A device for treating and recycling desulfurization wastewater of thermal power generation

Abstract

This invention provides a device for treating and reusing desulfurization wastewater from thermal power plants, relating to the field of desulfurization wastewater treatment. The device includes a flue with a stop ring installed at its upper end and spiral blades installed on its inner wall. It also includes a preheating box with an inlet and an outlet on its side, the inlet being above the outlet. A diffuser is installed at the outlet, with its other end connected to the middle side wall of the flue. A heat exchange mechanism is also included, installed inside the preheating box. A deflector pipe is installed at the inlet of the heat exchange mechanism, with its other end connected to the bottom side of the flue. This device, through the heat exchange mechanism and flue, allows high-temperature exhaust gas in the flue to be blown upwards from the bottom, causing the desulfurization wastewater to evaporate, crystallize, and fall to the bottom of the flue for collection. This achieves high-efficiency heat exchange and a fast crystallization rate in the flue.

Description

Technical Field

[0001] This invention relates to the field of desulfurization wastewater treatment, specifically to a device for treating and reusing desulfurization wastewater from thermal power plants. Background Technology

[0002] Wastewater generated during wet desulfurization in thermal power plants is extremely difficult to treat. Common methods include evaporation crystallization, spray drying, and spraying the desulfurization wastewater into a high-temperature flue (after the air preheater) to evaporate the salt in the wastewater into powdered salt, which is then captured by the dust collector along with the flue dust and recycled.

[0003] Chinese Patent Publication (Announcement) No. CN206173007U discloses a device for evaporating desulfurization wastewater using a spray cooling tower heated by hot water. The device collects the desulfurization wastewater into a concentration tank; a circulating pump pumps the desulfurization wastewater from the concentration tank to a plastic heat exchanger; the desulfurization wastewater is heated to a certain temperature in the plastic heat exchanger and then enters the spray cooling tower, where it is sprayed into fine particles from the nozzles and falls down. Steam evaporates from the top of the spray cooling tower, and the concentrated desulfurization wastewater enters the water pool of the spray cooling tower, where salt is crystallized through heating and evaporation.

[0004] The device that uses hot water to heat the desulfurization wastewater spray cooling tower for evaporation has low heat exchange efficiency and is prone to scaling during the wastewater treatment process. Moreover, the desulfurization wastewater heats up slowly in the flue after heating, so the wastewater is still in a liquid state after falling. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a device for treating and reusing desulfurization wastewater from thermal power plants, which solves the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a device for treating and reusing desulfurization wastewater from thermal power plants, comprising a flue, a stop ring installed at the upper end of the flue, and spiral blades installed on the inner wall of the flue; a preheating box, with an inlet and an outlet installed on the side of the preheating box, the inlet being above the outlet; a diffusion device installed at the outlet, the other end of which is connected to the middle side wall of the flue; and a heat exchange mechanism installed inside the preheating box, with a diverting pipe installed at the inlet of the heat exchange mechanism, the other end of which is connected to the bottom side of the flue; and an exhaust pipe installed at the bottom of the heat exchange mechanism, the other end of which is connected to the bottom side of the flue.

[0007] Preferably, the heat exchange mechanism includes a heat-conducting pipe, which is annular with pleated sides, allowing it to contract and expand; it also includes multiple expansion tubes, arranged annularly within the heat-conducting pipe and positioned within the pleats of the heat-conducting pipe, with their sides fixed to the heat-conducting pipe. After being filled with water, the expansion tubes can open the pleats of the heat-conducting pipe; and it further includes two air chambers, located on the upper and lower sides of the heat-conducting pipe, respectively. Each of the upper and lower ends of the expansion tube is equipped with an elastic tube communicating with its interior, and the other end of the elastic tube is installed on and communicates with the corresponding air chamber. The two air chambers are respectively connected to the upper and lower ends of the preheating box.

[0008] Preferably, an air inlet pipe is installed on the upper air chamber, and a central tube is installed at the end of the air inlet pipe near the air chamber. The steering pipe is connected to the side of the central tube and communicates with its interior.

[0009] Preferably, the heat pipe is suspended inside the preheating box, and the desulfurization wastewater entering from the water inlet can pass through the inner and outer sides of the preheating box respectively.

[0010] Preferably, the diffusion device includes a water spray pipe and a diversion pipe. One end of the water spray pipe is connected to the water outlet and the other end is connected to the flue. Multiple diversion pipes are provided, with one end connected to the water spray pipe and the other end connected to the flue. The multiple diversion pipes are arranged longitudinally to divert the desulfurization wastewater inside the water spray pipe.

