Carbon calcining rotary kiln middle part fuel supply system

Abstract

The present invention relates to a fuel system, and in particular to a fuel supplement system for the middle part of a carbon calcining rotary kiln body. The system comprises a rotary kiln body, characterized in that the rotary kiln body passes through the center of an annular fuel tank, an open annular protrusion is provided on the kiln head side end face of the annular fuel tank, a circular annular rotary sealing steel plate is provided inside the annular protrusion, the circular annular rotary sealing steel plate is perpendicular to the axis of the rotary kiln body, a plurality of fixing frames are arranged on the circumference of the rotary kiln body shell, each fixing frame connects the rotary sealing steel plate and the rotary kiln body, the inner wall of the raised part of the annular protrusion is fixed to one end of an annular soft sealing sheet respectively at the upper and lower sides, the other ends of the two annular soft sealing sheets are respectively contacted and sealed with the rotary sealing steel plate, an air outlet is provided on the rotary sealing steel plate, the air outlet extends to the air outlet of the secondary air duct through a fuel gas nozzle, an air pump is provided on the fuel gas nozzle, the kiln tail side end face of the annular fuel tank is provided at the air inlet, and the annular fuel tank is slightly negative pressure.

Description

Technical Field

[0001] The present invention relates to a fuel system, in particular to a fuel supplement system in the middle of a carbon calcining rotary kiln body, and belongs to production equipment for producing calcined coke for anodes and cathodes for aluminum and graphite electrodes for steelmaking in the carbon industry. Background Art

[0002] The furnace equipment commonly used for calcining green coke (including oil-based coke and coal-based coke) mainly includes pot calciners and rotary kilns. Compared with pot calciners, rotary kilns have the advantages of large production capacity, low cost, high degree of automation, and good working environment. In addition, when calcining needle coke, the calcination temperature is relatively high, generally reaching 1400-1500℃. The pot body of the pot calciner is usually made of refractory silica bricks, and the general maximum operating temperature is 1350℃, which cannot meet the requirements of needle coke calcination. Therefore, rotary kilns are generally used for needle coke calcination.

[0003] In the traditional carbon calcining rotary kiln, only a burner is installed at the kiln head of the rotary kiln to add fuel to the rotary kiln when the volatile matter in the raw materials is insufficient. The rotary kiln is divided into a preheating zone, a calcining zone and a cooling zone from the kiln tail to the kiln head. The kiln head of the rotary kiln is at the end of the cooling zone. The burner installed at the kiln head of the rotary kiln will inevitably reheat the calcined coke that has been calcined and cooled in the cooling zone while adding fuel to the rotary kiln. The disadvantages of adding fuel at the kiln head are: (1) Since the calcined coke has been heated twice, the carbon loss rate of the calcined petroleum coke is increased; (2) Since the high-temperature flue gas generated by the fuel added from the kiln head must first pass through the cooling zone and then pass through the secondary air in the middle of the kiln body, it does not directly act on the calcining zone, which is not conducive to controlling the temperature of the calcining zone, and also wastes a lot of heat and energy; (3) The temperature of the calcined coke entering the subsequent cooling equipment increases, which increases the load of the subsequent cooling equipment and shortens the service life of the refractory lining of the cooling equipment. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a carbon calcining rotary kiln middle fuel supplement system, the purpose of which is to increase the fuel supply in the middle of the rotary kiln and facilitate the control of the calcining zone temperature.

