A device for preparing calcium oxide from dry calcium carbide slag

Abstract

The utility model provides a kind of device for preparing calcium oxide by dry method calcium slag, and the device for preparing calcium oxide by dry method calcium slag includes: calcium slag receiving and conveying mechanism, for receiving dry method calcium slag generated by acetylene and conveying to pretreatment mechanism;Pretreatment mechanism, for removing silicon iron impurities in calcium slag;Drying mechanism, for drying calcium slag after removing impurities;Calcining mechanism, for calcining dry calcium slag to generate calcium oxide;And waste heat recovery mechanism, including system waste heat distributor, intermediate bag filter and intermediate fan, the input end of system waste heat distributor is connected with calcining mechanism, for distributing waste heat to each energy-using device, intermediate bag filter is used to recover calcium oxide in tail gas, and the gas outlet of intermediate bag filter is connected to the heat source inlet of drying machine.The device for preparing calcium oxide by dry method calcium slag can recover waste heat in calcining process to realize cascade utilization and reduce system energy consumption.

Description

Technical Field

[0001] This application relates to the field of chemical solid waste disposal technology, and in particular to an apparatus for preparing calcium oxide from dry carbide slag. Background Technology

[0002] In the production of chemical products such as polyvinyl chloride (PVC), acetylene gas is typically produced by reacting calcium carbide with water. The dry acetylene process is widely used due to its advantages such as water conservation and environmental friendliness. The calcium carbide slag generated during the dry acetylene production process is a major industrial solid waste, and currently, the industry primarily uses landfill disposal.

[0003] However, landfilling dry-process calcium carbide slag leads to soil alkalization and groundwater pollution, causing serious damage to the ecological environment. On the other hand, calcium carbide slag contains a large amount of usable calcium resources, and landfilling results in a significant waste of these resources. Meanwhile, traditional calcium oxide production primarily uses limestone as raw material, which suffers from high mining costs, high energy consumption, and high carbon emissions. Therefore, developing a device that can efficiently convert dry-process calcium carbide slag into calcium oxide, achieving solid waste resource utilization, reducing environmental pollution, and replacing the traditional limestone-based calcium oxide production process, has significant economic and environmental value. Utility Model Content

[0004] In view of this, this application provides a device for preparing calcium oxide from dry carbide slag, which can recover the waste heat in the calcination process to achieve cascade utilization and reduce system energy consumption.

[0005] This application provides an apparatus for preparing calcium oxide from dry carbide slag, the apparatus comprising: The carbide slag receiving and conveying mechanism is used to receive carbide slag produced by dry acetylene processing and convey it to the pretreatment mechanism. A pretreatment mechanism is used to remove ferrosilicon impurities from carbide slag, and the feed end of the pretreatment mechanism is connected to the discharge port of the carbide slag receiving and conveying mechanism. Drying unit, used to dry carbide slag after impurities have been removed; Calcination mechanism, used to calcine dried carbide slag to produce calcium oxide; and The waste heat recovery mechanism includes a system waste heat distributor, an intermediate bag filter, and an intermediate fan. The input end of the system waste heat distributor is connected to the calcination mechanism and is used to distribute waste heat to each energy-consuming device. The input end of the intermediate bag filter is connected to the outlet end of the system waste heat distributor and is used to recover calcium oxide in the exhaust gas. The outlet end of the intermediate bag filter is connected to the heat source inlet of the dryer through the intermediate fan.

[0006] The drying mechanism includes a dryer, a cyclone dust collector, a bag filter dust collector, and a system fan. The input end of the cyclone dust collector is connected to the discharge end of the dryer, the input end of the bag filter dust collector is connected to the air outlet end of the cyclone dust collector, the output ends of both the cyclone dust collector and the bag filter dust collector are connected to the calcination mechanism, the input end of the system fan is connected to the air outlet end of the bag filter dust collector, and the output end of the system fan is connected to the chimney.

