Rotary expansion furnace for preparing expanded graphite

Abstract

The expansion furnace comprises a base, a furnace bin is arranged on the upper surface of the base, an outer cylinder is arranged in the furnace bin, the two ends of the outer cylinder are connected with a left circular cover plate and a right circular cover plate respectively, and the two ends of the outer cylinder are connected with the two ends of an inner cylinder through bearings respectively; a heat preservation and insulation layer is arranged on the inner surface of the outer barrel, an electric heating coil is arranged around the inner barrel in a space formed by the outer side of the inner barrel and the heat preservation and insulation layer, the electric heating device further comprises a feeding hopper and a discharging pipe, and a motor rotating in two directions is connected with the left end of the inner barrel through a transmission rod after being connected through a belt and a transmission shaft penetrating through a left circular cover plate; a spiral stirring blade is arranged on the inner surface of the inner cylinder in a surrounding mode, and a temperature sensor is arranged on the inner side of the right circular cover plate. By means of the expansion furnace, continuous and uniform expansion of expandable graphite is achieved, the expansion efficiency is greatly improved while the expansion temperature is reduced, and high-quality expanded graphite is produced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of preparation of expanded graphite, and particularly relates to a rotary puffing furnace for preparing expanded graphite. BACKGROUND

[0002] Expanded graphite is a new type of functional carbon material, which has the characteristics of loose structure, bending and porous, large surface area, low density, high surface energy and the like, and occupies an important position in the fields of chemical industry, materials and new energy. The preparation method is to use expandable graphite as raw material, and the interlayer substance is instantaneously vaporized under high temperature conditions, the interlayer rapidly expands, and the volume expands to finally form worm-like expanded graphite.

[0003] The existing preparation methods of expanded graphite mainly include high-temperature puffing and microwave method. The high-temperature puffing method is to put the raw material expandable graphite into a muffle furnace or a tube furnace and the like in a high-temperature environment, and the puffing temperature is generally as high as 900-1000 DEG C. Chinese patents CN1273378C and CN107285306A disclose the method for preparing expanded graphite by the high-temperature puffing method. However, this method has large power consumption, and needs manual feeding of the raw material into the furnace in batches, and has poor process continuity, low product uniformity and certain danger. The microwave puffing method utilizes the high electrical conductivity of graphite, and the microwave can make it generate strong eddy current to rapidly heat and expand the raw material. Chinese patents CN100540468C and CN105948033B disclose the method for preparing expanded graphite by the microwave method. Although this method shortens the expansion time, due to the particularity and industrial limitation of the microwave, it cannot realize high-throughput production of expanded graphite. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, and provide a rotary puffing furnace for preparing expanded graphite.

[0005] The technical scheme of the present application is summarized as follows:

[0006] A kind of preparation expanded graphite is rotated and is expanded in rotary furnace, including base 1, cylindrical outer tube 14 and cylindrical inner tube 23, the upper surface of base is provided with furnace bin 5, outer tube 14 is arranged in the furnace bin 5, the both ends of outer tube are connected with left circular cover plate 17 and right circular cover plate 8 respectively, the both ends of outer tube are connected with the both ends of inner tube through bearing 16 respectively;Heat insulating layer 3 is arranged on the inner surface of outer tube, electric heating coil 4 is arranged around inner tube in the space formed by heat insulating layer outside inner tube, feed hopper 2 is arranged through the top wall of furnace bin 5 and left circular cover plate 17;Discharge pipe 7 is arranged through right circular cover plate 8 and the side wall of furnace bin 5, bidirectional rotating motor 20 is arranged in furnace bin 5, bidirectional rotating motor is connected with the left end of the inner tube 23 through transmission rod 18 in turn by being connected with transmission shaft 6 penetrating left circular cover plate through belt 19;Spiral stirring blade 15 is arranged around the inner surface of inner tube, outer tube is connected with the inner surface of furnace bin 5 and the upper surface of base through fixed support 21 respectively, temperature sensor 24 is arranged on the inboard of right circular cover plate 8, and general power switch is arranged on the furnace bin wall.

[0007] The advantages of the present application are:

[0008] 1、The rotary expansion furnace for preparing expanded graphite of the present application can continuously turn over the materials, increase the contact area, make the materials in the furnace evenly heated, improve the expansion efficiency, and the expanded graphite produced has high expansion degree and uniform quality distribution.

[0009] 2、The rotary expansion furnace of the present application continuously advances the materials during the rotation, saves the manual operation process in the high-temperature environment, and simplifies the production process.

[0010] 3、The rotary expansion furnace of the present application has uniform temperature distribution in the furnace, and the required temperature for the expandable graphite to expand is reduced from 900-1000℃ to 300-450℃, which greatly saves the energy consumption in the production process of expanded graphite.

[0011] 4、The rotary expansion furnace of the present application uses electric energy as the heat source, which is more energy-saving and environmentally friendly than the existing natural gas combustion expansion method. Compared with the microwave expansion method, the method of the present application can realize continuous high-throughput production of expanded graphite, and has advantages in productivity and product uniformity.

