Quench tower for purifying dioxin and dust in primary flue gas of electric furnace

Abstract

The application discloses a quenching tower for purifying dioxin and dust in primary flue gas of an electric furnace, and belongs to the field of industrial dust removal. In view of the problems of poor purifying effect of the quenching tower and low stability of the primary flue gas dust removal system in the prior art, the application provides the quenching tower for purifying dioxin and dust in primary flue gas of an electric furnace, which comprises a tower body, a plurality of spraying devices I arranged in the tower body, a dust storage bin arranged at the bottom of the tower body, an air inlet and an exhaust core pipe arranged at the top of the tower body, the air inlet being tangent to the top of the tower body, and the exhaust core pipe being inserted into the tower body from the top of the tower body; a spraying device II is arranged directly below the exhaust core pipe, and the plurality of spraying devices I are annularly distributed in the tower body. In the application, dust-containing flue gas rotates in the tower body, the reaction time of the flue gas and the solutions sprayed by the two spraying devices is increased, the synthesis of dioxin is avoided to the maximum extent, and the efficiency of the quenching tower in purifying dioxin and pre-dust removal is improved; the application has the advantages of simple structure, high purifying efficiency, stable operation and low maintenance cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of industrial dust removal, and more particularly to a quench tower for removing dioxin and dust in primary flue gas of an electric furnace. BACKGROUND

[0002] With the rapid development of the steel industry technology in China, the electric furnace steelmaking technology using scrap steel as the main raw material has developed rapidly. The scrap steel generally contains oil, plastic and the like, which is preheated by the primary flue gas of the electric furnace to generate a large amount of flue gas containing dioxin in the continuous charging process. Meanwhile, a part of the flue gas containing dioxin and dust is also generated in the electric furnace smelting process. Dioxin is a highly toxic substance, which is 130 times more toxic than cyanide and 900 times more toxic than arsenic. Once dioxin enters the atmosphere to cause pollution, it will have a great impact on human health. The current "Steelmaking Industry Air Pollutant Emission Standard" GB28664-2012 clearly proposes that the dioxin emission standard of a newly built electric furnace is 0.5 ng-TEQ / Nm 3 , the Beijing local standard and the European Union standard have increased the dioxin emission standard to 0.1 ng-TEQ / Nm 3 . In addition, the recently introduced ultra-low emission standard of the state clearly stipulates that the dust particulate matter emission standard is 10 mg / Nm 3 . With the increasingly high requirements of the state on environmental protection standards, it can be predicted that the dioxin and dust treatment of the primary flue gas of the electric furnace steelmaking industry will become the focus.

[0003] The main technology for treating dioxin in the primary flue gas of an electric furnace at present is quenching, that is, the high-temperature flue gas is rapidly cooled from 800 DEG C to about 250 DEG C in 3s in a quenching tower, so as to reduce the generation of dioxin in the flue gas. However, the existing quenching tower still has the following three shortcomings in use. First, the air inlet mode of the quenching tower from the lower settling chamber will cause secondary dust raising, and in order to let a large amount of flue gas have sufficient reaction time with water mist in the quenching tower, the height of the quenching tower often needs to be very high. Second, the dust removal of the lower settling chamber of the existing quenching tower causes secondary pollution and cannot realize automatic dust removal. The dust accumulated in the lower settling chamber of the existing quenching tower needs to be removed by workers using a forklift, which causes secondary dust raising to the surrounding environment and also has an adverse effect on the physical and mental health of the workers. Third, the pre-purification effect of the quenching tower is poor, and the flue gas coming out of the quenching tower still contains a large amount of acid gas, chlorine-containing substances and dust. If the water injection amount of the spray gun is not controlled well during operation, the water content of the flue gas is often too high. The acid generated by the reaction of these acid gases and excessive water will corrode the inner wall of the quenching tower, affecting the service life of the quenching tower; the chlorine-containing substances will be catalyzed by some catalytic components in the fly ash at low temperature to re-generate dioxin; the excessive water and dust will be bonded and caked to block the flue, which needs workers to clean the accumulated dust in the flue frequently, and the more serious problem is that the flue gas with excessive water content entering the bag-type dust collector will cause bag sticking, leading to the failure of the primary flue gas dust removal of the electric furnace, thereby causing the interruption of the smelting production of the entire electric furnace.

