What is a reactor

What is a reactor?

Reactor is broadly understood as a vessel with physical or chemical reactions. Through the structural design and parameter configuration of the vessel, it can realize the heating, evaporation, cooling and low and high speed mixing functions required by the process.

Reactors are widely used in petroleum, chemical, rubber, pesticide, dyestuff, medicine and food, etc. They are pressure vessels used to complete the process of sulfidation, nitrification, hydrogenation, hydrocarbonization, polymerization, condensation, etc., such as reactors, reaction kettles, decomposition kettles, polymerization kettles, etc. The materials are generally carbon manganese steel, stainless steel, zirconium, nickel-based (Hastelloy, Monel, Inconel) alloys and other composite materials.

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Introduction of reaction kettle

Reaction kettle is broadly understood as a stainless steel vessel with physical or chemical reactions. The structural design and parameter configuration of the vessel are based on the demand of different process conditions, and the design conditions, process, inspection and manufacturing and acceptance need to be based on relevant technical standards in order to achieve the heating, evaporation, cooling and low and high speed mixing and matching reaction functions required by the process. The pressure vessel must follow the standard of GB150 {steel pressure vessel} and the atmospheric pressure vessel must follow the standard of NB/T47003.1-2009 {steel welded atmospheric pressure vessel}. The pressure requirements of the reaction process vary with the design requirements of the vessel. The production must be processed, tested and test run in strict accordance with the corresponding standards. Stainless steel reactor According to different production processes, operating conditions, etc. are not the same, the design structure and parameters of the reactor are different, i.e. the structure style of the reactor is different, which is a non-standard vessel equipment.
The reactor is a comprehensive reaction vessel, and the design of the reactor structure function and configuration accessories according to the reaction conditions. From the beginning of feeding-reaction-discharge can complete the pre-set reaction steps with a high degree of automation, and the important parameters such as temperature, pressure, mechanical control (stirring, air blowing, etc.) and concentration of reactants/products in the reaction process are strictly regulated. Its structure is generally composed of kettle body, transmission device, stirring device, heating device, cooling device and sealing device. Corresponding auxiliary equipment: fractionation column, condenser, water divider, collection tank, filter, etc.
Reaction kettle materials generally include carbon manganese steel, stainless steel, zirconium, nickel-based (Hastelloy, Monel) alloy and other composite materials. The reaction kettle can be made of SUS304, SUS316L and other stainless steel materials. The stirrers are anchor type, frame type, paddle type, turbine type, scraper type, combined type, and the rotating mechanism can adopt cycloid reducer, stepless speed reducer or frequency conversion speed control, etc., which can meet the special reaction requirements of various materials. Sealing device can adopt mechanical seal, packing seal and other sealing structures. The heating and cooling can adopt the structure of jacket, half pipe, coil, miller plate, etc. The heating methods are: steam, electric heating, heat-conducting oil, in order to meet the process needs of different working environments such as acid resistance, high temperature resistance, wear resistance and corrosion resistance. And it can be designed and manufactured according to users’ process requirements.

Reaction kettle classification

  • 1. According to the heating/cooling methods, it can be classified into electric heating, hot water heating, thermal oil circulation heating, far-infrared heating, external (internal) coil heating, etc., jacket cooling and coil cooling inside the kettle, etc. The choice of heating method is mainly related to the heating/cooling temperature required for chemical reaction and the size of heat required.
  • 2. According to the material of kettle body, it can be divided into carbon steel reactor, stainless steel reactor, glass-lined reactor (porcelain-lined reactor) and steel-lined reactor.

Carbon steel reactor

Carbon steel reactor is made of carbon steel (Q235) and consists of driving device, stirring system, sealing parts, barrel, heating or cooling device, supporting parts, pipe mouth for each purpose, etc.

Working principle of carbon steel reactor

All kinds of mediums that need to be mixed and reacted are entered into the carbon steel reactor according to the proportional formula, and in a certain temperature range with the external force of the stirring system, the raw materials are transformed into the target material, i.e. the product that needs to be obtained.
Stirrer: Mixing reaction is the core technology of carbon steel reactor, stirring operation involves fluid flow, heat and mass transfer. There are low viscosity stirrers and high viscosity stirrers. Paddle type, open turbine type, disc turbine type and propulsion type are low viscosity stirrers; high viscosity stirrers include screw belt type, propeller type, frame type, anchor type and our newly developed scraping wall stirrer.
Heat transfer method: external jacket and internal coil are the most common heating or cooling methods. Different heating methods are used for different process conditions and different heat sources.
Seal form: mechanical seal when the vacuum degree is high or the pressure is relatively high, and generally the packing seal can be used.
Installation form: placed in the operating platform with ear type support; as a single machine equipment used directly installed on the ground that is, with support type or leg type support. No matter which type of installation is required, the level is required.

