A high-temperature flue gas dust removal device for a waste incinerator

Abstract

The utility model discloses a high temperature flue gas dust removal device for garbage incinerator, solves the technical problem of reducing dioxin generation from the source. The high temperature flue gas dust removal device for garbage incinerator, the garbage incinerator is the waste heat recovery type garbage incinerator, including mechanical dust removal unit and high temperature filter dust removal unit, mechanical dust removal unit carries out mechanical dust removal through mechanical dust removal structure, and high temperature filter dust removal unit carries out filter dust removal through high temperature filter core, the flue gas inlet of mechanical dust removal unit is connected through the first gas passage located at the side of waste heat recovery type garbage incinerator the flue gas outlet of superheater on waste heat recovery type garbage incinerator, the flue gas outlet of mechanical dust removal unit is connected with the flue gas inlet of filter dust removal unit, and the flue gas outlet of filter dust removal unit is connected through the second gas passage located at the side of waste heat recovery type garbage incinerator the flue gas inlet of economizer on waste heat recovery type garbage incinerator.

Description

Technical Field

[0001] This utility model relates to the field of flue gas purification technology for waste incinerators, specifically to a high-temperature flue gas dust removal device for waste incinerators. Background Technology

[0002] Waste heat recovery incinerators are the main equipment in modern waste treatment. They generate heat energy by burning waste and utilize waste heat recovery devices such as superheaters and economizers to achieve efficient energy utilization. During waste incineration, a large amount of high-temperature flue gas containing pollutants such as dust, dioxins, and heavy metals is produced, which requires strict purification treatment to meet environmental emission requirements. Currently, waste heat recovery incinerators generally adopt the following multi-stage treatment processes: 1) SNCR denitrification + in-furnace injection deacidification + dry deacidification + bag filter + wet desulfurization + SCR denitrification or 2) SNCR denitrification + in-furnace injection deacidification + semi-dry deacidification + dry deacidification + bag filter + SCR denitrification. These two processes are explained below.

[0003] See Figure 1As shown, in the multi-stage treatment process of SNCR denitrification + in-furnace injection deacidification + dry deacidification + bag filter + wet desulfurization + SCR denitrification, the waste first undergoes preliminary denitrification treatment using in-furnace SNCR (Selective Non-Catalytic Reduction) technology during combustion in the incinerator. Simultaneously, in-furnace injection deacidification pre-treats acidic substances in the flue gas. The high-temperature flue gas after combustion sequentially passes through waste heat recovery devices such as superheaters and economizers integrated with the waste incinerator for heat exchange, gradually reducing the flue gas temperature. After waste heat recovery, the flue gas mixes with the absorbent, which adsorbs pollutants such as dioxins and heavy metals under high dust conditions. The adsorbed flue gas then enters a bag filter for dust removal. Due to the operating temperature limitations of bag filters (usually below 200℃), the flue gas needs to be cooled to a suitable temperature before entering the bag filter to achieve the removal of pollutants such as dust, dioxins, and heavy metals. After being purified by the bag filter, the flue gas enters the first flue gas-gas heat exchanger (GGH) for heat exchange before entering the deacidification tower. In the deacidification tower, acidic substances such as sulfur dioxide are removed by an alkaline absorbent. The deacidified flue gas returns to the first flue gas-gas heat exchanger for further heating, and then enters the second flue gas-gas heat exchanger and steam gas heater (SGH) for further heating. Once the flue gas temperature reaches the required temperature for the low-temperature selective catalytic reduction (SCR) denitrification reaction, it enters the low-temperature selective catalytic reduction (SCR) reactor for denitrification, achieving further removal of nitrogen oxides from the emitted flue gas to meet environmental emission requirements. After denitrification treatment in the SCR reactor, the flue gas passes through the second flue gas-gas heat exchanger for heat recovery before being discharged through the chimney.