[0004] Corresponding improvements have also been made for the above problems, such as Chinese patent application No. CN201910800790.4, published on November 12, 2019, which discloses a high-efficiency energy-saving and environment-friendly quenching tower, belonging to the technical field of flue gas treatment. The quenching tower body is composed of a spraying section, a waste heat recovery section and a high-temperature flue gas inlet section. A low-temperature gas outlet is formed at the top end of the quenching tower body, and a dust and mud discharge outlet is formed at the bottom end of the quenching tower body. The spraying section is internally provided with spray heads at intervals. The waste heat recovery section is externally provided with a waste heat recovery pipeline. The surface of the high-temperature flue gas inlet section is connected with a Venturi tube opening, and the opening of the Venturi tube opening is provided with a flue gas treatment pipe. The shortcomings of this patent are as follows: the flow rate of the flue gas entering the Venturi tube opening is large, and the high-temperature flue gas containing dust directly washes the inner wall of the quenching tower, which easily causes serious wear of the inner wall of the quenching tower opposite to the inlet opening, and the inlet opening at the lower part will cause secondary dust raising of the dust and mud at the bottom end; although the content of dioxin can be effectively removed, the pre-dust removal and dust and mud discharge effects of the quenching tower are poor, and the tower bottom is easily accumulated, affecting the service life.

[0005] For example, Chinese patent application number CN201320110801.4, published on July 31, 2013, includes a quench tower device. It comprises a quench tower, a quench section water jacket, and a guide pipe. The quench tower is divided into a quench section and a reaction section. The quench section uses a water jacket structure, and atomizing nozzles are located at the flue gas inlet. A guide pipe is installed in the middle of the quench tower to cause spiral downward movement within the tower. The quench tower is lined with carbon steel and coated with anti-corrosion paint. The shortcomings of this patent are: poor pre-purification effect of the quench tower, and easy accumulation of substances at the bottom of the tower, affecting its service life. Summary of the Invention

[0006] 1. The problem to be solved

[0007] To address the problems of poor purification efficiency and low stability of primary flue gas dust removal systems in existing technologies, this invention provides a quench tower for purifying dioxins and dust in primary flue gas from electric furnaces. In this invention, the air inlet is tangentially connected to the top of the tower, causing the dust-laden flue gas to rotate within the tower. This increases the reaction time between the flue gas and the solutions sprayed by the two spray devices, minimizing dioxin synthesis and improving the efficiency of dioxin purification and pre-dust removal. Furthermore, the combination of the air inlet and exhaust core pipe extends the service life of the quench tower. The design is simple, highly efficient, stable in operation, and has low maintenance costs.

[0008] 2. Technical Solution

[0009] To solve the above problems, the present invention adopts the following technical solution.

[0010] A quench tower for purifying dioxins and dust from primary flue gas of an electric furnace includes a tower body with several spray devices I inside. A dust storage bin is located at the bottom of the tower body. An air inlet and an exhaust core pipe are located at the top of the tower body. The air inlet is tangent to the top of the tower body, and the exhaust core pipe is inserted into the tower body from the top. Spray devices II are located directly below the exhaust core pipe. Several spray devices I are arranged in a ring inside the tower body. The quench tower achieves a dust removal efficiency of over 95%, minimizes the formation of dioxins in the flue gas, reduces environmental pollution and harm to human health, and allows for smaller equipment size, reduced floor space, and lower investment costs, making it highly valuable for widespread application.

[0011] Furthermore, the tower body includes a cylinder connected to the air inlet, a cylinder connected to an inverted cone, and the inverted cone connected to an ash storage bin. This tower body has a simple structure, facilitates the rotation of dust-laden fumes inside the tower body, and facilitates the separation of dust and fumes.

[0012] Furthermore, the included angle α between the inverted cone and the ash storage bin is in the range of 45°≤α≤75°. This facilitates dust settling into the ash storage bin and prevents dust from returning to the interior of the cylinder, thereby improving the dust removal efficiency of the quench tower.

