Device and method for desulfurizing and dechlorinating flue gas of rotary hearth furnace

Abstract

The invention discloses a rotary hearth furnace flue gas desulfurization and dechlorination device and method, and belongs to the technical field of flue gas desulfurization and dechlorination, the rotary hearth furnace flue gas desulfurization and dechlorination device comprises a rotary hearth furnace, a waste heat boiler flue gas inlet, a rotary hearth furnace material distribution inlet injection device and a rotary hearth furnace flue gas inlet injection device, the rotary hearth furnace material distribution inlet injection device is located 0.5-0.8 m in front of a rotary hearth furnace material inlet, and the rotary hearth furnace flue gas inlet injection device is located in front of the rotary hearth furnace material inlet. The mounting point is located at the horizontal axis right above a furnace charge inlet of the rotary hearth furnace, the rotary hearth furnace flue gas outlet blowing device is located between a rotary hearth furnace flue gas outlet and a waste heat boiler flue gas inlet, and the mounting point is located at the horizontal axis of a flue. And blowing is also carried out at a smoke outlet of the rotary hearth furnace. According to the method, acid gas in the flue gas can be effectively removed before the flue gas enters the waste heat boiler, the acid gas is absorbed in the blowing agent to form solid particles, the solid particles are settled and collected when the flue gas passes through a radiation chamber of the waste heat boiler, and follow-up process equipment cannot be affected.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas desulfurization and dechlorination, and more specifically to a device and method for desulfurization and dechlorination of flue gas in a rotary hearth furnace. Background Art

[0002] In the existing rotary hearth furnace reduction treatment technology, since the raw materials of the rotary hearth furnace are mostly solid waste generated by steel enterprises, the sulfur and chlorine content in these solid wastes is relatively high due to the particularity of production. During the rotary hearth furnace reduction treatment, sulfides and chlorides evaporate into the flue gas, and the SOX gas present in the flue gas accelerates the sulfation of chlorides, increasing the content of hydrochlorides and sulfates in the flue gas. Hydrochlorides and sulfates condense and deliquesce into hydrates at high temperatures, causing corrosion to equipment. In addition, hydrates can bond with dust in the flue gas to form an adhesive, causing the rotary hearth furnace flue gas to deposit, causing blockage of the waste heat boiler system, and affecting the heat exchange efficiency of the waste heat boiler of the rotary hearth furnace and the smooth production.

[0003] After searching, the existing patent (publication number: CN110671946A) discloses a structure and anti-blocking method for preventing the clogging of the flue gas waste heat utilization system of the rotary hearth furnace. The patent configures multiple heat exchangers at intervals between the inlet and outlet ends of the flue gas duct of the rotary hearth furnace, and installs a sonic soot blower between every two adjacent heat exchangers. This design uses a cyclically purged sonic generator to clean the scale on the heat exchanger, thereby significantly extending the clogging cycle of the rotary hearth furnace heat exchanger. Although the sonic soot blower can clean the scale on the heat exchanger, the sonic cleaning may have limited effect on thick or strongly adhesive scales, and the long-term use of the sonic soot blower may cause fatigue and damage to the heat exchanger material, affecting the service life of the heat exchanger, and the existing patent (publication number: CN113509832A) discloses a double alkali flue spray system for removing sulfur dioxide from exhaust gas. A double-layer slurry pool and sodium hydroxide solution are used as desulfurizers, and a slurry circulation pump is used to spray the atomized desulfurizer solution into the flue to contact the flue gas for desulfurization. The desulfurized solution will fall to the bottom of the flue and flow into the regeneration tank from the collection structure. The regenerated solution is again sent to the sedimentation tank by the second slurry pump, and the supernatant in the sedimentation tank flows back to the desulfurizer solution pool. Due to the use of desulfurizer solution, corrosion and blockage will not occur during the circulation process, which is convenient for the normal operation and maintenance of the equipment. In addition, the regeneration tank and the sedimentation tank are arranged outside the flue, which improves the stability of the equipment and reduces the operation and maintenance costs. However, when the flue gas flow rate is too large, part of the absorbed sulfate may not be able to settle into the slurry collection mechanism, but condense again in the easy-to-block area of ​​the waste heat boiler, resulting in blockage, which affects the subsequent process. Therefore, in order to solve the above problems, the existence of a device and method for desulfurization and dechlorination of flue gas from a rotary hearth furnace is crucial. Summary of the invention

