A tangential air inlet belt type roaster dust agglomeration prevention device

Abstract

This utility model belongs to the field of iron and steel smelting, specifically disclosing a tangential air intake belt roaster anti-dust nodulation device. The device includes a roaster body, a flue, an air duct, and a combustion chamber. The air duct includes a first section inclined upwards along the airflow direction, and a fourth and sixth section tangentially connected to the combustion chamber. The first section allows some dust to remain in the flue or air duct without entering the combustion chamber. Simultaneously, when the airflow enters the combustion chamber through the fourth and sixth sections, it forms a co-directional swirling flow. This co-directional swirling flow prevents dust from accumulating at the bottom of the combustion chamber, making it easier for dispersed dust to be blown into the roaster body, thus reducing nodulation. Furthermore, it improves the stability of the flame within the combustion chamber, preventing flame adhesion to the walls or uneven burning, thereby avoiding concentrated heating of the dust and further reducing nodulation. This technical solution has good anti-nodulation effects and promising industrial application prospects.

Description

Technical Field

[0001] This utility model relates to the field of iron and steel smelting technology, specifically to a tangential air intake belt roaster dust prevention device. Background Technology

[0002] Sinter and pellets are two main raw materials for blast furnace ironmaking. The pellet production process reduces pollutants and carbon emissions by 60% and 30% respectively compared to sintering. Therefore, promoting the development of pelletizing technology and increasing the proportion of pellets used in blast furnaces has become one of the important carbon reduction technologies in my country's steel industry under the "dual carbon" context. Currently, my country's pellet production has reached over 220 million tons, and the average usage of pellets in blast furnaces has increased from about 15% to 20%. In the context of optimizing blast furnace burden structure, increasing the proportion of pellets used, and reducing carbon emissions from the long process, improving the production efficiency of the pelletizing process and reducing energy consumption and carbon emissions is crucial.

[0003] When implementing high-proportion pellet blast furnace smelting, it is necessary to produce basic pellets. During the production of basic pellets, a large amount of Ca and Mg-based additives are added to adjust the basicity. The presence of these additives causes the pellets to easily pulverize during roasting, resulting in a large amount of fine powder. This fine powder is carried into the combustion chamber by the strongly compressed cooling air in the cooling section of the belt roaster and tends to accumulate at the bottom of the combustion chamber. Because the high-temperature secondary air enters the combustion chamber from the top, the burner flame in the combustion chamber is forced close to the bottom by the secondary air. Under the high-temperature baking effect of the flame, the fine powder produces ferric oxide and decomposes, thus forming nodules at the bottom of the combustion chamber. If these fine powder particles are not removed in time, the nodules will accumulate, and in severe cases, they will block the combustion chamber, making production impossible with the belt roaster. Therefore, this invention proposes a tangential air intake belt roaster dust and nodule prevention device to reduce the formation of nodules. Utility Model Content

[0004] The main purpose of this invention is to provide a tangential air intake belt roaster anti-dust nodule device to solve the problem that the combustion chamber of the existing belt roaster is prone to nodule formation, which in turn causes combustion chamber blockage.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by this utility model is as follows:

[0006] A tangentially inlet belt roaster dust prevention device includes a roaster body, a flue, air ducts, and combustion chambers. Several combustion chambers are arranged on the side of the roaster body, and the outlet of each combustion chamber is connected to the side wall of the roaster body. The top of the cooling section of the roaster body is connected to the flue, which is connected to the secondary air inlet of each combustion chamber via several air ducts.

[0007] The duct includes a first section, a fourth section, and a sixth section. The first section is inclined upward along the direction of airflow. The fourth and sixth sections are tangentially connected to the combustion chamber to introduce tangential airflow into the combustion chamber, thereby forming superimposed and enhanced co-directional swirling flows within the combustion chamber.

[0008] This design ensures that dust particles must climb along the first pipe section and are blocked by the pipe wall, making passage difficult. Some fine dust particles are retained in the flue or duct, preventing them from entering the combustion chamber and reducing dust agglomeration. The first duct section can be directly connected to the flue or connected via other pipe sections. When directly connected, some fine dust particles remain in the flue. When connected via other pipe sections, some remain in the duct. The retained fine dust particles can be removed during maintenance. Furthermore, the flue or duct is equipped with inspection ports for dust removal during maintenance.

