CN117921323A - A sheet metal processing method for a high-pressure polymerization reaction low-temperature liquid nitrogen device - Google Patents

Abstract

The present invention relates to a sheet metal processing method for a high-pressure polymerization reaction cryogenic liquid nitrogen device, and belongs to the technical field of high-pressure new material preparation. A sheet metal processing method for a high-pressure polymerization reaction cryogenic liquid nitrogen device comprises the following steps: cutting according to the drawing, cutting to obtain a square box sheet metal part, a cylindrical sheet metal part and a round bottom sheet metal part respectively; bending the four sides of the square box sheet metal part, and welding the four side seams to form a rectangular parallelepiped; bending the cylindrical sheet metal part to form a cylindrical structure; welding the cylindrical structure to the circular hole and the round bottom sheet metal part respectively, and then cutting to remove the welding spots. The sheet metal processing method for the cryogenic liquid nitrogen device of the present invention is simple and low in cost. The present invention is applied to a high-pressure polymerization reaction device, which can realize a high-pressure polymerization reaction of gas raw materials, filling the gap in the prior art.

Description

A sheet metal processing method for a high-pressure polymerization reaction low-temperature liquid nitrogen device

Technical Field

The invention relates to the technical field of high-pressure new material preparation, and in particular to a sheet metal processing method for a high-pressure polymerization reaction low-temperature liquid nitrogen device.

Background technique

The synthesis of large-volume fluid samples requires the use of a top-to-bottom pressurization working method designed based on the large support principle. The reason is that the mechanical structure of top-to-bottom pressurization allows the high-pressure area to have a large horizontal space, which is convenient for the placement of low-temperature environments and pressurization control. The radial pressure gradient generated by uniaxial pressurization can be overcome by a pressure-transmitting medium. Based on this, a GH-type press dedicated to the development of high-energy materials was formed.

The principle of the high-pressure and low-temperature gas packaging technology of the GH press is as follows: the gas raw material is liquefied by low-temperature cooling, and enters the sealed cavity between the upper and lower anvils in the cooled B10 composite anvil structure, and the pressure slightly higher than the atmospheric pressure is used to ensure that it fills the cavity, and the upper and lower anvils are compressed by the GH press to make the anvil surface and the gasket in close contact, thereby sealing the gas raw material to be filled in the sample cavity. The GH press mainly includes anvil body, sealing device, gas introduction device and cooling device.

For the 100-ton GH press, the overall mass of the press is heavy and the volume is large. It needs to be pressurized by a hydraulic system. The sample reaction part needs to be cooled to meet the liquefaction conditions of the raw material gasification. The other parts are still at room temperature. In this way, low temperature and high pressure can be integrated to achieve the experimental purpose of gas low temperature liquefaction and high pressure polymerization. The low temperature liquefaction packaging of gas raw materials is a prerequisite and key step for high pressure polymerization reactions. The heat conduction of the device accessories under the existing assembly conditions is estimated.

Although the structure of the gas liquefaction packaging device in the prior art is compact, the gap between the container and the anvil is too small, which makes it impossible to inject liquid nitrogen into the container conveniently and quickly. Since the total heat capacity of the anvil-related parts is relatively large and there is some heat leakage between the anvil and the main body of the press, it is difficult for liquid nitrogen to remain in the low-temperature container, and the temperature at the anvil cannot be lowered. In addition, the heat leakage phenomenon is serious during the experiment, and the main body of the press begins to frost within 1-2 hours, which may directly lead to the freezing of the hydraulic oil inside the cylinder, resulting in the failure of the experiment due to the inability to pressurize.

Summary of the invention

In view of the above analysis, the present invention aims to provide a sheet metal processing method and a high-pressure polymerization reaction device for a low-temperature liquid nitrogen device for a high-pressure polymerization reaction, so as to solve one of the problems that the existing processing method is complicated and costly, the existing low-temperature liquid nitrogen device has serious leakage, which easily leads to pressurization failure in high-pressure polymerization, and the high-pressure polymerization reaction device only supports high-pressure reaction of condensed state samples at room temperature.

In a first aspect, a sheet metal processing method for a high-pressure polymerization reaction cryogenic liquid nitrogen device is provided, wherein the high-pressure polymerization reaction cryogenic liquid nitrogen device comprises a rectangular parallelepiped located at an upper portion and a cylinder located at a lower portion, and the sheet metal processing method comprises the following steps:

(1) Cutting the stainless steel plate according to the drawing to obtain a square box sheet metal part, a cylindrical sheet metal part and a round bottom sheet metal part;

(2) bending the four sides of the square box sheet metal part and welding the four side seams to form a cuboid;

(3) bending the cylindrical sheet metal part and forming a cylindrical structure by welding the gap;

(4) welding the upper end of the cylindrical structure to the rectangular parallelepiped, and welding the lower end of the cylindrical structure to the round bottom sheet metal part, to obtain a preformed sheet metal part of a low-temperature liquid nitrogen container;

(5) Cutting the welding parts of the sheet metal of the initially formed low-temperature liquid nitrogen container to remove the welding spots, thereby obtaining a low-temperature liquid nitrogen device.

Furthermore, in step (1), the square box sheet metal part, the cylindrical sheet metal part and the round bottom sheet metal part are all made of 304 stainless steel.

Furthermore, a circular hole is cut on the square box sheet metal, and the distances from the center of the circular hole to two opposite side surfaces of the cuboid are different.

Furthermore, in step (2), the four sides of the square box sheet metal are bent 90°, and after bending, the side gaps are welded to ensure that the welding points are watertight.

Furthermore, in step (3), the cylindrical sheet metal is formed into a cylindrical structure along the long side, the outer diameter of the cylindrical structure is 82 mm, the inner diameter is 80 mm, and the size of the circular hole opened at the bottom of the cuboid is matched, and the cylindrical structure and the edge of the circular hole are welded.

Furthermore, in step (4), the diameter of the round bottom sheet metal part is 80 mm, matching the inner diameter of the cylindrical structure, and is aligned along the edge of the round bottom and welded to the cylindrical structure.

