Coal powder interconnection and intercommunication conveying device of coal injection system

Abstract

The utility model relates to a kind of pulverized coal interconnected transport device of coal injection system, including injection tank, powder collector, mill, main exhaust fan and pulverized coal bin;The mill is connected in one side of powder collector;The main exhaust fan is connected in the other side of powder collector;The pulverized coal bin is connected below powder collector;Injection tank output side is connected to blast furnace tuyere by coal injection main pipeline on one side;Coal injection valve I and coal injection valve II are sequentially arranged on the coal injection main pipeline;The coal injection main pipeline between coal injection valve I and coal injection valve II is connected to the inlet of powder collector by a branch pipeline.The utility model can realize the interconnection of pulverized coal conveying between different blast furnace coal injection systems, and the lack of production capacity is supplemented by the surplus, to realize the production capacity complementation between each coal injection system, production and maintenance without conflict, without affecting the normal pulverized coal injection of blast furnace.At the same time, the drawbacks of conveying pulverized coal into pulverized coal bin are avoided, so that the service life of the improved equipment is extended, and the normal operation of the original coal injection system is not affected.

Description

Technical Field

[0001] This utility model relates to the field of iron coke calcination technology, and in particular to a coal powder interconnection and conveying device for a pulverized coal injection system. Background Technology

[0002] Blast furnace pulverized coal injection (PPO) technology typically involves one PPO system per blast furnace, or several blast furnaces sharing a single system. This solution is applicable to establishing connections between unrelated blast furnace PPO systems. Changes in production conditions, such as mill maintenance or equipment aging, can lead to capacity shortages or shutdowns between multiple blast furnace PPO systems, while some mills may have excess capacity even during normal operation. Before system connectivity is achieved, the usual solutions are to reduce the PPO injection rate or simply shut down the blast furnace.

[0003] Patent CN106987666A discloses a technical solution for interconnecting pulverized coal silos with other systems via a return pipe of a jet-blown system. However, this connection method has the following drawbacks: ① A pulverized coal silo without a top dust collector is a relatively closed container. If a large amount of pulverized coal carrying carrier gas is injected, it will create positive pressure inside the silo, causing a large amount of pulverized coal to overflow at the pulverized coal screen, polluting the environment. ② If pulverized coal is injected into a pulverized coal silo equipped with a top dust collector, the high conveying pressure and large air volume will cause severe erosion of the top dust collector and the inner wall of the silo, reducing the service life of the pulverized coal silo. ③ The impact force after the pulverized coal is injected into the silo will cause vibration, affecting the weighing value of the silo. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this utility model is to provide a coal powder interconnection and conveying device for a pulverized coal injection system, which effectively avoids the drawbacks of conveying coal powder into the coal powder silo, extends the service life of the improved equipment, and does not affect the normal operation of the original pulverized coal injection system.

[0005] The technical solution adopted in this utility model is as follows:

[0006] The present invention discloses a coal powder interconnection and conveying device for a pulverized coal injection system, comprising a pulverized coal injection tank, a coal collector, a mill, a main exhaust fan, and a coal pulverizer; the mill is connected to one side of the coal collector; the main exhaust fan is connected to the other side of the coal collector; the coal pulverizer is connected below the coal collector; characterized in that: one side of the output end of the pulverized coal injection tank is connected to the blast furnace tuyeres via a main pulverized coal injection pipeline; a pulverized coal injection valve I and a pulverized coal injection valve II are sequentially arranged on the main pulverized coal injection pipeline; a branch pipeline connects the main pulverized coal injection pipeline between the pulverized coal injection valve I and the pulverized coal injection valve II to the inlet of the coal collector.

[0007] Furthermore, a coal feeding valve is installed on the side of the branch pipeline near the main coal injection pipeline, and a check valve is installed on the side near the inlet of the coal collector.

[0008] Furthermore, wear-resistant bends with a radius of curvature >20D are used at the bends of the main pulverized coal injection pipeline and branch pipelines.

[0009] Furthermore, the powder collector is a cloth bag powder collector.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] 1. After the coal powder is interconnected between the various systems, when the mill is under maintenance, other systems with surplus coal powder can be used to supplement it, avoiding the reduction or shutdown of the mill due to insufficient coal powder supply, which would increase the cost of blast furnace smelting and has certain economic benefits.

[0012] 2. If a blast furnace is shut down for maintenance, there will be residual pulverized coal in the pulverized coal bin or injection tank of the pulverized coal injection system. The pulverized coal should not be stored in the bin for more than 8 hours. Once the time limit is exceeded, there will be a risk of spontaneous combustion and explosion. The residual pulverized coal can be transported to other pulverized coal injection systems by connecting them to each other to ensure safety.

[0013] 3. Direct feeding of pulverized coal into the baghouse dust collector avoids wear on the inner wall of the equipment, extends the service life of the equipment, and reduces production costs.

