Small rotary kiln for laboratory roasting

Abstract

The utility model discloses a small rotary kiln for laboratory roasting, which comprises a barrel, a kiln head cover and a kiln tail cover are respectively arranged at two ends of the barrel, an air outlet is arranged on the kiln tail cover, an air inlet is arranged on the kiln head cover, and the air outlet is communicated with the air inlet through a flue gas return pipe to form a flue gas return passage. According to the rotary kiln system, by arranging the smoke backflow channel, high-temperature tail gas can be recycled at the kiln drying stage and the roasting stage at the same time, on one hand, the high-temperature tail gas is circularly introduced into the barrel, waste heat of the high-temperature tail gas can be used for heating the barrel and materials, and therefore the energy utilization rate of the whole rotary kiln system can be increased; on the other hand, by recycling the high-temperature tail gas, the flue gas can be shunted, the flue gas treatment capacity is reduced, the treatment difficulty of the tail gas can be reduced, further, the treatment pressure of the tail gas of the cooling part at the tail gas treatment end of the rotary kiln system can be reduced, and the stable operation of the flue gas system is facilitated.

Description

Technical Field

[0001] The utility model belongs to the technical field of rotary kiln equipment and relates to a small rotary kiln used for laboratory roasting. Background Art

[0002] The small-scale roasting equipment used in the laboratory is mainly the muffle furnace. The muffle furnace has defects such as small material handling capacity, uneven material roasting, incomplete combustion, high energy consumption, high cost, and small experimental volume. In addition, the roasting method in the muffle furnace is quite different from that in the rotary kiln. Therefore, the roasting experimental results of the muffle furnace cannot clearly simulate the roasting effect of the rotary kiln.

[0003] In response to the above problems, researchers proposed a small rotary kiln suitable for roasting test samples, including a kiln body, a burner, a kiln body rotary drive assembly, a kiln body support assembly and a kiln body smoke exhaust assembly. However, the small rotary kiln still needs to be improved in the following aspects: (1) The rotary kiln is not equipped with a flue gas recycling assembly, and only the kiln tail of the rotary kiln is connected to the kiln body smoke exhaust assembly, and the high-temperature flue gas at the kiln tail is treated through the smoke exhaust duct, cooling mechanism and dust removal mechanism; although this method can achieve dust removal and desulfurization of high-temperature flue gas, the heat in the high-temperature flue gas is also discharged, which not only has the defect of large high-temperature flue gas treatment volume, but also has the shortcomings of poor thermal effect, large heat loss and low energy utilization rate; (2) Only by changing the inclination angle of the kiln body and configuring a double material retaining ring to turn the material, the effect of lifting the material is poor, resulting in poor combustion effect of the flame on the material in the kiln during the roasting process, and there are shortcomings such as uneven combustion of the material and serious under-burning.

[0004] Therefore, it is necessary to obtain a small rotary kiln with uniform material combustion, high energy utilization and low energy consumption in order to obtain usable roasting data and promote the smooth progress of large rotary kiln equipment research. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a small rotary kiln for laboratory roasting with uniform material combustion, high energy utilization rate and low energy consumption in view of the deficiencies in the prior art.

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions.

[0007] A small rotary kiln for laboratory roasting comprises a cylinder, wherein two ends of the cylinder are respectively provided with a kiln head cover and a kiln tail cover, the kiln tail cover is provided with an air outlet, the kiln head cover is provided with an air inlet, the air outlet is connected with the air inlet through a smoke return pipe to form a smoke return passage.

[0008] As a further improvement of the above technical solution: the flue gas reflux pipe is provided with a flue gas outlet; the flue gas outlet is connected to at least one of a dust removal component, a desulfurization component and a denitrification component through a flue gas diversion pipe.

[0009] As a further improvement of the above technical solution: a fan is provided on the smoke return pipe, and the fan is located between the smoke exhaust port and the air outlet; a metal expansion joint is provided between the fan and the smoke exhaust port; the surface of the smoke return pipe is coated with thermal insulation material.

[0010] As a further improvement of the above technical solution: a refractory material layer and a lifting plate are provided on the inner surface of the cylinder;

[0011] One end of the lifting plate is detachably fixed to the inner wall of the cylinder, and the other end extends out from the refractory material layer;

[0012] The height of the lifting plate is greater than the thickness of the refractory material layer; the lifting plate is parallel to the axial direction of the cylinder; the length of the lifting plate is the same as the length of the cylinder; the number of the lifting plates is at least 3.

