IMPROVEMENTS IN THE MANUFACTURE OF STARCH, GLUCOSE, AND OTHER STARCH PRODUCTS
Year: 1885

page_text: COMPLETE SPECIFICATION,
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for IMPROVEMENTS IN
THE MANUFACTURE OF STARCH, GLUCOSE, AND OTHER STARCH PRODUCTS (a com-
munication to me from abroad by The Davenport Glucose Manufacturing Company
of Davenport in the County of Scott and State of Iowa United States of America,)
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :—
This Invention relates to the manufacture of starch, glucose, and other subsequent
starch products from corn and other grain, and consists in precipitating the starch-
milk after it comes from the separators with sulphuric acid whereby ammoniacal
putrefaction is immediately stopped and the separation of solid matter therein
more rapidly and effectually obtained, and it furthermore consists in the subsequent
treatment of the residue after the acid water has been drawn off, with dilute
sulphuric acid and passing of the liquid over the starch depositors where the starch
settles in a hard mass, nearly free from gluten and other impurities of the grain
substantially as hereinafter set forth.
Heretofore in the manufacture of starch from corn and other grain, the efforts
of those engaged in such production have been principally directed to liberating
the starch from the cells of the grain, and for this purpose a solution of caustic
soda has been used with more or less success by means of apparatus in which the
prepared starch-stock and water was first passed through a separator into a settling
vat, and, after the water had been decanted, the caustic alkali added and the mass
then agitated and pumped into a depositor where the starch was deposited and
the gluten, dissolved by the alkali, passed off, after which the starch was again
mixed with water, agitated, settled, and drained. Conspicuous among the
advantages of this process was the destructive action of the soda on the ferments
which by their interference prevented the starch from settling in a hard mass on

page_text: the long planes used for the purpose. It was accordingly invariably required to
add a surplus of caustic alkali in order to obtain the greatest possible yield of
starch. But the more soda was added, the more albumenoids were dissolved.
A considerable quantity of the lye was accordingly taken up by the starch and it
required several washings to free it again from these impurities. This invention
overcomes these difficulties as follows.
I precipitate with sulphuric acid the starch milk coming from the separators and
collected in tanks; the liquid containing from 0.1 to 0.2 per cent sulphuric acid,
more or less The acid stops fermentation and ammoniacal putrefaction instantly
and the separation of the solid matter is effected in a much shorter time than by
the ordinary process of settling. The acid water containing most of the soluble
constituents of the corn or other grain is drawn off and the residue again stirred
up in dilute sulphuric acid of about 0.1 to 0.2 per cent, SO, H. This liquid is
then allowed to flow over the starch planes where the starch settles in a hard mass
nearly free from gluten and other impurities of the corn or grain.
The starch manufactured by this process contains a small quantity of sulphuric
acid which however is of no detriment when the starch is to be used in the
manufacture of glucose or grape sugar. In cases where the remaining acid would
be injurious, it can be neutralized with soda or other alkali and the sulphates
washed out in the ordinary way.
The advantages of this improved process, over the soda process, are, first the
immediate stoppage of fermentation and ammoniacal putrefaction, whereby the
starch and offal are obtained in a much purer state. Secondly the the process will
be found much less costly than the soda one heretofore practised, and thirdly, no
gluten is lost in a soluble form as the general effect of the process is to dissolve as
little as possible of the ground grain.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed I declare that what
I claim is
1. The process of arresting ammoniacal putrefaction in the starch milk, after it
has been separated and precipitating the solid matter more quickly and effectually,
which consists in adding to the ground up grain or starch liquor, sulphuric acid
substantially in the manner and for the purposes described.
2. The process herein described of manufacturing starch, glucose and other starch
products from corn and other grain, which consists in first passing the crushed
grain and water through separators, then precipitating the separated starch milk
with sulphuric acid, then drawing off the acid water and soluble constituents of
the grain contained in it, and stirring up the residue in dilute sulphuric acid, and
afterwards passing the liquid thus obtained over the starch depositors, substantially
as and for the purposes specified.