Dry-process deacidification reaction device for baking soda

Abstract

The utility model discloses a baking soda dry-method deacidification reaction device which comprises a waste heat boiler, a smoke outlet of the waste heat boiler is connected with a first reaction kettle through a first Venturi tube, the first reaction kettle is connected with a plurality of reaction kettles in series through a Venturi tube, and a smoke outlet of the last reaction kettle is connected with a deacidification tower through a pipeline. A discharging opening in the bottom of the reaction kettle is connected with a material collecting pipe, an air inlet of the material collecting pipe is provided with a fan, a discharging opening of the material collecting pipe is connected with the side wall of the first Venturi pipe, a baking soda nozzle is arranged in the first Venturi pipe, the nozzle faces the first reaction kettle, and the baking soda nozzle is connected with a baking soda spraying device through a pipeline. The device disclosed by the utility model is suitable for different working conditions of different power plants, can be independently used, can also be combined with a semi-dry method for use without influencing the efficiency of baking soda dry-method deacidification, and is not limited by items of garbage blending combustion or large concentrated water absorption amount; the method is of great significance in upgrading and reconstruction of garbage power plants, coping with increasingly strict emission standards, and making pollution-reducing and carbon-reducing synergistic interaction.

Description

Technical Field

[0001] The utility model belongs to the technical field of flue gas treatment, and particularly relates to a baking soda dry-process deacidification reaction device. Background Art

[0002] With growing environmental awareness, flue gas emissions from waste incineration plants are becoming increasingly stringent, and national standards for controlling pollutant emissions from waste incineration are becoming increasingly stringent. Furthermore, with the surge in the number of waste-to-energy plants and the reduction in waste volumes, many plants are incorporating aged waste, industrial waste, and sludge into the combustion process. This leads to a significant increase in flue gas pollutant concentrations, making emission targets difficult to control and posing significant environmental risks. Currently, waste incineration plants typically use a combination of semi-dry or dry / wet deacidification processes. Semi-dry processes require a relatively large footprint, while wet deacidification is subject to equipment corrosion and produces large amounts of deacidification wastewater. Currently, the hydrated lime dry deacidification process is often used as a backup, but its deacidification efficiency only reaches ~30%, resulting in low hydrated lime utilization. The deacidification efficiency of this combined hydrated lime (semi-dry + dry) process cannot meet increasingly stringent flue gas emission targets. Given its advantages, such as baking soda deacidification efficiencies exceeding 95%, simple operation, low equipment investment, and the absence of deacidification wastewater, some power plants are gradually adopting this dry deacidification process. However, the dry deacidification method of baking soda still has some defects. For example, the price of baking soda is relatively high, and the reaction requires high temperature conditions and a certain reaction time. When used in combination with the semi-dry method, it leads to a lower reaction temperature, reduced deacidification efficiency, reduced raw material utilization, and increased costs. At the same time, the dry deacidification method of baking soda is not suitable for waste incineration projects that need to dispose of large amounts of concentrated water.

[0003] Utility model CN212396370U, "A Baking Soda Dry Desulfurization Device," provides a baking soda dry desulfurization device. This device incorporates a stirring mechanism to ensure a full reaction between the desulfurizer and exhaust gas, improving reaction efficiency, and a heating mechanism to increase reaction rate. While this system ensures thorough mixing of the desulfurizer and exhaust gas, it does not guarantee sufficient reaction time. Furthermore, the heating mechanism significantly increases energy consumption.

[0004] Utility model CN212663207U, "Baking Soda Dry Purification Device for Waste Incineration Flue Gas Treatment," provides a baking soda dry purification device. This device has a simple structure, accurately determines the amount of large-particle baking soda stored in the bin, controls the outflow of large-particle baking soda, and effectively purifies flue gas at the edges of the flue. However, this system cannot guarantee the reaction time between baking soda and flue gas, and it cannot solve the problem of large concentrated water consumption.

[0005] Invention CN111359422A, "An Efficient Dry-Process Deacidification Device and Method for Waste Incineration Flue Gas," discloses a baking soda dry-process deacidification device. This device uses a coal economizer to discharge the high-temperature flue gas from the incineration process into a high-efficiency deacidification tower for deacidification, eliminating the need for cooling and improving deacidification efficiency. However, this system has significant project limitations and is unsuitable for projects requiring the disposal of concentrated water. Unreacted baking soda is not recycled in this system, resulting in a waste of raw materials.

