A calcium carbide sensible heat utilization system based on the recycling of heat-taking medium

Abstract

The present invention relates to the technology of utilizing sensible heat of calcium carbide, and particularly relates to a calcium carbide sensible heat utilization system based on the recycling of heat extraction medium. A calcium carbide sensible heat utilization system based on the recycling of heat extraction medium includes a calcium carbide tundish. The calcium carbide tundish is connected to a rotary drum through a calcium carbide flow trough. The rotary drum has openings at both ends, and an intake buffer chamber and an exhaust buffer chamber are respectively arranged at the discharge end and the feed end of the rotary drum. A rotary gear ring is arranged on the outer wall of the rotary drum, and the rotary gear ring cooperates with a rotary motor. Driven by the rotary motor, the rotary drum rotates continuously. A scraping device is arranged inside the rotary drum. This kind of calcium carbide sensible heat utilization system changes the traditional process of using a calcium carbide pot for cooling, directly uses a high-speed heat extraction gas flow to impact the calcium carbide liquid into scattered point-like falling materials for cooling, which is convenient for the high-speed heat extraction gas flow to absorb heat and utilize the sensible heat, and the heat extraction gas medium can be recycled, saving energy and protecting the environment.

Description

Technical Field

[0001] The present invention relates to the technology for utilizing the sensible heat of calcium carbide, and particularly to a calcium carbide sensible heat utilization system based on the recycling of a heat extraction medium. Background Art

[0002] Calcium carbide is an important raw material, which is widely used in the fields of acetylene production, chemical industry, iron and steel, agriculture, and environmental protection. However, the production of calcium carbide is an energy-intensive industry. Generally, 3000 - 3500 kWh of electricity is required to produce 1 ton of calcium carbide. Among them, 20% of the energy is wasted in the form of heat after the calcium carbide flows out of the electric furnace. The traditional calcium carbide cooling process is that after the calcium carbide flows out of the calcium carbide furnace, it is poured into a calcium carbide pot. After cooling in the calcium carbide pot, it enters the crushing workshop for crushing and packing. Since the calcium carbide pot is an open device, after the calcium carbide is poured into the calcium carbide pot, the temperature rapidly drops from 1800 °C to the surface temperature of the calcium carbide pot, which is 600 °C. This stage is short and the heat cannot be recovered and utilized. At present, the heat recovery of the calcium carbide pot cooling production process mainly adopts the method of tunnel ventilation to recover the heat after the outer wall temperature of the calcium carbide pot is reduced to 600 °C. On the one hand, the volume of the calcium carbide lump is huge, and the thermal conductivity of calcium carbide is very low, so the heat inside the calcium carbide lump is difficult to transfer outward, resulting in a very low heat recovery efficiency of the tunnel ventilation heat extraction method. On the other hand, using air as the heat extraction medium increases the probability of the reaction between nitrogen and oxygen in the air and calcium carbide, ultimately affecting the quality of the calcium carbide product. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a calcium carbide sensible heat utilization system based on the recycling of a heat extraction medium. This kind of calcium carbide sensible heat utilization system changes the traditional calcium carbide cooling process using a calcium carbide pot, and uses a high-speed heat extraction air flow to impact the calcium carbide liquid into scattered point drop cooling, which is convenient for the high-speed heat extraction air flow to absorb heat and conduct sensible heat utilization. Moreover, the whole system is in a closed state, and the heat extraction gas medium can be recycled, which is energy-saving, environmentally friendly, and has high economic value.

[0004] To solve the problems of the prior art, the present invention discloses a calcium carbide sensible heat utilization system based on the recycling of a heat extraction medium, including a calcium carbide tundish. The calcium carbide tundish is connected to a rotary drum through a calcium carbide flow channel. Both ends of the rotary drum are open, and an intake buffer chamber and an exhaust buffer chamber are respectively arranged at both ends. The intake buffer chamber is located at the end of the rotary drum where the calcium carbide is discharged, and the exhaust buffer chamber is located at the end of the rotary drum where the calcium carbide enters. A rotary gear ring is arranged on the outer wall of the rotary drum. The rotary gear ring cooperates with a rotary motor, and the rotary drum rotates continuously under the drive of the rotary motor. A scraping device is arranged inside the rotary drum.

