Reaction Kettle

In a broad sense, a reaction kettle is a container for physical or chemical reactions. Through the structural design and parameter configuration of the container, it realizes the heating, evaporation, cooling, and low-to-high speed mixing functions required by the process.A reaction kettle is mainly composed of a kettle body, kettle cover, jacket, agitator, transmission device, shaft seal device, and support.This equipment is widely used in petroleum, chemical, rubber, pesticide, dye, pharmaceutical, and food industries. It is a pressure vessel used to complete process such as vulcanization, nitration, hydrogenation, alkylation, polymerization, and condensation, including reactors, reaction pots, decomposition pots, and polymerization kettles. Common materials include carbon-manganese steel, stainless steel, zirconium, nickel-based (Hastelloy, Monel, Inconel) alloys, and other composite materials.

A reaction kettle is an integrated reaction container, whose structure, functions, and accessory configurations are designed according to reaction conditions.It can complete preset reaction steps with a high degree of automation from feeding, reaction to discharging, and strictly control important parameters during the reaction process, such as temperature, pressure, mechanical control (agitation, air blowing, etc.), and reactant/product concentration.Reaction kettles can be made of stainless steel materials such as SUS304 and SUS316L.Agitators come in anchor type, frame type, paddle type, turbine type, scraper type, and combined type. The rotating mechanism can adopt cycloid pinwheel reducers, stepless speed change reducers, or frequency conversion speed regulation, which can meet the special reaction requirements of various materials.Sealing devices can adopt mechanical seals, packing seals, and other sealing structures.For heating and cooling, structures such as jackets, half-pipes, coils, and Miller plates can be used. Heating methods include steam heating, electric heating, and heat-conducting oil heating, which can meet the process needs of different working environments such as acid resistance, high-temperature resistance, wear resistance, and corrosion resistance.Moreover, it can be designed and manufactured according to the user's process requirements.

Working Principle:

The reaction solvent can be placed in the inner layer for stirring reaction, and different cold and heat sources (refrigerant, hot water, or hot oil) can be passed through the interlayer for cyclic heating or cooling reactions.Through the interlayer of the reaction kettle, a constant-temperature (high-temperature or low-temperature) heat transfer medium or cooling medium is injected to heat or cool the materials in the kettle at a constant temperature.At the same time, stirring reactions can be carried out under normal pressure or negative pressure according to usage requirements.Materials react in the reaction kettle, and the evaporation and reflux of the reaction solution can be controlled. After the reaction is completed, materials can be discharged from the outlet at the bottom of the kettle, ensuring convenient operation.

Reactor Structure:

• A reaction kettle is composed of a kettle body, kettle cover, jacket, agitator, transmission device, shaft seal device, and support.When the height-diameter ratio of the stirring device is large, multi-layer stirring blades can be used, and they can also be optionally matched according to the user's requirements.A jacket can be installed outside the kettle wall, or a heat exchange surface can be installed inside the device, and heat exchange can also be carried out through external circulation.The support base includes support-type or lug-type supports.A gear reducer is recommended when the rotation speed exceeds 160 rpm.The number of openings, specifications, and other requirements can be designed and manufactured according to user requirements.
• Packing seals are usually used under normal pressure or low pressure, with a general operating pressure of less than 2 kg.
• Mechanical seals are used under general medium pressure or vacuum conditions, with a general pressure of negative pressure or 4 kg.
• Magnetic seals are used under high pressure or high volatility of the medium, with a general pressure of more than 14 kg. Except for magnetic seals which use water for cooling, other seal types will be equipped with an additional cooling water jacket when the temperature exceeds 120°C.

Classification And Usage:

Stainless Steel Reaction Kettle:The stainless steel reaction kettle is composed of a kettle body, kettle cover, jacket, agitator, transmission device, shaft seal device, and support.Common materials include carbon-manganese steel, stainless steel, zirconium, nickel-based (Hastelloy, Monel, Inconel) alloys, and other composite materials. According to the manufacturing structure, it can be divided into three categories: open flat cover reaction kettles, open butt-welded flange reaction kettles, and closed reaction kettles.The stirring forms of stainless steel reaction kettles generally include anchor type, paddle type, turbine type, propeller type, or frame type. When the height-diameter ratio of the stirring device is large, multi-layer stirring blades can be used, and they can also be optionally matched according to the user's requirements.According to different sealing types, stainless steel reaction kettles can be divided into: packing seal, mechanical seal, and magnetic seal.Heating methods include electric heating, hot water heating, heat-conducting oil circulation heating, external (internal) coil heating, etc. Cooling methods include jacket cooling and internal coil cooling.Stainless steel reaction kettles are widely used in petroleum, chemical, rubber, pesticide, dye, pharmaceutical, and food industries. They are pressure vessels used to complete processes such as vulcanization, hydrogenation, alkylation, polymerization, and condensation, including reactors, reaction kettles, decomposition pots, and polymerization kettles.

