A method and apparatus for preparing high-density magnesium oxide tubes

Abstract

This invention discloses a method and apparatus for preparing high-density magnesium oxide tubes, belonging to the field of new materials technology. Magnesium oxide raw material is 600 mesh (23µm) powder, from which cellulose adhesive is prepared. The magnesium oxide is thoroughly stirred into lumps, extruded into magnesium oxide tubes, and then dried, cut, and calcined. This invention solves the technical problems of magnesium oxide tubes hardening due to hydration during stirring, and the accelerated hydration reaction of magnesium oxide during extrusion due to increased pressure. Smaller particle sizes and larger specific surface areas result in faster hydration, causing solidification and preventing extrusion. Furthermore, magnesium oxide particles often detach from the surface of the tubes after drying and calcination, leading to defective products. This invention is mainly applied to the production of magnesium oxide tubes.

Description

Technical Field

[0001] This invention belongs to the field of new materials technology, specifically relating to a method and apparatus for preparing high-density magnesium oxide tubes. Background Technology

[0002] Magnesium oxide insulating ceramics possess excellent high-temperature insulation properties and superior thermal conductivity, making them widely used in high-temperature insulation applications. Industries such as electric heating tubes, armored heating cables, and temperature measuring wires require magnesium oxide tubes. High-density magnesium oxide tubes are a type of ceramic material with high temperature resistance and good insulation properties. Previously, magnesium oxide tubes were manufactured using extrusion molding or hot pressing with magnesium oxide powder of approximately 300 mesh, resulting in a finished magnesium oxide tube density of 2.3 g / ml. If finer magnesium oxide powder is used, extrusion molding and hot pressing have the following problems:

[0003] 1. Magnesium oxide dough is difficult to prepare. As the particle size of magnesium oxide powder decreases, its surface area increases, and the rate at which magnesium oxide reacts with water to form magnesium hydroxide accelerates. During the stirring process, the hydration reaction occurs, causing the dough to harden and become unusable.

[0004] 2. During the extrusion process, the increased pressure accelerates the hydration reaction of magnesium oxide. The smaller the particle size and the larger the specific surface area, the faster the hydration reaction, causing solidification and making extrusion impossible.

[0005] 3. When the drying and calcination of magnesium oxide pipe fittings are completed, magnesium oxide particles always fall off the surface, resulting in defective products. Summary of the Invention

[0006] Purpose of the invention: The purpose of this invention is to provide a method and apparatus for preparing high-density magnesium oxide pipes, in order to solve the technical problems of magnesium oxide pipes becoming unusable due to hydration reaction during stirring, accelerating the hydration reaction of magnesium oxide during extrusion due to increased pressure, and solidifying and becoming unextrusive due to smaller particle size and larger specific surface area, and the production of defective products due to magnesium oxide particles falling off the surface of the pipes after drying and calcination.

[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a method for preparing high-density magnesium oxide tubes, characterized by comprising the following steps:

[0008] Step 1: Add 2% oleic acid to the magnesium oxide raw material and ball mill it into 600 mesh (23um) powder;

[0009] Step 2: Hydroxypropyl methylcellulose is mixed with cold water at around 5°C in a mass ratio of 1:4 and stirred thoroughly to prepare a cellulose adhesive;

[0010] Step 3: Place the cellulose adhesive obtained in Step 2 into a mixer, add the magnesium oxide powder obtained in Step 1, and stir thoroughly until the magnesium oxide lumps form. The mass ratio of magnesium oxide powder, oleic acid, cellulose adhesive, and oleic acid is 100:2:16:4.

[0011] Step 4: Place the magnesium oxide lumps obtained in Step 3 into an extrusion molding machine and extrude them into magnesium oxide tubes;

[0012] Step 5: The magnesium oxide tubes extruded in Step 4 are dried, dried to 100 degrees Celsius, cut, and calcined at 1600 degrees Celsius. After 3 hours, the tubes are cooled to room temperature in the furnace to obtain the desired high-density magnesium oxide tubes.

[0013] Furthermore, after the magnesium oxide tube is dried, the inner and outer tubes are coated with high-temperature resistant inorganic adhesive, and then it is cut and calcined. This process is to prevent the outer wall of the magnesium oxide tube from being heated, which would reduce the bonding ability of the cellulose adhesive and cause the magnesium oxide particles to escape and fall off.