[0004] See Figure 2As shown, in the multi-stage treatment process of SNCR denitrification + in-furnace injection desulfurization + semi-dry desulfurization + dry desulfurization + bag filter + SCR denitrification, the waste first undergoes preliminary denitrification using in-furnace SNCR technology during combustion in the incinerator. Simultaneously, in-furnace injection desulfurization pre-treats acidic substances in the flue gas. The high-temperature flue gas after combustion sequentially passes through waste heat recovery devices integrated with the waste incinerator, such as a superheater and economizer, for heat exchange, gradually reducing the flue gas temperature. After waste heat recovery, the flue gas enters the spray reactor, reacting with lime slurry to remove acidic substances such as sulfur dioxide. The flue gas after semi-dry desulfurization is mixed with an absorbent, which adsorbs pollutants such as dioxins and heavy metals in the flue gas. The adsorbed flue gas then enters a bag filter for dust removal. The flue gas purified by the bag filter enters a steam heater for further heating. Once the flue gas temperature reaches the required temperature for the low-temperature selective catalytic reduction (STCR) denitrification reaction, it enters the STCR reactor for further denitrification, achieving the removal of nitrogen oxides from the emitted flue gas to meet environmental emission requirements. The flue gas, after denitrification treatment in the STCR reactor, is then discharged through a chimney.

[0005] The main problems with existing technologies are: 1) The passive approach of "adsorption treatment after generation" is used to treat dioxins generated by waste incineration. Activated carbon is used to adsorb dioxins, concentrating the pollution and reducing emissions, but not eliminating or reducing them. This results in a large amount of solid hazardous waste and secondary pollution. 2) The superheaters and economizers of waste heat recovery incinerators operate in high-dust environments. On the one hand, the dust in the high-temperature flue gas causes severe erosion and wear on these heat exchangers; on the other hand, it affects the heat exchange efficiency of the superheaters and economizers, thus impacting the overall thermal efficiency of the waste heat recovery incinerator. Utility Model Content

[0006] The purpose of this invention is to provide a high-temperature flue gas dust removal device for waste incinerators, which solves the technical problem of reducing dioxin generation at the source.

[0007] A high-temperature flue gas dust removal device for a waste incinerator, wherein the waste incinerator is a waste heat recovery type waste incinerator, comprising a mechanical dust removal unit and a high-temperature filtration dust removal unit. The mechanical dust removal unit performs mechanical dust removal through a mechanical dust removal structure, and the high-temperature filtration dust removal unit performs filtration dust removal through a high-temperature resistant filter element. The flue gas inlet of the mechanical dust removal unit is connected to the flue gas outlet of the superheater on the waste heat recovery type waste incinerator through a first gas transmission channel located next to the waste heat recovery type waste incinerator. The flue gas outlet of the mechanical dust removal unit is connected to the flue gas inlet of the filtration dust removal unit. The flue gas outlet of the filtration dust removal unit is connected to the flue gas inlet of the economizer on the waste heat recovery type waste incinerator through a second gas transmission channel located next to the waste heat recovery type waste incinerator.

[0008] As an optimization and / or instantiation of the above-mentioned high-temperature flue gas dust removal device for waste incinerators, further: the filtration and dust removal unit is a gravity dust collector.

[0009] As an optimization and / or instantiation of the above-mentioned high-temperature flue gas dust removal device for waste incinerators, further: the high-temperature resistant filter element of the high-temperature filtration dust removal unit adopts a metal filter element or a ceramic filter element.

[0010] As an optimization and / or instantiation of the above-mentioned high-temperature flue gas dust removal device for waste incinerators, further: the shell of the mechanical dust removal unit and the shell of the high-temperature filtration dust removal unit constitute an integrated shell, and the integrated shell is separated into a compartment where the mechanical dust removal unit is located and a compartment where the high-temperature filtration dust removal unit is located by a partition.

[0011] As an optimization and / or instantiation of the above-mentioned high-temperature flue gas dust removal device for waste incinerator, further: a diversion flue is provided between the flue gas outlet of the mechanical dust removal unit and the flue gas inlet of the economizer, so that at least a portion of the flue gas from the flue gas outlet of the mechanical dust removal unit bypasses the high-temperature filtration dust removal unit and enters the flue gas inlet of the economizer, and a diversion control valve is provided on the diversion flue.

[0012] As an optimization and / or instantiation of the above-mentioned high-temperature flue gas dust removal device for waste incinerators, further: when the shell of the mechanical dust removal unit and the shell of the high-temperature filtration dust removal unit form an integrated shell, and the integrated shell is separated into a compartment where the mechanical dust removal unit is located and a compartment where the high-temperature filtration dust removal unit is located by a partition, the integrated shell is provided with a flue gas duct that connects the flue gas outlet of the mechanical dust removal unit and the flue gas outlet of the high-temperature filtration dust removal unit, and a lift valve as a diversion control valve is provided on the flue gas duct.

