A heat extraction system for calcium carbide sensible heat recovery

Abstract

The utility model relates to calcium carbide sensible heat utilization technology, concretely relates to a kind of heat extraction system for calcium carbide sensible heat recovery.A kind of heat extraction system for calcium carbide sensible heat recovery, including calcium carbide tundish and rotary cylinder, CO2 inlet pipe is provided at rotary cylinder feed end, the CO2 inlet pipe is connected booster fan, the air outlet of the CO2 inlet pipe is located just below calcium carbide flow groove, the inner wall of the feed end of rotary cylinder is fixedly set with material scraping knife, the material scraping knife is fixed in the upper and lower of rotary cylinder, a plurality of hinge ladles are provided in the middle section of rotary cylinder, the hinge ladle occurs open-close activity along the radial direction of rotary cylinder, CO2 jet cylinder is provided at the position of the discharge end of rotary cylinder, a plurality of nozzles are provided on the CO2 jet cylinder, each nozzle passes through booster fan and imports CO2 into rotary cylinder.The kind of heat extraction system for calcium carbide sensible heat recovery can increase the contact area and time of calcium carbide and heat extraction medium, improve heat extraction efficiency.

Description

Technical Field

[0001] This utility model relates to the technology of utilizing the sensible heat of calcium carbide, specifically to a heat recovery system for recovering the sensible heat of calcium carbide. Background Technology

[0002] Calcium carbide production is an energy-intensive industry. Currently, the main production method is electrothermal, with the calcium carbide furnace being the core equipment. Relying on electric arc heating, it requires a huge amount of electricity; producing one ton of calcium carbide typically requires 3000-3500 kWh of electricity. Of this, 20% of the energy is wasted as heat after the calcium carbide leaves the furnace. Traditional calcium carbide production involves pouring the calcium carbide from the furnace into a calcium carbide pot, where it cools before entering a crushing workshop for further processing and packaging. Because the calcium carbide pot is an open system, the temperature drops rapidly after the calcium carbide is poured in, reaching a surface temperature of 600°C before stabilizing. Therefore, the traditional calcium carbide pot cooling process cannot recover the heat during the period from when the calcium carbide exits the furnace (around 1800°C) until the surface temperature of the calcium carbide pot reaches a relatively stable 600°C.

[0003] Currently, the main cooling process for calcium carbide pots uses tunnel ventilation to recover some of the waste heat from the calcium carbide. However, this method primarily recovers heat from when the outer wall temperature of the calcium carbide pot reaches 600°C. When the calcium carbide is cooled to 600°C inside the pot, the large volume of the calcium carbide mass and its low thermal conductivity (approximately 1.5-2.5 W / (m·K) below 600°C) make it difficult for the heat inside the mass to transfer outwards. This results in very low heat recovery efficiency for the tunnel ventilation method. Furthermore, using air as the heat extraction medium increases the probability of nitrogen and oxygen reacting with the calcium carbide, ultimately affecting the quality of the calcium carbide product.

[0004] Considering the limitations of calcium carbide sensible heat recovery methods and the low thermal conductivity of calcium carbide, our team started by reducing the volume of calcium carbide and provided a calcium carbide sensible heat utilization system based on the recycling of heat extraction medium, as detailed in the invention patent with publication number CN119901157B. After testing and improvement, we further improved the heat extraction system in the patent. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a heat recovery system for calcium carbide sensible heat recovery. This calcium carbide sensible heat recovery system can increase the contact area and time between calcium carbide and the heat recovery medium, thereby improving the heat recovery efficiency.

[0006] To address the existing technical problems, this utility model discloses a heat recovery system for calcium carbide sensible heat recovery, including a calcium carbide intermediate jar and a rotary drum. The calcium carbide intermediate jar is connected to the rotary drum through a calcium carbide flow channel. The rotary drum is driven to rotate by an external force. A CO2 inlet pipe is provided at the feed end of the rotary drum. The CO2 inlet pipe is connected to a booster fan. The outlet of the CO2 inlet pipe is located directly below the calcium carbide flow channel.

[0007] A scraper is fixedly installed on the inner wall of the feed end of the rotary drum. The scraper is fixed above and below the rotary drum. Several hinged lifting plates are installed in the middle section of the rotary drum. The opening and closing direction of the hinged lifting plates is the same as the rotation direction of the rotary drum. A CO2 jet tube is installed at the discharge end of the rotary drum. Several nozzles are installed on the CO2 jet tube. Each nozzle introduces CO2 into the rotary drum through a booster fan.

