A desulfurization wastewater evaporation reduction device based on a vaporization membrane

Abstract

The utility model belongs to desulfurization wastewater treatment technical field especially relates to a kind of desulfurization wastewater evaporation reduction device based on vaporization membrane, device is placed in the center position inside indirect air cooling tower, utilize the low-grade hot air of indirect air cooling tower originally direct discharge as free heat source, make it from bottom to top flow through vaporization membrane evaporator, when the desulfurization wastewater in concentration pool is transported to evaporator top and evenly distributed on vaporization membrane surface, with the hot air that rises in indirect air cooling tower carries out counterflow heat exchange on membrane surface, realizes the concentration reduction of desulfurization wastewater.This process significantly reduces the dependence of traditional evaporation technology on steam or electric energy, achieves significant energy-saving effect.At the same time, the device utilizes the waste heat originally direct discharge, realizes the collaborative management of waste heat and desulfurization wastewater, provides an effective technical approach for low-cost, low-energy-consumption treatment of desulfurization wastewater.

Description

Technical Field

[0001] This utility model belongs to the field of desulfurization wastewater treatment technology, and in particular relates to a desulfurization wastewater evaporation reduction device based on vaporization membrane. Background Technology

[0002] Desulfurization wastewater is high-salinity, highly polluting wastewater generated by desulfurization systems in industrial production processes such as thermal power plants and chemical plants. Its composition is complex, typically containing heavy metals, chloride ions, sulfate ions, and other pollutants, making it difficult to treat. Currently, mainstream treatment technologies include evaporation crystallization and membrane separation. Evaporation crystallization is widely used because it can achieve "zero discharge" of desulfurization wastewater; however, this method mainly relies on steam or electric heating, resulting in high energy consumption.

[0003] In industrial systems, indirect air-cooled towers are widely used in heat exchange processes, and the low-temperature hot air they discharge contains a large amount of low-grade heat energy. Because this type of heat energy is of low grade, it is difficult to utilize it directly and efficiently, and currently most of it is directly discharged into the atmosphere, resulting in heat waste.

[0004] To address the aforementioned issues, this paper proposes a desulfurization wastewater evaporation reduction device based on vaporization membrane. This device utilizes the low-grade hot air originally directly discharged from the indirect air-cooled tower as a heat source to perform evaporation reduction treatment on desulfurization wastewater. The aim is to effectively utilize waste heat energy, reduce treatment energy consumption, and provide a new approach for efficient and energy-saving treatment of desulfurization wastewater. Utility Model Content

[0005] The purpose of this invention is to provide a desulfurization wastewater evaporation reduction device based on vaporization membrane to solve the above-mentioned problems.

[0006] To achieve the above objectives, this utility model provides the following solution:

[0007] A desulfurization wastewater evaporation reduction device based on vaporization film includes: a desulfurization wastewater evaporation reduction system and an air-cooled heat exchange system;

[0008] The air-cooled heat exchange system includes an indirect air-cooled tower, with multiple air-cooled radiators arranged circumferentially on the outer side of the indirect air-cooled tower. An air inlet is provided on the indirect air-cooled tower for communicating with the exhaust end of the air-cooled radiator, and the air inlet is located at the lower part of the indirect air-cooled tower.

[0009] The desulfurization wastewater evaporation reduction system includes a concentration tank, which is located inside the indirect air-cooled tower and in the middle of the indirect air-cooled tower. At least one vaporization membrane evaporator is provided above the concentration tank, and a conveying mechanism for conveying the desulfurization wastewater to the top of the vaporization membrane evaporator is provided inside the concentration tank.

[0010] Preferably, the vaporization film evaporator includes a frame, in which a plurality of vaporization films are arranged sequentially from left to right. Each vaporization film has a fixing rod passing through both ends. The two fixing rods are parallel and symmetrically designed. Each fixing rod extends out of the frame and is threaded with a nut. The nut abuts against the outer wall of the frame.

[0011] Preferably, the conveying mechanism includes a water distribution pipe, the bottom end of which is located inside the thickening tank and connected to a submersible pump. The other end of the water distribution pipe is connected to multiple spray pipes, which are located above the vaporization membrane. The multiple spray pipes are arranged in a one-to-one correspondence with multiple vaporization membranes. The bottom end of each spray pipe is connected to multiple atomizing nozzles, which are arranged at equal intervals along the length of the vaporization membrane.