Furthermore, in step (5), water is poured in after the solder joints are removed to verify that all solder joints are leak-proof, and the processing is completed. If there is a leak, re-welding is required and the solder joints are cleaned again.

In a second aspect, the present invention provides a high-pressure polymerization reaction low-temperature liquid nitrogen device prepared by the above method.

In a third aspect, the present invention provides a high-pressure polymerization reaction device, comprising the low-temperature liquid nitrogen device.

Furthermore, the device comprises, from top to bottom, an upper thermal insulation plate, an upper pad, an upper anvil seat, an upper anvil, a lower anvil, a lower anvil seat and a lower thermal insulation plate which are arranged concentrically; a sealing ring is arranged between the upper anvil and the lower anvil, a gasket is arranged inside the sealing ring, a low-temperature liquid nitrogen device is arranged outside the upper anvil seat, the upper anvil, the sealing ring and the lower anvil, and the lower anvil seat; the upper anvil seat, the upper anvil and the sealing ring are located in the cuboid, and the lower anvil and the lower anvil seat are located in the cylinder.

Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

(1) The sheet metal processing method of the cryogenic liquid nitrogen device of the present invention is simple and low in cost. The heat leakage at the bottom of the cryogenic liquid nitrogen device prepared by the present invention is greatly reduced, thereby ensuring the slow evaporation of liquid nitrogen, and more is used for cooling the anvil part. The cooling can be carried out for a long time, and the temperature of the press body will not be overcooled due to heat leakage during the experiment. The refrigeration effect caused by the heat absorption of the press body from the external environment and the heat leakage from the bottom of the cryogenic liquid nitrogen container can be balanced;

(2) The sealing ring in the high-pressure polymerization device of the present invention can realize the liquefaction packaging of gaseous raw material samples and realize the high-pressure polymerization reaction of gaseous raw materials, filling the gap in the prior art. The device of the present invention has good sealing performance and will not have the problem of leakage. The gasket design ensures that it is not easy to crack and damage. The design of the sealing ring and the upper and lower anvils improves the compression rate of the reaction chamber. The liquid nitrogen cooling device has high cooling efficiency and reduces the pressure module to the liquid nitrogen temperature. The addition of liquid nitrogen is convenient. The low-temperature liquid nitrogen device can realize the loading of gaseous samples, which is a prerequisite for subsequent high-pressure polymerization reactions.

In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be achieved and obtained through the contents particularly pointed out in the description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings are only for the purpose of illustrating specific embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

FIG1 is a schematic cross-sectional view of a high-pressure polymerization reaction device of the present invention;

FIG2 is a schematic structural diagram of a sealing ring assembly according to the present invention;

FIG2-1 is a physical diagram of the sealing ring of the present invention;

FIG3 is a schematic structural diagram of a sealing gasket according to the present invention;

FIG3-1 is a physical diagram of the gasket of the present invention;

FIG4 is a schematic structural diagram of a cryogenic liquid nitrogen device according to the present invention;

FIG5 is a schematic structural diagram of the low-temperature liquid nitrogen device of the present invention;

FIG6 is a schematic structural diagram of a square box sheet metal component of the present invention;

FIG7 is a schematic diagram of a cylindrical sheet metal of the present invention;

FIG8 is a schematic diagram of a round bottom sheet metal of the present invention;

FIG9 is a rectangular parallelepiped formed by welding a square box sheet metal part of the present invention;

FIG10 is a cylindrical structure formed by welding a cylinder according to the present invention;

FIG11 is a front view of a cryogenic liquid nitrogen device in Comparative Example 1 of the present invention;

FIG12 is a diagram showing a state when the upper anvil and the lower anvil begin to contact in Comparative Example 2 of the present invention;

FIG13 is a diagram showing the state of the upper anvil and the lower anvil when they are compressed to the limit in Comparative Example 2 of the present invention;

FIG14 is a schematic diagram of the structure of a beryllium copper soft metal ring in Comparative Example 2 of the present invention;

FIG. 15 is a photograph of a rubbish bin with a broken seal and punctured parts during a test using a square seal in the prior art.

Reference numerals:

1-upper anvil, 11-upper anvil seat, 12-upper pad, 13-first concentric ring, 14-first top pad, 15-second top pad, 2-lower anvil, 21-lower anvil seat, 22-second concentric ring, 3-upper thermal insulation plate, 4-lower thermal insulation plate, 5-sealing ring, 51-groove, 52-air guide tube, 53-circular hole, 54-sealing pad, 55-opening, 56-temperature sensor, 57-temperature sensor placement part, 6-low-temperature liquid nitrogen device, 61-rectangle, 62-cylinder, 63-first side, 64-second side, 7-upper anvil fixing sleeve, 8-positioning ring, 9-press, 10-glass fiber insulation ring, 101-beryllium copper soft metal ring.

Detailed ways

The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

In the prior art, the cryogenic liquid nitrogen device is a cryogenic container with both the upper and lower parts being cylindrical, and this structure is relatively compact. In actual gas liquefaction packaging experiments, it is often impossible to pressurize the experiment, resulting in experimental failure. Studies have shown that this phenomenon is related to the structure of the cryogenic liquid nitrogen device. Based on this, the present invention has made an original design for the cryogenic liquid nitrogen device 6 and its related structures. In addition, the existing processing methods are complicated and costly.

A specific embodiment of the present invention, as shown in FIGS. 6-10 , discloses a sheet metal processing method of a cryogenic liquid nitrogen device of a specific structural form, wherein the high-pressure polymerization reaction cryogenic liquid nitrogen device comprises a rectangular parallelepiped located at the top and a cylinder located at the bottom, and the sheet metal processing method comprises the following steps:

(1) Cut the stainless steel plate according to the drawing to obtain a square box sheet metal part (see FIG6 ), a cylindrical sheet metal part (see FIG7 ) and a round bottom sheet metal part (see FIG8 );

(2) bending the four sides of the square box sheet metal part and welding the four side seams to form a cuboid;

(3) bending the cylindrical sheet metal part and forming a cylindrical structure by welding the gap;

(4) welding the upper end of the cylindrical structure to the rectangular parallelepiped, and welding the lower end of the cylindrical structure to the round bottom sheet metal part, to obtain a preformed sheet metal part of a low-temperature liquid nitrogen container;

(5) Cutting the welding parts of the sheet metal of the initially formed low-temperature liquid nitrogen container to remove the welding spots, thereby obtaining a low-temperature liquid nitrogen device.

