A method and apparatus for producing sintered ore using alternating top and bottom ventilation

Abstract

A method for producing sintered ore using alternating top-bottom ventilation includes the following steps: 1) feeding the sintering mixture onto a sintering trolley and igniting it for sintering; 2) when the sintering trolley enters the ventilation zone, air is drawn into the sintering material layer using a periodic alternating top-bottom ventilation pattern, and the high-temperature combustion zone gradually moves downwards. When the sintering trolley carrying the sintering mixture reaches the tail of the machine, the high-temperature combustion zone moves from the surface to the bottom layer, completing the sintering process. Using the periodic alternating top-bottom ventilation method described in this invention for sintering ore production improves the control of the downward speed of the combustion zone, i.e., the sintering speed. Furthermore, the sintered ore already sintered in the upper part of the combustion zone will not cool rapidly due to continuous ventilation, effectively alleviating the "cold extraction" phenomenon in the sintered ore. It also allows for secondary heating of the residual carbon inside the sintering material layer, ensuring complete combustion and effectively eliminating energy waste and the problem of re-burning due to residual carbon.

Description

Technical Field

[0001] This invention relates to a method and apparatus for producing sintered ore, specifically to a method and apparatus for producing sintered ore using alternating top and bottom ventilation, belonging to the field of sintering technology. Background Technology

[0002] In the iron and steel smelting process, sintering is a crucial and core step, serving to provide high-quality, low-sulfur sinter for the blast furnace. The sintering process can be roughly divided into seven stages from start to finish: batching, mixing, charging, ignition, sintering, cooling, and granulation. Among these, the cooling stage involves recovering the waste heat of the red-hot sintered ore through heat exchange with ambient air, and using the waste gas after heat exchange to generate steam for power generation. The quality of its operation directly affects the energy efficiency of the entire sintering process.

[0003] The existing sintering process flow diagram is as follows: Figure 1 As shown: After mixing, the sintering mixture is evenly distributed onto the sintering machine trolley by a nine-roller distributor. The sintering machine trolley, filled with sintered ore, first enters the ignition furnace. The high-temperature flame inside the furnace is used to ignite the material surface, igniting the coke powder on the fuel surface and forming a high-temperature combustion zone of a certain thickness. Then, the trolley leaves the ignition furnace and enters the open ventilation area. As air is drawn into the material layer, the high-temperature combustion zone gradually moves downward. When the trolley carrying the sintered material reaches the tail of the machine, the high-temperature combustion zone has just moved from the surface to the bottom layer. At this time, the sintering process is completed. The trolley flips at the large gear at the tail of the machine to unload the sintered finished ore into the rear cooling process. The empty trolley moves back from the bottom, ready to carry out the next cycle of sintering operation. While the sintering machine is in operation, the exhaust duct located at the bottom of the trolley draws the flue gas from the combustion zone within the material layer into the main flue. All the flue gas drawn from the exhaust duct eventually converges and is sent from the machine head to the main electrostatic precipitator, desulfurization and denitrification processes, and is finally discharged through the main chimney.

[0004] The reaction of the material layer inside the sintering machine trolley is as follows: Figure 2 As shown: After the material is laid and ignited, a uniform high-temperature zone is formed on the surface of the sintering material layer. As the lower ventilation proceeds, when the sintering machine trolley reaches the tail position, the high-temperature zone has already descended from the upper part of the material layer to the bottom of the material layer. During the operation, the upper part of the high-temperature zone is filled with sintered finished ore, and the lower part is filled with mixed material to be sintered.

[0005] With the increasing national requirements for energy conservation and emission reduction in the steel industry, the precision of sintering processes has become increasingly stringent. Currently, the sintering process has the following deficiencies in the ventilation stage:

[0006] 1. Poor control of sintering speed: Since the existing sintering process is mainly based on the exhaust operation, it has limitations in controlling the sintering speed (i.e. the downward speed of the combustion zone). It relies on the opening and closing of valves on the exhaust flue to control the speed, which can easily lead to incomplete combustion due to reduced exhaust volume. In addition, the sintering exhaust flues are all connected in series. If the valves of some flues are closed slightly, the exhaust volume of other flues will increase uncontrollably, which will lead to poor sintering production.

[0007] 2. Excessive cooling rate of sintered ore: As above, since the existing sintering process mainly relies on ventilation operation and the sintering speed cannot be precisely controlled, it is easy to cause insufficient residence time of the combustion zone in the sintered ore. The sintered ore is exposed to a large amount of cold air at high temperature, resulting in excessive cooling rate and "cold extraction". This causes a significant increase in the return rate of the sintering process and a low yield.

[0008] 3. Excessive residual carbon in the sintering bed: Due to poor speed control in the existing sintering process, some large coke particles in the bed are forced to come into contact with the cold air drawn into the bed and are cooled before they are fully burned. This results in residual carbon in the sintering bed reaching more than 3%, and even as high as 10% in the upper bed area. This causes serious energy waste. Moreover, after entering the downstream cooling process, the residual carbon is easily mixed with the red-hot ore and can easily cause secondary combustion. This makes the cooling process inefficient and may even cause accidents where large pieces of material generated during secondary sintering get stuck in the feed chute due to secondary combustion. Summary of the Invention

[0009] To address the shortcomings of the existing technology, this invention proposes a method and apparatus for producing sintered ore using alternating top and bottom ventilation. In this invention, the existing continuous bottom ventilation mode is replaced with a periodic alternating top and bottom ventilation mode. That is, after the sintering material layer undergoes a certain period of bottom ventilation, it is then subjected to a periodic top ventilation. This periodic alternating ventilation allows the combustion zone to periodically remain within the sintering material layer, or even move upwards a short distance. Therefore, using the periodic alternating top and bottom ventilation method described in this invention for sintering production improves the control of the downward speed of the combustion zone, i.e., the sintering speed. Furthermore, the sintered ore at the top of the combustion zone will not cool rapidly due to continuous ventilation, effectively alleviating the "cold extraction" phenomenon in the sintered ore. It also allows for secondary heating of the residual carbon inside the sintering material layer, ensuring its complete combustion and effectively eliminating energy waste and the problem of re-burning due to residual carbon.

