ISSN:0009-286X    

DOI:10.1002/cite.330621002

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractWhat does statistical thermodynamics do for the chemical engineer?Statistical thermodynamics introduces molecular properties of a particular system into model equations for the thermodynamic functions of fluid mixtures. It thus contributes to the prediction, extrapolation or estimation of fluid properties, in particular phase and reaction equilibria, which are fundamental to numerous processes in thermochemical engineering. For systems of small, rigid molecules, as frequently encountered in natural gas and refrigeration applications, this method has reached a high level that is beginning to be introduced into industrial practice. For systems of complicated organic molecules, models from molecular thermodynamics have firmly established themselves in industrial applications.

ISSN:0009-286X    

DOI:10.1002/cite.330621003

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractAerosol formation on absorption and partial condensation.The phenomenon of aerosol or mist formation on absorption and partial condensation has hardly been investigated but causes serious problems in the practice of industrial exhaust air purification, e.g. in the absorption of hydrogen chloride or on low‐temperature condensation of solvent vapours. The mist droplets formed in these processes remain suspended in the gas phase and lead to unacceptably high pollutant concentrations in the exhaust air. This present study first surveys currently available knowledge and then goes on to explain under what thermodynamic boundary conditions aerosols are formed by certain substance systems. The author also applies known results relating to nucleation and growth mechanisms from aerosol physics to technical processes. It is seen that aerosols with very small droplet sizes, which are difficult to precipitate, are formed particularly during absorption processe

ISSN:0009-286X    

DOI:10.1002/cite.330621004

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330621005

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractScale‐up problems in experimental process development.The experimental process development of a new product can be performed in test facilities of varying dimensions. Small miniplants from a laboratory scale up to larger pilot plants, in which a few tons of product per day can be produced, are used. The scale‐up factors, the risks involved in process and construction design, and a possible necessity of a limited production are important criteria for the size of the first technical realisation of the new process. The following examples highlight some special problems and their solutions in the experimental process development. Whereas a process, involving mainly fluids can be developed relatively well in a miniplant (laboratory scale), it is normally necessary to work on process development for a solid product involving difficult solid handling in a larger pilot plant. At the end of the paper some other scale‐up criteria for process design are expl

ISSN:0009-286X    

DOI:10.1002/cite.330621006

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330621007

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractQuality assurance in process engineering with solids.The properties of solid products depend not only on chemical composition but also on the state of dispersion. The knowledge of the effect of the state on the product quality is necessary for the development, production, and handling of disperse systems. The most important step of quality assurance and quality improvement is to find a way to define the quality of product by objective criteria, allowing a reproducible control based on measurements. After defining the criteria and tolerances for quality assurance, a layout for a reproducible and controllable processing must be developed and realized on a suitable plant. It is important to define quantifiable criteria for the product state in early stages in order to recognize deviations as early as possible. This is necessary to compensate fluctuations by the means of process control. It is not sufficient to do this separately for each process step but the whole process must be considered. Nevertheless a model for the whole process, which is able to describe the correlations between product properties, processing properties, and product quality, should be available in order to recognize the quality‐sensitive parameter

ISSN:0009-286X    

DOI:10.1002/cite.330621008

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330621009

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractContinuous fluidized bed spray granulation.Spray granulation in a fluidized bed can transform originally liquid products (suspensions, melts, solutions) into freeflowing, largely dust‐free granular solids. In the ideal case, the process steps of nucleation, drying/crystallization, shaping, and selective exiting of those particles which have reached the desired size proceed simultaneously in a single unit. The present contribution describes the state of the art of this process as presented in the literatur

ISSN:0009-286X    

DOI:10.1002/cite.330621010

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330621011

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY