Submerged arc furnace stokehole floor mold pouring waste heat recycling system

Abstract

A waste heat recycling system for stokehold floor mold pouring of a submerged arc furnace comprises a small tap hole smoke hood and a waste heat recycling smoke hood. The waste heat recovery smoke hood is communicated with the small tap hole smoke hood, radiant heat exchange pipelines are longitudinally and uniformly distributed in the waste heat recovery smoke hood, the radiant heat exchange pipelines are connected through heat-resistant steel sheets, and a high-temperature flue is arranged in the waste heat recovery smoke hood; the inlet end of the circulating fan is communicated with the tap hole small smoke hood, and the outlet end is communicated with the top of the waste heat recovery smoke hood; the inlet end of the waste heat boiler communicates with the outlet end of the high-temperature flue. The back pressure steam turbine receives steam generated by the waste heat boiler; the dust remover receives low-temperature flue gas generated by the waste heat boiler and exhausts the low-temperature flue gas through the exhaust fan; the power input end of the exhaust fan is connected with the output end of the back pressure turbine through a speed reducer and a clutch, and the power output end is connected with a permanent magnet motor which is connected with a four-quadrant frequency converter. The softened water deaerator receives condensed water generated by the back pressure steam turbine and conveys the condensed water to the waste heat boiler through a pipeline for recycling.

Description

Technical Field

[0001] This invention relates to the field of submerged arc furnace technology, and in particular to a system for recovering and utilizing waste heat from casting the ground mold in front of a submerged arc furnace. Background Technology

[0002] Submerged arc furnaces are indispensable equipment in the iron and steel metallurgical industry, and the recovery and utilization of waste heat resources is of great significance for reducing energy consumption and environmental pollution. Currently, while submerged arc furnace flue gas waste heat recovery power generation systems can meet certain heat recovery needs, some problems remain, such as high concentrations of dust in the casting process and low waste heat utilization rates. In particular, during the casting process, the high-temperature flue gas generated by the submerged arc furnace contains a large amount of carbon particles and carbon dust. These substances not only pose safety hazards to the working environment and human health at the production site but also easily cause environmental pollution.

[0003] Existing waste heat recovery systems typically recover only the flue gas from the blast furnace production process, using conventional intake ducts for the tapping and casting flue gas, circulating fans, and return ducts for the annular cooler connected to a dust collector. While this system can recover some particulate matter from the flue gas, it still has several shortcomings: First, it does not recover the waste heat from tapping and casting, wasting the heat carried by the molten iron during these processes; second, the heat carried by the molten iron is dissipated into the production workshop as radiant heat, significantly impacting the workers' working environment, and prolonged exposure to this environment can easily lead to health problems for workers. Summary of the Invention

[0004] In order to solve the technical problems existing in the above-mentioned technologies, it is necessary to provide a waste heat recovery and utilization system for casting the ground mold in front of the ferroelectric furnace.

[0005] A waste heat recovery and utilization system for casting pre-furnace molds in a submerged arc furnace includes:

[0006] A small smoke hood at the taphole is installed on the outside of the molten iron pipe connecting the electric arc furnace and the ground mold;

[0007] The waste heat recovery fume hood is installed on the outside of the ground mold. The waste heat recovery fume hood is connected to the small fume hood at the iron outlet. The interior of the waste heat recovery fume hood is longitudinally distributed with radiant heat exchange pipes. Each radiant heat exchange pipe is connected by heat-resistant steel sheets. The interior of the waste heat recovery fume hood has a high-temperature flue for discharging high-temperature flue gas.

[0008] The circulating fan has its inlet end connected to the small smoke hood at the iron outlet and its outlet end connected to the inlet end of the top of the waste heat recovery smoke hood.

[0009] Waste heat boiler, the inlet end of which is connected to the outlet end of the high-temperature flue;

[0010] Back-pressure steam turbines are used to receive steam generated by waste heat boilers;

[0011] The dust collector is used to receive the low-temperature flue gas generated by the waste heat boiler and purify the low-temperature flue gas before it is discharged through the exhaust fan; the power input end of the exhaust fan is connected to the output end of the back pressure steam turbine through a reducer and a clutch; the power output end of the exhaust fan is connected to a permanent magnet motor, and the permanent magnet motor is connected to a four-quadrant frequency converter.

[0012] The softened water deaerator is used to receive condensate generated by the back-pressure steam turbine and, after treatment, transport the condensate through pipelines to the waste heat boiler for reuse.

[0013] Preferably, the waste heat boiler is equipped with a steel ball cleaning device for cleaning ash accumulated in the heat exchange tubes inside the waste heat boiler. The steel ball cleaning device includes a support frame, a drive wheel, a guide wheel, a double-row chain, and a steel ball transport hopper.

