A flue gas purification system and treatment method for non-gas boiler

Abstract

The present invention relates to a flue gas purification system and a treatment method for a non-gas-fired boiler. The waste heat of a hot flue is used to heat water in a hot water storage device. The generated water vapor is mixed with the dense smoke to increase the humidity in the flue gas, increase the weight of the smoke ash, and increase the precipitation speed. When the water-containing dense smoke enters the dense smoke storage chamber, there is a temperature difference between the ground level and the ground level. Then, through collision with the partition, the coal ash and soluble pollutants in the dense smoke are condensed on the partition and flow into the water layer along the partition. After treatment, the clean smoke enters the clean smoke storage chamber. The temperature difference between the ground level and the dense smoke storage chamber and the reduction of the flow rate are used to further condense the water vapor in the clean smoke, and then it is discharged through the chimney. In addition, the arrangement of a smoke hood on the top of the chimney also plays a role in further condensing the water vapor in the flue gas, thereby realizing the precipitation and recovery of the water vapor in the flue. The coal-fired boiler of the present technical solution does not require a tall chimney, and the coal smoke and water vapor cannot be seen.

Description

Technical Field

[0001] The present invention belongs to the field of environmental protection technology, in particular to the field of boiler environmental protection technology, and in particular to a purification system and a treatment method for removing thick smoke and odor of a non-gas boiler. Background Art

[0002] Boilers are an indispensable source of heat or steam for modern industrial production. Most industrial production cannot be separated from the use of boilers. Early boilers were mainly coal-fired boilers because the cost of coal was low and the storage capacity of coal was large. Some large boilers are still coal-fired boilers today.

[0003] However, coal-fired boilers still have inevitable defects. The first is that the combustion value of coal is low. The second is that the thermal utilization efficiency of coal-fired boilers is low. In addition, during use, a large amount of coal slag and coal ash are generated, which involves the problem of later treatment. However, the biggest problem facing coal-fired boilers is that during the combustion process, a large amount of flue gas is generated, which causes pollution to the atmosphere.

[0004] Since 2000, with the rapid development of industry, the use of boilers has also increased, and mainly small and medium-sized coal-fired boilers, with low flue gas treatment efficiency or no treatment, directly discharged into the atmosphere, is the main source of air pollution. In order to protect the atmospheric environment and allow people to enjoy fresh air and live in blue skies and green waters while developing industry, the country has issued the most stringent measures on the use of coal-fired boilers, and strictly prohibited the use of coal-fired boilers in certain areas, and replaced coal-fired boilers with gas boilers.

[0005] The fuel source of gas boilers is natural gas, and the products of its combustion are carbon dioxide and water. The impact on the environment is very small, and the calorific value is high. However, the disadvantage of gas boilers is that the price of natural gas is more than twice that of coal, which leads to increased costs. In addition, my country's natural gas reserves are not sufficient to support domestic needs, and a large amount of imports are required, which will lead to the impact of the international environment.

[0006] For large coal-fired boilers, the flue gas also needs to be treated before it is discharged into the atmosphere, and the cost of flue gas treatment is very high. For small and medium-sized coal-fired boilers, the cost of flue gas treatment is even higher. How to reduce the cost of tail gas treatment for small and medium-sized coal-fired boilers and achieve safe discharge of tail gas is a research topic in the current field. Summary of the invention

[0007] The purpose of the present invention is to provide a flue gas purification system and treatment method for a non-gas-fired boiler, so as to solve the problem that the flue gas treatment cost of existing small and medium-sized coal-fired boilers is high and the flue gas treatment effect is poor, resulting in pollution of the atmospheric environment and inability to use.

