Lime melting machine

Abstract

The invention provides a lime slaking machine which comprises a lime inlet, a water inlet, a barrel, a motor, a pushing shoveling plate and a fixing cover, the lime inlet and the water inlet are formed in the front end of the barrel, the motor, a rolling ring and a tug device are arranged on the outer side of the barrel, the pushing shoveling plate is arranged on the inner side of the barrel, the fixing cover is arranged at the rear end of the barrel, and the fixing cover comprises a circular rotary screen, a discharging port and a steam exhaust chimney. A steam exhaust chimney is arranged on the upper portion of the fixed cover, a discharging port is formed in the lower portion of the fixed cover, a circular rotary screen is arranged in the fixed cover and comprises an inner rotary screen body and an outer rotary screen body arranged outside the inner rotary screen body, and the outer rotary screen body comprises a first-stage rotary screen body close to the rear end of the barrel and a second-stage rotary screen body connected with the first-stage rotary screen body. Screen holes of the rotary screen are different in diameter, the outer hole diameter is larger than the inner hole diameter, blocking can be effectively prevented, the round rotary screen used by the lime slaking machine is of a two-layer three-level structure, lime milk good in dispersity can be extracted, grading treatment of solid particles is achieved, and the effect of saving energy is achieved while the raw material conversion rate is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of soda ash production, and more specifically, mainly relates to a ash dissolving machine. Background Art

[0002] Lime digestion machine, also known as lime digestion machine or quicklime digestion device, is a special equipment for digesting quicklime (calcium oxide) into lime milk. It is mainly used in soda ash manufacturing, steelmaking, chemical industry, metallurgy, papermaking, biopharmaceuticals and other industries. In the soda ash production process, a large amount of lime milk is consumed, so the digestion of quicklime to produce lime milk is a necessary production process in the soda ash production process.

[0003] In the prior art, the ash dissolving machine is mainly composed of a feed end, a cylinder, a power device, a screening device, and a discharge end. The screening device of the ash dissolving machine is mainly a single-layer rotary screen and a double-layer rotary screen. In the ash dissolving process, there may be solid impurities remaining after burning and lime particles that are not completely burned. Therefore, the single-layer rotary screen will cause slag leakage, which will lead to a large amount of slag in the lime milk discharged from the ash dissolving machine discharge port, and cause the rotary screen filter to be blocked; for the double-layer rotary screen, for example, the utility model patent CN207221455U discloses a double-layer filter device for the discharge end of the ash dissolving machine. Although it can realize the screening of lime milk and solid impurities remaining after burning and lime particles that are not completely burned, and reduce the slag content in the lime milk, it cannot achieve the purpose of recycling the lime particles that are not completely burned. At the same time, the ash dissolving machine will release a large amount of reaction heat during the digestion reaction of quicklime and water, and a large amount of dust will be generated during the production process, which will cause environmental pollution and affect the health of the workers. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention discloses a lime dissolving machine to solve the above problems in the prior art. The lime dissolving machine of the present invention uses a two-layer three-stage rotary screen to extract lime milk with good dispersibility and realizes the classification treatment of solid particles, thereby improving the raw material conversion rate and saving energy. In addition, a spray device is provided to recover the latent heat of ash powder and steam to prevent pollution of the plant, and realize heat utilization at the same time, and the generated hot water can be recycled and reused.

[0005] In order to achieve the above technical objectives, the present invention proposes a lime dissolving machine, including a lime inlet, a water inlet, a cylinder, a motor, a propulsion shovel, 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 roller and a tugboat device, the inside of the cylinder is provided with a propulsion shovel, and the rear end of the cylinder is provided with a fixed cover. The fixed cover includes a circular rotary screen, a discharge port and an exhaust chimney. The upper part of the fixed cover is provided with an exhaust chimney, the lower part of the fixed cover is provided with a discharge port, and the inside of the fixed cover is provided with a circular rotary screen. The circular rotary screen includes an inner rotary screen and an outer rotary screen arranged outside the inner rotary screen. The outer rotary screen includes a primary rotary screen close to the rear end of the cylinder and a secondary rotary screen connected to the primary rotary screen.

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

[0007] Exemplarily, the first-stage rotary screen 71 has an inner pore diameter of 10 mm and an outer pore diameter of 12 mm, the second-stage rotary screen 72 has an inner pore diameter of 40 mm and an outer pore diameter of 48 mm, and the inner rotary screen 8 has an inner pore diameter of 20 mm and an outer pore diameter of 24 mm.

