Biomass boiler emission system with dry desulfurization, high-temperature dust removal and low-temperature denitration

Abstract

The utility model relates to the technical field of biomass boiler emission system, and disclose a kind of dry desulfurization high-temperature dedusting low-temperature denitration's biomass boiler emission system, including boiler, the side of the boiler is provided with multi-tube dust collector, the flue gas output end of the multi-tube dust collector is connected with dry SDS desulfurization tower by pipeline, the output end of the dry SDS desulfurization tower is connected with bag filter by flue, the particle in flue gas is handled by classification by multi-tube dust collector and bag filter;Low-temperature SCR denitration tower. By setting multi-tube dust collector and bag filter, first, the dust with larger particle size in flue gas, such as more than 5 μm, is filtered and removed by multi-tube dust collector, and then, the dust with more than 0.1 μm in flue gas is filtered and removed by bag filter, the dust particles in flue gas are filtered by classification, the burden on bag filter during filtering is reduced, the service life of filter bag is increased, and the maintenance cost is reduced.

Description

Technical Field

[0001] This utility model relates to the technical field of biomass boiler emission systems, specifically a biomass boiler emission system with dry desulfurization, high-temperature dust removal, and low-temperature denitrification. Background Technology

[0002] Biomass boilers are a type of boiler that uses biomass energy as fuel. However, they still release a large amount of dust-laden flue gas after combustion. If directly emitted into the atmosphere, this will cause some pollution to the environment. Therefore, an emission system is needed to treat the flue gas and reduce environmental pollution.

[0003] For example, Chinese Patent CN202311054872.1 discloses an ultra-low emission system for biomass boiler flue gas, which includes: a boiler system for generating flue gas, and the boiler system includes at least one flue gas exhaust pipe; a cyclone dust collector connected to the flue gas exhaust pipe, and an exhaust pipe connected to the cyclone dust collector, with the other end of the flue gas exhaust pipe connected to an integrated dust and nitrogen removal device; the integrated dust and nitrogen removal device is used for dust removal and nitrogen removal of the flue gas. A desulfurization and ammonia injection module is also connected to the exhaust pipe, which is used for desulfurization and ammonia injection treatment of the flue gas in the exhaust pipe; and a heat exchange module is also connected to the integrated dust and nitrogen removal device, which is used for heat exchange treatment of the flue gas. This invention effectively improves the problems of poor flue gas treatment and low flue gas utilization rate in existing biomass boilers during combustion, thereby achieving ultra-low emissions from biomass boilers. In traditional flue gas emission treatment, bag filters are used to filter particles in the flue gas. However, the particles in the flue gas are of different sizes, and bag filters can filter both small and large particles, which greatly increases the filtration burden on the bag filters and reduces their service life. Therefore, a dry desulfurization, high-temperature dust removal, and low-temperature denitrification biomass boiler emission system is proposed to solve the above problems. Utility Model Content

[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this utility model provides a biomass boiler emission system with dry desulfurization, high-temperature dust removal, and low-temperature denitrification. It has the advantages of tiered filtration of flue gas particles and solves the problem of heavy filtration burden in traditional single-equipment systems.

[0005] (II) Technical Solution To achieve the above-mentioned graded filtration of flue gas particles, this utility model provides the following technical solution: a biomass boiler emission system for dry desulfurization, high-temperature dust removal, and low-temperature denitrification, including a boiler, a multi-tube dust collector installed on one side of the boiler, a dry SDS desulfurization tower connected to the flue gas output end of the multi-tube dust collector via a pipe, and a bag filter connected to the output end of the dry SDS desulfurization tower via a flue, wherein the multi-tube dust collector and the bag filter are used to grade the particles in the flue gas; The low-temperature SCR denitrification tower is fixedly connected to the flue gas output end of the bag filter through a pipeline, and the flue gas output end of the low-temperature SCR denitrification tower is equipped with a two-stage air preheater.

[0006] Preferably, an energy-saving device is fixedly installed at the top of the secondary air preheater. The flue gas after denitrification is recycled for waste heat through the secondary air preheater and the energy-saving device, and then used to preheat the air or process medium.

[0007] Preferably, the output end of the energy-saving device is connected to an induced draft fan via a pipe, and the output end of the induced draft fan is connected to a chimney, through which the exhaust is sent into the chimney for discharge.

