CN112516919A

CN112516919A - High-temperature-resistant and negative-pressure-resistant polytetrafluoroethylene plate lining technology

Info

Publication number: CN112516919A
Application number: CN202011282475.6A
Authority: CN
Inventors: 潘兆金
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-11-17
Filing date: 2020-11-17
Publication date: 2021-03-19
Anticipated expiration: 2040-11-17
Also published as: CN112516919B

Abstract

The invention discloses a high temperature and negative pressure resistant tetrafluoro plate lining technology, belonging to the technical field of chemical reaction production equipment manufacturing, in particular to a high temperature and negative pressure resistant tetrafluoro plate lining technology, wherein a transition layer is fixedly connected with the upper inner wall of an upper shell of equipment, a tetrafluoro plate lining layer is arranged inside the transition layer, a plurality of through holes which are uniformly distributed are drilled on the transition layer, fixing materials are filled inside the through holes, and the tetrafluoro lining layer is firmly combined with the inner surface of the shell of the equipment under the action of the transition layer, so that the difficult problem that the tetrafluoro plate lining layer in steel lining tetrafluoro anticorrosion equipment at home and abroad can not resist high temperature and negative pressure is solved, the higher requirements of steel lining tetrafluoro equipment on chemical production, high purity material production of noble and rare metals, semiconductor polysilicon and the like, high temperature chemical exhaust gas purification treatment and the like can be met, various high temperature and negative pressure resistant at 200 ℃ can be really manufactured, the steel lining PTFE anticorrosion equipment can resist various strong chemical corrosion.

Description

High-temperature-resistant and negative-pressure-resistant polytetrafluoroethylene plate lining technology

Technical Field

The invention relates to the technical field of chemical reaction production equipment manufacturing, in particular to a high-temperature-resistant and negative-pressure-resistant tetrafluoro plate lining technology.

Background

The polytetrafluoroethylene polymer material has excellent corrosion resistance, aging resistance and high insulation. The surface has no scaling and other performances, is applied to the advanced fields of spaceflight, military industry, electronics and the like in the early stage, has the high price which is gradually popularized and applied to the field of chemical anticorrosion for nearly thirty years, and makes an important contribution to solving the problem of strong corrosion in chemical reaction production equipment. In order to solve the problem of corrosion resistance of the inner surface of equipment for various chemical reactions, the lining of the lining made of the tetrafluoro plate is widely adopted at home and abroad at present, and the lining can ensure that the equipment can resist corrosion for a long time under the use conditions of various strong acids, particularly hydrofluoric acid, hot sulfuric acid, hot hydrochloric acid and even aqua regia. Has excellent corrosion resistance.

Hitherto, the polytetrafluoroethylene plate lining for chemical equipment adopts a lining process that the surface of a polytetrafluoroethylene plate is subjected to sodium treatment and then is adhered to the inner surface of steel equipment into a whole through an adhesive, the joint of the polytetrafluoroethylene plate and the plate is mostly welded by a PFA welding rod, the thickness of the lining is 2-3 mm, the high-voltage electric spark detected by the lining is 15-20 KV, and the lining layer is only suitable for being used at normal temperature (at most not more than 100 ℃) and normal pressure. When the working temperature of the equipment exceeds 100 ℃, the adhesive can lose efficacy, and the sodium layer of the adhesive can be damaged under the repeated action of thermal expansion and cold contraction of the PTFE sheet, so that the service life of the equipment is influenced, particularly when the working temperature of the equipment exceeds 120 ℃, negative pressure exists in the equipment, even instantaneous negative pressure exists, the PTFE sheet of the lining can be immediately peeled off from the equipment, and thus, the serious loss is caused, so that the PTFE sheet lining is not adopted on the equipment requiring the working condition of high temperature or negative pressure so far.

