Study Ice Crystals Mechanism On Fish Ball Boiled Liquid By Freeze Concentration

In the production of fish balls,it will produce a lot of boiled liquid,which contains starch,protein and many other nutrients.If the liquid discarded,then it would not only waste the resources,but also pollute the environment.This study attempts to take the advantage of frozen concentrated technology to concentrate on the boiled liquid,and achieve the purposes of resource conservation and environment protection.At the same time,in the freeze concentration process,the low temperature can maximize the retention of food material,like the food color,smell,taste,etc.However,the solute and entrainment of ice is difficult to be separated,so it limits the promotion of the frozen concentrated technology.In this study,the author applies phase field model,which is a world-famous way to make further explore on mcroscopic growing process of ice crystals fish ball boiled liquid,and analyze ice entrainment mechanism in the frozen concentrated processing.Then provide the theoretical support for frozen concentrated industrialization.Microstructure numerical simulation is widely used in materials science to simulate crystal growth.This simulation method includes deterministic methods,phase-field method and probabilistic methods.The excellent advantage of the phase-field method is that the explorer just need to use phase field variables,and no need to trace solid-liquid interface,which is ideally suited for complex non-equilibrium state of the solid-liquid interface.Currently in the field of microscopic numerical simulation,phase-field method is in the forefront of international research for its powerful advantage.In this paper,the author applies phase-field method to establish phase field model to analyze the frozen concentrated process of two dualistic fish ball boiled liquid and the related factors in influencing the growth of morphology evolution of ice crystal from the microscopic point.This phase-field method provide a theoretical guidance for the freeze concentration of fish ball boiled liquid,and improve the efficiency of freeze concentration.(1)Deducing the Ginzburg-Landau phase transition theory by analyzing the free energy theory,and establish binary phase-field model of fish ball boiled liquid under diffusion conditions.(2)Discretting the phase-field equations into data equation by selecting a suitable calculate method.Using adiabatic boundary conditions—Zero-Neumann boundary conditions processes the boundary.Making the use of the finite difference method to separate solute and phase field equations.Alternating direction iymplicit method(ADI algorithm)processes temperature field equations,At the same time,use the uniform mesh size to discrete space equation,and then improve the calculating efficiency of the mould by saving computing time.(3)Studying the influence of the impact of space step,anisotropic coefficient and the interface thickness on authenticity of the simulation results.And determining the optimal values of these parameters are:the key space step length is 6.0 × 10-7m;the strength anisotropy coefficient is 0.024;and the value of interface thickness is 3dx.then that can ensure to get a reliable simulation morphology of ice crystals at a certain computational rate.(4)Under isothermal crystallization condition,studying the crystallization process of the liquid in different simulation time and degree,analyzing the growth of ice crystals and the directed evolution of it;reproducing the actual crystallization process by tecplot software;studying the solute segregation of ice dendrite growth and ice lateral branching competitive growth process,dendrite tip growth rate,dendrite tip radius of curvature and the solid fraction etc.on ice crystal growth process.The results show that:the shorter of crystallization time,the rapider dendrite growth and the main crystal is thicker.Then the main crystal axis thinner with time,and the secondary dendrite growth and develop to form the void.When the subcooling value increases,it will increase the growth rate of ice crystals and make a faster growth of the secondary dendrite branching,and then ultimately get a higher solid fraction.Meanwhile,the solute segregation of dendrite become more and more serious,and solute effective distribution of dendrite tip is becoming smaller which improved the solute of entrainment.And this is coincided with the classical theory.The conclusions show that the ice crystal growth morphology,solute segregation and the influential parameters of ice crystal growth processes are good agreements with previous experimental results,which illustrate the reliability of the phase-field simulation in solidification structure.And make it a theoretical foundation to frozen concentrated technology,reduce the solute entrainment,promote the frozen concentrated technology industrialization.