[0009] The tangential connection of the fourth and sixth pipe sections to the combustion chamber allows the airflow to flow along the inner wall of the combustion chamber after entering, thus forming a swirling flow. The airflow entering the combustion chamber from the fourth and sixth pipe sections rotates in the same direction, such as both rotating clockwise or both rotating counterclockwise, thereby enhancing the superposition of the swirling flow. Dust can disperse everywhere after entering the combustion chamber with the airflow, avoiding accumulation in the combustion chamber. This facilitates the dust being blown into the roasting machine body by the secondary and primary air. At the same time, the swirling flow formed in the combustion chamber avoids direct blowing of the nozzle flame, which has a stabilizing effect on the nozzle flame. Compared with the direct blowing of the secondary air flame, the swirling flow can prevent the nozzle flame from sticking to the wall or burning off-center, thus avoiding concentrated heating of the dust by the flame, and further preventing dust agglomeration.

[0010] Specifically, the calciner body comprises eight sequentially connected process sections: a forced-air drying section, a forced-air drying section, a preheating section, a first-stage calcination section, a second-stage calcination section, a third-stage calcination section, a first-stage cooling section, and a second-stage cooling section. The pellets are processed sequentially through these sections. In the first-stage cooling section, cold air blown in from below the trolley exchanges heat with the high-temperature pellet bed, generating high-temperature exhaust gas at approximately 900°C. The flue connects to the top of the first-stage cooling section and transports this high-temperature exhaust gas to each combustion chamber via various ducts. This high-temperature exhaust gas not only introduces sensible heat into the combustion chambers but also acts as a combustion aid for the fuel within the combustion chambers. Depending on specific production needs and conditions, the combustion chambers can be located on one or both sides of the calciner body.

[0011] Preferably, the flue extends along the length of the roasting machine body. A plurality of combustion chambers are symmetrically arranged on both sides of the roasting machine body. A plurality of air ducts are symmetrically arranged on both sides of the flue. The number of air ducts corresponds to the number of combustion chambers, and each air duct connects to a corresponding combustion chamber.

[0012] In one embodiment, there are eight air ducts and eight combustion chambers, which correspond one-to-one. The eight combustion chambers are symmetrically arranged on both sides of the preheating section, the first roasting section, the second roasting section, and the third roasting section of the roasting machine body. The eight air ducts are symmetrically arranged on both sides of the flue, and the eight air ducts are respectively connected to the eight combustion chambers.

[0013] Preferably, the duct further includes a second section, a third section, and a fifth section. One end of the first section is connected to the upper part of the flue, and the other end of the first section is connected to one end of the second section. One end of the third section and one end of the fifth section are respectively connected to the other end of the second section. The other end of the third section is connected to one end of the fourth section, and the other end of the fourth section is tangentially connected to the combustion chamber. The other end of the fifth section is connected to one end of the sixth section, and the other end of the sixth section is tangentially connected to the combustion chamber.

[0014] The airflow entering the duct from the flue passes through the first and second pipe sections, and splits into the third and fifth pipe sections at the end of the second pipe section. The airflow in the third pipe section enters the combustion chamber through the fourth pipe section, and the airflow in the fifth pipe section enters the combustion chamber through the sixth pipe section.

[0015] Preferably, the fourth pipe segment and the sixth pipe segment are parallel to each other.

[0016] This facilitates the formation of a uniform, stable, and symmetrical strong swirling flow field, further enhancing the effect of preventing dust agglomeration. Specifically, the combustion chamber is equipped with a first air inlet connected to the fourth pipe section and a second air inlet connected to the sixth pipe section, with the first and second air inlets symmetrically positioned on both sides of the combustion chamber. The first and second air inlets can be located on the left and right sides of the combustion chamber, the upper and lower sides of the combustion chamber, or other symmetrical positions.

[0017] Preferably, the combustion chamber is cylindrical. One end of the combustion chamber is perpendicularly connected to the side wall of the roasting machine body, and the other end of the combustion chamber is provided with a burner for injecting flame into the combustion chamber. The cylindrical shape of the combustion chamber is more conducive to cooperating with the tangential air intake to form a uniform and stable swirling field. The nozzle is located at the end of the combustion chamber away from the roasting machine body.

