Dumping process high-temperature flue gas trapping device and trapping method based on high-speed jet flow induction

Abstract

The invention discloses a dumping process high-temperature flue gas gathering device based on high-speed jet flow induction, which comprises a molten iron receiving tank, a dust removal cover is arranged right above the molten iron receiving tank, the dust removal cover is connected to one end of an exhaust pipeline, an electric control valve is arranged on the exhaust pipeline, and a molten iron dumping tank is arranged above one side of the molten iron receiving tank. An industrial camera is arranged above the other side of the molten iron receiving tank, and a jet fan is arranged between the industrial camera and the molten iron receiving tank. The invention further discloses a pouring process high-temperature flue gas trapping method based on high-speed jet flow induction. The problem that high-temperature flue gas cannot be efficiently trapped in the molten iron pouring process is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of ventilation and dust removal in a molten iron pouring process, and relates to a high-temperature smoke capture device in a pouring process based on high-speed jet induction. The invention also relates to a high-temperature smoke capture method in a pouring process based on high-speed jet induction. Background Art

[0002] The pouring of molten iron is an important transfer process for the supply of molten iron to blast furnaces and steelmaking in converters. During the process of molten iron pouring and colliding with the tank body, a large amount of dusty flue gas with high temperature and strong thermal buoyancy will be generated, which will rapidly increase the flue gas flow and escape range due to the entrainment of the surrounding airflow. The existing ventilation capture has the following three problems: ① The commonly used top suction or side top suction exhaust system captures flue gas, which is far away from the flue gas molten iron receiving tank at the pouring port, has a limited exhaust range, and requires a large amount of controlled air volume, resulting in high subsequent operating costs; ② Affected by the operation of the crane hanging tank, the installation position of the dust hood is limited, and it is difficult to effectively cover the dust source, resulting in poor capture effect. A large amount of escaped flue gas accumulates in the upper part of the workshop, seriously affecting the quality of the workshop environment; ③ There are certain safety risks in the process of pouring the tank nearby, and the high temperature and high concentration of flue gas on site will cause line of sight obstruction and affect the adjustment of the exhaust system. In view of the above difficulties, in order to reduce the air volume and effectively remove the high-temperature flue gas in the workshop, it is necessary to reduce the adverse effects of the non-ideal installation position of the dust hood and guide the high-temperature dust-containing flue gas to move to the exhaust range. A method to enhance the directional capture performance of the side top suction exhaust system is proposed, and an exhaust control system with automatic operation and adjustment is established. Summary of the invention

[0003] The purpose of the present invention is to provide a high-temperature flue gas capture device for a pouring process based on high-speed jet induction, which solves the problem that high-temperature flue gas cannot be efficiently captured during the molten iron pouring process.

[0004] Another object of the present invention is to provide a method for capturing high-temperature flue gas in a dumping process based on high-speed jet induction.

[0005] The first technical solution adopted by the present invention is a high-temperature flue gas capture device based on a high-speed jet-induced dumping process, comprising a molten iron receiving tank, a dust hood is provided directly above the molten iron receiving tank, the dust hood is connected to one end of the exhaust duct, an electric regulating valve is provided on the exhaust duct, a molten iron dumping tank is provided obliquely above one side of the molten iron receiving tank, an industrial camera is provided obliquely above the other side of the molten iron receiving tank, and a jet fan is provided between the industrial camera and the molten iron receiving tank.

[0006] The first technical solution of the present invention is also characterized in that:

[0007] The molten iron pouring tank is moved to the pouring station by hook 1.

[0008] A filter is provided at the air intake of the jet fan.

[0009] A flow equalizing device is provided at the air outlet of the jet fan.

[0010] The flow balancing device comprises a first layer of orifice plates, a second layer of orifice plates and a honeycomb plate which are arranged in sequence, and the first layer of orifice plates is arranged relatively close to the inner side of the air outlet.

[0011] The first layer of orifice plates has a uniform aperture, while the second layer of orifice plates has a non-uniform aperture, with the aperture on the side close to the jet fan volute being larger and the aperture on the side away from the jet fan volute being smaller.

