CN113062980A

CN113062980A - PTFE lining pressure container and manufacturing method thereof

Info

Publication number: CN113062980A
Application number: CN202110513519.XA
Authority: CN
Inventors: 齐泽民; 胡俊飞; 古洪杰; 曹媛媛; 滑翔
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-05-11
Filing date: 2021-05-11
Publication date: 2021-07-02
Anticipated expiration: 2041-05-11
Also published as: CN113062980B

Abstract

The invention discloses a PTFE lining pressure vessel and a manufacturing method thereof, and relates to the field of pressure vessel manufacturing.A vessel main body comprises a cylinder body and end enclosures arranged at two ends of the cylinder body, wherein the inner wall of the cylinder body is provided with a plurality of annular bulges which are uniformly distributed along the axial direction of the cylinder body; the invention has the beneficial effects that: the inner wall of pressure vessel is provided with a plurality of annular archs, and the PTFE protective layer outer wall of inside lining has a plurality of second annular grooves, and PTFE protective layer integrated into one piece, can be so that the laminating between PTFE protective layer and the pressure vessel is inseparabler, when receiving cold and hot alternating stress, have annular sunken and bellied PTFE protective layer can take place partial deformation and not take place to separate with the pressure vessel lateral wall in annular sunken and bulge, have better protection effect to pressure vessel.

Description

PTFE lining pressure container and manufacturing method thereof

Technical Field

The invention belongs to the field of pressure vessel manufacturing, and particularly relates to a PTFE (polytetrafluoroethylene) lining pressure vessel and a manufacturing method thereof.

Background

The pressure container is very common in the fields of chemical industry and new energy, and is used for storing various chemical raw materials; PTFE, namely polytetrafluoroethylene, commonly known as 'plastic king', is a high molecular polymer prepared by polymerizing tetrafluoroethylene as a monomer, is white wax-like, semitransparent, heat-resistant and cold-resistant, and can be used at the temperature of minus 180-260 ℃ for a long time. The material has the characteristics of acid resistance, alkali resistance and various organic solvents resistance, is almost insoluble in all solvents, meanwhile, the polytetrafluoroethylene has the characteristic of high temperature resistance, has extremely low friction coefficient, can be used for lubricating, has no real melting point for an ideal coating on the inner layer of an easily cleaned water pipe, is insoluble in any solvent, can react with molten alkali metal, is not corroded by any substance, and does not change even if boiled in hydrofluoric acid, aqua regia or fuming sulfuric acid, and sodium hydroxide; PTFE is therefore the lining material of choice in many strong acid or strong base vessels to protect the tank body.

Present pressure vessel inside lining PTFE is through scribbling high temperature glue inside pressure vessel, later will paste the lamellar body of PTFE material again, prior art's PTFE lining pressure vessel is when receiving alternating temperature or repeated scour's stress, the easy fracture of concatenation department of PTFE lamellar body, and the PTFE inner liner breaks away from because the inner wall of expend with heat and contract with cold easily with pressure vessel, thereby lead to the inner liner to be destroyed, make medium and container direct contact in the container, further corrode the container, cause the container to destroy, and then probably have the risk of revealing.

Disclosure of Invention

In order to solve the above problems of the prior art, it is an object of the present invention to provide a PTFE-lined pressure vessel and a method for manufacturing the same.

The technical scheme adopted by the invention is as follows:

the utility model provides a PTFE lining pressure vessel, the vessel main part includes the barrel and installs the head at the barrel both ends, and the barrel inner wall has a plurality of annular archs, and a plurality of annular archs are along barrel axial upward evenly distributed, and the barrel inner wall is tightly lined with the PTFE protective layer of integrated into one piece, and PTFE protective layer outer wall has the second annular groove, and the second annular groove closely laminates with the annular arch.

Furthermore, a plurality of supports are arranged on the container main body.

