A rotary kiln lime calcining system and process for realizing dust ash recycling

Abstract

This invention provides a rotary kiln lime calcination system and process for realizing the recycling of dust collector ash, belonging to the field of lime calcination technology. It solves the technical problems of existing rotary kiln lime calcination systems, which cannot recycle dust collector ash generated during production, cannot completely eliminate waste ash emissions, and cannot scientifically proportion and mix dust collector ash from different sources and with different activities to achieve precise adjustment of the activity of the finished lime. The rotary kiln lime calcination system and process for realizing the recycling of dust collector ash includes a feeding device, a raw material preheater connected to the feeding device, a rotary kiln connected to the raw material preheater's discharge trough, and a cyclone dust collector connected to the flue gas outlet of the raw material preheater via pipeline. In this invention, by setting up three independent dust collector ash recycling systems for raw materials, flue gas, and finished products, the dust collector ash generated throughout the entire lime production process is systematically collected and reused entirely as a raw material component in the product.

Description

Technical Field

[0001] This invention belongs to the field of lime calcination technology, and relates to a rotary kiln lime calcination system, particularly a rotary kiln lime calcination system and process for realizing the recycling of dust. Background Technology

[0002] The activity of lime is a key quality indicator that directly affects downstream applications, such as the efficiency and cost of steel smelting, calcium carbide production, and flue gas desulfurization. Traditionally, the control of activity has relied entirely on the precise adjustment of calcination process parameters. The rotary kiln is a crucial piece of equipment in lime production, and its system typically includes units for feeding, preheating, calcination, cooling, dust removal, and finished product storage. During production, a large amount of dust-laden gas is generated during raw material feeding, rotary kiln flue gas emissions, and the conveying, screening, and storage of calcined lime.

[0003] A search revealed a Chinese patent document disclosing a calcination system and process for quicklime [Application No.: CN201910944477.8; Publication No.: CN110526598A]. This quicklime calcination system includes a raw material silo, a calcination powder preparation subsystem, an intermediate silo, a feeding subsystem, a calcination subsystem, a finished product silo, and a tail gas emission subsystem. The calcination powder preparation subsystem includes a dryer, a crusher, a screening device, a cyclone dust collector, and a bag filter dust collector.

[0004] Although the active lime calcination system disclosed in this patent makes full use of small-diameter limestone, a large amount of dust is generated during the production process, including raw material feeding, flue gas emission, and finished product transportation. Currently, cyclone dust collectors and bag filters are commonly used in industry to collect this dust. However, the collected dust is usually regarded as industrial solid waste, and its disposal methods are mostly landfill or low-price sales. This not only wastes calcium resources but also increases the environmental burden and disposal costs of enterprises. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a rotary kiln lime calcination system and process for realizing the recycling and utilization of dust collector ash. The technical problem to be solved by this invention is: how to recycle and utilize dust collector ash during the production process, eliminate waste ash discharge, and achieve precise adjustment of the activity of the finished lime by scientifically proportioning and mixing dust collector ash from different sources and with different activities.

[0006] The objective of this invention can be achieved through the following technical solutions: A rotary kiln lime calcination system for realizing dust collection and utilization includes a feeding device, a raw material preheater connected to the feeding device, a rotary kiln connected to the raw material preheater discharge trough, and a cyclone dust collector connected to the flue gas outlet of the raw material preheater via a pipeline. The discharge end of the rotary kiln is connected to a vertical cooling component, the bottom of the vertical cooling component is connected to a finished product bin via a conveying device, an air mixing component is installed at the top inlet of the vertical cooling component, and three conveying pipes are fixedly connected to the top of the air mixing component. The three conveying pipes are respectively connected to a raw material dust removal component, a finished product dust removal device, and a flue gas dust removal component, and each of the three conveying pipes is equipped with an electrically controlled valve. The raw material dust removal assembly is connected to the feeding device via an air duct, and the bottom of the finished product dust removal device passes through it; The finished product dust removal device is fixedly installed at the dust generation point in the finished product warehouse; The flue gas dust removal assembly is connected to the flue gas outlet pipe of the cyclone dust collector via a pipeline; The air mixing assembly includes a mixing cylinder with a hollow cone shape at the bottom, and a baffle is fixedly installed at the top inside the mixing cylinder. A centrifugal fan is connected above the baffle. A connecting pipe is fixedly installed at the bottom of the mixing cylinder, and a smart control valve is installed below the connecting pipe. A feeding pipe is fixedly connected to the bottom end of the smart control valve, and the feeding pipe is fixedly connected to the inlet of the vertical cooling assembly at the bottom end. The vertical cooling assembly includes a vertical box, with the discharge end of a feeding pipe and the discharge end of a rotary kiln connected to the top of the vertical box. A grate unit is fixedly connected inside the vertical box, and the grate unit is fixedly installed on the inner top wall of the vertical box in an "in" shape. A cooling air duct is fixedly installed at the bottom of the vertical box, and a wind cap is fixedly connected to one end of the cooling air duct. The upright box is rotatably connected to a rotating shaft, which is located between the vent cap and the grate unit. The rotating shaft is driven by a drive motor, which is fixedly installed on the outside of the upright box. Multiple connecting arms are circumferentially and staggeredly distributed on the outer wall of the rotating shaft, and a mixing blade is fixedly installed at the outer end of each connecting arm.

