Device and method for online cleaning of scale and pressure replenishment in the discharge pipeline of an iron removal autoclave

Abstract

The present invention discloses a device and method for online cleaning of scale and pressure supplementation in the discharge pipeline of an iron removal autoclave. The device includes: a feeding pump, a booster pump, a heat exchanger, an iron removal autoclave, a flash tank, and a discharge pipeline. The feeding pump is connected to the booster pump; the booster pump is connected to the heat exchanger; the discharge pipeline is located between the iron removal autoclave and the flash tank. The discharge pipeline includes a main pipeline and a branch pipeline. A first valve and a second valve are provided on the main pipeline. The first valve is close to the iron removal autoclave, and the second valve is close to the flash tank. The branch pipeline is connected to a high-pressure cleaner, and a fifth valve is provided on the branch pipeline; the heat exchanger is connected to the discharge pipeline through a conveying pipeline, a third valve is provided on the conveying pipeline, an emptying pipe is connected to the conveying pipeline, and a fourth valve is provided on the emptying pipe. Thus, the device of the present invention can remove scale in the discharge pipeline online and efficiently, and when using the device of the present invention for scale removal, it is not necessary to repeatedly raise and lower the temperature of the iron removal autoclave, avoiding damage to the iron removal autoclave.

Description

Technical Field

[0001] The present invention belongs to the field of metallurgical technology, and particularly relates to a device and method for online cleaning of scale and pressure replenishment in the discharge pipeline of an iron removal autoclave. Background Art

[0002] The iron removal process for hematite can achieve efficient separation of zinc and iron and resource utilization of iron in the zinc hydrometallurgy process. Its main equipment is an iron removal autoclave. After long-term operation of the iron removal autoclave, due to the process characteristics of forming hematite slag in the iron removal process and the characteristics that high-concentration metal ions such as zinc and iron are prone to crystallize and precipitate under high temperature and high pressure conditions, scale formation of hematite and other metal compounds in the discharge pipeline of the autoclave is likely to occur, which restricts the operation efficiency of the autoclave and affects production stability. Therefore, it is necessary to clean the discharge pipeline of the autoclave in a timely manner.

[0003] When cleaning the discharge pipeline of the autoclave, usually the autoclave is cooled and depressurized, then the discharge pipeline is removed, and then the discharge pipeline is cleaned. This not only takes a long time, but also repeated temperature rise and fall are extremely likely to cause damage to the autoclave body.

[0004] Therefore, it is necessary to improve the method for cleaning the scale of the discharge pipeline of the iron removal autoclave. Summary of the Invention

[0005] The present invention aims to at least partially improve at least one of the above technical problems.

[0006] The present invention provides a device for online cleaning of scale and pressure replenishment in the discharge pipeline of an iron removal autoclave. The device includes: a feeding pump, a booster pump, a heat exchanger, an iron removal autoclave, a flash tank, and a discharge pipeline. The feeding pump is connected to the booster pump; the booster pump is connected to the heat exchanger; the discharge pipeline is located between the iron removal autoclave and the flash tank. The discharge pipeline includes a main pipeline and a branch pipeline. A first valve and a second valve are provided on the main pipeline. The first valve is located on the side close to the iron removal autoclave, and the second valve is located on the side close to the flash tank. The branch pipeline is located on the side close to the flash tank. One end of the branch pipeline is connected to a high-pressure cleaner, and a fifth valve is provided on the branch pipeline; the heat exchanger is connected to the discharge pipeline through a conveying pipeline, a third valve is provided on the conveying pipeline, one end of an emptying pipe is connected to the conveying pipeline, and a fourth valve is provided on the emptying pipe. Thus, by using the device of the present invention, the scale in the discharge pipeline of the iron removal autoclave can be removed online and efficiently. Moreover, when using the device of the present invention for scale removal, it is not necessary to repeatedly raise and lower the temperature of the iron removal autoclave, avoiding damage to the iron removal autoclave. In addition, the device of the present invention also has the advantages of simple structure and convenient operation.

[0007] According to an embodiment of the present invention, the booster pump is a diaphragm pump; the heat exchanger includes a first sub-heat exchanger and a second sub-heat exchanger connected in series. The outlet of the booster pump is communicated with the inlet of the first sub-heat exchanger, the outlet of the first sub-heat exchanger is communicated with the inlet of the second sub-heat exchanger, and the outlet of the second sub-heat exchanger is connected to the conveying pipeline.