[0014] An apparatus for preparing high-density magnesium oxide tubes, characterized in that it comprises a base, a ball mill, a mixer, a bag filter, a pipe extruder, a glue storage tank, a dryer, a meter counter, a PLC controller, a central positioning tube, a support tube, a first glue injection bend, a first electric valve, a second glue injection bend, a second electric valve, a glue application assembly, a cutting assembly, a holding cylinder, and a conveyor. A ladder is installed on the base for convenient manual maintenance. The ball mill, mixer, bag filter, and PLC controller are mounted on the base. The ball mill grinds magnesium oxide particles, and the mixer mixes the cellulose adhesive and the ground magnesium oxide powder. The ball mill and mixer are connected to the bag filter via pipes. The bag filter discharges air from the ball mill and mixer during feeding. The PLC controller controls the operation of all machines. The pipe extruder is connected to the mixer and extrudes the mixed material into tubes. A central positioning tube is installed in the spiral pusher of the pipe extruder. A first bearing is installed between the central positioning tube and the spiral pusher of the pipe extruder. A set of support pipes is installed on the wall. The cross-section of the central positioning pipe is concentric with the extrusion port of the pipe extruder. A dryer is fitted onto the extrusion port of the pipe extruder to preliminarily dry the formed magnesium oxide pipe. A meter counter is also installed on the extrusion port of the pipe extruder to measure the length of the magnesium oxide pipe. A first glue injection bend is installed between the central positioning pipe and the support pipes, with one end of the first glue injection bend penetrating the side wall of the pipe extruder. A first electric valve is installed on the first glue injection bend. A second glue injection bend is installed on the first glue injection bend. A second electric valve is installed on the top. The wall of the second glue injection bend is in contact with the dryer. One end of the second glue injection bend is connected to the glue application assembly, and the other end of the second glue injection bend is connected to the glue storage tank. The other end of the first glue injection bend passes through into the glue application assembly. The glue application assembly is used to apply glue to the inner and outer walls of the pipe. A retaining cylinder is installed on the side of the glue application assembly. The retaining cylinder is used to ensure the shape and prevent workers from touching it. A cutting assembly is installed between the glue application assembly and the retaining cylinder. The cutting assembly cuts the pipe to the confirmed length and applies glue to the side wall of the pipe. A conveyor is installed on the side of the retaining cylinder.

[0015] Furthermore, the gluing assembly includes an outer tube, an inner tube, a wide-mouth tube, an annular groove, an inclined plate, a groove, a first annular steel outer ring, a first annular steel inner ring, and a first thickened microfiber sleeve. The inner tube is fitted inside the outer tube, and the inner tube is connected to the central positioning tube with the same diameter. The first gluing bend enters the inner tube. The wide-mouth tube is installed on one side of the outer tube, and the annular groove is installed on the other side. An inclined plate is installed between the wide-mouth tube and the extrusion port of the pipe extruder. An annular groove is installed at the opening of the second gluing bend for connection and fixation. A groove is provided on the inner tube near the annular groove. The opening of the first gluing bend is connected and fixed to the groove. The first annular steel outer ring is installed in the annular groove, and the first annular steel inner ring is installed in the groove. The first thickened microfiber sleeve is fitted on both the first annular steel outer ring and the first annular steel inner ring. The first thickened microfiber sleeve is used to absorb glue.

[0016] Furthermore, the cutting assembly includes a support platform, an electric push rod, a second outer steel ring, a second thickened microfiber sleeve, and an upper support component. The support platform is mounted on the gluing assembly and the retaining cylinder. The electric push rod is fixedly installed through the support platform. The second thickened microfiber sleeve is provided on both the second outer steel ring and the second inner steel ring. The second inner steel ring is located inside the second outer steel ring and the two are connected by a set of connecting plates. The second outer steel ring and the second inner steel ring are in the same plane and are concentric circles. An upper support component is provided on one side of the second outer steel ring, and the support component is fixedly connected to the telescopic rod of the electric push rod. A lower support component is provided on the other side of the second outer steel ring, and an electric reciprocating saw is fixedly installed on the lower support component.

[0017] Furthermore, the blade length of the electric reciprocating saw is greater than the diameter of the outer ring of the second circular steel ring.

[0018] Furthermore, the second circular steel outer ring, the upper support, and the lower support are all on the same plane.