[0008] Exemplarily, the first-stage rotary screen 71 has an inner pore diameter of 5 mm and an outer pore diameter of 6 mm, the second-stage rotary screen 72 has an inner pore diameter of 30 mm and an outer pore diameter of 36 mm, and the inner rotary screen 8 has an inner pore diameter of 16 mm and an outer pore diameter of 19 mm.

[0009] Exemplarily, the first-stage rotary screen 71 has an inner pore diameter of 15 mm and an outer pore diameter of 18 mm, the second-stage rotary screen 72 has an inner pore diameter of 50 mm and an outer pore diameter of 60 mm, and the inner rotary screen 8 has an inner pore diameter of 29 mm and an outer pore diameter of 35 mm.

[0010] Furthermore, the circular rotary screen is provided with uniform sieve holes, which are holes of different diameters, with an outer pore diameter of bmm and an inner pore diameter of amm, where b=(1.05-1.3)*a. Usually, the opening of the rotary screen of the ash machine is prone to blockage by solid particles. The present invention sets the sieve holes of the rotary screen of the ash machine as holes of different diameters, and the rotary screen has a certain thickness. The outer pore diameter is larger than the inner pore diameter, which can effectively prevent blockage. After the solid particles pass through the inner pore diameter, the particles pass more smoothly due to the increase in pore diameter, which reduces the probability of stuck holes and blocked holes.

[0011] Furthermore, a spiral belt is arranged inside the secondary rotary screen, and a flat steel block is arranged on the spiral belt. The spiral belt can push the solid to move backward more efficiently. The arrangement of the flat steel block 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 block and the material is relatively large, which helps to better push or pull the material to move along the spiral belt.

[0012] Furthermore, the discharge port includes a lime milk outlet, a waste rock outlet and a return rock outlet. The lime milk outlet is arranged at the lower end of the first rotary screen, the waste rock outlet is arranged at the lower end of the second rotary screen, and the return rock outlet is arranged at the rear end of the inner rotary screen. The solid-liquid mixed slurry rotates with the cylinder to the circular rotary screen. The particles with smaller particle size and the lime milk slurry can pass through the inner rotary screen and reach the outer rotary screen, wherein the lime milk is first screened out from the first rotary screen and flows out from the lime milk outlet. At this time, the screened lime milk has a lower solid content and higher dispersion, and can provide more active Ca(OH)2 more quickly, thereby increasing the reaction rate of the lime milk used in the subsequent ammonia pre-ash barrel; the particles with smaller particle size are screened out from the second rotary screen and fall directly from the waste rock outlet. The aperture of the second rotary screen is larger than that of the inner rotary screen, and the stone jam phenomenon is not easy to occur here. The smaller particles are mostly solid impurities remaining after burning, and the main components are SiO2, etc., which are not worth burning again. Larger particles cannot pass through the inner rotating screen and rotate with the inner rotating screen to above the return stone outlet and fall from the return stone outlet. Most of them are unburned lime particles, which are returned to the lime kiln for re-burning to improve the utilization rate of limestone.

[0013] Furthermore, a spray device is provided in the exhaust chimney to recover the latent heat of ash and steam, prevent pollution of the plant, and realize heat utilization and recycling of generated hot water. The spray device includes several spray pipe inlets and hot water outlets. Several spray pipe inlets are arranged at different heights in the exhaust chimney, which improves the uniformity of spraying, ensures the spray density, and improves the efficiency of recovering ash. The hot water outlet is arranged at the lower end of the spray pipe inlet.

[0014] Furthermore, a washing pipe is provided on the upper side of the outer rotary screen, and a washing pipe is provided on the inner side of the inner rotary screen, which are used to regularly wash the clogged sieve holes of the rotary screen.

[0015] Furthermore, a conical channel is arranged inside the lime inlet to prevent lime powder from returning to pollute the factory building. The propulsion plates in the cylinder are distributed in a stepped and progressive horizontal spiral, which pushes the lime and the ash water to move to the rear end while turning the lime and the ash water over to produce a better mixing effect.

[0016] Furthermore, the rolling ring is in direct contact with the tugboat device, the number of which is 2 or 3, and is located at the bottom of the ash dissolving machine. The rolling ring is fixed to the cylinder by countersunk screws, and the countersunk screw holes on the inner side of the cylinder are plug-welded. The plug-welding treatment of the countersunk screw holes can eliminate the leakage of ash milk in the cylinder.

