Magnesium slag waste heat utilization device and method

Abstract

This application discloses a device and method for utilizing waste heat from magnesium slag, relating to the field of industrial waste treatment technology. The device includes a boiler, a heat exchange system, a conveyor belt system, and a steam-water separation system. The conveyor belt system and the heat exchange system are located inside the boiler. The heat exchange system surrounds the upper part of the conveyor belt system, and its internal pipes form a heat system circulation loop for absorbing heat from the high-temperature magnesium slag. A flue pipe is provided at the top of the boiler, and an inlet and an outlet are respectively provided on the side wall and bottom of the boiler. The steam-water separation system is located above the heat exchange system and is connected to it to separate the steam-water mixture introduced by the heat exchange system. Therefore, this application embodiment rapidly collects the waste heat from high-temperature magnesium slag through the magnesium slag waste heat utilization device, solving the technical problems of unutilized waste heat from magnesium slag, land occupation due to magnesium slag stockpiling, and environmental pollution.

Description

Technical Field

[0001] This application relates to the field of industrial waste treatment technology, and in particular to a device and method for utilizing waste heat from magnesium slag. Background Technology

[0002] With economic development, the demand for metallic magnesium is increasing. Research data shows that approximately 8 to 10 tons of magnesium slag are produced for every ton of metallic magnesium produced, and the furnace temperature is very high, generally between 1200℃ and 1400℃.

[0003] Existing magnesium slag recycling equipment cannot perform pre-treatment to cool down the high-temperature magnesium slag. In production, the high-temperature magnesium slag is often left to cool naturally in the air before being recycled, which wastes a lot of heat energy. In addition, the natural cooling of magnesium slag takes a long time, generally 5-7 days. The stockpiling of magnesium slag also requires a lot of land resources. Its high hygroscopicity can easily cause soil compaction, which seriously damages the natural environment. Summary of the Invention

[0004] This application provides a device and method for utilizing the waste heat of magnesium slag, which solves the technical problems of unutilized waste heat of magnesium slag, land occupation caused by magnesium slag stockpiling, and environmental pollution in the prior art.

[0005] In a first aspect, embodiments of the present invention provide a magnesium slag waste heat utilization device, including a boiler, a heat exchange system, a crawler conveyor system, and a steam-water separation system; the crawler conveyor system and the heat exchange system are located inside the boiler; the heat exchange system surrounds the upper part of the crawler conveyor system, and the internal pipes of the heat exchange system form a heat system circulation loop for absorbing heat from the high-temperature magnesium slag; a flue pipe is provided at the top of the boiler, and a feed inlet and a discharge outlet are respectively provided on the side wall and bottom of the boiler; the steam-water separation system is located above the heat exchange system and is connected to the heat exchange system to separate the steam-water mixture introduced by the heat exchange system.

[0006] In conjunction with the first aspect, in one possible implementation, the heat exchange system includes a water collection pipe, a boiler drum, and water-cooled wall tubes; the boiler drum is disposed above the water collection pipe, multiple rows of the water collection pipes are arranged in an array along a first direction, and the boiler drum and the water collection pipes are respectively connected to the inner wall of the boiler; multiple water-cooled wall tubes are arranged in an array along the first direction, and the two ends of the water-cooled wall tubes are respectively connected to the water collection pipe and the boiler drum located at the bottom.

[0007] In conjunction with the first aspect, in one possible implementation, the heat exchange system further includes a flue wall; multiple rows of the flue walls are arranged below the boiler drum, and the flue walls are installed around the inner wall of the water collection pipe; the multiple rows of the flue walls divide the heat exchange system into multiple heat exchange chambers, each heat exchange chamber has an air outlet at its top, and the multiple air outlets are arranged alternately along the first direction to form a tortuous flue.

[0008] In conjunction with the first aspect, in one possible implementation, the heat exchange system further includes flushing pipes; the flushing pipes are connected to the smoke deflector wall and communicate with the water collection pipe; a plurality of the flushing pipes are arranged along a third direction, and multiple rows are arranged along the first direction.

[0009] In conjunction with the first aspect, in one possible implementation, the flushing pipes are embedded in the flue wall and arranged alternately to form a sealed flue.

