Gasification fine slag grading combustion-supporting melting combustion device

Abstract

The utility model discloses a graded combustion-supporting melting combustion device for gasified fine slag, and belongs to the technical field of combustion of gasified fine slag. The device comprises a combustion-supporting chamber, a main combustion chamber and a melting pool which are communicated with one another, the combustion-supporting chamber is connected above the main combustion chamber, the melting pool is connected below the main combustion chamber, a melting burner is arranged in the melting pool, a slag outlet is formed in the side wall of the melting pool, and a smoke outlet is formed in the upper side of the melting pool. According to the utility model, gasification fine slag in the combustion-supporting chamber is combusted by utilizing preheating of the combustion-supporting material; and then high-temperature flue gas generated in the combustion-supporting chamber is used for preheating the gasified fine slag in the main combustion chamber, sufficient combustion of a large amount of refractory gasified fine slag driven by combustion-supporting gas with the minimum amount is achieved, meanwhile, large-particle gasified fine slag which does not react completely in the main combustion chamber enters a high-temperature melting pool on the lower portion to continue to react, and thorough reaction of the gasified fine slag is achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of the combustion of gasification fine slag, and more specifically, relates to a gasification fine slag staged combustion-supporting and melting combustion device. Background Technique

[0002] Gasification fine slag is considered a typical representative of difficult-to-treat coal-based solid waste, and it is very difficult to recycle, which seriously restricts the sustainable development of coal chemical enterprises. It is urgent to find advanced and reasonable technologies to treat gasification fine slag and convert it from the original industrial solid waste into fly ash that can be applied to industries such as cement, concrete, aerated bricks, and ceramsite, so as to realize the resource utilization of gasification fine slag solid waste.

[0003] The prominent characteristics of gasification fine slag are that it is very difficult to ignite, stably burn, and burn out, with low calorific value, high ash content, and a large particle size distribution span. In order to ensure stable operation and burnout rate of such fuels, it is necessary to add combustion-supporting fuels (generally high-calorific value gas) for combustion support and co-combustion. Usually, the proportion of the fuel quantity required for combustion support and co-combustion in the total fuel quantity calorific value is generally >5%. The combustion-supporting fuel quantity of more than 5% in industrial applications results in a relatively high combustion-supporting cost, which has a greater impact on the improvement of operation efficiency. At the same time, it is more difficult to burn out the larger particle size particles in gasification fine slag, and it is necessary to further use the melting combustion method to further burn out the unburned large particle gasification fine slag.

[0004] After retrieval, patent CN113074364A discloses a treatment system and method for co-combusting gasification fine slag in a pulverized coal boiler. In this method, the mixture of gasification fine slag filter cake and fuel coal is simultaneously sprayed into the pulverized coal boiler device through the lower burner, middle burner, and upper burner; during the combustion process, the air distribution is optimized to achieve the full combustion of the mixture, but the amount of combustion-supporting fuel used in this method is large.

[0005] Another example is patent CN116972381A, which discloses a cascade combustion-supporting reaction burner and a combustion-supporting method. The invention includes a combustion-supporting chamber and a main combustion chamber that are interconnected. The combustion-supporting chamber is provided with a combustion-supporting fuel passage and a first main fuel passage, and the main combustion chamber is provided with a second main fuel passage; among them, the combustion-supporting fuel enters the combustion-supporting chamber through the combustion-supporting fuel passage, and a part of the main fuel enters the combustion-supporting chamber through the first main fuel passage, and the other part enters the main combustion chamber through the second main fuel passage. However, it does not deal with the large particles that are difficult to burn out. Summary of the Invention

[0006] 1. Problems to be Solved

[0007] Aiming at the problem that the existing gasification fine slag is difficult to burn out, the utility model provides a gasification fine slag staged combustion-supporting and melting combustion device, which can achieve the complete combustion of gasification fine slag.

[0008] 2. Technical Solutions

[0009] To solve the above problems, the utility model adopts the following technical solutions.

