A multi-stage composite purification high-temperature condensate water recycling device

Abstract

The utility model discloses a kind of high-temperature condensate water recycling devices of multistage composite purification, including the iron ion removal tank, ammonia water adding jar, heat exchanger and ultrafiltration equipment that outlet and import are sequentially connected;The iron ion removal tank inside is equipped with detachable aeration pipe group, inlet is located at the position close to top, outlet is located at the position close to bottom;The ultrafiltration equipment inside is equipped with filter membrane, top is also equipped with backflush inlet pipe, and the outlet of backflush inlet pipe is located in the water production side of filter membrane.The utility model is through multistage collaborative purification, efficiently removes various iron impurities in high-temperature condensate water, impurity removal is thorough, stable in operation, maintenance is simple, significantly improves water quality, prolongs equipment life, reduces operating cost, and has economic and environmental benefits.

Description

Technical Field

[0001] This utility model relates to the technical field of high-temperature condensate reuse devices, specifically to a multi-stage composite purification high-temperature condensate reuse device. Background Technology

[0002] In many industrial production processes such as chemical, power, and metallurgy, steam is widely used as an important energy carrier, which generates a large amount of high-temperature condensate. This high-temperature condensate is usually at a high temperature, contains a large amount of heat energy, and is relatively pure. If it can be effectively recycled and utilized, it can not only significantly save precious water resources, but also recover a large amount of heat energy, reduce system energy consumption, and reduce cooling load, resulting in significant economic benefits and environmental benefits of energy conservation and emission reduction.

[0003] However, during condensate recovery, steam inevitably undergoes oxidation and corrosion during transportation and use, coming into contact with carbon steel pipes and equipment. This generates iron oxides or hydroxides, resulting in a certain concentration of iron ions in the condensate, primarily Fe²⁺ and Fe³⁺, along with suspended solids, colloidal substances, and other impurities introduced due to pipe corrosion or external factors. The iron content can significantly increase, especially during system start-up and shutdown, load fluctuations, or equipment aging, causing the condensate to exhibit varying degrees of turbidity or color. If this untreated high-temperature condensate is directly returned to the boiler feedwater system or reused as process water, the iron impurities will deposit on the heating surfaces of the high-temperature, high-pressure boiler, forming iron oxide scale. This severely affects heat transfer efficiency, leading to tube overheating, reduced boiler efficiency, increased fuel consumption, and even serious safety accidents such as tube rupture. It also shortens the service life of the boiler and related equipment. Therefore, high-temperature condensate must be effectively purified to remove iron and other impurities before safe reuse.

[0004] Currently, commonly used industrial condensate purification methods mainly include filtration, ion exchange, and electromagnetic iron removal. However, these traditional methods generally have significant technical limitations when treating high-temperature condensate. For example, conventional filtration devices such as Y-type filters, bag filters, or ordinary media filters can remove larger suspended particles, but their removal effect on micron- or even nano-sized colloidal iron, dissolved iron ions, and fine particles is limited, making it difficult to meet the requirements for high-precision reuse. In addition, single purification technologies are usually limited in function and cannot simultaneously and efficiently remove multiple forms of impurities in condensate. This leads to existing purification devices generally having problems such as poor adaptability, unsatisfactory treatment effect, complex operation and maintenance, and high overall cost, making it difficult to meet the urgent needs of modern industry for efficient, stable, long-term, and low-cost purification and reuse of high-temperature condensate. Summary of the Invention

[0005] Traditional methods for treating high-temperature condensate are inadequate due to their inability to withstand high temperatures, resulting in incomplete impurity removal, low efficiency, and high cost. This invention provides a multi-stage composite purification device that can adapt to high-temperature operating conditions, integrate multiple purification mechanisms, and efficiently and synergistically remove various iron impurities and suspended solids from condensate.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows: A multi-stage composite purification high-temperature condensate reuse device includes an iron ion removal tank, an ammonia water addition tank, a heat exchanger, and an ultrafiltration device connected sequentially to the outlet and inlet. The iron ion removal tank is equipped with a detachable aeration pipe assembly, with the inlet located near the top and the outlet located near the bottom. The ultrafiltration device is equipped with a filter membrane and a backwash inlet pipe at the top, with the outlet of the backwash inlet pipe located on the product water side of the filter membrane.

