A pellet drying bed

Abstract

This application provides a pellet drying bed, relating to the field of pellet drying technology; it includes an upper drying bed and a lower drying bed arranged from top to bottom in a vertical furnace. The upper drying bed is inclined in an inverted "V" shape, and the lower drying bed is inclined downwards from the outside to the inside, forming a feeding port in the middle of the lower drying bed. The feeding end of the upper drying bed is located above the feeding end of the lower drying bed. A material conveyor belt is provided at the top of the upper drying bed, and the feeding end of the material conveyor belt extends to the outside of the vertical furnace. A hot gas diversion drying wall is provided inside the vertical furnace, penetrating the feeding port. An in-furnace air guide wall is provided below the hot gas diversion drying wall, and guide plates are symmetrically provided at the lower part of the hot gas diversion drying wall. Compared with the prior art, this utility model changes the lower drying bed to be inclined downwards from the outside to the inside, and through the guide plates, in conjunction with the hot gas diversion drying wall and the in-furnace air guide wall, the hot gas is reasonably distributed to the upper and lower drying beds, ensuring that each layer of green pellets can obtain sufficient heat and improving the drying effect.

Description

Technical Field

[0001] This application relates to the field of pellet drying technology, and more specifically, to a pellet drying bed. Background Technology

[0002] In the production process of pellets, iron concentrate powder is mixed with water and then made into green pellets in a pelletizing machine. The green pellets are dried to remove moisture, then roasted at high temperature to solidify and strengthen them, and finally cooled and screened to obtain qualified products.

[0003] Among them, drying of pellets is carried out using a drying bed. Patent publication number CN201621942U discloses a diversion-type double-layer drying bed, including an upper drying bed, a lower drying bed, and a hot air diversion drying wall. The upper and lower drying beds are inclined in a ridge shape, and the hot air diversion drying wall is located at the top of the ridge of the lower drying bed. The material conveyor belt is located directly above the upper drying bed. Directly below the hot air diversion drying wall is the furnace air guide wall. The entire device is dust collected from the top of the furnace. The device encloses the drying bed within a hood. The upper and lower drying beds are assembled from heat-resistant grates, connecting ribs, and cooling water beams, respectively. The hot gas diversion drying wall is constructed of refractory bricks. This device employs a double-layer drying bed setup, overcoming the drawbacks of traditional drying beds such as small drying area and low efficiency. It also solves the problems of excessively long drying zones and material segregation in the "new type of vertical furnace drying bed" (patent number 00267276.6). By utilizing the weight of the green pellets for material distribution and drying, the drying efficiency of the green pellets in the vertical furnace can be significantly improved.

[0004] However, while the double-layer drying bed design solves the problems of excessively long drying zones and material segregation, when the green balls flow longitudinally from the upper drying bed to the lower drying bed, they only fall into the area from the lower end of the lower drying bed to the lower end of the upper drying bed. The top of the ridge of the lower drying bed is connected to the hot air diversion drying wall. In the lower drying bed section from the lower end of the upper drying bed to the top of the ridge of the lower drying bed, there will be a "void" where the material layer is too thin (a small number of green balls fall from the gaps in the heat-resistant grate of the upper drying bed) or even no material. The hot air coming out of the guide wall in the furnace directly passes through the "void" of the lower drying bed and mixes with the hot air coming out of the outlet of the hot air diversion drying wall, affecting the hot air flow diversion and thus affecting the drying effect of the material layer in the lower drying bed. Summary of the Invention

[0005] The purpose of this application is to provide a pellet drying bed that can solve the technical problems mentioned in the background art.

[0006] This application provides a pellet drying bed, including an upper drying bed and a lower drying bed arranged from top to bottom in a vertical furnace. The upper drying bed is inclined in an inverted "V" shape, and the lower drying bed is inclined downward from the outside to the inside, forming a discharge port in the middle of the lower drying bed. The discharge end of the upper drying bed is located above the feed end of the lower drying bed. A material conveyor belt is provided at the top of the upper drying bed, and the feed end of the material conveyor belt extends to the outside of the vertical furnace. A hot gas diversion drying wall is provided inside the vertical furnace, penetrating the discharge port. An in-furnace air guide wall is provided below the hot gas diversion drying wall, and guide plates are symmetrically provided at the lower part of the hot gas diversion drying wall.