[0012] The honeycomb panel is a hexagonal honeycomb body.

[0013] The interface between the dust hood and the exhaust duct should be equipped with a fire-proof and high-temperature resistant flexible seal.

[0014] A dust removal bellows is arranged at the other end of the exhaust duct.

[0015] The second technical solution adopted by the present invention is a high-temperature flue gas capture method based on a high-speed jet-induced pouring process, which specifically includes the following processes: when the molten iron pouring operation is performed, the molten iron receiving tank is transported to the molten iron pouring station by a traveling trolley, and the molten iron receiving tank is placed directly below the dust hood, and the molten iron pouring tank filled with molten iron is lifted to the pouring station by hook one, and the molten iron pouring tank is lifted to a predetermined height, and the molten iron pouring tank is controlled by the lifting and lowering of hook two to pour the molten iron into the molten iron receiving tank fixed on the traveling trolley; the molten iron collides with the wall of the molten iron pouring tank to generate smoke, and at this time, the jet fan is turned on, and the negative pressure generated by the jet fan jet is used to induce the smoke to deflect, and then the smoke is captured through the dust hood.

[0016] The beneficial effects of the present invention are as follows:

[0017] (1) Improve the collection effect of the exhaust system on high-temperature flue gas: To address the thorny problem of low collection efficiency and large air volume required for high-temperature dusty flue gas when the dust hood is installed in a limited position, a jet fan is cleverly installed behind the receiving tank. With the help of the high-speed jet and the pressure difference on both sides of the contaminated molten iron receiving tank, the flow direction of the local high-temperature dusty flue gas is adjusted and guided to move to the range of action of the side top suction and exhaust system, thereby greatly enhancing the directional collection ability of the side top suction and exhaust airflow;

[0018] (2) Reduce the operating energy consumption of industrial plant exhaust systems: Although increasing the exhaust volume is an effective means to control smoke diffusion, excessive exhaust volume will bring many problems, such as limited improvement in capture efficiency, surge in fan energy consumption, and a sharp increase in operating costs. The present invention uses jets to optimize the exhaust system. Under the same smoke control effect, the air volume required by the system is greatly reduced, and the energy-saving effect is significant, providing strong support for industrial enterprises to reduce operating costs.

[0019] (3) Jet air outlet with flow equalization function: Due to the rotation of the fan blades, the static pressure on the outlet side close to the volute is very small and the air speed is quite large, while the air speed on the outlet side away from the volute is relatively small. After installing a double-layer porous plate and honeycomb on the air outlet, a uniform airflow can be generated to achieve a better induction effect and absorb part of the noise generated by the rotation of the impeller.

[0020] (4) Online infrared image monitoring and jet ventilation control linkage system: The infrared radiation energy collected by the industrial camera is transmitted to the processor of the monitoring system for analysis, accurately judging the state of the canning process, and linking with the side suction dust hood and the jet generator fan. The fan operation time period is accurately determined through start-stop control, and the supply and exhaust air state parameters are flexibly changed through speed adjustment, which not only reduces the fan operation energy consumption, but also fully guarantees the safety of operators, and safeguards the safe and efficient operation of industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional schematic diagram of the jet induced ventilation system in the high-temperature smoke capture device of the pouring process based on high-speed jet induction of the present invention;

[0022] Figure 2 It is a two-dimensional plane schematic diagram of the jet induced ventilation system in the high-temperature smoke capture device of the pouring process based on high-speed jet induction of the present invention;

[0023] Figure 3 It is a front view of a jet fan in a high-temperature smoke capture device of a dumping process based on high-speed jet induction according to the present invention;

[0024] Figure 4 It is a top view of the jet fan in the high-temperature smoke capture device of the dumping process based on high-speed jet induction of the present invention;

[0025] Figure 5 It is a structural schematic diagram of a flow balancing device in a high-temperature flue gas capture device based on a high-speed jet-induced dumping process according to the present invention;

