Archive for the ‘Heat Transfer’ Category
By : M.B Mwaba
Eindhoven Technische Universiteit Eindhoven
An example of a process industry where scaling leads to high economic penalties is the manufacture of sugar from cane sugar. In this thesis, the problem of scaling of heat exchangers in the cane sugar industry is studied. A cane sugar factory in Zambia is used as an example. Deposit samples taken from juice and syrup heaters are analysed so as to identify the scale causing components. From samples investigated it is found that CaSO4 is the main scale causing component Further particles are found in both the deposit samples and the process. This leads to the conclusion that crystallization of CaSO4 is the main cause for scaling in syrup heaters. Because particles are also present it is concluded that particulate fouling also contributes to deposit formation.
Experiments are conducted in order to study how the various operational parameters affect the scaling process The focus is on the velocity and on the species concentration. No influence is found at low Reynolds numbers. At higher Reynolds numbers. however the rate of scaling decreases Since CaSO4 crystallization is reaction controlled the findings at low Reynolds numbers are not unusual. It is therefor concluded that the decrease observed at higher Reynolds numbers is due to removal effects. Read the rest of this entry »