[0012] Preferably, a base is fixed to the bottom end of the frame, and the base is fixed to the inner bottom wall of the thickening tank. The bottom end of the frame is higher than the liquid level of the desulfurization wastewater in the thickening tank.

[0013] Preferably, a sedimentation tank is provided on one side of the thickening tank, and the overflow port of the sedimentation tank is connected to the thickening tank. The liquid level of the desulfurization wastewater in the thickening tank is lower than the height of the overflow port. After sedimentation, the desulfurization wastewater in the sedimentation tank flows through the overflow port to the thickening tank.

[0014] Preferably, the sedimentation tank is connected to the outlet end of the desulfurization wastewater transfer pump, and the inlet end of the desulfurization wastewater transfer pump is connected to the desulfurization wastewater pool through the desulfurization wastewater inlet pipe.

[0015] Preferably, a sewage pump is installed in the thickening tank, and the outlet of the sewage pump is connected to a thickened water discharge pipe.

[0016] Compared with the prior art, the present invention has the following advantages and technical effects:

[0017] This invention provides a desulfurization wastewater evaporation reduction device based on a vaporization membrane. The evaporation reduction device is placed at the center of an indirect air-cooled tower, utilizing the low-grade hot air directly discharged from the tower as a free heat source. When the desulfurization wastewater from the concentration tank is transported to the top of the evaporator and evenly distributed on the vaporization membrane surface, it undergoes sufficient heat and mass exchange with the rising hot air, thus achieving efficient evaporation reduction of the desulfurization wastewater. This process significantly reduces the dependence of traditional evaporation technology on steam or electricity, achieving significant energy savings. Simultaneously, the device utilizes the previously directly discharged waste heat, realizing the synergistic treatment of waste heat and desulfurization wastewater, providing an effective technical approach for low-cost, low-energy-consumption treatment of desulfurization wastewater. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the vaporization film evaporator in this utility model;

[0021] Figure 3 This is a schematic diagram showing the connection between the atomizing nozzle and the vaporization film evaporator in this utility model;

[0022] Figure 4 This is one arrangement of the vaporization film evaporator in this utility model;

[0023] Figure 5 This is another arrangement of the vaporization film evaporator in this utility model;

[0024] Among them, 1. Indirect air-cooled tower; 2. Air-cooled radiator; 3. Wastewater inlet pipe; 4. Wastewater transfer pump; 5. Sedimentation tank; 6. Overflow outlet; 7. Concentrator; 8. Submersible sewage pump; 9. Water distribution pipe; 10. Atomizing nozzle; 11. Vaporizing film evaporator; 12. Base; 13. Sewage pump; 14. Concentrated water discharge pipe; 1101. Frame; 1102. Fixing rod; 1103. Nut; 1104. Vaporizing film. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Reference Figures 1 to 5 This utility model discloses a desulfurization wastewater evaporation reduction device based on vaporization film, including: a desulfurization wastewater evaporation reduction system and an air-cooled heat exchange system;

[0028] The air-cooled heat exchange system includes an indirect air-cooled tower 1, with multiple air-cooled radiators 2 arranged circumferentially on the outer side of the indirect air-cooled tower 1. An air inlet is provided on the indirect air-cooled tower 1 for communicating with the exhaust end of the air-cooled radiator 2, and the air inlet is located at the lower part of the indirect air-cooled tower 1.

[0029] The desulfurization wastewater evaporation reduction system includes a thickening tank 7, which is located inside and in the middle of the indirect air-cooled tower 1. At least one vaporization membrane evaporator 11 is installed above the thickening tank 7, and a conveying mechanism is installed inside the thickening tank 7 to transport the desulfurization wastewater to the top of the vaporization membrane evaporator 11.

[0030] The indirect air-cooled tower 1 generates suction force, causing outside air to pass through the air-cooled radiator 2. After heat exchange with the air-cooled radiator 2, low-grade hot air is formed. The low-grade hot air enters the indirect air-cooled tower 1 and flows upward. During this process, it flows through the vaporization film evaporator 11, accelerating the evaporation of desulfurization wastewater on the vaporization film evaporator 11.