[0014] An opening guide rail is horizontally fixed at the upper end of the support frame, and a closing guide rail is horizontally fixed at the lower end of the support frame; a limiting rail is horizontally fixed above the opening guide rail and the closing guide rail, so that a channel for the steel ball transport bucket to run is formed between the limiting rail and the opening rail, and between the limiting rail and the closing rail.

[0015] The drive wheel and guide wheel are rotatably mounted on the support frame;

[0016] The double-row chain is mounted around the drive wheel and the guide wheel, enabling the double-row chain to rotate along the drive wheel and the guide wheel;

[0017] The ball bearing transport bucket is rotatably installed between the two chains of the double-row chain. When the ball bearing transport bucket moves to the opening guide rail, the lower end of the ball bearing transport bucket forms a rolling contact with the opening guide rail, causing the bottom outlet end of the ball bearing transport bucket to open and release the ball bearings in the ball bearing transport bucket. When the ball bearing transport bucket moves to the closing guide rail, the lower end of the ball bearing transport bucket forms a rolling contact with the closing guide rail, causing the bottom outlet end of the ball bearing transport bucket to close and receive the recovered ball bearings.

[0018] Preferably, the upper end of the ball bearing transport hopper has a guide wheel, and brackets are fixedly installed on the two opposite side walls of the ball bearing transport hopper. A sealing plate for sealing the bottom outlet end of the ball bearing transport hopper is slidably installed between the two brackets. A rolling assembly is rotatably installed at the lower end of the two side walls of the ball bearing transport hopper with brackets. After the rolling assembly contacts the opening guide rail or closing guide rail, it rotates, so that the rolling assembly can drive the sealing plate to slide along the lower part of the bracket, thereby controlling the opening or closing of the bottom outlet end of the ball bearing transport hopper.

[0019] Preferably, the rolling assembly includes a rotating shaft and rollers; the rotating shaft is symmetrically rotatably mounted on the lower ends of the two side walls of the steel ball transport hopper with a support, a rotating gear is fixedly mounted on the rotating shaft, and the rollers are fixedly mounted on the rotating shaft.

[0020] Preferably, a rack that meshes with a rotating gear is fixedly installed on the upper surface of the two ends of the sealing plate facing the bracket, so that the rotating gear can drive the sealing plate to slide along the bracket when it rotates.

[0021] Preferably, the lower part of the bracket has a guide groove for the sealing plate to slide, and the inner wall of the guide groove is equipped with balls evenly distributed along the sliding direction of the sealing plate.

[0022] Preferably, the device further includes a secondary steel ball separation mechanism for further separating the steel balls from the residual ash and impurities. The secondary steel ball separation mechanism includes a separation box and a negative pressure suction unit. The left end of the separation box is higher than the right end, so that the separation box is arranged at an angle. The left end of the separation box has a feed inlet for receiving steel balls, and the right end of the separation box has a discharge outlet. The interior of the separation box has a partition parallel to the bottom of the separation box, and the partition has ash leakage holes. The negative pressure suction unit is connected to the interior of the separation box through a pipe along the bottom of the separation box to discharge the separated residual ash and impurities.

[0023] Preferably, a buffer ball-throwing assembly is provided inside the separation box near the feed inlet. The buffer ball-throwing assembly includes a buffer plate and a spring. The lower end of the buffer plate is rotatably connected to the side wall of the separation box. The left end of the spring is connected to the side wall of the feed inlet, and the right end of the spring is connected to the upper end of the buffer plate, so that the buffer plate is inclined upward and forms an angle with the partition.

[0024] Preferably, the upper surface of the partition is provided with convex strips at equal intervals on the side facing the feed inlet, and the upper surface of the partition is provided with convex strips evenly distributed on the side facing the bead discharge outlet.

[0025] Preferably, the protrusions and the tops of the protrusions have an arc-shaped structure.

