Device and method for deoxidizing ammonia washing water of purification device

Abstract

The invention relates to the technical field of coal chemical industry and industrial water treatment, and discloses a device and method for deoxidizing ammonia washing water of a purification device, the device comprises a first booster pump, a degassing tank, a nitrogen-sealed buffer tank, a second booster pump and an ammonia washing tower which are connected in sequence, a partition plate is arranged in the degassing tank, a center cylinder is arranged in the degassing tank, and the nitrogen-sealed buffer tank is arranged in the center cylinder. A central liquid inlet pipe is arranged in the central cylinder, the outer surface of the central cylinder is coaxially sleeved with a first flow guide sleeve, a negative pressure suction cavity is formed by the outer surface of the central cylinder and the inner surface of the first flow guide sleeve, a siphon is arranged at the bottom end of the negative pressure suction cavity, and a cylindrical fixing support is arranged at the lower end of the partition plate; and a plurality of degassing films are wound on the outer surfaces of the central cylinder and the cylindrical fixed bracket in a threaded manner. A normal-temperature membrane method is adopted for deoxidation, energy conservation and consumption reduction are achieved, the occupied area is reduced by half, starting is rapid, and a brand-new efficient and low-carbon deoxidation scheme is provided for ammonia washing water in the coal chemical industry.

Description

Technical Field

[0001] This invention relates to the fields of coal chemical industry and industrial water treatment technology, specifically to a device and method for deoxygenating ammonia washing water in a purification unit. Background Technology

[0002] Coal chemical industry is an important pillar of my country's energy and chemical industry. With the development of large-scale, high-efficiency, and low-carbon plants, the requirements for energy conservation, stability, and environmental protection of process water systems are constantly increasing. In the coal gasification conversion and purification unit, the dissolved oxygen content of the water used in the ammonia washing tower needs to be controlled at a low level to prevent equipment corrosion and ensure the long-term safe operation of the system. Therefore, the deoxygenation process has become a key technology in the preparation of ammonia washing water.

[0003] The industry currently widely adopts the traditional process route of thermal deoxygenation + circulating water cooling: ambient temperature demineralized water is first heated to above 100°C by low-pressure steam and then enters the thermal deaerator to complete high-temperature deoxygenation; then, the high-temperature deoxygenated water is cooled to about 40°C through a circulating water heat exchanger before being sent to the ammonia washing tower as washing water. This process relies on high-temperature heating to achieve deoxygenation, which has a significant temperature difference with the actual water temperature in the ammonia washing tower, forming an inherent process of "heating up first and then cooling down".

[0004] The aforementioned traditional process suffers from obvious "hot and cold" defects. It first consumes steam to raise the temperature and then consumes circulating water to cool it down, resulting in energy cancellation and a double waste of steam and circulating water. At the same time, the thermal deaerator is bulky, has a slow start-up time (≥2h), and requires regular addition of chemical deaerators, leading to a series of problems such as secondary pollution, large footprint, and poor operational flexibility.

[0005] Therefore, this application proposes a device and method for deoxygenating ammonia washing water in a purification unit. The aim is to completely eliminate the heating and cooling links from the source of the process by using membrane-based room temperature deep deoxygenation technology, thereby achieving efficient energy utilization, equipment miniaturization and rapid start-up and shutdown, and providing a replicable, low-energy-consumption solution for ammonia washing water preparation for large-scale coal chemical projects. Summary of the Invention

[0006] The purpose of this invention is to provide a device and method for deoxygenating ammonia washing water in a purification device, and to solve the following technical problems: the existing ammonia washing water preparation process of purification devices generally adopts the method of first consuming steam to heat up and then consuming circulating water to cool down, which cancels out each other's energy and causes a double waste of steam and circulating water; at the same time, the thermal deaerator is bulky, has a slow start-up (≥2h), and requires the periodic addition of chemical deoxygenating agents, which brings a series of problems such as secondary pollution, large footprint, and poor operational flexibility.

[0007] The objective of this invention can be achieved through the following technical solutions: A device for deoxygenating ammonia washing water in a purification system includes a first booster pump, a degassing tank, a nitrogen-sealing buffer tank, a second booster pump, and an ammonia washing tower connected in sequence. The degassing tank is equipped with a flow turbulence component, which includes a baffle horizontally arranged inside the degassing tank. The degassing tank is also equipped with a central cylinder, which is equipped with a central liquid inlet pipe. The upper end of the central cylinder is provided with a ring array of multiple overflow holes. The outer surface of the central cylinder is coaxially fitted with a first guide sleeve, and the outer surface of the central cylinder and the inner surface of the first guide sleeve form a negative pressure suction cavity. A siphon tube is provided at the bottom end of the negative pressure suction cavity. A cylindrical fixing bracket is provided at the lower end of the partition. A second guide sleeve is coaxially provided at the lower end of the partition and on the outside of the cylindrical fixing bracket. Multiple degassing membranes are threaded around the outer surfaces of the central cylinder and the cylindrical fixing bracket. The lower end of the siphon tube extends to the lower end of the partition.

