Nitrogen purging device for double-chamber kiln

Abstract

The utility model discloses a nitrogen purging device for a double-chamber kiln, which belongs to the technical field of lime production equipment and comprises a chamber A, a chamber B, a combustion fan and a cooling fan, the chamber A and the chamber B are communicated with each other through a middle channel, the combustion fan is connected with the upper parts of the chamber A and the chamber B, the chamber A and the chamber B are respectively provided with a gas ring pipe, and the upper parts of the chamber A and the chamber B are respectively provided with a spray gun. The spray gun is connected with the gas pipe through a gas ring pipe, the gas ring pipe is connected with a nitrogen ring pipe, the cooling fan is connected with the lower portion of the A chamber and the lower portion of the B chamber, cooling air flashboards are arranged on the lower portion of the A chamber and the lower portion of the B chamber, and the cooling fan is connected with the gas ring pipe of the A chamber and the gas ring pipe of the B chamber through spray gun cooling air pipelines. And spray gun cooling air pipe check valves and spray gun cooling air pipe quick switching valves are arranged on the spray gun cooling air pipes of the gas ring pipe leading to the chamber A and the gas ring pipe leading to the chamber B. The double-chamber kiln nitrogen purging device solves the problem of high nitrogen consumption in the existing double-chamber kiln nitrogen purging mode.

Description

Technical Field

[0001] The utility model belongs to the technical field of lime production equipment and relates to a device for reducing nitrogen consumption in nitrogen purging of a double-chamber kiln. Background Art

[0002] The double-chamber vertical kiln has two barrels, which are connected by a connecting channel located in the middle of the two chambers. The biggest advantages in the calcination process are parallel flow and heat storage. "Parallel flow" means that when the combustion tube is calcined with coal gas, the coal gas, combustion air and limestone are parallel and downward, and the combustion flue gas also goes downward, which is conducive to calcining high-quality active lime. "Heat storage" refers to the high-temperature flue gas, the fuel combustion product in the combustion tube, entering the heat storage chamber through the connecting channel between the two kiln chambers. In the heat storage chamber, the high-temperature flue gas flows from bottom to top, transporting heat to the limestone raw material in the preheating zone, and preheating the stone to a higher temperature. At the same time, the high-temperature exhaust gas drops to a lower temperature after heat exchange, and is discharged from the kiln chamber through the flue gas bag filter. After heat exchange, the heat of the flue gas is used to preheat the stone, and the flue gas temperature is reduced, so that the purpose of utilizing the waste heat of the exhaust gas is achieved, thereby ensuring that the furnace has a high thermal efficiency.

[0003] During the combustion operation, the two kiln barrels of the double-chamber kiln perform a functional conversion every 12 to 14 minutes, that is, when one kiln chamber is in the calcining state, the other kiln chamber is in the heat storage state. In contrast to the sleeve kiln, the atmosphere in the double-chamber vertical kiln is a positive pressure environment. Under normal conditions, the system delivers a large amount of coal gas and combustion-supporting air to the combustion chamber to ensure normal combustion in the combustion chamber, while the flue gas dust collector ensures that the top of the heat storage chamber is in a negative pressure environment, so the combustion chamber pressure is always higher than the heat storage chamber pressure, allowing the high-temperature flue gas to flow smoothly to the heat storage chamber to achieve heat storage.