[0007] The calcination mechanism includes a calcination intermediate chamber, a rotary unloader, a mixer, a dynamic calcination furnace, a static calcination furnace, and a hot air supply unit. The discharge port of the calcination intermediate chamber is connected to the input end of the mixer via the rotary unloader. The mixer is also connected to hot air from the waste heat recovery mechanism. The output end of the mixer is connected to the input end of the dynamic calcination furnace. The discharge end of the dynamic calcination furnace is connected to the input end of the static calcination furnace. The high-temperature hot air of the dynamic calcination furnace is provided by the hot air supply unit.

[0008] The hot air supply unit includes a hot air furnace, a decarbonization furnace, and a low-NOx burner, wherein the decarbonization furnace and the low-NOx burner provide heat sources for the hot air furnace, respectively.

[0009] The apparatus for preparing calcium oxide from dry carbide slag further includes a finished product processing mechanism, which includes an air-cooling system and a finished calcium oxide silo. The input end of the air-cooling system is connected to the calcination mechanism and the waste heat recovery mechanism, respectively. The air-cooling system recovers sensible heat through a blower, and its output end is connected to the finished calcium oxide silo. The exhaust gas of the air-cooling system is sent to the system waste heat distributor.

[0010] The finished product processing mechanism also includes a tanker loading device, a tubular conveying device, a bag packaging machine, and a dust collection device. The tanker loading device and the tubular conveying device are located below the calcium oxide finished product silo. The output end of the tubular conveying device is connected to the bag packaging machine. The input end of the dust collection device is connected to the dust outlet of the bag packaging machine. The output end of the dust collection device is connected to the calcium oxide finished product silo.

[0011] The apparatus for preparing calcium oxide from dry carbide slag provided in this application addresses the problem that low-moisture carbide slag produced by dry acetylene processing is difficult to utilize directly and pollutes the environment through landfill. Through an integrated design of receiving, conveying, pretreatment, drying, and calcination, it transforms bulk solid waste into high-value calcium oxide, solving the disposal problem of this type of solid waste and reducing ecological and environmental pressure. Simultaneously, the waste heat recovery mechanism precisely distributes the waste heat from the calcination exhaust gas to energy-consuming devices such as the drying mechanism and mixer through a system waste heat distributor. Combined with an intermediate fan, hot air is reused. The drying heat source relies entirely on the waste heat from calcination, eliminating the need for additional fossil fuel consumption, significantly reducing system energy consumption, and complying with energy conservation and emission reduction policies. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the framework of the apparatus for preparing calcium oxide from dry carbide slag provided in the embodiments of this application; Figure 2 This is a schematic diagram of the apparatus for preparing calcium oxide from dry carbide slag provided in the embodiments of this application; Figure 3 This is a schematic diagram of the apparatus for preparing calcium oxide from dry carbide slag according to another embodiment of this application.

[0014] Explanation of reference numerals in the attached figures: 1-Apparatus for preparing calcium oxide from dry carbide slag; 10-Carbide slag receiving and conveying mechanism; 20-Pretreatment mechanism; 30-Drying mechanism; 40-Calcination mechanism; 50-Waste heat recovery mechanism; 60-Finished product processing mechanism; 31-Dryer; 32-Cyclone dust collector; 33-Drying bag dust collector; 34-System fan; 41-Calcination intermediate silo; 43-Mixer; 44-Dynamic calcination furnace; 45-Static calcination furnace; 51-Waste heat distributor; 52-Intermediate bag dust collector; 53-Intermediate fan; 61-Air cooling system; 62-Calcium oxide finished product silo; 63-Tank loading device. Detailed Implementation

[0015] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. 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.

