Tail gas waste heat utilization system for gas generator of large-scale titanium slag smelting totally-enclosed direct-current electric furnace

Abstract

The invention relates to the technical field of titanium slag smelting equipment, in particular to a large titanium slag smelting fully-closed direct current electric furnace gas generator tail gas waste heat utilization system which comprises an SCR denitration device, one end of the SCR denitration device is connected with a tail gas gathering pipe, electric furnace gas generator tail gas is led into the tail gas gathering pipe, and the tail gas gathering pipe is connected with a tail gas waste heat utilization device. The outer side of the end, close to the tail gas gathering pipe, of the SCR denitration device is connected with an ammonia spraying pipe, the end, away from the tail gas gathering pipe, of the SCR denitration device is connected with two branch pipelines, the outer end of one branch pipeline is connected to a raw material drying fluidized bed furnace, and the outer end of the other branch pipeline is connected to a titanium slag finished product bin; and the exhaust ends of the raw material drying fluidized bed furnace and the titanium slag finished product bin are connected to a dust collecting device through pipelines. According to the tail gas waste heat utilization system for the large titanium slag smelting fully-closed direct-current electric furnace gas generator, nitric oxide in tail gas of the fully-closed direct-current electric furnace gas generator is efficiently treated through the SCR denitration device.

Description

Technical Field

[0001] The present invention relates to the technical field of titanium slag smelting equipment, and more specifically, to a waste heat utilization system for the tail gas of a large-scale fully enclosed DC electric furnace gas generator for titanium slag smelting. Background Art

[0002] During the process of large-scale titanium slag smelting, as an important energy conversion device, the fully enclosed DC electric furnace gas generator will generate a large amount of tail gas during operation. These tail gases usually have a relatively high temperature and a certain amount of harmful substances, such as nitrogen oxides.

[0003] At present, there are many deficiencies in the treatment and waste heat utilization methods for these tail gases. On the one hand, if harmful substances such as nitrogen oxides in the tail gas are directly discharged into the atmosphere, it will cause serious pollution to the environment and does not meet the environmental protection requirements. And the existing denitration treatment technologies often have low efficiency and are difficult to treat the nitrogen oxides in the tail gas to the level that meets the emission standards.

[0004] On the other hand, a large amount of waste heat carried by the tail gas has not been effectively recovered and utilized. If this waste heat is directly discharged, it not only causes energy waste but also increases the production cost of the enterprise. In some traditional tail gas waste heat utilization systems, the tail gas is often simply used for some low-efficiency heating or drying processes, without fully exploring the potential value of the tail gas waste heat and unable to achieve efficient cascade utilization of energy.

[0005] In addition, during the process of tail gas treatment and waste heat utilization, the operation stability and maintenance cost of the equipment are also important factors that need to be considered. The existing tail gas treatment equipment is prone to problems such as blockage and wear, resulting in unstable operation of the equipment and requiring frequent maintenance and repair, which increases the operation cost of the enterprise. Summary of the Invention

[0006] The purpose of the present invention is to provide a waste heat utilization system for the tail gas of a large-scale fully enclosed DC electric furnace gas generator for titanium slag smelting, so as to solve the problems of many deficiencies in the treatment and waste heat utilization methods for these tail gases as mentioned in the above background art.

[0007] To achieve the above purpose, the present invention provides a waste heat utilization system for the tail gas of a large-scale fully enclosed DC electric furnace gas generator for titanium slag smelting, including an SCR denitration device. One end of the SCR denitration device is connected to a tail gas collecting pipe, and the tail gas collecting pipe leads to the tail gas of the electric furnace gas generator. The outer side of one end of the SCR denitration device close to the tail gas collecting pipe is connected to an ammonia injection pipe. The other end of the SCR denitration device is connected to two sub-pipes. The outer end of one sub-pipe is connected to the raw material drying fluidized bed furnace, and the outer end of the other sub-pipe is connected to the titanium slag finished product bin. The exhaust ends of the raw material drying fluidized bed furnace and the titanium slag finished product bin are connected to a dust collection device through pipelines.

[0008] As a preferred embodiment of the present invention, the SCR denitration device includes a housing, and a plurality of catalytic components are installed inside the housing. A plurality of dust collection bags are connected to the bottom of the housing, and an ammonia injection fixing plate is installed inside the housing near the ammonia injection pipe.

