Three-tank and two-furnace type pulverized coal injection device

Abstract

The utility model belongs to the technical field of iron and steel smelting equipment, and particularly relates to a three-tank and two-furnace type pulverized coal injection device. Comprising three injection tanks and two injection main pipes, the output ends of the three injection tanks are sequentially provided with coal feeding valves and pulverized coal mixers, the pulverized coal mixers are connected with two coal conveying valves in parallel through injection branch pipes, the two coal conveying valves are communicated with the two injection main pipes respectively, and the output ends of the injection main pipes are connected with air supplementing pipes in parallel. An air supply adjusting valve is installed on the air supply pipe, and the air inlet end of the pulverized coal mixer is connected with an injection valve through an air inlet pipe. According to the utility model, three injection tanks correspond to two blast furnaces, so that the quantity of standby pressurization of the injection tanks is reduced, the nitrogen consumption during pressurization of the injection tanks is reduced, and the influence of standby pressurization on injection operation is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of steel smelting equipment, in particular to a three-tank spray two-furnace type coal powder injection device. Background Art

[0002] Blast furnaces in steel mills require pulverized coal injection devices to aid combustion. These devices typically include a pulverized coal injection tank and a main injection pipe. The working method is to add pulverized coal to the pulverized coal injection tank, then blow nitrogen into the tank to pressurize it. The pulverized coal is then blown into the blast furnace through the injection pipe at the bottom of the blast furnace. Currently, each blast furnace has two pulverized coal injection tanks. While one is operating, the other is pressurized and kept in standby mode. Eight blast furnaces correspond to 16 pulverized coal injection tanks, and up to eight blast furnaces may be pressurized. Multiple blast furnaces being pressurized and kept in standby mode can dramatically increase nitrogen consumption, affecting the nitrogen pressure of the blast furnace in operation. Reduced injection pressure can easily cause blockage in the hot air return pipe, affecting pulverized coal injection and directly impacting blast furnace production. In addition, the two injection tanks corresponding to one blast furnace are emptied according to the operation of stopping coal - supplying air - supplying coal - stopping air. Once the connection of tank emptying is not smooth, the flow and pressure fluctuations will affect the condition of the blast furnace. At the same time, the connection errors of the tank emptying process (such as supplying coal too early or supplying air too late) will make the coal injection flow and pressure too low, causing the blast furnace tempering to damage the spray gun and hose, resulting in spare parts loss, which is not conducive to the smooth operation of the blast furnace. Summary of the Invention

[0003] The purpose of the utility model is to provide a three-tank two-furnace type pulverized coal injection device to solve the problems existing in the prior art.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] A three-tank, two-furnace type pulverized coal injection device comprises an injection tank and an injection main pipe. There are three injection tanks and two injection main pipes. The output ends of the three injection tanks are sequentially equipped with a coal feeding valve and a pulverized coal mixer. The pulverized coal mixer has two coal delivery valves connected in parallel via an injection branch pipe. The two coal delivery valves are respectively connected to the two injection main pipes. The output ends of the injection main pipes are connected in parallel with an air supply pipe, on which an air supply regulating valve is installed. The air inlet end of the pulverized coal mixer is connected to the injection valve via an air inlet pipe.

[0006] Furthermore, the spray tank is a tank body with a conical bottom, a filling bell valve, a stamping valve and a pressure relief valve are installed on the top of the spray tank, and a fluidizing valve is connected to the side of the conical bottom of the spray tank.

[0007] Furthermore, an injection shut-off valve, a filter, and a check valve are sequentially installed on the injection branch pipe at the output end of the pulverized coal mixer.

[0008] Furthermore, an intake pressure sensor and an intake flow meter are installed on the intake pipe between the injection valve and the pulverized coal mixer.

[0009] Further, the automatic air supplement cut-off valve and the manual air supplement cut-off valve are installed on the air supplement pipe of the input end of the air supplement regulating valve, and the air supplement pressure sensor and the air supplement flow meter are installed on the air supplement pipe of the output end of the air supplement regulating valve.

[0010] Further, the air supplement pipe is inclined to communicate with the blowing main pipe, and the inclination direction of the air supplement pipe is towards the output direction of the blowing main pipe.

[0011] The utility model has the following beneficial effects:

[0012] 1. The utility model discloses a three blowing tanks correspond to two blast furnaces to reduce the number of standby pressurization of the blowing tank, thereby reducing the nitrogen consumption when the blowing tank is pressurized, and further reducing the influence of pressurization standby on the blowing operation.

[0013] 2. The air supplement pipe is inclined to communicate with the blowing main pipe, the nitrogen gas is towards the output end of the blowing main pipe, and the air supplement pipe is communicated at the output end of the blowing main pipe, so that the settled coal powder can flow quickly when the pipe is blocked, thereby reducing the influence of pipe blocking on the blast furnace operation as soon as possible.

