Lime shaft kiln with secondary inlet air cooling function
By designing a secondary air inlet cooling system in a lime vertical kiln to cool lime in partitions, the problem of lime and CO2 prone to reverse reaction is solved, the yield and product quality of lime are improved, and the production and maintenance costs are reduced.
Patent Information
- Application Number
- CN202421433680.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-21
- Publication Date
- 2025-05-27
- Estimated Expiration
- 2034-06-21
AI Technical Summary
In the existing lime production process, lime and CO2 are prone to reverse reaction, reducing product quality and output, and the cooling pipeline is prone to damage, low production efficiency and high maintenance costs.
A lime vertical kiln with secondary air inlet cooling is designed. The cooling zone is divided into low-temperature zone, reverse reaction zone and high-temperature zone. By cooling the primary and secondary air in the partition, the lime and primary air can avoid reverse reaction in the reverse reaction zone and achieve sufficient cooling.
It effectively avoids lime reverse reaction, improves lime yield and product quality, reduces the risk of damage to cooling pipelines, improves production efficiency and reduces maintenance costs.
Smart Images
Figure CN222907778U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a lime shaft kiln, in particular to a lime shaft kiln with secondary air inlet cooling, belonging to the technical field of lime production. Background Art
[0002] Lime is an air-hardening inorganic cementitious material with calcium oxide as its main component. Lime is widely used in the civil engineering industry, pharmaceutical industry, steel industry, calcium carbide industry and alumina industry, and its demand is huge. In the past decade, my country's lime production has continued to grow. In 2020, the domestic lime production reached 300 million tons, and the CO generated 2 Emissions reached more than 330 million tons, accounting for the largest share of CO 2 Key targets for emission reduction and carbon capture.
[0003] The original lime production process is to lay limestone and fuel (wood) in layers, ignite the fire and calcine for one week. Modern production uses mechanized and semi-mechanized vertical kilns, rotary kilns, boiling furnaces and other equipment. The calcination time is also shortened accordingly. It only takes 2 to 4 hours to produce lime with a rotary kiln, which can increase production efficiency by more than 5 times compared with vertical kiln production. There are also processes and equipment with significant energy-saving effects such as cross-flow, double-slope, oil-fired circular vertical kilns and short rotary kilns with preheaters. The fuel has also been expanded to coal, coke, heavy oil or liquefied gas. The parallel flow regenerative double-chamber lime vertical kiln is currently the most advanced type of industrial lime production equipment and mainstream kiln type. It uses double-chamber reversing heat storage technology. Compared with other kiln types such as rotary kilns and mechanized vertical kilns, it has the advantages of high system energy efficiency, uniform product roasting and low pollution emissions. However, the tail flue gas CO generated by the current conventional lime production process 2 The concentration is relatively low, generally below 20%. Since the cost of carbon capture increases as the concentration of carbon dioxide in the capture source decreases, most manufacturers directly discharge tail gas into the atmosphere, causing great waste of resources and environmental pollution. 2 Too low a concentration greatly limits the large-scale application of carbon capture technology.
[0004] There is a carbon dioxide enrichment technology that increases the CO 2 The main process of this method is: during the lime cooling process, circulating flue gas is introduced into the kiln to replace air, and the CO in the flue gas during the cooling process is reduced. 2 The concentration will continue to increase, and pure oxygen + circulating flue gas calcination is used to obtain high concentration CO 2 However, high concentration CO is directly introduced into the lime cooling area. 2 Flue gas can easily cause the lime to undergo a reverse carbonization reaction, regenerating calcium carbonate and reducing the quality and output of lime products. Utility Model Content
[0005] In view of the lime and CO existing in the prior art 2 The utility model proposes a lime shaft kiln with secondary air inlet cooling. The primary air cools the lime in the low temperature zone and then bypasses the reverse reaction zone to directly enter the high temperature zone. The reverse reaction zone is cooled by directly introducing the secondary air, thereby avoiding the reverse reaction between the lime and the primary air in the reverse reaction zone, reducing the lime yield, and fully cooling the lime.