[0008] Preferably, an economizer is fixedly connected to the flue gas output end of the boiler, and a primary air preheater is connected to the output end of the economizer. The primary air preheater is fixedly connected to a multi-tube dust collector through a pipeline. The flue gas generated by the boiler first enters the economizer to recover the waste heat of the flue gas to heat the boiler feedwater, reduce the exhaust gas temperature to improve the boiler thermal efficiency, and at the same time create a suitable operating temperature for subsequent equipment. Then, the primary air preheater uses the waste heat of the flue gas to preheat the air required for combustion, thereby enhancing the completeness of fuel combustion.

[0009] Preferably, the multi-tube dust collector has several sets of cylindrical bodies fixedly installed inside. A dust collection chamber is set at the bottom of the cylindrical body inside the multi-tube dust collector. An air inlet is set on one outer surface of the cylindrical body. An exhaust port is opened at the top of the cylindrical body. A dust discharge port is opened at the bottom of the cylindrical body. The flue gas enters from the air inlet and uses the centrifugal separation principle to discharge the particles in the flue gas from the dust discharge port into the dust collection chamber, removing more than 90% of coarse dust particles, and then discharges from the exhaust port.

[0010] (III) Beneficial Effects Compared with existing technologies, this utility model provides a dry desulfurization, high-temperature dust removal, and low-temperature denitrification biomass boiler emission system, which has the following beneficial effects: By setting up a multi-tube dust collector and a bag filter, the multi-tube dust collector first filters out larger dust particles (5μm and above) in the flue gas, and then the bag filter filters out dust particles larger than 0.1μm. This staged approach effectively filters dust particles in the flue gas, reducing the burden on the bag filter during filtration, increasing the service life of the filter bags, and reducing maintenance costs. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the emission system of this utility model; Figure 2 This is a schematic diagram of the internal structure of the multi-tube dust collector of this utility model; Figure 3 This is a schematic diagram of the structure of the cylindrical body of this utility model.

[0012] In the diagram: 1. Boiler; 11. Economizer; 12. Primary air preheater; 2. Multi-tube dust collector; 21. Shell; 22. Dust collection chamber; 23. Exhaust port; 24. Air inlet; 25. Dust discharge port; 3. Dry SDS desulfurization tower; 4. Bag filter; 5. Low-temperature SCR denitrification tower; 6. Secondary air preheater; 61. Economizer; 7. Exhaust fan; 8. Chimney. Detailed Implementation

[0013] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0014] Please see Figure 1-3 The present invention provides the following technical solution: a biomass boiler emission system with dry desulfurization, high temperature dust removal, and low temperature denitrification, including a boiler 1, a multi-tube dust collector 2 is provided on one side of the boiler 1, the flue gas output end of the multi-tube dust collector 2 is connected to a dry SDS desulfurization tower 3 through a pipe, and the output end of the dry SDS desulfurization tower 3 is connected to a bag filter 4 through a flue, and the particles in the flue gas are classified and treated by the multi-tube dust collector 2 and the bag filter 4. In this embodiment, the multi-tube dust collector 2 has several sets of cylindrical bodies 21 fixedly installed inside. The dust collection chamber 22 is set at the bottom of the cylindrical body 21 inside the multi-tube dust collector 2. An air inlet 24 is set on one outer surface of the cylindrical body 21. An exhaust port 23 is opened at the top of the cylindrical body 21. A dust discharge port 25 is opened at the bottom of the cylindrical body 21. The flue gas enters from the air inlet 24 and uses the centrifugal separation principle to discharge the particles in the flue gas from the dust discharge port 25 into the dust collection chamber 22, removing more than 80% of the coarse dust particles, and then discharges from the exhaust port. In this embodiment, the low-temperature SCR denitrification tower 5 is fixedly connected to the flue gas output end of the bag filter 4 through a pipeline, and the flue gas output end of the low-temperature SCR denitrification tower 5 is equipped with a two-stage air preheater 6.

[0015] Among them, an energy-saving device 61 is fixedly installed at the top of the secondary air preheater 6. The flue gas after denitrification is recycled by the secondary air preheater 6 and the energy-saving device 61 to further preheat the air or process medium. The output end of the energy-saving device 61 is connected to an induced draft fan 7 through a pipeline. The output end of the induced draft fan 7 is connected to a chimney 8 and is discharged into the chimney 8 by the induced draft fan 7.

