A complete equipment for producing desulfurizer by using carbide slag

Abstract

This invention discloses a complete set of equipment for producing desulfurizing agents using calcium carbide slag. It adopts a modular integrated design, including a raw material storage and metering module, a premixing and digestion module, a maturation and screening module, a grinding and powder selection module, and an integrated dust removal module connected in sequence. The modules are connected through a sealed conveying channel to form a complete calcium hydroxide desulfurizing agent production line. This invention relates to the field of calcium carbide slag utilization technology. Through modular integrated design, functions such as raw material storage, metering, mixing, digestion, screening, grinding, and powder selection are integrated into a compact equipment system. Compared with the decentralized layout of existing technologies, the footprint can be reduced, and equipment investment costs are lowered. A PLC control system is used to realize automatic control of processes such as raw material metering, mixing, digestion, screening, and grinding, ensuring stable production.

Description

Technical Field

[0001] This invention relates to the field of calcium carbide slag utilization technology, specifically to a complete set of equipment for producing desulfurizing agents using calcium carbide slag. Background Technology

[0002] Calcium carbide slag is an industrial waste generated during the calcium carbide process for producing polyvinyl chloride (PVC). Its main component is calcium hydroxide (Ca(OH)2), typically ranging from 60% to 70%. my country produces over 10 million tons of calcium carbide slag annually. Large-scale stockpiling of this slag not only occupies land but also pollutes the environment. The resource utilization of calcium carbide slag has become an important issue in the field of environmental protection.

[0003] Calcium hydroxide desulfurizers are widely used in flue gas desulfurization in coal-fired power plants, waste incineration plants, and other applications, with a large market demand. Traditional calcium hydroxide desulfurizers are mainly prepared from quicklime (CaO) through a digestion reaction. Using calcium carbide slag to partially replace quicklime in the production of desulfurizers not only reduces production costs but also enables the resource utilization of industrial solid waste, resulting in significant economic and environmental benefits.

[0004] A search revealed that patent (CN216499033U) discloses a system for manufacturing desulfurizing agents using calcium carbide slag, and patent (CN117819839A) discloses a high-efficiency, high-quality mixing device for producing calcium hydroxide from calcium carbide slag. Analysis of the existing technologies revealed the following drawbacks: (1) The equipment is scattered and occupies a large area: Most of the functional equipment in the existing production equipment is set up independently and the equipment is connected by conveying devices, resulting in a large production line area, high equipment investment costs, and dust pollution during material transfer.

[0005] (2) Poor uniformity of mixing: Existing mixing equipment mostly adopts a simple stirring method. Due to the high water content of carbide slag (usually 30%-35%) and the dry powder of quicklime, the two have large differences in density and fluidity, making it difficult to achieve uniform mixing and affecting the effect of subsequent digestion reaction.

[0006] (3) Dust control is difficult: Carbide slag and quicklime are both powdery materials, which are prone to generating a large amount of dust during transportation, mixing and digestion. Existing dust removal systems are mostly set up independently, with low integration with production equipment, and the dust removal effect is not ideal. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a complete set of equipment for producing desulfurizing agents using carbide slag, thus solving the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solution: a complete set of equipment for producing desulfurizing agent using calcium carbide slag, which adopts a modular integrated design, including a raw material storage and metering module, a premixing and digestion module, a maturation and screening module, a grinding and powder selection module and an integrated dust removal module connected in sequence. The modules are connected through a closed conveying channel to form a complete calcium hydroxide desulfurizing agent production line.

[0009] The aforementioned raw material storage and metering module includes a carbide slag storage silo, a quicklime storage silo, a carbide slag metering device, and a quicklime metering device. The bottom discharge hopper of the carbide slag storage silo is connected to the carbide slag metering device via a variable frequency speed-regulating screw feeder, and the bottom of the quicklime storage silo is connected to the quicklime metering device via a vibrating feeder.