[0019] Furthermore, the diameter of the outer ring of the second circular steel ring is the same as the diameter of the outer ring of the first circular steel ring, and the diameter of the inner ring of the first circular steel ring is the same as the diameter of the inner ring of the second circular steel ring.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] This invention uses 600-mesh magnesium oxide powder with added oleic acid. During ball milling, the oleic acid is thoroughly mixed with the magnesium oxide powder, forming an oil film on the surface of the magnesium oxide particles. This slows down the hydration reaction rate of magnesium oxide during kneading and extrusion, while simultaneously improving the material's flowability and facilitating extrusion. The small particle size of the magnesium oxide powder increases the specific surface area, allowing for increased cellulose usage and improved molding and bonding properties. The density of the extruded preform increases by more than 10%, the shrinkage ratio at 1600°C increases by 5%, and the density of the magnesium oxide tube reaches 2.7 g / ml.

[0022] By setting up a gluing component and a cutting component, the gluing component can coat the inner and outer walls of the magnesium oxide tube during the discharge process. At the same time as cutting, the cut of the magnesium oxide tube is coated with high-temperature resistant inorganic adhesive. The main components of the high-temperature resistant inorganic adhesive are inorganic substances such as silicates, borates, and phosphates. At high temperatures, it can form a hard ceramic-like substance, thereby achieving the bonding effect and preventing magnesium oxide particles from falling off and causing defects. Attached Figure Description

[0023] Figure 1 This is a partial production diagram of the present invention;

[0024] Figure 2 This is the invention Figure 1 A magnified view of a portion at point A';

[0025] Figure 3 This is the invention Figure 2 A magnified view of part B';

[0026] Figure 4 This is a perspective view of the outer tube, inner tube, annular groove, and recess in this invention;

[0027] Figure 5 This is a component diagram of the first circular steel outer ring, the first circular steel inner ring, and the first thickened microfiber sleeve in the present invention;

[0028] Figure 6 This is the invention Figure 1 Enlarged parts Figure 1 ;

[0029] Figure 7 This is the invention Figure 1 Enlarged parts Figure 2 ;

[0030] Figure 8 This is the invention Figure 7 A magnified view of a portion of point C';

[0031] Figure 9 The cutting component of this invention is shown in the front view without the supporting platform.

[0032] Figure 10 This is a side view of the cutting component of the present invention without the support platform.

[0033] In the diagram: a. Base; b. Ball mill; c. Mixer; d. Bag filter; e. Pipe extruder; f. Glue storage tank; g. Dryer; h. Meter counter; i. PLC controller; j. Conveyor; k. Ladder; 1. Center positioning tube; 2. First bearing; 3. Support tube; 4. First glue injection bend; 5. First electric valve; 6. Second glue injection bend; 7. Second electric valve; 8. Glue application assembly; 801. Outer tube; 802. Inner tube; 803. Wide-mouth tube; 804. 805. Circular groove; 806. Inclined plate; 807. Groove; 808. First circular steel outer ring; 809. First circular steel inner ring; 8000. First thickened microfiber sleeve; 9001. Cutting assembly; 901. Support platform; 902. Electric push rod; 903. Second circular steel outer ring; 904. Second circular steel inner ring; 905. Second thickened microfiber sleeve; 906. Connecting plate; 907. Support component; 908. Lower support component; 909. Electric reciprocating saw; 10. Holding cylinder. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0035] Example

[0036] A method for preparing high-density magnesium oxide tubes, characterized by comprising the following steps:

[0037] Step 1: Add 2% oleic acid to the magnesium oxide raw material and ball mill it into 600 mesh (23um) powder;

[0038] Step 2: Hydroxypropyl methylcellulose is mixed with cold water at around 5°C in a mass ratio of 1:4 and stirred thoroughly to prepare a cellulose adhesive;

[0039] Step 3: Place the cellulose adhesive obtained in Step 2 into a mixer, add the magnesium oxide powder obtained in Step 1, and stir thoroughly until the magnesium oxide forms lumps; the mass ratio of magnesium oxide powder, oleic acid, cellulose adhesive, and oleic acid is 100:2:16:4.

[0040] Step 4: Place the magnesium oxide lumps obtained in Step 3 into an extrusion molding machine and extrude them into magnesium oxide tubes;

[0041] Step 5: The magnesium oxide tubes extruded in Step 4 are dried, dried to 100 degrees Celsius, cut, and calcined at 1600 degrees Celsius. After 3 hours, the tubes are cooled to room temperature in the furnace to obtain the desired high-density magnesium oxide tubes.

