Gas-solid separation device and calcium carbonate preparation process

Abstract

The application discloses a gas-solid separation device and a calcium carbonate preparation process. The gas-solid separation device comprises an outer cylinder, a gas inlet pipe fixedly connected with the side wall of the outer cylinder and communicating with the top of the outer cylinder, an inner cylinder fixedly connected with the inner top wall of the outer cylinder and communicating with the inner top wall, and outer spiral blades fixedly sleeved on the inner cylinder and located between the inner cylinder and the inner wall of the outer cylinder. The top of the outer cylinder is fixedly connected with a gas outlet pipe for discharging the gas entering from the lower end of the inner cylinder. The bottom of the outer cylinder is provided with a discharge assembly. The top of the outer cylinder is provided with a central shaft rotatably connected with the top. The bottom of the inner cylinder is provided with a filter screen assembly sleeved on the central shaft. The outer cylinder is provided with a driving mechanism for controlling the rotation of the central shaft to make the filter screen assembly vibrate. The application can vibrate and clean the filter screen assembly, and ensures the filtering effect and the gas-solid separation efficiency.

Description

Technical Field

[0001] This invention relates to the field of separation device technology, and in particular to a gas-solid separation device and a calcium carbonate preparation process. Background Technology

[0002] A gas-solid separation device is a device used to separate gas and solid particles. Its working principle is mainly based on the differences in physical properties (such as density, particle size, inertial force, centrifugal force, etc.) between gas and solid particles. Through specific structural design and operation, gas and solid are separated, thereby achieving the purpose of purifying gas or recovering solid particles. Common gas-solid separation devices include cyclone separators, bag filters, and electrostatic precipitators.

[0003] In the process of calcium carbonate production, whether through natural ore processing or chemical synthesis methods (such as carbonation), a gaseous mixture containing calcium carbonate particles is generated. For example, in the carbonation process for calcium carbonate production, the calcium carbonate particles generated by the reaction are suspended in gases (such as carbon dioxide, air, etc.). In order to obtain pure calcium carbonate products and achieve gas recycling or compliant emissions, a gas-solid separation device is needed to separate the calcium carbonate particles from the gas.

[0004] Existing general-purpose cyclone separators typically include an outer cylinder, an inlet pipe fixed to and connected to the side wall of the outer cylinder near its top, an inner cylinder fixed to and connected to the inner top wall of the outer cylinder, external spiral blades fixedly sleeved on the inner cylinder and located between the inner and outer cylinder walls, an outlet pipe fixed to and connected to the top of the outer cylinder for discharging gas entering from the bottom of the inner cylinder, and a discharge assembly at the bottom of the outer cylinder. To filter the gas entering the inner cylinder, a filter screen is usually installed at the bottom of the inner cylinder. However, after prolonged use, the filter screen easily becomes covered with dust, which affects subsequent normal filtration and normal gas discharge. Summary of the Invention

[0005] To address the above problems, this invention provides a gas-solid separation device and a calcium carbonate preparation process.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a gas-solid separation device, comprising an outer cylinder, an air inlet pipe fixed and connected to the side wall of the outer cylinder near its top, an inner cylinder fixed and connected to the inner top wall of the outer cylinder, and an outer spiral blade fixedly sleeved on the inner cylinder and located between the inner cylinder and the inner wall of the outer cylinder. An air outlet pipe for discharging gas entering from the lower end of the inner cylinder is fixedly connected to the top of the outer cylinder. A discharge assembly is provided at the bottom of the outer cylinder. A central shaft rotatably connected to the top of the outer cylinder is provided through the outer cylinder. A filter screen assembly sleeved on the central shaft is provided at the bottom of the inner cylinder. A drive mechanism for controlling the rotation of the central shaft to cause the filter screen assembly to vibrate is provided on the outer cylinder.

[0007] By adopting the above technical solution, the gas-solid-liquid mixture containing calcium carbonate particles enters the outer cylinder through the inlet pipe. Under the action of centrifugal force, the airflow spirals down along the outer spiral blades between the outer and inner cylinders. Subsequently, under the action of the outlet pipe connected to the external air extraction system, the airflow passes through the filter screen assembly and then through the movable plate, and is finally discharged through the outlet pipe. In the above process, the drive mechanism can cause the filter screen assembly to vibrate by driving the central shaft to rotate, thereby causing the fine particles intercepted by the filter screen assembly to be trapped and fall to the bottom of the outer cylinder, ensuring the normal filtration effect of the filter screen assembly and the normal use of the gas-solid separation device.

