AN IMPROVE- MENT IN BOILING OR EVAPORATING SOLUTIONS OF SUGAR AND OTHER LIQUIDS
Year: 1828

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
DAVIS, of Leman Street, Goodman's Fields, in the County of Middlesex, Sugar
Refiner, send greeting.
WHEREAS in consequence of a communication mado to me by a certain
Foreigner residing abroad, I am in possession of an Invention of "AN IMPROVE-
MENT IN BOILING OR EVAPORATING SOLUTIONS OF SUGAR AND OTHER LIQUIDS;" and
whereas His present most Excellent Majesty King George the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Twenty-ninth day of March, in the ninth year of His
reign, did, for Himself, His heirs and successors, give and grant unto me,
the said John Davis, His especial licence that I, the said John Davis, my
executors, administrators, and assigns, or such others as I, the said John
Davis, my exors, adiñiors, or assigns, should at any time agree with, and no
others, from time to time and at all times during the term of years therein
expressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, and also in all His
said Majesty's Colonies and Plantations abroad, the said Invention of "An
Improvement in Boiling or Evaporating Solutions of Sugar and other Liquids;"
in which said Letters Patent is contained a proviso obliging me, the said
John Davis, by an instrument in writing under my hand and seal, particu-
larly to describe and ascertain the nature of the said Invention, and in what
manner the same is to be performed, and to cause the same to be inrolled in

page_text: Ilis Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the said recited Letters Patent, as in and
by the same, reference being thereunto had, will more fully and at largo
appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Davis, do hereby declare the nature of the said Invention to consist
in an apparatus attached to a sugar-boiling pan, whereby a vacuum is forned
without the aid of air-pumps beretofore employed for that purpose, by means
of water, which is introduced into the said apparatus and then partially with-
drawn from it; and which apparatus is constructed in such manner that the
steam issuing from the said pan divides itself into two portions, ono portion
forcing water into the condenser for the purposes of condensation, while the
other portion enters into the condenser to be condensed; the water so forced
into the condenser having been previously deprived of the ordinary portion of
air which water is known to contain. And in further compliance with the said
proviso, I, the said John Davis, do hereby describe the manner in which the
said Invention is to be performed, by the following description thereof,
reference being bad to the Drawing annexed, and to the figures and letters
marked thereon (that is to say):-
DESCRIPTION OF THE DRAWING.
Figure 1 represents a sugar-boiling pan with my said apparatus attached
thereto, having such portions of the apparatus shown in section as it was thought
would give the clearest explanation of it. A, B, C, D, E, F, are the sugar pan,
measure, feed pipe, proof stick, discharge cock, furnace, &c. &c. &c., all of
which are too well known to need any further explanation; and G is the pipe
which connects tho pan with my said apparatus, the different parts of which I
will now proceed to describe :-H is a water-tight vat filled with water for the
purpose of keeping the apparatus which is within it always covered with water,
and thus air-tight. I is a stout cask set into the vat II, with an agitator inside
it, which agitator is turned by the handle J working in stuffing boxes to pre-
vent the admission of air. K is a glass tube, communicating at each end with
the inside of the cask I, through the sides of the vat II, serving as a guage to
show the quantity of water in the cask. L is a discharge cock for the vat.
M is a feed pipe, supposed to lead from an elevated reservoir of cold water.
N is a feed cock, to fill the vat. O is a feed cock, to fill the cask I through
the pipe P, P; and Q is an air cock, to let the air escape from the cask as it
fills. R is a stopcock, for the purpose of cutting off or opening the communica-
tion between the cask I and the pipe S, the use of which pipe will be explained

page_text: hereafter. T is a supply pipe, leading from the cask I to the condenser V, for
the purpose of supplying cold water to the condenser; and r is a stopcock to
regulate the supply. Now this condenser is a small cask set within another
cask, the outer cask being filled with water to keep the inner one air-tight, and
is fitted with shelves of wicker or basket work, represented by the dotted lines,
to divide the steam and the condensing water, thereby operating as refrigerators.
W is a shelf of wood or iron perforated with holes and arched upwards, so as
the better to resist the force of the steam when it first rushes into the con.
denser. U is a stopcock to cut off the communication between the pipe G
and the pipe X. X is the steam pipe which receives the steam from the
pan A, and through which the steam rushes into the pipe S. Now this pipe S
it will be seen communicates at its lower end with the condenser V, and at its
upper end through the cock R and pipe P with the cask I, the effect of which
is to divide the course of the steam, and to cause the upper portion to be acting
on the surface of the water in the cask while the lower portion enters into the
condenser, as will bo hereafter more particularly explained. Y is a waste pipe
leading from the condenser to the vessel Z, which is supposed to be in a well
somewhat more than thirty-four feet below the bottom of the condenser, for the
length of the pipe Y should be exactly thirty-four feet, in order to form, as will
of course be suggested by this precise length being given, a Torricellian column,
the use of which will be more particularly described hereafter. It will be
observed that the pipe Y is immersed a few inches in the vessel Z, which is
filled with water, the waste running over into the well. The pipe Y and this
part of the Figure generally is shown as broken off, it not being thought neces-
sary to give the whole length in the Drawing, as it is stated in the description,
and is merely a continuation of the pipe Y, the cord t, and the well to join the
upper parts of the same; is a small cord or trigger, to open the valve 9 from
above; the valve is kept closed by the weight a, and when this weight is raised
the valve opens.
Having now described the various parts of the said apparatus, I shall
proceed to describe the manner of using the same, and the mode of creating
and keeping up a vacuum therewith during the process of sugar boiling. The
first thing to be dono is, to fill the outer casing of the condenser with cold
water, and also the vat H, and then stop the cocks N, L, and U, and the
valve, and open the cocks O, Q, R, and r; this will admit water from
the elevated reservoir of cold water through the pipe M into the cask I, the
condenser V, and all the pipes of the apparatus, while the air that the water
displaces will find vent at the air cock Q. When every part of the apparatus