[0026] Compared with existing technologies, the waste heat recovery and utilization system for casting pre-furnace ground molds provided by this invention effectively improves the heat recovery efficiency by setting up a waste heat and radiant heat collection hood on the upper part of the casting ground mold and setting up radiant heat exchange pipes inside the hood. Compared with traditional iron tapping and casting flue gas recovery systems, this invention can better utilize the waste heat and radiant heat generated during the iron tapping process of the electric arc furnace, significantly reducing energy consumption. The use of a small hood at the iron tapping outlet to connect the electric arc furnace iron tapping outlet hood and the ground mold radiant heat and waste heat recovery hood effectively solves the problem of large amounts of air leakage during iron tapping in traditional systems. By precisely controlling the blower air volume and cooling time, a large amount of sensible heat loss from the sintered ore is avoided. The waste heat boiler's inlet water circuit is connected to the deaerator and water treatment system of the turbine generator set in the existing waste heat recovery system of the electric arc furnace smelting process, and the steam circuit of the waste heat boiler is connected to the turbine generator set, realizing the conversion and utilization of heat energy. Through optimized design of multiple heat exchange processes, the overall thermal efficiency of the system was improved, effectively reducing the ambient temperature in the production workshop and providing a safe, environmentally friendly, and well-ventilated working environment for production workers. By incorporating a back-pressure turbine unit and a four-quadrant frequency converter, the system achieved intelligent control and automated regulation. The system can dynamically adjust operating parameters according to actual conditions, ensuring stable operation under different operating conditions and demonstrating strong adaptability. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the process flow of the present invention.

[0029] Figure 2 This is a schematic diagram of the waste heat recovery fume hood of the present invention.

[0030] Figure 3 This is a schematic diagram of the steel ball cleaning device of the present invention.

[0031] Figure 4 This is a front view structural schematic diagram of the steel ball transport bucket of the present invention.

[0032] Figure 5 For the present invention Figure 4 A side view structural diagram.

[0033] Figure 6 For the present invention Figure 4 A schematic diagram of the cross-sectional structure of AA.

[0034] Figure 7For the present invention Figure 4 A structural diagram from another angle.

[0035] Figure 8 This is a front view of the secondary steel ball separation mechanism of the present invention.

[0036] Figure 9 For the present invention Figure 8 A side view structural diagram.

[0037] Figure 10 For the present invention Figure 8 Schematic diagram of the cross-sectional structure of BB.

[0038] Figure 11 For the present invention Figure 10 A magnified view of a portion of point A in the middle.

[0039] In the diagram: Support frame 01, opening guide rail 11, closing guide rail 12, limit rail 13, drive wheel 02, guide wheel 03, double-row chain 04, steel ball transport hopper 05, guide wheel 51, bracket 52, sealing plate 53, rolling assembly 54, rotating shaft 541, roller 542, rotating gear 543, rack 55, guide groove 56, ball bearing 57, connecting lug 58, limit plate 59, secondary steel ball separation mechanism 06, separation box 61, feed inlet 611 612. Bead discharge port 613. Partition plate 614. Ash leakage hole 615. Negative pressure suction part 62. Buffer bead throwing assembly 63. Buffer plate 631. Spring 632. Raised bar 64. Raised bar 65. Waste heat boiler 07. Receiving hopper 08. Steel ball distribution pipe 09. Steel ball separation and collection device 10. Iron outlet small smoke hood 100. Waste heat recovery smoke hood 200. Radiant heat exchange pipe 201. Heat-resistant steel sheet 202. High temperature flue 203. Ground mold 300. Molten iron pipe 400. Detailed Implementation

[0040] 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.

[0041] In the description of this invention, it should be understood that the terms "upper", "middle", "outer", "inner", "lower", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0042] Please refer to Figure 1 , Figure 2The present invention provides a waste heat recovery and utilization system for casting in front of the furnace of a submerged arc furnace, including a small smoke hood 100 at the tapping outlet, a waste heat recovery smoke hood 200, a circulating fan, a waste heat boiler 07, a back pressure steam turbine, and a dust collector.

[0043] The small smoke hood 100 at the tapping outlet is installed on the outside of the molten iron pipe 400 connecting the electric arc furnace and the ground mold 300. The small smoke hood 100 at the tapping outlet is set in an L-shape and is insulated with a high-temperature resistant insulation layer and a high-temperature resistant castable. Considering that the heat recovery of this part is relatively small, only the outside of the pipe is insulated, and the insulation thickness is 5-8cm.

[0044] The waste heat recovery fume hood 200 is installed outside the ground mold 300 and is connected to the small fume hood 100 at the iron outlet. Radiant heat exchange pipes 201 are evenly distributed longitudinally inside the waste heat recovery fume hood 200. Each radiant heat exchange pipe 201 is connected by a heat-resistant steel sheet 202. The lower end of each radiant heat exchange pipe 201 faces the ground mold 300. The interior of the waste heat recovery fume hood 200 has a high-temperature flue 203 for discharging high-temperature flue gas. An insulation layer with a thickness of 10-15 cm is provided between the outside of the radiant heat exchange pipes 201 and the fume hood. The top of the waste heat recovery fume hood 200 is funnel-shaped, meaning the upper part of the fume hood is smaller than the lower part, to facilitate the dispersion of flue gas into each radiant heat exchange pipe 201.