[0013] As a further improvement of the above technical solution: a discharge port is also provided on the kiln head hood; a material blocking door is provided on the outer side of the discharge port, and the material blocking door is fixed to the kiln head hood by hinges; the material of the material blocking door is alloy steel; the surface of the material blocking door close to the cylinder is covered with refractory coating; a material receiving hopper is provided below the discharge port.

[0014] As a further improvement of the above technical solution: it also includes a combustion assembly; the combustion assembly is connected to the outer side of the kiln head cover; the combustion assembly includes a burner; the burner nozzle of the burner passes through the kiln head cover and enters into the cylinder; the burner nozzle is located on the central axis of the cylinder.

[0015] As a further improvement of the above technical solution: the sealing method between the kiln tail hood and the cylinder is fish scale sealing; a feed port is provided on the kiln tail hood, and the feed port is connected to the cylinder through a feeding funnel; a sealing blind plate is provided at the inlet of the feeding funnel.

[0016] As a further improvement of the above technical solution: it also includes a driving component; the driving component includes a ring gear, a stopper wheel, a driving motor and a reducer; the ring gear is fixed on the outer surface of the cylinder; the ring gear is located in the middle position of the cylinder, and the stopper wheels are located at both ends of the cylinder; the output end of the driving motor is connected to the reducer, and the output end of the reducer is transmission-connected to the ring gear.

[0017] As a further improvement of the above technical solution: the output end of the reducer is meshingly connected with the gear ring.

[0018] As a further improvement of the above technical solution: it also includes a support assembly; the support assembly is located below the cylinder; the support assembly includes a support plate; the drive assembly is fixed on the support plate through a base.

[0019] Compared with the prior art, the advantages of the utility model are:

[0020] (1) In the present invention, by providing a flue gas recirculation passage, the high-temperature exhaust gas can be recycled in both the kiln baking stage and the roasting stage. On the one hand, the high-temperature exhaust gas is circulated into the cylinder, and the waste heat of the high-temperature exhaust gas can be used to heat the cylinder and the material, thereby improving the energy utilization rate of the entire rotary kiln system and making the thermal effect of the equipment more efficient. On the other hand, by recycling the high-temperature exhaust gas, the flue gas can be diverted and the flue gas treatment volume can be reduced, which is beneficial to reducing the difficulty of exhaust gas treatment. Furthermore, it can also reduce the treatment pressure of the cooling part of the exhaust gas at the exhaust gas treatment end of the rotary kiln system, which is beneficial to the stable operation of the flue gas system.

[0021] (2) In the utility model, by arranging a lifting plate in the cylinder, the material in the cylinder can be caused to flip / turn over during the rotation of the cylinder, so that the material gradually falls downward at a temperature close to the angle of repose. During the falling process, on the one hand, the mixing uniformity of the material inside the rotary kiln cylinder can be increased, and the material can be prevented from agglomerating inside the cylinder, thereby avoiding uneven roasting, thereby effectively avoiding overburning or underburning. On the other hand, the contact time and contact area between the material in the cylinder and the flame can be increased, which can make the material burn more fully while efficiently utilizing energy, thereby ensuring uniform combustion of the material in the cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present utility model clearer, the technical solution in the embodiments of the present utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the present utility model.

[0023] Figure 1 It is a schematic structural diagram of a small rotary kiln used for laboratory roasting in an embodiment of the utility model.

[0024] Figure 2 for Figure 1 AA section view.

[0025] Legend:

[0026] 1. Burner; 2. Flow meter; 3. Kiln head cover; 4. Discharge port; 5. Cylinder; 6. Refractory material layer; 7. Lifting plate; 8. Gear ring; 9. Block wheel; 10. Driving motor; 11. Receiving hopper; 12. Kiln tail cover; 13. Air outlet; 14. Feeding funnel; 15. Feed port; 16. Fan; 17. Metal expansion joint; 18. Smoke exhaust port; 19. Smoke diversion pipe; 20. Smoke return pipe; 21. Base; 22. Reducer. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0028] Example

[0029] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0030] In the description of the present utility model, it should be noted that the terms "center", "up", "down", "symmetric", "third phase limit", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present utility model.