[0010] A gasification fine slag classification and auxiliary melting combustion device includes a combustion assisting chamber, a main combustion chamber and a melting pool which are interconnected. The main combustion chamber is connected to the combustion assisting chamber above and the melting pool below.

[0011] Above the combustion assisting chamber, there are a combustion assisting fuel channel and a first main fuel channel. Above the main combustion chamber, there is a second main fuel channel. Among them, the combustion assisting fuel enters the combustion assisting chamber through the combustion assisting fuel channel for co-combustion. A small amount of gasification fine slag enters the combustion assisting chamber through the first main fuel channel to be mixed and burned with the combustion assisting fuel, and the remaining gasification fine slag enters the main combustion chamber through the second main fuel channel for combustion.

[0012] Above the combustion assisting chamber, there is a central air channel, and above the main combustion chamber, there is a main fuel air channel. Through the settings of the central air channel and the main fuel air channel, according to the actual combustion requirements, a certain amount of air volume is supplemented into the corresponding combustion assisting chamber and main combustion chamber to ensure the full combustion of the gasification fine slag.

[0013] Furthermore, the center lines of the combustion assisting chamber and the main combustion chamber are consistent. The air volume enters the combustion assisting chamber from above the combustion assisting chamber and then vertically enters the main combustion chamber, so that the air volume is utilized to the maximum extent.

[0014] Furthermore, the combustion chamber of the combustion assisting chamber is smaller than that of the main combustion chamber; the combustion assisting fuel and the main fuel are quickly heated up in the smaller combustion assisting chamber to reach the ignition point and achieve combustion.

[0015] Furthermore, the combustion assisting fuel channel, the first main fuel channel and the central air channel are sequentially sleeved above the combustion assisting chamber, that is, the first main fuel channel is sleeved outside the combustion assisting fuel channel, and the central air channel is sleeved outside the first main fuel channel. The combustion assisting fuel channel, the first main fuel channel and the central air channel are all arranged above the combustion assisting chamber. The second main fuel channel and the main fuel air channel are sequentially sleeved outside the combustion assisting chamber, that is, the second main fuel channel is sleeved outside the combustion assisting chamber, and the main fuel air channel is sleeved outside the second main fuel channel.

[0016] In order to make the heat of the main combustion chamber be effectively utilized, the inner wall of the main combustion chamber adopts a heat-insulating material structure.

[0017] Furthermore, at least one first preheating pipe and at least one second preheating pipe are arranged in the main combustion chamber. The first preheating pipe and the second preheating pipe are arranged alternately. The first preheating pipe is communicated with the first main fuel channel, and the second preheating pipe is communicated with the second main fuel channel. The preheating of the combustion assisting fuel, the combustion assisting air and the main fuel in the combustion assisting chamber is realized, which is beneficial to increasing the temperature of the main fuel in the combustion assisting chamber and making it reach its ignition point as soon as possible; at the same time, the heat of the main combustion chamber is fully utilized, which is beneficial to cost saving.

[0018] Furthermore, both the first preheating pipe and the second preheating pipe are U-shaped pipes.

[0019] Furthermore, a spray head is provided on the side wall of the main combustion chamber. The spray head is arranged between the first preheating pipe and the second preheating pipe. Preferably, the spray head extends out of the first preheating pipe and the second preheating pipe. The spray head is provided with multiple groups annularly along the inner wall of the main combustion chamber. Each group includes multiple spray heads distributed up and down, and the blowing direction of each spray head is downward. So that the ash generated during the combustion process is blown by the high-speed cold air flow before approaching the first preheating pipe, the second preheating pipe and the inner wall of the main combustion chamber, and no ash accumulation or coking occurs.

[0020] A melting burner is provided in the melting pool to control the temperature of the melting pool at 1350-1450 °C. Under this temperature, the large-particle gasified fine slag has sufficient reaction conditions, and the gasified fine slag is in a flowing state at this temperature. A slag outlet is opened on the side wall of the melting pool, and a flue gas outlet is opened on the upper side of the melting pool. The molten slag flows out through the slag outlet, and the flue gas during the combustion process flows out through the flue gas outlet.

