Nitrogen reducing device in carbon material drying process

Abstract

The utility model provides a nitrogen reduction device in a carbon material drying process. The nitrogen reduction device comprises a urea solution preparation tank, a liquid transfer pump and a carbon drying furnace which are sequentially connected in series, the urea solution blending tank is respectively connected with a urea feeder, a water supply pipeline and a compressed air pipeline; the charcoal drying furnace comprises a hearth and a drying cylinder; the interior of the hearth is divided into an upper auxiliary hearth and a lower main hearth through a grid plate. The auxiliary hearth is communicated with the drying cylinder through a flue; and a plurality of spray guns are arranged in the main hearth, are arranged close to the grid plate, and are respectively connected with a liquid transfer pump and a compressed air pipeline. According to the device, through cooperative use of the equipment, the urea solution is sprayed into the hearth to react with nitric oxide generated in the fuel combustion process, so that the nitric oxide in the flue gas is removed, the content of the nitric oxide in the flue gas is effectively reduced, and the defects that in the semi-coke drying process, the content of the nitric oxide in the flue gas is high, and the flue gas is polluted are overcome. And environmental pollution is caused.

Description

Technical Field

[0001] This application relates to the field of calcium carbide production technology, and in particular to a nitrogen reduction device in the drying process of charcoal materials. Background Technology

[0002] Calcium carbide, also known as calcium carbide, is an important basic chemical industrial raw material, mainly used in organic synthesis and the manufacture of acetylene. It also has wide applications in light industry, metallurgy, pharmaceuticals, textiles, and machinery. Industrially, calcium carbide is mainly produced using an electrothermal method, where calcium oxide and carbon are fed into a calcium carbide furnace and combined at high temperatures. Carbon is the main raw material for synthesizing calcium carbide, primarily semi-coke. Before feeding the semi-coke into the calcium carbide furnace, its moisture needs to be dried. Current methods use drying furnaces, such as fluidized bed furnaces, to dry the semi-coke. In these devices, hot air generated by burning coal dries the semi-coke in the drying drum. However, during coal combustion, nitrogen oxides (NOx) are produced in the flue gas due to nitrogen in the air and nitrogen-containing compounds in the coal. These flue gas emissions cause air pollution, making it necessary to remove the NOx. Utility Model Content

[0003] This application provides a nitrogen reduction device for the drying process of charcoal materials, which is used to solve the problem of high nitrogen oxide content in the flue gas emitted during the drying process of semi-coke, causing environmental pollution.

[0004] This application provides a nitrogen reduction device for the drying process of charcoal materials, including a urea solution mixing tank, a transfer pump and a charcoal drying furnace connected in series;

[0005] The urea solution mixing tank is connected to the urea feeder, water supply line, and compressed air line, respectively.

[0006] A charcoal drying furnace includes a furnace chamber and a drying cylinder;

[0007] The furnace chamber is divided into an upper auxiliary furnace chamber and a lower main furnace chamber by a grate plate; the auxiliary furnace chamber is connected to the drying cylinder through a flue.

[0008] Multiple spray guns are installed inside the main furnace. The spray guns are located near the grate and are connected to the liquid transfer pump and compressed air pipeline respectively.

[0009] Optionally, a filter is provided between the transfer pump and the spray gun.

[0010] Optionally, the main furnace is connected to the gas outlet of the dust collector via a first valve, and the gas inlet of the dust collector is connected to the lime kiln.

[0011] Optionally, the gas outlet of the dust collector is also connected to the drying cylinder via a second valve.

[0012] Optionally, the urea solution mixing tank is divided into a mixing zone and a storage zone by vertically arranged baffles, and the mixing zone and the storage zone are connected by a transfer pump;

[0013] The mixing zone is horizontally arranged with upper and lower partition nets from top to bottom;

[0014] A guide funnel connected to a urea feeder is installed at the top of the mixing zone of the urea solution mixing tank. The guide tube of the guide funnel extends into the mixing zone through the upper partition net.

