A lime grinder

Abstract

The application provides a lime slaking machine, which comprises a lime inlet, a water inlet, a cylinder, a motor, a pushing scraper, a fixed cover, the front end of the cylinder is provided with the lime inlet and the water inlet, the outer side of the cylinder is provided with the motor, a rolling ring and a towing wheel device, the inner side of the cylinder is provided with the pushing scraper, the rear end of the cylinder is provided with the fixed cover, the fixed cover comprises a circular rotary screen, a discharge port and a steam exhaust chimney, the upper part of the fixed cover is provided with the steam exhaust chimney, the lower part of the fixed cover is provided with the discharge port, the inside of the fixed cover is provided with the circular rotary screen, the circular rotary screen comprises an inner rotary screen and an outer rotary screen arranged outside the inner rotary screen, the outer rotary screen comprises a first-stage rotary screen close to the rear end of the cylinder and a second-stage rotary screen connected with the first-stage rotary screen. The rotary screen screen hole is a variable-diameter hole, the outer diameter is greater than the inner diameter, which can effectively prevent blockage, the circular rotary screen used by the lime slaking machine is a two-layer three-stage structure, which can extract lime milk with good dispersity, realizes the grading treatment of solid particles, improves the raw material conversion rate, and saves energy.

Description

Technical Field

[0001] This invention relates to the field of soda ash production technology, and more specifically, to a soda ash smelting machine. Background Technology

[0002] A lime slurry machine, also known as a lime digester or quicklime digester, is a specialized piece of equipment that digests quicklime (calcium oxide) into lime slurry. It is mainly used in industries such as soda ash manufacturing, steelmaking, chemical engineering, metallurgy, papermaking, and biopharmaceuticals. In the soda ash production process, a large amount of lime slurry is consumed; therefore, the digestion of quicklime to produce lime slurry is a necessary step in the soda ash production process.

[0003] In existing technology, lime slaking machines mainly consist of a feeding end, a cylinder, a power unit, a screening device, and a discharge end. The screening devices in lime slaking machines are mainly single-layer and double-layer rotary screens. During the lime slaking process, there may be solid impurities remaining after burning and incompletely burned lime particles. Therefore, single-layer rotary screens can cause slag leakage, resulting in a high slag content in the lime slurry discharged from the lime slaking machine's outlet and clogging of the rotary screen filter. For double-layer rotary screens, for example, utility model patent CN207221455U discloses a double-layer filter device for the discharge end of a lime slaking machine. Although this can separate lime slurry from remaining solid impurities and incompletely burned lime particles, reducing the slag content in the lime slurry, it cannot achieve the purpose of recycling incompletely burned lime particles. Furthermore, the lime slaking machine releases a large amount of heat during the slaking reaction of quicklime and water, and generates a large amount of dust during production, which will cause environmental pollution and affect the health of workers. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention discloses a lime slurry extractor to solve the aforementioned problems. This lime slurry extractor uses a two-layer, three-stage rotating screen to extract well-dispersed lime slurry while simultaneously classifying solid particles. This improves the raw material conversion rate and saves energy. The additionally installed spraying device can recover lime powder and latent heat of steam, preventing pollution of the plant, while also utilizing heat; the generated hot water can be recycled and reused.

[0005] To achieve the above technical objectives, this invention proposes a lime smelting machine, comprising a lime inlet, a water inlet, a cylinder, a motor, a propulsion lifting plate, and a fixed cover. The front end of the cylinder is provided with a lime inlet and a water inlet. The outside of the cylinder is provided with a motor, a rolling ring, and a drag wheel device. The inside of the cylinder is provided with a propulsion lifting plate. The rear end of the cylinder is provided with a fixed cover, which includes a circular rotating screen, a discharge port, and a steam exhaust chimney. The upper part of the fixed cover is provided with a steam exhaust chimney, and the lower part of the fixed cover is provided with a discharge port. The inside of the fixed cover is provided with a circular rotating screen, which includes an inner rotating screen and an outer rotating screen located outside the inner rotating screen. The outer rotating screen includes a primary rotating screen near the rear end of the cylinder and a secondary rotating screen connected to the primary rotating screen.

[0006] Furthermore, the inner diameter of the screen holes in the first-stage rotary screen is 5mm to 15mm, the inner diameter of the screen holes in the second-stage rotary screen is 30mm to 50mm, the inner diameter of the screen holes in the inner rotary screen is 16mm to 29mm, and the outer diameter of the screen holes is greater than or equal to the inner diameter.