[0026] Figure 6(a) to Figure 6(c) It is a schematic plan view of the first layer of perforated plates, the second layer of perforated plates, and the honeycomb plate in the high-temperature flue gas capture device based on the high-speed jet-induced dumping process of the present invention;

[0027] Figure 7 It is a left view of the jet fan in the high-temperature smoke capture device of the dumping process based on high-speed jet induction of the present invention;

[0028] Figure 8(a) to Figure 8(b) This is a cloud diagram of the smoke concentration distribution in the factory building under Example 7 of the present invention;

[0029] Figure 9(a) to Figure 9(b) This is the smoke flow line diagram of the plant in Example 7 of the present invention;

[0030] Fig.10 This is a comparison chart of the control effect of different induced ratios on flue gas in the present invention.

[0031] In the figure, 1. molten iron receiving tank, 2. molten iron dumping tank, 3. Hook 1, 4. Dust hood, 5. Electric regulating valve, 6. Exhaust duct, 7. Bracket, 8. Industrial camera, 9. Support mechanism, 10. Jet fan, 11. Fan support, 12. Traveling trolley, 13. Hook 2, 14. Air intake, 15. Filter, 16. First layer orifice plate, 17. Second layer orifice plate, 18. Honeycomb plate, 19. Air outlet, 20. Impeller, 21. Motor. DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] The high-temperature flue gas capture device based on the dumping process induced by high-speed jets of the present invention has the basic principle of utilizing the induction effect of high-speed jets. After adding high-speed jets, the pressure on the side close to the jets is small, and the pressure on the side away from the jets is large, resulting in a pressure difference on both sides of the high-temperature flue gas, thereby deflecting the movement trajectory of the flue gas, so that it can be effectively captured by the dust hood. The induced dust removal device can not only improve the capture effect of the local dust hood on the flue gas, effectively control the dust concentration in the environment, but also reduce the energy consumption of the fan operation to a certain extent.

[0034] Example 1

[0035] The invention is based on a high-speed jet-induced dumping process high-temperature flue gas capture device, such as Figure 1 , 2 As shown, it includes a molten iron receiving tank 1, which is placed just below the dust cover 4, a hook 3 moves the molten iron pouring tank 2 to the pouring station, the dust cover 4 is connected to one end of the exhaust duct 6, the exhaust duct 6 is provided with an electric regulating valve 5, the exhaust duct 6 is fixed on the bracket 7, the fan support 11 is fixed on the ground, the jet fan 10 is placed on the fan support 11, and an industrial camera 8 (model: Pyroview1920N; function: mainly used for non-contact temperature measurement in the metallurgical industry, especially temperature measurement between 600 and 1800°C. It can monitor the temperature distribution of high-temperature metal materials, the inside of the furnace, etc. in real time, help operators to grasp the temperature changes in the production process, adjust the process parameters in time, and ensure production safety and product quality) is fixed on the supporting mechanism 9.

[0036] Example 2

[0037] A filter screen 15 is arranged at the air inlet 14 of the jet fan 10 (see Figure 3 ).

[0038] Example 3

[0039] In order to maintain a uniform velocity distribution at the air outlet 19 of the jet fan 10, a flow equalizing device is installed at the air outlet 19 of the jet fan 10, such as Figure 4 , 5 As shown, the flow balancing device includes a first layer of orifice plates 16, a second layer of orifice plates 17 and a honeycomb plate 18 arranged in sequence. The first layer of orifice plates 16, the second layer of orifice plates 17 and the honeycomb plate 18 of the flow balancing device can reduce the air turbulence intensity and make the velocity distribution of the air outlet uniform.

[0040] The high-temperature flue gas is captured by the dust removal hood 4, and the dust removal bellows on the exhaust duct 6 reduces the high-temperature and high-concentration flue gas to below the national standard limit before being discharged outdoors.

[0041] Example 4

[0042] FIG6(a) shows the structure of the first layer of orifice plate 16. The first layer of orifice plate 16 has a uniform aperture.