[0015] A water inlet is provided on the upper side wall of the mixing zone of the urea solution mixing tank, and the water inlet is connected to the water supply pipeline through a float valve.

[0016] A compressed air inlet is provided on the lower side wall of the mixing zone of the urea solution mixing tank, and the compressed air inlet is connected to a compressed air pipeline.

[0017] The water inlet is located between the top of the upper partition screen and the top of the urea solution mixing tank, and the compressed air inlet is located between the bottom of the lower partition screen and the bottom of the urea solution mixing tank.

[0018] An outlet is provided on the lower side wall of the liquid storage area.

[0019] Optionally, the compressed air inlet is connected to an aeration pipe located in the mixing zone;

[0020] The inlet is connected to a liquid guide pipe located in the mixing zone, and the output end of the liquid guide pipe passes through the upper partition screen.

[0021] Optionally, a level gauge and a concentration meter are installed in the liquid storage area;

[0022] The level gauge, concentration meter, transfer pump, and urea feeder are all electrically connected to the controller.

[0023] The device of this application supplies urea solution to the spray gun in the main furnace through a urea solution mixing tank, and simultaneously supplies compressed air to the spray gun through a compressed air pipeline, so that the urea solution can be evenly sprayed into a mist in the furnace. Through the combined use of the above equipment, the sprayed urea solution in the furnace reacts with the nitrogen oxides produced during fuel combustion, thereby removing nitrogen oxides from the flue gas, effectively reducing the nitrogen oxide content in the flue gas, and overcoming the drawback of high nitrogen oxide content in the flue gas emitted during semi-coke drying, which causes environmental pollution. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a nitrogen reduction device during the drying process of charcoal provided in an embodiment of this application;

[0026] Figure 2 This is a schematic diagram of a nitrogen reduction device during the drying process of charcoal provided in another embodiment of this application;

[0027] Figure 3 A schematic diagram of a nitrogen reduction device during the drying process of charcoal provided in another embodiment of this application;

[0028] Figure 4 This is a schematic diagram of the structure of a urea solution mixing tank provided in one embodiment of this application;

[0029] Figure 5 This is a schematic diagram of the structure of a urea solution mixing tank provided in another embodiment of this application.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Urea solution mixing tank; 2. Coal drying furnace; 3. Urea feeder; 4. Dust collector; 5. Lime kiln; 10. Water supply pipeline; 11. Baffle plate; 12. Feed funnel; 14. Aeration pipe; 15. Liquid guide pipe; 16. Level gauge; 17. Concentration meter; 18. Controller; 20. Compressed air pipeline; 21. Furnace; 22. Drying cylinder; 23. Spray gun; 24. Filter; 100. Transfer pump; 101. Water inlet; 102. Compressed air inlet; 103. Liquid outlet; 110. Transfer pump; 111. Upper baffle; 112. Lower baffle; 211. Grate; 212. Auxiliary furnace; 213. Main furnace; 1000. First valve; 2000. Second valve; 3000. Float valve. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0033] like Figure 1 As shown, this application provides a nitrogen reduction device for the drying process of charcoal materials, including a urea solution mixing tank 1, a liquid transfer pump 100 and a charcoal drying furnace 2 connected in series.

[0034] The urea solution mixing tank 1 is connected to the urea feeder 3, the water supply line 10, and the compressed air line 20, respectively.

[0035] The charcoal drying furnace 2 includes a furnace chamber 21 and a drying cylinder 22;

[0036] The furnace chamber 21 is divided into an upper auxiliary furnace chamber 212 and a lower main furnace chamber 213 by a grate plate 211; the auxiliary furnace chamber 212 is connected to the drying cylinder 22 through a flue.

[0037] Multiple spray guns 23 are installed inside the main furnace 213. The spray guns 23 are located near the grate plate 211 and are respectively connected to the liquid transfer pump 100 and the compressed air pipeline 20.

