Compact flue gas white smoke elimination tower

Abstract

The utility model discloses a compact flue gas white smoke eliminating tower. Comprising a condensation section, a spraying demisting section and a heating section which are integrally arranged in sequence from bottom to top. The heating section adopts a tubular MGGH heat exchange device, and the tubular MGGH heat exchange device comprises an MGGH flue gas cooler and an MGGH flue gas reheater; in the MGGH flue gas cooler, original high-temperature flue gas is used for heating heat medium water and cooling the flue gas at the same time; and heating the purified flue gas after the water spraying condenser by using the heated heat medium water in the MGGH flue gas reheater, and cooling the heat medium water at the same time. According to the utility model, three white smoke elimination technologies of condensation dehumidification, spray demisting and heating heat exchange are organically combined in one tower, the single tower simultaneously has multiple functions of flow equalization, condensation, demisting, heating, smoke discharge and the like, and compared with a traditional white smoke elimination system with a single technology such as a condensation white smoke elimination tower and a heating white smoke elimination tower, the white smoke elimination system has the advantages of more thorough condensation dehumidification, high smoke discharge temperature, low energy consumption and the like. The white elimination effect is obvious, and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of industrial smoke wet plume treatment, in particular to a compact smoke whitening tower. Background Art

[0002] Definition of wet plume (white smoke): When the saturated wet flue gas discharged from the chimney comes into contact with the ambient air at a lower temperature, the water vapor contained in the flue gas condenses into supersaturated form during the cooling process of the flue gas. The condensed water droplets refract and scatter the light, making the plume appear white or gray. This is called "wet plume" (commonly known as "big white smoke").

[0003] Generally speaking, the severity of white smoke plumes is: winter > autumn ≈ spring > summer. In winter, due to the relatively low ambient temperature, wet smoke plumes are more likely to appear, while in summer, due to the high temperature, the probability of wet smoke plumes is greatly reduced.

[0004] Through research, we found the factors that affect the length of the white plume:

[0005] The lower the ambient temperature, the longer the white smoke plume increases exponentially. The lower the ambient temperature, the more difficult it is to control the wet smoke plume.

[0006] like Figure 1 As shown:

[0007] When the ambient humidity is relatively high, the length of the white smoke plume increases exponentially. Figure 2 As shown: the flue gas temperature decreases, the water vapor in the flue gas condenses, and a white plume is formed. The flue gas diffuses, diluting the water vapor concentration, and the liquid water continues to evaporate, and the white plume dissipates.

[0008] Through mechanism analysis, there are two main technical routes for wet smoke plume management:

[0009] (1) Direct heating: wet smoke plumes can be eliminated under certain conditions, but as the ambient temperature decreases and the relative humidity of the atmosphere increases, it becomes increasingly uneconomical to completely eliminate wet smoke plumes. There are two heating methods: shell-and-tube heaters GGH and water-coal heaters MGGH.

[0010] (2) Condensation before heating: It has the widest application range and good technical and economic performance under certain conditions. First, the clean flue gas is condensed and dehumidified to reduce the moisture content in the flue gas. Then the flue gas is appropriately heated to a small temperature and then sent to the chimney for discharge. The heating method can be water-based MGGH or GGH, which is determined according to the actual situation of the project.

[0011] The desulfurization process of condensation followed by heating can achieve dust reduction of 20%-40%, reduce the emission of SO3 and soluble sulfate, save water consumption for flue gas purification, recover moisture in flue gas and utilize waste heat, etc. Condensation followed by heating can select different condensation target temperatures and heating target temperatures according to project needs and local meteorological conditions to make the best combination, such as Figure 3 shown.

[0012] The solution of directly heating flue gas to eliminate whitening has problems such as heat exchanger blockage, corrosion, smoke cross-talk, high cost, tight installation space, increased resistance loss and insufficient ability to reduce the absolute moisture content of flue gas. Utility Model Content

[0013] In order to overcome the above-mentioned defects, the purpose of the utility model is to provide a compact flue gas whitening tower.