[0031] The conveying mechanism lifts the desulfurization wastewater in the concentration tank 7 to above the vaporization film evaporator 11, and causes the desulfurization wastewater to flow down the vaporization film evaporator 11, forming a water film on the surface of the vaporization film evaporator 11. This increases the contact area between the desulfurization wastewater and the low-grade hot air, strengthens the convective heat exchange between the desulfurization wastewater and the hot air, and facilitates the evaporation of the desulfurization wastewater.

[0032] This invention achieves functional coupling of two major systems, using the waste heat energy of the indirect air-cooled tower 1 as a heat source to drive the evaporation of desulfurization wastewater, thus laying the foundation for the subsequent evaporation reduction process.

[0033] In a further optimized design, the vaporization film evaporator 11 includes a frame 1101. Multiple vaporization films 1104 are arranged sequentially from left to right within the frame 1101. Fixed rods 1102 are inserted through both ends of the vaporization film 1104. The two fixed rods 1102 are parallel and symmetrically designed. Both ends of the fixed rods 1102 extend out of the frame 1101 and are respectively threaded with nuts 1103. The nuts 1103 abut against the outer wall of the frame 1101.

[0034] The vaporization membrane 1104 is preferably a glass fiber vaporization membrane, including a glass fiber nonwoven fabric base layer with a porosity of 85% and a fiber diameter of 10μm, providing a high specific surface area heat exchange substrate.

[0035] The fiberglass nonwoven fabric base layer is inlaid with fiberglass mesh fabric with a mesh count of 50 mesh, which improves the mechanical strength of the fiberglass nonwoven fabric base layer and prevents deformation.

[0036] The surface of the glass fiber nonwoven base layer is coated with an epoxy hydrophilic resin with a thickness of 8μm to improve the spreadability of desulfurization wastewater and prevent water droplets from accumulating.

[0037] Multiple vaporization membranes 1104 are reliably fixed by fixing rods 1102 and nuts 1103 and installed at equal intervals within the frame 1101, forming a huge specific surface area and constructing a stable and uniform vaporization heat exchange interface. This ensures that desulfurization wastewater can be fully spread on the membrane surface, while facilitating the flow of hot air, thus providing structural support for efficient heat and mass exchange.

[0038] The scheme is further optimized. The conveying mechanism includes a water distribution pipe 9. The bottom end of the water distribution pipe 9 is located in the thickening tank 7 and is connected to a submersible sewage pump 8. The other end of the water distribution pipe 9 is connected to multiple spray pipes. The spray pipes are located above the vaporization membrane 1104. The multiple spray pipes are set one-to-one with multiple vaporization membranes 1104. The bottom end of the spray pipe is connected to multiple atomizing nozzles 10. The multiple atomizing nozzles 10 are set at equal intervals along the length direction of the vaporization membrane 1104.

[0039] Submersible pump 8 pumps the desulfurization wastewater in thickening tank 7 into distribution pipe 9, then diverts it into multiple spray pipes, and finally sprays it onto the top of vaporization film 1104 through multiple atomizing nozzles 10.

[0040] The atomizing nozzles 10, which are evenly spaced along the length of the vaporization film 1104, can achieve uniform water distribution on the top of the vaporization film evaporator 11, ensuring that the desulfurization wastewater can cover as much of the vaporization film 1104 surface as possible, thus creating conditions for subsequent uniform evaporation.

[0041] In a further optimized design, a base 12 is fixedly connected to the bottom of the frame 1101. The base 12 is fixedly connected to the inner bottom wall of the thickening tank 7. The bottom of the frame 1101 is higher than the liquid level of the desulfurization wastewater in the thickening tank 7.

[0042] Supported by the base 12, the bottom of the entire frame 1101 and the vaporization membrane 1104 inside it is kept above the liquid level in the thickener 7, which effectively prevents the static desulfurization wastewater in the thickener 7 from soaking the vaporization membrane, avoids membrane pore blockage, and ensures the normal operation of the system.

