CN103008216B - The interior wall processing technology of aluminium alloy pressure cylinder and treating apparatus - Google Patents

Abstract

The invention discloses an inner wall treatment process and a spraying device of an aluminum alloy pressure gas cylinder. The process includes the following steps on the inner surface of the gas cylinder: A. Cleaning: using an aluminum alloy cleaning agent and clear water to remove residual pollutants such as grease; B. Ozone passivation: using ozone to make the inner surface inert; C, silanization: spraying a silane coupling agent on the inner surface to form a dense silanized coating; D, forming a silicon oxide coating: using tetraethyl orthosilicate hydrolysis solution Spraying the inner surface to form a silicon oxide coating; E. Forming a fluorocarbon resin coating: spraying a fluorocarbon resin paint on the inner surface to form a fluorocarbon resin coating. It can be used for the inner wall treatment of aluminum alloy pressure gas cylinders. It has the characteristics of simple process and equipment. The gas cylinders after treatment can be used for the storage of adsorptive and corrosive gases without affecting the value of gas standard substances and have better stability. sex.

Description

Inner wall treatment process and treatment device of aluminum alloy pressure gas cylinder

technical field

The invention relates to the field of metal surface treatment, and provides a treatment process for the inner surface of an aluminum alloy gas cylinder and a corresponding treatment device.

Background technique

_The analysis of gas samples in the fields of environmental testing, petrochemical industry, and electronics industry all require the use of gas standard substances. For example, NH ₃ and NO _x are one of the key detection objects in the field of environmental testing. Such industries are valued, and strong active gases such as Cl ₂ and HCl are often used in the electronic semiconductor industry; gas analysis in these fields often requires trace level (generally referring to tens of μmol/mol) gas standard substances to calibrate the corresponding instruments . However, due to the characteristics of adsorption and corrosiveness of the above-mentioned gases themselves, complex physical and chemical processes will occur between them and the inner wall of the vessel in ordinary pressure vessels. On the one hand, this physical and chemical process affects the change in the value of the gas standard substance, resulting in poor stability; on the other hand, it will cause potential danger.

Generally, aluminum alloy gas cylinders are used as pressure vessels in the storage and transportation of standard gases. In order to solve the stability problem of gas standard substances containing active components in aluminum alloy gas cylinders, ensure the accuracy and long-term stability of gas standard substance values , it is necessary to provide a treatment method and corresponding equipment for its inner wall.

Contents of the invention

Based on the above purpose, the present invention provides a treatment process for the inner wall of an aluminum alloy gas cylinder, and also provides a treatment device.

For reaching this purpose, the present invention adopts following technical scheme:

A process for treating the inner wall of an aluminum alloy pressure gas cylinder, comprising the following steps on the inner surface of the gas cylinder:

A. Cleaning: Use aluminum alloy cleaning agent and water to remove grease and oxide layer;

B. Ozone passivation: use ozone to make the inner surface inert;

C. Silanization: Spray a silane coupling agent on the inner surface to form a dense silanized coating;

D. Forming a silicon oxide coating: using tetraethyl orthosilicate hydrolysis solution to spray the inner surface to form a silicon oxide coating;

E. Formation of fluorocarbon resin coating: Spray fluorocarbon resin paint on the inner surface to form a fluorocarbon resin coating.

Further, the step A includes: after diluting the special cleaning agent for aluminum alloy and warm water at 50-60°C at a ratio of 1:5, pour 500mL of the diluted solution into the gas cylinder, add wear-resistant balls, and place the gas cylinder in the Horizontal rolling machine, continuous rolling for about 10min, the rolling speed is controlled at 25~35rpm, then rinse with tap water for 3~5 times, then wash with deionized water for at least 2 times, put the cylinder in an oven at 80°C and dry it with pure nitrogen After sealing.

Further, the step B includes: connecting the dry gas cylinder to an ozone generator, controlling the ozone concentration to be 30-100mg/ ^m3 , the flow rate to be 0.5-2L/min, and continuously ventilating for 10-20min to make the gas cylinder A dense oxide layer is formed on the surface, and then dry compressed air is passed through to remove residual ozone.

Further, a silane coupling agent compatible with the aluminum alloy is selected, and the silane coupling agent is sprayed onto the inner surface of the container with a spraying device at a thickness of 1-5 μm.