How to resist high temperature and negative pressure of the tetrafluoro plate lining is a great problem in the tetrafluoro anticorrosion industry and a key item for upgrading the tetrafluoro anticorrosion technology, the problem is overcome, the tetrafluoro plate lining is really and firmly attached to the inner surface of metal equipment, the equipment can be ensured to work safely and reliably for a long time even under the negative pressure of high temperature (100-200 ℃) and even in a vacuum state, and the tetrafluoro plate lining has an important effect on the technical development and the safety production of various aspects such as chemistry, metallurgy, environmental protection, electronics, semiconductors and the like.

Disclosure of Invention

1. Technical problem to be solved

Aiming at the problems in the existing PTFE sheet lining technology, the invention aims to provide a PTFE sheet lining technology with high temperature resistance and negative pressure resistance, which completely abandons the original technique of sodium-modified gluing and lining pasting of PTFE sheets, realizes the firm combination of the PTFE sheet lining and the inner surface of the equipment shell through the following technical scheme, and achieves the effect that the PTFE sheet lining can not bulge and delaminate when the negative pressure is pumped at the high temperature of 200 ℃ for a long time and even the limit vacuum is approached, and the effect is not achieved at home and abroad so far.

2. Technical scheme

In order to solve the above problems, the present invention adopts the following technical solutions.

The utility model provides a high temperature resistant negative pressure's tetrafluoro board lining technique, includes the equipment shell, shell inner wall fixedly connected with transition layer, the inside tetrafluoro board lining layer that is equipped with of transition layer, it has a plurality of evenly distributed's through-hole to open on the transition layer, the inside packing of through-hole has fixed material, and fixed material and tetrafluoro board lining layer fixed connection, and fixed material fuses as an organic wholely with tetrafluoro board lining layer through high temperature sintering, and it has abandoned the sodium modification rubber coating of original tetrafluoro board and has pasted lining process technology completely, through above process scheme, has realized the firm combination of tetrafluoro board lining and equipment casing internal surface, reaches and takes out the negative pressure simultaneously for a long time at 200 ℃ high temperature, and even when being close the limit vacuum, the effect that can not the delaminating in the tetrafluoro board lining can not bulge, and this kind of effect has not reached so far at home.

Furthermore, a PFA material film is compounded on the outer surface of the lining layer of the PTFE sheet, and the fixing material is PFA fluoroplastic, so that the anti-permeation performance of the lining layer of the PTFE sheet can be improved, and the corrosion resistance of the PTFE sheet lining is further improved.

Furthermore, the lining layer of the tetrafluoro plate is combined with the transition layer into a whole through a series of fluoroplastic sintering processes, and one surface of the transition layer is welded with the shell into a whole, and the other surface of the transition layer is fused with the lining layer of the tetrafluoro plate through the action of a fixing material, so that the transition connection effect is achieved.

Furthermore, the joint of the tetrafluoro plate lining layer is manufactured by adopting a welding process of lapping the tetrafluoro plate, the lapping surface is 40mm, and the welding seam of lapping welding of the tetrafluoro plate has higher strength.

Further, the shell internal surface passes through welded fastening with the transition layer, welds effectual fixed stability that has promoted, effectively avoids the transition layer to drop.

Further, the thickness of the transition layer is 1.5mm, the thickness of the lining layer of the PTFE sheet is 4mm, the durability and the negative pressure resistance of the thicker PTFE sheet lining layer are improved to a certain extent, and the service life is prolonged.

3. Advantageous effects

Compared with the existing tetrafluoro plate lining technology, the invention has the advantages that:

(1) the technical scheme completely abandons the original process technology of sodium modification gluing and lining pasting of the tetrafluoro plate, and through the technical scheme, the firm combination of the tetrafluoro plate lining and the inner surface of the equipment shell is realized, the effects that the tetrafluoro plate lining can not bulge and delaminate at the high temperature of 200 ℃ for a long time and even when the tetrafluoro plate lining is close to the limit vacuum are achieved, and the effects are not achieved at home and abroad.

(2) The outer surface of the lining layer of the tetrafluoro plate is compounded with a PFA material film, and the fixing material is PFA fluoroplastic, so that the anti-permeation performance of the lining layer of the tetrafluoro plate can be improved, and the corrosion resistance of the tetrafluoro plate lining is further improved.