[0045] The circulating fan's inlet is connected to the small smoke hood at the iron outlet, and its outlet is connected to the inlet of the top of the waste heat recovery smoke hood. Both the inlet and outlet pipes of the circulating fan are externally insulated with a thickness of 5-8cm. The exhaust fan is a centrifugal fan with a dual-drive main shaft. One side is connected to a permanent magnet variable frequency motor, which can be used for both electric drive and as a generator. The power supply end of the permanent magnet variable frequency motor is connected to a four-quadrant frequency converter, which controls the speed. It can also be used as a power output device. The fan's outlet is connected to the chimney. The four-quadrant frequency converter uses a thyristor-type structure with a rated capacity of 380V-10kV. The output power is automatically adjusted by the industrial control system according to actual conditions. The AC power supply side of the frequency converter is connected to the plant's power distribution network, and the DC bus side is connected to the permanent magnet variable frequency motor.

[0046] The inlet of the waste heat boiler 07 is connected to the outlet of the high-temperature flue via a pipeline, and the outlet of the waste heat boiler 07 is connected to the back-pressure steam turbine and dust collector via a pipeline. The waste heat boiler 07 adopts a composite multi-layer structure for insulation, which is made of an outer layer of color steel plate and an inner layer of refractory insulation material. The heat from the ground radiant heat and waste heat recovery is converted into superheated steam. A flue gas outlet is set at the tail of the boiler, which is connected to the inlet of the dust collector.

[0047] The back-pressure steam turbine receives steam generated by the waste heat boiler 07 via a pipeline at its inlet. Its outlet is connected to a softened water deaerator via a pipeline, thus transporting the condensate generated by the back-pressure turbine to the deaerator. The back-pressure steam turbine employs a DCS and DEH automatic control system to automatically control the intake air volume and pressure. The turbine speed is set between 3000-6600 rpm. The DEH system automatically controls the intake air volume based on the DCS control system settings. The exhaust pressure is between 0.8-1.6 MPa, set according to the operating conditions (the exhaust steam temperature is between 180-250℃, suitable for raw material and material drying, and also for deaerator heating in the waste heat recovery system of the steam turbine generator set during the smelting process of an electric arc furnace). The output shaft of the back-pressure steam turbine is connected to a reducer, and the reducer's output shaft is connected to an automatic coupling clutch. The clutch output is connected to the aforementioned exhaust fan.

[0048] The dust collector's inlet receives low-temperature flue gas generated by the waste heat boiler 07 via a pipeline, and then purifies the flue gas before discharging it. The dust collector is a bag filter with multiple layers of filter bags inside to capture particulate matter in the flue gas. A dust removal system is installed at the bottom of the dust collector to filter dust carried in the flue gas. The dust collector's outlet is connected to the fan's inlet. The exhaust fan is a common centrifugal fan, and its outlet is connected to the exhaust chimney.

[0049] The outlet of the softened water deaerator is connected to the waste heat boiler 07 via a pipeline, and the treated condensate is transported to the waste heat boiler 07 for reuse via the pipeline.

[0050] When the molten iron is tapped from the electric arc furnace, it flows into the ground mold 300 through the molten iron pipe 400. At the same time, the generated flue gas and the heat exchanged with the air are drawn into the radiant heat exchange pipe 201 inside the waste heat recovery hood 200 by an external circulating fan. After radiant heat exchange in the pipe, the flue gas is blown onto the surface of the molten iron in the ground mold, which cools the molten iron and heats the flue gas at the same time, forming flowing hot flue gas. The flowing hot flue gas after heat exchange enters the high-temperature flue and then enters the waste heat boiler 07 to exchange heat with water. The low-temperature flue gas is discharged after being treated by a dust collector. The steam generated by the boiler enters the condensing turbine to convert thermal energy into mechanical energy and then into electrical energy, realizing the rational recovery and utilization of radiant heat and waste heat from the furnace casting.

[0051] In one embodiment, a steel ball cleaning device is installed on the waste heat boiler 07 for cleaning the ash accumulated in the heat exchange tubes inside the waste heat boiler 07. The steel ball cleaning device includes a support frame 01, a drive wheel 02, a guide wheel 03, a double-row chain 04, and a steel ball transport bucket 05.

[0052] The upper end of the support frame 01 is horizontally fixed with an opening guide rail 11, and the lower end of the support frame 01 is horizontally fixed with a closing guide rail 12. A limiting rail 13 is horizontally fixedly installed above the opening guide rail 11 and the closing guide rail 12, so that a channel for the steel ball transport bucket 05 to run is formed between the limiting rail 13 and the opening rail, and between the limiting rail 13 and the closing rail, thus ensuring that the steel ball transport bucket 05 can operate stably.