[0009] As a preferred embodiment of the present invention, an opening is provided in the middle of the ammonia injection fixing plate, and a plurality of nozzles are evenly installed inside the opening. One side of the ammonia injection fixing plate is connected to a connecting pipe, one end of the connecting pipe is externally connected to the ammonia injection pipe, and the other end of the connecting pipe is connected to each nozzle through a plurality of pipelines.

[0010] As a preferred embodiment of the present invention, the catalytic component includes a fixing plate, a vertical slot is provided inside the fixing plate, a catalytic module is arranged in the slot, the material of the catalytic module is a titanium oxide-based catalyst, and dust-proof nets are installed on both sides of the fixing plate.

[0011] As a preferred embodiment of the present invention, an ultrasonic vibrator is installed at the bottom of the catalytic module.

[0012] As a preferred embodiment of the present invention, a cover plate is provided at the top of the catalytic module, and the cover plate is fixed to the top of the housing by bolts.

[0013] As a preferred embodiment of the present invention, the dust collection device includes a vertical cylinder, an exhaust port is provided at the top of the vertical cylinder, a perforated plate is installed above the inside of the vertical cylinder, a plurality of spray heads are installed at the bottom of the perforated plate, and the input end of the spray head is externally connected to a water pipe.

[0014] As a preferred embodiment of the present invention, an air inlet is provided on one side of the upper part of the vertical cylinder, the exhaust ends of the raw material drying fluidized bed furnace and the titanium slag finished product bin are connected to the air inlet, and the height of the air inlet is lower than that of the spray head.

[0015] As a preferred embodiment of the present invention, a sewage discharge pipe is connected to one side of the bottom of the vertical cylinder, and a valve is installed on the sewage discharge pipe.

[0016] As a preferred embodiment of the present invention, a soot blower is installed on the upper side surface of the catalytic component, and the soot blower blows air vertically downward to blow the dust attached to the surface of the catalytic component into the dust collection bag.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. In the waste heat utilization system of the large-scale titanium slag smelting fully enclosed DC electric furnace gas generator, the system efficiently treats nitrogen oxides in the tail gas of the fully enclosed DC electric furnace gas generator through an SCR denitration device. The SCR denitration device uses a titanium oxide-based catalyst and combines a reasonable ammonia injection system design to ensure that ammonia is fully mixed with nitrogen oxides in the tail gas and undergoes a catalytic reduction reaction, thereby reducing the nitrogen oxide concentration to a level that meets environmental protection emission standards and effectively reducing environmental pollution.

[0019] 2. In the waste heat utilization system of the large-scale titanium slag smelting fully enclosed DC electric furnace gas generator, the waste heat in the tail gas is respectively guided to the raw material drying fluidized bed furnace and the titanium slag finished product bin through sub-pipes, realizing the efficient cascade utilization of waste heat. In the raw material drying fluidized bed furnace, the waste heat in the tail gas is used for drying the raw materials, improving the energy utilization efficiency; in the titanium slag finished product bin, the waste heat in the tail gas can be used to maintain the temperature in the bin, prevent the titanium slag from caking, and improve the product quality.

[0020] 3. In the waste heat utilization system of the large-scale titanium slag smelting fully enclosed DC electric furnace gas generator, in the design of the catalytic component, an ultrasonic vibrator is installed at the bottom of the catalytic module, which can effectively prevent the surface of the catalytic module from being blocked by ash accumulation and ensure the continuous progress of the catalytic reaction. At the same time, a soot blower is installed on the upper side of the catalytic component, and by blowing vertically downward, the dust attached to the surface of the catalytic component is blown into the dust collection bag, realizing the self-cleaning function of the equipment and reducing the maintenance cost.

