, an iron ion on-line monitor 4, a PH detector 5, a distribution box 46, a passivator supply system, a water supply system, a circulating cleaning system, and a PLC control system 39 inside a box body 32; among them, the iron ion on-line monitor 4 is used to monitor the iron ion content in the passivator cleaning solution in real time; the PH detector 5 is used to monitor the PH value in the passivator cleaning solution in real time, the passivator supply system is used to inject the passivator solution into the dissolving tank 21; the water supply system is used to inject industrial water into the dissolving tank 21; the circulating cleaning system is used to clean the equipment 30 to be cleaned; the PLC control system 39 is used to accurately control the automatic proportioning and injection of industrial water and the passivator solution, and automatically judge whether the passivation cleaning is qualified, and the distribution box 46 is used to supply power to each electrical load. Ferrous sulfide remains in the equipment 30 to be cleaned.

[0054] The described dissolving tank 21 is provided with a water inlet. A safety valve 3 and a vent solenoid valve 35 are also installed at the top of the dissolving tank 21. The opening and closing of the safety valve 3 and the vent solenoid valve 35 control the connection between the vent pipe 34 and the outside. A drain pipe 42 is installed at the bottom of the dissolving tank 21, and a drain valve 22 is provided on the drain pipe 42 to facilitate the discharge of the medium in the dissolving tank 21 from the drain pipe 42 into the waste water tank. The water supply system includes a water inlet pipe 41 connected to the water inlet and a pneumatic regulating ball valve 1 and an electromagnetic flowmeter A2 on the water inlet pipe 41. The pneumatic regulating ball valve 1 and the electromagnetic flowmeter A2 are electrically connected through a signal line 38. The pneumatic regulating ball valve 1 automatically adjusts the opening degree according to the signal of the electromagnetic flowmeter A2 through the PLC control system 39. A magnetic flap level gauge B49 is provided on the side of the dissolving tank 21. A ball valve D50 is installed between both ends of the magnetic flap level gauge B49 and the dissolving tank 21. A sampling valve 8, an instrument valve 13 and a pressure gauge 14 are also installed on the dissolving tank 21. The sampling valve 8 is provided to facilitate the operator to sample and test the medium in the dissolving tank 21. The pressure gauge 14 is used to measure the pressure in the dissolving tank 21. When the pressure is too high, the safety valve 3 is opened for pressure relief. The electromagnetic flowmeter A2 is used to collect flow values, and the flow values include industrial water flow values and industrial water cumulative flow values. The magnetic flap level gauge B49 is used to monitor the medium liquid level in the dissolving tank 21. When the liquid level is higher than 80% or lower than 20% of the liquid level, after the PLC control system 39 receives the signal, it starts the safety interlock and controls the opening degree of the second pneumatic V-ball valve 25.

[0055] The described passivating agent supply system includes an electric pump A15, an electromagnetic flowmeter B12, a first pneumatic V-ball valve 11, a check valve A10, a pneumatic diaphragm pump 20, a buffer tank 17 and a ball valve A16; the passivating agent supply system provides a source of passivating agent liquid through a passivating agent solution tank 31;

[0056] The pneumatic diaphragm pump 20 is installed on the liquid supply pipeline at the outlet end of the passivator solution tank 31. The output end of the pneumatic diaphragm pump 20 is connected to the buffer tank 17 through the liquid supply pipeline. A ball valve A 16 is provided at the outlet end of the buffer tank 17. The other end of the ball valve A 16 is connected to the electric pump A 15 through a pipeline. The output end of the electric pump A 15 is connected to the electromagnetic flowmeter B 12. The electromagnetic flowmeter B 12 is connected to the first pneumatic V-ball valve 11. The first pneumatic V-ball valve 11 is connected to the check valve A 10 through a pipeline. The check valve A 10 is connected to the inlet end of the dissolution tank 21 through a pipeline. A breather valve 37 and a breathing port 36 are provided at the top of the buffer tank 17. The breather valve 37 and the breathing port 36 are used to discharge the passivator liquid in case of emergency. A ball valve E 40 is also provided at the bottom end of the buffer tank 17. The purpose of setting the ball valve E 40 is to drain the cleaning liquid in the pipeline and the buffer tank 17 after the cleaning is completed, prevent the pipeline from freezing, and avoid corrosion caused by the long-term retention of the passivator liquid. A magnetic flap level gauge A 19 is also installed on the side of the buffer tank 17. A ball valve B 18 is provided between both ends of the magnetic flap level gauge A 19 and the buffer tank 17. A first solenoid valve 28 is also provided between the pneumatic diaphragm pump 20 and the magnetic flap level gauge A 19. By providing the buffer tank 17 and the pneumatic diaphragm pump 20, the problem that when the passivator solution tank 31 needs to be replaced during the process of the electric pump A 15 extracting the passivator, part of the gas enters the pipeline and the electric pump A 15 cannot extract the passivator is solved. An instrument valve 13 and a pressure gauge 14 are provided on the pipeline between the electromagnetic flowmeter B 12 and the electric pump A 15. The pressure gauge 14 is used to monitor the pressure of the passivator liquid supply pipeline. The electromagnetic flowmeter B 12 is used to collect flow values, and the flow values include the passivator liquid flow value and the passivator liquid cumulative flow value. The magnetic flap level gauge A 19 is used to monitor the level of the passivator liquid in the buffer tank 17. When the level is higher than 80% of the level or lower than 20% of the level, after the PLC control system 39 receives the signal, it starts the safety interlock and controls the first solenoid valve 28 for interlocking.

