Condensed water on-line monitoring and sampling device for phosphoric acid concentration system

Abstract

The invention relates to the technical field of phosphoric acid concentration production, in particular to a condensed water on-line monitoring and sampling device for a phosphoric acid concentration system, which comprises a condensed water storage tank, a condensed water heat exchanger, a balance container I and a balance container II which are connected in sequence, the balance container I is horizontally arranged, the end of the balance container I is connected with a conductivity meter, a cooling medium of the condensed water heat exchanger is process water, and the balance container II is vertically arranged and a manual sampling port is formed in a water outlet in the top of the balance container II. Condensed water is temporarily stored through the condensed water storage tank, the condensed water is further subjected to heat exchange with process water through the condensed water heat exchanger, steam is further condensed, gas in the condensed water is further stably discharged through the horizontally-arranged balance container I and the vertically-arranged balance container II, and meanwhile stable sampling and discharging of the condensed water are ensured. The influence of a steam-water mixing state on conductivity measurement is avoided, and the monitoring stability of a conductivity meter and the safety of manual sampling are improved.

Description

Technical Field

[0001] The invention relates to the technical field of phosphoric acid concentration production, in particular to an online condensate water monitoring and sampling device for a phosphoric acid concentration system. Background Art

[0002] The concentration of dilute phosphoric acid prepared after the decomposition of phosphate slurry is relatively low. After purification, it needs to be concentrated to meet the use requirements of subsequent processes. In the process of dilute phosphoric acid concentration, a graphite heat exchanger is generally used to exchange heat with dilute phosphoric acid through low-pressure steam. The heated dilute phosphoric acid enters the flash evaporator for concentration, and part of it enters the graphite heat exchanger as circulating acid to repeat the concentration process. After the low-pressure steam is condensed, condensate will be produced. This low-pressure steam is a by-product in the sulfur-to-sulfuric acid system. After heat exchange, the condensate returns to the desalted water process of the sulfur-to-sulfuric acid system for recycling. In order to ensure that the condensate meets the use requirements, sampling is generally carried out at the condensate storage tank and its conductivity is tested. Because the condensate is in a mixed state of steam and water, the measured data fluctuates greatly. At the same time, there are certain safety hazards in manual sampling. Therefore, a condensate online monitoring and sampling device is continued to be developed. Summary of the invention

[0003] The object of the present invention is to provide an online monitoring and sampling device for condensate water in a phosphoric acid concentration system, so as to solve the problems of large fluctuations in the existing condensate water conductivity measurement and high risk of manual sampling.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: an online monitoring and sampling device for condensate water in a phosphoric acid concentration system, characterized in that it comprises a condensate water storage tank, a condensate water heat exchanger, a balance container I, and a balance container II which are connected in sequence, the condensate water storage tank is connected to the condensate water outlet of the graphite heat exchanger, the balance container I is horizontally arranged and a conductivity meter is connected to the end thereof, the cooling medium of the condensate water heat exchanger is process water, the balance container II is vertically arranged and an artificial sampling port is arranged at the water outlet at the top.

[0005] Preferably, the condensate heat exchanger is a horizontally arranged hollow tube body, a first baffle is vertically arranged downward near the inlet end of the condensate heat exchanger, a second baffle is vertically arranged upward near the outlet end of the condensate heat exchanger, and a heat exchange coil is arranged between the first baffle and the second baffle.

[0006] Preferably, the heat exchange coil comprises, from top to bottom, a connected upper coil, a spiral tube and a lower coil, the upper coil and the lower coil are both horizontally arranged serpentine tubes, the process water inlet and the process water outlet of the heat exchange coil are arranged on the flange connection structure at the top of the condensate heat exchanger, and are respectively connected to the process water supply device and the circulating water station.

[0007] Preferably, the balance container I is a horizontally arranged hollow tube with a water inlet at one end and a conductivity meter connected to the other end. An upward vertical baffle is arranged in the middle of the bottom of the balance container I, and a water outlet is arranged at the top of the balance container I near the conductivity meter.

[0008] Preferably, the balancing container II is a vertically arranged hollow tube with a water inlet at the bottom and a water outlet at the top. A third baffle is horizontally arranged in the middle of the balancing container II. The third baffle is a circular plate and is coaxially arranged with the balancing container II. The third baffle is connected to the inner wall of the balancing container II through a connecting rod.

[0009] Preferably, the connecting rods are provided in four pieces and are in strip shape and evenly distributed radially along the third baffle.