[0038] During use, the water supply pipeline 10 supplies clean water (from the circulating water of the slag cooler) to the urea solution mixing tank 1, while the urea feeder 3 adds urea granules to the urea solution mixing tank 1. The compressed air pipeline 20 introduces compressed air into the urea solution mixing tank 1 to stir the urea solution, thereby preparing a urea solution of qualified concentration (such as a urea aqueous solution with a concentration of 10wt%).

[0039] The urea solution prepared in the urea solution mixing tank 1 is transferred to the spray gun 23 by the transfer pump 100. Simultaneously, compressed air supplied by the compressed air pipeline 20 is also introduced into the spray gun 23, mixing with the urea solution and causing it to be sprayed as a mist from the spray gun 23 into the main furnace 213. In the main furnace 213, the sprayed urea solution reacts with nitrogen oxides produced by the combustion of fuel (e.g., pulverized coal), reducing the nitrogen oxides into harmless nitrogen and water, thereby reducing the nitrogen oxide content in the flue gas discharged from the furnace. The high-temperature flue gas after the reaction enters the drying cylinder 22 through the flue duct to dry the semi-coke in the drying cylinder 22. After drying the semi-coke in the drying cylinder 22, the flue gas is discharged to the corresponding flue gas treatment section for harmless treatment before being released.

[0040] The device of this application supplies urea solution to the spray gun 23 of the main furnace 213 through a urea solution mixing tank 1, and simultaneously supplies compressed air to the spray gun 23 through a compressed air pipeline 20, so that the urea solution can be evenly sprayed into the furnace 21 in a mist. Through the combined use of the above equipment, the sprayed urea solution in the furnace 21 reacts with the nitrogen oxides produced during fuel combustion, thereby removing nitrogen oxides from the flue gas, effectively reducing the nitrogen oxide content in the flue gas, and overcoming the drawback of high nitrogen oxide content in the flue gas emitted during the semi-coke drying process, which causes environmental pollution.

[0041] like Figure 2 As shown, optionally, a filter 24 is provided between the transfer pump 100 and the spray gun 23.

[0042] In this application, the filter 24 is provided to trap solid impurities in the urea solution, thereby preventing the presence of solid impurities from clogging the spray gun 23.

[0043] like Figure 3 As shown, optionally, the main furnace 213 is connected to the gas outlet of the dust collector 4 through the first valve 1000, and the gas inlet of the dust collector 4 is connected to the lime kiln 5.

[0044] In this application, when the charcoal drying furnace 2 is working, the flue gas generated by the lime kiln 5 calcining lime is filtered by the dust collector 4 (cyclone dust collector or bag dust collector) and then partially introduced into the furnace 21. Since the main component of the flue gas generated by the lime kiln 5 calcining lime is carbon dioxide, introducing it into the furnace 21 can reduce the oxygen content of the furnace air, thereby reducing the content of nitrogen oxides generated by the oxygen-rich combustion of fuel during the combustion process.

[0045] like Figure 3 As shown, optionally, the gas outlet of the dust collector 4 is also connected to the drying cylinder 22 via a second valve 2000.

[0046] In this application, the flue gas generated by calcining lime in lime kiln 5 has a high temperature and can be used as a heat source for drying semi-coke in drying cylinder 22. This reduces the use of fuel in charcoal drying furnace 2, thereby saving resources and reducing production costs.

[0047] like Figure 4 As shown, optionally, the urea solution mixing tank 1 is divided into a mixing zone and a storage zone by a vertically arranged partition 11, and the mixing zone and the storage zone are connected by a transfer pump 110;

[0048] The mixing zone is provided with an upper partition net 111 and a lower partition net 112 arranged horizontally from top to bottom;

[0049] The top of the mixing zone of the urea solution mixing tank 1 is provided with a guide funnel 12 connected to the urea feeder 3. The guide tube of the guide funnel 12 passes through the upper partition 111 and extends into the mixing zone.