[0014] In order to achieve the above-mentioned purpose, the compact flue gas demisting tower of the utility model comprises a condensing section, a spraying demisting section and a heating section which are integrally arranged from bottom to top.

[0015] Furthermore, a cylindrical air inlet cylinder is arranged below the condensation section, and a guide plate is arranged inside the cylindrical air inlet cylinder.

[0016] Furthermore, the condensation section adopts a condenser; cooling water is introduced into the condenser through a cooling circulating water pipeline.

[0017] Furthermore, the spray demisting section adopts a two-stage spray demisting device for spray demisting, and the spray demisting device as a whole is composed of a ridge-type demisting module, and the ridge-type demisting module is provided with spray pipes and nozzles on the upper and lower sides.

[0018] Furthermore, the temperature rising section adopts a tubular MGGH heat exchange device, which includes an MGGH flue gas cooler and an MGGH flue gas reheater; wherein, the original high-temperature flue gas is used to heat the heat medium water and cool the flue gas at the same time in the MGGH flue gas cooler; and then, the heated heat medium water is used in the MGGH flue gas reheater to heat the clean flue gas after the water spray condenser and cool the heat medium water at the same time.

[0019] Furthermore, a condensate outlet is provided at the bottom of the tower, and the condensate discharged from the condenser and the flushing water discharged from the two-stage spray demister are connected to the condensate outlet through a pipeline.

[0020] Furthermore, a straight steel chimney is arranged on the top of the tower, and a non-metallic compensator is arranged between the temperature rising section and the straight steel chimney.

[0021] Furthermore, an anti-corrosion layer is provided inside the flue structure.

[0022] Furthermore, the tower body support frame is made of a steel structure frame form or a reinforced concrete frame form, and is provided with a ladder, a guardrail, and a maintenance platform.

[0023] In order to achieve the above-mentioned object, the utility model provides a compact flue gas deoxidation tower deoxidation method, wherein the method comprises the following steps:

[0024] The flue gas first enters the whitening tower from the cylindrical air inlet tube set at the bottom of the tower;

[0025] After being rectified and equalized by the cylindrical air inlet, the flue gas enters the first condenser dehumidification section for condensation and dehumidification to reduce the moisture content in the flue gas.

[0026] The flue gas after condensation and dehumidification continues to move upward into the second two-stage spray demister for spray demisting, further removing the fine water mist entrained in the low-temperature flue gas;

[0027] The defogged flue gas continues to move upward into the third heating heat exchanger section for flue gas heating. After passing through the flue gas heating section of the tubular heat medium water flue gas heat exchanger, the flue gas temperature increases to above about 90°C, and is finally discharged into the air through the straight exhaust chimney installed on the top of the tower.

[0028] The utility model combines the tubular MGGH and condenser condensation phase change heat dehumidification technology, uses the tubular MGGH to recover waste heat and heat the flue gas at the same time, adds a set of phase change heat condensers on the flue gas duct, greatly reduces the absolute moisture content of the flue gas, and at the same time, the condensation dehumidification can also condense most of the residual fine dust particles, sulfur dioxide, acid, heavy metals and other pollutants into the drainage, achieving ultra-low near-zero emissions. In addition, the tubular MGGH system can increase the flue gas temperature at the chimney entrance. After the desulfurization system and the phase change condenser, the net flue gas temperature is generally about 45°C, which is nearly 20°C lower than the acid dew point. After passing through the flue gas heating section of the tubular heat medium water flue gas heat exchanger, the net flue gas temperature increases to about 90°C or more, which can reduce flue gas condensation and dew, increase the flue gas lifting force, promote flue gas diffusion, minimize the chimney white smoke phenomenon, and effectively improve the public visual image of white smoke diffusion of flue gas.

[0029] Heating and deoxidizing system: The original high-temperature flue gas is introduced to the tubular MGGH (the tubular MGGH is divided into the MGGH flue gas cooler and the MGGH flue gas reheater), and the high-temperature flue gas is used to heat the heat medium water in the MGGH flue gas cooler (the flue gas is cooled at the same time), and then the heated heat medium water is used to heat the clean flue gas after the water spray condenser in the MGGH flue gas reheater (the heat medium water is cooled at the same time). The heat of the original flue gas or the surrounding high-temperature flue gas is used to heat the heat medium water for temperature increase and heat exchange. The process is simple and the energy consumption is low, and there is no need to use fuel for direct heating.