[0010] Preferably, the graphite heat exchanger is provided with an acid inlet, an acid outlet and a low-pressure steam inlet, the condensate storage tank uses part of the condensate as desalted water through a water pump, the condensate storage tank is connected to the inlet end of the condensate heat exchanger through a 1# valve, the outlet end of the condensate heat exchanger is connected to the water inlet of the balance container I through a 2# valve, the water outlet of the balance container I is connected to the water inlet of the balance container II through a 3# valve, the water outlet of the balance container II is connected to the artificial sampling port through a 4# valve, and the water outlet of the balance container II is connected to the drainage device through a 5# valve.

[0011] Preferably, a 8# valve is provided at the bottom of the condensate heat exchanger, the process water inlet of the heat exchange coil is connected to the process water supply device through a 7# valve, and the process water outlet of the heat exchange coil is connected to the circulating water station through a 6# valve.

[0012] Preferably, the operating method of the device comprises the following steps:

[0013] S1. Using low-pressure steam with a temperature of ≤180°C and a pressure of ≤0.7MPa from the sulfuric acid system, after cooling and reducing pressure, the low-pressure steam with a temperature of ≤139°C and a pressure of ≤0.25MPa is sent to the graphite heat exchanger to heat the dilute phosphoric acid;

[0014] S2. Control the temperature of the dilute phosphoric acid at 75 to 87 ° C to concentrate the dilute phosphoric acid;

[0015] S3. Low-pressure steam continuously exchanges heat with dilute phosphoric acid, and the steam temperature is ≤100℃ to form condensate mixed with steam and water, which is stored in a condensate storage tank. Part of the condensate is pumped to the desalted water process of sulfuric acid production, and part of it enters the sampling and monitoring link under the condensate's own pressure;

[0016] S4. Open valve 7# to allow process water to enter the heat exchange coil of the condensate heat exchanger, open valve 8# to observe whether there is any leakage in the heat exchange coil, close valve 8# after confirming that there is no leakage, and open valve 6#;

[0017] S5. Make the process water flow through, and the process water flowing out of the condensate heat exchanger flows into the circulating water station;

[0018] S6. When the process water is put into use normally, open valves 2# and 3# in sequence, close valve 4#, open valve 5# by 10%, and slowly open valve 1# by 10%;

[0019] S7. Measure the surface temperature of balance container I and balance container II. When the temperature rises, pay attention to whether there is condensed water discharged from valve 5#;

[0020] S8. When condensate is discharged from the 5# valve, slowly open the 1# valve and observe whether there is splashing at the 5# valve outlet. If there is splashing, adjust the opening of the 5# valve until there is no splashing at the outlet.

[0021] S9. After the condensate is drained normally, slowly open valve 4# for manual sampling;

[0022] S10. After sampling, conduct conductivity analysis on the condensed water and compare it with the online conductivity meter.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: a condensate online monitoring and sampling device for a phosphoric acid concentration system with a simple structure and convenient control is provided, condensate is temporarily stored in a condensate storage tank, condensate is further heat-exchanged with process water through a condensate heat exchanger, steam therein is further condensed, gas in the condensate is further smoothly discharged through a horizontally arranged balance container I and a vertically arranged balance container II, while ensuring smooth sampling and discharge of condensate, avoiding the influence of the steam-water mixing state on the conductivity measurement, improving the stability of conductivity meter monitoring and the safety of manual sampling, and at the same time, the reduction in condensate temperature reduces the material requirements of the conductivity meter, reduces procurement costs and effectively prolongs the service life of the conductivity meter, which is more practical in actual production.

[0024] In the condensate heat exchanger, a baffle is set vertically downward at the inlet. After the condensate combined with steam and water enters, the gas will impact on the baffle to avoid airflow impact; the condensate exchanges heat with the process water in the heat exchange coil section, and the heat exchange area is greatly increased through the serpentine tubes and the middle spiral tubes set parallel to each other up and down, thereby improving the heat exchange efficiency; and then the baffle set vertically upward at the outlet overflows to keep the liquid level entering the balance container stable, further reducing the impact of gas impact.

[0025] Balance container I is set horizontally and a baffle is set in the middle to further stabilize the liquid level, making the liquid level measured by the conductivity meter more stable and the measured data more accurate. Balance container II is set vertically and has a baffle and water outlet on the top to further prevent liquid level fluctuations caused by air pressure and ensure the safety of manual sampling and drainage stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they provide further detailed explanations but do not constitute a limitation of the present invention.

