A CERTAIN IMPROVEMENT IN THE CON- DENSER USED WITH MY APPARATUS FOR BOILING SUGAR IN VACUO
Year: 1829

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 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-eighth day of April, in the tenth 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 exors,
admors, and assigns, or such others as I, the said John Davis, my exors,.
admiors, or assigns, should at any time agree with, and no other persons, 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 in all His Majesty's Colonies and
Plantations abroad, the Invention of "A CERTAIN IMPROVEMENT IN THE CON-
DENSER USED WITH MY APPARATUS FOR BOILING SUGAR IN VACUO," for which a
Patent was granted to me the Twenty-ninth day of March 1828, intitled
"An Improvement in Boiling or Evaporating Solutions of Sugar and other
Liquids," communicated to me by a certain foreigner residing abroad; in
which said Letters Patent is contained a proviso, obliging me, the said John
Davis, by an instrument in writing under my hand seal, particularly to describe
and ascertain the nature of the said Invention, and in what manner the samė

page_text: is to be performed, and to cause the same to be enrolled in His said 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 large 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 a certain improvement in the condenser used with the said John Davis's
former patent apparatus for boiling sugar, whereby the necessary vacuum is
not formed by the admission and' eduction of water, as therein described, but
by the introduction of steam from the boiler or pan into the condenser, thus
doing away the Torrecellian column mentioned in the former Patent of the said
John Davis. And in further compliance with the said proviso, I the said John
Davis, do hereby describe the manner in which my said Invention is to be
performed by the following description thereof, reference being had to the
Drawing annexed, and to the letters marked thereon (that is to say):-
DESCRIPTION OF THE DRAWINGS.
The Drawing No. 1 represents a sugar-boiling pan on the former principle,
with the said 'condenser applied 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, the feed pipe, proof stick, discharge
cock, furnace, ash-pit, &c. &c., all of which are two well known to need any
*further. explanation; and G is the pipe which connects the pan with the said
condenser, and is in fact a steam pipe; 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 H, with an agitator
insido it, which agitator is turned by the handle J working in 'stuffing boxes to
prevent 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 H, 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 and Q is an air cock to let the air escape from the cask as it fills;
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 stop-cock to regulate the
supply. Now, this condenser is a large cask set within another cask, the outer
-cask being filled with water to keep the inner one air-tight. W is a shelf of
wood or iron perforated with holes to spread the steam when it first rushes into

page_text: the condenser; U is a stop-cock to cut off the communication between the pan
and the condenser; S is a steam pipe, which receives the steam from the pan A
through the pipe G. Now this pipe S, it will be seen, communicates at its
upper end with the cask I, the effect of which is, that when the steam from the
pan A is allowed to pass,into the pipe G, a portion of the steam passes up the
pipe S and acts on the surface of the water in the cask, thus driving a portion
of that water through the pipe T into the condenser, while the other portion of
steam passes down into the condenser, and is there.condensed by the water that
is so forced in, as aforesaid. Y is a waste pipe leading from the condenser to
the reservoir or waste place Z.
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 done is to fill the outer casing of the condenser with cold
water, and also the vat H, then stop the cocks N, R, and r, and open the cocks
O and Q, this will admit water from the elevated reservoir of cold water
through the pipe M into the cask I, and the pipes S and T, while the air that
the water displaces will find vent at the air-cock Q. When the cask is coru-
pletely filled with water the cocks O, U, and Q are to be stopped, and the
cock opened; this will cause a portion of the water in the cask I and pipe S
to fall into the condenser, and when it has dropped eight or ten inches, which
will be seen by observing the guage or glass tube K, the cock r must be
stopped again, and the agitator in the cask I must be turned round by means
of the handle 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 then be opened again and more water
admitted, which will again fill the cask and expel the air that has been dis-
engaged, 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 cock O and Q must now be closed again for the last time
during the operation; 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, the liquor measured into the boiler or pan,. and heated in the
ordinary way. When the steam in the pan has been got up to a pressure of
more than fifteen pounds to the square inch, the water in the condenser must
be drawn off by the pipe Y, and the cocks U and X must be opened; the
steam from the pan will rush into the condenser and expel what atmospheric
air may be in it, and rush out of the waste pipe Y. When this is accomplished,

page_text: shut the waste cock X and open the cock R and partly open the cock r, a
portion of the steam will instantly rush up the pipe S into the upper part of
the cask I, and thus cause a pressure on the surface of the water in the cask,
while another portion will rush downwards into the condenser V, striking.upon
the perforated plate W, and distributing, itself for condensation; the cock r
being partly opened, 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 suffi-
cient 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
the cock r into the condenser V, which quantity may be regulated by the cock";
the cold water tlius flowing constantly into the condenser will condense the
steam there, and the condenser must be of a size to hold all the condensing
and condensed water required for one operation, as 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 the
'steam that will be generated in one operation of the boiling pan, as it cannot
be replenished during the process of boiling, and the condenser of the relative
size, herein-before shewn. When the operation is concluded, it is hardly
necessary to observe that the water is drawn out of the condenser. by the waste
pipe Y, and the cask I again filled as before for the next operation. h is merely
a guage to ascertain the quantity of water in the condenser.
Now, whereas I claim only as the Invention the following improvements,
viz', the substitution of the common waste pipe to the bottom of the condensor
instead of the Torricelliam column, and an enlargement of the condenser to
'about six times the size of that required in the said John Davis's former appa-
ratus; by which said improvement I am enabled to form the required vacuum
by the introduction of steam from the boiler or pan into the condenser, as herein-
before described, which does away with the necessity of the Torricellian column,
and the consequent height of the apparatus above the well of waste water, which
is often extremely difficult to procure, while it greatly simplifies the operation.
'And such the 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, His said Dominion of
Wales, or Town of Berwick-upon-Tweed, nor in any of His Colonies and
Plantations abroad, I do hereby declare this to be my Specification of the same,

page_text: 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 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 Second day of October, in the year of our Lord One
thousand eight hundred and twenty-nine.