[0008] The hinge plate includes a base, a plate, a rotating shaft, and a return spring. The base is fixed to the inner wall of the rotary drum, and a return spring is provided between the base and the plate. The rotating shaft passes through the return spring to fix the base and the plate together.

[0009] Preferably, the rotary drum is set at 10°-15° to the horizontal plane, the scraper is set parallel to the inner wall of the rotary drum, the nozzle is set inclined from the inner wall of the rotary drum toward the central axis of the rotary drum, and the CO2 inlet pipe is set inclined to the central axis of the rotary drum and is set upward toward the central axis.

[0010] Preferably, a counterweight is provided at the end of the plate away from the rotating shaft, on the side near the return spring.

[0011] Preferably, the length of the end of the plate furthest from the rotating shaft is greater than the length of the end closest to the rotating shaft.

[0012] Preferably, the end of the plate away from the rotating shaft has a serrated structure.

[0013] Preferably, the width of the plate is greater than the width of the base.

[0014] Preferably, the nozzles are connected together by a support frame.

[0015] Preferably, there is a width of 1-3 cm between the scraper and the inner wall of the rotary drum.

[0016] The beneficial effects of this utility model are as follows:

[0017] 1. Reduced calcium carbide volume. The CO2 inlet pipe is inclined to the central axis of the rotary drum and faces upward towards the central axis. After being pressurized by the booster fan, the CO2 is ejected at high speed, which can impact the molten calcium carbide flowing out of the calcium carbide flow tank into droplets, reducing the calcium carbide volume and avoiding the problem of large calcium carbide lumps having slow heat dissipation and being unfavorable for heat collection.

[0018] 2. Increased contact time between calcium carbide and the heat extraction medium CO2 effectively improves heat extraction efficiency. On one hand, several nozzles on the CO2 jet nozzle at the discharge end of the rotary drum spray CO2 in a counter-current direction into the drum, contacting the flowing calcium carbide droplets and absorbing the heat from them. This heat is then carried into the heat collection device as the CO2 is discharged. On the other hand, hinged lifting plates continuously throw the calcium carbide droplets out, increasing the contact time between the droplets and the counter-current CO2, thus improving heat extraction efficiency.

[0019] 3. The problem of calcium carbide adhering to the inner wall of the rotary drum is solved. A scraper is installed at the feed end of the rotary drum. It is fixedly set. As the rotary drum rotates continuously, the relative movement between the scraper and the scraper scrapes off the molten calcium carbide droplets adhering to the inner wall of the rotary drum. The calcium carbide droplets dissipate heat quickly and, after being scraped off, retain their solid shape and will not adhere to the inner wall of the rotary drum again.

[0020] 4. If the width of the hinge plate is greater than the width of the base, the plate can cover the base when moving back and forth. This ensures that the calcium carbide droplets are thrown outwards instead of getting stuck in the return spring between the plate and the base, thus affecting its return movement. Alternatively, a protective sleeve can be wrapped around the return spring. The longer, serrated end of the hinge plate allows the calcium carbide droplets to be thrown outwards over a wider area, increasing the throwing height. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0022] Figure 2 This is a schematic diagram of the hinge plate in this utility model;

[0023] Figure 3 This is a schematic diagram of the CO2 jet tube in this utility model.

[0024] Figure label:

[0025] 1. Calcium carbide tundish; 2. Rotary drum; 3. Calcium carbide flow channel; 4. CO2 inlet pipe; 5. Booster fan; 6. Scraper; 7. Hinge lifting plate; 71. Base; 72. Plate; 73. Shaft; 74. Return spring; 75. Counterweight; 8. CO2 jet tube; 81. Nozzle; 82. Support frame. Detailed Implementation

[0026] The following description, in conjunction with the accompanying drawings, provides further details. The embodiments described below are merely for illustrating the technical solution of this utility model more clearly and should not be construed as limiting the scope of protection of this utility model.

[0027] like Figure 1 and Figure 3 As shown, a heat recovery system for calcium carbide sensible heat recovery includes a calcium carbide intermediate ladle 1 and a rotary drum 2. The calcium carbide intermediate ladle 1 is connected to the rotary drum 2 via a calcium carbide flow channel 3. The rotary drum 2 is driven to rotate by an external force. A CO2 inlet pipe 4 is provided at the feed end of the rotary drum 2, and the CO2 inlet pipe 4 is connected to a booster fan 5. The outlet of the CO2 inlet pipe 4 is located directly below the calcium carbide flow channel 3. Under the drive of the external force, the rotary drum 2 rotates continuously, and the molten calcium carbide in the calcium carbide intermediate ladle 1 flows continuously down from the calcium carbide flow channel 3. During the flow of the molten calcium carbide, it is dispersed into droplets by the high-pressure, high-speed CO2 gas sprayed from the CO2 inlet pipe 4 and falls into the inner wall of the rotary drum 2, thereby reducing the volume of calcium carbide and facilitating the rapid dispersion and transfer of heat.