[0010] According to a first embodiment of the present invention, a method for producing sintered ore by alternating vertical and horizontal ventilation is provided.

[0011] A method for producing sintered ore using alternating top and bottom ventilation, the method comprising the following steps:

[0012] 1) Place the sintering mixture onto the sintering trolley and ignite for sintering.

[0013] 2) When the sintering trolley enters the exhaust area, it uses a periodic alternating up and down exhaust mode to draw air into the sintering material layer. The high-temperature combustion zone gradually moves downward. When the sintering trolley carries the sintering mixture from the head to the tail of the machine, the high-temperature combustion zone moves from the surface to the bottom layer, and sintering is completed.

[0014] In this invention, the periodic alternating up and down ventilation mode described in step 2) further includes a step of calculating the up ventilation intensity, specifically including the following sub-steps:

[0015] 201) Detect the particle size, basicity, moisture content, and feed rate of the sintering mixture to calculate the theoretical sintering rate suitable for the current sintering layer. Specifically:

[0016]

[0017] In the formula: V 理论 η is the theoretical sintering rate. η is the basicity of the sintering mixture. λ is the moisture content of the sintering mixture. G is the feed rate of the sintering mixture. d is the average particle size of the sintering mixture. a is the sintering rate coefficient, ranging from 0.3 to 0.9.

[0018] 202) Based on the cross-sectional condition of the sintered ore layer at the tail of the sintering machine, estimate the current actual sintering rate V. 实际 .

[0019] 203) Combining the theoretical sintering rate and the actual sintering rate, calculate the required upper exhaust intensity for the sintering material layer at this point. Specifically:

[0020]

[0021] In the formula: ψ is the required upper exhaust intensity of the sintering material layer. b is the exhaust coefficient, with a value ranging from 0.1 to 1.

[0022] Adjust the upper exhaust intensity according to formula (2) so that the actual sintering speed is consistent with the theoretical sintering speed.

[0023] In this invention, in sub-step 203), the upper exhaust air volume and pressure of the first half of the sintering machine, and the upper exhaust air volume and pressure of the second half of the sintering machine are calculated based on the required upper exhaust air intensity of the current sintering material layer, specifically as follows:

[0024]

[0025]

[0026]

[0027]

[0028] In the formula: W 前 P represents the upward exhaust air volume of the first half of the sintering machine. 前 This refers to the upward exhaust air pressure in the first half of the sintering machine. (W) 后 P represents the upward exhaust air volume of the latter half of the sintering machine. 后 This refers to the upward exhaust air pressure in the first half of the sintering machine. β 风量 This is the intensity airflow coefficient, with a value ranging from 1000 to 5000. β 风压 δ represents the strength wind pressure coefficient, with a value ranging from 10,000 to 30,000. δ represents the porosity of the sintered material layer, with a value ranging from 0.1 to 0.3.

[0029] In this invention, in sub-step 203), the required range of upward exhaust positions for the sintering machine is calculated based on the required upward exhaust intensity of the current sintering material layer. Specifically:

[0030]

[0031]

[0032]

[0033] H 起n =H 起1 +(n-1)×H 间隔 ……(10).

[0034] In the formula: L is the length of the sintering machine. V 机 This refers to the sintering machine speed. In the aforementioned periodic alternating up and down exhaust mode: H 起1 H is the distance from the starting point of the upward exhaust fan on the sintering machine to the head of the sintering machine. 持续 H represents the continuous distance of the upward exhaust fan in each section of the sintering machine. 间隔 H is the distance between the starting points of the exhaust systems on two adjacent sections of the sintering machine. 起n This is the distance from the starting point of the nth segment of the sintering machine's exhaust fan to the machine head.

[0035] According to a second embodiment of the present invention, an alternating top and bottom ventilation sintering ore production apparatus is provided.

[0036] An alternating top-bottom exhaust sintering ore production apparatus, or an alternating top-bottom exhaust sintering ore production apparatus for the method described in the first embodiment, is disclosed. The apparatus includes a sintering trolley, a lower exhaust system, and an upper exhaust system. The lower exhaust system includes multiple air boxes located below the sintering trolley, air box branch pipes connected to each air box, and a lower exhaust flue located below the air box branch pipes. The air outlets of each air box are connected to the lower exhaust flue via their respective air box branch pipes. The upper exhaust system includes multiple upper exhaust hoods located above the sintering trolley, upper exhaust flue pipes connected to each upper exhaust hood, and an upper exhaust flue located above the upper exhaust flue pipes. The air outlets of each upper exhaust hood are connected to the upper exhaust flue via their respective upper exhaust flue pipes.

[0037] In this invention, the upper exhaust hood of the upper exhaust system and the air box of the lower exhaust system are arranged alternately on the upper and lower parts of the sintering trolley, and the upper exhaust hood is set with respect to the gap between the adjacent air boxes below.