[0008] Furthermore, the filter assembly includes a movable plate sleeved on and fitted with the central shaft with a clearance, a connecting block fixed to the bottom of the movable plate, a filter body fixed to the connecting block, and a flexible plate fixed to the side wall of the filter body. The side wall of the movable plate slides with the inner wall of the inner cylinder. The top of the filter body extends to the side near the central shaft. There are three connecting blocks, three filter bodies, and three flexible plates. The three filter bodies and the flexible plates are alternately arranged and together form a frustum-shaped filter structure. The filter assembly also includes an annular cloth sheet fixed to the inner wall of the inner cylinder. The inner side of the annular cloth sheet is fixed to the outer side of the bottom of the flexible plate and the outer side of the bottom of the filter body. An exhaust hole is provided through the movable plate.

[0009] By adopting the above technical solution, the three frustum-shaped filter structures formed by the filter screen and the three flexible plates, together with the annular cloth, play a good filtering role for calcium carbonate particles mixed in the airflow, reducing the probability of calcium carbonate particles being discharged from the exhaust pipe with the airflow.

[0010] Furthermore, a Y-shaped connecting frame is fixed to the inner wall of the inner cylinder near its bottom. The central shaft passes through the middle of the Y-shaped connecting frame and is clearance-fitted. The drive mechanism includes a connecting assembly, which includes a rotating rod rotatably mounted on the support rod of the Y-shaped connecting frame, an inner spiral blade fixedly sleeved on the rotating rod, a connecting rod fixed to the inner side of the filter screen body, and an inclined rod fixed to the side of the connecting rod away from the filter screen body. The inclined rods are arranged in pairs, and the sides of the two inclined rods that are close to each other abut against the two sides of the inner spiral blade. The drive mechanism also includes a drive assembly, which includes a power unit for driving the central shaft to rotate and a transmission unit for driving the rotating rod to rotate when the central shaft rotates.

[0011] By adopting the above technical solution, after the power unit drives the central shaft to rotate, the rotating rod rotates synchronously with the central shaft under the action of the transmission unit. Since both ends of the connecting rod are fixed to the filter screen body and the two inclined rods respectively, and the two inclined rods abut against the two sides of the inner spiral blades, the movable plate, connecting block, filter screen body and flexible plate body all rise synchronously in the vertical direction. The annular cloth undergoes adaptive deformation during this process. As the inner spiral blades rotate with the rotating rod, the filter screen assembly vibrates, thereby shaking off the small amount of calcium carbonate particles attached to the filter screen body and the annular cloth, reducing the probability of the filter screen body and the annular cloth becoming clogged and affecting the filtration effect and gas-solid separation efficiency.

[0012] Furthermore, the connecting assembly has three sets evenly distributed about the axis of the central shaft. The transmission unit includes a lower driving gear fixedly sleeved on the central shaft and a lower driven gear fixed to the upper end of the rotating rod and meshing with the lower driving gear. There are three lower driven gears, and the three lower driven gears are respectively fixed to the upper end of the rotating rod of the three sets of connecting assemblies.

[0013] Furthermore, the central shaft has a tubular structure with an open upper end and a closed lower end. The upper end of the central shaft is connected to a connecting pipe via a rotary joint. The connecting pipe is connected to an external high-pressure inflation system via a flexible hose. An air outlet is provided on the side wall of the central shaft near its lower end. An L-shaped hole extending to the lower end of the rotating rod is provided at the position corresponding to the air outlet on the Y-shaped connecting frame. An air distribution hole extending to the upper end of the inner spiral blade is provided at the lower end of the rotating rod. Air outlets are provided at the relative positions of the side wall of the rotating rod and the inner spiral blade.

[0014] By adopting the above technical solution, in order to enhance the cleaning effect of the filter screen, the staff only needs to input high-pressure air into the central shaft through the external high-pressure air inflation system. The high-pressure airflow is discharged sequentially through the air outlet, L-shaped hole, air distribution hole and air outlet. Since the inner spiral blades rotate continuously with the rotating rod, and the movable plate, connecting block, filter screen and flexible plate all rise synchronously in the vertical direction, the high-pressure airflow blown out from multiple air outlets can fully clean the filter screen, further reducing the efficiency of filter screen clogging and ensuring gas-solid separation efficiency.

