Large down draught calcining furnace

Abstract

The utility model discloses a kind of large lower fire opening calcining furnaces, including furnace body, screw feeder, calcining tank, bunker, gas pipeline and heating fire channel, furnace body is provided with calcining tank group, furnace body is provided with the bunker that can be by screw feeder to the material conveying of calcining tank group, heating fire channel is provided in furnace body and located at the both sides of calcining tank, gas pipeline provides combustible to heating fire channel, every one transverse arrangement of the fire channel in heating fire channel is respectively provided with fire channel section control component.The large lower fire opening calcining furnace, by mechanical adjustment the width of heating fire channel, when air flow is slow or air resistance is big, air supplement bottleneck appears, by adjusting the width of heating fire channel, make air supplement gas reach fire channel, break through air supplement bottleneck, solve a series of problems caused by insufficient air supplement amount in rear portion.

Description

Technical Field

[0001] This utility model relates to the field of tank calcining furnace technology, specifically the design of a lower fire port or heating fire channel for a tank calcining furnace. Background Technology

[0002] A pot-type calcining furnace consists of several identical calcining pots constructed of refractory materials and arranged vertically. Generally, four calcining pots form a group, and the number of groups can be set according to configuration and capacity requirements to meet production needs. Each calcining pot has heating flues on both sides, and the flue gas indirectly heats the material inside the pot. After calcination, the material is cooled by a cooling water jacket located at the bottom of the calcining furnace and then discharged by a discharge mechanism. During the heating process, the volatiles released from the raw materials are sent to the flues through the volatiles collection channel located at the top of the furnace and mixed with the combustion air for combustion, providing continuous heat to the furnace.

[0003] The 8-layer co-flow pot-type calcining furnace has the following structural features: the total furnace height is 7680cm (1020cm for the furnace bottom, 5440cm for the silica brick pot, and 1220cm for the furnace top), and the design height of each fire channel is 250×680mm. Since the cross-section of the fire channel is fixed, it is easy to cause a serious shortage of make-up air, incomplete combustion of volatiles in the fire channel, resulting in local high-temperature hot spots that burn through the wall and large fluctuations in furnace temperature that cannot be stabilized. Therefore, technical improvements have been made to the existing technology. Utility Model Content

[0004] The purpose of this invention is to provide a large-bottom-fired furnace to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: A large-bottom-fired calcining furnace includes a furnace body, a screw feeder, calcining tanks, a silo, a gas pipeline, and heating flues. The furnace body is equipped with a group of calcining tanks, and the furnace body is equipped with a silo that can convey materials into the calcining tank group via the screw feeder. Heating flues are located on both sides of the calcining tanks in the furnace body. The gas pipeline supplies combustibles into the heating flues. Each horizontally arranged heating flue is equipped with a flue cross-section control component. The fire channel section control component includes a section wall, a cylinder, and a guide rail component. The cylinder is installed inside the furnace body, and a movable section wall is installed inside the heating fire channel via the guide rail component. The section wall is fixed to the telescopic end of the cylinder, and the cylinder pushes the section wall to move on the guide rail component to control the cross-sectional width of the heating fire channel.

[0006] As a further embodiment of this utility model: the interior of the heating flue is divided into a flue gas chamber and a positive pressure chamber by a cross-sectional wall. The flue gas chamber is used for flue gas to flow and heat the calcining tank. The positive pressure chamber is connected to a positive pressure pipeline. The positive pressure pipeline is connected to an air pump through a main pipeline. The air pump delivers gas to the positive pressure chamber through the main pipeline and the positive pressure pipeline to maintain positive pressure in the chamber.

[0007] As a further improvement of this utility model: an air valve is provided on the positive pressure pipeline, and the air valve controls the air flow rate entering the positive pressure chamber by adjusting the opening degree.

[0008] As a further improvement of this utility model: the furnace body is provided with a guide rail mounting platform located inside the heating fire channel. The top and bottom of the guide rail mounting platform are respectively installed with the cross-sectional wall through guide rail components to control the movement trajectory and stability of the cross-sectional wall.