[0021] Through the above-mentioned staged combustion-aided melting combustion method, it is finally realized to drive the complete combustion of a large amount of difficult-to-gasify fine slag under the condition of burning with the least amount of combustion-aided gas.

[0022] When using this device for staged combustion-aided melting combustion of gasified fine slag, first, the combustion-aided fuel and part of the gasified fine slag are introduced into the combustion-aided chamber through the combustion-aided fuel channel and the first main fuel channel for combustion; then, the high-temperature flue gas generated in the combustion-aided chamber is used to preheat the gasified fine slag in the main combustion chamber, so that the gasified fine slag in the main combustion chamber reaches its own ignition point; the more difficult-to-burn large-particle gasified fine slag enters the lower melting pool along with the flue gas and melts at the temperature of 1350-1450 °C in the melting pool, and finally realizes the complete combustion reaction of all the gasified fine slag.

[0023] 3. Beneficial effects

[0024] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0025] (1) The present utility model uses the high-temperature flue gas generated in the combustion-aided chamber to preheat the gasified fine slag in the main combustion chamber to realize the combustion of the gasified fine slag. At the same time, the high-temperature melting pool at the bottom further conducts high-temperature reaction on the large-particle gasified fine slag that has not reacted completely in the main combustion chamber, so as to realize the complete combustion of all the gasified fine slag;

[0026] (2) The present utility model introduces the combustion-aided fuel and a small amount of gasified fine slag into the combustion-aided chamber, and uses the high-temperature flue gas generated in the combustion-aided chamber to preheat the gasified fine slag in the main combustion chamber, which can effectively reduce the usage amount of the combustion-aided fuel and save costs;

[0027] (3) In the device of the present utility model, the auxiliary fuel channel, the first main fuel channel, and the central air channel are sequentially sleeved above the combustion-supporting chamber, and the second main fuel channel and the main fuel air channel are sequentially sleeved outside the combustion-supporting chamber, which is beneficial to improving the mixing effect of the auxiliary fuel, the gasified fine slag, and the combustion-supporting air, and making full use of the later heat;

[0028] (4) In the device of the present utility model, a first preheating pipeline and a second preheating pipeline are arranged in the main combustion chamber, and the heat in the main combustion chamber is recovered by using the preheating pipelines, and the reactants introduced into the combustion-supporting chamber are further preheated;

[0029] (5) In the device of the present utility model, a number of spray nozzles are arranged up and down between the first preheating pipeline and the second preheating pipeline, and the spraying direction of the spray nozzles is downward; the high-speed cold air flow ejected by the spray nozzles can prevent ash accumulation and coking, ensure the heat transfer effect of the preheating pipelines and the cleanliness of the inner wall of the main combustion chamber, and is beneficial to extending the service life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The technical solutions of the present utility model will be further described in detail below in conjunction with the drawings and embodiments. However, it should be understood that these drawings are only designed for the purpose of explanation and therefore do not limit the scope of the present utility model. In addition, unless otherwise specified, these drawings are only intended to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0031] Figure 1 It is a schematic diagram of a gasified fine slag classified combustion-supporting and melting combustion device of the present invention;

[0032] In the figure:

[0033] 1. Combustion-supporting chamber: 11. Auxiliary fuel channel; 12. First main fuel channel; 13. Central air channel;

[0034] 2. Main combustion chamber; 21. Second main fuel channel; 23. Main fuel air channel; 24. First preheating pipeline; 25. Second preheating pipeline; 26. Spray nozzle;

[0035] 3. Melting pool; 31. Melting burner; 32. Flue gas outlet; 33. Molten slag outlet. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The following detailed description of the present utility model and the exemplary embodiments can be better understood in conjunction with the drawings, in which the elements and features of the present utility model are identified by reference numerals.

[0037] Embodiment 1

[0038] As Figure 1As shown in the figure, a gasification fine slag classification and auxiliary melting combustion device of this embodiment includes a combustion support chamber 1, a main combustion chamber 2, and a melting pool 3 that are interconnected. The main combustion chamber 2 is connected to the combustion support chamber 1 above and the melting pool 3 below.