[0015] Furthermore, the exhaust vent extends in an arc shape, and three exhaust vents are evenly arranged around the rotating shaft. The bottom of the air inlet pipe is higher than the top of the outer spiral blade, and the orthographic projection of the air outlet pipe is located within the orthographic projection area of ​​the inner cylinder.

[0016] Furthermore, the lower end of the inner spiral blade extends to a position near the top of the Y-shaped connecting frame, a support leg is fixed to the bottom of the outer cylinder, the bottom of the outer cylinder is funnel-shaped, and the discharge assembly includes a discharge pipe fixed to and connected to the bottom of the outer cylinder and a solenoid valve set on the discharge pipe to control the discharge.

[0017] By adopting the above technical solution, after the solenoid valve is opened, the calcium carbonate material that has fallen to the bottom of the inner cylinder is directly discharged from the discharge pipe.

[0018] Furthermore, the power unit includes a motor fixed to the top of the outer cylinder, an upper drive gear fixed to the output end of the motor, and an upper driven gear fixedly sleeved on the central shaft and meshing with the upper drive gear.

[0019] By adopting the above technical solution, after the motor is started, the motor drives the upper driving gear, the upper driven gear meshing with the upper driving gear, and the central shaft fixed to the upper driven gear to rotate. This causes the lower driving gear fixed to the central shaft, the lower driven gear meshing with the lower driving gear, the rotating rod fixed to the lower driven gear, and the inner spiral blade fixed to the rotating rod to rotate, thereby controlling the movable plate, connecting block, filter screen body, and flexible plate body to rise synchronously in the vertical direction.

[0020] This application also discloses a calcium carbonate preparation process, which uses the aforementioned gas-solid separation device and includes the following steps:

[0021] S1. After crushing and grinding limestone, mix it with water and heat it in a digester to generate lime milk. At the same time, the industrial CO2 gas is washed with water and dried for purification.

[0022] S2. The lime slurry is fed into the carbonization reactor, and purified CO2 gas is introduced. The carbonization reaction is carried out under stirring conditions to generate a gas-solid-liquid mixture containing calcium carbonate particles.

[0023] S3. The mixture enters the annular space between the outer and inner cylinders of the gas-solid separation device tangentially through the inlet pipe. Under the action of centrifugal force, larger calcium carbonate particles are thrown against the outer cylinder wall and fall down along the wall. The airflow spirals down along the outer spiral blades between the outer and inner cylinders. Subsequently, under the action of the outlet pipe connected to the external air extraction system, the airflow passes through the filter screen assembly and then through the movable plate, and is finally discharged through the outlet pipe. After the separated and discharged gas is purified, part of it is returned to the carbonization reactor for recycling, and the rest is treated to meet the standards.

[0024] S4. The drive mechanism drives the central shaft to rotate, causing the filter screen assembly at the bottom of the inner cylinder to vibrate. Fine particles intercepted by the filter screen and the annular cloth are trapped and fall to the bottom of the outer cylinder. Calcium carbonate particles are discharged through the discharge assembly, mixed with the liquid to form a slurry, and then filtered to obtain a filter cake. After the filter cake is dried, it is processed into calcium carbonate products of the required particle size by a pulverizer.

[0025] Furthermore, in step S1, the CO2 gas is industrial waste gas or CO2 gas produced by calcining limestone. The CO2 gas is passed into a water washing tower to remove impurities such as dust and sulfides, and then passed into an alkaline washing tower containing a 5-10% NaOH solution to further remove acidic gases. Finally, it is dried in a drying tower until the CO2 purity is ≥98% and the water content is ≤0.1%.

[0026] By adopting the above technical solution, the purity of CO2 gas used in the preparation of calcium carbonate is guaranteed, and the product quality is improved. The above gas-solid separation device can guarantee the gas-solid separation effect and efficiency, and reduce the probability of the gas-solid separation efficiency being affected by the clogging of the filter screen components.

