Solid waste incineration device suitable for low-nitrogen combustion waste heat recovery

Abstract

The present application relates to solid waste incineration technical field, and disclose a kind of solid waste incineration device suitable for low nitrogen combustion waste heat recovery, including hearth body;Feed hopper, communication is arranged in hearth body bottom;Two air inlets, are used for passing into secondary air, two The air inlet is communicated and arranged in the side wall of hearth body;Partition, fixedly installed in hearth body inside.This scheme is separated by not burning gas and combustion gas first, then mixes, and passes into secondary air in mixing process, so that combustible gas can more fully contact oxygen and burn completely, by rational layout airflow path, enhance the mixing effect between gas, this design effectively improves the utilization of fuel, reduces energy waste, improves the overall thermal efficiency and purification efficiency of incinerator, while it can reduce the final emission concentration of nitrogen oxides, the environmental protection performance of entire incineration system is significantly enhanced, can better meet the increasingly stringent emission standard requirements.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of solid waste incineration, and in particular to a solid waste incineration device suitable for low-nitrogen combustion waste heat recovery. BACKGROUND

[0002] NOx in the atmosphere X After being dissolved in water, the NOx generates nitric acid rain, which causes extensive harm to the environment and huge economic losses, such as corrosion of buildings and industrial equipment, damage to open-air cultural relics, damage to plant leaves leading to forest death, death of fish and shrimp in lakes, damage to soil components leading to reduction or even death of crops, and harm of acidified groundwater to human bodies, therefore, the most direct method for reducing the emission of NOx is to reduce the generation at the source, and therefore, improving the waste incinerator is the most direct method for solving the problem of excessive emission of NOx. SUMMARY

[0003] The application aims to solve the problems in the prior art and provides a solid waste incineration device suitable for low-nitrogen combustion waste heat recovery.

[0004] In order to achieve the above-mentioned purpose, the application adopts the following technical scheme:

[0005] The solid waste incineration device suitable for low-nitrogen combustion waste heat recovery comprises a hearth body, a feeding hopper which is in communication with the bottom of the hearth body, two air inlets which are both used for introducing secondary air and are both in communication with the side wall of the hearth body, and a partition which is used for improving the mixing effect between the secondary air and the gas generated by waste incineration and is fixedly installed in the hearth body.

[0006] As a preferred technical scheme of the application, the hearth body comprises a side wall one and a side wall two, and the two air inlets are in communication with the side wall one and the side wall two respectively.

[0007] As a preferred technical scheme of the application, the bottom of the hearth body is arranged in an inclined manner, and the bottom of the hearth body is sequentially divided from high to low into a drying zone, a combustion zone and a burnout zone, wherein the drying zone is used for preliminarily heating the waste entering the hearth and achieving the purpose of dehydration and drying, the combustion zone is filled with oxygen and is used for waste incineration, and the burnout zone is used for burning out the unburned carbon particles and ash carbon brought out from the combustion zone.

[0008] As a preferred technical scheme of the application, the feeding hopper is located at the highest position of the bottom of the hearth body.

[0009] As a preferred technical scheme of the application, the partition is located between the air inlet and the bottom of the hearth body, the side wall one and the side wall two both have passages with the partition, and the passages are used for passing the gas generated by waste incineration.

[0010] As a preferred technical scheme of the present application, the cross section of the partition piece is triangular structure, and one of the sharp corners of the partition piece is located between the two air inlets.

[0011] As a preferred technical scheme of the present application, the partition piece is a water-cooled wall structure.

[0012] As a preferred technical scheme of the present application, the inner side of the side wall one and the side wall two are both provided with a water-cooled wall, and the water-cooled wall is used for recovering the combustion waste heat.

[0013] As a preferred technical scheme of the present application, a passage one is arranged between the partition piece and the side wall one, and the passage one is located above the drying zone; a passage two is arranged between the partition piece and the side wall two, and the passage two is located above the combustion zone and the burnout zone.

[0014] A use method of a solid waste incineration device suitable for low-nitrogen combustion waste heat recovery, based on any one of the above-mentioned solid waste incineration devices suitable for low-nitrogen combustion waste heat recovery, comprising the following steps: step 1: drying the garbage in the drying zone to produce unburned gas, and the unburned gas enters the passage one and moves upward; step 2: the dried garbage enters the combustion zone and the burnout zone for incineration to produce combustion gas, and the combustion gas enters the passage two and moves upward; step 3: introducing secondary air into the air inlet; step 4: under the guidance of the partition piece, the unburned gas and the combustion gas collide in the upper region of the partition piece, and at the same time mix with the secondary air, and the three react with each other to reduce the emission of pollutants.