Stainless steel reactor

Stainless steel reactor with rapid heating, high temperature resistance, corrosion resistance, health, no environmental pollution, do not need boiler automatic heating, easy to use and other characteristics, widely used in petroleum, chemical, rubber, pesticides, dyes, pharmaceuticals, food, used to complete the vulcanization, nitrification, hydrogenation, hydrocarbonation, polymerization, condensation and other processes, is to participate in the full mixture of reaction substances as a prerequisite for heating, cooling, and liquid extraction For heating, cooling, and liquid extraction, and gas absorption and other physical changes need to use stirring device to get to good results, and can be designed for customers, processing external coil reactor.
The atmospheric pressure stainless steel electric heating reactor has the characteristics of rapid heating, high temperature resistance, corrosion resistance, hygiene, no environmental pollution, electric heating stainless steel reactor, do not need boiler automatic heating, easy to use, cheap and so on. Widely used in chemical, pharmaceutical, food and other industries, the material is made of 304 stainless steel.
Reaction kettle construction principle, characteristics: the reaction kettle consists of pot body, pot cover, stirrer, jacket, support and transmission device, shaft sealing device, etc. The material and opening can be made according to the user’s process requirements. Heating forms include electric heating, oil heating, gas heating, water heating (or cooling), open fire heating, etc. The jacket form is divided into: jacket type and outer half pipe type, jacket oil heating type are equipped with inflow device. Stirring form generally has paddle type, anchor type, frame type, spiral type, scraping wall type, etc. The high speed category includes dispersion impeller type, turbine type, high shear type and propeller type for customers to choose according to the process. The transmission forms are ordinary motor, explosion-proof motor, electromagnetic speed control motor, frequency converter, etc. The reducer is cycloid, worm wheel, planetary infinitely variable speed type. Shaft seal is ordinary water-cooled packing seal, combined tetrafluoro packing seal, mechanical seal. The discharge form is ball valve, lower spreading valve.

Application scope of stainless steel reactor

Stainless steel reactor is widely used in chemical, food, coating, hot melt adhesive, silica gel, paint, pharmaceutical, petrochemical production in the reaction, evaporation, synthesis, polymerization, saponification, sulfonation, chlorination, nitrification and other process pressure vessels, such as reactor, reaction kettle, decomposition kettle, polymerization kettle, etc. The reaction kettle is mainly composed of four parts: inner tank body, jacket, stirring device and support seat (with insulation structure can be used according to the process needs).
The inner tank body is made of stainless steel (SUS304, SUS316L or SUS321) according to the process needs, with mirror polishing treatment on the inner surface and online CIP cleaning and SIP sterilization, which meets the requirements of sanitary standards.
The jacket is made of stainless steel (SUS304) or carbon steel (Q235-B) etc. according to the process needs.
Suitable diameter to height ratio design, customized agitation device as required; stirring shaft seal using pressure-resistant sanitary mechanical sealing device to maintain the working pressure in the tank and prevent unnecessary pollution and material loss caused by the leakage of materials in the tank.
The support type adopts hanging lug type or floor support leg type according to the operation requirements.

Glass-lined reactor

Glass lined reactor is a glass containing high silica, lined on the inner surface of the steel vessel, which is burned at high temperature and firmly adhered to the metal surface to become a composite product. Therefore, it is an excellent corrosion resistant equipment.