[0038] Preferably, the multiple upper exhaust hoods of the upper exhaust system are divided into multiple upper exhaust sections according to the running direction of the sintering trolley. Preferably, each upper exhaust section has the same length, and the spacing between two adjacent upper exhaust sections is also the same.

[0039] In this invention, multiple upper exhaust hoods of the upper exhaust system and multiple air boxes of the lower exhaust system are symmetrically arranged on the upper and lower parts of the sintering trolley. Each upper exhaust hood is connected to an upper exhaust duct pipe via an upper exhaust gas exchange pipe. Each air box is connected to a lower exhaust gas exchange pipe via a corresponding air box branch pipe.

[0040] As a preferred option, each upper exhaust and air exchange pipe is equipped with an upper exhaust and air exchange valve.

[0041] As a preferred option, each downdraft exhaust duct is equipped with a downdraft exhaust valve.

[0042] As a preferred option, each upward exhaust flue pipe is equipped with an upward exhaust flue valve.

[0043] As a preferred option, each air box branch pipe is equipped with a downward exhaust flue valve.

[0044] In this invention, the device also includes a tail section visual recognition device located downstream of the sintering machine tail.

[0045] In existing technologies, the sintering process primarily relies on downward ventilation, which limits the control of sintering speed (i.e., the downward speed of the combustion zone). This results in poor sintering speed control and consequently, poor sinter production. Poor sintering speed control easily leads to insufficient residence time of the combustion zone at the already sintered ore location. The sintered ore, suddenly exposed to a large amount of cold air at high temperatures, cools too rapidly, causing "cold extraction," which significantly increases the return rate of the sintering process and results in a low yield. Furthermore, poor sintering speed control also causes large coke particles in the sintering bed to be forced into contact with the cold air before complete combustion, leading to increased residual carbon and significant energy waste. Moreover, this residual carbon, when entering the downstream cooling process, is highly susceptible to secondary combustion due to mixing with the red-hot ore, severely impacting the efficiency of the cooling process.

[0046] To address the aforementioned shortcomings, this invention proposes a method for producing sintered ore using alternating top and bottom ventilation. This method replaces the existing continuous bottom ventilation mode with a periodic alternating top and bottom ventilation mode. Specifically, after the sintering material layer undergoes a certain period of bottom ventilation, it is then subjected to a periodic top ventilation. This periodic alternating top and bottom ventilation allows the combustion zone to periodically remain within the sintering material layer and even shift upwards a short distance (e.g., ...). Figure 11 (As shown). Therefore, using the periodic alternating up-and-down ventilation method described in this invention for sinter production can improve the control effect on the downward speed of the combustion zone, i.e., the sintering speed, and improve the production efficiency of sinter. Moreover, the sinter that has already been sintered in the upper part of the combustion zone will not cool down rapidly due to continuous ventilation, effectively alleviating the "cold extraction" phenomenon of the sintered ore, and the return rate of the sintering process will also be greatly reduced. It can also allow large particles of coke powder that have not been completely burned in the sintering material layer to have enough time to contact the high-temperature combustion zone or the sub-high-temperature zone, thereby effectively reducing the amount of residual carbon in the sintering material layer and eliminating the energy waste and cooling re-burning problems caused by residual carbon.

[0047] As a preferred embodiment, in the periodic alternating upper and lower exhaust mode described in this invention, the required upper exhaust intensity for the current sintering material layer is specifically calculated and adjusted in real time to achieve precise control of the sintering speed. First, the particle size, alkalinity, moisture content, and feed amount of the sintering mixture are detected and obtained. The theoretical sintering speed suitable for the current sintering material layer is calculated using formula (1). Then, based on the cross-sectional condition of the sintering ore layer at the tail of the sintering machine, the actual sintering speed is predicted (based on the height position of the red layer on the cross-section; if the actual sintering speed matches the design speed, the cross-section seen at the tail of the machine shows that the red layer is basically at the bottom of the material layer, and sintering is complete at this time). Finally, combining the theoretical sintering speed and the actual sintering speed, the required upper exhaust intensity for the current sintering material layer is calculated using formula (2) and adjusted in real time to ensure that the actual sintering speed is consistent with the theoretical sintering speed, that is, to ensure that the difference between the real-time sintering speed and the theoretical sintering speed is always kept within a reasonable small range, thereby achieving precise control of the sintering speed. The formula is as follows:

[0048]

[0049]

[0050] Generally, the theoretical sintering rate is the optimal or near-optimal sintering rate. As can be seen from formula (2), when there is a difference between the actual sintering rate obtained from the cross-sectional state of the tail ore layer and the theoretical sintering rate calculated from the original working conditions, it is necessary to calculate and adjust the upper exhaust intensity required at this time to control the sintering rate; while when the actual sintering rate is consistent with the theoretical sintering rate (i.e. there is no difference or the difference is very small), the upper exhaust intensity required to be adjusted is 0, that is, no adjustment is needed, and the current exhaust parameters can be maintained and continued to operate.

[0051] It should be noted that when the actual sintering speed does not match the theoretical sintering speed when only the bottom exhaust is used for production, the calculated top exhaust intensity is the initial top exhaust intensity when the alternating top and bottom exhaust mode is turned on. However, when the actual sintering speed does not match the theoretical sintering speed when the alternating top and bottom exhaust mode is already in use for production, the calculated top exhaust intensity is the exhaust intensity that needs to be adjusted based on the original top exhaust intensity.