[0007] Furthermore, the lower air inlet of the hot gas diversion drying wall is smaller than the air outlet of the furnace guide wall, the cross-section of the guide plate is triangular, and the coverage area of ​​the guide plate is larger than the air outlet range of the furnace guide wall.

[0008] Furthermore, the airflow channel of the hot gas diversion drying wall is T-shaped, and diversion plates are fixed at the two air outlets of the hot gas diversion drying wall. The diversion plates are used to divert part of the airflow flowing out of the air outlets of the hot gas diversion drying wall and direct it to the lower drying bed.

[0009] Furthermore, the cross-section of the diverter plate is a right-angled triangle, and the inclined side is arranged downwards from the inside out.

[0010] Furthermore, both the upper drying bed and the lower drying bed include heat-resistant grates, support frames, and cooling water beams. Multiple heat-resistant grates are fixed in a stepped manner on the support frame, and multiple cooling water beams are fixed at the bottom of the support frame. The inlet and outlet ends of the cooling water beams extend outside the vertical furnace.

[0011] Furthermore, the hot gas diversion drying wall is made of refractory bricks, and the surfaces of the hot gas diversion drying wall, the diversion plate, the guide plate, and the heat-resistant grate are all coated with a wear-resistant layer.

[0012] Furthermore, the vertical furnace is provided with a material-pumping window on its side wall, which is located between the upper drying bed and the lower drying bed, and the material-pumping window is provided with a suitable sealing door.

[0013] The beneficial effects of this utility model are:

[0014] Compared with the prior art, this utility model changes the lower drying bed to be inclined downward from the outside to the inside, and symmetrical guide plates are provided at the lower part of the hot air diversion drying wall. In conjunction with the hot air diversion drying wall and the air guide wall in the furnace, the hot air is reasonably distributed to the upper and lower drying beds, ensuring that each layer of green pellets can obtain sufficient heat and improve the drying effect. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 These are schematic diagrams of structures in some embodiments of this application;

[0017] Figure 2 This is a schematic diagram of the upper drying bed in some embodiments of this application;

[0018] The reference numerals in the attached figures are as follows:

[0019] 1. Vertical shaft furnace; 2. Upper drying bed; 21. Heat-resistant grate; 22. Support frame; 23. Cooling water beam; 3. Lower drying bed; 4. Material conveyor belt; 5. Hot air diversion drying wall; 6. Furnace air guide wall; 7. Guide plate; 8. Diversion plate; 9. Material chute; 10. Sealing door. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the description of this application, 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, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application 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 on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0024] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" 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 application based on the specific circumstances. Specific implementation examples:

[0027] like Figure 1 As shown, this application provides a pellet drying bed, including an upper drying bed 2 and a lower drying bed 3 arranged from top to bottom inside a vertical furnace 1. The upper drying bed 2 is inclined in an inverted "V" shape, and the lower drying bed 3 is inclined downward from the outside to the inside, with a discharge port formed in the middle of the lower drying bed 3. The discharge end of the upper drying bed 2 is located above the feed end of the lower drying bed 3. A material conveyor belt 4 is provided at the top of the upper drying bed 2, and the feed end of the material conveyor belt 4 extends to the outside of the vertical furnace 1. A through-type lower drying bed is provided inside the vertical furnace 1. The hot air diversion drying wall 5 at the feed inlet is equipped with an in-furnace air guide wall 6 below it, and guide plates 7 are symmetrically arranged at the lower part of the hot air diversion drying wall 5. Compared with the prior art, the lower drying bed 3 is modified to be inclined downward from the outside to the inside, and guide plates 7 are symmetrically arranged at the lower part of the hot air diversion drying wall 5. In conjunction with the hot air diversion drying wall 5 and the in-furnace air guide wall 6, the hot air is reasonably distributed to the upper drying bed 2 and the lower drying bed 3, ensuring that each layer of green pellets can obtain sufficient heat and improve the drying effect.

