Compact in-furnace dust removal and denitration structure of water-cooling vibration grate straw boiler
By setting up a medium-low temperature superheating chamber, a coarse-dividing cyclone separator and a furnace denitrification equipment in the water-cooled vibrating grate straw boiler, combined with ash bucket and ash drop pipe, the problems of low-temperature corrosion and blockage of the tail heating surface and excessive NOx emission are solved, and the efficient operation and land-occupying of the boiler are achieved.
Patent Information
- Application Number
- CN202422463003.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-12
- Publication Date
- 2025-08-29
- Estimated Expiration
- 2034-10-12
AI Technical Summary
When the existing water-cooled vibrating grate straw boilers burn biomass fuel, there are problems of low temperature corrosion, blockage and excessive NOx emissions at the tail heating surface. The existing SCR equipment can only be processed before the tail heating surface and cannot effectively solve the blockage problem.
A furnace denitrification equipment is set up between the medium and low temperature superheating chamber and the coarse-dividing cyclone separator, combined with ash bucket and ash drop pipe, and the medium and low temperature superheating chamber cools down and the coarse-dividing cyclone separator are initially removed. The flue gas is denitrided in front of the heated end of the tail to reduce the corrosion and blockage of the heated end of the tail.
It effectively prevents low-temperature corrosion and blockage of the tail heating surface, reduces NOx emissions, improves the boiler operation cycle, and has a compact structure and a small footprint.
Smart Images
Figure CN223283089U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of straw boilers, in particular to a compact in-furnace dust removal and denitration structure of a water-cooled vibrating grate straw boiler. Background Art
[0002] Biomass energy is a clean, renewable, and environmentally friendly energy source that is widely found in nature. It primarily consists of crop straw, forestry waste, and livestock manure. There are various ways to utilize it, including direct combustion, thermoelectric conversion in boilers, and biofermentation. In the power generation sector, agricultural, forestry, and building material waste are commonly burned to generate steam, which drives steam turbines for electricity generation. Currently, the mainstream boiler type for biomass fuel is the direct-fired, water-cooled vibrating grate boiler. This type of boiler offers stable, full combustion and low coking properties. However, due to the high moisture content, high volatility, low ash content, and low melting point of biomass fuel, grate combustion requires sufficient residence time and sufficient air on the grate surface to ensure complete combustion. Excessive air oxygen can increase NOx emissions, necessitating the use of SCR equipment to reduce emissions.
[0003] However, biomass fuel flue gas has a complex composition, with alkali metals and ash having much higher adhesion than other fuels. This can cause severe low-temperature corrosion and clogging of the tail heating surface, making it difficult to remove with sootblowing equipment. Therefore, placing the necessary SCR equipment before the tail heating surface is more beneficial for protecting the tail heating surface.
[0004] Using this in-furnace SCR equipment to pre-treat the flue gas only before the rear heating surface can slow down the low-temperature corrosion of the rear heating surface and reduce NOx emissions, but it cannot solve the problem of blockage and extend the operating cycle. Summary of the Invention
[0005] In order to solve the low temperature corrosion, blockage and NO x To solve the problem of excessively high emissions, the utility model provides a compact in-furnace dust removal and denitrification structure for a water-cooled vibrating grate straw boiler, which can effectively prevent low-temperature corrosion and blockage of the tail heating surface, reduce NO x It has compact structure and occupies a small area.
[0006] The technical solution is as follows: a compact in-furnace dust removal and denitrification structure for a water-cooled vibrating grate straw boiler, characterized in that it includes a medium- and low-temperature superheating chamber, the bottom front end of the medium- and low-temperature superheating chamber is a flue gas inlet, and the top two sides are respectively connected to the flue gas inlet of the coarse cyclone separator through connecting flues, the flue gas outlet of the coarse cyclone separator is connected to the tail flue, the upper part of the tail flue is provided with an in-furnace denitrification equipment, and the lower part is provided with a tail heating surface, and the bottom of the medium- and low-temperature superheating chamber, the bottom outlet of the coarse cyclone separator, and the bottom of the tail flue are all provided with ash hoppers.
[0007] It is further characterized in that the two coarse cyclone separators are symmetrically arranged;
[0008] The bottom of the ash hopper is connected to an ash dropping pipe with a gate valve.