[0010] In conjunction with the first aspect, one possible implementation also includes air chambers; a plurality of the air chambers are disposed inside the tracked conveyor system along a second direction and are configured to blow the heat of the high-temperature magnesium slag into the interior of the heat exchange system.

[0011] In conjunction with the first aspect, in one possible implementation, a support frame is also included; the top of the support frame is connected to the tracked transmission system, and the support frame is placed on the ground.

[0012] In conjunction with the first aspect, in one possible implementation, the surface of the tracked conveyor system is provided with a grate.

[0013] Secondly, embodiments of the present invention provide a method for utilizing waste heat from magnesium slag. High-temperature magnesium slag is fed into a conveyor system through the feed inlet; the high-temperature magnesium slag is transported into the boiler through the conveyor system; the high-temperature flue gas generated by the high-temperature magnesium slag rises to the heat exchange system by its own thermal buoyancy; the high-temperature flue gas enters the exhaust pipe through the outlet of each heat exchange chamber in a tortuous manner; the high-temperature flue gas undergoes radiative heat exchange with the water-cooled wall tubes and convective heat exchange with the flushing tubes, and the water temperature in the water-cooled wall tubes and flushing tubes rises rapidly after heat exchange, forming a steam-water mixture in the cold wall tubes; the steam-water mixture enters the steam-water separation system through the boiler drum, and the steam-water separation system separates the steam-water mixture; the low-temperature magnesium slag after heat exchange is discharged into the discharge port through the conveyor system.

[0014] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0015] The magnesium slag waste heat utilization device provided in this embodiment of the invention includes a boiler, a heat exchange system, a crawler conveyor system, and a steam-water separation system. A slag-carrying trolley feeds high-temperature magnesium slag into the crawler conveyor system through the feed inlet. The crawler conveyor system transports the high-temperature magnesium slag into the furnace. The high-temperature flue gas generated by the high-temperature magnesium slag rises to the heat exchange system due to its own buoyancy, transferring heat to the heat exchange system. During the heat exchange process between the high-temperature flue gas and the heat exchange system, the water in the heat exchange system is heated and becomes a steam-water mixture, which enters the steam-water separation system. The steam-water separation system separates the steam-water mixture from the heat exchange system. The separated steam is collected and utilized, while the separated water falls back into the heat exchange system, repeating the heating-floating-separation cycle. The high-temperature flue gas after heat exchange flows into the exhaust pipe at the top of the boiler and is sent to the downstream flue gas purification system for treatment. The low-temperature magnesium slag after heat exchange is discharged into the discharge port through the crawler conveyor system and transported out by the slag-carrying trolley. Therefore, the embodiment of this application can quickly collect the waste heat of high-temperature magnesium slag through the magnesium slag waste heat utilization device, cool the high-temperature magnesium slag, greatly improve the utilization efficiency of magnesium slag, solve the technical problems of unutilized magnesium slag waste heat, magnesium slag pile-up occupying land and causing environmental pollution, and can fully and efficiently utilize the high-temperature thermal energy of hot furnace slag to achieve the purpose of energy saving, consumption reduction and production cost reduction. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments of the present invention or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the high-temperature magnesium slag waste heat treatment device provided in the embodiments of this application;

[0018] Figure 2 A schematic diagram of the smoke deflector wall and flushing pipe structure of the high-temperature magnesium slag waste heat treatment device provided in the embodiments of this application;

[0019] Figure 3 for Figure 1 Sectional view of section BB;

[0020] Figure 4 for Figure 1 A sectional view of section AA in the middle.

[0021] Attached reference numerals: 1-Boiler; 2-Crawler conveyor system; 3-Grate; 4-Air chamber; 5-Heat exchange system; 51-Gas outlet; 52-Boiler drum; 53-Water collection pipe; 54-Water-cooled wall pipe; 55-Flush pipe; 56-Flush wall; 6-Heat exchange chamber; 7-Steam system; 8-Exhaust pipe; 9-Feed inlet; 10-Discharge outlet; 11-Slag trolley; 12-Support frame. Detailed Implementation

[0022] 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, not all, of the embodiments of the present invention. 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.