[0028] like Figure 1As shown, the lower air inlet of the hot gas diversion drying wall 5 is smaller than the air outlet of the furnace guide wall 6. The cross-section of the guide plate 7 is triangular, and the coverage area of ​​the guide plate 7 is larger than the air outlet range of the furnace guide wall 6. The hot air output from the furnace guide wall 6 first enters the coverage area of ​​the triangular guide plate 7. The triangular cross-section of the guide plate 7 diverts the hot air, guiding a part of the hot air to diffuse smoothly to both sides, while the other part of the hot air enters the hot gas diversion drying wall 5 and then flows out from the upper air outlet of the hot gas diversion drying wall 5, thus realizing the reasonable distribution of hot air between the upper and lower drying beds 3.

[0029] like Figure 1 As shown, the airflow channel of the hot gas diversion drying wall 5 is T-shaped. Diverter plates 8 are fixed at the two air outlets of the hot gas diversion drying wall 5. The diverter plates 8 are used to divert part of the airflow from the air outlets of the hot gas diversion drying wall 5 and let it flow to the lower drying bed 3. After the hot gas enters the T-shaped airflow channel of the hot gas diversion drying wall 5 through the furnace guide wall 6, the main airflow flows upward along the channel. When it reaches the two air outlets of the hot gas diversion drying wall, part of the airflow changes direction under the obstruction and guidance of the diverter plates 8 and flows downward to the lower drying bed 3. The remaining airflow continues to flow upward into the upper drying bed 2, thereby realizing the distribution of hot gas between the upper and lower drying beds 3. The airflow that flows downward to the lower drying bed 3 and the airflow that is guided upward from the lower drying bed 3 by the guide plates 7 work together to act on the green balls on the lower drying bed 3, improving the efficiency of hot gas utilization and further improving the drying effect.

[0030] like Figure 1 As shown, the cross-section of the diverter 8 is a right-angled triangle, and the inclined side is set downward from the inside out. The inclined surface design of the right-angled triangle diverter 8 can efficiently guide the airflow to change direction by utilizing the airflow impact angle, thereby reducing energy loss during the diversion process.

[0031] like Figure 1 and Figure 2 As shown, both the upper drying bed 2 and the lower drying bed 3 include heat-resistant grate plates 21, support frames 22, and cooling water beams 23. Multiple heat-resistant grate plates 21 are fixed in a stepped manner on the support frame 22, and multiple cooling water beams 23 are fixed at the bottom of the support frame 22. The inlet and outlet ends of the cooling water beams 23 extend outside the vertical furnace 1. In the upper drying bed 2 and the lower drying bed 3, multiple heat-resistant grate plates 21 fixed in a stepped manner on the support frame 22 form a bearing surface for placing green balls. The green balls move gradually on the stepped structure with the help of gravity, and in the process, they come into full contact with the hot air penetrating the grate plates to achieve drying. The support frame 22 provides stable support for the heat-resistant grate plates 21. Multiple cooling water beams 23 fixed at the bottom of the support frame 22 are connected to an external circulating cooling system through the inlet and outlet ends extending outside the vertical furnace 1 to continuously remove heat and appropriately regulate the temperature inside the vertical furnace 1.

[0032] like Figure 1As shown, the hot gas diversion drying wall 5 is made of refractory bricks. The surfaces of the hot gas diversion drying wall 5, the diversion plate 8, the guide plate 7, and the heat-resistant grate 21 are all coated with a wear-resistant layer (not shown in the figure). Specifically, the wear-resistant layer is a 0.5mm thick ceramic wear-resistant layer. The ceramic wear-resistant layer can significantly improve the wear resistance and erosion resistance of the surfaces of each component and extend their service life.

