Surface Character and Integrity of Multi-Component Systems During Spray Drying

喷雾干燥过程中多组分系统的表面特性和完整性

基本信息

批准号：
EP/G042527/1
负责人：
Andrew Stapley
金额：
$ 5.9万
依托单位：
Loughborough University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2009
资助国家：
英国
起止时间：
2009 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FG042527%2F1
关键词：
Surface Character Integrity Multi Component

项目摘要

Food powders are commodity products which constitute an important category of food ingredients worldwide. They are typically produced by the spray drying method in which a solution or suspension is sprayed into a chamber and contacted with hot air to dry the atomised droplets and form particles. These commodity products are made with very low margins, which makes it economically difficult to improve the properties of such powders by changing their bulk composition. However, for many properties (such as stickiness and wettability) it is the surface of the powder that is important as it is the surface that interacts most directly with its environment. The proposed Visiting Researcher, Dr Jim Jones, has found that the surface composition of spray dried powders containing fats can be influenced by changes in processing conditions (chiefly outlet air temperature) and the addition of small amounts of surfactants. This potentially offers a route by which added value can be given to powders by tailoring the surfaces at relatively modest cost. This proposal described here aims to acquire a greater understanding of the mechanisms determining how food components distribute (or partition) themselves between the main body and the surface of a powder during drying, and how this can be influenced by changing process conditions and using small amounts of additives. This will be achieved by a combined experimental and mathematical modelling approach. The modelling will seek to estimate the scale of recirculating flows within droplets which may help or hinder the partitioning of components. All the experimental and modelling results will then be used to produce a mechanistic model for the partitioning of components during drying. The project will involve Dr. Jim Jones of the Department of Chemical Engineering of Massey University in New Zealand working in collaboration with Dr. Andy Stapley and Prof. Chris Rielly at the Department of Chemical Engineering at Loughborough University for a period of seven months, as a Visiting Researcher. The project will study the spray drying of food-based suspension-emulsions containing small, but variable, amounts of thickeners and plasticisers (which alter the viscosity) and surfactants. Dr Jones will use the Fellowship to perform a set of experiments whereby feed composition and outlet temperature are varied, and the product materials (particularly surface composition) are analysed using a variety of characterization techniques available at Loughborough. He will collaborate with Dr Stapley in the design of the experiments and in the development of a mechanistic model, and they will both collaborate with Prof Rielly who will perform computational fluid dynamics (CFD) modelling. The CFD modelling will first be performed to calculate the flow fields within a whole spray dryer to assess the forces acting at the surfaces of droplets. This information will then be used as input to separate simulations which will model the circulating flow within drying drops. The information gained will help to assess whether recirculation within droplets helps or hinders partitioning. Once this is understood a mechanistic model for partitioning will be developed, and ultimately provide operational recommendations for manufacturers to make designer surfaces for powders.

食品粉是构成全球食品成分的重要类别的商品产品。它们通常是通过喷雾干燥方法产生的，在该方法中，将溶液或悬浮液喷洒到腔室中，并与热空气接触以干燥雾化的液滴并形成颗粒。这些商品产品的利润率非常低，这在经济上很难通过改变其散装组成来改善此类粉末的特性。但是，对于许多特性（例如粘性和润湿性），粉末的表面很重要，因为它的表面与环境最直接相互作用。拟议的来访研究人员吉姆·琼斯（Jim Jones）博士发现，含有脂肪的喷粉的表面组成可能会受到加工条件变化（主要是出口空气温度）的变化和少量表面活性剂的影响。这可能提供了一条路线，可以通过以相对适中的成本来定制表面，从而给粉末提供附加值。此处描述的该提案旨在对决定食物成分在干燥过程中如何在主体和粉末表面之间分布（或分隔）的机制有更深入的了解，以及如何通过变化的过程条件以及使用少量添加剂来影响这。这将通过一种结合的实验和数学建模方法来实现。该建模将旨在估算液滴中循环流的规模，这可能有助于或阻碍组件的分区。然后，所有实验和建模结果将用于生成一种机械模型，用于在干燥过程中分配组件。该项目将涉及新西兰梅西大学化学工程系的吉姆·琼斯（Jim Jones）博士与安迪·斯塔普利（Andy Stapley）博士和克里斯·瑞尔利（Chris Rielly）博士合作，在拉夫堡大学化学工程系的克里斯·瑞尔利（Chris Rielly）教授担任七个月的化学工程系。该项目将研究含有小但变化的食物悬浮液乳液的喷雾干燥，这些乳液的增稠剂和增塑剂（会改变粘度）和表面活性剂。琼斯博士将使用奖学金进行一组实验，从而将饲料成分和出口温度变化，并且使用多种在拉夫伯勒（Loughborough）提供的特征技术分析产品材料（尤其是表面组成）。他将在实验设计和机械模型的开发中与斯塔普利博士合作，他们都将与Rielly教授合作，Rielly教授将执行计算流体动力学（CFD）建模。首先将执行CFD建模，以计算整个喷雾干燥机中的流场，以评估作用在液滴表面上的力。然后，该信息将用作单独模拟的输入，该输入将模拟干燥液滴中的循环流。获得的信息将有助于评估液滴内的再循环是否有助于或阻碍分区。一旦理解了这一点，将开发出一种用于分区的机械模型，并最终为制造商提供操作建议，使制造商制作粉末的设计师表面。