[0021] 4. In the waste heat utilization system of the large-scale titanium slag smelting fully enclosed DC electric furnace gas generator, the dust removal device realizes the efficient capture and purification of dust in the tail gas through the combined design of a perforated plate and a spray head. The water mist sprayed by the spray head combines with the dust in the tail gas to form larger particulate matter, which is effectively intercepted under the action of the perforated plate and finally discharged through the sewage pipe to ensure the cleanliness of the discharged gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is the overall structural schematic diagram of the present invention;

[0023] Figure 2 is the structural schematic diagram of the SCR denitration device in the present invention;

[0024] Figure 3 is the structural schematic diagram of the catalytic component in the present invention;

[0025] Figure 4 is the structural schematic diagram of the ammonia injection fixing plate in the present invention;

[0026] Figure 5 is the structural schematic diagram of the dust removal device in the present invention;

[0027] The meanings of the labels in the figure are as follows:

[0028] 1. SCR denitration device; 11. Outer shell; 12. Catalytic component; 121. Fixed plate; 122. Dust-proof net; 123. Catalytic module; 124. Cover plate; 125. Ultrasonic vibrator; 13. Dust collection bag; 14. Ammonia injection fixed plate; 141. Opening; 142. Sprayer; 143. Connecting pipe; 2. Tail gas collecting pipe; 3. Ammonia injection pipe; 4. Branch pipe; 5. Raw material drying fluidized bed furnace; 6. Titanium slag finished product bin; 7. Dust collection device; 71. Vertical cylinder; 72. Exhaust port; 73. Mesh plate; 74. Spray head; 75. Air inlet; 76. Drain pipe; 8. Soot blower. Specific implementation mode

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] Embodiment 1

[0031] The present invention provides a waste heat utilization system for the tail gas of a large-scale titanium slag smelting fully enclosed DC electric furnace gas generator, as Figures 1 - 5 shown, which includes an SCR denitration device 1. One end of the SCR denitration device 1 is connected to a tail gas collecting pipe 2, and the tail gas collecting pipe 2 is introduced into the tail gas of the electric furnace gas generator. The outer side of one end of the SCR denitration device 1 close to the tail gas collecting pipe 2 is connected to an ammonia injection pipe 3. The other end of the SCR denitration device 1 far from the tail gas collecting pipe 2 is connected to two branch pipes 4. The outer end of one branch pipe 4 is connected to a raw material drying fluidized bed furnace 5, and the outer end of the other branch pipe 4 is connected to a titanium slag finished product bin 6. The exhaust ends of the raw material drying fluidized bed furnace 5 and the titanium slag finished product bin 6 are connected to a dust collection device 7 through pipelines. As the core processing unit of the system, the SCR denitration device 1 performs efficient denitration treatment on the tail gas of the electric furnace gas generator introduced into the tail gas collecting pipe 2 through its unique structure and function. Its internal design can promote the uniform injection of ammonia from the connected ammonia injection pipe 3, fully mix with the nitrogen oxides in the tail gas and undergo a catalytic reduction reaction, greatly reducing the content of nitrogen oxides in the tail gas, making it meet the environmental protection emission standards, effectively reducing the pollution to the atmospheric environment, and solving the problems of low treatment efficiency of nitrogen oxides and difficult to meet the emission standards in traditional tail gas treatment.

[0032] The SCR denitration device 1 is far away from the two sub-pipes 4 connected to one end of the tail gas collecting pipe 2, and reasonably distributes the tail gas after denitration treatment. One sub-pipe 4 transports the tail gas to the raw material drying fluidized bed furnace 5 to dry the raw materials by using the waste heat of the tail gas, improve the energy utilization efficiency, and reduce the energy consumption in the raw material drying link; the other sub-pipe 4 transports the tail gas to the titanium slag finished product bin 6 to maintain the appropriate temperature in the bin, prevent the titanium slag from caking, and ensure the product quality. This precise way of distributing waste heat realizes the efficient cascade utilization of energy, fully exploits the potential value of the tail gas waste heat, and solves the problems of single traditional tail gas waste heat utilization method and serious energy waste.

[0033] The exhaust ends of the raw material drying fluidized bed furnace 5 and the titanium slag finished product bin 6 are connected to the dust collection device 7 through pipelines. The dust collection device 7 can perform secondary purification treatment on the tail gas after waste heat utilization. It can effectively capture impurities such as dust carried in the tail gas, further reduce the emission of harmful substances in the tail gas, ensure that the finally emitted tail gas meets the environmental protection requirements, reduce the secondary pollution to the environment, and improve the environmental protection performance of the entire system.