[0008] As a further aspect of the present invention: all of the plurality of degassing membranes are permeable to the partition, and epoxy resin is disposed between each of them and the partition.

[0009] As a further embodiment of the present invention: one end of the siphon tube extends to the lower end of the partition and is provided with an annular tube; The annular tube has multiple spray holes.

[0010] As a further aspect of the present invention: the upper end of the second guide sleeve is provided with a plurality of first drain holes in an annular array.

[0011] As a further aspect of the present invention: a feeding assembly is provided at the upper end of the degassing tank, the feeding assembly including a feeding tank fixedly disposed at the top of the degassing tank, and the interior of the feeding tank is divided into a demineralized water feeding chamber and an exhaust chamber by a ring. The lower end of the deaeration tank is provided with a discharge assembly, which includes a discharge tank located at the lower end of the deaeration tank. The discharge tank is divided into a demineralized water discharge chamber and an air inlet chamber by a ring.

[0012] As a further aspect of the present invention: a water inlet pipe connector is connected to the top of the desalination feed chamber; The bottom of the demineralized water feed chamber is provided with a ring array of multiple drainage holes; The bottom end of the exhaust chamber has a ring array of multiple air outlets, and the top end of the exhaust chamber has an air extraction port.

[0013] As a further aspect of the present invention: the upper end of the air intake chamber is provided with a plurality of air intake holes in a ring array, and the lower end of the air intake chamber is connected to an air intake interface.

[0014] As a further aspect of the present invention: a purge air mold assembly is provided on one side of the degassing tank; The purging air mold assembly includes a storage box disposed on the outer wall of the degassing tank, an air inlet disposed at the bottom of the storage box, and a gas-liquid separator disposed at the bottom of the interior of the storage box. A moisture-absorbing component is installed inside the storage tank and above the gas-liquid separator.

[0015] As a further embodiment of the present invention, the moisture-absorbing component may be selected as an adsorption layer filled with activated carbon particles or a small membrane dryer.

[0016] A method for deoxygenating ammonia washing water in a purification device, using the aforementioned ammonia washing water deoxygenation device, is characterized by comprising the following steps: S1 First-stage pressurization process: The room temperature demineralized water is sent into the first pressurization pump and pressurized to the pressure range that meets the operating requirements of the deaeration tank; S2 membrane deoxygenation process: Pressurized demineralized water is sent into a degassing tank, where dissolved oxygen is removed from the water under the action of a hydrophobic microporous membrane and gas transport driving force at room temperature. S3 nitrogen-sealed storage process: The deoxygenated demineralized water is sent into a nitrogen-sealed buffer tank and temporarily stored under nitrogen gas sealing. S4 Secondary pressurization process: The room temperature deoxygenated water in the nitrogen-sealing buffer tank is sent to the second pressurization pump to increase the pressure to the conveying pressure required by the ammonia washing tower; S5 Ammonia Washing Process: The final pressurized room temperature deoxygenated water is sent to the ammonia washing tower.

[0017] The beneficial effects of this invention are: (1) This invention completely eliminates the energy waste of the traditional "thermal deoxygenation + circulating water cooling" process, which involves heating first and then cooling. By directly employing membrane deoxygenation at ambient temperatures of 15-40℃, it eliminates the dual requirements for low-pressure steam heating and circulating water cooling from the source of the process. This innovation not only avoids energy mutual cancellation but also significantly improves the overall energy efficiency of the heat recovery unit, achieving an annual production capacity of 150m³. 3 Based on a deoxygenation capacity of [number] m³ / h, it can save 2000 m³ / h annually. 3 With a circulating water capacity of 9t / h and a steam capacity of 9t / h, the operating cost is reduced by approximately 10 million yuan, achieving a significant energy-saving and consumption-reducing effect; (2) Unlike traditional thermal deaerators that are bulky and slow to start (≥2h), this invention uses a modularly designed deaerator tank, which reduces the footprint of the deaerator by more than 50%. At the same time, this technology has the ability to start and stop quickly, and can stabilize the dissolved oxygen content of the effluent to ≤7ppb within 30 minutes. It can flexibly adapt to the production needs of coal chemical plants that rapidly increase or decrease load, and greatly improve the system's operational flexibility and response speed. (3) The membrane deoxygenation process of the present invention is a purely physical separation process, which does not require the addition of chemical deoxygenating agents, thus completely eliminating the consumption of chemical agents and the risk of secondary pollution. This process not only achieves the first successful coupling of low-temperature membrane deoxygenation and ammonia washing water system in a large-scale coal-to-olefins project, but its modular design also gives the solution strong replicability and scalability, providing the coal chemical industry with a new path for efficient, energy-saving, compact and environmentally friendly ammonia washing water deoxygenation.