[0008] According to an embodiment of the present invention, the first sub-heat exchanger and the second sub-heat exchanger are shell-and-tube heat exchangers.

[0009] The present invention also provides a method for online cleaning of scale and pressure supplementation in the discharge pipeline of an iron removal autoclave by using the device described above. The method includes: closing the first valve, performing heat preservation and pressure maintenance shutdown on the iron removal autoclave; closing the second valve, opening the third valve and the fourth valve, and performing pressure relief and evacuation isolation on the discharge pipeline to be cleaned; opening the fifth valve, introducing a solvent at the inlet of the high-pressure cleaner, pressurizing the solvent by using the high-pressure cleaner, and introducing the pressurized solvent into the evacuated discharge pipeline to clean the scale on the discharge pipeline. The washed scale and solvent are discharged through the evacuation pipe; closing the fourth valve and the fifth valve, opening the second valve, introducing a filling liquid at the inlet of the feeding pump, passing the filling liquid through the heat exchanger to preheat the filling liquid, and using the preheated filling liquid to fill the cleaned discharge pipeline. After filling is completed, close the second valve, turn on the switch of the booster pump, and pressurize the discharge pipeline to meet the starting conditions of the iron removal autoclave.

[0010] According to an embodiment of the present invention, the solvent includes water; the pressure of the solvent flowing out from the outlet of the high-pressure cleaner is 70-100 Mpa.

[0011] According to an embodiment of the present invention, the temperature of the filling liquid introduced into the inlet of the feeding pump is 50-60 °C; the temperature of the filling liquid flowing out from the outlet of the heat exchanger is 90-95 °C; the filling liquid includes water or a dilute acid solution; when the filling liquid is a dilute acid solution, the pH of the filling liquid is 4-5.

[0012] According to an embodiment of the present invention, when the heat exchanger includes a first sub-heat exchanger and a second sub-heat exchanger connected in series, the difference between the temperature at the outlet of the first sub-heat exchanger and the temperature at the inlet of the first sub-heat exchanger is 20-25 °C, and the difference between the temperature at the outlet of the second sub-heat exchanger and the temperature at the inlet of the second sub-heat exchanger is 20-25 °C.

[0013] According to an embodiment of the present invention, the flow rate of the filling liquid is 10-15m 3 / h, and the filling time of the discharge pipeline is 5-10 min.

[0014] According to an embodiment of the present invention, the start-up conditions of the iron removal autoclave are as follows: the absolute value of the difference between the pressure in the discharge pipeline and the pressure in the iron removal autoclave is 0.2 to 0.3 Mpa; optionally, the start-up conditions of the iron removal autoclave are as follows: the pressure in the discharge pipeline is 0.2 to 0.3 Mpa higher than the pressure in the iron removal autoclave.

[0015] According to an embodiment of the present invention, the method further includes: when the start-up conditions of the iron removal autoclave are met, stop feeding the filling liquid, close the third valve, open the first valve and the second valve, and perform iron removal. Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of a device for online cleaning of scale and pressure compensation of the discharge pipeline of an iron removal autoclave in an embodiment of the present invention;

[0017] Figure 2 It is a schematic structural diagram of a device for online cleaning of scale and pressure compensation of the discharge pipeline of an iron removal autoclave in another embodiment of the present invention;

[0018] Figure 3 It is a flowchart of a method for online cleaning of scale and pressure compensation of the discharge pipeline of an iron removal autoclave in an embodiment of the present invention;

[0019] Figure 4 It is a flowchart of a method for online cleaning of scale and pressure compensation of the discharge pipeline of an iron removal autoclave in another embodiment of the present invention.

[0020] Description of the Reference Numerals

[0021] 100 - Feed pump, 200 - Booster pump, 300 - Heat exchanger, 310 - First sub - heat exchanger, 320 - Second sub - heat exchanger, 400 - Iron removal autoclave, 500 - Flash tank, 600 - Discharge pipeline, 600a - Main pipeline, 600b - Branch pipeline, 610 - First valve, 620 - Second valve, 630 - Fifth valve, 700 - Delivery pipeline, 710 - Third valve, 800 - Drain pipe, 810 - Fourth valve, 900 - High - pressure cleaner. Detailed Embodiments

[0022] The following will explain the solution of the present invention in combination with embodiments. Those skilled in the art will understand that the following embodiments are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. For those not specified in the embodiments regarding specific technologies or conditions, they shall be carried out according to the technologies or conditions described in the literature in the art or according to the product specifications.