[0007] Furthermore, the iron ion removal box is equipped with a removable cover on top, with mounting holes and several vent holes on the cover; the aeration pipe assembly includes a main pipe and at least two sets of branch pipes, with the two sets of branch pipes staggered on the main pipe; the top of the main pipe extends outward through the mounting hole, and the bottom extends downward to the bottom of the box, with several air outlets evenly distributed on the pipe body. During air supply, the gas is connected to the main pipe through the factory's air inlet pipe, and dispersed in the high-temperature condensate through the air outlets on the main pipe and the aeration holes on the branch pipes, reacting with dissolved iron ions to form precipitates, effectively removing iron ions; the removable cover and mounting holes facilitate the installation and subsequent maintenance of the aeration pipe assembly, while the vent holes can promptly discharge the gas accumulated during aeration, preventing air blockage from affecting water flow and oxidation effect; the branch pipes are connected to the main pipe and are equipped with aeration holes, forming a multi-layer three-dimensional aeration structure, which makes the air evenly dispersed in the condensate, significantly improving the oxidation efficiency of Fe²⁺, enhancing the removal effect of iron impurities, and the overall structure is easy to disassemble and assemble, facilitating cleaning and maintenance, and ensuring long-term stable operation of the device under high-temperature conditions.

[0008] Furthermore, each branch pipe group includes three annular connecting pipes set on the outer wall of the main pipe, with several aeration holes evenly distributed on the pipe body. The staggered arrangement of the three annular connecting pipes in each group enhances the gas-liquid mixing disturbance, avoids airflow short-circuiting, and improves the uniformity and thoroughness of the oxidation reaction. The water after the reaction carries the sediment downwards, and under the action of gravity, some flocs settle at the bottom of the tank, achieving preliminary solid-liquid separation. Subsequently, the water flows out from the bottom outlet to enter the subsequent ammonia water conditioning and ultrafiltration process. When maintenance is required, the removable top cover can be opened to pull the entire aeration pipe group out of the installation hole, facilitating the cleaning of aeration hole blockages or replacement of parts, ensuring long-term stable operation of the device.

[0009] Furthermore, a filter screen is inclinedly installed at the bottom of the iron ion removal box, with an aeration pipe assembly on the left and a water outlet pipe on the right. This inclined filter screen effectively traps Fe(OH)3 flocs and suspended impurities generated during oxidation, preventing them from entering the water outlet pipe and reducing subsequent ultrafiltration membrane fouling. The filter screen can be periodically disassembled and cleaned, ensuring long-term stable operation of the device under high-temperature conditions.

[0010] Furthermore, a drain outlet with a drain valve is provided on the left side of the inclined filter screen. With the drain outlet and drain valve installed on the left side of the inclined filter screen, the iron flocs and impurities generated by oxidation accumulate along the lower left side of the filter screen under the influence of water flow and gravity. The deposits are discharged by periodically opening the drain valve, effectively preventing impurities from accumulating at the bottom of the tank and clogging the filter screen, maintaining filter screen permeability and processing efficiency, reducing maintenance frequency, simplifying operation, and improving the stability and automation level of the device.

[0011] Furthermore, the ammonia addition tank is equipped with an inlet and an outlet on both sides, and an ammonia addition pipe with a switch valve is installed on the top surface. A metering pump is also connected to the top of the ammonia addition pipe. The inlet of the metering pump is connected to the ammonia storage tank. When condensate enters the tank through the inlet via the pipeline, the ammonia addition pipe on the top is controlled by the switch valve and connected to the metering pump to achieve precise and quantitative ammonia addition. This stabilizes the pH of the condensate at 8.5–9.5, promoting the complete conversion of iron ions into insoluble hydroxides and preventing system corrosion. The condensate then flows out from the outlet into the subsequent ultrafiltration system. The metering pump can automatically adjust the dosage according to the initial settings to ensure a stable and reliable ammonia addition. The ammonia and condensate mix naturally within the tank, eliminating the need for additional stirring devices. The structure is simple, the dosing response is fast, and the operation is stable, effectively ensuring the safe operation of the subsequent ultrafiltration equipment and the overall iron removal effect.