[0008] The present invention is achieved through the following technical solutions:

[0009] A flue gas purification system for a non-gas-fired boiler, comprising:

[0010] A hot water storage device, the hot water storage device is sleeved on the hot flue of the boiler, and is provided with a water inlet, a water outlet and a steam outlet, wherein the steam outlet is connected to the hot flue through a humidification pipeline;

[0011] The primary flue gas treatment device comprises a dense smoke storage chamber, a partition and a coal ash precipitation tank; the dense smoke storage chamber is a semi-underground storage space; a dense smoke inlet is arranged on the left wall of the above-ground part of the dense smoke storage chamber, and a smoke outlet is arranged on the lower side of the underground part of the right wall; the outlet of the hot flue is connected to the dense smoke inlet;

[0012] The partition is obliquely arranged in the thick smoke storage chamber, the upper end of the partition is connected to the right side wall of the thick smoke storage chamber, and the lower end of the partition is not connected to the left side wall and the bottom of the thick smoke storage chamber;

[0013] The coal ash precipitation tank is arranged at the bottom of the smoke storage chamber close to the left side wall;

[0014] A secondary flue gas treatment device, wherein the secondary flue gas precipitation device is a clean smoke storage chamber, and the clean smoke storage chamber is arranged below the ground level; a clean smoke inlet is arranged at the lower side of the left side wall of the clean smoke storage chamber, connected to the smoke outlet, and a clean smoke outlet is arranged at the lower side of the right side wall; the lower bottom of the clean smoke storage chamber is an inclined surface, extending from the clean smoke outlet to the clean smoke inlet, and the lower bottom of the clean smoke storage chamber gradually decreases;

[0015] An exhaust fan is arranged at the smoke outlet;

[0016] A chimney, wherein the upper part of the chimney is located above the ground level, a smoke inlet is arranged at the lower side of the chimney and is connected to the smoke removal outlet, a smoke hood is arranged at the outlet of the chimney, and the smoke hood is inverted at the outlet of the chimney.

[0017] Furthermore, a pipe is provided between the drain outlet of the hot water storage device and the boiler water supply pipe to add hot water into the boiler.

[0018] Furthermore, an air inlet observation chamber is provided below the hot water storage device, an exhaust valve is provided below the hot water storage device in the air inlet observation chamber, and a maintenance valve is provided on the hot flue.

[0019] Furthermore, the coal ash sedimentation tank is connected to a sewage well arranged outside the thick smoke storage chamber.

[0020] Furthermore, a lower smoke channel is formed between the partition and the left side wall of the dense smoke storage chamber, and a side smoke channel is formed between the partition and the bottom of the dense smoke storage chamber; the lower smoke channel and the side smoke channel are connected above the coal ash sedimentation tank.

[0021] Furthermore, a liquid level indicator is provided in the coal ash sedimentation tank.

[0022] Furthermore, the inclination angle of the lower bottom of the clean smoke storage chamber is greater than 15 degrees.

[0023] Furthermore, an inspection port is provided above the clean smoke storage chamber.

[0024] A treatment method using any of the above flue gas purification systems comprises the following steps:

[0025] S1. A water layer is provided at the bottom of the dense smoke storage chamber, and the liquid level of the water layer is slightly higher than the lowest edge of the smoke outlet;

[0026] S2. The dense smoke generated by the boiler during operation enters the hot flue. The heat of the hot flue heats the water in the hot water storage device. The generated steam enters the hot flue through the humidification pipeline and mixes with the dense smoke to form water-containing dense smoke.

[0027] S3, after entering the smoke storage chamber, the water-containing smoke collides with the partition, and by utilizing the temperature difference between the underground part and the aboveground part in the smoke storage chamber, the coal ash and soluble substances in the water-containing smoke flow downward along the partition into the water layer; the smoke after preliminary treatment passes through the lower smoke channel and the side smoke channel in turn into the smoke storage space below the partition and becomes clean smoke and is discharged through the smoke outlet;

[0028] S4. The clean smoke discharged through the smoke outlet enters the clean smoke storage chamber. By utilizing the temperature difference between the clean smoke storage chamber below the ground level and the outside, the water vapor containing pollutants dissolved in the clean smoke is further cooled and flows back to the water layer at the bottom of the dense smoke treatment chamber through the slope of the lower bottom of the clean smoke storage chamber.