[0034] In this embodiment, the SCR denitration device 1 includes a housing 11. A number of catalytic components 12 are installed inside the housing 11. A number of dust collection bags 13 are connected to the bottom of the housing 11. An ammonia injection fixing plate 14 is installed inside the housing 11 near the ammonia injection pipe 3. The housing 11 serves as the main structure of the SCR denitration device 1, provides an installation space and protection for the internal components, ensures the stable operation of the device in a complex working environment, and extends the service life of the equipment. The catalytic components 12 are installed inside the housing 11 and are the core part of the denitration reaction. The titanium oxide-based catalyst module 123 inside it can effectively promote the catalytic reduction reaction between ammonia and nitrogen oxides in the tail gas, convert nitrogen oxides into harmless nitrogen and water, achieve efficient denitration of the tail gas, and reduce environmental pollution. The dust collection bags 13 are connected to the bottom of the housing 11 and can collect the dust generated during the catalytic reaction and the particulate matter separated from the tail gas, preventing the dust from accumulating in the device, affecting the catalytic effect and the normal operation of the equipment, and ensuring the continuity and stability of the denitration process. The ammonia injection fixing plate 14 is installed inside the housing 11 near the ammonia injection pipe 3, and its function is to fix the ammonia injection device, ensure that ammonia can be accurately and evenly sprayed into the tail gas, provide sufficient ammonia for the catalytic reaction, and improve the denitration efficiency.

[0035] Specifically, an opening 141 is provided in the middle of the ammonia injection fixing plate 14. A number of spray nozzles 142 are evenly installed inside the opening 141. One side of the ammonia injection fixing plate 14 is connected with a connecting pipe 143. One end of the connecting pipe 143 is externally connected to the ammonia injection pipe 3, and the other end of the connecting pipe 143 is connected to each spray nozzle 142 through a number of pipelines respectively. The opening 141 is provided in the middle of the ammonia injection fixing plate 14, providing an installation position for the spray nozzles 142, enabling the spray nozzles 142 to be reasonably arranged, and ensuring the uniformity of ammonia injection. The spray nozzles 142 are evenly installed inside the opening 141, and can spray ammonia into the tail gas in a mist form, increasing the contact area between ammonia and the tail gas, promoting the full mixing and reaction of ammonia and nitrogen oxides, and improving the denitration effect. The connecting pipe 143 is connected to one side of the ammonia injection fixing plate 14, with one end externally connected to the ammonia injection pipe 3 and the other end connected to each spray nozzle 142 through a number of pipelines respectively. It plays the role of ammonia transportation and distribution, ensuring that ammonia can be stably and evenly supplied to each spray nozzle 142, and guaranteeing the normal progress of the denitration reaction.

[0036] Furthermore, the catalytic component 12 includes a fixing plate 121. A vertical slot is provided inside the fixing plate 121. A catalytic module 123 is arranged in the slot. The material of the catalytic module 123 is a titanium oxide-based catalyst. Dust-proof nets 122 are installed on both sides of the fixing plate 121. The vertical slot is provided inside the fixing plate 121, providing an installation basis for the catalytic module 123, enabling the catalytic module 123 to be firmly installed on the fixing plate 121, ensuring the stability of the catalytic module 123 during the denitration process, and preventing its shaking or falling off from affecting the denitration effect. The dust-proof nets 122 are installed on both sides of the fixing plate 121, which can block impurities such as dust in the tail gas from entering the inside of the catalytic module 123, avoiding the dust covering the surface of the catalyst, affecting the activity of the catalyst and the denitration efficiency, and prolonging the service life of the catalytic module 123. The catalytic module 123 uses a titanium oxide-based catalyst, which is a key substance for the denitration reaction. It can effectively reduce the activation energy of the reaction between nitrogen oxides and ammonia, accelerate the reaction rate, achieve the efficient removal of nitrogen oxides in the tail gas, and meet the environmental protection emission requirements.

[0037] Furthermore, an ultrasonic vibrator 125 is installed at the bottom of the catalytic module 123. The ultrasonic vibrator 125 is installed at the bottom of the catalytic module 123 and can generate high-frequency vibration. Through the vibration effect, the impurities such as dust attached to the surface of the catalytic module 123 can be shaken off, preventing the dust from blocking the pores of the catalytic module 123, ensuring the activity of the catalyst, maintaining the efficient progress of the denitration reaction, and reducing the equipment maintenance frequency caused by dust accumulation.