In a specific embodiment, the square box sheet metal part, the cylindrical sheet metal part and the round bottom sheet metal part in step (1) are all made of 304 stainless steel.

In a specific embodiment, a circular hole is cut on the square box sheet metal, and the distances from the center of the circular hole to two opposite sides of the cuboid are different.

In a specific embodiment, in step (2), the four sides of the square box sheet metal are bent 90 degrees. After bending, the side gaps are welded to ensure that the welding points are watertight.

Specifically, the four side seams of the square box sheet metal are welded by argon arc welding, and the circular hole cut in the middle matches the outer diameter of the cylindrical structure. The cylindrical sheet metal is a rectangular flat plate, which is bent. The width of the crack after bending is about 0.5mm, and argon arc welding is used for welding.

In a specific embodiment, in step (3), the cylindrical sheet metal part is surrounded along the long side to form a cylindrical structure, the outer diameter of the cylindrical structure is 82 mm, the inner diameter is 80 mm, and the size of the circular hole opened at the bottom of the cuboid is matched, and the cylindrical structure and the edge of the circular hole are welded.

In a specific embodiment, in step (4), the diameter of the round bottom sheet metal part is 80 mm, matching the inner diameter of the cylindrical structure, and is aligned along the edge of the round bottom and welded to the cylindrical structure.

In a specific embodiment, in step (5), water is poured into the solder joints after the solder joints are removed to verify that all solder joints are leak-proof, and the processing is completed. If there is a leak, re-welding is required and the solder joints are cleaned again.

It should be noted that in order to avoid protruding welds generated when welding the upper and lower ends of the cylindrical structure, which would affect subsequent assembly and use, the present invention needs to lathe the inner diameter of the weld between the cylinder and the cuboid and the outer diameter of the weld at the round bottom sheet metal after the cylindrical structure is welded to remove the protruding welds. The welding points of the cryogenic liquid nitrogen device of the present invention are all located in the unstressed parts, and ultimately it only needs to ensure that the cryogenic liquid nitrogen device does not leak.

Another specific embodiment of the present invention discloses a high-pressure polymerization reaction low-temperature liquid nitrogen device prepared by the above method.

The low-temperature liquid nitrogen device of the present invention is configured as an asymmetric structure with a rectangular upper body and a cylindrical lower body, which is not only convenient for adding liquid nitrogen, but also can greatly reduce the heat leakage at the bottom of the low-temperature liquid nitrogen container, thereby ensuring the slow evaporation of liquid nitrogen, and more for cooling the anvil part. The temperature can be lowered for a long time, and the temperature of the main body of the press will not be overcooled due to heat leakage during the experiment. The refrigeration effect caused by the heat absorption of the main body of the press from the external environment and the heat leakage from the bottom of the low-temperature liquid nitrogen container can be balanced. The low-temperature liquid nitrogen device can realize the loading of gaseous samples, which is a prerequisite for subsequent high-pressure polymerization reactions.

Another specific embodiment of the present invention, as shown in Figures 1-5, discloses a high-pressure polymerization reaction device, which includes, from top to bottom, a concentrically arranged upper insulation plate 3, an upper pad 12, an upper anvil seat 11, an upper anvil 1, a lower anvil 2, a lower anvil seat 21 and a lower insulation plate 4, a sealing ring 5 is arranged between the upper anvil 1 and the lower anvil 2, and a gasket 54 is arranged in the sealing ring 5, the upper anvil seat 11, the upper anvil 1, the sealing ring 5, the lower anvil 2 and the lower anvil seat 21 are arranged in a low-temperature liquid nitrogen device 6, and the low-temperature liquid nitrogen device 6 is composed of an upper rectangular parallelepiped 61 and a lower cylinder 62, the axis of the cylinder 62 is at different distances from the two opposite sides of the rectangular parallelepiped 61, the upper anvil seat 11, the upper anvil 1 and the sealing ring 5 are located in the rectangular parallelepiped 61, and the lower anvil 2 and the lower anvil seat 21 are located in the cylinder 62.

Compared with the prior art, the sealing ring 5 in the high-pressure polymerization device of the present invention can realize the liquefaction packaging of the gaseous raw material sample and realize the high-pressure polymerization reaction of the gaseous raw material, filling the gap in the prior art. The device of the present invention has good sealing performance and will not have the problem of air leakage. The gasket design ensures that it is not easy to crack and damage. The liquid nitrogen cooling device has high cooling efficiency, which can reduce the pressure module to the liquid nitrogen temperature, and the addition of liquid nitrogen is convenient.

In a specific embodiment, as shown in FIG. 2 , the upper and lower surfaces of the sealing ring 5 are both provided with a circle of grooves 51 , and a circle of indium wire is correspondingly provided in the grooves 51 .

Specifically, as shown in FIG1 , when the device of the present invention is used, a press is used to apply force to the lower end of the device, so that the upper anvil 1, the sealing gasket 54 and the lower anvil 2 are squeezed and contacted to form a cavity for raw material reaction. The diameter of the indium wire is matched with the depth and width of the groove 51, and the groove 51 provides a fixed position for the indium wire. When the upper anvil 1, the sealing gasket 54 and the lower anvil 2 begin to contact, the indium wire is compacted in the groove 51 and can fit tightly, so that the sealing ring 5 is sealed with the upper and lower anvils. The sealing ring 5 forms a chamber between the upper anvil 1 and the lower anvil 2 to contain liquefied gas. The contact surface of the sealing ring 5 and the upper anvil 1 and the lower anvil 2 forms a sealed environment through the deformation of the indium wire, so there will be no problem of gas leakage or liquid leakage. Among them, the upper heat insulation sheet 3 and the upper end of the press are also provided with a first top pad 14 and a second top pad 15, and the first top pad 14 and the second top pad 15 can reduce the force on the upper heat insulation sheet 3 and reduce damage.