[0013] As an optimization and / or instantiation of the above-mentioned high-temperature flue gas dust removal device for waste incinerators, further: the waste incinerator is a waste heat recovery type waste incinerator that adopts in-furnace SNCR denitrification and in-furnace injection deacidification.

[0014] By installing a high-temperature flue gas dust removal device between the superheater and economizer of the waste heat recovery type waste incinerator, a two-stage dust removal process using mechanical dust removal unit and high-temperature filtration dust removal unit effectively removes dust particles from the high-temperature flue gas. This avoids dust erosion and wear on subsequent heat exchange equipment such as the economizer, improving heat exchange efficiency and the overall thermal efficiency of the waste heat recovery type waste incinerator. Simultaneously, dust removal under high-temperature conditions reduces the dust concentration in the flue gas, minimizing the dust's carrying capacity for pollutants such as dioxins. This reduces the generation and spread of dioxins at the source, avoiding the large amounts of solid hazardous waste and secondary pollution problems caused by the passive approach of "adsorption and treatment after generation" in traditional processes. Furthermore, by reducing the amount of dust entering the economizer, the risk of low-temperature corrosion in the economizer is reduced, extending equipment lifespan and reducing maintenance costs.

[0015] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice. Attached Figure Description

[0016] The accompanying drawings, which form part of this specification, are used to aid in understanding the present invention. The contents provided in the drawings and their related descriptions in this specification can be used to explain the present invention, but do not constitute an undue limitation on the present invention.

[0017] Figure 1 This is a schematic diagram of the existing multi-stage treatment process of SNCR denitrification + in-furnace injection deacidification + dry deacidification + bag filter + wet desulfurization + SCR denitrification.

[0018] Figure 2 This is a schematic diagram of the existing multi-stage treatment process of SNCR denitrification + in-furnace injection deacidification + semi-dry deacidification + dry deacidification + bag filter dust collection + SCR denitrification.

[0019] Figure 3 This is a schematic diagram of a high-temperature flue gas dust removal device for a waste incinerator, according to an embodiment of the present invention.

[0020] The following are labeled in the diagram: Mechanical dust removal unit 1, High-temperature filtration dust removal unit 2, First gas transmission channel 3, Superheater 4, Second gas transmission channel 5, Economizer 6, Flue gas duct 7, Lifting valve 8. Detailed Implementation

[0021] The present invention will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that:

[0022] The technical solutions and features provided in the various sections, including the following description, can be combined with each other without conflict. Furthermore, where possible, these technical solutions, features, and related combinations can be given specific technical subject matter and protected by relevant patents.

[0023] The embodiments of the present invention described below are generally only some embodiments and not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of patent protection.

[0024] Regarding terminology and units in this specification: The term "comprising" and any variations thereof in this specification, the corresponding claims, and related sections are intended to cover a non-exclusive inclusion. Furthermore, other related terms and units can be reasonably interpreted based on the relevant information provided in this specification.

[0025] See Figure 3 As shown, this utility model provides a high-temperature flue gas dust removal device for a waste incinerator. This device, applied to a waste heat recovery type waste incinerator, includes a mechanical dust removal unit 1 and a high-temperature filtration dust removal unit 2. The mechanical dust removal unit 1 performs mechanical dust removal through a mechanical dust removal structure, while the high-temperature filtration dust removal unit 2 performs filtration dust removal through a high-temperature resistant filter element. The flue gas inlet of the mechanical dust removal unit 1 is connected to the flue gas outlet of the superheater 4 on the waste heat recovery type waste incinerator via a first gas transmission channel 3 located beside the waste heat recovery type waste incinerator. The flue gas outlet of the mechanical dust removal unit 1 is connected to the flue gas inlet of the high-temperature filtration dust removal unit 2. The flue gas outlet of the high-temperature filtration dust removal unit 2 is connected to the flue gas inlet of the economizer 6 on the waste heat recovery type waste incinerator via a second gas transmission channel 5 located beside the waste heat recovery type waste incinerator.

[0026] In a specific embodiment, the high-temperature filtration and dust removal unit 2 can adopt the structure of a gravity dust collector, further removing fine dust particles from the flue gas through gravity settling. The high-temperature resistant filter element in the high-temperature filtration and dust removal unit 2 can be a metal filter element or a ceramic filter element. These filter element materials can withstand the working environment of high-temperature flue gas and have good filtration effect and service life. Metal filter elements are usually made of stainless steel or other high-temperature resistant alloy materials.