[0018] (4) The present invention uses the structure formed by the central cylinder, overflow hole and first guide sleeve in the turbulence component to make the liquid fully contact the spirally wound degassing membrane in the upper and lower areas and form a stable liquid film; the pulse system composed of siphon tube and annular tube is automatically triggered by liquid level to break the liquid in the negative pressure suction chamber into fine droplets at high speed and spray it to the lower area, so that the specific surface area increases by hundreds of times and deoxygenates in a vacuum environment. At the same time, the high-level drain hole on the second guide sleeve forms a stable liquid holding layer to ensure sufficient contact time with the degassing membrane; the purge gas membrane component performs gas-liquid separation and moisture absorption and drying on the humid nitrogen discharged from the membrane cavity and then recycles it. While maintaining the oxygen partial pressure difference on both sides of the membrane according to Dalton's partial pressure law, it significantly reduces nitrogen consumption, and finally realizes the preparation of energy-saving and environmentally friendly ammonia washing water with reduced footprint, rapid start and stop and no chemical reagents.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The invention will now be further described with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram of the ammonia washing water preparation process of the present invention; Figure 2 This is a schematic diagram of the overall structure of the degassing tank of the present invention; Figure 3 This is a schematic diagram of the feeding assembly of the present invention; Figure 4 This is a schematic diagram of the material discharge assembly of the present invention; Figure 5 This is a schematic cross-sectional view of the degassing tank of the present invention. Figure 6 This is a schematic diagram of the traditional ammonia washing water preparation process.

[0022] In the diagram: 100, First booster pump; 200, Second booster pump; 300, Deaeration tank; 400, Feeding assembly; 401, Feed tank; 402, Demineralized water feed chamber; 403, Exhaust chamber; 404, Water inlet; 405, Water inlet pipe connector; 406, Drain hole; 407, Air outlet; 408, Air extraction interface; 500, Turbulence assembly; 501, Central cylinder; 502, Central liquid inlet pipe; 503, Overflow hole; 504, First guide sleeve; 505, Negative pressure suction chamber; 506, Siphon pipe; 507. 508. Partition plate; 509. Cylindrical fixed bracket; 510. Second guide sleeve; 511. Degassing membrane; 512. Annular pipe; 603. First drain hole; 604. Discharge assembly; 605. Discharge tank; 606. Demineralized water discharge chamber; 607. Air inlet chamber; 708. Second drain hole; 609. Water outlet pipe connector; 600. Air inlet; 601. Air inlet; 702. Air inlet; 703. Moisture absorption assembly; 704. Pump body; 900. Nitrogen sealing buffer tank. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar symbols denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0025] In the fields of coal chemical and industrial water treatment technology, existing purification units generally adopt a two-stage process for preparing ammonia washing water: thermal deoxygenation + circulating water cooling. The ambient temperature demineralized water is first heated by low-pressure steam for thermal deoxygenation, and then cooled to 40°C by circulating water before being sent to the ammonia washing tower. This process suffers from severe "heat and cold defects," meaning that a large amount of steam is consumed to heat the water to over 100°C for deoxygenation, and then circulating water is used to cool it to 40°C, resulting in double energy waste. Simultaneously, this process involves bulky equipment, slow start-up (requiring more than 2 hours), poor operational flexibility, and reliance on chemical deoxygenators, leading to secondary pollution. Overall, the operating cost is high, failing to meet the energy-saving, consumption-reducing, and rapid response requirements of large-scale coal chemical projects. Therefore, this application proposes a device and method for deoxygenating ammonia washing water in purification units. It aims to completely eliminate the heating and cooling stages at the source of the process through membrane-based ambient temperature deep deoxygenation technology, achieving efficient energy utilization, equipment miniaturization, and rapid start-up and shutdown. It also provides a replicable, low-energy-consumption solution for preparing ammonia washing water for large-scale coal chemical projects.

[0026] Example 1: Please refer to Figure 6 As shown, the traditional ammonia washing solution preparation process steps are as follows: S1. Heating process: The demineralized water at room temperature is fed into the heater and preheated to above 100°C by low-pressure steam. S2. Thermal deoxygenation process: The preheated demineralized water is sent to the thermal deaerator and deoxygenated by low-pressure steam to obtain deoxygenated water (above 100℃). S3. Cooling process: The high-temperature deoxygenated water is cooled to 40°C through a circulating water heat exchanger and sent to the ammonia washing tower as washing water.

[0027] Traditional coal chemical purification plants use a two-stage process for ammonia washing, consisting of thermal deoxygenation and circulating water cooling. This process is energy-intensive. It requires consuming steam to heat the ammonia and then consuming circulating water to cool it, resulting in energy waste of both steam and circulating water. Furthermore, the thermal deaerator is bulky, slow to start (≥2 hours), and requires periodic addition of chemical deoxygenating agents, leading to secondary pollution, large footprint, and poor operational flexibility.

