IMPROVEMENTS IN FILTERS
Year: 1868

page_text: LETTERS PATENT to William Robert Lake, of the "International
Patent Office," No. 8, Southampton Buildings, Chancery Lane,
in the County of Middlesex, Consulting Engineer, for the
Invention of "IMPROVEMENTS IN FILTERS."-A communication from
abroad by Henry Torstrick, of the City and State of New York,
United States of America.
Sealed the 25th September 1868, and dated the 28th March 1868.
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition, on
the 28th March 1868.
I, WILLIAM ROBERT LAKE, of the "International Patent Office,"
No. 8, Southampton Buildings, Chancery Lane, in the County of
Middlesex, Consulting Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN FILTERS," a communication, to be
as follows:-
It has hitherto been necessary to carefully sift the bone coal prepared
for filters, such as are commonly employed by sugar refiners for the

page_text: purpose of removing the fine dust; and the waste from this source
occasioned by the repeated and necessary handlings in placing it in the
filters and removing it from them, and in re-burning and sifting has
been a very important element in the cost of the production of
refined sugar. Although the dust presents a greater surface over which
the syrup should pass in its flow through the filter than an equal weight
of coal in larger bits or fragments, it has been found impracticable to
use it for the reason that when it becomes fully saturated, it forms a
pasty mass through which the syrup is unable to run with the rapidity
requisite for its practical use. When it may be attempted to hasten or
assist the operation by means of pressure on the surface of the liquor in
the filter, or by centrifugal action an opening or channel is forced
through the mass by which the liquor escapes without deriving any
benefit from the main body of the coal. In a similar manner, when the
coal has not been sifted to remove the dust, the latter fills up the pores
or insterstices between the larger pieces and speedily clogs it to a degree
that renders the filter practically useless long before the decolorizing
power of the bone is exhausted.
The object of my Invention is to utilize the bone dust that has
hitherto been of no value for filtering purposes, either for saccharine
solutions or other liquids; and this object is accomplished by mixing
the bone dust with sand or anthracite coal or other similar substance, or
material that is insoluble in the liquid to be filtered, and not liable to
disintegration by its action, and which will hold the particles of bone
dust apart and prevent their forming either by themselves or with the
mixing agent, a paste that is comparatively impervious to the solution or
liquid it is desired to filter.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Robert Lake in the Great Seal Patent
Office on the 26th September 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the "International Patent Office," No. 8, Southampton
Buildings, Chancery Lane, in the County of Middlesex, Consulting
Engineer, send grecting.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the "International Patent Office," No. 8, Southampton
Buildings, Chancery Lane, in the County of Middlesex, Consulting
Engineer, send grecting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of March, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-first year of Her reign, did, for Herself, Her heirs and successors,
5 give and grant unto me, the said William Robert Lake, Her special
licence that I, the said William Robert Lake, my executors, adminis-
trators, and assigns, or such others as I, the said William Robert Lake,
my executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN FILTERS," upon the condition (amongst others) that
I, the said William Robert Lake, my executors or administrators,
by an instrument in writing under my, or their, or one of their
hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Scal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patont.
NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement:-
It has hitherto been necessary to carefully sift the bone coal
prepared for filters, such as are commonly used by sugar refiners for
the purpose of removing the fine dust, and the waste from this source
occasioned by the repeated and necessary handlings in placing it in the
filters and removing it from them, and in re-burning and sifting has
been a very important element in the cost of the production of refined
sugar. Although the dust presents a greater surface over which the
syrup should pass in its flow through the filter than an equal weight
of coal in larger bits or fragments, it has been found impracticable to
use it for the reason that when it becomes fully saturated, it forms a
pasty mass through which the syrup is unable to run with the rapidity
requisite for its practical use. When it may be attempted to hasten
or assist the operation by means of pressure on the liquor in the filter,
or by suction beneath the filtering material, an opening or channel is

