Tail gas treatment device for lithium iron phosphate sintering kiln

Abstract

The utility model discloses a lithium iron phosphate sintering kiln tail gas treatment device which comprises a first three-way pipe and a second three-way pipe. According to the lithium iron phosphate sintering kiln tail gas treatment device, a first three-way pipe is connected to a first valve, second valves are connected to two ports of the first three-way pipe correspondingly, reaction pipe sections are connected to the second valves correspondingly, third valves are connected to the ends of the two reaction pipe sections correspondingly, and a second three-way pipe is connected to the third valves jointly; one end of the second three-way pipe is connected with a fourth valve, the fourth valve is connected with an air inlet pipe, flow division is carried out through the first three-way pipe to form two channels, air outlet of the two channels is converged through the second three-way pipe to be output through one pipeline, and meanwhile the pipeline is closed and opened in cooperation with the first valve, the second valve, the third valve and the fourth valve; therefore, work switching can be carried out on the two reaction pipe sections, and when overhaul and maintenance are needed, a passage formed by the other reaction pipe section can be switched.

Description

Technical Field

[0001] The utility model relates to the technical field of tail gas treatment, in particular to a tail gas treatment device for a lithium iron phosphate sintering kiln. Background Art

[0002] The tail gas treatment device of lithium iron phosphate sintering kiln is planned to adopt the process method of TO furnace incineration → waste heat recovery → low temperature denitrification → water spraying (treating escaped ammonia) → exhaust pipe emission up to standard. The roller kiln exhaust gas is sent to the TO furnace inlet by the roller kiln after being merged by the high-temperature fan replaced by it through the pipeline. A flame arrester is set on the pipeline. After the tail gas enters the TO furnace, it is mixed with the high-temperature flue gas incinerated by the burner that burns natural gas. The tail gas is stably increased to above 850℃, and then mixed with the secondary air in the middle of the TO furnace. The tar and other organic matter in it are burned into carbon dioxide and water and removed. The burner adopts a burner type that is easy to control. The natural gas and air are burned and mixed in proportion under the control of the self-contained control system. The burner control system has its own flame arrester and safety facilities. The secondary supplementary air is sent into the TO furnace by the blower, and can enter the flue gas tangentially, can be fully mixed, and is conducive to the full combustion of the exhaust gas. The secondary supplementary air fan is controlled by the frequency converter, and the air supplement amount is controlled according to the outlet temperature of the flue gas of the TO furnace and the incineration effect. The outlet temperature of the TO furnace is controlled within 850-1000°C. The flue gas after combustion enters the waste heat boiler and produces steam. After the waste heat is recovered, the flue gas temperature drops to 180-220°C and enters the denitrification device for treatment and purification.

[0003] A common exhaust gas treatment method is catalytic reduction flue gas denitrification, which uses 20% ammonia water as a denitrification agent and is equipped with ammonia water storage and transportation equipment. Ammonia water is sprayed into the flue in front of the SCR reactor through an ammonia water spray gun and atomized into droplets with a particle size of 50 to 80 μm by compressed air. The hot flue gas is fully in contact with ammonia water, and the ammonia water is vaporized into ammonia gas. The ammonia / smoke is evenly mixed and enters the SCR denitrification reactor. NOx and NH3 in the flue gas react in the denitrification reactor to generate N2 and H2O through the action of the catalyst, completing the denitrification process.

[0004] Long-term denitrification and purification of flue gas requires inspection and maintenance of the catalyst installation pipe section to extend the service life of the catalyst and maintain the catalytic reaction effect. However, direct disassembly of the pipe section during inspection and maintenance will cause the flue gas to be unable to pass and be processed, and then the treatment work will be suspended. Therefore, a lithium iron phosphate sintering kiln exhaust gas treatment device is proposed to solve the above situation. Utility Model Content

[0005] The purpose of the utility model is to provide a lithium iron phosphate sintering furnace tail gas treatment device to solve the problems raised in the above background technology.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A tail gas treatment device for a lithium iron phosphate sintering kiln, comprising a first valve installed on a flue gas pipeline, the first valve being connected to a first three-way pipe, the two ports of the first three-way pipe being connected to a second valve, the second valve being connected to a reaction pipe section, the ends of the two reaction pipe sections being connected to a third valve, the third valve being commonly connected to a second three-way pipe, one end of the second three-way pipe being connected to a fourth valve, the fourth valve being connected to an air intake pipe, the air intake pipe being fixedly connected to a water washing tower, the flue gas pipeline, the first valve, the first three-way pipe, the second valve, the reaction pipe section, the third valve, the second three-way pipe, the fourth valve and the air intake pipe being connected by flanges, and the flanges being fixed to each other by bolts;