[0004] The main technical problem solved by the present invention is to provide a device and method for desulfurization and dechlorination of flue gas from a rotary hearth furnace, which can solve the problems raised by the above-mentioned background technology.

[0005] To solve the above technical problems, according to one aspect of the present invention, more specifically, a device and method for desulfurization and dechlorination of flue gas from a rotary hearth furnace, comprising a rotary hearth furnace, a flue gas inlet of a waste heat boiler, a rotary hearth furnace charge inlet blowing device and a rotary hearth furnace flue gas inlet blowing device, wherein the rotary hearth furnace charge inlet blowing device is located 0.5-0.8m in front of the rotary hearth furnace charge inlet, and the installation point is located at the horizontal axis directly above the rotary hearth furnace charge inlet, and the rotary hearth furnace flue gas outlet blowing device is located between the rotary hearth furnace flue gas outlet and the waste heat boiler flue gas inlet, and the installation point is located at the horizontal axis of the flue.

[0006] Furthermore, the rotary hearth furnace material inlet blowing device includes a spray gun mechanism, a storage mechanism and a fan mechanism, the spray gun mechanism includes a water spray gun, a talcum powder spray gun and a lime spray gun, the storage mechanism includes a water storage tank, a talcum powder storage tank and a lime storage tank, the water spray gun, the talcum powder spray gun and the lime spray gun are spaced 0.1m apart, the water spray gun, the talcum powder spray gun and the lime spray gun have an angle of 90° with the furnace wall directly above the rotary hearth furnace inlet, the fan mechanism includes three fans, the water storage tank, the talcum powder storage tank and the lime storage tank are vertically arranged on one side of the water spray gun, the talcum powder spray gun and the lime spray gun inlet, respectively, and the three fans are horizontally arranged at one end of the water spray gun, the talcum powder spray gun and the lime spray gun inlet, respectively.

[0007] Going further,.

[0008] Furthermore, the rotary hearth furnace flue gas inlet blowing device includes a fan, a lime slurry storage tank, a weighing device, a lime slurry spray gun and a bracket, the bracket is fixedly arranged on the front and rear sides of the lime slurry spray gun, the connection between the bracket and the lime slurry spray gun is / of the length of the lime slurry spray gun, the length of the bracket is flexibly adjusted, and is used to control the angle between the lime slurry spray gun and the rotary hearth furnace flue gas outlet to be 110°~120°, the lime slurry storage tank is vertically arranged on one side of the lime slurry spray gun inlet, the fan is horizontally arranged at one end of the lime slurry spray gun inlet, the weighing device is fixedly arranged at the connection between the fan, the lime slurry storage tank and the lime slurry spray gun, and the weighing device is used to control the specific blowing amount of the lime slurry to achieve quantitative blowing.

[0009] According to another aspect of the present invention, a method for desulfurization and dechlorination of flue gas from a rotary hearth furnace is provided, comprising the following steps:

[0010] S1. Raw material processing: Before the raw materials enter the furnace, they are processed inside the charge inlet through the rotary hearth furnace charge inlet blowing device;

[0011] S2, raw material reduction: the raw materials treated by the blowing device at the rotary hearth furnace charge inlet enter the rotary hearth furnace through the charge inlet for reduction;

[0012] S3. Gas recovery: The acidic gas in the flue gas from the evaporation of sulfur and chloride in the raw materials in the rotary hearth furnace is absorbed by the material sprayed from the rotary hearth furnace flue gas outlet spray device and enters the waste heat boiler for treatment.