[0004] When the kiln is burning, the system starts the blower and sends combustion air from top to bottom to the top of the kiln tube A. When the combustion air passes through the preheating zone, it exchanges heat with the higher temperature stone at the top of the combustion chamber and reaches a higher temperature. When the combustion air reaches the calcining zone of the kiln, it mixes with the gas delivered by the gas spray gun in the combustion chamber. Since the temperature of the stone at the lower end of the spray gun is relatively high, close to about 700℃, the gas reaches the ignition point and burns immediately with the combustion air to generate heat. As the unloading platform at the bottom of the kiln discharges materials, the material column moves downward, and the combustion air, stone, and combustion products flow downward together. This process is called "parallel flow". In the "parallel flow" state, the combustion air can give full play to its thermal efficiency, and the gas combustion flame can fully contact the stone to maintain a high thermal efficiency. When approaching the cooling zone and below the hanging cylinder, the surface temperature of the limestone gradually decreases. When the lime enters the cooling zone after burning, the cooling air cools the lime and performs heat exchange to reduce the surface temperature of the lime to a certain level. Then the finished product is discharged into the lime silo and discharged by the kiln bottom feeder. After the cooling air and the calcined lime undergo heat exchange, the temperature rises, and it is mixed with the combustion products through the connecting channel and enters the kiln barrel B. In the kiln barrel B, the exhaust gas passes through the calcination zone from bottom to top and reaches the top of the regenerator. At the top of the regenerator, the stone added by the rotary hopper is equivalent to a large "heat exchanger". Through heat exchange, the flue gas temperature drops to about 160℃~180℃ and is discharged from the top of the kiln. After the flue gas is preheated in the regenerator, the stone temperature rises to about 700℃. Under high production capacity, the "charging during combustion" production mode can be selected. In this mode, the system charges the regenerator three times during the combustion process, and each cycle takes about 12 to 14 minutes to complete.

[0005] There is a method to reduce nitrogen consumption in a gas-fired double-chamber kiln (Announcement No.: CN114739160A). When the double-chamber kiln completes a calcination cycle, the system enters the reversing period. The entire reversing period takes about 45 seconds. About 100 seconds before entering the reversing period (burnout time, which can be adjusted by system parameters), the system will immediately cut off the gas to the kiln, and nitrogen will purge the gas ring pipe and the spray gun ring pipe to clean up the residual gas. During the reversing period, the combustion air release valve and the cooling air release valve of the double-chamber kiln are opened successively to release the pressure in the kiln, and nitrogen will continue to purge the gas ring pipe and the spray gun ring pipe. At the same time, the platform unloading gate is opened at 6.27 meters, and the lime blocks stored on the upper part of the gate are discharged into the small silo. The spray gun cooling air reversing valve changes its position and starts to cool the spray gun pipe of the new heat storage cylinder. The combustion air reversing gate acts to realize the functional conversion of the heat storage cylinder and the calcination cylinder, and the next cycle of calcination begins again. The system sets the burnout time mainly to ensure that the residual gas in the combustion cycle is fully burned. At the same time, nitrogen mainly acts on the reversal and burnout time of the gas-fired double-chamber kiln, and is used to clean the residual gas in the gas ring pipe and the spray gun ring pipe to avoid mixing gas and air and causing explosion.

[0006] In the above prior art, after the burnout time is reached, the gas quick-cut valve is closed to cut off the gas entering the spray gun. At the same time, the first nitrogen purge valve of the combustion kiln chamber is opened, and the nitrogen pipeline delivers nitrogen to the nitrogen ring pipe for the first time, passes through the check valve, enters the gas ring pipe of the double-chamber kiln, and purges the gas spray gun; after the burnout time is 0, the second nitrogen purge valve is opened, and the nitrogen pipeline delivers nitrogen to the spray gun cooling air ring pipe for the second time, enters the kiln through the gas spray gun, and realizes the purge of the spray gun. This technology uses the secondary nitrogen delivery method, which has the problem of large nitrogen consumption. Utility Model Content

[0007] The problem solved by the utility model is to provide a nitrogen purge device for a double-chamber kiln, so as to solve the problem of large nitrogen consumption in the existing nitrogen purge method for the double-chamber kiln.

[0008] In order to solve the above problems, the technical solution adopted by the utility model is: it includes A chamber, B chamber, combustion-supporting fan and cooling fan, the A chamber and the B chamber are connected to each other through an intermediate channel, the combustion-supporting fan is connected to the upper part of the A chamber and the B chamber, the A chamber and the B chamber are both provided with a gas ring pipe, the upper part of the A chamber and the B chamber are both provided with a spray gun, the spray gun is connected to the gas pipe through the gas ring pipe, the gas ring pipe is connected to the nitrogen ring pipe, the cooling fan is connected to the lower part of the A chamber and the B chamber, the lower part of the A chamber and the B chamber is provided with a cooling air damper, the cooling fan is connected to the gas ring pipe of the A chamber and the gas ring pipe of the B chamber through a spray gun cooling air duct, and the spray gun cooling air duct leading to the gas ring pipe of the A chamber and the spray gun cooling air duct leading to the gas ring pipe of the B chamber are both provided with a spray gun cooling air duct check valve and a spray gun cooling air duct quick-cut valve.

