Reducing type electromagnetic heating rotary kiln system

Abstract

The invention discloses a variable-diameter electromagnetic heating rotary kiln system, which belongs to the technical field of rotary kiln heating, and comprises a kiln body, and an electromagnetic heating coil formed by a hollow-core spiral lead is wound on an electromagnetic heating coil rack positioned outside a charging barrel; the electromagnetic heating coil is characterized in that the electromagnetic heating coil is formed by combining a preset number of independent electromagnetic heating coil units, and each independent electromagnetic heating coil unit comprises an electromagnetic heating coil rack and an electromagnetic heating coil; the charging barrel comprises a heating tube pass and a heat preservation tube pass; the inner diameters of the charging barrels of the heating tube pass and the thermal insulation tube pass are different, and the adjacent raising plates along the axis of the thermal insulation tube pass are symmetrically arranged in a staggered manner. The rotary kiln has the beneficial effects that the inner diameter of the charging barrel of the heat preservation tube pass is larger than that of the heating tube pass, on the premise that the occupied area is not increased, the calcination time of materials in the rotary kiln is prolonged, and the calcination capacity is improved; and the lifting plate ensures that enough calcining time is reserved for the materials in the rotary kiln under the condition that the materials are turned over, so that the materials are more uniform.

Description

Technical field:

[0001] The invention belongs to the technical field of rotary kiln heating, and more particularly relates to a variable diameter electromagnetic heating rotary kiln system. Background technology:

[0002] The rotary kiln is an important heat treatment equipment, mainly used in the fields of coke production and biomass pyrolysis. The bottom of the gas rotary kiln is equipped with gears and a reducer. The motor drives the gears to rotate, thereby driving the kiln body to rotate. At the same time, the gas enters the bottom of the furnace body and is sent into the kiln through the gas exhaust fan.

[0003] The rotary kiln requires sufficient temperature for heat exchange during pyrolysis. Using traditional coal-fired or gas-fired heating methods will result in large amounts of carbon dioxide emissions and cause environmental pollution.

[0004] The national utility model patent No. 202322534104.8 discloses an electromagnetic heating device for a rotary kiln, which solves the above problems very well. The rotary kiln is heated by electromagnetic induction. The principle of electromagnetic heating is to generate an alternating magnetic field through an electromagnetic heating coil. When an iron-containing container is placed on it, the surface of the container cuts the alternating magnetic field lines and generates alternating current (i.e. eddy current) in the metal part at the bottom of the container. The eddy current causes the carriers at the bottom of the container to move irregularly at high speed. The carriers collide and rub with atoms to generate heat energy, thereby achieving the effect of heating the object.

[0005] This structure can only be applied to general physics. For materials that are difficult to calcine, it will lead to insufficient calcination. However, simply extending the length of the barrel to extend the calcination time will make the equipment too long and occupy too much floor space. Summary of the invention:

[0006] In order to solve the above problems and overcome the shortcomings of the prior art, the present invention provides a variable diameter electromagnetic heating rotary kiln system;

[0007] The first technical problem to be solved is that the existing electromagnetic heating rotary kiln will lead to insufficient calcination of materials that are difficult to calcine, and blindly extending the length of the barrel to extend the calcination time will cause the equipment to be too long and occupy too much floor space.

[0008] The specific technical solution of the present invention to solve the above technical problems is: a variable diameter electromagnetic heating rotary kiln system, including a kiln body, wherein the kiln body is sequentially provided with a feeding part, a heating part and a discharging part from front to back, the heating part has an axially extending barrel, an electromagnetic heating coil frame is rotatably connected and sleeved on the outer side of the barrel, the barrel is supported and rotated by a barrel support frame, and the electromagnetic heating coil frame located outside the barrel is wound with an electromagnetic heating coil composed of a hollow spiral wire. When energized, the electromagnetic heating coil induces eddy currents in the barrel shell through electromagnetic induction, thereby heating the barrel shell. The system is characterized in that:

[0009] The electromagnetic heating coil is composed of a preset number of independent electromagnetic heating coil units, each of which includes an electromagnetic heating coil frame and an electromagnetic heating coil;

[0010] The barrel includes a heating pipe and an insulation pipe; the inner diameters of the heating pipe and the insulation pipe are different.

[0011] The inner wall of the barrel of the insulation pipe is provided with a lifting plate, which is L-shaped, and the lifting plates adjacent to each other along the axis of the insulation pipe are staggered and symmetrically arranged.

[0012] Furthermore, the inner diameter of the barrel of the insulation tube is larger than the inner diameter of the heating tube.