Further, the step D includes four steps of tetraethyl orthosilicate hydrolysis, polycondensation, spraying and curing, mixing and dissolving tetraethyl orthosilicate and absolute ethanol at a ratio of 1:9; then adding oxalic acid aqueous solution for pre-hydrolysis to control the pH =3±0.5, preferably 2.8~3.5, the pre-hydrolysis time is 2h~3h, to obtain tetraethyl orthosilicate hydrolysis solution; add 2% ammonia water to the above hydrolysis solution, adjust the pH to 8~11, and the polycondensation process occurs ;After the polycondensation, the solution should be sprayed or sprayed immediately, and immediately after the completion, it should be ventilated and dried at a constant temperature of no more than 60°C for 8~12h, and the film thickness should be controlled at 10~30μm.

Further, the step E includes:

Spray sealing primer: Mix the sealing primer, the special curing agent for room temperature curing fluorocarbon resin, and the diluent according to the ratio of 10:1:4, and spray it on the inner wall of the gas cylinder to obtain a sealing primer layer with a film thickness of 10 μm. 5~10min;

Topcoat spraying: mix fluorocarbon resin with room temperature curing fluorocarbon resin special curing agent and thinner according to the ratio of 10:1:4 and stir evenly, spray three times on the inner surface of the pressure vessel, bake at 60~90℃ for 30~ 60min.

Preferably, the silane coupling agent is a silane coupling agent containing an amino group or an acrylic group.

Preferably, multiple sprays are used when spraying the silane coupling agent. After each spraying, the cylinder is transferred to a dryer, and baked at a temperature of 40-50°C for at least 20 minutes under a state of dry compressed air or nitrogen.

Preferably, the sealing primer is an acrylic resin type sealing primer, and the fluorocarbon resin is a fluoroolefin-ethylene multi-polymer copolymer type fluorocarbon resin.

At the same time, a spraying device for the inner wall treatment process of the above-mentioned aluminum alloy pressure gas cylinder is provided, including an air compressor, a spray gun, a base and a deck, the gas cylinder is fixed by the deck on the base, and the air compressor Provide material supply power, atomizing gas source and switch control gas for the spray gun; the spray gun is installed on the base through the vertical movement mechanism of the spray gun, and has a long-rod atomizing head, which can be extended into the gas cylinder for spraying on the inner wall.

The inner wall treatment process and spraying device of the aluminum alloy pressure gas cylinder described in the present invention can be used for the inner wall treatment of the aluminum alloy pressure gas cylinder, and has the characteristics of simple process and device, and the treated gas cylinder can be used for storage and transportation of corrosive gases , will not affect the value of the gas standard substance, and has better stability.

Description of drawings

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and through specific implementation methods.

Fig. 1 is a schematic diagram of the structure and principle of the gas cylinder inner wall spraying device of the present invention.

In the picture:

1. Air compressor; 2. Paint barrel; 3. Oil-water separator; 4. Globe valve; 5. Spray gun; 6. Gas cylinder; 7. Deck; 8. Base; 9. Vertical movement mechanism of spray gun; 10. Long rod atomizing head.

Detailed ways

The specific process of processing the inner wall of an aluminum alloy gas cylinder is given below:

1. Cleaning and ozone passivation of the inner surface of aluminum alloy pressure vessel

First, according to the cleaning steps of the inner surface of the pressure vessel mentioned above, after diluting the aluminum alloy special cleaning agent and 60 ℃ warm water at a ratio of 1:5, take 500mL of the diluted solution and pour it into the gas cylinder, and place the gas cylinder horizontally on the rolling machine Roll for 10 minutes at a rolling speed of 30 rpm, then pour out the diluent, rinse 5 times with tap water, then wash 3 times with deionized water, place the pressure vessel in an oven at 80°C and blow it with pure nitrogen for 60 minutes; then connect the gas cylinder Put on the ozone generator, and let in the oxygen containing 80mg/ ^m3 ozone at a flow rate of 1L/min for about 10min; then use dry compressed air to rinse for 10min at 1L/min to passivate the adsorption active sites on the inner surface of the gas cylinder.