The production process of glass-lined reactor

The glass lined reactor firstly presses the steel plate with the tire tool into the folding plate which meets the requirements of firing, its cross section becomes similar to the letter “Ω” shape, the width of the folding plate H is 1/8-1/6 of the diameter of the kettle body, the radius of the radius of the top surface of the folding plate R is: 3δ≤R≤150mm, δ is the thickness of the steel plate of the folding plate, the radius of the side radius r is 6-50mm, and then according to the volume of the reactor, the radius of the top surface of the folding plate is 3δ≤R≤150mm. 50mm, then according to the size of the reactor volume, the folded flow plate is made into one or more layers, welded on the inner wall of the kettle, and after the welded seam is handled round and smooth, it is enameled and assembled into finished products, which better improves the flow state of reaction materials and enhances the reaction efficiency. Glass-lined equipment running after stopping the inspection of domestic and foreign high-quality manufacturers are selected high-quality steel plate, welding rod, enamel, steel plate welding rod containing carbon, sulfur, phosphorus impurities low, steel plate lattice structure and tight and trace elements to inhibit the manufacturing process of hydrogen absorption, enamel selection of good corrosion resistance, excellent resistance to rapid temperature changes, low melting point of the enamel.
Enamel firing using “low temperature long firing”, “slow cooling after firing” firing process, generally in the firing three times after the firing without pores, the next three to four firing is only the thickening of the porcelain layer, more than half of the thickness of the porcelain layer is dense and non-conductive, so the porcelain layer Excellent corrosion resistance, corrosion, friction, collision, even if the porcelain layer thickness thinning will not affect the performance of the porcelain layer.

Steel lined PE reactor

Steel lined mixing tank using high molecular polyethylene (LLDPE) raw materials and steel tank body through rotomolding process technology processed products. That is, the outer surface layer of carbon steel layer, the inner layer of polyethylene plastic layer, two layers through the middle of the embedded tortoise steel mesh closely connected steel-plastic composite products. With high molecular polyethylene steel lined plastic mixing tank using high molecular polyethylene (LLDPE) raw materials and steel tank body through rotomolding technology and processing of products. That is, the outer surface layer of carbon steel layer, the inner layer of polyethylene plastic layer, two layers through the middle of the embedded tortoise shell steel mesh closely connected steel-plastic composite products. With the physical characteristics of polymer polyethylene storage tank and steel tank rigid strength, tank size, interface and manhole location in line with the rotomolding process technology and transport and other factors under the conditions of the user can be designed and manufactured by us according to their own process requirements.

Steel lined mixing tank process

  • 1. First of all, the steel lined mixing tank storage tank should be accepted according to the technical agreement, design drawings and technical terms of the contract made by the manufacturer and the customer. 
  • 2. Steel lined mixing tank storage tank steel body part can be accepted according to JB/T 4735-1997 steel welded atmospheric pressure vessel. 
  • 3. Steel body outer dimensions according to the drawing size, error bar more than ± 5 mm. 
  • 4. Steel system for garden-type (elliptical) tanks must be garden whole, full, no obvious bump phenomenon, square tanks storage tanks should be vertical level. 
  • 5. 6mm steel plate above (including 6mm) weld 12-20 mm. weld seam should be flat, straight, continuous. Contains a seam residual height of 0-3mm. 
  • 6 Mixing tank tank welding should be staggered, staggered seam distance should be greater than 300. 
  • 7. Storage tanks The manhole flange of the storage tank should not be opened at the weld. If welding should be added to strengthen the composite plate. 
  • 8. Check the tank body steel thickness with the weighing method or ultrasonic thickness gauge should meet the standard. 
  • 9. Pressure Ⅰ, Ⅱ, Ⅲ class storage tanks storage tanks, there should be relevant qualification certificate, welding seam should be x-ray film qualified. 
  • 10. Mixing tank storage tank storage tank tank plastic plastic thickness should be uniform, flat, the surface is with the steel network natural concave and smooth plane. The surface is free of porosity, no obvious color spots, there can be no obvious bumps or depressions. 
  • 11. Mixing tank tank plastic plastic thickness thickness of the temporary method of side determination, must have the plant plastic input weight control, visual inspection of the plastic layer stencil should be completely embedded in the sense of the plastic layer. 
  • 12. Manhole, flange lining plastic layer should be complete, flange plane should be flat, hole lining layer is complete.

The physical properties and rigid strength of the steel tank, tank size, interface and manhole location in line with the rotomolding process technology and transport and other factors under the conditions of the user can be designed and manufactured by us according to their own process requirements.