[0023] The present invention provides a device for online cleaning of scale and pressure compensation of the discharge pipeline of an iron removal autoclave. Refer to Figure 1, the device includes: a feeding pump 100, a boosting pump 200, a heat exchanger 300, an iron removal autoclave 400, a flash tank 500, and a discharge pipeline 600. The feeding pump 100 is connected to the boosting pump 200; the boosting pump 200 is connected to the heat exchanger 300; the discharge pipeline 600 is located between the iron removal autoclave 400 and the flash tank 500. The discharge pipeline 600 includes a main pipeline 600a and a branch pipeline 600b. A first valve 610 and a second valve 620 are provided on the main pipeline 600a. The first valve 610 is located on the side close to the iron removal autoclave 400, and the first valve 610 is used to cut off or connect the iron removal autoclave 400 and the discharge pipeline 600. The second valve 620 is located on the side close to the flash tank 500, and the second valve 620 is used to cut off or connect the discharge pipeline 600 and the flash tank 500. The branch pipeline 600b is located on the side close to the flash tank 500. One end of the branch pipeline 600b is connected to a high-pressure cleaning machine 900. A fifth valve 630 is provided on the branch pipeline 600b, and the fifth valve 630 is used to cut off or connect the discharge pipeline 600 and the high-pressure cleaning machine 900; the heat exchanger 300 is connected to the discharge pipeline 600 through a conveying pipeline 700. A third valve 710 is provided on the conveying pipeline 700, and the third valve 710 is used to cut off or connect the conveying pipeline 700 and the discharge pipeline 600. One end of an emptying pipe 800 is connected to the conveying pipeline 700, and a fourth valve 810 is provided on the emptying pipe 800. Thus, by using the device of the present invention, the scale in the discharge pipeline 600 of the iron removal autoclave can be removed online and efficiently. Moreover, when using the device of the present invention for descaling, it is not necessary to repeatedly raise and lower the temperature of the iron removal autoclave, avoiding damage to the iron removal autoclave. In addition, the device of the present invention also has the advantages of simple structure and convenient operation.

[0024] According to an embodiment of the present invention, the boosting pump 200 is a diaphragm pump. Thus, the boosting pump 200 can play a role in boosting the filling liquid. Specifically, the diaphragm pump can be a piston diaphragm pump. Further, the piston diaphragm pump includes a front-end feeding port and a discharging port, and a pressure detection device is provided at the discharging port to check the pressure of the fluid flowing out of the piston diaphragm pump.

[0025] According to an embodiment of the present invention, referring to Figure 2 , the heat exchanger 300 includes a first sub-heat exchanger 310 and a second sub-heat exchanger 320 connected in series. The outlet of the boosting pump 200 is connected to the inlet of the first sub-heat exchanger 310. The outlet of the first sub-heat exchanger 310 is connected to the inlet of the second sub-heat exchanger 320. The outlet of the second sub-heat exchanger 320 is connected to the conveying pipeline 700.

[0026] According to an embodiment of the present invention, the first sub-heat exchanger 310 and the second sub-heat exchanger 320 are shell-and-tube heat exchangers.

[0027] It should be noted that, in addition to the structures described above, the device for online cleaning of scale and pressure compensation of the discharge pipeline of the iron removal autoclave may further include conventional structures, for example, it may further include connecting pipelines, valves, flow meters, and so on.

[0028] The present invention also provides a method for online cleaning of scale and pressure compensation of the discharge pipeline of the iron removal autoclave by using the device described above. Referring to Figure 3 , the method includes:

[0029] S100. Close the first valve 610, and perform heat preservation and pressure maintenance shutdown on the iron removal autoclave 400;

[0030] During the process of cleaning the scale in the discharge pipeline 600 of the present invention, it is not necessary to repeatedly heat up and cool down the iron removal autoclave 400. The first valve 610 can be closed, and the scale in the discharge pipeline 600 can be efficiently cleaned under the condition of ensuring heat preservation and pressure maintenance of the iron removal autoclave 400.