[0018] The number of nozzles should be at least one, and the number should be set according to the specific working conditions.

[0019] Preferably, the device further includes a wind speed regulating device. The wind speed regulating device is disposed in the air duct to change the area of ​​the ventilation cross-section of the air duct, thereby regulating the wind speed inside the air duct, and further regulating the air intake speed of the combustion chamber.

[0020] Preferably, the wind speed regulating device includes a baffle plate and a driving device. The baffle plate has a plurality of ventilation openings that penetrate the plate thickness evenly. An insertion port is provided on the air duct, and the baffle plate extends into the insertion port to change the area of ​​the ventilation cross-section of the air duct. The driving device drives the baffle plate to move along a direction perpendicular to the axis of the duct segment containing the baffle plate.

[0021] The evenly spaced ventilation openings on the wind deflector not only regulate wind speed but also ensure a more uniform airflow. Specifically, the ventilation openings can be rectangular, circular, or diamond-shaped. Furthermore, the device includes a mounting bracket for installing the drive unit to reduce the impact of high temperatures on the drive unit. The mounting bracket can be directly connected to the ductwork or to a specific mounting base.

[0022] Specifically, the deeper the baffle is inserted into the pipe section, the smaller the ventilation cross-sectional area of ​​the pipe section, and the faster the wind speed.

[0023] Preferably, both the fourth pipe section and the sixth pipe section are equipped with the wind speed regulating device.

[0024] Specifically, the wind speed regulating device includes a first wind speed regulating device installed in the fourth pipe section and a second wind speed regulating device installed in the sixth pipe section. A first insertion port is provided on the fourth pipe section, and a second insertion port is provided on the sixth pipe section. The baffle plate of the first wind speed regulating device is perpendicular to the axis of the fourth pipe section and is inserted into the fourth pipe section through the first insertion port. The baffle plate of the second wind speed regulating device is perpendicular to the axis of the sixth pipe section and is inserted into the sixth pipe section through the second insertion port.

[0025] In one embodiment, the vent is rectangular. The driving device is an electric actuator. The electric actuator is fixed to the outside of the pipe section, and the movable end of the electric actuator is connected to one end of the baffle plate. The electric actuator can drive the baffle plate to move in a direction perpendicular to the axis of the pipe section, thereby changing the area of ​​the ventilation cross-section of the pipe section and thus changing the air intake velocity of the combustion chamber.

[0026] Preferably, the device further includes a dust thickness detection device, which is disposed at the bottom of the combustion chamber.

[0027] In one embodiment, the dust thickness detection device is an ultrasonic dust thickness detector (such as the SONOTEC SONOCHEK series). Ultrasonic dust thickness detectors are existing technology and will not be described in detail here.

[0028] In addition, this solution also includes a method for an anti-dust nodulation device applied to a belt roaster with tangential air intake, the method comprising:

[0029] Step 1: Detect the dust accumulation thickness at two time points in the combustion chamber at a preset time interval (e.g., 1 hour) using the dust thickness detection device, and calculate the dust accumulation rate:

[0030] .

[0031] In the formula, The dust accumulation rate is expressed as the percentage increase in dust thickness over a preset time interval, expressed as %. The dust accumulation thickness at the first time point is expressed in mm. t represents the dust accumulation thickness at the second time point, in mm. t is the time difference between the second and first time points, in hours. , h, is the system adjustment coefficient used to unify the units on both sides of the equation, and its value ranges from 0.8 to 1.2.

[0032] Step 2: Adjust the air intake velocity of the combustion chamber according to the dust accumulation rate:

[0033] like Repeat step 1 and the subsequent steps.

[0034] like Adjust the air intake speed of the combustion chamber.

[0035] in, This is the limiting dust accumulation rate (this value is related to the maintenance cycle of the baking line in the factory; in principle, the longer the maintenance cycle, the greater the allowable limiting dust accumulation rate).

[0036] Specifically, the intake air velocity of the combustion chamber is controlled and adjusted by the depth of the baffle plate inserted into the pipe section.