Steel lined PTFE reactor

Steel lined PTFE reactor is a kind of large scale equipment for storing and transporting chemical agents made of stainless steel exterior and lined with PTFE. Steel lined PTFE reactor series is suitable for all strong acid and strong alkali, and any proportion of oxidizing acid and non-oxidizing acid mixed liquid, also is a high quality vessel for preparing acid (alkali) liquid, the heating temperature outside the kettle shall not exceed 180℃ The operating temperature inside the kettle is ≤180℃. The heating speed should be slow and the temperature outside the kettle can be controlled by PID temperature control system to gradually control the temperature inside the kettle.
Because the stainless steel kettle is lined with PTFE inside and outside the temperature measurement tube, special attention should be paid to the temperature difference between the heating temperature outside the furnace and the temperature inside the kettle measured by the temperature measurement tube. The steel lined PTFE reaction kettle should not be used for evacuation. After the reaction is finished, wait for the temperature to decrease and the pressure to disappear before opening the cover to take the material, and do not use the open valve to deflate the temperature to avoid emptying the PTFE set.

Hydrofluoric acid is an aqueous solution of hydrogen fluoride (HF), which is a colorless transparent liquid to light yellow liquid as the concentration increases, with irritating odor, highly toxic and a high-risk chemical. Therefore, the steel lined tetrafluorine reaction kettle and pipeline produced by Xinyutong are in full accordance with the relevant national standards for hazardous chemical storage and transportation equipment, and have excellent performance of safety and no leakage.

Jacketed reactor

Jacketed reactor is generally a kettle reactor with stirring device, which is a typical equipment commonly used in chemical, pharmaceutical, dyestuff and coating, etc. As a typical equipment in the industry production, jacket also has the meaning of sandwich, which mainly imports heating medium inside the jacket thus completing the function of humidification or heating in the kettle. Their mechanical design involves different design and calculation requirements in addition to the contents of chemical vessel design in the basic chemical machinery and equipment textbook. The figure below shows a typical reactor with stirring and jacketed heat transfer. As can be seen from the diagram, the reactor is usually composed of the reactor body, heat transfer, stirring, transmission, sealing and other devices and related accessories.

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The jacketed reactor body and the lower head are generally welded. The connection between the upper head and the cylinder body is determined by the diameter of the kettle body. When the diameter of the kettle body D<800, the activities of people in the kettle are small, so flange welding is generally used. When the diameter of the kettle body D>800, the head and the cylinder body can be welded as well. Sometimes, to facilitate installation, disassembly and maintenance, flanges are used to connect the head and the barrel, and manholes are opened in the head.
The kettle body is the space where the materials are reacted and consists of the barrel and the upper and lower heads. The heat transfer device is designed to provide the heat required for the chemical reaction or to take away the heat generated by the reaction. In addition to the jacketed heat transfer in the figure, there are also heat transfer devices in the form of serpentine tubes (outer half coils), as well as internal coil heating and other forms. The stirring device consists of stirrer and stirring shaft, whose function is to quickly and evenly mix the material and strengthen the process of mass and heat transfer, thus speeding up the reaction rate. In order to enable the stirrer to rotate at a certain speed, a transmission device consisting of motor and reducer is required. In addition to static sealing structure such as equipment flange and pipe flange on the reaction kettle, there is also a dynamic sealing device to ensure the sealing of the rotating shaft. Packing seal or mechanical seal can be used.
In addition, according to the process and maintenance requirements, the jacketed reactor body is equipped with process interface pipe, man (hand) hole, sight glass, support and many other accessories. The mechanical design of its reactor has to be customized according to the operating volume, accessories, speed, material, etc. configured by its production process.

Structure of reaction kettle

Reaction kettle is composed of kettle body, cover, jacket, stirrer, transmission device, shaft seal device, support, etc. When the stirring device is large in height and diameter, multi-layer stirring paddle can be used, and it can also be optional according to the user’s requirements. A jacket is set outside the kettle wall, or a heat exchange surface is set inside the vessel, and heat exchange can also be carried out through external circulation. The support seat has support type or ear type support, etc. It is advisable to use gear reducer for rotating speed over 160 rpm. The number of openings, specifications or other requirements can be designed and made according to user requirements.

  • 1. Normally, packing seal is used under normal pressure or low pressure, and the general pressure is less than 2kg.
  • 2. In general, mechanical seal will be used under medium pressure or vacuum, and the general pressure is negative pressure or 4 kg.
  • 3. In the case of high pressure or high volatility of the medium will be used magnetic seal, the general pressure of more than 14 kg or more. In addition to the magnetic seal, water is used to cool down the temperature, while other seal forms will increase the cooling water jacket when the temperature exceeds 120 degrees.