[0053] The drive wheel 02 and guide wheel 03 are rotatably mounted on the support frame 01; there is at least one drive wheel 02 and at least three guide wheels 03, which are distributed at the four corners of the support frame 01.

[0054] The double-row chain 04 is mounted around the drive wheel 02 and the guide wheel 03. The drive wheel 02 transmits power, while the guide wheel 03 guides the double-row chain 04, enabling it to rotate along the drive wheel 02 and the guide wheel 03. The drive wheel 02 can be driven by a drive motor and a compatible reducer.

[0055] The ball bearing transport bucket 05 is rotatably installed between the two chains of the double-row chain 04. When the ball bearing transport bucket 05 runs to the opening guide rail 11, the lower end of the ball bearing transport bucket 05 forms a rolling contact with the opening guide rail 11, causing the bottom outlet end of the ball bearing transport bucket 05 to open and release the ball bearings in the ball bearing transport bucket 05. When the ball bearing transport bucket 05 runs to the closing guide rail 12, the lower end of the ball bearing transport bucket 05 forms a rolling contact with the closing guide rail 12, causing the bottom outlet end of the ball bearing transport bucket 05 to close and receive the recovered ball bearings. By relying on the cooperation between the steel ball transport bucket 05 and the opening guide rail 11 and closing guide rail 12 during operation, the power of the steel ball transport bucket 05 when moving is converted into the power to open or close the bottom of the steel ball transport bucket 05. On the one hand, it realizes the automatic dumping and conveying of steel balls, avoids the tedious operation of traditional manual cleaning, improves the dust removal efficiency, and reduces labor costs. On the other hand, it also reduces the extra load on the steel ball transport bucket 05, reduces equipment energy consumption, and reduces the wear of the double-row chain 04.

[0056] Please refer to Figures 3 to 7In one embodiment, the upper end of the ball bearing transport hopper 05 has a guide wheel 51. The guide wheel 51 forms rolling friction after contacting the limiting rail 13, which reduces wear between the ball bearing transport hopper 05 and the limiting rail 13, and also limits the upward movement of the ball bearing transport hopper 05, ensuring smooth horizontal movement. Supports 52 are fixedly installed on two opposite side walls of the ball bearing transport hopper 05. A sealing plate 53 for sealing the bottom outlet end of the ball bearing transport hopper 05 is slidably installed between the two supports 52. A rolling assembly 54 is rotatably installed at the lower end of the two side walls of the ball bearing transport hopper 05 with the supports 52. The rolling assembly 54 contacts the opening guide rail 11 or the closing guide rail 12 and rotates along the opening guide rail 11 or the closing guide rail 12, allowing the rolling assembly 54 to drive the sealing plate 53 to slide along the lower part of the support 52, thereby controlling the opening or closing of the bottom outlet end of the ball bearing transport hopper 05. When the steel ball transport bucket 05 moves to the upper end of the support frame 01, and the rolling component 54 rolls along the opening guide rail 11, the sealing plate 53 can slide along the lower part of the bracket 52, thereby opening the bottom outlet end of the steel ball transport bucket 05 and discharging the steel balls to the waste heat boiler 07. When the steel ball transport bucket 05 moves to the lower end of the support frame 01, and the rolling component 54 rolls along the closing guide rail 12, the sealing plate 53 can slide along the lower part of the bracket 52, thereby closing the bottom outlet end of the steel ball transport bucket 05 and receiving the recovered steel balls.

[0057] In order to facilitate the installation of the steel ball transport bucket 05 and the double-row chain 04, a connecting ear 58 is also installed on the bracket 52.

[0058] Of course, to ensure the steel balls can enter the waste heat boiler 07 more effectively, a receiving hopper with a diameter larger than the length of the opening guide rail 11 can be installed at the top of the waste heat boiler 07. This ensures that all steel balls can fall in during the initial opening to full opening of the sealing plate 53. Secondly, to ensure even distribution of the steel balls, multiple steel ball distribution pipes are installed below the receiving hopper. The inlet end of the steel ball distribution pipe connects to the receiving hopper, while the outlet end connects to the interior of the waste heat boiler 07. For the steel ball distribution pipes, a pipe with a diameter of 50 mm can be used; however, other suitable pipe diameters can be selected according to actual usage requirements. The steel balls enter the waste heat boiler 07 through the steel ball distribution pipes and fall freely under gravity, striking the surface of the heat pipes to generate resonance and vibrate up the high-temperature adhesive dust on the heat pipe surface.