[0027] In summary, the present invention has the following beneficial effects:

[0028] 1. In this application, the gas-solid-liquid mixture containing calcium carbonate particles enters the outer cylinder through the inlet pipe. Under the action of centrifugal force, the airflow spirals down along the outer spiral blades between the outer and inner cylinders. Subsequently, under the action of the outlet pipe connected to the external air extraction system, the airflow passes through the filter screen assembly and then through the movable plate, and is finally discharged through the outlet pipe. In the above process, the drive mechanism can cause the filter screen assembly to vibrate by driving the central shaft to rotate, thereby causing the fine particles intercepted by the filter screen assembly to be trapped and fall to the bottom of the outer cylinder, ensuring the normal filtration effect of the filter screen assembly and the normal use of the gas-solid separation device.

[0029] 2. In this application, to enhance the cleaning effect of the filter screen, the operator only needs to input high-pressure air into the central shaft through the external high-pressure air inflation system. The high-pressure airflow is discharged sequentially through the air outlet, L-shaped hole, air distribution hole and air outlet. Since the inner spiral blades rotate continuously with the rotating rod, and the movable plate, connecting block, filter screen and flexible plate all rise synchronously in the vertical direction, the high-pressure airflow blown out from multiple air outlets can fully clean the filter screen, further reducing the efficiency of filter screen clogging and ensuring gas-solid separation efficiency. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention;

[0031] Figure 2 This is a cross-sectional structural diagram illustrating the internal structure of the outer cylinder in an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram illustrating the structure of the filter assembly in an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram illustrating the structure of the connecting component in an embodiment of the present invention;

[0034] Figure 5 yes Figure 4 Enlarged view of point A in the middle;

[0035] Figure 6 This is a cross-sectional structural diagram of the air distribution hole and air outlet hole according to an embodiment of the present invention;

[0036] Figure 7 yes Figure 6 Enlarged diagram of point B in the middle.

[0037] In the diagram: 1. Outer cylinder; 11. Inlet pipe; 12. Outer spiral blade; 13. Outlet pipe; 14. Support leg; 2. Inner cylinder; 21. Y-shaped connecting frame; 211. L-shaped hole; 3. Discharge assembly; 31. Discharge pipe; 32. Solenoid valve; 4. Central shaft; 41. Connecting pipe; 42. Outlet; 5. Filter assembly; 51. Movable plate; 511. Exhaust vent; 52. Connecting block; 53. Filter body; 54. Flexible plate; 55. Annular cloth 6. Drive mechanism; 61. Connecting assembly; 611. Rotating rod; 6111. Air distribution hole; 6112. Air outlet; 612. Inner spiral blade; 613. Connecting rod; 614. Diagonal rod; 62. Drive assembly; 621. Power unit; 6211. Motor; 6212. Upper drive gear; 6213. Upper driven gear; 622. Transmission unit; 6221. Lower drive gear; 6222. Lower driven gear; 7. Rotary joint. Detailed Implementation

[0038] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0039] like Figure 1-7 As shown in the embodiment of this application, a gas-solid separation device is disclosed, including an outer cylinder 1, an air inlet pipe 11 fixed and connected to the side wall of the outer cylinder 1 near its top, an inner cylinder 2 fixed and connected to the inner top wall of the outer cylinder 1, and an outer spiral blade 12 fixedly sleeved on the inner cylinder 2 and located between the inner wall of the inner cylinder 2 and the inner wall of the outer cylinder 1. An air outlet pipe 13 for discharging gas entering from the lower end of the inner cylinder 2 is fixedly connected to the top of the outer cylinder 1. A discharge assembly 3 is provided at the bottom of the outer cylinder 1. A central shaft 4 is rotatably connected to the top of the outer cylinder 1. A filter screen assembly 5 sleeved on the central shaft 4 is provided at the bottom of the inner cylinder 2. A drive mechanism 6 is provided on the outer cylinder 1 for controlling the rotation of the central shaft 4 so that the filter screen assembly 5 vibrates.

[0040] A gas-solid-liquid mixture containing calcium carbonate particles enters the outer cylinder 1 through the inlet pipe 11. Under the action of centrifugal force, the airflow spirals down along the outer spiral blades 12 between the outer cylinder 1 and the inner cylinder 2. Subsequently, under the action of the outlet pipe 13 connected to the external air extraction system, the airflow passes through the filter screen assembly 5 and then through the movable plate 51, and is finally discharged through the outlet pipe 13. In the above process, the drive mechanism 6 drives the central shaft 4 to rotate, which causes the filter screen assembly 5 to vibrate, thereby trapping the fine particles intercepted by the filter screen assembly 5 and causing them to fall to the bottom of the outer cylinder 1, ensuring the normal filtration effect of the filter screen assembly 5 and the normal use of the gas-solid separation device.