[0023] In the description of the embodiments of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0024] The magnesium slag waste heat utilization device provided in the embodiments of this application is as follows: Figures 1 to 4 As shown. Figure 1 This is a schematic diagram of the high-temperature magnesium slag waste heat treatment device provided in the embodiments of this application. Figure 2 This is a partial enlarged view of the flue wall and flushing pipe of the high-temperature magnesium slag waste heat treatment device provided in the embodiments of this application. Figure 3 for Figure 1 Sectional view of section BB. Figure 4 for Figure 1 A sectional view of section AA in the middle.

[0025] like Figure 1As shown in the embodiment of this application, a magnesium slag waste heat utilization device includes a boiler 1, a heat exchange system 5, a crawler conveyor system 2, and a steam-water separation system 6. The crawler conveyor system 2 and the heat exchange system 5 are located inside the boiler 1.

[0026] Specifically, the tracked transmission system 2 can be made of metal, with the principle of being able to withstand the high temperature of magnesium slag.

[0027] like Figure 1 As shown, the heat exchange system 5 surrounds the upper part of the tracked transmission system 2, and the internal pipes of the heat exchange system 5 form a heat system circulation loop to absorb the heat of high-temperature magnesium slag.

[0028] Continue to refer to Figure 1 As shown, a flue pipe 8 is installed at the top of the boiler 1. After the high-temperature flue gas is heated by the heat exchange system 5, it flows into the flue pipe 8 and is sent to the downstream flue gas purification system for treatment, so as to avoid pollution to the atmosphere and achieve the effect of energy saving and emission reduction.

[0029] In one implementation of this application, the boiler 1 has a feed inlet 9 and a discharge outlet 10 on its side wall and bottom, respectively. High-temperature magnesium slag flows into the tracked conveyor system 2 by gravity through the feed inlet 9, and the magnesium slag that has completed the heat dissipation process falls into the discharge outlet 10 by gravity at the end of the tracked conveyor system 2.

[0030] Continue to refer to Figure 1 As shown, the steam-water separation system is located above the heat exchange system 5 and is connected to the heat exchange system 5 to separate the steam-water mixture introduced by the heat exchange system 5.

[0031] The slag-carrying trolley 11 transfers high-temperature magnesia slag through the feed inlet 9 of boiler 1 into the crawler conveyor system 2. The crawler conveyor system 2 transports the high-temperature magnesia slag into the boiler 1. The high-temperature flue gas generated by the magnesia slag rises to the heat exchange system 5 by its own buoyancy, transferring heat to the heat exchange system 5. During the heat exchange process between the high-temperature flue gas and the heat exchange system 5, the water in the heat exchange system 5 is heated and becomes a steam-water mixture, which enters the steam-water separation system 6. The steam-water separation system 6 separates the steam-water mixture transferred from the heat exchange system 5. The separated steam is collected and utilized, while the separated water falls back into the heat exchange system 5, re-entering the heating-floating-separation cycle. The low-temperature magnesia slag, after heat exchange, is discharged through the crawler conveyor system 2 into the discharge outlet 10 and transported out by the slag-carrying trolley 11. High-temperature magnesia slag typically requires 5-7 days to cool naturally. This magnesia slag waste heat utilization device can shorten the natural cooling time to 1-2 hours, fully and efficiently utilizing the waste heat of high-temperature magnesia slag to achieve energy conservation, consumption reduction, and lower production costs. It also effectively releases occupied land resources and accelerates the utilization efficiency of magnesia slag.

[0032] For example, such as Figure 1The document provides a specific structural form of the heat exchange system 5. Specifically, the heat exchange system 5 includes a water collection pipe 53, a boiler drum 52, and water-cooled wall tubes 54. The boiler drum 52 is arranged above the water collection pipe 53, and multiple rows of water collection pipes 53 are arranged along a first direction. The boiler drum 52 and the water collection pipes 53 are respectively connected to the inner wall of the boiler 1. Multiple water-cooled wall tubes 54 are arranged along the first direction, and both ends of the water-cooled wall tubes 54 are respectively connected to the water collection pipes 53 and the boiler drum 52 located at the bottom.