[0038] Further, a cover plate 124 is provided on the top of the catalytic module 123, and the cover plate 124 is fixed to the top of the outer shell 11 by bolts. The cover plate 124 is arranged on the top of the catalytic module 123 and fixed to the top of the outer shell 11 by bolts. It not only plays a role in fixing the catalytic module 123, preventing the catalytic module 123 from shifting or being damaged during operation, but also facilitates the installation and disassembly of the catalytic module 123, and is convenient for equipment maintenance and catalyst replacement.

[0039] Example 2

[0040] In order to further improve the dust collection effect, on the basis of Example 1, the dust collection device 7 includes a vertical cylinder 71. An exhaust port 72 is provided at the top of the vertical cylinder 71. Above the interior of the vertical cylinder 71, a perforated plate 73 is installed. At the bottom of the perforated plate 73, a number of spray heads 74 are installed. The input ends of the spray heads 74 are externally connected to a water pipe. The vertical cylinder 71 serves as the main structure of the dust collection device 7, providing space for the purification treatment of the tail gas, ensuring that the tail gas can fully contact the purification medium within the vertical cylinder 71, and achieving effective dust collection and purification. The exhaust port 72 is provided at the top of the vertical cylinder 71 and is used to discharge the qualified tail gas after purification treatment, ensuring the normal operation of the system and the smooth discharge of the tail gas. The perforated plate 73 is installed above the interior of the vertical cylinder 71, which can intercept larger particulate matters and some droplets carried in the tail gas, playing a preliminary filtering and separating role and improving the subsequent spray purification effect. The spray heads 74 are installed at the bottom of the perforated plate 73, and the input ends are externally connected to a water pipe. By spraying water mist, the fine dust and harmful gases in the tail gas can be further captured, enabling the tail gas to be more thoroughly purified and reducing the emission concentration of harmful substances in the tail gas.

[0041] Further, an air inlet 75 is provided on one side of the upper part of the vertical cylinder 71. The exhaust ends of the raw material drying fluidized bed furnace 5 and the titanium slag finished product bin 6 are connected to the air inlet 75, and the height of the air inlet 75 is lower than that of the spray heads 74. The air inlet 75 is provided on one side of the upper part of the vertical cylinder 71. The exhaust ends of the raw material drying fluidized bed furnace 5 and the titanium slag finished product bin 6 are connected to this air inlet 75, and the height of the air inlet 75 is lower than that of the spray heads 74. This design enables the tail gas to enter the vertical cylinder 71 at an appropriate flow rate and direction, ensuring that the tail gas can fully contact the water mist sprayed by the spray heads 74, improving the dust collection and purification efficiency, and preventing the reverse flow of the tail gas from affecting the normal operation of the equipment.

[0042] Further, a sewage discharge pipe 76 is connected to one side of the bottom of the vertical cylinder 71, and a valve is installed on the sewage discharge pipe 76. The sewage discharge pipe 76 is connected to one side of the bottom of the vertical cylinder 71 and is equipped with a valve. During the dust collection and purification process, the collected dust, impurities, and sewage generated by spraying can be discharged through the sewage discharge pipe 76, facilitating the cleaning and maintenance of the dust collection device 7 and ensuring the long-term stable operation of the dust collection device 7.

[0043] Furthermore, a soot blower 8 is installed on the upper side of the catalytic assembly 12. The soot blower 8 blows air vertically downward, blowing the dust adhering to the surface of the catalytic assembly 12 into the dust collection bag 13. The soot blower 8 is installed on the upper side of the catalytic assembly 12 and blows air vertically downward. The airflow generated by it can blow the dust adhering to the surface of the catalytic assembly 12 into the dust collection bag 13, realizing automatic dust cleaning of the catalytic assembly 12, reducing the frequency and difficulty of manual cleaning, lowering the equipment maintenance cost, ensuring the cleanliness of the catalytic assembly 12, and maintaining its efficient denitration performance.