[0012] 5、The rotary expansion furnace of the present application has hot gas flow assistance to push the expanded graphite out of the furnace, and avoids the backflow of waste gas generated during the expansion process. In combination with the beneficial effects 1-2, the high-throughput continuous production of expanded graphite can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a structural schematic diagram of a rotary expansion furnace for preparing expanded graphite.

[0014] Figure 2is an optical photograph of expanded graphite produced by the rotary puffing furnace of Example 2.

[0015] Figure 3 is a scanning electron microscope (SEM) photograph of expanded graphite produced by the rotary puffing furnace of Example 2.

[0016] Figure 4 is a scanning electron microscope (SEM) photograph of expanded graphite produced by the rotary puffing furnace of Example 2.

[0017] Figure 1 in the middle:

[0018] 1, base, 2, feed hopper, 3, heat insulation layer, 4, electric heating coil, 5, furnace bin, 6, transmission shaft, 7, discharge pipe, 8, right circular cover plate, 14, cylindrical outer tube, 15, spiral stirring blade, 16, bearing, 17, left circular cover plate, 18, transmission rod, 19, belt, 20, two-way rotating motor, 21, fixed support rod, 23, cylindrical inner tube, 24, temperature sensor. DETAILED DESCRIPTION

[0019] The application will be further described below through specific examples and the accompanying drawings.

[0020] A rotary puffing furnace for preparing expanded graphite, as shown in Figure 1 , comprises a base 1, a cylindrical outer tube 14 and a cylindrical inner tube 23, a furnace bin 5 is arranged on the upper surface of the base, the outer tube 14 is arranged in the furnace bin 5, the two ends of the outer tube are respectively connected with a left circular cover plate 17 and a right circular cover plate 8, and the two ends of the outer tube are respectively connected with the two ends of the inner tube through bearings 16; a heat insulation layer 3 is arranged on the inner surface of the outer tube, an electric heating coil 4 is arranged around the inner tube in the space formed by the heat insulation layer outside the inner tube; a feed hopper 2 is arranged through the top wall of the furnace bin 5 and the left circular cover plate 17; a discharge pipe 7 is arranged through the right circular cover plate 8 and the side wall of the furnace bin 5; a two-way rotating motor 20 is arranged in the furnace bin 5 near the left circular cover plate 17, the two-way rotating motor is connected with the transmission shaft 6 through the belt 19 in turn, and then connected with the left end of the inner tube 23 through the transmission rod 18 (the rotation of the two-way rotating motor drives the rotation of the inner tube); a spiral stirring blade 15 is arranged around the inner surface of the inner tube (the spiral stirring blade pushes the material to move towards the discharge pipe 7), the outer tube is connected with the inner surface of the furnace bin 5 and the upper surface of the base through the fixed support rod 21, a temperature sensor 24 is arranged on the inner side of the right circular cover plate 8, and a main power switch is arranged on the wall of the furnace bin.

[0021] The use of a rotary puffing furnace for preparing expanded graphite comprises the following steps:

[0022] 1) Turn on the total power switch of a rotating puffing furnace for preparing expanded graphite, set the rotating speed and turn the bidirectional rotating motor 20 clockwise to rotate the inner cylinder, and control the rotating speed of the inner cylinder at 10-30 rpm; control the temperature of the electric heating coil; deliver the hot gas stream through the feeding hopper 2, the temperature of the hot gas stream is 80-200℃, and the flow rate of the hot gas stream is 0.5-20 L / s; the gas stream is at least one of air stream, nitrogen stream and argon stream; and the temperature in the inner cylinder is 300-450℃.

[0023] 2) When the temperature sensor 24 indicates that the inner cylinder is preheated to the set temperature, continuously feed the raw material expandable graphite from the feeding hopper 2; the material is uniformly heated and puffed, and is moved to the discharge pipe under the pushing of the spiral stirring blade and the blowing of the hot gas stream, and is intercepted by the gas-solid separation screen to obtain expanded graphite.

[0024] When the inner cylinder volume is 200 L, the feeding amount of the expandable graphite is 200-2000 g / min.

[0025] Example 1

[0026] The use of a rotating puffing furnace for preparing expanded graphite includes the following steps:

[0027] 1) Turn on the total power switch of a rotating puffing furnace for preparing expanded graphite, set the rotating speed and turn the bidirectional rotating motor 20 clockwise to rotate the inner cylinder, and control the rotating speed of the inner cylinder at 20 rpm; control the temperature of the electric heating coil; deliver the hot gas stream through the feeding hopper 2, the temperature of the hot gas stream is 200℃, and the flow rate of the hot gas stream is 10 L / s; the gas stream is nitrogen stream; and the temperature in the inner cylinder is 400℃.

[0028] 2) When the temperature sensor 24 indicates that the inner cylinder is preheated to the set temperature, continuously feed the raw material expandable graphite from the feeding hopper 2; the material is uniformly heated and puffed, and is moved to the discharge pipe under the pushing of the spiral stirring blade and the blowing of the hot gas stream, and is intercepted by the gas-solid separation screen to obtain expanded graphite.