[0037] In step 2 above, adjusting the air intake speed of the combustion chamber includes the following steps:

[0038] Step 201: Calculate the required increase in intake air velocity for the combustion chamber:

[0039] .

[0040] In the formula, The required increase in intake air velocity for the combustion chamber, in m / s. Dust bulk density, t / m 3 . The thickness of the baked pellet layer is in mm. The diameter of the pellet is in mm. The speed of the baking machine trolley is m / min. This is a system adjustment coefficient used to unify the units on both sides of the equation. The value range is 4.8 × 10. 8 -7.2×10 8 Among them, the dust bulk density, the thickness of the roasted pellet layer, the pellet diameter, and the speed of the roasting machine trolley were all obtained through on-site testing.

[0041] Step 202: Adjust the air intake velocity of the combustion chamber according to the calculation results of Step 1.

[0042] Specifically, an anemometer (such as a POLYTEC LDV series laser Doppler velocimeter) is installed at the secondary air inlet of the combustion chamber to detect the increased intake air velocity. The air velocity within the pipe section is adjusted by changing the depth of the baffle inserted into the pipe section, thereby altering the intake air velocity of the combustion chamber.

[0043] Specifically, the device also includes a controller (such as a microcontroller), which communicates with the dust thickness detection device, the anemometer, and the drive device (such as via Bluetooth) for precise control.

[0044] It should be noted that all formulas in this utility model were obtained by the R&D personnel based on experiments and engineering applications. All calculations are calculated by substituting the converted values ​​into the formulas after the units are converted (after the units are converted, only the values ​​are substituted into the formulas, not the units; the units are only used to adjust the size of the values).

[0045] In the technical solution of this utility model, since the first section of the air duct is inclined upward along the airflow direction, fine dust particles need to climb along the duct section when passing through the first section and are blocked by the duct wall, making it difficult for them to pass through. Some fine dust particles will be trapped in the flue or air duct, and these fine dust particles will not enter the combustion chamber, which helps to reduce dust agglomeration in the combustion chamber. The fourth and sixth sections are tangentially connected to the combustion chamber, which allows the airflow to flow along the inner wall of the combustion chamber after entering the combustion chamber, thus forming a vortex. The airflow entering the combustion chamber from the fourth and sixth sections rotates in the same direction, thereby enhancing the superposition of the vortices. After the dust enters the combustion chamber with the airflow, it can disperse everywhere and avoid accumulating in the combustion chamber. This is conducive to the dust being blown into the roasting machine body by the secondary air and the primary air. At the same time, the vortex formed in the combustion chamber avoids direct blowing of the nozzle flame, which has a stabilizing effect on the nozzle flame. Compared with the direct blowing of the secondary air flame, the vortex can prevent the nozzle flame from sticking to the wall or burning off-center, which avoids the flame heating the dust in a concentrated manner, thereby further preventing dust agglomeration.

[0046] Compared with the prior art, the beneficial technical effects of this utility model are as follows:

[0047] 1. The tangential air intake belt roaster anti-dust nodule device of this utility model can reduce the entry of fine dust particles into the combustion chamber through the first pipe section of the air duct set at an incline, thereby reducing dust nodule formation in the combustion chamber. It has a simple structure and low cost.

[0048] 2. The anti-dust accumulating device of the belt roaster with tangential air intake of this utility model generates swirling flow in the combustion chamber by tangentially connecting the fourth and sixth pipe sections to the combustion chamber, thereby preventing dust from accumulating in the combustion chamber and preventing the nozzle flame from sticking to the wall or burning off-center. This reduces dust accumulating in the combustion chamber, avoids combustion chamber blockage, and has a good anti-accumulating effect, which is conducive to improving the operating efficiency of the belt roaster.

[0049] 3. The tangential air intake belt roaster dust-prevention method of this utility model can control the air intake speed of the combustion chamber, thereby reducing dust accumulation in the combustion chamber, further improving the effect and efficiency of dust prevention, and facilitating normal production operations. Attached Figure Description

[0050] Figure 1This is a schematic diagram of the first embodiment of the anti-dust and anti-nodulation device for a belt roaster with tangential air intake according to the present invention.