[0050] A water inlet 101 is provided on the side wall of the upper part of the mixing zone of the urea solution mixing tank 1. The water inlet 101 is connected to the water supply pipeline 10 through a float valve 3000.

[0051] A compressed air inlet 102 is provided on the lower side wall of the mixing zone of the urea solution mixing tank 1, and the compressed air inlet 102 is connected to the compressed air pipeline 20.

[0052] The water inlet 101 is located between the upper partition 111 and the top of the urea solution mixing tank 1, and the compressed air inlet 102 is located between the lower partition 112 and the bottom of the urea solution mixing tank 1.

[0053] An outlet 103 is provided on the lower side wall of the liquid storage area.

[0054] When preparing urea solution in urea solution mixing tank 1, clean water supplied by water supply pipeline 10 enters the mixing zone through inlet 101 via float valve 3000. At the same time, urea feeder 3 transfers urea granules into feed funnel 12. The urea granules pass through the guide tube of feed funnel 12 and enter the mixing zone through upper partition 111. At this time, compressed air supplied by compressed air pipeline 20 enters the mixing zone through compressed air inlet 102 and aerates from bottom to top. After entering the mixing zone, the compressed air passes through lower partition 112, stirring the urea and clean water between upper and lower partitions 112 to accelerate the dissolution of urea. The urea solution obtained after dissolution is stirred by compressed air to make the urea solution evenly mixed. The mixed urea solution is transferred from the mixing zone to the storage zone by transfer pump 110 for storage. The compressed air introduced into the mixing zone is discharged from the exhaust port set at the top to maintain the stable air pressure in the storage zone.

[0055] In this application, the upper partition 111 and lower partition 112 can isolate a space for urea particles to dissolve in the mixing zone. Because of the presence of the upper partition 111, it can prevent undissolved urea particles from being drawn away by the delivery pump 110 (during operation, the suction port of the delivery pump 110 is located above the upper partition 111), thereby affecting the concentration of the prepared urea solution. At the same time, it can also intercept some insoluble solid impurities in the urea solution. The lower partition 112 can prevent urea particles from falling to the bottom of the tank and being difficult to be stirred by compressed air, resulting in an undesirable consequence of excessive concentration at the bottom of the tank. It can also prevent insoluble solid particles in the urea solution from clogging the pipe opening. In addition, the lower partition 112 can also buffer and evenly distribute the compressed air.

[0056] like Figure 5 As shown, optionally, the compressed air inlet 102 is connected to the aeration pipe 14 disposed in the mixing zone;

[0057] The inlet 101 is connected to the liquid guide pipe 15 located in the mixing zone, and the output end of the liquid guide pipe 15 passes through the upper partition 111.

[0058] In this application, the aeration pipe 14 increases the distribution range of compressed air, which is beneficial for aerating and stirring the urea solution. The liquid guide pipe 15 is a pipe with an elbow, which is connected to the water inlet 101. The output end of the liquid guide pipe 15 is located in the space separated by the upper partition 111 and the lower partition 112, which can prevent the delivery pump 110 from sucking in the input clean water and causing the urea solution concentration to deviate.

[0059] like Figure 5 As shown, optionally, a level gauge 16 and a concentration meter 17 are provided in the liquid storage area;

[0060] The level gauge 16, concentration meter 17, transfer pump 110 and urea feeder 3 are all electrically connected to the controller 18.

[0061] During use, the level gauge 16 and concentration meter 17 installed in the storage area detect the liquid level and concentration of the urea solution stored in the storage area in real time, and feed the corresponding data back to the controller 18 in real time. When the liquid level in the storage area reaches the preset high value, the controller 18 controls the transfer pump 110 to stop transferring liquid, and at the same time controls the urea feeder 3 to stop feeding. Due to the presence of the float valve 3000 installed at the inlet 101, the clean water input to the mixing area will close when it reaches a certain liquid level, and at this time the supply of clean water to the mixing area will stop. In actual use, the liquid transfer flow rate of the transfer pump 100 can be adjusted to match the supply flow rate of clean water. In this way, when the transfer pump 100 stops working, the liquid level in the mixing area can be maintained at a height that can close the float valve 3000 in time.