[0006] A lime shaft kiln with secondary air inlet cooling, the upper part of the lime shaft kiln is a calcining zone, the lower part is a cooling zone, and a smoke dispersing channel is arranged at the top of the cooling zone. The cooling zone is divided into a low temperature zone, a reverse reaction zone and a high temperature zone from bottom to top. A gas guide plate is also arranged in the cooling zone, and the gas guide plate includes an upper baffle, a middle baffle and a lower baffle. The outer end of the upper baffle is in the high temperature zone and connected to the inner wall of the lime shaft kiln. The outer end of the lower baffle is in the low temperature zone and connected to the inner wall of the lime shaft kiln. The upper baffle and the lower baffle are both annular plate structures arranged along the inner wall of the lime shaft kiln. The middle baffle is arranged in the middle of the lime shaft kiln between the upper baffle and the lower baffle, and is an annular structure. The upper end of the middle baffle is connected to the inner end of the upper baffle, and the lower end of the middle baffle is connected to the inner end of the lower baffle. The upper baffle, the middle baffle, the lower baffle and the inner side wall of the cooling zone together form a cavity recessed to the inner side of the lime shaft kiln. Air guide holes are provided on the upper and lower baffles. A secondary air duct and a primary air duct are provided at the bottom of the low temperature zone, the outlet end of the primary air duct is connected to the low temperature zone, and the outlet end of the secondary air duct extends vertically from the bottom center of the low temperature zone upward through the low temperature zone to the bottom of the material discharge channel surrounded by the cavity or into the material discharge channel.
[0007] Preferably, the upper end of the middle separator is arranged at the junction of the high temperature zone and the reverse reaction zone or in the high temperature zone, and the lower end of the middle separator is arranged at the junction of the low temperature zone and the reverse reaction zone or in the low temperature zone.
[0008] Preferably, the middle partition is a retractable structure, and the angles between the upper partition and the lower partition and the side wall of the cooling zone are adjustable.
[0009] Preferably, the gas guide plate is a continuous structure arranged along the inner wall of the cooling zone, and the upper baffle, the middle baffle, the lower baffle and the inner wall of the cooling zone together form a continuous annular cavity.
[0010] Preferably, the gas guide plate is n discontinuous structures arranged along the inner wall of the cooling zone, and the upper partition plate, the middle partition plate, the lower partition plate and the inner wall of the cooling zone constitute n discontinuous cavities, wherein the value of n is 2-8, preferably 3-6.
[0011] Preferably, the n discontinuous cavities are all in the shape of a sector ring. Preferably, in a horizontal cross section, the sum of the central angles of the n sector ring cavities is 150° to 330°, preferably 180° to 300°.
[0012] Preferably, in the n discontinuous cavities, the spacing distance between any two adjacent cavities is less than 10 to 80 times, preferably 20 to 60 times, the diameter of the secondary air duct.
[0013] Preferably, the outlet end of the secondary air duct is located at the junction of the reverse reaction zone and the low temperature zone, and the outlet end is covered with a guide plate, and the guide plate is provided with secondary air vents. Preferably, the guide plate is conical.
[0014] Preferably, the outlet end of the secondary air duct is an inclined structure with a lower inner side and a higher outer side, and the inclination angle is 30° to 60°, preferably 40° to 50°. Preferably, the secondary air vents on the guide plate are inclined, and the inclination angle is equal to the outlet inclination angle of the secondary air duct.
[0015] Preferably, the secondary air duct is also coated with an insulation layer. Preferably, the height of the inner side of the upper end of the insulation layer is the same as the height of the outer side of the secondary air duct outlet, and the inclination angle of the upper end of the insulation layer is equal to the inclination angle of the secondary air duct outlet.
[0016] Preferably, the height of the secondary air duct is adjustable. Preferably, the secondary air duct is a telescopic structure.
[0017] Preferably, the upper partition has a structure with a high outer end and a low inner end, and the angle between the upper partition and the horizontal plane is 30-75°, preferably 45-60°.
[0018] Preferably, the bottom of the low temperature zone further comprises a permeable baffle. The permeable baffle is a truncated cone without a top or bottom, and the secondary air duct passes through the center of the permeable baffle. The bottom of the permeable baffle is a primary air inlet, and the primary air duct is connected to the primary air inlet.
[0019] In the utility model, the cooling zone inside the lime shaft kiln is divided into a plurality of temperature zones, and primary air is introduced from the bottom of the low temperature zone. After the primary air cools the material in the kiln in the low temperature zone, it bypasses the reverse reaction zone through the cavity and directly enters the high temperature zone to cool the material therein, thereby preventing the primary air from reacting reversely with the lime in the reverse reaction zone. In addition, a secondary air duct is provided that enters the cooling zone from the bottom of the low temperature zone and extends to the bottom or inside of the material discharge channel surrounded by the cavity, and the secondary cooling air is introduced into the reverse reaction zone. Since the initial temperature of the secondary cooling air is relatively low, it will not react reversely with the lime in the reverse reaction zone, and has a better cooling effect on the lime, while ensuring the output of lime. After the secondary cooling air exchanges heat with the lime in the reverse reaction zone, since the amount of the secondary cooling air is less than that of the primary cooling air, the temperature after mixing with the primary cooling air is slightly higher than the temperature at which the reverse reaction will occur. Mixing with the primary cooling air can effectively reduce the temperature of the primary cooling air and improve the cooling efficiency of the mixed air in the high temperature zone.