[0009] As a further improvement of this utility model: the cylinder barrel extends to the outside of the furnace body for heat dissipation, and two symmetrically distributed cylinders are configured on each cross-section wall. These two cylinders form a group, and the two cylinders in this group operate synchronously.

[0010] As a further embodiment of this utility model: the heating flue is divided into a transverse flue and a longitudinal flue. The transverse flues are arranged horizontally and are separated from each other by partition walls. The partition walls have longitudinal flues that connect the first and second ends of the transverse flues to form an S-shaped flue gas flow path. The cross-sectional wall extends to the opening of the longitudinal flue. When the cross-sectional wall is moved to adjust the width of the flue cross-section, it will also affect the width of the flue gas cross-section of the longitudinal flue.

[0011] As a further improvement of this utility model, the bottom of the calcining tank is also equipped with a cooling water jacket, a discharge machine and a vibrating conveyor. The material is cooled by the cooling water jacket, enters the discharge machine and is discharged from the vibrating conveyor.

[0012] Compared with the prior art, the beneficial effects of this utility model are: This large-bottom-fire-gate calcining furnace uses mechanical adjustment of the width of the heating flue to address the bottleneck in air supply when there is high resistance or slow air flow. By adjusting the width of the heating flue, the supply gas can reach the flue, overcoming the bottleneck and solving a series of problems caused by insufficient supply air in the downstream section. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the calcining tank structure of a large-bottom-fire-mouth calcining furnace; Figure 2 This is a schematic diagram of the heating flue in a large-bottom-fire-mouth calcining furnace. Figure 3 An exploded view of the structure of a fire channel section control component in a large lower fire port calciner; Figure 4 This is a top view of the structure of a fire channel section control component in a large lower firebox calcining furnace.

[0014] In the diagram: 1. Furnace body; 2. Screw feeder; 3. Calcining tank; 4. Silo; 5. Cooling water jacket; 6. Discharge machine; 7. Vibrating conveyor; 8. Air pump; 9. Gas pipeline; 10. Heating flue; 11. Flue; 12. Partition wall; 13. Main pipeline; 14. Positive pressure pipeline; 15. Section wall; 16. Guide rail components; 17. Longitudinal flue; 18. Cylinder; 19. Cylinder bracket; 20. Guide rail mounting platform. Detailed Implementation

[0015] Please see Figures 1-4 In this embodiment of the utility model, a large-bottom-fire-mouth calcining furnace includes a furnace body 1, a screw feeder 2, a calcining tank 3, a silo 4, a gas pipeline 9, and a heating flue 10. The end of the heating flue 10 is connected to a flue 11. The furnace body 1 is provided with a group of calcining tanks 3. The furnace body 1 is provided with a silo 4 that can convey materials into the group of calcining tanks 3 through the screw feeder 2. The furnace body 1 is provided with heating flues 10 located on both sides of the calcining tanks 3. The gas pipeline 9 provides combustibles into the heating flues 10. Each horizontally arranged flue of the heating flue 10 is provided with a flue section control component. The fire channel cross-section control component includes a cross-section wall 15, a cylinder 18, and a guide rail component 16. The cylinder 18 is installed inside the furnace body 1. The movable cross-section wall 15 is installed inside the heating fire channel 10 via the guide rail component 16. The cross-section wall 15 is fixed to the telescopic end of the cylinder 18. The cylinder 18 pushes the cross-section wall 15 to move on the guide rail component 16 to control the cross-sectional width of the heating fire channel 10. The cylinder 18 moves the cross-section wall 15 by telescopic movement. When the cylinder 18 extends, it pushes the cross-section wall 15 towards the calcining tank 3, compressing the cross-sectional width of the fire channel. When the cylinder 18 retracts, it pulls the cross-section wall 15 towards the cylinder 18, expanding the cross-sectional width of the fire channel. By adjusting the cross-sectional width of the fire channel opening, the following problems can be solved. Excessively large flues can lead to slow airflow and reduced turbulence. In this case, the mixing of air and volatiles is mainly laminar diffusion, which can easily result in localized areas of oxygen deficiency and volatile enrichment or areas of superoxygenated air enrichment. This reduces the uniformity of air supply. When the flue is too long or too wide, the air pressure loss along the way is uneven, with higher pressure near the air supply port and lower pressure at the far end. This results in significant differences in the amount of air supplied in different areas of the flue and a sharp increase in air supply resistance. At the same time, after volatiles escape from the calcining tank, they diffuse rapidly, reducing their concentration. Furthermore, they do not mix sufficiently with the low-speed air, causing some volatiles to be discharged with the flue gas without combustion, resulting in incomplete combustion. The heat released by the combustion of volatiles is diluted by the excessive space, the average temperature in the fire channel decreases, and it cannot meet the high temperature requirements of the calcining tank, so additional fuel needs to be consumed. If the fire channel is too small, volatiles will accumulate in the confined space, and the concentration may exceed the explosion limit, such as 5%-15% methane volume fraction. This can easily cause localized and violent combustion, a sudden rise in local temperature in the fire channel, and overheating and burning of the silica brick lining. The combustion is intense but prone to localized overheating, increasing the risk of coking and many other risks.