[0041] The filter assembly 5 includes a movable plate 51 sleeved on and fitted with the central shaft 4 with a clearance, a connecting block 52 fixed to the bottom of the movable plate 51, a filter body 53 fixed to the connecting block 52, and a flexible plate 54 fixed to the side wall of the filter body 53. The side wall of the movable plate 51 slides against the inner wall of the inner cylinder 2. The top of the filter body 53 extends to the side near the central shaft 4. The details of the mesh holes in the connecting block 52 and the filter body 53 are only shown in the image below. Figure 3 As shown in the diagram, both the filter screen 53 and the flexible plate 54 are provided with three filters. The three filter screens 53 and the flexible plate 54 are alternately arranged to form a frustum-shaped filter structure. The filter screen assembly 5 also includes an annular cloth sheet 55 fixed to the inner wall of the inner cylinder 2. The inner side of the annular cloth sheet 55 is fixed to the outer bottom of the flexible plate 54 and the outer bottom of the filter screen 53. An exhaust hole 511 is provided through the movable plate 51. The frustum-shaped filter structure formed by the three filter screens 53 and the three flexible plates 54, together with the annular cloth sheet 55, plays a good filtering role for calcium carbonate particles mixed in the airflow, reducing the probability of calcium carbonate particles being discharged from the exhaust pipe with the airflow.

[0042] A Y-shaped connecting frame 21 is fixed to the inner wall of the inner cylinder 2 near its bottom. The central shaft 4 passes through the middle of the Y-shaped connecting frame 21 and is clearance-fitted. The drive mechanism 6 includes a connecting assembly 61, which includes a rotating rod 611 rotatably mounted on the support rod of the Y-shaped connecting frame 21, an inner spiral blade 612 fixedly sleeved on the rotating rod 611, a connecting rod 613 fixed to the inner side of the filter screen body 53, and an inclined rod 614 fixed to the side of the connecting rod 613 away from the filter screen body 53. The inclined rods 614 are arranged in pairs, and the sides of the two inclined rods 614 that are close to each other abut against the two sides of the inner spiral blade 612 respectively. The drive mechanism 6 also includes a drive assembly 62, which includes a power unit 621 for driving the central shaft 4 to rotate and a transmission unit 622 for driving the rotating rod 611 to rotate when the central shaft 4 rotates.

[0043] After the power unit 621 drives the central shaft 4 to rotate, the rotating rod 611 rotates synchronously with the central shaft 4 under the action of the transmission unit 622. Since the two ends of the connecting rod 613 are fixed to the filter screen body 53 and the two inclined rods 614 respectively, and the two inclined rods 614 abut against the two sides of the inner spiral blade 612, the movable plate 51, the connecting block 52, the filter screen body 53 and the flexible plate 54 all rise synchronously in the vertical direction. The annular cloth 55 undergoes adaptive deformation during this process. As the inner spiral blade 612 rotates with the rotating rod 611, the filter screen assembly 5 vibrates, thereby shaking off a small amount of calcium carbonate particles attached to the filter screen body 53 and the annular cloth 55, reducing the probability of the filter screen body 53 and the annular cloth 55 becoming clogged and affecting the filtration effect and gas-solid separation efficiency.

[0044] The connecting assembly 61 has three sets of gears evenly distributed about the axis of the central shaft 4. The transmission unit 622 includes a lower driving gear 6221 fixedly sleeved on the central shaft 4 and a lower driven gear 6222 fixed to the upper end of the rotating rod 611 and meshing with the lower driving gear 6221. There are three lower driven gears 6222, and the three lower driven gears 6222 are respectively fixed to the upper end of the rotating rod 611 of the three sets of connecting assemblies 61.