A method of manufacturing a PTFE-lined pressure vessel comprising the steps of:

s1: manufacturing each part of the tank body, including manufacturing a cylinder body, manufacturing a sealing head and manufacturing a pipe orifice;

s2: pretreating the cylinder, the end enclosure and the pipe orifice prepared in the step S1;

s3: integrally molding the PTFE liner on the cylinder, the end socket and the pipe orifice which are prepared in the step S2;

s4: welding the cylinder body, the end socket and the pipe orifice which are lined with PTFE in the step S3 together according to a design drawing;

s5: performing plastic welding on the seam of the PTFE inner liner layer of the heat affected zone welded in the step S4;

s6: standing for 7-15 days.

Further, the integral molding in step S3 includes:

s31: installing a barrel mould and an end enclosure mould, cleaning and polishing the outer wall of the barrel mould and the outer wall of the end enclosure mould before installation, and ensuring that the surface roughness of the outer wall of the barrel mould and the outer wall of the end enclosure mould is lower than that of the barrel and the end enclosure;

s32: filling PTFE powder, and then carrying out mould pressing treatment under the mould pressing pressure of 13-15 MPa for 20-30 minutes;

s33: and (3) heating the product subjected to the die pressing treatment of S32, wherein the temperature is raised from room temperature at a speed of 60-80 ℃/H, the temperature is kept for 2-4 hours when the temperature is raised to 370-385 ℃, and then the temperature is slowly reduced to room temperature at a speed of 20-30 ℃/H.

Further, the barrel mould comprises an inner mould, the inner mould is arranged in the barrel cavity and is coaxial with the barrel, a plurality of first annular grooves are formed in the outer wall of the inner mould, and the first annular grooves correspond to the annular protrusions one to one.

Further, the barrel mould also comprises pressing plates arranged at two ends of the barrel, an outer ring wall and an inner ring wall are vertically arranged on the pressing plate bag, a splicing groove is formed between the outer ring wall and the inner ring wall, and the inner mould is arranged in the splicing groove.

Furthermore, a plurality of threaded holes are uniformly formed in the pressing plate, and the pressing plates at the two ends of the cylinder body penetrate through the mounting holes through the connecting pieces to be connected.

Further, in step S3, the barrel forms a lining protection layer after the PTFE lining, and both ends of the lining protection layer are spaced from both ends of the barrel by a distance a.

Further, in step S2, the preprocessing includes: and (4) polishing the processing part, and performing sand blasting and cleaning treatment on the inner walls of the barrel and the air duct.

The invention has the beneficial effects that:

the invention provides a PTFE liner pressure vessel, wherein a plurality of annular bulges are arranged on the inner wall of the pressure vessel, a plurality of second annular grooves are arranged on the outer wall of a PTFE protective layer of a liner, the PTFE protective layer of the pressure vessel is integrally formed, so that the PTFE protective layer is more tightly attached to the pressure vessel, and the annular bulges are in one-to-one correspondence with and tightly attached to the second annular grooves; meanwhile, the invention provides a PTFE lining method of a pressure container, which is characterized in that the PTFE lining layer is tightly attached to the pressure container by integrally molding the PTFE lining on the cylinder body, the seal head and the pipe orifice.

Drawings

FIG. 1 is a schematic structural view of example 1;

FIG. 2 is a schematic view of the mounting structure of the barrel and the barrel mold of the present invention;

FIG. 3 is a schematic structural view of the barrel and the PTFE protective layer of the present invention;

FIG. 4 is a schematic structural view of the inner mold;

FIG. 5 is a schematic view of the construction of the platen;

in the figure, 1-container body, 11-cylinder, 12-end enclosure, 2-annular bulge, 3-nozzle, 4-PTFE protective layer, 41-second annular groove, 5-support, 6-inner mold, 61-first annular groove, 7-pressing plate, 71-outer annular wall, 72-splicing groove, 73-inner annular wall and 74-mounting hole.