[0013] Further, the bottom of the ash storage bin is inverted conical, and a bin wall vibrator and a high-low material level meter are arranged at the inverted conical bottom.

[0014] Further, the angle β between the bottom of the ash storage bin and the horizontal plane is in the range of 55°≤β≤75°. Accumulation of dust on the inner wall of the ash storage bin is avoided.

[0015] Further, a manual plug valve, a star-shaped ash unloading valve, an ash unloading pipe and an ash suction and discharge device are sequentially connected below the ash storage bin. The transfer of dust in the ash storage bin is timely completed.

[0016] Further, the ash suction and discharge device comprises a screw feeder, a gas-dust mixing device and a suction pipe joint, the screw feeder is connected with the bottom of the ash unloading pipe, one end of the gas-dust mixing device is connected with one side of the screw feeder, and the other end is connected with the suction pipe joint. The discharge is uniform, so that the dust can smoothly enter the suction and discharge tank car to complete transportation.

[0017] Further, the spray device I is a double-fluid spray gun composed of compressed air and alkaline solution, and the spray device II is a double-fluid spray gun composed of ammonia gas and water. The generation of dioxin is reduced, and the purification effect of the quenching tower is improved.

[0018] Further, the spray device I is arranged at the middle position of the cylinder.

[0019] Further, temperature sensors are arranged at the inlet of the gas inlet and the outlet of the exhaust core pipe. The corresponding adjustment can be made in time according to the temperature, so that the quenching tower can be efficiently and stably operated.

[0020] 3. Advantageous effects

[0021] Compared with the prior art, the advantageous effects of the present application are:

[0022] (1) The tangential inlet mode of the tower body top makes the dust-containing gas flow form a rotating flow in the tower body, and the spray devices I are annularly distributed in the tower body, and the spray device II is arranged directly below the exhaust core pipe. The dust-containing gas flow rotates in the tower body, increases the reaction time of flue gas and the solution sprayed by the two spray devices, maximally avoids the synthesis of dioxin, improves the efficiency of dioxin purification and pre-dust removal of the quenching tower, and avoids the direct washing of the dust-containing flue gas at the gas inlet on the inner wall of the tower body by adopting the tangential inlet mode, which can prolong the service life of the quenching tower. The exhaust core pipe is inserted into the tower body for exhaust, which can greatly reduce the "short circuit" of the dust-containing flue gas. The dust removal efficiency of the whole quenching tower reaches more than 95%, the equipment volume is reduced, and the occupied area is reduced.

[0023] (2) The tower body in the application includes two parts, the upper part is a cylinder connected with the air inlet, the inner space of the cylinder is annular, which is large and convenient for the rotational movement of the dust-containing smoke on the inner wall of the cylinder; the lower part is an inverted cone connected with the ash storage bin, the setting of the inverted cone facilitates the separation of the dust-containing smoke at the lower part of the tower body, so that the dust can smoothly enter the ash storage bin; and the included angle a between the inverted cone and the ash storage bin is between 45° and 75°, which is beneficial to the falling of the dust from the inverted cone to the lower ash storage bin, maximally reduces the return of the dust to the inner part of the cylinder, and improves the dust removal efficiency of the quenching tower;

[0024] (3) The bottom of the ash storage bin is inverted conical, which is beneficial to the transfer of the dust in the ash storage bin; and the warehouse wall vibrator and the high-low material level meter are arranged at the bottom of the inverted cone, the high-low material level meter has a monitoring and early warning effect on the amount of dust in the ash storage bin, when the amount of dust in the ash storage bin reaches the highest limit, the high-low material level meter alarms and then the warehouse wall vibrator works, so that the dust accumulated at the bottom of the ash storage bin is quickly transferred and transported away from the ash storage bin;