[0059] In detail, the rolling assembly 54 includes a rotating shaft 541 and a roller 542. The rotating shaft 541 is symmetrically rotatably mounted on the lower ends of the two side walls of the steel ball transport hopper 05 with a bracket 52. A rotating gear 543 is fixedly mounted on the rotating shaft 541, and the roller 542 is fixedly mounted on the rotating shaft 541.

[0060] To elaborate further, racks 55 that mesh with rotating gears 543 are fixedly installed on the upper surfaces of the two ends of the sealing plate 53 facing the bracket 52, so that when the rotating gears 543 rotate, they can drive the sealing plate 53 to slide along the bracket 52. It should be noted that the sliding distance of the sealing plate 53 is adapted to the number of rotations of the roller 542 and the lengths of the opening guide rail 11 and the closing guide rail 12. That is, if the roller 542 rotates N times, and the diameter of the roller 542 is known, then the circumference of the roller 542 is a constant value. Correspondingly, the length formed by the roller 542 after rotating N times is consistent with the length of the opening guide rail 11 or the closing guide rail 12. At this time, the sliding distance of the sealing plate 53 is exactly the length of the opening guide rail 11 or the closing guide rail 12, which corresponds to the fully open or closed state of the sealing plate 53.

[0061] In this technical solution, when the roller 542 rolls along the opening guide rail 11, it converts the horizontal movement of the steel ball transport bucket 05 into the rotation of the shaft 541. At this time, the rotating gear 543 also rotates synchronously. The rotating gear 543 meshes with the rack 55, which again converts the rotational power into the horizontal sliding power of the sealing plate 53. The sealing plate 53 is slowly opened, and at this time, the sealing plate 53 no longer seals the bottom outlet end of the steel ball transport bucket 05. After the bottom outlet end of the steel ball transport bucket 05 is fully opened, the steel ball can be transported out. The balls are completely discharged into the waste heat boiler 07. When the roller 542 rolls along the opening guide rail 11, it converts the power of the horizontal movement of the steel ball transport bucket 05 into the power of the rotation of the shaft 541. At this time, the rotating gear 543 also rotates synchronously. The rotating gear 543 meshes with the rack 55, which again converts the rotational power into the power of the horizontal sliding of the sealing plate 53. The sealing plate 53 slowly seals the bottom outlet end of the steel ball transport bucket 05. After the bottom outlet end of the steel ball transport bucket 05 is completely closed, the recovered steel balls can be received.

[0062] Specifically, the lower part of the bracket 52 has a guide groove 56 for the sealing plate 53 to slide. The inner wall of the guide groove 56 is fitted with evenly distributed ball bearings 57 along the sliding direction of the sealing plate 53. This design ensures less friction between the sealing plate 53 and the guide groove 56, facilitating the sliding movement of the sealing plate 53 and preventing it from getting stuck. Limiting plates 59 are also provided at both ends of the guide groove 56 to prevent the sealing plate 53 from sliding out of the guide groove 56.

[0063] Please refer to Figures 8 to 11In one embodiment, to prevent the steel balls from carrying more dust and impurities, a secondary steel ball separation mechanism 06 is added to further separate the steel balls from the remaining dust and impurities. The secondary steel ball separation mechanism 06 includes a separation box 61 and a negative pressure suction unit 62. The left end of the separation box 61 is higher than the right end, making the separation box 61 inclined, with an inclination angle of 5-10° relative to the horizontal direction. The left end of the separation box 61 has a feed inlet 611 for receiving steel balls, and the right end has a discharge outlet 612. The interior of the separation box 61 has a partition 613 parallel to the bottom of the separation box 61, with a dust leakage hole 614 on the partition 613. Correspondingly, the negative pressure suction unit 62 connects to the interior of the separation box 61 through a pipe along the bottom of the separation box 61 to discharge the separated remaining dust and impurities. The negative pressure suction unit 62 can be a dust collector.

[0064] In this technical solution, the feed inlet 611 of the separation box 61 receives steel balls discharged from the steel ball separation and collection device installed at the bottom of the waste heat boiler 07. The discharge of the steel balls is achieved by counterweight. The discharged steel balls carry some dust and impurities. After the steel balls fall into the separation box 61, due to the inclined arrangement of the partition 613, the steel balls roll to the lowest point under their own gravity, while the dust and impurities they carry fall to the bottom of the separation box 61 through the ash leakage hole 614. The negative pressure suction unit 62 continuously sucks away the separated dust, and the dust-removed steel balls are discharged from the separation box 61 and recycled back to the steel ball transport hopper 05 for reuse.

