Molten steel slag sensible heat recovery device

Abstract

The invention discloses a molten steel slag sensible heat recovery device in the technical field of steel slag waste heat recovery, the molten steel slag sensible heat recovery device comprises a steel slag conveying device and a heat radiation waste heat boiler, the heat radiation waste heat boiler is arranged above the steel slag conveying device, and a conveying channel is formed between the heat radiation waste heat boiler and the steel slag conveying device; the steel slag conveying device is used for conveying steel slag to penetrate through the conveying channel, the heat radiation waste heat boiler can directly exchange heat with the steel slag below the heat radiation waste heat boiler so as to heat a working medium in the heat radiation waste heat boiler, and smoke dust is not generated.

Description

Technical Field

[0001] The present invention relates to the technical field of steel slag waste heat recovery, and particularly relates to a sensible heat recovery device for molten steel slag. Background Art

[0002] Steel slag is a main solid waste generated by iron and steel enterprises. About 130 kg of steel slag is generated for every 1 t of molten steel produced, and the slag tapping temperature is between 1400 and 1600 °C. The heat contained in each ton of steel slag is approximately equal to the heat released by the complete combustion of 60 kg of standard coal.

[0003] From the perspective of the iron and steel industry, the steel slag treatment technologies mainly include processes such as the hot splash method, the rotary drum method, the pool type hot soaking method, and the pressurized hot soaking method. Currently, the newly built steel slag treatment projects mainly adopt the pressurized hot soaking process. These steel slag treatment processes first perform appropriate cooling treatment on the high-temperature molten slag and then process it to extract the metal therein for resource utilization. However, during the steel slag treatment process, the waste heat of the steel slag has not been effectively recovered, which not only wastes standard coal every year but also causes serious environmental pollution. Therefore, developing high-temperature steel slag waste heat recovery technologies and methods is of great significance.

[0004] CN202120570709.0 discloses a high-temperature steel slag waste heat recovery device that transports steel slag through a conveyor belt, exchanges heat between the normal-temperature circulating air and the high-temperature steel slag, and then exchanges heat between the heat radiation waste heat boiler and the high-temperature circulating air to generate the steam required for production. Although this method recovers the waste heat of the high-temperature steel slag, the waste heat utilization process undergoes two heat exchanges, resulting in insufficient heat recovery rate. Moreover, dust is still generated during the heat exchange between the normal-temperature air and the high-temperature steel slag, and a dust removal process is still required subsequently, which is not only cumbersome but also increases the operating energy consumption. Summary of the Invention

[0005] To solve the above technical problems, the present invention specifically provides a sensible heat recovery device for molten steel slag, including a steel slag conveying device and a heat radiation waste heat boiler. The heat radiation waste heat boiler is arranged above the steel slag conveying device, and a conveying channel is formed between the heat radiation waste heat boiler and the steel slag conveying device. The steel slag conveying device is used to convey steel slag through the conveying channel, and the heat radiation waste heat boiler can directly conduct dust-free heat exchange with the steel slag below to heat the working medium in the heat radiation waste heat boiler.

[0006] As a preferred solution of the present invention, if the heat radiation waste heat boiler only needs to output saturated steam, a plurality of heat radiation waste heat boilers are arranged along the conveying direction of the high-temperature steel slag, and the power of the plurality of heat radiation waste heat boilers is adapted to the temperature of the steel slag passing below them;

[0007] If the heat-radiation waste heat boiler needs to output superheated steam, the heat-radiation waste heat boiler is set as a sectional heat-radiation waste heat boiler. The low-temperature section is a economizer, the medium-temperature section is an evaporator, the sub-high-temperature section is a superheater, and the highest-temperature section is an economizer.

[0008] As a preferred embodiment of the present invention, the molten steel slag sensible heat recovery device further includes a material box disposed on the steel slag conveying device. The material box is used to hold the steel slag to isolate the high-temperature steel slag from the steel slag conveying device.

[0009] As a preferred embodiment of the present invention, the steel slag conveying device includes a heavy-duty roller path, a tail-end translation roller path, a light-duty roller path, and a head-end translation roller path that are connected end to end, and can form an annular conveying path; wherein,

[0010] The heavy-duty roller path is located inside the conveying channel, and the light-duty roller path, the tail-end translation roller path, and the head-end translation roller path are all located outside the conveying channel;

[0011] The tail-end translation roller path is used to convey the slag-containing material box at the tail end of the heavy-duty roller path to the head end of the light-duty roller path, and the head-end translation roller path is used to convey the empty material box at the tail end of the light-duty roller path to the head end of the heavy-duty roller path;

[0012] A push rod is disposed on one side of the tail-end translation roller path close to the heat-radiation waste heat boiler. The push rod can push one side of the material box on the tail-end translation roller path upward to pour the steel slag in the material box into the slag receiving tank.

