A design for an air-cooled test tube, with a series of modular and movable rings (cylindrical “crystallization comb”), installed in a laboratory crucible furnace is presented. The setup allows easy regulation simult...A design for an air-cooled test tube, with a series of modular and movable rings (cylindrical “crystallization comb”), installed in a laboratory crucible furnace is presented. The setup allows easy regulation simultaneous crystallization tests of a series of different crystallization rates in several columns (matrix) of test tubes, enabling fast studies of obtaining crystals. This low-budget, portable device (i.e. adjustable airstream with more simple control options), can also be applied in tube and chamber furnaces. The relations between the crystallization rate and parameters of air-cooled test tube are given and numerically analyzed.展开更多
This paper applies techniques of containerless processing, drop tube and glass fluxing, to undercool and solidify Ni77P23 alloys. Different diameter spheres were collected at the bottom of a 52-m long drop tube. Both ...This paper applies techniques of containerless processing, drop tube and glass fluxing, to undercool and solidify Ni77P23 alloys. Different diameter spheres were collected at the bottom of a 52-m long drop tube. Both crystalline and amorphous phase were formed in various size specimens due to the different cooling rate. The variation of partial undercooling with bulk undercooling is calculated for the Ni77P23 alloys. The deep undercooling and rapid solidification behaviour of Ni77P23 melts has been analysed with respect to microstructure formation and transition during fluxing and 52-m drop process of undercooled melts.展开更多
The suspension state of crystals in the crystallizer is one of the important indicators for evaluating the adaptability of the crystallizer.This study adopted the Euler-Eulerian two-fluid model to simulate and analyze...The suspension state of crystals in the crystallizer is one of the important indicators for evaluating the adaptability of the crystallizer.This study adopted the Euler-Eulerian two-fluid model to simulate and analyze the fluid motion of solid-liquid two-phase flow in the industrial-grade DTB crystallization kettle,as well as the phase suspension distribution of crystal particles.The main influencing factors investigated are:the heat transfer effect,the height of the bottom of the crystallizer,the number and position of the stirring paddle,crystal size and crystal volume fraction.Based on the research of Euler-Eulerian method to simulate fluids,the Euler-Lagrangian method was further used to simulate the motion state of particle phases with different particle sizes in the crystallizer.It was found that the designed DTB crystallizer has good recycle mixing effect.The particles can be mixed evenly during the operation,which can fully realize the solid-liquid mixing and suspension effect of the drug under study.展开更多
文摘A design for an air-cooled test tube, with a series of modular and movable rings (cylindrical “crystallization comb”), installed in a laboratory crucible furnace is presented. The setup allows easy regulation simultaneous crystallization tests of a series of different crystallization rates in several columns (matrix) of test tubes, enabling fast studies of obtaining crystals. This low-budget, portable device (i.e. adjustable airstream with more simple control options), can also be applied in tube and chamber furnaces. The relations between the crystallization rate and parameters of air-cooled test tube are given and numerically analyzed.
基金Project supported by Hebei province Natural Science Foundation of China (Grant No A200700296)National Natural Science Foundation of China (Grant No 50731005)National Basic Research Program of China (Grant No 2007CB616915/2006CB605201)
文摘This paper applies techniques of containerless processing, drop tube and glass fluxing, to undercool and solidify Ni77P23 alloys. Different diameter spheres were collected at the bottom of a 52-m long drop tube. Both crystalline and amorphous phase were formed in various size specimens due to the different cooling rate. The variation of partial undercooling with bulk undercooling is calculated for the Ni77P23 alloys. The deep undercooling and rapid solidification behaviour of Ni77P23 melts has been analysed with respect to microstructure formation and transition during fluxing and 52-m drop process of undercooled melts.
基金support from 2024 Key Scientific Research Project Plan for Institutions of Higher Education in Henan Province(grant No.24A530006)Kaifeng City Science and Technology Development Plan Science and Technology Research Project(grant No.2303057).
文摘The suspension state of crystals in the crystallizer is one of the important indicators for evaluating the adaptability of the crystallizer.This study adopted the Euler-Eulerian two-fluid model to simulate and analyze the fluid motion of solid-liquid two-phase flow in the industrial-grade DTB crystallization kettle,as well as the phase suspension distribution of crystal particles.The main influencing factors investigated are:the heat transfer effect,the height of the bottom of the crystallizer,the number and position of the stirring paddle,crystal size and crystal volume fraction.Based on the research of Euler-Eulerian method to simulate fluids,the Euler-Lagrangian method was further used to simulate the motion state of particle phases with different particle sizes in the crystallizer.It was found that the designed DTB crystallizer has good recycle mixing effect.The particles can be mixed evenly during the operation,which can fully realize the solid-liquid mixing and suspension effect of the drug under study.