[0005] To achieve the above-mentioned purpose, the present invention discloses a fuel replenishing system for the middle part of a carbon calcining rotary kiln, comprising a rotary kiln cylinder, a trolley is provided below the rotary kiln cylinder in the calcining zone, an annular fuel tank is provided on the trolley, the rotary kiln cylinder passes through the center of the annular fuel tank, an open annular protrusion is provided on the kiln head side end face of the annular fuel tank, a circular annular rotary sealing steel plate is provided in the annular protrusion, a plurality of fixing frames are arranged on the circumference of the rotary kiln cylinder shell, each fixing frame connects the rotary sealing steel plate and the rotary kiln cylinder, the inner wall of the protruding part of the annular protrusion is fixed to one end of an annular soft sealing sheet respectively at the upper and lower sides, the other ends of the two annular soft sealing sheets are respectively in contact and sealed with the rotary sealing steel plate, an air outlet is provided on the rotary sealing steel plate, the air outlet extends to the air outlet of the secondary air duct through a fuel gas nozzle, an air pump is provided on the fuel gas nozzle, an air inlet is provided on the kiln tail side end face of the annular fuel tank, and there is a slight negative pressure in the annular fuel tank.

[0006] The trolley is arranged on a guide rail, the guide rail is located on a platform, the annular fuel tank is perpendicular to the axis of the rotary kiln cylinder, and the trolley moves in a series along the axis of the rotary kiln cylinder.

[0007] The air inlet is connected to the fuel gas flow controller through an air inlet pipeline, a first electromagnetic stop valve is provided on the air inlet pipeline, the air inlet, the air inlet pipeline, the fuel gas flow controller and the first electromagnetic stop valve are arranged at the lower part of the annular fuel tank, a compressed air pipeline is provided at the lower part of the annular fuel tank, and a fourth electromagnetic stop valve is provided on the compressed air pipeline.

[0008] A second electromagnetic stop valve is arranged on the outlet side of the air pump on the fuel gas nozzle, the air pump is fixed on the rotary kiln shell, and the fuel gas nozzle, the air pump and the second electromagnetic stop valve rotate with the rotary kiln cylinder.

[0009] A pressure measuring device is arranged on the upper part of the annular fuel tank, and a third electromagnetic stop valve and a venting pipe are arranged on the top of the annular fuel tank.

[0010] Each of the fixing frames is in a right angle shape.

[0011] A heat insulation board is arranged between the inner and outer walls of the annular fuel tank and the rotary kiln cylinder, and the heat insulation board and the inner and outer walls of the annular fuel tank are connected by tension bars.

[0012] A slip ring power supply system is arranged on the outer shell of the rotary kiln cylinder at the kiln tail side, and the slip ring power supply system supplies power to the variable frequency motor of the air pump and the second electromagnetic stop valve.

[0013] The negative pressure in the annular fuel tank is -5 to -15 Pa.

[0014] The guide rail has the same inclination as the rotary kiln cylinder, and the annular fuel tank is perpendicular to the axis of the rotary kiln cylinder.

[0015] The outer shell of the rotary kiln cylinder is provided with a secondary air main pipe, the secondary air pipe is led out from the secondary air main pipe and inserted into the rotary kiln cylinder, the fuel gas nozzle is inserted into the secondary air main pipe and then extends from a secondary air pipe into the rotary kiln cylinder.

[0016] Advantages and effects of the present invention: the present invention avoids secondary heating of the calcined petroleum coke passing through the cooling zone of the rotary kiln during the production process, thereby reducing the carbon burnout rate of the petroleum coke; the supplementary fuel in the production process directly acts on the calcining zone, which is beneficial to the control of the temperature of the calcining zone and saves energy; the temperature of the calcined coke entering the subsequent cooling equipment is reduced, the load of the subsequent cooling equipment is reduced, and the service life of the refractory lining of the cooling equipment is extended; the total flue gas volume of the rotary kiln is reduced, and the load of the subsequent flue gas treatment system of the calcining system is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention.

[0018] Figure 2 yes Figure 1 AA cross-sectional diagram of .

[0019] Figure 3 yes Figure 1 Enlarged view of point I in the middle.

[0020] Figure 4 It is a schematic diagram of the gap between the rotating sealing steel plate and the annular protrusion.