[0013] As a preferred embodiment of the present invention, a plurality of material boxes are disposed on the steel slag conveying device. The plurality of material boxes are arranged linearly on the heavy-duty roller path. The head end and the tail end of adjacent material boxes are detachably connected, and both the head end and the tail end of each material box are open to form a continuous strip-shaped steel slag holding area.

[0014] As a preferred embodiment of the present invention, the molten steel slag sensible heat recovery device further includes a slag spreading roller disposed in front of the heat-radiation waste heat boiler. The slag spreading roller is used to control the thickness of the high-temperature steel slag entering the conveying channel to increase the cooling rate of the steel slag.

[0015] As a preferred embodiment of the present invention, a lifting gate is further disposed at the entrance of the conveying channel. The lifting gate can finely adjust the thickness of the slag layer behind the slag spreading roller.

[0016] As a preferred embodiment of the present invention, a crushing tooth roller is disposed inside the conveying channel. The crushing tooth roller is used to crush the crust formed on the surface of the steel slag after cooling to improve the heat exchange efficiency between the heat-radiation waste heat boiler and the steel slag;

[0017] A plurality of the crushing tooth rollers are arranged along the length direction of the conveying channel, and each of the crushing tooth rollers can be lifted and lowered to allow large pieces of steel slag formed by rapid cooling or metal hard blocks that cannot be crushed to pass through.

[0018] As a preferred embodiment of the present invention, the slag distributing roller, the crushing tooth roller and the heavy-duty roller table are all connected to a water cooling system.

[0019] As a preferred embodiment of the present invention, the molten steel slag sensible heat recovery device further includes a steel slag feeding device arranged in front of the heat radiation waste heat boiler, and the steel slag feeding device is used to feed high-temperature steel slag into the material box.

[0020] The present invention has the following beneficial effects compared with the prior art:

[0021] In the present invention, the heat radiation waste heat boiler is directly erected above the steel slag conveying device. When the steel slag conveying device conveys high-temperature steel slag and passes under the heat radiation waste heat boiler, the heat radiation waste heat boiler can directly exchange heat with the high-temperature steel slag, directly heating the working medium in the heat radiation waste heat boiler, without secondary heat exchange, and having a high heat recovery rate. At the same time, this form of heat recovery does not generate a large amount of dust, saves the dust removal process, and reduces the operating energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary, and for those of ordinary skill in the art, without creative efforts, other implementation drawings can be obtained according to the provided drawings.

[0023] Figure 1 It is a schematic structural diagram of an embodiment of the molten steel slag sensible heat recovery device in the present invention;

[0024] Figure 2 It is a top view structural diagram of the steel slag conveying device in the present invention;

[0025] Figure 3 It is a schematic structural diagram of an embodiment of the multiple cooling system of the steel slag in the present invention;

[0026] Figure 4 It is a schematic structural diagram of the composite material box in the present invention;

[0027] Figure 5 It is a schematic structural diagram when a plurality of composite material boxes are arranged in a straight line in the present invention.

[0028] The reference numerals in the drawings are respectively represented as follows:

[0029] 1 - Steel slag conveying device, 101 - Heavy-duty roller table, 102 - Tail-end translation roller table, 103 - Light-duty roller table, 104 - Head-end translation roller table, 105 - Push rod, 106 - Slag receiving tank, 2 - Heat radiation waste heat boiler, 3 - Conveying channel, 4 - Material box, 401 - Metal shell, 402 - Refractory lining, 403 - V-shaped claw nails, 5 - Slag spreading roller, 6 - Lifting gate, 7 - Crushing tooth roller, 8 - Steel slag feeding device, 801 - Feeding platform, 802 - Feeding port, 803 - Extrusion roller, 804 - Vibrating screen, 805 - Chute, 9 - Spiral diversion tower, 901 - Tower body, 902 - Spiral diversion fins, 903 - Support column, 904 - Steel slag inlet, 905 - Steel slag outlet, 906 - Air inlet, 907 - Air outlet, 10 - Screw conveyor, 11 - Bucket elevator, 12 - Gas circulation pipeline, 13 - Dust collector, 14 - High-temperature air waste heat boiler, 15 - Circulation fan. Specific embodiments

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] The present invention provides a molten steel slag sensible heat recovery device, a vertical static spiral countercurrent heat exchange system for steel slag, a composite material box for accommodating liquid or semi-liquid high-temperature steel slag, and a multiple cooling system for steel slag.

[0032] Molten steel slag sensible heat recovery device

[0033] The molten steel slag sensible heat recovery device includes a steel slag conveying device 1 and a heat radiation waste heat boiler 2. The heat radiation waste heat boiler 2 is arranged above the steel slag conveying device 1. A conveying channel 3 is formed between the heat radiation waste heat boiler 2 and the steel slag conveying device 1. The steel slag conveying device 1 is used to convey steel slag to pass through the conveying channel 3. The heat radiation waste heat boiler 2 can directly conduct dust-free heat exchange with the steel slag below to heat the working medium in the heat radiation waste heat boiler 2.