Stirring device of reaction kettle: stirrer

The role of the stirrer

To push the stationary liquid to move and maintain the fluid flow state required for the stirring process in order to achieve the purpose of stirring. The main part of the agitator is the paddle, so the geometry, size, number and speed of the paddle have an important influence on the function and mixing effect of the agitator.

Paddle mixer

It is composed of paddle, key, shaft ring and vertical shaft. The paddle is generally made of flat steel or stainless steel or non-ferrous metal. The rotational speed of paddle stirrer is low, generally 20-80r/min. The diameter of paddle stirrer is Di/3-2/3 of the inner diameter of the reactor, the paddle should not be too long, and two or more paddles are used when the diameter of the reactor is large.
The paddle stirrer is suitable for liquid materials with high fluidity and low viscosity, and also for fibrous and crystalline dissolved liquids, and several rows of paddles can be installed on the shaft when the material layer is deep.

Turbine type agitator

Turbine mixer is divided into disc turbine mixer and open turbine mixer; according to the impeller, it can be divided into flat and curved leaves. Turbine mixer speed is larger, 300 – 600 r/min.
The main advantage of turbine stirrer is that when the energy consumption is not much, the stirring efficiency is high and the stirring produces a strong radial flow. Therefore it is suitable for emulsions, suspensions, etc.

Propulsion type stirrer

Propulsion stirrer, when stirring, can make the material circulate in the reactor, and the effect is mainly volumetric circulation, with less shearing effect and good up and down tumbling effect. When a larger flow rate is needed, the reactor is equipped with a flow guide cylinder.
The diameter of the pusher stirrer is about 1/4-1/3 of the inner diameter Di of the reactor, 300-600 r/min, and the material of the stirrer is often cast iron and cast steel.

Frame and anchor type stirrer

The frame stirrer can be regarded as the deformation of the paddle stirrer, and its structure is relatively strong and the amount of material stirred is large. If the shape of the bottom of this type of stirrer is similar to the shape of the lower head of the reactor, it is usually called anchor stirrer.
The diameter of frame stirrer is larger, usually 2/3 to 9/10 of the inner diameter of the reactor, 50-70r/min. The gap between frame stirrer and kettle wall is small, which is conducive to the heat transfer process, and when rotating fast, the liquid driven by the stirrer blade brings down the static layer from the reactor wall; when rotating slowly, the stirrer with scraper can produce good heat transfer. This kind of stirrer is often used in heat transfer, crystal analysis operation and mixing of high viscosity liquid, high concentration slurry and settling slurry.

Spiral belt agitator and screw type agitator

The spiral belt stirrer is often made of flat steel wound in the shape of a spiral, with a larger diameter, and often made into several strips close to the inner wall of the kettle, with a small gap between the wall and the kettle, so that the sediment stuck to the wall of the kettle can be scraped off continuously when stirring. The height of the spiral belt is usually taken as the height from the bottom of the tank to the liquid level.
The rotational speed of both the spiral belt agitator and screw agitator is low, usually not more than 50r/min, and the flow is mainly up and down circulation, which is mainly used for the agitation of high viscosity liquid.

Selection of stirrer

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It is mainly based on the material nature, mixing purpose and performance characteristics of various agitators.
1. Selecting according to material viscosity
For low viscosity liquid, small diameter, high speed agitator should be used, such as propulsion type, turbine type.
For high viscosity liquids, use large diameter, low speed agitators, such as anchor, frame and paddle type.
2. Select the type according to the purpose of mixing
For low-viscosity homogeneous liquid mixing, the main consideration is the circulation flow rate, and the circulation flow rate of various stirrers is listed in the order from largest to smallest: propulsion type, turbo type, paddle type.
For non-homogeneous liquid-liquid dispersion process, the first consideration is the shearing effect, while requiring a larger circulation flow, the shearing effect of various stirrers in the order of large to small: turbine, propeller, paddle.