[0045] The central shaft 4 has a tubular structure with an open upper end and a closed lower end. The upper end of the central shaft 4 is connected to a connecting pipe 41 via a rotary joint 7. The connecting pipe 41 is connected to an external high-pressure inflation system via a flexible hose. An air outlet 42 is provided on the side wall of the central shaft 4 near its lower end. An L-shaped hole 211 extending to the lower end of the rotating rod 611 is provided on the Y-shaped connecting frame 21 at the position corresponding to the air outlet 42. An air distribution hole 6111 extending to the upper end of the inner spiral blade 612 is provided at the lower end of the rotating rod 611. An air outlet 6112 is provided on the side wall of the rotating rod 611 and at the relative positions of the inner spiral blade 612.

[0046] To enhance the cleaning effect of the filter body 53, the operator only needs to input high-pressure air into the central shaft 4 through the external high-pressure air inflation system. The high-pressure airflow is discharged sequentially through the air outlet 42, L-shaped hole 211, air distribution hole 6111 and air outlet 6112. Since the inner spiral blade 612 rotates continuously with the rotating rod 611, and the movable plate 51, connecting block 52, filter body 53 and flexible plate 54 all rise synchronously in the vertical direction, the high-pressure airflow blown out from the multiple air outlets 6112 can fully clean the filter body 53, further reducing the clogging efficiency of the filter body 53 and ensuring the gas-solid separation efficiency.

[0047] The exhaust vent 511 extends in an arc shape, and three exhaust vents 511 are evenly arranged around the rotating shaft. The bottom of the air inlet pipe 11 is higher than the top of the outer spiral blade 12, and the orthographic projection of the exhaust pipe 13 is located within the orthographic projection area of ​​the inner cylinder 2. The lower end of the inner spiral blade 612 extends to a position close to the top of the Y-shaped connecting frame 21. A support leg 14 is fixed to the bottom of the outer cylinder 1, and the bottom of the outer cylinder 1 is funnel-shaped. The discharge assembly 3 includes a discharge pipe 31 fixed to and connected to the bottom of the outer cylinder 1, and a solenoid valve 32 set on the discharge pipe 31 to control the discharge. After the solenoid valve 32 is opened, the calcium carbonate material that falls to the bottom of the inner cylinder 2 is directly discharged from the discharge pipe 31.

[0048] The power unit 621 includes a motor 6211 fixed to the top of the outer cylinder 1, an upper drive gear 6212 fixed to the output end of the motor 6211, and an upper driven gear 6213 fixedly sleeved on the central shaft 4 and meshing with the upper drive gear 6212. After the motor 6211 is started, the motor 6211 drives the upper drive gear 6212, the upper driven gear 6213 meshing with the upper drive gear 6212, and the central shaft 4 fixed to the upper driven gear 6213 to rotate. This causes the lower drive gear 6221 fixed to the central shaft 4, the lower driven gear 6222 meshing with the lower drive gear 6221, the rotating rod 611 fixed to the lower driven gear 6222, and the inner spiral blade 612 fixed to the rotating rod 611 to rotate, thereby controlling the movable plate 51, the connecting block 52, the filter screen 53, and the flexible plate 54 to rise synchronously in the vertical direction.

[0049] This embodiment also discloses a calcium carbonate preparation process, which uses the aforementioned gas-solid separation device, and the process steps are as follows:

[0050] S1. After crushing and grinding limestone, mix it with water and heat it in a digester to generate lime milk. At the same time, the industrial CO2 gas is washed with water and dried for purification.

[0051] S2. The lime slurry is fed into the carbonization reactor, and purified CO2 gas is introduced. The carbonization reaction is carried out under stirring conditions to generate a gas-solid-liquid mixture containing calcium carbonate particles.

[0052] S3. The mixture enters the annular space between the outer cylinder 1 and the inner cylinder 2 of the gas-solid separation device tangentially through the inlet pipe 11. Under the action of centrifugal force, larger calcium carbonate particles are thrown against the wall of the outer cylinder 1 and fall down along the wall. The airflow spirals down along the outer spiral blades 12 between the outer cylinder 1 and the inner cylinder 2. Then, under the action of the outlet pipe 13 connected to the external air extraction system, the airflow passes through the filter screen assembly 5 and then through the movable plate 51, and is finally discharged through the outlet pipe 13. After the separated and discharged gas is purified, part of it is returned to the carbonization reactor for recycling, and the rest is treated to meet the standards.