[0016] In this embodiment, an economizer 11 is fixedly connected to the flue gas output end of the boiler 1. The output end of the economizer 11 is connected to a primary air preheater 12, and the primary air preheater 12 is fixedly connected to a multi-tube dust collector 2 through a pipeline. The flue gas generated by the boiler 1 first enters the economizer 11 to recover the waste heat of the flue gas to heat the feedwater of the boiler 1, thereby reducing the exhaust gas temperature and improving the boiler thermal efficiency, while creating a suitable operating temperature for subsequent equipment. Subsequently, the primary air preheater 12 uses the waste heat of the flue gas to preheat the air required for combustion, thereby enhancing the completeness of fuel combustion.

[0017] The working principle of this embodiment is as follows: The flue gas generated by boiler 1 first enters economizer 11 to recover waste heat from the flue gas and heat the feedwater of boiler 1, reducing the exhaust gas temperature to improve boiler thermal efficiency and creating a suitable operating temperature for subsequent equipment. Then, it passes through primary air preheater 12, utilizing the waste heat of the flue gas to preheat the air required for combustion, enhancing fuel combustion completeness. Next, the flue gas enters multi-tube dust collector 2, where centrifugal separation removes over 80% of coarse dust particles, reducing wear and operating load on subsequent equipment. Finally, it is introduced into dry SDS desulfurization tower 3, where dry powder desulfurizing agents such as sodium bicarbonate are sprayed, efficiently adsorbing sulfur dioxide through gas-solid reaction to generate sulfur dioxide. Solid by-products are produced, with a desulfurization efficiency of over 90% and no wastewater generation. The desulfurized flue gas enters the bag filter 4, where fine particulate dust and desulfurization by-products are precisely intercepted by the filter bags, achieving a dust removal efficiency of ≥99.9% and ensuring that the dust concentration meets the standards. The flue gas then enters the low-temperature SCR denitrification tower 5, where ammonia and nitrogen oxides undergo a reduction reaction under the action of a low-temperature catalyst at 180-250℃ to generate harmless nitrogen and water. The denitrified flue gas then passes through a secondary air preheater 6 and an energy saver 61 to recover the waste heat of the flue gas and further preheat the air or process medium. Finally, it is sent to the chimney 8 by the induced draft fan 7 for discharge.

[0018] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0019] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A biomass boiler emission system with dry desulfurization, high-temperature dust removal, and low-temperature denitrification, characterized in that, include: A boiler (1) is provided with a multi-tube dust collector (2) on one side. The flue gas output end of the multi-tube dust collector (2) is connected to a dry SDS desulfurization tower (3) through a pipe. The output end of the dry SDS desulfurization tower (3) is connected to a bag filter (4) through a flue. The multi-tube dust collector (2) and the bag filter (4) are used to classify the particles in the flue gas. The low-temperature SCR denitrification tower (5) is fixedly connected to the flue gas output end of the bag filter (4) through a pipeline. The flue gas output end of the low-temperature SCR denitrification tower (5) is equipped with a secondary air preheater (6).

2. The biomass boiler emission system for dry desulfurization, high-temperature dust removal, and low-temperature denitrification according to claim 1, characterized in that: An energy-saving device (61) is fixedly installed at the top of the secondary air preheater (6).

3. The biomass boiler emission system for dry desulfurization, high-temperature dust removal, and low-temperature denitrification according to claim 2, characterized in that: The output end of the energy-saving device (61) is connected to an induced draft fan (7) via a pipe, and the output end of the induced draft fan (7) is connected to a chimney (8).

4. The biomass boiler emission system for dry desulfurization, high-temperature dust removal, and low-temperature denitrification according to claim 1, characterized in that: The boiler (1) has an economizer (11) fixedly connected to its flue gas output end. The output end of the economizer (11) is connected to a primary air preheater (12), and the primary air preheater (12) is fixedly connected to a multi-tube dust collector (2) through a pipe.

5. The biomass boiler emission system for dry desulfurization, high-temperature dust removal, and low-temperature denitrification according to claim 1, characterized in that: The multi-tube dust collector (2) has several sets of cylinders (21) fixedly installed inside, and a dust collection chamber (22) is provided at the bottom of the cylinder (21) inside the multi-tube dust collector (2).

6. The biomass boiler emission system for dry desulfurization, high-temperature dust removal, and low-temperature denitrification according to claim 5, characterized in that: An air inlet (24) is provided on one side of the outer surface of the cylinder (21), an exhaust port (23) is provided at the top of the cylinder (21), and a dust discharge port (25) is provided at the bottom of the cylinder (21).

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