[0015] The present application has the following beneficial effects:

[0016] 1. Improve the combustion efficiency: the present scheme separates the unburned gas and the combustion gas first and then mixes them, and introduces secondary air during the mixing process, so that the combustible gas can more fully contact oxygen for complete combustion, and by reasonably arranging the airflow path, the mixing effect between the gases is enhanced, which effectively improves the utilization rate of fuel, reduces energy waste, and improves the overall thermal efficiency and purification efficiency of the incinerator;

[0017] 2. Reduce the emission of nitrogen oxides: the cooling effect of the partition piece with a water-cooled wall structure helps to inhibit the formation of high-temperature regions, thereby reducing the generation of thermal-type nitrogen oxides, and at the same time, ammonia gas as a reducing agent undergoes a selective non-catalytic reduction reaction with nitrogen oxides in the mixing zone to convert it into harmless nitrogen and water vapor, further reducing the final emission concentration of nitrogen oxides, and the environmental protection performance of the entire incineration system is significantly enhanced, which can better meet the increasingly stringent emission standard requirements;

[0018] 3. Improve the temperature distribution in the hearth: the presence of water-cooled walls can absorb a large amount of heat, prevent the occurrence of local overheating, and achieve uniform distribution of the internal temperature of the hearth. This good temperature control helps to maintain a stable combustion state, avoids equipment damage or combustion instability caused by temperature fluctuations, and protects the furnace wall from direct radiation and chemical corrosion at high temperatures, thereby delaying the aging of the refractory material, extending the service life of the incinerator as a whole, and reducing maintenance frequency and cost. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present specification, the drawings required to be used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present specification, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0020] Figure 1 It is a schematic diagram of the structure of the existing incinerator.

[0021] Figure 2 It is a schematic diagram of the structure of the solid waste incineration device suitable for low-nitrogen combustion waste heat recovery proposed by the present application.

[0022] In the figure: 1 hearth body, 11 side wall one, 12 side wall two, 13 drying zone, 14 combustion zone, 15 burnout zone, 2 feed hopper, 3 water-cooled wall, 4 partition, 41 passage one, 42 passage two, 5 air inlet. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments.

[0024] Before introducing the technical solutions recorded in the present specification, the structure and working principle of the solid waste incineration device in the prior art will be briefly introduced:

[0025] Please refer to the attached Figure 1 The existing garbage incinerator is composed of a hearth a and a feed hopper b. The hearth a is composed of front and rear arches and two side walls. According to the status of garbage incineration, the bottom of the hearth a is divided into different zones, which are zone one c, zone two d and zone three e. Garbage is preliminarily dewatered at the zone one c position, zone two d is the main incineration place, and residual substances are burned out in zone three e. Two air inlets f are provided on the side wall of the hearth a for the introduction of secondary air. One air inlet f is located above zone one c, and the other air inlet f is located above zone two d and zone three e. Nitrogen-containing garbage enters the hearth from the feed hopper b and is sequentially incinerated in the three zones, and the generated gases are different.

[0026] Specifically, mixed gas one is generated in part of region one c and region two d. Due to incomplete combustion of waste in the part of region, oxygen is not sufficient to completely oxidize all carbon-containing substances into carbon dioxide, thus carbon monoxide (CO) is generated. In addition, hydrogen (H2) may be generated in the waste incineration process containing moisture or other compounds capable of decomposing hydrogen. In addition, nitrogen-containing waste is not completely oxidized into nitrogen oxides (NOx) and by-products in the selective non-catalytic reduction (SNCR) process, which may release ammonia (NH3). Therefore, mixed gas one includes but is not limited to CO, H2 and NH3. In other regions of region two d and region three e, mixed gas two is generated. Due to the complete combustion of nitrogen-containing waste in the part of the region, carbon dioxide (CO2) and NOx are generated. In addition, the part of the region needs to inject excess oxygen (O2) for complete combustion of waste, thus mixed gas two includes but is not limited to CO2, NOx and O2. X X X

[0027] Mixed gas one goes up along the front wall of the furnace a, and mixed gas two goes up along the back wall of the furnace a. After being contacted with the secondary air in the air port f and combusted, they are discharged. Such a design has some problems:

[0028] Combustible components such as CO and H2 in mixed gas one need to be in sufficient contact with oxygen to completely combust. If these gases directly contact with secondary air without being fully mixed with other combustion products, part of the combustible gas may not be able to contact enough oxygen for combustion, thereby reducing the overall combustion efficiency.