[0052] In this invention, the adjustment of the upper exhaust intensity is mainly achieved by adjusting the upper exhaust air volume and upper exhaust air pressure. Therefore, based on the calculated upper exhaust intensity, this invention proposes formulas (3)-(6) to calculate the upper exhaust air volume and upper exhaust air pressure of the first half of the sintering machine, as well as the upper exhaust air volume and upper exhaust air pressure of the second half of the sintering machine, according to the upper exhaust intensity. It should be noted that, because there is a special phenomenon called the over-wet layer during the sintering process, the evaporated moisture will be carried to the lower part under the action of exhaust and gravity, and then condensation will occur in a certain lower unit, resulting in a humid high pressure resistance in that unit. As sintering proceeds, the over-wet layer will eventually disappear. After the over-wet layer disappears, the resistance of the sintering downward exhaust will be smaller, so the upper exhaust intensity should be increased accordingly. Therefore, this application uses the disappearance of the over-wet layer as the node to divide the sintering machine into the first and second halves, and controls them separately. To further improve the precision of control, this invention also proposes formulas (7)-(10) to calculate the range of locations on the sintering machine that require upper exhaust based on the upper exhaust intensity. The formulas are as follows:

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060] H 起n =H 起1 +(n-1)×H 间隔 ……(10).

[0061] This application adopts a periodic alternating upper and lower exhaust mode for exhaust sintering, with upper and lower exhaust alternating. Therefore, the exhaust area from downstream of the ignition furnace to the sintering endpoint includes multiple upper exhaust areas. During production, the starting position of the upper exhaust on the sintering machine (i.e., the distance from the starting position of the upper exhaust on the sintering machine to the head of the sintering machine), the duration of each upper exhaust area, the interval between the starting points of two adjacent upper exhaust areas, and the starting position of the nth upper exhaust area are calculated based on the calculated upper exhaust intensity and multi-condition parameters using the above formulas (7)-(10). At the same time, the upper exhaust air volume and upper exhaust air pressure of the first half of the sintering machine, and the upper exhaust air volume and upper exhaust air pressure of the second half of the sintering machine are calculated based on the upper exhaust intensity using the above formulas (3)-(6). Then, the upper exhaust position range and the corresponding upper exhaust air volume and upper exhaust air pressure are precisely adjusted according to the calculated upper exhaust position range, so that the actual sintering speed is consistent with the theoretical sintering speed, and the sintering speed is accurately controllable.

[0062] This invention also proposes an apparatus for the aforementioned alternating upper and lower exhaust sintering production method. In this invention, the apparatus includes a sintering trolley, a lower exhaust system, and an upper exhaust system. Since existing sintering processes primarily rely on lower exhaust operations, the lower exhaust system includes multiple air boxes located at the bottom of the sintering trolley, air box branch pipes connected to each air box, and a main lower exhaust flue located below the air box branch pipes. Correspondingly, the upper exhaust system added in this invention includes multiple upper exhaust hoods located on the top of the sintering trolley (with the upper exhaust hoods softly sealed to the sintering trolley), upper exhaust flue pipes connected to each upper exhaust hood, and a main upper exhaust flue located above the upper exhaust flue pipes.

[0063] In this application, the upper exhaust system includes two configuration schemes. In the first scheme, the upper exhaust hood located on the upper part of the sintering trolley and the air box located on the lower part of the sintering trolley are arranged alternately, as shown below. Figure 3As shown, the upper exhaust hood is positioned in the gap between adjacent lower air boxes. In this scheme, once the location requiring upper exhaust is determined, the bottom exhaust duct (i.e., air box) at the corresponding location is changed to a top exhaust duct (i.e., upper exhaust hood), while the original lower air box configuration is retained in other locations. Since this invention adopts a periodic alternating upper and lower exhaust mode, the multiple upper exhaust hoods of the upper exhaust system are divided into multiple upper exhaust sections according to the running direction of the sintering trolley. To facilitate the control of the upper exhaust intensity, each upper exhaust section can be set to have the same length, and the spacing between two adjacent upper exhaust sections can also be the same. Preferably, an upper exhaust duct valve is also provided on the upper exhaust duct pipe, which functions to adjust the upper exhaust air volume and air pressure of the corresponding upper exhaust duct pipe in real time. Once the required air volume and air pressure of the upper exhaust fan in the first and second halves of the sintering machine are determined, the valve opening of the upper exhaust fan valve at the corresponding position can be adjusted to control the sintering speed, ultimately making the actual sintering speed consistent with the theoretical sintering speed.

[0064] In the second scheme, multiple upper exhaust hoods located on the upper part of the sintering trolley and multiple air boxes located on the lower part of the sintering trolley are arranged symmetrically, such as... Figure 6 As shown in the diagram. In this scheme, since the exhaust area from downstream of the ignition furnace to the sintering endpoint is equipped with an upper exhaust hood, the position range of the upper exhaust can be adjusted in real time according to the actual sintering conditions, offering greater flexibility. It should be noted that because the upper exhaust hood and the lower wind box are symmetrically arranged, an upper exhaust gas exchange pipe needs to be connected to the upper exhaust flue pipe corresponding to the upper exhaust hood, and a lower exhaust gas exchange pipe needs to be connected to the wind box branch pipe corresponding to the wind box, thus enabling smooth upper or lower exhaust. For ease of control, an upper exhaust flue valve is installed on the upper exhaust flue pipe, a lower exhaust flue valve is installed on the wind box branch pipe, an upper exhaust gas exchange valve is installed on the upper exhaust gas exchange pipe, and a lower exhaust gas exchange valve is installed on the lower exhaust gas exchange pipe. When upper exhaust is required, the corresponding upper exhaust flue valve and lower exhaust gas exchange valve are opened, while the corresponding lower exhaust flue valve and upper exhaust gas exchange valve are closed simultaneously. Once the location range requiring upward ventilation is determined, the opening and closing of the valves at the corresponding locations are adjusted. Based on the required upward ventilation volume and pressure for the first and second halves of the sintering machine, the valve opening of the corresponding upward ventilation flue valve is adjusted to control the sintering speed, ultimately ensuring that the actual sintering speed matches the theoretical sintering speed.