[0010] The aforementioned premixed digestion module includes a premixing zone and a digestion zone. The premixing zone includes a horizontal twin-shaft paddle premixer with two parallel stirring shafts inside. The stirring shafts are equipped with helical blades and paddles, and the two stirring shafts are respectively connected to independent servo drive mechanisms. The discharge port of the premixer is connected to the inlet of the digestion zone through a closed screw conveyor. The digestion zone is a horizontal twin-shaft paddle digester with two stirring shafts with paddles inside. The two stirring shafts are respectively connected to independent servo drive mechanisms. The digester is equipped with a heating jacket on the outside and a temperature detection device and a humidity control device inside.

[0011] The aforementioned maturation and screening module includes a maturation chamber. The top of the maturation chamber is connected to the discharge port of the premixed digestion module, and the bottom is connected to a vibrating screening device. The vibrating screening device is equipped with a double-layer screen. Coarse and medium materials are discharged through different discharge ports, while fine materials directly enter the finished product chamber.

[0012] The aforementioned grinding and classifying module includes a Raymond mill, a classifier, and a circulating conveying device. The feed inlet of the Raymond mill is connected to the coarse material outlet and the medium material outlet of the vibrating screen device. The discharge outlet of the Raymond mill is connected to the feed inlet of the classifier. The classifier separates the ground material into qualified powder and unqualified powder. The qualified powder is sent into the finished product silo through the pneumatic conveying device, and the unqualified powder is returned to the Raymond mill for re-grinding through the circulating conveying device.

[0013] The aforementioned integrated dust removal module includes a bag filter, an induced draft fan, and a dust collection chamber. The bag filter is connected to each dust-generating point through a pipeline system. The dust collection chamber is located below the bag filter. The collected dust can be returned to the premixing and digestion module for reuse via a pneumatic conveying device. The induced draft fan is located behind the bag filter to provide negative pressure for the entire dust removal system.

[0014] This invention provides a complete set of equipment for producing desulfurizing agents using calcium carbide slag. It has the following beneficial effects: This complete set of equipment for producing desulfurizing agents using calcium carbide slag... (1) Through modular integrated design, functions such as raw material storage, metering, mixing, digestion, screening, grinding and powder selection are integrated into a compact equipment system. Compared with the decentralized layout of existing technologies, the floor space can be reduced and the equipment investment cost can be lowered.

[0015] (2) The premixed digestion module adopts a double helix stirring device with staggered blades. In the premixing zone, the stirring shaft is controlled by differential speed. The two stirring shafts with opposite directions and different speeds form differential stirring and multiple shearing effects, which can realize efficient and uniform forced mixing of carbide slag and quicklime, and improve the mixing uniformity of carbide slag and quicklime. In the digestion zone, when the stirring shafts rotate at the same speed, the two stirring shafts with opposite directions and the same speed can push the material to move along the axial direction, ensuring the continuity of production.

[0016] (3) By setting up temperature and humidity control devices in the digestion zone and controlling the material movement speed, the digestion process parameters can be flexibly adjusted according to the material characteristics to ensure that the quicklime digestion reaction is fully carried out.

[0017] (4) Through the integrated environmental protection dust removal system, the dust in the whole production process is effectively collected and treated, and the dust in the whole production process is effectively collected to meet the national environmental protection emission standards; the collected dust is returned to the production system for reuse, achieving zero emissions.

[0018] (5) By combining graded screening and circulating grinding, the particle size distribution of the product can be precisely controlled. The particle size distribution of the product can be precisely controlled, and the pass rate of 200 mesh can reach more than 95%. The calcium hydroxide content can reach 90%-95%, and the product quality is stable and reliable.

[0019] (6) High degree of automation: The PLC control system is adopted to realize automatic control of processes such as raw material metering, mixing, digestion, screening and grinding, and the production process is stable. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the main structure of a complete set of equipment for producing desulfurizing agent using carbide slag, as described in this invention.

[0021] Figure 2 This is a schematic diagram of the front cross-sectional structure of the digestive region described in this invention.

[0022] Figure 3 This is a top view cross-sectional structural diagram of the digestive region described in this invention.

