固态发酵生长动力学模拟的研究进展

数学模型是SSF生物反应器设计、优化和操作的重要工具,它不仅可以指导SSF过程生物反应器的设计和操作,而且可以深入分析发酵系统内的各种现象从而控制整个发酵过程。文中综述了近几年SSF过程动力学数学模型的发展,深入分析如何用数学方法描述SSF系统的各种动力学现象,对模拟结果进行讨论,并指出了该模型需要进一步改进的问题。     

移动式填充床固态发酵反应器的设计及单宁酶中试发酵

通过对单宁酶固态发酵工艺分析,结合传统厚层通风制曲的结构,设计了移动式填充床固态发酵反应器。利用设计的固态发酵反应器以发酵茶梗为基质中试化生产单宁酶,探究10、15、20 m3/h通风量对单宁酶中试化发酵效果。结果表明:在通风量为10、15、20 m3/h的条件下,发酵达到的最大酶活分别为8.21、8.08、8.41 U·gds-1,达到最大酶活的时间分别96、120、144 h。利用设计的填充床固态发酵反应器以茶梗为基质发酵生产单宁酶,不仅原料来源广泛、价格低廉,还能有效提高单宁酶酶活。     

固态发酵技术的研究进展

为了对固态发酵机理有进一步的认识,介绍了固态发酵的优点,并对温度、pH值和水活度等工艺控制参数进行了讨论,同时主要对浅盘式反应器、转鼓式反应器、填充床反应器和流化床反应器等固态发酵设备进行了应用研究,最后展望了固态发酵技术的发展前景.     

固态发酵过程中气体传质控制策略的研究进展

固态发酵在一些生物制品的生产及生物处理过程中具有明显的优势,特别是近年来随着对固态发酵理论模型和发酵设备的研究不断深入,固态发酵的应用范围越来越广。对于好氧的固态发酵来说,氧气的传质效率低仍然是工艺优化和提高产量的主要限制因素,同时它也影响了固态发酵生产规模的扩大。该文分析了固态发酵过程中气体传质的原理及过程,并对此提出了一些提高固态发酵过程中气体传质效率的策略,如控制固体基质特性、选择合适的搅拌通风方式等,最后展望了固态发酵技术的发展前景。     

自吸式生物反应器放大方法研究进展

自吸式反应器具有操作简单、传质性能好等优点,特别是不需要空气压缩机等附件,节省了供气机械的投资和运行,在化学工程、环境工程、生化工程中得到了越来越广泛的应用。自吸式反应器内涉及气液两相体系,这种两相流体流动过程中的混合、传热和传质等过程非常复杂,仍有大量问题需要理论解释。文章对自吸式生物反应器的临界转速、吸气速率、功率、气含率和传质系数的理论模型,以及经验公式进行综述,并对其CFD模拟研究进展做出概括,对于自吸式反应器的放大应用有一定的参考价值。     

固态发酵数学模型研究进展

固态发酵是一项很有前景的发酵技术.数学模型是优化固态发酵反应器的设计和操作的重要工具.近年来,由于新型反应器的研制和先进数学模型的建立,固态发酵技术的研究取得了很大成就.本文综述了固态发酵数学模型的研究进展、所得成果,并指出了现有模型需要解决的重要问题.     

采用固定化酵母以带渣的薯干糖化醪进行酒精发酵的研究

研制了海藻酸钙膜片状固定化酵母填充床生物反应器,以带渣的低温蒸煮薯干糖化醪为基质,进行酒精发酵试验,获得了如下结果:淀粉利用率达90％;生物反应器的乙醇生产能力可达32mg乙醇/g凝胶·小时,以床层体积计为9.8g乙醇/l反应器·小时,为传统式酒精发酵罐乙醇生产能力的12倍;操作性能良好,反复活化运转三个月以上,发酵活力未见明显下降。     

压力脉动用于固态发酵过程的研究进展

压力脉动用于固态发酵主要是对一个密闭低压容器内的气相压力施以周期脉动,固体培养基为静态,通过气相的压力波动,使发酵料层内的气相传质由分子扩散变为强制对流扩散。气体产生的力为法向力,利用法向力动量传递手段强化传质。压力脉动发酵系统由空气调节系统和发酵系统两部分组成。压力脉动具有强化功能,可解决固态发酵传热、传质差和难于大规模纯种培养等问题。现已实现纯种培养与大规模产业化生产,在抗生素、酶制剂、有机酸、食品添加剂、生物农药和生物肥料方面得到广泛应用,但也存在操作条件的确定、优化及失水等问题。     

宁波浩邦生物技术有限公司

宁波浩邦生物技术有限公司在分离、传质、传热工程及生物反应器和工艺设计等方面拥有多项国家专利和专有核心技术，在国内外处于领先地位，给食品、制药、环保、电力和医疗等行业提供高新技术产品和系统解决方案。     

脉动热管激励机制强化传热数值研究

文章以脉动热管内传热传质为出发点,利用数值模拟方法,建立二维模型,采用混合模型(Mixture model)和欧拉模型(Euler model)对脉动热管内传热传质进行了研究,通过对计算结果的比较分析确定哪种模型更适合用于研究脉动热管内传热传质的流动过程。     