[0008] Catalysts are fixedly connected at equal distances in the reaction pipe section, coils are fixedly connected to the front sides of the reaction pipe sections corresponding to the catalysts, atomizing nozzles are evenly fixedly connected to the coils, the water inlet end of the coils passes through the reaction pipe section and is fixedly connected to an externally threaded pipe joint, a third three-way pipe is commonly provided on the outer sides of the two corresponding externally threaded pipe joints, both ends of the third three-way pipe corresponding to the externally threaded pipe joints are rotatably connected to internally threaded pipe joints, the internally threaded pipe joints are threadedly connected to the externally threaded pipe joints, and a first regulating valve is installed at one end of the third three-way pipe corresponding to each internally threaded pipe joint.

[0009] As a further solution of the utility model: the other port of the third three-way pipe is fixedly connected to a connecting transverse pipe, and the connecting transverse pipe is connected to an external ammonia water supply device through a pipeline.

[0010] As a further solution of the utility model: a partition is fixedly connected to the lower part of the connection of the inner side of the water washing tower corresponding to the air inlet pipe, and electric valves are fixedly installed on the bottom of the partition and the water washing tower. The electric valve is externally connected to a power supply and a switch, and the electric valve at the bottom of the water washing tower is connected to an external ammonia water collecting device.

[0011] As a further solution of the utility model: an air outlet pipe is provided on the top of the water washing tower.

[0012] As a further solution of the utility model: a spray plate is fixedly connected to the inner side of the top of the water washing tower, the spray plate is hollow, spray holes are evenly opened on the bottom surface of the spray plate, and connecting pipes are evenly penetrated and fixedly connected on the spray plate.

[0013] As a further solution of the utility model: a water supply pipe is fixedly connected to one side of the spray plate, one end of the water supply pipe is fixedly connected to the bottom of the water washing tower and is communicated with the water washing tower, a water pump is connected to the water supply pipe, the water pump is externally connected to a power supply and a switch, the water pump is fixedly installed on the side wall of the water washing tower, a branch pipe is fixedly connected to the part of the water supply pipe corresponding to the water inlet end of the water pump, the branch pipe is connected to an external water source, a second regulating valve is connected to the branch pipe, and the branch pipe is connected to an external water supply device.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] 1. The utility model divides the flow through the first three-way pipe to form two channels, and the second three-way pipe merges the outlet gases of the two channels and outputs them through one pipeline. At the same time, the first valve, the second valve, the third valve and the fourth valve are used to close and open the pipeline, so that the two reaction tube sections can be switched to work. When inspection and maintenance are required, the passage formed by the other reaction tube section can be switched to keep the flue gas passing during the inspection and maintenance, and maintain the denitrification treatment of the flue gas to avoid suspension of the treatment work.

[0016] 2. The utility model divides the water washing tower into two upper and lower chambers by a partition, and at the same time, the bottom end of the water supply pipe forms an additional water inlet branch through a branch pipe. When the absorption of ammonia gas in the water liquid in the water washing tower is close to saturation, the bottom of the water washing tower can be isolated by an electric valve, and water is supplied by the branch pipe to maintain spraying. The ammonia water inside the water washing tower is extracted through the electric valve at the bottom, so that the spraying water can be replaced conveniently without stopping the machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The figure is a schematic diagram of the structure of a tail gas treatment device for a lithium iron phosphate sintering furnace.

[0018] Figure 2 The figure is a schematic diagram of the connection of the reaction tube section in a tail gas treatment device for a lithium iron phosphate sintering furnace.

[0019] Figure 3 This is a schematic diagram of the interior of a reaction tube section in a lithium iron phosphate sintering furnace exhaust gas treatment device.

[0020] Figure 4 This is a schematic diagram of a water washing tower in a lithium iron phosphate sintering furnace exhaust gas treatment device.