[0007] The working principle of this invention is as follows: Limestone raw materials are conveyed through a feeding device. Dust generated in the feeding device is collected by a raw material dust removal component, which then supplies the air mixing component via a raw material ash conveying pipe. The fed raw materials are preheated by a raw material preheater before entering a rotary kiln for calcination. The high-temperature flue gas generated during the preheating process is purified by a cyclone dust collector and a flue gas dust removal device, and the flue gas dust is collected in an ash storage tank. This flue gas dust is then supplied to the air mixing component via a flue gas ash conveying pipe. Furthermore, the finished product dust removal device collects dust from the finished product silo and supplies it to the air mixing component via a finished product ash conveying pipe. By independently installing an electrically controlled valve on each conveying pipe, users can mix the three types of dust according to the different activity levels required for lime production, achieving precise control of each conveying pipe. Starting a centrifugal fan allows the three types of dust to be mixed. The dust collector ash enters the mixing drum, where the three types of dust collector ash are subjected to high-speed swirling under the action of the cone-shaped mixing drum below, achieving efficient mixing of the three types of dust collector ash. At the same time, the calcined high-temperature lime is discharged from the rotary kiln head, and the dust collector ash that is efficiently mixed with the air mixing component enters the vertical cooler component. The addition of high-temperature lime to the dust collector ash produces a considerable cooling effect, effectively reducing the heat load of the subsequent vertical cooler, thereby saving energy consumption of the cooling fan. Moreover, the setting of the intelligent control valve ensures the accuracy of the discharge of the air mixing component. The grate unit set inside the vertical cooler component ensures the accuracy of the feeding of dust collector ash and high-temperature lime. Furthermore, driven by the drive motor, the rotating shaft drives the mixing blade to rotate through the connecting arm, so that the dust collector ash and high-temperature lime are mechanically stirred inside the vertical box, achieving cooling and final mixing of the dust collector ash and high-temperature lime, which is convenient for the final product to enter the finished product silo.

[0008] The intelligent control valve includes a valve body, which is fixedly connected to the bottom end of the connecting pipe. A feeding pipe is fixedly installed at the bottom end of the valve body. A cylinder is fixedly installed on one side of the valve body, and a valve plate is fixedly connected to the output end of the cylinder. The valve plate is horizontally telescopically arranged inside the valve body.

[0009] By adopting the above structure, the valve plate is moved and extended inside the valve body by the cylinder, which enables the feeding pipe to feed the material precisely. This allows the dust mixed inside the air mixing component to enter the vertical cooling component precisely, thus achieving precise control of the dust feeding.

[0010] The grate unit includes a first grate, which is located below the discharge end of the rotary kiln. A second grate is fixedly connected to the bottom end of the first grate, which is located below the discharge end of the feeding pipe. Connecting plates are fixedly connected to the outer ends of the first and second grates, and the three connecting plates are fixedly installed on the inner wall of the vertical box.

[0011] By adopting the above structure, the first and second grate plates are set in an "in" shape, which allows the upper feed inlet of the vertical box to be precisely divided by the grate plate unit. This facilitates the rapid mixing of the high-temperature lime from the rotary kiln and the dust from the feed pipe into the interior of the vertical box through the first and second grate plates, avoiding interference with the discharge of the rotary kiln and ensuring the working effect of the rotary kiln.

[0012] The three conveying pipes are the finished ash conveying pipe, the flue gas ash conveying pipe, and the raw material ash conveying pipe, respectively. The finished ash conveying pipe is fixedly connected between the air mixing component and the finished dust removal device, and a finished ash electric control valve is connected to the finished ash conveying pipe. The flue gas ash conveying pipe is fixedly connected between the flue gas dust removal component and the air mixing component, and a flue gas ash electric control valve is fixedly connected to the flue gas ash conveying pipe. The raw material ash conveying pipe is fixedly installed between the air mixing component and the raw material dust removal component, and a raw material ash electric control valve is fixedly installed on the raw material ash conveying pipe.

[0013] By adopting the above structure and installing an electric control valve on each conveying pipe, the electric control valve can accurately control the amount of dust ash conveyed in each conveying pipe, which facilitates the precise proportioning of dust ash inside the mixing drum. Thus, by adjusting the blending ratio of three different types of dust ash, the activity of the final finished lime can be directly and flexibly adjusted, achieving intelligent and precise proportioning.