[0007] For example, the inner diameter of the primary rotary screen 71 is 10 mm and the outer diameter is 12 mm, the inner diameter of the secondary rotary screen 72 is 40 mm and the outer diameter is 48 mm, and the inner diameter of the inner rotary screen 8 is 20 mm and the outer diameter is 24 mm.

[0008] For example, the inner diameter of the primary rotary screen 71 is 5 mm and the outer diameter is 6 mm, the inner diameter of the secondary rotary screen 72 is 30 mm and the outer diameter is 36 mm, and the inner diameter of the inner rotary screen 8 is 16 mm and the outer diameter is 19 mm.

[0009] For example, the inner diameter of the primary rotary screen 71 is 15mm and the outer diameter is 18mm, the inner diameter of the secondary rotary screen 72 is 50mm and the outer diameter is 60mm, and the inner diameter of the inner rotary screen 8 is 29mm and the outer diameter is 35mm.

[0010] Furthermore, the circular rotary screen has uniformly sized holes with varying diameters: an outer diameter of b mm and an inner diameter of a mm, where b = (1.05~1.3) * a. Solid particles often clog the openings of the rotary screen in a typical ash-making machine. This invention addresses this by setting the screen holes of the rotary screen to varying diameters. The rotary screen has a certain thickness, and the outer diameter is larger than the inner diameter, effectively preventing clogging. After solid particles pass through the inner diameter, the increased aperture allows for smoother passage, reducing the probability of jamming and clogging.

[0011] Furthermore, the secondary rotary screen is equipped with a spiral belt with flat steel blocks on it. The spiral belt can push the solid backward more efficiently, and the flat steel blocks can improve the material conveying effect, making the material conveying more uniform and stable, reducing blockage and accumulation. The friction between the flat steel blocks and the material is relatively large, which helps to better push or pull the material along the spiral belt.

[0012] Furthermore, the discharge outlets include a lime slurry outlet, a waste rock outlet, and a return rock outlet. The lime slurry outlet is located at the lower end of the primary rotary screen, the waste rock outlet at the lower end of the secondary rotary screen, and the return rock outlet at the rear end of the inner rotary screen. The solid-liquid mixed slurry rotates with the cylinder to the circular rotary screen. Smaller particles and lime slurry slurry can pass through the inner rotary screen and reach the outer rotary screen. The lime slurry is first screened out from the primary rotary screen and flows out from the lime slurry outlet. At this point, the screened lime slurry has a lower solid content and higher dispersibility, which can quickly provide highly active Ca(OH)2, improving the reaction rate of the lime slurry in the subsequent ammonia stripping and pre-ashing tank. Smaller particles are screened out from the secondary rotary screen and fall directly from the waste rock outlet. The aperture of the secondary rotary screen is larger than that of the inner rotary screen, making it less likely for stone to get stuck. The smaller particles are mostly solid impurities remaining after calcination, mainly composed of SiO2, etc., and have no value for recalcination. Larger particles cannot pass through the inner rotary screen and rotate with it to the top of the return stone outlet, where they fall. These are mostly incompletely burned lime particles, which are returned to the lime kiln for re-burning, thus improving the utilization rate of limestone.

[0013] Furthermore, a spray system is installed inside the exhaust chimney to recover ash and latent heat of steam, preventing pollution of the plant while simultaneously utilizing heat and recycling the generated hot water. The spray system includes several spray pipe inlets and a hot water outlet. The spray pipe inlets are located at different heights within the exhaust chimney, improving spray uniformity, ensuring spray density, and increasing the efficiency of ash recovery. The hot water outlet is located below the spray pipe inlets.

[0014] Furthermore, a washing pipe is provided on the upper side of the outer rotating screen and a washing pipe is provided on the inner side of the inner rotating screen, which are used to periodically rinse the clogged screen holes.

[0015] Furthermore, the lime inlet is designed with a conical channel to prevent lime powder from returning and contaminating the plant. The propulsion plates inside the cylinder are distributed in a stepped, progressive horizontal spiral pattern, which pushes the lime and slaked water towards the rear end while causing the lime and slaked water to tumble, resulting in a better mixing effect.

[0016] Furthermore, the rolling ring is in direct contact with the towing wheel device, which consists of two or three towing wheels located at the bottom of the ash-making machine. The rolling ring is fixed to the cylinder by countersunk screws, and the countersunk screw holes inside the cylinder are plugged and welded to eliminate ash leakage inside the cylinder.