Note on the use of reaction kettle

Reaction kettle is a kind of reaction equipment, which must be paid attention when operating, otherwise it will cause damage for many reasons and lead to forced production stop. There are many aspects to pay attention to when operating a reaction kettle.
First of all, the reactor must be operated in strict accordance with the rules and regulations.
Secondly, before operation, check carefully for any abnormalities. In normal operation, do not open the upper cover and touch the terminals on the board to avoid electric shock; operation under pressure is strictly forbidden; in the process of test pressure with nitrogen, observe the change of pressure gauge carefully and close the nitrogen valve switch immediately when the test pressure is reached; the speed of heating up should not be too fast, and the pressurization should be carried out slowly, especially the stirring speed, which is only allowed to rise slowly.
Finally, when the kettle is heated to a higher temperature, do not contact with the kettle to avoid burns; the experiment should be cooled down first. No quick cooling should be allowed to prevent damage caused by excessive temperature pressure difference. At the same time, the power should be unplugged in time.
At the same time, you should pay attention to maintenance after using the reactor, so that the autoclave can have a better service life.

Installation and operation specification of reaction kettle

  • 1. The autoclave should be placed indoors. When equipping multiple autoclaves, they should be placed separately. Each operation room should have an exit that leads directly to the outdoors or to a channel, and should ensure that the equipment is well ventilated.
  • 2. When installing the cover, prevent the sealing surface between the kettle body and cover from bumping against each other. Put the cover on the kettle body carefully according to the fixed position, when tightening the main nut, it must be tightened gradually by diagonal and symmetrical times. Tighten the main nut diagonally and symmetrically for several times. Use even force and do not allow the cover to tilt to one side to achieve a good sealing effect.
  • 3, positive and negative nut connection, only allowed to rotate positive and negative nut, two arc sealing surface shall not be relative rotation, all nut pattern coupling parts have assembly, should be coated with lubricant.
  • 4. The needle valve is line sealed, only need to gently turn the valve needle and press the tight cover to achieve a good sealing effect.
  • 5. Turn the kettle on the rotary body by hand to check whether the operation is flexible.
  • 6. The controller should be placed flat on the operating table, its working environment temperature is 10-40℃, relative humidity is less than 85%, and the surrounding medium does not contain conductive dust and corrosive gas.
  • 7, check the panel and back panel on the movable parts and fixed contacts are normal, pull open the upper cover, check whether the contact plug is loose, whether there is damage or rust caused by poor transport and storage.
  • 8, the controller should be reliably grounded.
  • 9. Connect all the wires, including the power line, furnace line between the controller and kettle, motor line and temperature sensor and tachometer wire.
  • 10. Close the “power” air switch on the panel, and the digital display should show.
  • 11. Set various parameters (such as upper alarm temperature, working temperature, etc.) on the digital display table, then press the “heating” switch, the furnace will be connected, and the indicator light on the “heating” switch will be on. Adjust the “regulating” knob, you can adjust the heating power of the electric furnace.
  • 12, press the “stirring” switch, the stirring motor is energized, while the “stirring” switch on the light is on, slowly turn the “speed” knob, so that the motor slowly rotate, observe the motor If there is no error, stop the machine and hang up the belt, then restart it.
  • 13. After the operation, it can be naturally cooled, cooled by water or placed in the bracket air cooling. After the temperature drops, release the pressurized gas in the kettle and make the pressure drop to normal pressure (the pressure gauge shows zero), then loosen the main nut symmetrically and equally, then remove the main nut and carefully take off the kettle cover and put it on the bracket.
  • 14. After each operation, clear the residues on the kettle body and cover. The main sealing mouth should be cleaned frequently and kept clean. Wiping with hard objects or surface roughness is not allowed.