[0023] In the diagram: 1. Calcium carbide slag storage silo; 2. Quicklime storage silo; 3. Calcium carbide slag metering device; 4. Quicklime metering device; 5. Premixing zone; 6. Digestion zone; 61. Main stirring shaft; 62. Auxiliary stirring shaft; 63. Spiral blade; 64. Paddle blade; 65. Heating jacket; 66. Temperature detection device; 67. Humidity control device; 7. Maturation silo; 8. Vibrating screen device; 9. Raymond mill; 10. Air classifier; 11. Finished product silo; 12. Bag filter dust collector; 13. Exhaust fan; 14. Dust collection silo; 15. Circulating conveying device; 16. Pneumatic conveying device one; 17. Pneumatic conveying device two. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example: Refer to the appendix of the instruction manual Figure 1-3 As can be seen, this application specifically designs a complete set of equipment for producing calcium hydroxide desulfurizing agent using carbide slag. It adopts a modular integrated design, including a raw material storage and metering module, a premixing and digestion module, a maturation and screening module, a grinding and powder selection module, and an integrated dust removal module connected in sequence. The modules are connected by a closed conveying channel to form a complete calcium hydroxide desulfurizing agent production line.

[0026] The raw material storage and metering module includes a carbide slag storage silo 1, a quicklime storage silo 2, a carbide slag metering device 3, and a quicklime metering device 4; The top of the carbide slag storage silo 1 is equipped with a feed inlet and a dust removal interface, and the bottom is equipped with a conical discharge hopper. The inner wall of the discharge hopper is equipped with an anti-sticking liner to prevent wet carbide slag from adhering and clogging. The bottom of the discharge hopper is equipped with a variable frequency speed-regulating screw feeder, which is connected to the carbide slag metering device 3. The top of the quicklime storage silo 2 is equipped with a feed inlet and a dust removal interface. The silo is equipped with a material level detection device and a temperature and humidity monitoring device to prevent the quicklime from getting damp and deteriorating. The bottom of the silo is equipped with a vibrating feeder, which is connected to the quicklime metering device 4.

[0027] It should be further noted that both the carbide slag metering device 3 and the quicklime metering device 4 mentioned above adopt loss-in-weight metering scales with a metering accuracy of ±0.5%. Automatic proportioning adjustment is achieved through a PLC control system, and the proportion of carbide slag to quicklime can be set to (1.0-2.0):1 according to product requirements.

[0028] The premixed digestion module includes a premixing zone 5 and a digestion zone 6, wherein... The premixing zone 5 is a horizontal twin-shaft paddle premixer with two parallel stirring shafts inside. The stirring shafts are equipped with spiral blades and paddle blades. The two stirring shafts rotate at different speeds to create a differential mixing effect, which is used to shear, disperse, and tumble mix the carbide slag and quicklime. The inner wall of the premixer is lined with a polymer anti-sticking plate to prevent wet materials from sticking to the wall. The discharge port of the premixer is connected to the inlet of the digestion zone 6 through a closed screw conveyor.

[0029] The digestion zone 6 is configured as a horizontal twin-shaft paddle digester 64, which has two main stirring shafts 61 with spiral blades 63 and paddles 64 and an auxiliary stirring shaft 62 inside, which strongly mixes and conveys the materials; the residence time of the digester can be controlled by adjusting the stirring shaft speed, and is set to 15-25 minutes; the digester is equipped with a heating jacket 65, a temperature detection device 66 and a humidity regulating device 67.

[0030] After the mixture enters the digester, it mixes with the moisture inherent in the carbide slag and water added through water mist nozzles, undergoing a digestion reaction. A heating jacket 65 is installed on the outer wall of the digester, and hot water or steam can be introduced into the jacket. The temperature detection device 66 includes multiple temperature sensors located at different positions on the tank to monitor the material temperature in real time. The PLC control system automatically adjusts the flow rate of the heating medium to achieve precise temperature control, maintaining the material temperature inside the tank at 80~95℃, thus promoting the digestion reaction of quicklime.

[0031] The humidity control device 67 includes a water mist nozzle and a humidity sensor located on the top of the digester. When the material humidity is detected to be lower than the set value, the water mist nozzle automatically starts to spray atomized water into the tank to adjust the material humidity to the optimal digestion humidity (moisture content 25%-35%).

