Method for desorbing fly ash dioxin by utilizing boiler high-temperature flue gas
By using boiler high-temperature flue gas to heat fly ash, the problems of high energy consumption and high investment in the desorption process of fly ash in the prior art are solved, and the low-cost and low-energy-consuming desorption effect of dioxin is achieved.
Patent Information
- Application Number
- CN202411605222.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-12
- Publication Date
- 2025-02-18
AI Technical Summary
In the prior art, the desorption process of fly ash dioxin requires an external high-temperature heat source, resulting in high energy consumption and high investment. At the same time, the desorption of the dioxin needs to be further decomposed, increasing energy consumption and cost.
The high-temperature flue gas of the boiler is used to heat the fly ash through a closed indirect heating screw conveyor to achieve desorption of the fly ash and the dioxin in the flue gas, and the desorbed dioxin is sent back to the high-temperature boiler furnace through a small flow induced fan. Completely decompose within.
Low investment, low energy consumption and low cost fly ash dioxin desorption has been achieved to ensure that the dioxin content after desorption is lower than that required by national regulations.
Smart Images
Figure CN119468225A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of fly ash dioxin treatment, and in particular to a method for desorbing fly ash dioxin by utilizing boiler high-temperature flue gas. Background Art
[0002] At present, the mainstream dioxin desorption from domestic waste fly ash generally adopts external high-temperature heat source desorption, such as natural gas furnace, electric heating furnace, microwave heating furnace, plasma furnace, electric arc furnace, etc. The above-mentioned need to add various types of heating equipment and its auxiliary facilities, and the investment amount is relatively high; the desorption process consumes a lot of energy during operation, and the dioxins after desorption also need to add a secondary combustion chamber to completely decompose the dioxins, which further increases energy consumption and raises costs. Summary of the invention
[0003] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a method for desorbing dioxins from fly ash using high-temperature flue gas from a boiler.
[0004] To achieve the above purpose, the technical solution adopted by the present invention is: a method for desorbing fly ash dioxins using boiler high-temperature flue gas, comprising the following steps: S1. Connect the bottom of the existing ash hopper of the waste incineration power plant to a closed indirect heating screw conveyor, and convey the fly ash stored in the ash hopper to the closed indirect heating screw conveyor; S2, draw out high-temperature flue gas of 400-600℃ from the boiler flue, and convey the high-temperature flue gas to the closed indirect heating screw conveyor; S3. After the fly ash is heated to 400-600℃ by the high-temperature flue gas in the closed indirect heating screw conveyor, the dioxins in the fly ash and the high-temperature flue gas are desorbed and sent back to the furnace of the high-temperature boiler by the fan to be completely decomposed by high temperature; S4. After dioxins are desorbed from the high-temperature flue gas in the closed indirect heating screw conveyor, the high-temperature flue gas after desorption of dioxins is introduced into the rear flue of the boiler economizer through the fan, and is treated by the flue gas treatment system before being discharged in compliance with the emission standards.
[0005] Preferably, the fly ash from which dioxins are desorbed is conveyed from a closed indirect heating screw conveyor to an ash silo.
[0006] Preferably, the high temperature in the furnace of the high temperature boiler is 850-1000°C.
[0007] Preferably, the fan is a small flow induced draft fan.
[0008] The present scheme also discloses a device for desorbing dioxins from fly ash using high-temperature flue gas from a boiler, comprising a high-temperature boiler furnace, a fan, an ash hopper, a closed indirect heating screw conveyor, an ash bin and an economizer. The flue of the high-temperature boiler furnace is connected to the closed indirect heating screw conveyor through a pipeline, the feed port of the closed indirect heating screw conveyor is connected to the ash hopper through a pipeline, the discharge port of the closed indirect heating screw conveyor is connected to the ash bin through a pipeline, the air outlet of the closed indirect heating screw conveyor is installed on the side of the high-temperature boiler furnace through a pipeline, the smoke exhaust port of the closed indirect heating screw conveyor is connected to the rear flue of the economizer, and the economizer is installed outside the flue of the high-temperature boiler furnace.
[0009] Compared with the prior art, the present invention has the following beneficial effects: This solution utilizes the high-temperature flue gas in the boiler to heat the closed indirect heating screw conveyor. The heated closed indirect heating screw conveyor desorbs dioxins in the fly ash and high-temperature flue gas through high temperature, and the dioxins in the closed indirect heating screw conveyor are transported to the boiler through a fan for thorough decomposition at high temperature, so that the dioxin content in the fly ash and flue gas after desorption is lower than the requirements of national regulations; low investment, low energy consumption, and low cost desorption of dioxins in fly ash is achieved. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 The present invention is a schematic diagram of the structure of a device for desorbing dioxins from fly ash using high-temperature flue gas from a boiler.