[0021] In the figure: 1. rotary kiln cylinder; 2. trolley; 3. annular fuel tank; 4. annular protrusion; 5. rotary sealing steel plate; 6. fixing frame; 7. annular soft sealing sheet; 8. fuel gas nozzle; 9. secondary air duct; 10. air pump; 11. guide rail; 12. air intake pipeline; 13. fuel gas flow controller; 14. first electromagnetic stop valve; 15. second electromagnetic stop valve; 16. pressure measuring device; 17. third electromagnetic stop valve; 18. vent pipe; 19. heat insulation board; 20. tensioning bar; 21. slip ring power supply system; 22. secondary air main; 23. fourth electromagnetic stop valve; 24. compressed air pipeline; 25. gap. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the accompanying drawings.

[0023] As shown in the figure, the carbon calcining rotary kiln kiln body middle fuel supplement system of the present invention comprises a rotary kiln cylinder 1, a trolley 2 is arranged below the rotary kiln cylinder 1 in the calcining zone, an annular fuel tank 3 is arranged on the trolley 2, the rotary kiln cylinder 1 passes through the center of the annular fuel tank 3, an open annular protrusion 4 is arranged on the kiln head side end surface of the annular fuel tank 3, a circular annular rotary sealing steel plate 5 is arranged in the annular protrusion 4, and a plurality of fixing frames 6 are arranged on the circumference of the outer shell of the rotary kiln cylinder 1, and each fixing frame 6 is connected to the rotary kiln cylinder 1. The sealing steel plate 5 and the rotary kiln cylinder 1, the inner wall of the raised part of the annular protrusion 4 are fixed with one end of an annular soft sealing sheet 7 respectively, and the other ends of the two annular soft sealing sheets 7 are respectively in contact with the rotary sealing steel plate 5 for sealing. The annular soft sealing sheet 7 is an elastic sheet. An air outlet is provided on the rotary sealing steel plate 5, and the air outlet extends to the air outlet of the secondary air duct 9 through the fuel gas nozzle 8. An air pump 10 is provided on the fuel gas nozzle 8. An air inlet is provided on the kiln tail side end face of the annular fuel tank 3, and there is a slight negative pressure in the annular fuel tank 3. There is a gap 25 between the rotary sealing steel plate 5 and the raised bottom of the annular protrusion 4, and the gap 25 ensures that the rotary sealing steel plate can smoothly rotate with the rotary kiln cylinder 1.

[0024] The trolley 2 is arranged on a guide rail 11 , the guide rail 11 is located on a platform, the annular fuel tank 3 is perpendicular to the axis of the rotary kiln cylinder 1 , and the trolley 2 moves in a series along the axis of the rotary kiln cylinder 1 .

[0025] The air inlet is connected to the fuel gas flow controller 13 through an air inlet pipeline 12, and a first electromagnetic stop valve 14 is provided on the air inlet pipeline 12. The air inlet, the air inlet pipeline 12, the fuel gas flow controller 13 and the first electromagnetic stop valve 14 are arranged at the lower part of the annular fuel tank 3, and a compressed air pipeline 24 is provided at the lower part of the annular fuel tank 3, and a fourth electromagnetic stop valve 23 is provided on the compressed air pipeline 24.

[0026] A second electromagnetic stop valve 15 is provided on the outlet side of the air pump 10 on the fuel gas nozzle 8. The air pump 10 is fixed on the rotary kiln shell 1. The fuel gas nozzle 8, the air pump 10 and the second electromagnetic stop valve 15 rotate with the rotary kiln shell 1.

[0027] A pressure measuring device 16 is provided on the upper portion of the annular fuel tank 3 , and a third electromagnetic stop valve 17 and a vent pipe 18 are provided on the top of the annular fuel tank 3 .

[0028] Each of the fixing frames 6 is of right angle, one of which is inserted from the protruding opening and fixed on the outside of the rotary sealing steel plate 5 , and the other is fixed on the rotary kiln cylinder 1 . The fuel gas nozzle 8 is arranged on the outside of the fixing frame 6 .