[0020] In the utility model, the upper end of the middle partition is defined to be at the junction of the high temperature zone and the reverse reaction zone or in the high temperature zone. When the upper end of the middle partition is at the junction of the high temperature zone and the reverse reaction zone, the primary cooling air enters the high temperature zone from the upper partition and mixes with the secondary cooling air at the junction of the high temperature zone and the reverse reaction zone; when the upper end of the middle partition is in the high temperature zone, the primary air and the secondary air are mixed in the high temperature zone. Both of the above situations can achieve the effect of mixing the primary cooling air and the secondary cooling air, thereby improving the cooling efficiency.
[0021] In the utility model, the cavity can be a continuous structure arranged along the middle partition, and the upper partition and the lower partition are provided with air guide holes. After passing through the low temperature zone, the primary air enters the cavity from the air guide hole of the lower partition, and enters the high temperature zone from the air guide hole of the upper partition to cool the lime in the high temperature zone. The primary cooling air in different areas of the cooling zone can be mixed in the primary air cavity to improve the uniformity of cooling the lime in the high temperature zone. In addition, the cavity can also be n discontinuous fan-shaped structures arranged along the side wall of the cooling zone. After the primary air cools the lime in the low temperature zone, it is sucked into the n discontinuous cavities, bypasses the reverse reaction zone and enters the high temperature zone. Multiple discontinuous fan-shaped cavities can prevent all materials from concentrating at the center of the lime shaft kiln, speed up the material discharge speed, and avoid material blockage. Preferably, the sum of the central angles of the n fan-shaped cavities is limited to 150°~330°, ensuring that most or even all of the primary air enters the fan-shaped cavities. Even if a small amount of primary air enters the discharge channel corresponding to the reverse reaction zone, the impact on the secondary air temperature is small, and no reverse reaction occurs with the lime. Preferably, the distance between any two primary air guiding devices is limited to further ensure that the primary air is introduced into the primary air cavity.
[0022] In the present invention, a guide plate is provided on the outlet end of the secondary air duct to prevent the material from blocking the outlet of the secondary air duct. Preferably, the outlet end of the secondary air duct is set to an inclined structure, and the secondary air vents on the guide plate are also set to an inclined structure, so that the secondary air is ejected obliquely upward, which is opposite to the flow direction of the material, thereby improving the heat exchange efficiency.
[0023] In the utility model, an insulation layer is coated on the outside of the secondary air duct to prevent the temperature of the secondary air from rising in the low temperature zone, ensuring that the temperature of the secondary air is low when it reaches the junction of the low temperature zone and the reverse reaction zone, thereby preventing the occurrence of reverse reaction. In addition, the secondary air duct is set as a retractable structure, and when the temperature in the kiln fluctuates, the ejection position of the secondary air is changed.
[0024] In the utility model, the upper partition is defined as a structure with a high outer end and a low inner end, and the angle between the upper partition and the horizontal plane is defined to ensure that the lime can roll down smoothly after falling on the upper partition.
[0025] In the utility model, a breathable baffle is provided so that after the primary air enters the low temperature zone, it can be ejected in a direction inclined toward the periphery of the kiln chamber, which is beneficial for the primary air to be evenly diffused to various places in the low temperature zone and improves the uniformity of cooling.
[0026] In the utility model, the telescopic structure of the secondary air duct
[0027] Compared with the prior art, the utility model has the following beneficial effects:
[0028] 1. The utility model provides a lime shaft kiln with secondary air inlet cooling, in which primary air and secondary air are introduced into the lime shaft kiln, the primary air cools the materials in the low temperature zone and the high temperature zone, and the secondary air cools the materials in the reverse reaction zone, so as to avoid the reverse reaction between the primary air and the lime in the reverse reaction zone. After the secondary cooling air exchanges heat with the lime in the reverse reaction zone, it is mixed with the primary cooling air, so as to reduce the temperature of the primary cooling air and improve the cooling efficiency.