[0044] When the large-scale titanium slag smelting fully enclosed DC electric furnace gas generator tail gas waste heat utilization system of the present invention is in use, first, ammonia enters from the ammonia injection pipe 3 and is distributed to each nozzle 142 on the ammonia injection fixing plate 14 through the connecting pipe 143. The ammonia is evenly sprayed in a mist form at the nozzle 142. Since the ammonia injection fixing plate 14 is installed inside the outer shell 11 near the ammonia injection pipe 3, it can ensure that the ammonia can be accurately and evenly sprayed into the tail gas inside the outer shell 11, increasing the contact area between the ammonia and the tail gas and promoting the full mixing of the ammonia and nitrogen oxides.

[0045] The tail gas mixed with ammonia enters the area of the catalytic assembly 12. The catalytic module 123 (titanium oxide-based catalyst) in the catalytic assembly 12 can effectively reduce the activation energy of the reaction between nitrogen oxides and ammonia, accelerate the catalytic reduction reaction between the two, and convert nitrogen oxides into harmless nitrogen and water. The fixing plate 121 provides an installation foundation for the catalytic module 123 to ensure its stability; the dust-proof nets 122 on both sides can block impurities such as dust in the tail gas from entering the inside of the catalytic module 123, preventing the dust from covering the catalyst surface and affecting its activity and denitration efficiency.

[0046] During the catalytic reaction process, some impurities such as dust will adhere to the surface of the catalytic module 123. The ultrasonic vibrator 125 is installed at the bottom of the catalytic module 123 and can generate high-frequency vibration to shake off the impurities such as dust adhering to the surface of the catalytic module 123. At the same time, the soot blower 8 blows air vertically downward, blowing the shaken-off dust and the dust carried in the tail gas into the dust collection bag 13, preventing the dust from accumulating in the device and ensuring the continuity and stability of the denitration process. A cover plate 124 is provided at the top of the catalytic module 123, and the cover plate 124 is fixed to the top of the outer shell 11 by bolts. When it is necessary to maintain or replace the catalytic module 123, the cover plate 124 can be removed for convenient and quick operation.

[0047] The exhaust ends of the raw material drying fluidized bed furnace 5 and the titanium slag finished product silo 6 are connected to the air inlet 75 at the upper part of the vertical cylinder 71, and the height of the air inlet 75 is lower than that of the spray head 74. The tail gas enters the vertical cylinder 71 at an appropriate flow rate and direction. A perforated plate 73 is installed above the interior of the vertical cylinder 71. During the upward movement of the tail gas, the perforated plate 73 can intercept larger particulate matters and some droplets carried in the tail gas, playing a role in preliminary filtration and separation. The spray head 74 is installed at the bottom of the perforated plate 73, and the input end is externally connected to a water pipe. Water sprays out from the spray head 74 to form water mist, which fully contacts the preliminarily filtered tail gas, further capturing fine dust and harmful gases in the tail gas, and making the tail gas more thoroughly purified. The qualified tail gas after purification treatment is discharged from the exhaust port 72 at the top of the vertical cylinder 71, ensuring the normal operation of the system and the smooth discharge of the tail gas. During the dust collection and purification process, the collected dust, impurities, and sewage generated by spraying accumulate at the bottom of the vertical cylinder 71. One side of the bottom of the vertical cylinder 71 is connected to a sewage discharge pipe 76, and a valve is installed on the sewage discharge pipe 76. When cleaning is required, the valve is opened to discharge the sewage and impurities, facilitating the cleaning and maintenance of the dust collection device 7 and ensuring its long-term stable operation.

[0048] Finally, it should be noted that for the ultrasonic vibrator 125 and the like in this embodiment, the electronic components in the above components are all general standard components or components known to those skilled in the art. Their structures and principles can be known by those skilled in the art through technical manuals or obtained through conventional experimental methods. At the idle places of this device, all the above electrical components are respectively connected through wires. The specific connection means should refer to the sequential working order among the electrical components in the above working principle to complete the electrical connection, and all of them are well-known technologies in the art.