[0031] like Figure 1 and Figure 2 As shown, the small rotary kiln used for laboratory roasting in this embodiment includes a cylinder 5, and a kiln head hood 3 and a kiln tail hood 12 are respectively provided at both ends of the cylinder 5. The kiln tail hood 12 is provided with an air outlet 13, and the kiln head hood 3 is provided with an air inlet. The air outlet 13 is connected with the air inlet through a smoke return pipe 20 to form a smoke return passage. In this embodiment, by setting a smoke return passage, the high-temperature tail gas can be recycled in the kiln drying stage and the roasting stage. On the one hand, the high-temperature tail gas is circulated into the cylinder, and the waste heat of the high-temperature tail gas can be used to heat the cylinder and the material, thereby improving the energy utilization rate of the entire rotary kiln system, and the thermal effect of the equipment is more efficient. On the other hand, by recycling the high-temperature tail gas, the smoke can be diverted, the smoke treatment amount can be reduced, which is conducive to reducing the difficulty of tail gas treatment. Further, it can also reduce the treatment pressure of the cooling part of the tail gas at the tail gas treatment end of the rotary kiln system, which is conducive to the stable operation of the smoke system.

[0032] In this embodiment, a flue gas outlet 18 is provided on the flue gas return pipe 20, and the flue gas outlet 18 is connected to a dust removal component, a desulfurization component and a denitration component through a flue gas diversion pipe 19. In the utility model, the dust removal component, the desulfurization component and the denitration component are provided to process the flue gas discharged to the outside, so that the emission of these tail gases can meet the relevant standards.

[0033] In this embodiment, a fan 16 is provided on the smoke return pipe 20, and the fan 16 is located between the smoke exhaust port 18 and the air outlet 13. A metal expansion joint 17 is provided between the fan 16 and the smoke exhaust port 18, and the surface of the smoke return pipe 20 is covered with thermal insulation material.

[0034] In this embodiment, the cylinder 5 is made of low-alloy high-strength structural steel that is rolled and then welded. A refractory material layer 6 and a lifting plate 7 are provided on the inner surface of the cylinder 5. The refractory material layer 6 is formed by stacking refractory bricks. One end of the lifting plate 7 is detachably fixed to the inner wall of the cylinder 5, and the other end extends from the refractory material layer 6, so that the height of the lifting plate 7 is greater than the thickness of the refractory material layer 6. Specifically, the height of the lifting plate 7 can be set according to the type of roasting material and the diameter of the cylinder; in this embodiment, there are eight lifting plates 7, which are all parallel to the axial direction of the cylinder 5 and are evenly arranged inside the cylinder; the length of the lifting plate 7 is the same as the length of the cylinder 5. In this embodiment, by arranging a lifting plate in the cylinder, the material in the cylinder can be caused to flip / turn over during the rotation of the cylinder, so that the material gradually falls downward at a temperature close to the angle of repose. During the falling process, on the one hand, the mixing uniformity of the material inside the rotary kiln cylinder can be increased, and the material can be prevented from agglomerating inside the cylinder, thereby avoiding uneven roasting, thereby effectively avoiding overburning or underburning. On the other hand, the contact time and contact area between the material and the flame can be increased, which can efficiently utilize energy while allowing the material to burn more fully, thereby ensuring uniform combustion of the material in the cylinder.

[0035] In this embodiment, a discharge port 4 is also provided on the kiln head hood 3. The discharge port 4 is rectangular. A material blocking door is provided on the outer side of the discharge port 4. The material blocking door is fixed to the kiln head hood 3 by hinges to control the opening and closing of the discharge port 4. The material of the material blocking door is alloy steel. The surface of the material blocking door close to the cylinder 5 is covered with refractory coating. A material receiving hopper 11 is provided below the discharge port 4, and the material receiving hopper 11 is movable.