[0027] Figure 1 It is a schematic diagram of the process of the present invention;

[0028] Figure 2 It is a schematic diagram of the condensate heat exchanger in the present invention;

[0029] Figure 3 It is a schematic diagram of the structure of the heat exchange coil of the present invention;

[0030] Figure 4 This is a schematic diagram of the installation structure of the baffles in the balance container I of the present invention;

[0031] Figure 5 This is a schematic diagram of the installation structure of the baffles in the balance container II of the present invention;

[0032] The meaning of each number in the figure:

[0033] 1. Graphite heat exchanger, 2. Condensate storage tank, 3. Water pump, 4. Condensate heat exchanger, 401. First baffle, 402. Second baffle, 5. Balance container I, 501. Vertical baffle, 6. Conductivity meter, 7. Balance container II, 701- Third baffle, 8. Heat exchange coil, 81. Upper coil, 82. Spiral tube, 83. Lower coil. DETAILED DESCRIPTION

[0034] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0035] Example

[0036] Figure 1-5 The invention shows an online monitoring and sampling device for condensate water in a phosphoric acid concentration system, comprising a condensate water storage tank 2, a condensate water heat exchanger 4, a balance container I5 and a balance container II7 which are connected in sequence. The condensate water storage tank 2 is connected to the condensate water outlet of the graphite heat exchanger 1. The balance container I5 is arranged horizontally and a conductivity meter 6 is connected to the end thereof. The cooling medium of the condensate water heat exchanger 4 is process water. An artificial sampling port is arranged at the water outlet of the balance container II7.

[0037] The graphite heat exchanger 1 is provided with an acid inlet, an acid outlet, and a low-pressure steam inlet. The condensate storage tank 2 uses part of the condensate as desalted water through a water pump. The condensate storage tank 2 is connected to the inlet end of the condensate heat exchanger 4 through a 1# valve, and the outlet end of the condensate heat exchanger 4 is connected to the water inlet of the balance container I5 through a 2# valve. The water outlet of the balance container I5 is connected to the water inlet of the balance container II7 through a 3# valve, and the water outlet of the balance container II7 is connected to the artificial sampling port through a 4# valve, and the water outlet of the balance container II7 is connected to the drainage device through a 5# valve.

[0038] The bottom of the condensate heat exchanger 4 is provided with a 8# valve, the process water inlet of the heat exchange coil 8 is connected to the process water supply device through a 7# valve, and the process water outlet of the heat exchange coil 8 is connected to the circulating water station through a 6# valve.

[0039] The condensate heat exchanger 4 is a horizontally arranged hollow tube body, a first baffle 401 is arranged vertically downward near the inlet end of the condensate heat exchanger 4, a second baffle 402 is arranged vertically upward near the outlet end of the condensate heat exchanger 4, and a heat exchange coil 8 is arranged between the first baffle 401 and the second baffle 402.

[0040] The heat exchange coil 8 includes, from top to bottom, an upper coil 81, a spiral tube 82 and a lower coil 83 which are connected to each other. The upper coil 81 and the lower coil 83 are both horizontally arranged serpentine tubes. The process water inlet and the process water outlet of the heat exchange coil 8 are arranged on the flange connection structure at the top of the condensate heat exchanger 4, and are respectively connected to the process water supply device and the circulating water station.

[0041] A φ25×2.5 pipe is connected to the tank body of the condensate storage tank 2 to lead out the condensate, and then transport it to the condensate heat exchanger 4. The condensate heat exchanger 4 uses a φ219×9.5 stainless steel pipe to prepare a 600mm long equal-diameter tee. Both ends are blocked with blind plates and set with water inlets and outlets. A small opening is opened on the top and a flange is set. The flange is fixed with a blind plate. Two φ25mm holes are opened on the blind plate as process water inlets. The heat exchange area prepared by the 1.5-meter φ25×2.5 pipe is 0.0785m 2 The heat exchange coil 8 is installed on the blind plate, and the connection between the blind plate and the heat exchange coil 8 is fixed by welding. The first baffle 401 and the second baffle 402 are welded at 100mm from the inlet end and 100mm from the outlet end, respectively, and the first baffle 401 and the second baffle 402 are 6mm thick.