In the low temperature test, the sealing is achieved by the metal fitting, which requires very high processing accuracy and assembly accuracy of the accessories. In addition, the difference in thermal expansion coefficients between different metals at low temperatures makes it difficult to control the sealing during the cooling process. Metal indium has good ductility at low temperatures. Therefore, the sealing ring of the present invention is made of aluminum with a thickness of 2 mm, and the indium wire is used as the sealing layer. When the high-pressure polymerization reaction device is in the high-pressure experiment, aluminum is soft and easily deformed under pressure. At this time, the indium wire in the groove 51 cooperates with the sealing ring 5 to play a sealing role.

The study found that the thickness of the sealing ring 5 has an important influence on the high-pressure polymerization reaction. When the thickness of the sealing ring is too thick, more of the pressure applied by the device is consumed on the sealing ring, and the pressure acting on the anvil surface of the upper anvil 1 and the anvil surface of the lower anvil 2 and the sample is insufficient, which leads to the inability to complete the polymerization phase change. When the thickness of the sealing ring 5 is too thin, the sealing ring 5 is prone to cracking, damage, and leakage.

In a specific embodiment, as shown in FIG. 2 , the sealing ring 5 is provided with two air guide tubes 52 fixedly connected thereto. In a further preferred embodiment, the air guide tubes 52 are welded to the sealing ring 5 , and the welding method can avoid air leakage.

It should be noted that the two air guide pipes 52 are respectively an air inlet pipe and an air outlet pipe. The function of the air inlet pipe is to pass the gaseous raw materials into the closed chamber formed by the sealing ring 5 and the upper and lower anvils during the sample loading stage, and cool it down until the gaseous raw materials begin to liquefy therein, and gradually fill the high-pressure cavity of the polymerization reaction and the sealed cavity formed by the entire aluminum sealing ring 5. When the sample is packaged, the remaining liquid in the sealed cavity will gradually vaporize during the heating process and be discharged from the sealed cavity along the air outlet pipe. The discharged gas is recycled to the gas cylinder through the post-processing gas path or directly discharged to the outside through the fume hood.

Specifically, the air guide tube 52 is made of aluminum, and its diameter is 1/16 inch to 3 mm, preferably, its diameter is 3 mm. The air guide tube 52 is made of the same material as the sealing ring 5, and the same strength can reduce the possibility of fracture at the welding point.

In a specific embodiment, as shown in FIG. 5 , the two air guide tubes 52 are arranged in a spiral shape in the cryogenic liquid nitrogen device 6 .

It should be noted that the inventors found in the experiment that during the cooling process, the air pressure inside the aluminum sealing ring 5 changes very drastically, and the temperature inside the sealing ring 5 will hover near the liquefaction temperature for a long time, and cannot be further reduced to achieve gas liquefaction. This is because the gas introduced is directly blown onto the liquefied raw material. Therefore, the air guide pipe 52 is placed in the low-temperature liquid nitrogen device 6 in a quasi-spiral shape, which can extend the length of the air intake pipe and allow the air intake pipe to be fully immersed in liquid nitrogen, so that the raw material gas can be liquefied in advance in the air intake pipe and flow into the sealing ring in a liquefied form. Similarly, the quasi-spiral shape of the air outlet pipe also increases the area where the gas is cooled, which is more conducive to the liquefaction of the gas.

In a specific embodiment, as shown in FIGS. 2 and 2-1 , the included angle between the air inlet pipe and the air outlet pipe on the circular surface where the sealing ring is located is 90°.

It should be noted that the air inlet and outlet pipes are arranged at 90° because the high-pressure polymerization reaction device of the present invention needs to be fixed on a press base for use, and the arrangement at 90° is conducive to the operation of the test, and is convenient for gas line connection, making the operation more convenient. At the same time, it is also conducive to the spiral arrangement of the air inlet and outlet pipes.

In a specific embodiment, as shown in FIG. 2 , a temperature sensor 56 is disposed inside the sealing ring 5 .

Specifically, the temperature sensor 56 is two PT100 temperature sensors, which are respectively arranged on the upper and lower sides of the gasket 54 during the synthesis of the p-CO sample, and can display the temperature gradient distribution in the cavity of the sealing ring 5 in the vertical direction, thereby inferring the amount of the generated liquid sample.

It should be noted that a hole is punched in the side wall of the sealing ring 5, and two PT100 temperature sensor leads are led out through the side wall of the sealing ring 5. At the same time, the PT100 temperature sensor is connected to the digital source meter, and the resistance value of the PT100 temperature sensor is read out by a computer, thereby converting the real-time temperature inside the sealing ring 5.

In a specific embodiment, as shown in Figures 3 and 3-1, the sealing gasket 54 is a circular ring structure, and two inwardly concave openings 55 are provided on the sealing gasket 54 corresponding to the two air guide tubes 52, and a temperature sensor placement portion 57 is provided on the sealing gasket 54 corresponding to the temperature sensor 56.

It should be noted that the cavity (circular hole 53) in the middle of the gasket 54 is a high-pressure cavity for the raw materials to react.

In a specific embodiment, the thickness of the gasket 54 matches the height of the sealing ring 5 , and the outer diameter of the gasket 54 matches the inner diameter of the sealing ring 5 , so that the gasket 54 is sleeved inside the sealing ring 5 .

It should be noted that the thickness of the gasket 54 needs to match the height of the aluminum sealing ring 5. The ideal situation is that after the sealing ring 5 is compacted, the upper and lower anvils are almost close to the gasket 54 after sealing, but there is still a small gap. The liquefied raw material flows into the high-pressure cavity in the middle of the sealing ring 5 through the gap. At this time, only a slight pressure is needed to close the upper and lower anvils with the gasket 54 to achieve the encapsulation of the liquefied raw material.

The outer diameter of the gasket 54 matches the inner diameter of the sealing ring 5, so that the gasket 54 cannot move radially during the process of cryogenically liquefying and packaging the sample. The air inlet and outlet pipes are located at the two openings 55, respectively, so as not to affect the normal operation of the air inlet and outlet pipes.