[0005] The exhaust buffer chamber is connected to the exhaust pipeline, and the exhaust pipeline is connected to the heat exchanger. The hot air after heat exchange in the heat exchanger is recycled through the recovery pipeline. The cold air after heat exchange in the heat exchanger is divided into two paths. One path enters the discharge end of the rotary drum through the air supply pipeline I and the intake buffer chamber, and the other path enters the feed end of the rotary drum through the air supply pipeline II. A discharge hopper is arranged at the bottom of the intake buffer chamber, and the discharge hopper is located at the position where calcium carbide is discharged from the discharge end of the rotary drum.

[0006] Preferably, both ends of the rotary drum are open and are arranged at an angle of 10° - 20° with the horizontal line. The position of the feed end of the rotary drum is higher than that of the discharge end. Two rotary gear rings are arranged on the outer wall of the rotary drum, and each rotary gear ring meshes with the motor gear of the rotary motor. The module of the rotary gear ring and the motor gear is the same.

[0007] Preferably, the scraping device includes a scraping base. A scraping disc is connected to the scraping base through a connecting rod. Scraping knives are evenly arranged at intervals on the scraping disc, and the scraping knives are arranged at the inner wall position on one side of the feed end of the rotary drum.

[0008] Preferably, a discharge plate is arranged at the discharge port position of the discharge hopper. The discharge plate is of a double-plate structure, and the connection between the two plates adopts a staggered connection method. An elastic rubber pad is installed at the connection position, and the discharge hopper and the discharge plate are connected through a spring hinge.

[0009] Preferably, a calcium carbide liquid inlet is arranged on the calcium carbide tundish, and a sealing plate is arranged at the calcium carbide liquid inlet position. The sealing plate is movably connected to the cover of the calcium carbide tundish.

[0010] Preferably, the rotary drum is connected to the side walls of the intake buffer chamber and the exhaust buffer chamber in a groove type, and a refractory cotton felt is installed at the groove connection surface position.

[0011] Preferably, the outflow direction of the high-speed heat-taking medium is set at an upward angle difference of 15° - 35° with the central axis of the rotary drum.

[0012] Preferably, the high-speed heat-taking medium is carbon dioxide gas.

[0013] Preferably, control valves, induced draft fans, carbon dioxide concentration meters, pressure gauges and other instruments are arranged on the exhaust pipeline, the air supply pipeline I and the air supply pipeline II.

[0014] The working process of the present invention is as follows: The molten calcium carbide liquid flows into the calcium carbide tundish, and then enters the feeding end of the rotary drum through the calcium carbide flow channel. It meets the high-speed heat-taking medium flow introduced, and is impacted by the high-speed heat-taking medium flow into a scattered state and falls into the rotary drum, where it is cooled into blocks. Under the rotation of the rotary drum, it continuously advances and falls into the discharge hopper and is discharged. The high-speed heat-taking medium flow after heat-taking carries a large amount of heat, exchanges heat with the heat exchanger through the exhaust pipe, and realizes the recovery and utilization of heat.

[0015] The beneficial effects of the present invention are as follows: 1. High heat-taking temperature. The present invention changes the original cooling method of the molten calcium carbide liquid in the calcium carbide pot. Instead, it uses a high-speed heat-taking medium flow to impact the molten calcium carbide liquid and make it fall in a scattered state. In this way, the high-speed heat-taking medium flow can take heat from the heat that rapidly drops from 1800 °C after the molten calcium carbide liquid leaves the furnace, and the heat grade is higher. 2. High heat-taking efficiency. The molten calcium carbide flow is impacted by the high-speed heat-taking medium flow into a scattered state and falls, avoiding the problem of slow heat dissipation of the calcium carbide lump in the traditional cooling process. Moreover, the calcium carbide blocks falling in a scattered state are continuously thrown up and then fall under the continuous rotation of the rotary drum. Since the rotary drum is placed at an angle to the ground and the position of the discharge end is lower than that of the feeding end, with continuous throwing up and falling, the calcium carbide blocks also continuously move forward until they fall into the discharge hopper. The state of continuously being thrown up and falling in a small block state not only increases the heat-taking area but also prolongs the heat-taking time, and the heat-taking efficiency is higher. 3. The heat-taking medium can be recycled. The whole system is in an approximately closed state, and the introduced heat-taking medium can be recycled, avoiding the problem of continuously introducing the heat-taking medium, reducing the heat-taking cost. Using carbon dioxide gas as the heat-taking medium can avoid reacting with calcium carbide and has a low cost. Description of the Drawings

[0016] Figure 1 is the overall structural schematic diagram of the present invention;

[0017] Figure 2 is the specific structural schematic diagram of the scraping device in the present invention;

[0018] Figure 3 is the structural schematic diagram of the discharge plate in the present invention.