[0016] This application addresses the bottleneck in air supply caused by mechanically adjusting the width of the heating channel. When the air supply resistance is high or the air flow is slow, the air supply can reach the channel by adjusting the width of the heating channel, thus overcoming the bottleneck and solving a series of problems caused by insufficient air supply in the later part.

[0017] In a preferred embodiment, the heating flue 10 is divided into a flue gas chamber and a positive pressure chamber by a cross-sectional wall 15. The flue gas chamber is used for flue gas to flow and heat the calcining tank 3. The positive pressure chamber is connected to a positive pressure pipeline 14, which is connected to an air pump 8 via a main pipeline 13. The air pump 8 supplies gas to the positive pressure chamber through the main pipeline 13 and the positive pressure pipeline 14 to maintain positive pressure inside the chamber. During the process of adjusting the air supply to the flue by moving the cross-sectional wall 15, the air pressure inside the flue gas chamber is higher than the ambient air pressure, making it easy for flue gas to enter the positive pressure chamber or leak out. By using the air pump 8 to introduce gas with a pressure higher than that inside the flue gas chamber into the positive pressure chamber, it is possible not only to prevent flue gas from entering the positive pressure chamber and reduce the temperature inside the positive pressure chamber, but also to supplement oxygen into the heating flue and improve combustion efficiency.

[0018] In a preferred embodiment, a gas valve is installed on the positive pressure pipeline 14. The gas valve controls the gas flow rate entering the positive pressure chamber by adjusting the opening degree. The heating flue 10 is divided into a transverse flue and a longitudinal flue 17. The transverse flues are arranged horizontally and are separated from each other by a partition wall 12. The partition wall 12 has a longitudinal flue 17. The longitudinal flue 17 connects the first and second ends of the transverse flues in series to form an S-shaped flue gas flow path. The cross-sectional wall 15 extends to the opening of the longitudinal flue 17. When the cross-sectional wall 15 moves to adjust the flue cross-sectional width, it will also affect the flue gas flue cross-sectional width of the longitudinal flue 17. By controlling the multiple transverse flues separately, each transverse flue can be adjusted individually. The flue cross-sectional width is controlled according to the specific combustion conditions and the temperature distribution inside the furnace.

[0019] In a preferred embodiment, the furnace body 1 is provided with a guide rail mounting platform 20 located inside the heating flue 10. The top and bottom of the guide rail mounting platform 20 are respectively mounted to the cross-sectional wall 15 via guide rail components 16 to control the movement trajectory and stability of the cross-sectional wall 15. The outer side of the cross-sectional wall 15 is made of refractory bricks. Due to its increased weight, the bottom and sides of the cross-sectional wall 15 will generate a certain amount of friction with the heating flue 10. In order to reduce the wear of the heating flue 10 and the interior of the cross-sectional wall 15, guide rail components 16 are provided for support.

[0020] In a preferred embodiment, the cylinder barrel of the cylinder 18 extends to the outside of the furnace body 1 for heat dissipation. A cylinder bracket 19 is installed on the outside of the furnace body 1. The part of the cylinder 18 extending out of the furnace body 1 is installed on the cylinder bracket 19. Two symmetrically distributed cylinders 18 are configured on each cross-sectional wall 15. These two cylinders 18 form a group. The two cylinders 18 in this group work synchronously to ensure the uniformity of force during the driving process.