[0065] The present invention also adds a tail section visual recognition device downstream of the sintering machine tail. The tail section visual recognition device can be used to observe the cross-sectional state of the sintered ore layer at the tail in real time, thereby intelligently calculating the current sintering speed of the sintering machine.

[0066] All formulas in this invention were obtained by the inventor based on experimental and engineering applications. All calculations are calculated by substituting the converted values ​​into the formulas according to the prescribed units (after converting the units, only the values ​​are substituted into the formulas, not the units; the units are only used to adjust the size of the values).

[0067] Compared with the prior art, the present invention has the following beneficial technical effects:

[0068] 1. Improved control over sintering speed: This invention changes the existing continuous bottom ventilation mode to a periodic alternating up and down ventilation mode. That is, after the sintering material layer undergoes a certain period of down ventilation, it undergoes an up ventilation. This periodic alternating up and down ventilation allows the combustion zone to periodically stay or even move up a small distance within the sintering material layer, thereby improving the control over sintering speed and thus enhancing the production efficiency of sintered ore.

[0069] 2. Precise control of sintering speed: Under the technology of this invention, the system can observe the sintering speed in real time through the visual recognition device of the tail section and compare it with the theoretical sintering speed. If there is a difference, the sintering speed of the current sintering machine will be adjusted and controlled immediately through the upper exhaust system, so that the difference between the real-time sintering speed and the theoretical sintering speed is always kept within a certain small range, and the sintering speed is precisely controllable.

[0070] 3. Effectively prevents rapid cooling of sintered ore: Under the technology of this invention, the combustion zone in the sintering machine material layer is affected by the upward suction effect every once in a while, stopping its downward movement or floating upward at a certain position. This prevents the sintered ore that has been sintered in the upper part from cooling rapidly due to continuous suction, effectively alleviating the "cold extraction" phenomenon of sintered ore, and significantly reducing the return rate of ore in the sintering process.

[0071] 4. Reduces residual carbon in the sintering bed: Under the technology of this invention, the combustion zone in the sintering machine bed is affected by the upward suction effect every once in a while, stopping its downward movement or floating upward to a certain position. In this way, large particles of coke powder that have not been burned in the sintering bed will have enough time to contact the high-temperature combustion zone or the sub-high-temperature zone, thereby effectively reducing the amount of residual carbon in the sintering bed and eliminating the energy waste and cooling re-burning problems caused by residual carbon.

[0072] In summary, the new technology of this invention effectively solves the defects and shortcomings of the prior art without bringing any other negative impacts, and has low investment and operating costs, and can be expected to have high application value in the future market. Attached Figure Description

[0073] Figure 1 A simplified diagram of the existing sintering process;

[0074] Figure 2 This is a schematic diagram of the high-temperature combustion zone in the existing sintering process;

[0075] Figure 3 This is a schematic diagram of the structure of an alternating top and bottom ventilation sintering ore production device according to the present invention;

[0076] Figure 4 for Figure 3 Schematic diagram of the upper and middle exhaust system;

[0077] Figure 5 for Figure 3 Partial side view of the upper and lower exhaust systems;

[0078] Figure 6 This is a schematic diagram of another type of alternating top and bottom ventilation sintering ore production device according to the present invention.

[0079] Figure 7 for Figure 6 Schematic diagram of the upper and middle exhaust system;

[0080] Figure 8 for Figure 6 Schematic diagram of the middle and lower exhaust system;

[0081] Figure 9 This is a schematic diagram of the sintering material layer being subjected to downward exhaust in this invention;

[0082] Figure 10 This is a schematic diagram of the sintering material layer being subjected to upward exhaust in this invention;

[0083] Figure 11 This is a schematic diagram of the high-temperature combustion zone when using the process of the present invention;

[0084] Figure 12 This is a flowchart of a method for producing sintered ore using alternating top and bottom ventilation according to the present invention;

[0085] Figure 13 This is a flowchart of another method for producing sintered ore using alternating top and bottom ventilation according to the present invention.

[0086] Figure label:

[0087] 1: Sintering trolley; 2: Lower exhaust system; 201: Air box; 202: Air box branch pipe; 203: Lower exhaust main flue; 204: Lower exhaust air exchange pipe; 205: Lower exhaust air exchange valve; 206: Lower exhaust flue valve; 3: Upper exhaust system; 301: Upper exhaust fume hood; 302: Upper exhaust flue pipe; 303: Upper exhaust main flue; 304: Upper exhaust air exchange pipe; 305: Upper exhaust air exchange valve; 306: Upper exhaust flue valve; 4: Tail section visual recognition device. Detailed Implementation

[0088] The technical solution of the present invention will be illustrated below with examples. The scope of protection sought by the present invention includes, but is not limited to, the following embodiments.

[0089] According to a second embodiment of the present invention, an alternating top and bottom ventilation sintering ore production apparatus is provided.