[0039] Above the combustion support chamber 1, there are a combustion support fuel channel 11 and a first main fuel channel 12. Above the main combustion chamber 2, there is a second main fuel channel 21. Among them, the combustion support fuel enters the combustion support chamber 1 through the combustion support fuel channel 11 for co-combustion. A small amount of gasification fine slag enters the combustion support chamber 1 through the first main fuel channel 12 to be mixed and burned with the combustion support fuel. The remaining part of the gasification fine slag enters the main combustion chamber 2 through the second main fuel channel 21 for combustion.

[0040] The gasification fine slag can be pneumatically transported into the corresponding combustion chamber. However, the air volume used for this part of transportation may not be sufficient to meet the air volume required for the full combustion of the fuel in the corresponding combustion chamber, which may lead to incomplete combustion of the fuel.

[0041] Therefore, a central air channel 13 is provided above the combustion support chamber 1, and a main fuel air channel 23 is provided on the main combustion chamber 2. Through the settings of the central air channel 13 and the main fuel air channel 23, according to the actual combustion requirements, a certain amount of air volume is supplemented into the corresponding combustion support chamber 1 and main combustion chamber 2 to ensure the full combustion of the gasification fine slag.

[0042] First, the combustion support fuel and part of the gasification fine slag are introduced through the combustion support fuel channel 11 and the first main fuel channel 12. Using the co-combustion heat of the combustion support fuel in the combustion support chamber 1, the gasification fine slag in the combustion support chamber 1 reaches its own ignition point and burns. Then, the high-temperature flue gas generated in the combustion support chamber 1 is used to preheat the gasification fine slag in the main combustion chamber 2, so that the gasification fine slag in the main combustion chamber 2 reaches its own ignition point and burns. The more difficult-to-burn large-particle gasification fine slag enters the lower melting pool 3 along with the flue gas. The melting pool 3 controls the temperature at 1350 - 1450 °C through the melting burner 31, and finally realizes the complete combustion reaction of all the gasification fine slag.

[0043] The centerlines of the combustion support chamber 1 and the main combustion chamber 2 are the same. The air volume enters the combustion support chamber 1 from above the combustion support chamber 1 and then vertically enters the main combustion chamber 2 to maximize the utilization of the air volume.

[0044] The combustion chamber of the combustion support chamber 1 is smaller than that of the main combustion chamber 2. The combustion support fuel and the main fuel quickly heat up in the smaller combustion support chamber 1 to reach the ignition point and achieve combustion.

[0045] To further improve the mixing effect of the auxiliary fuel, gasification fine slag, and combustion-supporting air, and make full use of the heat in the later stage, the auxiliary fuel channel 11, the first main fuel channel 12, and the central air channel 13 are sequentially sleeved above the combustion-supporting chamber 1, that is, the first main fuel channel 12 is sleeved outside the auxiliary fuel channel 11, and the central air channel 13 is sleeved outside the first main fuel channel 12. The auxiliary fuel channel 11, the first main fuel channel 12, and the central air channel 13 are all arranged above the combustion-supporting chamber 1. The second main fuel channel 21 and the main fuel air channel 23 are sequentially sleeved outside the combustion-supporting chamber 1, that is, the second main fuel channel 21 is sleeved outside the combustion-supporting chamber 1, and the main fuel air channel 23 is sleeved outside the second main fuel channel 21.