[0013] Furthermore, in the S1, before the raw materials enter the rotary hearth furnace, water is first sprayed above the charge inlet, then talcum powder is sprayed, and finally lime is sprayed. Water is first sprayed to moisten the surface of the pellets entering the rotary hearth furnace, then talcum powder is sprayed to make the surface adhesive, and finally lime is sprayed to form a layer of lime coating on the surface of the pellets.

[0014] Furthermore, during the reduction process of the raw material in S2 in the rotary hearth furnace, the sulfur and chloride in the raw material first react with the lime coating on the surface and are solidified when evaporating.

[0015] Furthermore, the acidic gas in the flue gas in S3 is absorbed by the lime slurry sprayed at the flue gas outlet of the rotary hearth furnace and forms solid sediment particles.

[0016] Furthermore, the atomized particle size of the water sprayed at the rotary hearth furnace material inlet in S1 is 50-80 μm, the particle size of the talcum powder is 0.5-0.8 mm, and the particle size of the lime is 1.2-1.5 mm; the concentration of the spraying agent lime slurry sprayed at the rotary hearth furnace flue gas outlet is 80-100 g / L, and the atomized diameter of the sprayed lime slurry is 200-300 μm.

[0017] The beneficial effects of the device and method for desulfurization and dechlorination of flue gas from a rotary hearth furnace of the present invention are:

[0018] Before the raw materials enter the rotary hearth furnace, water is first sprayed above the charge inlet, then talcum powder is sprayed, and finally lime is sprayed. Water is first sprayed to moisten the surface of the pellets entering the rotary hearth furnace, then talcum powder is sprayed to make the surface cohesive, and finally lime is sprayed to form a layer of lime coating on the surface of the pellets. During the reduction process of the rotary hearth furnace, the sulfur and chloride in the raw materials first react with the lime coating on the surface and are solidified when evaporating. The acidic gas in the flue gas is absorbed by the lime slurry sprayed at the flue gas outlet of the rotary hearth furnace and forms solid sedimentation particles. This method can effectively remove the acidic gas in the flue gas before the flue gas enters the waste heat boiler, so that it is absorbed in the spraying agent to form solid particles. When the flue gas passes through the radiation chamber of the waste heat boiler, the solid particles are settled and collected, and will not affect the subsequent process equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0020] Figure 1 It is a schematic diagram of the overall structure of a device and method for desulfurization and dechlorination of flue gas from a rotary hearth furnace according to the present invention;

[0021] Figure 2 It is a schematic diagram of the installation structure of the rotary hearth furnace material inlet blowing device of the device and method for desulfurization and dechlorination of flue gas in the rotary hearth furnace of the present invention;

[0022] Figure 3 The present invention is a schematic diagram of the installation structure of a rotary hearth furnace flue gas inlet blowing device of a device and method for desulfurization and dechlorination of rotary hearth furnace flue gas.

[0023] In the figure: 1. Water spray gun; 2. Talcum powder spray; 3. Lime spray gun; 4. Lime storage tank; 5. Talcum powder storage tank; 6. Water storage tank; 7. Fan; 8. Lime slurry storage tank; 9. Weighing device; 10. Lime slurry spray gun; 11. Bracket; 12. Waste heat boiler flue gas inlet. DETAILED DESCRIPTION

[0024] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Example 1

[0026] like Figure 1-Figure 3 As shown, according to one aspect of the present invention, a device and method for desulfurization and dechlorination of flue gas from a rotary hearth furnace are provided, comprising a rotary hearth furnace, a flue gas inlet 12 of a waste heat boiler, a rotary hearth furnace charge inlet blowing device and a rotary hearth furnace flue gas inlet blowing device, the rotary hearth furnace charge inlet blowing device is located 0.5-0.8m in front of the rotary hearth furnace charge inlet, and the installation point is located at the horizontal axis directly above the rotary hearth furnace charge inlet, the rotary hearth furnace flue gas outlet blowing device is located between the rotary hearth furnace flue gas outlet and the waste heat boiler flue gas inlet, and the installation point is located at the horizontal axis of the flue.