[0033] like Figure 1 As shown, a material-pumping window 9 is provided on the side wall of the vertical furnace 1. The material-pumping window 9 is located between the upper drying bed 2 and the lower drying bed 3. The material-pumping window 9 is equipped with a suitable sealing door 10. When green balls accumulate or become blocked between the upper drying bed 2 and the lower drying bed 3, the operator can open the sealing door 10 of the material-pumping window 9 and insert a tool through the material-pumping window 9 to clear the blocked material.

[0034] Working principle:

[0035] After the vertical shaft furnace 1 is started, the green balls are conveyed to the top of the upper drying bed 2 via the material conveyor belt 4. Then, under the action of gravity, they slide down the upper drying bed 2, which is inclined in an inverted "V" shape. Inside the vertical shaft furnace 1, the high-temperature hot air is guided by the furnace guide wall 6. Some of the hot air rises to the bottom of the lower drying bed 3. Some of this hot air directly passes through the lower drying bed 3 to dry the green balls on the lower drying bed 3. The other part is guided upward by the hot air diversion drying wall 5 to dry the green balls on the upper drying bed 2. The guide plates 7 symmetrically arranged at the bottom of the hot air diversion drying wall 5 can guide and adjust the flow of hot air, so that the hot air is reasonably distributed to the upper drying bed 2 and the lower drying bed 3, ensuring that each layer of green balls can obtain sufficient heat and improve the drying effect. After the green balls are dried, they fall into the roasting zone of the vertical shaft furnace 1 for high-temperature reaction.

[0036] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A pellet drying bed, characterized in that: The furnace includes an upper drying bed and a lower drying bed arranged from top to bottom within the vertical furnace. The upper drying bed is inclined in an inverted "V" shape. The lower drying bed is inclined downwards from the outside to the inside and forms a discharge port in the middle of the lower drying bed. The discharge end of the upper drying bed is located above the feed end of the lower drying bed. A material conveyor belt is provided at the top of the upper drying bed, and the feed end of the material conveyor belt extends to the outside of the vertical furnace. A hot gas diversion drying wall is provided inside the vertical furnace, penetrating the discharge port. An in-furnace air guide wall is provided below the hot gas diversion drying wall, and guide plates are symmetrically provided at the lower part of the hot gas diversion drying wall.

2. The pellet drying bed according to claim 1, characterized in that: The lower air inlet of the hot gas diversion drying wall is smaller than the air outlet of the furnace guide wall. The cross-section of the guide plate is triangular, and the coverage area of ​​the guide plate is larger than the air outlet range of the furnace guide wall.

3. The pellet drying bed according to claim 1, characterized in that: The airflow channel of the hot gas diversion drying wall is T-shaped, and diversion plates are fixed at the two air outlets of the hot gas diversion drying wall. The diversion plates are used to divert part of the airflow from the air outlets of the hot gas diversion drying wall to the lower drying bed.

4. The pellet drying bed according to claim 3, characterized in that: The cross-section of the diverter plate is a right-angled triangle, and the inclined side is set downwards from the inside out.

5. A pellet drying bed according to claim 4, characterized in that: Both the upper drying bed and the lower drying bed include heat-resistant grates, support frames, and cooling water beams. Multiple heat-resistant grates are fixed in a stepped manner on the support frame, and multiple cooling water beams are fixed at the bottom of the support frame. The inlet and outlet ends of the cooling water beams extend outside the vertical furnace.

6. A pellet drying bed according to claim 5, characterized in that: The hot gas diversion drying wall is made of refractory bricks, and the surfaces of the hot gas diversion drying wall, the diversion plate, the guide plate, and the heat-resistant grate are all coated with a wear-resistant layer.

7. A pellet drying bed according to claim 1, characterized in that: The vertical furnace has a material-feeding window on its side wall, which is located between the upper drying bed and the lower drying bed. The material-feeding window is equipped with a suitable sealing door.

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