[0046] In a gasification fine slag staged combustion-supporting melting combustion device of this embodiment, the heat generated in the combustion-supporting chamber 1 is reused by flowing into the main combustion chamber 2 through the high-temperature flue gas. A large amount of heat is also generated in the main combustion chamber 2. Since the amount of main fuel in the main combustion chamber 2 is greater than that in the combustion-supporting chamber 1, more heat is generated in the main combustion chamber 2. In order to effectively utilize the heat of the main combustion chamber 2, the inner wall of the main combustion chamber 2 adopts a heat-insulating material structure. At least one first preheating pipe 24 and at least one second preheating pipe 25 are arranged in the main combustion chamber 2. The first preheating pipe 24 and the second preheating pipe 25 are alternately arranged. The first preheating pipe 24 is communicated with the first main fuel channel 12, and the second preheating pipe 25 is communicated with the second main fuel channel 21. Among them, part of the main fuel and part of the combustion-supporting air enter through the first preheating pipe 24, exchange heat through the combustion chamber of the main combustion chamber 2, and then enter the combustion-supporting chamber 1 through the first main fuel channel 12; another part of the combustion-supporting air enters through the second preheating pipe 25, exchanges heat through the combustion chamber of the main combustion chamber 2, and then enters the combustion-supporting chamber 1. The preheating of the auxiliary fuel, combustion-supporting air, and main fuel in the combustion-supporting chamber 1 is realized, which is beneficial to increasing the temperature of the main fuel in the combustion-supporting chamber 1 and making it reach its ignition point as soon as possible; at the same time, making full use of the heat of the main combustion chamber 2 is beneficial to cost saving.

[0047] To further improve the heat exchange effect, both the first preheating pipe 24 and the second preheating pipe 25 are U-shaped pipes. That is, the main fuel and the combustion-supporting air first move downward along the inner wall of the main combustion chamber 2 and then move upward along the inner wall of the main combustion chamber 2, thereby increasing the moving path and time of the main fuel and the combustion-supporting air, improving the heat exchange effect, making the main fuel and the combustion-supporting air after heat exchange have higher temperatures, and ultimately being beneficial to the main fuel reaching the ignition point.

[0048] In addition, since a certain amount of ash slag is generated during the combustion process in the main combustion chamber 2, this part of the ash slag will be in a molten state at high temperatures and is easily adhered to the inner wall of the main combustion chamber 2 and the preheating pipes, which not only affects the heat transfer effect of the preheating pipes but also affects the service life of the main combustion chamber 2.

[0049] In this embodiment, a spray head 26 is provided on the side wall of the main combustion chamber 2. The spray head 26 is arranged between the first preheating pipe 24 and the second preheating pipe 25. Preferably, the spray head 26 extends out of the first preheating pipe 24 and the second preheating pipe 25. A plurality of groups of the spray heads 26 are annularly arranged along the inner wall of the main combustion chamber 2. Each group includes a plurality of spray heads 26 distributed up and down, and the blowing direction of each spray head 26 is downward.

[0050] By spraying high-speed cold air flow through the spray head 26, on the one hand, the temperature control of the inner wall of the main combustion chamber 2 can be realized; on the other hand, the ash generated during the combustion process can be purged by the high-speed cold air flow before approaching the first preheating pipe 24, the second preheating pipe 25 and the inner wall of the main combustion chamber 2, so as to prevent ash accumulation and coking.

[0051] A method for gasification fine slag staged combustion-assisted melting combustion in this embodiment adopts a staged combustion method. Compared with the traditional direct co-combustion, it can not only achieve the full combustion of the main fuel, but also effectively reduce the consumption of the auxiliary fuel, saving costs. It is especially suitable for the independent combustion of gasification fine slag with ultra-low calorific value, very high ignition point and too high ash content, and the combustion reaction of fuels that need to be assisted by external fuels. It has the advantages of high-efficiency combustion with ultra-low auxiliary combustion amount and effective prevention of coking and wall sticking.

[0052] Most of the gasification fine slag in the combustion-supporting chamber 1 and the main combustion chamber 2 has been burned, but the particle size of the gasification fine slag is uneven, and there are still large particles of gasification fine slag that are more difficult to burn. These large particles to be processed fall into the lower melting pool 3. The melting pool 3 controls the temperature at 1350-1450 °C through the melting burner 31. Under this temperature, the large particles of gasification fine slag have the conditions for sufficient reaction, and the gasification fine slag is in a flowing state at this temperature. Finally, it flows out from the slag melting outlet 33 at the bottom of the melting pool 3, realizing the continuous and stable operation of the whole system.