[0031] S200. Close the second valve 620, open the third valve 710 and the fourth valve 810, and perform pressure relief and evacuation isolation on the discharge pipeline 600 to be cleaned;

[0032] S300. Open the fifth valve 630, introduce a solvent at the inlet of the high-pressure cleaner 900, pressurize the solvent by using the high-pressure cleaner 900, and make the pressurized solvent flow into the evacuated discharge pipeline 600 to clean the scale on the discharge pipeline 600. The washed scale and solvent are discharged through the evacuation pipe 800;

[0033] In this step, the discharge pipeline 600 and the flash tank 500 are separated. This step can clean the discharge pipeline 600, and the washed scale and solvent are discharged from the evacuation pipe 800.

[0034] According to an embodiment of the present invention, the scale is mainly hematite slag formed by the iron removal reaction and other metal sulfate crystals.

[0035] According to an embodiment of the present invention, the solvent includes water.

[0036] According to an embodiment of the present invention, the pressure of the solvent flowing out from the outlet of the high-pressure cleaner 900 is 70-100 Mpa, such as 70 Mpa, 80 Mpa, 90 Mpa, 100 Mpa. The high-pressure solvent is beneficial to the flushing of the scale and can strengthen the cleaning effect of the scale.

[0037] S400. Close the fourth valve 810 and the fifth valve 630, open the second valve 620, introduce the filling liquid at the inlet of the feeding pump 100, make the filling liquid pass through the heat exchanger 300, preheat the filling liquid, and use the preheated filling liquid to fill the cleaned discharge pipeline 600. After the filling is completed, close the second valve 620, turn on the switch of the booster pump 200, and boost the pressure of the discharge pipeline 600 to meet the starting conditions of the iron removal autoclave 400.

[0038] In the filling step, it can play the roles of preheating the filling liquid, filling the discharge pipeline 600, and discharging the air in the discharge pipeline 600. It should be noted that when filling the cleaned discharge pipeline 600, the switch of the heat exchanger 300 needs to be turned on to preheat the filling liquid. The preheated filling liquid is transported to the discharge pipeline 600 through the conveying pipeline 700. In this step, the booster pump 200 only acts as a communicating vessel and does not pressurize the filling liquid.

[0039] According to an embodiment of the present invention, the temperature of the filling liquid introduced into the inlet of the feeding pump 100 is 50 - 60 °C.

[0040] According to some embodiments of the present invention, the heat exchanger 300 may further include a heat medium inlet and a heat medium outlet. When the filling liquid flows through the heat exchanger 300, the heat medium can be introduced into the heat medium inlet of the heat exchanger 300, so that the heat medium with a higher temperature exchanges heat with the filling liquid with a lower temperature in the heat exchanger 300 to increase the temperature of the filling liquid. Specifically, the heat medium can be steam, the pressure of the heat medium can be 2 - 4 bar, such as 2 bar, 3 bar, 4 bar, and the temperature of the heat medium can be 155 - 175 °C, such as 155 °C, 160 °C, 165 °C, 170 °C, 175 °C.

[0041] According to an embodiment of the present invention, the temperature of the filling liquid flowing out of the outlet of the heat exchanger 300 is 90 - 95 °C. Since the temperature inside the iron removal autoclave 400 is relatively high, if the temperature of the filling liquid flowing out of the outlet of the heat exchanger 300 is too low, when the solution inside the iron removal autoclave 400 comes into contact with the solution in the discharge pipeline 600 after the scale cleaning is completed and the first valve 610 is opened, problems such as expansion and foaming will occur. If the temperature of the filling liquid flowing out of the outlet of the heat exchanger 300 is too high, it is easy to shorten the service life of equipment, pipelines, etc.

[0042] According to an embodiment of the present invention, the filling liquid includes water or a dilute acid solution. Using water or a dilute acid solution as the filling liquid can play the roles of filling the discharge pipeline 600 and discharging the air in the discharge pipeline 600.

[0043] When the filling liquid is a dilute acid solution, the pH of the filling liquid is 4 - 5. The dilute acid solution is a medium required for the reaction in the iron removal autoclave 400. This medium can also be used as the filling liquid to fill the discharge pipeline 600, expel the air in the discharge pipeline 600, and increase the pressure of the discharge pipeline 600.

[0044] According to an embodiment of the present invention, referring to Figure 2 , when the heat exchanger 300 includes a first sub - heat exchanger 310 and a second sub - heat exchanger 320 connected in series, the difference between the temperature at the outlet of the first sub - heat exchanger 310 and the temperature at the inlet of the first sub - heat exchanger 310 is 20 - 25 °C, and the difference between the temperature at the outlet of the second sub - heat exchanger 320 and the temperature at the inlet of the second sub - heat exchanger 320 is 20 - 25 °C.