[0021] Figure 5 This is a schematic diagram of the flue gas reaction in a tail gas treatment device for a lithium iron phosphate sintering furnace.

[0022] Figure 6 This is a schematic diagram of the dual active site center of the catalyst in a lithium iron phosphate sintering furnace exhaust gas treatment device.

[0023] Figure 7 It is a catalyst ion splitting-catalytic reduction mechanism in a lithium iron phosphate sintering furnace tail gas treatment device.

[0024] Figure 8 This is a schematic diagram of the alkali metal ion exchange-coordination mechanism in a lithium iron phosphate sintering furnace exhaust gas treatment device.

[0025] In the figure: 1, flue gas duct; 2, first valve; 3, first three-way pipe; 4, second valve; 5, reaction tube section; 6, third valve; 7, second three-way pipe; 8, fourth valve; 9, air inlet pipe; 10, water scrubber; 11, catalyst; 12, coil; 13, atomizing nozzle; 14, external threaded pipe joint; 15, third three-way pipe; 16, internal threaded pipe joint; 17, first regulating valve; 18, connecting cross pipe; 19, partition; 20, electric valve; 21, air outlet pipe; 22, spray plate; 23, spray hole; 24, connecting pipe; 25, water supply pipe; 26, water pump; 27, branch pipe; 28, second regulating valve. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] See also Figures 1 to 8 In an embodiment of the utility model, a tail gas treatment device for a lithium iron phosphate sintering kiln comprises a first valve 2 installed on a flue gas pipeline 1, the first valve 2 is connected to a first three-way pipe 3, two ports of the first three-way pipe 3 are connected to a second valve 4, the second valve 4 is connected to a reaction pipe section 5, the ends of the two reaction pipe sections 5 are connected to a third valve 6, the third valve 6 is commonly connected to a second three-way pipe 7, one end of the second three-way pipe 7 is connected to a fourth valve 8, the fourth valve 8 is connected to an intake pipe 9, the intake pipe 9 is fixedly connected to a water washing tower 10, the flue gas pipeline 1, the first valve 2, the first three-way pipe 3, the second valve 4, the reaction pipe section 5, the third valve 6, the second three-way pipe 7, the fourth valve 8 and the intake pipe 9 are all connected by flanges, and the flanges are fixed to each other by bolts, thereby forming an assembled installation, which is convenient for disassembly of each component;

[0028] The catalyst 11 is fixedly connected at equal distances in the reaction tube section 5. The catalyst 11 adopts a sulfur-resistant and alkali-resistant low-temperature catalyst. The sulfur-resistant and alkali-resistant low-temperature catalyst adopts a double active site center to effectively improve the low-temperature activity of the catalyst. It uses the ion splitting-catalytic reduction mechanism of anti-ABS poisoning to effectively improve the low-temperature activity of the catalyst and decompose ammonium bisulfate at low temperatures. It can tolerate sulfur dioxide concentrations up to 2000mg / Nm 3The sulfur-resistant and alkali-resistant low-temperature catalyst has established an alkali metal ion exchange-coordination mechanism, has an alkali metal ion capture site, and its resistance to alkali metal poisoning is far superior to that of ordinary catalysts. The reaction tube section 5 corresponds to the front side of the catalyst 11, and the coil 12 is evenly and fixedly connected to the atomizing nozzle 13. The water inlet end of the coil 12 passes through the reaction tube section 5 and is fixedly connected to an external threaded pipe joint 14. The outer sides of the corresponding two external threaded pipe joints 14 are jointly provided with a third three-way pipe 15. The third three-way pipe 15 and the two ends corresponding to the external threaded pipe joint 14 are rotatably connected with the internal threaded pipe joint 16, and the internal threaded pipe joint 16 is threadedly connected to the external threaded pipe joint 14. The third three-way pipe 15 is installed with a first regulating valve 17 at one end corresponding to each internal threaded pipe joint 16. The third three-way pipe 15 is assembled with the reaction tube section 5 through the cooperation of the internal threaded pipe joint 16 and the external threaded shut-off head 14, which can be easily disassembled and assembled.

[0029] Denitrification reaction is carried out by ammonia atomization in combination with catalyst and flue gas: 4NO+4NH3+O2→4N2+6H2O, 6NO2+8NH3→7N2+12H2O, NO+NO2+2NH3→2N2+3H2O.

