A solid salt fractional melting salt melting furnace

Abstract

The application discloses a solid salt grading melting salt dissolving furnace, which comprises a salt dissolving furnace body, an inclined grate plate and a heating module. An upper end of the salt dissolving furnace body is provided with a feeding port, the inclined grate plate is arranged on the inner wall of the salt dissolving furnace body, and the inclined grate plate is arranged at intervals from the bottom of the salt dissolving furnace body. An end of the inclined grate plate, which is towards the feeding port, is a high-position end, and an end of the inclined grate plate, which is away from the feeding port, is a low-position end. A plurality of salt liquid gaps are arranged at intervals on the inclined grate plate along the inclined direction of the inclined grate plate. The heating module is used for heating the solid salt in the salt dissolving furnace body to form salt liquid. The salt blocks are lifted in the furnace by the inclined grate plate with the salt liquid gaps, the salt blocks are melted while sliding, the molten salt liquid is discharged downwards in time, the solid salt is fully heated, and the heat exchange condition is obviously improved.

Description

Technical Field

[0001] This invention belongs to the field of molten salt energy storage technology, specifically relating to a salt melting furnace for staged melting of solid salt. Background Technology

[0002] Molten salt energy storage systems are widely used in solar thermal power generation and industrial energy storage. When the system is first put into operation or when salt is replenished during operation, bagged or block-shaped solid salt needs to be put into the salt melting furnace. The solid salt is heated and melted into liquid molten salt by the heating components in the furnace before the molten salt circulation system can be started. The salt melting efficiency directly determines the system's commissioning progress and the duration of salt replenishment.

[0003] In existing salt-melting furnaces, solid salt blocks are directly fed into the furnace cavity through the feeding port. The salt blocks fall to the bottom of the furnace under gravity, causing large solid salt blocks to accumulate and compact. This compacted state results in poor heat exchange between the salt blocks, making it difficult for heat to transfer to their interiors. Consequently, the melting rate is low, leading to a prolonged overall salt-melting time. Furthermore, the outer surface of large salt blocks melts first, while the interior remains solid, easily creating unmelted salt blocks. The accumulation of these unmelted salt blocks at the bottom further reduces salt-melting efficiency and, in severe cases, forms a paste-like molten salt coating on the heating elements, impacting heating efficiency and negatively affecting the stable operation of the salt-melting furnace.

[0004] Therefore, how to prevent large salt blocks from sinking and accumulating directly to the bottom and improve the melting efficiency of solid salt is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a salt melting furnace for staged melting of solid salt, which addresses the shortcomings of the prior art. The solid salt moves and melts gradually along the inclined grate in the high-temperature zone of the furnace, thereby reducing the direct sinking of large pieces of salt and improving the salt melting efficiency. This solves the technical problem that the direct sinking and accumulation of large pieces of salt affects the melting efficiency of solid salt.

[0006] The present invention adopts the following technical solution: Furthermore, the present invention is characterized by: a salt melting furnace for graded melting of solid salt, comprising a salt melting furnace body, an inclined grate plate, and a heating module; The upper end of the salt-melting furnace body is provided with a feeding port, the inclined grate is provided on the inner wall of the salt-melting furnace body, and the inclined grate is arranged at intervals with the bottom of the salt-melting furnace body; The end of the inclined grate facing the feed inlet is the high end, and the end of the inclined grate facing away from the feed inlet is the low end. Multiple salt solution gaps are provided at intervals along the inclined direction on the inclined grate. The heating module is used to heat the solid salt in the salt furnace to form a brine.

[0007] Preferably, the size of the brine gap near the higher end is larger than the size of the brine gap near the lower end.

[0008] Preferably, the inclined grate includes multiple grate bars arranged in parallel from the high end to the low end, and the gap between two adjacent grate bars constitutes the brine gap.

[0009] Preferably, the size of the brine gap gradually decreases from the high end to the low end.

[0010] Preferably, the grate bars are made of stainless steel.