Detailed Description

The first embodiment is as follows:

in this embodiment, as shown in fig. 1 and 3, a PTFE-lined pressure vessel, in this embodiment, the pressure vessel is a vertical storage tank, the internal medium includes strong acid, and when the medium is discharged or enters, a temperature change of 50 to 100 ℃ is generated, the vessel body 1 includes a cylinder body 11 and end sockets 12 installed at both ends of the cylinder body 11, and is characterized in that, the inner wall of the cylinder body 11 has a plurality of annular protrusions 2, the plurality of annular protrusions 2 are uniformly distributed along the axial direction of the cylinder body 12, the inner wall of the cylinder body 11 is tightly lined with an integrally formed PTFE protection layer 4, the outer wall of the PTFE protection layer 4 has a second annular groove 41, the second annular groove 41 is tightly attached to the annular protrusions 2, the present invention provides a PTFE-lined pressure vessel, the inner wall of the pressure vessel is provided with a plurality of annular protrusions 2, the outer wall of the PTFE protection layer 4 of the liner has a plurality of second annular grooves 41, can make the laminating between PTFE protective layer 4 and the container body 1 inseparabler, through annular arch 41 and second annular groove 41 one-to-one and inseparable laminating, when receiving cold and hot alternating stress, it can take place partial deformation and not take place to separate with container body 1 lateral wall at annular sunken and bellied PTFE protective layer 4 to have annular sunken, better protection effect has to pressure vessel, it is concrete, barrel 11 evenly is provided with three rings of annular arch 2 on following the axis in this embodiment, three rings of annular arch 2 are 250mm respectively with the distance at barrel 11 edge, 500mm and 750 mm.

This embodiment provides a method of manufacturing a PTFE lined pressure vessel comprising the steps of:

s1: manufacturing various parts of the tank body, including manufacturing a cylinder body 11, manufacturing a seal head 12 and manufacturing a pipe orifice 3;

the cylinder body 11 and the end enclosure 12 are manufactured according to GB150 and other related national standards or industries, the pipe orifice 3 is formed by welding a seamless steel pipe and a flange, and the selection and welding of the seamless steel pipe and the flange at least meet related regulations in HG/T20592-20635, because the container body 1 is lined with a PTFE material, the material of the cylinder body 11, the end enclosure 12 and the pipe orifice 3 is preferably Q345 carbon steel with low cost.

S2: pretreating the cylinder 11, the end enclosure 12 and the pipe orifice 3 which are prepared in the step S1; the pretreatment at least comprises removing flash and burr existing in blanking, polishing and welding a groove and cleaning the inner wall, the inner walls of the cylinder 11, the end enclosure 12 and the pipe orifice 3 are not required to have rust slag and other factors which influence the lining quality, and organic solvents such as alcohol or acetone and the like are required to be used for wiping the inner walls of the cylinder to remove oil stains on the inner walls of the cylinder 11, the end enclosure 12 and the pipe orifice 3.

S3: integrally molding the PTFE liner on the cylinder 11, the end enclosure 12 and the pipe orifice 3 which are prepared in the step S2;

s4: welding the cylinder 11 with the PTFE inner liner, the end enclosure 12 and the pipe orifice 3 obtained in the step S3 together according to the design drawing;

s5: performing plastic welding on the seam of the PTFE inner liner layer of the heat affected zone welded in the step S4; the plastic welding is carried out after the heat affected zone is completely cooled and the heating device is removed;

s6: standing for 7-15 days can effectively release stress generated when the PTFE protective layer and the container body 1 are welded.

The method leads the PTFE inner liner 4 to be tightly attached to the container main body 1 by integrally molding the PTFE inner liner on the cylinder body 11, the seal head 12 and the pipe orifice 3.

Example two:

in the present embodiment, as shown in fig. 1, the present embodiment is different from the first embodiment in that a plurality of supports 5 are provided on the container body 1, the supports 5 are used for supporting the installation of the container body 1, in order to ensure uniform stress and better supporting effect, it is preferable that the supports 5 have four, and the four supports 5 are uniformly distributed on the same circumferential plane of the container body 1.