[0016] In this document, references to "embodiment" or "implementation" mean that a particular feature, structure, or characteristic described in connection with an embodiment or implementation may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0017] Please see Figure 1and Figure 2 This application provides an apparatus 1 for preparing calcium oxide from dry calcium carbide slag. The apparatus 1 includes a calcium carbide slag receiving and conveying mechanism 10, a pretreatment mechanism 20, a drying mechanism 30, a calcination mechanism 40, and a waste heat recovery mechanism 50. The calcium carbide slag receiving and conveying mechanism 10 receives calcium carbide slag produced by the dry acetylene process and conveys it to the pretreatment mechanism 20. The pretreatment mechanism 20 removes ferrosilicon impurities from the calcium carbide slag, and its feed end is connected to the discharge port of the calcium carbide slag receiving and conveying mechanism 10. The drying mechanism 30 dries the calcium carbide slag after impurity removal. The calcination mechanism 40 calcines the dried calcium carbide slag to produce calcium oxide. The waste heat recovery mechanism 50 includes a system waste heat distributor 51, an intermediate bag filter 52, and an intermediate fan 53. The input end of the system waste heat distributor 51 is connected to the calcination mechanism 40 and is used to distribute waste heat to each energy-consuming device. The input end of the intermediate bag filter 52 is connected to the outlet end of the system waste heat distributor 51 and is used to recover calcium oxide in the exhaust gas. The outlet end of the intermediate bag filter 52 is connected to the heat source inlet of the dryer 31 through the intermediate fan 53.

[0018] Optionally, the carbide slag receiving and conveying mechanism 10 includes a tank truck receiving device, a dense phase airflow conveying device, and a carbide slag storage tank. After the carbide slag produced by the dry acetylene process is transported to the site by tank truck, it is unloaded through the tank truck receiving device and then conveyed to the carbide slag storage tank via the dense phase airflow conveying device for temporary storage.

[0019] Optionally, the pretreatment mechanism 20 adopts a permanent magnet drum magnetic separator. After the calcium carbide slag in the slag tank is weighed by a quantitative metering belt scale, it enters the magnetic separator to remove ferrosilicon impurities, thereby avoiding wear and tear on subsequent equipment and a decrease in the purity of calcium oxide products.

[0020] Optionally, the waste heat distributor 51 of the system has built-in temperature and flow regulating valves to distribute waste heat proportionally. A portion of the medium-temperature hot air is sent to the mixer 43 of the calcination mechanism 40, where it mixes with the dried carbide slag before entering the dynamic calcination furnace 44 of the calcination mechanism 40. Another portion of the low-temperature hot air is sent to the dryer 31 of the drying mechanism 30 as a drying heat source, achieving cascaded utilization of waste heat.

[0021] The exhaust gas discharged from the system waste heat distributor 51 still contains some calcium oxide dust. It enters the intermediate bag filter 52 for deep dust removal. The collected calcium oxide dust is sent to the finished product processing unit 60 to avoid material waste and improve product yield. The hot air purified by the intermediate bag filter 52 is sent to the dryer 31 of the drying unit 30 by the intermediate fan 53 for further waste heat recovery.

[0022] In summary, the apparatus 1 for preparing calcium oxide from dry carbide slag provided in this embodiment addresses the problem that low-moisture carbide slag produced by dry acetylene processing is difficult to utilize directly and pollutes the environment through landfill. By integrating receiving, conveying, pretreatment, drying, and calcination, it transforms bulk solid waste into high-value calcium oxide, solving the disposal problem of this type of solid waste and reducing ecological and environmental pressure. Simultaneously, the waste heat recovery mechanism 50, through the system waste heat distributor 51, precisely distributes the waste heat from the calcination exhaust gas to energy-consuming devices such as the drying mechanism 30 and the mixer 43. Combined with the intermediate fan 53, hot air is reused. The drying heat source relies entirely on the calcination waste heat, eliminating the need for additional fossil fuel consumption, significantly reducing system energy consumption, and conforming to energy conservation and emission reduction industrial policies.