[0025] (4) The manual plug-in valve, the star-shaped ash unloading valve, the ash unloading pipe and the ash suction and removal device are sequentially connected below the ash storage bin, when the dust in the ash storage bin needs to be transferred, the dust is sequentially transferred to the ash suction and removal device through the manual plug-in valve, the star-shaped ash unloading valve and the ash unloading pipe, and then the ash suction and removal device is negatively extracted by the suction and removal tank car, the whole process is carried out in a closed environment, and no dust spills out; the collection, storage and automatic ash removal of the dust are realized, the production automation is realized without stopping the furnace, the pollution to the surrounding environment is avoided, and the risk of occupational diseases of workers is avoided;

[0026] (5) The screw feeder in the ash suction and removal device has the functions of metering and feeding, solves the uneven ash unloading of the star-shaped ash unloading valve, makes the whole ash suction and removal device uniformly unload, connects the suction pipe with the suction and removal tank car to suck out the dust, prevents blockage, and has the advantages of simple structure, reasonable design and easy manufacturing;

[0027] (6) The spray device I in the application is a double-fluid spray gun composed of compressed air and alkaline solution, which can neutralize other acidic gases in the flue gas, avoid the corrosion of acidic gases to the quenching tower equipment and the flue, prolong the service life of the equipment, and the spray device I is arranged at the middle position of the cylinder to maximize the avoidance of dioxin synthesis; the spray device II is a double-fluid spray gun composed of ammonia and water, which can save water resources and avoid excessive water and dust in the flue gas from sticking and blocking the flue and causing bag sticking; on the other hand, when the flue gas temperature exceeds 250℃, the injection of ammonia can effectively inhibit the generation of dioxin in the flue gas, and improve the ability of the quenching tower to purify dioxin;

[0028] (7) The present application is provided with temperature sensors at the inlet of the air inlet and the outlet of the exhaust core pipe. When the temperature at the air inlet exceeds 800℃, the spraying capacity of the annularly arranged spraying device I is increased to ensure that the flue gas temperature can be rapidly cooled to about 250℃ within a specified time. When the outlet flue gas temperature exceeds 250℃, the spraying device II below the exhaust core pipe is opened. The spraying device II is used for fine adjustment to ensure that there is no synthesis of dioxin in the flue gas and the flue gas temperature is stabilized within the set value range, thereby ensuring the efficient and stable operation of the entire rapid cooling tower. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a structural schematic diagram of the present application;

[0030] Figure 2 is Figure 1 is a view in A-A direction;

[0031] Figure 3 is Figure 1 is a view in B-B direction;

[0032] Figure 4 is Figure 1 is an enlarged view of part C.

[0033] In the figure: 1, air inlet; 2, cylinder; 3, spraying device I; 4, inverted cone; 5, ash storage bin; 6, bin wall vibrator; 7, manual gate valve; 8, star-shaped ash discharge valve; 9, ash suction and discharge device; 10, exhaust core pipe; 11, spraying device II; 12, temperature sensor; 13, high-low material level meter. DETAILED DESCRIPTION

[0034] The present application will be further described below in combination with specific embodiments and the accompanying drawings.

[0035] Most existing rapid cooling towers adopt air inlet from the bottom of the settling chamber, and the exhaust gas is directly discharged in a straight line connected to the top of the tower body. This air inlet and exhaust gas discharge mode will form secondary dust raising when the air is introduced at the bottom of the settling chamber, and the exhaust pipe directly connected to the top of the tower body increases the dust concentration of the flue gas at the outlet of the rapid cooling tower, which increases the filtration load of the subsequent bag-type dust collector and requires frequent replacement of the filter bags, thereby increasing the operating cost. In order to allow a large amount of flue gas to have sufficient reaction time with the water mist in the rapid cooling tower, the height of the rapid cooling tower often needs to be very high, and the occupied area is large. The flue gas discharged from the rapid cooling tower still contains a large amount of acid gas, chlorine-containing substances and dust. The chlorine-containing substances will be catalyzed by certain catalytic components in the fly ash at low temperature to re-generate dioxin, causing serious pollution hazards. The inventor has proposed a rapid cooling tower for purifying dioxin and dust in primary flue gas of an electric furnace through repeated experiments and field surveys, which can solve the problems of the existing rapid cooling tower during operation and has a wide application prospect.