[0029] Due to incomplete combustion of CO into carbon dioxide, the emission of CO is increased. In addition, NH3 itself is a reducing agent and can be used to reduce the emission of NOx under appropriate conditions. If NH3 is not fully reacted with NOx and is discharged from the system, not only its role as a reducing agent is lost, but also it may be directly discharged into the atmosphere as another source of pollution. In addition, if there is a local hypoxic area, it may promote the generation of more NOx. Therefore, the pollutants in the exhaust gas are increased, which may be difficult to meet the increasingly stringent environmental regulations.

[0030] In summary, the existing incinerator in the prior art has the problems of low treatment efficiency and increased emission of pollutants in dealing with nitrogen-containing waste.

[0031] Therefore, please refer to the accompanying drawings Figure 2 ​​​The application provides a solid waste incineration device suitable for low-nitrogen combustion waste heat recovery, which comprises a hearth body 1 and a feeding hopper 2, wherein the hearth body 1 is composed of front and rear arches and side wall one 11 and side wall two 12 and is made of refractory bricks and refractory castables, water cooling walls 3 are arranged on the side wall one 11 and the side wall two 12, the bottom of the hearth body 1 is arranged to be inclined, so that the ash and slag can move towards the collection opening, the bottom of the hearth body 1 is sequentially divided into a drying zone 13, a combustion zone 14 and a burnout zone 15 from high to low, the feeding hopper 2 is arranged at the highest position of the bottom of the hearth body 1, the garbage enters the three zones in sequence from the feeding hopper 2, air inlets 5 are arranged on the side wall one 11 and the side wall two 12 and are used for introducing secondary air, the air inlets 5 are horizontally arranged, so that the secondary air can fully collide and mix with the upward moving gas generated by incineration, commonly, the secondary air is air, which is used for providing the gas generated at the bottom of the hearth body 1 with combustion conditions such as oxygen;

[0032] Further, a partition 4 is arranged in the hearth body 1 and is used for improving the mixing effect between the secondary air and the gas generated by garbage incineration, the partition 4 is located between the air inlets 5 and the combustion zone 14, the side wall one 11 and the side wall two 12 are both provided with passages with the partition 4, and the passages are used for passing the gas generated by garbage incineration;

[0033] Further, the partition 4 has a triangular cross section and each corner has a circular arc structure, there is a passage one 41 between the partition 4 and the side wall one 11, the passage one 41 is located above the drying zone 13, there is a passage two 42 between the partition 4 and the side wall two 12, the passage two 42 is located above the combustion zone 14 and the burnout zone 15, and it is worth mentioning that the flow range of the passage one 41 is greater than that of the passage two 42.

[0034] Further, the partition 4 has a water cooling wall structure, specifically, including but not limited to a membrane type water cooling wall structure, under the action of the partition 4, the unburned gas CO, H2 and NH3 generated in the drying zone 13 and the combustion zone 14 move upwards to the inside of the hearth body 1 through the passage one 41, the combustion gas CO2, NO X and excess O2 existing in the other regions of the combustion zone 14 and the burnout zone 15 move upwards through the passage two 42, in addition, the partition 4 can reduce the temperature in the inside of the hearth body 1, and the NO X Mainly including nitrogen monoxide (NO) and nitrogen dioxide (NO2), which are mainly generated by the reaction of nitrogen (N2) and oxygen (O2) in the air under high temperature conditions, especially when the temperature exceeds 1300 DEG C, the water cooling wall can effectively absorb the heat released in the combustion process, thereby reducing the thermal NO XThe generation of unburnt gas, while one of the sharp corners of the partition 4 is located between the two air inlets 5, plays a guiding role, which helps the gas to mix with the secondary air after being cooled, and specifically, when the three meet above the partition 4, the chemical reactions involved include but are not limited to:

[0035] CO + 0.5O2→ CO2;

[0036] H2 + 0.5O2→ H2O;

[0037] 4NH3 + 5O2→ 4NO + 6H2O;

[0038] 4NH3 + 4NO + O2→ 4N2 + 6H2O;

[0039] 2NO + O2→ 2NO2;

[0040] 4NH3 + 2NO2 + O2→ 3N2 + 6H2O;

[0041] Among them, the generated H2O is water vapor in the high-temperature environment of the incinerator, and if there is a small amount of volatile organic compounds (VOCs) in the unburnt gas, the substance will also be completely burned under the condition of oxygen:

[0042] CxHy + (x + y / 4)O2→ xCO2 + (y / 2)H2O;

[0043] As can be seen, the sufficient mixing of unburnt gas, combustion gas and secondary air and the cooling effect of the partition 4 help to reduce the emission of pollutants.