[0033] Specifically, the water-cooled wall tubes 54, the boiler drum 52, and the water-cooled wall tubes 54 together form a square shape in the furnace chamber, with the water-cooled wall tubes 54 arranged in a close-packed configuration. This close-packing of the water-cooled wall tubes 54 effectively improves the sealing performance of the heat exchange system 5, reduces air leakage, and lowers heat loss, thereby increasing heat exchange efficiency. During the operation of this magnesium slag waste heat utilization device, the water in the water-cooled wall tubes 54 absorbs radiant heat from the high-temperature flue gas, gradually transforming from subcooled water with a certain enthalpy deficit into a steam-water mixture, which rises and enters the upper boiler drum 52.

[0034] The water collection pipe 53, boiler drum 52, and water-cooled wall tubes 54 of the heat exchange system 5 can be made of steel. The water collection pipe 53, boiler drum 52, and water-cooled wall tubes 54 are galvanized to improve their corrosion resistance. The outer surfaces of the water collection pipe 53, boiler drum 52, and water-cooled wall tubes 54 should be free from defects such as cracks, flattening, and severe corrosion.

[0035] The water-cooled wall tubes 54 are connected to the boiler drum 52 and the water collection pipe 53 by expansion joints. This expansion joint method primarily reduces the mutual influence between the water-cooled wall tubes 54, boiler drum 52, and water collection pipe 53, and reduces or eliminates the effects of various stresses. In the event of a failure in the water-cooled wall tube 54, it can be quickly replaced with minimal impact on the boiler drum 52 and water collection pipe 53. However, the connection between the water-cooled wall tubes 54 and the boiler drum 52 and water collection pipe 53 is not limited to expansion joints; expansion welding can also be used. Using a combination of expansion welding and expansion welding not only improves the fatigue resistance of the connection but also eliminates stress corrosion and crevice corrosion, extending its service life. In traditional boilers, the water-cooled wall tubes 54 are sparsely arranged, and their connections are typically made by welding. In this magnesium slag waste heat utilization device, since the water-cooled wall tubes 54 are arranged in close rows, if welding is used, it will cause large plastic deformation at the connection between the water-cooled wall tubes 54 and the boiler drum 52 and the water collection pipe 53, affecting their service life.

[0036] In one implementation of this application, to facilitate the installation of various pipes, the water-cooled wall pipe 54 is vertically connected to the boiler drum 52 and to the water collection pipe 53. However, this application is not limited to vertical connections; non-vertical connections between the water-cooled wall pipe 54 and the boiler drum 52, and between the water-cooled wall pipe 54 and the water collection pipe 53, are also possible.

[0037] Before the heat exchange in the magnesium slag waste heat utilization device, the feedwater, which has been treated by the water treatment equipment and meets the water quality requirements of boiler 1, is pressurized by the water pump and enters the interior of boiler 1. The high-temperature flue gas generated by the high-temperature magnesium slag undergoes intense radiative heat exchange with the cold wall tubes 54, and the temperature of the water in the cold wall tubes 54 rises rapidly, forming a steam-water mixture inside the cold wall tubes 54. This mixture flows upward into the boiler drum 52. Inside the boiler drum 52, the steam-water mixture is separated by the steam-water separation system 6 and the gravity separation of the water itself. The separated steam is collected, and the separated water falls back into the boiler drum 52 and flows back into the water-cooled wall 54, re-entering the heating-floating-separation cycle.

[0038] Specifically, the main function of boiler drum 52 is to supply steam-water mixture to steam-water separation system 6 and to supply water to the circulation loop.

[0039] Furthermore, the heat exchange system 5 also includes a flue wall 56. Multiple rows of flue walls 56 are provided below the boiler drum 52, and the flue walls 56 are installed around the inner wall of the water collection pipe 53. The multiple rows of flue walls 56 divide the heat exchange system 5 into multiple heat exchange chambers 57. Each heat exchange chamber 57 is provided with an air outlet 51 at the top. The multiple air outlets 51 are arranged alternately along the first direction to form a tortuous flue.