[0009] After adopting the utility model, the flue gas enters the medium and low temperature superheating chamber for cooling, and is then introduced into the coarse cyclone separator through the connecting flue for rough cyclone dust removal, and then enters the tail flue, where it is first denitrified by the denitrification equipment in the furnace. After the flue gas comes out, it is clean enough and then enters the tail heating surface area for heat exchange. At this time, the flue gas has little effect on the corrosion and clogging of the tail heating surface, which can greatly improve the overall operating cycle of the boiler. It also has a compact structure and occupies a small area. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 This is the main view of the structure of the utility model;
[0011] Figure 2 This is a top view of the structure of the utility model;
[0012] Figure 3 for Figure 1 Middle AA section view. DETAILED DESCRIPTION
[0013] See Figure 1 , Figure 2 , Figure 3 As shown, a compact in-furnace dust removal and denitrification structure of a water-cooled vibrating grate straw boiler comprises a medium- and low-temperature superheating chamber 1, the bottom front end of the medium- and low-temperature superheating chamber 1 being a flue gas inlet, the top two sides being connected to the flue gas inlet of a coarse cyclone separator 3 through two symmetrically arranged connecting flues 2, the flue gas outlet of the coarse cyclone separator 3 being connected to a tail flue 4, an in-furnace denitrification device 5 being provided at the upper part of the tail flue 4, a tail heating surface 6 being provided at the lower part, an ash hopper 1 7, an ash hopper 2 8, and an ash hopper 3 9 being provided at the bottom of the medium- and low-temperature superheating chamber 1, the bottom outlet of the coarse cyclone separator 3, and the bottom of the tail flue 4 respectively, the bottoms of the ash hopper 1 7, the ash hopper 2 8, and the ash hopper 3 9 being connected to an ash drop pipe 11 with a gate valve 10.
[0014] The working principle is as follows: Flue gas enters from the lower part of the medium and low temperature superheating chamber 1, and some larger ash particles will be collected by the ash hopper 7 and fall into the corresponding ash drop pipe 11. The rest of the flue gas flows through the heating surface in the medium and low temperature superheating chamber 1, and the flue gas temperature will gradually drop to the temperature range within which the denitrification equipment in the furnace can be normally used. It is then led out from both sides and enters the coarse cyclone separator 3 through the connecting flue ducts 2 on both sides. The first coarse cyclone dust removal is carried out in the coarse cyclone separator 3, which can effectively separate 30~40% of the smoke dust in the flue gas and is discharged by the ash hoppers 8 arranged on both sides. The flue gas is collected and enters the corresponding ash drop pipe 11. The separated flue gas is collected through the central tube of the separator and then flows into the in-furnace denitrification equipment 5 in the middle tail flue 4 for denitrification treatment. The flue gas is clean enough after coming out of the in-furnace denitrification equipment 5, and then enters the tail heating surface area for heat exchange. At this time, the flue gas has little effect on the corrosion and blockage of the tail heating surface, which can greatly improve the overall operation cycle of the boiler. After the flue gas comes out of the tail heating surface, it enters the ash hopper three 9. Some ash will be deposited, and most of it will be drawn out from the outlet and enter the subsequent flue gas treatment equipment.
[0015] The compact in-furnace dust removal and denitrification layout structure not only effectively prevents low-temperature corrosion and blockage of the tail heating surface and reduces NOx emissions, but also has the advantages of compact structure, small footprint and easy layout.
Claims
1. A compact in-furnace dust removal and denitrification structure for a water-cooled vibrating grate straw boiler, characterized in that: It includes a medium- and low-temperature superheating chamber, the front end of the bottom of the medium- and low-temperature superheating chamber is a flue gas inlet, and the two sides of the top are connected to the flue gas inlet of the coarse cyclone separator through connecting flues. The flue gas outlet of the coarse cyclone separator is connected to the tail flue, and the upper part of the tail flue is provided with an in-furnace denitrification equipment and the lower part is provided with a tail heating surface. Ash hoppers are provided at the bottom of the medium- and low-temperature superheating chamber, the bottom outlet of the coarse cyclone separator, and the bottom of the tail flue.
2. The compact in-furnace dust removal and denitrification structure of a water-cooled vibrating grate straw boiler according to claim 1 is characterized in that: The two coarse cyclone separators are arranged symmetrically.
3. The compact in-furnace dust removal and denitrification structure of a water-cooled vibrating grate straw boiler according to claim 1 is characterized in that: The bottom of the ash hopper is connected to an ash dropping pipe with a gate valve.