Specifically, the diameter of the circular hole 53 in the middle of the gasket 54 is 6 mm, the outer diameter of the gasket 54 is 53.7 mm, and the thickness is 1 mm. Preferably, the gasket 54 is made of T301 stainless steel. The inner diameter of the sealing ring is 54 mm, and the outer diameter is 58 mm.

In a preferred embodiment, the circular hole 53 in the middle of the gasket is much smaller than the outer diameter of the gasket 54, so as to avoid the gasket 54 from cracking from the circular hole 53 to the edge when under pressure.

In the prior art, the seal 54 is a square with a circular hole in the middle, and the size is 30mm×30mm×1mm. The diameter of the circular hole is 6mm. During the test, it may crack from a certain direction and eject fragments outward, which brings great safety hazards. As shown in Figure 15, the seal used previously broke and shot out the garbage can. After many tests, the seal of the present invention did not crack from a certain direction and eject fragments outward.

The gasket 54 of the present invention matches the sealing ring 5 in all directions, so as long as the position of the sealing ring 5 is fixed and concentrically arranged with the upper and lower anvil surfaces, the gasket 54 will be fixed at a position concentric with the anvil surfaces. In addition, the large-sized circular gasket 54 fills a considerable part of the sealing ring cavity, and only a small amount of raw material gas needs to be liquefied each time to fill the cavity in the middle of the gasket 54, which greatly saves the gas required for each test.

In addition, the sealing gasket 54 of the present invention has a circular ring structure and two inwardly concave openings 55. The inwardly concave openings on the circular ring structure can not only match the installation of the air inlet pipe and the air outlet pipe.

The material of the gasket is T301 stainless steel, or a softer material, as long as the material can withstand a certain pressure, it can reduce the pressure loss of the high-pressure polymerization device and make the high-pressure test easier to perform. Secondly, the gasket 54 has sufficient strength to withstand the radial pressure in the sample chamber.

It should be noted that in the prior art, the cryogenic liquid nitrogen device is a circular cryogenic container, which is a relatively compact structure. When actually conducting a gas liquefaction packaging experiment, the press is prone to frost, and it is often impossible to pressurize, resulting in experimental failure. Research has found that this phenomenon is related to the structure of the cryogenic liquid nitrogen device. Based on this, the present invention has made an original design for the cryogenic liquid nitrogen device 6 and its related structures. By adopting the cryogenic liquid nitrogen device 6 of the present invention, the press will not frost.

In a specific embodiment, the cryogenic liquid nitrogen device 6 is composed of an upper cuboid 61 and a lower cylinder 62 , and the upper surface of the cuboid 62 is an open structure.

It should be noted that, as shown in FIGS. 4 and 5 , the cryogenic liquid nitrogen device 6 is an integrally formed structure with a rectangular parallelepiped 61 on the top and a cylindrical body 62 on the bottom, and the distances from the axis of the cylindrical body 62 to the first side 63 and the second side 64 of the rectangular parallelepiped 61 are different. An asymmetric structure is formed, with the end of the cylindrical body 62 with the axis of the cylindrical body 62 facing outwards, which is conducive to pouring liquid nitrogen through the opening on the top during the test. At the same time, the rectangular parallelepiped structure is relatively large and can hold more cryogenic liquid nitrogen without having to add it frequently. In addition, the air duct 52 can be more partially immersed in the cryogenic liquid, so that the gas will be cooled and liquefied by the liquid nitrogen during the process of passing through the air duct 52, thereby increasing the efficiency of gas liquefaction.

In a specific embodiment, the low-temperature liquid nitrogen device 6 is wrapped with a heat-insulating layer on the outside, which can further reduce the volatilization speed of the liquid nitrogen and improve the cooling efficiency of the upper and lower anvil parts.

Specifically, the lower anvil 21 and the lower heat insulation sheet 4 are respectively arranged above and below the bottom surface of the cylinder 62 below the cryogenic liquid nitrogen device 6, and the lower heat insulation sheet 4 is directly placed in the groove of the press 9. A positioning ring 8 is arranged between the cylinder 62 of the cryogenic liquid nitrogen device 6 and the groove of the press 9 to separate the cylinder and the press. In the present invention, the upper anvil 1 and the upper anvil seat 11 have the same outer diameter, and the lower anvil 2 and the lower anvil seat 21 have the same outer diameter, wherein the upper anvil 1, the upper anvil seat 11, the lower anvil 2 and the lower anvil seat 21 are all assembled from multiple modules.

In a specific embodiment, as shown in Figure 1, the upper anvil 1 and the upper anvil seat 11 are arranged in a first concentric ring 13 made of copper, the lower anvil 2 and the lower anvil seat 21 are arranged in a second concentric ring 22 made of copper, and an upper anvil fixing sleeve 7 is arranged on the outer side of the upper thermal insulation plate 3, the upper pad 12, the upper anvil seat 11 and the upper anvil 1. The upper anvil fixing sleeve 7 is made of glass fiber, which can reduce heat leakage.

It should be noted that the above-mentioned copper concentric rings and upper anvil fixing sleeve 7 are used to ensure that the various components are arranged concentrically.

In a specific embodiment, a heat insulating material layer is provided between the outer side of the pressing anvil 21 and the cylinder 62 to isolate the heat transfer from the cryogenic liquid container to the press body.

The cryogenic liquid nitrogen device 6 of the present invention can be cooled for a long time. During the test, the temperature of the compressor body will not be overcooled due to liquid leakage. The refrigeration effect caused by the heat absorption of the compressor body from the external environment and the heat leakage from the bottom of the cryogenic liquid nitrogen device 6 can be balanced. Liquid nitrogen can also be injected into the container conveniently and quickly. During the experiment, the compressor body will not be obviously frosted, and there is no pressurization failure caused by overcooling of the compressor.