[0027] In the present embodiment, the blowing device at the rotary hearth furnace material inlet includes a spray gun mechanism, a storage mechanism and a fan mechanism, the spray gun mechanism includes a water spray gun 1, a talcum powder spray 2 and a lime spray gun 3, the storage mechanism includes a water storage tank 6, a talcum powder storage tank 5 and a lime storage tank 4, the interval between the water spray gun 1, the talcum powder spray 2 and the lime spray gun 3 is 0.1m, the angle between the water spray gun 1, the talcum powder spray 2 and the lime spray gun 3 and the furnace wall directly above the rotary hearth furnace inlet is 90°, the fan mechanism includes three fans 7, the water storage tank 6, the talcum powder storage tank 5 and the lime storage tank 4 are respectively vertically arranged on one side of the inlet of the water spray gun 1, the talcum powder spray 2 and the lime spray gun 3, and the three fans 7 are respectively horizontally arranged on one end of the inlet of the water spray gun 1, the talcum powder spray 2 and the lime spray gun 3.

[0028] In the present embodiment, the rotary hearth furnace flue gas inlet blowing device comprises a fan 7, a lime slurry storage tank 8, a weighing device 9, a lime slurry spray gun 10 and a bracket 11. The bracket 11 is fixedly arranged at the front and rear sides of the lime slurry spray gun 10. The connection between the bracket 11 and the lime slurry spray gun 10 is 3 / 4 of the length of the lime slurry spray gun 10. The length of the bracket 11 is flexibly adjusted to control the angle between the lime slurry spray gun 10 and the rotary hearth furnace flue gas outlet to be 110°~120°. The lime slurry storage tank 8 is vertically arranged on the inlet side of the lime slurry spray gun 10, and the fan 7 is horizontally arranged at one end of the inlet of the lime slurry spray gun 10. The weighing device 9 is fixedly arranged at the connection between the fan 7, the lime slurry storage tank 8 and the lime slurry spray gun 10. The weighing device 9 is used to control the specific blowing amount of the lime slurry to achieve quantitative blowing.

[0029] According to another aspect of the present invention, a method for desulfurization and dechlorination of flue gas from a rotary hearth furnace is provided, comprising the following steps:

[0030] S1. Raw material treatment: before the raw materials enter the furnace, they are treated by the rotary furnace charge inlet spraying device inside the charge inlet. Before the raw materials enter the furnace, water is first sprayed just above the charge inlet, then talcum powder is sprayed, and finally lime is sprayed. Water is first sprayed to moisten the surface of the pellets entering the rotary furnace, then talcum powder is sprayed to make the surface cohesive, and finally lime is sprayed to form a layer of lime coating on the surface of the pellets. The atomized particle size of the water sprayed at the rotary furnace charge inlet is 50-80 μm, the particle size of talcum powder is 0.5-0.8 mm, and the particle size of lime is 1.2-1.5 mm; the concentration of the spraying agent lime slurry sprayed at the rotary furnace flue gas outlet is 80-100 g / L, and the atomized diameter of the sprayed lime slurry is 200-300 μm;

[0031] S2. Raw material reduction: The raw materials treated by the blowing device at the rotary hearth furnace charge inlet enter the rotary hearth furnace through the charge inlet for reduction. During the reduction process of the raw materials in the rotary hearth furnace, the sulfur and chloride in the raw materials first react with the lime coat on the surface during evaporation and are solidified;

[0032] S3. Gas recovery: The acidic gas in the flue gas from the evaporation of sulfur and chloride in the raw materials in the rotary hearth furnace is absorbed by the material sprayed from the rotary hearth furnace flue gas outlet spraying device and enters the waste heat boiler for treatment. The acidic gas in the flue gas is absorbed by the lime slurry sprayed at the rotary hearth furnace flue gas outlet and forms solid sedimentation particles.