[0036] In this embodiment, a combustion assembly is also included; the combustion assembly includes a burner 1, a flow meter 2, a temperature gauge, a pressure gauge, a check valve, an automatic flow cut-off device, a natural gas burner, a gas valve and a combustion-supporting fan; the natural gas and compressed air are introduced into the burner 1 through an alloy pipe, and the gas flow meter, the temperature gauge, the pressure gauge, the check valve and the automatic flow cut-off device are arranged on the alloy pipe. The temperature gauge is used to measure the temperature of the kiln head cover, specifically an infrared thermometer. The combustion assembly is connected to the outside of the kiln head cover 3, specifically, the burner of the burner 1 passes through the kiln head cover 3 and enters the cylinder 5, the burner is located on the central axis of the cylinder 5, and is fixed to the kiln head cover by welding. In this embodiment, the combustion assembly used includes a burner and a variety of detection equipment, mainly to ensure the continuous supply of natural gas, to prevent the natural gas from being suddenly cut off during the roasting process and causing the roasting failure, and also for safety considerations, the kiln head temperature and natural gas are detected to prevent excessive temperature and natural gas leakage. In addition, natural gas and combustion air are controlled by independent opening valves. By controlling the opening of the natural gas and combustion air valves, the air-fuel ratio can be adjusted. At the same time, controlling the opening of the natural gas valve can control the combustion temperature, making it easier to control the temperature inside the rotary kiln.

[0037] In this embodiment, the sealing method between the kiln tail hood 12 and the cylinder 5 is fish scale sealing; the kiln tail hood 12 is provided with a feed port 15, and the feed port 15 is connected to the cylinder 5 through a feeding funnel 14; a sealing blind plate is provided at the inlet of the feeding funnel 14.

[0038] like Figure 1 and Figure 2 As shown, in this embodiment, a driving assembly is also included, wherein the driving assembly includes a gear ring 8, a stopper wheel 9, a driving motor 10 and a reducer 22; the gear ring 8 is fixed on the outer surface of the cylinder 5 and is located in the middle of the cylinder 5, and the stopper wheel 9 is located at both ends of the cylinder 5; the output end of the driving motor 10 is connected to the reducer 22, and the output end of the reducer 22 is meshedly connected with the gear ring 8. In this embodiment, the driving motor 10 drives the reducer 22 to rotate, and then drives the cylinder to rotate through the gear ring 8.

[0039] In this embodiment, a support assembly is also included. The support assembly includes a support plate located below the cylinder 5, wherein the kiln head cover and the kiln tail cover are both fixed on the support plate; the drive assembly is fixed on the support plate through a base 21.

[0040] In this embodiment, the method for using a small rotary kiln for laboratory roasting includes the following steps:

[0041] (1) Open the sealing blind plate and feed the roasting material into the cylinder of the rotary kiln through the feed port and the feed funnel. Compared with the traditional continuous feeding method, the one-time feeding method adopted by the utility model has the following advantages: the laboratory experiment scale is small, the demand for roasting raw materials is small, even a small amount of roasting raw materials can be roasted in this way, which is more suitable for small-scale roasting in the laboratory.

[0042] (2) After the feeding is completed, the sealing blind plate is closed to form a fully enclosed space, the fan is turned on, and then the drive motor can be turned on to drive the rotary kiln cylinder to rotate, and the burner is turned on to heat the rotary kiln cylinder and the materials in the cylinder. While the rotary kiln is being dried, the materials are also roasted.

[0043] (3) During the kiln drying and roasting process, the fan is used to drive the high-temperature exhaust gas to flow back into the cylinder through the flue gas return pipe, and the high-temperature exhaust gas is recycled until the roasting is completed and the operation is stopped.

[0044] Compared with conventional small rotary kilns, the utility model has the following advantages: (1) By setting up a flue gas recirculation path, the high-temperature exhaust gas can be recycled in both the kiln baking stage and the roasting stage. On the one hand, the high-temperature exhaust gas is circulated into the cylinder, and the waste heat of the high-temperature exhaust gas can be used to heat the cylinder and the material, thereby improving the energy utilization rate of the entire rotary kiln system and making the thermal effect of the equipment more efficient. On the other hand, by recycling the high-temperature exhaust gas, the flue gas can be diverted and the flue gas treatment volume can be reduced, which is beneficial to reducing the difficulty of exhaust gas treatment. Furthermore, it can also reduce the treatment pressure of the cooling part of the exhaust gas at the exhaust gas treatment end of the rotary kiln system, which is beneficial to the stable operation of the flue gas system. (2) By arranging a lifting plate in the cylinder, the material in the cylinder can be caused to flip / turn over during the rotation of the cylinder, so that the material gradually falls downward at a repose angle close to that of the repose angle. During the falling process, on the one hand, the mixing uniformity of the material inside the rotary kiln cylinder can be increased, and the material can be prevented from agglomerating inside the cylinder, thereby avoiding uneven roasting, thereby effectively avoiding overburning or underburning. On the other hand, the contact time and contact area between the material in the cylinder and the flame can be increased, which can make the material burn more fully while efficiently utilizing energy, thereby ensuring uniform combustion of the material in the cylinder.