Example three:

in this embodiment, on the basis of the first embodiment, the step S3 in the first embodiment is further described, and it should be particularly described that the pipe orifice 13 has a simple structure, and the PTFE inner liner with a smaller specification is easy to be manufactured through integral molding, which is not described herein again, and the integral molding in the step S3 includes:

s31: installing a cylinder die and an end socket die, cleaning and polishing the outer wall of the cylinder die and the outer wall of the end socket die before installation, and removing factors such as surface rust slag which easily cause the reduction of the bonding force of the PTFE inner liner, wherein the higher surface roughness can increase the bonding force with PTFE, so that the surface roughness of the outer wall of the cylinder die and the outer wall of the end socket die is lower than that of the cylinder 11 and the end socket 12 in order to facilitate the removal of the die after the PTFE protective layer is formed;

specifically, the installation of the cylinder body mold comprises the steps of calibrating the positions of the cylinder body 11 and the cylinder body mold, so that the cylinder body 11 and the cylinder body mold are coaxially arranged, the distance from each point of the inner wall of the cylinder body 11 to the outer wall of the cylinder body mold is consistent, and the thickness of the molded PTFE protective layer 4 is consistent; after the position calibration, the bottom of the gap between the cylinder 11 and the cylinder mold, which in this embodiment employs the inner mold 6, is sealed. (ii) a

Installing the end socket mould, namely firstly filling a large amount of PTFE powder into the end socket 12, then placing the end socket mould into the end socket 11, tamping the PTFE powder in the end socket 12 by using the end socket mould, and then positioning the end socket mould;

s32: after the cylinder 11 and the cylinder die are installed, the PTFE powder is filled, when the powder of the PTFE protective layer of the cylinder 11 is filled, the PTFE powder layer is tamped once every time a certain height is filled, specifically, in the embodiment, the cylinder is 1000mm long, when the powder of the PTFE protective layer of the cylinder is filled, the powder is tamped once every 200mm high, and the steps are repeated until the top is filled, when the top is filled, the tamping is repeated, and after the interface of the powder is lowered, the excessive PTFE powder is continuously supplemented, and the tamping is continued until the tamped powder interface reaches a predetermined boundary line, wherein the predetermined boundary line is an area reserved for welding the cylinder 11, the end enclosure 12 and the pipe orifice 3 in S4 according to a design drawing; after finishing filling, the pressing plate 7 is installed on the top of the barrel mould and the barrel 1 to seal, and then the mould pressing treatment is carried out, wherein the concrete mould pressing mode is as follows: pressing a pressing plate 7 arranged on the top of the cylinder body mould and the cylinder body 1 by using a hydraulic press or other pressing machines, wherein the pressing pressure is 13-15 MPa, and the pressure is maintained for 20-30 minutes, so that PTFE powder between the cylinder body 11 and the cylinder body mould can be further filled;

s33: and (3) heating the product subjected to the die pressing treatment of S32, wherein the temperature is raised from room temperature at a speed of 60-80 ℃/H, the temperature is kept for 2-4 hours when the temperature is raised to 370-385 ℃, then the temperature is slowly lowered to room temperature at a speed of 20-30 ℃/H, the temperature of the whole large pressure container is not easy to control, the large pressure container is not provided with the existing heating equipment, and preferably, the temperature is raised by an electric heating pipe (not shown in the figure) wound outside the container body 1.

Example four:

in this embodiment, as shown in fig. 2 and 4, the cylinder mold includes an inner mold 6, the inner mold 6 is disposed in a cavity of the cylinder 11, the inner mold 6 and the cylinder 11 are coaxially disposed, the outer wall of the inner mold 6 has a plurality of first annular grooves 61, the first annular grooves 61 correspond to the annular protrusions 2 one by one, that is, the inner wall of the container body 1 and the outer wall of the inner mold 6 always keep equal distances, after filling PTFE powder into a gap between the first annular grooves 61 and the annular protrusions 2, the PTFE protective layer can have a second annular groove 41 and a second annular protrusion, and the second annular groove 41 and the second annular protrusion are used for being alternately deformed at high and low temperatures so as to protect the bonding strength between the PTFE protective layer 4 at other positions and the container body 1.