[0040] Continue to refer to Figure 1 As shown, the flue wall 56 and the water collection pipe 53 form a sealed flue with only an outlet 51. Multiple rows of flue walls 56 are installed in an alternating manner. The flue walls 56 and the water collection pipe 53 divide the heat exchange system 5 into multiple heat exchange chambers 57, so that the high-temperature flue gas flows along each outlet 51 to form an S-shaped curve, which increases the residence time of the high-temperature flue gas in the heat exchange system 5 and further improves the heat exchange efficiency.

[0041] In one implementation of the embodiments of this application, such as Figure 1 As shown, the smoke deflector 56 is set in two rows, installed in an alternating manner, so that the smoke flows horizontally in an S-shaped tortuous manner.

[0042] like Figure 3 As shown, in one implementation of this application embodiment, the heat exchange system 5 further includes a flushing pipe 55.

[0043] like Figure 1As shown, the flushing pipe 55 is connected to the smoke deflector wall 56 and communicates with the water collection pipe 53. Multiple flushing pipes 55 are arranged along a third direction, and multiple rows are arranged along the first direction.

[0044] The flushing tubes 55, water collecting tubes 53, water-cooled wall tubes 54, and boiler drum 52 form a circulation loop in the heat exchange system 5. The flushing tubes 55 are arranged in a close-packed manner. After the flushing tubes 55 are arranged in a close-packed manner, the high-temperature flue gas exchanges heat with the flushing tubes 55 through convection, which can further increase the heat exchange area of ​​the heat exchange system 5, reduce heat loss, and thus further improve the heat exchange efficiency.

[0045] Specifically, the flushing pipe 55 can be made of steel and galvanized to improve its corrosion resistance. The outer surface of the flushing pipe 55 should be free of defects such as cracks, flattening, and severe rust. The connection between the flushing pipe 55 and the water collecting pipe 53 is an expansion joint. This expansion joint is primarily used to reduce the mutual influence between the flushing pipe 55 and the water collecting pipe 53, and to reduce or eliminate the effects of various stresses. In the event of a failure in the flushing pipe 55, it can be quickly replaced with minimal impact on the water collecting pipe 53. Of course, the connection between the flushing pipe 55 and the water collecting pipe 53 is not limited to expansion joints; expansion welding can also be used. Using a combination of expansion welding and expansion welding not only improves the fatigue resistance of the connection but also eliminates stress corrosion and crevice corrosion, thus extending its service life.

[0046] like Figure 2 As shown, the flushing pipes 55 are embedded in the flue wall 56 and arranged alternately to form a sealed flue. Specifically, the flue wall 56 is composed of multiple steel plates, with each steel plate connected to a flushing pipe 55, and they are arranged alternately to form a sealed flue.

[0047] like Figure 1 As shown in the illustration, the magnesium slag waste heat utilization device provided in this application embodiment also includes air chambers 4. Multiple air chambers 4 are arranged along a second direction inside the tracked conveyor system 2, configured to blow the heat from the high-temperature magnesium slag into the heat exchange system 5. Under the airflow from the air chambers 4, the radiative and convective heat dissipation during the magnesium slag heat dissipation process is further enhanced, further improving the heat exchange efficiency.

[0048] The magnesium slag waste heat utilization device provided in this application embodiment also includes a support frame 12. The top of the support frame 12 is connected to the tracked transmission system 2, and the support frame 12 is placed on the ground.

[0049] Continue to refer to Figure 1As shown, a grate 3 is provided on the surface of the tracked conveyor system 2. The grate 3 can withstand the high temperature of magnesia slag. Specifically, the grate 3 can be made of gray cast iron or ferromanganese. Gray cast iron or ferromanganese has a small coefficient of thermal expansion, is not easily deformed or damaged, and has a long service life. The grate 3 is detachably connected to the tracked conveyor system 2. The connection between the grate 3 and the tracked conveyor system 2 is achieved through a snap-fit ​​mechanism. The snap-fit ​​mechanism means that the inner side of the grate 3 is provided with an annular protrusion, and the outer side of the tracked conveyor system 2 is provided with an annular groove that mates with the annular protrusion; or the outer side of the tracked conveyor system 2 is provided with an annular protrusion, and the inner side of the grate 3 is provided with an annular groove that mates with the annular protrusion. Of course, the connection between the inner side of the grate 3 and the outer side of the track transmission system 2 is not limited to a snap-fit ​​connection. Other detachable connection methods, such as threaded connections, can also be used. For example, the inner side of the grate 3 can have an internal thread, and the outer side of the track transmission system 2 can have an external thread, or vice versa. This application does not limit the specific structural form of the detachable connection between the inner side of the grate 3 and the outer side of the track transmission system 2. The detachable connection between the inner side of the grate 3 and the outer side of the track transmission system 2 facilitates the removal of the grate 3 for maintenance or replacement.