[0028] A scraper 6 is fixedly installed on the inner wall of the feed end of the rotary drum 2. The scraper 6 is fixed above and below the rotary drum 2. Several hinged lifting plates 7 are provided in the middle section of the rotary drum 2. The opening and closing direction of the hinged lifting plates 7 is the same as the rotation direction of the rotary drum 2. There is a width of 1-3 cm between the scraper 6 and the inner wall of the rotary drum 2.

[0029] After the molten calcium carbide is dispersed into droplets, it easily adheres to the inner wall of the rotary drum 2. The fixed scraper 6 can scrape the calcium carbide droplets off the inner wall of the rotary drum 2 as the rotary drum 2 rotates continuously. Since the molten calcium carbide becomes hard after cooling, the relative shearing motion between the rotary drum 2 and the scraper 6 will cause it to fall off. After falling off, the calcium carbide droplets will not adhere again and will continue to move downwards to the discharge end of the rotary drum 2 under the action of gravity.

[0030] The rotary drum 2 rotates continuously along its central axis, causing the cooled calcium carbide droplets to be thrown up and down repeatedly, increasing the travel path of the calcium carbide droplets and extending the heat dissipation time. To further increase the throwing height of the calcium carbide droplets, several hinged lifting plates 7 are installed on the inner wall of the rotary drum 2. The hinge connection method facilitates the continuous opening and closing of the lifting plates to throw the calcium carbide droplets. A return spring 74 is installed between the plate 72 and the base 71. Under the elastic action of the return spring 74, the hinged lifting plates 7 can be continuously opened and closed, facilitating the continuous throwing of calcium carbide droplets.

[0031] like Figure 3As shown, a CO2 jet nozzle 8 is installed at the discharge end of the rotary drum 2. The CO2 jet nozzle 8 has several nozzles 81, each of which supplies CO2 into the rotary drum 2 via a booster fan 5. The nozzles 81 are connected together by a support frame 82. To extract heat from the calcium carbide droplets, a CO2 jet nozzle 8 is installed at the discharge end of the rotary drum 2. The high-pressure, high-speed CO2 jetted from the nozzle travels in the opposite direction to the calcium carbide droplets, thus increasing heat extraction efficiency. The gas ejected from the CO2 jet tube 8 extracts heat in the reverse direction from the discharge end to the feed end of the rotary drum 2, while the gas ejected from the CO2 inlet pipe 4 mainly impacts the molten calcium carbide liquid into droplets, and can also achieve forward heat extraction from the feed end to the discharge end of the rotary drum 2. Therefore, in addition to the heat extraction system, a heat collection system needs to be set at the feed end and discharge end of the rotary drum 2 to collect and utilize the heat extracted from the feed end and discharge end of the rotary drum 2. This heat collection device is a mature technology in the prior art, and this utility model does not involve related modifications, so it is not described in detail.

[0032] The rotary drum 2 is set at 10°-15° to the horizontal plane, the scraper 6 is set parallel to the inner wall of the rotary drum 2, the nozzle 81 is set inclined from the inner wall of the rotary drum 2 toward the central axis of the rotary drum 2, and the CO2 inlet pipe 4 is set inclined to the central axis of the rotary drum 2 and is set upward toward the central axis.

[0033] The rotating drum 2 is inclined downwards directly to the horizontal plane to facilitate the movement of calcium carbide droplets to the discharge end of the rotating drum 2 under the action of gravity. The scraper 6 is set parallel to the inner wall of the rotating drum 2 to peel off the calcium carbide droplets adhering to the inner wall of the rotating drum 2. Since the calcium carbide droplets cool down very quickly, once they are peeled off, they will no longer adhere to the inner wall of the rotating drum 2. Therefore, the scraper 6 is only set at the feed end of the rotating drum 2, while several hinged lifting plates 7 are set in the middle of the rotating drum 2. The nozzles 81 in the CO2 jet tube 8 are inclined from the inner wall of the rotating drum towards the central axis of the rotating drum 2, so that they spray heat-extracting gas in the direction of the central axis of the rotating drum 2. The nozzles 81 spray from all directions, and after converging, they can easily form vortices, which improves the heat extraction efficiency of the calcium carbide droplets. The CO2 inlet pipe 4 is inclined to the central axis of the rotary drum 2 and is oriented upwards towards the central axis. The gas it sprays blows the molten calcium carbide flowing down from the calcium carbide flow tank 3 in an oblique upward direction, and applies an upward force to the calcium carbide droplets formed, prolonging their falling time, so that the heat-extracting gas can extract heat, thereby reducing the temperature of the formed calcium carbide droplets and preventing them from adhering to the inner wall of the rotary drum 2.