[0036] Example 1

[0037] The instant patent application relates to a kind of quench tower for purifying dioxin and dust of electric furnace primary flue gas, comprising tower body, several spray devices I3 are arranged in the inside of tower body, dust storage bin 5 is arranged in the bottom of tower body, the top of tower body is provided with air inlet 1 and exhaust core pipe 10, air inlet 1 is tangent to the top of tower body, exhaust core pipe 10 is inserted into tower body from the top of tower body;Spray device II 11 is arranged directly below exhaust core pipe 10, and several spray devices I3 are annularly distributed in the inside of tower body;In the embodiment, air inlet 1 is arranged in the form of tangent to the top of tower body, so that the dust-containing flue gas entering the inside of tower body from air inlet 1 forms a rotating flow in the inside of tower body, the dust in flue gas moves downward along the direction of airflow under the action of centrifugal force, and the dust separates from flue gas when moving to the bottom of tower body, and falls into dust storage bin 5 due to its own gravity, and at the same time, the dust-containing flue gas at air inlet 1 can be prevented from directly washing the inner wall of tower body by using the tangential air inlet mode, so that the service life of quench tower can be prolonged;The dust-containing flue gas can be greatly reduced by using exhaust core pipe 10 inserted into the inside of tower body for exhaust, and the dust-containing flue gas is discharged from exhaust core pipe after being treated;The dust-containing flue gas rises from the bottom of tower body to exhaust core pipe 10 after cyclone action;Several spray devices I3 are arranged in the inside of tower body, and several spray devices I3 are annularly distributed in the inside of tower body, so as to increase the contact area with dust-containing flue gas, and spray device II 11 is arranged directly below exhaust core pipe 10;Due to the rotating motion of dust-containing flue gas in the inside of tower body, the reaction time of flue gas and the atomized solution sprayed by two spray devices is increased, the generation of dioxin is reduced, and the efficiency of quench tower for purifying dioxin and pre-dust removal is improved;And at the same time, the height of quench tower can be reduced, and the construction cost can be reduced.

[0038] The present application changes the inlet and exhaust mode of quench tower in the prior art by using the mode of tangential air inlet at the top of tower body and top exhaust by inserting into the inside of tower body, so that the dust removal efficiency of quench tower reaches more than 95%, the generation of dioxin in flue gas is minimized, the pollution to environment and the harm to personnel are reduced, the equipment volume is reduced, the occupied area is reduced, the investment cost is saved, and the present application has high popularization significance;And the present application not only reduces the volume and occupied area of quench tower by using the mode of tangential air inlet at the top of tower body and top exhaust by inserting into the inside of tower body, but also prevents excessive dust accumulation in dust removal pipeline at the outlet of quench tower from causing pipeline collapse safety accident by increasing the pre-dust removal efficiency, and prolongs the service life of filter material of subsequent bag filter, so that the present application has simple structure, high purification efficiency, low operation and maintenance cost, and can ensure long-term safe and stable operation of electric furnace primary flue gas dust removal system.

[0039] Example 2

[0040] The basic same as example 1, except that Figure 1 ,Figure 2 、 Figure 3 and Figure 4 As shown in the drawings, the tower body comprises a cylinder 2 connected with the gas inlet 1, the diameter of the cylinder 2 is D, the height of the cylinder 2 is H, the diameter of the gas inlet 1 is D1, the internal space of the cylinder 2 is annular, the space is large and convenient for the rotational movement of the dust-containing smoke body on the inner wall of the cylinder 2; specifically, the exhaust core pipe 10 is a circular pipe, the diameter of the exhaust core pipe 10 is D2, the length of the exhaust core pipe 10 inserted into the cylinder 2 is H1, and the range of H1 is: 0.1H≤H1≤0.5H, in this range, the exhaust efficiency of the exhaust core pipe 10 is higher and does not affect the separation of flue gas and dust, and the content of dust in the exhaust gas is reduced; the cylinder 2 is connected with the inverted cone 4, the inverted cone 4 is connected with the ash storage bin 5, and the setting of the inverted cone 4 facilitates the separation of the dust-containing smoke body at the lower part of the tower body, so that the dust can smoothly enter the ash storage bin 5; preferably, the included angle α between the inverted cone 4 and the ash storage bin 5 is in the range of: 45°≤α≤75°. The included angle α in this range is beneficial to the falling of dust from the inverted cone 4 to the lower ash storage bin 5, maximally reduces the return of dust to the inside of the cylinder 2, and improves the dust removal efficiency of the quenching tower; the included angle between the two is too large, which makes the volume of the quenching tower too large, and the included angle between the two is too small, which is not conducive to the falling of dust into the ash storage bin 5.