[0012] Furthermore, a circulation pump and a jet mixer are installed on the outside of the ammonia addition tank. The outlet of the jet mixer is connected to the ammonia addition tank, and its outlet is below the liquid surface. The inlet of the circulation pump is connected to the ammonia addition tank, and its outlet is connected to the main inlet of the jet mixer via a pipe fitting. The side suction port of the jet mixer is connected to the outlet of the metering pump via a pipe fitting. In use, the circulation pump draws liquid from the ammonia addition tank and sends it to the main inlet of the jet mixer. The metering pump accurately delivers ammonia to the side suction port of the jet mixer. Under the action of jet pressure, the ammonia is efficiently drawn in and mixed. The mixture is sprayed back into the addition tank from the outlet of the jet mixer, which is below the liquid surface, forming an external circulation. This structure achieves precise ammonia addition through the metering pump and rapid and uniform mixing through the jet mixer, avoiding excessively high local concentrations, improving mixing efficiency and pH control accuracy. The system operates stably, is easy to maintain, and effectively ensures uniform dosing and equipment safety.

[0013] Furthermore, the ammonia addition tank has a funnel-shaped bottom, with a drain pipe equipped with a drain valve at the very bottom. This funnel-shaped structure facilitates the accumulation of any small amounts of sediment or impurities that may form inside the tank, causing them to gather towards the center under gravity. The sediment is then periodically drained by opening the drain valve, preventing the accumulation of impurities from affecting dosing accuracy and subsequent system operation. Simultaneously, it avoids tank bottom contamination or blockage due to long-term operation, maintaining the cleanliness of the tank interior, ensuring uniform mixing of ammonia and condensate, stable dosing, and improving the system's automation level and operational reliability.

[0014] Furthermore, the ultrafiltration equipment uses a filter membrane with a pore size of 0.001-0.1 micrometers and employs a cross-flow filtration method. The pore size of the filter membrane (0.001–0.1 micrometers) provides excellent retention capacity, efficiently removing colloidal iron, suspended solids, large organic molecules, and fine particles from the water, ensuring low turbidity and stable water quality. The cross-flow filtration method allows condensate to flow parallel to the membrane surface at a certain velocity. Some water permeates through the membrane to become product water, while impurities are retained and carried away with the concentrate flow. This effectively reduces the accumulation of pollutants on the membrane surface, alleviates concentration polarization, lowers the membrane fouling rate, and extends the operating cycle. Combined with regular backwashing via the top backwash inlet pipe, this enhances the cleaning effect and the system's continuous operation capability.

[0015] Furthermore, the ultrafiltration device is equipped with a drain pipe with a drain valve at the bottom. The drain pipe facilitates the periodic emptying of residual water, concentrated water, or waste liquid from the device, effectively removing sediments and trapping impurities, preventing clogging and microbial growth, ensuring stable flux and long-term operating performance of the ultrafiltration membrane, and also facilitating equipment maintenance, chemical cleaning, and winter freeze protection drainage.