[0011] In the figure: high-temperature boiler furnace 1, fan 2, ash hopper 3, closed indirect heating screw conveyor 4, ash bin 5, economizer 6. DETAILED DESCRIPTION
[0012] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.
[0013] A method for desorbing fly ash dioxins using boiler high-temperature flue gas, comprising the following steps: S1. Connect the bottom of the existing ash hopper of the waste incineration power plant to a closed indirect heating screw conveyor, and convey the fly ash stored in the ash hopper to the closed indirect heating screw conveyor; S2, draw out high-temperature flue gas of 400-600℃ from the boiler flue, and convey the high-temperature flue gas to the closed indirect heating screw conveyor; S3. After the fly ash is heated to 400-600℃ by high-temperature flue gas in the closed indirect heating screw conveyor, the dioxins in the fly ash and high-temperature flue gas are desorbed and sent back to the furnace of the high-temperature boiler at a temperature of 850-1000℃ by a small flow induced draft fan to be completely decomposed by high temperature; S4. After dioxins are desorbed from the high-temperature flue gas in the closed indirect heating screw conveyor, the high-temperature flue gas with desorbed dioxins is introduced into the rear flue of the boiler economizer through a small-flow induced draft fan, and is treated by the flue gas treatment system to meet emission standards. The fly ash with desorbed dioxins is transported from the closed indirect heating screw conveyor to the ash bin.
[0014] like Figure 1 As shown, the present scheme also discloses a device for desorbing fly ash dioxins using high-temperature flue gas from a boiler, comprising a high-temperature boiler furnace 1, a fan 2, an ash hopper 3, a closed indirect heating screw conveyor 4, an ash bin 5 and an economizer 6. The flue of the high-temperature boiler furnace 1 is connected with the closed indirect heating screw conveyor 4 through a pipeline, the feed port of the closed indirect heating screw conveyor 4 is connected to the ash hopper 3 through a pipeline, the discharge port of the closed indirect heating screw conveyor 4 is connected to the ash bin 5 through a pipeline, the air outlet of the closed indirect heating screw conveyor 4 is installed on the side of the high-temperature boiler furnace 1 through a pipeline, the exhaust port of the closed indirect heating screw conveyor 4 is connected to the rear flue of the economizer 6, and the economizer 6 is installed outside the flue of the high-temperature boiler furnace 1.
[0015] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.
Claims
1. A method for desorbing dioxins from fly ash using high-temperature flue gas from a boiler, characterized in that: The following steps are involved: S1. Connecting the bottom of an existing ash hopper (2) of a waste incineration power plant to a closed indirect heating screw conveyor (4), and conveying the fly ash stored in the ash hopper (2) to the closed indirect heating screw conveyor (4); S2, high-temperature flue gas of 400-600°C is drawn out from the boiler flue, and the high-temperature flue gas is conveyed to a closed indirect heating screw conveyor (4); S3. After the fly ash is heated to 400-600℃ by high-temperature flue gas in a closed indirect heating screw conveyor, the dioxins in the fly ash are desorbed and sent back to the furnace of the high-temperature boiler by the fan to be completely decomposed by high temperature; S4. After dioxins are desorbed from the high-temperature flue gas in the closed indirect heating screw conveyor (4), the high-temperature flue gas after desorbing dioxins is introduced into the rear flue of the boiler economizer (6) through the fan (2) and is treated by the flue gas treatment system to meet the emission standards.
2. The method for desorbing dioxins from fly ash using high-temperature flue gas from a boiler according to claim 1, characterized in that: The fly ash from which dioxins have been desorbed is transported from a closed indirect heating screw conveyor (4) to an ash bin (5).
3. The method for desorbing dioxins from fly ash using boiler high-temperature flue gas according to claim 1, characterized in that: The high temperature in the high temperature boiler furnace (1) is 850-1000°C.
4. The method for desorbing dioxins from fly ash using high-temperature flue gas from a boiler according to claim 1, characterized in that: The fan (2) is a small flow induced draft fan.
5. According to claims 1 to 4, a device for desorbing dioxins from fly ash using high-temperature flue gas from a boiler is disclosed, comprising a high-temperature boiler furnace (1), a fan (2), an ash hopper (3), a closed indirect heating screw conveyor (4), an ash bin (5) and an economizer (6), characterized in that: The flue of the high-temperature boiler furnace (1) is connected to a closed indirect heating screw conveyor (4) through a pipeline, the feed port of the closed indirect heating screw conveyor (4) is connected to an ash hopper (3) through a pipeline, the discharge port of the closed indirect heating screw conveyor (4) is connected to an ash bin (5) through a pipeline, the air outlet of the closed indirect heating screw conveyor (4) is installed on the side of the high-temperature boiler furnace (1) through a pipeline, the exhaust port of the closed indirect heating screw conveyor (4) is connected to the rear flue of an economizer (6), and the economizer (6) is installed outside the flue of the high-temperature boiler furnace (1).