[0011] Preferably, the feeding port is arranged on the horizontal side of the upper end of the salt dissolving furnace body, and the high end is located directly below the feeding port.

[0012] Preferably, the inclined grate plate has an inclination angle of 30° relative to the horizontal plane. 60°.

[0013] Preferably, the heating module includes an electric heater arranged inside the salt-dissolving furnace body and located below the inclined grate.

[0014] Preferably, the heating module further includes an electric heat tracing device surrounding the outer wall of the salt furnace.

[0015] Preferably, both ends of the inclined grate are fixedly connected to the inner walls of the salt furnace body via support connectors.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: An inclined grate is installed inside the salt melting furnace. Solid salt is fed in from the top feeding port and supported by the inclined grate, preventing large pieces of salt from falling directly and accumulating at the bottom of the furnace. The grate is spaced apart from the bottom of the furnace, and the molten salt can flow down to the bottom of the furnace through the gaps in the molten salt. Combined with the heating module, the solid salt is heated and melted. The salt blocks can be continuously heated while moving on the surface of the grate, which improves the heat exchange conditions of the salt blocks, reduces the situation of the salt blocks melting on the outside but not inside, improves the melting efficiency of solid salt, and shortens the salt melting time.

[0017] Furthermore, the gap size of the brine at the higher end is larger than that at the lower end. Large pieces of salt fall to the higher end, and the large amount of brine produced in the initial melting can be quickly discharged downward through the larger gap at the higher end. As the salt blocks slide along the grate towards the lower end, their volume gradually decreases. The smaller gap at the lower end can intercept small pieces of salt that have not yet fully melted, allowing them to remain on the grate to continue to be heated and melted. This achieves graded melting of solid salt and prevents unmelted salt blocks from falling into the bottom of the furnace and accumulating.

[0018] Furthermore, the inclined grate is composed of multiple parallel grate bars, with gaps between adjacent grate bars forming the brine. The grate bars can stably support the salt blocks and simultaneously guide the molten brine downwards. It is also easy to install in existing salt furnaces, and is convenient to disassemble and maintain.

[0019] Furthermore, the size of the salt liquid gap gradually decreases from the high end to the low end, which matches the change law of the salt block volume continuously decreasing during the sliding process; the lower the salt block moves, the smaller the salt block that can pass through, so that the salt block continues to stay on the grate plate during the melting process from large to small, further enhancing the graded melting effect and fully melting the salt block.

[0020] Furthermore, the feeding port is located on the horizontal side of the upper part of the salt-making furnace body, with the higher end directly below the feeding port, which can maximize the travel path of solid salt on the inclined grate.

[0021] Furthermore, the heating module employs an electric heater positioned below the inclined grate. The electric heater is located in the space below the grate, which on the one hand continuously heats the dripping salt solution to the working temperature, and on the other hand simultaneously heats the air inside the furnace cavity, providing a high-temperature environment for the salt blocks on the grate and promoting the melting of the solid salt on the grate.

[0022] Furthermore, electric heat tracing is added to the outer wall of the furnace body on the basis of electric heaters. Electric heat tracing can usually maintain the overall high temperature environment inside the furnace. It forms an internal and external combined heating with the internal electric heater, making the temperature field inside the furnace more stable and uniform, and accelerating the melting rate of solid salt.

[0023] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0025] Figure 1 This is a longitudinal sectional view of a salt melting furnace for graded melting of solid salt according to the present invention.

[0026] The components include: 1. Salt furnace body; 2. Feeding port; 3. Salt block; 4. Inclined grate; 41. Salt solution gap; 42. Grate bar; 5. Electric heater; 6. Electric heat tracing; 7. Connecting lug. Detailed Implementation

[0027] 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.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "one side," "one end," and "one side," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing the invention and 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 this invention based on the specific circumstances.

[0030] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0031] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0032] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0033] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0034] Please see Figure 1 As shown, the present invention discloses a salt melting furnace for graded melting of solid salt, comprising a salt melting furnace body 1, an inclined grate plate 4, and a heating module.