[0033] In this embodiment, the amount of water sprayed at the rotary hearth furnace cloth inlet is 20L / h, the amount of talcum powder sprayed is 50kg / h, and the amount of lime sprayed is 80kg / h; the amount of lime slurry sprayed at the rotary hearth furnace flue gas outlet is 70kg / h. The acidic gas present in the flue gas is absorbed by the lime slurry sprayed at the flue gas outlet of the rotary hearth furnace, and solid sedimentation particles are formed. This method can effectively remove the acidic gas in the flue gas before the flue gas enters the waste heat boiler, so that it is absorbed in the spraying agent to form solid particles. When the flue gas passes through the radiation chamber of the waste heat boiler, the solid particles are settled and collected. Compared with the rotary hearth furnace waste heat boiler before the spraying device is set, the shutdown cycle of the rotary hearth furnace waste heat boiler is reduced from 1 month / time to 3 months / time.

[0034] Example 2

[0035] like Figure 1-Figure 3 As shown, according to one aspect of the present invention, a device and method for desulfurization and dechlorination of flue gas from a rotary hearth furnace are provided, comprising a rotary hearth furnace, a flue gas inlet 12 of a waste heat boiler, a rotary hearth furnace charge inlet blowing device and a rotary hearth furnace flue gas inlet blowing device, the rotary hearth furnace charge inlet blowing device is located 0.5-0.8m in front of the rotary hearth furnace charge inlet, and the installation point is located at the horizontal axis directly above the rotary hearth furnace charge inlet, the rotary hearth furnace flue gas outlet blowing device is located between the rotary hearth furnace flue gas outlet and the waste heat boiler flue gas inlet, and the installation point is located at the horizontal axis of the flue.

[0036] In the present embodiment, the blowing device at the rotary hearth furnace material inlet includes a spray gun mechanism, a storage mechanism and a fan mechanism, the spray gun mechanism includes a water spray gun 1, a talcum powder spray 2 and a lime spray gun 3, the storage mechanism includes a water storage tank 6, a talcum powder storage tank 5 and a lime storage tank 4, the interval between the water spray gun 1, the talcum powder spray 2 and the lime spray gun 3 is 0.1m, the angle between the water spray gun 1, the talcum powder spray 2 and the lime spray gun 3 and the furnace wall directly above the rotary hearth furnace inlet is 90°, the fan mechanism includes three fans 7, the water storage tank 6, the talcum powder storage tank 5 and the lime storage tank 4 are respectively vertically arranged on one side of the inlet of the water spray gun 1, the talcum powder spray 2 and the lime spray gun 3, and the three fans 7 are respectively horizontally arranged on one end of the inlet of the water spray gun 1, the talcum powder spray 2 and the lime spray gun 3.

[0037] In the present embodiment, the rotary hearth furnace flue gas inlet blowing device comprises a fan 7, a lime slurry storage tank 8, a weighing device 9, a lime slurry spray gun 10 and a bracket 11. The bracket 11 is fixedly arranged at the front and rear sides of the lime slurry spray gun 10. The connection between the bracket 11 and the lime slurry spray gun 10 is 3 / 4 of the length of the lime slurry spray gun 10. The length of the bracket 11 is flexibly adjusted to control the angle between the lime slurry spray gun 10 and the rotary hearth furnace flue gas outlet to be 110°~120°. The lime slurry storage tank 8 is vertically arranged on the inlet side of the lime slurry spray gun 10, and the fan 7 is horizontally arranged at one end of the inlet of the lime slurry spray gun 10. The weighing device 9 is fixedly arranged at the connection between the fan 7, the lime slurry storage tank 8 and the lime slurry spray gun 10. The weighing device 9 is used to control the specific blowing amount of the lime slurry to achieve quantitative blowing.