[0034] Optionally, the above-mentioned conveying channel 3 refers to the strip-shaped space between the steel slag conveying device 1 and the heat radiation waste heat boiler 2. The conveying channel 3 can be open on all four sides, or a tunnel structure with both sides in the length direction closed and both ends in the length direction open.

[0035] Preferably, a tunnel structure with both sides closed in the length direction and both ends open in the length direction. For example, a heat-radiation waste heat boiler 2 is covered from above by a housing structure, and the housing structure extends downward to the steel slag conveying device, forming a tunnel structure with both ends open. The steel slag conveying device 1 can convey steel slag through the tunnel, weakening the heat exchange between the high-temperature steel slag and the outside air. Under the same conditions, the temperature in the tunnel is higher, improving the heat exchange efficiency between the heat-radiation waste heat boiler 2 and the high-temperature steel slag, and increasing the heat recovery rate.

[0036] It can be understood that the length of the tunnel is determined by the amount of steel slag processed per unit time, and the length of the heat-radiation waste heat boiler covers the entire tunnel.

[0037] In the present invention, the heat-radiation waste heat boiler 2 is directly installed above the steel slag conveying device 1. When the steel slag conveying device 1 conveys high-temperature steel slag through below the heat-radiation waste heat boiler 2, the heat-radiation waste heat boiler 2 can directly exchange heat with the high-temperature steel slag, directly heating the working medium in the heat-radiation waste heat boiler 2 without secondary heat exchange, with a high heat recovery rate. At the same time, this form of heat recovery does not generate a large amount of dust, saving the dust removal process and reducing the operating energy consumption.

[0038] Furthermore, designed according to the actual heat usage requirements. If only saturated steam needs to be output, multiple independent or series-connected heat-radiation waste heat boilers 2 that generate saturated steam are set up. According to the characteristic that the heat flux density of steel slag is different at different temperatures, the technology of arranging heat-radiation waste heat boilers 2 with different powers in a cascade manner is adopted. High-power heat-radiation waste heat boilers 2 are arranged in the high-temperature section of 1500 - 1000 degrees, medium-power boilers are arranged in the medium-temperature section of 1000 - 600, and low-power boilers are arranged in the low-temperature section of 600 - 350 degrees, which can generate saturated steam separately or jointly.

[0039] If superheated steam is needed, a sectional heat-radiation waste heat boiler 2 is set up. The low-temperature section is an economizer, the medium-temperature section is an evaporator, the sub-high-temperature section is a superheater, and the highest-temperature section is an economizer.

[0040] Compared with the integrated heat-radiation waste heat boiler 2, for the heat-radiation waste heat boilers 2 with different powers arranged in a cascade manner or the sectional heat-radiation waste heat boiler 2, the temperature difference between the medium- and low-temperature steel slag downstream of the conveying channel 3 and the working medium in the heat-radiation waste heat boiler 2 above it is larger, improving the heat exchange efficiency and the cooling efficiency of the steel slag. That is, the design of the cascade heat-radiation waste heat boiler 2 can fully absorb the heat of the steel slag in different heat flux density regions.

[0041] Furthermore, at present, apron conveyors are generally used in the industry to convey steel slag. However, the temperature of high-temperature steel slag can reach 1500 degrees, which easily causes deformation failures of the apron conveyor. At the same time, the steel slag is easily stuck in the gaps between the apron chains of the apron conveyor, affecting the continuous operation of the device.

[0042] To solve this problem, the sensible heat recovery device for molten steel slag in the present invention further includes a material box 4 provided on the steel slag conveying device 1. The material box 4 is used to hold the steel slag to isolate the high-temperature steel slag from the steel slag conveying device 1, so that the high-temperature steel slag does not contact the steel slag conveying device 1, which can avoid the deformation failure of the apron conveyor caused by the high-temperature steel slag.

[0043] It should be noted that the above-mentioned steel slag conveying device 1 does not only include an apron conveyor. In practice, the chain of the apron conveyor is relatively easy to be damaged. On the basis of using the material box 4 to hold the steel slag, a roller conveyor system can be adopted to transport the material box 4, so as to achieve the purpose of transporting the high-temperature steel slag, and the roller conveyor system is more stable and durable than the apron conveyor.

[0044] Furthermore, multiple roller conveyor systems can be provided to form an annular transmission path, and the online turnover of the material box 4 can be realized through multiple roller drive systems.