[0029] A heat insulation board 19 is provided between the inner and outer walls of the annular fuel tank 3 and the rotary kiln cylinder 1 , and the heat insulation board 19 and the inner and outer walls of the annular fuel tank 3 are connected via tie bars 20 .

[0030] A slip ring power supply system 21 is provided on the outer shell of the rotary kiln cylinder 1 at the kiln tail side, and the slip ring power supply system 21 supplies power to the variable frequency motor of the air pump 10 and the second electromagnetic stop valve 15 .

[0031] The negative pressure in the annular fuel tank 3 is -5 to -15 Pa.

[0032] The guide rail 11 has the same inclination as the rotary kiln cylinder 1 , and the annular fuel tank 3 is perpendicular to the axis of the rotary kiln cylinder 1 .

[0033] The outer shell of the rotary kiln cylinder 1 is provided with a secondary air main pipe 22, a secondary air pipe 9 is led out from the secondary air main pipe 22 and inserted into the rotary kiln cylinder 1, a fuel gas nozzle 8 is inserted into the secondary air main pipe 22 and then extends from a secondary air pipe 9 into the rotary kiln cylinder 1. The secondary air main pipe 22 is arranged in the middle of the rotary kiln body.

[0034] The present invention adds a supplementary fuel system at the secondary air duct near the kiln tail side in the middle of the rotary kiln body. When the kiln is just started after drying or stopping, the original burner on the kiln head cover of the rotary kiln is used to provide fuel for the rotary kiln. Because the temperature in the kiln is relatively low at this time, the present invention is used to supplement the fuel for the rotary kiln. After the fuel enters the rotary kiln, it cannot burn immediately, and the fuel gas accumulates in the rotary kiln and is prone to deflagration. When the temperature in the rotary kiln is higher than the ignition temperature of the fuel gas, and the fuel gas can burn immediately after entering the rotary kiln, the fuel supply of the burner can be gradually reduced, and the supplementary fuel system in the middle of the kiln body can be used to supply fuel, so as to smoothly transition to normal production.

[0035] When the rotary kiln is in normal production, the amount of fuel gas entering the annular fuel tank 3 is controlled by the fuel gas flow controller 13 according to production needs. The amount of fuel gas sprayed into the rotary kiln cylinder 1 by the air pump 10 is interlockedly controlled according to the pressure value measured at the pressure measuring device 16, so that the pressure value measured at the pressure measuring device 16 is slightly negative pressure, maintained at about -5 to -15 Pa. Because the annular fuel tank 3 is negative pressure, the annular soft sealing sheet 7 is pressed against the rotating sealing steel plate 5 for sealing, thereby preventing the fuel gas in the annular fuel tank 3 from leaking.

[0036] When an abnormality occurs in the rotary kiln system and the fuel gas supply needs to be stopped, the air pump 10 is stopped immediately, the first electromagnetic stop valve 14 and the second electromagnetic stop valve 15 are closed, and the fuel gas supply to the annular fuel tank 3 and the rotary kiln is stopped; then the fourth electromagnetic stop valve 23 is opened to allow compressed air to enter the annular fuel tank 3 through the fourth electromagnetic stop valve 23, and the fuel gas in the annular fuel tank 3 is discharged into the atmosphere through the vent pipe 18 through the third electromagnetic stop valve 17 to prevent the fuel gas in the annular fuel tank 3 from exploding.

[0037] When the present invention is working, the rotary kiln body rotates, driving the secondary air main pipe, secondary air pipe, air pump, second electromagnetic stop valve, fuel gas nozzle, fixed frame and rotary sealing steel plate to rotate. The trolley drives the annular fuel tank, annular protrusion, annular soft sealing sheet, air intake pipeline, fuel gas flow controller, first electromagnetic stop valve, pressure measuring device, third electromagnetic stop valve, vent pipe, heat insulation board, tie rod, fourth electromagnetic stop valve and compressed air pipeline to move forward and backward along the axis direction of the rotary kiln body on the guide rail.