[0043] The aperture of the second layer of orifice plate 17 is non-uniform, with the aperture on the side close to the volute of the jet fan 10 being slightly larger, and the aperture on the side away from the volute of the jet fan 10 being slightly smaller.

[0044] The opening rate of the first layer of orifice plate 16 is 40%, the diameter of the circular hole is 5mm, and the distance between the centers of adjacent circular holes is 8mm;

[0045] FIG6( b ) shows the structure of the second layer of orifice plate 17 . The opening rate of the second layer of orifice plate 17 is 35%. The diameter of the small circular holes is 5 mm, the diameter of the large circular holes is 8 mm, the distance between the centers of adjacent small circular holes is 8 mm, and the distance between the centers of adjacent large circular holes is 10 mm.

[0046] FIG6( c ) shows a honeycomb panel structure, in which the honeycomb panel 18 is a hexagonal honeycomb body with a pore size of 5 mm.

[0047] Example 5

[0048] The dust hood 4 and the exhaust duct 6 should be provided with a fireproof and high temperature resistant flexible seal at the interface to prevent smoke from escaping from the connection gap.

[0049] A dust removal bellows is provided at the end of the exhaust duct 6 to reduce the smoke concentration to below the national standard limit before exhausting it outdoors.

[0050] When the impeller 20 in the jet fan 10 inhales air, the filter 15 can intercept foreign matter such as dust, debris, and fibers in the air, preventing these foreign matter from entering the jet fan 10 with the air flow, and preventing them from causing wear, blockage or damage to key components such as the impeller and the shaft, thereby extending the service life of the fan and ensuring the normal operation of the jet fan 10. Figure 7The central axis of the impeller 20 is connected to the main shaft of the motor 21.

[0051] The industrial camera 8 is fixed by a supporting mechanism 9, which includes a liftable bracket and a supporting plate. The supporting plate is fixed to the bracket by a connecting device. The industrial camera 8 is provided with a protective box on the outside (function: there is a lot of dust in the production environment of the metallurgical industry, and the protective box can prevent dust from entering the camera and avoid dust covering the lens and affecting the image clarity). The camera protection box is connected to the supporting plate through an installation interface (function: prevent the camera from loosening or shifting due to vibration or movement of the equipment, and ensure the accuracy of the camera shooting position and angle).

[0052] The industrial camera 8 transmits the collected radiation energy in the near-infrared band to the processor of the monitoring system, which then converts it into temperature to determine whether the operation of the molten iron dumping tank 2 is completed, and is linked with the dust removal hood 4 and the jet fan 10 to determine the operating time period of the jet fan 10 through start-stop control, and adjusts the speed of the jet fan by adjusting the speed of the motor 21 (the air volume is proportional to the speed. When the speed of the motor 21 increases, the rotation speed of the impeller 20 in the jet fan 10 increases, and the volume of gas passing through the fan per unit time will increase, thereby increasing the air volume; conversely, the speed decreases and the air volume decreases accordingly).

[0053] Example 6

[0054] The high-temperature flue gas capture method of the pouring process induced by high-speed jets of the present invention specifically includes the following processes: when the molten iron pouring operation is performed, the molten iron receiving tank 1 is transported to the molten iron pouring station by a walking trolley 12, and the molten iron receiving tank 1 is placed directly below a dust removal cover 4, and a molten iron pouring tank 2 filled with molten iron is lifted to the pouring station by a hook 1 3, and the molten iron pouring tank 2 is lifted to a predetermined height, and the molten iron pouring tank 2 is controlled to pour the molten iron into the molten iron receiving tank 1 fixed on the walking trolley 12 by lifting and lowering the hook 2 13;

[0055] The collision between molten iron and the wall of the molten iron pouring tank 2 will generate a large amount of high-temperature flue gas. The flue gas will be at a certain angle to the horizontal plane, causing the high-temperature flue gas to deflect toward the side of the pouring tank 2 during the rising process. The flue gas cannot be completely captured by the dust hood 4. At this time, the jet fan 10 is turned on, and the negative pressure generated by the high-speed jet is used to induce the flue gas to deflect to a certain extent, and then the flue gas is captured by the dust hood 4.