[0029] S5. The clean smoke after being processed in the clean smoke storage room enters the chimney through the exhaust fan;

[0030] S6. The flue gas entering the chimney is discharged from the top outlet of the chimney through the flue hood to further remove water vapor.

[0031] The beneficial effects of the present invention are:

[0032] The technical scheme firstly utilizes the waste heat of the hot flue to heat the water in the hot water storage device, further reduces the temperature of the flue gas, and mixes the water vapor generated by the hot water storage device with the thick smoke, thereby increasing the humidity in the flue gas and improving the thermal utilization efficiency of the boiler, and the coal ash and soluble substances in the thick smoke, such as sulfur-containing compounds and nitrogen-containing compounds, can be dissolved in the water vapor; when the water-containing thick smoke enters the thick smoke storage chamber, the volume increases and the flow rate decreases, and there is a temperature difference between the ground level and the above ground level. Then, through the collision with the partition, the coal ash and soluble pollutants in the thick smoke are condensed on the partition and flow along the partition into the water layer. After treatment, the clean smoke enters the clean smoke storage chamber, and the temperature difference below the ground level and the inside of the clean smoke storage chamber and the reduction in flow rate are utilized to further condense the water vapor in the clean smoke, and then it is discharged through the chimney. Moreover, the arrangement of the smoke hood on the top of the chimney also plays a role in further condensing the water vapor in the flue gas.

[0033] The coal-fired boiler of the present technical solution does not need a tall chimney, and no coal smoke or water vapor can be seen. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the structure of the flue gas purification system of the present invention.

[0035] Description of Reference Numerals

[0036] 1 boiler, 2 boiler water inlet pipe, 3 drainage pipeline, 4 hot water storage device, 5 humidification pipeline, 6 thick smoke inlet, 7 hot flue, 8 air inlet observation room, 9 air inlet, 10 water inlet, 11 drain valve, 12 thick smoke storage room, 13 partition, 14 fly ash sedimentation tank, 15 sewage well, 16 water pump, 17 liquid level indicator buoy, 18 smoke outlet, 19 exhaust fan, 20 chimney, 21 smoke hood, 22 inspection port, 23 ladder, 24 water layer, 25 clean smoke storage room. DETAILED DESCRIPTION

[0037] The technical solutions of the present invention are described in detail below through embodiments. The following technical solutions are merely exemplary and can only be used to explain and illustrate the technical solutions of the present invention, but cannot be construed as limiting the technical solutions of the present invention.

[0038] In the technical solution of the present application, all references to “left”, “right”, “up”, “down”, “front” and “back” refer to relative positions and are only used to illustrate the technical solution of the present application.

[0039] The present technical solution is not only used to purify the flue gas of small and medium-sized boilers, but also can achieve the appearance that only the boiler is visible but not the chimney, breaking the traditional requirement that a tall chimney must be erected whenever there is a boiler. On the other hand, the technology of the present application makes full use of the temperature difference between the underground and the ground to purify the flue gas. Specifically, in summer, the lower temperature of the thick smoke storage chamber is lower than the upper temperature; in winter, the upper temperature of the thick smoke storage chamber is lower than the lower temperature to purify the flue gas, thereby reducing the cost of flue gas purification and achieving a purification effect.

[0040] like Figure 1 As shown, the present application provides a flue gas purification system for a non-gas boiler, comprising:

[0041] The hot water storage device 4 is made of metal and is a double-layer water storage tank welded to the hot flue of the boiler 1. A water inlet 10, a drain and a steam outlet are provided on the hot water storage device, wherein the steam outlet is connected to the hot flue 7 through a humidification pipeline 5; the water inlet is connected to the water supply pipeline through a pipeline, and a control valve is provided on the water supply pipeline; the drain outlet is connected to the boiler water inlet pipe 2 through a drain pipeline 3, and a control valve is provided on the pipeline. In other embodiments of the present application, the drain outlet can also be connected to other pipelines to provide hot water for other production or heating.

[0042] An air inlet observation chamber 8 is provided below the hot water storage device, an exhaust valve 11 is provided below the hot water storage device in the air inlet observation chamber, and a maintenance valve is provided on the hot flue for purposes such as maintenance of the fan.