[0017] Furthermore, the circular rotary screen is made of one of stainless steel, duplex steel, or fiberglass; the cylinder is made of one of stainless steel or carbon steel; and the rolling ring is made of cast material, including cast steel. Wear-resistant cast materials can maintain good performance in long-term friction and wear environments, reducing component failure and replacement due to wear. Cast steel is preferred.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] (1) The lime slurry machine uses two layers of three-stage rotating screens to extract lime milk with good dispersibility, and at the same time realizes the classification of solid particles, which improves the conversion rate of raw materials and saves energy.

[0020] (2) The screen holes of the ash maker are different diameter holes. The outer diameter is larger than the inner diameter, which can effectively prevent clogging. After the solid particles pass through the inner diameter, the particles pass through more smoothly due to the increased diameter, reducing the probability of jamming and clogging. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0022] Figure 1 This is a main body diagram of the ash-making machine according to an embodiment of the present invention;

[0023] Figure 2 This is a partial side view of the ash-making machine according to an embodiment of the present invention;

[0024] Figure 3 This is a diagram of the eccentric aperture of the rotating screen in the ash-making machine according to an embodiment of the present invention.

[0025] The above figures include the following reference numerals:

[0026] 1. Lime inlet; 2. Cylinder; 3. Propeller plate; 4. Wash water pipe; 5. Exhaust chimney; 6. Hot water outlet; 7. External rotary screen; 8. Internal rotary screen; 9. Water inlet; 10. Motor; 11. Lime slurry outlet; 12. Waste rock outlet; 13. Return stone outlet; 14. Spray pipe inlet; 15. Fixing cover; 16. Spiral belt; 17. Rolling ring; 18. Tractor device; 71. Primary rotary screen; 72. Secondary rotary screen. Detailed Implementation

[0027] To facilitate understanding of the present invention, a more comprehensive description of the invention will be provided below, along with preferred embodiments. However, it should be understood that these embodiments are for more detailed explanation only and should not be construed as limiting the invention in any way, i.e., not limiting the scope of protection of the invention.

[0028] The invention will now be further described with reference to the accompanying drawings.

[0029] Example 1:

[0030] A lime slurry machine includes a lime inlet 1, a water inlet 9, a cylinder 2, a motor 10, a propulsion lifting plate 3, and a fixed cover 15. The cylinder 2 is made of stainless steel or carbon steel. The front end of the cylinder 2 has the lime inlet 1 and the water inlet 9. The outer side of the cylinder 2 has the motor 10, a rolling ring 17, and a drag wheel device 18. The propulsion lifting plate 3 is located inside the cylinder 2. The rear end of the cylinder 2 has the fixed cover 15, which includes a circular rotating screen, a discharge port, and a steam exhaust chimney 5. The upper part of the fixed cover 15 has the steam exhaust chimney 5, and the lower part of the fixed cover 15 has the discharge port. The circular rotating screen inside the fixed cover 15 includes an inner rotating screen 8 and an outer rotating screen 7 located outside the inner rotating screen 8. The outer rotating screen 7 includes a primary rotating screen 71 near the rear end of the cylinder 2 and a secondary rotating screen 72 connected to the primary rotating screen 71. The lime slurry machine uses two layers of three rotating screens to extract lime slurry with good dispersion, while simultaneously achieving the classification of solid particles. This improves the raw material conversion rate and saves energy.

[0031] Example 2:

[0032] Preferred embodiments of the present invention: Based on embodiment 1, the circular rotary screen is provided with uniform screen holes of varying diameters. The inner diameter of the primary rotary screen 71 is 10 mm and the outer diameter is 12 mm. The inner diameter of the secondary rotary screen 72 is 40 mm and the outer diameter is 48 mm. The inner diameter of the inner rotary screen 8 is 20 mm and the outer diameter is 24 mm. Alternatively, the inner diameter of the primary rotary screen 71 is 5 mm and the outer diameter is 6 mm. The inner diameter of the secondary rotary screen 72 is 30 mm and the outer diameter is 36 mm. The inner diameter of the inner rotary screen 8 is 16 mm and the outer diameter is 19 mm. Alternatively, the inner diameter of the primary rotary screen 71 is 15 mm and the outer diameter is 18 mm. The inner diameter of the secondary rotary screen 72 is 50 mm and the outer diameter is 60 mm. The inner diameter of the inner rotary screen 8 is 29 mm and the outer diameter is 35 mm. The above aperture sizes represent the best screening results achieved under specific working conditions. Other values ​​within the aperture size range can also be set according to specific working requirements.