[0028] Please see Figure 1 As shown, the present invention relates to a device and method for deoxygenating ammonia washing water in a purification device, comprising the following steps: S1: First-stage pressurization process: The room-temperature demineralized water is fed into the first booster pump 100 and pressurized to the pressure range required for the operation of the deaeration tank 300. ; S2: Membrane deoxygenation process: The pressurized demineralized water is sent into the deaeration tank 300. Under the action of hydrophobic microporous membrane and gas transmission driving force, dissolved oxygen in the water is removed at room temperature to obtain room temperature deoxygenated water with dissolved oxygen content ≤7ppb. S3: Nitrogen-sealed preservation process: The deoxygenated water is sent into a nitrogen-sealed buffer tank 900 and temporarily stored under nitrogen gas to isolate it from air and prevent the deoxygenated water from dissolving oxygen again. S4: Secondary pressurization process: The room temperature deoxygenated water in the nitrogen-sealing buffer tank 900 is sent to the second pressurization pump 200 to increase the pressure to the required delivery pressure of 7.0~8.0 MPaG for the ammonia washing tower; S5: Ammonia washing process: The final pressurized room temperature deoxygenated water is sent to the ammonia washing tower as washing water.

[0029] This application utilizes a low-temperature deoxygenation process to produce room-temperature deoxygenated water, significantly saving energy. With the increasing scale of domestic coal chemical projects, the energy recovery effect is becoming more prominent. This application eradicates the energy waste problem of "heating before cooling" through innovative technology, completely eliminating the traditional thermal deoxygenation step and achieving deoxygenation to ≤7ppb at room temperature (15-40℃) in a single step. This substantially reduces the consumption of steam, circulating water, and chemical reagents, and improves the energy utilization efficiency of the heat recovery unit. Meanwhile, this application can reduce the footprint of deoxygenation equipment by more than 50% and shorten the start-up time to within 30 minutes, meeting the flexible needs of rapid load increases and decreases in the unit. This technology is the first to achieve the coupling of low-temperature membrane deoxygenation and ammonia washing water system in a large-scale coal-to-olefins project, forming a replicable and scalable modular solution, providing the industry with a new, efficient, energy-saving, and compact deoxygenation path.

[0030] Compared to traditional technologies, the technology in this application possesses significant comprehensive advantages: its energy efficiency is extremely high, as it operates directly at room temperature without the need for preheating to high temperatures, fundamentally solving the "heating and cooling" problem inherent in traditional methods and avoiding energy waste; in terms of equipment and footprint, the small and modular design of the 300 deaerator tank significantly saves space; its start-up speed is extremely fast, achieving dissolved oxygen levels of <7 ppb within 30 minutes, demonstrating highly flexible response; simultaneously, the elimination of the thermal deaerator prevents steam emissions, and the equipment operates at room temperature with no additional heat loss; in terms of environmental protection and cost, the absence of chemical additives avoids chemical consumption and secondary pollution risks, and the modular design supports flexible expansion and low modification difficulty. From an economic perspective, with a production capacity of 150m³... 3 Based on a deoxygenated water volume of [per hour], this can save 2000 m³ / h annually. 3 The system provides 9t / h of circulating water and 9t / h of steam. Although the initial investment is about 3.5 million yuan more than the conventional thermal deaeration scheme, the annual operating cost can be reduced by about 10 million yuan, making the overall economic efficiency very outstanding.

[0031] Example 2: Based on Example 1, please refer to... Figures 2-4As shown, a device for deoxygenating ammonia washing water in a purification system includes a first booster pump 100, a degassing tank 300, a nitrogen-sealing buffer tank 900, a second booster pump 200, and an ammonia washing tower connected in sequence. The upper end of the deaeration tank 300 is provided with a feeding assembly 400. The feeding assembly 400 includes a feeding tank 401 fixedly installed on the top of the deaeration tank 300. The inside of the feeding tank 401 is divided into a demineralized water feeding chamber 402 and an exhaust chamber 403 by a ring. The top end of the demineralized water feeding chamber 402 is provided with a water inlet 404. The upper end of the water inlet 404 is connected to a water inlet pipe connector 405. The bottom end of the demineralized water feeding chamber 402 is provided with a ring array of multiple drainage holes 406. The ring array of drainage holes 406 allows the demineralized water entering the deaeration tank 300 through the demineralized water feeding chamber 402 to be dispersed in the initial stage.

[0032] The bottom end of the exhaust chamber 403 has a ring array of multiple air outlets 407, and the top end of the exhaust chamber 403 is provided with an air extraction interface 408 for connecting a vacuum pump. The vacuum pump is placed at the top of the feed tank 401 so as to evacuate the degassing tank 300 and form the vacuum environment required for degassing.