[0014] The raw material dust removal assembly includes a dust collection box, and a dust generation point of a feeding device is connected to the lower side of the dust collection box via a pipeline. Multiple filter bags are fixedly connected to the upper inner part of the dust collection box. A dust collection hopper is fixedly connected to the bottom of the dust collection box, and a dust discharge wheel is rotatably connected to the lower part of the dust collection hopper. A dust conveying box is fixedly connected to the discharge end of the dust discharge wheel, and the dust conveying box is connected to a raw material ash conveying pipe through a raw material ash electric control valve.

[0015] With the above structure, the filter bag is made of PTFE membrane filter bag to achieve surface filtration, ensuring extremely high collection efficiency and good dust removal effect. Moreover, through the setting of the raw material ash electric control valve, the raw material ash inside the ash feeding box can be accurately fed to the raw material ash conveying pipe, ensuring the proportioning effect and mixing accuracy of the subsequent air mixing components.

[0016] The lower part of the flue gas dust removal component is connected to an ash storage tank, and the ash storage tank is connected to a flue gas ash conveying pipe through a flue gas ash electric control valve. The flue gas dust removal component is also connected to a chimney to discharge purified air.

[0017] With the above structure, the flue gas dust removal component is connected downstream of the cyclone dust collector, which can perform fine dust removal on the flue gas after the cyclone dust collector and collect the fine particulate dust in the ash storage tank. The ash storage tank is then transported to the inside of the mixing drum through the flue gas ash conveying pipe.

[0018] The finished product dust removal device adopts a pulse jet bag filter, and the dust collection box of the finished product dust removal device is connected to the finished product ash conveying pipe.

[0019] With the above structure, the outer wall of the pulse jet bag filter is equipped with a heat insulation layer to prevent the highly active CaO dust from absorbing moisture and caking in the ash hopper. Moreover, the finished product dust removal device allows the highly active finished product powder to be reused and retains its chemical activity to the maximum extent.

[0020] A kiln head cover is fixedly installed between the rotary kiln and the vertical cooling assembly, and the kiln head cover is located on one side of the valve body.

[0021] The above structure ensures that the material inside the rotary kiln enters the vertical cooling assembly precisely, guaranteeing the stability of the equipment connection.

[0022] A rotary kiln lime calcination process for realizing the recycling of dust collector ash, employing the aforementioned rotary kiln lime calcination system for realizing the recycling of dust collector ash, includes the following steps: S1. Dust Collection: During the feeding process, the limestone raw material collects dust through the raw material dust collection component to obtain raw material dust. In the process of rotary kiln flue gas treatment, dust is collected sequentially by cyclone dust collector and flue gas dust removal components to obtain flue gas dust; During the conveying and screening process of calcined lime, dust is collected by a finished product dust removal device to obtain finished dust removal ash; S2. Proportional Mixing: Based on the required activity of the target finished lime, determine the mixing mass ratio between raw material dust collector ash, flue gas dust collector ash, and finished dust collector ash. Set the feeding speed of each dust collector ash by controlling the electric control valve on the conveying pipeline, so that the three types of dust collector ash are efficiently mixed in the air mixing component to achieve the initial homogenization of the dust collector ash. S3. Cooling and final mixing: The dust collected in the air mixing component is sent to the vertical cooling component through the intelligent control valve. In the vertical cooling component, it is rapidly mixed with the high-temperature lime discharged from the rotary kiln head. The material is cooled by counter-current cold air in the vertical cooling component and further mixed and homogenized by the internal mixing blades to finally obtain finished lime with the required temperature. The temperature of the high-temperature lime is 1100-1200℃; S4. Finished product output: The cooled and homogenized finished lime is transported to the finished product warehouse for storage.

[0023] By adopting the above process, the proportion of the three types of dust collector ash can be controlled by an electronically controlled valve according to the target activity of the finished product required for production. Combining the activity data of various types of dust collector ash and the basic activity of hot lime, the required total blending ratio of the three types of dust collector ash and the internal mass ratio of the three types of dust collector ash can be calculated. Thus, the activity of lime can be adjusted by using dust collector ash with different activities as a regulator. Furthermore, the closed-loop recycling and resource utilization of dust collector ash in the three major links of raw materials, flue gas and finished products is realized, completely eliminating ash and slag emissions and achieving significant environmental benefits.

[0024] The main component of the raw material dust in S1 is CaCO3, with an activity ≤50mL; The flue gas dust contains CaO and CaCO3, with an activity of 100-250 mL. The main component of the finished dust is CaO, with an activity ≥350mL; The total amount of raw material dust, flue gas dust, and finished product dust added in S3 accounts for 1.0wt%-10.0wt% of the mass of high-temperature lime.

[0025] Using the above process, the raw material dust has extremely low activity and mainly plays a role in physical dilution and auxiliary cooling. The flue gas dust has medium activity and plays a role in buffering and fine-tuning. The finished dust has high activity and is the key component for improving product activity. By adjusting the ratio of the three types of dust, we can ensure a significant and linear adjustment effect on product activity, ensure that all dust is completely absorbed, and maintain uniform mixing.