[0043] An air inlet 9 is provided in the air inlet observation room, and the air inlet can be used to adjust the exhaust power of the exhaust fan. The larger the exhaust power, the larger the air volume of the air inlet. When the exhaust fan stops, this place becomes a smoke outlet, which does not affect the use of the boiler.

[0044] The primary flue gas treatment device comprises a dense smoke storage chamber 12, a partition 13 and a coal ash sedimentation tank 14; the dense smoke storage chamber is a semi-underground storage space; in the technical solution of the present application, the dense smoke storage chamber usually adopts a concrete structure.

[0045] A thick smoke inlet 6 is arranged on the left wall of the above-ground part of the thick smoke storage chamber, and a smoke outlet 18 is arranged on the lower side of the underground part of the right wall; the outlet of the hot flue is connected to the thick smoke inlet.

[0046] The partition 13 is obliquely arranged in the thick smoke storage chamber, the upper end of the partition is connected to the right side wall of the thick smoke storage chamber, and the lower end of the partition is not connected to the left side wall and the bottom of the thick smoke storage chamber; the partition divides the thick smoke storage chamber into an upper part and a lower part, a lower smoke channel is formed between the partition and the left side wall of the thick smoke storage chamber, and a side smoke channel is formed between the partition and the bottom of the thick smoke storage chamber; the lower smoke channel and the side smoke channel are connected above the coal ash sedimentation tank 14.

[0047] The water-containing thick smoke entering from the thick smoke inlet enters the upper part of the thick smoke storage chamber. Because the area of ​​the thick smoke inlet is much smaller than the area of ​​the upper part of the thick smoke storage chamber, at this time, the flow velocity of the water-containing thick smoke decreases sharply. At this time, the particles in the thick smoke begin to fall under the action of gravity. At the same time, the thick smoke storage chamber above the partition is basically located above the ground level, and the thick smoke storage chamber below the partition is located below the ground level. The temperature below is lower than the temperature above, and the temperature below is about 10-12°C. The thick smoke collides with the partition during movement, and combined with the temperature difference between the upper and lower parts of the partition, most of the water vapor condenses and flows downward along the partition. At this time, the condensed water droplets will bring out the coal ash, sulfur-containing compounds and nitrogen-containing compounds soluble in water from the flue gas at the same time. At this time, the pollutant content in the thick smoke is reduced.

[0048] On the other hand, there is a water layer 24 at the bottom of the thick smoke storage chamber. When encountering the incoming hot flue gas, a large amount of water vapor will be generated at about 40-50°C. In addition, the thick smoke storage chamber is a sealed structure with only one smoke outlet at the bottom. The black smoke can only be converted into clean and harmless smoke in the thick smoke storage chamber and then be led out by the exhaust fan from the smoke outlet at the bottom layer.

[0049] The thick smoke from which some pollutants have been removed becomes lighter in color and becomes clean smoke. The clean smoke passes through the lower smoke channel and the side smoke channel between the partition and the side wall and enters the thick smoke storage chamber under the partition. Here, because the temperature is further reduced, more water vapor condenses and separates from the clean smoke and falls into the water layer at the bottom.

[0050] The coal ash sedimentation tank 14 is arranged at the bottom of the thick smoke storage room near the left side wall, with a slope of about 25° relative to the bottom of the thick smoke storage room. The coal ash sedimentation tank is connected to the sewage well 15 outside the thick smoke storage room. A water pump 16 and a liquid level indicating buoy 17 are arranged in the coal ash sedimentation tank. According to the indication of the liquid level, the water pump is turned on to extract the coal ash and sewage in the coal ash sedimentation tank for mixing with the coal to be burned, thereby reducing or avoiding sewage discharge. During maintenance, maintenance personnel can enter the thick smoke storage room through the sewage well.

[0051] A layer of water is injected into the bottom of the smoke storage chamber. The liquid level of the water layer is slightly higher than the bottom edge of the smoke outlet. The function of the water layer is to store pollutants separated from the smoke and ensure the temperature difference between the top and bottom of the partition.