[0032] The maturation and screening module includes a maturation chamber 7 and a vibrating screen device 8. The maturation chamber 7 is a vertical cylindrical structure with multiple partitions inside. Each partition has a material drop hole, and the material falls from top to bottom layer by layer, extending the maturation time. The chamber wall is equipped with an insulation layer to maintain the temperature inside the chamber and promote complete maturation reaction. The top of the maturation chamber 7 is connected to the discharge port of the premixed digestion module, and the bottom is connected to the vibrating screen device 8.

[0033] The vibrating screening device 8 includes a screen box, a screen mesh, a vibrating motor, and an elastic support. The screen mesh has two layers: the upper screen mesh has an aperture of 0.5 mm, and the lower screen mesh has an aperture of 0.074 mm (200 mesh). The upper screen mesh traps large particles as coarse material, the lower screen mesh traps medium material, and the material passing through the lower screen mesh is fine material. The coarse and medium materials are discharged through different outlets, while the fine material directly enters the finished product bin 11.

[0034] The grinding and classifying module includes a Raymond mill 9, a classifier 10, and a circulating conveyor 15. The feed inlet of the Raymond mill 9 is connected to the coarse and medium material outlets of the vibrating screen 8 for grinding the coarse and medium materials. The discharge outlet of the Raymond mill 9 is connected to the feed inlet of the classifier 10, which separates the ground material into qualified powder and unqualified powder. Qualified powder is sent to the finished product silo 11 via a pneumatic conveyor 16, while unqualified powder is returned to the Raymond mill 9 for re-grinding via the circulating conveyor 15.

[0035] The air classifier 10 is an impeller-type air classifier. By adjusting the impeller speed, the particle size can be controlled to be between 200-325 mesh. The finished product bin 11 is equipped with a dust removal interface at the top, and a material level detection device and a fluidization device are installed inside the bin to prevent material agglomeration.

[0036] The integrated dust removal module includes a bag filter 12, an induced draft fan 13, and a dust collection bin 14; The bag filter 12 is connected to various dust-generating points (such as the carbide slag storage silo 1, quicklime storage silo 2, premixed digester, slaking silo 7, Raymond mill 9, air classifier 10, finished product silo 11, etc.) through a pipeline system to centrally collect and treat the dust-laden gas generated at each dust-generating point. The bag filter 12 adopts a pulse jet cleaning method, and the filtration velocity is controlled at 0.8-1.2 m / min.

[0037] The dust collection chamber 14 is located below the bag filter 12. The collected dust can be returned to the premixing and digestion zone 6 for reuse via the pneumatic conveying device 17, achieving zero dust emissions. The induced draft fan 13 is located behind the bag filter 12, providing negative pressure for the entire dust removal system to ensure effective dust collection from each dust-generating point.

[0038] In summary, this complete set of equipment for producing desulfurizing agents using carbide slag, through modular integrated design, integrates functions such as raw material storage, metering, mixing, digestion, screening, grinding, and powder selection into a compact equipment system. Compared with the decentralized layout of existing technologies, it can reduce the floor space and lower equipment investment costs. The premixing and digestion module adopts a double-helix stirring device with staggered blades 64. In the premixing zone 5, the stirring shafts are differentially controlled. The two stirring shafts with opposite directions and different speeds form differential stirring and multiple shearing effects, which can achieve efficient and uniform forced mixing of carbide slag and quicklime, improving the mixing uniformity of carbide slag and quicklime. In the digestion zone 6, when the stirring shafts rotate at the same speed, the two stirring shafts with opposite directions and the same speed can push the material to move axially, ensuring the continuity of production. Temperature detection is set in the digestion zone 6. Device 66 and humidity control device 67 control the material movement speed, allowing for flexible adjustment of digestion process parameters based on material characteristics to ensure complete quicklime digestion reaction. An integrated environmental dust removal system effectively collects and treats dust throughout the entire production process, meeting national environmental emission standards. Collected dust is returned to the production system for reuse, achieving zero emissions. A combination of grading, screening, and circulating grinding precisely controls product particle size distribution, achieving a 200-mesh pass rate of over 95% and a calcium hydroxide content of 90%-95%, ensuring stable and reliable product quality. A PLC control system automates processes such as raw material metering, mixing, digestion, screening, and grinding, resulting in stable production and a high degree of automation.