[0057] The described circulating cleaning system includes a ball valve C23, an electric pump B24, a second pneumatic V-ball valve 25, a check valve B26, an integrated thermal resistor 9, and a filter A7. The ball valve C is installed on the circulating liquid outlet pipeline 43 at the outlet end of the dissolution tank 21. The other end of the ball valve C23 is connected to the electric pump B24 through a pipeline. The output end of the electric pump B24 is connected to the second pneumatic V-ball valve 25 through the circulating liquid outlet pipeline 43. The other end of the second pneumatic V-ball valve 25 is connected to the check valve B26 through the circulating liquid outlet pipeline 43. The other end of the check valve B26 is connected to the inlet end of the equipment to be cleaned 30 through the circulating liquid outlet pipeline 43. An integrated thermal resistor 9 and a filter A7 are also sequentially installed on the circulating liquid outlet pipeline 43 at the outlet end of the equipment to be cleaned 30. An instrument valve 13 and a pressure gauge 14 are provided on the circulating liquid outlet pipeline 43 between the electric pump B24 and the second pneumatic V-ball valve 25. The pressure gauge 14 is used to detect the pressure on the circulating liquid outlet pipeline 43. A glass window 29 is also provided on the circulating liquid outlet pipeline 43 between the outlet end of the equipment to be cleaned 30 and the integrated thermal resistor 9. The glass window 29 is a transparent pipeline and is used to directly observe the liquid in the pipeline. The filter A7 is connected in parallel with the filter B47. Opposed flange butterfly valves 6 are also installed at both ends of the filter A7 and the filter B47. By providing two parallel branches, it is convenient for replacement and maintenance without affecting the operation. For example, when the filter A7 is blocked, the opposed flange butterfly valves 6 at both ends of the filter A7 are closed, and then the filter A7 is removed for maintenance. At the same time, the opposed flange butterfly valves 6 at both ends of the filter B47 are opened for operation. The integrated thermal resistor 9 is used to monitor the temperature of the passivating agent cleaning solution in real time, and the degree of reaction between the passivating agent solution and iron sulfide is judged by measuring the temperature.

[0058] Further, the described circulating cleaning system also includes a return pipeline 44. One end of the return pipeline 44 is connected to the dissolution tank 21, and the other end is connected between the electric pump B24 and the second pneumatic V-ball valve 25. An opposed flange ball valve 27 is also installed on the return pipeline 44. The purpose of setting the return pipeline 44 and the opposed flange ball valve 27 is to adjust the outlet flow of the electric pump B24 on the circulating liquid outlet pipeline 43, and it can also have a stirring effect on the dissolution tank 21 after reflux, which is conducive to the full mixing of the passivating agent solution and industrial water.

[0059] One pH detector 5 is installed between the sampling valve 8 and the opposed flange butterfly valve 6 at the inlet end of the dissolution tank 21, and the other pH detector 5 is installed between the ball valve C23 and the electric pump B24 at the outlet end of the dissolution tank 21. The iron ion on-line monitor 4 is installed on the circulating liquid outlet pipeline 43 between the inlet end of the dissolution tank 21 and the pH detector 5.

