Silicone antifoams are
extensively used throughout the petroleum industry where product or
process foaming problems are encountered. This selector guide
describes a complete line of BMT Silicone Antifoams which have been
found particularly useful in many petrochemical
applications.
In selecting the best type and quantity of
silicone defoamer, the application must be consider separately,
because each petroleum processing system is different and has its
own peculiar needs. In addition to the primary differences of
non-aqueous and aqueous system requirements, there are differences
in the same process when formulations are changed. Thus, factors
such as the chemical nature of the foam forming agent, foaming
tendency, its solubility and concentration, the presence of
electrolytes, colloids or other surface active agents in the system,
temperatue, pH and viscosity of the system, as well as the type of
equipment involved must be considered.
For maximum defoaming efficiency, a low viscosity silicone should
be used in a high viscosity foaming system, while a high viscosity
silicone should be used in a low viscosity foaming system. This
basic principle takes advantage of the incompatibility of the
silicone which in turn maximises defoaming efficiency. Generally
speaking, it is best to evaluate the several possible antifoams in
each system requiring foam control to determine which will provide
the optium performance at minium concentration in that system. While
one defoamer may provide good performance, another may do even
better.
It is suggested that samples of different silicone antifoams be
obtained for laboratory evaluation. Of course, the best possible
evaluation is obtained only through actual plant trials. Results of
evaluation, combined with defoamer cost figures, will provide the
best method of determining the most efficient and economical
silicone antifoam to meet your specific requirements.
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