In a specific embodiment, the surfaces of the upper anvil 1 and the lower anvil 2 in contact with the gasket 54 are both flat plane structures. The sealing ring body and the grooves thereof are provided to seal with the upper and lower anvils. The sealing ring forms a chamber between the upper anvil 1 and the lower anvil 2 to contain the liquefied gas. The contact surfaces of the sealing ring 5 and the upper and lower anvils 1 and 2 form a sealed environment through the deformation of the indium wire. The indium wire can fit tightly when compacted in the groove 51. The gasket 54 is sleeved in the sealing ring 5. After the sealing is completed, the upper and lower anvils are almost close to the gasket but there is still a small gap. The liquefied raw material flows into the high-pressure cavity in the middle of the sealing ring through the gap. Only a slight pressure is needed to close the upper and lower anvils and the gasket to achieve the encapsulation of the liquefied raw material.

It should be noted that the high pressure polymerization reaction device of the present invention can be used for polymerization of carbon monoxide, etc. The heat leakage at the bottom of the low temperature liquid nitrogen container in the present invention refers to the total heat transfer power of the bottom and side of the cylinder.

The technical solution of the present invention is further explained below in conjunction with specific embodiments.

Example 1

As shown in FIGS. 6-10 , a sheet metal processing method of a cryogenic liquid nitrogen device of a specific structural form, wherein the high-pressure polymerization reaction cryogenic liquid nitrogen device comprises a rectangular parallelepiped located at the top and a cylinder located at the bottom, and the sheet metal processing method comprises the following steps:

(1) Cutting the materials according to the drawings, cutting the stainless steel plate to obtain a square box sheet metal part (see FIG6 ), a cylindrical sheet metal part (see FIG7 ) and a round bottom sheet metal part (see FIG8 ), wherein a circular hole is cut on the square box sheet metal part, and the distances from the center of the circular hole to the two opposite sides of the cuboid are different;

(2) The four sides of the square box sheet metal are bent 90 degrees. After bending, the gaps at the sides are welded to ensure that the welding points are watertight, so as to form a rectangular parallelepiped, as shown in FIG9 ;

(3) The cylindrical sheet metal part is enclosed along the long side into a cylindrical structure, as shown in FIG. 10 , the outer diameter of the cylindrical structure is 82 mm, the inner diameter is 80 mm, and the size of the circular hole opened at the bottom of the cuboid is matched, and the cylindrical structure and the edge of the circular hole are welded;

(4) welding the upper end of the cylindrical structure to the rectangular parallelepiped, and welding the lower end of the cylindrical structure to the round bottom sheet metal part, to obtain a preformed sheet metal part of a low-temperature liquid nitrogen container;

The diameter of the round bottom sheet metal part is 80 mm, which matches the inner diameter of the cylindrical structure, and is aligned with the cylindrical structure along the edge of the round bottom and welded;

(5) Cut the welding parts of the sheet metal of the initially formed low-temperature liquid nitrogen container, remove the welding points, pour water, verify that all welding points are leak-proof, and complete the processing. If there is leakage, repair welding is required, and the welding points are cleaned again to obtain a low-temperature liquid nitrogen device.

Example 2

A high-pressure polymerization reaction device of the present embodiment comprises an upper heat insulation sheet 3, an upper pad 12, an upper anvil seat 11, an upper anvil 1, a lower anvil 2, a lower anvil seat 21 and a lower heat insulation sheet 4 which are arranged concentrically from top to bottom. A sealing ring 5 is arranged between the upper anvil 1 and the lower anvil 2, and a gasket 54 is arranged inside the sealing ring 5. The upper anvil seat 11, the upper anvil 1, the sealing ring 5, the lower anvil 2 and the lower anvil seat 21 are arranged in a low-temperature liquid nitrogen device 6. The low-temperature liquid nitrogen device 6 is composed of an upper rectangular parallelepiped 61 and a lower cylinder 62. The distances from the axis of the cylinder 62 to the two opposite sides of the rectangular parallelepiped 61 are different. The upper anvil seat 11, the upper anvil 1 and the sealing ring 5 are located in the rectangular parallelepiped 61, and the lower anvil 2 and the lower anvil seat 21 are located in the cylinder 62. The surfaces of the upper anvil 1 and the lower anvil 2 in contact with the gasket 54 are both flat plane structures.

Among them, the upper surface of the rectangular parallelepiped 61 is an open structure. The outer side of the low-temperature liquid nitrogen device is wrapped with a thermal insulation layer. Specifically, the lower anvil 21 and the lower thermal insulation sheet 4 are respectively arranged above and below the bottom surface of the cylinder 62 below the low-temperature liquid nitrogen device 6, and the lower thermal insulation sheet 4 is directly placed in the groove of the press 9. A positioning ring 8 is arranged between the cylinder 62 of the low-temperature liquid nitrogen device 6 and the groove of the press 9 to separate the cylinder and the press. In this embodiment, the outer diameters of the upper anvil 1 and the upper anvil 11 are the same, and the outer diameters of the lower anvil 2 and the lower anvil 21 are the same. The inner diameter of the cylinder is 80mm, the outer diameter is 82mm, the distance between the side wall of the cylinder and the inner wall of the press is 7mm, the thickness of the lower thermal insulation sheet 4 is 8mm, and the material of the lower thermal insulation sheet 4 is glass fiber.

Specifically, the upper and lower surfaces of the sealing ring 5 are both provided with a circle of grooves 51, and a circle of indium wire is correspondingly provided in the grooves 51. An air inlet pipe and an air outlet pipe are welded on the sealing ring 5, and the angle between the air inlet pipe and the air outlet pipe on the circular surface where the sealing ring is located is 90°. The air inlet pipe and the air outlet pipe are arranged in a quasi-spiral shape in the low-temperature liquid nitrogen device 6, wherein the diameters of the air inlet pipe and the air outlet pipe are both 3 mm.

In this embodiment, the sealing ring 5 is made of aluminum and has a thickness of 2 mm.