[0060] The described PLC control system 39 (PLC programmable logic controller) is electrically connected to the electromagnetic flowmeter A2, electromagnetic flowmeter B12, iron ion on-line monitor 4, pH detector 5, integrated thermal resistor 9, magnetic flap level gauge A19, magnetic flap level gauge B49, first solenoid valve 28, and vent solenoid valve 35 through signal line 38, and is capable of collecting signals, storing data, and controlling the operation of each component. The PLC control system 39 has a historical data query function, and can view the historical data curves of ferrous sulfide content, pH value, temperature, liquid level, industrial water flow rate, passivator liquid flow rate, and total flow rate (industrial water flow rate + passivator liquid flow rate) by time period. It also has safety interlock and alarm functions. The electromagnetic flowmeter B12 and the electric pump A15 are also electrically connected through the signal line 38, and the electric pump A15 can automatically adjust the opening degree according to the signal of the electromagnetic flowmeter B12 through the PLC control system 39; the magnetic flap level gauge A19 and the first solenoid valve 28 are electrically connected through the signal line 38, and the magnetic flap level gauge B49 and the second pneumatic V-ball valve 25 are electrically connected through the signal line 38, and both are controlled by the PLC control system 39. After the sampling valve 8 of the dissolving tank 21 and the circulating cleaning system is used for manual sampling, the passivator cleaning solution is sent to the laboratory for chemical analysis and detection of various parameter indicators.

[0061] The water supply system injects industrial water into the dissolving tank 21, and the passivator liquid supply system injects passivator liquid into the dissolving tank 21. After the passivator liquid and industrial water fully react, a passivator cleaning solution is formed. The passivator cleaning solution flows out of the dissolving tank 21 and is pumped by the electric pump B24 to the equipment to be cleaned 30 for cleaning, and then flows back to the dissolving tank 21. During the liquid supply stage, the electromagnetic flowmeter A2 collects the industrial water flow rate value and the industrial water cumulative flow rate value, and the electromagnetic flowmeter B12 collects the passivator liquid flow rate value and the passivator liquid cumulative flow rate value. Through the PLC control system 39, the passivator liquid and industrial water are mixed in a set ratio; during the circulating cleaning stage, the iron ion on-line monitor 4 collects the iron ion content, and the reaction degree between the passivator cleaning solution and ferrous sulfide is judged by the change of the iron ion content; the pH detector 5 can collect the pH value, and the integrated thermal resistor 9 collects the temperature. The PLC control system 39 judges the reaction degree between the passivator liquid and ferrous sulfide through the collected iron ion content and pH value data, judges whether the cleaning is qualified, and thus gives corresponding control instructions, ultimately achieving the purpose of automatically detecting the cleaning effect. Among them, the average value is calculated by collecting two pH values at the inlet and outlet ends of the dissolving tank 21 for comprehensive judgment.

[0062] In practical applications, the cleaning method is as follows:

[0063] The cleaning includes four stages: preparation stage, liquid supply stage, circulation stage, and shutdown stage.

[0064] The preparation stage is the pre-operation inspection:

[0065] First, check whether the sewage discharge valve 22 is closed; check whether the air compressor outside the box body 32 supplies air; check whether the industrial water supply valve connected to the water inlet pipe 41 outside the box body 32 is open; check whether all the wafer check valves 6 before and after the filter A7 can be normally opened. Secondly, make the power connection to ensure firm connection. Finally, start the PLC control system 39 for parameter setting and select the corresponding cleaning and passivation scheme according to different equipment. During the cleaning and passivation process, it is allowed to adjust the concentration, temperature and flow rate of the passivation agent cleaning solution within a certain range. As the usage time of the passivation agent cleaning solution increases, the concentration of the liquid and the concentration of iron ions will change.

[0066] In the liquid supply stage, specifically, check whether the vent solenoid valve 35 is open to ensure that the inspection of the vent solenoid valve 35 is correct; then start the pneumatic diaphragm pump 20. After waiting for the liquid level in the buffer tank 17 to reach the set value, open the pneumatic regulating ball valve 1, the first pneumatic V-ball valve 11, and the electric pump A15. The pneumatic regulating ball valve 1 can be automatically adjusted according to the numerical signal displayed by the electromagnetic flowmeter A2 until the numerical value displayed by the electromagnetic flowmeter A2 is the set value. The first pneumatic V-ball valve 11 is automatically adjusted according to the numerical signal displayed by the electromagnetic flowmeter B12 until the numerical value displayed by the electromagnetic flowmeter B12 is the set value. At this time, industrial water and passivation agent are injected into the dissolution tank 21 according to the given ratio. Specifically, according to the formula: Y = KX + B; where X is the flow rate measured by the electromagnetic flowmeter B12 (cumulative flow rate of the passivation agent cleaning solution), Y is the flow rate measured by the electromagnetic flowmeter A2 (cumulative flow rate of industrial water), and K and B are coefficients set in the PLC control system 39 by itself. (The range of K: 8 - 12, and the range of B is -10 - 10). The air in the dissolution tank 21 is discharged through the vent pipe 34. When the magnetic flap level gauge A19 measures a 20% interlock of the liquid level, open the pneumatic diaphragm pump 20; when the magnetic flap level gauge A19 measures an 80% interlock of the liquid level, close the pneumatic diaphragm pump 20.