[0045] For example, the steel slag conveying device 1 in the present invention includes a heavy-duty roller path 101, a tail-end translation roller path 102, a light-duty roller path 103, and a head-end translation roller path 104 that are connected end to end. Multiple roller paths can form an annular conveying path to realize the turnover of the material box 4 on the roller path; among them,

[0046] The heavy-duty roller path 101 is located in the conveying channel 3, and the light-duty roller path 103, the tail-end translation roller path 102, and the head-end translation roller path 104 are all located outside the conveying channel 3;

[0047] The tail-end translation roller path 102 is used to transport the slag-loaded material box at the tail end of the heavy-duty roller path 101 to the head end of the light-duty roller path 103, and the head-end translation roller path 104 is used to transport the empty material box at the tail end of the light-duty roller path 103 to the head end of the heavy-duty roller path 101;

[0048] A push rod 105 is provided on one side of the tail-end translation roller path 102 close to the heat radiation waste heat boiler 2. The push rod 105 can push one side of the material box 4 on the tail-end translation roller path 102 upward to pour the steel slag in the material box 4 into the slag receiving tank 106.

[0049] It can be understood that the above-mentioned push rod 105 can be a hydraulic push rod. The lower end of the hydraulic push rod is hinged to the ground or platform, and a card slot is provided on the lower side of the material box 4 close to the edge of the hydraulic push rod, so that the top end of the hydraulic push rod can stably hold the material box 4. A stop bar can be provided on the side of the tail-end translation roller path 102 away from the heat radiation waste heat boiler 2. The upper edge of the stop bar is a right-angle plate, and the upper edge of the material box 4 fits with the right-angle plate. When the hydraulic push rod pushes the side edge of the material box 4 upward, the right-angle plate can resist the edge of the material box 4 from the opposite side, so that the material box 4 can be tilted to pour out the steel slag and will not fall out of the tail-end translation roller path 102. When the hydraulic push rod contracts, the material box 4 can be reset. At this time, the tail-end translation roller path 102 operates to transport the emptied material box 4 to the light-duty roller path 103.

[0050] Further, a plurality of material boxes 4 are arranged on the steel slag conveying device 1. The plurality of material boxes 4 are linearly arranged on the heavy-duty roller path 101. The head and tail ends of adjacent material boxes 4 are detachably connected, and the head and tail ends of each material box 4 are open, so as to form a continuous strip-shaped steel slag storage area.

[0051] Compared with the linear arrangement of a plurality of material boxes 4 with four sides closed, the steel slag can continuously cover the conveying channel 3 in the continuous strip-shaped steel slag storage area formed by the linear arrangement of a plurality of material boxes 4 with open head and tail ends. Under the condition of the same steel slag thickness, more steel slag can be accommodated, and the steel slag cooling efficiency is higher.

[0052] Moreover, the plurality of material boxes 4 are connected end to end to form a whole, and can move synchronously on the heavy-duty roller path 101, which can avoid the occurrence of unfixed gaps between the originally closely attached material boxes 4 during the transmission process due to the relative sliding between the bottom end surface of the material box 4 and the heavy-duty roller path 101, causing the steel slag to fall from the open ends of both ends of the material box 4.

[0053] Further, the molten steel slag sensible heat recovery device further includes a slag spreading roller 5 arranged on the front side of the heat radiation waste heat boiler 2. The slag spreading roller 5 is used to control the thickness of the high-temperature steel slag entering the conveying channel 3, reduce the heat energy contained in the high-temperature steel slag of the same length, reduce the distance from the thickness center of the steel slag to the surface of the steel slag, and thereby improve the cooling rate of the steel slag.

[0054] It can be understood that when the steel slag is put into the material box 4, since the steel slag can be piled up upward, the steel slag put into the material box 4 may exceed the normal capacity of the material box 4. If a material box 4 with four sides sealed is used, when the material box 4 passes through the slag spreading roller 5, the steel slag exceeding the material box 4 will be extruded out of the material box 4 by the slag spreading roller 5 and fall from the heavy-duty roller path 101. When the slag spreading roller 5 is used in combination with the continuous strip-shaped steel slag storage area formed by the linear arrangement of the above-mentioned plurality of material boxes 4 with open head and tail ends, the steel slag exceeding the capacity of the material box 4 will be squeezed into the next material box 4, and since the head end translation roller path 104 continuously conveys the empty material box 4 to the head end of the heavy-duty roller path 101, it can avoid the steel slag with excessive feeding being extruded out of the material box 4 and improve the heat recovery rate.

[0055] Further, it can be understood that since the slag spreading roller 5 itself has a large weight and is not convenient to move up and down, it can only control the steel slag at a certain fixed thickness and cannot further adjust the steel slag thickness. To further meet the adjustment requirement of the steel slag thickness, a lifting gate 6 is also arranged at the entrance of the conveying channel 3. The lifting gate 6 can finely adjust the thickness of the slag layer behind the slag spreading roller 5.

[0056] There are various installation methods for the lifting gate 6. For example, it is installed on the shell structure for forming a tunnel through a hydraulic telescopic rod.