[0013] Furthermore, the electromagnetic heating coils of the adjacent electromagnetic heating coil units of the barrel of the thermal insulation pipe are powered by three-phase alternating current with a phase difference of 120°.

[0014] Furthermore, the feed portion is provided with a feed port and a feed pipe, the front end of the feed pipe is communicated with the feed port, and the rear end of the feed pipe is connected to the heating portion.

[0015] Furthermore, the adjacent lifting plates are staggered and symmetrically arranged on the inner wall of the insulation pipe.

[0016] Furthermore, the lifting plate is L-shaped, and the corners of the L-shape are configured as rounded corner structures.

[0017] Furthermore, the barrel has an inclination that is higher at the front and lower at the back.

[0018] The beneficial effects of the present invention are:

[0019] One advantage of the present invention is that it provides a variable-diameter electromagnetic heating rotary kiln system. The inner diameter of the barrel of the insulation tube is larger than the inner diameter of the heating tube. Without increasing the floor space, the calcination time of the material in the rotary kiln is extended, thereby improving the calcination capacity.

[0020] One advantage of the present invention is that a lifting plate is provided to ensure that the material is turned over and that the material has sufficient calcination time in the rotary kiln, thereby making the material more uniform. Description of the drawings:

[0021] Attachment Figure 1 It is a schematic structural diagram of the present invention;

[0022] Attachment Figure 2 Schematic diagram of the structure of the lifting plate of the present invention; in the accompanying drawings:

[0023] 1. Feeding section; 2. Barrel support frame; 3. Power structure; 4. Electromagnetic heating coil frame; 5. Electromagnetic heating coil; 6. Barrel; 7. Heating pipe; 8. Insulation pipe; 9. Discharging section; 10. Lifting plate. Specific implementation method:

[0024] In describing the present invention, it should be understood that the terms "center," "upper," "lower," "left," "right," "rear," "lower left," "upper right," and "outer" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the scope of protection of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] Specific implementation of the present invention: The variable diameter electromagnetic heating rotary kiln system includes a kiln body, and the kiln body is sequentially provided with a feed part 1, a heating part and a discharge part 9 from front to back. The feed part 1 is provided with a feed port and a delivery pipe. The front end of the delivery pipe is connected to the feed port, and the rear end of the delivery pipe is connected to the heating part. The heating part has an axially extending barrel 6. The outer side of the barrel 6 is rotatably connected and sleeved with an electromagnetic heating coil frame 4. The barrel 6 is supported and rotated by the barrel support frame 2. The electromagnetic heating coil frame 4 located outside the barrel 6 is wound with an electromagnetic heating coil 5 composed of a hollow spiral wire. The barrel 6 has an inclination that is higher in the front and lower in the back, so that the material can be unloaded by gravity. The improvements of the present invention are:

[0026] The electromagnetic heating coil 5 is composed of a preset number of independent electromagnetic heating coil units, each of which includes an electromagnetic heating coil frame 4 and an electromagnetic heating coil 5. In this way, temperature control of multiple independent zones can be achieved, thereby realizing multi-stage zone heating.

[0027] The barrel 6 includes a heating tube 7 and an insulation tube 8. The inner diameters of the barrel 6 of the heating tube 7 and the insulation tube 8 are different. The inner diameter of the barrel 6 of the insulation tube 8 is larger than the inner diameter of the heating tube 7. This form of diameter change can increase the capacity of the insulation tube 8, thereby extending the calcination time of the material in the rotary kiln without increasing the floor space, thereby improving the calcination capacity.

[0028] However, this structure also has defects, such as the uneven heating of the internal materials. In order to compensate for the above defects, the inner wall of the barrel 6 of the insulation pipe 8 of the present invention is provided with a lifting plate 10.

[0029] Ensure that the material is turned over and allowed to have enough calcination time in the rotary kiln to make the material more uniform.

[0030] In order to increase the adaptability of the device, the lifting plate 10 is L-shaped, and the lifting plates 10 adjacent to each other along the axis of the insulation pipe 8 are staggered and symmetrically arranged. In this way, whether the barrel 6 rotates forward or reverse, the lifting plate 10 can turn, load and lift the material.

[0031] However, in actual use, it was found that the staggered symmetrical arrangement of the lifting plates 10 adjacent to the axis of the insulation pipe 8 resulted in incomplete calcination of the material, and the effect was no different from that without the lifting plates 10.