[0016] How to use this utility model: The ultrafiltration equipment and heat exchangers are commercially available, such as PVDF ultrafiltration integrated units and tubular heat exchangers. During operation, condensate enters from the top of the iron ion removal tank. As the water flows downwards, air is introduced through the aeration pipe assembly, causing Fe²⁺ in the water to be fully oxidized to Fe³⁺, forming ferric hydroxide colloids or precipitates. Initial iron removal is achieved through gravity settling. The detachable design of the aeration pipe assembly facilitates later maintenance and replacement, and is suitable for long-term operation under high-temperature conditions. The water then enters the ammonia addition tank to adjust the pH to a suitable range, typically 8.5. -9.5, on the one hand, further promotes the hydrolysis and precipitation of iron ions, and on the other hand, the addition of ammonia water can improve the buffering capacity of the water, stabilize the water quality, prevent secondary corrosion of the subsequent pipeline system, and help inhibit the scaling tendency on the surface of the ultrafiltration membrane; then, it is appropriately cooled to the temperature range that the ultrafiltration equipment can withstand through the heat exchanger; finally, it enters the ultrafiltration equipment, where the filter membrane intercepts residual fine suspended solids, colloidal iron and macromolecular impurities, resulting in high-quality purified water that is sent out for reuse; when the ultrafiltration membrane is fouled, it can be backwashed through the top backwash inlet pipe to restore the flux.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects: This invention utilizes a multi-stage synergistic effect of oxidation, pH adjustment, sedimentation, and ultrafiltration to effectively remove iron ions and impurities in different forms from high-temperature condensate. It is adaptable to high-temperature operating conditions, has high treatment efficiency, thorough impurity removal, and stable operation, significantly improving the quality of reclaimed water, extending equipment life, and reducing energy consumption and operating costs, thus providing good economic and environmental benefits. The combined purification mechanism not only significantly improves the removal rate of iron impurities, but also has excellent removal effects on difficult-to-treat ferrous ions and colloidal iron. At the same time, the system operates stably, is easy to maintain, and the backwashing design extends the service life of key components and reduces operating costs.

[0018] This device effectively removes iron ions and impurities from high-temperature condensate through multi-stage synergistic purification. The iron ion removal tank is equipped with a detachable aeration tube assembly and an inclined filter screen, combined with exhaust and sewage discharge design, to enhance oxidation sedimentation and solid-liquid separation and extend maintenance cycles. The ammonia addition tank integrates a metering pump and a jet mixing system to achieve precise pH control and efficient mixing, preventing corrosion and localized crystallization. The ultrafiltration equipment adopts a cross-flow filtration and backwashing design to improve membrane flux stability and anti-fouling capabilities. Attached Figure Description

[0019] Figure 1 This is a diagram showing the component connections of a multi-stage composite purification high-temperature condensate recycling device according to this utility model.

[0020] Figure 2 This is a schematic diagram of the aeration tube assembly of a multi-stage composite purification high-temperature condensate recycling device according to this utility model.

[0021] Attached image labels: Iron ion removal box-1, box cover-11, filter screen-12, drain outlet-13, drain valve-14, ammonia water addition tank-2, switch valve-21, metering pump-22, circulation pump-23, jet mixer-24, drain valve-25, drain pipe-26, heat exchanger-3, ultrafiltration equipment-4, drain valve-41, drain pipe-42, aeration pipe assembly-5, main pipe-51, air outlet-52, connecting pipe-53, aeration hole-54. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings.

[0023] Example 1: A multi-stage composite purification high-temperature condensate reuse device includes an iron ion removal tank 1, an ammonia water addition tank 2, a heat exchanger 3, and an ultrafiltration device 4 connected sequentially from the outlet to the inlet; the iron ion removal tank 1 is equipped with a detachable aeration pipe assembly 5, with the inlet located near the top and the outlet located near the bottom; the ultrafiltration device 4 is equipped with a filter membrane, and a backwash inlet pipe is also provided at the top, with the outlet of the backwash inlet pipe located on the product water side of the filter membrane.