[0030] The first three-way pipe 3 is used for diversion to form two channels, and the second three-way pipe 7 combines the outlet gases of the two channels and outputs them through one pipeline. At the same time, the first valve 2, the second valve 4, the third valve 6 and the fourth valve 8 are used to close and open the pipeline, so that the two reaction tube sections 5 can be switched in operation. When inspection and maintenance are required, the passage formed by the other reaction tube section 5 can be switched to keep the flue gas passing during the inspection and maintenance, and maintain the denitrification treatment of the flue gas to avoid suspension of the treatment work.

[0031] The other end of the third three-way pipe 15 is fixedly connected to a connecting transverse pipe 18 , and the connecting transverse pipe 18 is connected to an external ammonia water supply device through a pipeline.

[0032] A partition 19 is fixedly connected to the lower part of the connection of the air inlet pipe 9 on the inner side of the water washing tower 10, and an electric valve 20 is fixedly installed on the partition 19 and the bottom of the water washing tower 10. The electric valve 20 is externally connected to a power supply and a switch. The electric valve 20 at the bottom of the water washing tower 10 is connected to an external ammonia water collecting device.

[0033] An air outlet pipe 21 is provided at the top of the water washing tower 10 .

[0034] A spray plate 22 is fixedly connected to the inner side of the top of the water washing tower 10 . The spray plate 22 is hollow, and spray holes 23 are evenly opened on the bottom surface of the spray plate 22 . A connecting pipe 24 is evenly penetrated and fixedly connected to the spray plate 22 .

[0035] A water supply pipe 25 is fixedly connected to one side of the spray plate 22, one end of the water supply pipe 25 is fixedly connected to the bottom of the water washing tower 10 and is communicated with the water washing tower 10, a water pump 26 is connected to the water supply pipe 25, the water pump 26 is externally connected to a power supply and a switch, the water pump 26 is fixedly installed on the side wall of the water washing tower 10, a branch pipe 27 is fixedly connected to the part of the water supply pipe 25 corresponding to the water inlet end of the water pump 26, the branch pipe 27 is connected to an external water source, a second regulating valve 28 is connected to the branch pipe 27, and the branch pipe 27 is connected to an external water supply device.

[0036] The water washing tower 10 is divided into two upper and lower chambers by the partition 19. At the same time, the bottom end of the water supply pipe 25 forms an additional water inlet branch through the branch pipe 27. When the absorption of ammonia gas in the water liquid in the water washing tower 10 is close to saturation, the bottom of the water washing tower 10 can be isolated by the electric valve 20, and the branch pipe 27 is used to supply water to maintain spraying. The ammonia water inside the water washing tower 10 is extracted through the electric valve 20 at the bottom, so that the spraying water can be replaced conveniently without stopping the machine.

[0037] The working principle of the utility model is:

[0038] When in use, open the first valve 2 and the fourth valve 8, and at the same time open the second valve 4 and the third valve 6 corresponding to one of the reaction tube sections 5, and at the same time open the first regulating valve 17 corresponding to the corresponding reaction tube section 5, an external device supplies ammonia water through the connecting cross pipe 18, and the ammonia water enters the corresponding coil 12 through the third three-way pipe 15, and is sprayed out by the atomizing nozzle 13, and the water pump 26 is started, so that the water liquid at the bottom of the water washing tower 10 is pumped into the spray plate 22 through the water supply pipe 25, and is sprayed out from the spray hole 23, and the flue gas in the flue gas pipeline 1 enters the corresponding reaction tube section 5 through the first three-way pipe 3, and the ammonia water and the flue gas react under the action of the catalyst 11, and after the reaction, enter the air intake pipe 9 through the second three-way pipe 7, and then enter the water washing tower 10 to be sprayed by the water liquid falling from the spray hole 23, so as to absorb the ammonia in the flue gas, thereby completing the denitration treatment in the tail gas.

[0039] When the reaction tube segment 5 needs to be inspected and maintained, the second valve 4 and the third valve 6 are connected and switched to keep the other reaction tube segment 5 connected. At this time, the connection between the external threaded pipe joint 14 and the internal threaded pipe joint 16 on the corresponding reaction tube segment 5 is released, and the flange connection at both ends of the reaction tube segment 5 is released, and the corresponding reaction tube segment 5 is disassembled for inspection and maintenance.