[0030] Condenser phase change dehumidification system: a set of gas-liquid condensation phase change heat exchangers (hereinafter referred to as "condensers") is set up to condense and cool the low-temperature flue gas. Water is separated from the saturated wet flue gas by the difference in absolute humidity of the flue gas at different temperatures. The cooling water from the open-circulation cooling tower is used as the cold source (the circulating water of the cooling tower can be directly replaced by groundwater). The cooling water is directly introduced into the flue gas condenser to take away this part of the heat, and this part of the heat is brought to the cooling tower by the circulating water for dissipation.

[0031] The beneficial effects of the utility model are:

[0032] 1. The utility model is a compact flue gas dehumidification tower, which organically combines three dehumidification technologies of condensation dehumidification, spray demisting and heating and heat exchange in one tower. The single tower has multiple functions such as flow equalization, condensation, demisting, heating and smoke exhaust. Compared with traditional dehumidification systems with relatively single technologies such as condensation dehumidification tower and heating dehumidification tower, it has the advantages of more thorough condensation dehumidification, high smoke exhaust temperature and obvious dehumidification effect.

[0033] 2. The utility model is a compact flue gas whitening tower, the main functional structures are arranged on one tower, the structure is compact, and the space occupied is small, which is more suitable for renovation projects with small construction sites and insufficient space.

[0034] 3. The condenser of the compact flue gas whitening tower of the utility model can use the cooling circulating water produced by the open-cycle cooling tower, and the acquisition of the medium is relatively convenient.

[0035] 4. The utility model adopts a tubular MGGH as the heating heat exchanger of a compact flue gas deoxidation tower, which can utilize the heat of the original flue gas or the surrounding high-temperature flue gas to heat the heat medium water for heating and heat exchange. The process is simple and the energy consumption is low, and there is no need to use fuel for direct heating.

[0036] 5. The utility model is a compact flue gas dehumidification tower, which integrates multiple technologies such as condensation dehumidification, spray demisting and heating heat exchange. It has the characteristics of strong adaptability and wide range of use. The structure has a high degree of freedom and is easy to realize industrial design parameterization, which is conducive to industrial mass production. According to the temperature, humidity and flue gas composition of the flue gas to be treated, the corresponding condenser, demister and heating heat exchanger and other equipment can be selected, which greatly reduces the difficulty of designing the dehumidification tower facilities and greatly saves the design and installation period of the engineering project. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a graph showing the relationship between white smoke length and ambient temperature.

[0038] Figure 2 Graph showing the relationship between white smoke length and ambient humidity.

[0039] Figure 3Different combinations of flue gas decolorization condensation temperature and reheat temperature.

[0040] Figure 4 It is a schematic cross-sectional structure diagram of an embodiment of the utility model;

[0041] Figure 5 for Figure 4 A schematic diagram of a side cross-sectional structure;

[0042] In the figure: 1. Cylindrical air inlet cylinder; 2. Tianyuanfangdifang connecting pipe; 3. Condenser; 4. Two-stage spray demister; 5. Heating heat exchanger; 6. Tianyuanfangdifang connecting pipe; 7. Non-metallic compensator; 8. Straight steel chimney; 9. Condensate outlet; 10. Air duct; 11. Cooling circulating water pipe; 12. Heat medium water pipe; 13. Tower support frame. DETAILED DESCRIPTION

[0043] The embodiments of the utility model are described in detail below with reference to the accompanying drawings.

[0044] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0045] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "plurality" means two or more.