[0057] Furthermore, a crushing tooth roll 7 is arranged in the conveying channel 3. The crushing tooth roll 7 is used to crush the crust formed on the surface of the steel slag after cooling, so that the high-temperature steel slag inside the slag layer is exposed, which is beneficial to the heat exchange between the steel slag and the heat radiation waste heat boiler 2, so as to improve the heat exchange efficiency between the heat radiation waste heat boiler 2 and the steel slag;

[0058] The number of the crushing tooth rolls 7 is increased or decreased according to the measured cooling rate of the steel slag and the crust formation condition on the surface of the steel slag. The tooth pitch of the crushing tooth rolls 7 is 30 - 50 mm, and it is advisable that the steel slag be crushed into small particles less than 50 mm, which is beneficial to the radiation heat dissipation of the steel slag.

[0059] The crushing tooth roll 7 has a lifting function to prevent large steel slag blocks or other non-crushable metal hard blocks that may be formed due to rapid cooling from being unable to pass through, resulting in the abnormal continuous operation of the system. When the crushing tooth roll 7 encounters a non-crushable hard block, the pressure data sensed by the pressure sensor increases abnormally. The crushing tooth roll 7 triggers an alarm and automatically lifts. After the large block passes, the crushing tooth roll 7 automatically resets.

[0060] Preferably, the slag spreading roll 5, the crushing tooth roll 7 and the heavy-duty roller table 101 are all connected to a water cooling system.

[0061] Preferably, the molten steel slag sensible heat recovery device further includes a steel slag feeding device 8 arranged on the front side of the heat radiation waste heat boiler 2. The steel slag feeding device 8 is used to feed high-temperature steel slag into the material box 4.

[0062] Specifically, the steel slag feeding device 8 includes a feeding platform 801. A feeding port 802 is arranged on the feeding platform 801. A pair of squeezing rollers 803 are arranged in the feeding port 802. A vibrating screen 804 is arranged below the feeding port 802. A chute 805 is arranged below the vibrating screen 804.

[0063] The slag pot containing high-temperature steel slag pours the high-temperature steel slag into the feeding port 802 from the feeding platform 801. The squeezing rollers 803 roll and crush the high-temperature steel slag. The crushed small particle steel slag enters the chute 805 through the vibrating screen 804 and enters the material box 4 from the lower end outlet of the chute 805.

[0064] The slag outlet of the chute 805 is designed to be rectangular, and the opening length matches the width of the material box 4 for receiving slag at the bottom, being slightly smaller by 30%. The lowest point of the slag outlet of the chute 805 is 100 - 500 mm away from the surface of the material box 4.

[0065] The vertical static spiral countercurrent heat exchange system for steel slag includes:

[0066] A spiral guide tower 9. The steel slag moves spirally downward in the spiral guide tower 9, and the cooling working medium spirally flows upward in the spiral guide tower 9 to conduct countercurrent heat exchange with the steel slag;

[0067] The steel slag conveyor 10 is fixedly installed at the lower end of the spiral diversion tower 9 and is used to receive and transfer the cooled steel slag discharged from the spiral diversion tower 9.

[0068] The temperature measurement module is provided with a plurality of modules in the height direction of the spiral diversion tower 9.

[0069] The action mechanism of the steel slag conveyor 10 is as follows:

[0070] When the temperature measurement module in the low-temperature area at the bottom layer detects that the temperature of the steel slag is less than or equal to the permitted discharge temperature of the steel slag, the steel slag conveyor 10 starts.

[0071] When the temperature measurement module in the low-temperature area at the bottom layer detects that the temperature of the steel slag is greater than the permitted discharge temperature of the steel slag, the steel slag conveyor 10 stops running.

[0072] In the present invention, by installing the steel slag conveyor 10 below the spiral diversion tower 9 and establishing a feedback mechanism between the steel slag conveyor 10 and the temperature measurement module. When the temperature measurement module in the low-temperature area at the bottom layer detects that the temperature of the steel slag is less than or equal to the permitted discharge temperature of the steel slag, the steel slag conveyor 10 operates to transfer and convey the cooled steel slag discharged from the discharge port of the spiral diversion tower 9. When the temperature measurement module in the low-temperature area at the bottom layer detects that the temperature of the steel slag is greater than the permitted discharge temperature of the steel slag, the steel slag conveyor 10 does not operate. At this time, the steel slag conveyor 10 is equivalent to a closed valve, which can prevent the uncooled steel slag in the spiral diversion tower 9 from being discharged, so that the steel slag can be fully cooled and the heat energy in the steel slag can be fully recovered.

[0073] Optionally, the steel slag conveyor 10 is a screw conveyor or other conveyors with the same function that can achieve the purpose of the present invention.