Magnetic Stirring Reaction Kettle:The magnetic stirring reaction kettle adopts a static seal structure, and the agitator and motor transmission are connected by a magnetic coupling. Due to its non-contact torque transmission, it replaces dynamic seals with static seals, which can completely solve the leakage problem that could not be solved by mechanical seals and packing seals in the past. This ensures that all stirring components of the entire medium work in an absolutely sealed state. Therefore, it is more suitable for reactions involving various flammable, explosive, highly toxic, precious media, and other chemical media with strong permeability. It is an ideal leak-free reaction equipment for vulcanization, fluorination, hydrogenation, oxidation, and other reactions in petroleum, chemical, organic synthesis, polymer material polymerization, and food processes.

Electric Heating Reaction Kettle:The electric heating reaction kettle has the characteristics of fast heating, high-temperature resistance, corrosion resistance, and no environmental pollution. It is widely used in petroleum, chemical, rubber, pesticide, dye, pharmaceutical, and food industries, and is also used to complete processes such as vulcanization, nitration, hydrogenation, alkylation, condensation, and polymerization.Common materials for electric heating reaction kettles include carbon-manganese steel, stainless steel, zirconium, nickel-based (Hastelloy, Monel, Inconel) alloys, and other composite materials. According to the manufacturing structure, it can be divided into three categories: open flat cover reaction kettles, open butt-welded flange reaction kettles, and closed reaction kettles. Each structure has its own application scope, advantages, and disadvantages.

Operation Precautions:

• Strictly prevent any hard metal objects from falling into the reaction kettle.
• Try to avoid adding hot materials to a cold kettle or cold materials to a hot kettle to avoid affecting the service life.
• When using jacket heating, pressure and temperature should be increased slowly. Generally, first pass 0.1 Mpa (gauge pressure) steam, maintain it for 15 minutes, then slowly increase the pressure and temperature (the heating rate is preferably 0.1 Mpa per 10 minutes) until the required operating temperature is reached.
• When using jacket cooling, if cooling water is used, it can be directly passed into the jacket for cooling; if chilled water is used, the remaining water in the jacket should be drained first before passing in chilled water. After cooling, the chilled water should be pressed back to the chilled water tank with compressed air in a timely manner.
• For steam heating, adopt top-in and bottom-out; for hot water heating, adopt bottom-in and top-out; for cooling water and chilled water cooling, adopt bottom-in and top-out.
• When the reaction kettle is used as a reaction container, the filling volume should not exceed 75%; when used as a storage tank, it should not exceed 90%.
• During discharging, if the discharge valve or discharge pipe is blocked, use non-metallic tools (materials that do not react with the medium) to gently unclog it; knocking is not allowed.
• Do not use metal utensils when cleaning the interior of the reaction kettle. Materials adhering to the inner surface of the kettle must be cleaned thoroughly in a timely manner.
• Strong acid media are strictly prohibited for stainless steel reaction kettles, and fluorine-containing media are strictly prohibited for glass-lined reaction kettles.

Maintenance:

• Check whether all inlet and outlet valves of the reaction kettle are in good condition and usable; if there are problems, they must be handled in a timely manner.
• Check whether the bolts of the reaction kettle's flanges and machine bases are loose, and whether the safety shield is intact and reliable.
• Check whether the reaction kettle body has cracks, deformation, corrosion, leakage, etc., and whether the insulation and paint are intact without falling off or burning.
• Frequently check whether the reducer has oil leakage, whether the shaft seal is intact, whether the oil pump is supplying oil, check the oil level and oil quality changes in the gearbox, and whether the oil box for the kettle's mechanical seal is short of oil. Add or replace the corresponding oil if necessary.
• Frequently listen for abnormal vibration and noise inside the reaction kettle.
• Listen to whether the reducer and motor sound normal, and feel the operating temperature of the reducer, motor, machine base bearings, and other parts: the general temperature will not be higher than 40°C, and the maximum temperature will not be higher than 60°C.
• Check whether safety devices such as safety valves, explosion-proof membranes, pressure gauges, and thermometers are accurate, sensitive, and usable. Check whether the safety valves and pressure gauges have been calibrated with intact lead seals, whether the red line of the pressure gauge is marked correctly, and whether the explosion-proof membrane has internal leakage.
• Keep the stirring shaft clean and visible. For shafts connected with round nuts, check whether the rotation direction of the stirring shaft is clockwise; reverse rotation is strictly prohibited.
• Regularly enter the kettle to check the conditions of internal accessories such as agitators and coils, fasten loose bolts, and replace relevant parts if necessary.
• Do a good job in the sanitation of the reaction kettle equipment to ensure no oil stains and keep the equipment clean at all times.