[0033] Further, please refer to Figure 5As shown, a flow-turbulence assembly 500 is installed inside the degassing tank 300. The interior of the degassing tank 300 is divided into zone I and zone II by a horizontally arranged partition 507. The upper part is zone I, and the lower part is zone II. The flow-turbulence assembly 500 includes a central cylinder 501 located at the bottom of the feed tank 401. The upper end of the central cylinder 501 is connected to the bottom end of the feed tank 401, and the lower end is connected to the upper end of the partition 507. A central liquid inlet pipe 502 is provided at the lower end of the feed tank 401 and inside the central cylinder 501. The upper end of the central liquid inlet pipe 502 is connected to multiple drain holes 406. Demineralized water is introduced into the central liquid inlet pipe 502 through the multiple drain holes 406, and then enters the central cylinder 501 from the bottom end of the central liquid inlet pipe 502. Multiple overflow holes 503 are arranged in a ring array on the outer surface of the upper end of the central cylinder 501. A first guide sleeve 504 is coaxially sleeved on the outer surface of the central cylinder 501. The outer surface of 01 and the inner surface of the first guide sleeve 504 form a negative pressure suction chamber 505. A siphon tube 506 is provided at the bottom end of the negative pressure suction chamber 505. The upper end of the siphon tube 506 penetrates the side wall of the first guide sleeve 504 and extends to its outer side. A cylindrical fixing bracket 508 is provided at the lower end of the partition plate 507. The outer surface of the cylindrical fixing bracket 508 has a hollow structure to ensure that the sprayed desalinated water can pass through the bracket, evenly contact and wet the degassing membrane 510 wrapped around its outer side. A second guide sleeve 509 is coaxially provided at the lower end of the partition 507 and the outer side of the cylindrical fixed bracket 508. The upper end of the second guide sleeve 509 is connected to the partition 507, and the lower end is connected to the inner bottom of the degassing tank 300. Multiple degassing membranes 510 are threaded around the outer surfaces of the central cylinder 501 and the cylindrical fixed bracket 508. The upper ends of the multiple degassing membranes 510 are respectively connected to multiple air extraction ports 408, and the middle part passes through the partition 507 and extends to the lower end of the cylindrical fixed bracket 508. A sealing structure is provided between multiple degassing membranes 510 and partitions 507. The sealing structure can be epoxy resin. One end of the siphon tube 506 extends to the lower end of the partition 507 and is provided with an annular tube 511. Multiple spray holes are opened on the annular tube 511. After the lower end of the siphon tube 506 extends to the bottom end of the partition 507, it first forms a U-shaped bend and then connects upward to the annular tube 511. Multiple first drain holes 512 are opened on the outer surface of the second guide sleeve 509. The height of the first drain holes 512 is relatively high to ensure that the liquid level in Zone II is always maintained below the effective working area of ​​the degassing membrane 510. At the same time, this design allows the liquid to form a stable liquid holding layer in Zone II, ensuring sufficient contact time with the degassing membrane 510. After the dissolved oxygen is fully removed, the excess liquid overflows from the high-level drain holes, thereby achieving dual optimization of membrane deoxygenation efficiency and system stability.

[0034] The degassing membrane 510 is made of hydrophobic polymer. The degassing membrane 510 can be arranged vertically or spirally. Multiple degassing membranes 510 are reliably fixed inside the degassing tank 300 to avoid interference or entanglement during operation. To achieve higher mass transfer efficiency within a limited space, the degassing membrane 510 is preferably arranged spirally; this structure extends the contact path and residence time between the water flow and the membrane fibers, thereby significantly increasing the effective mass transfer area within the same tank volume. The upper ends of the multiple degassing membranes 510 are connected to corresponding air outlets 407.

[0035] After the demineralized water enters the demineralized water feed chamber 402 through the inlet pipe connector 405, it is evenly sprayed into the central liquid inlet pipe 502 through the drain holes 406 of the bottom annular array, achieving initial water distribution. After the demineralized water enters the central cylinder 501, the liquid level in the central cylinder 501 gradually rises, and the demineralized water flows out from the overflow hole 503. The degassing membrane 510 is set on the outer surface of the central cylinder 501, and the overflowing demineralized water will fully contact the degassing membrane 510. At the same time, after the demineralized water enters the negative pressure suction chamber 505, the liquid level in the negative pressure suction chamber 505 gradually rises, and the demineralized water fully contacts the degassing membrane 510. Simultaneously, the vacuum pump creates a vacuum environment inside the degassing membrane 510 through the suction port 408. Under the drive of the partial pressure difference, the oxygen dissolved in the water permeates through the membrane fibers into the gas phase, and is collected in the exhaust chamber 403 through the exhaust hole 407 and then extracted, thereby achieving deep deoxygenation of water at room temperature and ensuring that the dissolved oxygen content of the effluent meets the standard.