[0046] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] The utility model discloses a compact flue gas whitening tower, which combines three whitening technologies of condensation dehumidification, spray demisting and heating and heat exchange, and is designed to integrate multiple functions such as flow equalization, condensation, demisting, heating and smoke exhaust. The tower comprises the following specific contents: a cylindrical air inlet cylinder (1), a round-square connecting pipe (2), a condenser (3), a two-stage spray demister (4), a heating and heat exchanger (5), a round-square connecting pipe (6), a non-metallic compensator (7), a straight steel chimney (8), a condensate outlet (9), an air duct (10), a cooling circulating water pipe (11), a heat medium water pipe (12), a tower body support frame (13) and other parts.

[0048] like Figures 1 to 2 As shown, the flue gas after wet desulfurization or other types of wet flue gas are introduced into the cylindrical air inlet (1) at the bottom of the whitening tower through the induced air flue (10). The cylindrical air inlet (1) has the functions of rectifying and equalizing the flow. In actual design, in order to enhance the equalizing effect, an air flow distribution device such as a guide plate can be added inside the cylinder. The flue gas flow velocity inside the cylinder is generally controlled at 12-15 m / s, with the purpose of making the air flow distribution before entering the condenser (3) as uniform as possible. The cylindrical air inlet (1) can be erected on the whitening tower support frame (13) using the bottom bracket support structure. A round sky and square ground (2) is arranged on the upper part of the cylindrical air inlet (1) and connected to the bottom of the condenser (3). The lower part of the cylindrical air inlet (1) is a funnel structure, and a condensate outlet (9) is arranged at the bottom to connect to the external drainage pipe.

[0049] The condenser (3), the two-stage spray demister (4), and the temperature-raising heat exchanger (5) are arranged in sequence from bottom to top to form a three-stage structural layout, and the flue gas drawn out from the cylindrical air inlet cylinder (1) passes through the above three-stage structural areas in sequence from bottom to top.

[0050] The first stage uses a condenser (3) for condensation and dehumidification. For flue gas containing acidic substances or other corrosive substances, since the temperature is lower than the dew point temperature, the condenser body can be made of 2205 duplex stainless steel with strong corrosion resistance. The condenser can work normally after introducing cooling water through the cooling circulating water pipe (11). In actual design, a tubular condenser structure is often used, but there are higher requirements for equipment resistance. Generally, the equipment resistance shall not be higher than 600Pa (the condensation pipes should not be laid too densely).

[0051] The second section adopts a two-stage spray demister (4) for spray demister. The spray demister is composed of a ridge-type demister module. Spray pipes and nozzles are arranged on the upper and lower parts of the module. The spray pipes are connected to the production water delivery pipe. For highly corrosive flue gas, the demister shell can be made of 2205 duplex stainless steel with strong corrosion resistance. In actual design, the number of layers and the number of demister modules can be selected according to the different characteristics of the flue gas.

[0052] The third stage uses a heating heat exchanger (5) to heat the flue gas. For systems with high original flue gas temperatures, a tubular MGGH heat exchanger is generally used (the tubular MGGH is divided into an MGGH flue gas cooler and an MGGH flue gas reheater), that is, the original high-temperature flue gas is used to heat the heat medium water in the MGGH flue gas cooler (while the flue gas is cooled), and then the heated heat medium water is used in the MGGH flue gas reheater to heat the clean flue gas after the water spray condenser (while the heat medium water is cooled). The heat of the original flue gas or the surrounding high-temperature flue gas is used to heat the heat medium water for heating and heat exchange. The process is simple and has low energy consumption, and there is no need to use fuel for direct heating. (If there is no high-temperature flue gas in the system and the surrounding area, the flue gas can still be heated by a hot air furnace.)

[0053] In a preferred embodiment, the outlet of the heating heat exchanger (5) and the straight-discharge steel chimney (8) are connected by a non-metallic compensator (7), and the flue gas reaches the top of the whitening tower after three-stage whitening treatment and is discharged into the atmosphere through the straight-discharge steel chimney (8).

[0054] In a preferred embodiment, a condensate outlet (9) is provided at the bottom of the tower, so that the condensate discharged from the condenser (3) and the flushing water discharged from the two-stage spray demister (4) can be discharged centrally, and generally can be connected to the sewage sedimentation tank or the plant water treatment system. In actual design, the height difference can be used to directly drain the water into the plant sewage treatment tank.