[0006] To sum up, it is urgent to develop a baking soda dry deacidification device that is suitable for different working conditions of different power plants. It can be used alone or in combination with the semi-dry method without affecting the efficiency of the baking soda dry deacidification. It is not limited to projects with large amounts of garbage co-incineration and concentrated water disposal. It is of great significance for the upgrading and transformation of waste power plants to cope with increasingly stringent emission standards and to achieve synergistic efficiency improvement in pollution reduction and carbon reduction. Utility Model Content

[0007] Technical Problem Solved: To address the above technical problems, the present invention provides a baking soda dry deacidification reaction device that is energy-efficient and highly efficient, meets emission standards for various power plant operating conditions, and is helpful for upgrading waste-to-energy plants. During use, the device is not limited by co-incineration conditions and the impact of concentrated water disposal. Depending on the specific operating conditions of the waste incineration power plant, baking soda can be added alone or combined with a semi-dry process. While ensuring the baking soda reaction temperature and reaction time, it improves deacidification efficiency and raw material utilization.

[0008] Technical solution: A baking soda dry deacidification reaction device includes a waste heat boiler, the flue gas outlet of the waste heat boiler is connected to the first reactor through a first venturi tube, the first reactor is connected in series with multiple reactors through the venturi tube, the flue gas outlet of the last reactor is connected to the deacidification tower through a pipeline, the bottom discharge port of the reactor is connected to the collecting pipe, the air inlet of the collecting pipe is provided with a fan, the discharge port of the collecting pipe is connected to the side wall of the first venturi tube, a baking soda nozzle is provided in the first venturi tube, the baking soda nozzle faces the first reactor, and the baking soda nozzle is connected to the baking soda injection device through a pipeline.

[0009] Preferably, a grid is provided in each reactor, and the plane where the grid is located is parallel to the opening end face of the venturi tube.

[0010] Furthermore, the grid includes a first grid layer and a second grid layer, and the grid density of the first grid layer is greater than the grid density of the second grid layer.

[0011] Preferably, a rapper is provided at the bottom of each reactor.

[0012] Preferably, a first regulating valve is provided on the pipeline connecting the baking soda nozzle and the baking soda spraying device.

[0013] Preferably, a discharge valve is provided on the pipeline connecting the bottom discharge port of each reactor and the collecting pipe.

[0014] Preferably, a second regulating valve is provided on the pipeline connecting the discharge port of the collecting pipe and the side wall of the first venturi tube.

[0015] Preferably, the discharge port of the collecting pipe is connected to the side wall of the first venturi tube located between the baking soda nozzle and the first reaction kettle.

[0016] Beneficial effects: 1) The use of a venturi tube, multiple baking soda nozzles, and a grid design can promote the thorough mixing of flue gas and baking soda powder and prolong the gas-solid reaction time;

[0017] 2) Two layers of grids are set in the reactor to increase turbulence and reaction time. The first layer of grids has a denser mesh design, which is conducive to sufficient gas-solid mixing and prolonging the reaction time. The second layer of grids has a sparser mesh design, which is conducive to the flow of flue gas and baking soda powder into the next reactor and reduces the deposition of baking soda powder in the reactor.

[0018] 3) The vibrator at the bottom of the reactor prevents solid powder from being deposited in the reactor. At the same time, the solid powder in the reactor is collected in the collecting pipe and sprayed into the horizontal pipe under the action of the fan, and then re-enters the reactor for recycling, reducing the use of baking soda, improving the utilization rate of raw materials, and reducing costs.

[0019] 4) The baking soda dry deacidification device of this utility model is suitable for both new projects and upgrading and transformation of existing projects;

[0020] 5) The flue gas at the waste heat boiler outlet ensures the reaction temperature for baking soda deacidification. The three reactors with grilles connected in series ensure sufficient mixing and reaction time between the baking soda and the flue gas. This avoids the problem of insufficient baking soda reaction time and incomplete reaction caused by the short distance between the boiler outlet and the deacidification tower in existing power plants, greatly improving the baking soda deacidification efficiency and raw material utilization.

[0021] 6) The conflict between the existing baking soda dry deacidification and the disposal of concentrated water in power plants has been resolved. For power plants with high pollutant concentrations and large amounts of concentrated water to be disposed of, the combined process of baking soda dry deacidification and slaked lime semi-dry deacidification in the reaction tower can fully achieve the removal of acidic pollutants and the disposal of large amounts of concentrated water at the same time.