[0036] When the liquid level in the negative pressure suction chamber 505 continues to rise and submerges the U-shaped bend at the top of the siphon tube 506, the air inside the tube is sealed by water to form a negative pressure trigger condition, and the siphon phenomenon is instantly activated, drawing the accumulated liquid in the chamber at high speed through the siphon tube 506, and then through the U-shaped water trap at the bottom into the annular tube 511; multiple spray holes evenly opened on the annular tube 511 break the high-speed water flow into countless tiny droplets, which are precisely sprayed onto Zone II in an annular rain pattern, increasing the specific surface area of ​​the droplets by hundreds of times. In the vacuum environment, dissolved oxygen is instantly flashed out, thereby achieving efficient interface renewal and deoxygenation, and the droplets are in full contact with the degassing membrane 510 at the lower end.

[0037] The deoxygenated water flowing from the overflow hole 503 undergoes initial deoxygenation along the membrane surface. It then briefly gathers at the bottom of the negative pressure suction chamber 505. When the water level submerges the top of the siphon tube 506, it is instantly and rapidly drawn away and forcefully sprayed into the depths of the tank in the form of droplets through the bottom annular pipe 511, where it mixes violently with the lower liquid holding layer. At this time, the sprayed water, after mixing with the original water in the lower part, will not be completely drained away from the first drain hole 512. Since the first drain hole 512 is located in the upper middle part of the second guide sleeve 509 rather than the bottom, the upper clear liquid will only slowly overflow and be discharged when the mixed liquid level continues to rise to the height of this hole, while the lower water remains in the tank and continues to be in contact with the membrane fibers, waiting for the next wave of siphon spray to agitate and renew it again. This achieves multiple renewals and deep deoxygenation of each part of the water.

[0038] Based on the design principle of vacuum separation, this application allows deionized water to flow outside a degassing membrane 510 made of hydrophobic polymer. By changing the internal and external pressure of the degassing membrane 510, the gas and liquid are completely separated. According to Henry's Law, when the pressure decreases, the solubility of the gas decreases, causing the free gas in the water to dissolve. The degassing membrane 510 uses hydrophobic polymers (such as polypropylene, polyvinylidene fluoride, etc.) as raw materials, and its microporous structure has selective permeability to both liquids and gases. Due to the hydrophobic properties of the membrane, liquid water cannot wet the membrane pores and permeate due to surface tension (i.e., avoiding membrane pore wetting), while gaseous molecules (such as oxygen, nitrogen, carbon dioxide, etc.) can freely pass through the membrane pores under the drive of partial pressure difference, thereby achieving complete separation of the gas and liquid phases. This sieving and diffusion mechanism of non-porous dense membranes or microporous membranes is the basis for ensuring separation accuracy.

[0039] Further, please refer to Figure 4 As shown, a discharge assembly 600 is provided at the lower end of the deaeration tank 300. The discharge assembly 600 includes a discharge tank 601 located at the lower end of the deaeration tank 300. The lower end of the discharge tank 601 is fixedly mounted on a ring by multiple support columns. The interior of the discharge tank 601 is divided into a demineralized water discharge chamber 602 and an air inlet chamber 603 by the ring. The top of the demineralized water discharge chamber 602 has multiple second drain holes 604 arranged in a ring array. The lower end of the demineralized water discharge chamber 602 is connected to... The water outlet pipe connector 605 and the upper end of the air inlet chamber 603 are provided with multiple air inlets 606 in a ring array. The multiple air inlets 606 are respectively connected to the lower ends of multiple degassing membranes 510. The lower end of the air inlet chamber 603 is connected to an air inlet interface 607. The bottom side wall of the discharge tank 601 is provided with an active discharge port with a valve. When the equipment stops running, the active discharge port can be opened to quickly discharge the demineralized water remaining in the second guide sleeve 509 from the bottom end of the discharge tank 601.

[0040] During the degassing process, the demineralized water after deoxygenation treatment is collected at the bottom of the second guide sleeve 509, enters the demineralized water discharge chamber 602 through the second drain hole 604 of the annular array, and is finally continuously discharged through the water outlet pipe joint 605 and sent to the downstream process.

[0041] Further, please refer to Figure 5 As shown, a purge air mold assembly 700 is provided on one side of the degassing tank 300 for recovering and recycling the moist nitrogen gas discharged from the degassing membrane 510. The purge air mold assembly 700 includes a storage tank 701 disposed on the outer wall of the degassing tank 300. The bottom end of the storage tank 701 is provided with an air inlet 702. The nitrogen source of the air inlet 702 can be external nitrogen or surplus nitrogen from the system, which is recycled.

