Improvements in Apparatus for Separating from Liquors the Scum or Matter which Rises to the Surface during Boiling or Heating.
Year: 1891

page_text: Date of Application, 9th Nov.. 1891
Complete Specification Left, 9th Aug., 1892-Accepted, 17th Sept., 1892
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Separating from Liquors the
Scum or Matter which Rises to the Surface during Boiling
or Heating.
I, ALFRED CHAPMAN, of 17 York Street, Liverpool, Civil Engineer, do hereby
declare the nature of this invention to be as follows:-
My invention has reference to the separation from liquors of the scum or matter
which rises to the surface during the boiling operation and is more particularly
applicable to the treatment of saccharine solutions and especially sugar cane juice
which when boiled up or heated throw off feculencies and vegetable matters if any
are held in suspensiou. As is well known these feculencies retreat from the hottest
to the coldest part of the vessel in which the liquid is boiled up. Various more or
less imperfect devices in which advantage has been taken of this movement of the
feculencies have been adopted for the purpose of separating them from the liquor so
as to obtain a pure bright solution of sugar and water. Strainers have also been
employed through which the clear juice passes, leaving the scum on top, but the
strainers that will permit the juice to pass through them cannot prevent a large
portion of the vegetable matter held in suspension from passing through also.
Now for the purpose of preventing the vegetable matter which is of less specific
gravity than the juice from passing through the strainer, I construct as hereinafter
described an apparatus in which the scums are kept off or prevented passing through
the strainer by means of a quiet body of the liquid. My apparatus which may
appropriately be called an automatic skimmer, eliminator or clarifier is constructed
preferably as follows.
In a rectangular or other vessel into which the juice to be treated is run and which
is provided with means for heating same such as a steam worm, I form near one side
a partition extending from a short distance, say about three inches, from the bottom
of the vessel to some distance above the level of the liquor when not boiling. From
the top edge of this partition a cover plate extends to another partition which is in a
skimming pan at the side of the heating vessel and extends down to say an inch
from the bottom of this pan. In this pan at a level below that of the top edge of
the partition is a strainer or perforated plate. The side of the pan which is next
the heating vessel is at the same level as or preferably somewhat higher say one-
eighth of an inch than the perforated plate, and this side forms in combination with
the partition in the pan a sort of trap through which the liquor after passing through
the strainer returns from the pan to the heating vessel.
The action of the apparatus is as follows: High pressure steam having been
turned into the worm the liquor in the heating vessel quickly boils and the foam and
scum rise and pass over the top edge of the partition plate and over the cover plate
and come upon the strainer. The juice passes through the strainer until it fills up
that part of the pan which is below; it then begins to flow over the side of the pan
into the heating vessel and passing under the bottom edge of the partition in the
heating vessel it becomes again exposed to the action of the steam worm and again
boils up over the top of the partition; the liquor may thus be caused to make as
many circuits through the skimming pan as may be judged necessary.
The scums do not pass through the strainer because being lighter than the juice
they will float on top of it and as by the construction herein before described the
juice in the pan is kept at the level of the strainer or a little above it there is no
tendency for the scums to pass through the strainer or to stop up the perforations,
they are in fact kept up by the quiet body of juice in the pan below the strainer.
When the operation is finished the scums can easily be removed by an ordinary

page_text: skimmer without any fear of removing good liquid with them because all the clean
liquid has returned to the heating liquid except that left in the pan and this portion
can be run off into the vessel by opening a cock on a connecting pipe.
In order to apply my invention to skimming pans of a kind now in use having a
skimming gutter all round the upper part, I place concentrically within the body of
the pan a vertical cylinder or pipe of about six inches less diameter than the pan,
so as to leave a space between them. The lower end of the cylinder does not reach
the bottom of the pan while its upper edge is turned over outwards so as to dip into
the gutter and form with the inner edge of the gutter the sort of trap hereinbefore
described through which the juice or liquor returns from the gutter to the body
of the pan.
The space between the said turned over edge and the outside of the
gutter is covered with a strainer. The body of the pan has a steam worm or other
means for heating it, and when the liquor has boiled up the foam and scum rise, pass
over the turned over edge of the cylinder and come upon the strainer. The juice
passes through the strainer and when it has filled the gutter below it begins to flow
through the trap back to the body of the pan.
Dated this 9th day of November 1891
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Chartered Patent Agent.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Separating from Liquors the
Scum or Matter which Rises to the Surface during Boiling
or Heating.
I, ALFRED CHAPMAN of 17 York Street, Liverpool, Civil Engineer, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
My invention has reference to the separation from liquors of the scum or matter
which rises to the surface during the boiling operation and is more particularly
applicable to the treatment of saccharine solutions and especially sugar cane juice
which when boiled up or heated throw off feculencies and vegetable matters if any
are held in suspension. As is well known these feculencies retreat from the hottest
to the coldest part of the vessel in which the liquor is boiled up Various more or
less imperfect devices in which advantage has been taken of this movement of the
feculencies have been adopted for the purpose of separating them from the liquor
so as to obtain a pure, bright solution of sugar and water. Strainers have also been
employed through which the clear juice passes, leaving the scum on top, but the
strainers that will permit the juice to pass through them cannot prevent a large
portion of the vegetable matter held in suspension from passing through also.
Now for the purpose of preventing the vegetable matter which is of less specific
gravity than the juice from passing through the strainer I construct as hereinafter
described an apparatus in which the scums are kept off or prevented passing through
the strainer by means of a quiet body of the liquor. My apparatus which may
appropriately be called an automatic skimmer, eliminator or clarifier, is constructed
preferably as about to be described and as illustrated in vertical section in Figure 1
of the accompanying drawings.
In a rectangular or other vessel such as A into which the juice or liquor to be
treated is run and which is provided with means for heating same such as a steam
worm W, I form near one side a partition B extending from a short distance, say
about three inches from the bottom of the vessel A to some distance above the level
of the liquor when not boiling. From the top edge of this partition B a cover
plate C extends to another partition D which is in a skimming pan or trough such
as E at the side of the vessel A and extends down to say an inch from the bottom
of this pan. In this pan at a level below that of the top edge of the partition is a