Claims

1. A fuel supplement system in the middle of a carbon calcining rotary kiln, comprising a rotary kiln cylinder, characterized in that: The rotary kiln cylinder passes through the center of the annular fuel tank. An open annular protrusion is provided on the kiln head side end surface of the annular fuel tank. A circular annular rotary sealing steel plate is provided inside the annular protrusion. The circular annular rotary sealing steel plate is perpendicular to the axis of the rotary kiln cylinder. A number of fixing frames are arranged on the circumference of the rotary kiln cylinder shell. Each fixing frame connects the rotary sealing steel plate and the rotary kiln cylinder. The inner wall of the raised part of the annular protrusion is fixed to one end of an annular soft sealing sheet respectively. The other ends of the two annular soft sealing sheets are respectively in contact and sealed with the rotary sealing steel plate. An air outlet is provided on the rotary sealing steel plate. The air outlet extends to the air outlet of the secondary air duct through the fuel gas nozzle. An air pump is arranged on the fuel gas nozzle, an air inlet is arranged on the end face of the annular fuel box at the kiln tail, and there is a slight negative pressure in the annular fuel box; the annular fuel box is located on a trolley below the rotary kiln cylinder, the trolley is arranged on a guide rail, the guide rail is located on a platform, the slope of the guide rail is parallel to the axis of the rotary kiln cylinder, the annular fuel box is perpendicular to the axis of the rotary kiln cylinder, the trolley drives the annular fuel box to move along the axis of the rotary kiln cylinder with the circular rotating sealing steel plate; a secondary air main pipe is arranged on the outer shell of the rotary kiln cylinder, the secondary air main pipe is led out from the secondary air main pipe and inserted into the rotary kiln cylinder, the fuel gas nozzle is inserted into the secondary air main pipe and then extends from a secondary air pipe into the rotary kiln cylinder.

2. The carbon calcining rotary kiln body middle fuel supplement system according to claim 1, characterized in that: The air inlet is connected to the fuel gas flow controller through an air inlet pipeline, a first electromagnetic stop valve is provided on the air inlet pipeline, the air inlet, the air inlet pipeline, the fuel gas flow controller and the first electromagnetic stop valve are arranged at the lower part of the annular fuel tank, a compressed air pipeline is provided at the lower part of the annular fuel tank, and a fourth electromagnetic stop valve is provided on the compressed air pipeline.

3. The carbon calcining rotary kiln body middle fuel supplement system according to claim 1, characterized in that: A second electromagnetic stop valve is arranged on the outlet side of the air pump on the fuel gas nozzle, the air pump is fixed on the rotary kiln shell, and the fuel gas nozzle, the air pump and the second electromagnetic stop valve rotate with the rotary kiln cylinder.

4. The carbon calcining rotary kiln middle fuel supplement system according to claim 1, characterized in that: A pressure measuring device is arranged on the upper part of the annular fuel tank, and a third electromagnetic stop valve and a venting pipe are arranged on the top of the annular fuel tank.

5. The carbon calcining rotary kiln middle fuel supplement system according to claim 1, characterized in that: The fixing frame is in a right angle shape, and the negative pressure in the annular fuel tank is between -5 and -15 Pa.

6. The carbon calcining rotary kiln middle fuel supplement system according to claim 1 or 4, characterized in that: A heat insulation board is arranged between the inner and outer walls of the annular fuel tank and the rotary kiln cylinder, and the heat insulation board and the inner and outer walls of the annular fuel tank are connected by tension bars.

7. The carbon calcining rotary kiln middle fuel supplement system according to claim 3, characterized in that: A slip ring power supply system is arranged on the outer shell of the rotary kiln cylinder at the kiln tail side, and the slip ring power supply system supplies power to the variable frequency motor of the air pump and the second electromagnetic stop valve.

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