农业工程学报Issue(1)：47-54,8.DOI:10.3969/j.issn.1002-6819.2014.01.007
喷雾接种生物颗粒两相流及其对菌种活性的影响
Solid-liquid two-phase flow of microbial particle spraying inoculation and its influence on microbial viability
摘要
Abstract
Solid-state fermentation (SSF) technology has a very wide range of applications on account of the increasing energy shortage at present, especially on account of short fermentation time, low energy cost, high rate yield of product, and reduced environmental pollution for SSF. Currently, solid-state fermentation equipment should also adapt to this extensive demand. In order to create good production conditions, ensure pure solid-state fermentation, and the high quality of products, the inoculating tube must be arranged into the hermetic bioreactor. After sterilization, the nozzle of the inoculation spraying system can spray the microbial strain on the solid substrate, to realize sterilizing, cooling, inoculation, and fermentation inside one solid-state fermentation bioreactor. The microbial viability may be determined by the spraying system of the spraying inoculation of pure-culturing solid-state fermentation that could directly result in the death of the microorganisms. The solid-liquid two-phase flow of the microbial particle spray inoculation fluid system was analyzed. Fluid characteristics of the two-phase flow composed of microorganisms and sterile water was discussed, and the forced state of the microorganism particles was also analyzed. The energy component was deduced, and the theoretical basis, reliability, and practicability of the energy dissipation rate which could quantify the microbial particles’ damage within comprehensive hydrodynamic stresses were also discussed and analyzed. The effect of nozzle type and spraying parameters on the results of the spraying inoculation was studied by a simulation using FLUENT. A user-defined function was created in FLUENT to compute the energy dissipation rate from the flow field information. By setting reasonable boundary conditions and initial conditions, simulations of a hollow cone nozzle’s flow field of the pressure and energy dissipation rate were conducted for each size of the nozzle and the experimental inlet pressure. A set of spraying inoculation experimental flow devices was designed and manufactured. At the same time, an appropriate test method was determined. Microzyme was selected as the microbial particle in the spraying inoculation experimental system because it was easy to separate the living microzyme from the dead microzyme. It could be dyed with Loeffler basic methylene blue dye and the living microzyme with a strong reducing ability is colorless and the dead or weak dying microzyme is blue under microscope. Experimental and simulation results showed that it was feasible to use a spraying inoculation to realize automation and a pure solid state fermentation process and to ensure uniformity of the inoculation. The best spraying characteristic parameters could be found to ensure microbial viability after inoculation. It could be found that the maximum energy dissipation rate of different size nozzles were different. The larger the hollow cone nozzle size and the inlet pressure were, the higher the maximum energy dissipation rate and the mean mortality of microzyme became. Simulation results showed that the maximum energy dissipation rate in the hollow cone nozzle was not at the outlet, but at the junction of the tangent of two narrow ports and the swirl chamber. The results could provide the foundation for the applications of both the spraying inoculation of pure-culturing solid-state fermentation and the biological pesticide spraying, and could provide the references for studying the effect of other types of nozzles on the microbial viability.关键词
喷雾/喷头/两相流/计算流体力学/接种/酵母菌/能量耗散率Key words
spraying/nozzles/two phase flow/computational fluid dynamics/inoculation/microzyme/energy dissipation rate分类
化学化工引用本文复制引用
李建华,郑加强,余果..喷雾接种生物颗粒两相流及其对菌种活性的影响[J].农业工程学报,2014,(1):47-54,8.基金项目
江苏省普通高校研究生科研创新计划项目 （）