page_text: is completely filled with water, the cocks O and Q are to be stopped and the
valve g opened; this will cause the water in the cask I and pipe S to fall, and
when it has dropped eight or ten inches, which will be seen by observing the
guage or glass tube K, the valve g must be stopped again, and the agitator
in the cask I must be turned round by means of the bandle J in order to
disengage whatever portion of air may be in the water in the cask, and which
will by this means rise to the upper part of the cask. The cocks O and Q
must be opened again and more water admitted, which will again fill tho
apparatus and expel the air that has been disengaged, by which means
the water in the cask I will be as free from any portion of air as possible,
and thus fitted for the purpose it is intended to accomplish. The cocks
O and Q must now be closed again for the last time during the operation.
The whole apparatus being now filled with water the valve 9 must be again
opened, and a portion of the water drawn off, say till the guage K indicates
its elevation to be about at the dotted red line 6, which will leave the upper
part of the pipe S, the pipe P, P, and the upper part of the cask empty. The
cock r must then be closed to prevent any more water running out of the cask
I, and the valve g continuing open it will be evident that the water in the
lower part of the pipe S and in the condenser V will continue to fall 'till the
pressure of the atmosphere on the surface of the water in the vessel at the
bottom of the well Z will support the column of water above it in the pipe
Y; and the length of this pipe being regulated as before stated to something
less than thirty-four feet, it stands to reason that this will take place just as
the condenser is emptied, thus forming a Torricellian vacuum in the condenser
while the pipe Y is always kept full of water to preserve that vacuum; when
in this state the apparatus is ready for the process of boiling and condensation
to commence. The fire must now be lighted in the furnace, tho liquor
measured into the boiler or pan, and heated in the ordinary way; when the
the steam begins to rise, the air cock e must be opened, and the steam
rushing out will expel what atmospheric air may be in the upper part of
the pan when the boiling commenced. When this is accomplished stop
the cock e and open the cock U; the steam will instantly rush through the
pipe X into the pipe S; here it will divide itself into two portions, one portion
will rush upwards through the cock R, and down the pipe P, into the
previously unoccupied space in the upper part of the cask I, and thus cause a
pressure on the surface of the water in the cask, while the other portion will
rush downwards into the condenser V, striking upon the perforated plate W,
and distributing itself for condensation. At this moment the cock r should be

page_text: partly opened, and the effect produced will be as follows:-The force of the
steam which is passing up the pipe S into the cask I will act with sufficient
force of pressure on the surface of the water in the cask to force out as much
as is required for the purposes of condensation, through the pipe T and cock r
into the condenser V, which quantity may be regulated by the cock r; the
cold water thus flowing constantly into the condenser will condense the steam
there; and the accumulation of the water from the pipe T and condensed
water at the bottom of the condenser, as fast as it rises to a height greater than
the Torricellian column in the pipe Y can support, will displace a portion of the
water in the pipe Y, which will flow over the vessel Z into the well below, care
being taken that the waste water shall never rise in the well above the surface of
the water in the vessel Z, and this operation will continue till the whole of
the liquor in the pan is sufficiently evaporated for the purpose of the operator.
The general proportions of the apparatus, as attached to an ordinary sugar
pan holding about fifty gallons, are here shown; but, as a useful general
guide to the size of the apparatus, it is only necessary to observe that the
cask I should be large enough to hold sufficient water to condense all tho
steam that will be generated in one operation of the boiling pan, as it cannot
be replenished during the process of boiling.
Figure 2 is a plan of Figure 1, and, as similar letters are used to denote
similar parts in each Figure, no further description will be required.
Now whereas I claim as the said Invention an apparatus such as is hercin-
before described, attached to a sugar pan, whereby the operation of boiling in
vacuo may be performed without the use of air pumps as heretofore, by means
of a vacuum formed by the admission and eduction of water and a Torri-
cellian column, and in such manner that the steam which is generated in
the boiler escapes therefrom and divides itself into two portions, one passing
into the condenser, and the other at the same time acting with pressure
upon a surface of water, which is by that means forced into the condenser
to assist in condensing the first-mentioned portion, such water, so forced into
the condenser, having been previously deprived as much as possible of the air
it would naturally contain. And such said Invention being, to the best of my
knowledge and belief, entirely new, and never before used within that part of
His said Majesty's United Kingdom of Great Britain and Ireland called
England, Iis said Dominion of Wales, or Town of Berwick-upon-Tweed,
nor in any of His said Majesty's Colonies or Plantations abroad, I do hereby
declare this to be my Specification of the same, and that I do verily believe
this my said Specification doth comply in all respects fully and without
reserve or disguise with the proviso in the said herein-before in part recited

page_text: Letters Patent contained; wherefore I hereby claim to maintain exclusive
right and privilege to the said Invention.
In witness whereof, I, the said John Davis, have hereunto set my hand
and seal, this Twenty-seventh day of September, in the year of our
Lord One thousand eight hundred and twenty-eight.
DOWDESWELL.
AND BE IT REMEMBERED, that on the Twenty-seventh day of
September, in the year of our Lord 1828, the aforesaid John Davis camo
before our said Lord the King in llis Chancery, and acknowledged the
Specification aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute made for that purpose.