[0024] The ultrafiltration equipment 4 and heat exchanger 3 are commercially available, such as PVDF ultrafiltration integrated devices and tubular heat exchangers. During use, condensate enters from the top of the iron ion removal tank 1. As the water flows downward, it is aerated with air through the aeration pipe group 5, which fully oxidizes the Fe²⁺ in the water to Fe³⁺ and forms ferric hydroxide colloid or precipitate. The iron is initially removed by gravity sedimentation. The aeration pipe group 5 is designed to be detachable for easy maintenance and replacement, and is suitable for long-term operation under high-temperature conditions. Subsequently, the water enters the ammonia water addition tank 2 to adjust the pH to a suitable range, usually 8. The temperature range of 5–9.5 further promotes the hydrolysis and precipitation of iron ions. On the other hand, the addition of ammonia water can improve the buffering capacity of the water, stabilize the water quality, prevent secondary corrosion of the subsequent pipeline system, and help inhibit the scaling tendency on the surface of the ultrafiltration membrane. Then, the water is appropriately cooled by heat exchanger 3 to the temperature range that the ultrafiltration equipment 4 can withstand. Finally, the water enters the ultrafiltration equipment 4, where the filter membrane traps residual fine suspended solids, colloidal iron and macromolecular impurities, resulting in high-quality purified water that can be sent for reuse. When the ultrafiltration membrane is fouled, it can be backwashed through the top backwash inlet pipe to restore the flux.

[0025] Example 2: The difference from Example 1 is that the iron ion removal box 1 is provided with a detachable box cover 11 on the top, and the box cover 11 is provided with mounting holes and several vent holes; the aeration pipe group 5 includes a main pipe 51 and at least two sets of branch pipes, and the two sets of branch pipes are arranged alternately on the main pipe 51; the top of the main pipe 51 extends outward through the mounting hole, and the bottom extends downward to the bottom of the box body, and several air outlet holes 52 are evenly provided on the pipe body. During gas supply, the gas is connected to the main pipe 51 through the factory's air inlet pipe. It is then dispersed in the high-temperature condensate through the air outlet 52 on the main pipe 51 and the aeration holes 54 on the branch pipes, reacting with dissolved iron ions to form precipitates and effectively removing iron ions. The detachable cover 11, along with the mounting holes, facilitates the installation and subsequent maintenance of the aeration pipe assembly 5. At the same time, the exhaust holes can promptly discharge the gas accumulated during the aeration process, preventing air blockage from affecting water flow and oxidation effect. The branch pipes are connected to the main pipe 51 and are equipped with aeration holes 54, forming a multi-layer three-dimensional aeration structure that evenly disperses air in the condensate, significantly improving the oxidation efficiency of Fe²⁺ and enhancing the removal effect of iron impurities. The overall structure is easy to disassemble and assemble, facilitating cleaning and maintenance, and ensuring long-term stable operation of the device under high-temperature conditions.

[0026] The ammonia addition tank 2 has an inlet and an outlet on both sides, and an ammonia addition pipe with a switch valve 21 is installed on the top. The top of the ammonia addition pipe is also connected to a metering pump 22. The inlet of the metering pump 22 is connected to the ammonia storage tank. When condensate enters the tank through the inlet, the ammonia addition pipe on the top is controlled by the switch valve 21 and connected to the metering pump 22 to achieve precise and quantitative ammonia addition. This stabilizes the pH of the condensate at 8.5–9.5, promotes the complete conversion of iron ions into insoluble hydroxides, and prevents system corrosion. The condensate then flows out from the outlet and enters the subsequent ultrafiltration system. The metering pump 22 can automatically adjust the dosage according to the initial settings to ensure a stable and reliable ammonia addition. The ammonia and condensate mix naturally in the tank without the need for an additional stirring device. The structure is simple, the dosing response is fast, and the operation is stable, effectively ensuring the safe operation of the subsequent ultrafiltration equipment 4 and the overall iron removal effect.

[0027] The ultrafiltration device 4 uses a filter membrane with a pore size of 0.001-0.1 micrometers and employs a cross-flow filtration method. The pore size of the filter membrane (0.001–0.1 micrometers) provides excellent retention capacity, efficiently removing colloidal iron, suspended solids, large organic molecules, and fine particles from the water, ensuring low turbidity and stable water quality. The cross-flow filtration method allows condensate to flow parallel to the membrane surface at a certain velocity. Some water permeates through the membrane to become product water, while impurities are retained and carried away with the concentrate flow. This effectively reduces the accumulation of pollutants on the membrane surface, alleviates concentration polarization, lowers the membrane fouling rate, and extends the operating cycle. Combined with regular backwashing via the top backwash inlet pipe, this enhances the cleaning effect and the system's continuous operation capability.

