The Baumé scale was introduced by the French pharmacist Antoine Baumé in 1768 to determine the specific weight in liquids. He developed a scale for liquids heavier than water as well as a scale for liquids lighter than water. The unit of the scale is degree Bé (Baumé).
For liquids with a spec. weight higher than water (e.g. starch flows), the definition is: The number of deg. Bé in a liquid represent the % by mass of sodium chlorite in water at 60 deg. F (15,56 deg. C) giving the same spec. weight (kg/l). As a consequence, one degree Bé represents the spec. weight of 1 % sodium chlorite solved in water at 60 degr. F (15,56 deg. C).
For starch flows (spec. weight > 1,0000 kg/l), the Bé/Spec. weight relation is:
- Spec. weight = 145/(145 Bé) or
- Bé = 145 145/Spec. weight
The Bé scale is independent of temperature (example: a Baume reading of 4,0 always represents a spec. weight of the slurry equal to 1,0285 kg/l, independent of the slurrys temperature).
The advantage of using such a scale is obvious, just by reading the deg. Bé value from a Bé spindle gives the actual spec. weight of the flow.
Baumé table
For use in the starch industry the Bé scale is extended to a Baumé table, in which for each Bé value the related data for spec. weight as well as for concentration in % DS and in g(DS)/l are given. The basic Bé table is made for corn starch suspensions at 60 deg. F (15,56 deg. C). Note: Concentrations in % DS and in g(DS)/l are temperature dependent!
For some other temperatures than 100 deg. F, correction values are given, which are however dependent on temperature as well as on starch slurry concentration.
The data in the table are based on water/(pure)starch suspensions only.
New calculation method for degree Baumé (Bé), spec. weight, concentration % DS and g/l
MAT Consult has now developed a calculation method for the conversion of degree Bé into spec. weight, % DS and g/l or vice versa from % DS into Bé, spec. weight. and g/l or from g/l into Bé, spec. weight. and % DS at any operating temperature between 16 and 52 deg. C (60 125 deg. F) and for starch slurrys containing starch as well as other fractions, such as gluten (protein), fiber and others.
The App "Baumé Calculation" is an indispensable tool for any process-, service/maintenance-, lab. engineer, operator, etc. in the corn-, wheat-, potato-, or other starch type industry as well as for any engineering company or equipment supplier dealing with these industries.
The App "Baumé Calculation" enables calculations in either metric units or in (US) empirical units and allows storing of e.g. a number of samplings results as well as mailing those to recipients (e.g. lab. or process dept.).
Any questions or requests for support for using the App can be addressed to [email protected].
Process calculations for starch processes
MAT Consult has an extensive experience in the design of separation sections for the corn-, wheat-, potato- and tapioca industries and provides process calculations and other process support on request.
MAT Consult
Wim van der Ham