阅读说明：本技术 新型耐酸防渗弹性隔离材料、制备方法及应用 (Novel acid-resistant anti-seepage elastic isolation material, preparation method and application ) 是由 石蕾 谢谦 王鈜艳 肖万平 李立军 于 2020-05-25 设计创作，主要内容包括：本发明公开了一种新型耐酸防渗弹性隔离材料、制备方法及应用。所述材料包括耐酸防渗层和设在其上的隔离层,其中,所述耐酸防渗层采用乙烯基聚合物制备而成；所述隔离层采用橡胶弹性体制备而成。本发明新型耐酸防渗弹性隔离材料既可以起到隔离酸性物质防止其渗透的作用,又可以应对因温差效应引起的结构热胀冷缩变形。该材料通过聚合物压注橡胶成型工艺得到,使得层合界面致密紧固。该材料应用于塔衬里结构中可以防止硫酸渗透,可避免耐酸砖开裂时硫酸与壳体接触造成腐蚀,且可避免塔衬里结构因温差而变形进而产生内应力导致防腐蚀层损坏的问题。(The invention discloses a novel acid-resistant anti-seepage elastic isolation material, a preparation method and application. The material comprises an acid-resistant impermeable layer and an isolating layer arranged on the acid-resistant impermeable layer, wherein the acid-resistant impermeable layer is prepared from vinyl polymer; the isolation layer is prepared from a rubber elastomer. The novel acid-resistant anti-seepage elastic isolation material not only can play a role in isolating acid substances and preventing the acid substances from permeating, but also can cope with structural expansion caused by heat and contraction caused by temperature difference effect. The material is obtained by a polymer injection molding rubber molding process, so that a lamination interface is compact and tight. The material is applied to a tower lining structure, can prevent sulfuric acid from permeating, can avoid the corrosion caused by the contact of sulfuric acid and a shell when an acid-proof brick cracks, and can avoid the problem that the tower lining structure deforms due to temperature difference and then generates internal stress to cause the damage of an anti-corrosion layer.)

1. A novel acid-resistant impermeable elastic isolation material is characterized by comprising: the acid-proof anti-seepage layer is prepared from vinyl polymers; the isolation layer is prepared from a rubber elastomer.

2. The novel acid resistant barrier elastomeric insulation of claim 1 wherein said vinyl polymer is one of polytetrafluoroethylene, tetrafluoroethylene-ethylene copolymer and polyvinylidene fluoride; the rubber elastomer is one of nitrile rubber, fluororubber and silicone rubber.

3. The novel acid resistant barrier elastic barrier material of claim 1,

one side of the isolation layer is provided with a plurality of holes to form a porous layer;

pressing a surface of the vinyl polymer into the porous layer by a polymer injection molding process to form a bonding layer.

4. The novel acid-resistant impermeable elastic separation material as claimed in claim 3, wherein the thickness of the porous layer is 0.5-5 mm.

5. The novel acid-resistant impermeable elastic separation material as claimed in claim 3, wherein the porosity of the porous layer is 20-50%, and the pore size is 30-100 μm.

6. The novel acid-resistant impermeable elastic separation material as claimed in claim 3, wherein the side of the separation layer facing away from the acid-resistant impermeable layer is a dense layer with a thickness of 0.5-5 mm.

7. A process for the preparation of a novel acid resistant barrier elastomeric barrier material as claimed in any one of claims 1 to 6 comprising the steps of:

preparing an isolation layer by using a rubber elastomer;

heating a vinyl polymer to form a polymer solution;

heating the isolation layer, covering the heated isolation layer on the surface of the polymer solution, and performing injection molding to obtain the novel acid-resistant impermeable elastic isolation material.

8. The method for preparing the novel acid-resistant impermeable elastic barrier material as claimed in claim 7, wherein when the barrier layer is prepared by using a rubber elastomer, a pore-forming agent or an organic foaming agent is added, and the rubber elastomer is heated and crosslinked to form the barrier layer with a porous layer on one side, wherein the porous layer is used for being combined with the surface of the polymer solution.