[0042] After the magnesium oxide tube is dried, the inner and outer tubes are coated with high-temperature resistant inorganic adhesive, and then it is cut and calcined. This process is to prevent the outer wall of the magnesium oxide tube from being heated, which would reduce the bonding ability of the cellulose adhesive and cause the magnesium oxide particles to escape and fall off.

[0043] Reference Figure 1 An apparatus for preparing high-density magnesium oxide tubes, characterized in that it comprises a base a, a ball mill b, a mixer c, a bag filter d, a pipe extruder e, a glue storage tank f, a dryer g, a meter counter h, a PLC controller i, a central positioning tube 1, a support tube 3, a first glue injection bend 4, a first electric valve 5, a second glue injection bend 6, a second electric valve 7, a glue application assembly 8, a cutting assembly 9, a holding cylinder 10, and a conveyor j. A ladder k is installed on the base a to facilitate manual maintenance of the equipment. The system includes a ball mill (b), a mixer (c), a bag filter (d), and a PLC controller (i). Ball mill (b) is used to grind magnesium oxide particles, and mixer (c) is used to mix cellulose adhesive and the ground magnesium oxide powder. Ball mill (b) and mixer (c) are connected to bag filter (d) via pipe (10). Bag filter (d) is used to discharge air from inside ball mill (b) and mixer (c) during feeding. PLC controller (i) controls the operation of all machines. Pipe extruder (e) is connected to mixer (c) and extrudes the mixed material into pipes.

[0044] See Figure 7 and Figure 8A central positioning tube 1 is installed in the spiral pusher of the pipe extruder e. A first bearing 2 is installed between the central positioning tube 1 and the spiral pusher of the pipe extruder e. The central positioning tube 1 does not rotate with the rotation of the spiral pusher of the pipe extruder e. A set of support tubes 3 is installed on the side wall of the central positioning tube 1. The cross-section of the central positioning tube 1 is concentric with the extrusion port of the pipe extruder e. A dryer g is fitted on the extrusion port of the pipe extruder e. The dryer g is used to preliminarily dry the formed magnesium oxide tube. A meter counter h is also installed on the extrusion port of the pipe extruder e. The meter counter h is used to measure the length of the magnesium oxide tube. A first injection bend 4 is installed in the central positioning tube 1 and the support tube 3. One end of the first injection bend 4 penetrates the side wall of the pipe extruder e. A first electric valve 5 is installed on the first injection bend 4. A second injection bend 6 is installed on the first injection bend 4. The second electric valve 7 is installed, and the wall of the second injection bend 6 is in contact with the dryer g. The high-temperature resistant inorganic adhesive can also absorb the heat generated by the dryer g during operation, increasing the fluidity of the high-temperature resistant inorganic adhesive. One end of the second injection bend 6 is connected to the glue application assembly 8, and the other end of the second injection bend 6 is connected to the glue storage tank f. The other end of the first injection bend 4 passes through into the glue application assembly 8. Similarly, the high-temperature resistant inorganic adhesive can also absorb the heat generated by the dryer g during operation, which is also to increase the fluidity of the high-temperature resistant inorganic adhesive. The glue application assembly 8 is used to apply glue to the inner and outer walls of the pipe. A retaining cylinder 10 is installed on the side of the glue application assembly 8. The retaining cylinder 10 is used to ensure the shape and prevent workers from touching it. A cutting assembly 9 is installed between the glue application assembly 8 and the retaining cylinder 10. The cutting assembly 9 cuts the pipe to the confirmed length and applies glue to the side wall of the pipe. A conveyor j is installed on the side of the retaining cylinder 10.