[0041] Further, the bottom of the ash storage bin 5 is inverted conical, and a bin wall vibrator 6 and a high-low material level meter 13 are arranged at the bottom of the inverted conical shape; the inverted conical shape of the bottom of the ash storage bin 5 is beneficial to the falling and transfer of dust in the ash storage bin 5, and dust plugging does not occur; and the high-low material level meter 13 performs a monitoring and early warning function on the amount of dust in the ash storage bin 5, when the amount of dust in the ash storage bin 5 reaches the highest limit, the high-low material level meter 13 alarms and then the bin wall vibrator 6 works, so that the dust accumulated at the bottom of the ash storage bin 5 falls and transfers quickly, is transported away from the ash storage bin 5, and the excessive amount of dust in the ash storage bin 5 affects the purification effect of the quenching tower; specifically, in this embodiment, the included angle β between the bottom of the ash storage bin 5 and the horizontal plane is in the range of: 55°≤β≤75°; the included angle β in this range is mainly to prevent dust from accumulating on the side wall of the ash storage bin 5, so as to facilitate the smooth ash discharge of the ash storage bin 5 and improve the ash discharge efficiency of the quenching tower; the included angle between the two is too large, which makes the volume of the ash storage bin 5 equipment too large, and the included angle between the two is too small, which is not conducive to the discharge of dust removal ash.

[0042] Example 3

[0043] The embodiment is basically the same as that of the embodiment 2, but in the embodiment, the manual gate valve 7, the star-shaped dust discharging valve 8, the dust discharging pipe and the dust suction and discharging device 9 are sequentially connected below the dust storage bin 5; when the dust in the dust storage bin 5 reaches the high material level, the high and low material level meter 13 alarms, and the dust in the dust storage bin 5 is discharged under the action of the bin wall vibrator 6, sequentially passes through the manual gate valve 7, the star-shaped dust discharging valve 8 and the dust discharging pipe, and enters the dust suction and discharging device 9, the dust suction and discharging device 9 is connected with the suction and discharging tank car, and the dust in the dust suction and discharging device 9 is sucked into the tank car under the negative pressure of the suction and discharging tank car, the whole process is carried out in a closed environment, and no dust overflow is generated, so that the automatic dust discharging and no secondary pollution are realized; the embodiment changes the previous dust cleaning mode of the settling chamber at the lower part of the quenching tower, which can only be manually cleaned during shutdown, slows down the secondary dust generated in the dust cleaning process, reduces the pollution to the surrounding environment and the adverse effects on the physical and mental health of workers, and stores the dust separated from the quenching tower in the dust storage bin 5, and the dust suction and discharging tank car is regularly transported away when the stored dust reaches the high material level; the dust cleaning mode realizes the collection, storage and automatic discharging of the dust, realizes the production automation without shutdown, avoids the pollution to the surrounding environment, and avoids the risk of occupational diseases of workers; the height of the dust suction and discharging device 9 from the ground is H2, and the value range is 500mm≤H2≤1200mm, which is beneficial to the pipe connection and dust discharging of the suction and discharging tank car and the maintenance of the dust suction and discharging device 9 in the later period, and the height that is too large or too small is not conducive to the pipe connection and dust discharging and maintenance of the dust suction and discharging device 9.