[0035] Among them, such as Figure 1 As shown, a feeding port 2 is provided at the upper end of the salt-melting furnace body 1, and an inclined grate plate 4 is provided on the inner wall of the salt-melting furnace body 1, with the inclined grate plate 4 and the bottom of the salt-melting furnace body 1 arranged at intervals.

[0036] The inclined grate 4 has a higher end facing the feeding port 2, which is the high end. The inclined grate 4 extends downwards away from the feeding port 2, which is the lower end. Multiple brine gaps 41 are spaced along the inclined direction of the inclined grate 4. The heating module is used to heat the solid salt in the salt furnace body 1 to form brine.

[0037] In this embodiment, the two ends of the inclined grate plate 4 are fixedly connected to the two sides of the inner wall of the salt furnace body 1 through support connectors.

[0038] Specifically, the supporting connector includes connecting ears 7 arranged on the inner wall of the salt furnace body 1, corresponding to the position of the inclined grate plate 4. The end of the inclined grate plate 4 is fixedly connected to the connecting ears 7 by bolt assembly to complete the assembly. In other embodiments, the inclined grate plate 4 can also be fixedly connected to the salt furnace body 1 by welding or other methods.

[0039] With the above configuration, an inclined grate 4 is installed inside the salt melting furnace body 1. After solid salt is fed in from the upper feeding port 2, it is supported by the inclined grate 4, preventing large pieces of salt from falling directly and accumulating at the bottom of the furnace. The grate is arranged at intervals with the bottom of the furnace, and the molten salt can flow down to the bottom of the furnace through the gaps 41. The heating module heats and melts the solid salt. The salt block 3 can be continuously heated during its movement on the surface of the grate, improving the heat exchange conditions of the salt block 3, reducing the situation where the salt block 3 melts on the outside but not inside, improving the melting efficiency of solid salt, and shortening the salt melting time.

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0041] Please see Figure 1 As shown, preferably, in this embodiment, the size of the brine gap 41 near the high end is larger than the size of the brine gap 41 near the low end.

[0042] Large pieces of salt fall to the high end first, and the large amount of molten salt produced in the initial melting can be quickly discharged downward through the larger gap 41 at the high end. The salt block 3 slides along the grate to the low end and gradually shrinks in size. The smaller gap 41 at the low end can intercept small pieces of salt that have not been completely melted, allowing them to remain on the grate to be heated and melted, thus achieving graded melting of solid salt and preventing unmelted salt blocks 3 from falling into the bottom of the furnace and accumulating.

[0043] Specifically, in this embodiment, the size of the brine gap 41 gradually decreases along the direction from the high end to the low end. This setting matches the changing pattern of the brine gap 41 with the continuous decrease in volume of the salt block 3 during its sliding process; the lower the salt block 3 moves, the smaller the salt block 3 that can pass through, allowing the salt block 3 to remain on the grate plate continuously during the melting process from large to small, further enhancing the staged melting effect and fully melting the salt block 3.

[0044] In this embodiment, the brine gap 41 is gradually reduced from the high end to the low end. In order to keep the width of each grate bar 42 constant, the brine gap 41 is continuously reduced by gradually reducing the distance between adjacent grate bars 42.

[0045] In other embodiments, the spacing between the centers of adjacent grate bars 42 can be kept constant, and the gap 41 between the grate bars 42 can be gradually narrowed by gradually increasing the width of the grate bars 42 themselves.

[0046] Preferably, in this embodiment, the inclined grate 4 includes an outer frame, and inside the outer frame, a plurality of parallel grate bars 42 are arranged sequentially from the high end to the low end, and the gap between two adjacent grate bars 42 constitutes a brine gap 41.

[0047] The inclined grate plate 4 is composed of multiple parallel grate bars 42. A salt liquid gap 41 is formed between adjacent grate bars 42. The grate bars 42 can stably support the salt blocks 3 and at the same time realize the downward flow of molten salt liquid. It is also easy to install in the existing salt furnace and is convenient to disassemble and maintain.