[0042] It is worth noting that the heat exchange coil 8 is made of a φ25×2.5 pipe, and the overall heat exchange coil is arranged in a φ219×9.5 stainless steel pipe using a serpentine pipe + a spiral pipe. Figure 3 As shown, the heat exchange coil 8 includes an upper coil 81, a spiral tube 82 and a lower coil 83, which are connected in sequence.

[0043] The balance container I5 is a horizontally arranged hollow tube, one end of which is a water inlet and the other end is connected to a conductivity meter 6. An upward vertical baffle 501 is arranged in the middle of the bottom of the balance container I5, and a water outlet is arranged on the top of the balance container I5 near the conductivity meter 6. The balance container II7 is a vertically arranged hollow tube, the bottom of which is a water inlet and the top of which is a water outlet. A third baffle 701 is arranged horizontally and coaxially in the middle of the balance container II7. The third baffle 701 is a circular plate, which is connected to the inner wall of the balance container II7 by connecting rods 702 evenly distributed along the radial direction of the balance container II7. The third baffle 701 and the connecting rod 702 further stabilize the liquid level and divert the non-condensable gas. The condensed water fills the balance container, which effectively reduces the influence of the non-condensable gas on the conductivity measurement and improves the accuracy of the conductivity measurement; at the same time, the temperature of the condensed water is reduced, the safety of manual sampling is also improved, and the use time of the conductivity meter is extended.

[0044] Specifically, on the outlet pipe of the condensate heat exchanger 4, two balancing containers with a length of 200 mm were made using φ109×4.5 pipes, in which balancing container I5 was installed horizontally and balancing container II6 was installed vertically, so that the condensate maintains a stable liquid level in the balancing container, and process valves are added to the heat exchanger, balancing container, process water inlet and outlet, and sampling port for control.

[0045] In addition, if Figure 4 As shown, the balance container Ⅰ5 is 200 mm long, and a 50 mm high vertical baffle 501 is set in the middle of the horizontal position. The vertical baffle 501 is a stainless steel plate with a thickness of 6 mm. The liquid outlet of the balance container Ⅰ5 is set at 150 mm from the inlet, and the conductivity meter is installed at 50 mm in the vertical direction of the balance container Ⅰ5.

[0046] like Figure 5 As shown, the balancing container II is installed vertically with a height of 200 mm. Four third baffles 701 are arranged in the middle of the vertical position. The third baffle 701 is made of a stainless steel round plate with a thickness of 6 mm and a diameter of 50 mm. Stainless steel bars with a thickness of 6 mm and a width of 6 mm are used as connecting rods 702 at the four positions of 0°, 90°, 180°, and 270°. The baffles and the balancing container are connected by welding.

[0047] The operating method of the condensate online monitoring and sampling device for the phosphoric acid concentration system of the present invention comprises the following steps:

[0048] S1. Use the by-product low-pressure steam T≤180℃, P≤0.7MPa generated from the sulfuric acid system, and send the low-pressure steam T≤139℃, P≤0.25MPa through the temperature and pressure reducing device to the graphite heat exchanger to heat the dilute phosphoric acid;

[0049] S2. Control the temperature of the dilute phosphoric acid at 75.0-87.0°C to concentrate the dilute phosphoric acid;

[0050] S3. Low-pressure steam is continuously exchanged with dilute phosphoric acid to form condensate mixed with steam and water, and the steam temperature drops from 139°C to 100°C. This condensate is then sent to the desalted water process of sulfuric acid production for use. At the same time, an online monitoring and sampling device for condensate used in the phosphoric acid concentration system is installed at the condensate storage tank;

[0051] S4. Open valve 7# to allow process water to enter the heat exchange tube of condensate heat exchanger, open valve 8# to observe whether there is leakage in the heat exchange tube, close valve 8# after confirming that there is no leakage, and open valve 6#;

[0052] S5. Make the process water flow through, and the process water flowing out of the condensate heat exchanger flows into the circulating water pool;

[0053] S6. When the process water is put into use normally, open valves 2# and 3# in sequence, close valve 4#, open valve 5# by 10%, and slowly open valve 1# by 10%;

[0054] S7. Measure the surface temperature of the balance container. When the temperature rises, pay attention to whether there is condensed water discharged from the 5# valve. At the same time, monitor the safety of the surrounding personnel to prevent condensed water from splashing;

[0055] S8. When there is condensed water at the 5# valve, slowly open the 1# valve and observe whether there is splashing at the 5# valve outlet. If there is, adjust the opening of the 5# valve until there is no splashing at the outlet;

[0056] S9. After the condensate is drained normally, slowly open the 4# valve for manual sampling. The opening of the 4# valve should be such that sampling can be done safely.