[0053] S4. The drive mechanism 6 drives the central shaft 4 to rotate, causing the filter screen assembly 5 at the bottom of the inner cylinder 2 to vibrate. Fine particles intercepted by the filter screen body 53 and the annular cloth 55 are trapped and fall to the bottom of the outer cylinder 1. Calcium carbonate particles are discharged through the discharge assembly 3, mixed with liquid to form a slurry, and then filtered to obtain a filter cake. After the filter cake is dried, it is processed into calcium carbonate products of the required particle size by a pulverizer.

[0054] In step S1, the CO2 gas is industrial waste gas or CO2 gas produced by calcining limestone. The CO2 gas is passed into a water washing tower to remove impurities such as dust and sulfides, and then passed into an alkaline washing tower containing a 5-10% NaOH solution to further remove acidic gases. Finally, it is dried in a drying tower until the CO2 purity is ≥98% and the water content is ≤0.1%. This ensures the purity of the CO2 gas used in the preparation of calcium carbonate, improves product quality, and ensures the gas-solid separation effect and efficiency, reducing the probability of affecting the gas-solid separation efficiency due to filter clogging.

[0055] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A gas-solid separation device, comprising an outer cylinder (1), an inlet pipe (11) fixed and connected to the side wall of the outer cylinder (1) near its top, an inner cylinder (2) fixed and connected to the inner top wall of the outer cylinder (1), and an outer spiral blade (12) fixedly sleeved on the inner cylinder (2) and located between the inner walls of the inner cylinder (2) and the outer cylinder (1), wherein the top of the outer cylinder (1) is fixedly connected to an outlet pipe (13) for discharging gas entering from the lower end of the inner cylinder (2), and a discharge assembly (3) is provided at the bottom of the outer cylinder (1), characterized in that: The top of the outer cylinder (1) is provided with a central shaft (4) that is rotatably connected to it, the bottom of the inner cylinder (2) is provided with a filter screen assembly (5) sleeved on the central shaft (4), and the outer cylinder (1) is provided with a drive mechanism (6) for controlling the rotation of the central shaft (4) so ​​that the filter screen assembly (5) vibrates. The filter assembly (5) includes a movable plate (51) sleeved on the central shaft (4) and fitted with a gap therebetween, a connecting block (52) fixed to the bottom of the movable plate (51), a filter body (53) fixed to the connecting block (52), and a flexible plate (54) fixed to the side wall of the filter body (53). The side wall of the movable plate (51) is slidably fitted with the inner wall of the inner cylinder (2). The top of the filter body (53) extends toward the side closer to the central shaft (4). There are three of each of the connecting block (52), the filter body (53), and the flexible plate (54). The three filter bodies (53) and the flexible plate (54) are alternately arranged and together form a frustum-shaped filter structure. The filter assembly (5) also includes an annular cloth piece (55) fixed to the inner wall of the inner cylinder (2). The inner side of the annular cloth piece (55) is fixed to the outer side of the bottom of the flexible plate (54) and the outer side of the bottom of the filter body (53). An exhaust hole (511) is provided through the movable plate (51). A Y-shaped connecting frame (21) is fixed on the inner wall of the inner cylinder (2) near its bottom. The central shaft (4) passes through the middle of the Y-shaped connecting frame (21) and is clearance-fitted. The drive mechanism (6) includes a connecting assembly (61). The connecting assembly (61) includes a rotating rod (611) rotatably mounted on the support rod of the Y-shaped connecting frame (21), an inner spiral blade (612) fixedly sleeved on the rotating rod (611), a connecting rod (613) fixed to the inner side of the filter screen body (53), and a connecting rod (613) and a connecting rod (614). 613) An inclined rod (614) is fixed on the side away from the filter screen body (53). The inclined rods (614) are arranged in pairs. The sides of the two inclined rods (614) that are close to each other abut against the two sides of the inner spiral blade (612). The drive mechanism (6) also includes a drive assembly (62). The drive assembly (62) includes a power unit (621) for driving the central shaft (4) to rotate and a transmission unit (622) for driving the rotating rod (611) to rotate when the central shaft (4) rotates. The central shaft (4) is a tubular structure with an open top and a closed bottom. The upper end of the central shaft (4) is connected to a connecting pipe (41) via a rotary joint (7). The connecting pipe (41) is connected to an external high-pressure inflation system via a flexible hose. An air outlet (42) is provided on the side wall of the central shaft (4) near its lower end. An L-shaped hole (211) extending to the lower end of the rotating rod (611) is provided on the Y-shaped connecting frame (21) at the position corresponding to the air outlet (42). An air distribution hole (6111) extending to the upper end of the inner spiral blade (612) is provided at the lower end of the rotating rod (611). An air outlet (6112) is provided on the side wall of the rotating rod (611) and at the relative positions of the inner spiral blade (612).