[0040] When the water in the water washing tower 10 is saturated with ammonia, the second regulating valve 28 is opened to allow the branch pipe 27 to supply water. At this time, the electric valve 20 on the interlayer 19 is closed, and the electric valve 20 at the bottom of the water washing tower 10 is opened. At this time, the water at the bottom of the water washing tower 10 is pumped out through the electric valve 20 at the bottom of the water washing tower 10 through external equipment, and the branch pipe 27 directly supplies water to the water pump 26, thereby maintaining the spraying step.

[0041] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A lithium iron phosphate sintering furnace tail gas treatment device, comprising a first valve (2) installed on a flue gas pipeline (1), characterized in that: The first valve (2) is connected to a first three-way pipe (3), the two ends of the first three-way pipe (3) are connected to a second valve (4), the second valve (4) is connected to a reaction pipe section (5), the ends of the two reaction pipe sections (5) are connected to a third valve (6), the third valve (6) is commonly connected to a second three-way pipe (7), one end of the second three-way pipe (7) is connected to a fourth valve (8), the fourth valve (8) is connected to an air intake pipe (9), the air intake pipe (9) is fixedly connected to a water washing tower (10), the flue gas pipeline (1), the first valve (2), the first three-way pipe (3), the second valve (4), the reaction pipe section (5), the third valve (6), the second three-way pipe (7), the fourth valve (8) and the air intake pipe (9) are all connected via flanges, and the flanges are fixed to each other via bolts; A catalyst (11) is fixedly connected in an equidistant manner in the reaction pipe section (5); a coil (12) is fixedly connected to the front side of the reaction pipe section (5) corresponding to the catalyst (11); an atomizing nozzle (13) is evenly fixedly connected to the coil (12); a water inlet end of the coil (12) passes through the reaction pipe section (5) and is fixedly connected to an externally threaded pipe joint (14); a third three-way pipe (15) is provided on the outer sides of two corresponding externally threaded pipe joints (14); both ends of the third three-way pipe (15) corresponding to the externally threaded pipe joints (14) are rotatably connected to internally threaded pipe joints (16); the internally threaded pipe joints (16) are threadedly connected to the externally threaded pipe joints (14); and a first regulating valve (17) is installed at one end of the third three-way pipe (15) corresponding to each internally threaded pipe joint (16).

2. A lithium iron phosphate sintering furnace tail gas treatment device according to claim 1, characterized in that: The other end of the third three-way pipe (15) is fixedly connected to a connecting transverse pipe (18), and the connecting transverse pipe (18) is connected to an external ammonia water supply device through a pipeline.

3. The tail gas treatment device for lithium iron phosphate sintering furnace according to claim 1 is characterized in that: A partition (19) is fixedly connected below the connection point of the inner side of the water washing tower (10) corresponding to the air inlet pipe (9), and an electric valve (20) is fixedly installed at the bottom of the partition (19) and the water washing tower (10).

4. The tail gas treatment device for lithium iron phosphate sintering furnace according to claim 1, characterized in that: The top of the water washing tower (10) is provided with an air outlet pipe (21).

5. The tail gas treatment device for lithium iron phosphate sintering furnace according to claim 1, characterized in that: A spray plate (22) is fixedly connected to the inner side of the top of the water washing tower (10); the spray plate (22) is hollow, spray holes (23) are evenly opened on the bottom surface of the spray plate (22), and connecting pipes (24) are evenly penetrated and fixedly connected to the spray plate (22).

6. A lithium iron phosphate sintering furnace tail gas treatment device according to claim 5, characterized in that: A water supply pipe (25) is fixedly connected to one side of the spray plate (22), one end of the water supply pipe (25) is fixedly connected to the bottom of the water washing tower (10) and communicated with the water washing tower (10), a water pump (26) is connected to the water supply pipe (25), the water pump (26) is fixedly installed on the side wall of the water washing tower (10), a branch pipe (27) is fixedly connected to the part of the water supply pipe (25) corresponding to the water inlet end of the water pump (26), the branch pipe (27) is connected to an external water source, and a second regulating valve (28) is connected to the branch pipe (27).

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