Modelling Quality in Spray Drying: *da book*
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Contents

1.	Introduction	1
	Description of the problem	2
	The objective of this research project	3
	Outline of this thesis	4
	Note	5
	References	5
2.	Measurement and modelling of the airflow pattern	11
	Introduction	12
	Modelling the airflow pattern	13
	Present knowledge in literature	13
	Theory of CFD modelling	13
	Characteristics of the flow solver used	14
	Set-up of the problem in the flow solver	15
	The calculated flow field, convergence, and grid dependence	16
	The determination of the inlet conditions and the air flow pattern	18
	Flow conditions at the air inlet	18
	Hot-wire anemometry	19
	Experimental set-up and results	21
	Hot-wire set-up	21
	Measurements in the air inlet	21
	Measurement of the airflow pattern in the drying chamber	23
	Discussion	26
	Conclusion	27
3.	A device for measuring temperatures and humidities	29
	Introduction	30
	Devices described in literature	30
	Basic idea	32
	Simulation	32
	Results	34
	Design and construction	36
	Measurements	37
	Conclusion	37
4.	The temperature and humidity pattern	39
	Introduction	40
	Model	41
	Experiment	46
	Results and discussion	49
	Conclusion	55
5.	Particulate residence time distributions	59
	Introduction	60
	Model	60
	General description of the model	60
	Particle tracking	61
	Heat and mass transfer	62
	Experiment	63
	Approach	63
	Experimental set-up	64
	Results and discussion	66
	The airflow, temperature, and humidity pattern	66
	Calculation of particle residence time distributions	68
	Conclusion	73
6.	Thermal degradation	75
	Introduction	76
	Model	77
	Degradation and drying of a single particle	77
	Air temperature and humidity histories	78
	Experiment	79
	Choice of model system	79
	Analysis of the degradable compound	80
	Spray drying experiments	81
	Numerical solution	82
	Calculation methods	82
	Computational fluid dynamics	82
	Calculation of thermal degradation	83
	Relationships for drying rate and degradation rate	84
	Results and discussion	85
	Conclusion	89
7.	Discussion and conclusion	93
	Summary of the followed approach and the results presented in this thesis	93
	Validation and use of CFD in quantitative predictions of product quality	94
	CFD in the design of spray dryers and spray drying processes	95
	The use of CFD in industry	98
	Conclusion	99

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