[0051] Figure 2 This is a schematic diagram showing the connection of the flue, air duct, combustion chamber, and roaster body of the first embodiment of the tangential air intake belt roaster anti-dust nodule device of this utility model.

[0052] Figure 3 This is a schematic diagram showing the connection between the air duct and the combustion chamber of the first embodiment of the tangential air intake belt roaster anti-dust nodule device of this utility model.

[0053] Figure 4 This is a schematic diagram showing the connection between the air duct and the combustion chamber of the second embodiment of the tangential air intake belt roaster anti-dust nodule device of this utility model.

[0054] Figure 5 This is a schematic diagram of the wind speed adjustment device of the tangential air intake belt roaster anti-dust nodule device of this utility model.

[0055] Figure 6 This is a flowchart illustrating the method for preventing dust accumulation in a belt roaster with tangential air intake according to this utility model.

[0056] Figure reference numerals: 1: flue; 2: duct; 201: first pipe section; 202: second pipe section; 203: third pipe section; 204: fourth pipe section; 205: fifth pipe section; 206: sixth pipe section; 3: combustion chamber; 4: burner; 5: roaster body; 6: wind speed regulating device; 601: wind baffle; 602: vent; 7: dust thickness detection device. Detailed Implementation

[0057] The technical solution of this utility model is illustrated below. The scope of protection of this utility model includes, but is not limited to, the following embodiments.

[0058] Please refer to Figures 1 to 6 A tangentially inlet belt roaster dust prevention device includes a roaster body 5, a flue 1, air ducts 2, and combustion chambers 3. Several combustion chambers 3 are arranged on the side of the roaster body 5, and the outlet of each combustion chamber 3 is connected to the side wall of the roaster body 5. The top of the cooling section of the roaster body 5 is connected to the flue 1, and the flue 1 is connected to the secondary air inlet of each combustion chamber 3 through several air ducts 2.

[0059] The duct includes a first duct section 201, a fourth duct section 204, and a sixth duct section 206. The first duct section 201 is inclined upward along the direction of airflow. The fourth duct section 204 and the sixth duct section 206 are tangentially connected to the combustion chamber 3 to introduce tangential airflow into the combustion chamber 3, thereby forming superimposed and enhanced co-directional swirling flows within the combustion chamber 3.

[0060] Preferably, the flue 1 extends along the length of the roasting machine body 5. A plurality of combustion chambers 3 are symmetrically arranged on both sides of the roasting machine body 5. A plurality of air ducts 2 are symmetrically arranged on both sides of the flue 1. The number of air ducts 2 is the same as the number of combustion chambers 3, and they correspond one-to-one; each air duct 2 connects to its corresponding combustion chamber 3.

[0061] Preferably, the duct 2 further includes a second duct section 202, a third duct section 203, and a fifth duct section 205. One end of the first duct section 201 is connected to the upper part of the flue 1, and the other end of the first duct section 201 is connected to one end of the second duct section 202. One end of the third duct section 203 and one end of the fifth duct section 205 are respectively connected to the other end of the second duct section 202. The other end of the third duct section 203 is connected to one end of the fourth duct section 204, and the other end of the fourth duct section 204 is tangentially connected to the combustion chamber 3. The other end of the fifth duct section 205 is connected to one end of the sixth duct section 206, and the other end of the sixth duct section 206 is tangentially connected to the combustion chamber 3.

[0062] Preferably, the fourth pipe segment 204 and the sixth pipe segment 206 are parallel to each other.

[0063] Preferably, the combustion chamber 3 is cylindrical. One end of the combustion chamber 3 is vertically connected to the side wall of the roasting machine body 5, and the other end of the combustion chamber 3 is provided with a burner 4 for injecting fire into the combustion chamber 3.

[0064] Preferably, the device further includes a wind speed regulating device 6. The wind speed regulating device 6 is disposed in the air duct 2 to change the area of ​​the ventilation cross section of the air duct 2, thereby regulating the wind speed in the air duct 2, and further regulating the air intake speed of the combustion chamber 3.