page_text: strainer or perforated plate F. The side G of the pan E which is next the heating
vessel is at the same level as or preferably somewhat higher, say one-eighth of an
inch than the perforated plate F, and this side G forms in combination with the
partition D in the pan a sort of trap through which the liquor after passing through
the strainer F returns from the pan E to the heating vessel A.
The action of the apparatus is as follows:-High pressure steam having been
turned into the worm W the liquor in the heating vessel A quickly boils and the
foam and scum rise and pass over the top edge of the partition B and over the cover
plate C and come upon the strainer F. The juice passes through the strainer until
it fills up that part of the pan E which is below; it then begins to flow over
the side G of the pan into the heating vessel A and passing under the bottom edge
of the partition B in the heating vessel it becomes again exposed to the action of
the steam worm and again boils up over the top of the partition B; the liquor may
thus be caused to make as many circuits through the skimming pan E as may be
judged necessary.
The scums do not pass through the strainer F because being lighter than the
juice they will float on the top of it and as by the construction_hereinbefore
described the juice in the pan E is kept at the level of the strainer F or a little
above it there is no tendency for the scums to pass through the strainer or to stop
up the perforations; they are in fact kept up by the quiet body of juice in the pan
below the strainer. When the operation is finished the scums can easily be removed
by an ordinary skimmer without any fear of removing good liquor with them
because all the clean liquor has returned to the heating liquor except that left in the
pan, and this portion can be run off into the vessel by opening a cock on a connecting
pipe H.
It will be evident that the construction of my apparatus can be considerably
varied while retaining the characteristic feature of the invention, that is to say an
apparatus in which a quiet body of the boiling or hot liquor being maintained at, or
a little above the level of a strainer through which the liquor while circulating
flows downwards, keeps the scums off or prevents them passing through the strainer.
In order to apply my invention to skimming pans or heating vessels of a kind now
in use having a skimming gutter all round the upper part as shown in Figure 2 in
which A is the skimming pan or heating vessel and E the skimming gutter, I place
concentrically within the body of the pan A a vertical cylinder or pipe B of about
6 inches less diameter than the pan, so as to leave a space between them. The
lower end of the cylinder which may be made removable for cleaning does not
reach the bottom of the pan while its upper edge is turned over outwards at C so
as to dip at D into the gutter E and form with the inner side G of the gutter, the
sort of trap hereinbefore described through which the juice or liquor returns from
the gutter to the body of the pan A. The space between the said turned-over edge
and the outside of the gutter is covered with a strainer F. The body of the pan
has a steam worm W or other means for heating it and when the liquor has boiled
up the foam and scum rise, pass over the turned-over edge C of the cylinder B and
cone upon the strainer F. The juice passes through the strainer and when it has
filled the gutter below it begins to flow through the trap and over the edge of the
side G back to the body of the pan A.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. For separating from liquors the scum or matter which rises to the surface
during boiling or heating, an apparatus so constructed or arranged that a quiet
body of the boiling or hot liquor by being maintained at, or a little above, the level
of a strainer through which the liquor while circulating flows downwards, keeps the
said scum or matter off or prevents it passing through the strainer as set forth.
2. An apparatus constructed and acting substantially as hereinbefore described

page_text: and represented in Figure 1 for separating from liquors the scum or matter which
rises to the surface during boiling or heating.
3. An apparatus constructed and acting substantially as hereinbefore described
and represented in Figure 2 for separating from liquors the scum or matter which
rises to the surface during boiling or heating.
Dated this 9th day of August 1892.
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Chartered Patent Agent.