[0052] In the embodiment of the present application, the bottom of the thick smoke storage chamber is a plane or an inclined plane.

[0053] The secondary flue gas treatment device, the secondary flue gas precipitation device is a clean smoke storage chamber, the clean smoke storage chamber is arranged below the ground level, so under natural conditions, the temperature in the clean smoke storage chamber is lower than that in the thick smoke storage chamber. A clean smoke inlet is arranged at the lower side of the left side wall of the clean smoke storage chamber, connected to the smoke outlet, and a clean smoke outlet is arranged at the lower side of the right side wall; the lower bottom of the clean smoke storage chamber is an inclined surface greater than 15 degrees, extending from the clean smoke outlet to the clean smoke inlet, and the lower bottom of the clean smoke storage chamber gradually decreases; after the clean smoke enters the clean smoke storage chamber, the water vapor in the smoke is cooled and condensed again, and the corresponding pollutants are taken out from the clean smoke.

[0054] An inspection port 22 and a ladder 23 are provided above the clean smoke storage chamber 25 to facilitate maintenance of the clean smoke storage chamber.

[0055] The exhaust fan 19 is arranged at the clean smoke outlet and is used to introduce the smoke into the chimney 20.

[0056] A chimney, wherein the upper part of the chimney is located above the ground level, a smoke inlet is arranged at the lower side of the chimney and is connected to the smoke removal outlet, a smoke hood 21 is arranged at the outlet of the chimney, the smoke hood is inverted at the outlet of the chimney, there is a gap between the smoke hood and the top of the chimney, and the smoke is discharged outward from the gap.

[0057] The present application also provides a treatment method using any of the above flue gas purification systems, comprising the following steps:

[0058] S1. A water layer is provided at the bottom of the dense smoke storage chamber, and the liquid level of the water layer is slightly higher than the lowest edge of the smoke outlet;

[0059] S2. The dense smoke generated by the boiler during operation enters the hot flue. The heat of the hot flue heats the water in the hot water storage device. The generated steam enters the hot flue through the humidification pipeline and mixes with the dense smoke to form water-containing dense smoke.

[0060] S3, after entering the smoke storage chamber, the water-containing smoke collides with the partition, and by utilizing the temperature difference between the underground part and the aboveground part in the smoke storage chamber, the coal ash and soluble substances in the water-containing smoke flow downward along the partition into the water layer; the smoke after preliminary treatment passes through the lower smoke channel and the side smoke channel in turn into the smoke storage space below the partition and becomes clean smoke and is discharged through the smoke outlet;

[0061] S4. The clean smoke discharged through the smoke outlet enters the clean smoke storage chamber. By utilizing the temperature difference between the clean smoke storage chamber below the ground level and the outside, the water vapor containing pollutants dissolved in the clean smoke is further cooled and flows back to the water layer at the bottom of the dense smoke treatment chamber through the slope of the lower bottom of the clean smoke storage chamber.

[0062] S5. The clean smoke after being processed in the clean smoke storage room enters the chimney through the exhaust fan;

[0063] S6. The flue gas entering the chimney is discharged from the top outlet of the chimney through the flue hood to further remove water vapor.