[0017] Furthermore, the material of the circular rotary screen is one of stainless steel, duplex steel, and fiberglass; the material of the cylinder is one of stainless steel and carbon steel; the material of the rolling ring is a casting, which includes cast steel, etc. The wear-resistant casting can maintain good performance in a long-term friction and wear environment, reduce component failure and replacement due to wear, and cast steel is preferred.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The lime machine uses a two-layer three-stage rotary screen to extract lime milk with good dispersion and realize the classification of solid particles, which not only improves the raw material conversion rate but also saves energy.

[0020] (2) The sieve holes of the ash machine are of different diameters. 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 more smoothly due to the increase in the diameter, reducing the probability of stuck and blocked holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0022] Figure 1 The main body diagram of the ash removal machine according to the embodiment of the present invention;

[0023] Figure 2 A partial side view of an ash removal machine according to an embodiment of the present invention;

[0024] Figure 3 This is a diagram of different diameter holes of the ash machine rotary screen according to an embodiment of the present invention.

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

[0026] 1. Lime inlet; 2. Cylinder; 3. Pushing plate; 4. Washing water pipe; 5. Exhaust chimney; 6. Hot water outlet; 7. External rotary screen; 8. Internal rotary screen; 9. Water inlet; 10. Motor; 11. Lime milk outlet; 12. Waste rock outlet; 13. Return rock outlet; 14. Spray pipe inlet; 15. Fixed cover; 16. Spiral belt; 17. Rolling ring; 18. Tugboat device; 71. Primary rotary screen; 72. Secondary rotary screen. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below, and preferred embodiments of the present invention are given. However, it should be understood that the embodiments are only used for more detailed description and should not be understood as limiting the present invention in any form, that is, not intended to limit the scope of protection of the present invention.

[0028] The present invention will be further described below in conjunction with the accompanying drawings.

[0029] Embodiment 1:

[0030] A lime dissolving machine comprises a lime inlet 1, a water inlet 9, a cylinder 2, a motor 10, a pusher plate 3, and a fixed cover 15. The cylinder 2 is made of one of stainless steel and carbon steel. 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 roller 17, and a tugboat device 18. The inside of the cylinder 2 is provided with a pusher plate 3. The rear end of the cylinder 2 is provided with a fixed cover 15. The fixed cover 15 comprises a circular rotary screen, a discharge port, and an exhaust chimney 5. The upper part of the fixed cover 15 is provided with an exhaust chimney 5. The lower part of the fixed cover 15 is provided with a discharge port. The inside of the fixed cover 15 is provided with a circular rotary screen. The circular rotary screen comprises an inner rotary screen 8 and an outer rotary screen 7 arranged outside the inner rotary screen 8. The outer rotary screen 7 comprises a primary rotary screen 71 near the rear end of the cylinder 2 and a secondary rotary screen 72 connected to the primary rotary screen 71. The lime dissolving machine uses a two-layer three-stage rotary screen to extract lime milk with good dispersion, and at the same time realizes the classification treatment of solid particles, which improves the raw material conversion rate and saves energy.

[0031] Embodiment 2:

[0032] A preferred embodiment of the present invention: On the basis of Example 1, the circular rotary screen is provided with uniform sieve holes, and the sieve holes are holes of different diameters, the inner pore diameter of the first-stage rotary screen 71 is 10 mm, and the outer pore diameter is 12 mm, the inner pore diameter of the second-stage rotary screen 72 is 40 mm, and the outer pore diameter is 48 mm, the inner pore diameter of the inner rotary screen 8 is 20 mm, and the outer pore diameter is 24 mm, or the inner pore diameter of the first-stage rotary screen 71 is 5 mm, and the outer pore diameter is 6 mm, the inner pore diameter of the second-stage rotary screen 72 is 30 mm, and the outer pore diameter is 36 mm, the inner pore diameter of the inner rotary screen 8 is 16 mm, and the outer pore diameter is 19 mm, or the inner pore diameter of the first-stage rotary screen 71 is 15 mm, and the outer pore diameter is 18 mm, the inner pore diameter of the second-stage rotary screen 72 is 50 mm, and the outer pore diameter is 60 mm, the inner pore diameter of the inner rotary screen 8 is 29 mm, and the outer pore diameter is 35 mm. The above aperture sizes are for better screening effects achieved in combination with specific working conditions. Other values ​​within the aperture size range may also be set in combination with specific working conditions.

