IMPROVEMENTS IN SATURATING, WASHING, AND CLEANSING CHARCOAL AND OTHER MATTERS, APPLICABLE ALSO TO THE SEPARATION OF SYRUPS FROM SUGAR
Year: 1863

page_text: LETTERS PATENT to Lauchlan Mackirdy, of Greenock, in the County
of Renfrew, Sugar Refiner, for the Invention of "IMPROVEMENTS IN
SATURATING, WASHING, AND CLEANSING CHARCOAL AND OTHER MATTERS,
APPLICABLE ALSO TO THE SEPARATION OF SYRUPS FROM SUGAR."
Sealed the 10th May 1864, and dated the 14th November 1863.
PROVISIONAL SPECIFICATION left by the said Lauchlan Mackirdy at the
Office of the Commissioners of Patents, with his Petition, on the 14th
November 1863.
I, LAUCHLAN MACKIRDY, of Greenock, in the County of Renfrew, Sugar
Refiner, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN SATURATING; WASHING, AND CLEANSING CHARCOAL AND OTHER MATTERS,
APPLICABLE ALSO TO THE SEPARATION OF SYRUPS FROM SUGAB," to be as
follows:-
My Invention consists in the employment of the vacuum pump either alone
or in connection with the vacuum pan to the exhaustion of air from charcoal
cisterns, thereby increasing the power of the charcoal to receive and absorb a
much larger quantity of liquor than it could do by any process at present in
use, charged as it is with air in all its cells, which the present gravitation
system of charging cannot drive out.
My Invention for carrying out more perfectly this operation is to create a
vacuum in the char cistern after it is filled with charcoal, an operation per-

page_text: formed in four or five minutes; after which the "brown liquor" cock is
opened, and the cistern containing, say, 20 tons of charcoal fills itself, and
completely saturates, according to the condition of the charcoal, in about
forty minutes; but if the air pump is kept upon the cistern it can be per-
formed in even less time than this. After the quantity of sugar liquor is
passed upon the charcoal intended, the washing out, cleansing, and purifying
by my Invention, in connection with either the pump and vacuum pan, or
pump and cistern with vacuum therein, can be easily effected.
My Invention possesses among other advantages this, that the pans, liquor
cisterns, char cisterns, and brown liquor cisterns can be arranged all
upon the same floor. I am enabled also to double run my cisterns, or I can
pass my liquor over as many cisterns as I desire by simply exhausting the air
with the vacuum pump, thereby drawing the liquor from one to the other as
often as desired. This application of vacuum to close vessels will be effective
in obtaining the same result on any other matter or material which requires
similar treatment by water, in saturating, mixing, cleansing, or purifying as
may be required in other branches of manufacture.
I now explain the use of compressed atmosphere in connection with this
Invention of mine, and as a powerful adjunct thereto, viz., by the application
of an air force pump to the top of the cistern when the liquors are inferior
and tough, or the charcoal has too large a proportion of dust therein for the
present process. I then apply the air pump, as described, to the close-topped
vessel or cistern, and drive the tough liquor or water through most effectually,
acting upon the entire body of charcoal. I also apply my Invention to
the filtrations and purification of liquor from the "blow-ups," instead of the
present mode of filter bags. This operation is also effected and completed by
the application, as before described, of the air pump as a vacuum pump, and
of the air pump as a force pump, applied to air-tight vessels fitted up with
cotton, wool, wood, metal, or any other suitable material.
My Invention is also applicable to the separation of syrups from sugar.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of November, in the year of our Lord
One thousand eight hundred and sixty-three, in the twenty-seventh year
of Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Lauchlan Mackirdy, Her special licence that I, the said Lauchlan
Mackirdy, my executors, administrators, and assigns, or such others as I, the
said Lauchlan Mackirdy, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times there-
after 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 "IMPROVE-
MENTS IN SATURATING, WASHING, AND CLEANSING CHARCOAL AND OTHER MATTERS,
APPLICABLE ALSO TO THE SEPARATION OF SYRUPS FROM SUGAR,"
the con-
dition (amongst others) that I, the said Lauchlan Mackirdy, 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 Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
upon
NOW KNOW YE, that I, the said Lauchlan Mackirdy, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:
My Invention has reference to improvements in saturating the charcoal in
charcoal cisterns with the sugar liquor that is to be thereby purified. Hitherto
after filling the char cistern with charcoal the liquor has been allowed to run
into the cistern, and after remaining a comparatively long time in contact
with the charcoal it has been drawn off. Now, in consequence of the air
contained in the numberless small cells of the charcoal, this operation has
been by this plan both slowly and imperfectly performed, and the whole value
of the entire contact of the liquor with the quantity of charcoal in the cistern
has never been obtained, because the minute divisions of the cells of the
charcoal have made it very difficult, if not impossible, for any liquid intro-
duced into the cistern with the charcoal in the state described entirely to
expel the air therefrom, thus entire contact of the liquor with the charcoal
in all its interstics and divisions is hindered; also in the case of sugar
liquor the syrupy nature of the liquor helps to increase this difficulty; the