[0026] Compared with the prior art, the rotary kiln lime calcination system and process for realizing the recycling of dust ash of the present invention has the following advantages: 1. In this invention, by setting up three independent dust collection and utilization systems for raw materials, flue gas, and finished products, the dust generated in the entire lime production process is systematically collected and reused as a raw material component in the product. This achieves full resource utilization and zero emission of dust, completely solving the environmental pollution problem caused by the discharge of dust as solid waste in traditional processes, and realizing true clean production and resource recycling.

[0027] 2. In this invention, under the action of the air mixing component, the mixing cylinder with a hollow cone ensures the direct mixing effect of the three types of dust, breaking through the traditional mode of adjusting the activity by relying solely on calcination parameters. It innovatively uses dust with different activity levels as a regulator, and through the setting of the electric control valve, the amount added can be precisely adjusted, which can flexibly and accurately produce lime products with different activity levels, thereby increasing the added value of the products.

[0028] 3. In this invention, by placing the air mixing component before the vertical cooling component, the lower-temperature dust can mix and exchange heat with the high-temperature lime just discharged from the rotary kiln upon entering the vertical cooling component. This not only utilizes waste heat to improve mixing efficiency but also significantly reduces the initial temperature of the material entering the cooler, thereby reducing the heat load on the vertical cooling component, lowering the energy consumption of the cooling fan, and achieving process integration and energy saving.

[0029] 4. In this invention, a two-stage mixing process is formed by the aerodynamic mixing in the air mixing component and the mechanical mixing inside the vertical cooling component. This ensures that the dust and the main lime are fully and uniformly mixed, effectively avoiding fluctuations in product activity caused by uneven mixing, and ensuring the consistency and reliability of the final product quality. Attached Figure Description

[0030] Figure 1 This is a top view schematic diagram of a rotary kiln lime calcination system for realizing the recycling of dust ash according to the present invention; Figure 2 This is a side view structural diagram of a rotary kiln lime calcination system for realizing the recycling of dust ash according to the present invention. Figure 3 This is a schematic diagram of the air mixing component in this invention; Figure 4 This is a cross-sectional structural diagram of the air mixing component in this invention; Figure 5 This is a cross-sectional three-dimensional structural diagram of the mixing cylinder in this invention; Figure 6 This is a cross-sectional structural diagram of the vertical cooling assembly in this invention; Figure 7 This is a schematic diagram of the structure of the grate unit in this invention; Figure 8 This is a schematic diagram of the connection structure between the rotating shaft and the connecting arm in this invention; Figure 9 This is a cross-sectional structural diagram of the raw material dust removal component in this invention; Figure 10 This is a flowchart of a rotary kiln lime calcination process for realizing the recycling of dust ash in this invention.

[0031] In the diagram, 1. Feeding device; 2. Raw material dust removal assembly; 201. Dust collector; 202. Filter bag; 203. Ash collection hopper; 204. Ash discharge wheel; 205. Ash delivery box; 3. Raw material preheater; 4. Rotary kiln; 41. Kiln head hood; 5. Cyclone dust collector; 6. Flue gas dust removal assembly; 61. Chimney; 62. Ash storage tank; 7. Vertical cooling assembly; 701. Vertical box; 702. Grate unit; 7021. Connecting plate; 7022. First grate; 7023. Second grate; 703. Cooling duct; 7 04. Air cap; 705. Rotating shaft; 706. Connecting arm; 707. Mixing blade; 8. Air mixing assembly; 801. Mixing cylinder; 802. Baffle; 803. Centrifugal fan; 804. Connecting pipe; 805. Valve body; 806. Cylinder; 807. Valve plate; 808. Feeding pipe; 9. Finished product ash conveying pipe; 10. Finished product dust removal device; 11. Finished product silo; 12. Flue gas ash conveying pipe; 13. Raw material ash conveying pipe; 14. Finished product ash electric control valve; 15. Flue gas ash electric control valve; 16. Raw material ash electric control valve. Detailed Implementation