[0023] Please see Figure 2 and Figure 3 The drying mechanism 30 includes a dryer 31, a cyclone dust collector 32, a bag filter dust collector 33, and a system fan 34. The input end of the cyclone dust collector 32 is connected to the discharge end of the dryer 31, and the input end of the bag filter dust collector 33 is connected to the air outlet end of the cyclone dust collector 32. The output ends of both the cyclone dust collector 32 and the bag filter dust collector 33 are connected to the calcining mechanism 40. The input end of the system fan 34 is connected to the air outlet end of the bag filter dust collector 33, and the output end of the system fan 34 is connected to the chimney.

[0024] Optionally, the purified carbide slag enters the dryer 31, where the drying temperature is controlled at 200℃-400℃ (preferably 250℃-350℃), and the drying heat source comes from the cascaded waste heat recovery system. During the drying process, the carbide slag is fully turned over in the dryer 31 by the lifting plate structure, exchanging heat with the hot air, so that the moisture content of the dried carbide slag is ≤1%.

[0025] Further, the dried carbide slag is carried by the airflow into a cyclone dust collector 32 for preliminary separation, and the material collected by the cyclone dust collector 32 enters the calcination intermediate silo 41. The exhaust gas from the cyclone dust collector 32 enters a drying bag dust collector 33 for deep dust removal, and the carbide slag collected by the drying bag dust collector 33 is also sent to the calcination intermediate silo 41. The exhaust gas purified by the drying bag dust collector 33 is sent to the chimney by the system fan 34 for emission in compliance with standards.

[0026] In this embodiment, the dryer 31 can rapidly reduce the moisture content of the carbide slag after impurity removal, providing raw materials with adequate dryness for subsequent calcination processes, effectively improving the calcination conversion rate and product purity of calcium oxide. Furthermore, through the combined dust collection structure of the cyclone dust collector 32 and the drying bag filter 33, the cyclone dust collector 32 first efficiently recovers the dried coarse-particle carbide slag, and then the drying bag filter 33 deeply captures fine-particle materials in the exhaust gas, avoiding material waste and improving resource utilization.

[0027] Please refer to it again. Figure 2 and Figure 3 The calcination mechanism 40 includes a calcination intermediate chamber 41, a rotary unloader, a mixer 43, a dynamic calcination furnace 44, a static calcination furnace 45, and a hot air supply component. The discharge port of the calcination intermediate chamber 41 is connected to the input end of the mixer 43 through the rotary unloader. The mixer 43 is also connected to hot air from the waste heat recovery mechanism 50. The output end of the mixer 43 is connected to the input end of the dynamic calcination furnace 44. The discharge end of the dynamic calcination furnace 44 is connected to the input end of the static calcination furnace 45. The high-temperature hot air of the dynamic calcination furnace 44 is provided by the hot air supply component.

[0028] The dried carbide slag in the intermediate calcination chamber 41 is fed into the mixer 43 by a rotary unloader. After mixing with the medium-temperature hot air from the system waste heat distributor 51, it enters the dynamic calcination furnace 44 for preliminary calcination, where the calcium hydroxide in the carbide slag decomposes into calcium oxide and water vapor.

[0029] Furthermore, the high-temperature hot air of the dynamic calcining furnace 44 is provided by a hot air furnace. The material after preliminary calcination enters the cyclone dust collector 32 with the airflow for separation, and the collected material enters the static calcining furnace 45 for deep calcination to ensure complete decomposition of calcium hydroxide.

[0030] In this embodiment, the dynamic calcining furnace 44 achieves rapid preheating and preliminary decomposition of the calcium carbide slag, while the static calcining furnace 45 completes deep calcination. This two-stage process ensures the decomposition rate of calcium hydroxide and the purity of the calcium oxide product. The intermediate calcination chamber 41 acts as a material buffer, balancing the material flow between the drying and calcination systems to prevent material interruption or accumulation. The rotary unloader enables continuous unloading and sealed isolation, preventing the high-temperature hot air from the dynamic calcining furnace 44 from flowing back into the intermediate calcination chamber 41, ensuring stable system pressure, and preventing the material from becoming damp and deteriorating. Simultaneously, the mixer 43 premixes the dried calcium carbide slag in the intermediate calcination chamber 41 with the medium-temperature hot air from the waste heat recovery mechanism 50, preheating the material and reducing the high-temperature heat source consumption of the dynamic calcining furnace 44.