[0033] The lime dissolving machine of the present invention is applied to the 60,000 tons / year soda ash expansion project, and can run stably and continuously for 8,000 hours, meeting the continuous production requirements of soda ash, and has a low failure rate. The lime milk produced by this lime dissolving machine has a high dispersion, a fast reaction rate when entering the downstream reaction tank, a low solid content in the lime milk, and a small solid particle size, which reduces the risk of downstream pipeline and equipment blockage, and extends the operation cycle of the downstream ammonia distillation tower from 3 months to 1 year; the multi-stage rotary screen and the setting of waste rock and return rock can realize the separation of return rock and waste rock, save calcination energy, and improve the utilization rate of limestone.

[0034] Embodiment 3:

[0035] A preferred embodiment of the present invention: On the basis of embodiment 1, a spiral belt is provided inside the secondary rotary screen 72, and the spiral belt 16 is fixed by evenly distributed flat steel blocks. The spiral belt 16 can more efficiently push the solid to move backward. The provision of 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 relatively large, which helps to better push or pull the material to move along the spiral belt.

[0036] Embodiment 4:

[0037] A preferred embodiment of the present invention: Based on Example 1, the discharge port is preferably set as a lime milk outlet 11, a waste rock outlet 12 and a return rock outlet 13, the lime milk outlet 11 is set at the lower end of the first rotary screen 71, the waste rock outlet 12 is set at the lower end of the second rotary screen 72, and the return rock outlet 13 is set at the rear end of the inner rotary screen 8. The solid-liquid mixed slurry rotates with the cylinder to the circular rotary screen, and the particles with smaller particle size and the lime milk slurry can pass through the inner rotary screen 8 to reach the outer rotary screen 7, wherein the lime milk is first screened out from the primary rotary screen 71 and flows out from the lime milk outlet 11. At this time, the screened lime milk has less solid content and higher dispersion, and can provide more active Ca(OH)2 more quickly, thereby improving the reaction rate of the lime milk used in the subsequent ammonia pre-ash barrel; the particles with smaller particle size are screened out from the secondary rotary screen 72 and fall directly from the waste rock outlet 12. The smaller particles are mostly solid impurities remaining after burning, and the main components are SiO2, etc., which have no value for re-burning; the larger particles cannot pass through the inner rotary screen 8, and rotate with the inner rotary screen 8 to above the return rock outlet 13, and fall from the return rock outlet 13. Most of them are lime particles that are not completely burned, and they are returned to the lime kiln for re-burning, thereby improving the utilization rate of the limestone.

[0038] Embodiment 5:

[0039] Preferred embodiment of the present invention: Based on embodiment 1, a spray device is arranged in the exhaust chimney 5, and the spray device includes a plurality of spray pipe inlets 14 and a hot water outlet 6. The plurality of spray pipe inlets 14 are arranged at different heights in the exhaust chimney 5, which improves the spray uniformity, ensures the spray density, and improves the efficiency of recycling ash powder. The spray device can recycle the latent heat of ash powder and steam to prevent pollution of the plant, and at the same time realizes heat utilization, and the generated hot water can be recycled and reused.

[0040] Embodiment 6:

[0041] A 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. The washing pipe 4 takes in water from the end of the fixed cover 15 and is used to regularly flush the blocked rotating screen holes.

[0042] Embodiment 7:

[0043] A preferred embodiment of the present invention: Based on embodiment 1, a conical channel is arranged inside the lime inlet 1, which prevents lime powder from returning to pollute the factory building. The pushing plates in the cylinder 2 are distributed in a stepped progressive horizontal spiral, which pushes the lime and the ash water to move toward the rear end while turning the lime and the ash water over to produce a better mixing effect.

[0044] During the use of a ash dissolving machine in a certain project, there was no conical channel at the lime inlet of the ash dissolving machine in the early stage. The burned limestone entered the ash dissolving machine from the lime silo through the lime feeder. A large amount of dust was generated during the falling of the lime and sprayed out from the lime inlet. The dust was diffused near the ash dissolving machine inlet, polluting the factory building, which was not conducive to workers' operation and inspection, and also caused a waste of lime raw materials. In view of the above problems, a conical channel was optimized and set. The inlet channel gradually became narrower, 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, which solved the problem of polluting the factory building and saved lime raw materials.