[0050] High-temperature magnesia slag falls onto the grate 3 under its own weight in the slag-carrying trolley 11. The grate 3, with the help of the crawler conveyor system 2, carries the high-temperature magnesia slag into the boiler. The magnesia slag moves slowly backward while exchanging heat. After completing the heat dissipation process, the magnesia slag falls into the discharge port 10 at the end of the grate 3 under its own weight and is then transported out by the slag-carrying trolley 11. The magnesia slag waste heat utilization device provided in this application embodiment greatly improves the utilization efficiency of magnesia slag and fundamentally solves the problems of land occupation and environmental pollution caused by magnesia slag stockpiling.

[0051] like Figure 1 As shown, the magnesium slag waste heat utilization device provided in this application embodiment further includes a steam system 7, which is located above the boiler 1. The two ends of the steam-water separation system 6 are respectively connected to the boiler drum 52 of the heat exchange system 5 and the steam system 7. The steam system 7 is used to collect the steam separated by the steam-water separation system 6.

[0052] Continue to refer to Figure 1 As shown, the boiler can be installed in a semi-basement or on the ground floor. If the boiler is installed in a semi-basement, the tracked transmission system 2, support frame 12, feed inlet 9, and discharge outlet 10 are all located in the semi-basement.

[0053] This application provides a method for utilizing the waste heat of magnesium slag, including: high-temperature magnesium slag being fed into a conveyor belt system 2 through a feed inlet 9; the high-temperature magnesium slag being transported into a boiler 1 through the conveyor belt system 2; high-temperature flue gas generated by the high-temperature magnesium slag rising to a heat exchange system 5 by its own thermal buoyancy; the high-temperature flue gas entering the exhaust pipe 8 through the outlet 51 of each heat exchange chamber in a tortuous manner; the high-temperature flue gas undergoing radiative heat exchange with water-cooled wall tubes 54 and convective heat exchange with flushing pipes 55, the water temperature in the water-cooled wall tubes 54 and flushing pipes 55 rapidly increasing after heat exchange, forming a steam-water mixture in the cold wall tubes; the steam-water mixture entering a steam-water separation system through a boiler drum 52, the steam-water separation system separating the steam-water mixture; and the low-temperature magnesium slag after heat exchange being discharged into the discharge port through the conveyor belt system 2.

[0054] The magnesium slag waste heat utilization device provided in this application embodiment can collect the waste heat of magnesium slag while mechanically cooling it. It can utilize the waste heat generated during the process of reducing the temperature of magnesium slag from 1200°C to 200°C to produce a large amount of steam or hot water for use in process flow or domestic hot water, thereby reducing the use of other forms of fuel (such as coal and natural gas) and lowering production costs.

[0055] The magnesium slag waste heat utilization device of this application embodiment modifies a traditional chain grate coal-fired steam boiler by removing the combustion section. Through the design of the airflow path inside the boiler 1, the waste heat from the magnesium slag undergoes radiative heat exchange with the water-cooled wall tubes 54 and convective heat exchange with the flushing tubes 55, thus achieving mechanical cooling of the magnesium slag while simultaneously collecting its waste heat. The waste heat collection process of this application embodiment involves no secondary combustion, making it a low-carbon heat generation process. Widespread adoption of this technology can effectively reduce the carbon emissions of the entire industry.