[0032] According to the method of GB / T 35156-2017, the free calcium oxide content of cement clinker is tested to determine the product qualification rate and uniformity.

[0033] For samples from different locations or production time points in the same batch, perform multiple strength tests according to GB / T 17671 and calculate the standard deviation or coefficient of variation CV;

[0034] The results are shown in Table 1:

[0035] Table 1: Effects of different settings on the calcination effect of the rotary kiln

[0036]

[0037] From the data analysis in Table 1, we can see that:

[0038] [1] Compared with Comparative Example 1 and Comparative Example 2, the present invention has the following characteristics:

[0039] Since comparative example 1 uses gas heating and there is no barrel diameter change, under the same barrel length setting, the calcination time of the material in the rotary kiln is short, the calcination effect is poor, and it does not meet the test indicators of free calcium oxide content to determine the product qualification rate and uniformity. According to GB / T 17671, multiple strength tests were carried out, and the calculated standard deviation or coefficient of variation CV was greater than 5%;

[0040] Since Comparative Example 2 uses conventional electromagnetic heating with no phase difference and cross-power supply, the calcination time of the material in the rotary kiln is shorter under the same barrel length setting, and the calcination effect is not much different from that of Comparative Example 1.

[0041] [2] Compared with Comparative Example 3, the present invention has the following characteristics:

[0042] Comparative Example 3 is an embodiment with defects discovered during the research and development of the present invention. In order to increase the adaptability of the device, the lifting plate 10 is L-shaped, and the lifting plates 10 adjacent to the axis of the insulation pipe 8 are staggered and symmetrically arranged. In this way, whether the barrel 6 rotates forward or reverse, the lifting plates 10 can turn, load, and lift the material. In actual use, it was found that the staggered and symmetrical arrangement of the lifting plates 10 adjacent to the axis of the insulation pipe 8 resulted in incomplete calcination of the material, and the effect was no different from that of Comparative Example 2 without the lifting plates 10.

[0043] [3] Compared with Comparative Example 4, the present invention has the following characteristics:

[0044] In order to further study the defects of comparative example 3, the present invention further studies the influence of the structure of the lifting plate on the calcination effect, and modifies the structure of the L-shaped iron lifting plates arranged symmetrically and staggered to have consistent angles, directions and positions, specifically arranged in a linear matrix along the axis of the insulation pipe 8.

[0045] It was unexpectedly found that the calcination effect of Example 4 was improved, but the uniformity was poor and still did not meet the standards.

[0046] [4] Compared with Comparative Example 5, the present invention has the following characteristics:

[0047] In order to further study the defects of comparative example 4, the cross power supply without phase difference was corrected to the cross phase of the present invention, and it was found that there was no difference in the calcination effect between comparative example 5 and comparative example 4.

[0048] It can be seen that the variable diameter barrel used in the present invention, in combination with the staggered symmetrical arrangement and the use of three-phase AC power supply with a phase difference of 120°, can extend the calcination time of the material in the rotary kiln and improve the calcination capacity without increasing the floor space.

[0049] In particular, the problem of incomplete calcination of materials caused by the staggered and symmetrical arrangement of the material lifting plates 10 adjacent to the axis of the insulation pipe 8 is solved;

[0050] The inventors have made a principled inference on the above issues:

[0051] The tip or corner of the L-shaped structure may cause magnetic field distortion, resulting in uneven heating of the material. In particular, the staggered and symmetrically arranged L-shaped iron material lifting plates cause magnetic field distortion, reducing the heating efficiency of the material.

[0052] Faced with the technical bottleneck of L-shaped iron material lifting plates causing magnetic field distortion and reducing the heating efficiency of the material, the inventors creatively introduced an electromagnetic heating coil composed of a preset number of independent electromagnetic heating coil units and a three-phase AC power supply method with a phase difference of 120 degrees. A traveling wave magnetic field is formed through electromagnetic coupling. In the formed traveling wave magnetic field, when the moving magnetic field penetrates the staggered and symmetrically arranged L-shaped iron material lifting plates, magnetic field distortion can be generated at the corners of the lifting plates, and a heated material heating area is generated at the L-shaped tip.

[0053] More importantly, the alternating induced electric field generated according to Maxwell's equations forces the eddy current path to be dynamically adjusted through the movement of the magnetic field. Through the coupling of the movement of the turning plate and the magnetic field distortion, the thermal field distribution is periodically changed, and dynamic phase compensation of the material heating area is achieved to ensure the continuity of the magnetic field in the variable diameter section, effectively solve the problem of uneven electromagnetic heating in the variable diameter rotary kiln, and improve energy efficiency and process stability.