[0057] S10. After sampling, conduct conductivity analysis on the condensed water and compare and calibrate it with the online conductivity meter.

[0058] The invention utilizes low-pressure steam with T≤180°C and P≤0.7MPa, which is a byproduct of a sulfuric acid production system. After passing through a temperature and pressure reducing device, the low-pressure steam with T≤139°C and P≤0.25MPa is sent to a graphite heat exchanger to heat dilute phosphoric acid; the temperature of the dilute phosphoric acid is controlled at 75.0-87.0°C to concentrate the dilute phosphoric acid; the low-pressure steam is continuously and indirectly heat-exchanged with the dilute phosphoric acid, and the steam temperature drops from 139°C to below 100°C to form condensed water mixed with steam and water, so the condensed water is sent to the desalted water process of the sulfuric acid production system for use, and a condensed water online monitoring and sampling device for the phosphoric acid concentration system is arranged at the condensed water storage tank. The condensate from the graphite heat exchanger enters the condensate storage tank. One stream of the condensate in the tank is transported by the condensate pump to the desalted water process of sulfuric acid production for use; the other stream is installed with an online condensate monitoring and sampling device for the phosphoric acid concentration system to reduce the temperature of the condensate, improve the accuracy of the conductivity meter measurement, and reduce the risk of manual sampling.

[0059] The online monitoring and sampling device for condensate water in the phosphoric acid concentration system is put into use: open valve 7# to allow process water to enter the heat exchange coil of the condensate heat exchanger, open valve 8# to observe whether there is any leakage in the heat exchange coil, close valve 8# after confirming that there is no leakage, open valve 6# to allow the process water flow to pass, and the process water flowing out of the condensate heat exchanger flows into the circulating water pool.

[0060] When the process water is put into use normally, open valves 2# and 3# in turn, close valve 4#, open valve 5# by 10%, and slowly open valve 1# by 10%. Measure the surface temperature of the balance container. When the temperature rises, pay attention to whether there is condensate discharged from valve 5#. At the same time, monitor the safety of the surrounding personnel to prevent condensate from splashing and injuring people. When there is condensate at valve 5#, slowly open valve 1# and observe whether there is splashing at the drain outlet of valve 5#. If there is, adjust the opening of valve 5# until there is no splashing at the drain outlet. In the early stage of commissioning, if the condensate heat exchanger and balance container have abnormal conditions such as steam-water impact and vibration, it is mostly caused by a large amount of condensate entering. Valve 1# should be closed until the abnormal condition is eliminated.

[0061] After the condensate is drained normally, slowly open the 4# valve for manual sampling. The opening of the 4# valve should be safe for sampling. After sampling, the 4# valve should be closed. After sampling, the condensate is subjected to conductivity analysis and compared with the online conductivity meter. When the measurement results of the two are within the error range, it means that the condensate conductivity meets the requirements and is in normal operation. If the results of the two are beyond the error range, it means that the condensate is abnormal and needs to be shut down for maintenance.

[0062] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An online monitoring and sampling device for condensate water in a phosphoric acid concentration system, characterized in that: The invention comprises a condensate storage tank (2), a condensate heat exchanger (4), a balance container I (5), and a balance container II (7) which are connected in sequence. The condensate storage tank (2) is connected to the condensate outlet of the graphite heat exchanger (1). The balance container I (5) is arranged horizontally and has an electrical conductivity meter (6) connected to its end. The cooling medium of the condensate heat exchanger (4) is process water. The balance container II (7) is arranged vertically and has an artificial sampling port at the water outlet on the top.

2. The condensate online monitoring and sampling device for a phosphoric acid concentration system according to claim 1, characterized in that: The condensate heat exchanger (4) is a horizontally arranged hollow tube body, a first baffle (401) is arranged vertically downward near the inlet end of the condensate heat exchanger (4), a second baffle (402) is arranged vertically upward near the outlet end of the condensate heat exchanger (4), and a heat exchange coil (8) is arranged between the first baffle (401) and the second baffle (402).

3. The condensate online monitoring and sampling device for a phosphoric acid concentration system according to claim 2, characterized in that: The heat exchange coil (8) includes, from top to bottom, an upper coil (81), a spiral tube (82) and a lower coil (83) which are connected to each other. The upper coil (81) and the lower coil (83) are both horizontally arranged serpentine tubes. The process water inlet and the process water outlet of the heat exchange coil (8) are arranged on the flange connection structure at the top of the condensate heat exchanger (4), and are respectively connected to the process water supply device and the circulating water station.