[0065] Preferably, the wind speed regulating device 6 includes a baffle plate 601 and a driving device. The baffle plate 601 has a plurality of ventilation openings 602 that penetrate the plate thickness evenly. The air duct 2 has an insertion port, into which the baffle plate 601 extends to change the area of ​​the ventilation cross-section of the air duct 2. The driving device drives the baffle plate 601 to move along a direction perpendicular to the axis of the pipe segment containing the baffle plate 601.

[0066] Preferably, both the fourth pipe section 204 and the sixth pipe section 206 are equipped with the wind speed regulating device 6.

[0067] Preferably, the device further includes a dust thickness detection device 7, which is disposed at the bottom of the combustion chamber 3.

[0068] Please refer to Figure 6 A method for using a dust-prevention device in a tangentially inlet belt roaster to prevent dust accumulation, the method comprising:

[0069] Step 1: Detect the dust accumulation thickness at two time points with a preset time interval in the combustion chamber 3 using the dust thickness detection device 13, and calculate the dust accumulation rate:

[0070] .

[0071] In the formula, The dust accumulation rate is expressed as the percentage increase in dust thickness over a preset time interval, expressed as %. The dust accumulation thickness at the first time point is expressed in mm. t represents the dust accumulation thickness at the second time point, in mm. t is the time difference between the second and first time points, in hours. , h, is the system adjustment coefficient used to unify the units on both sides of the equation, and its value ranges from 0.8 to 1.2.

[0072] Step 2: Adjust the air intake speed of combustion chamber 3 according to the dust accumulation rate:

[0073] like Repeat step 1 and the subsequent steps.

[0074] like Adjust the air intake speed of combustion chamber 3.

[0075] in, This is the limiting dust accumulation rate (this value is related to the maintenance cycle of the baking line in the factory; in principle, the longer the maintenance cycle, the greater the allowable limiting dust accumulation rate).

[0076] In step 2 above, adjusting the air intake speed of combustion chamber 3 includes the following steps:

[0077] Step 201: Calculate the required increase in intake air velocity for combustion chamber 3:

[0078] .

[0079] In the formula, The required increase in intake air velocity for the combustion chamber, in m / s. Dust bulk density, t / m 3 . The thickness of the baked pellet layer is in mm. The diameter of the pellet is in mm. The speed of the baking machine trolley is m / min. This is a system adjustment coefficient used to unify the units on both sides of the equation. The value range is 4.8 × 10. 8 -7.2×10 8 .

[0080] Step 202: Adjust the air intake velocity of combustion chamber 3 according to the calculation results of step 1.

[0081] Example 1

[0082] like Figure 1-6 As shown, a tangentially inlet belt roaster dust prevention device includes a roaster body 5, a flue 1, air ducts 2, and combustion chambers 3. Several combustion chambers 3 are arranged on the side of the roaster body 5, and the outlet of each combustion chamber 3 is connected to the side wall of the roaster body 5. The top of the cooling section of the roaster body 5 is connected to the flue 1, and the flue 1 is connected to the secondary air inlet of each combustion chamber 3 through several air ducts 2.

[0083] The duct includes a first duct section 201, a fourth duct section 204, and a sixth duct section 206. The first duct section 201 is inclined upward along the direction of airflow. The fourth duct section 204 and the sixth duct section 206 are tangentially connected to the combustion chamber 3 to introduce tangential airflow into the combustion chamber 3, thereby forming superimposed and enhanced co-directional swirling flows within the combustion chamber 3.

[0084] Example 2

[0085] The embodiment 1 is repeated, except that the flue 1 extends along the length of the roasting machine body 5. Eight combustion chambers 3 are symmetrically arranged on both sides of the roasting machine body 5. Eight air ducts 2 are symmetrically arranged on both sides of the flue 1. Each air duct 2 corresponds to one combustion chamber 3, and the air duct 2 is connected to the corresponding combustion chamber 3.

[0086] Example 3

[0087] The embodiment 2 is repeated, except that the duct 2 further includes a second duct section 202, a third duct section 203, and a fifth duct section 205. One end of the first duct section 201 is connected to the upper part of the flue 1, and the other end of the first duct section 201 is connected to one end of the second duct section 202. One end of the third duct section 203 and one end of the fifth duct section 205 are respectively connected to the other end of the second duct section 202. The other end of the third duct section 203 is connected to one end of the fourth duct section 204, and the other end of the fourth duct section 204 is tangentially connected to the combustion chamber 3. The other end of the fifth duct section 205 is connected to one end of the sixth duct section 206, and the other end of the sixth duct section 206 is tangentially connected to the combustion chamber 3.