[0027] To achieve a compact structure and save installation space, the housing of the mechanical dust removal unit 1 and the housing of the high-temperature filtration dust removal unit 2 can be integrated into a single unit. Within this integrated housing, a partition separates the compartment containing the mechanical dust removal unit 1 from the compartment containing the high-temperature filtration dust removal unit 2. This integrated design not only reduces the equipment's footprint but also facilitates unified management and maintenance.

[0028] To improve the system's flexibility and reliability, a diversion flue is provided between the flue gas outlet of the mechanical dust removal unit 1 and the flue gas inlet of the economizer 6. This diversion flue allows at least a portion of the flue gas from the mechanical dust removal unit 1 to bypass the high-temperature filtration dust removal unit 2 and enter the flue gas inlet of the economizer 6. A diversion control valve is installed on the diversion flue. By controlling the opening and closing of the diversion control valve, it is possible to select whether all the flue gas passes through the high-temperature filtration dust removal unit 2 or at least partially bypasses it, based on actual operating needs.

[0029] When the waste heat recovery type waste incinerator is running at a low load, by opening the diversion control valve, at least a portion of the flue gas from the outlet of the mechanical dust removal unit 1 bypasses the high-temperature filter dust removal unit 2 and enters the flue gas inlet of the economizer 6. This increases the dust content of the inlet gas of the economizer 6, promotes the formation of dust film on the inner wall of the flue of the economizer 6, effectively slows down the low-temperature corrosion that may occur inside the economizer, thereby extending the service life of the economizer and ensuring the stable operation of the system.

[0030] When an integrated shell structure is adopted, a flue gas duct 7 is provided inside the integrated shell, which connects the flue gas outlet of the mechanical dust removal unit 1 with the flue gas outlet of the high-temperature filtration dust removal unit 2. A lift valve 8, acting as a flow control valve, is installed on the flue gas duct 7. By controlling the opening and closing state of the lift valve 8, the flue gas flow direction can be flexibly adjusted. When the lift valve 8 is closed, the flue gas from the outlet of the mechanical dust removal unit 1 must pass through the high-temperature filtration dust removal unit 2 for filtration and dust removal; when the lift valve 8 is open, a portion of the flue gas from the outlet of the mechanical dust removal unit 1 flows to the economizer 6 through the flue gas duct 7.

[0031] This utility model's high-temperature flue gas dust removal device can be applied to existing multi-stage treatment processes involving SNCR denitrification + in-furnace injection deacidification + dry deacidification + bag filter + wet desulfurization + SCR denitrification. For example... Figure 1 In the process flow shown, by setting up the high-temperature flue gas dust removal device of this invention between the superheater 4 and the economizer 6, the high-temperature flue gas exiting the superheater 4 first undergoes two-stage dust removal treatment through the mechanical dust removal unit 1 and the high-temperature filtration dust removal unit 2, effectively removing most of the dust particles before entering the economizer 6 for waste heat recovery. The flue gas that has undergone high-temperature dust removal continues to undergo subsequent acid removal, bag filter dust collection, wet desulfurization, and SCR denitrification treatments according to the original process flow. However, due to the significant reduction in dust concentration, the working efficiency and service life of the subsequent treatment equipment are significantly improved.

[0032] Similarly, the high-temperature flue gas dust removal device of this invention can also be applied to a multi-stage treatment process of SNCR denitrification + in-furnace injection deacidification + semi-dry deacidification + dry deacidification + bag filter + SCR denitrification. For example... Figure 2In the process flow shown, by setting up the high-temperature flue gas dust removal device of this invention between the superheater 4 and the economizer 6, the high-temperature flue gas exiting the superheater 4 first undergoes high-temperature dust removal treatment through the mechanical dust removal unit 1 and the high-temperature filtration dust removal unit 2, significantly reducing the dust concentration in the flue gas before entering the economizer 6. The flue gas that has undergone high-temperature dust removal continues to enter the spray reactor for semi-dry deacidification treatment, followed by dry deacidification, bag filter dust collection, and SCR denitrification treatment. Due to the significant reduction in the dust concentration in the flue gas, not only is the wear and ash accumulation problem of the economizer 6 reduced, but the processing efficiency of subsequent equipment such as the spray reactor and bag filter dust collector is also improved, while reducing the carrying and generation of pollutants such as dioxins.

