Calcium hydroxide feeding device for dry desulfurization process

Abstract

The utility model relates to the technical field of flue gas desulfurization, in particular to a calcium hydroxide feeding device for a dry desulfurization process, which comprises a gas source, the gas source is communicated with an air inlet of a blowing pipeline, and an air outlet of the blowing pipeline is communicated with a desulfurization tower; a desulfurized fly ash ejector and a calcium hydroxide ejector are sequentially connected to the injection pipeline from near to far away from the gas source, a feed port of the desulfurized fly ash ejector is communicated with a discharge port of the desulfurized fly ash bin, and a feed port of the calcium hydroxide ejector is communicated with a discharge port of the calcium hydroxide bin. The desulfurization ash ejector and the calcium hydroxide ejector are sequentially connected into the injection pipeline between the gas source and the desulfurization tower, and desulfurization ash containing CaSO4 is mixed with high-activity calcium hydroxide, so that the high-activity calcium hydroxide is prevented from absorbing water and being bonded, and the injection pipeline is effectively prevented from being blocked.

Description

Technical Field

[0001] This utility model relates to the field of flue gas desulfurization technology, specifically to a calcium hydroxide feeding device for dry desulfurization processes. Background Technology

[0002] Flue gas desulfurization (FGD) refers to a series of methods used to remove sulfur dioxide (SO2) from flue gas, thereby reducing the environmental pollution caused by sulfur oxides. Based on whether water is added during the desulfurization process and the dry / wet state of the desulfurization products, FGD processes can be divided into wet FGD, semi-dry FGD, and dry FGD. In wet FGD, flue gas is sprayed onto an alkaline solution. The alkaline substances in the solution react with the sulfur dioxide in the flue gas to form sulfites or sulfates, thus achieving desulfurization. Wet FGD has high desulfurization efficiency, but it suffers from problems such as high water consumption and severe equipment corrosion. Semi-dry FGD utilizes spray drying technology to allow the desulfurizing agent to react with sulfur dioxide in the flue gas in a dry state, generating solid desulfurization products, thus achieving desulfurization. Semi-dry FGD has the advantages of lower equipment investment and lower operating costs, but it has stricter requirements for operating conditions. Dry desulfurization process mainly refers to the process of removing sulfur dioxide from flue gas in a dry state by using solid absorbents, adsorbents or catalysts. The advantages of this process are that there is no wastewater discharge and the equipment is less corroded. However, since the reaction rate between solid absorbents, adsorbents or catalysts and sulfur dioxide in flue gas is relatively slow, it is usually necessary to reduce the particle size of solid absorbents, adsorbents or catalysts or increase the reaction temperature to improve desulfurization efficiency.

[0003] Currently, sodium-based desulfurizers, represented by sodium bicarbonate, and calcium-based desulfurizers, represented by calcium hydroxide, are widely used in dry desulfurization processes. Sodium bicarbonate desulfurizers, in particular, exhibit high desulfurization efficiency and good adsorption performance. However, the desulfurization ash generated from sodium-based desulfurizers is a highly water-soluble mixture of sodium sulfate, sodium sulfite, and sodium carbonate, making its post-treatment difficult. Desulfurization ash generated from calcium-based desulfurizers, such as calcium hydroxide, is easier to separate and treat, and causes no environmental pollution. To improve desulfurization efficiency, existing technologies typically use desulfurizers with a specific surface area greater than 20 m². 2 / g, high-activity calcium hydroxide with a particle size of 1-10µm is used for dry desulfurization. High-activity calcium hydroxide has a strong adsorption capacity and is very easy to caking on the inner wall of the injection pipe, which leads to frequent blockage of the injection pipe and affects the stable operation of the desulfurization system. Utility Model Content

[0004] To address the technical problem that highly active calcium hydroxide desulfurizing agent in dry desulfurization processes easily caks on the inner wall of the injection pipeline, leading to frequent blockages, this invention provides a calcium hydroxide feeding device for dry desulfurization processes. A desulfurization ash injector and a calcium hydroxide injector are sequentially connected to the injection pipeline between the gas source and the desulfurization tower. This mixes the desulfurization ash containing CaSO4 with the highly active calcium hydroxide, preventing the highly active calcium hydroxide from absorbing water and adhering, thus effectively preventing blockages in the injection pipeline.

