Various kettle-type reactors, reaction principle, structure and composition, collected! _ Heat Transfer _ Chemical Reaction _ Temperature

ScottSouza
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Original title: Various kettle reactors, reaction principle, structure and composition, collected! Chemical reactions are everywhere! When we stand under the blue sky and breathe the fresh air, the chemical reaction has already taken place. The O2 we breathe becomes CO2, and our human body is the "reactor" of this reaction. What do you want to know about the reactor? Reactor is the carrier of chemical reaction, which provides the necessary space and conditions for the reaction. As long as there is a place for reaction, the reactor is indispensable. Reactors in chemical plants are more diverse. Today, Xiaobian brings you the reaction principle and structure of the kettle reactor. Let's take a look! Kettle-type reactor is also called tank-type or pot-type reactor. The reaction principle is shown in the figure: Classification of tank reactors 1 Water heating reaction kettle When the temperature requirement is not high, this heating method can be used. There are two kinds of heating systems: open type and closed type. The open type is simpler and consists of a circulating pump, a water tank, a pipeline and a regulator for controlling a valve. When high-pressure water is used, the mechanical strength of the equipment is required to be high, a coil is welded on the outer surface of the reaction kettle, and a gap exists between the coil and the kettle wall, so that the thermal resistance is increased, and the heat transfer effect is reduced. 2 The steam heats the reaction kettle When the heating temperature is below 100 ℃, steam below one atmospheric pressure can be used for heating; when the heating range is 100-180 ℃, saturated steam can be used; when the temperature is higher, high-pressure superheated steam can be used. 3 Reactors heated by other media If the process requires operation at high temperature or to avoid the use of high-pressure heating system, other media can be used instead of water and steam, such as mineral oil (275-300 ℃), diphenyl ether mixture (boiling point 258 ℃), molten salt (140-540 ℃) and liquid lead (melting point 327 ℃). Expand the full text 4 Lectric heat reaction kettle The resistance wire is wound on the insulating layer of the barrel of the reaction kettle, or is installed on a special insulator at a certain distance from the reaction kettle, so that the reaction can be heated by electricity. The first three methods all need to add a jacket on the kettle body to obtain high temperature. Because of the large range of temperature change, the jacket and shell of the kettle bear the temperature change and produce temperature difference pressure. When electric heating is used, the equipment is light and simple, the temperature is easy to adjust, and there is no need for pumps, furnaces, chimneys and other facilities. It is also very simple to start, with low risk and low cost. However, the operation cost is higher than other heating methods, and the thermal efficiency is below 85%. Therefore, it is suitable for places where the heating temperature is below 400 ℃ and the price of electric energy is low. 5 Carbon steel reactor It is suitable for the environment without corrosive liquid, such as the processing of some oil products. 6 Stainless steel reactor With excellent mechanical property, it can work under high pressure and bear the impact of massive solid materials. Good heat resistance, wide working temperature range (-196-600 ℃), no oxygen peeling at higher temperature, and can be used for direct open fire heating. It has high wear resistance and corrosion resistance. The heat transfer effect is good, and the heating and cooling speed is fast. Has excellent processing performance, can be made into reaction kettles with different shapes and structures according to different process requirements, and can also be polished. 7 Glass-lined reaction kettle The glass containing high silicon dioxide is lined on the inner surface of a steel container and firmly adhered to the metal surface by high temperature burning to form a composite material product. Therefore, the glass-lined reaction kettle has the dual advantages of the stability of glass and the strength of metal, and is an excellent corrosion-resistant equipment. 8 Steel lined reactor Steel is used as the substrate for lining, such as a layer of steel pipe outside, which can be lined with rubber, plastic, etc., to achieve the inevitable problems of pure steel, such as corrosive media, high temperature or low temperature media. There are common steel-lined PE reactors, steel-lined ETFE reactors and so on. Steel lining PE reactor, the lining material is polyethylene, suitable for liquid food and medicine extraction. The steel lining ETFE reactor is made of ethylene-tetrafluoroethylene copolymer. This kind of reaction kettle has excellent anticorrosive performance and can resist various concentrations of acid, alkali, salt, strong oxidant, organic compounds and other chemical media with strong corrosiveness. Structure of kettle type reactor The kettle reactor is mainly composed of kettle body, jacketed glass reactor ,winterization filtration, heat transfer device, stirring device, transmission device, shaft seal device and various process nozzles. 1 Kettle body The kettle body provides the space required by the reaction. It is composed of a shell and upper and lower heads, and the ratio of its height to diameter is generally between 1 and 3. In pressurized operation, the upper and lower heads are mostly hemispherical or ellipsoidal; while in normal pressure operation, the upper and lower heads can be made into flat covers. For the convenience of feeding, the lower bottom can also be made into a conical shape. 