[0049] The above has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A waste heat utilization system for the tail gas of a large-scale titanium slag smelting fully enclosed DC electric furnace gas generator, including an SCR denitration device (1), characterized in that: One end of the SCR denitration device (1) is connected to an exhaust gas collecting pipe (2), and the exhaust gas collecting pipe (2) admits the exhaust gas of an electric furnace gas generator. One side of the SCR denitration device (1) close to the exhaust gas collecting pipe (2) is connected to an ammonia injection pipe (3). The other end of the SCR denitration device (1) far from the exhaust gas collecting pipe (2) is connected to two branch pipes (4). The outer end of one branch pipe (4) is connected to a raw material drying fluidized bed furnace (5), and the outer end of the other branch pipe (4) is connected to a titanium slag finished product bin (6). The exhaust ends of the raw material drying fluidized bed furnace (5) and the titanium slag finished product bin (6) are connected to a dust collecting device (7) through pipelines.

2. The waste heat utilization system for the tail gas of a large-scale titanium slag smelting fully enclosed DC electric furnace gas generator according to claim 1, characterized in that: The SCR denitration device (1) includes a housing (11). Inside the housing (11), a number of catalytic components (12) are installed. At the bottom of the housing (11), a number of dust collection bags (13) are connected. Inside the housing (11) near the ammonia injection pipe (3), an ammonia injection fixing plate (14) is installed.

3. The waste heat utilization system of the tail gas of the large-scale titanium slag smelting fully enclosed DC electric furnace gas generator according to claim 1, characterized in that: In the middle of the ammonia injection fixing plate (14), an opening (141) is provided. Inside the opening (141), a number of spray nozzles (142) are evenly installed. One side of the ammonia injection fixing plate (14) is connected to a connecting pipe (143). One end of the connecting pipe (143) is externally connected to the ammonia injection pipe (3), and the other end of the connecting pipe (143) is connected to each spray nozzle (142) through a number of pipelines.

4. The waste heat utilization system for the tail gas of the large-scale titanium slag smelting fully enclosed DC electric furnace gas generator according to claim 1, characterized in that: The catalytic component (12) includes a fixing plate (121). Inside the fixing plate (121), a vertical slot is provided. Inside the slot, a catalytic module (123) is provided. The material of the catalytic module (123) is a titanium oxide-based catalyst. On both sides of the fixing plate (121), dust-proof nets (122) are installed.

5. The waste heat utilization system for the tail gas of a large-scale titanium slag smelting fully enclosed DC electric furnace gas generator according to claim 4, characterized in that: At the bottom of the catalytic module (123), an ultrasonic vibrator (125) is installed.

6. The waste heat utilization system for the tail gas of the large-scale titanium slag smelting fully enclosed DC electric furnace gas generator according to claim 1, characterized in that: At the top of the catalytic module (123), a cover plate (124) is provided. The cover plate (124) is fixed to the top of the housing (11) by bolts.

7. The waste heat utilization system for the tail gas of a large-scale titanium slag smelting fully enclosed DC electric furnace gas generator according to claim 1, characterized in that: The dust collecting device (7) includes a vertical cylinder (71). At the top of the vertical cylinder (71), an exhaust port (72) is provided. Above the inside of the vertical cylinder (71), a perforated plate (73) is installed. At the bottom of the perforated plate (73), a number of spray heads (74) are installed. The input end of the spray heads (74) is externally connected to a water pipe.

8. The waste heat utilization system of the tail gas of the large-scale titanium slag smelting fully enclosed DC electric furnace gas generator according to claim 7, characterized in that: On one side of the upper part of the vertical cylinder (71), an air inlet (75) is provided. The exhaust ends of the raw material drying fluidized bed furnace (5) and the titanium slag finished product bin (6) are connected to the air inlet (75). The height of the air inlet (75) is lower than that of the spray heads (74).

9. The waste heat utilization system for the tail gas of the large-sized titanium slag smelting fully enclosed DC electric furnace gas generator according to claim 8, characterized in that: On one side of the bottom of the vertical cylinder (71), a sewage discharge pipe (76) is connected. A valve is installed on the sewage discharge pipe (76).

10. The waste heat utilization system of the tail gas of the large-scale titanium slag smelting fully enclosed DC electric furnace gas generator according to claim 2, characterized in that: On the upper side of the catalytic component (12), a soot blower (8) is installed. The soot blower (8) blows air vertically downward to blow the dust attached to the surface of the catalytic component (12) into the dust collection bag (13).

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