9. The method for preparing the novel acid-resistant impermeable elastic separation material as claimed in claim 7, wherein the thickness of the polymer melt is 0.5-5 mm.

10. Use of a novel acid resistant barrier elastomeric insulation according to any of claims 1 to 6 in a tower lining construction with the novel acid resistant barrier elastomeric insulation being disposed between a mastic layer and a shell, wherein the acid resistant barrier layer is disposed on the outside of the mastic layer and the insulation layer is disposed on the inside of the shell.

Technical Field

The invention relates to the technical field of materials, in particular to a novel acid-resistant anti-seepage elastic isolation material, a preparation method and application.

Background

In the production of sulfuric acid, a drying tower and an absorption tower are main devices of the whole process flow, and the drying of gas and the absorption of sulfur trioxide gas and the production of sulfuric acid are completed in the two towers in sequence. The operating conditions of the two towers are harsh, the liquid phase is 93-98.5% sulfuric acid, and the temperature is 60-110 ℃; the gas phase is mixed flue gas of sulfur dioxide and sulfur trioxide, and the temperature is 90-180 ℃. Therefore, the requirement for corrosion prevention of tower equipment is high, and the quality of the corrosion prevention performance of the tower equipment becomes an important factor for restricting the production of sulfuric acid. In order to prevent acid corrosion to the steel shell, a lining structure is usually added in the design process of the dry absorption tower (i.e. the drying tower and the absorption tower), and the acid-resistant bricks, the daub layer, the isolation layer and the steel shell are arranged from the inside to the outside of the tower.

In the design of domestic traditional sulphuric acid dry absorption tower, select the asbestos board to make the lining isolation layer, thickness is 3 ~ 5mm, during the construction, pastes it in steel casing inner wall with thin water glass cement earlier, then builds by laying bricks or stones resistant brick again to fill up the space between brickwork and the asbestos board with resistant acid cement. Asbestos sheets have been gradually replaced by fiber mats due to occupational health requirements.

A composite film of asphalt mastic and fluoroplastic film was developed in the united states. The column wall film layer is usually formed by overlapping a fluorocarbon plastic film with the thickness of 0.13mm on asphalt mastic with the thickness of 3mm, and the mastic at the bottom is usually 1.5mm and overlapped by fluorocarbon plastic with the thickness of 0.25 mm. In order to ensure the use effect of the film, some special treatment measures are adopted at important parts of the tower body in the design, for example, at a high-temperature gas inlet, a foamed borosilicate glass block material with heat insulation capacity ten times that of an acid-resistant brick is used for replacing the acid-resistant brick so as to ensure the temperature of the daub and the fluorocarbon plastic film. The bottom of the tower with concentrated stress adopts a disc-shaped steel bottom or adopts a joint for eliminating stress in the brick masonry at the bottom, thereby effectively avoiding the brick masonry from swelling and damaging due to factors such as unrecoverable expansion of daub and acid-resistant bricks and the like to cause deformation or overheating damage of the film layer.

In addition, in the acid making device designed or introduced abroad, polyisobutylene rubber is selected as a lining isolation layer of the dry absorption tower, the thickness of the polyisobutylene rubber is 3-5 mm, and the rubber plates form an isolation whole by fusion welding.

The above prior art has the following problems:

the contact parts of the drying tower, the absorption tower and the sulfuric acid are usually protected by acid-resistant ceramic tiles lined with sodium silicate cement, the damage period of the lining is found to be short in the using process, the leakage of equipment perforation caused by corrosion is mainly found at the lower part of the tower, the phenomena of brick plate breakage, brick falling, brick plate and cement cracking and the like are found in the maintenance process, and potassium sodium silicate (KPI) cement-lined acid-resistant ceramic tiles are widely used as the corrosion-resistant lining in the industry at present to improve the defects. Adopt KPI daub lining acid-proof ceramic tile as anticorrosive lining, asbestos board and fibrofelt are as the isolation layer, though can all resist the corruption of concentrated sulfuric acid, but because its compactness is poor, can not play the effect of prevention of seepage to the concentrated sulfuric acid, in case appear the space between ceramic tile and asbestos board/fibrofelt, concentrated sulfuric acid can be fast with steel casing direct contact, cause the corruption to the equipment shell, when the temperature is higher, the corruption aggravation, sulphuric acid leakage phenomenon can appear, this has just provided very high requirement to the masonry construction, the masonry degree of difficulty of acid-proof lining has been increased. Moreover, the KPI daub lining acid-proof ceramic tile is adopted as the anti-corrosion lining, although the bonding strength and the thermal expansion amount of the daub can be improved, the problem that the daub (or the acid-proof ceramic tile) cracks is not fundamentally solved due to the design and the manufacture of a steel shell, the KPI material, the construction level, environmental factors, external force influence and the like. After sulfuric acid penetrates through the cracks, the steel shell of the tower equipment is corroded, and dangerous accidents such as acid leakage and the like are caused.

The asphalt mastic fluoridated plastic film is used as an anticorrosive lining, so that the requirement on the use temperature is very strict, the surface temperature of the asphalt mastic needs to be lower than 65 ℃, and the method is not suitable for an absorption tower in sulfuric acid production.

The polyisobutylene rubber is selected as the lining isolation layer and is only suitable for the operation temperature lower than 80 ℃.

Therefore, the performances of corrosion resistance, seepage prevention, deformation prevention and the like of the materials in the tower lining structure in the prior art need to be improved.

Disclosure of Invention

Based on the problems, the invention aims to provide a novel acid-resistant anti-seepage elastic isolation material, a preparation method and application, so as to solve the problem that the material in the existing tower lining structure has poor effects of corrosion resistance, seepage resistance, deformation prevention, isolation and the like.

The above purpose is realized by the following technical scheme:

according to one aspect of the present invention, there is provided a novel acid resistant barrier elastomeric barrier material comprising: the acid-proof anti-seepage layer is prepared from vinyl polymers; the isolation layer is prepared from a rubber elastomer.

Preferably, the vinyl polymer is one of polytetrafluoroethylene, tetrafluoroethylene-ethylene copolymer and polyvinylidene fluoride; the rubber elastomer is one of nitrile rubber, fluororubber and silicone rubber.

Preferably, one side of the isolation layer has a plurality of pores forming a porous layer; pressing a surface of the vinyl polymer into the porous layer by a polymer injection molding process to form a bonding layer. Thereby bonding the acid resistant barrier layer and the barrier layer.

Preferably, the thickness of the porous layer is 0.5-5 mm. More preferably, the porous layer has a thickness of 0.5 to 2 mm. Particularly preferably, the porous layer has a thickness of 1 mm.

Preferably, the porosity of the porous layer is 20% -50%, and the pore size is 30-100 μm.

Preferably, one side of the isolation layer, which is far away from the acid-resistant anti-seepage layer, is a dense layer, and the thickness of the dense layer is 0.5-5 mm. More preferably, the thickness of the dense layer is 0.5-2 mm. Particularly preferably, the thickness of the dense layer is 1 mm.

According to another aspect of the invention, the invention provides a preparation method of a novel acid-resistant impermeable elastic isolation material, which comprises the following steps:

preparing an isolation layer by using a rubber elastomer; heating a vinyl polymer to form a polymer melt; heating the isolation layer, covering the isolation layer on the surface of the polymer melt, and performing injection molding to obtain the novel acid-resistant anti-seepage elastic isolation material.

Preferably, when the isolating layer is prepared by using a rubber elastomer, a pore-forming agent or an organic foaming agent is added, the rubber elastomer is heated and crosslinked to form the isolating layer with a porous layer on one side, and the porous layer is used for being combined with the surface of the polymer melt.