[0029] 2. The utility model provides a secondary air inlet cooling lime shaft kiln, the primary air flow guide device can be a continuous structure or multiple discontinuous structures, while ensuring the cooling efficiency, it can adapt to a variety of different working conditions. The inclined secondary duct outlet and secondary air vents are set to improve the heat exchange efficiency between the secondary air and the material. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 The utility model provides a structural schematic diagram of a secondary air-inlet cooling lime shaft kiln.
[0031] Figure 2 The utility model provides a top view of a secondary air duct and a primary air duct of a lime shaft kiln with secondary air inlet cooling.
[0032] Figure 3 The utility model provides a schematic structural diagram of an annular cavity in a secondary air-inlet cooling lime shaft kiln.
[0033] Figure 4 The utility model provides a structural schematic diagram of a discontinuous fan annular cavity in a secondary air inlet cooling lime shaft kiln.
[0034] Figure 5 For CaO in pure CO 2 atmosphere with CO 2 Test diagram of the temperature range in which the reaction occurs.
[0035] Figure symbols: A: calcination zone; B: cooling zone; B1: low temperature zone; B2: reverse reaction zone; B3: high temperature zone; 1: gas-material guide plate; 101: upper partition; 102: middle partition; 103: lower partition; 2: secondary air duct; 3: primary air duct; 4: material guide plate; 5: insulation layer; 6: air-permeable baffle; 7: primary air inlet; 8: cavity. DETAILED DESCRIPTION
[0036] The technical solution of the utility model is illustrated below, and the scope of protection requested for the utility model includes but is not limited to the following embodiments.
[0037] A lime shaft kiln with secondary air inlet cooling, the upper part of the lime shaft kiln is a calcining zone A, the lower part is a cooling zone B, and a smoke exhaust channel C is arranged at the top of the cooling zone B. The cooling zone B is divided into a low temperature zone B1, a reverse reaction zone B2 and a high temperature zone B3 from bottom to top. A gas guide plate 1 is also arranged in the cooling zone B, and the gas guide plate 1 includes an upper baffle 101, a middle baffle 102 and a lower baffle 103. The outer end of the upper baffle 101 is in the high temperature zone B3 and connected to the inner wall of the lime shaft kiln. The outer end of the lower baffle 103 is in the low temperature zone B1 and connected to the inner wall of the lime shaft kiln. The upper baffle 101 and the lower baffle 103 are both annular plate structures arranged along the inner wall of the lime shaft kiln. The middle partition 102 is arranged in the middle of the lime shaft kiln between the upper partition 101 and the lower partition 103, and is an annular structure. The upper end of the middle partition 102 is connected to the inner end of the upper partition 101, and the lower end of the middle partition 102 is connected to the inner end of the lower partition 103. The upper partition 101, the middle partition 102, the lower partition 103, and the inner side wall of the cooling zone B together form a cavity 8 that is recessed toward the inner side of the lime shaft kiln. Air guide holes are provided on the upper partition 101 and the lower partition 103. A secondary air duct 2 and a primary air duct 3 are provided at the bottom of the low-temperature zone B1. The outlet end of the primary air duct 3 is connected to the low-temperature zone B1. The outlet end of the secondary air duct 2 extends vertically from the bottom center of the low-temperature zone B1 upward through the low-temperature zone B1 to the bottom of the material discharge channel surrounded by the cavity 8 or inside the material discharge channel.
[0038] Preferably, the upper end of the middle separator 102 is arranged at the junction of the high temperature zone B3 and the reverse reaction zone B2 or in the high temperature zone B3, and the lower end of the middle separator 102 is arranged at the junction of the low temperature zone B1 and the reverse reaction zone B2 or in the low temperature zone.
[0039] Preferably, the middle partition 102 is a retractable structure, and the angles between the upper partition 101 and the lower partition 103 and the side wall of the cooling zone B are adjustable.
[0040] Preferably, the gas guide plate is a continuous structure arranged along the inner wall of the cooling zone B, and the upper partition plate 101, the middle partition plate 102, the lower partition plate 103 and the inner wall of the cooling zone B together constitute a continuous annular cavity 8.
[0041] Preferably, the gas guide plate 1 is n discontinuous structures arranged along the inner wall of the cooling zone B, and the upper partition plate 101, the middle partition plate 102, the lower partition plate 103 and the inner wall of the cooling zone B constitute n discontinuous cavities 8. The value of n is 2-8, preferably 3-6.
[0042] Preferably, the n discontinuous cavities 8 are all in the shape of a sector ring. Preferably, in a horizontal cross section, the sum of the central angles of the n sector ring cavities 8 is 150° to 330°, preferably 180° to 300°.