[0011] Preferably, a tapered tube is provided between the water outlet and the spray pipe, with the large end of the tapered tube connected to the water outlet and the small end connected to the spray pipe.

[0012] Preferably, the positions where the diverter pipe and the water spray pipe connect to the flue correspond to the spiral blades.

[0013] Preferably, the spiral blade is annular, with its upper end extending to the top of the flue.

[0014] Preferably, a contraction tube is installed at the bottom end of the flue.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. This desulfurization wastewater treatment and reuse device for thermal power plants, through the setting of a heat exchange mechanism and a flue, allows the desulfurization wastewater to be discharged into the flue after passing through a preheating box. A portion of the high-temperature flue gas from the flue is first fed into an expansion tube before entering the flue, while the remaining portion enters directly into the flue. The flue gas entering the expansion tube heats the heat-conducting tube, thus the high-temperature expansion tube and heat-conducting tube heat the desulfurization wastewater inside the preheating box. The heated wastewater then enters the flue through a diffusion device. The high-temperature exhaust gas in the flue blows the desulfurization wastewater upwards from the bottom, causing it to evaporate, crystallize, and fall to the bottom of the flue for collection. After the heat-conducting tube is fully charged, the bottom gas chamber valve is closed, and the expansion tube continues to expand, allowing multiple expansion tubes to open the heat-conducting tube, removing external scale and maintaining the preheating effect on the wastewater. This achieves high-efficiency heat exchange and a fast flue crystallization rate.

[0017] 2. This desulfurization wastewater treatment and reuse device for thermal power plants uses spiral blades to separate the wastewater entering the flue into multiple streams, which are then dispersed by the high-temperature flue gas. At this time, the flue gas carries water mist and spirals upward along the spiral blades, which can increase the heating time. The water mist is evaporated before it is completely discharged from the flue. Moreover, because the wastewater has been preheated in the early stage and is divided into multiple streams, it is not easy for it to fall downward.

[0018] 3. The wastewater treatment and reuse device for desulfurization of thermal power plants is equipped with a spray pipe. After being preheated in the preheating box, the wastewater can pass through the conical pipe and be transformed into a water mist with a faster flow rate and better diffusion effect. The gaps between water molecules are increased, making it easier to be heated. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention;

[0020] Figure 2 This is a cross-sectional view of the structure of the present invention;

[0021] Figure 3 This is a diagram showing the internal structure of the flue of the present invention;

[0022] Figure 4 This is a schematic diagram of the preheating box of the present invention;

[0023] Figure 5 This is a schematic diagram of the heat exchange mechanism of the present invention;

[0024] Figure 6 This is an exploded view of the heat exchange mechanism of the present invention;

[0025] Figure 7 For the present invention Figure 6 Enlarged view of the structure at point A in the image.

[0026] In the diagram: 1. Flue; 2. Cut-off ring; 3. Spiral blade; 4. Preheating box; 5. Water inlet; 6. Water outlet; 7. Diffusion device; 701. Spray pipe; 702. Diverter pipe; 703. Conical pipe; 8. Heat exchange mechanism; 801. Heat conduction pipe; 802. Expansion pipe; 803. Gas chamber; 804. Elastic pipe; 805. Air inlet pipe; 806. Central pipe; 9. Diverting pipe; 10. Exhaust pipe; 11. Contraction pipe. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0028] It should be noted that all directional indications in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0029] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0030] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0031] like Figures 1-7As shown, a device for treating and reusing desulfurization wastewater from a thermal power plant includes a flue 1, a stop ring 2 installed at the upper end of the flue 1, a spiral blade 3 installed on the inner wall of the flue 1, a preheating box 4, an inlet end 5 and an outlet end 6 installed on the side of the preheating box 4, the inlet end 5 being above the outlet end 6, a diffusion device 7 installed on the outlet end 6, the other end of the diffusion device 7 being connected to the middle side wall of the flue 1, and a heat exchange mechanism 8 installed inside the preheating box 4. A diverting pipe 9 is installed at the air inlet end of the heat exchange mechanism 8, the other end of the diverting pipe 9 being connected to the bottom side of the flue 1, and an exhaust pipe 10 is installed at the bottom of the heat exchange mechanism 8, the other end of the exhaust pipe 10 being connected to the bottom side of the flue 1.

