The neat soap
coming either from a modern continuous saponification plant or
from a traditional batch saponification plant has a temperature
of about 80 °C and a 30 % water content.
This soap must be cooled before it can be converted into bars
or tablets. When this operation is performed in vacuum spraying
plant some moisture evaporates with a relevant increase of its
TFM content.
The TFM content
of the neat soap is ca. 63 %, while a "good" laundry
soap may have 72 % TFM.
To reduce costs in laundry soap the TFM content can be reduced
even below the 63 % by the addition of builders and fillers.
Builders have the effect to improve the detergency while fillers
only increase the production yield. The builders generally are
sodium silicate or sodium carbonate. Usually the addition of
builders or fillers is carried out in a crutcher before feeding
the soap to the vacuum plant, or downstream either by liquid
injection or by post-dosing of powder to the already cooled noodles.
Today the vacuum
cooling and drying process is the most commonly used for laundry
soaps because it is flexible and suitable for the production
of a wide range of products.
A Vacuum Cooling and Drying Plant includes the following units:
PRUDUCTION RATES
MECCANICHE MODERNE supplies Vacuum Cooling and Drying Plants
for Laundry Soap from 500 to 6000 kg/hour production rate.
FLOW SHEETS
The following pages present Flow Sheets of typical installation
for Vacuum Cooling and Drying.