4. The condensate online monitoring and sampling device for a phosphoric acid concentration system according to claim 1, characterized in that: The balancing container I (5) is a horizontally arranged hollow tube, one end of which is a water inlet and the other end is connected to the conductivity meter (6). An upward vertical baffle (501) is arranged in the middle of the bottom of the balancing container I (5), and a water outlet is arranged at the top of the balancing container I (5) on the side close to the conductivity meter (6).

5. The condensate online monitoring and sampling device for a phosphoric acid concentration system according to claim 1, characterized in that: The balancing container II (7) is a vertically arranged hollow tube, the bottom of which is a water inlet, and the top of which is a water outlet. A third baffle (701) is horizontally arranged in the middle of the balancing container II (7). The third baffle (701) is a circular plate and is coaxially arranged with the balancing container II (7). The third baffle (701) is connected to the inner wall of the balancing container II (7) through a connecting rod (702).

6. The condensate online monitoring and sampling device for a phosphoric acid concentration system according to claim 5, characterized in that: The connecting rods (702) are provided in four pieces and are in strip shape and are evenly distributed radially along the third baffle (701).

7. The condensate online monitoring and sampling device for a phosphoric acid concentration system according to claim 1, characterized in that: The graphite heat exchanger (1) is provided with an acid inlet, an acid outlet, and a low-pressure steam inlet. The condensate storage tank (2) uses part of the condensate as desalted water through a water pump. The condensate storage tank (2) is connected to the inlet end of the condensate heat exchanger (4) through a 1# valve. The outlet end of the condensate heat exchanger (4) is connected to the water inlet of the balance container I (5) through a 2# valve. The water outlet of the balance container I (5) is connected to the water inlet of the balance container II (7) through a 3# valve. The water outlet of the balance container II (7) is connected to the manual sampling port through a 4# valve. The water outlet of the balance container II (7) is connected to the drainage device through a 5# valve.

8. The condensate online monitoring and sampling device for a phosphoric acid concentration system according to claim 3, characterized in that: The condensate heat exchanger (4) is provided with a 8# valve at the bottom, the process water inlet of the heat exchange coil (8) is connected to the process water supply device through a 7# valve, and the process water outlet of the heat exchange coil (8) is connected to the circulating water station through a 6# valve.

9. The condensate online monitoring and sampling device for a phosphoric acid concentration system according to any one of claims 1 to 8, characterized in that: The operation method of the device comprises the following steps: S1. Using low-pressure steam with a temperature of ≤180°C and a pressure of ≤0.7MPa from a sulfuric acid system, after cooling and reducing pressure, the low-pressure steam with a temperature of ≤139°C and a pressure of ≤0.25MPa is sent to a graphite heat exchanger (1) to heat the dilute phosphoric acid; S2. Control the temperature of the dilute phosphoric acid at 75 to 87 ° C to concentrate the dilute phosphoric acid; S3. Low-pressure steam is continuously exchanged with dilute phosphoric acid to form condensate mixed with steam and water at a steam temperature of ≤100°C, which is stored in a condensate storage tank (2). A portion of the condensate is pumped to the desalted water process of sulfuric acid production, and a portion of the condensate enters the sampling and monitoring link under the condensate's own pressure; S4. Open valve 7# to allow process water to enter the heat exchange coil (8) of the condensate heat exchanger (4), open valve 8# to observe whether the heat exchange coil (8) has any leakage, confirm that there is no leakage, close valve 8#, and open valve 6#; S5. The process water flow is connected, and the process water flowing out of the condensate heat exchanger (4) flows into the circulating water station; S6. When the process water is put into use normally, open valves 2# and 3# in sequence, close valve 4#, open valve 5# by 10%, and slowly open valve 1# by 10%; S7. Measure the surface temperature of the balance container I (5) and balance container II (7). When the temperature rises, pay attention to whether there is condensed water discharged from the 5# valve; S8. When condensate is discharged from the 5# valve, slowly open the 1# valve and observe whether there is splashing at the 5# valve outlet. If there is splashing, adjust the opening of the 5# valve until there is no splashing at the outlet. S9. After the condensate is drained normally, slowly open valve 4# for manual sampling; S10. After sampling, the condensate water is subjected to conductivity analysis and compared with the online conductivity meter (6).

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