[0009] In the above technical solution, a more specific technical solution may also be: a check valve is provided between the coal gas ring pipe and the nitrogen ring pipe.

[0010] Further: the combustion-supporting blower is connected to the A chamber and the B chamber via a combustion-supporting air duct, and the combustion-supporting air duct is provided with a combustion-supporting air release valve.

[0011] Furthermore: a combustion air reversing valve is provided between the combustion air release valve and the A chamber and between the A chambers.

[0012] Further: the cooling fan is connected to the A chamber and the B chamber via a cooling air duct, and the cooling air duct is provided with a cooling air release valve.

[0013] Due to the adoption of the above technical solution, the utility model has the following beneficial effects compared with the prior art: the cooling fan is connected to the gas ring pipe through the spray gun cooling air duct, that is, the cooling fan is used only to purge the gas ring pipe before the combustion chamber gas ends and before the gas is delivered, which effectively utilizes the cooling air, reduces the existing nitrogen consumption while ensuring safety. The original spray gun cooling air ring pipe is cancelled, and the spray gun cooling air duct is connected to the gas ring pipe, which better realizes the simplicity of the pipeline and saves the nitrogen used for the original spray gun cooling air duct purge. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of combustion in chamber A of a double-chamber kiln of the utility model.

[0015] Figure 2 It is a schematic diagram of the nitrogen purge principle of the double-chamber kiln of the utility model.

[0016] Figure 3 It is a schematic diagram of nitrogen purge for a double-chamber kiln of the utility model.

[0017] In the figure: 1. Combustion-supporting fan; 2. Combustion-supporting air duct; 3. Combustion-supporting air release valve; 4. Combustion-supporting air reversing valve; 5. A chamber; 6. Middle channel; 7. B chamber; 8. Cooling fan; 9. Cooling air duct; 10. Cooling air release valve; 11. Cooling air damper; 12. Nitrogen ring pipe; 13. Gas ring pipe; 14. Check valve; 15. Gas quick-cut valve; 16. Gas pipe; 17. Nitrogen purge valve; 18. Nitrogen pipeline; 19. Spray gun cooling air duct; 20. Spray gun cooling air duct check valve; 21. Spray gun cooling air duct quick-cut valve; 22. Spray gun. DETAILED DESCRIPTION

[0018] The utility model is further described in detail below with reference to the accompanying drawings:

[0019] like Figures 1 to 3The nitrogen purge device of the double-chamber kiln shown in the figure comprises chamber A 5, chamber B 7, a combustion-supporting blower 1 and a cooling blower 8. Chamber A 5 and chamber B 7 are connected to each other through an intermediate channel 6. The combustion-supporting blower 1 is connected to the upper parts of chamber A 5 and chamber B 7. Chamber A 5 and chamber B 7 are both provided with a gas ring pipe 13. The upper parts of chamber A 5 and chamber B 7 are both provided with a spray gun 22. The spray gun 22 is connected to a gas pipe 16 through the gas ring pipe 13. The gas ring pipe 13 is connected to a nitrogen ring pipe 12. Then, the cooling fan 8 is connected to the lower part of the A chamber 5 and the B chamber 7, and the lower part of the A chamber 5 and the B chamber 7 is provided with a cooling air damper 11. The cooling fan 8 is connected to the gas ring pipe 13 of the A chamber 5 and the gas ring pipe 13 of the B chamber 7 through the spray gun cooling air duct 19. The spray gun 22 cooling air duct 9 leading to the gas ring pipe 13 of the A chamber 5 and the gas ring pipe 13 of the B chamber 7 is provided with a spray gun cooling air duct check valve and a spray gun cooling air duct quick cut valve 21. A check valve 14 is provided between the gas ring pipe 13 and the nitrogen ring pipe 12. The combustion-supporting fan 1 is connected to the A chamber 5 and the B chamber 7 through the combustion-supporting air duct 2, and the combustion-supporting air duct 2 is provided with a combustion-supporting air release valve 3. A combustion-supporting air reversing valve 4 is provided between the combustion-supporting air release valve 3 and the A chamber 5 and between the A chamber 5. The cooling fan 8 is connected to the A chamber 5 and the B chamber 7 via a cooling air duct 9, and the cooling air duct 9 is provided with a cooling air release valve.