[0065] In one embodiment, to reduce the impact of falling steel balls, a buffer ball-throwing assembly 63 is provided inside the separator 61 near the feed inlet 611. The buffer ball-throwing assembly 63 includes a buffer plate 631 and springs 632. The lower end of the buffer plate 631 is rotatably connected to the side wall of the separator 61, the left end of the spring 632 is connected to the side wall of the feed inlet 611, and the right end of the spring 632 is connected to the upper end of the buffer plate 631, causing the buffer plate 631 to be inclined upwards and form an angle with the partition plate 613. Multiple springs 632 can be arranged, each spring 632 being evenly distributed along the buffer plate 631.

[0066] The buffer plate 631 has evenly distributed elongated holes, which allow the dust and impurities to fall through the holes to the partition plate 613 and eventually to the bottom of the separation box 61 when the steel ball falls.

[0067] In this technical solution, when the steel ball falls from the feed inlet 611 to the buffer plate 631, it will impact the buffer plate 631 due to the gravity and high potential energy of the steel ball. This will force the spring 632 to stretch and the buffer plate 631 to move downward. After the spring 632 reaches its limit deformation, it will return to its original deformation. The restoring force generated at this time will cause the buffer plate 631 to move upward, so that the buffer plate 631 will throw the steel ball towards the discharge port 612 of the separation box 61, thereby dispersing the steel ball and dust impurities.

[0068] Of course, a rubber pad layer can also be laid on the upper surface of the partition 613 and the buffer plate 631 to prevent the steel balls from impacting or abrading the partition 613 and the buffer plate 631.

[0069] Specifically, raised strips 64 are arranged at equal intervals on the upper surface of the partition 613 facing the feed inlet 611, with the raised strips 64 arranged along the short side of the partition 613; and raised protrusions 65 are evenly distributed on the upper surface of the partition 613 facing the ball discharge port 612. Correspondingly, the tops of the raised strips 64 and raised protrusions 65 have an arc-shaped structure. When the steel balls are scattered by the buffer plate 631, they first land on the side of the partition plate 613 with the protrusions 64. Due to the downward tilt of the partition plate 613, the steel balls accelerate downward due to their own weight. The protrusions 64 cause the steel balls to jump and collide with each other, thus separating the steel balls from the dust and impurities. With the help of the negative pressure suction unit 62, the dust can be collected at the bottom of the separation box 61 and discharged. When the steel balls move to the side of the partition plate 613 with the protrusions 65, the protrusions 65 cause the steel balls to move downward irregularly, further causing the steel balls to collide with each other. This forces the dust to fall from the dust leakage holes 614 on the partition plate 613 to the bottom of the separation box 61, so that the negative pressure suction unit 62 can suck it out, thereby achieving the separation of the steel balls from the dust.

[0070] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the invention. Those skilled in the art will understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A system for recovering and utilizing waste heat from casting in front of a submerged arc furnace, characterized in that: include A small smoke hood at the taphole is installed on the outside of the molten iron pipe connecting the electric arc furnace and the ground mold; The waste heat recovery fume hood is installed on the outside of the ground mold. The waste heat recovery fume hood is connected to the small fume hood at the iron outlet. The interior of the waste heat recovery fume hood is longitudinally distributed with radiant heat exchange pipes. Each radiant heat exchange pipe is connected by heat-resistant steel sheets. The interior of the waste heat recovery fume hood has a high-temperature flue for discharging high-temperature flue gas. The circulating fan has its inlet end connected to the small smoke hood at the iron outlet and its outlet end connected to the inlet end of the top of the waste heat recovery smoke hood. Waste heat boiler, the inlet end of which is connected to the outlet end of the high-temperature flue; Back-pressure steam turbines are used to receive steam generated by waste heat boilers; The dust collector is used to receive the low-temperature flue gas generated by the waste heat boiler and purify the low-temperature flue gas before it is discharged through the exhaust fan; the power input end of the exhaust fan is connected to the output end of the back pressure steam turbine through a reducer and a clutch; the power output end of the exhaust fan is connected to a permanent magnet motor, and the permanent magnet motor is connected to a four-quadrant frequency converter. The softened water deaerator is used to receive condensate generated by the back-pressure steam turbine and, after treatment, transport the condensate through pipelines to the waste heat boiler for reuse.