[0014] 3. The air supplement regulating valve can be always opened to continuously blow in nitrogen, thereby completely eliminating the pipe blocking phenomenon.

[0015] 4. The number of the blowing tank is reduced, thereby reducing the investment cost of the equipment. DRAWINGS

[0016] Figure 1 It is the structure schematic diagram of the utility model.

[0017] Among them: 1. blowing tank, 2. blowing main pipe, 3. coal feeding valve, 4. coal powder mixer, 5. blowing branch pipe, 6. coal conveying valve, 7. air supplement pipe, 8. air supplement regulating valve, 9. blowing valve, 10. tank filling clock valve, 11. punch valve, 12. pressure relief valve, 13. fluidization valve, 14. blowing cut-off valve, 15. filter, 16. check valve, 17. inlet pressure sensor, 18. inlet flow meter, 19. automatic air supplement cut-off valve, 20. manual air supplement cut-off valve, 21. air supplement pressure sensor, 22. air supplement flow meter, 23. inlet pipe. CONCRETE IMPLEMENTATION

[0018] In order to make the purpose, technical scheme and advantages of the utility model more clear and obvious, the following will be further described in detail by combining with specific embodiments and drawings. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.

[0019] As Figure 1As shown, a three-tank two-furnace type pulverized coal injection device includes an injection tank 1 and an injection main pipe 2. There are three injection tanks 1 and two injection main pipes 2. The output ends of the three injection tanks 1 are successively equipped with a coal feeding valve 3 and a pulverized coal mixer 4. The pulverized coal mixer 4 has two coal delivery valves 6 in parallel through an injection branch pipe 5. The two coal delivery valves 6 are respectively connected to the two injection main pipes 2. The output end of the injection main pipe 2 is connected in parallel with an air supply pipe 7, and an air supply regulating valve 8 is installed on the air supply pipe 7. The air inlet end of the pulverized coal mixer 4 is connected to the injection valve 9 through an air inlet pipe 23.

[0020] The spray tank 1 is a tank with a conical bottom. A filling bell valve 10, a punch valve 11, and a pressure relief valve 12 are installed at the top of the spray tank 1. A fluidizing valve 13 is connected to the side of the conical bottom of the spray tank 1. The filling bell valve 10 is used to fill the pulverized coal, the punch valve 11 is used to add nitrogen for pressurization, the pressure relief valve 12 is used to relieve pressure before filling the pulverized coal, and the fluidizing valve 13 is used to fluidize the pulverized coal at the bottom of the spray tank 1 to increase its fluidity.

[0021] The injection branch pipe 5 at the output end of the pulverized coal mixer 4 is sequentially installed with an injection shut-off valve 14, a filter 15, and a check valve 16. The injection shut-off valve 14 is used to quickly cut off the passage, the filter 15 filters out large particles in the pulverized coal, and the check valve 16 prevents the pulverized coal from flowing back.

[0022] An intake pressure sensor 17 and an intake flow meter 18 are installed on the intake pipe 23 between the injection valve 9 and the pulverized coal mixer 4 to detect the intake air pressure and flow. Under normal circumstances, the air pressure and flow are maintained within a certain range. When blockage occurs, the air pressure is overpressured, but the flow is zero or below the lower limit.

[0023] An automatic air shut-off valve 19 and a manual air shut-off valve 20 are installed on the air supply pipe 7 at the input end of the air supply regulating valve 8, respectively for automatic and manual control of air supply shut-off. An air supply pressure sensor 21 and an air supply flowmeter 22 are installed on the air supply pipe 7 at the output end of the air supply regulating valve 8, for detecting the air pressure and flow within the air supply pipe 7.

[0024] When the hot air return pipe is blocked, the pulverized coal in the injection main pipe 2 will also settle, resulting in poor fluidity. The air supply pipe 7 is connected to the injection main pipe 2 at an angle, and the inclination direction of the air supply pipe 7 is toward the output direction of the injection main pipe 2. In this way, after the air supply valve is opened, the pulverized coal in the front is pushed into the blast furnace, and a certain negative pressure is formed on the pulverized coal in the rear, attracting it to move forward, thereby making the pulverized coal in the injection main pipe 2 flow.

[0025] The working principle of this utility model is:

[0026] During operation, connect the stamping valve 11, fluidizing valve 13, intake pipe 23, and air supply pipe 7 to the nitrogen tank. Electronically controlled valves can be used for valve control. Valves, sensors, and flowmeters requiring automatic control are electrically connected to the PLC programmable controller to achieve automatic control of the entire system. During setup, set the upper and lower monitoring limits for the intake pressure sensor 17 and intake flowmeter 18. If the pressure exceeds the upper limit and the flow rate falls below the lower limit, a blockage is detected, and the air supply valve is activated, automatically activating the valve. The air supply valve is also set to always be open to prevent blockage.

