Rotary kiln for producing light calcined magnesia

Abstract

The utility model discloses a rotary kiln for producing light calcined magnesia, which relates to the technical field of rotary kilns and comprises a bottom plate, an inclined plate is fixedly arranged on the bottom plate, a rotary drum is rotatably mounted on the upper surface of the inclined plate through a plurality of fixing rings, a feeding pipe is fixedly arranged at one end, close to the high side of the rotary drum, of the inclined plate, and a spiral heat exchange pipe is wound on the side wall of the feeding pipe. A discharging box is fixedly arranged at the end, close to the lower side of the rotary drum, of the inclined plate, one end of the rotary drum is rotationally connected into the discharging box, an inclined pipe part is arranged below one side of the discharging box, an upper air box and a lower air box are arranged on the upper side and the lower side of the inclined pipe part respectively, and the upper air box and the lower air box are connected through a plurality of communicating pipes penetrating through the inclined pipe part. According to the device, gas in the communicating pipe, the upper gas box and the lower gas box can be heated through discharged high-temperature materials, the heated gas is pumped into the spiral heat exchange pipe through the gas pump, low-temperature magnesium oxide raw materials in the feeding pipe are preheated, a closed loop of waste heat recovery and raw material preheating is achieved, and extra heating energy consumption is reduced.

Description

Technical Field

[0001] This utility model relates to the field of rotary kiln technology, specifically a rotary kiln for the production of lightly calcined magnesium oxide. Background Technology

[0002] Light-burned magnesia is an active magnesia product obtained by calcining and decomposing raw materials such as magnesite and brucite, with magnesium carbonate as the main component, at a relatively low temperature (700-1000℃). At present, the mainstream equipment for large-scale industrial production of light-burned magnesia is the rotary kiln. The rotary kiln is a long cylindrical thermal device that is slightly inclined and rotates slowly. The material is added from the high end (kiln tail) and slowly moves to the low end (kiln head) as the cylinder rotates and is heated to complete the physical and chemical reactions.

[0003] For example, the utility model patent with announcement number CN222231256U discloses a magnesia calcination rotary kiln, which includes a rotary kiln, a collection component installed at the bottom of a dust collection hood, a disassembly component installed inside the dust collection hood and inside the smoke chamber, the disassembly component being located at the top of the collection component, the collection component including a sealing strip located on one side of the smoke chamber, a collection cloth fixedly connected to one end of the sealing strip, a drive strip fixedly connected to the other end of the collection cloth away from the sealing strip, drive rods fixedly connected to both sides of the collection cloth near the drive rods, the drive rods being L-shaped, the drive rods passing through the sealing strip and being movably sleeved with it, a connecting rod fixedly connected to the other end of the drive rod away from the collection cloth, a hinge plate movably connected to the inner side of the connecting rod, the hinge plate being located outside the smoke chamber;

[0004] However, the material exiting the kiln after calcination is at a high temperature. Existing technology directly discharges the material out of the kiln without recovering or utilizing the heat. Meanwhile, the temperature of the magnesium oxide raw material is low before entering the kiln, requiring more energy to heat the magnesium oxide raw material during calcination, thus increasing energy consumption. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides a rotary kiln for the production of lightly calcined magnesia, thereby solving the problems mentioned in the background section.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A rotary kiln for the production of light-burned magnesia includes a base plate, an inclined plate fixedly mounted on the base plate, a rotating cylinder rotatably mounted on the upper surface of the inclined plate via multiple fixing rings, a feed pipe fixedly mounted on the end of the inclined plate near the high side of the rotating cylinder, one end of the feed pipe extending into the rotating cylinder, a feed hopper connected above the other end of the feed pipe, a spiral heat exchange tube wound around the side wall of the feed pipe, a discharge box fixedly mounted on the end of the inclined plate near the low side of the rotating cylinder, one end of the rotating cylinder rotatably connected to the discharge box, an inclined tube section located below one side of the discharge box, an upper gas box and a lower gas box respectively located on the upper and lower sides of the inclined tube section, the upper and lower gas boxes being connected by multiple connecting pipes penetrating the inclined tube section, an outlet gas pipe connected to the upper gas box, a supply gas pipe connected to the lower gas box, the outlet gas pipe and the supply gas pipe being connected to both ends of the spiral heat exchange tube, and an air pump mounted on the outlet gas pipe.