[0045] In one embodiment, see Figures 2 to 5The gluing assembly 8 includes an outer tube 801, an inner tube 802, a wide-mouth tube 803, an annular groove 804, a slanted plate 805, a groove 806, a first annular steel outer ring 807, a first annular steel inner ring 808, and a first thickened microfiber sleeve 809. The inner tube 802 is fitted inside the outer tube 801. The inner tube 802 is connected to the central positioning tube 1 and has the same diameter. The first gluing bend 4 enters the inner tube 802. A wide-mouth tube 803 is installed on one side of the outer tube 801, and an annular groove 804 is installed on the other side. A slanted plate 805 connects the wide-mouth tube 803 to the extrusion port of the pipe extruder e. The slanted plate 805 and the wide-mouth tube 803 allow the initially dried magnesium oxide pipe to dissipate its heat, facilitating the next gluing operation. This design also facilitates alignment and prevents defective products. An annular groove 804 is installed at the opening of the second gluing bend 6 for connection and fixation. The high-temperature resistant inorganic adhesive is introduced through a groove 806 on the inner tube 802 near the annular groove 804. The opening of the first injection bend 4 is connected and fixed to the groove 806, which also facilitates the entry of the high-temperature resistant inorganic adhesive. A first annular steel outer ring 807 is installed in the annular groove 804, and a first annular steel inner ring 808 is installed in the groove 806. A first thickened microfiber sleeve 809 is fitted on both the first annular steel outer ring 807 and the first annular steel inner ring 808. The first thickened microfiber sleeve 809 is used to absorb the adhesive. The high-temperature resistant inorganic adhesive flows into the groove through the pipe and is immersed in the first thickened microfiber sleeve 809 from top to bottom. The first thickened microfiber sleeve 809 can be touched to see if it is fully absorbed. The first electric valve 5 and the second electric valve 7 are adjusted to allow the adhesive to slowly flow out of the storage tank f. With the entry of the dried magnesium oxide tube, the inner and outer walls are coated with the high-temperature resistant inorganic adhesive.

[0046] In one embodiment, see Figure 1 , Figure 9 and Figure 10The cutting assembly 9 includes a support platform 901, an electric push rod 902, a second outer steel ring 903, a second inner steel ring 904, a second thickened microfiber sleeve 905, and an upper support 907. The support platform 901 is mounted on the gluing assembly 8 and the retaining cylinder 10. The electric push rod 902 is fixedly mounted through the support platform 901. The electric push rod 902 is essential for ensuring the up-and-down movement of the electric reciprocating saw 909 during operation. The second thickened microfiber sleeve 905 is provided on both the second outer steel ring 903 and the second inner steel ring 904. The second inner steel ring 904 is located inside the second outer steel ring 903, and the two are connected by a set of components. The plates 906 are connected. The second outer ring 903 and the second inner ring 904 of the steel ring are in the same plane and are concentric circles. An upper support 907 is provided on one side of the second outer ring 903. The support 907 is fixedly connected to the telescopic rod of the electric push rod 902. A lower support 908 is provided on the other side of the second outer ring 903. An electric reciprocating saw 909 is fixedly installed on the lower support 908. When the first thickened microfiber sleeve 809 on the first outer ring 807 and the first inner ring 808 of the steel ring is impregnated with high-temperature resistant inorganic glue, the electric push rod 902 is extended. At this time, the first outer ring 807 and the first inner ring 804 of the steel ring are extended. The first thickened microfiber sleeve 809 on the 08 makes overall contact with the second thickened microfiber sleeve 905 on the outer ring 903 and inner ring 904 of the second circular steel ring, allowing the high-temperature resistant inorganic adhesive to penetrate. After a period of time, the worker touches the second thickened microfiber sleeve 905 to confirm that work can begin. At this time, the electric push rod 902 retracts. The second thickened microfiber sleeve 905 contains adhesive. The meter counter h confirms the length of the magnesium oxide tube and sends a signal to the PLC controller i to stop the pipe extruder e. At this time, the cutting operation begins. As the electric reciprocating saw 909 slowly descends, the cutting is performed. The small amplitude brought by the electric reciprocating saw 909... The vibration acts on the second thickened microfiber sleeve 905 on the second outer ring 903 and the second inner ring 904 of the second circular steel ring, shaking and brushing the high-temperature resistant inorganic adhesive inside onto the cut of the magnesium oxide tube. At the same time, it can also coat the tail of the previous magnesium oxide tube, completing the coating of the entire magnesium oxide tube. The electric push rod 902 then slowly retracts, while simultaneously absorbing the high-temperature resistant inorganic adhesive that is about to overflow from the first thickened microfiber sleeve 809 on the first outer ring 807 and the first inner ring 808 of the first circular steel ring. After the electric push rod 902 completes the retraction, it sends a signal to the PLC controller i, and the pipe extruder e continues to work and extrude, while the meter counter h confirms the length of the magnesium oxide tube.