[0031] Please refer to it again. Figure 2 and Figure 3 The hot air supply unit includes a hot air furnace, a decarbonization furnace, and a low-NOx burner, wherein the decarbonization furnace and the low-NOx burner provide heat sources for the hot air furnace, respectively.

[0032] In this embodiment, the decarbonization furnace can recover carbon-containing tail gas generated during chemical production as a core heat source, realizing the resource utilization of industrial by-product waste gas and reducing fossil energy consumption. The low-NOx burner serves as a backup heat source, ensuring continuous and stable calcination. The hot blast stove, powered by both the decarbonization furnace and the low-NOx burner, ensures a stable heat source during calcination, preventing temperature fluctuations from affecting calcium oxide decomposition efficiency and ensuring product quality uniformity.

[0033] Please refer again to Figure 2 and Figure 3 . The apparatus 1 for preparing calcium oxide from dry-process calcium carbide residue further comprises a finished product processing mechanism 60, the finished product processing mechanism 60 comprises an air cooling system 61 and a calcium oxide finished product bin 62, the input end of the air cooling system 61 is connected with the calcining mechanism 40 and the waste heat recovery mechanism 50 respectively, the air cooling system 61 recovers sensible heat through a blower, the output end thereof is connected with the calcium oxide finished product bin 62, and the tail gas of the air cooling system 61 is sent to the system waste heat distributor 51.

[0034] Specifically, the cooled calcium oxide product enters the calcium oxide finished product bin 62 for storage. A tank truck loading device 63 is arranged below the first discharge port of the calcium oxide finished product bin 62, and is used for tank truck transportation for bulk users. The second discharge port is connected with a full-automatic quantitative bag-type packaging machine through a tubular conveying device.

[0035] In this embodiment, the air cooling system 61 recovers the sensible heat of high-temperature calcium oxide through the blower, so as to avoid direct heat loss, and meanwhile sends the tail gas carrying sensible heat to the system waste heat distributor 51, which further improves the overall waste heat utilization rate and reduces the comprehensive energy consumption of the system.

[0036] Please refer again to Figure 2 and Figure 3 . The finished product processing mechanism 60 further comprises a tank truck loading device 63, a tubular conveying device, a bag-type packaging machine and a dust collecting member, the tank truck loading device 63 and the tubular conveying device are arranged below the calcium oxide finished product bin 62, the output end of the tubular conveying device is connected with the bag-type packaging machine, the input end of the dust collecting member is connected with the dust outlet of the bag-type packaging machine, and the output end of the dust collecting member is connected to the calcium oxide finished product bin 62.

[0037] In this embodiment, the tank truck loading device 63 and the tubular conveying device are arranged in parallel below the calcium oxide finished product bin 62, which can simultaneously meet the bulk transportation demand of tank trucks for bulk users and the bagged procurement demand of small and medium-sized users, no additional transfer equipment is required, the adaptability of the apparatus to different market demands is greatly improved, and the product application scenarios are broadened. Moreover, the dust collecting member matched with the bag-type packaging machine can efficiently capture the calcium oxide dust generated in the packaging process, and return the recovered dust to the calcium oxide finished product bin 62, which not only avoids environmental pollution caused by dust escape and meets the clean production requirements, but also eliminates material waste, so that the comprehensive product yield is further improved.