[0027] During the injection process, a three-tank, two-furnace system is used. This means three injection tanks 1 correspond to two blast furnaces. Two of the three injection tanks 1 are performing injection operations, while the remaining one is in standby mode for replenishing pulverized coal and pressurizing. This replenishment and pressurization process is short, fully meeting the injection needs of two blast furnaces. For eight blast furnaces, only four are pressurizing, a reduction of half compared to two tanks per furnace. After the injection operation is completed, the tank is transferred to the standby injection tank 1, whereupon replenishment and pressurization are immediately performed.

[0028] The specific operation is as follows: when adding pulverized coal, the bell valve 10 of the tank is opened, and after adding pulverized coal, it is closed, and the stamping valve 11 is opened to pressurize and standby. During injection, the fluidizing valve 13 is opened to fluidize the pulverized coal at the bottom of the injection tank 1. Then, the air inlet pipe 23 is opened, the coal feeding valve 3 is opened, and the pulverized coal and nitrogen are mixed in the pulverized coal mixer 4. The corresponding coal delivery valve 6 is opened as needed to allow the pulverized coal to enter the blast furnace through the corresponding injection main pipe 2. During this process, the intake pressure sensor 17 and the intake flowmeter 18 detect the intake pressure and flow. If the pressure exceeds the limit value and the flow is zero or lower than the limit value, it indicates a pipe blockage. At this time, the air supply regulating valve 8 is opened to blow nitrogen into the injection main pipe 2. When the hot air return pipe is blocked, the pulverized coal in the injection main pipe 2 will also settle, resulting in poor fluidity. Since the air supply pipe 7 is inclined and connected to the output end of the injection main pipe 2 (the connection point between the injection branch pipe 5 and the injection main pipe 2 is located at the input end of the injection main pipe 2), nitrogen flows toward the output end of the injection main pipe 2. In this way, after the air supply valve is opened, the pulverized coal in the front is pushed into the blast furnace, and a certain negative pressure is formed on the pulverized coal in the rear, attracting it to move forward, thereby causing the pulverized coal in the injection main pipe 2 to flow.

[0029] Another way is to keep the air supply regulating valve 8 open and continuously blow in nitrogen, thereby completely eliminating the pipe blockage phenomenon. In particular, when the tank is being emptied, the air supply regulating valve 8 is continuously opened to prevent the flow and pressure fluctuations caused by problems in the tank being emptied from affecting the blast furnace condition.

[0030] The above-described embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the concept and scope of the present invention. Any modifications and improvements to the technical solution of the present invention made by a person of ordinary skill in the art without departing from the design concept of the present invention shall fall within the scope of protection of the present invention.

[0031] The technology, shape and structure that are not described in detail in this utility model are all well-known technologies.

Claims

1. A three-tank two-furnace pulverized coal injection device, characterized in that: It includes injection tanks and injection main pipes. There are three injection tanks and two injection main pipes. The output ends of the three injection tanks are successively equipped with coal feeding valves and pulverized coal mixers. The pulverized coal mixer is connected to two coal delivery valves in parallel through the injection branch pipe. The two coal delivery valves are connected to the two injection main pipes respectively. The output end of the injection main pipe is connected to an air supply pipe, and an air supply regulating valve is installed on the air supply pipe. The air inlet end of the pulverized coal mixer is connected to the injection valve through the air inlet pipe.

2. The three-tank two-furnace type pulverized coal injection device according to claim 1 is characterized in that: The spray tank is a tank body with a conical bottom. A filling bell valve, a punching valve and a pressure relief valve are installed on the top of the spray tank. The side of the conical bottom of the spray tank is connected to a fluidizing valve.

3. The three-tank two-furnace pulverized coal injection device according to claim 1 is characterized in that: The injection branch pipe at the output end of the pulverized coal mixer is sequentially installed with an injection cut-off valve, a filter, and a check valve.

4. The three-tank two-furnace pulverized coal injection device according to claim 1 is characterized in that: An intake pressure sensor and an intake flow meter are installed on the intake pipe between the injection valve and the pulverized coal mixer.

5. The three-tank two-furnace pulverized coal injection device according to claim 1 is characterized in that: An automatic air supply shut-off valve and a manual air supply shut-off valve are installed on the air supply pipe at the input end of the air supply regulating valve, and an air supply pressure sensor and an air supply flow meter are installed on the air supply pipe at the output end of the air supply regulating valve.

6. The three-tank two-furnace type pulverized coal injection device according to claim 1 is characterized in that: The air supply pipe is connected to the injection main pipe in an inclined manner, and the inclined direction of the air supply pipe is toward the output direction of the injection main pipe.

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