Example five:

in this embodiment, on the basis of the fourth embodiment, a further description is made on the third embodiment, in this embodiment, as shown in fig. 1 and fig. 5, the cylinder mold further includes a pressing plate 7 installed at two ends of the cylinder 11, the pressing plate 7 is wrapped with an outer annular wall 71 and an inner annular wall 73, a splicing groove 72 is formed between the outer annular wall 71 and the inner annular wall 72, and the inner mold 6 is installed in the splicing groove 72, so that the pressing plate 7 has a positioning function of installation between the inner mold 6 and the cylinder 11, after the installation is completed, a space is formed between the outer annular wall 71, the inner wall of the cylinder 11, and the outer wall of the inner mold 6, and the space is filled with PTFE powder, and after the compression molding and the sintering molding, the PTFE protective layer 4 of the.

Example six:

in this embodiment, as shown in fig. 1 and 5, a plurality of mounting holes 74 are further uniformly formed in the pressing plate 7, the pressing plates 7 at two ends of the cylinder 11 penetrate through the mounting holes 74 through connecting members to be connected, the filled powder can be further tamped by tightening two pressing plates 7 which are oppositely arranged, specifically, 12 mounting holes 74 are uniformly formed in the pressing plate 7, the mounting holes 74 are through holes, the pressing plates 7 at the upper and lower ends are locked towards the middle by a stud nut assembly, the tightening force of the pressing plate 7 can be adjusted by rotating the nut, when the two pressing plates 7 are tightened towards the middle, the filled PTFE powder can be pressed more tightly, and the quality problem of integral molding can be reduced.

Example seven:

this embodiment is an explanation of the first embodiment, in this embodiment, as shown in fig. 3, in step S3, the barrel 11 forms the lining protection layer 4 after lining with PTFE, the distance a between the two ends of the lining protection layer 4 and the two ends of the barrel 11 is determined by the heat affected zone of the weld, and is generally 15 to 30mm, the PTFE protection layer 4 can be effectively prevented from being degraded or softened when the barrel 11 is welded to the head 12 and separated from the container body 1, after the welding between the barrel 11 and the head 12 is completed, the weld is ground and polished, and after the heat affected zone is completely cooled, the PTFE protection layer is supplemented in the reserved area a, the supplemented protection layer is performed by coating high temperature glue and bonding sheet PTFE with corresponding sizes, after the bonding is completed and stabilized, plastic welding is performed on the joint, and the supplemented PTFE protection layer is combined with the integrally formed PTFE protection layer, meanwhile, the height of the outer annular wall 71 of the pressing plate 7 should be close to the distance a and kept at 20-30 mm, the plastic welding in this embodiment specifically refers to heating the two adjacent PTFE protective layers at the joint to a molten state, so that the adjacent PTFE materials are bonded together, the plastic welding is usually ultrasonic welding, hot plate welding or laser welding, and for convenience of operation, the laser welding, the ultrasonic welding, the hot plate welding or the laser welding are common techniques for thermoplastic welding, and details are not repeated here.

Example eight:

to further explain step S2 in the first embodiment, in step S2, the preprocessing includes: the processing position is polished, and the barrel 11 and the 12 inner walls of head are sandblasted and cleaned, and the workpiece surface is polished by the angle grinder, and the pretreatment also comprises the following steps:

high-temperature oil removal: and (3) preserving the heat of the polished workpieces such as the barrel 11, the end socket 12, the pipe orifice 3 and the like for 5-10 min, thoroughly burning residual oil of the material, wherein the specific heating temperature and the heat preservation time are set according to the size and the weight of the workpiece, and the larger and heavier the workpiece is, the higher the temperature and the longer heat preservation time can be selected.