[0028] Example 3: Unlike Example 2, each branch pipe group includes three annular connecting pipes 53 arranged on the outer wall of the main pipe 51. Several aeration holes 54 are evenly distributed along the body of each connecting pipe 53. The staggered arrangement of the three annular connecting pipes 53 in each group enhances gas-liquid mixing disturbance, avoids airflow short-circuiting, and improves the uniformity and thoroughness of the oxidation reaction. The reacted water carrying the sediment flows downwards, and under gravity, some flocs settle at the bottom of the tank, achieving preliminary solid-liquid separation. The water then flows out from the bottom outlet to the subsequent ammonia water conditioning and ultrafiltration processes. When maintenance is required, the removable top cover 11 can be opened, and the entire aeration pipe group 5 can be pulled out of the mounting hole for easy cleaning of clogged aeration holes 54 or replacement of components, ensuring long-term stable operation of the device.

[0029] The bottom of the iron ion removal box 1 is also equipped with an inclined filter screen 12. The aeration pipe group 5 is on the left side of the filter screen 12, and the water outlet pipe is on the right side. The inclined filter screen 12 can effectively intercept Fe(OH)3 flocs and suspended impurities generated by oxidation, preventing them from entering the water outlet pipe and reducing subsequent ultrafiltration membrane fouling. The filter screen 12 can be disassembled and cleaned regularly to ensure long-term stable operation of the device under high temperature conditions.

[0030] A drain outlet 13 is also provided on the left side of the inclined filter screen 12, and a drain valve 14 is installed at the drain outlet 13. With the drain outlet 13 and drain valve 14 installed at the drain outlet 13, the iron flocs and impurities generated by oxidation accumulate to the lower left of the filter screen 12 under the influence of water flow and gravity. By periodically opening the drain valve 14, the deposits are discharged, effectively preventing impurities from accumulating at the bottom of the tank and clogging the filter screen 12, maintaining the permeability and processing efficiency of the filter screen 12, reducing maintenance frequency, simplifying operation, and improving the stability and automation level of the device.

[0031] Example 4: The difference from Example 2 is that the ammonia addition tank 2 is provided with a circulation pump 23 and a jet mixer 24 on the outside. The outlet of the jet mixer 24 is connected to the ammonia addition tank 2 and the outlet end is below the liquid surface. The inlet of the circulation pump 23 is connected to the ammonia addition tank 2, and the outlet is connected to the main inlet of the jet mixer 24 through a pipe. The lateral suction port of the jet mixer 24 is connected to the outlet of the metering pump 22 through a pipe. In use, the circulating pump 23 draws liquid from the ammonia addition tank 2 and sends it to the main inlet of the jet mixer 24. The metering pump 22 accurately delivers the ammonia to the side suction port of the jet mixer 24. Under the action of jet pressure, the ammonia is efficiently drawn in and mixed. The mixture is sprayed back into the addition tank 2 from the outlet of the jet mixer 24, and the outlet is located below the liquid surface, forming an external circulation. This structure achieves precise ammonia addition through the metering pump 22 and achieves rapid and uniform mixing in combination with the jet mixer 24, avoiding excessively high local concentrations, improving mixing efficiency and pH control accuracy. The system operates stably, is easy to maintain, and effectively ensures uniform dosing and equipment safety.

[0032] The ammonia addition tank 2 has a funnel-shaped bottom, and a drain pipe 26 with a drain valve 25 is installed at the bottom. The funnel-shaped structure facilitates the accumulation of small amounts of sediment or impurities that may be generated inside the tank under the action of gravity. By periodically opening the drain valve 25, the sediment is discharged, preventing the accumulation of impurities from affecting the dosing accuracy and subsequent system operation. At the same time, it avoids tank bottom contamination or blockage due to long-term operation, keeps the inside of the tank clean, ensures uniform mixing of ammonia and condensate, stable dosing, and improves the automation level and operational reliability of the system.