2. Silanization of the inner surface of aluminum alloy pressure vessel and formation of silicon oxide coating

The above-mentioned gas cylinder passivated by ozone is further silanized on the inner surface, preferably a silane coupling agent containing amino or acrylic group, such as KH550 silane coupling agent, according to KH550 silane coupling agent: deionized water: isopropyl Mix the alcohol in a ratio of 4:1:95, add acetic acid to adjust the pH value to 4~5, stir for 20 minutes to obtain the silane coupling agent working solution, spray the silane coupling agent working solution on the inner surface of the pressure vessel; control the output pressure of the paint bucket 2kg/cm ² , the vertical movement speed of the spray gun is 3cm/s. After spraying, blow dry with pure nitrogen for 5 minutes, then spray and dry 2 times, and form a silane film layer of 1~10μm on the inner surface of the gas cylinder.

Then mix and dissolve ethyl orthosilicate and absolute ethanol at 1:9; then add oxalic acid aqueous solution for pre-hydrolysis, control PH=3±0.5, preferably 2.8~3.5; pre-hydrolysis time 2h~3h; obtain ethyl orthosilicate Ester hydrolysis solution, add 2% ammonia water to the above hydrolysis solution, adjust the pH to 8~11, preferably 9.5~9.7, and the polycondensation process occurs to obtain the working solution. Then spray the above-mentioned working solution to the inner surface of the gas cylinder with the silane film layer. After the polycondensation, the solution is sprayed or flow-coated immediately to avoid the formation of SiO ₂ gel. Control the output pressure of the paint bucket to 2kg/cm ² and the vertical movement speed of the spray gun It is 3cm/s. After spraying, blow dry with pure nitrogen for 5 minutes. Then spray and dry twice to form a 1-10μm silicon oxide layer on the inner surface of the gas cylinder, and finally dry the gas cylinder at a temperature of 60°C for 8-12 hours with ventilation and constant temperature.

3. Fluorocarbon resin coating is formed on the inner surface of aluminum alloy pressure vessel

Further generate a fluorocarbon resin coating on the above inner surface, the sealing primer is preferably an acrylic resin type sealing primer, and mix the sealing primer, a special curing agent for fluorocarbon resin cured at room temperature, and a general thinner in a ratio of 10:1:4 , Stir evenly, control the output pressure of the paint barrel to 2kg/cm ² , and the vertical movement speed of the spray gun to 3cm/s, spray to the inner wall of the gas cylinder. After spraying, blow dry with pure nitrogen for 5 minutes, then spray and dry for 2 times to form a 1-10 μm sealing primer layer on the inner surface of the pressure vessel; finally spray fluorocarbon varnish for 3 times, preferably fluorocarbon resin Fluorocarbon resin of the type of fluoroolefin-ethylene multi-polymer copolymer, curing agent, and diluent are mixed and stirred evenly at a ratio of 10:1:4, sprayed on the inner surface of the pressure vessel, and baked at 60~90°C for 30~60min, preferably Bake at 80°C for 40min.

Fig. 1 has provided the spraying device inside the gas cylinder that is used for above-mentioned technology, and air compressor 1 is as the auxiliary gas source of spraying device, mainly provides power gas for feeding device paint barrel 2 and spray gun 5, is arranged in paint barrel 2 A pressure regulator controls the pressure of the power gas and indirectly adjusts the feeding rate; the compressed air entering the spray gun 5 needs to be processed by the oil-water separator 3 in advance, and then divided into two paths, one of which is used as the switch control air of the spray gun 5 and passes through the stop valve 4 Control the gas pressure to switch the paint supply inside the spray gun 5; the other way is used as the atomizer source of the spray gun.

The spray gun 5 is arranged on the vertical movement mechanism 9 on the base 8, and the vertical movement speed of the spray gun 5 is controlled by a computer program. The purpose is to obtain coatings of different thicknesses at a certain feed rate; 10. The length of the long-rod atomizing head 10 is not less than 80 cm, so that the atomizing head 10 can enter the bottom of the gas cylinder 6. The gas cylinder 6 is fixed by the clamp 7 on the base 8. When in use, adjust the spray gun 5 The long-rod atomizing head 10 is just located in the center of the gas cylinder 6, and can form a uniform thickness coating on the inner wall.

