In the early 1990s, Manz et al. first proposed the concept of a micro-analysis system. In 1995, it first reported microfluidic technology for chemical synthesis. Since then, it has been successfully used in many important organic reactions. It is superior to the macro-scale response and demonstrates its broad and unique application prospects. With the development of materials, manufacturing and micro-mixing technology, microfluidic technology has become one of the research hotspots in the field of organic chemistry.
According to the widely accepted definition of microsystems, microreactors generally refer to small reaction systems fabricated by micromachining and precision machining techniques. The microchannels in the microreactor have dimensions down to the order of millimeters, typically between 10 and 300 μm. Chemical synthesis using a microreactor is called microfluidic synthesis. Compared to conventional reactors, microfluidic synthesis technology has many advantages:
High heat transfer and mass transfer efficiencyThe specific reactor surface area is only 1.0×10^2～1.0×10^3 m 2• m-3; the size of the microreactor is small, up to 1.0×10^4～5.0×10^4 m2•m-3, heat conduction The rate is up to 1.0×10^4 W•m-2•K-1, which is much higher than the conventional reactor. The small size of the microreactor makes the diffusion distance of the material very short. Because the diffusion coefficient is inversely proportional to the square of the diffusion distance, the mixing speed of the material in the microreactor is extremely fast.
The reaction parameters are easier to control accurately and safer.Due to the fast heat transfer, reaction conditions such as reaction temperature and effective reaction time can be precisely controlled. The reaction time can be adjusted by adjusting the flow rate. The amount of reactants is small, which can reduce the use of toxic reagents and reduce the risk of high temperature, high pressure and explosive reaction. Therefore, microreactors are particularly suitable for studying hazardous reactions.
Increased reaction efficiencyDue to the high heat transfer efficiency, the temperature can be lowered or increased respectively at high or low temperature reactions; the reaction time can also be greatly shortened. For a sharp exothermic reaction, the heat of reaction can be quickly dissipated, eliminating hot spots; reducing side reactions and increasing product selectivity, yield and purity.
Low environmental hazardThe amount of reactants is very small, the amount of toxic, expensive reactants and solvents used is small, and the resulting pollution is small. Therefore, microfluidic synthesis provides a technology platform for the development of environmentally friendly chemistry.
Easy to implement online detectionThe amount of microreactor product is close to the injection volume of modern analytical instruments, and the extent to which the reaction is carried out can be directly monitored online using modern analytical instruments.
Shorten the cycle of scientific research and explorationThe amount of information obtained by the microreactor in unit volume and unit time is large; the parallel integration technology of the microreactor itself and the series integration technology with other instruments make the screening cost of the new compound synthesis and new drugs lower, the efficiency is improved, and the efficiency is shortened. The cost and time of research.
Simple post-reaction treatmentFor example, when an immobilized catalytic bed microreactor is used, the reaction product exits the reactor without any treatment and can be separated from the catalyst, whereas the conventional reaction requires filtration to separate the product from the catalyst.
Microreactors have an important impact on organic synthesis methods and organic chemicals. Due to the small amount of reactants, the amount of toxic and expensive reactants and solvents used is greatly reduced, and the pollutants produced are also reduced. Therefore, the microreactor is particularly suitable for the exploration of reaction conditions and provides for the development of environmentally friendly chemistry. Technology platform; due to the small amount of reactants, the risk of high temperature, high pressure and explosive reaction can be reduced. Therefore, microreactors are particularly suitable for studying hazardous reactions.
With the advancement of microfluidic synthesis technology, more chemical companies will use this advanced synthesis technology to replace the existing inefficient chemical production technology.
Stator and rotor laminations are an important part of motors and generators. For medium-sized laminations with a great quantity, we usually use compound puncing. The advantages of compound punching is the process is suitable for mass production of medium-sized stator and rotor laminations. And the lead time is shorter. Usually the outer diameter is from 300mm-580mm.
Stator And Rotor Lamination By Compound Punching,Laminated Stator,Core Stator,Motor Laminations
Henan Yongrong Power Technology Co., Ltd , https://www.hnyongrongglobal.com