Preferably, the thickness of the polymer melt is 0.5-5 mm. More preferably, the thickness of the polymer melt is 0.5 to 2 mm. Particularly preferably, the thickness of the polymer melt is 2 mm.

According to another aspect of the invention, the invention provides a novel acid-resistant impermeable elastic isolation material, which is applied to a tower lining structure, and the novel acid-resistant impermeable elastic isolation material is arranged between a daub layer and a shell, wherein the acid-resistant impermeable layer is arranged on the outer side of the daub layer, and the isolation layer is arranged on the inner side of the shell.

Compared with the prior art, the novel acid-resistant anti-seepage elastic isolation material disclosed by the invention adopts the vinyl polymer and the rubber elastomer to form the composite isolation layer, so that the effect of isolating acidic substances and preventing the acidic substances from permeating is achieved, and the thermal expansion and cold contraction deformation caused by temperature difference can be coped with, so that the damage of an anti-corrosion layer caused by the internal stress generated by the deformation of equipment is avoided. The invention is suitable for the operation temperature below 150 ℃, and the applicable temperature range is wider.

The novel acid-resistant anti-seepage elastic isolation material is prepared by adopting a polymer pressure injection rubber molding process, so that a lamination interface is compact and tight, and is not layered or leaked.

The novel acid-resistant anti-seepage elastic isolation material is applied to a tower lining structure, namely, aiming at the structural design of a drying tower and an absorption tower, a composite isolation layer formed by the rubber elastomer and the vinyl polymer is additionally arranged between plaster and a steel shell, so that the corrosion of acid substances such as sulfuric acid and the like penetrating through a brick board or the plaster to the steel shell is prevented, and the thermal expansion and cold contraction deformation caused by the asynchronous deformation of an equipment steel shell and an acid-resistant brick masonry due to the temperature difference effect when the environmental temperature changes greatly can be absorbed.

Drawings

FIG. 1 is a schematic structural view of the novel acid resistant barrier elastomeric barrier material of the present invention;

FIG. 2 is a schematic view of the layer structure of the separator layer comprising a porous layer according to the present invention;

FIG. 3 is a schematic of the layer structure of the tower liner structure of the present invention.

In fig. 1-3, 1 acid-resistant brick, 2 daub layer, 3 composite isolating layer, 4 shell, 31 acid-resistant impervious layer, 32 combining layer, 33 isolating layer, 331 dense layer and 332 porous layer.

Detailed Description

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention and the accompanying drawings:

the vinyl polymer has excellent chemical stability, can resist almost all common strong-corrosion and strong-oxidation chemical substances, and has the characteristics of high and low temperature resistance, so that the vinyl polymer is an ideal anticorrosive material. However, vinyl polymers are thermoplastic, have a thermal expansion coefficient 10 times greater than that of steel, have low mechanical strength, are prone to creep, and are not suitable as separate structural materials. Because the vinyl polymer has large molecular cohesion and stable performance, and is hardly dissolved in any solvent, the vinyl polymer is difficult to prepare into a coating and is difficult to realize good bonding with other materials (or the vinyl polymer itself). And the vinyl polymer is expensive and has high cost. The above factors all restrict the wide industrial application of vinyl polymers as anticorrosive materials. In the sulfuric acid industry, vinyl polymers are typically used in pipes, vessels, pumps and valves where corrosion resistance is a demanding property requirement.

The rubber is a corrosion-resistant material, only strong oxidizing acids such as concentrated sulfuric acid, nitric acid, chromic acid and the like have a swelling effect on the rubber, and the rubber has no pollution or little pollution to products. The rubber lining technology is to stick rubber material on metal or other base body to form continuous and closed isolating layer to prevent medium from corroding, abrading and other physical and chemical damage to the base body. Compared with other anticorrosion methods, the rubber lining technology has many excellent characteristics, such as better corrosion resistance, wear resistance and higher reliability, and can be used for on-site lining of large-scale equipment. The application of rubber lining technology in petroleum, chemical industry, chemical fertilizer, metallurgy, machinery, pesticide, medicine, food, feed, printing and dyeing, electric power and other industries has a long history, and its importance is continuously rising. However, in the sulfuric acid industry, rubber is used as a lining material, and the rubber can generate a severe swelling phenomenon at high sulfuric acid concentration and high temperature, so that the rubber cannot achieve the anti-corrosion effect.