Sand blasting: blasting sand by 0.8Mpa pressure and uniformly blasting sand on the surface of 20# diamond grit;

cleaning can be carried out after all the pretreatment is finished, firstly, all sand grains and rust residues are removed, then, alcohol and acetone are used for repeatedly wiping until no visible oil stain or other impurities exist, and then, air drying is carried out.

The present invention is not limited to the above-described alternative embodiments, and various other forms of products can be obtained by anyone in light of the present invention. The above detailed description should not be taken as limiting the scope of the invention, which is defined in the claims, and which the description is intended to be interpreted accordingly.

Claims

1. The utility model provides a PTFE liner pressure vessel, vessel (1) includes barrel (11) and installs head (12) at barrel (11) both ends, its characterized in that, barrel (11) inner wall has a plurality of annular protruding (2), and is a plurality of annular protruding (2) are followed barrel (12) is evenly distributed in the axial, barrel (11) inner wall is tightly lined with integrated into one piece's PTFE protective layer (4), PTFE protective layer (4) outer wall has second annular groove (41), second annular groove (41) with annular protruding (2) closely laminate.

2. A PTFE-lined pressure vessel according to claim 1, wherein a number of seats (5) are provided on the vessel body (1).

3. A method of manufacturing a PTFE-lined pressure vessel, comprising the steps of:

s1: manufacturing various parts of the tank body, including manufacturing a cylinder body (11), manufacturing a seal head (12) and manufacturing a pipe orifice (3);

s2: pretreating the cylinder (11), the end socket (12) and the pipe orifice (3) which are prepared in the step S1;

s3: integrally molding the PTFE liner of the cylinder (11), the end socket (12) and the pipe orifice (3) which are prepared in the step S2;

s4: welding the cylinder (11) lined with PTFE, the end socket (12) and the pipe orifice (3) in the step S3 together according to the design drawing;

s6: standing for 7-15 days.

4. The method of claim 3, wherein the step S3 of integrally forming comprises:

s31: installing a cylinder mould and an end enclosure mould, cleaning and polishing the outer wall of the cylinder mould and the outer wall of the end enclosure mould before installation, and ensuring that the surface roughness of the outer wall of the cylinder mould and the outer wall of the end enclosure mould is lower than that of the cylinder (11) and the end enclosure (12);

5. The manufacturing method of the PTFE lining pressure vessel is characterized in that the cylinder body mould comprises an inner mould (6), the inner mould (6) is arranged in the cavity of the cylinder body (11), the inner mould (6) is coaxially arranged with the cylinder body (11), the outer wall of the inner mould (6) is provided with a plurality of first annular grooves (61), and the first annular grooves (61) are in one-to-one correspondence with the annular protrusions (2).

6. The method for manufacturing a PTFE-lined pressure vessel according to claim 5, wherein the cylinder mold further comprises pressing plates (7) installed at both ends of the cylinder (11), the pressing plates (7) are vertically provided with an outer annular wall (71) and an inner annular wall (73), a splicing groove (72) is formed between the outer annular wall (71) and the inner annular wall (72), and the inner mold (6) is installed in the splicing groove (72).

7. The manufacturing method of the PTFE lining pressure vessel is characterized in that a plurality of mounting holes (74) are uniformly formed on the pressing plate (7), and the pressing plates (7) at the two ends of the cylinder body (11) are connected through the mounting holes (74) by connecting pieces.

8. The method of claim 3, wherein the barrel (11) forms a lining protection layer (4) after the PTFE lining in step S3, and both ends of the lining protection layer (4) are spaced from both ends of the barrel (11) by a distance A.

9. The method of manufacturing a PTFE-lined pressure vessel of claim 3, wherein in step S2, the pretreating comprises: the processing part is polished, and the inner walls of the cylinder body (11) and the air duct (12) are subjected to sand blasting and cleaning.