[0047] In one embodiment, the blade length of the electric reciprocating saw 909 is greater than the diameter of the outer ring 903 of the second circular steel ring, enabling it to perform complete cuts.

[0048] In one embodiment, see Figure 9The second outer ring 903, the upper support 907, and the lower support 908 are all on the same plane. The diameter of the second outer ring 903 is the same as the diameter of the first outer ring 807, and the diameter of the first inner ring 808 is the same as the diameter of the second inner ring 904, ensuring that the cut is a whole surface.

[0049] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention.

Claims

1. An apparatus for preparing high-density magnesium oxide tubes, characterized in that, The system includes a base, ball mill, mixer, bag filter, pipe extruder, glue storage tank, dryer, meter counter, PLC controller, central positioning tube, support tube, first glue injection bend, first electric valve, second glue injection bend, second electric valve, glue application assembly, cutting assembly, holding cylinder, and conveyor. The ball mill, mixer, bag filter, and PLC controller are mounted on the base. The ball mill and mixer are connected to the bag filter via pipes. The pipe extruder is connected to the mixer. A central positioning tube is installed in the screw pusher of the pipe extruder. A first bearing is installed between the central positioning tube and the screw pusher of the pipe extruder. A support tube is installed on the side wall of the central positioning tube. The cross-section of the central positioning tube is concentric with the extrusion port of the pipe extruder. A dryer is fitted onto the extrusion port of the pipe extruder. A meter counter is also installed on the extrusion port of the pipe extruder. A first glue injection bend is installed in the central positioning tube and the support tube, with one end of the first glue injection bend penetrating the side wall of the pipe extruder. A first electric valve is installed on the first glue injection bend. A second glue injection bend is installed on the first glue injection bend. A second electric valve is installed on the second glue injection bend. The wall of the second glue injection bend is in contact with the dryer. One end of the second glue injection bend is connected to the glue application assembly. The other end of the second glue injection bend is connected to the glue storage tank. The other end of the first glue injection bend penetrates into the glue application assembly. The glue application assembly is used to apply glue to the inner and outer walls of the pipe. A retaining cylinder is installed on the side of the glue application assembly. A cutting assembly is installed between the glue application assembly and the retaining cylinder. A conveyor is installed on the side of the retaining cylinder.

2. The apparatus for preparing high-density magnesium oxide tubes according to claim 1, characterized in that, The gluing assembly includes an outer tube, an inner tube, a circular groove, a recess, a first outer circular steel ring, a first inner circular steel ring, and a first thickened microfiber sleeve. The inner tube is fitted inside the outer tube, and the inner tube is connected to the central positioning tube with the same diameter. The first gluing bend enters the inner tube. A wide-mouth tube is installed on one side of the outer tube, and a circular groove is installed on the other side. An inclined plate is installed between the wide-mouth tube and the extrusion port of the pipe extruder. A circular groove is installed at the opening of the second gluing bend for connection and fixation. A recess is provided on the inner tube near the circular groove, and the opening of the first gluing bend is connected and fixed to the recess. The first outer circular steel ring is installed in the circular groove, and the first inner circular steel ring is installed in the recess. The first thickened microfiber sleeve is fitted on both the first outer and the first inner circular steel rings.

3. The apparatus for preparing high-density magnesium oxide tubes according to claim 2, characterized in that, The cutting assembly includes a support platform, a second outer steel ring, a second outer steel ring, and a second thickened microfiber sleeve. The support platform is mounted on the gluing assembly and the retaining cylinder. An electric push rod is fixedly installed through the support platform. The second thickened microfiber sleeve is provided on both the second outer steel ring and the second inner steel ring. The second inner steel ring is located inside the second outer steel ring and the two are connected by a set of connecting plates. The second outer steel ring and the second inner steel ring are in the same plane and are concentric circles. An upper support is provided on one side of the second outer steel ring, and the support is fixedly connected to the telescopic rod of the electric push rod. A lower support is provided on the other side of the second outer steel ring, and an electric reciprocating saw is fixedly installed on the lower support. The second outer steel ring, the upper support, and the lower support are all in the same plane. The diameter of the second outer steel ring is the same as the diameter of the first outer steel ring, and the diameter of the first outer steel ring is the same as the diameter of the second outer steel ring.

4. The apparatus for preparing high-density magnesium oxide tubes according to claim 3, characterized in that, The blade length of the electric reciprocating saw is greater than the diameter of the outer ring of the second circular steel ring.

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