[0032] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0033] like Figures 1-10As shown, a rotary kiln lime calcination system for realizing dust collection and utilization includes a feeding device 1, a raw material dust removal assembly 2, a dust collector 201, a filter bag 202, an ash collection hopper 203, an ash discharge wheel 204, an ash delivery box 205, a raw material preheater 3 connected to the feeding device 1, a rotary kiln 4 connected to the raw material preheater 3's discharge chute, a kiln head hood 41, a cyclone dust collector 5 connected to the flue gas outlet of the raw material preheater 3 via a pipeline, and a flue gas... Dust removal assembly 6, chimney 61, ash storage tank 62, vertical cooling assembly 7, vertical box 701, grate unit 702, connecting plate 7021, first grate 7022, second grate 7023, cooling air duct 703, air cap 704, rotating shaft 705, connecting arm 706, mixing blade 707, air mixing assembly 8, mixing cylinder 801, baffle 802, centrifugal fan 803, connecting pipe 804, valve body 805, cylinder 8 06, Valve plate 807, Feeding pipe 808, Finished ash conveying pipe 9, Finished dust removal device 10, Finished product silo 11, Flue gas ash conveying pipe 12, Raw material ash conveying pipe 13, Finished ash electric control valve 14, Flue gas ash electric control valve 15 and Raw material ash electric control valve 16. The discharge end of the rotary kiln 4 is connected to a vertical cooling assembly 7. A kiln head hood 41 is fixedly installed between the rotary kiln 4 and the vertical cooling assembly 7 to ensure that the material inside the rotary kiln 4 accurately enters the interior of the vertical cooling assembly 7 and ensures the stability of the equipment connection. The finished product silo 11 is connected to the bottom of the vertical cooling assembly 7 through a conveying device. An air mixing assembly 8 is installed at the top inlet of the vertical cooling assembly 7, and three conveying pipes are fixedly connected to the top of the air mixing assembly 8. The three conveying pipes are respectively connected to the raw material dust removal assembly 2, the finished product dust removal device 10 and the flue gas dust removal assembly 6, and each of the three conveying pipes is equipped with an electric control valve. Furthermore, the three conveying pipes are the finished ash conveying pipe 9, the flue gas ash conveying pipe 12, and the raw material ash conveying pipe 13. The finished ash conveying pipe 9 is fixedly connected between the air mixing component 8 and the finished product dust removal device 10, and a finished ash electric control valve 14 is connected to the finished ash conveying pipe 9. The flue gas ash conveying pipe 12 is fixedly connected between the flue gas dust removal component 6 and the air mixing component 8, and a flue gas ash electric control valve 15 is fixedly connected to the flue gas ash conveying pipe 12. The raw material ash conveying pipe 13 is fixedly installed between the air mixing component 8 and the raw material dust removal component 2, and a raw material ash electric control valve 16 is fixedly installed on the raw material ash conveying pipe 13. By setting an electric control valve on each conveying pipe, the electric control valve can accurately control the amount of dust removal ash conveyed in each conveying pipe, which facilitates the precise proportioning of dust removal ash inside the mixing cylinder 801. Thus, by adjusting the mixing ratio of three different types of dust removal ash, the activity of the final finished lime can be directly and flexibly adjusted, achieving intelligent and precise proportioning.