[0044] Specifically, in the embodiment, the dust suction and discharging device 9 includes a screw feeder, a gas-dust mixing device and a suction pipe joint, the screw feeder is connected with the bottom of the dust discharging pipe, one end of the gas-dust mixing device is connected with one side of the screw feeder, and the other end is connected with the suction pipe joint, the dust suction and discharging device 9 is connected with the suction and discharging tank car through the suction pipe joint to realize the transfer and transportation of the dust; the screw feeder has the functions of metering and feeding, solves the uneven dust discharging of the star-shaped dust discharging valve 8, and makes the whole dust suction and discharging device 9 uniformly discharge; and the gas-dust mixing device is a cylindrical barrel, which has a simple structure and a large internal space, and can effectively discharge the dust.

[0045] Embodiment 4

[0046] The same as in Example 3, specifically, the spraying device I3 is a two-fluid spraying gun composed of compressed air and alkaline solution, and the spraying device II11 is a two-fluid spraying gun composed of ammonia and water; because the spraying devices I3 are arranged in a ring on the inner wall of the cylinder 2, i.e. the spraying devices I3 are arranged on the same circle, the diameter of the circle is D3, and the diameter of the circle is between the diameter D of the cylinder 2 and the diameter D2 of the exhaust core pipe 10, specifically, in this embodiment, D3 = 0.5(D+D2), such arrangement enables the spraying device I3 to be in sufficient contact with the dust-containing flue gas, thereby reducing the generation of dioxin; the spraying device I3 is a two-fluid spraying gun composed of compressed air and alkaline solution, and the spraying device I3 arranged in a ring can rapidly quench the flue gas from 800℃ high temperature to 250℃, which can reduce the effective chlorine source of the flue gas in this temperature range, avoid the synthesis of dioxin in the flue gas, and at the same time, the alkaline atomized solution can neutralize the acidic gas and pretreat fine particulate matter; while the spraying device II11 is a two-fluid spraying gun composed of ammonia and water, and the water mist sprayed by the spraying device II11 is fine, the fine water mist is used to finely adjust the outlet temperature of the quenching tower, and ammonia can effectively inhibit the re-synthesis of dioxin at about 250℃.

[0047] The spray mode of the existing quench tower is changed, and further, the spray device I3 is arranged at the middle position of the cylinder 2. If the spray device I3 is arranged too high in the cylinder 2, the flue gas cannot react with the atomized solution in the spray device I3 sufficiently, the flue gas cannot be quenched, and the generation of dioxin cannot be prevented. If the spray device I3 is arranged too low in the cylinder 2, the dust-containing flue gas can be discharged from the exhaust core pipe 10 without being sufficiently cooled, which can cause the high-temperature flue gas to burn the bag of the subsequent bag-type dust collector, and the dioxin can be discharged beyond the standard. When the flue gas at a temperature of about 600-800 ℃ flows downward from the upper part and meets the alkaline atomized solution sprayed by the spray device I3, on the one hand, the alkaline solution can rapidly reduce the temperature of the flue gas to about 250 ℃ when the alkaline solution is gasified, and the alkaline atomized solution can effectively reduce the chlorine source in this temperature range, thereby avoiding the synthesis of dioxin to the maximum extent. On the other hand, the alkaline solution can also neutralize other acidic gases in the flue gas, thereby avoiding the corrosion of the acidic gases to the quench tower equipment and the flue, and prolonging the service life of the equipment. In addition, the ammonia and water sprayed by the spray device II11 directly below the exhaust core pipe 10 are mainly used for inhibiting the generation of dioxin and adjusting the temperature of the flue gas. When the temperature of the exhaust core pipe 10 exceeds 250 ℃, in order to prevent the flue gas from being too high to cause the burning of the filter bag of the bag-type dust collector in the subsequent process, the spray device II11 is used to supplement some fine water mist and ammonia. This adjustment mode is different from the previous overall adjustment of the water mist of the spray gun, which can save water resources and avoid the excessive water and dust in the flue gas from being bonded and causing the flue to be blocked and the bag to be pasted. On the other hand, when the temperature of the flue gas exceeds 250 ℃, the spraying of ammonia can effectively inhibit the generation of dioxin in the flue gas, thereby improving the efficiency of the quench tower in purifying dioxin. The spray device I3 and the spray device II11 that can spray atomized solution can be used in the embodiment.