[0033] When the high-temperature flue gas dust removal device of this invention is applied to existing multi-stage treatment processes such as SNCR denitrification + in-furnace injection deacidification + dry deacidification + bag filter + wet desulfurization + SCR denitrification, or SNCR denitrification + in-furnace injection deacidification + semi-dry deacidification + dry deacidification + bag filter + SCR denitrification, the high-temperature flue gas dust removal device effectively removes most of the dust particles in the flue gas under high-temperature conditions, significantly reducing the dust concentration in the flue gas. Therefore, the bag filter stage in the original process can be eliminated. Simultaneously, because the high-temperature dust removal process reduces the carrying capacity of dust for pollutants such as dioxins, it reduces the generation and spread of dioxins at the source. This also eliminates the need for the dry deacidification stage, which requires a large amount of activated carbon absorbent, avoiding the large amount of solid hazardous waste and secondary pollution problems caused by the "post-generation adsorption treatment" in traditional dry deacidification processes. This simplified process not only reduces equipment investment and operating costs but also improves overall treatment efficiency, achieving cleaner and more economical flue gas purification. Flue gas treated by the high-temperature dust removal device can directly enter subsequent wet desulfurization or SCR denitrification processes, greatly simplifying the complexity of the entire flue gas purification system.

[0034] The foregoing has described the relevant content of this utility model. Those skilled in the art will be able to implement this utility model based on these descriptions. All other embodiments obtained by those skilled in the art based on the foregoing content of this specification without inventive effort should fall within the scope of patent protection.

Claims

1. A high-temperature flue gas dedusting device for a waste incinerator, the waste incinerator being a waste incinerator of a waste heat recovery type, characterized by: It includes a mechanical dust removal unit and a high-temperature filtration dust removal unit. The mechanical dust removal unit performs mechanical dust removal through a mechanical dust removal structure, and the high-temperature filtration dust removal unit performs filtration dust removal through a high-temperature resistant filter element. The flue gas inlet of the mechanical dust removal unit is connected to the flue gas outlet of the superheater on the waste heat recovery waste incinerator through a first gas transmission channel located next to the waste heat recovery waste incinerator. The flue gas outlet of the mechanical dust removal unit is connected to the flue gas inlet of the filtration dust removal unit. The flue gas outlet of the filtration dust removal unit is connected to the flue gas inlet of the economizer on the waste heat recovery waste incinerator through a second gas transmission channel located next to the waste heat recovery waste incinerator.

2. A high temperature flue gas dedusting device for a waste incinerator as claimed in claim 1, characterized in that: The dust removal unit is a gravity dust collector; and / or, the high-temperature resistant filter element of the high-temperature dust removal unit is a metal filter element or a ceramic filter element.

3. A high temperature flue gas dedusting device for a waste incinerator as claimed in claim 1, characterized in that: The shell of the mechanical dust removal unit and the shell of the high-temperature filtration dust removal unit form an integrated shell. The integrated shell is separated into the compartment where the mechanical dust removal unit is located and the compartment where the high-temperature filtration dust removal unit is located by a partition.

4. A high temperature flue gas dedusting device for a waste incinerator according to any one of claims 1 to 3, characterized in that: A diversion flue is provided between the flue gas outlet of the mechanical dust removal unit and the flue gas inlet of the economizer, allowing at least a portion of the flue gas from the flue gas outlet of the mechanical dust removal unit to bypass the high-temperature filtration dust removal unit and enter the flue gas inlet of the economizer. A diversion control valve is provided on the diversion flue.

5. A high temperature flue gas dedusting device for a waste incinerator as claimed in claim 4, characterized in that: When the shell of the mechanical dust removal unit and the shell of the high-temperature filtration dust removal unit form an integrated shell, and the integrated shell is separated into the compartment where the mechanical dust removal unit is located and the compartment where the high-temperature filtration dust removal unit is located by a partition, the integrated shell is provided with a flue gas duct that connects the flue gas outlet of the mechanical dust removal unit and the flue gas outlet of the high-temperature filtration dust removal unit, and a lift valve as a diversion control valve is provided on the flue gas duct.

6. A high temperature flue gas dedusting device for a waste incinerator as claimed in any one of claims 1 to 3, characterized in that: The waste incinerator is a waste heat recovery type waste incinerator that uses in-furnace SNCR denitrification and in-furnace injection deacidification.

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