[0055] In a preferred embodiment, a straight steel chimney (8) is provided at the top of the tower. Since the hot flue gas after heating has a certain amount of thermal expansion, a non-metallic compensator (7) needs to be provided between the temperature-raising heat exchanger (5) and the straight steel chimney (8).

[0056] In a preferred embodiment, since wet flue gas is often lower than the dew point temperature and the flue gas temperature is even lower after condensation and dehumidification, it is more corrosive. The interior of the flue structure, such as the cylindrical air inlet cylinder (1), the round-square connecting pipe (2), the round-square connecting pipe (6), the straight steel chimney (8), and the air duct (10), needs to be treated with corrosion protection. After rust removal, 2 mm glass flake resin is applied.

[0057] Optionally, the tower body support frame (13) can be made in the form of a steel structure frame or a reinforced concrete frame, and can be provided with necessary ladders, guardrails and maintenance platforms.

[0058] The utility model uses the utility model owner to design the Jizhong Energy Group Huarui (Handan) Casting Pipe Co., Ltd. 120m 2 The equipment test data of the sintering machine flue gas denitrification and denitrification project was used as the design basis. At the same time, computer simulation calculation results were used as an auxiliary means to carry out comprehensive simulation and testing of the denitrification tower to ensure its feasibility.

[0059] The utility model adopts a flue gas dehumidification process route of first cooling and condensing to dehumidify, and then heating. The wet flue gas is first dehumidified by the condenser, which greatly reduces the absolute moisture content of the flue gas. At the same time, condensation and dehumidification can also condense most of the residual fine particles of dust, sulfur dioxide, acid, heavy metals and other pollutants into the drainage, achieving ultra-low near-zero emissions.

[0060] The condensed flue gas is defogged by a two-stage spray demister to remove most of the fine water mist.

[0061] After passing through the phase change condenser and demister, the flue gas temperature is generally about 45°C, which is nearly 20°C lower than the acid dew point. After passing through the flue gas heating section of the tubular heat medium water flue gas heat exchanger, the net flue gas temperature increases to about 90°C or above, which can reduce flue gas condensation, increase flue gas lifting force, promote flue gas diffusion, and improve the white smoke phenomenon in the chimney.

[0062] The condensate and the spray flushing water of the demister enter the condensate outlet (9) collecting tank at the bottom of the denitrification tower, and then are led out to the sewage pool through the drainage pipe at the bottom of the tank for later purification treatment.

[0063] The utility model is described in detail above in conjunction with the accompanying drawings, but the utility model is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the utility model. Many other changes and modifications that do not depart from the concept and scope of the utility model should be considered as the protection scope of the utility model.

[0064] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0065] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A compact flue gas whitening tower, characterized in that: It includes a condensing section, a spray demisting section and a heating section which are arranged in sequence from bottom to top; the heating section adopts a tubular MGGH heat exchange device, and the tubular MGGH heat exchange device includes an MGGH flue gas cooler and an MGGH flue gas reheater; wherein, the MGGH flue gas cooler uses the original high-temperature flue gas to heat the heat medium water and cool the flue gas at the same time; and then, the MGGH flue gas reheater uses the heated heat medium water to heat the clean flue gas after the water spray condenser and cool the heat medium water at the same time; A cylindrical air inlet cylinder is arranged below the condensation section, and a guide plate is arranged inside the cylindrical air inlet cylinder.

2. The compact flue gas whitening tower according to claim 1, characterized in that: The condensation section adopts a condenser; cooling water is introduced into the condenser through a cooling circulating water pipeline.

3. The compact flue gas whitening tower according to claim 1, characterized in that: The spray demisting section adopts a two-stage spray demisting device for spray demisting. The spray demisting device is composed of a ridge-type demisting module as a whole. Spray pipes and nozzles are arranged above and below the ridge-type demisting module.

4. The compact flue gas whitening tower according to claim 1, characterized in that: An anti-corrosion layer is provided inside the flue structure.

Images