2. The waste heat recovery and utilization system for casting the pre-furnace mold of a submerged arc furnace according to claim 1, characterized in that: The waste heat boiler is equipped with a steel ball cleaning device for cleaning the ash accumulated in the heat exchange tubes inside the waste heat boiler. The steel ball cleaning device includes a support frame, a drive wheel, a guide wheel, a double-row chain, and a steel ball transport bucket. An opening guide rail is horizontally fixed at the upper end of the support frame, and a closing guide rail is horizontally fixed at the lower end of the support frame; a limiting rail is horizontally fixed above the opening guide rail and the closing guide rail, so that a channel for the steel ball transport bucket to run is formed between the limiting rail and the opening rail, and between the limiting rail and the closing rail. The drive wheel and guide wheel are rotatably mounted on the support frame; The double-row chain is mounted around the drive wheel and the guide wheel, enabling the double-row chain to rotate along the drive wheel and the guide wheel; The ball bearing transport bucket is rotatably installed between the two chains of the double-row chain. When the ball bearing transport bucket moves to the opening guide rail, the lower end of the ball bearing transport bucket forms a rolling contact with the opening guide rail, causing the bottom outlet end of the ball bearing transport bucket to open and release the ball bearings in the ball bearing transport bucket. When the ball bearing transport bucket moves to the closing guide rail, the lower end of the ball bearing transport bucket forms a rolling contact with the closing guide rail, causing the bottom outlet end of the ball bearing transport bucket to close and receive the recovered ball bearings.

3. The waste heat recovery and utilization system for casting the pre-furnace mold of a submerged arc furnace according to claim 2, characterized in that: The upper end of the ball bearing transport hopper has a guide wheel, and brackets are fixedly installed on the two opposite side walls of the ball bearing transport hopper. A sealing plate for sealing the bottom outlet end of the ball bearing transport hopper is slidably installed between the two brackets. A rolling assembly is rotatably installed at the lower end of the two side walls of the ball bearing transport hopper with brackets. After the rolling assembly contacts the opening guide rail or closing guide rail, it rotates, so that the rolling assembly can drive the sealing plate to slide along the lower part of the bracket to control the opening or closing of the bottom outlet end of the ball bearing transport hopper.

4. The waste heat recovery and utilization system for casting the pre-furnace mold of a submerged arc furnace according to claim 3, characterized in that: The rolling assembly includes a rotating shaft and rollers; the rotating shaft is symmetrically and rotatably installed at the lower ends of the two side walls of the steel ball transport hopper with a support, a rotating gear is fixedly installed on the rotating shaft, and the rollers are fixedly installed on the rotating shaft.

5. The waste heat recovery and utilization system for casting the pre-furnace mold of a submerged arc furnace according to claim 4, characterized in that: The sealing plate has racks fixedly installed on the upper surfaces of its two ends facing the bracket, which mesh with the rotating gear, so that the rotating gear can drive the sealing plate to slide along the bracket when it rotates.

6. The waste heat recovery and utilization system for casting the pre-furnace mold of a submerged arc furnace according to claim 5, characterized in that: The lower part of the bracket has a guide groove for the sealing plate to slide, and the inner wall of the guide groove is equipped with balls evenly distributed along the sliding direction of the sealing plate.

7. The waste heat recovery and utilization system for casting the pre-furnace mold of a submerged arc furnace according to claim 6, characterized in that: It also includes a secondary steel ball separation mechanism for further separating steel balls from residual ash and impurities. The secondary steel ball separation mechanism includes a separation box and a negative pressure suction unit. The left end of the separation box is higher than the right end, so that the separation box is arranged at an angle. The left end of the separation box has a feed port for receiving steel balls, and the right end of the separation box has a discharge port. The interior of the separation box has a partition parallel to the bottom of the separation box, and the partition has ash leakage holes. The negative pressure suction unit is connected to the interior of the separation box through a pipe along the bottom of the separation box to discharge the separated residual ash and impurities.

8. The waste heat recovery and utilization system for casting the pre-furnace mold of a submerged arc furnace according to claim 7, characterized in that: The separation chamber is equipped with a buffer ball-throwing assembly near the feed inlet. The buffer ball-throwing assembly includes a buffer plate and a spring. The lower end of the buffer plate is rotatably connected to the side wall of the separation chamber. The left end of the spring is connected to the side wall of the feed inlet, and the right end of the spring is connected to the upper end of the buffer plate, so that the buffer plate is inclined upward and forms an angle with the partition.

9. The waste heat recovery and utilization system for casting the pre-furnace mold of a submerged arc furnace according to claim 8, characterized in that: The upper surface of the partition is provided with convex strips at equal intervals on the side facing the feed inlet, and the upper surface of the partition is provided with convex strips at equal intervals on the side facing the bead discharge outlet.

10. The waste heat recovery and utilization system for casting the pre-furnace mold of a submerged arc furnace according to claim 9, characterized in that: The raised strip and the top of the raised strip have an arc-shaped structure.

Images