[0044] The specific working principle of the present application is as follows: After the low-nitrogen combustion garbage enters the furnace body 1 from the feed hopper 2, it is dried in the drying zone 13 to produce unburnt gas. The unburnt gas moves upward through the channel one 41, the garbage passing through the drying zone 13 enters the combustion zone 14 and the burnout zone 15, and then is incinerated in the combustion zone 14 and the burnout zone 15 to produce combustion gas. The unburnt gas and the combustion gas are mixed and reacted sufficiently, and the secondary air is injected into the furnace body 1 through the air inlet 5. The design helps to achieve more efficient and clean combustion, not only makes full use of the residual oxygen in the combustion gas to promote the complete combustion of the unburnt gas and improve the combustion efficiency, but also promotes the mixing of the secondary air and the flue gas through the partition 4, increases the area of waste heat recovery in the furnace, reduces the temperature of the combustion position, and reduces the generation of incomplete combustion products and nitrogen oxides, thereby effectively reducing the emission of pollutants and improving the environmental protection and energy utilization rate of the incineration process.

[0045] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art, according to the technical solution and inventive concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A solid waste incineration device suitable for low-nitrogen combustion waste heat recovery, comprising a hearth body (1) and a feed hopper (2), the feed hopper (2) being in communication with the bottom of the hearth body (1), characterized in that, Also include: Two air inlets (5), both for the secondary air, both said air inlet (5) is communicated with the side wall of the hearth body (1) is arranged; Partition (4) for improving the mixing effect between the secondary air and the gas generated by waste incineration, the partition (4) is fixedly installed in the hearth body (1) inside; The hearth body (1) includes side wall one (11) and side wall two (12), two said air inlet (5) is communicated with the side wall one (11) and side wall two (12) are arranged respectively, the air inlet (5) is horizontally arranged, the bottom of the hearth body (1) is inclined, the bottom of the hearth body (1) is divided from high to low: drying zone (13): for the preliminary heating of the waste into the furnace, realize the purpose of dehydration and drying; Combustion zone (14): filled with oxygen inside, for waste incineration; Burnout zone (15): for burning out the unburned carbon particles and ash residual carbon from the combustion zone (14), the partition (4) and side wall one (11) are provided with channel one (41), the channel one (41) is located above the drying zone (13), the partition (4) and side wall two (12) are provided with channel two (42), the channel two (42) is located above the combustion zone (14) and burnout zone (15) together; The cross section of the partition (4) is triangular structure, and one of the sharp corners of the partition (4) is located between the two air inlets (5).

2. The solid waste incineration device suitable for low-nitrogen combustion waste heat recovery according to claim 1, characterized in that, The feeding hopper (2) is located at the highest position of the bottom of the hearth body (1).

3. The solid waste incineration device suitable for low-nitrogen combustion waste heat recovery according to claim 2, characterized in that, The partition (4) is located between the air inlet (5) and the bottom of the hearth body (1), the side wall one (11) and the side wall two (12) are provided with channel with the partition (4), and the channel is used for passing the gas generated by waste incineration.

4. The solid waste incineration device suitable for low-nitrogen combustion waste heat recovery according to claim 3, characterized in that, The partition (4) is a water cooled wall structure.

5. The solid waste incineration device suitable for low-NOx combustion waste heat recovery according to claim 4, characterized in that, The inner side of the side wall one (11) and the side wall two (12) are provided with water cooled wall (3), and the water cooled wall (3) is used for recycling the combustion waste heat.

6. A method of using a solid waste incineration device suitable for low-nitrogen combustion waste heat recovery based on the solid waste incineration device suitable for low-nitrogen combustion waste heat recovery according to any one of claims 1-5, characterized in that, Including the following steps: Step 1: drying the waste in the drying zone (13), generating unburned gas, the unburned gas enters the channel one (41) and moves upward; Step 2: the dried waste enters the combustion zone (14) and burnout zone (15) for incineration, generating combustion gas, the combustion gas enters the channel two (42) and moves upward; Step 3: the secondary air is introduced into the air inlet (5); Step 4: under the guidance of the partition (4), the unburned gas and the combustion gas collide in the area above the partition (4), and at the same time, the secondary air is mixed, the three react with each other, reducing the emission of pollutants.

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