[0043] Preferably, in the n discontinuous cavities 8 , the spacing distance between any two adjacent cavities 8 is less than 10 to 80 times, preferably 20 to 60 times, the diameter of the secondary air duct 2 .
[0044] Preferably, the outlet end of the secondary air duct 2 is located at the junction of the reverse reaction zone B2 and the low temperature zone B1, and the outlet end is covered with a guide plate 4, and a secondary air vent is provided on the guide plate 4. Preferably, the guide plate 4 is conical.
[0045] Preferably, the outlet end of the secondary air duct 2 is an inclined structure with a lower inner side and a higher outer side, and the inclination angle is 30° to 60°, preferably 40° to 50°. Preferably, the secondary air vents on the guide plate 4 are inclined, and the inclination angle is equal to the outlet inclination angle of the secondary air duct 2.
[0046] Preferably, the outer side of the secondary air duct 2 is also covered with an insulation layer 5. Preferably, the height of the inner side of the upper end of the insulation layer 5 is the same as the height of the outer side of the secondary air duct 2 outlet, and the inclination angle of the upper end of the insulation layer 5 is equal to the inclination angle of the secondary air duct 2 outlet.
[0047] Preferably, the height of the secondary air duct 2 is adjustable. Preferably, the secondary air duct 2 is a telescopic structure.
[0048] Preferably, the upper partition 101 is a structure with a high outer end and a low inner end, and the angle between the upper partition 101 and the horizontal plane is 30-75°, preferably 45-60°.
[0049] Preferably, the bottom of the low temperature zone B1 further includes a breathable baffle 6. The breathable baffle 6 is a truncated cone without a top or bottom, and the secondary air duct 2 passes through the center of the breathable baffle 6. The bottom of the breathable baffle 6 is a primary air inlet 7, and the primary air duct 3 is connected to the primary air inlet 7. Example 1
[0050] A lime shaft kiln with secondary air inlet cooling, the upper part of the lime shaft kiln is a calcining zone A, the lower part is a cooling zone B, and a smoke exhaust channel C is arranged at the top of the cooling zone B. The cooling zone B is divided into a low temperature zone B1, a reverse reaction zone B2 and a high temperature zone B3 from bottom to top. A gas guide plate 1 is also arranged in the cooling zone B, and the gas guide plate 1 includes an upper baffle 101, a middle baffle 102 and a lower baffle 103. The outer end of the upper baffle 101 is in the high temperature zone B3 and connected to the inner wall of the lime shaft kiln. The outer end of the lower baffle 103 is in the low temperature zone B1 and connected to the inner wall of the lime shaft kiln. The upper baffle 101 and the lower baffle 103 are both annular plate structures arranged along the inner wall of the lime shaft kiln. The middle partition 102 is arranged in the middle of the lime shaft kiln between the upper partition 101 and the lower partition 103, and is an annular structure. The upper end of the middle partition 102 is connected to the inner end of the upper partition 101, and the lower end of the middle partition 102 is connected to the inner end of the lower partition 103. The upper partition 101, the middle partition 102, the lower partition 103, and the inner side wall of the cooling zone B together form a cavity 8 that is recessed toward the inner side of the lime shaft kiln. Air guide holes are provided on the upper partition 101 and the lower partition 103. A secondary air duct 2 and a primary air duct 3 are provided at the bottom of the low-temperature zone B1. The outlet end of the primary air duct 3 is connected to the low-temperature zone B1. The outlet end of the secondary air duct 2 extends vertically from the bottom center of the low-temperature zone B1 upward through the low-temperature zone B1 to the bottom of the material discharge channel surrounded by the cavity 8. Example 2
[0051] Example 1 is repeated, except that the upper end of the middle separator 102 is arranged at the junction of the high temperature zone B3 and the reverse reaction zone B2, and the lower end of the middle separator 102 is arranged at the junction of the low temperature zone B1 and the reverse reaction zone B2. Example 3
[0052] Example 2 is repeated, except that the middle partition 102 is a retractable structure, and the angles between the upper partition 101 and the lower partition 103 and the side wall of the cooling zone B are adjustable. Example 4
[0053] Example 3 is repeated, except that the gas guide plate is a continuous structure arranged along the inner wall of the cooling zone B, and the upper partition plate 101, the middle partition plate 102, the lower partition plate 103 and the inner wall of the cooling zone B together form a continuous annular cavity 8. Example 5
[0054] Example 3 is repeated, except that the gas guide plate 1 is a five discontinuous structure arranged along the inner wall of the cooling zone B, and the upper partition plate 101, the middle partition plate 102, the lower partition plate 103 and the inner wall of the cooling zone B constitute five discontinuous cavities 8.