Influence of heat shock on glycerol production in alcohol fermentation

The influence of single and double heat shocks induced during the exponential growth phase of the Saccharomyces cerevisiae fermentation of cultivar Sauvignon Blanc grape must was examined. Rapid temperature changes from 18 degrees C to 34 degrees C have been applied. The effect of the duration of exposure to a high temperature has been analyzed. By the applications of a single heat shock and a double heat shock, up to 8.2 g l(-1) and 11.0 g l(-1) glycerol have been produced, respectively. To prevent the evaporation of fine wine bouquet compounds during the temperature changes, reflux coolers on the top of bioreactors have been employed. By using this method, glycerol production was increased by up to 65%.     

BioJN发酵技术服务系统PC端的设计、开发及应用

为解决发酵行业传统操作模式的弊端问题,利用Python 3.6设计并开发了BioJN发酵技术服务系统PC端.BioJN系统PC端具有简单明了的操作界面和功能齐全的数据可视化模块,依靠MySQL数据库建立了用于存储、检索和管理数据的完整数据库系统,且在通信模块预留了DDE、OPC DA、OPC UA三种通信接口用于数据采...     

通用发酵罐结构的改进

针对通用型发酵罐普遍存在的问题，对通用发酵罐的搅拌装置、传热装置、通气装置、传动装置、轴封装置、稳流装置等方面结构进行了改进。改进后的发酵罐结构更为简单、合理，具有降低能耗，减少染菌率，提高产量和经济效益。     

A comprehensive review of thin-layer drying models used in agricultural products

Drying is one of the widely used methods of grain, fruit, and vegetable preservation. The important aim of drying is to reduce the moisture content and thereby increase the lifetime of products by limiting enzymatic and oxidative degradation. In addition, by reducing the amount of water, drying reduces the crop losses, improves the quality of dried products, and facilitates its transportation, handling, and storage requirements. Drying is a process comprising simultaneous heat and mass transfer within the material, and between the surface of the material and the surrounding media. Many models have been used to describe the drying process for different agricultural products. These models are used to estimate drying time of several products under different drying conditions, and how to increase the drying process efficiency and also to generalize drying curves, for the design and operation of dryers. Several investigators have proposed numerous mathematical models for thin-layer drying of many agricultural products. This study gives a comprehensive review of more than 100 different semitheoretical and empirical thin-layer drying models used in agricultural products and evaluates the statistical criteria for the determination of appropriate model.     

Supercritical CO2 extraction of oilseeds: review of kinetic and equilibrium models

Mass transfer models on supercritical carbon dioxide (SC-CO2) extraction of vegetable oils are reviewed, that may facilitate the scale-up of laboratory data for industrial design purposes. Reviewed mechanisms of oil transport within the solid matrix include the desorption from the solid, the formation of a shrinking core of condensed oil in a non-adsorbing porous matrix, and diffusion in a homogenous medium. Analyzed simplificat ions of a general mass transfer model include external control of mass transfer rates, internal control of mass transfer rates, consideration of a linear driving force, and steady state approximations, among others. More complex two-stage models, and critical comparisons of some of the proposed models are also included. Trends for the external mass transfer coefficient and effective diffusivity in the solid matrix from studies on SC-CO2 extraction of oil from vegetable substrates are thoroughly discussed and contrasted with those obtained using simpler model systems. The possible effect of the axial dispersion on the rate of extraction is also discussed. Finally, the high-pressure vegetable oil-CO2 phase equilibrium is discussed in connection with its influence on the mass transfer process. Special emphasis is given to the role of the solid matrix on high-pressure phase equilibrium.     

短管节流件的流量特性

制冷剂流经短管节流件时具有两相临界流动非均匀性、非平衡性的特点并存在阻塞情况 ,而影响质量流量的主要参数有上游压力、下游压力、过冷度或干度以及短管几何尺寸等 .近年来有关制冷剂流经短管节流件的两相流动模型主要有由实验结果直接关联的半经验模型和基于一些假设而建立的分析模型 ,而它们都是针对某种工质而言的 ,不适应当前空调制冷及热泵系统所采用的工质种类较多的状况 .因此 ,建立普适性好、在热力学参数变化较宽的范围内仍有较高精度的质量流量模型是有待进一步研究解决的问题 .     

The application of computational fluid dynamics codes to simulate heat and moisture transfer in stored grains

An aim of stored-grains technologists has been to develop robust and flexible mathematical analyses of the heat and moisture transfer phenomena that occur in bulks of stored grains. A requirement has been that the models are able to simulate the wide range of storage geometries and operating conditions that occur in practice. Software packages developed from the discipline of computational fluid dynamics offer these possibilities. Such packages can be used to attack an extremely wide range of problems by solving the equations that govern the conservation of heat, mass and momentum. However, they need to be customised if they are to calculate velocity, temperature and moisture distributions in bulk stored grains. This paper demonstrates how these modifications can be made and how the results can be portrayed graphically in a way that permits insights into the processes that occur in grain stores.