[0090] An alternating top and bottom ventilation sintering ore production apparatus, or an alternating top and bottom ventilation sintering ore production apparatus for the method described in the first embodiment, is disclosed. The apparatus includes a sintering trolley 1, a lower ventilation system 2, and an upper ventilation system 3. The lower ventilation system 2 includes multiple air boxes 201 disposed below the sintering trolley 1, air box branch pipes 202 connected to each air box 201, and a lower ventilation flue 203 disposed below the air box branch pipes 202. The air outlets of each air box 201 are connected to the lower ventilation flue 203 via their respective air box branch pipes 202. The upper exhaust system 3 includes multiple upper exhaust hoods 301 installed on the upper part of the sintering trolley 1, upper exhaust flue pipes 302 connected to each upper exhaust hood 301, and an upper exhaust main flue 303 installed above the upper exhaust flue pipes 302. The air outlets of each upper exhaust hood 301 are connected to the upper exhaust main flue 303 through their respective upper exhaust flue pipes 302.

[0091] In this invention, the upper exhaust hood 301 of the upper exhaust system 3 and the air box 201 of the lower exhaust system 2 are arranged in an alternating manner on the upper and lower parts of the sintering trolley 1, and the upper exhaust hood 301 is set to correspond to the gap between the adjacent air boxes 201 below.

[0092] Preferably, the plurality of upper exhaust hoods 301 of the upper exhaust system 3 are divided into multiple upper exhaust sections according to the running direction of the sintering trolley 1. Preferably, each upper exhaust section has the same length, and the spacing between two adjacent upper exhaust sections is also the same.

[0093] In this invention, multiple upper exhaust hoods 301 of the upper exhaust system 3 and multiple air boxes 201 of the lower exhaust system 2 are symmetrically arranged on the upper and lower parts of the sintering trolley 1. Each upper exhaust hood 301 is connected to an upper exhaust flue pipe 304 via an upper exhaust air exchange pipe 304. Each air box 201 is connected to a lower exhaust air exchange pipe 204 via an air box branch pipe 202.

[0094] As a preferred option, each upper exhaust and air exchange pipe 304 is equipped with an upper exhaust and air exchange valve 305.

[0095] As a preferred option, each downdraft exhaust duct 204 is equipped with a downdraft exhaust valve 205.

[0096] Preferably, each upward exhaust flue pipe 302 is equipped with an upward exhaust flue valve 306.

[0097] As a preferred option, each air box branch pipe 202 is equipped with a downward exhaust flue valve 206.

[0098] In this invention, the device also includes a tail section visual recognition device 4 located downstream of the sintering machine tail.

[0099] Example 1

[0100] An alternating upper and lower exhaust sintering ore production device includes a sintering trolley 1, a lower exhaust system 2, and an upper exhaust system 3. The lower exhaust system 2 includes multiple air boxes 201 located below the sintering trolley 1, air box branch pipes 202 connected to each air box 201, and a lower exhaust flue 203 located below the air box branch pipes 202. The air outlets of each air box 201 are connected to the lower exhaust flue 203 via their respective air box branch pipes 202. The upper exhaust system 3 includes multiple upper exhaust hoods 301 located above the sintering trolley 1, upper exhaust flue pipes 302 connected to each upper exhaust hood 301, and an upper exhaust flue 303 located above the upper exhaust flue pipes 302. The air outlets of each upper exhaust hood 301 are connected to the upper exhaust flue 303 via their respective upper exhaust flue pipes 302.

[0101] Example 2

[0102] like Figure 3-5 As shown, Embodiment 1 is repeated, except that the upper exhaust hood 301 of the upper exhaust system 3 and the air box 201 of the lower exhaust system 2 are arranged in an alternating manner on the upper and lower parts of the sintering trolley 1, and the upper exhaust hood 301 is set with a gap between the adjacent air box 201 below.

[0103] Example 3

[0104] Repeat Example 2, except that, according to the running direction of the sintering trolley 1, the multiple upper exhaust hoods 301 of the upper exhaust system 3 are divided into multiple upper exhaust sections.

[0105] Example 4

[0106] Repeat Example 3, except that the length of each upper exhaust section is the same, and the spacing between two adjacent upper exhaust sections is also the same.

[0107] Example 5

[0108] Repeat Example 4, except that each upper exhaust flue pipe 302 is equipped with an upper exhaust flue valve 306.

[0109] Example 6

[0110] Repeat Example 5, except that each air box branch pipe 202 is equipped with a downward exhaust flue valve 206.

[0111] Example 7

[0112] The embodiment 6 is repeated, except that the device also includes a tail section visual recognition device 4 located downstream of the sintering machine tail.

[0113] Example 8

[0114] like Figure 6-8 As shown, Embodiment 1 is repeated, except that the multiple upper exhaust hoods 301 of the upper exhaust system 3 and the multiple air boxes 201 of the lower exhaust system 2 are symmetrically arranged at the upper and lower parts of the sintering trolley 1. Each upper exhaust hood 301 is connected to an upper exhaust flue pipe 304 via an upper exhaust air exchange pipe 304. Each air box 201 is connected to a lower exhaust air exchange pipe 204 via an air box branch pipe 202.

[0115] Example 9

[0116] Example 8 is repeated, except that each upper exhaust duct 304 is equipped with an upper exhaust duct valve 305. Each lower exhaust duct 204 is equipped with a lower exhaust duct valve 205.

[0117] Example 10

[0118] Example 9 is repeated, except that each upper exhaust flue pipe 302 is equipped with an upper exhaust flue valve 306. Each air box branch pipe 202 is equipped with a lower exhaust flue valve 206.

[0119] Example 11

[0120] The embodiment 10 is repeated, except that the device also includes a tail section visual recognition device 4 located downstream of the sintering machine tail.