[0043] In one alternative, a sedimentation tank 5 is provided on one side of the thickening tank 7. The overflow port 6 of the sedimentation tank 5 is connected to the thickening tank 7. The liquid level of the desulfurization wastewater in the thickening tank 7 is lower than the height of the overflow port 6. After sedimentation, the desulfurization wastewater in the sedimentation tank 5 flows to the thickening tank 7 through the overflow port 6.

[0044] The raw water from the desulfurization wastewater pond undergoes preliminary sedimentation in sedimentation tank 5, and the supernatant overflows into thickening tank 7 through overflow outlet 6. After the wastewater evaporates, its volume decreases, creating a level difference between sedimentation tank 5 and thickening tank 7.

[0045] The sedimentation tank 5 not only serves as a pre-sedimentation tank, but also naturally introduces the desulfurization wastewater into the thickening tank 7 through overflow. It also maintains the stability of the liquid level in the thickening tank 7 by utilizing the liquid level difference, preventing the liquid level from being too high and submerging the evaporator.

[0046] In one alternative, the sedimentation tank 5 is connected to the outlet of the desulfurization wastewater transfer pump 4, and the inlet of the desulfurization wastewater transfer pump 4 is connected to the desulfurization wastewater pool through the desulfurization wastewater inlet pipe 3.

[0047] The desulfurization wastewater transfer pump 4 draws desulfurization wastewater from the desulfurization wastewater pool through the desulfurization wastewater inlet pipe 3 and pumps it into the sedimentation tank 5. This achieves stable initial transport of desulfurization wastewater from the storage unit to the treatment unit, providing continuous feed for subsequent sedimentation and evaporation treatments.

[0048] In one alternative, a sewage pump 13 is installed in the thickening tank 7, and the outlet of the sewage pump 13 is connected to a concentrated water discharge pipe 14.

[0049] As the desulfurization wastewater continuously evaporates on the surface of the vaporization membrane evaporator 11, the salt content of the desulfurization wastewater in the concentration tank 7 gradually increases. When the predetermined concentration is reached, the sewage pump 13 is started to discharge the concentrated desulfurization wastewater from the system through the concentrated water discharge pipe 14. This achieves the controlled discharge of concentrated desulfurization wastewater, fulfills the desulfurization wastewater reduction target, and prepares the conditions for subsequent final treatment.

[0050] Workflow: Desulfurization wastewater is first stored in a desulfurization wastewater tank. The desulfurization wastewater transfer pump 4 is started, and the wastewater is pumped into the sedimentation tank 5 through the desulfurization wastewater inlet pipe 3. Preliminary sedimentation occurs in the sedimentation tank 5, separating some suspended solids. The supernatant after sedimentation overflows into the thickening tank 7 through the overflow port 6. Since the liquid level in the thickening tank 7 is set lower than that in the overflow port 6, this process relies on the liquid level difference to proceed naturally and maintain the stability of the liquid level in the thickening tank 7. The desulfurization wastewater in the thickening tank 7 is drawn out by the submersible pump 8 and transported to the spray pipe at the top of the device through the water distribution pipe 9. The desulfurization wastewater is then distributed to multiple atomizing nozzles 10 and evenly sprayed onto the top of the vaporization film evaporator 11. Under the action of gravity, the desulfurization wastewater flows downwards along the surface of the vertically suspended vaporization film 1104, forming a liquid film. Simultaneously, the heated air generated after the air-cooled radiator 2 cools the process fluid rises in the indirect air-cooled tower 1 and is discharged from the top outlet of the tower. The low-grade hot air passes through a narrow channel composed of multiple vaporization films 1104. Within the channel, the rising hot air comes into full contact with the desulfurization wastewater film flowing beneath the vaporization films 1104, resulting in efficient heat and mass exchange. The water in the desulfurization wastewater absorbs the sensible heat of the hot air and evaporates, with the water vapor being released into the atmosphere, thus concentrating and reducing the volume of the desulfurization wastewater. As the evaporation process continues, the salt concentration of the desulfurization wastewater in the concentration tank 7 continuously increases. When the concentration reaches a set value, the sewage pump 13 is activated, discharging the concentrated desulfurization wastewater from the system through the concentrated water discharge pipe 14 for further treatment or disposal.