[0033] The ultrafiltration device 4 is equipped with a drain pipe 42 with a drain valve 41 at the bottom. The drain pipe 42 facilitates the periodic emptying of residual water, concentrated water or waste liquid in the device, effectively removing sediment and intercepting impurities, preventing fouling and microbial growth, ensuring stable flux and long-term operating performance of the ultrafiltration membrane, and also facilitating equipment maintenance, chemical cleaning and winter antifreeze emptying.

[0034] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of this invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A multi-stage composite purification high-temperature condensate reuse device, characterized in that: The equipment includes an iron ion removal tank (1), an ammonia water addition tank (2), a heat exchanger (3), and an ultrafiltration device (4) connected in sequence from the outlet to the inlet; the iron ion removal tank (1) is equipped with a detachable aeration pipe assembly (5), with the inlet located near the top and the outlet located near the bottom; the ultrafiltration device (4) is equipped with a filter membrane, and a backwash inlet pipe is also provided at the top, with the outlet of the backwash inlet pipe located on the product water side of the filter membrane.

2. The high-temperature condensate reuse device with multi-stage composite purification as described in claim 1, characterized in that: The iron ion removal box (1) is provided with a detachable box cover (11) on the top. The box cover (11) is provided with mounting holes and several exhaust holes. The aeration pipe group (5) includes a main pipe (51) and at least two sets of branch pipes. The two sets of branch pipes are arranged alternately on the main pipe (51). The top of the main pipe (51) extends outward through the mounting hole, and the bottom extends downward to the bottom of the box body. Several air outlet holes (52) are evenly provided on the pipe body.

3. The high-temperature condensate reuse device with multi-stage composite purification as described in claim 2, characterized in that: Each branch pipe includes three annular connecting pipes (53) set on the outer wall of the main pipe (51), and several aeration holes (54) are evenly provided on the pipe body of the connecting pipe (53).

4. The high-temperature condensate reuse device with multi-stage composite purification as described in claim 1, characterized in that: The bottom of the iron ion removal box (1) is also provided with a filter screen (12) at an angle. The aeration pipe group (5) is on the left side of the filter screen (12) and the water outlet pipe is on the right side.

5. The high-temperature condensate reuse device with multi-stage composite purification as described in claim 4, characterized in that: The filter screen (12) is also provided with a drain outlet (13) on the left side, and a drain valve (14) is provided at the drain outlet (13).

6. The high-temperature condensate reuse device with multi-stage composite purification as described in claim 1, characterized in that: The ammonia addition tank (2) is equipped with a circulation pump (23) and a jet mixer (24) on the outside. The outlet of the jet mixer (24) is connected to the ammonia addition tank (2), and the outlet end is below the liquid surface. The inlet of the circulation pump (23) is connected to the ammonia addition tank (2), and the outlet is connected to the main inlet of the jet mixer (24) through a pipe. The lateral suction port of the jet mixer (24) is connected to the outlet of the metering pump (22) through a pipe.

7. A high-temperature condensate reuse device with multi-stage composite purification as described in any one of claims 1 or 6, characterized in that: The bottom of the ammonia addition tank (2) is shaped like a bucket, and the bottom is also equipped with a drain pipe (26) with a drain valve (25).

8. The high-temperature condensate reuse device with multi-stage composite purification as described in claim 1, characterized in that: The ultrafiltration device (4) uses a filter membrane with a pore size of 0.001-0.1 micrometers and adopts a cross-flow filtration method.

9. A high-temperature condensate reuse device with multi-stage composite purification as described in claim 8, characterized in that: The ultrafiltration device (4) is equipped with a drain pipe (42) with a drain valve (41) at the bottom.

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