[0042] A gas-liquid separator is installed at the bottom of the storage tank 701. This gas-liquid separator is existing technology. In this embodiment, a cyclone gas-liquid separator, model HY-DBQF150A low pressure, can be selected. It mainly consists of a tangential air inlet, a cylindrical shell, a central air outlet pipe, a bottom liquid collection chamber, and an automatic or manual drain valve. It uses centrifugal force to throw the liquid droplets entrained in the gas onto the wall and then collect and discharge them, thereby achieving gas-liquid separation.

[0043] A moisture-absorbing component 703 is installed in the middle of the storage tank 701. This moisture-absorbing component 703 is located above the gas-liquid separator and is used to dry the nitrogen gas after gas-liquid separation. The moisture-absorbing component 703 can be filled with an adsorption layer of activated carbon particles or a small membrane dryer, depending on the actual working conditions, to further remove residual water vapor in the nitrogen gas and ensure that the gas entering the downstream is dry and clean.

[0044] A pump body 704 is installed at the upper end of the storage tank 701. The inlet end of the pump body 704 is connected to the exhaust port at the upper end of the storage tank 701, and the outlet end of the pump body 704 is connected to the air inlet 607 at the lower end of the degassing tank 300 through a conduit. Nitrogen gas, after gas-liquid separation and drying, is pressurized by the pump body 704 and sent into the interior of the degassing membrane 510 as a purging gas source, forming a closed-loop recycling of nitrogen gas.

[0045] When nitrogen gas is introduced into the inner side of the membrane as a purge gas, according to Dalton's law of partial pressures, the presence of the purge gas further dilutes the partial pressure of the removed oxygen, creating a larger oxygen partial pressure difference (i.e., concentration gradient driving force) across the membrane. This continuous concentration gradient ensures that oxygen molecules continuously migrate from the liquid phase (high concentration side) to the gas phase (low concentration side) until a new dynamic equilibrium is reached.

[0046] When the degassing membrane 510 is in operation, the circulating purge nitrogen will carry a large amount of water vapor and a small amount of liquid droplets from the membrane module. If it is directly recycled, the liquid water and excessive humidity will destroy the selectivity of the hydrophobic membrane, causing the membrane pores to be wetted by water and unable to achieve normal gas-liquid separation, which will greatly reduce the deoxygenation effect or even cause the device to fail. At the same time, the gas-liquid separation and drying device can remove the moisture from the nitrogen, keeping the nitrogen in a dry state, and then use it as purge gas to be circulated into the inner cavity of the degassing membrane 510. This can not only stably maintain the oxygen partial pressure difference on both sides of the membrane and ensure the deep deoxygenation capacity, but also realize the recovery and reuse of nitrogen, significantly reducing the consumption of external nitrogen supply to the system and improving the economic efficiency and stability of the device operation.

[0047] The flow path of the liquid ( Figure 5 (Indicated by the middle arrow): Water inlet pipe connector 405 → Demineralized water feed chamber 402 → Drain hole 406 → Central liquid inlet pipe 502 → Central cylinder 501 → Overflow hole 503 → Negative pressure suction chamber 505 → Siphon pipe 506 → U-shaped bend → Ring pipe 511 → Spray hole → Zone II (inside the second guide sleeve 509) → Contact with degassing membrane 510 → Second drain hole 604 → Demineralized water discharge chamber 602 → Water outlet pipe connector 605; Gas flow path: dissolved oxygen in liquid → through degassing membrane 510 into membrane cavity → ascending along membrane cavity → outlet 407 → exhaust chamber 403 → suction port 408 → vacuum pump. Purging gas circulation path: Inlet port 607 → Inlet chamber 603 → Inlet hole 606 → Lower end of degassing membrane 510 → Upward movement within the membrane cavity → Carrying gas → Outlet hole 407 → Exhaust chamber 403 → Extraction port 408 → Purging air mold assembly 700 (gas-liquid separation → moisture absorption and drying) → Pump body 704 → Back to inlet port 607.