[0121] Example 12

[0122] A method for producing sintered ore using alternating top and bottom ventilation, the method comprising the following steps:

[0123] 1) Place the sintering mixture onto the sintering trolley and ignite for sintering.

[0124] 2) When the sintering trolley enters the exhaust area, it uses a periodic alternating up and down exhaust mode to draw air into the sintering material layer. The high-temperature combustion zone gradually moves downward. When the sintering trolley carries the sintering mixture from the head to the tail of the machine, the high-temperature combustion zone moves from the surface to the bottom layer, and sintering is completed.

[0125] Example 13

[0126] like Figure 12 As shown, a method for producing sintered ore using alternating top and bottom ventilation, employing the apparatus described in Example 7, includes the following steps:

[0127] 1) Place the sintering mixture onto the sintering trolley and ignite for sintering.

[0128] 2) When the sintering trolley enters the exhaust area, it uses a periodic alternating up and down exhaust mode to draw air into the sintering material layer. The high-temperature combustion zone gradually moves downward. When the sintering trolley carries the sintering mixture from the head to the tail of the machine, the high-temperature combustion zone moves from the surface to the bottom layer, and sintering is completed.

[0129] The periodic alternating up and down ventilation mode described in step 2) further includes a step of calculating the up ventilation intensity, specifically including the following sub-steps:

[0130] 201) Detect the particle size, basicity, moisture content, and feed rate of the sintering mixture to calculate the theoretical sintering rate suitable for the current sintering layer. Specifically:

[0131]

[0132] In the formula: V 理论 η is the theoretical sintering rate. η is the basicity of the sintering mixture, η = 2. λ is the moisture content of the sintering mixture, λ = 0.07. G is the feed rate of the sintering mixture, G = 2.8 t / h. d is the average particle size of the sintering mixture, d = 3.5 mm. a is the sintering rate coefficient, a = 0.9.

[0133] 202) Based on the cross-sectional condition of the sintered ore layer at the tail of the sintering machine, estimate the current actual sintering rate V. 实际 =0.3mm / s.

[0134] 203) Combining the theoretical sintering rate and the actual sintering rate, calculate the required upper exhaust intensity for the sintering material layer at this point. Specifically:

[0135]

[0136] In the formula: ψ is the required upper exhaust intensity of the sintering material layer. b is the exhaust coefficient, b = 0.9.

[0137] In sub-step 203), the upper exhaust air volume and pressure of the first half of the sintering machine, as well as the upper exhaust air volume and pressure of the second half of the sintering machine, are calculated based on the required upper exhaust air intensity of the current sintering material layer. Specifically:

[0138]

[0139]

[0140]

[0141]

[0142] In the formula: W 前 P represents the upward exhaust air volume of the first half of the sintering machine.前 This refers to the upward exhaust air pressure in the first half of the sintering machine. (W) 后 P represents the upward exhaust air volume of the latter half of the sintering machine. 后 This refers to the upward exhaust air pressure in the first half of the sintering machine. β 风量 β is the intensity air volume coefficient. 风量 =2000. β 风压 β is the intensity wind pressure coefficient. 风压 =30000. δ is the porosity of the sintered material layer, δ=0.3.

[0143] Based on the calculated air volume and pressure of the upper exhaust fan in the first half of the sintering machine, and the air volume and pressure of the upper exhaust fan in the second half of the sintering machine, adjust the valve opening of the upper exhaust fan valve at the corresponding position to make the actual sintering speed consistent with the theoretical sintering speed.

[0144] Example 14

[0145] like Figure 13 As shown, a method for producing sintered ore using alternating top and bottom ventilation, employing the apparatus described in Example 11, includes the following steps:

[0146] 1) Place the sintering mixture onto the sintering trolley and ignite for sintering.

[0147] 2) When the sintering trolley enters the exhaust area, it uses a periodic alternating up and down exhaust mode to draw air into the sintering material layer. The high-temperature combustion zone gradually moves downward. When the sintering trolley carries the sintering mixture from the head to the tail of the machine, the high-temperature combustion zone moves from the surface to the bottom layer, and sintering is completed.

[0148] The periodic alternating up and down ventilation mode described in step 2) further includes a step of calculating the up ventilation intensity, specifically including the following sub-steps:

[0149] 201) Detect the particle size, basicity, moisture content, and feed rate of the sintering mixture to calculate the theoretical sintering rate suitable for the current sintering layer. Specifically:

[0150]

[0151] In the formula: V 理论 η is the theoretical sintering rate. η is the basicity of the sintering mixture, η = 1.8. λ is the moisture content of the sintering mixture, λ = 0.07. G is the feed rate of the sintering mixture, G = 1.9 t / h. d is the average particle size of the sintering mixture, d = 1.5 mm. a is the sintering rate coefficient, a = 0.8.

[0152] 202) Based on the cross-sectional condition of the sintered ore layer at the tail of the sintering machine, estimate the current actual sintering rate V. 实际 =0.3mm / s.

[0153] 203) Combining the theoretical sintering rate and the actual sintering rate, calculate the required upper exhaust intensity for the sintering material layer at this point. Specifically:

[0154]

[0155] In the formula: ψ is the required upper exhaust intensity of the sintering material layer. b is the exhaust coefficient, b = 0.9.