Maintenance of reaction kettle

  • (1) Device place: The reaction kettle should be installed in a high pressure operation room that meets the requirements of explosion-proof. When equipping more than one reaction kettle, they should be placed separately, and a safe explosion-proof wall should be used to separate between each two units, and each operation room should have access and exit to the outdoors, and good ventilation should be ensured when there are explosive media.
  • (2) Open the package and check whether the equipment is damaged, install the equipment according to the structure according to the equipment type, and check the parts according to the packing list. If the heating method is heat-conducting oil electric heating, please purchase the appropriate type of heat-conducting oil in accordance with the use of temperature (Note: heat-conducting oil is absolutely not allowed to contain moisture) to join, join the upper part of the jacket to open the refueling port and the upper part of the jacket to open the oil level port. Add oil through the oiling port and wait for the oil level port to flow; then screw the oil level port to death, do not screw the oiling port to death to avoid pressure.
  • (3) Installation and sealing of kettle body and cover: The kettle body and cover adopt gaskets or conical surface and circular arc surface line contact, and make them press each other by tightening the main nut to achieve good sealing effect. When tightening the nut, it must be symmetrical diagonally and tighten gradually for many times with even force, and do not allow the kettle cover to tilt to one side to achieve good sealing effect. When tightening the main nut, do not exceed the specified tightening torque of 40-120N.M to prevent the sealing surface from being crushed or worn out by overload. Before each installation, wipe the upper and lower sealing surface with a soft paper or cloth, and pay special attention not to touch the sealing surface of the kettle body and cover to make scars. If operated reasonably, it can be used more than ten thousand times. If the sealing surface is damaged, it should be reworked and repaired to achieve good sealing performance. When disassembling the lid, lift the lid up and down slowly to prevent the sealing surface between the body and lid from colliding with each other. If the seal is sealed by gasket (teflon, aluminum, copper, asbestos, etc.), a good seal can be achieved by tightening the main nut.
  • (4) The installation of valves, pressure gauges and safety valves can be sealed by tightening the nuts, and the circular sealing surfaces of the two ends of the coupling must not be rotated. The use of valves: needle valve system line seal, only need to gently turn the valve needle, press tight cover that can achieve good sealing performance, prohibit excessive force, so as not to damage the sealing surface.
  • (5) After the installation of the equipment, through a certain amount of nitrogen pressure for 30 minutes, check whether there is leakage, such as the discovery of leakage, please use soap foam to find the pipeline, orifice leakage point, find out after releasing the gas tightened, again through the nitrogen pressure test, to ensure that no leakage began to work normally.
  • (6) When cooling down, use water for internal cooling through the cooling coil, forbid rapid cooling to prevent excessive temperature difference stress from cracking the cooling coil and kettle body. When the temperature inside the kettle exceeds 100℃, the water jacket between the magnetic stirrer and the kettle cover should be connected with cooling water to ensure that the water temperature is less than 35℃ to avoid demagnetization of the magnet.
  • (7) Safety device: Adopt positive arch type metal bursting disc, material is stainless steel, manufactured according to the national standard GB567-89 “Arch type metal bursting technical conditions”, which has been tested at the factory and shall not be adjusted at will. If it has burst, need to be replaced again, the replacement period by the use of the unit according to the actual situation of the unit to determine, for more than the rupture disc calibrated burst pressure and not burst should be replaced, often used preferably not more than 80% of the lower pressure of the rupture disc, the replacement should pay attention to the convex side of the rupture disc up.
  • (8) After the reaction is finished, cool down the kettle first, then vent the gas inside the kettle to outdoor through pipeline, make the pressure inside the kettle drop to normal pressure, disassemble with pressure is strictly prohibited, then loosen the main bolts and nuts symmetrically and unload them, then carefully take off the kettle cover (or raise the cover) and put it on the support, special attention should be paid to protect the sealing surface in the process of unloading the cover.
  • (9) Cleaning of the kettle: After each operation, use cleaning liquid (care should be taken to avoid corrosion of the main material when using cleaning liquid) to remove the residues from the kettle body and sealing surface.

Selection of reactor

For a specific reaction process, the selection of reactor should take into account technical, economic and safety factors.
The basic characteristics of the reaction process determine the appropriate reactor form. For example, the gas-solid phase reaction process is generally using fixed-bed reactor, fluidized-bed reactor or moving-bed reactor. However, the appropriate type of reactor is determined by considering the thermal effect of the reaction, the requirement of conversion rate and selectivity, the physical and chemical properties and deactivation of the catalyst, and even by conceptual design and technical and economic analysis of different reactors.
In addition to the reactor form, the operation and charging methods of the reactor also need to be considered. For example, for processes with tandem or parallel side reactions, a segmented feed may be preferable to a single feed. The temperature sequence is also an important factor in reactor sizing. For example, for exothermic reversible reactions, a high and then low temperature sequence should be used. Multi-stage and inter-stage heat transfer reactors can make the temperature sequence of the reactor reasonable. The reactor occupies an important position in the process industry production. In terms of the construction investment and operation cost of the whole process, the proportion of reactors may not be large. However, its performance and operation affects the yield and quality of pre and post-processing and products, and has an important impact on raw material consumption, energy consumption and product cost. Therefore, the research and development work of reactors is of great importance for the development of various process industries.

Source: China Pipe Fittings Manufacturer – Yaang Pipe Industry (www.steeljrv.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

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