1,720,972 research outputs found
Determination of the Heat Transfer Coefficient in Polymerization Reactors by Temperature Oscillation Calorimetry
No full textThe use of different calorimetric techniques permits the determination of global kinetic and thermodynamic parameters as well as heat transfer, stirrer power and safety data under a wide range of operations. In this work emphasis is put on the use of Temperature Oscillation Calorimetry, an innovative technique that allows quasi-isothermal heat flow calorimetric studies under conditions of variable heat transfer. The data obtained using different calorimeters are in good agreement
La calorimetria di processo: uno strumento per il monitoraggio e controllo di reattori industriali
No full textDevelopment of a flexible low cost system of lab scale calorimeters
No full textA simple, low cost system of laboratory scale calorimeters is being developed in our laboratory for research, teaching and routine purposes. The system is computer controlled and has been assembled from commercially available components. Its use will be illustrated by a study of the hydrolysis of acetic anhydride
Determination of the heat transfer coefficient in polymerization reactors by temperature oscillation calorimetry
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Applicazione della Calorimetria a Temperatura Oscillante allo studio di processi di polimerizzazione
No full textTemperature Oscillation Calorimetry (TOC) is a technique for the on line determination
of heat transfer coefficient UA, and is therefore suitable for studying processes where there
is a large increase in the viscosity and a consequent decrease in UA as the reaction
proceeds.
The free radical polymerization of methyl methacrylate in ethyl acetate has been studied
in a stirred, jacketed calorimeter with a volume of two litres. Sinusoidal temperature oscillation
of amplitude 1-2°C and period 5-6 minutes are imposed on the fluid circulating in
the jacket. The heat transfer coefficient is obtained from an analysis of the oscillating
parts of the jacket and reactor temperatures, while the chemical heat flow is obtained from
the non-oscillating parts of these temperatures.
The results obtained show the utility of TOC in studying polymerization processes. A limitation
has been encountered with concentrated solution where both the temperature
oscillation and the value of UA may become irregular. Under these conditions a correlation
between UA and the stirred torque may be used to correct the values of UA
Analisi di sicurezza di processi altamente reattivi mediante l'uso di tecniche calorimetriche integrate
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