[0053] A melting burner 31 is provided in the melting pool 3 to control the temperature of the melting pool 3 at 1350-1450 °C. Under this temperature, the large particles of gasification fine slag have the conditions for sufficient reaction, and the gasification fine slag is in a flowing state at this temperature. A slag melting outlet is opened on the side wall of the melting pool 3, and a flue gas outlet 32 is opened on the upper side of the melting pool 3. The molten slag at the bottom of the melting pool 3 flows out through the slag melting outlet, and the flue gas during the combustion process flows out through the flue gas outlet 32.

[0054] Among them, the high-temperature flue gas generated in the combustion-supporting chamber 1 flows into the main combustion chamber 2. A part of the large amount of heat generated in the main combustion chamber 2 is used to promote the combustion of the gasification fine slag in the main combustion chamber 2, and the other part is introduced into the melting pool 3 to promote the rapid heating and melting of the gasification fine slag in the melting pool 3.

[0055] Through the above-mentioned staged combustion-assisted melting combustion method, finally, the complete combustion of a large amount of difficult-to-burn gasification fine slag is realized under the condition of the least amount of auxiliary combustion gas for co-combustion.

[0056] The above has schematically described the present invention and its embodiments. Such description is not restrictive. What is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if those of ordinary skill in the art are inspired thereby and, without departing from the gist of the present invention, design similar structural modes and embodiments to the technical solution without creative efforts, they shall fall within the protection scope of the present invention.

Claims

1. A gasified fine slag graded combustion-supporting melting combustion device, comprising a combustion-supporting chamber (1) and a main combustion chamber (2) which are interconnected, wherein the main combustion chamber (2) is connected to the combustion-supporting chamber (1) at the top, characterized in that: It also comprises a melt pool (3), wherein the melt pool (3) is arranged below the main combustion chamber (2); A molten burner (31) is provided in the melt pool (3), a slag outlet is provided on the side wall of the melt pool (3), and a smoke outlet (32) is provided on the upper side of the melt pool (3); An auxiliary fuel channel (11) and a first main fuel channel (12) are provided above the auxiliary combustion chamber (1), and a second main fuel channel (21) is provided above the main combustion chamber (2); a central air channel (13) is provided above the auxiliary combustion chamber (1), and a main fuel air channel (23) is provided on the main combustion chamber (2).

2. The gasified fine slag graded combustion-supporting melting combustion device according to claim 1, characterized in that: The auxiliary fuel channel (11), the first main fuel channel (12), and the central air channel (13) are sequentially sleeved above the auxiliary combustion chamber (1), and the second main fuel channel (21) and the main fuel air channel (23) are sequentially sleeved outside the auxiliary combustion chamber (1).

3. The gasified fine slag graded combustion-supporting melting combustion device according to claim 1, characterized in that: The center lines of the auxiliary combustion chamber (1) and the main combustion chamber (2) are consistent.

4. The gasified fine slag graded combustion-supporting melting combustion device according to claim 1, characterized in that: The combustion chamber of the auxiliary combustion chamber (1) is smaller than the combustion chamber of the main combustion chamber (2).

5. The gasified fine slag graded combustion-supporting melting combustion device according to claim 1, characterized in that: The inner wall of the main combustion chamber (2) is made of a heat-insulating material structure.

6. The gasified fine slag graded combustion-supporting melting combustion device according to claim 1, characterized in that: At least one first preheating pipe (24) and at least one second preheating pipe (25) are provided in the main combustion chamber (2), the first preheating pipe (24) and the second preheating pipe (25) are arranged alternately, the first preheating pipe (24) is connected to the first main fuel channel (12), and the second preheating pipe (25) is connected to the second main fuel channel (21).

7. The gasified fine slag graded combustion-supporting melting combustion device according to claim 6, characterized in that: The first preheating pipe (24) and the second preheating pipe (25) are both U-shaped pipes.

8. The gasified fine slag graded combustion-supporting melting combustion device according to claim 7, characterized in that: A nozzle (26) is provided on the side wall of the main combustion chamber (2), and the nozzle (26) is arranged between the first preheating pipe (24) and the second preheating pipe (25).

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