[0038] According to another aspect of the present invention, a method for desulfurization and dechlorination of flue gas from a rotary hearth furnace is provided, comprising the following steps:

[0039] S1. Raw material treatment: before the raw materials enter the furnace, they are treated by the rotary furnace charge inlet spraying device inside the charge inlet. Before the raw materials enter the furnace, water is first sprayed just above the charge inlet, then talcum powder is sprayed, and finally lime is sprayed. Water is first sprayed to moisten the surface of the pellets entering the rotary furnace, then talcum powder is sprayed to make the surface cohesive, and finally lime is sprayed to form a layer of lime coating on the surface of the pellets. The atomized particle size of the water sprayed at the rotary furnace charge inlet is 50-80 μm, the particle size of talcum powder is 0.5-0.8 mm, and the particle size of lime is 1.2-1.5 mm; the concentration of the spraying agent lime slurry sprayed at the rotary furnace flue gas outlet is 80-100 g / L, and the atomized diameter of the sprayed lime slurry is 200-300 μm;

[0040] S2. Raw material reduction: The raw materials treated by the blowing device at the rotary hearth furnace charge inlet enter the rotary hearth furnace through the charge inlet for reduction. During the reduction process of the raw materials in the rotary hearth furnace, the sulfur and chloride in the raw materials first react with the lime coat on the surface during evaporation and are solidified;

[0041] S3. Gas recovery: The acidic gas in the flue gas from the evaporation of sulfur and chloride in the raw materials in the rotary hearth furnace is absorbed by the material sprayed from the rotary hearth furnace flue gas outlet spraying device and enters the waste heat boiler for treatment. The acidic gas in the flue gas is absorbed by the lime slurry sprayed at the rotary hearth furnace flue gas outlet and forms solid sedimentation particles.

[0042] In this embodiment, the amount of water sprayed at the rotary hearth furnace cloth inlet is 10L / h, the amount of talcum powder sprayed is 30kg / h, and the amount of lime sprayed is 60kg / h; the amount of lime slurry sprayed at the rotary hearth furnace flue gas outlet is 100kg / h. The acidic gas present in the flue gas is absorbed by the lime slurry sprayed at the flue gas outlet of the rotary hearth furnace, and solid sedimentation particles are formed. This method can effectively remove the acidic gas in the flue gas before the flue gas enters the waste heat boiler, so that it is absorbed in the spraying agent to form solid particles. When the flue gas passes through the radiation chamber of the waste heat boiler, the solid particles are settled and collected. Compared with the rotary hearth furnace waste heat boiler before the spraying device is set, the shutdown cycle of the rotary hearth furnace waste heat boiler is reduced from 1 month / time to 5 months / time.

[0043] It can be concluded that this method can effectively remove acidic gases in flue gas before it enters the waste heat boiler, so that the acidic gases are absorbed in the injection agent to form solid particles. When the flue gas passes through the radiation chamber of the waste heat boiler, the solid particles are settled and collected, and will not affect subsequent process equipment.

[0044] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. A device and method for desulfurization and dechlorination of flue gas from a rotary hearth furnace, comprising a rotary hearth furnace, a flue gas inlet (12) for a waste heat boiler, a blowing device for a rotary hearth furnace material inlet and a blowing device for a rotary hearth furnace flue gas inlet, characterized in that: The rotary hearth furnace charge inlet blowing device is located 0.5-0.8m in front of the rotary hearth furnace charge inlet, and the installation point is located at the horizontal axis directly above the rotary hearth furnace charge inlet. The rotary hearth furnace flue gas outlet blowing device is located between the rotary hearth furnace flue gas outlet and the waste heat boiler flue gas inlet, and the installation point is located at the horizontal axis of the flue.

2. The device and method for desulfurization and dechlorination of flue gas from a rotary hearth furnace according to claim 1, characterized in that: The rotary hearth furnace charge inlet blowing device comprises a spray gun mechanism, a storage mechanism and a fan mechanism, wherein the spray gun mechanism comprises a water spray gun (1), a talcum powder spray gun (2) and a lime spray gun (3), wherein the storage mechanism comprises a water storage tank (6), a talcum powder storage tank (5) and a lime storage tank (4), wherein the interval between the water spray gun (1), the talcum powder spray gun (2) and the lime spray gun (3) is 0.1 m, wherein the angle between the water spray gun (1), the talcum powder spray gun (2) and the lime spray gun (3) and the furnace wall directly above the rotary hearth furnace inlet is 90°, wherein the fan mechanism comprises three fans (7), wherein the water storage tank (6), the talcum powder storage tank (5) and the lime storage tank (4) are respectively arranged vertically on one side of the inlet of the water spray gun (1), the talcum powder spray gun (2) and the lime spray gun (3), and wherein the three fans (7) are respectively arranged horizontally on one end of the inlet of the water spray gun (1), the talcum powder spray gun (2) and the lime spray gun (3).

