IMPROVEMENTS IN REFINING SUGAR
Year: 1882

page_text: LETTERS PATENT to Alexander Scott, Junior, Joseph Duncan Scott, and
Thomas Robertson Ogilvie, all of Greenock, in the County of Renfrew. North
PROVISIONAL SPECIFICATION left by the said Alexander Scott j', Joseph
Duncan Scott, & Thomas Robertson Ogilvie at the Office of the Commissioners
of Patents on the 9th May 1882.
ALEXANDER SCOTT, Junior, JOSEPH DUNCAN SCOTT, and THOMAS ROBERTSON
OGILVIE, all of Greenock in the County of Renfrew, North Britain, "IMPROVEMENTS
IN REFINING SUGAR
وو
This Invention relates to one of the principal operations in the processes of
refining sugar and which has for its object the. removal from the raw material of
the various matters mixed with it that are insoluble in water. In this operation
as usually practised a solution of the sugar in water is made of a strength of about
28 degrees Beaumé and is filtered through cloth bags arranged in a form known as
Taylor filters. The saccharine solution especially when made from cane sugar of
an inferior grade deposits gummy and other matters in or on the filter cloth which
very soon seriously retard the passage of the solution and render the subsequent
complete removal of saccharine matter from the deposited or separated sludge
difficult and protracted
By the present Invention the filtration of saccharine solutions and the washing
of the insoluble matters separated from such solutious are rendered more expeditious
and economical by the use of one or other of the alkaline earths, an insoluble
Compound of such earth being either formed in the solution or introduced therein
in a finely granulated state or as a powder such as is obtainable by precipitation,
and being mixed with the solution in the ordinary "blow-up" or other convenient
vessel. The insoluble earth compound entangles the gummy and insoluble matters
in the saccharine solution, and whilst the combination thus formed remains
sufficiently granular and permeable it prevents the filling up of the pores of the

page_text: filtering cloth. Any saccharine matter adhering to the earthy and gummy
combination is afterwards removed therefrom with comparative ease.
In carrying out the Invention it is preferred to employ sulphate of lime which
has been freshly prepared by adding sulphuric acid to milk of lime. In ordinary
cases from 2 to 20 parts by weight of the sulphate of lime may be added to every
1000 parts of the saccharine solution; but the best proportion in different cases
can be easily ascertained by trial. Freshly precipitated carbonate of lime may be
used instead of the sulphate; or milk of lime may first be added to the saccharine
solution, and this may afterwards be neutralised by adding dilute sulphuric acid,
or by passing carbonic acid through the solution. Any insoluble compound or salt
of an alkaline earth may be used whether it be a bye-product of some other
manufacturing process, or specially prepared or formed in any manner provided it
is in a suitable finely granulated condition and is free from soluble matters. Where
convenient lime in the form of sucrate of lime may be added to the saccharine
solution and be subsequently converted therein into carbonate or sulphate.
The earthy compound is by preference mixed with or formed in the saccharine
solution when the solution is in a cold state; but as soon as the combined
precipitate of the earth and gummy and other insoluble matters has been formed
the solution may be heated to 150 degrees Fahrenheit or whatever temperature is
usual or considered best for the filtering operation, which may be effected in filter
presses or in any other suitable filtering apparatus.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Scott jr, Joseph Duncan Scott, & Thomas Robertson
Ogilvie in the Great Seal Patent Office on the 7th November 1882.
ALEXANDER SCOTT, Junior, JOSEPH DUNCAN SCOTT, and THOMAS ROBERTSON
OGILVIE, all of Greenock, in the County of Renfrew, North Britain, "IMPROVEMENTS
IN REFINING SUGAR"
Our said Invention relates to one of the principal operations in the processes of
refining sugar and which has for its object the removal from the raw material of
the various matters mixed with it that are insoluble in water. In this operation
as usually practised a solution of the sugar in water is made of a strength of about
28 degrees Beaumé, and is filtered through cloth bags arranged in a forin known as
Taylor's filters. The saccharine solution, especially when made from cane sugar of
an inferior grade, deposits in or on the filter cloth gummy and other matters which
very soon seriously retard the passage of the solution, and render the subsequent
complete removal of saccharine matter from the deposited or separated sludge
difficult and protracted.
By our present Invention the filtration of saccharine solutions, and the washing
of the insoluble matters separated from such solutions are rendered more expeditious
and economical by the use of one or other of the alkaline earths, an insoluble
compound of such earth being either formed in the solution or introduced therein
in a finely granulated state or as a powder such as is obtainable by precipitation,
and being mixed with the saccharine solution in the ordinary "blow-up" or other
convenient vessel. The insoluble earth compound entangles the gummy and
insoluble matters in the saccharine solution; and whilst the combination thus
formed remains sufficiently granular and permeable it prevents the filling up of the
pores of the filtering cloth. Any saccharine matter adhering to the earthy and
gummy combination is afterwards removed therefrom with comparative ease.
In carrying out our Invention we prefer to employ sulphate of lime which has
been freshly prepared by adding sulphuric acid to milk of lime. In ordinary cases
from 2 to 20 parts, by weight, of the sulphate of lime may be added to every
1000 parts of the saccharine solution; but the best proportions in different cases
can be easily ascertained by trial. Freshly precipitated carbonate of lime may be
used instead of the sulphate; or milk of lime may first be added to the saccharine
solution, and this may afterwards be neutralised by adding dilute sulphuric acid,
or by passing carbonic acid through the solution. Any insoluble compound or salt
of an alkaline earth may be used, whether it be a bye-product of some other
manufacturing process, or specially prepared or formed in any suitable manner
provided it is in a suitable finely granulated condition and is free from soluble
matters. Where convenient lime in the form of sucrate of lime may be added to
the saccharine solution and be subsequently converted therein into carbonate or
sulphate.
When the earthy compound is formed in the solution no heat is applied until
after the combined precipitate of the earth and gummy and other insoluble matters
has been formed, this feature distinguishing our process from certain known
processes having different objects in view. Also when the earthy compound is
formed separately we prefer to mix it with the saccharine solution in a cold state;
but in either case, as soon as the combined precipitate of the earth and gummy
and other insoluble matters has been formed, the solution may be heated to
150 degrees Fahrenheit or whatever temperature is usual or is considered best for
the filtering operation, which may be effected in filter presses or in any other

page_text: suitable filtering apparatus. The insoluble compound employed as herein before
described may in some cases be used over again with or without washing.
Having thus particularly described our said Invention and the manner of
performing the same we have to state that we do not restrict ourselves to the
precise details hereinbefore described but that what we believe to be novel and
original and claim as the Invention secured to us by and in terms of the
hereinbefore in part recited Letters Patent is.
The improved process for separating gummy and other insoluble matters from
saccharine solutions wherein an insoluble compound or salt of an alkaline earth is
employed to form a precipitate substantially in the manner hereinbefore described.
In Witness whereof I, the said Thomas Robertson Ogilvie, on behalf of the
said Alexander Scott Junior, Joseph Duncan Scott, and myself, have
hereunto set my hand and seal this fourth day of November in the year of
our Lord One thousand eight hundred and eighty-two.
Witness
EDMUND HUNT
Patent Agent
Glasgow.
THOMAS ROBERTSON OGILVIE. (L.S.)