[0048] Preferably, in this embodiment, both the grate bars 42 and the outer frame are made of stainless steel. This allows them to withstand the long-term corrosion of high-temperature molten salt, preventing rust and damage, extending the service life of the inclined grate 4, and ensuring the grate stably supports the salt blocks 3 for an extended period. In other embodiments, other materials resistant to molten salt corrosion may be used depending on actual usage requirements; no limitations are imposed here.

[0049] Preferably, in this embodiment, the horizontal projection dimension of the entire inclined grate plate 4 is a circle that fits the inner cavity of the salt furnace body 1. The cross-section of the grate bar 42 is rectangular. In other embodiments, the cross-section of the grate bar 42 may also adopt other shapes suitable for carrying the salt blocks 3, such as circular or elliptical shapes.

[0050] In other embodiments, the cross-section of the grate bar 42 can also be a trapezoidal cross-section that is wider at the top and narrower at the bottom. When a trapezoidal cross-section is used, the upper surface of the grate bar 42 is wider, which can increase the contact bearing area with the salt block 3; the lower side of the grate bar 42 is narrower, which can reduce the flow resistance when the molten salt flows downward, reduce the probability of salt adhering to the wall and crystallizing on the grate bar 42, and reduce the risk of the gaps in the grate bar 42 being blocked by salt crystals.

[0051] In this embodiment, the inclination angle, length, diameter or width, and spacing of the inclined grate plate 4 can be determined according to the furnace body dimensions. Preferably, the inclination angle of the inclined grate plate 4 relative to the horizontal plane is 30°. 60°, to ensure that the salt block 3 can slide smoothly from the high end to the low end by gravity, and to ensure that the salt block 3 has sufficient heating time on the inclined grate plate 4.

[0052] Preferably, in this embodiment, the angle of inclination of the inclined grate plate 4 relative to the horizontal plane is 30°. In other embodiments, it may also be 20°, 40°, 60°, etc.

[0053] Preferably, in this embodiment, such as Figure 1 As shown, the heating module includes an electric heater 5 arranged inside the salt melting furnace body 1 and located below the inclined grate 4. The electric heater 5 consists of multiple electric heating rods spaced apart in a horizontal direction. The electric heater 5 is located in the space below the grate, and on the one hand, it continuously heats the dripping salt solution to the working temperature, and on the other hand, it heats the air in the furnace cavity, providing a high-temperature environment for the salt blocks 3 on the grate, promoting the melting of the solid salt on the grate.

[0054] In this embodiment, the heating module also includes an electric heat tracing 6 surrounding the outer wall of the salt melting furnace body 1. The electric heat tracing 6 is an electric heating wire spirally wound from top to bottom around the outer wall of the salt melting furnace body 1. Adding the electric heat tracing 6 to the outer wall of the furnace body based on the electric heater 5 typically maintains a high-temperature environment throughout the furnace; together with the internal electric heater 5, it forms an internal and external combined heating system, resulting in a more stable and uniform temperature field within the furnace and accelerating the melting rate of solid salt.

[0055] Preferably, in this embodiment, such as Figure 1 As shown, the salt dissolving furnace body 1 is a vertical container, with the feeding port 2 located on the upper horizontal side of the furnace body 1, and the higher end located directly below the feeding port 2. This maximizes the travel path of solid salt on the inclined grate plate 4.

[0056] The working process of the salt melting furnace for staged melting of solid salt according to the present invention is as follows: Solid salt is fed into the salt furnace body 1 through the feeding port 2. The salt block 3 first falls on the high end of the inclined grate plate 4. Under the action of the electric heater 5 and the electric heat tracing 6, the surface of the salt block 3 gradually melts, and the resulting salt liquid flows downward through the salt liquid gap 41 between adjacent grate bars 42.