[0020] During use, when chamber A 5 is in the combustion chamber process, the quick-cut valve 21 of the spray gun cooling air duct 19 of chamber A 5 is closed; the quick-cut valve 21 of the spray gun cooling air duct 19 of chamber B 7 is opened, and the cooling fan 8 sends cooling air into the gas ring pipe 13 of chamber B 7 to cool the spray gun 22 in chamber B 7. When chamber A 5 is in the combustion chamber and enters the burnout time, the quick-cut valve 15 of chamber A 5 is cut off. Chamber A 5 sends nitrogen into the gas ring pipe 13 of chamber A 5 through the nitrogen ring pipe 12 and the check valve 14 for about 20 seconds. Afterwards, during the remaining burnout time and reversing period, the nitrogen purge valves 17 of chamber A 5 and chamber B 7 are closed. The quick-cut valve 21 of the spray gun cooling air duct leading to chamber A 5 and chamber B 7 is opened, and cooling air is sent into the gas ring pipe 13 of chamber A 5 and chamber B 7 to cool the spray guns 22 of chamber A 5 and chamber B 7. During the combustion period of chamber B 7, the quick-cut valve 21 of the spray gun cooling air duct on the spray gun cooling air duct 19 of chamber B 7 is closed. Before the quick-cut valve 15 of the gas leading to chamber B 7 is opened, the nitrogen purge valve 17 leading to chamber B 7 is opened to send nitrogen into chamber B 7. The quick-cut valve 21 of the spray gun cooling air duct of chamber A 5 continues to be in the open state, and the cooling fan 8 sends cooling air into the gas ring pipe 13 of chamber A 5 to cool the spray gun 22 in chamber A 5.

Claims

1. A nitrogen purge device for a double-chamber kiln, comprising a chamber A, a chamber B, a combustion-supporting blower and a cooling blower, wherein the chamber A and the chamber B are connected to each other through an intermediate channel, the combustion-supporting blower is connected to the upper parts of the chamber A and the chamber B, the chamber A and the chamber B are both provided with a gas ring pipe, the upper parts of the chamber A and the chamber B are both provided with a spray gun, the spray gun is connected to the gas pipe through the gas ring pipe, the gas ring pipe is connected to the nitrogen ring pipe, the cooling blower is connected to the lower parts of the chamber A and the chamber B, the lower parts of the chamber A and the chamber B are both provided with a cooling air damper, characterized in that: The cooling fan is connected to the gas ring pipe of the A chamber and the gas ring pipe of the B chamber through a spray gun cooling air duct. The spray gun cooling air duct leading to the gas ring pipe of the A chamber and the spray gun cooling air duct leading to the gas ring pipe of the B chamber are both provided with a spray gun cooling air duct check valve and a spray gun cooling air duct quick-cut valve.

2. The double-chamber kiln nitrogen purging device according to claim 1 is characterized in that: A check valve is provided between the coal gas ring pipe and the nitrogen ring pipe.

3. The double-chamber kiln nitrogen purging device according to claim 1 or 2, characterized in that: The combustion-supporting blower is connected to the A chamber and the B chamber via a combustion-supporting air duct, and the combustion-supporting air duct is provided with a combustion-supporting air release valve.

4. The double-chamber kiln nitrogen purging device according to claim 3 is characterized in that: Combustion air reversing valves are provided between the combustion air release valve and the A chamber and between the A chambers.

5. The double-chamber kiln nitrogen purging device according to claim 4 is characterized in that: The cooling fan is connected to the A chamber and the B chamber via a cooling air duct, and the cooling air duct is provided with a cooling air release valve.

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