Magnetic stirring high-pressure reactorAs the core equipment for high-temperature and high-pressure chemical reactions, its cleaning and maintenance must strictly follow technical specifications. The following is an explanation from four aspects: cleaning methods, maintenance points, operating specifications, and safety precautions:

1、 Cleaning method

1. Physical cleaning

-Applicable scenarios: Daily residue cleaning, slight scaling.

-Operation steps:

-After the reaction is complete, inject the reaction solvent through the exhaust valve to preliminarily dissolve most of the residue.

-Inject half a kettle of clean water and start stirring for 10 minutes to remove the attached substances.

-Open the kettle lid and wipe the inner wall with a soft brush or non-woven fabric to avoid scratching the surface.

-For stubborn scaling, soak in 5% sodium bicarbonate (NaHCO?) solution in warm water and wipe.

-Caution: It is prohibited to use hard tools (such as wire brushes) to directly scrape to prevent damage to the inner surface coating.

2. Chemical cleaning

-Applicable scenarios: high molecular weight polymers, coking materials, or oil stains.

-Operation steps:

-Select specialized solvents (such as toluene, acetone) based on the composition of the dirt, and confirm that the solvent is compatible with the material of the kettle body (such as stainless steel, concentrated hydrochloric acid is prohibited).

-Rinse after soaking to avoid solvent residue.

-After alkaline washing (applicable to alloy kettle bodies), the alkaline solution needs to be rinsed with clean water; After pickling (such as austenitic stainless steel), it is necessary to immediately remove hydrogen treatment (bake at 200 ℃ for 3 hours) and neutralize the acid solution.

-Attention: The halogen content in the solvent of the titanium and titanium alloy kettle body should be controlled (less than 1%).

3. Mechanical cleaning

-Applicable scenarios: Hard scale, oxide skin, or corrosion rust.

-Operation steps:

-Polishing: Remove carbon deposits.

-Dry blown sand/wet blown sand: suitable for oxide scale and slightly adhesive sediment respectively.

-Grinding wheel: Remove severe corrosion or rust (prohibited when there is a coating or weld layer inside the kettle).

-Caution: Mechanical cleaning may damage the surface and should be handled with caution.

4. Other cleaning methods

-Solvent removal: Dissolve oil and oil film with alcohol, acetone, etc., but not suitable for inorganic substances.

-Ultrasonic cleaning: Used in conjunction with solvents, suitable for small volume kettles, ensuring that the components are immersed in the cleaning tank.

IIMagnetic stirring high-pressure reactorMaintenance points

1. Maintenance of sealing system

-Regularly check the aging degree of O-rings and gaskets, and replace them immediately if hardening, cracking, or deformation occurs (fluororubber seals are recommended to be replaced every 2 years).

-Before disassembling the kettle cover, wipe the sealing groove with an alcohol swab to prevent residue from being embedded; Apply silicone grease for rust prevention when not in use for a long time.

-Check the tightness of bolts on the flange and electrode interface of the kettle body every month, and use a torque wrench to tighten them according to the nominal value (such as M12 bolt torque 18-22N · m).

2. Maintenance of magnetic coupling system

-Check the gap between the inner and outer magnetic rotors daily (usually 5-8mm) to ensure there are no foreign objects obstructing them.

-Manually rotate the outer magnet and confirm that there is no jamming or abnormal noise; If the mixing speed is lower than 80% of the rated value, it is necessary to check whether the magnetic cylinder is demagnetized or the gap is too large.

3. Maintenance of transmission parts

-Add high-temperature resistant lubricating grease (such as Mobil XHP 222) to the motor bearings and mixing shaft support frame every quarter to avoid wear caused by dry friction.

4. Maintenance of Pressure and Safety Accessories

-Verify the flexibility of the pressure gauge pointer weekly and send it for inspection and calibration annually; The popping pressure of the safety valve should be verified according to the design value (usually 1.1-1.3 times the working pressure), and it is strictly prohibited to adjust it without authorization.

-Conduct a water pressure test at 1.5 times the working pressure every six months (such as a design pressure of 2MPa and a test pressure of 3MPa), and hold the pressure for 30 minutes without any leakage to be considered qualified.

3、 Operating standards

1. Pre use inspection

-Conduct a sealing test, prioritize the use of inert gases (such as nitrogen), and strictly prohibit the use of flammable and explosive gases or oxygen.

-Check if the temperature control system, heating elements, and mixer are working properly.

2. Monitoring during operation

-The heating rate should be controlled at ≤ 5 ℃/min to avoid uneven thermal stress caused by sudden heating; Slowly release pressure during depressurization (not exceeding 0.1MPa per minute) to prevent negative pressure collapse.

-Adjust the stirring speed according to the viscosity of the material to avoid material splashing or vortex wear on the kettle wall during high-speed operation; Prohibit idling stirring to prevent demagnetization caused by dry friction of the magnetic rotor.

3. Post use processing

-After the reaction is complete, cool down first (by water or air cooling) and then exhaust. After the pressure drops to atmospheric pressure, open the kettle lid.

-Timely remove residues, clean the kettle body with warm water and neutral detergent, and keep it dry.

4、 Safety precautions

1. Explosion proof and ventilation

-Ensure explosion-proof distance during installation, place multiple sets of equipment separately, and maintain good ventilation.

-When dealing with flammable and explosive media (such as methanol and hydrogen), replace them with inert gas three times to ensure that the oxygen content is less than 0.5%.

2. Treatment of corrosive media

-Immediately rinse with clean water and dry after handling acidic materials (such as concentrated sulfuric acid); Alkaline media should be controlled with pH<12, and 316L stainless steel material should be used for long-term use.

3. Storage management

-Clean and dry, place desiccants (such as silicone bags) inside the kettle, seal and store.

-The controller is powered off, and the motor and heating elements are covered with dust covers; Disassemble the mixing system and pressure gauge, and package them separately; The kettle body is fixed with soft pads and tilted at an angle of less than 30 °.