[0062] When the concentration of urea in the storage zone deviates from the preset concentration, such as when the concentration of urea is too low, the controller 18 can control the urea feeder 3 to increase the feeding power, thereby increasing the amount of urea fed into the mixing zone. Similarly, when the concentration of urea solution is too high, the controller 18 can control the urea feeder 3 to decrease the feeding power, thereby reducing the amount of urea fed into the mixing zone.

[0063] A nitrogen reduction device for charcoal drying process, the working process of which is as follows:

[0064] During use, the water supply pipeline 10 supplies clean water (from the circulating water of the slag cooler) to the urea solution mixing tank 1, while the urea feeder 3 adds urea granules to the urea solution mixing tank 1. The compressed air pipeline 20 introduces compressed air into the urea solution mixing tank 1 to stir the urea solution.

[0065] When preparing urea solution in urea solution mixing tank 1, clean water supplied by water supply pipeline 10 enters the liquid guide pipe 15 through the inlet 101 via float valve 3000, and then enters the mixing zone. At the same time, urea feeder 3 transfers urea particles into the feed funnel 12. The urea particles pass through the guide tube of feed funnel 12 and through the upper partition 111 into the mixing zone. At this time, compressed air supplied by compressed air pipeline 20 enters the aeration pipe 14 from the compressed air inlet 102, aerating from bottom to top. After entering the mixing zone, the compressed air passes through the lower partition 112, stirring the urea and clean water between the upper and lower partitions 112 to accelerate the dissolution of urea. The urea solution obtained after dissolution is stirred by compressed air to make the urea solution evenly mixed. The mixed urea solution is transferred from the mixing zone to the storage zone by the transfer pump 110 for storage. The compressed air introduced into the mixing zone is discharged from the exhaust port correspondingly set at the top to maintain the stable air pressure in the storage zone. The level gauge 16 and concentration meter 17 installed in the storage area monitor the liquid level and concentration of the urea solution stored in the storage area in real time, and feed the corresponding data back to the controller 18 in real time. When the liquid level in the storage area reaches the preset high value, the controller 18 controls the transfer pump 110 to stop transferring liquid and at the same time controls the urea feeder 3 to stop feeding. Due to the presence of the float valve 3000 installed at the inlet 101, the clean water entering the mixing area will close when it reaches a certain liquid level, and the supply of clean water to the mixing area will stop. In actual use, the transfer flow rate of the transfer pump 110 can be adjusted to match the supply flow rate of clean water. In this way, when the transfer pump stops working, the liquid level in the mixing area can be maintained at a height that can close the float valve in time.

[0066] When the concentration of urea in the storage zone deviates from the preset concentration, such as when the concentration of urea is too low, the controller 18 can control the urea feeder 3 to increase the feeding power, thereby increasing the amount of urea fed into the mixing zone. Similarly, when the concentration of urea solution is too high, the controller 18 can control the urea feeder 3 to decrease the feeding power, thereby reducing the amount of urea fed into the mixing zone.

[0067] The urea solution prepared in the urea solution mixing tank 1 is transferred from the outlet 103 of the storage area via the transfer pump 100. After being filtered by the filter 24 to remove solid impurities, it is transferred into the spray gun 23. Simultaneously, compressed air supplied by the compressed air pipeline 20 is also introduced into the spray gun 23, mixing with the urea solution and causing it to be sprayed out of the spray gun 23 as a mist into the main furnace 213. In the main furnace 213, the sprayed urea solution reacts with nitrogen oxides produced by the combustion of fuel (such as pulverized coal), reducing the nitrogen oxides into harmless nitrogen and water, thereby reducing the nitrogen oxide content of the flue gas discharged from the furnace 21. The high-temperature flue gas after the reaction enters the drying cylinder 22 through the flue, where it, together with the dust removal flue gas output from the lime kiln 5, dries the semi-coke in the drying cylinder 22. After drying the semi-coke in the drying cylinder 22, the flue gas is discharged to the corresponding flue gas treatment section for harmless treatment before being released.