3. The device and method for desulfurization and dechlorination of flue gas from a rotary hearth furnace according to claim 2, characterized in that: The rotary hearth furnace flue gas inlet blowing device comprises a fan (7), a lime slurry storage tank (8), a weighing device (9), a lime slurry spray gun (10) and a bracket (11). The bracket (11) is fixedly arranged at the front and rear sides of the lime slurry spray gun (10). The connection between the bracket (11) and the lime slurry spray gun (10) is at 3 / 4 of the length of the lime slurry spray gun (10). The length of the bracket (11) is flexibly adjusted to control the angle between the lime slurry spray gun (10) and the rotary hearth furnace flue gas outlet to be 110° to 120°. The lime slurry storage tank (8) is vertically arranged at one side of the lime slurry spray gun (10) inlet. The fan (7) is horizontally arranged at one end of the lime slurry spray gun (10) inlet. The weighing device (9) is fixedly arranged at the connection between the fan (7), the lime slurry storage tank (8) and the lime slurry spray gun (10). The weighing device (9) is used to control the specific blowing amount of the lime slurry to achieve quantitative blowing.

4. A method for desulfurization and dechlorination of flue gas from a rotary hearth furnace, comprising a device for desulfurization and dechlorination of flue gas from a rotary hearth furnace according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Raw material processing: Before the raw materials enter the furnace, they are processed inside the charge inlet through the rotary hearth furnace charge inlet blowing device; S2, raw material reduction: the raw materials treated by the blowing device at the rotary hearth furnace charge inlet enter the rotary hearth furnace through the charge inlet for reduction; S3. Gas recovery: The acidic gas in the flue gas from the evaporation of sulfur and chloride in the raw materials in the rotary hearth furnace is absorbed by the material sprayed from the rotary hearth furnace flue gas outlet spray device and enters the waste heat boiler for treatment.

5. The method for desulfurization and dechlorination of flue gas from a rotary hearth furnace according to claim 4, characterized in that: In the S1, before the raw materials enter the rotary hearth furnace, water is first sprayed above the charge inlet, then talcum powder is sprayed, and finally lime is sprayed. Water is first sprayed to moisten the surface of the pellets entering the rotary hearth furnace, then talcum powder is sprayed to make the surface adhesive, and finally lime is sprayed to form a layer of lime coating on the surface of the pellets.

6. The method for desulfurization and dechlorination of flue gas from a rotary hearth furnace according to claim 4, characterized in that: During the reduction process of the raw material in S2 in the rotary hearth furnace, the sulfur and chloride in the raw material first react with the lime coating on the surface during evaporation and are solidified.

7. The method for desulfurization and dechlorination of flue gas from a rotary hearth furnace according to claim 4, characterized in that: The acidic gas in the flue gas in S3 is absorbed by the lime slurry sprayed at the flue gas outlet of the rotary hearth furnace and forms solid sediment particles.

8. The method for desulfurization and dechlorination of flue gas from a rotary hearth furnace according to claim 5, characterized in that: The atomized particle size of the water sprayed at the rotary hearth furnace material inlet in S1 is 50-80 μm, the particle size of the talcum powder is 0.5-0.8 mm, and the particle size of the lime is 1.2-1.5 mm; the concentration of the spraying agent lime slurry sprayed at the rotary hearth furnace flue gas outlet is 80-100 g / L, and the atomized diameter of the sprayed lime slurry is 200-300 μm.

Images