[0039] In practical implementation, as a preferred option, the double-helix mixing device can be a single-helix mixing device combined with a baffle structure. The baffles change the material flow direction, achieving a mixing effect similar to double-helix mixing. This solution is simple in structure and low in cost, but the mixing effect is slightly inferior to double-helix mixing. The vibrating screen 8 can be replaced by a drum screen. The drum screen achieves material screening through rotation, resulting in higher screening efficiency and lower noise, but the equipment structure is more complex and maintenance costs are higher. The Raymond mill 9 can be replaced by a ball mill or a vertical mill. The ball mill has higher grinding efficiency but higher energy consumption; the vertical mill has a smaller footprint but higher equipment investment. The appropriate grinding equipment can be selected based on the production scale and site conditions. The bag filter 12 can be replaced by a cartridge dust collector or a wet scrubber. The cartridge dust collector has a large filtration area and a small footprint; the wet scrubber can remove dust and harmful gases simultaneously, but it generates wastewater treatment issues. Appropriate dust removal equipment can be selected based on environmental protection requirements and site conditions.

[0040] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A complete set of equipment for producing desulfurizing agent using carbide slag, characterized by a modular integrated design, wherein... It includes a raw material storage and metering module, a premixed digestion module, a maturation and screening module, a grinding and powder selection module, and an integrated dust removal module connected in sequence. The modules are connected by a closed conveying channel to form a complete calcium hydroxide desulfurizer production line.

2. The complete set of equipment for producing desulfurizing agent using carbide slag according to claim 1, characterized in that, The raw material storage and metering module includes a carbide slag storage silo, a quicklime storage silo, a carbide slag metering device, and a quicklime metering device. The bottom discharge hopper of the carbide slag storage silo is connected to the carbide slag metering device via a variable frequency speed-regulating screw feeder, and the bottom of the quicklime storage silo is connected to the quicklime metering device via a vibrating feeder.

3. The complete set of equipment for producing desulfurizing agent using carbide slag according to claim 2, characterized in that, The premixed digestion module includes a premixing zone and a digestion zone. The premixing zone includes a horizontal twin-shaft paddle premixer with two parallel stirring shafts inside. The stirring shafts are equipped with helical blades and paddles. The two stirring shafts are connected to independent servo drive mechanisms. The discharge port of the premixer is connected to the inlet of the digestion zone through a closed screw conveyor. The digestion zone is a horizontal twin-shaft paddle digester with two stirring shafts with paddles inside. The two stirring shafts are connected to independent servo drive mechanisms. The digester is equipped with a heating jacket on the outside and a temperature detection device and a humidity control device inside.

4. The complete set of equipment for producing desulfurizing agent using carbide slag according to claim 3, characterized in that, The maturation and screening module includes a maturation chamber. The top of the maturation chamber is connected to the discharge port of the premixed digestion module, and the bottom is connected to a vibrating screening device. The vibrating screening device adopts a double-layer screen. Coarse and medium materials are discharged through different discharge ports, while fine materials directly enter the finished product chamber.

5. A complete set of equipment for producing desulfurizing agent using carbide slag according to claim 4, characterized in that, The grinding and classifying module includes a Raymond mill, a classifier, and a circulating conveying device. The feed inlet of the Raymond mill is connected to the coarse material outlet and the medium material outlet of the vibrating screen. The discharge outlet of the Raymond mill is connected to the feed inlet of the classifier. The classifier separates the ground material into qualified powder and unqualified powder. Qualified powder is sent into the finished product silo through a pneumatic conveying device, while unqualified powder is returned to the Raymond mill for re-grinding through a circulating conveying device.

6. The complete set of equipment for producing desulfurizing agent using carbide slag according to claim 5, characterized in that, The integrated dust removal module includes a bag filter, an induced draft fan, and a dust collection chamber. The bag filter is connected to each dust-generating point through a pipeline system. The dust collection chamber is located below the bag filter. The collected dust can be returned to the premixing and digestion module for reuse via a pneumatic conveying device. The induced draft fan is located behind the bag filter to provide negative pressure for the entire dust removal system.

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