[0068] When the charcoal drying furnace 2 is working, the flue gas produced by the lime kiln 5 calcining lime is filtered by the dust collector 4 (cyclone dust collector or bag dust collector) and then partially introduced into the furnace 21. Since the main component of the flue gas produced by the lime kiln 5 calcining lime is carbon dioxide, introducing it into the furnace 21 can reduce the oxygen content of the furnace air, thereby reducing the content of nitrogen oxides produced by the oxygen-rich combustion of fuel during the combustion process.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A nitrogen reduction device for charcoal drying process, characterized in that, It includes a urea solution mixing tank (1), a transfer pump (100), and a charcoal drying furnace (2) connected in series. The urea solution mixing tank (1) is connected to the urea feeder (3), the water supply line (10) and the compressed air line (20) respectively; The charcoal drying furnace (2) includes a furnace chamber (21) and a drying cylinder (22); The furnace chamber (21) is divided into an upper auxiliary furnace chamber (212) and a lower main furnace chamber (213) by a grate plate (211); the auxiliary furnace chamber (212) is connected to the drying cylinder (22) through a flue. The main furnace (213) is equipped with multiple spray guns (23), which are located close to the grate (211) and are connected to the liquid transfer pump (100) and the compressed air pipeline (20) respectively.

2. The nitrogen reduction device during the charcoal drying process according to claim 1, characterized in that, A filter (24) is provided between the transfer pump (100) and the spray gun (23).

3. The nitrogen reduction device during the charcoal drying process according to claim 1, characterized in that, The main furnace (213) is connected to the gas outlet of the dust collector (4) through the first valve (1000), and the gas inlet of the dust collector (4) is connected to the lime kiln (5).

4. The nitrogen reduction device during the charcoal drying process according to claim 3, characterized in that, The gas outlet of the dust collector (4) is also connected to the drying cylinder (22) through a second valve (2000).

5. The nitrogen reduction device during the charcoal drying process according to any one of claims 1 to 4, characterized in that, The urea solution mixing tank (1) is divided into a mixing zone and a storage zone by a vertically arranged partition (11), and the mixing zone and the storage zone are connected by a transfer pump (110); The mixing zone is provided with an upper partition net (111) and a lower partition net (112) arranged horizontally from top to bottom. The top of the mixing zone of the urea solution mixing tank (1) is provided with a guide funnel (12) connected to the urea feeder (3), and the guide tube of the guide funnel (12) passes through the upper partition (111) and extends into the mixing zone; The urea solution mixing tank (1) has an inlet (101) on the upper side wall of the mixing zone. The inlet (101) is connected to the water supply pipeline (10) through a float valve (3000). A compressed air inlet (102) is provided on the side wall of the lower part of the mixing zone of the urea solution mixing tank (1), and the compressed air inlet (102) is connected to the compressed air pipeline (20); The water inlet (101) is located between the upper partition (111) and the top of the urea solution mixing tank (1), and the compressed air inlet (102) is located between the lower partition (112) and the bottom of the urea solution mixing tank (1). An outlet (103) is provided on the side wall at the bottom of the liquid storage area.

6. The nitrogen reduction device during the charcoal drying process according to claim 5, characterized in that, The compressed air inlet (102) is connected to the aeration pipe (14) located in the mixing zone; The inlet (101) is connected to the liquid guide pipe (15) located in the mixing zone, and the output end of the liquid guide pipe (15) passes through the upper partition (111).

7. The nitrogen reduction device during the charcoal drying process according to claim 5, characterized in that, The liquid storage area is equipped with a level gauge (16) and a concentration meter (17). The level gauge (16), concentration meter (17), transfer pump (110) and urea feeder (3) are all electrically connected to the controller (18).

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