[0074] Further, the spiral diversion tower 9 includes a tower body 901, a support column 903 fixedly installed at the center of the tower body, and spiral diversion vanes 902 fixedly installed between the tower body 901 and the support column 903. The tower body 901, the support column 903 and the spiral diversion vanes 902 can jointly form a spiral diversion channel with closed sides.

[0075] The tower body 901 is provided with a steel slag inlet 904 and a steel slag outlet 905. The steel slag is put into the starting end of the spiral diversion vanes 902 through the steel slag inlet 904, and the steel slag is discharged to the steel slag conveyor 10 through the steel slag outlet 905.

[0076] The bottom of the tower body 901 is provided with an air inlet 906 for inputting cooling air into the lower port of the spiral diversion channel, and the top of the tower body 901 is provided with an air outlet 907 for discharging the high-temperature air after heat exchange.

[0077] The solid high-temperature steel slag spirally descends along the spiral diversion channel under the action of gravity, while the cooling gas ascends along the spiral diversion channel under the action of external force, enabling the solid high-temperature steel slag to convect with the cooling gas, and the cooling gas is in close contact with the solid high-temperature steel slag. Even if the thermal radiation of the solid high-temperature steel slag is relatively low, the cooling gas can still fully exchange heat with the solid high-temperature steel slag.

[0078] Further, to fully recover the heat energy of the steel slag, the air inlet 906 and the air outlet 907 are respectively connected to the outlet end and the inlet end of the gas circulation pipeline 12. Along the gas flow direction on the gas circulation pipeline 12, a dust collector 13 for removing dust in the high-temperature gas, a high-temperature air waste heat boiler 14 for exchanging heat with the high-temperature gas, and a circulation fan 15 for generating air flow are sequentially arranged;

[0079] The circulation fan 15 agitates the air flow to circulate between the spiral diversion channel and the gas circulation pipeline 12. After the cooling gas exchanges heat with the solid steel slag, it becomes high-temperature gas and enters the gas circulation pipeline 12. After passing through the dust removal process at high temperature, it enters the high-temperature air waste heat boiler 14 for heat exchange and then becomes low-temperature gas again, and then re-enters the spiral diversion channel through the circulation fan 15 to exchange heat with the solid high-temperature steel slag.

[0080] The high-temperature air waste heat boiler 14 here is in direct contact with the high-temperature air and can maintain a relatively high heat exchange efficiency. Different from the thermal radiation waste heat boiler 2, it cannot be in direct contact with the molten steel slag and can only absorb the radiant heat energy of the molten steel slag.

[0081] The circulation fan 15 can be connected to the outside air to make up for the air volume lost during the gas circulation process.

[0082] It can be understood that the dust collector 13 can include cyclone dust removal and fine dust removal with a metal filter cartridge.

[0083] Further, the layer spacing of the spiral guide vanes 902 decreases from top to bottom.

[0084] Further, it can be understood that even the temperatures of the steel slag at the same height on the spiral guide vanes 902 may differ. If only one temperature measurement module is set in the low-temperature area at the bottom layer of the tower body 901, it may occur that the temperature measurement module detects that the temperature of the steel slag is lower than the permitted discharge temperature, but the temperatures of other steel slag in the low-temperature area at the bottom layer of the tower body 901 are higher than the permitted discharge temperature. Therefore, at least two temperature measurement modules are set in the low-temperature area at the bottom layer of the tower body 901. The two temperature measurement modules can calibrate each other, and the higher of the two temperature data is compared with the permitted discharge temperature to determine whether to allow the steel slag to be discharged.

[0085] Multiple cooling system for steel slag

[0086] Compared with the vertical static spiral countercurrent heat exchange system of molten steel slag and steel slag, molten steel slag has higher radiant heat energy and mainly dissipates heat through radiation. The molten steel slag sensible heat recovery device can recover the radiant heat energy of high-temperature molten steel slag faster [for example, it can reduce the temperature of steel slag from 1500 degrees to 800 degrees faster]. When the temperature of the steel slag drops below 800 degrees Celsius, the radiant heat decreases. In order to ensure the heat recovery efficiency of the steel slag, it is not advisable to continue using a heat radiation waste heat boiler with radiant heating to exchange heat with the steel slag. Although the vertical static spiral countercurrent heat exchange system of steel slag has a lower heat exchange efficiency in the high and medium temperature sections than the molten steel slag sensible heat recovery device, it can fully exchange heat with solid high-temperature steel slag through countercurrent forced convection and cool the steel slag to normal temperature or the temperature required by the system.

[0087] The combination of the molten steel slag sensible heat recovery device and the vertical static spiral countercurrent heat exchange system of steel slag can form a multiple cooling system for steel slag. The solid high-temperature steel slag discharged from the molten steel slag sensible heat recovery device is fed into the vertical static spiral countercurrent heat exchange system of steel slag through a bucket elevator 11. The molten steel slag sensible heat recovery device is used to recover the radiant heat of medium and high-temperature steel slag; the vertical static spiral countercurrent heat exchange system of steel slag is used to further cool the steel slag after temperature reduction, so that the temperature of the steel slag is reduced to normal temperature or the temperature required by the system. The molten steel slag sensible heat recovery device and the vertical static spiral countercurrent heat exchange system of steel slag complement each other, ensuring that the steel slag is cooled to normal temperature while improving the heat recovery rate and heat recovery efficiency of the steel slag.