[0045] Embodiment 8:

[0046] A preferred embodiment of the present invention: Based on Example 1, the rolling ring 17 is in direct contact with the tug device 18, the number of the tug devices 18 is 2 or 3, and they are located at the bottom of the ash 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 plug-welded.

[0047] During the use of a ash machine in a certain project, the initial design was that the roller 17 was fixed to the cylinder 2 by ordinary screws, and lime milk leakage often occurred at the fixed position. The optimized design used countersunk screws for plug welding fixation, which effectively solved the problem of lime milk leakage.

[0048] It should be noted that the above contents are further detailed descriptions of the present invention in combination with specific implementation methods, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions; the dimensional data of this embodiment does not limit the technical solution, but only shows several specific working conditions. For ordinary technicians in the technical field to which the present invention belongs, several simple improvements and modifications can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A lime dissolving machine, comprising a lime inlet (1), a water inlet (9), a cylinder (2), a motor (10), a propulsion shovel (3), and a fixed cover (15), wherein the front end of the cylinder (2) is provided with a lime inlet (1) and a water inlet (9), the outer side of the cylinder (2) is provided with a motor (10), a roller (17) and a tugboat device (18), the inside of the cylinder (2) is provided with a propulsion shovel (3), and the rear end of the cylinder (2) is provided with a fixed cover (15), characterized in that: An exhaust chimney (5) is provided at the top of the fixed cover (15), a material discharge port is provided at the bottom of the fixed cover (15), a circular rotary screen is provided inside the fixed cover (15), the circular rotary screen comprises an inner rotary screen (8) and an outer rotary screen (7) arranged outside the inner rotary screen (8), and the outer rotary screen (7) comprises a primary rotary screen (71) close to the rear end of the cylinder (2) and a secondary rotary screen (72) connected to the primary rotary screen (71).

2. The ash dissolving machine according to claim 1, characterized in that: The inner diameter of the sieve hole of the first rotary screen (71) is 5 mm to 15 mm, the inner diameter of the sieve hole of the second rotary screen (72) is 30 mm to 50 mm, the inner diameter of the sieve hole of the inner rotary screen (8) is 16 mm to 29 mm, and the outer diameter of the sieve hole is greater than or equal to the inner diameter.

3. The aperture according to claim 2, characterized in that: The circular rotary screen is provided with uniform sieve holes, the sieve holes are holes of different diameters, the outer pore diameter is bmm, the inner pore diameter is amm, and b=(1.05-1.3)*a.

4. The ash dissolving machine according to claim 1, characterized in that: A spiral belt (16) is arranged inside the secondary rotary screen (72), and a flat steel block is arranged on the spiral belt.

5. The ash dissolving machine according to claim 1, characterized in that: The discharge port comprises a lime milk outlet (11), a waste rock outlet (12) and a return rock outlet (13); the lime milk outlet (11) is arranged at the lower end of the first rotary screen (71), the waste rock outlet (12) is arranged at the lower end of the second rotary screen (72), and the return rock outlet (13) is arranged at the rear end of the inner rotary screen (8).

6. The ash dissolving machine according to claim 1, characterized in that: A spray device is arranged inside the exhaust chimney (5), and the spray device comprises a plurality of spray pipe inlets (14) and a hot water outlet (6). The plurality of spray pipe inlets (14) are arranged at different heights inside the exhaust chimney (5), and the hot water outlet (6) is arranged at the lower end of the spray pipe inlet (14).

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

8. The ash dissolving machine according to claim 1, characterized in that: The lime inlet (1) is provided with a conical channel, and the pushing and lifting plates (3) in the cylinder (2) are arranged in a stepped and progressive horizontal spiral.

9. The ash dissolving machine according to claim 1, characterized in that: The rolling ring (17) is in direct contact with the tug device (18). The number of the tug devices (18) is 2 or 3 and they are located at the bottom of the ash dissolving 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 plug-welded.

10. The ash dissolving machine according to claim 1, characterized in that: The material of the circular rotary screen is one of stainless steel, duplex steel and glass fiber reinforced plastic; And / or, the material of the cylinder (2) is one of stainless steel and carbon steel; And / or, the rolling ring (17) is made of a casting material, preferably cast steel.

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