[0021] In a preferred embodiment, the bottom of the calcining tank 3 is also equipped with a cooling water jacket 5, a discharge machine 6 and a vibrating conveyor 7. The material is cooled by the cooling water jacket 5, enters the discharge machine 6 and is discharged from the vibrating conveyor 7.

[0022] It should be noted that all the above embodiments belong to the same utility model concept, and the descriptions of each embodiment have different focuses. Where the description in a particular embodiment is not detailed, please refer to the description in other embodiments.

[0023] The embodiments described above merely illustrate the implementation of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A large-bottom-fired calcining furnace, comprising a furnace body (1), a screw feeder (2), calcining tanks (3), a silo (4), a gas pipeline (9), and heating channels (10), wherein a group of calcining tanks (3) is provided inside the furnace body (1), a silo (4) is provided on the furnace body (1) for conveying materials to the group of calcining tanks (3) via the screw feeder (2), and heating channels (10) are provided on both sides of the calcining tanks (3) inside the furnace body (1), and the gas pipeline (9) provides combustible material to the heating channels (10), characterized in that, Each of the horizontally arranged heating fire channels (10) is equipped with a fire channel cross-section control component. The fire channel section control component includes a section wall (15), a cylinder (18), and a guide rail component (16). The cylinder (18) is installed inside the furnace body (1). The movable section wall (15) is installed inside the heating fire channel (10) via the guide rail component (16). The section wall (15) is fixed to the telescopic end of the cylinder (18). The cylinder (18) pushes the section wall (15) to move on the guide rail component (16) to control the cross-sectional width of the heating fire channel (10).

2. The large lower firehead calcining furnace according to claim 1, characterized in that, The heating flue (10) is divided into a flue gas chamber and a positive pressure chamber by a cross-sectional wall (15). The flue gas chamber is used for flue gas to flow and heat the calcining tank (3). The positive pressure chamber is connected to a positive pressure pipeline (14). The positive pressure pipeline (14) is connected to a gas pump (8) through a main pipeline (13). The gas pump (8) delivers gas to the positive pressure chamber through the main pipeline (13) and the positive pressure pipeline (14) to maintain positive pressure in the chamber.

3. A large-bottom-fire-mouth calcining furnace according to claim 2, characterized in that, A gas valve is installed on the positive pressure pipeline (14), and the gas valve controls the flow rate of gas entering the positive pressure chamber by adjusting the opening degree.

4. The large lower firehead calcining furnace according to claim 1, characterized in that, The furnace body (1) is provided with a guide rail mounting platform (20) located inside the heating fire channel (10). The top and bottom of the guide rail mounting platform (20) are respectively installed with the cross-sectional wall (15) through guide rail components (16) to control the movement trajectory and stability of the cross-sectional wall (15).

5. A large-bottom-fire-mouth calcining furnace according to claim 1, characterized in that, The cylinder (18) extends to the outside of the furnace body (1) for heat dissipation. Each cross-section wall (15) is equipped with two symmetrically distributed cylinders (18). These two cylinders (18) form a group, and the two cylinders (18) in this group work synchronously.

6. A large-bottom-fire-mouth calcining furnace according to claim 1, characterized in that, The heating flue (10) is divided into a transverse flue and a longitudinal flue (17). The transverse flues are arranged horizontally and are separated from each other by a partition wall (12). The partition wall (12) has a longitudinal flue (17). The longitudinal flue (17) connects the first and second ends of the transverse flues to form an S-shaped flue gas flow path. The cross-sectional wall (15) extends to the opening of the longitudinal flue (17). When the cross-sectional wall (15) moves to adjust the width of the flue cross-section, it will also affect the width of the flue gas flue cross-section of the longitudinal flue (17).

7. A large-bottom-fire-mouth calcining furnace according to any one of claims 1-6, characterized in that, The bottom of the calcining tank (3) is also equipped with a cooling water jacket (5), a discharge machine (6) and a vibrating conveyor (7). The material is cooled by the cooling water jacket (5) and enters the discharge machine (6) and is sent out by the vibrating conveyor (7).

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