[0029] When the inner cylinder volume is 200 L, the feeding amount of the expandable graphite is 1000 g / min.

[0030] The expanded graphite obtained in this example is in a worm-like structure, as shown in Figure 2 , Figure 3 , Figure 4 . The length is 1-15 mm, the diameter is 0.3-0.8 mm, and the interlayer spacing of the expanded graphite is 0.5-5 μm.

[0031] When the rotating puffing furnace for preparing expanded graphite needs to be cleaned, the bidirectional rotating motor 20 is started to rotate counterclockwise.

[0032] Example 2

[0033] A use of a rotary expansion furnace for preparing expanded graphite, comprising the following steps:

[0034] 1) Turn on the total power switch of a rotary expansion furnace for preparing expanded graphite, set the rotating speed and turn on the clockwise rotation of the bidirectional rotating motor 20 to drive the rotation of the inner cylinder, and control the rotating speed of the inner cylinder at 10 rpm; control the temperature of the electric heating coil; deliver the hot gas stream through the feeding hopper 2, the temperature of the hot gas stream is 80°C, and the flow rate of the hot gas stream is 0.5 L / s; the gas stream is air stream; and the temperature in the inner cylinder is 300°C;

[0035] 2) When the temperature sensor 24 indicates that the inner cylinder is preheated to the set temperature, continuously feed the raw material expandable graphite from the feeding hopper 2; the material is uniformly heated and expanded, and is moved to the discharge pipe under the pushing of the helical stirring blade and the blowing of the hot gas stream, and is intercepted by the gas-solid separation screen to obtain expanded graphite.

[0036] When the volume of the 200 L inner cylinder is 2000 g / min.

[0037] The expanded graphite obtained in this example has a worm-like structure, the length is 1-15 mm, the diameter is 0.3-0.8 mm, and the interlayer spacing of the expanded graphite is 0.5-5 μm.

[0038] Example 3

[0039] A use of a rotary expansion furnace for preparing expanded graphite, comprising the following steps:

[0040] 1) Turn on the total power switch of a rotary expansion furnace for preparing expanded graphite, set the rotating speed and turn on the clockwise rotation of the bidirectional rotating motor 20 to drive the rotation of the inner cylinder, and control the rotating speed of the inner cylinder at 30 rpm; control the temperature of the electric heating coil; deliver the hot gas stream through the feeding hopper 2, the temperature of the hot gas stream is 200°C, and the flow rate of the hot gas stream is 20 L / s; the gas stream is a mixed gas stream of nitrogen stream and argon stream with a volume ratio of 1:1; and the temperature in the inner cylinder is 450°C;

[0041] 2) When the temperature sensor 24 indicates that the inner cylinder is preheated to the set temperature, continuously feed the raw material expandable graphite from the feeding hopper 2; the material is uniformly heated and expanded, and is moved to the discharge pipe under the pushing of the helical stirring blade and the blowing of the hot gas stream, and is intercepted by the gas-solid separation screen to obtain expanded graphite.

[0042] When the volume of the 200 L inner cylinder is 2000 g / min.

[0043] The expanded graphite obtained in this example has a worm-like structure, the length is 1-15 mm, the diameter is 0.3-0.8 mm, and the interlayer spacing of the expanded graphite is 0.5-5 μm.

[0044] Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principles of the present application. Various changes and improvements can be made to the present application without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of protection of the present application. The scope of protection of the present application is defined by the claims and their equivalents.

Claims

1. A rotating exfoliation furnace for producing expanded graphite, comprising a base (1), a cylindrical outer cylinder (14) and a cylindrical inner cylinder (23), a furnace chamber (5) being provided on the upper surface of the base, characterized in that, The outer cylinder (14) is arranged in the furnace bin (5), and left and right circular cover plates (17 and 8) are connected to the two ends of the outer cylinder respectively, and the two ends of the outer cylinder are connected with the two ends of the inner cylinder through bearings (16); a heat preservation and insulation layer (3) is arranged on the inner surface of the outer cylinder, and an electric heating coil (4) is arranged around the inner cylinder in the space formed by the heat preservation and insulation layer outside the inner cylinder; a feeding hopper (2) is arranged through the top wall of the furnace bin (5) and the left circular cover plate (17); a discharging pipe (7) is arranged through the right circular cover plate (8) and the side wall of the furnace bin (5), a bidirectional rotating motor (20) is arranged in the furnace bin (5), the bidirectional rotating motor is connected with the left end of the inner cylinder (23) through a transmission rod (18) after being connected with a transmission shaft (6) penetrating through the left circular cover plate in sequence through a belt (19); helical stirring blades (15) are arranged around the inner surface of the inner cylinder, the outer cylinder is connected with the inner surface of the furnace bin (5) and the upper surface of the base through fixing support rods (21) respectively, a temperature sensor (24) is arranged on the inner side of the right circular cover plate (8), and a main power switch is arranged on the furnace bin wall.

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