[0045] The above is only a preferred embodiment of the utility model, and does not limit the utility model in any form. Although the utility model has been disclosed as above in the preferred embodiment, it is not used to limit the utility model. Any technician familiar with the field can make many possible changes and modifications to the technical solution of the utility model by using the methods and technical contents disclosed above without departing from the spirit and technical solution of the utility model, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical essence of the utility model without departing from the content of the technical solution of the utility model, still fall within the scope of protection of the technical solution of the utility model.

Claims

1. A small rotary kiln for laboratory roasting, comprising a cylinder (5), wherein a kiln head cover (3) and a kiln tail cover (12) are respectively provided at both ends of the cylinder (5), an air outlet (13) is provided on the kiln tail cover (12), and an air inlet is provided on the kiln head cover (3), characterized in that: The air outlet (13) is connected to the air inlet via a smoke return pipe (20) to form a smoke return passage.

2. The small rotary kiln for laboratory roasting according to claim 1, characterized in that: The flue gas return pipe (20) is provided with a flue gas outlet (18); the flue gas outlet (18) is connected to at least one of a dust removal component, a desulfurization component and a denitration component via a flue gas diversion pipe (19).

3. The small rotary kiln for laboratory roasting according to claim 2, characterized in that: The smoke return pipe (20) is provided with a fan (16), and the fan (16) is located between the smoke exhaust port (18) and the air outlet (13); a metal expansion joint (17) is provided between the fan (16) and the smoke exhaust port (18); and the surface of the smoke return pipe (20) is coated with thermal insulation material.

4. The small rotary kiln for laboratory roasting according to claim 3, characterized in that: A refractory material layer (6) and a lifting plate (7) are provided on the inner surface of the cylinder (5); one end of the lifting plate (7) is detachably fixed to the inner wall of the cylinder (5), and the other end extends out of the refractory material layer (6); the height of the lifting plate (7) is greater than the thickness of the refractory material layer (6); the lifting plate (7) is parallel to the axial direction of the cylinder (5); the length of the lifting plate (7) is the same as the length of the cylinder (5); the number of the lifting plates (7) is at least 3.

5. The small rotary kiln for laboratory roasting according to any one of claims 1 to 4, characterized in that: The kiln head cover (3) is also provided with a discharge port (4); a material blocking door is provided on the outer side of the discharge port (4), and the material blocking door is fixed to the kiln head cover (3) by means of hinges; the material of the material blocking door is alloy steel; the surface of the material blocking door close to the cylinder (5) is covered with refractory coating; and a material receiving hopper (11) is provided below the discharge port (4).

6. The small rotary kiln for laboratory roasting according to any one of claims 1 to 4, characterized in that: It also includes a combustion assembly; the combustion assembly is connected to the outside of the kiln head cover (3); the combustion assembly includes a burner (1); the burner of the burner (1) passes through the kiln head cover (3) and enters into the cylinder (5); the burner is located on the central axis of the cylinder (5).

7. The small rotary kiln for laboratory roasting according to any one of claims 1 to 4, characterized in that: The sealing method between the kiln tail cover (12) and the cylinder (5) is fish scale sealing; the kiln tail cover (12) is provided with a feed port (15), and the feed port (15) is connected to the cylinder (5) through a feeding funnel (14); a sealing blind plate is provided at the inlet of the feeding funnel (14).

8. The small rotary kiln for laboratory roasting according to any one of claims 1 to 4, characterized in that: The invention also comprises a driving assembly; the driving assembly comprises a ring gear (8), a stopper wheel (9), a driving motor (10) and a reducer (22); the ring gear (8) is fixed on the outer surface of the cylinder (5); the ring gear (8) is located in the middle of the cylinder (5), and the stopper wheel (9) is located at both ends of the cylinder (5); the output end of the driving motor (10) is connected to the reducer (22), and the output end of the reducer (22) is drivingly connected to the ring gear (8).

9. The small rotary kiln for laboratory roasting according to claim 8, characterized in that: The output end of the reducer (22) is meshingly connected with the ring gear (8).

10. The small rotary kiln for laboratory roasting according to claim 9, characterized in that: It also includes a support assembly; the support assembly is located below the cylinder (5); the support assembly includes a support plate; and the drive assembly is fixed on the support plate via a base (21).

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