[0055] The five discontinuous cavities 8 are all in the shape of a sector ring. In a horizontal section, the sum of the central angles of the n sector ring cavities 8 is 240°. Example 6
[0056] Example 5 is repeated, except that in the five discontinuous cavities 8 , the spacing distance between any two adjacent cavities 8 is less than 40 times the diameter of the secondary air duct 2 . Example 7
[0057] Example 4 is repeated, except that the outlet end of the secondary air duct 2 is located at the junction of the reverse reaction zone B2 and the low temperature zone B1, and the outlet end is covered with a guide plate 4, and secondary air holes are provided on the guide plate 4. The guide plate 4 is conical. Example 8
[0058] Example 6 is repeated, except that the outlet end of the secondary air duct 2 is located at the junction of the reverse reaction zone B2 and the low temperature zone B1, and the outlet end is covered with a guide plate 4, and a secondary air vent is provided on the guide plate 4. The guide plate 4 is conical. Example 9
[0059] Example 7 is repeated, except that the outlet end of the secondary air duct 2 is an inclined structure with a lower inner side and a higher outer side, with an inclination angle of 45°. The secondary air vents on the guide plate 4 are inclined, with an inclination angle equal to that of the outlet of the secondary air duct 2. Example 10
[0060] Example 8 is repeated, except that the outlet end of the secondary air duct 2 is an inclined structure with a lower inner side and a higher outer side, with an inclination angle of 45°. The secondary air vents on the guide plate 4 are inclined, with an inclination angle equal to that of the outlet of the secondary air duct 2. Embodiment 11
[0061] Example 9 is repeated, except that the outer side of the secondary air duct 2 is further coated with an insulation layer 5. The height of the inner side of the upper end of the insulation layer 5 is the same as the height of the outer side of the secondary air duct 2 outlet, and the inclination angle of the upper end of the insulation layer 5 is equal to the inclination angle of the secondary air duct 2 outlet. Example 12
[0062] Example 10 is repeated, except that the outer side of the secondary air duct 2 is further coated with an insulation layer 5. The height of the inner side of the upper end of the insulation layer 5 is the same as the height of the outer side of the secondary air duct 2 outlet, and the inclination angle of the upper end of the insulation layer 5 is equal to the inclination angle of the secondary air duct 2 outlet. Embodiment 13
[0063] Example 11 is repeated, except that the height of the secondary air duct 2 is adjustable. The secondary air duct 2 is a telescopic structure.
[0064] The upper partition 101 is a structure with a high outer end and a low inner end, and the angle between the upper partition 101 and the horizontal plane is 45°. Embodiment 14
[0065] Example 12 is repeated, except that the height of the secondary air duct 2 is adjustable. The secondary air duct 2 is a telescopic structure.
[0066] The upper partition 101 is a structure with a high outer end and a low inner end, and the angle between the upper partition 101 and the horizontal plane is 45°. Embodiment 15
[0067] Example 13 is repeated, except that the bottom of the low temperature zone B1 further includes a breathable baffle 6. The breathable baffle 6 is a truncated cone without a top or bottom, and the secondary air duct 2 passes through the center of the breathable baffle 6. The bottom of the breathable baffle 6 is a primary air inlet 7, and the primary air duct 3 is connected to the primary air inlet 7. Example 16
[0068] Example 14 is repeated, except that the bottom of the low temperature zone B1 further includes a breathable baffle 6. The breathable baffle 6 is a truncated cone without a top or bottom, and the secondary air duct 2 passes through the center of the breathable baffle 6. The bottom of the breathable baffle 6 is a primary air inlet 7, and the primary air duct 3 is connected to the primary air inlet 7.