In view of the above, the applicant provides a novel acid-resistant impermeable elastic barrier material. Fig. 1 schematically illustrates the structure of the novel acid resistant barrier elastomeric barrier material of the present invention. As shown in FIG. 1, the present invention provides a novel acid resistant barrier elastomeric barrier material comprising: the acid-resistant anti-seepage layer 31 and the isolation layer 33 arranged on the acid-resistant anti-seepage layer, wherein the acid-resistant anti-seepage layer 31 is prepared from vinyl polymer; the isolation layer 33 is made of rubber elastomer. The invention adopts the vinyl polymer and the rubber elastomer as the composite isolation layer 3, the vinyl polymer can play a role of isolating sulfuric acid and preventing permeation, and can prevent the equipment steel shell from directly contacting with the sulfuric acid when the acid-proof brick cracks, so that the corrosion of the steel shell is further caused; the rubber elastomer can deal with thermal expansion and cold contraction deformation caused by a temperature difference effect, so that the equipment cannot be damaged by the internal stress generated by the equipment. Wherein, the vinyl polymer can be one of polytetrafluoroethylene, tetrafluoroethylene-ethylene copolymer and polyvinylidene fluoride; the rubber elastomer is one of nitrile rubber, fluororubber and silicon rubber.

Fig. 2 schematically shows the layer structure of the separation layer 33 containing the porous layer 332, and fig. 1 also schematically shows the structure of the bonding layer 32 formed at the porous layer 332 of the separation layer 33. In an alternative embodiment, as shown in fig. 1 and 2, one side (i.e., one side) of the isolation layer 33 is provided with a plurality of holes to form a porous layer 332; the acid-resistant barrier layer 31 and the barrier layer 33 are bonded by pressing a surface of the vinyl polymer into the porous layer 332 by a polymer injection rubber (porous) molding process to form the bonding layer 32. The polymer pressure injection porous rubber molding process is that the vinyl polymer is heated into liquid state and enters the holes of the porous layer 332 of the rubber elastomer through pressure injection molding equipment, the cooled vinyl polymer and the rubber elastomer realize firm and tight permeation combination, and a lamination interface is compact and tight without layering and leakage. One side (the other side) of the isolating layer 33, which is far away from the acid-resistant and impervious layer 31, can be a dense layer 331, and the thickness can be 0.5-5 mm; for example, it may be 1 mm. The porous layer 332 may have a thickness of 0.5 to 5 mm. The porosity of the porous layer 332 may be in the range of 20% to 50%, and the pore size may be 30 to 100 μm.

The preparation process of the novel acid-resistant impermeable elastic isolation material comprises the following steps:

the isolation layer 33 is prepared using a rubber elastomer. Preferably, when the isolation layer 33 is made of a rubber elastomer, a pore-forming agent or an organic foaming agent is added, and the rubber elastomer is heated and crosslinked to form the isolation layer 33, as shown in fig. 2, the isolation layer 33 includes a porous layer 332 with a plurality of pores and a dense and dense layer 331, the porous layer 332 is used for being combined with the surface of the polymer melt, and the dense layer 331 can be attached and lined on the inner wall of the shell 4 when being applied in a tower liner structure.

Placing the vinyl polymer in a mould of pressure injection molding equipment, and heating the vinyl polymer to form polymer melt; wherein the thickness of the polymer melt can be 0.5-5 mm.

Heating a rubber plate, namely the isolation layer 33, covering the heated isolation layer 33 on the surface of the polymer melt, and performing injection molding to obtain the novel acid-resistant anti-seepage elastic isolation material. Preferably, the porous layer 332 of the separator 33 is contacted with the polymer melt and then injection molded.