[0045] According to an embodiment of the present invention, the flow rate of the filling liquid is 10 - 15 m 3 / h. For example, it can be 10 m 3 / h, 11 m 3 / h, 12 m 3 / h, 13 m 3 / h, 14 m 3 / h, 15 m 3 / h. Thus, the discharge pipeline 600 can be filled in a relatively short time.

[0046] According to an embodiment of the present invention, the filling time of the discharge pipeline 600 is 5 - 10 min. The filling time of the discharge pipeline 600 refers to the time from starting to pass the filling liquid from the feeding pump 100 into the discharge pipeline 600 until the discharge pipeline 600 is filled with the filling liquid. And when starting to pass the filling liquid from the feeding pump 100, it is necessary to turn on the heat exchange switch of the heat exchanger 300 and pass a hot medium with a higher temperature from the hot medium inlet of the heat exchanger 300. Then, after the filling liquid enters the heat exchanger 300, the hot medium with a higher temperature can exchange heat with the filling liquid to pre - heat the filling liquid.

[0047] According to an embodiment of the present invention, a pressure sensor is provided in the discharge pipeline 600. The pressure sensor is arranged at the outlet of the discharge pipeline 600, that is, on the side close to the flash tank 500, and is used to detect the pressure of the fluid in the discharge pipeline 600. As the filling liquid enters the discharge pipeline 600, the pressure of the pressure sensor in the discharge pipeline 600 increases. Through the pressure value of the pressure sensor, the filling degree of the filling liquid in the discharge pipeline 600 can be judged. When the pressure of the pressure sensor reaches the specified pressure value, it indicates that the discharge pipeline 600 is filled with the filling liquid.

[0048] According to some embodiments of the present invention, when the filling liquid fills the discharge pipeline 600, that is, after the filling is completed, the switch of the booster pump 200 is turned on, and the booster pump 200 is used to boost the pressure of the discharge pipeline 600 to meet the starting conditions of the iron removal autoclave 400.

[0049] According to an embodiment of the present invention, the starting conditions of the iron removal autoclave 400 are as follows: the absolute value of the difference between the pressure in the discharge pipeline 600 and the pressure in the iron removal autoclave 400 is 0.2 - 0.3 Mpa. If the absolute value of the difference between the pressure in the discharge pipeline 600 and the pressure in the iron removal autoclave 400 is too small or too large, when the first valve 610 is opened to resume normal production, due to the too large pressure difference, the first valve 610 is likely to vibrate, and safety accidents such as solution leakage are likely to occur.

[0050] Specifically, the starting conditions of the iron removal autoclave 400 are as follows: the pressure in the discharge pipeline 600 is 0.2 - 0.3 Mpa higher than the pressure in the iron removal autoclave 400. Thus, the pressure of the discharge pipeline 600 can be compensated, which is convenient for the normal operation of the iron removal process after the first valve 610 is opened.

[0051] According to an embodiment of the present invention, the method further includes: S500. When the starting conditions of the iron removal autoclave 400 are met, stop feeding the filling liquid, close the third valve 710, open the first valve 610 and the second valve 620, and perform iron removal. In this step, the feeding pump 100, the booster pump 200, and the heat exchanger 300 also need to be closed. Thus, by using the method of the present invention, the scale in the discharge pipeline 600 of the autoclave can be efficiently cleaned and the normal production can be safely resumed under the condition of heat preservation and pressure maintenance of the iron removal autoclave 400. Moreover, the time from step S100 to step S500 of the present invention is 2 - 3 h, that is, by using the method of the present invention, the scale in the discharge pipeline 600 can be efficiently removed in a relatively short time, and the impact on normal production is small.

[0052] Compared with the existing method of cleaning the scale in the discharge pipeline 600 after reducing the temperature and pressure of the iron removal autoclave 400, by using the method of the present application, on the one hand, the time required for maintenance is significantly reduced, from 24 - 30 h in the traditional method to 2 - 3 h, and on the other hand, the damage to the autoclave body of the iron removal autoclave caused by frequent temperature rise and fall is avoided. Thus, by using this method, the scale in the discharge pipeline of the iron removal autoclave can be efficiently cleaned and the pipeline pressure can be compensated.

[0053] Next, the present invention will be described with reference to specific embodiments. It should be noted that these embodiments are only descriptive and do not limit the present invention in any way.