[0034] like Figure 2As shown, the hinge plate 7 includes a base 71, a plate 72, a rotating shaft 73, and a return spring 74. The base 71 is fixed to the inner wall of the rotary cylinder 2. The return spring 74 is disposed between the base 71 and the plate 72. The rotating shaft 73 passes through the return spring 74 to fix the base 71 and the plate 72 together. A counterweight 75 is disposed at the end of the plate 72 away from the rotating shaft 73, near the return spring 74. The length of the end of the plate 72 away from the rotating shaft 73 is greater than the length of the end near the rotating shaft 73. The end of the plate 72 away from the rotating shaft 73 has a serrated structure. The width of the plate 72 is greater than the width of the base 71.

[0035] The hinged lifting plates 7 can be arranged linearly on the inner wall of the rotary drum 2, or they can be distributed on the inner wall of the rotary drum 2. Their bases 71 are fixed to the inner wall of the rotary drum 2 and do not affect the movement of the calcium carbide droplets. A protective sleeve can be added to the outside of the return spring 74 to prevent it from being stuck by the calcium carbide droplets. Even if the return spring 74 is stuck, it will easily flow out under the continuous rotation of the rotary drum 2. Furthermore, to avoid this situation, the width of the plate 72 is greater than the width of the base 71, allowing it to throw calcium carbide droplets over a wider area, preventing them from falling into the middle of the return spring 74. To increase the throwing height, a counterweight 75 is provided on the side near the return spring 74, and the length of the end of the plate 72 is made longer, with a serrated structure at the end.

[0036] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A heat recovery system for calcium carbide sensible heat recovery, comprising a calcium carbide tundish and a rotary drum, wherein the calcium carbide tundish is connected to the rotary drum via a calcium carbide flow channel, and the rotary drum is driven to rotate by an external force, characterized in that: A CO2 inlet pipe is installed at the feed end of the rotary drum. The CO2 inlet pipe is connected to a booster fan, and the outlet of the CO2 inlet pipe is located directly below the calcium carbide flow tank. A scraper is fixedly installed on the inner wall of the feed end of the rotary drum, with the scraper fixed above and below the drum. Several hinged lifting plates are installed in the middle section of the rotary drum, opening and closing radially. A CO2 jet nozzle is installed at the discharge end of the rotary drum, with several nozzles on it. Each nozzle introduces CO2 into the rotary drum via a booster fan. The hinge plate includes a base, a plate, a rotating shaft, and a return spring. The base is fixed to the inner wall of the rotary drum, and a return spring is provided between the base and the plate. The rotating shaft passes through the return spring to fix the base and the plate together.

2. The heat recovery system for calcium carbide sensible heat recovery according to claim 1, characterized in that: The rotary drum is set at an angle of 10°-15° to the horizontal plane, the scraper is set parallel to the inner wall of the rotary drum, the nozzle is set inclined from the inner wall of the rotary drum toward the central axis of the rotary drum, and the CO2 inlet pipe is set inclined toward the central axis of the rotary drum.

3. The heat recovery system for calcium carbide sensible heat recovery according to claim 1, characterized in that: The hinge plate's rotation axis is aligned with the rotation axis of the rotary drum, and the plate opens and closes around the rotation axis.

4. A heat recovery system for calcium carbide sensible heat recovery according to claim 3, characterized in that: A counterweight is placed at the end of the plate away from the rotating shaft and on the side near the return spring.

5. A heat recovery system for calcium carbide sensible heat recovery according to claim 3, characterized in that: The length of the end of the plate furthest from the shaft is greater than the length of the end closest to the shaft.

6. A heat recovery system for calcium carbide sensible heat recovery according to claim 4 or 5, characterized in that: The end of the plate furthest from the pivot has a serrated structure.

7. A heat recovery system for calcium carbide sensible heat recovery according to claim 1, characterized in that: The width of the plate is greater than the width of the base.

8. A heat recovery system for calcium carbide sensible heat recovery according to claim 1, characterized in that: The nozzles are connected together by a support frame.

9. A heat recovery system for calcium carbide sensible heat recovery according to claim 1, characterized in that: There is a width of 1-3 cm between the scraper and the inner wall of the rotary drum.

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