[0005] The technical solution of this utility model is as follows:

[0006] A calcium hydroxide feeding device for a dry desulfurization process includes a gas source connected to the inlet of a jet pipeline, and the outlet of the jet pipeline connected to a desulfurization tower. Desulfurization ash injectors and calcium hydroxide injectors are sequentially connected to the jet pipeline from near to far from the gas source. The inlet of the desulfurization ash injector is connected to the outlet of the desulfurization ash silo, and the inlet of the calcium hydroxide injector is connected to the outlet of the calcium hydroxide silo. The desulfurization ash silo stores desulfurization ash with CaSO4 as the main component. The calcium hydroxide silo stores highly active Ca(OH)2 powder with a specific surface area greater than 20 m². 2 / g, with a particle size of 1-10µm and a purity greater than 95%. The highly active Ca(OH)2 powder has a porous or irregular crystalline structure.

[0007] Furthermore, the air source is connected to the air inlet of the injection pipeline via a Roots blower, and the air source is air.

[0008] Furthermore, both the desulfurization ash injector and the calcium hydroxide injector are Venturi ejectors.

[0009] Furthermore, a desulfurization ash weighing device is installed between the outlet of the desulfurization ash silo and the inlet of the desulfurization ash injector, and a calcium hydroxide weighing device is installed between the outlet of the calcium hydroxide silo and the inlet of the calcium hydroxide injector.

[0010] Furthermore, both the desulfurization ash weighing device and the calcium hydroxide weighing device are reducing scales.

[0011] Furthermore, electric control valves are installed at the discharge ports of the desulfurization ash silo and the calcium hydroxide silo.

[0012] Furthermore, a screw feeder is installed between the outlet of the calcium hydroxide silo and the calcium hydroxide weighing device.

[0013] The beneficial effects of this utility model are as follows:

[0014] This utility model provides a calcium hydroxide feeding device for dry desulfurization processes. A desulfurization ash injector and a calcium hydroxide injector are sequentially connected to the injection pipeline between the gas source and the desulfurization tower, from closest to furthest from the gas source. The desulfurization ash injector sprays desulfurization ash, primarily composed of CaSO4, from the desulfurization ash bin into the injection pipeline between the calcium hydroxide injector and the desulfurization tower, ensuring uniform mixing of the desulfurization ash and calcium hydroxide. This prevents the calcium hydroxide powder from absorbing moisture and adhering to each other, depositing on the inner wall of the injection pipeline and causing blockage. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the connection relationship in Example 1.

[0017] In the diagram, 1-desulfurization ash injector, 2-injection pipeline, 3-calcium hydroxide injector, 4-Roots blower, 5-electric control valve for desulfurization ash silo, 6-desulfurization ash silo, 7-desulfurization ash reduction scale, 8-electric control valve for calcium hydroxide silo, 9-calcium hydroxide silo, 10-screw feeder, 11-calcium hydroxide reduction scale, 12-desulfurization tower. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0019] Example 1

[0020] A calcium hydroxide feeding device for dry desulfurization processes, such as Figure 1As shown, the system includes an air source, which is connected to the air inlet of the injection pipeline 2 via a Roots blower 4. The air outlet of the Roots blower 4 is also connected to the air inlet of the injection pipeline 2. A desulfurization ash injector 1 and a calcium hydroxide injector 3 are connected in series on the injection pipeline 2, arranged from closest to furthest from the air source. The air outlet of the injection pipeline 2 is connected to the desulfurization tower 12. Specifically, the air inlet of the desulfurization ash injector 1 is connected to the air outlet of the Roots blower 4 via the injection pipeline 2; the discharge outlet of the desulfurization ash injector 1 is connected to the air inlet of the calcium hydroxide injector 3 via the injection pipeline 2; and the discharge outlet of the calcium hydroxide injector 3 is connected to the desulfurization tower 12 via the injection pipeline 2. The inlet of the desulfurization ash injector 1 is connected to the outlet of the desulfurization ash silo 6. The desulfurization ash silo 6 is used to store desulfurization ash powder with CaSO4 as the main component. A desulfurization ash reduction scale 7 is installed between the outlet of the desulfurization ash silo 6 and the inlet of the desulfurization ash injector 1. An electric control valve 5 for the desulfurization ash silo 6 is installed at the outlet of the desulfurization ash silo 6. The inlet of the calcium hydroxide injector 3 is connected to the outlet of the calcium hydroxide silo 9. The calcium hydroxide silo 9 is used to store highly active Ca(OH)2 powder with a specific surface area greater than 20 m². 2 / g, particle size 1-10µm, purity greater than 95%. High-activity Ca(OH)2 powder has a porous structure or irregular crystal structure. A calcium hydroxide reducing scale 11 is installed between the outlet of the calcium hydroxide silo 9 and the inlet of the calcium hydroxide injector 3. A screw feeder 10 is installed between the outlet of the calcium hydroxide silo 9 and the calcium hydroxide reducing scale 11. An electric control valve 8 for the calcium hydroxide silo 9 is installed at the outlet of the calcium hydroxide silo 9. Both the desulfurization ash injector 1 and the calcium hydroxide injector 3 are Venturi ejectors. Air control valves and quick connectors can also be installed on the blowing pipeline 2 for convenient maintenance operations. The Roots blower is model ZW-506 and was purchased from Zhangqiu Blower Co., Ltd. The drive motor of the Roots blower is an explosion-proof motor, model YBX3-160M-4-11KW-380V, purchased from Wolong Electric Nanyang Explosion-proof Motor Co., Ltd. The maximum feed rate of the Venturi ejector is 250 kg / h. All pipelines in the calcium hydroxide feeding device are made of wear-resistant materials.