[0056] When the impeller 20 in the jet fan 10 is sucking air, the filter 15 on the air inlet 14 can intercept foreign matter such as dust, debris, and fibers in the air, preventing these foreign matter from entering the interior of the jet fan 10 with the air flow, and preventing them from causing wear, blockage or damage to key components such as the impeller and the shaft, thereby extending the service life of the fan and ensuring the normal operation of the jet fan 10.

[0057] When the molten iron pouring operation is completed, lower the height of hook 2 13 to keep the molten iron pouring tank 2 horizontal, and then move the molten iron pouring tank 2 to a position away from the pouring station through hook 1 3, then turn off the jet fan 10 and the dust hood 4, use the walking trolley 12 to move the molten iron receiving tank 1 out of the pouring station, and use hook 1 3 to send the molten iron receiving tank 1 to the next process.

[0058] Example 7

[0059] In order to prove that the jet induced dust removal device is effective, this embodiment uses numerical simulation to compare and analyze the control effect of the jet fan with / without the jet fan on the high-temperature flue gas. Different induced ratios have different control effects on the flue gas. Therefore, a solution with better control effect is selected for analysis. Table 1 is the analysis working condition of the numerical simulation, which is as follows:

[0060] Table 1

[0061]

[0062] The boundary condition settings are shown in Table 2:

[0063] Table 2. Numerical simulation boundary condition parameters

[0064]

[0065] Compared with the case without the high-speed jet induction device, the present invention reduces the escape amount of polluted airflow and gradually reduces the concentration of smoke in the upper space of the plant. Figure 8(a) to Figure 8(b) and Figure 9(a) to Figure 9(b) It is the XOZ mid-axis plane flue gas concentration distribution cloud map and streamline diagram of working conditions 1 and 4 (the numbers in Figure 8(a) and Figure 8(b) represent the mass fraction of flue gas. The mass fraction refers to the proportion of the mass of a certain gas in the mixed gas to the total mass of the mixed gas. It is between 0 and 1. The larger the mass fraction, the higher the concentration of flue gas).

[0066] Figure 8(a) shows the smoke concentration distribution in a plant without a jet fan (corresponding to working condition 1), and Figure 8(b) shows the smoke concentration distribution in a plant with a jet fan (corresponding to working condition 4);

[0067] Figure 9(a) is the smoke flow diagram of the plant without jet fans (corresponding to working condition 1), and Figure 9(b) is the smoke flow diagram of the plant with jet fans (corresponding to working condition 4);

[0068] It can be seen from Figure 8(a) and Figure 9(a) that when no jet is added, the dust hood has limited control effect on the smoke, and a large amount of smoke escapes along the edge of the dust hood, causing a large amount of smoke to accumulate in the top space of the plant, which in turn leads to a high level of smoke concentration in this area;

[0069] As can be seen from Figure 8(b) and Figure 9(b), under the action of the high-speed jet induction device, the direction of the flue gas flow changes and deflects significantly to the side where the high-speed jet is located. In this process, the dust hood's efficiency in collecting flue gas is significantly improved, and most of the flue gas can be effectively collected by the dust hood. In addition, the flue gas concentration in the top space of the plant has dropped significantly due to the significant reduction in the amount of escape.

[0070] The dimensionless number induced ratio is used to measure the effect of induced flow volume and exhaust volume on the collection efficiency of the dust collector. The induced ratio can be expressed as:

[0071]

[0072] Where ε is the induced ejection ratio, Qj is the jet air volume, m3 / h; Qe is the dust hood exhaust volume, m3 / h.

[0073] The flue gas capture efficiency η can be expressed as:

[0074]

[0075] In the formula, ρ exh is the density of smoke at the exhaust duct, v is the wind speed in the exhaust duct, Y i is the mass fraction of flue gas at the exhaust pipe, ρ0 is the density of flue gas at the molten iron receiving tank, v0 is the emission speed of flue gas at the molten iron receiving tank, S0 is the area of ​​the molten iron receiving tank mouth, and Y0 is the mass fraction of flue gas at the molten iron receiving tank.