[0034] The raw material dust collection assembly 2 is connected to the feeding device 1 via a duct, and passes through the bottom of the finished product dust collection device 10. The raw material dust collection assembly 2 includes a dust collection box 201, and the dust generation point of the feeding device 1 is connected to the lower side of the dust collection box 201 via a pipe. Multiple filter bags 202 are fixedly connected to the upper inner part of the dust collection box 201. A dust collection hopper 203 is fixedly connected to the bottom of the dust collection box 201, and a dust discharge wheel 204 is rotatably connected to the lower part of the dust collection hopper 203. The discharge end of the dust discharge wheel 204... A fixed ash feeding box 205 is connected, and the ash feeding box 205 is connected to the raw ash conveying pipe 13 through the raw ash electric control valve 16. The filter bag 202 is a PTFE membrane filter bag to achieve surface filtration, ensuring extremely high collection efficiency and good dust removal effect. Moreover, through the setting of the raw ash electric control valve 16, the raw ash inside the ash feeding box 205 can accurately supply the raw ash conveying pipe 13, ensuring the proportioning effect and mixing accuracy of the subsequent air mixing component 8. The finished product dust removal device 10 is fixedly installed at the dust generation point of the finished product warehouse 11. The finished product dust removal device 10 adopts a pulse jet bag filter, and the dust collection box of the finished product dust removal device 10 is connected to the finished product ash conveying pipe 9. The outer wall of the pulse jet bag filter is provided with a heat insulation layer to prevent the high-activity CaO dust from absorbing moisture and caking in the ash hopper. Moreover, through the installation of the finished product dust removal device 10, the high-activity finished product micro powder is reused and its chemical activity is preserved to the maximum extent. The flue gas dust removal component 6 is connected to the flue gas outlet pipe of the cyclone dust collector 5 via a pipeline. The lower part of the flue gas dust removal component 6 is connected to an ash storage tank 62, and the ash storage tank 62 is connected to a flue gas ash conveying pipe 12 via a flue gas ash electric control valve 15. The flue gas dust removal component 6 is also connected to a chimney 61 to discharge purified air. By connecting to the downstream of the cyclone dust collector 5, the flue gas dust removal component 6 can perform fine dust removal on the flue gas after cyclone dust removal and collect the fine particulate dust in the ash storage tank 62. The ash storage tank 62 is conveyed to the inside of the mixing cylinder 801 via the flue gas ash conveying pipe 12. Furthermore, the air mixing assembly 8 includes a mixing cylinder 801 with a hollow cone-shaped lower part, and a baffle 802 is fixedly installed inside the mixing cylinder 801 at its upper part. A centrifugal fan 803 is connected above the baffle 802. A connecting pipe 804 is fixedly installed at the bottom of the mixing cylinder 801, and a smart control valve is installed below the connecting pipe 804. A feeding pipe 808 is fixedly connected to the bottom end of the smart control valve, and the feeding pipe 808 is fixedly connected to the inlet of the vertical cooling assembly 7 at its bottom end. Specifically, the smart control valve includes a valve body 805, and the valve body 805 is fixedly connected to the connecting pipe 804 at its lower part. A feeding pipe 808 is fixedly installed at the bottom end of the pipe 804 and the bottom end of the valve body 805. A cylinder 806 is fixedly installed on one side of the valve body 805, and a valve plate 807 is fixedly connected to the output end of the cylinder 806. The valve plate 807 is horizontally telescopically installed inside the valve body 805. By driving the cylinder 806 to extend and retract the valve plate 807 inside the valve body 805, the feeding pipe 808 can accurately feed the material, so that the dust mixed inside the air mixing component 8 can accurately enter the interior of the vertical cooling component 7, thus realizing precise control of the dust feeding. The vertical cooling assembly 7 includes a vertical box 701. The upper part of the vertical box 701 is connected to the discharge end of the feeding pipe 808 and the discharge end of the rotary kiln 4. The internal part of the vertical box 701 is fixedly connected to a grate unit 702, and the grate unit 702 is fixedly installed on the inner top wall of the vertical box 701 in an "in" shape. The lower part of the vertical box 701 is fixedly installed with a cooling air duct 703, and one end of the cooling air duct 703 is fixedly connected to an air cap 704. The cooling air duct 703 and the air cap 704 are existing vertical cooler structures, which will not be described in detail here. Furthermore, a rotating shaft 705 is rotatably connected inside the vertical box 701. The rotating shaft 705 is located between the air cap 704 and the grate unit 702. The rotating shaft 705 is driven by a drive motor, which is fixedly installed on the outside of the vertical box 701. Multiple connecting arms 706 are circumferentially and staggeredly connected to the outer wall of the rotating shaft 705, and a mixing blade 707 is fixedly installed at the outer end of each connecting arm 706. The mixing blade 707 is arranged in a "U" shape to facilitate high-speed mixing of high-temperature lime and dust during rotation. The grate unit 702 includes a first grate 7022, which is located below the discharge end of the rotary kiln 4, and the bottom end of the first grate 7022 is fixedly connected to... A second grate plate 7023 is connected, located below the discharge end of the feed pipe 808. The outer ends of the first grate plate 7022 and the second grate plate 7023 are fixedly connected to connecting plates 7021. The three connecting plates 7021 are fixedly installed on the inner wall of the vertical box 701. The first grate plate 7022 and the second grate plate 7023 are arranged in an "in" shape, so that the upper feed port of the vertical box 701 is precisely divided by the grate plate unit 702. This allows the high-temperature lime of the rotary kiln 4 and the dust from the feed pipe 808 to enter the interior of the vertical box 701 through the first grate plate 7022 and the second grate plate 7023 respectively for rapid mixing, avoiding interference with the discharge of the rotary kiln 4 and ensuring the working effect of the rotary kiln 4.

[0035] A rotary kiln 4 lime calcination process for realizing the recycling of dust collector ash, employing a rotary kiln 4 lime calcination system for realizing the recycling of dust collector ash, the process includes the following steps: S1. Dust Collection: During the feeding process, the limestone raw material collects dust through the raw material dust collection component 2 to obtain raw material dust. The main component of the raw material dust is CaCO3, with an activity of ≤50mL. The raw material dust has extremely low activity and mainly plays a role in physical dilution and auxiliary cooling. During the flue gas treatment process of rotary kiln 4, dust is collected sequentially by cyclone dust collector 5 and flue gas dust removal component 6 to obtain flue gas dust. The flue gas dust contains CaO and CaCO3, with an activity of 100-250mL. The flue gas dust has moderate activity and plays a buffering and fine-tuning role. The finished dust has high activity and is a key component for improving product activity. During the conveying and screening process of calcined lime, dust is collected by the finished product dust removal device 10 to obtain finished dust removal ash. The main component of the finished dust removal ash is CaO, with an activity of ≥350mL. The finished dust removal ash has high activity and is a key component for improving product activity. S2. Proportional Mixing: Based on the target finished lime activity requirements, determine the mixing mass ratio between raw material dust collector ash, flue gas dust collector ash, and finished dust collector ash. By controlling the electric control valve on the conveying pipeline, set the feeding speed and feed amount of each dust collector ash, so that the three dust collector ashes are efficiently mixed in the air mixing component 8 to achieve the initial homogenization of the dust collector ash. S3. Cooling and Final Mixing: The dust collected in the air mixing component 8 is precisely fed into the vertical cooling component 7 through an intelligent control valve. The total amount of raw material dust, flue gas dust, and finished product dust added accounts for 1.0wt%-10.0wt% of the mass of high-temperature lime. Within this range, it can ensure a significant and linear adjustment effect on the activity of the product, ensure that all dust is completely absorbed, and maintain the uniformity of mixing. The dust collected in the vertical cooling component 7 is rapidly mixed with the high-temperature lime discharged from the kiln head of the rotary kiln 4 at a temperature of 1100-1200℃. The material is cooled by counter-current cold air in the vertical cooling component 7 and further mixed and homogenized by the internal mixing blade 707, finally obtaining finished lime with the required temperature. S4. Finished product output: The cooled and homogenized finished lime is transported to the finished product warehouse 11 for storage.