Claims
1. A lime shaft kiln with secondary air cooling, characterized in that: The upper part of the lime shaft kiln is a calcining zone (A), and the lower part is a cooling zone (B). A smoke dispersing channel (C) is arranged at the top of the cooling zone (B); the cooling zone (B) is divided into a low temperature zone (B1), a reverse reaction zone (B2) and a high temperature zone (B3) from bottom to top; a gas guide plate (1) is also arranged in the cooling zone (B), and the gas guide plate (1) comprises an upper baffle (101), a middle baffle (102) and a lower baffle (103); the outer end of the upper baffle (101) is in the high temperature zone (B3) and connected to the inner wall of the lime shaft kiln; the outer end of the lower baffle (103) is in the low temperature zone (B1) and connected to the inner wall of the lime shaft kiln; the upper baffle (101) and the lower baffle (103) are both annular plate structures arranged along the inner wall of the lime shaft kiln; the middle baffle (102) is arranged between the upper baffle (101) and the lower baffle (103). 03) and is an annular structure, the upper end of the middle partition (102) is connected to the inner end of the upper partition (101), the lower end of the middle partition (102) is connected to the inner end of the lower partition (103), and the upper partition (101), the middle partition (102), the lower partition (103), and the inner side wall of the cooling zone (B) together form a cavity (8) that is recessed toward the inner side of the lime shaft kiln; air guide holes are provided on the upper partition (101) and the lower partition (103); a secondary air duct (2) and a primary air duct (3) are provided at the bottom of the low temperature zone (B1), the outlet end of the primary air duct (3) is connected to the low temperature zone (B1), and the outlet end of the secondary air duct (2) extends from the bottom center of the low temperature zone (B1) upward through the low temperature zone (B1) and then vertically extends to the bottom of the material discharge channel surrounded by the cavity (8) or into the material discharge channel.
2. The lime shaft kiln according to claim 1, characterized in that: The upper end of the middle partition (102) is arranged at the junction of the high temperature zone (B3) and the reverse reaction zone (B2) or in the high temperature zone (B3), and the lower end of the middle partition (102) is arranged at the junction of the low temperature zone (B1) and the reverse reaction zone (B2) or in the low temperature zone.
3. The lime shaft kiln according to claim 2, characterized in that: The middle partition (102) is a retractable structure, and the angles between the upper partition (101) and the lower partition (103) and the side wall of the cooling zone (B) are adjustable.
4. The lime shaft kiln according to any one of claims 1 to 3, characterized in that: The gas guide plate is a continuous structure arranged along the inner wall of the cooling zone (B), and the upper baffle (101), the middle baffle (102), the lower baffle (103) and the inner wall of the cooling zone (B) together form a continuous annular cavity (8).
5. The lime shaft kiln according to any one of claims 1 to 3, characterized in that: The gas guide plate (1) is n discontinuous structures arranged along the inner wall of the cooling zone (B), and the upper partition plate (101), the middle partition plate (102), the lower partition plate (103) and the inner wall of the cooling zone (B) constitute n discontinuous cavities (8); wherein the value of n is 2 to 8.
6. The lime shaft kiln according to claim 5, characterized in that: The value of n is 3 to 6.
7. The lime shaft kiln according to claim 6, characterized in that: The n discontinuous cavities (8) are all in the shape of a sector ring.
8. The lime shaft kiln according to claim 7, characterized in that: On a horizontal cross section, the sum of the central angles of the n sector annular cavities (8) is 150° to 330°.
9. The lime shaft kiln according to claim 8, characterized in that: On a horizontal cross section, the sum of the central angles of the n sector annular cavities (8) is 180° to 300°.
10. The lime shaft kiln according to claim 5, characterized in that: In the n discontinuous cavities (8), the spacing distance between any two adjacent cavities (8) is less than 10 to 80 times the diameter of the secondary air duct (2).
11. The lime shaft kiln according to claim 10, characterized in that: In the n discontinuous cavities (8), the spacing distance between any two adjacent cavities (8) is less than 20 to 60 times the diameter of the secondary air duct (2).
12. The lime shaft kiln according to any one of claims 1 to 3 and 6 to 11, characterized in that: The air outlet end of the secondary air duct (2) is located at the junction of the reverse reaction zone (B2) and the low temperature zone (B1), and the air outlet end is covered with a material guide plate (4), and the material guide plate (4) is provided with secondary air vents.
13. The lime shaft kiln according to claim 4, characterized in that: The air outlet end of the secondary air duct (2) is located at the junction of the reverse reaction zone (B2) and the low temperature zone (B1), and the air outlet end is covered with a material guide plate (4), and the material guide plate (4) is provided with secondary air vents.
14. The lime shaft kiln according to claim 5, characterized in that: The air outlet end of the secondary air duct (2) is located at the junction of the reverse reaction zone (B2) and the low temperature zone (B1), and the air outlet end is covered with a material guide plate (4), and the material guide plate (4) is provided with secondary air vents.
15. The lime shaft kiln according to claim 12, characterized in that: The material guide plate (4) is conical.
16. The lime shaft kiln according to claim 13 or 14, characterized in that: The material guide plate (4) is conical.
17. The lime shaft kiln according to claim 12, characterized in that: The air outlet end of the secondary air duct (2) is an inclined structure with a lower inner side and a higher outer side, and the inclination angle is 30° to 60°.