[0054] As a preferred embodiment of the present invention: the lifting plate 10 is L-shaped, and the corners of the L-shape are set to a rounded structure. Under the premise of ensuring the above-mentioned effects, it can avoid the problem of the L-shaped corners being too sharp, resulting in the magnetic field distortion threshold being too large, resulting in exceeding the dynamic phase compensation.

[0055] In summary:

[0056] The present invention creatively provides a variable-diameter electromagnetic heating rotary kiln system. The inner diameter of the barrel of the insulation tube is larger than the inner diameter of the heating tube. Without increasing the floor space, the calcination time of the material in the rotary kiln is extended, thereby improving the calcination capacity.

[0057] The present invention creatively provides a lifting plate to ensure that the material has sufficient calcination time in the rotary kiln while turning the material, so that the material is more uniform.

[0058] Faced with the technical bottleneck of L-shaped iron material lifting plates causing magnetic field distortion and reducing the heating efficiency of the material, the inventors creatively introduced an electromagnetic heating coil composed of a preset number of independent electromagnetic heating coil units and a three-phase AC power supply method with a phase difference of 120 degrees. A traveling wave magnetic field is formed through electromagnetic coupling. In the formed traveling wave magnetic field, when the moving magnetic field penetrates the staggered and symmetrically arranged L-shaped iron material lifting plates, magnetic field distortion can be generated at the corners of the lifting plates, and a heated material heating area is generated at the L-shaped tip.

[0059] More importantly, the alternating induced electric field generated according to Maxwell's equations forces the eddy current path to be dynamically adjusted through the movement of the magnetic field. Through the coupling of the movement of the turning plate and the magnetic field distortion, the thermal field distribution is periodically changed, and dynamic phase compensation of the material heating area is achieved to ensure the continuity of the magnetic field in the variable diameter section, effectively solve the problem of uneven electromagnetic heating in the variable diameter rotary kiln, and improve energy efficiency and process stability.

Claims

1. A variable diameter electromagnetic heating rotary kiln system, comprising a kiln body, wherein the kiln body is provided with a feeding part (1), a heating part and a discharging part (9) in sequence from front to back, the heating part having an axially extending barrel (6), an electromagnetic heating coil frame (4) being rotatably connected and sleeved on the outer side of the barrel (6), the barrel (6) being supported and rotatable by a barrel support frame (2), an electromagnetic heating coil (5) consisting of a hollow spiral conductor being wound around the electromagnetic heating coil frame (4) located outside the barrel (6), and characterized in that: The electromagnetic heating coil (5) is composed of a preset number of independent electromagnetic heating coil units, and the independent electromagnetic heating coil units include an electromagnetic heating coil frame (4) and an electromagnetic heating coil (5); The barrel (6) includes a heating pipe (7) and a heat-insulating pipe (8); the inner diameters of the barrel (6) of the heating pipe (7) and the heat-insulating pipe (8) are different. The inner wall of the barrel (6) of the heat-insulating pipe (8) is provided with a lifting plate (10), which is L-shaped. The lifting plates (10) adjacent to each other along the axis of the heat-insulating pipe (8) are staggered and symmetrically arranged.

2. The variable diameter electromagnetic heating rotary kiln system according to claim 1, characterized in that The inner diameter of the barrel (6) of the heat-insulating pipe (8) is larger than the inner diameter of the heating pipe (7).

3. The variable diameter electromagnetic heating rotary kiln system according to claim 1, characterized in that The electromagnetic heating coils (5) of the adjacent electromagnetic heating coil units of the barrel (6) of the heat-insulating pipe (8) adopt a cross-phase power supply structure to form a moving magnetic field.

4. The variable diameter electromagnetic heating rotary kiln system according to claim 1, characterized in that The feeding portion (1) is provided with a feeding port and a feeding pipe, the front end of the feeding pipe is connected to the feeding port, and the rear end of the feeding pipe is connected to the heating portion.

5. The variable diameter electromagnetic heating rotary kiln system according to claim 1, characterized in that The adjacent lifting plates (10) are staggered and symmetrically arranged on the inner wall of the insulation pipe (8).

6. The variable diameter electromagnetic heating rotary kiln system according to claim 1, characterized in that The lifting plate (10) is L-shaped, and the corners of the L-shape are configured as rounded corner structures.

7. The variable diameter electromagnetic heating rotary kiln system according to claim 1, characterized in that The barrel (6) has an inclination that is higher at the front and lower at the back.

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