[0007] Preferably, a heating cylinder is fixedly mounted on the upper surface of the inclined plate by multiple support rods, and the heating cylinder is fitted onto the outside of the rotating cylinder.

[0008] Preferably, a plurality of the connecting pipes are arranged in the inclined pipe section, and the connecting pipes in adjacent rows are staggered.

[0009] Preferably, the bottom of the inclined tube is provided with a cylindrical part, an impeller is rotatably disposed inside the cylindrical part, and a motor for driving the impeller to rotate is fixedly disposed on the outer wall of one side of the cylindrical part.

[0010] Preferably, a filling rotating rod is rotatably arranged inside the feeding pipe, and a spiral blade is fixedly arranged on the outer surface of the filling rotating rod. A second motor for driving the filling rotating rod to rotate is fixedly arranged on the outside of the feeding pipe.

[0011] Preferably, a material flow channel with an annular cross-section is formed between the outer surface of the filling rotating rod and the inner wall of the feeding pipe, and the thickness of the annular cross-section is 5cm to 10cm.

[0012] Preferably, a gear ring is fixedly mounted on the rotating drum, a reducer is fixedly mounted on the inclined plate, a motor is connected to the power input end of the reducer, and a gear that meshes with the gear ring is connected to the power output end of the reducer.

[0013] This utility model provides a rotary kiln for the production of lightly calcined magnesium oxide, which has the following beneficial effects:

[0014] When the high-temperature material (after calcination) flows through the inclined tube section, it can heat the gas in the connecting pipe, upper gas box, and lower gas box. The gas pump pumps the heated gas into the spiral heat exchange tube to preheat the low-temperature magnesium oxide raw material in the feed pipe, realizing a closed loop of "waste heat recovery → raw material preheating", reducing additional heating energy consumption, meeting energy-saving requirements, and reducing calcination time.

[0015] The spiral blades can stably push the magnesium oxide raw material, avoiding material blockage. They greatly increase the contact area between the magnesium oxide raw material and the feeding pipe, creating a thin material flow channel of 5cm to 10cm, making the magnesium oxide raw material heat more evenly and the preheating effect better.

[0016] The staggered arrangement of the connecting pipes can disperse the high-temperature materials flowing through, prolong the contact time between the materials and the connecting pipes, increase the contact area, avoid the heat waste caused by the "rapid passage" of materials, and further improve the waste heat recovery efficiency.

[0017] The impeller rotation speed can be controlled by adjusting the speed of motor one, thereby controlling the material discharge rate of the inclined tube section and ensuring that the material has enough time to release heat in the inclined tube section. Attached Figure Description

[0018] Figure 1 This is a perspective view of the present utility model;

[0019] Figure 2 This is a cross-sectional view of the present invention;

[0020] Figure 3 This is a sectional view of the inclined tube section.