[0032] The flue duct 1 is placed vertically and needs to be of a certain length to ensure that the heat of the high-temperature flue gas is utilized as much as possible. The stop ring 2 can prevent the flue gas from flowing too fast due to siphon effect. The water inlet 5 of the preheating box 4 is connected to the desulfurization wastewater pump and water tank or upstream treatment equipment. The water inlet 5 is located at the top so that the heated wastewater can flow downwards, ensuring that the heat inside the entire preheating box 4 is balanced.

[0033] The heat exchange mechanism 8 includes a heat-conducting pipe 801, which is annular with pleated sides, allowing it to contract and expand; it also includes multiple expansion pipes 802, which are annularly distributed within the heat-conducting pipe 801 and located within the pleats of the heat-conducting pipe 801, with their sides fixed to the heat-conducting pipe 801. After being filled with water, the expansion pipes 802 can push open the pleats of the heat-conducting pipe 801; and it also includes two air chambers 803, located on the upper and lower sides of the heat-conducting pipe 801, respectively. Both ends of the expansion pipes 802 are equipped with elastic tubes 804 that communicate with their interiors. The other end of the elastic tubes 804 is installed on and communicates with the corresponding air chambers 803. The two air chambers 803 are respectively connected to the upper and lower ends of the preheating box 4.

[0034] The heat pipe 801 can be made of high-temperature resistant plastic material, which is not easy to accumulate scale. Even if scale does accumulate, it can be broken off by deformation. The expansion pipe 802 is also made of high-temperature resistant elastic deformable material, which can expand after being inflated. The elastic pipe 804 is a flexible tube that can be deformed.

[0035] An air inlet pipe 805 is installed on the upper air chamber 803. A central pipe 806 is installed at one end of the air inlet pipe 805 near the air chamber 803. The steering pipe 9 is connected to the side of the central pipe 806 and communicates with its interior.

[0036] The central tube 806 mainly diverts high-temperature hot air, transferring the majority of it into flue 1, and using a small portion to heat the wastewater.

[0037] The heat pipe 801 is suspended inside the preheating box 4, and the desulfurization wastewater entering from the water inlet 5 can pass through the inner and outer sides of the preheating box 4 respectively.

[0038] Suspended heating can rapidly raise the temperature of wastewater, and the pleated structure of both methods makes heat transfer more efficient and allows for more frequent heat exchange.

[0039] The diffusion device 7 includes a water spray pipe 701 and a diversion pipe 702. One end of the water spray pipe 701 is connected to the water outlet 6, and the other end is connected to the flue 1. There are multiple diversion pipes 702, one end of which is connected to the water spray pipe 701, and the other end is connected to the flue 1. The multiple diversion pipes 702 are arranged longitudinally to divert the desulfurization waste inside the water spray pipe 701.

[0040] Both the water spray pipe 701 and the diversion pipe 702 are relatively thin, and the high-pressure water pumped in can be diffused into a water mist. In order to ensure the spray quality, a nozzle can also be installed at the water spray end in the flue 1. The nozzle needs to be equipped with anti-clogging features.

[0041] A tapered tube 703 is provided between the water outlet 6 and the water spray pipe 701. The large end of the tapered tube 703 is connected to the water outlet 6, and the small end is connected to the water spray pipe 701.

[0042] Used to increase flow rate and disperse wastewater after heating.

[0043] The positions where the diversion pipe 702 and the water spray pipe 701 connect to the flue 1 correspond to the spiral blade 3.

[0044] The spiral blade 3 is annular, with its upper end extending to the top of the flue 1.

[0045] The spiral blade 3 allows for maximum heat exchange between the flue gas and the wastewater.

[0046] A contraction pipe 11 is installed at the bottom of flue 1.

[0047] The shrink tube 11 is used to collect fallen salt residue and dust from the flue gas.