[0054] Embodiment 1

[0055] Reference Figure 2, The device for online cleaning of scale and pressure replenishment in the discharge pipeline of the iron removal autoclave includes a feeding pump 100, a booster pump 200, a first sub-heat exchanger 310, a second sub-heat exchanger 320, an iron removal autoclave 400, and related pipeline valves and detection instruments. The outlet of the feeding pump 100 is connected to the inlet of the booster pump 200, the outlet of the booster pump 200 is connected to the inlet of the first sub-heat exchanger 310, the outlet of the first sub-heat exchanger 310 is connected to the inlet of the second sub-heat exchanger 320. The booster pump 200 is used to boost the filling liquid, and the first sub-heat exchanger 310 and the second sub-heat exchanger 320 are used to perform gradient heating on the filling liquid. A pressure detection device is provided at the outlet of the booster pump 200. The outlet of the second sub-heat exchanger 320 is connected to the discharge pipeline 600 through pipelines and valves. The discharge pipeline 600 includes a main pipeline 600a and a branch pipeline 600b. A first valve 610 and a second valve 620 are provided on the main pipeline 600a. The first valve 610 is located on the side close to the iron removal autoclave 400, and the second valve 620 is located on the side close to the flash tank 500. The branch pipeline 600b is located on the side close to the flash tank 500. One end of the branch pipeline 600b is connected to the high-pressure cleaner 900, and a fifth valve 630 is provided on the branch pipeline 600b; the heat exchanger 300 is connected to the discharge pipeline 600 through a conveying pipeline 700, and a third valve 710 is provided on the conveying pipeline 700. One end of the emptying pipe 800 is connected to the conveying pipeline 700, and a fourth valve 810 is provided on the emptying pipe 800. The high-temperature and high-pressure filling liquid enters the discharge pipeline 600 for filling, preheating and pressurization to meet the start-up conditions of the iron removal autoclave 400. A pressure detection device is provided on the discharge pipeline 600 to judge that the pressure in the discharge pipeline 600 is 0.2 - 0.3 Mpa higher than the pressure in the iron removal autoclave 400.

[0056] A method for online cleaning of scale and pipeline pressure replenishment in the discharge pipeline of an iron removal autoclave, the method includes:

[0057] (1) Close the first valve 610, and keep the iron removal autoclave 400 connected to the discharge pipeline 600 to be cleaned under heat preservation and pressure maintenance for shutdown. At this time, the iron removal autoclave 400 is in a high-temperature and high-pressure state;

[0058] Close the second valve 620, open the third valve 710 and the fourth valve 810, and relieve the pressure and empty the discharge pipeline 600 to be cleaned for isolation, so that the discharge pipeline 600 is in a normal temperature and empty state and has the conditions for cleaning;

[0059] (2) Open the fifth valve 630, let water flow in at the inlet of the high-pressure cleaner 900, pressurize the water, and make the high-pressure water enter the emptied discharge pipeline 600 in step (1) for physical cleaning, ensuring that the pressure of the high-pressure water is 70 Mpa to achieve the purpose of cleaning the scale in the discharge pipeline 600;

[0060] (3) Close the fourth valve 810 and the fifth valve 630, and use the filling liquid to preheat, fill, and pressurize the discharge pipeline 600 after cleaning in step (2) to meet the start-up conditions of the autoclave, where the temperature of the filling liquid after heating is 90 °C. The method includes: After the scale cleaning is completed, use the filling liquid to fill the discharge pipeline 600, and use the first sub-heat exchanger 310 and the second sub-heat exchanger 320 to heat the filling liquid. Use the preheated filling liquid to fill the cleaned discharge pipeline 600 to discharge the air in the discharge pipeline 600. After filling is completed, close the second valve 620, and use the booster pump 200 to pressurize the discharge pipeline 600 to meet the start-up conditions of the autoclave. The start-up conditions of the autoclave are: the pressure in the discharge pipeline 600 is 0.2 Mpa higher than the pressure in the iron removal autoclave 400.

[0061] In Example 1, the total time from step (1) to step (3) is 2 to 3 hours. After step (3) is completed, the first valve 610 and the second valve 620 can be opened to resume normal production.

[0062] Example 2

[0063] The device for online cleaning of scale and pressure compensation of the discharge pipeline of the iron removal autoclave has the same structure as the device in Example 1.