[0057] As the salt block 3 moves towards the lower end along the inclined grate plate 4 under the action of gravity, the size of the salt block 3 gradually decreases; the large molten salt that has not yet melted continues to be supported and heated by the inclined grate plate 4 until it melts or shrinks to a size that can pass through the gaps in the grate bars 42, thereby reducing the situation where large salt blocks are directly deposited at the bottom of the furnace.

[0058] During operation, a small amount of salt crystallization residue may adhere to the grate bar 42; since the grate plate is in a high-temperature environment inside the furnace, the adhered salt residue will be heated and melted again, reducing the probability of salt residue clogging the salt liquid gap 41.

[0059] In summary, this invention provides a solid salt melting furnace for staged melting. In existing furnaces, solid salt falls directly to the bottom, causing large chunks to compact and hindering heat transfer to the core of the salt blocks 3, easily resulting in large, unmeltable solid molten salt lumps. This invention utilizes inclined grate plates 4 with gradually changing salt liquid gaps 41. These plates support the salt blocks 3 within the furnace, preventing large chunks from sinking directly to the bottom. The salt blocks 3 slide and melt along the inclined grate plates 4, gradually dispersing into smaller pieces, facilitating continuous staged melting and accelerating the melting process. The salt liquid gaps 41 between the grate bars 42 allow molten salt to drain downwards promptly, ensuring the salt blocks 3 are fully heated, significantly improving heat exchange conditions and promoting rapid heating of the molten salt. Furthermore, the entire device is fixed with no moving parts, eliminating the need for motors and transmission mechanisms, preventing jamming and ensuring high reliability. Besides molten salt storage furnaces, this device can also be applied to other industrial furnaces requiring high-temperature melting of solid blocks.

[0060] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A salt melting furnace for staged melting of solid salt, characterized in that, It includes a salt-melting furnace body (1), an inclined grate plate (4), and a heating module; The upper end of the salt furnace body (1) is provided with a feeding port (2), the inclined grate plate (4) is provided on the inner wall of the salt furnace body (1), and the inclined grate plate (4) is arranged at intervals with the bottom of the salt furnace body (1). The inclined grate (4) has a high end facing the feeding port (2) and a low end facing away from the feeding port (2). Multiple salt solution gaps (41) are provided on the inclined grate (4) at intervals along its inclined direction. The heating module is used to heat the solid salt in the salt furnace body (1) to form a salt solution.

2. The salt-melting furnace for staged melting of solid salt according to claim 1, characterized in that, The size of the brine gap (41) near the higher end is larger than the size of the brine gap (41) near the lower end.

3. The salt-melting furnace for staged melting of solid salt according to claim 2, characterized in that, The inclined grate (4) includes multiple grate bars (42) arranged in parallel from the high end to the low end, and the gap between two adjacent grate bars (42) constitutes the brine gap (41).

4. The salt-melting furnace for staged melting of solid salt according to claim 3, characterized in that, Along the direction from the high end to the low end, the size of the salt solution gap (41) gradually decreases.

5. The salt melting furnace for staged melting of solid salt according to claim 3, characterized in that, The grate bars (42) are made of stainless steel.

6. The salt-melting furnace for staged melting of solid salt according to claim 1, characterized in that, The feeding port (2) is arranged on the horizontal side of the upper end of the salt furnace body (1), and the high end is located directly below the feeding port (2).

7. The salt melting furnace for staged melting of solid salt according to claim 1, characterized in that, The inclined grate (4) has an angle of 30° with respect to the horizontal plane. 60°.

8. The salt melting furnace for graded melting of solid salt according to claim 1, characterized in that, The heating module includes an electric heater (5) arranged inside the salt furnace body (1) and located below the inclined grate (4).

9. The salt-melting furnace for graded melting of solid salt according to claim 8, characterized in that, The heating module also includes an electric heat tracing (6) surrounding the outer wall of the salt furnace body (1).

10. The salt-melting furnace for staged melting of solid salt according to claim 1, characterized in that, The two ends of the inclined grate (4) are fixedly connected to the inner walls of the salt furnace body (1) through support connectors.

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