[0056] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0057] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A device for utilizing waste heat from magnesium slag, characterized in that, It includes a boiler (1), a heat exchange system (5), a tracked conveyor system (2), and a steam-water separation system (6); The tracked conveyor system (2) and the heat exchange system (5) are located inside the boiler (1); The heat exchange system (5) surrounds the upper part of the tracked transmission system (2), and the internal pipes of the heat exchange system (5) form a heat system circulation loop for absorbing the heat of high-temperature magnesium slag. The boiler (1) is provided with a flue pipe (8) at the top, and the boiler (1) is provided with a feed inlet (9) and a discharge outlet (10) at the side wall and bottom respectively. The steam-water separation system (6) is located above the heat exchange system (5) and is connected to the heat exchange system (5) to separate the steam-water mixture introduced by the heat exchange system (5); the heat exchange system (5) includes a water collection pipe (53), a boiler drum (52) and a water-cooled wall tube (54). The boiler drum (52) is arranged above the water collection pipe (53), and multiple rows of water collection pipes (53) are arranged along the first direction. The boiler drum (52) and the water collection pipes (53) are respectively connected to the inner wall of the boiler (1). Multiple water-cooled wall tubes (54) are arranged in a second direction, and the two ends of the water-cooled wall tubes (54) are respectively connected to the water collection pipe (53) and the boiler drum (52) located at the bottom; The heat exchange system (5) also includes a smoke deflector wall (56); Multiple rows of smoke deflectors (56) are provided below the boiler drum (52), and the smoke deflectors (56) are installed around the inner wall of the water collection pipe (53). The multiple rows of the flue walls (56) divide the heat exchange system (5) into multiple heat exchange chambers (57), and each heat exchange chamber (57) is provided with an air outlet (51) at the top. The multiple air outlets (51) are arranged alternately along the first direction to form a tortuous flue. The heat exchange system (5) also includes a flushing pipe (55); The flushing pipe (55) is connected to the smoke deflector wall (56) and is also connected to the water collection pipe (53). The plurality of flushing pipes (55) are arranged along a third direction, and multiple rows are arranged along the first direction; The flushing pipe (55) is embedded in the smoke deflector wall (56) and arranged alternately to form a sealed flue; the smoke deflector wall (56) is composed of multiple steel plates, one steel plate is connected to one flushing pipe (55), and they are arranged alternately to form a sealed flue; The tracked transmission system (2) and support frame (12), feed inlet (9) and discharge outlet (10) are all located in the semi-basement.

2. The magnesium slag waste heat utilization device according to claim 1, characterized in that, It also includes wind turbines (4); Multiple air chambers (4) are arranged inside the tracked conveyor system (2) along the second direction and are configured to blow the heat of the high-temperature magnesium slag into the heat exchange system (5).

3. The magnesium slag waste heat utilization device according to claim 1, characterized in that, It also includes a support frame (12); The top of the support frame (12) is connected to the tracked transmission system (2), and the support frame (12) is placed on the ground.

4. The magnesium slag waste heat utilization device according to claim 1, characterized in that, The surface of the tracked transmission system (2) is provided with a grate (3).

5. A method for utilizing waste heat from magnesium slag, based on the magnesium slag waste heat utilization device according to any one of claims 1 to 4, characterized in that, include: High-temperature magnesium slag is fed into the tracked conveyor system (2) through the feed inlet (9); High-temperature magnesium slag is transported into the boiler (1) via a crawler conveyor system (2); The high-temperature flue gas generated by the high-temperature magnesium slag rises to the heat exchange system by its own thermal buoyancy (5). High-temperature flue gas enters the exhaust pipe (8) in a tortuous manner through the outlet (51) of each heat exchange chamber (57); High-temperature flue gas undergoes radiative heat exchange with the water-cooled wall tube (54) and convective heat exchange with the flushing tube (55). After heat exchange, the water temperature in the water-cooled wall tube (54) and the flushing tube (55) rises rapidly, forming a steam-water mixture in the water-cooled wall tube (54). The steam-water mixture enters the steam-water separation system (6) through the boiler drum (52), and the steam-water separation system (6) separates the steam-water mixture; The low-temperature magnesium slag after heat exchange is discharged into the discharge port (10) through the crawler conveyor system (2).

Images