[0021] In the diagram: 1. Base plate; 2. Inclined plate; 3. Fixing ring; 4. Rotary drum; 5. Feed pipe; 6. Feed hopper; 7. Spiral heat exchange tube; 8. Discharge box; 9. Inclined tube section; 10. Upper air box; 11. Lower air box; 12. Connecting pipe; 13. Air outlet pipe; 14. Air supply pipe; 15. Air pump; 16. Support rod; 17. Heating cylinder; 18. Cylindrical section; 19. Impeller; 20. Motor 1; 21. Filling rotating rod; 22. Spiral blade; 23. Motor 2; 24. Gear ring; 25. Reducer; 26. Motor 3; 27. Gear. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0023] Please see Figures 1-3This utility model provides a technical solution: a rotary kiln for producing light-burned magnesia, including a bottom plate 1, an inclined plate 2 fixedly mounted on the bottom plate 1, a rotating cylinder 4 rotatably mounted on the upper surface of the inclined plate 2 via multiple fixing rings 3, a feed pipe 5 fixedly mounted on the inclined plate 2 near the higher side of the rotating cylinder 4, one end of the feed pipe 5 extending into the rotating cylinder 4 for feeding material into the rotary kiln, a feed hopper 6 connected above the other end of the feed pipe 5, a spiral heat exchange tube 7 wound around the side wall of the feed pipe 5, the heat exchange medium flowing in the spiral heat exchange tube 7 heating the feed pipe 5, thereby heating the magnesia raw material entering the rotating cylinder 4, a discharge box 8 fixedly mounted on the inclined plate 2 near the lower side of the rotating cylinder 4, one end of the rotating cylinder 4 rotatably connected to the discharge box 8, the material discharged from the rotating cylinder 4 entering the discharge box 8, and a heat recovery device located on one side of the discharge box 8. The inclined tube section 9 has an upper gas box 10 and a lower gas box 11 on its upper and lower sides, respectively. The upper gas box 10 and the lower gas box 11 are connected by multiple connecting pipes 12 that pass through the inclined tube section 9. The upper gas box 10 is connected to an outlet pipe 13, and the lower gas box 11 is connected to a supply pipe 14. The outlet pipe 13 and the supply pipe 14 are connected to both ends of the spiral heat exchange tube 7 to form a gas circulation pipeline. In addition, an explosion-proof valve (not shown in the figure) can be installed on this circulation pipeline. An air pump 15 is installed on the outlet pipe 13. When the air pump 15 is started, it can make the gas flow. When the gas passes through the lower gas box 11, the connecting pipe 12, and the upper gas box 10, it is heated by the material in the inclined tube section 9. The high-temperature gas flows into the spiral heat exchange tube 7 through the pipeline under the pumping of the air pump 15, thereby heating the feed pipe 5 and heating the magnesium oxide raw material inside it through the feed pipe 5.

[0024] As an embodiment of this utility model, a heating cylinder 17 is fixedly installed on the upper surface of the inclined plate 2 by a plurality of support rods 16. The heating cylinder 17 is fitted on the outside of the rotating drum 4. An electromagnetic coil is installed inside the heating cylinder 17. The rotating drum 4 is heated by the electromagnetic coil to heat the material inside the rotating drum 4. The electromagnetic coil used in this application is a conventional technology. The specific detailed structure will not be described in detail here.

[0025] As an embodiment of this utility model, multiple connecting pipes 12 are arranged in the inclined pipe section 9, and the connecting pipes 12 in adjacent rows are staggered, so that the high-temperature material is dispersed, aggregated and dispersed when passing through multiple connecting pipes 12, so as to fully recover the heat in the material and improve the heat exchange effect.

[0026] As an embodiment of this utility model, a cylindrical part 18 is provided at the bottom of the inclined tube part 9, and an impeller 19 is rotatably arranged inside the cylindrical part 18. A motor 20 for driving the impeller 19 to rotate is fixedly arranged on the outer wall of one side of the cylindrical part 18. The impeller 19 and the motor 20 form a fan-lock structure. By controlling the rotation speed of the impeller 19, the residence time of the material in the inclined tube part 9 can be controlled, so as to avoid the material passing through the inclined tube part 9 too quickly and reducing the heat recovery effect.

[0027] As an embodiment of this utility model, a filling rotating rod 21 is rotatably arranged inside the feeding pipe 5, and a spiral blade 22 is fixedly arranged on the outer surface of the filling rotating rod 21. A second motor 23 for driving the filling rotating rod 21 to rotate is fixedly arranged on the outside of the feeding pipe 5. Starting the second motor 23 can make the filling rotating rod 21 rotate, and the material in the feeding pipe 5 is driven to move into the rotating drum 4 through the spiral blade 22.

[0028] Furthermore, a material flow channel with an annular cross-section is formed between the outer surface of the filling rotating rod 21 and the inner wall of the feeding pipe 5. The thickness of the annular cross-section is 5cm to 10cm. The magnesium oxide raw material can be more easily heated through the flow channel with a thickness of 5cm to 10cm.

[0029] As an embodiment of this utility model, a gear ring 24 is fixedly installed on the rotating drum 4, and a reducer 25 is fixedly installed on the inclined plate 2. The power input end of the reducer 25 is connected to a motor 26, and the power output end of the reducer 25 is connected to a gear 27 that meshes with the gear ring 24. The motor 26 is started and its speed is reduced by the reducer 25 to drive the rotating drum 4 to rotate.