[0022] 7) Based on the different processes, different operating conditions and economic analysis of the power plant, it is possible to flexibly choose to use the baking soda dry deacidification process alone or the baking soda dry and semi-dry process in combination. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1This is a schematic diagram of the overall structure of a baking soda dry deacidification reaction device of the utility model;

[0024] Figure 2 This is a schematic diagram of the grille structure of the utility model;

[0025] Serial numbers in the figure: 1, waste heat boiler, 2, first venturi tube, 3, first regulating valve, 4, baking soda nozzle, 5, first reactor, 6, grid, 6-1, first grid layer, 6-2, second grid layer, 7, vibrator, 8, second venturi tube, 9, second reactor, 10, third venturi tube, 11, third reactor, 12, deacidification tower, 13, fan, 14, collecting pipe, 15, discharge valve, 16, second regulating valve. DETAILED DESCRIPTION

[0026] The technical solution of the present utility model is further described in detail below with reference to the accompanying drawings. Example 1

[0027] Reference Figure 1-Figure 2 The outlet flue gas temperature of the waste heat boiler 1 is about 200°C, which can meet the reaction temperature of baking soda. A plurality of baking soda nozzles 4 are provided on the horizontal pipe after the first venturi tube 2, which is conducive to the uniform dispersion of baking soda in the pipe. A first regulating valve 3 is provided on the pipe connecting the baking soda injection device and the baking soda nozzle 4, which can automatically adjust the valve opening according to the concentration of flue gas pollutants and thus adjust the dosage of baking soda. Because the particle size of baking soda has a great influence on the deacidification efficiency, the baking soda powder used in the reaction is ground with a particle size of less than 30 μm. After passing through the first Venturi tube 2, the flue gas rapidly mixes with the baking soda and enters the first reactor 5 for further reaction. The flue gas then passes through the first grid 6-1 and then the second grid 6-2. The different meshes of the two grids further increase turbulence and ensure more complete gas-solid mixing. The dense mesh of the first grid 6-1 increases turbulence and facilitates thorough gas-solid mixing, while the coarser mesh of the second grid 6-2 facilitates the passage of the flue gas and baking soda powder through the reactor into the pipeline. After being accelerated by the second Venturi tube 8, the flue gas enters the second reactor 9. After passing through the grid 6, the flue gas is accelerated by the third Venturi tube 10 before entering the third reactor 11 and finally entering the deacidification tower 12. The powder deposited in each reactor passes through the discharge valve 15 and enters the collection pipe 14. The vibrator 7 at the bottom of the reactor prevents the powder from accumulating on the inner wall of the reactor bottom. Under the action of the fan 13, the powder in the collection pipe 14 is sprayed through the second regulating valve 16 into the first Venturi tube 2 behind the baking soda nozzle 4, and then enters the reactor again for reaction, repeating the above steps. The automatic control system adopts DCS or PLC, etc.

[0028] The embodiments of this specific implementation method are all preferred embodiments of the present utility model, and are not intended to limit the scope of protection of the present utility model. Therefore, any equivalent changes made based on the structure, shape, and principle of the present utility model should be included in the scope of protection of the present utility model.

Claims

1. A baking soda dry deacidification reaction device, characterized in that: It includes a waste heat boiler, the flue gas outlet of the waste heat boiler is connected to the first reactor through a first venturi tube, the first reactor is connected in series with multiple reactors through the venturi tube, the flue gas outlet of the last reactor is connected to the deacidification tower through a pipeline, the bottom discharge port of the reactor is connected to the collecting pipe, the air inlet of the collecting pipe is provided with a fan, the discharge port of the collecting pipe is connected to the side wall of the first venturi tube, a baking soda nozzle is provided in the first venturi tube, the baking soda nozzle faces the first reactor, and the baking soda nozzle is connected to the baking soda injection device through a pipeline.

2. A baking soda dry deacidification reaction device according to claim 1, characterized in that: A grid is provided in each reactor, and the plane where the grid is located is parallel to the opening end surface of the venturi tube.

3. A baking soda dry deacidification reaction device according to claim 2, characterized in that: The grid includes a first grid layer and a second grid layer, and the grid density of the first grid layer is greater than the grid density of the second grid layer.

4. A baking soda dry deacidification reaction device according to claim 1, characterized in that: There is a rapper at the bottom of each reactor.

5. A baking soda dry deacidification reaction device according to claim 1, characterized in that: A first regulating valve is provided on a pipeline connecting the baking soda nozzle and the baking soda spraying device.

6. A baking soda dry deacidification reaction device according to claim 1, characterized in that: A discharge valve is provided on the pipe connecting the bottom discharge port of each reactor and the collecting pipe.

7. A baking soda dry deacidification reaction device according to claim 1, characterized in that: A second regulating valve is provided on the pipeline connecting the discharge port of the collecting pipe and the side wall of the first venturi tube.

8. A baking soda dry deacidification reaction device according to claim 1, characterized in that: The discharge port of the collecting pipe is connected to the side wall of the first venturi tube located between the baking soda nozzle and the first reaction kettle.

Images