[0067] Circulation stage:

[0068] When the magnetic flap level gauge B49 of the dissolution tank 21 reaches the set liquid level, usually the set liquid level is set to be equal to 75% of the volume of the equipment to be cleaned 30, open the electric pump B24, and open the second pneumatic V-ball valve 25. The opening degree of the second pneumatic V-ball valve 25 is adjusted and controlled according to the liquid level signal measured by the magnetic flap level gauge B49 and fed back to the PLC control system 39. When the liquid level is high, increase the opening degree of the second pneumatic V-ball valve 25; when the liquid level is low, decrease the opening degree of the second pneumatic V-ball valve 25.

[0069] When the level of the magnetic flap level gauge B49 in the dissolution tank 21 reaches the set 80% level, the second pneumatic V-ball valve 25 is fully opened, and the electric pump B24 will continuously supply liquid into the equipment 30 to be cleaned until the PLC control system 39 prompts that the cumulative flow reaches the set value. The cumulative flow = the cumulative flow of the electromagnetic flowmeter A2 + the cumulative flow of the electromagnetic flowmeter B12. The pneumatic regulating ball valve 1 is closed, the first pneumatic V-ball valve 11 is closed, and the electric pump A15 is closed (or manually enter the circulation stage). At this time, the PLC control system 39 will prompt to close the vent solenoid valve 35. After closing the vent solenoid valve 35, enter the circulation stage; when the magnetic flap level gauge B49 in the dissolution tank 21 measures a level lower than 20%, the electric pump B24 is interlocked and closed; when the magnetic flap level gauge B49 in the dissolution tank 21 measures a level higher than 80%, the electric pump A15 is interlocked and closed, the pneumatic regulating ball valve 1 is interlocked and closed, and the first pneumatic V-ball valve 11 is interlocked and closed.

[0070] Manually open the circulation return valve outside the box body 32. At this time, the electric pump B24 is opened, the second pneumatic V-ball valve 25 is fully opened, and the electric pump B24 continues to supply liquid into the equipment 30 to be cleaned. At the same time, the solution at the bottom of the equipment 30 to be cleaned flows back into the dissolution tank 21, and the solution circulates in and out of the equipment 30 to be cleaned; after the circulation runs stably for a certain period of time, the PLC control system 39 automatically controls the first pneumatic V-ball valve 11 and the electric pump A15 according to the numerical change of the PH detector 5 to supplement a certain amount of passivating agent liquid into the system.

[0071] The PLC control system 39 automatically judges that the cleaning is completed according to the parameter change of the iron ion on-line monitor 4 detected. When the circulation cleaning is 12 hours and the change of the iron ion content in the last two hours does not exceed 10%.

[0072] Shutdown stage:

[0073] Check whether the industrial water valve outside the box body 32 is closed, check whether the electric pump B24 and the second pneumatic V-ball valve 25 are closed. After confirmation, carry out the discharge operation; open the drain valve 22 to drain the waste liquid back to the waste water tank; finally, turn off the main power supply.

[0074] In this embodiment, the reflux tank of the stripping tower T5101 is cleaned.

[0075] At 20:00 on March 31st, 8 tons of passivator were added according to the set ratio (Y = KX + B, K = 10, B = 0), and the total soaking time was 7 hours. At 6:00 on April 1st, the reflux drum of the stripping column T5101 was circulated. At 8:30, the pH value showed an obvious downward trend, dropping from 7.3 to 6.07. At 11:00, a total of 2 tons of passivator were automatically added; the pH value before adding the agent was 6.07, and the pH value was 6.54 half an hour after the addition of the passivator ended. At 16:00, the pH value was 7.70. On April 2nd, the passivation cleaning ended at 10:00. During the cleaning process, the iron ion content of the circulating cleaning solution was monitored online, and the analysis results are shown in Table 1:

[0076] Table 1: Changes in iron ion content and pH value

[0077] Online monitoring time pH value Iron ion content, ug / ml April 1st (6:30) 6.34 196.20 April 1st (8:30) 7.30 128.10 April 1st (9:00) 6.07 145.26 April 1st (11:00) 6.67 100.97 April 1st (11:30) 6.52 110.21 April 1st (14:00) 7.51 64.09 April 1st (16:00) 7.70 43.06 April 1st (21:00) 7.28 22.31 April 1st (22:00) 7.24 21.22

[0078] As can be seen from Table 1 above, the iron ion content in the stripping column T5101 system was relatively high in the initial stage, indicating that the cleaning reaction in the system was relatively intense in the initial stage of adding the passivator. In the middle stage, since the cleaning effect was not achieved, 2 tons of passivator were automatically supplemented. In the later stage of the cleaning process, as the detected iron ion content tended to be stable and the change in iron ion content within two hours did not exceed 10%, the passivation cleaning was automatically judged to be completed. Using the present invention saves more than half of the planned cleaning time and 2 tons of the planned passivator dosage. Only 2 employees are required to complete the operation on site.

[0079] As Figure 5 shown, this embodiment also cleans the debutanizer and the top reflux drum T1101 / V1108 system:

[0080] On May 11th, the passivation cleaning was carried out using the cleaning device. At 17:00, industrial water and passivator were added to the debutanizer T1101 system according to the set ratio (Y = KX + B, K = 9, B = -5). At 20:00, a total of 9 tons of passivator were added to the system, and the total soaking time was 10 hours. At 6:30 on May 12th, the system started circulating cleaning. At 14:00 on May 12th, the cleaning device showed that the pH value of the system return water was 7.73 and the circulating water temperature was 27°C. The system was kept circulating until 23:00 on May 12th. During the cleaning process, the iron ion content and pH value of the cleaning solution were monitored, and the analysis results are shown in Table 2. It can be seen from this that the iron ion content in the debutanizer T1101 system was unstable in the initial stage. As the detected iron ion content tended to be stable and the change in iron ion content within two hours did not exceed 10%, the passivation cleaning was automatically judged to be completed.

[0081] Table 2: Changes in iron ion content and pH value

[0082] Online monitoring time pH value Iron ion content, ug / ml May 12th (6:30) 6.8 225.46 May 12th (10:00) 7.03 143.96 May 12th (12:00) 7.32 122.87 May 12th (14:00) 7.73 84.64 May 12th (16:00) 7.5 35.32 May 12th (21:00) 7.4 22.83 May 12th (22:00) 7.43 21.26 May 12th (23:00) 7.42 20.57

[0083] The above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent replacements or changes should be covered within the protection scope of the present invention.

Claims

1. A ferrous sulfide cleaning device, characterized in that, It includes a dissolution tank (21), an iron ion on-line monitor (4), a pH detector (5), a distribution box (46), a passivator liquid supply system, a water supply system, a circulating cleaning system, and a PLC control system (39) inside a box body (32); among them, the iron ion on-line monitor (4) is used to monitor the iron ion content in the passivator cleaning liquid in real time; the pH detector (5) is used to monitor the pH value in the passivator cleaning liquid in real time, the passivator liquid supply system is used to inject passivator liquid into the dissolution tank (21); the water supply system is used to inject industrial water into the dissolution tank (21); the circulating cleaning system is used to clean the equipment to be cleaned (30); the PLC control system (39) is used to accurately control the automatic proportioning and filling of industrial water and passivator liquid, and automatically judge whether the passivation cleaning is qualified, and the distribution box (46) is used to supply power to the electrical load.

2. The ferrous sulfide cleaning device according to claim 1, characterized in that, The dissolution tank (21) is provided with a water inlet. A safety valve (3) and a vent solenoid valve (35) are also installed at the top of the dissolution tank (21). A drain pipe (42) is installed at the bottom of the dissolution tank (21). A drain valve (22) is provided on the drain pipe (42). A magnetic flap level gauge B (49) is provided on the side of the dissolution tank (21). Ball valves D (50) are installed between both ends of the magnetic flap level gauge B (49) and the dissolution tank (21). A sampling valve (8), an instrument valve (13) and a pressure gauge (14) are also installed on the dissolution tank (21); the water supply system includes a water inlet pipe (41) connected to the water inlet and a pneumatic regulating ball valve (1) and an electromagnetic flowmeter A (2) on the water inlet pipe (41).