[0036] In summary, this invention, by setting up three independent dust collection and utilization systems for raw materials, flue gas, and finished products, systematically collects the dust generated throughout the entire lime production process and reuses it as a raw material component in the product. This achieves full resource utilization and zero emissions of dust, completely solving the environmental pollution problem caused by the discharge of dust as solid waste in traditional processes. It realizes truly clean production and resource recycling, and solves the technical problems of existing rotary kiln lime calcination systems that cannot recycle dust during the production process, cannot eliminate waste ash emissions, and cannot scientifically proportion and mix dust from different sources and with different activities to achieve precise adjustment of the activity of the finished lime.

[0037] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A rotary kiln lime calcination system for realizing the recycling of dust, comprising a feeding device (1), a raw material preheater (3) connected to the feeding device (1), a rotary kiln (4) connected to the discharge trough of the raw material preheater (3), and a cyclone dust collector (5) connected to the flue gas outlet of the raw material preheater (3) via a pipeline, characterized in that, The discharge end of the rotary kiln (4) is connected to a vertical cooling assembly (7). The bottom of the vertical cooling assembly (7) is connected to a finished product bin (11) via a conveying device. An air mixing assembly (8) is installed at the top feed inlet of the vertical cooling assembly (7). Three conveying pipes are fixedly connected to the top of the air mixing assembly (8). The three conveying pipes are respectively connected to a raw material dust removal assembly (2), a finished product dust removal device (10), and a flue gas dust removal assembly (6). Each of the three conveying pipes is equipped with an electric control valve. The raw material dust removal component (2) is connected to the feeding device (1) through a duct, and the bottom of the finished product dust removal device (10) passes through it; The finished product dust removal device (10) is fixedly installed at the dust generation point of the finished product warehouse (11); The flue gas dust removal assembly (6) is connected to the flue gas outlet pipe of the cyclone dust collector (5) via a pipeline; The air mixing assembly (8) includes a mixing cylinder (801) with a hollow cone shape at the bottom, and a baffle (802) is fixedly installed inside the mixing cylinder (801) at the top. A centrifugal fan (803) is connected above the baffle (802). A connecting pipe (804) is fixedly installed at the bottom of the mixing cylinder (801), and a smart control valve is installed below the connecting pipe (804). A feeding pipe (808) is fixedly connected to the bottom end of the smart control valve, and the inlet of the vertical cooling assembly (7) is fixedly connected to the bottom end of the feeding pipe (808). The vertical cooling assembly (7) includes a vertical box (701), with the discharge end of a feeding pipe (808) and the discharge end of a rotary kiln (4) connected to the top of the vertical box (701). A grate unit (702) is fixedly connected inside the vertical box (701), and the grate unit (702) is fixedly installed on the inner top wall of the vertical box (701) in an "in" shape. A cooling air duct (703) is fixedly installed below the vertical box (701), and a wind cap (704) is fixedly connected to one end of the cooling air duct (703). The upright box (701) is rotatably connected to a rotating shaft (705). The rotating shaft (705) is located between the vent cap (704) and the grate unit (702). The rotating shaft (705) is driven by a drive motor, which is fixedly installed on the outside of the upright box (701). Multiple connecting arms (706) are connected to the outer wall of the rotating shaft (705) in an interlocking ring. A mixing blade (707) is fixedly installed at the outer end of each connecting arm (706).

2. The rotary kiln lime calcination system for realizing the recycling of dust collector ash according to claim 1, characterized in that, The intelligent control valve includes a valve body (805), which is fixedly connected to the bottom end of the connecting pipe (804). A feeding pipe (808) is fixedly installed at the bottom end of the valve body (805). A cylinder (806) is fixedly installed on one side of the valve body (805), and a valve plate (807) is fixedly connected to the output end of the cylinder (806). The valve plate (807) is horizontally telescopically arranged inside the valve body (805).