Example 3

The high-pressure polymerization reaction device of this embodiment is the same as that of the embodiment 2, except that, as shown in FIG3 , the sealing gasket 54 is a circular ring structure, and two inwardly concave openings 55 are provided on the sealing gasket 54 corresponding to the two air guide pipes 53, and a temperature sensor placement portion 57 is provided on the sealing gasket 54 corresponding to the temperature sensor 56. The two temperature sensors 56 are respectively provided on the upper and lower sides of the sealing gasket 54, so that the temperature distribution in the vertical direction of the middle chamber of the sealing ring 5 can be obtained, thereby reflecting the degree of liquefaction of the raw material.

Specifically, holes are punched on the side wall of the sealing ring 5, and two PT100 temperature sensor leads are led out through the side wall of the sealing ring 5. At the same time, the holes are bonded with epoxy resin to maintain a sealed state. At the same time, the PT100 temperature sensor is connected to the digital source meter, and the resistance value of the PT100 temperature sensor is read out by a computer, thereby converting the real-time temperature inside the sealing ring.

In a further solution, the thickness of the gasket 54 matches the height of the sealing ring 5, the thickness of the gasket is 1 mm, the height of the sealing ring is 6.5 mm, and the outer diameter of the gasket 54 matches the inner diameter of the sealing ring 5, so that the gasket 54 is sleeved in the sealing ring 5. The diameter of the circular hole 53 in the middle of the gasket 54 is 6 mm, and the outer diameter of the gasket 54 is 53.7 mm.

Example 4

The high-pressure polymerization reaction device of this embodiment is the same as that of Embodiment 2, except that, as shown in FIG1 , the upper anvil 1 and the upper anvil seat 11 are arranged in a first concentric ring 13 made of copper, the lower anvil 2 and the lower anvil seat 21 are arranged in a second concentric ring 22 made of copper, and an upper anvil fixing sleeve 7 is arranged on the outer side of the upper thermal insulation sheet 3, the upper pad 12, the upper anvil seat 11 and the upper anvil 1. The upper anvil fixing sleeve 7 is made of glass fiber to reduce heat leakage, and a thermal insulation material layer is also arranged between the outer side of the lower anvil seat 21 and the cylinder 62.

Comparative Example 1

The low-temperature liquid nitrogen device of this comparative example is different from that of Example 2. When assembled in a high-pressure polymerization reaction device, it is specifically composed of two upper and lower cylinders, as shown in Figure 11. The lower anvil 2 and the lower anvil seat 21 are located in the lower cylinder, and the lower cylinder is directly nested in the groove of the press 9. The outer diameter of the lower cylinder is 90 mm, which matches the inner diameter of the groove of the press 9, which is 92 mm. There is no positioning ring between the lower cylinder and the press. The thickness of the lower insulation sheet 4 is 8 mm, with a 1 mm thick side edge, and the material of the lower insulation sheet 4 is glass fiber. The side wall of the lower cylinder is 1 mm away from the side wall of the press 9. A glass fiber insulation ring 10 with a height of 6 mm is arranged on the outer side of the upper end of the lower cylinder. The height of the lower cylinder without the insulation ring is 16 mm.

Comparative Example 2

The high-pressure polymerization reaction device of this comparative example is the same as that of Example 3, except that the middle of the upper anvil 1 and the lower anvil 2 are both inwardly recessed structures, and a beryllium copper soft metal ring 101 is arranged between the upper anvil 1 and the lower anvil 2, as shown in Figure 14. When the upper anvil 1 and the lower anvil 2 are squeezed, the beryllium copper is easily deformed, and the beryllium copper soft metal ring 101 is deformed to form a sealing structure. The inwardly recessed structures on the upper anvil 1 and the lower anvil 2 are fitted with the step surface in the beryllium copper soft metal ring 10, and the cavity in the middle of the beryllium copper soft metal ring and the inwardly recessed structure in the middle of the upper anvil 1 and the lower anvil 2 together constitute a sample reaction chamber.

FIG. 12 shows the state when the concave structures of the upper anvil 1 and the lower anvil 2 begin to contact with the external beryllium copper soft metal ring 101 but have not yet been compressed, and FIG. 13 shows the state when the upper anvil 1 and the lower anvil 2 are compressed to the limit.

Test Example 1

The thermal conductivity of glass fiber is 0.40W/(m·k), and the thermal conductivity of air is 0.023W/(m·k). The heat transfer power is proportional to the contact area and inversely proportional to the distance.

Calculate the heat transfer power at the bottom of the cylinder and the heat transfer power at the side of the cylinder of the low-temperature liquid nitrogen device of Example 2;

The heat transfer power at the bottom of the cylinder of the cryogenic liquid nitrogen device is calculated as follows:

0.4W/(m·k)×area(3.14×80×80/ ^4mm2 )/distance(8mm)×temperature difference(300-77K)

=56.02W;

The lateral heat transfer power of the cylinder includes two parts: glass fiber heat transfer and air heat transfer. The height of the air part is 21 mm, and the height of the glass fiber contact part is 1 mm.

The heat transfer power of glass fiber is calculated as follows:

0.4W/(m·k)×area(3.14×82×1mm ² )/distance(7mm)×temperature difference(300-77K)

=3.28W;

The air heat transfer power is calculated as follows:

0.023W/(m·k)×area(3.14×82×21mm ² )/distance(7mm)×temperature difference(300-77K)

=3.96W;

The lateral heat transfer of the cylinder = the heat transfer power of the glass fiber and the heat transfer power of the air is 3.28W+3.96W=7.24W.

The total heat transfer power of the cylinder in the low-temperature liquid nitrogen device of Example 2 is 56.02W+7.24W=63.26W.

The heat transfer power at the bottom of the cylinder below the cryogenic liquid nitrogen device of Comparative Example 1 is calculated as follows:

0.4W/(m·k)×area(3.14×92×92/4mm ² )/distance(8mm)×temperature difference(300-77K)

=74.08W.

The heat transfer power of the side of the cylinder below the cryogenic liquid nitrogen device of Comparative Example 1 is calculated as follows: the lateral heat transfer includes two parts: glass fiber heat transfer and air heat transfer, where the air part is 16 mm high and the glass fiber contact part is 6 mm high:

Glass fiber heat transfer power:

0.4W/(m·k)×area (3.14×92×6mm ² )/distance (1mm)×temperature difference (300-77K)=154.61W;

Air heat transfer power:

0.023W/(m·k)×area(3.14×92×16mm ² )/distance(1mm)×temperature difference(300-77K)

=23.71W; the total lateral heat transfer power is 154.61W+23.71W=178.32W.