[0021] Working principle: First, the Roots blower 4 is turned on to supply air, and then the electric control valve 5 of the desulfurization ash silo is turned on. At this time, the desulfurization ash silo 6 begins to discharge desulfurization ash. The desulfurization ash enters the desulfurization ash reduction scale 7 from the desulfurization ash silo 6 and is weighed. Then, it enters the injection pipe 2 through the feed port of the desulfurization ash injector 1 and is injected for 30 seconds. Since the calcium sulfate powder in the desulfurization ash is less likely to clump compared with the calcium hydroxide powder and will not have an adverse effect on the desulfurization process, the calcium sulfate powder is injected into the injection pipe 2 before the calcium hydroxide powder is injected. This allows the calcium sulfate powder to be pre-attached to the pipe wall of the injection pipe 2, thereby preventing the calcium hydroxide powder injected later from adhering to the pipe wall. Then, the electric control valve 8 of the calcium hydroxide silo is turned on, and the calcium hydroxide silo 9 begins to discharge calcium hydroxide powder. The calcium hydroxide powder is conveyed to the calcium hydroxide reduction scale 11 by the screw feeder 10. Desulfurization ash and calcium hydroxide are weighed using desulfurization ash reduction scale 7 and calcium hydroxide reduction scale 11 respectively. The desulfurization ash and calcium hydroxide are mixed in the injection pipeline 2 through the inlet of desulfurization ash injector 1 and the inlet of calcium hydroxide injector 3 respectively, according to the mass ratio of desulfurization ash: calcium hydroxide ≥ 1. This achieves anti-clogging protection for the injection pipeline and improves the utilization rate of desulfurization ash.

[0022] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the present invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be included within the protection scope of the present invention.

Claims

1. A calcium hydroxide feeding device for a dry desulfurization process, comprising a gas source, characterized in that, The air source is connected to the air inlet of the injection pipeline, and the air outlet of the injection pipeline is connected to the desulfurization tower. The desulfurization ash injector and the calcium hydroxide injector are connected to the injection pipeline in sequence from the nearest to the farthest point from the air source. The feed inlet of the desulfurization ash injector is connected to the discharge outlet of the desulfurization ash silo, and the feed inlet of the calcium hydroxide injector is connected to the discharge outlet of the calcium hydroxide silo.

2. The calcium hydroxide feeding device for dry desulfurization process as described in claim 1, characterized in that, The air source is connected to the air inlet of the injection pipeline through the Roots blower.

3. The calcium hydroxide feeding device for dry desulfurization process as described in claim 1, characterized in that, A desulfurization ash weighing device is installed between the discharge port of the desulfurization ash silo and the inlet of the desulfurization ash injector, and a calcium hydroxide weighing device is installed between the discharge port of the calcium hydroxide silo and the inlet of the calcium hydroxide injector.

4. A calcium hydroxide feeding device for a dry desulfurization process as described in claim 3, characterized in that, Both the desulfurization ash weighing device and the calcium hydroxide weighing device are reducing scales.

5. A calcium hydroxide feeding device for a dry desulfurization process as described in claim 1, characterized in that, Electric control valves are installed at the discharge ports of the desulfurization ash silo and the calcium hydroxide silo.

6. A calcium hydroxide feeding device for a dry desulfurization process as described in claim 1, characterized in that, A screw feeder is installed between the discharge port of the calcium hydroxide silo and the calcium hydroxide weighing device.

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