[0014] 4. Utilize the price difference between peak, off-peak, and flat electricity to rationally schedule mill start-up and shutdown times, thereby saving electricity costs. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0016] In the attached drawings, the following labels are used: 1-Pulverizing tank; 2-Pulverizer; 3-Mill; 4-Main exhaust fan; 5-Pulverized coal silo; 6-Main pulverized coal injection pipeline; 7-Pulverized coal injection valve I; 8-Pulverized coal injection valve II; 9-Branch pipeline; 10-Coal feeding valve; 11-Check valve. Detailed Implementation

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] It should be noted that in the description of this utility model, the terms "upper", "lower", "top", "bottom", "one side", "the other side", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not mean that the device or component must have a specific orientation, or be constructed and operated in a specific orientation.

[0019] See appendix Figure 1 The present invention proposes a coal powder interconnection and conveying device for a pulverized coal injection system, comprising a pulverized coal injection tank 1, a coal collector 2, a mill 3, a main exhaust fan 4, and a coal pulverizer 5; wherein, the coal collector is a baghouse coal collector; the mill 3 is connected to the inlet side of the coal collector 2; the main exhaust fan 4 is connected to the outlet side of the coal collector 2; and the coal pulverizer 5 is connected below the coal collector 2.

[0020] One side of the output end of the injection tank 1 is connected to the blast furnace tuyeres via a main pulverized coal injection pipeline 6; a pulverized coal injection valve I7 and a pulverized coal injection valve II8 are sequentially installed on the main pulverized coal injection pipeline 6; the section of the main pulverized coal injection pipeline 6 between the pulverized coal injection valve I7 and the pulverized coal injection valve II8 is connected to the inlet of the coal collector 2 via a branch pipeline 9. The bends in both the main pulverized coal injection pipeline 6 and the branch pipeline 9 are made of wear-resistant bends with a radius of curvature >20D.

[0021] Among them, a coal feeding valve 10 is installed on the side of the branch pipe 9 near the main coal injection pipe 6, and a check valve 11 is installed on the side of the branch pipe 9 near the inlet of the dust collector 2. The check valve 11 should be as close as possible to the inlet pipe of the bag dust collector 2 to prevent coal dust from entering the coal conveying pipe and caking and blocking the pipe.

[0022] By connecting all adjacent pulverized coal injection systems in the same way, the mutual transport of pulverized coal between systems can be achieved.

[0023] If there is a shortage of pulverized coal in the pulverized coal silo 5, the pulverized coal can be transported to the pulverizer 2 using the injection canister 1: the pulverized coal injection valve I7 is opened, the pulverized coal injection valve II8 is closed, the injection canister 1 is filled with pulverized coal, the injection canister 1 is pressurized to 0.25-0.3 MPa, the main exhaust fan 4 is started, and the coal feeding valve 10 is opened. The pulverized coal can then be transported to the pulverized coal silo 5 by the pulverizer 2.

[0024] The pulverized coal in injection tank 1 needs to be fluidized using its existing bottom and side fluidization systems, and then transported out via secondary air supply. The secondary air supply flow rate is controlled at 300–400 m³ / h. 3 The amount of pulverized coal loaded into injection tank 1 can be calculated based on the injection cycle of another injection tank that normally injects pulverized coal into the blast furnace.

[0025] This invention can be implemented when one pulverized coal injection system is short of pulverized coal while another has a surplus. It is applicable to pulverized coal injection systems with two or three injection tanks corresponding to one blast furnace. One injection tank supplies pulverized coal to the blast furnace normally, while the other injection tanks utilize the time intervals between tank rotations to supply pulverized coal to other systems. When one pulverized coal injection system is shut down or the blast furnace is undergoing maintenance, the surplus pulverized coal from that system can be transferred to other systems. Furthermore, this scheme can effectively utilize peak-valley-flat power consumption periods, thereby optimizing mill production time.

[0026] All matters not detailed in this utility model are common knowledge.

[0027] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A pulverized coal interconnection and intercommunication conveying device for a coal injection system, comprising a coal injection tank, a coal collector, a mill, a main air extractor, and a pulverized coal bin; the mill is connected to one side of the coal collector; the main air extractor is connected to the other side of the coal collector; the pulverized coal bin is connected below the coal collector; characterized in that The blast furnace is provided with a coal injection system, and the coal injection system comprises a coal injection tank, a coal injection main pipeline, a coal injection valve I, a coal injection valve II and a powder collector.

2. The pulverized coal interconnected conveying device of a coal injection system according to claim 1, characterized in that: The side of the coal injection tank output end is connected to the blast furnace tuyere through the coal injection main pipeline.

3. The pulverized coal interconnected conveying device of a coal injection system according to claim 1, characterized in that: The side of the coal injection main pipeline close to the coal injection valve I is provided with a coal injection valve I, and the side of the coal injection main pipeline close to the coal injection valve II is provided with a coal injection valve II.

4. The pulverized coal interconnected conveying device of a coal injection system according to claim 1, characterized in that: The side of the coal injection main pipeline close to the coal injection valve I is provided with a coal injection valve I, and the side of the coal injection main pipeline close to the coal injection valve II is provided with a coal injection valve II. The side of the coal injection main pipeline close to the coal injection valve I is provided with a coal injection valve I, and the side of the coal injection main pipeline close to the coal injection valve II is provided with a coal injection valve II. The turning parts of the coal injection main pipeline and the branch pipeline are provided with wear-resistant elbow pipes with a curvature radius of >20D. The powder collector is a cloth bag powder collector.

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