2. The gas-solid separation device according to claim 1, characterized in that: The connecting assembly (61) has three sets of gears evenly distributed about the axis of the central shaft (4). The transmission unit (622) includes a lower driving gear (6221) fixedly sleeved on the central shaft (4) and a lower driven gear (6222) fixed to the upper end of the rotating rod (611) and meshing with the lower driving gear (6221). There are three lower driven gears (6222), and the three lower driven gears (6222) are respectively fixed to the upper end of the rotating rod (611) of the three sets of connecting assemblies (61).

3. The gas-solid separation device according to claim 1, characterized in that: The exhaust vent (511) extends in an arc shape. Three exhaust vents (511) are evenly arranged around the central axis (4). The bottom of the air inlet pipe (11) is higher than the top of the outer spiral blade (12). The orthographic projection of the air outlet pipe (13) is located within the orthographic projection area of ​​the inner cylinder (2).

4. The gas-solid separation device according to claim 1, characterized in that: The lower end of the inner spiral blade (612) extends to a position close to the top of the Y-shaped connecting frame (21). The bottom of the outer cylinder (1) is fixed with a support leg (14). The bottom of the outer cylinder (1) is funnel-shaped. The discharge assembly (3) includes a discharge pipe (31) fixed to and connected to the bottom of the outer cylinder (1) and a solenoid valve (32) set on the discharge pipe (31) to control the discharge.

5. A gas-solid separation device according to claim 1, characterized in that: The power unit (621) includes a motor (6211) fixed to the top of the outer cylinder (1), an upper drive gear (6212) fixed to the output end of the motor (6211), and an upper driven gear (6213) fixedly sleeved on the central shaft (4) and meshing with the upper drive gear (6212).

6. A calcium carbonate preparation process, employing the gas-solid separation device as described in claim 5, characterized in that, Includes the following steps: S1. After crushing and grinding limestone, mix it with water and heat it in a digester to generate lime milk. At the same time, the industrial CO2 gas is washed with water and dried for purification. S2. The lime slurry is fed into the carbonization reactor, and purified CO2 gas is introduced. The carbonization reaction is carried out under stirring conditions to generate a gas-solid-liquid mixture containing calcium carbonate particles. S3. The mixture enters the annular space between the outer cylinder (1) and the inner cylinder (2) of the gas-solid separation device tangentially through the inlet pipe (11). Under the action of centrifugal force, larger calcium carbonate particles are thrown against the wall of the outer cylinder (1) and fall down along the wall. The airflow spirals down along the outer spiral blades (12) between the outer cylinder (1) and the inner cylinder (2). Then, under the action of the outlet pipe (13) connected to the external air extraction system, the airflow passes through the filter screen assembly (5) and then through the movable plate (51), and is finally discharged through the outlet pipe (13). After the separated and discharged gas is purified, part of it is returned to the carbonization reactor for recycling, and the rest is treated to meet the standards. S4. The drive mechanism (6) drives the central shaft (4) to rotate, causing the filter screen assembly (5) at the bottom of the inner cylinder (2) to vibrate. The fine particles intercepted by the filter screen body (53) and the annular cloth (55) fall to the bottom of the outer cylinder (1). The calcium carbonate particles are discharged through the discharge assembly (3), mixed with the liquid to form a slurry, and then filtered to obtain a filter cake. After the filter cake is dried, it is processed into calcium carbonate products of the required particle size by a pulverizer.

7. A calcium carbonate preparation process according to claim 6, characterized in that, step... In S1, the CO2 gas is industrial waste gas or CO2 gas produced by calcining limestone. The CO2 gas is passed into a water washing tower to remove dust and sulfide impurities, and then passed into an alkaline washing tower containing a 5-10% NaOH solution to further remove acidic gases. Finally, it is dried in a drying tower until the CO2 purity is ≥98% and the water content is ≤0.1%.

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