[0051] With the concentration ratio controlled at 3.5, the evaporation rate of desulfurization wastewater reaches 60%-70%, and there is no obvious corrosion or scaling after 30 days of continuous operation. The utilization rate of waste heat from the air is over 80%.

[0052] The vaporization membrane 1104 is inspected every three months to determine whether it needs to be cleaned or replaced. The surface cleaning is done with 0.3MPa high-pressure water to wash away the salt deposited on the surface of the vaporization membrane 1104 after the desulfurization wastewater is evaporated, so as to ensure that the pores of the vaporization membrane 1104 are unobstructed.

[0053] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0054] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A desulfurization wastewater evaporation reduction device based on vaporization membrane, characterized in that, include: Desulfurization wastewater evaporation reduction system and air-cooled heat exchange system; The air-cooled heat exchange system includes an indirect air-cooled tower (1), and multiple air-cooled radiators (2) are equally spaced around the outer periphery of the indirect air-cooled tower (1). An air inlet is provided on the indirect air-cooled tower (1) for communicating with the exhaust end of the air-cooled radiator (2), and the air inlet is located at the lower part of the indirect air-cooled tower (1). The desulfurization wastewater evaporation reduction system includes a thickening tank (7), which is located in the middle of the indirect air-cooled tower (1). At least one vaporization membrane evaporator (11) is provided above the thickening tank (7), and a conveying mechanism for conveying the desulfurization wastewater to the top of the vaporization membrane evaporator (11) is provided in the thickening tank (7).

2. The desulfurization wastewater evaporation reduction device based on vaporization membrane according to claim 1, characterized in that: The vaporization film evaporator (11) includes a frame (1101), in which a plurality of vaporization films (1104) are arranged sequentially from left to right. The two ends of the vaporization film (1104) are provided with fixing rods (1102). The two fixing rods (1102) are parallel and symmetrically designed. The two ends of the fixing rods (1102) extend out of the frame (1101) and are respectively threaded with nuts (1103). The nuts (1103) abut against the outer wall of the frame (1101).

3. The desulfurization wastewater evaporation reduction device based on vaporization membrane according to claim 2, characterized in that: The conveying mechanism includes a water distribution pipe (9), the bottom end of which is located inside the thickening tank (7) and connected to a submersible sewage pump (8). The water distribution pipe (9) is connected to multiple spray pipes, which are located above the vaporization membrane (1104). The multiple spray pipes are arranged in a one-to-one correspondence with the multiple vaporization membranes (1104). The bottom end of the spray pipe is connected to multiple atomizing nozzles (10), which are equally spaced along the length of the vaporization membrane (1104).

4. The desulfurization wastewater evaporation reduction device based on vaporization membrane according to claim 2, characterized in that: The bottom end of the frame (1101) is fixedly connected to a base (12), which is fixedly connected to the inner bottom wall of the thickening tank (7). The bottom end of the frame (1101) is higher than the liquid level of the desulfurization wastewater in the thickening tank (7).

5. The desulfurization wastewater evaporation reduction device based on vaporization membrane according to claim 1, characterized in that: A sedimentation tank (5) is provided on one side of the thickening tank (7). The overflow port (6) of the sedimentation tank (5) is connected to the thickening tank (7). The liquid level of the desulfurization wastewater in the thickening tank (7) is lower than the height of the overflow port (6). After sedimentation, the desulfurization wastewater in the sedimentation tank (5) flows through the overflow port (6) to the thickening tank (7).

6. The desulfurization wastewater evaporation reduction device based on vaporization membrane according to claim 5, characterized in that: The sedimentation tank (5) is connected to the outlet end of the desulfurization wastewater transfer pump (4), and the inlet end of the desulfurization wastewater transfer pump (4) is connected to the desulfurization wastewater pool through the desulfurization wastewater inlet pipe (3).

7. The desulfurization wastewater evaporation reduction device based on vaporization membrane according to claim 1, characterized in that: The thickening tank (7) is equipped with a sewage pump (13), and the outlet of the sewage pump (13) is connected to a concentrated water discharge pipe (14).

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