18. The lime shaft kiln according to claim 13, characterized in that: The air outlet end of the secondary air duct (2) is an inclined structure with a lower inner side and a higher outer side, and the inclination angle is 30° to 60°.
19. The lime shaft kiln according to claim 14, characterized in that: The air outlet end of the secondary air duct (2) is an inclined structure with a lower inner side and a higher outer side, and the inclination angle is 30° to 60°.
20. The lime shaft kiln according to any one of claims 17 to 19, characterized in that: The inclination angle is 40°~50°.
21. A lime shaft kiln according to any one of claims 17 to 19, characterized in that: The secondary air vent holes on the guide plate (4) are arranged at an angle, and the angle of inclination is equal to the angle of inclination of the air outlet of the secondary air duct (2).
22. A lime shaft kiln according to any one of claims 1-3, 6-11, 13-15, 17-19, characterized in that: The outer side of the secondary air duct (2) is also coated with a thermal insulation layer (5).
23. The lime shaft kiln according to claim 4, characterized in that: The outer side of the secondary air duct (2) is also coated with a thermal insulation layer (5).
24. The lime shaft kiln according to claim 5, characterized in that: The outer side of the secondary air duct (2) is also coated with a thermal insulation layer (5).
25. The lime shaft kiln according to claim 22, characterized in that: The height of the inner side of the upper end of the thermal insulation layer (5) is the same as the height of the outer side of the air outlet of the secondary air duct (2), and the inclination angle of the upper end of the thermal insulation layer (5) is equal to the inclination angle of the air outlet of the secondary air duct (2).
26. A lime shaft kiln according to claim 23 or 24, characterized in that: The height of the inner side of the upper end of the thermal insulation layer (5) is the same as the height of the outer side of the air outlet of the secondary air duct (2), and the inclination angle of the upper end of the thermal insulation layer (5) is equal to the inclination angle of the air outlet of the secondary air duct (2).
27. A lime shaft kiln according to any one of claims 1-3, 6-11, 13-15, 17-19, 23-25, characterized in that: The height of the secondary air duct (2) is adjustable; and / or The upper partition (101) is a structure with a high outer end and a low inner end, and the angle between the upper partition (101) and the horizontal plane is 30-75°.
28. The lime shaft kiln according to claim 4, characterized in that: The height of the secondary air duct (2) is adjustable; and / or The upper partition (101) is a structure with a high outer end and a low inner end, and the angle between the upper partition (101) and the horizontal plane is 30-75°.
29. The lime shaft kiln according to claim 5, characterized in that: The height of the secondary air duct (2) is adjustable; and / or The upper partition (101) is a structure with a high outer end and a low inner end, and the angle between the upper partition (101) and the horizontal plane is 30-75°.
30. The lime shaft kiln according to claim 27, characterized in that: The secondary air duct (2) is a retractable structure; and / or The angle between the upper partition (101) and the horizontal plane is 45-60 degrees.
31. A lime shaft kiln according to claim 28 or 29, characterized in that: The secondary air duct (2) is a retractable structure; and / or The angle between the upper partition (101) and the horizontal plane is 45-60 degrees.
32. A lime shaft kiln according to any one of claims 1-3, 6-11, 13-15, 17-19, 23-25, 28-30, characterized in that: The bottom of the low-temperature zone (B1) also includes a breathable baffle (6); the breathable baffle (6) is in the shape of a truncated cone without a top or a bottom, and the secondary air duct (2) passes through the center of the breathable baffle (6); the bottom of the breathable baffle (6) is a primary air inlet (7), and the primary air duct (3) is connected to the primary air inlet (7).
33. The lime shaft kiln according to claim 4, characterized in that: The bottom of the low-temperature zone (B1) also includes a breathable baffle (6); the breathable baffle (6) is in the shape of a truncated cone without a top or a bottom, and the secondary air duct (2) passes through the center of the breathable baffle (6); the bottom of the breathable baffle (6) is a primary air inlet (7), and the primary air duct (3) is connected to the primary air inlet (7).
34. The lime shaft kiln according to claim 5, characterized in that: The bottom of the low-temperature zone (B1) also includes a breathable baffle (6); the breathable baffle (6) is in the shape of a truncated cone without a top or a bottom, and the secondary air duct (2) passes through the center of the breathable baffle (6); the bottom of the breathable baffle (6) is a primary air inlet (7), and the primary air duct (3) is connected to the primary air inlet (7).