[0088] Example 4

[0089] Example 3 is repeated, except that the fourth pipe segment 204 and the sixth pipe segment 206 are parallel to each other.

[0090] Example 5

[0091] Example 4 is repeated, except that the combustion chamber 3 is cylindrical. One end of the combustion chamber 3 is vertically connected to the side wall of the roasting machine body 5, and the other end of the combustion chamber 3 is provided with a burner 4 for injecting fire into the combustion chamber 3.

[0092] Example 6

[0093] The same method as Embodiment 5 is used, except that the device further includes a wind speed regulating device 6. The wind speed regulating device 6 is disposed in the air duct 2 to change the area of ​​the ventilation cross section of the air duct 2, thereby regulating the wind speed in the air duct 2, and further regulating the air intake speed of the combustion chamber 3.

[0094] Example 7

[0095] The embodiment 6 is repeated, except that the wind speed regulating device 6 includes a baffle plate 601 and a driving device. The baffle plate 601 has a plurality of ventilation openings 602 that penetrate the plate thickness evenly. The air duct 2 has an insertion port, into which the baffle plate 601 extends to change the area of ​​the ventilation cross-section of the air duct 2. The driving device drives the baffle plate 601 to move along a direction perpendicular to the axis of the pipe segment containing the baffle plate 601.

[0096] The drive unit is an electric push rod, and the ventilation opening is a rectangular opening.

[0097] Example 8

[0098] The embodiment 7 is repeated, except that both the fourth pipe section 204 and the sixth pipe section 206 are equipped with the wind speed regulating device 6.

[0099] Example 9

[0100] The embodiment 8 is repeated, except that the device further includes a dust thickness detection device 7, which is disposed at the bottom of the combustion chamber 3.

[0101] Application Example 1

[0102] Taking a 5 million-ton / year belt roasting production line of a large domestic steel plant as an example, the raw material ore is hematite, and the dust bulk density is 2.5 t / m³. 3 The pellet bed thickness of the belt roaster is 400mm, the pellet diameter is 12mm, the trolley speed is 2.5m / min, and there are a total of 32 combustion chambers on both sides of the belt roaster. The primary air volume (air entering from the burner nozzle) of a single combustion chamber is 400m³. 3 / h, the secondary air volume (air entering the combustion chamber from the top secondary air duct) is 9000 m³ / h. 3 / h, the iron content of the dust is 40%, and the production limit dust accumulation rate is set at no more than 10% per hour. Then:

[0103] Step 1: The dust accumulation thickness in combustion chamber 3 is measured at two time points with a 1-hour interval (t=1) using dust thickness detection device 13 (measured as follows: =60mm, =68mm), system adjustment coefficient Use a value of 1 (range 0.8~1.2) and calculate the dust accumulation rate:

[0104] .

[0105] Step 2: Determine the range of dust accumulation rate.

[0106] Since 13.3% > 10%, that is... The system determines that the air intake speed of combustion chamber 3 needs to be adjusted.

[0107] Step 3: Calculate the required increase in intake air velocity for combustion chamber 3:

[0108] Calculate the required increase in intake air velocity for combustion chamber 3, and the system adjustment coefficient. Value 6×10 8 (Value range 4.8×10) 8 -7.2×10 8 ):

[0109] m / s.

[0110] Step 4: Based on the calculation results in Step 3, adjust the air intake speed of the first and second air intakes of the combustion chamber 3 by 0.69 m / s using the wind speed adjustment device 6.

[0111] Step 5: After the adjustment is complete, return to Step 2 and check the dust accumulation rate. It is found that the dust accumulation rate is only increasing by 9.6% per hour. 9.6% < 13.3% and 9.6% < 10%, which proves that the operation is effective and the operation of this cycle is completed.