[0038] In this application, the terms "embodiment" and "implementation" mean that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of these phrases in various locations throughout the specification does not necessarily refer to the same embodiment, nor are they independent or alternative embodiments mutually exclusive with other embodiments. Those skilled in the art will understand, explicitly and implicitly, that the embodiments described in this application can be combined with other embodiments. Furthermore, it should be understood that the features, structures, or characteristics described in the various embodiments of this application can be arbitrarily combined to form another embodiment that does not depart from the spirit and scope of the technical solution of this application, provided there is no contradiction between them.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims

1. An apparatus for preparing calcium oxide from carbide slag using a dry process, characterized in that, The apparatus for preparing calcium oxide from dry carbide slag includes: The carbide slag receiving and conveying mechanism is used to receive carbide slag produced by dry acetylene processing and convey it to the pretreatment mechanism. A pretreatment mechanism is used to remove ferrosilicon impurities from carbide slag, and the feed end of the pretreatment mechanism is connected to the discharge port of the carbide slag receiving and conveying mechanism. Drying unit, used to dry carbide slag after impurities have been removed; Calcination mechanism, used to calcine dried carbide slag to produce calcium oxide; and The waste heat recovery mechanism includes a system waste heat distributor, an intermediate bag filter, and an intermediate fan. The input end of the system waste heat distributor is connected to the calcination mechanism and is used to distribute waste heat to each energy-consuming device. The input end of the intermediate bag filter is connected to the outlet end of the system waste heat distributor and is used to recover calcium oxide in the exhaust gas. The outlet end of the intermediate bag filter is connected to the heat source inlet of the dryer through the intermediate fan.

2. The apparatus for preparing calcium oxide from dry carbide slag as described in claim 1, characterized in that, The drying mechanism includes a dryer, a cyclone dust collector, a bag filter dust collector, and a system fan. The input end of the cyclone dust collector is connected to the discharge end of the dryer, the input end of the bag filter dust collector is connected to the air outlet end of the cyclone dust collector, the output ends of both the cyclone dust collector and the bag filter dust collector are connected to the calcination mechanism, the input end of the system fan is connected to the air outlet end of the bag filter dust collector, and the output end of the system fan is connected to the chimney.

3. The apparatus for preparing calcium oxide from dry carbide slag as described in claim 1, characterized in that, The calcination mechanism includes a calcination intermediate chamber, a rotary unloader, a mixer, a dynamic calcination furnace, a static calcination furnace, and a hot air supply unit. The discharge port of the calcination intermediate chamber is connected to the input end of the mixer via the rotary unloader. The mixer is also connected to hot air from the waste heat recovery mechanism. The output end of the mixer is connected to the input end of the dynamic calcination furnace. The discharge end of the dynamic calcination furnace is connected to the input end of the static calcination furnace. The high-temperature hot air of the dynamic calcination furnace is provided by the hot air supply unit.

4. The apparatus for preparing calcium oxide from dry carbide slag as described in claim 3, characterized in that, The hot air supply unit includes a hot air furnace, a decarbonization furnace, and a low-NOx burner, wherein the decarbonization furnace and the low-NOx burner provide heat sources for the hot air furnace, respectively.

5. The apparatus for preparing calcium oxide from dry carbide slag as described in claim 1, characterized in that, The apparatus for preparing calcium oxide from dry carbide slag also includes a finished product processing mechanism, which includes an air-cooling system and a calcium oxide finished product silo. The input end of the air-cooling system is connected to the calcination mechanism and the waste heat recovery mechanism, respectively. The air-cooling system recovers sensible heat through a blower, and its output end is connected to the calcium oxide finished product silo. The exhaust gas of the air-cooling system is sent to the system waste heat distributor.

6. The apparatus for preparing calcium oxide from dry carbide slag as described in claim 5, characterized in that, The finished product processing mechanism also includes a tanker loading device, a tubular conveying device, a bag packaging machine, and a dust collection device. The tanker loading device and the tubular conveying device are located below the calcium oxide finished product silo. The output end of the tubular conveying device is connected to the bag packaging machine. The input end of the dust collection device is connected to the dust outlet of the bag packaging machine. The output end of the dust collection device is connected to the calcium oxide finished product silo.

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