IMPROVEMENTS IN TREATING MAIZE FOR THE OBTAINMENT OF FLOUR AND OTHER PRODUCTS, AND IN APPARATUS THEREFOR."
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Robertson Blair Robertson at the
Office of the Commissioners of Patents on the 4th July 1877.
ROBERTSON BLAIR ROBERTSON, of Glasgow, in the County of Lanark, North
Britain. "IMPROVEMENTS IN TREATING MAIZE FOR THE OBTAINMENT OF FLOUR
AND OTHER PRODUCTS, AND IN APPARATUS THEREFOR."
This Invention has for its object, by treating maize by improved processes, to
effect a better or more complete separation of its constituents so as to obtain flour
or starch and oil or fatty matter from it in a more advantageous manner than
heretofore.
In carrying out the Invention the grain is first crushed or broken by passing it
between rollers, or in any other convenient way, and the fragments or crushed
materials are theri carefully sorted according to their sizes. The portions in which
the embryo or germ is found to be concentrated are then exposed to a current of air
in such a manner as to separate the grains according to their specific gravities.
The separated embryo is treated for the obtainment of its oil or fatty matter in
apparatus of the kind commonly used for expressing oil from seeds, fruits, or the
like.
The perisperm from which the embryo has been separated, as herein-before
described, is converted into flour or starch in the ordinary way, and forms a com-
paratively larger yield than is obtained by the processes heretofore in use.
It will facilitate the subsequent processes if the shell or skin of the grain is first
removed, but this should not be done by a wet process.
When the broken grain has been sorted into sizes, each size may be passed
between rollers to assist the separation of the starchy constituents from the
embryo.
In one modification of apparatus for more or less completely effecting the
separation of the heavy perisperm from the light embryo, a circular vessel rotating
about its own axis is employed, and the sorted grain fragments being put into this
vessel the heavy portions are by the centrifugal force thrown to the outer edge,
whilst the lighter portions remain at or nearer the centre. In a second modification,
which may be better adapted for particular sizes of the broken grain, a sieve is

page_text: employed having a jigging motion whilst a current of air is directed through or over
it to carry off the embryo or light portions. Or a scraper for removing the upper
and lighter layer consisting of the embryo may be used in combination with a sieve
In another modification a circular vessel
having a circular or reciprocating motion.
is employed, but is stationary, whilst a rotatory or other suitable motion is imparted
to the broken and sized grain by a central rotating shaft having blades on it.
In some cases the broken and sized grain may be treated for the separation of the
embryo and perisperm by being put into water or a solution which has a specific
gravity intermediate to those of the embryo and perisperm. The result is that the
perisperm sinks whilst the embryo rises to the surface and can be skimmed off or
decanted. When this treatment is employed the embryo must be dried before having
the oil expressed from it.