page_text: forced through the mass by which the liquor escapes without deriving
In a similar manner,
any benefit from the main body of the coal.
when the bone has not been sifted to remove the dust, the latter fills
up the pores or interstices between the larger pieces and speedily
clogs it to a degree that renders the filter practically useless long
before the decolorizing and purifying power of the bone is exhausted.
The object of my Invention is to utilize for filtering purposes the bone
dust that has hitherto been of but little value; and this object is
accomplished by mixing the bone dust with fine anthracite coal or other
similar substance or material that is insoluble in the liquid to be filtered
and remains unaffected under the conditions of heating, washing, and
steaming to which it may be subjected, except when thereby brought
into a condition more favorable for the intended purpose, and which
will hold the particles of the bone dust apart and prevent their
forming either by themselves or with the dividing agent a paste that
is comparatively impervious to the solution or liquid it is desired to
filter.
And in order that my Invention may be fully understood I will
proceed to describe in detail the manner of carrying it into effect.
I mix the bone black as thoroughly and intimately as may be possible
with about the same measure of fine anthracite coal, and after heating
the mixture place it in a filter of any of the ordinary forms provided at
the bottom with a lining of flannel or felt to prevent the washing out of
the dust. The same end may be attained by the employment as a
divider or separating agent instead of fine anthracite or stone coal of
any other material with a similar nature that is insoluble and not acted
upon in the liquid to be filtered, and under the conditions incident to
filtration and renovation of the bone by steaming and heating, or by
fermentation with acids or other treatment to which it may be subjected
while in use, or for subsequent cleansing. By the use of a mixing agent
that fulfils these requirements and the particles of which are of a hard,
sharp, and glazed character, the bone dust is so separated that it can
no longer form a pasty mass that is comparatively impervious to the
fluid to be filtered, and all portions of its surface are thus brought into
efficient action in the filter. If found desirable the bone dust may be
ground for the purpose of making it as fine as possible, so as to expose
the largest amount of surface.

page_text: The same principle may be applied to burnt blood or other
decolorizing agent or filtering medium in a finely divided state that
may be used instead of bone coal, and which would otherwise pack
itself together, so that the fluid to be filtered would fail to pass readily
through it. The liquor and the filter should be kept heated to promote
its efficiency, and it is believed that the mixture of fine anthracite, as
described, retains the heat better than bone coal alone. I prefer the
dust of anthracite as a dividing agent on account of its cheapness
occasioned by the large quantities necessarily produced in the mining
and working of coal for which there has hitherto been no profitable use,
and although its power of decolorizing and separating impurities as a
filter may not be sufficient to warrant its separate use for the purpose,
its virtue in this respect is an addition to its intended function of
permitting the profitable use of the fine dust of burnt bone.
By the admixture of a finely divided glazed material as described the
bone dust may be more thoroughly cleaned by washing and steaming
as a preliminary to its restoration by fermentation, or acids, or other
agents. The re-burning of bone black dust also that has been hitherto
impracticable for the reason that it aggregates into a mass when wet
with syrup, and sticks together in irregular lumps, and adheres to the
calcinating vessels, may be accomplished by the addition of a dividing
agent of the character hercin-before described, by which means the
carbonization may be more perfectly regulated and rendered more
uniform, and both the over and the under calcination that are so
detrimental to the efficiency of its action may be easily avoided. The
proportionate quantity of anthracite or other divider may be adjusted so
that the percolation will be slow owing to the preponderance of the bone
dust, or with a larger quantity of the divider the filtration will be more
rapid, and a thicker stratum of the mixed material will be required to
retain the liquid in contact with the bone a sufficient time to become
thoroughly decolorized.
By the method herein described, more particularly in connection with
bone black and its employment by sugar refiners, but which is applicable
to other material and for other filtering purposes, the fine dust of bone
black that would otherwise be useless for a filter is rendered of value,
and advantage may be taken of the larger proportion of surface afforded
by the same weight of dust compared with bits of greater size, and a
proportionately less amount of bone may be used; and, finally, the

page_text: same method of separating the molecules of dust admits of their
complete and uniform renovation or restoration by washing, re-
burning, or other means that requires access to every particle of the
fine dust.
Having thus fully described the said Invention, as communicated to
me by my foreign correspondent, and shown how the same may be
conveniently and advantageously carried into practise, I claim, the use
of a dividing agent, substantially as described in connection with the
filtering material for the purpose of filtration.
In witness whereof, I, the said William Robert Lake, have hereunto I
set my hand and seal, this Twenty-sixth day of September, in
the year of our Lord One thousand eight hundred and sixty-
eight.
WILLIAM ROBERT LAKE.
(L.S.)
Witness,
THOS. N. PALMER,
Clerk to Messrs. Haseltine, Lake, & Co.,
8, Southampton Buildings,
W.C.