(3) The lining layer of the PTFE sheet is fused with the transition layer into a whole through a series of fluoroplastic sintering processes, and one surface of the transition layer is welded with the shell into a whole, and the other surface of the transition layer is fused with the lining layer of the PTFE sheet through the action of a fixing material, so that the transition connection effect is realized.

(4) The joint of the PTFE sheet lining layer is made by adopting a welding process of lapping the PTFE sheet, the lapping surface is 40mm, and the welding seam of lapping welding of the PTFE sheet has higher strength.

(5) The shell internal surface passes through welded fastening with the transition layer, welds the effectual fixed stability that has promoted, effectively avoids the transition layer to drop.

(6) The transition layer thickness is 1.5mm, and tetrafluoro board lining layer thickness is 3 ~ 5mm, and the durability and the resistant negative pressure ability of having promoted to a certain extent of thick tetrafluoro board lining layer have prolonged life.

Drawings

FIG. 1 is a sectional view of a combination of a housing 1, a transition layer 2, and a PTFE liner 3 according to the present invention;

FIG. 2 is a partial enlarged view of the invention at A

Fig. 3 is an appearance diagram of the present invention.

The reference numbers in the figures illustrate:

1 outer shell, 2 transition layers, 3 tetrafluoro plate lining layers, 4 through holes and 5 fixing materials.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention; it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and all other embodiments obtained by those skilled in the art without any inventive work are within the scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top/bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "connected," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a detachable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Example 1:

referring to fig. 1-3, a teflon plate lining technology with high temperature resistance and negative pressure resistance comprises a shell 1, a transition layer 2 is fixedly connected to the inner wall of the shell 1, and the inner surface of the shell 1 and the transition layer 2 are fixed by electric welding, so that the fixing stability is effectively improved by welding, and the transition layer 2 is effectively prevented from falling off. The shell 1 is made of carbon steel or stainless steel plates, the thickness of the shell is 8mm, the polytetrafluoroethylene plate lining layer 3 is arranged on the inner side of the transition layer 2, the PFA material film covers the outer surface of the polytetrafluoroethylene plate lining layer 3, the fixing material 5 is PFA fluoroplastic, the anti-permeation performance of the polytetrafluoroethylene plate lining plate layer can be improved, and the corrosion resistance of the polytetrafluoroethylene plate lining is further improved. The fixing material 5 penetrates through each small hole of the transition layer 2 to achieve the effect of a rivet, so that the tetrafluoro plate lining layer 3 is firmly combined with the transition layer 2, the tetrafluoro plate lining layer 3 is combined with the transition layer 2 into a whole through a series of fluoroplastic sintering processes, one surface of the transition layer 2 is welded with the shell 1 into a whole, and the other surface of the transition layer is fused with the tetrafluoro plate lining layer 3 together through the effect of the fixing material 5, so that the transition connection effect is achieved. The same sample is subjected to dozens of times of heating, negative pressure pumping, cooling and equipment opening for inspection, the lining of the sample is always intact, no abnormal sample occurs, a 240 ℃ high-temperature test is carried out, the lining is still intact, and the voltage of an electric spark test on the lining with the thickness of 2.5mm reaches 30 KV. The new PTFE plate lining process can be used for manufacturing high-temperature and negative-pressure working condition reaction kettles, reaction towers, chemical storage containers, large-caliber steel-lined PTFE pipelines, evaporation and concentration equipment, heat exchanger shells, filter shells and other steel-lined PTFE equipment. The face of transition layer 2 is last to cut a plurality of evenly distributed's through-hole 4, and through-hole 4 is inside to be filled with fixed material 5, and fixed material 5 and tetrafluoro plate lining layer 3 fixed connection.

Referring to fig. 3, the butt seam of the lining layer 3 of the tetrafluoro plate is made by a welding process of overlapping the tetrafluoro plate, and the overlapping surface is 40mm, and the welding seam of the overlap welding of the tetrafluoro plate has higher strength, so that the butt seam is welded by overlap welding instead of using a fluoroplastic welding rod to ensure the reliable strength of the seam.