[0019] Reference Signs:

[0020] 1. Calcium carbide tundish; 2. Calcium carbide flow trough; 3. Rotary drum; 4. Inlet buffer chamber; 5. Exhaust buffer chamber; 6. Rotary gear ring; 7. Rotary motor; 8. Scraping device; 81. Scraping base; 82. Connecting rod; 83. Scraping plate; 84. Scraping knife; 9. Ladle cover; 10. Sealing plate; 11. Exhaust pipe; 12. Heat exchanger; 13. Gas supply pipe Ⅰ; 14. Gas supply pipe Ⅱ; 15. Discharge hopper; 16. Control valve; 17. Induced draft fan; 18. Carbon dioxide concentration meter; 19. Pressure gauge; 20. Discharge plate; 21. Partition wall; 22. Recovery pipe. Detailed implementation mode

[0021] The following will be further described in conjunction with the accompanying drawings of the specification. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0022] As Figure 1 shown, a calcium carbide sensible heat utilization system based on the recycling of heat transfer medium includes a calcium carbide tundish 1. The calcium carbide tundish 1 is connected to a rotary drum 3 through a calcium carbide flow trough 2. The rotary drum 3 has openings at both ends, and an inlet buffer chamber 4 and an exhaust buffer chamber 5 are respectively arranged at both ends. The inlet buffer chamber 4 is located at the end where calcium carbide enters the rotary drum 3, and the exhaust buffer chamber 5 is located at the end where calcium carbide is discharged from the rotary drum 3. A rotary gear ring 6 is arranged on the outer wall of the rotary drum 3. The rotary gear ring 6 cooperates with a rotary motor 7, and the rotary drum 3 rotates continuously under the drive of the rotary motor 7. A scraping device 8 is arranged inside the rotary drum 3.

[0023] The calcium carbide tundish 1 receives the molten calcium carbide flow discharged from the calcium carbide furnace and discharges the molten calcium carbide flow into the rotary drum 3 through the calcium carbide flow trough 2. The calcium carbide tundish 1 has a ladle cover 9, which plays a role in isolating air. Since the feeding of the calcium carbide furnace is intermittent, when the calcium carbide furnace pauses feeding the calcium carbide tundish 1, in order to prevent external air from entering the calcium carbide tundish 1 from the position of the calcium carbide liquid inlet, a sealing plate 10 is specially provided. The sealing plate 10 is movably connected to the ladle cover 9 of the calcium carbide tundish 1 and is vertically arranged. When the discharge of calcium carbide liquid pauses, the sealing plate 10 drops downward from the position of the ladle cover 9 to cover the calcium carbide liquid inlet.

[0024] The rotary drum 3 has openings at both ends and is inclined, preferably at an angle of 10°-20° with the horizontal line. The position of the calcium carbide liquid feeding end is higher than the position of the discharging end, and the rotary drum 3 is driven by a rotary motor 7 to drive the rotary gear ring 6 to rotate continuously. Thus, the molten calcium carbide in the rotary drum 3 is continuously thrown up and dropped. Due to the inclined setting, the molten calcium carbide moves forward continuously. Since the temperature of calcium carbide drops extremely fast, it quickly changes from the molten state to solid small pieces after falling until it is discharged.

[0025] The intake buffer chamber 4 and the exhaust buffer chamber 5 are respectively arranged at both ends of the rotary cylinder 3, which play a buffering role and are also convenient for collecting carbon dioxide gas for pipeline transmission. To improve the sealing performance of the entire device, the side walls of the rotary cylinder 3, the intake buffer chamber 4 and the exhaust buffer chamber 5 are connected in a groove type, and a refractory cotton felt is installed at the position of the groove connection surface.

[0026] The exhaust buffer chamber 5 is connected to the exhaust pipeline 11, and the exhaust pipeline 11 is connected to the heat exchanger 12. The hot air after heat exchange by the heat exchanger 12 is recycled through the recovery pipeline 22, and the cold air after heat exchange by the heat exchanger 12 is divided into two paths. One path enters the discharge end of the rotary cylinder 3 through the air supply pipeline I 13 and the intake buffer chamber 4, and the other path enters the feeding end of the rotary cylinder 3 through the air supply pipeline II 14 and the exhaust buffer chamber 5; A discharge hopper 15 is arranged at the bottom of the intake buffer chamber 4, and the discharge hopper 15 is located at the position where the calcium carbide is discharged from the discharge end of the rotary cylinder 3.