3. The rotary kiln lime calcination system for realizing the recycling of dust collector ash according to claim 1, characterized in that, The grate unit (702) includes a first grate (7022), which is located below the discharge end of the rotary kiln (4). A second grate (7023) is fixedly connected to the bottom end of the first grate (7022), which is located below the discharge end of the feed pipe (808). A connecting plate (7021) is fixedly connected to the outer ends of the first grate (7022) and the second grate (7023). The three connecting plates (7021) are fixedly installed on the inner wall of the vertical box (701).

4. The rotary kiln lime calcination system for realizing the recycling of dust collector ash according to claim 1, characterized in that, The three conveying pipes are the finished ash conveying pipe (9), the flue gas ash conveying pipe (12), and the raw material ash conveying pipe (13). The finished ash conveying pipe (9) is fixedly connected between the air mixing component (8) and the finished dust removal device (10), and the finished ash conveying pipe (9) is connected to the finished ash electric control valve (14). The flue gas ash conveying pipe (12) is fixedly connected between the flue gas dust removal component (6) and the air mixing component (8), and a flue gas ash electric control valve (15) is fixedly connected to the flue gas ash conveying pipe (12). The raw material ash conveying pipe (13) is fixedly installed between the air mixing component (8) and the raw material dust removal component (2), and a raw material ash electric control valve (16) is fixedly installed on the raw material ash conveying pipe (13).

5. A rotary kiln lime calcination system for realizing the recycling of dust collector ash according to claim 4, characterized in that, The raw material dust removal assembly (2) includes a dust removal box (201), and the dust generation point of the feeding device (1) is connected to the lower side of the dust removal box (201) through a pipeline. Multiple filter bags (202) are fixedly connected to the upper inner part of the dust removal box (201). A dust collection hopper (203) is fixedly connected to the bottom end of the dust removal box (201), and a dust discharge wheel (204) is rotatably connected to the lower part of the dust collection hopper (203). A dust discharge box (205) is fixedly connected to the discharge end of the dust discharge wheel (204), and a raw material ash conveying pipe (13) is connected to the dust discharge box (205) through a raw material ash electric control valve (16).

6. A rotary kiln lime calcination system for realizing the recycling of dust collector ash according to claim 4, characterized in that, The lower part of the flue gas dust removal assembly (6) is connected to an ash storage tank (62), and the ash storage tank (62) is connected to a flue gas ash conveying pipe (12) through a flue gas ash electric control valve (15). The flue gas dust removal assembly (6) is also connected to a chimney (61) to discharge purified air.

7. A rotary kiln lime calcination system for realizing the recycling of dust collector ash according to claim 4, characterized in that, The finished product dust removal device (10) adopts a pulse jet bag filter, and the dust collection box of the finished product dust removal device (10) is connected to the finished product ash conveying pipe (9).

8. A rotary kiln lime calcination system for realizing the recycling of dust collector ash according to claim 1, characterized in that, A kiln head cover (41) is fixedly installed between the rotary kiln (4) and the vertical cooling assembly (7), and the kiln head cover (41) is located on one side of the valve body (805).

9. A rotary kiln lime calcination process for realizing the recycling of dust, characterized in that, The rotary kiln lime calcination system for realizing dust ash recovery and utilization according to any one of claims 1-8 includes the following steps: S1. Dust collection: During the feeding process, the limestone raw material collects dust through the raw material dust collection component (2) to obtain raw material dust. During the flue gas treatment process of the rotary kiln (4), dust is collected sequentially by the cyclone dust collector (5) and the flue gas dust removal assembly (6) to obtain flue gas dust; During the conveying and screening process of calcined lime, dust is collected by the finished product dust removal device (10) to obtain finished dust removal ash; S2, Proportional Mixing: Based on the target finished lime activity requirements, determine the mixing mass ratio between raw material dust, flue gas dust and finished dust, and set the feeding speed of each dust by controlling the electric control valve on the conveying pipeline, so that the three dusts are efficiently mixed in the air mixing component (8) to achieve the initial homogenization of dust. S3, Cooling and final mixing: The dust collected in the air mixing component (8) is sent to the vertical cooling component (7) through the intelligent control valve. In the vertical cooling component (7), it is rapidly mixed with the high-temperature lime discharged from the kiln head of the rotary kiln (4). The material is cooled by counter-current cold air in the vertical cooling component (7) and further mixed and homogenized by the internal mixing blade (707) to finally obtain finished lime with the required temperature. The temperature of the high-temperature lime is 1100-1200℃; S4. Finished product output: The cooled and homogenized finished lime is transported to the finished product warehouse (11) for storage.

10. A rotary kiln lime calcination process for realizing the recycling of dust collector ash according to claim 9, characterized in that, The main component of the raw material dust in S1 is CaCO3, with an activity ≤50mL; The flue gas dust contains CaO and CaCO3, with an activity of 100-250 mL. The main component of the finished dust is CaO, with an activity ≥350mL; The total amount of raw material dust, flue gas dust, and finished product dust added in S3 accounts for 1.0wt%-10.0wt% of the mass of high-temperature lime.

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