Claims

1. A tangentially inlet belt roaster dust prevention device, comprising a roaster body (5), a flue (1), an air duct (2), and a combustion chamber (3), characterized in that: The roasting machine body (5) has several combustion chambers (3) on its side, and the outlet of each combustion chamber (3) is connected to the side wall of the roasting machine body (5); the top of the cooling section of the roasting machine body (5) is connected to the flue (1), and the flue (1) is connected to the secondary air inlet of each combustion chamber (3) through several air ducts (2). The duct includes a first section (201), a fourth section (204), and a sixth section (206); the first section (201) is inclined upward along the flow direction of the airflow; the fourth section (204) and the sixth section (206) are tangentially connected to the combustion chamber (3) to introduce tangential airflow into the combustion chamber (3), thereby forming superimposed and enhanced co-directional swirling flow in the combustion chamber (3).

2. The anti-dust nodulation device for a belt roaster with tangential air intake according to claim 1, characterized in that: The flue (1) extends along the length of the roasting machine body (5); a number of combustion chambers (3) are symmetrically arranged on both sides of the roasting machine body (5); a number of air ducts (2) are symmetrically arranged on both sides of the flue (1); the number of air ducts (2) is the same as that of the combustion chambers (3), and they correspond one-to-one, and the air ducts (2) are connected to the corresponding combustion chambers (3).

3. The anti-dust and anti-nodulation device for a belt roaster with tangential air intake according to claim 1, characterized in that: The duct (2) further includes a second pipe section (202), a third pipe section (203), and a fifth pipe section (205); one end of the first pipe section (201) is connected to the upper part of the flue (1), and the other end of the first pipe section (201) is connected to one end of the second pipe section (202); one end of the third pipe section (203) and one end of the fifth pipe section (205) are respectively connected to the other end of the second pipe section (202); the other end of the third pipe section (203) is connected to one end of the fourth pipe section (204), and the other end of the fourth pipe section (204) is tangentially connected to the combustion chamber (3); the other end of the fifth pipe section (205) is connected to one end of the sixth pipe section (206), and the other end of the sixth pipe section (206) is tangentially connected to the combustion chamber (3).

4. The anti-dust and anti-nodulation device for a belt roaster with tangential air intake according to claim 1, characterized in that: The fourth pipe segment (204) and the sixth pipe segment (206) are parallel to each other.

5. The anti-dust and anti-nodulation device for a belt roaster with tangential air intake according to claim 1, characterized in that: The combustion chamber (3) is cylindrical; one end of the combustion chamber (3) is vertically connected to the side wall of the roasting machine body (5), and the other end of the combustion chamber (3) is provided with a burner (4) for spraying fire into the combustion chamber (3).

6. The anti-dust and anti-nodulation device for a belt roaster with tangential air inlet according to any one of claims 1 to 5, characterized in that: The device also includes a wind speed regulating device (6); the wind speed regulating device (6) is disposed in the air duct (2) to change the area of ​​the ventilation cross section of the air duct (2), thereby regulating the wind speed in the air duct (2) and thus regulating the air intake speed of the combustion chamber (3).

7. The anti-dust and anti-nodulation device for a belt roaster with tangential air intake according to claim 6, characterized in that: The wind speed regulating device (6) includes a wind deflector (601) and a driving device; the wind deflector (601) is evenly provided with a plurality of ventilation openings (602) that penetrate the thickness of the plate; the air duct (2) is provided with an insertion port, and the wind deflector (601) extends into the insertion port to change the area of ​​the ventilation cross section of the air duct (2); the driving device drives the wind deflector (601) to move along the axis direction perpendicular to the pipe section where the wind deflector (601) is located.

8. The anti-dust and anti-nodulation device for a belt roaster with tangential air intake according to claim 7, characterized in that: The fourth pipe section (204) and the sixth pipe section (206) are both equipped with the wind speed regulating device (6).

9. The anti-dust and anti-nodulation device for a belt roaster with tangential air intake according to any one of claims 1-5 and 7-8, characterized in that: The device also includes a dust thickness detection device (7), which is located at the bottom of the combustion chamber (3).

10. The anti-dust nodulation device for a belt roaster with tangential air intake according to claim 6, characterized in that: The device also includes a dust thickness detection device (7), which is located at the bottom of the combustion chamber (3).

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