[0064] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A flue gas purification system for a non-gas boiler, characterized in that: include: A hot water storage device, the hot water storage device is sleeved on the hot flue of the boiler, and is provided with a water inlet, a water outlet and a steam outlet, wherein the steam outlet is connected to the hot flue through a humidification pipeline; The primary flue gas treatment device comprises a thick smoke storage chamber, a partition and a coal ash precipitation tank; the thick smoke storage chamber is a semi-underground storage space; a thick smoke inlet is arranged on the left wall of the above-ground part of the thick smoke storage chamber, and a smoke outlet is arranged on the lower side of the underground part of the right wall; the outlet of the hot flue is connected to the thick smoke inlet, and a layer of water is injected into the bottom of the thick smoke storage chamber, and the liquid level of the water layer is slightly higher than the bottom edge of the smoke outlet; The partition is obliquely arranged in the thick smoke storage chamber, the upper end of the partition is connected to the right side wall of the thick smoke storage chamber, and the lower end of the partition is not connected to the left side wall and the bottom of the thick smoke storage chamber; The coal ash precipitation tank is arranged at the bottom of the smoke storage chamber close to the left side wall; A secondary smoke treatment device, the secondary smoke treatment device is a clean smoke storage chamber, the clean smoke storage chamber is arranged below the ground level; a clean smoke inlet is arranged at the lower side of the left side wall of the clean smoke storage chamber, connected to the smoke outlet, and a clean smoke outlet is arranged at the lower side of the right side wall; the lower bottom of the clean smoke storage chamber is an inclined surface, extending from the clean smoke outlet to the clean smoke inlet, and the lower bottom of the clean smoke storage chamber gradually decreases; An exhaust fan is arranged at the smoke outlet; A chimney, wherein the upper part of the chimney is located above the ground level, a smoke inlet is arranged at the lower side of the chimney and is connected to the smoke outlet, a smoke hood is arranged at the outlet of the chimney, and the smoke hood is inverted at the outlet of the chimney; The coal ash sedimentation tank is connected to a sewage well arranged outside the dense smoke storage chamber; A lower smoke passage is formed between the partition and the left side wall of the dense smoke storage chamber, and a side smoke passage is formed between the partition and the bottom of the dense smoke storage chamber; The lower flue gas channel is connected to the side flue gas channel above the coal ash precipitation tank; The temperature below the partition is lower than the temperature above the partition.

2. The flue gas purification system for a non-gas boiler according to claim 1, characterized in that: The drain outlet of the hot water storage device is connected to the boiler water adding pipe through a pipeline for adding hot water into the boiler.

3. The flue gas purification system for a non-gas boiler according to claim 1, characterized in that: An air inlet observation chamber is arranged below the hot water storage device, an exhaust valve is arranged below the hot water storage device in the air inlet observation chamber, and a maintenance valve is arranged on the hot flue.

4. The flue gas purification system for a non-gas boiler according to claim 1, characterized in that: A liquid level indicator is arranged in the coal ash sedimentation tank.

5. The flue gas purification system for a non-gas boiler according to claim 1, characterized in that: The inclination angle of the lower bottom of the clean smoke storage chamber is greater than 15 degrees.

6. The flue gas purification system for a non-gas boiler according to claim 1, characterized in that: An inspection port is arranged above the clean smoke storage chamber.

7. A treatment method using the flue gas purification system according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. A water layer is provided at the bottom of the dense smoke storage chamber, and the liquid level of the water layer is slightly higher than the lowest edge of the smoke outlet; S2. The dense smoke generated by the boiler during operation enters the hot flue. The heat of the hot flue heats the water in the hot water storage device. The generated steam enters the hot flue through the humidification pipeline and mixes with the dense smoke to form water-containing dense smoke. S3, after entering the smoke storage chamber, the water-containing smoke collides with the partition, and by utilizing the temperature difference between the underground part and the aboveground part in the smoke storage chamber, the coal ash and soluble substances in the water-containing smoke flow downward along the partition into the water layer; After the preliminary treatment, the smoke passes through the lower smoke channel and the side smoke channel in turn and enters the dense smoke storage space below the partition, and then becomes clean smoke and is discharged through the smoke outlet; S4. The clean smoke discharged through the smoke outlet enters the clean smoke storage chamber. By utilizing the temperature difference between the clean smoke storage chamber below the ground level and the outside, the water vapor containing pollutants dissolved in the clean smoke is further cooled and flows back to the water layer at the bottom of the dense smoke treatment chamber through the slope of the lower bottom of the clean smoke storage chamber. S5. The clean smoke after being processed in the clean smoke storage room enters the chimney through the exhaust fan; S6. The flue gas entering the chimney is discharged from the top outlet of the chimney through the flue hood to further remove water vapor.

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