[0076] Fig.10 The variation law of collection efficiency with the ejection ratio is expressed by Fig.10 It can be seen that the high-temperature flue gas capture efficiency of the high-speed jet-induced dumping process high-temperature flue gas capture device shows a trend of first increasing and then decreasing with the increase of the injection ratio. When the injection ratio is 0.17, the dust removal system has the best control effect on high-temperature flue gas. When the injection ratio is greater than 0.17, due to the excessive jet air volume, part of the airflow is sucked into the dust hood, so the capture efficiency will decrease.

Claims

1. A high-temperature flue gas capture device based on high-speed jet-induced dumping process, characterized in that: The invention comprises a molten iron receiving tank (1), a dust hood (4) is arranged directly above the molten iron receiving tank (1), the dust hood (4) is connected to one end of an exhaust duct (6), an electric regulating valve (5) is arranged on the exhaust duct (6), a molten iron dumping tank (2) is arranged obliquely above one side of the molten iron receiving tank (1), an industrial camera (8) is arranged obliquely above the other side of the molten iron receiving tank (1), and a jet fan (10) is arranged between the industrial camera (8) and the molten iron receiving tank (1).

2. The high-temperature smoke capture device based on high-speed jet induction in the dumping process according to claim 1 is characterized in that: The molten iron pouring tank (2) is moved to the pouring station via a hook (3).

3. The high-temperature smoke capture device based on high-speed jet induction in the dumping process according to claim 1 is characterized in that: A filter screen (15) is provided at the air intake port (14) of the jet fan (10).

4. The high-temperature smoke capture device based on high-speed jet induction in the dumping process according to claim 3 is characterized in that: A flow equalizing device is provided at the air outlet (19) of the jet fan (10).

5. The high-temperature smoke capture device based on high-speed jet induction in the dumping process according to claim 4 is characterized in that: The flow balancing device comprises a first layer of orifice plates (16), a second layer of orifice plates (17) and a honeycomb plate (18) which are arranged in sequence, and the first layer of orifice plates (16) is arranged relatively close to the inner side of the air outlet (19).

6. The high-temperature smoke capture device for dumping process based on high-speed jet induction according to claim 5 is characterized in that: The first layer of orifice plates (16) has a uniform aperture, while the second layer of orifice plates (17) has a non-uniform aperture, with the aperture being larger on the side close to the volute of the jet fan (10) and smaller on the side away from the volute of the jet fan (10).

7. The high-temperature smoke capture device of the dumping process based on high-speed jet induction according to claim 6 is characterized in that: The honeycomb plate (18) is a hexagonal honeycomb body.

8. The high-temperature smoke capture device for dumping process based on high-speed jet induction according to claim 6 is characterized in that: The dust hood (4) and the exhaust duct (6) should be provided with a fireproof and high temperature resistant flexible sealing member at the interface.

9. The high-temperature smoke capture device based on high-speed jet induction in the dumping process according to claim 6 is characterized in that: The other end of the exhaust duct (6) is provided with a dust removal bellows.

10. A high-temperature flue gas capture method based on a high-speed jet-induced dumping process, characterized in that: Specifically, the process includes the following steps: when the molten iron pouring operation is performed, the molten iron receiving tank (1) is transported to the molten iron pouring station by a traveling trolley (12), and the molten iron receiving tank (1) is placed directly below the dust removal hood (4); a molten iron pouring tank (2) filled with molten iron is lifted to the pouring station by a hook 1 (3), and the molten iron pouring tank (2) is lifted to a predetermined height; the molten iron pouring tank (2) is controlled to pour the molten iron into the molten iron receiving tank (1) fixed on the traveling trolley (12) by lifting and lowering a hook 2 (13); the molten iron collides with the wall of the molten iron pouring tank (2) to generate smoke, and at this time, the jet fan (10) is turned on, and the negative pressure generated by the jet fan (10) during the jet flow is used to induce the smoke to deflect, and then the smoke is captured by the dust removal hood (4).

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