3. The ferrous sulfide cleaning device according to claim 2, characterized in that, The passivator liquid supply system includes an electric pump A (15), an electromagnetic flowmeter B (12), and a first pneumatic V-ball valve (11). The passivator liquid supply system provides passivator liquid through a passivator solution barrel (31). An electric pump A (15), an electromagnetic flowmeter B (12), and a first pneumatic V-ball valve (11) are sequentially installed on the pipeline between the passivator solution barrel (31) and the dissolution tank (21).

4. The ferrous sulfide cleaning device according to claim 3, characterized in that, A pneumatic diaphragm pump (20), a buffer tank (17) and a ball valve A (16) are also provided on the pipeline between the passivator solution barrel (31) and the electric pump A (15). A breather valve (37) and a breather port (36) are provided at the top of the buffer tank (17). A magnetic flap level gauge A (19) is also installed on the side of the buffer tank (17). A ball valve B (18) is also provided between both ends of the magnetic flap level gauge A (19) and the buffer tank (17). A first solenoid valve (28) is also provided between the pneumatic diaphragm pump (20) and the magnetic flap level gauge A (19); a ball valve E (40) is also provided at the bottom of the buffer tank (17).

5. The ferrous sulfide cleaning device according to claim 4, characterized in that, The circulating cleaning system includes a ball valve C (23), an electric pump B (24), a second pneumatic V-ball valve (25), an equipment to be cleaned (30), an integrated thermal resistor (9) and a filter A (7). A ball valve C (23), an electric pump B (24) and a second pneumatic V-ball valve (25) are successively installed on the circulating liquid outlet pipeline (43) between the outlet end of the dissolution tank (21) and the equipment to be cleaned (30); an integrated thermal resistor (9) and a filter A (7) are successively installed on the circulating liquid outlet pipeline (43) between the equipment to be cleaned (30) and the inlet end of the dissolution tank (21).

6. The ferrous sulfide cleaning device according to claim 5, characterized in that, The circulating cleaning system further includes a return pipeline (44). One end of the return pipeline (44) is communicated with the dissolution tank (21), and the other end is connected between the electric pump B (24) and the second pneumatic V-ball valve (25). A wafer check valve (27) is also installed on the return pipeline (44).

7. The ferrous sulfide cleaning device according to claim 5, characterized in that, The filter A (7) is in parallel with the filter B (47), and wafer check valves (6) are installed at both ends of the filter A (7) and the filter B (47).

8. The ferrous sulfide cleaning device according to claim 5, characterized in that, A glass window (29) is also provided on the circulating liquid outlet pipeline (43) between the integrated thermal resistor (9) and the equipment to be cleaned (30), and the glass window (29) is used to directly observe the liquid in the pipeline.

9. The ferrous sulfide cleaning device according to claim 6, characterized in that, The pH detector (5) is respectively installed at the inlet end and the outlet end of the dissolution tank (21), and the iron ion on-line monitor (4) is installed on the circulating liquid outlet pipeline (43) between the inlet end of the dissolution tank (21) and the pH detector (5). A sampling valve (8) is also installed on the circulating liquid outlet pipeline (43) between the iron ion on-line monitor (4) and the pH detector (5).

10. The ferrous sulfide cleaning device according to claim 9, characterized in that, The PLC control system (39) is electrically connected to an electromagnetic flowmeter A (2), an electromagnetic flowmeter B (12), an iron ion on-line monitor (4), a pH detector (5), an integrated thermal resistor (9), a magnetic flap level gauge A (19), a magnetic flap level gauge B (49), a first solenoid valve (28) and a vent solenoid valve (35) through a signal line (38); the electromagnetic flowmeter B (12) and an electric pump A (15) are also electrically connected through the signal line (38), and the electric pump A (15) can automatically adjust the opening degree according to the signal of the electromagnetic flowmeter B (12) through the PLC control system (39); the pneumatic regulating ball valve (1) and the electromagnetic flowmeter A (2) are electrically connected through the signal line (38), and the pneumatic regulating ball valve (1) automatically adjusts the opening degree according to the signal of the electromagnetic flowmeter A (2) through the PLC control system (39); the magnetic flap level gauge A (19) and the first solenoid valve (28) are electrically connected through the signal line (38), the magnetic flap level gauge B (49) and the second pneumatic V-ball valve (25) are electrically connected through the signal line (38), and the second pneumatic V-ball valve (25) automatically adjusts the opening degree according to the signal of the magnetic flap level gauge B (49) by the PLC control system (39).

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