[0088] Composite material box for containing liquid or semi-liquid high-temperature steel slag

[0089] The above-mentioned material box 4 can be set as a composite material box for containing liquid or semi-liquid high-temperature steel slag. The composite material box includes an outer metal shell 401 and an inner refractory lining 402. The metal shell 401 and the refractory lining 402 are anchored and connected by several claw nails. The refractory lining 402 can isolate the high-temperature steel slag from the metal shell 401 to prevent the metal shell 401 from creeping and cracking, and the metal shell 401 can reinforce the refractory lining 402 to prevent the refractory lining 402 from vibrating and cracking.

[0090] Specifically, the thickness of the metal shell 401 is 10 mm, the thickness of the refractory lining 402 is 100 - 150 mm, and the overall length of the material box is 5 m, the width is 3 m, and the height is 0.3 m.

[0091] The material box in the present invention is composed of an outer metal shell 401 and an inner refractory lining 402 in combination. Through the optimized combination of the metal shell 401 and the refractory lining 402, the refractory lining 402 has excellent heat resistance and can isolate the high-temperature steel slag from the metal shell 401 to avoid the creeping and cracking of the metal shell 401. The metal shell 401 has excellent seismic resistance and can reinforce the refractory lining 402 to prevent the refractory lining 402 from vibrating and cracking.

[0092] Further, the claw nails are V-shaped claw nails 403, and the V-shaped claw nails 403 are evenly arranged between the metal shell 401 and the refractory lining 402, and each V-shaped claw nail 403 is welded to the metal shell 401 to anchor the metal shell 401 and the refractory lining 402.

[0093] Specifically, the height of the V-shaped claw nail 403 is 2 / 3 of the lining thickness, and the V-shaped claw nails 403 are evenly distributed on the inner surface of the metal shell 401 in a matrix with a spacing of 200 mm × 200 mm.

[0094] The material of the V-shaped claw nail 403 is Cr25Ni20, and the opening angle is 60°.

[0095] Further, the composite material box is set as a U-shaped material box with a flat bottom to facilitate the dumping of the cooled steel slag in the composite material box.

[0096] It can be understood that the two sides of the U-shaped material box are open, and the steel slag is easy to leak from the openings. In the present invention, adjacent composite material boxes can be fixedly connected through a locking structure, so that the open sides of adjacent composite material boxes are closely attached, and multiple composite material boxes are connected into a whole to form a continuous steel slag storage area. On the one hand, the steel slag capacity can be increased when the number of material boxes is the same, and on the other hand, the number of leakable openings is reduced, so that there are only two leakable openings in multiple material boxes.

[0097] The above-mentioned locking structure is a prior art and can lock and fix two adjacent composite material boxes. For example, positioning holes can be formed by extending outward on the metal shell 401, and through a double-headed plug, it can be inserted into the positioning holes on two composite material boxes at the same time to fix the two composite material boxes.

[0098] When the composite material box is used in the above-mentioned steel slag conveying device 1, when the composite material box is transferred to the head end of the heavy-duty roller path 101, it is connected to the whole composed of multiple composite material boxes through a locking structure. When the composite material box is transferred to the tail end of the heavy-duty roller path 101, it is removed from the whole composed of multiple composite material boxes so that it can be transferred to the light-duty roller path 103 by the tail-end translation roller path 102.

[0099] Further, the metal shell 401 is a high-temperature resistant alloy steel plate, and the refractory lining 402 is a steel fiber high-aluminum refractory castable.

[0100] Specifically, the material of the high-temperature resistant alloy steel plate is 310S stainless steel or 15CrMo steel, the Al2O3 content in the steel fiber high-aluminum refractory castable is ≥ 70%, and the steel fiber addition amount is 3-5 wt%.

[0101] The preparation method of the composite material box is as follows:

[0102] Laser cut the steel plate and weld it into a U-shaped groove body;

[0103] Weld V-shaped claw nails 403 (spacing 200 mm) on the inner surface of the steel plate;

[0104] Formwork and pour steel fiber high-aluminum castable, and bake it to 600 °C after curing for 72 hours.

[0105] Implementation effect:

[0106] In the continuous conveying test of 1400 °C steel slag in a certain steel plant, the service life reached 18 months (the traditional trough ≤ 6 months);

[0107] The thermal shock cycle test (1400 °C → water cooling) ≥ 50 times without cracking.