The above description is a specific description of a feasible embodiment of the present invention, and the embodiment is not intended to limit the patent scope of the present invention, and any equivalent implementation or change that does not depart from the technical spirit of the present invention shall be included in the In the scope of the patents claimed for protection in this application.

Claims (6)

1. an inner wall treatment process of an aluminum alloy pressure gas cylinder, characterized in that comprising the following steps to the inner surface of the gas cylinder: A. Cleaning: Use aluminum alloy cleaning agent and water to remove grease and oxide layer; after diluting special aluminum alloy cleaning agent and 50-60℃ warm water at a ratio of 1:5, take 500mL of the diluted solution and pour it into the gas cylinder, add wear-resistant small Put the cylinder on a horizontal rolling machine, roll it continuously for about 10 minutes, and control the rolling speed at 25-35rpm, then wash it with tap water for 3-5 times, then wash it with deionized water for at least 2 times, and place the cylinder at 80 ℃ oven and airtight with pure nitrogen at the same time; B. Ozone passivation: Use ozone to make the inner surface inert; connect the dry gas cylinder to an ozone generator, control the ozone concentration to 30-100mg/m ³ , the flow rate to 0.5-2L/min, and continue to ventilate for 10-20min , deactivate the adsorption active points on the inner surface of the gas cylinder, and then pass dry compressed air to remove residual ozone; C. Silanization: Spray a silane coupling agent on the inner surface to form a dense silanized coating; select a silane coupling agent compatible with aluminum alloy, and use a spraying device to spray the silane coupling agent to the inner surface of the container with a spray thickness of 1 ~5μm; D. Forming a silicon oxide coating: using tetraethyl orthosilicate hydrolysis solution to spray or flow coat the inner surface to form a silicon oxide coating; the step D includes hydrolysis, polycondensation, spraying or curtain coating, and curing of tetraethyl orthosilicate The first step is to mix and dissolve ethyl orthosilicate and absolute ethanol at a ratio of 1:9; then add oxalic acid aqueous solution for pre-hydrolysis, control pH=3±0.5, and pre-hydrolyze for 2h to 3h to obtain ethyl orthosilicate hydrolysis solution; Slowly add ammonia water with a mass percentage of 2% to the above hydrolysis solution, adjust the pH to between 8 and 11, and the polycondensation process occurs; after the polycondensation, the solution is immediately sprayed or showered, and immediately after the completion, the temperature is ventilated and kept at a temperature not exceeding 60°C. Dry for 8-12 hours, and control the film thickness at 10-30 μm; E. Formation of fluorocarbon resin coating: Spray fluorocarbon resin paint on the inner surface to form a fluorocarbon resin coating. 2 . The process for treating the inner wall of an aluminum alloy pressure gas cylinder according to claim 1 , characterized in that oxalic acid aqueous solution is added for pre-hydrolysis, and the pH is controlled to be 2.8 to 3.5. 3. The process for treating the inner wall of an aluminum alloy pressure gas cylinder according to claim 1, wherein said step E comprises: Spray sealing primer: Mix the sealing primer, the special curing agent for room temperature curing fluorocarbon resin, and the diluent according to the ratio of 10:1:4, and spray it on the inner wall of the gas cylinder to obtain a sealing primer layer with a film thickness of 10 μm. 5～10min; Topcoat spraying: mix fluorocarbon resin with room temperature curing fluorocarbon resin special curing agent and diluent according to the ratio of 10:1:4 and stir evenly, spray three times on the inner surface of the pressure vessel, bake at 60-90°C for 30- 60min. 4. The process for treating the inner wall of an aluminum alloy pressure gas cylinder according to claim 1, wherein the silane coupling agent is a silane coupling agent containing an amino group or an acrylic group. 5. The inner wall treatment process of an aluminum alloy pressure gas cylinder according to claim 1, characterized in that multiple sprays are used when spraying the silane coupling agent, and the gas cylinder is transferred to a dryer after each spraying, and the Under dry compressed air or nitrogen state, bake at 40-60°C for at least 20 minutes. 6. The process for treating the inner wall of an aluminum alloy pressure gas cylinder according to claim 3, wherein the sealing primer is an acrylic resin type sealing primer, and the fluorocarbon resin is a fluoroolefin-ethylene multi-polymer copolymer type of fluorocarbon resin.