[0030] The working principle and usage process of this utility model are as follows: In use, magnesium oxide raw material is fed into the feeding pipe 5 through the feeding hopper 6. Starting the motor 23 causes the spiral blades 22 to rotate, which feeds the magnesium oxide raw material into the rotating drum 4. The heating cylinder 17 heats the rotating drum 4 and sinters the magnesium oxide inside. After sintering, the material flows into the discharge box 8. When the material passes through the inclined tube 9, it heats the gas in the lower gas box 11, the connecting pipe 12, and the upper gas box 10. The heated gas is then transported to the spiral heat exchanger tube 7 by the air pump 15. Heat pipe 7 heats the material in feed pipe 5, achieving heat recovery. Finally, the gas in spiral heat exchanger 7 flows back to lower gas box 11, ready to be heated again. Multiple rows of staggered connecting pipes 12 can improve the recovery of heat in the material. Filling rod 21 can reduce the thickness of magnesium oxide raw material when flowing in feed pipe 5, thereby improving the heating effect of magnesium oxide raw material. The rotation speed of impeller 19 can be controlled by starting motor 20. By controlling the rotation speed of impeller 19, the discharge rate of material in inclined tube 9 can be controlled to ensure that the material can fully contact the connecting pipe 12.

[0031] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A rotary kiln for the production of light-burned magnesia, characterized in that, Includes a base plate (1), on which an inclined plate (2) is fixedly mounted. A rotating cylinder (4) is rotatably mounted on the upper surface of the inclined plate (2) via multiple fixing rings (3). A feeding pipe (5) is fixedly mounted on one end of the inclined plate (2) near the high side of the rotating cylinder (4). One end of the feeding pipe (5) extends into the rotating cylinder (4), and a feed hopper (6) is connected above the other end of the feeding pipe (5). A spiral heat exchange tube (7) is wound around the side wall of the feeding pipe (5). A discharge box (8) is fixedly mounted on one end of the inclined plate (2) near the low side of the rotating cylinder (4). One end of the rotating cylinder (4) rotates... The material is dynamically connected inside the discharge box (8). An inclined tube section (9) is provided on one side of the discharge box (8). An upper air box (10) and a lower air box (11) are respectively provided on the upper and lower sides of the inclined tube section (9). The upper air box (10) and the lower air box (11) are connected by multiple connecting pipes (12) that penetrate the inclined tube section (9). The upper air box (10) is connected to an air outlet pipe (13). The lower air box (11) is connected to an air supply pipe (14). The air outlet pipe (13) and the air supply pipe (14) are connected to both ends of the spiral heat exchange tube (7). An air pump (15) is provided on the air outlet pipe (13).

2. The rotary kiln for producing light-burned magnesia according to claim 1, characterized in that, A heating cylinder (17) is fixedly mounted on the upper surface of the inclined plate (2) by multiple support rods (16), and the heating cylinder (17) is fitted on the outside of the rotating cylinder (4).

3. The rotary kiln for producing light-burned magnesia according to claim 1, characterized in that, Multiple connecting pipes (12) are arranged in the inclined pipe section (9), and the connecting pipes (12) in adjacent rows are staggered.

4. The rotary kiln for producing light-burned magnesia according to claim 1, characterized in that, The bottom of the inclined tube (9) is provided with a cylindrical part (18), and an impeller (19) is rotatably provided inside the cylindrical part (18). A motor (20) for driving the impeller (19) to rotate is fixedly provided on the outer wall of one side of the cylindrical part (18).

5. A rotary kiln for producing light-burned magnesia according to claim 1, characterized in that, A filling rotating rod (21) is rotatably installed inside the feeding pipe (5). A spiral blade (22) is fixedly installed on the outer surface of the filling rotating rod (21). A second motor (23) for driving the filling rotating rod (21) to rotate is fixedly installed on the outer side of the feeding pipe (5).

6. The rotary kiln for producing light-burned magnesia according to claim 5, characterized in that, The outer surface of the filling rotating rod (21) and the inner wall of the feeding pipe (5) form a material flow channel with an annular cross section, the thickness of which is 5cm to 10cm.

7. A rotary kiln for producing light-burned magnesia according to claim 1, characterized in that, A gear ring (24) is fixedly installed on the rotating drum (4), and a reducer (25) is fixedly installed on the inclined plate (2). The power input end of the reducer (25) is connected to a motor (26), and the power output end of the reducer (25) is connected to a gear (27) that meshes with the gear ring (24).

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