[0033] The lime slurry machine described in this invention is applied to a 60,000-ton / year soda ash expansion project. It can operate continuously and stably for 8,000 hours, meeting the requirements for continuous soda ash production, and has a low failure rate. The lime slurry produced by this machine has a high degree of dispersion, resulting in a faster reaction rate in the downstream reaction tank. The lime slurry has a low solid content and small particle size, reducing the risk of blockage in downstream pipelines and equipment, and extending the operating cycle of the downstream ammonia stripping tower from 3 months to 1 year. The multi-stage rotating screen and the setting of waste stone and return stone can realize the separation of return stone and waste stone, saving calcination energy and improving the utilization rate of limestone.

[0034] Example 3:

[0035] Preferred embodiment of the present invention: Based on embodiment 1, a spiral belt is provided inside the secondary rotary screen 72. The spiral belt 16 is fixed by evenly distributed flat steel blocks. The spiral belt 16 can push the solid backward more efficiently. The flat steel blocks can improve the material conveying effect, make the material conveying more uniform and stable, and reduce blockage and accumulation. The friction between the flat steel blocks and the material is large, which helps to better push or pull the material along the spiral belt.

[0036] Example 4:

[0037] Preferred embodiment of the present invention: Based on embodiment 1, the discharge outlet is preferably configured as lime slurry outlet 11, waste rock outlet 12 and return rock outlet 13. Lime slurry outlet 11 is located at the lower end of primary rotary screen 71, waste rock outlet 12 is located at the lower end of secondary rotary screen 72, and return rock outlet 13 is located at the rear end of inner rotary screen 8. The solid-liquid mixture rotates with the cylinder to the circular rotary screen. Smaller particles and lime slurry can pass through the inner rotary screen 8 and reach the outer rotary screen 7. The lime slurry is first screened out by the primary rotary screen 71 and flows out from the lime slurry outlet 11. At this point, the lime slurry has a low solid content and high dispersibility, which can quickly provide highly active Ca(OH)2, improving the reaction rate of the lime slurry in the subsequent ammonia stripping and pre-ashing tank. Smaller particles are screened out by the secondary rotary screen 72 and fall directly from the waste stone outlet 12. The smaller particles are mostly solid impurities remaining after calcination, mainly composed of SiO2, etc., and have no value for recalcination. Larger particles cannot pass through the inner rotary screen 8 and rotate with the inner rotary screen 8 to the top of the return stone outlet 13, falling from the return stone outlet 13. These are mostly incompletely calcined lime particles, which are returned to the lime kiln for recalcination, improving the utilization rate of limestone.

[0038] Example 5:

[0039] A preferred embodiment of the present invention: Based on embodiment 1, a spraying device is installed inside the exhaust chimney 5. The spraying device includes several spray pipe inlets 14 and hot water outlets 6. The several spray pipe inlets 14 are located at different heights inside the exhaust chimney 5, which improves the uniformity of spraying, ensures the spraying density, and improves the efficiency of ash recovery. The spraying device can recover ash and latent heat of steam, prevent pollution of the plant, and simultaneously realize heat utilization. The generated hot water can be recycled and reused.

[0040] Example 6:

[0041] Preferred embodiment of the present invention: Based on embodiment 1, a washing pipe 4 is provided at the upper end of the outer rotating screen 7 and inside the inner rotating screen 8. Water enters from the end of the fixed cover 15 through the washing pipe 4 to periodically rinse the blocked rotating screen holes.

[0042] Example 7:

[0043] Preferred embodiment of the present invention: Based on embodiment 1, the lime inlet 1 is configured as a conical channel to prevent lime powder from returning and contaminating the plant. The propulsion plates inside the cylinder 2 are distributed in a stepped, progressive horizontal spiral pattern, which pushes the lime and slaked water to the rear end while causing the lime and slaked water to flip over, resulting in a better mixing effect.

[0044] During the initial use of the lime sintering machine in a certain project, a conical channel was not initially installed at the lime inlet. The calcined limestone entered the lime sintering machine from the lime silo through the lime feeder. During the limefall process, a large amount of dust was generated and sprayed out from the lime inlet, causing dust to permeate the area near the lime sintering machine inlet, polluting the plant, hindering worker operation and inspection, and wasting lime raw materials. To address these issues, a conical channel was installed. The inlet channel gradually narrowed, and most of the dust generated by the falling lime was blocked by the conical channel and could not be sprayed out from the inlet, thus solving the problem of polluting the plant and saving lime raw materials.