[0064] A method for online cleaning of scale and pressure compensation of the discharge pipeline of an iron removal autoclave, the method includes:

[0065] (1) Close the first valve 610, and keep the iron removal autoclave 400 connected to the discharge pipeline 600 to be cleaned under heat preservation and pressure maintenance for parking. At this time, the iron removal autoclave 400 is in a high-temperature and high-pressure state;

[0066] Close the second valve 620, open the third valve 710 and the fourth valve 810, and relieve the pressure and evacuate and isolate the discharge pipeline 600 to be cleaned, so that the discharge pipeline 600 is in a normal temperature evacuated state and has the conditions for cleaning;

[0067] (2) Open the fifth valve 630, let water flow in at the inlet of the high-pressure cleaner 900, pressurize the water, and make the high-pressure water flow into the evacuated discharge pipeline 600 in step (1) for physical cleaning, ensuring that the pressure of the high-pressure water is 80 Mpa to achieve the purpose of cleaning the scale in the discharge pipeline 600;

[0068] (3) Close the fourth valve 810 and the fifth valve 630, and use the filling liquid to preheat, fill, and pressurize the discharge pipeline 600 after cleaning in step (2) to meet the start-up conditions of the autoclave, where the temperature of the filling liquid after heating is 95 °C. The method includes: after the scale cleaning is completed, use the filling liquid to fill the discharge pipeline 600, and use the first sub-heat exchanger 310 and the second sub-heat exchanger 320 to heat the filling liquid, and use the preheated filling liquid to fill the cleaned discharge pipeline 600 to discharge the air in the discharge pipeline 600. After the filling is completed, close the second valve 620, and use the booster pump 200 to pressurize the discharge pipeline 600 to meet the start-up conditions of the autoclave. The start-up conditions of the autoclave are: the pressure of the discharge pipeline 600 is 0.3 Mpa higher than the pressure in the iron removal autoclave 400.

[0069] The total time for steps (1) to (3) in Example 2 is 2 to 3 hours. After step (3) is completed, the first valve 610 and the second valve 620 can be opened to resume normal production.

[0070] Example 3

[0071] The device for online cleaning of scale and pressure replenishment of the discharge pipeline of the iron removal autoclave has the same structure as the device in Example 1.

[0072] A method for online cleaning of scale and pressure replenishment of the discharge pipeline of an iron removal autoclave, the method includes:

[0073] (1) Close the first valve 610, and keep the iron removal autoclave 400 connected to the discharge pipeline 600 to be cleaned under heat preservation and pressure maintenance for parking. At this time, the iron removal autoclave 400 is in a high-temperature and high-pressure state;

[0074] Close the second valve 620, open the third valve 710 and the fourth valve 810, and relieve the pressure and evacuate and isolate the discharge pipeline 600 to be cleaned, so that the discharge pipeline 600 is in a normal-temperature evacuated state and has the conditions for cleaning;

[0075] (2) Open the fifth valve 630, let water flow in at the inlet of the high-pressure cleaner 900, pressurize the water, and make the high-pressure water flow into the evacuated discharge pipeline 600 in step (1) for physical cleaning, ensuring that the pressure of the high-pressure water is 100 Mpa to achieve the purpose of cleaning the scale in the discharge pipeline 600;

[0076] (3) Close the fourth valve 810 and the fifth valve 630, and use the filling liquid to preheat, fill, and pressurize the discharge pipeline 600 after cleaning in step (2) to meet the autoclave startup conditions, where the temperature of the filling liquid after heating is 95°C. The method includes: after the scale cleaning is completed, use the filling liquid to fill the discharge pipeline 600, and use the first sub-heat exchanger 310 and the second sub-heat exchanger 320 to heat the filling liquid, and use the preheated filling liquid to fill the cleaned discharge pipeline 600 to discharge the air in the discharge pipeline 600. After the filling is completed, close the second valve 620, and use the booster pump 200 to pressurize the discharge pipeline 600 to meet the autoclave startup conditions. The autoclave startup conditions are: the pressure of the discharge pipeline 600 is 0.25 Mpa higher than the pressure in the iron removal autoclave 400.

[0077] The total time for steps (1) to (3) in Example 3 is 2 to 3 hours. After step (3) is completed, the first valve 610 and the second valve 620 can be opened to resume normal production.

[0078] It should be noted that in this specification, the terms "first", "second", "third", "fourth", and "fifth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features.