[0156] In sub-step 203), the upper exhaust air volume and pressure of the first half of the sintering machine, as well as the upper exhaust air volume and pressure of the second half of the sintering machine, are calculated based on the required upper exhaust air intensity of the current sintering material layer. Specifically:

[0157]

[0158]

[0159]

[0160]

[0161] In the formula: W 前 P represents the upward exhaust air volume of the first half of the sintering machine. 前 This refers to the upward exhaust air pressure in the first half of the sintering machine. (W) 后 P represents the upward exhaust air volume of the latter half of the sintering machine. 后 This refers to the upward exhaust air pressure in the first half of the sintering machine. β 风量 β is the intensity air volume coefficient. 风量 =3000. β 风压 β is the intensity wind pressure coefficient. 风压 =20000. δ is the porosity of the sintered material layer, δ = 0.2.

[0162] In sub-step 203), the required range of locations for upward air extraction in the sintering machine is calculated based on the required upward air extraction intensity of the current sintering material layer. Specifically:

[0163]

[0164]

[0165]

[0166] In the formula: L is the length of the sintering machine, L = 90m. 机 V is the speed of the sintering machine. 机 =0.035m / s. d is the average particle size of the sintered mixture, d = 0.0015m. In the aforementioned periodic alternating up and down ventilation mode: H 起1H is the distance from the starting point of the upward exhaust fan on the sintering machine to the head of the sintering machine. 持续 H represents the continuous distance of the upward exhaust fan in each section of the sintering machine. 间隔 This is the distance between the starting points of the exhaust systems on two adjacent sections of the sintering machine.

[0167] Based on the calculated starting position of the upper exhaust, the duration of each upper exhaust segment, and the interval between the starting points of two adjacent upper exhaust segments, according to formulas (7)-(9), open the upper exhaust flue valve and the lower exhaust air exchange valve at the corresponding positions, and simultaneously close the lower exhaust flue valve and the upper exhaust air exchange valve at the corresponding positions. Based on the calculated upper exhaust air volume and upper exhaust air pressure of the first half of the sintering machine, as well as the upper exhaust air volume and upper exhaust air pressure of the second half of the sintering machine, according to formulas (3)-(6), adjust the valve opening of the upper exhaust flue valve at the corresponding positions to make the actual sintering speed consistent with the theoretical sintering speed.

Claims

1. A method for producing sintered ore using alternating top and bottom ventilation, the method comprising the following steps: 1) Place the sintering mixture onto the sintering trolley and ignite for sintering; 2) When the sintering trolley enters the exhaust zone, a periodic alternating up-and-down exhaust mode is used to draw air into the sintering material layer. The high-temperature combustion zone gradually moves downwards. When the sintering trolley carrying the sintering mixture reaches the tail of the machine from the head, the high-temperature combustion zone moves from the surface to the bottom layer, and sintering is completed. The periodic alternating up-and-down exhaust mode also includes a step of calculating the exhaust intensity, specifically including the following sub-steps: 201) Detect the particle size, basicity, moisture content, and feed rate of the sintering mixture to calculate the theoretical sintering rate suitable for the current sintering bed; specifically: ……(1)； In the formula: V 理论 η is the theoretical sintering rate, mm / s; η is the basicity of the sintering mixture; λ is the moisture content of the sintering mixture; G is the feed rate of the sintering mixture, t / h; d is the average particle size of the sintering mixture, mm; a is the sintering rate coefficient, ranging from 0.3 to 0.

9. 202) Based on the cross-sectional condition of the sintered ore layer at the tail of the sintering machine, estimate the current actual sintering rate V. 实际 mm / s; 203) Combining the theoretical sintering rate and the actual sintering rate, calculate the required upper exhaust intensity of the sintering material layer at this time; specifically: ……(2)； In the formula: ψ is the required upper exhaust intensity of the sintering material layer; b is the exhaust coefficient, with a value range of 0.1-1; Adjust the upper exhaust intensity according to formula (2) so that the actual sintering speed is consistent with the theoretical sintering speed.

2. The method for producing sintered ore according to claim 1, characterized in that: In sub-step 203), the upper exhaust air volume and pressure of the first half of the sintering machine, as well as the upper exhaust air volume and pressure of the second half of the sintering machine, are calculated based on the required upper exhaust air intensity of the current sintering material layer. Specifically: ……(3)； ……(4)； ……(5)； ……(6)； In the formula: W 前 The exhaust air volume of the first half of the sintering machine is in m. 3 / t;P 前 The exhaust pressure of the first half of the sintering machine is measured in Pa and W. 后 The exhaust air volume (m) for the latter half of the sintering machine. 3 / t;P 后 The exhaust pressure of the first half of the sintering machine is Pa; β 风量 The intensity air volume coefficient, with a value ranging from 1000 to 5000; β 风压 δ is the strength wind pressure coefficient, with a value range of 10000-30000; δ is the porosity of the sintered material layer, with a value range of 0.1-0.

3.

3. The method for producing sintered ore according to claim 1, characterized in that: In sub-step 203), the required range of locations for upward air extraction in the sintering machine is calculated based on the required upward air extraction intensity of the current sintering material layer. Specifically: ……(7)； ……(8)； ……(9)； ……(10)； In the formula: L is the length of the sintering machine, in meters; V 机 The sintering machine speed is [speed] m / s; in the periodic alternating up and down exhaust mode: H 起1 H is the distance, in meters, from the starting point of the upward exhaust fan on the sintering machine to the head of the sintering machine. 持续 H represents the continuous distance of the upward exhaust in each section of the sintering machine, in meters (m). 间隔 H is the distance between the starting points of the exhaust ducts on two adjacent sections of the sintering machine, in meters (m). 起n Let m be the distance from the starting point of the nth section of the sintering machine's exhaust fan to the machine head.

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