[0048] Example 3: Based on Examples 1 and 2, please refer to... Figure 1 As shown, an embodiment of this application project is as follows: This invention will be implemented in the first phase of the olefins, aromatics, and deep processing engineering project of the Shaanxi Coal Yulin Chemical 15 million tons / year coal-to-olefins clean and efficient conversion demonstration project. The project is currently in the implementation phase. (This invention requires no chemical reagents, avoiding chemical consumption and secondary pollution risks; its modular design supports capacity expansion and is easy to modify. It can save 2000m³ of capacity.) 3 The initial investment for a 9t / h circulating water and 9t / h steam system is approximately 3.5 million yuan higher than that of a conventional thermal deaeration scheme, but the operating costs can be reduced by approximately 10 million yuan per year. The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A device for deoxygenating ammonia washing water in a purification system, characterized in that, It includes a first booster pump (100), a degassing tank (300), a nitrogen-sealing buffer tank (900), a second booster pump (200), and an ammonia washing tower connected in sequence; The degassing tank (300) is provided with a flow turbulence assembly (500) inside. The flow turbulence assembly (500) includes a partition (507) horizontally arranged inside the degassing tank (300). The degassing tank (300) is provided with a central cylinder (501) inside. The central cylinder (501) is provided with a central liquid inlet pipe (502) inside. The upper end of the central cylinder (501) is provided with a plurality of overflow holes (503) in an annular array. The outer surface of the central cylinder (501) is coaxially fitted with a first guide sleeve (504), and the outer surface of the central cylinder (501) and the inner surface of the first guide sleeve (504) form a negative pressure suction cavity (505). A siphon tube (506) is provided at the bottom end of the negative pressure suction cavity (505). A cylindrical fixing bracket (508) is provided at the lower end of the partition (507). A second flow guide sleeve (509) is coaxially provided at the lower end of the partition (507) and on the outside of the cylindrical fixing bracket (508). Multiple degassing membranes (510) are threaded around the outer surfaces of the central cylinder (501) and the cylindrical fixing bracket (508). The lower end of the siphon tube (506) extends to the lower end of the partition (507).

2. The apparatus for deoxygenating ammonia washing water in a purification device according to claim 1, characterized in that, Each of the degassing membranes (510) penetrates the partition (507), and epoxy resin is disposed between each of them and the partition (507).

3. The apparatus for deoxygenating ammonia washing water in a purification device according to claim 1, characterized in that, One end of the siphon tube (506) extends to the lower end of the partition (507) and is provided with an annular tube (511). The annular tube (511) has multiple spray holes.

4. The apparatus for deoxygenating ammonia washing water in a purification device according to claim 1, characterized in that, The upper end of the second guide sleeve (509) has a ring array of multiple first drain holes (512).

5. The apparatus for deoxygenating ammonia washing water in a purification device according to claim 1, characterized in that, The upper end of the deaeration tank (300) is provided with a feeding assembly (400), the feeding assembly (400) includes a feeding tank (401) fixedly installed on the top of the deaeration tank (300), and the inside of the feeding tank (401) is divided into a demineralized water feeding chamber (402) and an exhaust chamber (403) by a ring. The lower end of the deaeration tank (300) is provided with a discharge assembly (600), which includes a discharge tank (601) located at the lower end of the deaeration tank (300). The interior of the discharge tank (601) is divided into a demineralized water discharge chamber (602) and an air inlet chamber (603) by a ring.

6. The apparatus for deoxygenating ammonia washing water in a purification device according to claim 5, characterized in that, The top of the desalination feed chamber (402) is connected to a water inlet pipe connector (405). The bottom of the demineralized water feed chamber (402) is provided with a ring array of multiple drainage holes (406). The bottom end of the exhaust chamber (403) is provided with a ring array of multiple air outlets (407), and the top end of the exhaust chamber (403) is provided with an air extraction port (408).

7. The apparatus for deoxygenating ammonia washing water in a purification device according to claim 5, characterized in that, The upper end of the air intake chamber (603) is provided with a plurality of air intake holes (606) arranged in a ring array, and the lower end of the air intake chamber (603) is connected to an air intake interface (607).

8. The apparatus for deoxygenating ammonia washing water in a purification device according to claim 1, characterized in that, A purge air mold assembly (700) is provided on one side of the degassing tank (300). The purge air mold assembly (700) includes a storage box (701) disposed on the outer wall of the degassing tank (300), the bottom end of the storage box (701) is provided with an air inlet (702), and the bottom end of the storage box (701) is provided with a gas-liquid separator. A moisture-absorbing component (703) is provided inside the storage tank (701) and above the gas-liquid separator.

9. The apparatus for deoxygenating ammonia washing water in a purification device according to claim 8, characterized in that, The moisture-absorbing component (703) can be selected to be an adsorption layer filled with activated carbon particles or a small membrane dryer.

10. A method for deoxygenating ammonia washing water in a purification device, using the ammonia washing water deoxygenation device according to any one of claims 1-9, characterized in that, Includes the following steps: S1 First-stage pressurization process: The room temperature demineralized water is sent into the first pressurization pump (100) and pressurized to the pressure range that meets the operating requirements of the degassing tank (300); S2 membrane deoxygenation process: Pressurized demineralized water is sent into a degassing tank (300), where dissolved oxygen is removed from the water under the action of hydrophobic microporous membrane and gas transport driving force at room temperature. S3 nitrogen sealing preservation process: The deoxygenated demineralized water is sent into the nitrogen sealing buffer tank (900) and temporarily stored under nitrogen sealing; S4 Secondary pressurization process: The room temperature deoxygenated water in the nitrogen sealing buffer tank (900) is sent into the second pressurization pump (200) to increase the pressure to the conveying pressure required by the ammonia washing tower; S5 Ammonia Washing Process: The final pressurized room temperature deoxygenated water is sent to the ammonia washing tower.

Images