2 Heat transfer device The function of that heat transfer device is to meet the temperature require by the reaction, and the types are various. Jacket heat transfer Jacket means a jacket applied to the outside of the vessel wall. Heat medium such as steam, hot water or hot oil can be adde to heat that material in the container (or pipeline), or cooling medium such as cooling wat or other cooling fluid can be introduced to cool the material in the container (or pipeline). Coil heat transfer It is suitable for reactors with large heat transfer area, which can not be met by the heat transfer area of the jacket alone, or reactors lined with rubber. Tubular heat transfer For a large reactor, when high-speed heat transfer is required, a tubular heat exchanger can be installed in the reactor. The invention has the advantages of large heat exchange area, good heat transfer effect, simple structure and large operation elasticity. External circulation type heat transfer When the heat transfer area of the jacket and the coil can not meet the process requirements, or the coil and the jacket can not be installed in the reactor, and the heat transfer area can not meet the process requirements, the feed liquid in the reactor can be pumped out by a pump and circulated back to the reactor after heat exchange by an external heat exchanger. Reflux condensation type heat transfer The steam generated in the reactor is condensed by an external condenser and the condensate is returned to the reactor. 3 Stirring device Comprises a stirrer, a stirring shaft and the like. Stirrer: to push the static liquid material to move and maintain the fluid flow state required by the stirring process, so as to achieve the purpose of stirring. There are many types of mixers, and the following picture shows the common types of mixers. Selection of Agitator 1. Type selection according to material viscosity For low viscosity liquid, the agitator with small diameter and high rotating speed, such as propeller type and turbine type, shall be selected; For high viscosity liquids, large diameter, low speed agitators, such as anchor, frame and paddle, are used. 2. Type selection according to mixing purpose For the mixing of low-viscosity homogeneous liquid, the circulation flow is mainly considered. The circulation flow of various agitators is arranged in the order from large to small: pusher type, turbine type and paddle type. For the heterogeneous liquid-liquid dispersion process, the shear effect is considered first, and a large circulation flow is required. The shear effects of various agitators are arranged in the order from large to small: turbine type, pusher type, and paddle type. 4 Transmission Its function is to provide power for stirring. The reaction kettle needs to be driven by a motor and a transmission device. The transmission device of the agitator is generally placed on the top of the kettle body and is usually arranged vertically, as shown in the figure. The rotating speed of the motor is relatively high, which can be reduced to the stirring speed required by the process through the reducer, and then the stirring shaft is driven to rotate through the coupling. 5 Shaft seal device Its function is to ensure the formation of sealing conditions during operation and prevent the leakage of media. It can be divided into stuffing box seal and mechanical seal. Stuffing box seal Structure: It is composed of bushing, packing box, packing ring, gland, hold-down bolt, etc. Principle: The packing filled in the annular gap between the mixing shaft and the stuffing box will generate radial compaction force along the surface of the mixing shaft under the action of gland pressure. The lubricant in the packing is squeezed out under the action of the radial pressing force, and a very thin liquid film is formed on the surface of the stirring shaft. On the one hand, the layer of liquid film lubricates the stirring shaft, and on the other hand, it plays a role in preventing the leakage of fluid in the equipment or the infiltration of external fluid, so as to achieve the purpose of axial sealing. Mechanical seal Mechanical seal is a relatively new sealing structure. It has less leakage, long service life, less friction power loss, no wear of shaft or shaft sleeve, good vibration resistance, and is often used in high and low temperature, flammable, explosive and toxic media occasions. But that structure is complex, the proces precision requirement of the seal ring is high, the installation technical requirement is high, the assembly and disassembly are inconvenient, and the cost is high. Service conditions of sealing device 6 Process nozzle Return to Sohu to see more Raw material inlet pipe (gray) Replacement air inlet pipe (blue) Replacement nitrogen inlet pipe (black) Cleaning water inlet pipe (green) Solid material inlet pipe (raw material, solid catalyst, etc.) Product discharge tube (gray) Inlet and outlet pipes of heat exchange medium (steam pipe is red) Responsible Editor: (function() { function getBrandHtml() { var brands = [],molecular distillation systems, html = ''; for(var i = 0; i < brands.length; i++) { var brand = brands[i]; if(brands.length i+1) { html+= ''+brand.name+''; } else { html+= ''+brand.name+'、'; } } return html; }; if(document.getElementById('linkBtn')){ document.getElementById('linkBtn').onclick = function() { $('#brands').removeClass('brand');$ ( '# tipInfo').text ( 'Real name responded'); $ ('#linkBtn').remove();$ ('.real-response .content').css('line-height', '20px');$ ('.real-response .time').css('line-height', '20px'); }; document.getElementById('brands').innerHTML = getBrandHtml(); }; })();。 toptiontech.com
Last edited: 13.09.2022, 09:50
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jendy
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The fact that I read this article of yours is 1001 games both amazing and fortunate for me because it made me aware of many things that have taught me and many others to live more sociably.
Last edited: 24.11.2022, 04:17
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