page_text: charcoal is thus prevented from being in the best condition to receive the
liquor.
Now my Invention removes this difficulty by withdrawing all the air from
the charcoal before the liquor is run into the cistern. For this purpose I use
a charcoal cistern so constructed as that it may be made perfectly air-tight,
and also made strong enough to bear the unbalanced pressure of the
atmosphere. After the charcoal is filled in and the man-hole made air-tight,
the air contained in the cistern is drawn out by an air pump; when all the
air has thus been exhausted, not only from the cistern but also from the
charcoal and from all the cells and interstices of the charcoal, the liquor is
introduced by opening the "brown liquor cock," and as the air has been
entirely removed the liquor will enter into instant and complete contact with
the charcoal, and thus thorough saturation will very soon be accomplished.
When the liquor is sufficiently purified it is drawn off, either in the ordinary
way by opening the outlet valve, or it is drawn into an air-tight cistern by
means of a vacuum which has been produced therein; in either case in
drawing off the liquor at the bottom, air is allowed to enter in at the top part
of the cistern. For insuring the more perfect effect of this operation on some
inferior and tough liquors I proceed as follows:-After the air has been (as
before described) all drawn out of the cistern and these inferior liquors
brought therein, I use an air pump to force air into the cistern on the top of
the liquor, and by this pressure force the liquor into every part of the char-
coal, and afterwards on opening the valve to draw off the liquor (either in
connection with a vacuum in the cistern into which the liquor is being drawn,
or otherwise, as the case may require,) by continuing the working of the air
force pump I drive the liquor through the charcoal most thoroughly and
effectively. When the liquor cistern has done its work and remains full of
charcoal saturated with liquor or dense solution of sugar, the process of
washing commences. This is effected by closing the cock which supplies
liquor" to the top of the cistern, and opening cock which supplies hot
water. The liquor is continuously drawn from the bottom of the cistern, and
as the water is specifically lighter than the liquor the two fluids do not much
intermix. When the liquor has been drawn away a quantity of fluid lighter in
density follows, this is called "sweet water." After the sweet water has been
"
drawn off, a vacuum pump, which is in connection with the bottom of the cistern,
is brought into action, and a copious supply of hot or cold water is introduced
to the top of the cistern. The continued action of the pump draws the water.
through the cistern with such force that it effectually cleanses and, absterges

page_text: the charcoal from all its impurities. When the water runs pure the supply is
cut off, and by opening an air valve air is drawn through the mass of charcoal
and dries it.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim,-
First, the saturating of charcoal in charcoal cisterns by means of a
vacuum, or of a vacuum and pressure of air combined, in manner herein-
before described.
Second, the washing and cleansing of charcoal by the means herein-before
described.
In witness whereof, I, the said Lauchlan Mackirdy, have hereunto set
my hand and seal, this Tenth day of May, One thousand eight
hundred and sixty-four.
LAUCHLAN MACKIRDY. (L.S.)
LAUCHLAN MACKIRDY. (L.S.)