[0048] During use, the desulfurization wastewater is pumped through the preheating box 4 and then discharged into the flue 1. A small portion of the high-temperature flue gas in the flue 1 is first sent into the expansion tube 802 and then into the flue 1. The other portion of the high-temperature flue gas enters the flue 1 directly. The flue gas entering the expansion tube 802 can heat the heat conduction tube 801, so the high-temperature expansion tube 802 and heat conduction tube 801 can heat the desulfurization wastewater inside the preheating box 4. After heating, the wastewater can enter the flue 1 through the diffusion device 7. The wastewater entering the flue 1 will be divided into multiple streams and then blown away by the high-temperature flue gas. At this time, the flue gas carrying water mist rises spirally along the spiral blade 3, which can increase the heating time. The water mist is evaporated before it is completely discharged from the flue 1. The high-temperature exhaust gas in the flue 1 can blow the desulfurization wastewater from the bottom upwards, and then evaporate and crystallize, falling to the bottom of the flue 1 for collection. After the external structure of the heat conduction pipe 801 is completed, the valve of the bottom air chamber 803 is closed. The expansion pipe 802 continues to be filled with air and will expand and enlarge. Thus, multiple expansion pipes 802 can open the heat conduction pipe 801, and the external scale can be removed.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0050] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for treating and reusing desulfurization wastewater from thermal power plants, comprising a flue (1), characterized in that: A stop ring (2) is installed at the upper end of the flue (1), a spiral blade (3) is installed on the inner wall of the flue (1), and a preheating box (4) is also included. A water inlet (5) and a water outlet (6) are installed on the side of the preheating box (4). The water inlet (5) is located above the water outlet (6). A diffusion device (7) is installed on the water outlet (6). The other end of the diffusion device (7) is connected to the middle side wall of the flue (1). A heat exchange mechanism (8) is also included, which is installed in the preheating box (4). A diverting pipe (9) is installed at the air inlet of the heat exchange mechanism (8). The other end of the diverting pipe (9) is connected to the bottom side of the flue (1). An exhaust pipe (10) is installed at the bottom of the heat exchange mechanism (8). The other end of the exhaust pipe (10) is connected to the bottom side of the flue (1). The heat exchange mechanism (8) includes a heat-conducting pipe (801), which is annular and has a pleated side that can contract and expand; it also includes an expansion pipe (802), which is provided in multiple annularly distributed inside the heat-conducting pipe (801) and located within the pleats of the heat-conducting pipe (801). Its side is fixed to the heat-conducting pipe (801). After the expansion pipe (802) is inflated, it can push open the pleats of the heat-conducting pipe (801); it also includes two air chambers (803), which are located on the upper and lower sides of the heat-conducting pipe (801) respectively. Both the upper and lower ends of the expansion pipe (802) are equipped with elastic tubes (804) that communicate with their interiors. The other end of the elastic tube (804) is installed on the corresponding air chamber (803) and communicates with it. The two air chambers (803) are connected to the upper and lower ends of the preheating box (4) respectively.

2. The device for treating and reusing desulfurization wastewater from thermal power plants according to claim 1, characterized in that: An air inlet pipe (805) is installed on the upper air chamber (803). A central tube (806) is installed at one end of the air inlet pipe (805) near the air chamber (803). A steering pipe (9) is connected to the side of the central tube (806) and communicates with its interior.

3. The device for treating and reusing desulfurization wastewater from thermal power plants according to claim 2, characterized in that: The heat pipe (801) is suspended inside the preheating box (4), and the desulfurization wastewater entering from the water inlet (5) can pass through the inner and outer sides of the preheating box (4).

4. The device for treating and reusing desulfurization wastewater from thermal power plants according to claim 1, characterized in that: The diffusion device (7) includes a water spray pipe (701) and a diversion pipe (702). One end of the water spray pipe (701) is connected to the water outlet (6), and the other end is connected to the flue (1). There are multiple diversion pipes (702), one end of which is connected to the water spray pipe (701), and the other end is connected to the flue (1). The multiple diversion pipes (702) are arranged longitudinally to divert the desulfurization wastewater inside the water spray pipe (701).

5. The device for treating and reusing desulfurization wastewater from thermal power plants according to claim 4, characterized in that: A tapered tube (703) is provided between the water outlet (6) and the water spray pipe (701). The large end of the tapered tube (703) is connected to the water outlet (6), and the small end is connected to the water spray pipe (701).

6. The device for treating and reusing desulfurization wastewater from thermal power plants according to claim 5, characterized in that: The positions where the diversion pipe (702) and the water spray pipe (701) are connected to the flue (1) correspond to the spiral blade (3).

7. The device for treating and reusing desulfurization wastewater from thermal power plants according to claim 6, characterized in that: The spiral blade (3) is annular, with its upper end extending to the top of the flue (1).

8. The device for treating and reusing desulfurization wastewater from thermal power plants according to claim 1, characterized in that: A shrink tube (11) is installed at the bottom end of the flue (1).

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