The total heat transfer power of the lower cylinder in the low-temperature liquid nitrogen device of Comparative Example 1 is 74.08W+178.32W=252.4W.

By comparison, it can be seen that the total heat transfer power of the lower cylinder of the cryogenic liquid nitrogen device of Comparative Example 1 (252.4 W) is greater than the total heat transfer power of the cylinder of the cryogenic liquid nitrogen device of Example 2 (63.26 W), indicating that the cryogenic liquid nitrogen device of the present invention can reduce heat leakage.

Test Example 2

(1) Calculate the compression ratio of the reaction chamber of the sample of Comparative Example 2 as follows:

After calculation, as shown in Figure 12, the volume of the sample reaction chamber before compression is 80.34 ^mm3 . As shown in Figure 13, when compressed to the limit, the volume of the sample reaction chamber is 46.41 ^mm3 .

Calculate the sample chamber compressibility as:

(1-reaction chamber volume after compression/reaction chamber volume before compression)×100%=(1-46.41/80.34)×100%=42.23%.

(2) Calculate the compression rate of the reaction chamber in Example 3 as follows:

In Example 3, the sample reaction chamber is the circular hole 53 on the sealing gasket 54. The volume of the reaction chamber before compression is V=3.14×3×3×1=28.26 mm ³ . After the extreme compression, the upper and lower anvil surfaces are in direct contact, and the volume of the reaction chamber is zero.

Calculate the sample chamber compression rate = (1-volume after compression/volume before compression) × 100%

=(1-0/28.26)×100%=100%.

Under extreme compression conditions, by comparing the compression rates of the reaction chambers of Example 3 and Comparative Example 2, it can be seen that the compression rate of the reaction chamber of the present invention is greater. Due to the high compression rate, the raw materials can easily meet the phase change requirements, which is beneficial to the reaction. The high-pressure polymerization reaction of gaseous raw materials usually has a large proportion of volume shrinkage. The present device has significant advantages in the high-pressure reaction of gas raw material samples with a large compression rate.

Test Example 3

The p-CO sample was synthesized by using the high-pressure polymerization reaction device of Example 3. CO gas entered the sample chamber through the gas guide pipe 52. The sample chamber had a diameter of 6 mm and a height of 1 mm. The volume of the sample chamber was 3.14×3×3×1=28.26 mm ³ . The density of liquid CO was 0.8 g/cm ³ , so the amount of sample sealed in the sample chamber was 22.608 mg. Under the action of an oil pressure of 18000 psi (about 120 tons), the pressure was maintained for 12 hours. After the pressure was released, 6.2 mg of p-CO solid was obtained. Therefore, the reaction yield was 27.4%.

The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims (10)

1. The sheet metal machining method of the high-pressure polymerization reaction low-temperature liquid nitrogen device is characterized in that the high-pressure polymerization reaction low-temperature liquid nitrogen device comprises a cuboid positioned above and a cylinder positioned below, and comprises the following steps of:

(1) Blanking according to a drawing, and cutting a stainless steel plate to obtain a square box sheet metal part, a cylinder sheet metal part and a round bottom sheet metal part respectively;

(2) Four sides of the square box sheet metal part are bent, and four side seams are welded to form a cuboid;

(3) Bending the cylindrical sheet metal part, and forming a cylindrical structure through welding gaps;

(4) Welding the upper end of the cylindrical structure with the cuboid, and welding the lower end of the cylindrical structure with the round bottom sheet metal part to obtain a sheet metal part of the preformed low-temperature liquid nitrogen container;

(5) Cutting the welding part of the sheet metal part of the preformed low-temperature liquid nitrogen container, and removing welding spots to obtain the low-temperature liquid nitrogen device.

2. The method of claim 1, wherein the square box sheet metal part, the cylindrical sheet metal part and the round bottom sheet metal part in the step (1) are all made of 304 stainless steel.

3. The method according to claim 1, wherein the square box sheet metal part is cut with a circular hole, and distances from the center of the circular hole to two opposite side surfaces in the cuboid are different.

4. The method according to claim 1, wherein in the step (2), four sides of the sheet metal part of the square box are bent by 90 degrees, and after bending, the side seam is welded to ensure that the welded part is watertight.

5. The method according to claim 3, wherein in the step (3), the cylindrical sheet metal part is surrounded along the long edge to form a cylindrical structure, the outer diameter of the cylindrical structure is 82mm, the inner diameter of the cylindrical structure is 80mm, the cylindrical structure is matched with the size of a round hole formed in the bottom of the cuboid, and the cylindrical structure and the edges of the round hole are welded.

6. The method of claim 5, wherein in step (4), the round bottom sheet metal part has a diameter of 80mm, matches the inner diameter of the cylindrical structure, and is welded to the cylindrical structure along the edge alignment of the round bottom.

7. The method of claim 1, wherein in step (5), water is poured after the welding spots are removed, all the welding spots are verified to be watertight, the processing is completed, repair welding is required if there is a leak, and the welding spots are cleaned again.

8. A high pressure polymerization low temperature liquid nitrogen apparatus prepared by the method of any one of claims 1-7.

9. A high-pressure polymerization reaction device, comprising the low-temperature liquid nitrogen device according to claim 8.

10. The high-pressure polymerization reaction device according to claim 9, wherein the device comprises an upper heat insulation sheet, an upper base plate, an upper anvil, a lower anvil and a lower heat insulation sheet which are concentrically arranged from top to bottom, a sealing ring is arranged between the upper anvil and the lower anvil, a sealing gasket is arranged in the sealing ring, a low-temperature liquid nitrogen device is arranged outside the upper anvil, the sealing ring and the lower anvil, the upper anvil and the sealing ring are positioned in the cuboid, and the lower anvil are positioned in the cylinder.