[0027] Control valves 16, induced draft fans 17, carbon dioxide concentration meters 18, pressure gauges 19 and other instruments are arranged on the exhaust pipeline 11, the air supply pipeline I 13 and the air supply pipeline II 14 to control, guide and monitor the transmission of carbon dioxide.

[0028] Since the molten calcium carbide falls in a scattered state and will adhere to the inner wall on one side of the feeding end of the rotary cylinder, a scraping device 8 needs to be set. After the calcium carbide falls, its temperature drops extremely fast, and the calcium carbide quickly changes from the molten liquid state to the solidified solid state. Therefore, the scraping device 8 only needs to be set at the feeding end of the rotary cylinder 3. During the subsequent movement, it will solidify into a solid and gradually move during the rotation process without adhering to the inner wall. As Figure 2 shown, the scraping device 8 includes a scraping base 81. A scraping disc 83 is connected to the scraping base 81 through a connecting rod 82. Scraping blades 84 are evenly arranged at intervals on the scraping disc 83, and the scraping blades 84 are in contact with the inner wall of the rotary cylinder 3. A scraping blade 84 is arranged every 45°. There are 8 scraping blades 84 on the scraping disc 83. The scraping blades 84 are of a fixed structure. As the rotary cylinder 3 rotates continuously, the scraping blades 84 continuously clean the calcium carbide adhered to the inner wall. Since calcium carbide is an inorganic compound, the connection between it and the metal on the inner wall of the rotary cylinder 3 is not very tight after cooling. Therefore, the scraping blades 84 do not need to be closely attached to the inner wall of the rotary cylinder 3, but have a certain distance from the inner wall of the rotary cylinder 3. As long as the end of the scraping blade 84 can scrape the head end of the calcium carbide dot material, under the rotation of the rotary cylinder 3, the two move relatively, and the calcium carbide dot material can be scraped off.

[0029] As Figure 3As shown, a discharge plate 20 is provided at the discharge port of the discharge hopper 15. The discharge plate 20 is a double-plate structure, and the intersection of the two plates is staggered. An elastic rubber pad is installed at the intersection. The discharge hopper 15 and the discharge plate 20 are connected by a spring hinge. The calcium carbide falling into the discharge hopper 15 has become a small block of cooled solid state. In order to avoid the continuous falling and the entry of external air, a discharge plate 20 that can automatically rebound is provided at the discharge port of the discharge hopper 15. The discharge plate 20 and the discharge hopper 15 are connected by a spring hinge. When the material accumulates to a certain extent, its gravitational potential energy breaks through the elastic potential energy of the spring hinge in the discharge plate 20, and the intersection of the two discharge plates 20 opens downward to discharge the small pieces of calcium carbide.

[0030] The outflow direction of the high-speed heat extraction medium is set at an upward angle difference of 15°-35° with the central axis of the rotary drum 3, and the high-speed heat extraction medium is carbon dioxide gas.

[0031] In the whole system, on the one hand, heat is extracted and on the other hand, heat is exchanged, and the two are connected by a pipeline, wherein high-speed carbon dioxide gas is used as the heat extraction medium, which impacts the molten calcium carbide flow into a scattered state and absorbs the heat therein, and enters the heat exchanger 12 from the exhaust pipe 11 for heat exchange, and the high-speed carbon dioxide gas flow that is cooled after the heat exchange is divided into two paths and enters the discharge end and the feed end of the rotary drum 3 from the air supply pipe Ⅰ13 and the air supply pipe Ⅱ14 respectively, wherein the high-speed carbon dioxide gas flow in the air supply pipe Ⅱ13 can extract heat from the high-temperature molten calcium carbide at the feed end of the rotary drum 3, and the air supply pipe Ⅰ14 enters from the discharge end of the rotary drum 3 and is discharged from the feed end, so as to extract heat from the calcium carbide in the entire rotary drum 3, and the two airflows converge in the air intake buffer chamber 4 and enter the heat exchanger 12 from the exhaust pipe 11, thereby realizing the whole heat extraction process.

[0032] In order to improve production safety, a separation wall 21 is provided between the devices with heat extraction function and heat exchange function.

[0033] In order to achieve the sealing of the system, many measures have been taken, such as setting a sealing plate 10 at the calcium carbide inlet of the calcium carbide ladle 1, the side walls of the air intake buffer chamber 4 and the exhaust buffer chamber 5 of the rotary drum 3 are connected by grooves, and the discharge hopper 15 and the discharge plate 20 are connected by an automatic rebound spring hinge.