[0079] In the description of this specification, the description with reference to terms such as "one embodiment", "another embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0080] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. An on-line device for cleaning scale and supplementing pressure in the discharging pipeline of an iron removal autoclave, characterized in that, The device includes: A feeding pump; A booster pump, the feeding pump being connected to the booster pump; A heat exchanger, the booster pump being connected to the heat exchanger; An iron removal autoclave; A flash tank; A discharge pipeline, the discharge pipeline being located between the iron removal autoclave and the flash tank. The discharge pipeline includes a main pipeline and a branch pipeline. A first valve and a second valve are provided on the main pipeline. The first valve is located on the side close to the iron removal autoclave, and the second valve is located on the side close to the flash tank. The branch pipeline is located on the side close to the flash tank. One end of the branch pipeline is connected to a high-pressure cleaner, and a fifth valve is provided on the branch pipeline; the heat exchanger is connected to the discharge pipeline through a conveying pipeline. A third valve is provided on the conveying pipeline. One end of an emptying pipe is connected to the conveying pipeline, and a fourth valve is provided on the emptying pipe.

2. The device according to claim 1, characterized in that The booster pump is a diaphragm pump; The heat exchanger includes a first sub-heat exchanger and a second sub-heat exchanger connected in series. The outlet of the booster pump is connected to the inlet of the first sub-heat exchanger. The outlet of the first sub-heat exchanger is connected to the inlet of the second sub-heat exchanger. The outlet of the second sub-heat exchanger is connected to the conveying pipeline.

3. The device according to claim 2, characterized in that The first sub-heat exchanger and the second sub-heat exchanger are shell-and-tube heat exchangers.

4. A method for online cleaning of scale and pressure replenishment in the discharge pipeline of an iron removal autoclave using the device according to any one of claims 1 to 3, characterized in that, The method includes: Closing the first valve and performing heat preservation and pressure maintenance shutdown on the iron removal autoclave; Closing the second valve, opening the third valve and the fourth valve, and performing pressure relief and evacuation isolation on the discharge pipeline to be cleaned; Opening the fifth valve, introducing a solvent at the inlet of the high-pressure cleaner, pressurizing the solvent by the high-pressure cleaner, and introducing the pressurized solvent into the evacuated discharge pipeline to clean the scale on the discharge pipeline. The washed scale and the solvent are discharged through the emptying pipe; Closing the fourth valve and the fifth valve, opening the second valve, introducing a filling liquid at the inlet of the feeding pump, passing the filling liquid through the heat exchanger to preheat the filling liquid, and using the preheated filling liquid to fill the cleaned discharge pipeline. After filling is completed, closing the second valve and turning on the switch of the booster pump to pressurize the discharge pipeline to meet the start-up conditions of the iron removal autoclave.

5. The method according to claim 4, characterized in that, The solvent includes water; The pressure of the solvent flowing out from the outlet of the high-pressure cleaner is 70-100 Mpa.

6. The method according to claim 4, characterized in that, The temperature of the filling liquid introduced into the inlet of the feeding pump is 50-60 °C; The temperature of the filling liquid flowing out from the outlet of the heat exchanger is 90-95 °C; The filling liquid includes water or a dilute acid solution; When the filling liquid is a dilute acid solution, the pH of the filling liquid is 4-5.

7. The method according to claim 6, characterized in that, When the heat exchanger includes a first sub-heat exchanger and a second sub-heat exchanger connected in series, the difference between the temperature at the outlet of the first sub-heat exchanger and the temperature at the inlet of the first sub-heat exchanger is 20-25 °C, and the difference between the temperature at the outlet of the second sub-heat exchanger and the temperature at the inlet of the second sub-heat exchanger is 20-25 °C.

8. The method according to claim 4, characterized in that, The flow rate of the filling liquid is 10 to 15 m 3 / h, and the filling time of the discharge pipeline is 5 to 10 min.

9. The method according to claim 4, characterized in that The start-up conditions of the iron removal autoclave are: the absolute value of the difference between the pressure in the discharge pipeline and the pressure in the iron removal autoclave is 0.2-0.3 Mpa.

10. The method according to claim 4, characterized in that The starting conditions of the iron removal autoclave are as follows: the pressure in the discharge pipeline is 0.2 - 0.3 Mpa higher than the pressure inside the iron removal autoclave.

11. The method according to claim 4, characterized in that, The method further includes: when the starting conditions of the iron removal autoclave are met, stop feeding the filling liquid, close the third valve, open the first valve and the second valve, and perform iron removal.

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