Referring to fig. 1-3, the thickness of the transition layer 2 is 1-1.5 mm, the thickness of the tetrafluoro plate lining layer 3 is 3-5 mm, and the thicker tetrafluoro plate lining layer 3 improves the durability and the negative pressure resistance to a certain extent, and prolongs the service life. The invention is completely different from the traditional PTFE sheet lining technology (glue pasting sheet technology), the PTFE sheet lining technology of the invention manufactures a transition layer through repeated research and test, the transition layer is formed by compounding a steel perforated plate and a meltable PTFE PFA, the transition layer is positioned between the PTFE sheet lining and the inner surface of the steel wall of the equipment, one surface of the transition layer is in electric welding connection with the inner surface of the steel equipment, the other surface of the transition layer and the PTFE sheet lining are in electric welding connection with each other through PFA, the PTFE sheet lining and the inner surface of the equipment are firmly combined through the transition layer, the invention is the core technology of the invention, wherein, the transition layer which enables the PTFE sheet and the inner surface of the steel equipment to be firmly connected is the key for realizing the technology. The invention is not only theoretical, but also passes repeated tests and destructive tests for up to two years, and provides the manufactured equipment for chemical enterprises, and the reliability of the invention is proved by practice.

The working principle is as follows: in the use process of the device, because the PFA fluoroplastic still has stable shape and tensile strength at 250 ℃, the transition layer 2 welded on the shell 1 still cannot deform and fall off at high temperature, and the fixing material 5 penetrating through dense hemp pores on the tetrafluoro plate lining layer 3 firmly strains the tetrafluoro plate lining layer 3, so that the tetrafluoro plate lining layer cannot delaminate. The combined action realizes the high temperature resistance and negative pressure resistance of the PTFE sheet lining. The device completely abandons the original process technology of sodium modification gluing and lining pasting of the tetrafluoro plate, and through the above process scheme, the firm combination of the tetrafluoro plate lining and the inner surface of the equipment shell is realized, the effects that the tetrafluoro plate lining can not bulge and delaminate at the high temperature of 200 ℃ for a long time and even when the tetrafluoro plate lining is close to the limit vacuum are achieved, and the effects are not achieved at home and abroad.

The foregoing is only a preferred embodiment of the present invention; the scope of the invention is not limited thereto. Any person skilled in the art should be able to cover the technical scope of the present invention by equivalent or modified solutions and modifications within the technical scope of the present invention.

Claims

1. The utility model provides a high temperature resistant negative pressure's tetrafluoro board lining technique, includes shell (1), its characterized in that: shell (1) inner wall fixedly connected with transition layer (2), transition layer (2) inboard is equipped with tetrafluoro board lining layer (3), it has a plurality of evenly distributed's through-hole (4) to cut on transition layer (2), through-hole (4) inside packing has fixed material (5), and fixed material (5) and tetrafluoro board lining layer (3) fixed connection.

2. The tetrafluoro plate lining technology of claim 1, which is characterized in that: the outer surface of the tetrafluoro plate lining layer (3) is compounded with a PFA material film, and the fixing material (5) is PFA fluoroplastic.

3. The tetrafluoro plate lining technology of claim 1, which is characterized in that: the tetrafluoro plate lining layer (3) is integrated with the transition layer (2) through a series of fluoroplastic sintering processes.

4. The tetrafluoro plate lining technology of claim 1, which is characterized in that: the joint of the tetrafluoro plate lining layer (3) is made by adopting a welding process of lapping of the tetrafluoro plate, and the lapping surface is 40 mm.

5. The tetrafluoro plate lining technology of claim 1, which is characterized in that: the inner surface of the shell (1) and the transition layer (2) are fixed through welding.

6. The tetrafluoro plate lining technology of claim 1, which is characterized in that: the thickness of the transition layer (2) is 1.5mm, and the thickness of the tetrafluoro plate lining layer (3) is 3-5 mm.