[0034] During use, it is necessary to first evacuate the air in the system, then fill it with carbon dioxide gas at a certain pressure, and then the calcium carbide liquid enters the calcium carbide tundish 1 to start the heat exchange process. Generally speaking, during the evacuation of air in the system, the pressure gauge 19 in the pipeline shows that the pressure in the system should be below 300 Pa before carbon dioxide gas can be filled. When the filled carbon dioxide gas reaches 3 atmospheres, open the valves on the exhaust pipeline 11, the gas supply pipeline I 13, and the gas supply pipeline II 14 to start the carbon dioxide circulation heat extraction stage. When the carbon dioxide concentration meter 18 installed on the pipeline shows that the carbon dioxide purity is lower than 50%, evacuate the gas in the pipeline and refill it with carbon dioxide to enter a new heat extraction cycle stage.

[0035] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A calcium carbide sensible heat utilization system based on the recycling of heat medium, comprising a calcium carbide tundish, characterized in that: The calcium carbide tundish is connected to the rotary drum via a calcium carbide flow trough. The rotary drum is open at both ends, and an air intake buffer chamber and an exhaust buffer chamber are respectively arranged at both ends. The air intake buffer chamber is located at the end of the rotary drum where calcium carbide is discharged, and the exhaust buffer chamber is located at the end of the rotary drum where calcium carbide is entered; a rotary gear ring is arranged on the outer wall of the rotary drum, and the rotary gear ring cooperates with the rotary motor. Driven by the rotary motor, the rotary drum continuously rotates, and a scraper device is arranged inside the rotary drum; the scraper device includes a scraper base, and a scraper plate is connected to the scraper base through a connecting rod, and scraper knives are evenly spaced on the scraper plate, and the scraper knives are arranged at the inner wall position on one side of the feeding end of the rotary drum; The exhaust buffer chamber is connected to the exhaust pipe, and the exhaust pipe is connected to the heat exchanger. The hot air after heat exchange in the heat exchanger is recycled from the recovery pipe, and the cold air after heat exchange in the heat exchanger is divided into two paths, one path passes through the air delivery pipe I and the air intake buffer chamber to enter the discharge end of the rotary drum, and the other path passes through the air delivery pipe II to enter the feed end of the rotary drum; A discharge hopper is arranged at the bottom of the air intake buffer chamber, and the discharge hopper is located at the position where calcium carbide is discharged from the discharge end of the rotary drum; a discharge plate is arranged at the discharge port of the discharge hopper, and the discharge plate is a double-plate structure, and the intersection of the two plates adopts a staggered connection method, and an elastic rubber pad is installed at the intersection position, and the discharge hopper and the discharge plate are connected by a spring hinge.

2. The calcium carbide sensible heat utilization system based on the recycling of heat medium according to claim 1 is characterized by: The rotating drum is open at both ends and is arranged at 10°-20° with the horizontal line. The position of the feeding end of the rotating drum is higher than the position of the discharging end. Two rotating gear rings are arranged on the outer wall of the rotating drum, and each rotating gear ring is meshed with the motor gear of the rotating motor, and the module of the rotating gear ring is the same as that of the motor gear.

3. The calcium carbide sensible heat utilization system based on the recycling of heat medium according to claim 1 is characterized in that: The calcium carbide tundish is provided with a calcium carbide liquid inlet, and a sealing plate is provided at the position of the calcium carbide liquid inlet, and the sealing plate is movably connected to the calcium carbide tundish cover.

4. The calcium carbide sensible heat utilization system based on the recycling of heat medium according to claim 1 is characterized in that: The rotary drum is connected to the side walls of the air intake buffer chamber and the exhaust buffer chamber in a groove-type manner, and fire-resistant cotton felt is installed at the position of the groove connection surface.

5. The calcium carbide sensible heat utilization system based on the recycling of heat medium according to claim 1 is characterized in that: The outflow direction of the heat extraction medium is set at an upward angle difference of 15°-35° with the central axis of the rotary drum.

6. The calcium carbide sensible heat utilization system based on the recycling of heat medium according to claim 1 is characterized by: The heat extraction medium is carbon dioxide gas.

7. The calcium carbide sensible heat utilization system based on the recycling of heat medium according to claim 1 is characterized by: The exhaust pipe, air supply pipe I and air supply pipe II are all provided with control valves, induced draft fans, carbon dioxide concentration meters and pressure gauges.

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