[0045] Example 8:

[0046] Preferred embodiment of the present invention: Based on embodiment 1, the rolling ring 17 is in direct contact with the towing wheel device 18. The number of towing wheel devices 18 is 2 or 3, located at the bottom of the ash-making machine. The rolling ring 17 is fixed to the cylinder 2 by countersunk screws, and the countersunk screw holes on the inner side of the cylinder 2 are plugged and welded.

[0047] During the operation of a lime slurry machine in a certain project, the initial design involved fixing the rolling ring 17 to the cylinder 2 with ordinary screws, which frequently resulted in lime slurry leakage at the fixing point. The optimized design used countersunk screws for plug welding fixation, effectively solving the lime slurry leakage problem.

[0048] It should be noted that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions; the dimensional data in this embodiment do not limit the technical solution, but merely illustrate several specific working conditions. For those skilled in the art, several simple improvements and modifications can be made without departing from the concept of the present invention, and all such improvements and modifications should be considered to fall within the scope of protection of the present invention.

Claims

1. A lime slaking machine, comprising a lime inlet (1), a water inlet (9), a cylinder (2), a motor (10), a propulsion lifting plate (3), and a fixing cover (15), wherein the front end of the cylinder (2) is provided with a lime inlet (1) and a water inlet (9), the outside of the cylinder (2) is provided with a motor (10), a rolling ring (17) and a drag wheel device (18), the inside of the cylinder (2) is provided with a propulsion lifting plate (3), and the rear end of the cylinder (2) is provided with a fixing cover (15), characterized in that: The upper part of the fixed cover (15) is provided with a steam exhaust chimney (5), the lower part of the fixed cover (15) is provided with a discharge port, and the inside of the fixed cover (15) is provided with a circular rotating screen. The circular rotating screen includes an inner rotating screen (8) and an outer rotating screen (7) located outside the inner rotating screen (8). The outer rotating screen (7) includes a primary rotating screen (71) near the rear end of the cylinder (2) and a secondary rotating screen (72) connected to the primary rotating screen (71). The circular rotary screen has uniform screen holes with varying diameters. The outer diameter is b mm and the inner diameter is a mm, where b = (1.05~1.3) * a. The inner diameter of the sieve holes of the first-stage rotating sieve (71) is 5mm to 15mm, the inner diameter of the sieve holes of the second-stage rotating sieve (72) is 30mm to 50mm, the inner diameter of the sieve holes of the inner rotating sieve (8) is 16mm to 29mm, and the outer diameter of the sieve holes is greater than or equal to the inner diameter. The discharge outlets include a lime slurry outlet (11), a waste rock outlet (12), and a return rock outlet (13). The lime slurry outlet (11) is located at the lower end of the primary rotating screen (71), the waste rock outlet (12) is located at the lower end of the secondary rotating screen (72), and the return rock outlet (13) is located at the rear end of the inner rotating screen (8).

2. The ash-making machine according to claim 1, characterized in that: The secondary rotating screen (72) is equipped with a spiral belt (16) inside, and flat steel blocks are set on the spiral belt.

3. The ash-making machine according to claim 1, characterized in that: The exhaust chimney (5) is equipped with a spray device, which includes several spray pipe inlets (14) and hot water outlets (6). The several spray pipe inlets (14) are located at different heights inside the exhaust chimney (5), and the hot water outlets (6) are located at the lower end of the spray pipe inlets (14).

4. The ash-making machine according to claim 1, characterized in that: The outer rotating screen (7) is provided with a washing pipe (4) on its upper side, and the inner rotating screen (8) is provided with a washing pipe (4) on its inner side.

5. The ash-making machine according to claim 1, characterized in that: The lime inlet (1) is set as a cone-shaped channel, and the propulsion plates (3) inside the cylinder (2) are distributed in a stepped, progressive horizontal spiral.

6. The ash-making machine according to claim 1, characterized in that: The rolling ring (17) is in direct contact with the towing wheel device (18). There are 2 or 3 towing wheel devices (18) located at the bottom of the ash-making machine. The rolling ring (17) is fixed to the cylinder (2) by countersunk screws. The countersunk screw holes on the inner side of the cylinder (2) are plugged and welded.

7. The ash-making machine according to claim 1, characterized in that: The circular rotating screen is made of one of the following materials: stainless steel, duplex steel, or fiberglass. And / or, the material of the cylinder (2) is one of stainless steel and carbon steel; And / or, the material of the rolling ring (17) is a casting.

8. The ash-making machine according to claim 7, characterized in that: The material of the rolling ring (17) is cast steel.

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