[0108] The above embodiments are only exemplary embodiments of the present application and are not used to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements within the essence and protection scope of the present application, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the present application.

Claims

1. A sensible heat recovery device for molten steel slag, characterized in that: The invention comprises a slag conveying device (1) and a heat radiation waste heat boiler (2), wherein the heat radiation waste heat boiler (2) is arranged above the slag conveying device (1), a conveying channel (3) is formed between the heat radiation waste heat boiler (2) and the slag conveying device (1), the slag conveying device (1) is used to convey the slag through the conveying channel (3), and the heat radiation waste heat boiler (2) can directly perform dust-free heat exchange with the slag below to heat the working medium in the heat radiation waste heat boiler (2).

2. A sensible heat recovery device for molten steel slag according to claim 1, characterized in that: If the heat radiation waste heat boiler (2) only needs to output saturated steam, multiple heat radiation waste heat boilers (2) are arranged along the conveying direction of the high-temperature slag, and the power of the multiple heat radiation waste heat boilers (2) is adapted to the temperature of the slag passing thereunder; If the thermal radiation waste heat boiler (2) needs to output superheated steam, the thermal radiation waste heat boiler (2) is configured as a segmented thermal radiation waste heat boiler (2), wherein the low temperature segment is an economizer, the medium temperature segment is an evaporator, the second high temperature segment is a superheater, and the highest temperature segment is an economizer.

3. The sensible heat recovery device for molten steel slag according to claim 1, characterized in that: The molten steel slag sensible heat recovery device also includes a material box (4) arranged on the steel slag conveying device (1), and the material box (4) is used to contain steel slag to isolate the high-temperature steel slag from the steel slag conveying device (1).

4. A sensible heat recovery device for molten steel slag according to claim 3, characterized in that: The slag conveying device (1) comprises a heavy-load roller conveyor (101) connected end to end, a rear end translation roller conveyor (102), a light-load roller conveyor (103) and a front end translation roller conveyor (104), which can form a ring-shaped conveying path; wherein: The heavy-load roller conveyor (101) is located inside the conveying channel (3), and the light-load roller conveyor (103), the tail end translation roller conveyor (102) and the head end translation roller conveyor (104) are all located outside the conveying channel (3); The rear end translation roller (102) is used to transport the slag-loaded material box at the rear end of the heavy-load roller (101) to the front end of the light-load roller (103), and the front end translation roller (104) is used to transport the empty material box at the rear end of the light-load roller (103) to the front end of the heavy-load roller (101); A push rod (105) is provided on one side of the tail end translation roller (102) close to the heat radiation waste heat boiler (2), and the push rod (105) can push up one side of the material box (4) located on the tail end translation roller (102) to pour the steel slag in the material box (4) into the slag receiving pot (106).

5. The sensible heat recovery device for molten steel slag according to claim 4, characterized in that: A plurality of material boxes (4) are arranged on the slag conveying device (1), and the plurality of material boxes (4) are arranged in a straight line on the heavy-load roller conveyor (101). The head and tail ends of adjacent material boxes (4) are detachably connected, and the head and tail ends of each material box (4) are open to form a continuous strip-shaped slag containing area.

6. The sensible heat recovery device for molten steel slag according to claim 1, characterized in that: The molten steel slag sensible heat recovery device also includes a slag distribution roller (5) arranged on the front side of the heat radiation waste heat boiler (2), and the slag distribution roller (5) is used to control the thickness of the high-temperature steel slag entering the conveying channel (3) to increase the cooling rate of the steel slag.

7. A molten steel slag sensible heat recovery device according to claim 6, characterized in that: The entrance of the conveying channel (3) is also provided with a lifting gate (6), and the lifting gate (6) can fine-tune the thickness of the slag layer behind the slag distribution roller (5).

8. The sensible heat recovery device for molten steel slag according to claim 1, characterized in that: A crushing tooth roller (7) is arranged in the conveying channel (3), and the crushing tooth roller (7) is used to crush the crust formed on the surface of the steel slag after the temperature is reduced, so as to improve the heat exchange efficiency between the heat radiation waste heat boiler (2) and the steel slag; A plurality of crushing tooth rollers (7) are arranged along the length direction of the conveying channel (3), and each crushing tooth roller (7) can be raised and lowered to allow large pieces of steel slag formed by rapid cooling or hard metal blocks that cannot be crushed to pass through.

9. A molten steel slag sensible heat recovery device according to claim 4, 6 or 8, characterized in that: The slag distribution roller (5), the crushing tooth roller (7) and the heavy-load roller table (101) are all connected to a water cooling system.

10. The sensible heat recovery device for molten steel slag according to claim 3, characterized in that: The molten steel slag sensible heat recovery device also includes a steel slag delivery device (8) arranged on the front side of the heat radiation waste heat boiler (2), and the steel slag delivery device (8) is used to deliver high-temperature steel slag into the material box (4).

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