[0048] Embodiment 5

[0049] The temperature sensors 12 are arranged at the inlet 1 and the outlet of the exhaust core pipe 10, respectively. When the temperature at the inlet 1 exceeds 800 ℃, the spraying capacity of the annular spray device I3 is increased, so that the temperature of the flue gas can be quenched to about 250 ℃ within a specified time. When the temperature of the outlet flue gas exceeds 250 ℃, the spray device II11 below the exhaust core pipe 10 is started, and the spray device II11 is used for fine adjustment, so that the synthesis of dioxin in the flue gas is prevented, and the temperature of the flue gas is stabilized within the set value range, thereby ensuring the efficient and stable operation of the entire quench tower.

[0050] The examples described in the present application are merely to describe the preferred embodiments of the present application, and are not intended to limit the concept and scope of the present application. Without departing from the design idea of the present application, various modifications and improvements of the technical solutions of the present application made by the engineering technicians in the field shall fall within the protection scope of the present application.

Claims

1. A quench tower for purifying dioxins and dust from primary flue gas of an electric furnace, comprising a tower body, wherein a plurality of spray devices I (3) are provided inside the tower body, and an ash storage bin (5) is provided at the bottom of the tower body, characterized in that: The top of the tower body is provided with an air inlet (1) and an exhaust core pipe (10) connected to the cylinder (2). The air inlet (1) is tangent to the top of the cylinder (2) of the tower body. The exhaust core pipe (10) is inserted into the tower body from the top of the tower body. A spray device II (11) is provided directly below the exhaust core pipe (10). Several spray devices I (3) are arranged in a ring inside the tower body. The length of the exhaust core tube (10) inserted into the cylinder (2) of the tower body is H1, and the range of H1 is: 0.1H≤H1≤0.5H, where H is the height of the cylinder (2); the spray device I (3) is set in the middle position of the cylinder (2); the plurality of spray devices I (3) are set on the same circle, the diameter of which is between the diameter of the cylinder (2) and the diameter of the exhaust core tube (10).

2. The quench tower for purifying dioxins and dust in primary flue gas of an electric furnace according to claim 1, characterized in that: The bottom of the cylinder (2) is connected to the inverted cone (4), and the bottom of the inverted cone (4) is connected to the ash storage bin (5).

3. The quench tower for purifying dioxins and dust in primary flue gas of an electric furnace according to claim 2, characterized in that: The included angle α between the inverted cone (4) and the ash storage bin (5) is in the range of 45°≤α≤75°.

4. A quench tower for purifying dioxins and dust in primary flue gas of an electric furnace according to claim 1 or 3, characterized in that: The bottom of the ash storage silo (5) is inverted cone shape, and a silo wall vibrator (6) and a high and low level gauge (13) are installed at the bottom of the inverted cone shape.

5. A quench tower for purifying dioxins and dust in primary flue gas of an electric furnace according to claim 4, characterized in that: The angle β between the bottom of the ash storage silo (5) and the horizontal plane is in the range of 55°≤β≤75°.

6. A quench tower for purifying dioxins and dust in primary flue gas of an electric furnace according to claim 5, characterized in that: Below the ash storage silo (5), a manual slide valve (7), a star-shaped ash discharge valve (8), an ash discharge pipe, and an ash suction and discharge device (9) are connected in sequence.

7. A quench tower for purifying dioxins and dust in primary flue gas of an electric furnace according to claim 6, characterized in that: The ash suction and discharge device (9) includes a screw feeder, an air-ash mixing device and a suction pipe connector. The screw feeder is connected to the bottom of the ash discharge pipe. One end of the air-ash mixing device is connected to the feeding side of the screw feeder, and the other end is connected to the suction pipe connector.

8. A quench tower for purifying dioxins and dust in primary flue gas of an electric furnace according to claim 2, characterized in that: Spray device I (3) is a two-fluid spray gun composed of compressed air and alkaline solution, and spray device II (11) is a two-fluid spray gun composed of ammonia and water.

9. A quench tower for purifying dioxins and dust in primary flue gas of an electric furnace according to claim 1, characterized in that: Temperature sensors (12) are installed at both the air inlet (1) and the outlet of the exhaust core pipe (10).

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