CERTAIN IMPROVE- MENTS IN CERTAIN APPARATUS USED IN THE MANUFACTURE OF SUGAR, WHICH APPARATUS IS COMMONLY CALLED SUGAR PANS OR COPPERS
Year: 1845

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
BARR PURBRICK, of Tonbridge, in the County of Kent, Engineer, send.
greeting."
WHEREAS I did, by Petition, humbly represent unto Her present most
Excellent Majesty Queen Victoria, that I had invented "CERTAIN IMPROVE-
MENTS IN CERTAIN APPARATUS USED IN THE MANUFACTURE OF SUGAR, WHICH
APPARATUS IS COMMONLY CALLED SUGAR PANS OR COPPERS," and Her said Majesty
being willing to give encouragement to all arts and inventions which may be for
the public good, was graciously pleased, by Her Royal Letters Patent under the
Great Seal of the United Kingdom of Great Britain and Ireland, bearing date
at Westminster, the Thirteenth day of March, One thousand eight hundred
and forty-five, in the eighth year of Her reign, for Herself, Her heirs and
successors, to give and grant unto me, the said Robert Barr Purbrick, my
executors, administrators, and assigns, Her especial licence, full power, sole
privilege and authority, that I or they, by myself or themselves, or by my
or their deputies, servants, or agents, or such others as I or they should agree,
with, and no others, during the term of fourteen years from the date of the.
said Letters Patent, should and lawfully might make, use, exercise, and vend,
my said Invention within that part, of Her said Majesty's Dominions. called;
England, Her Dominion of Wales, and Town of Berwick-upon-Tweed,,and,
the Islands of Jersey, Guernsey, Alderney, Sark, and Man, and also in all
Her said Majesty's Colonies and Plantations abroad, in such manner as to:
me, my executors, administrators, and assigns, shall seem meet, and that
I or they shall enjoy the whole profit and advantage arising by reason of the
:

page_text: said Invention, during the said term of fourteen years; and for that end Her
said Majesty requires and strictly commands, all Her subjects whatsoever,
within England, Wales, and Berwick-upon Tweed, and in the Islands and Colo-
nies and Plantations aforesaid, that they shall not, neither directly nor indirectly,
make, use, or put in practice my said Invention, or any part thereof, nor in
any wise counterfeit, imitate, or resemble the same, nor make any addition
thereto or subtraction therefrom, whereby to pretend himself or themselves,
to be the inventor or inventors thereof; and whereas the said Letters. Pa-
tent contain a proviso obliging me, the said Robert Barr Purbrick, parti-
cularly to describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, by an instrument in writing
under my hand and seal, and to cause the same to be enrolled in Her Majesty's
High Court of Chancery within six calendar months next and immediately.
after the date of the said 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
Robert Barr Purbrick, do hereby declare that my said Invention is described
and ascertained in manner following, and by the aid of the Sheet of Drawings
hereunto annexed, that is to say:-.
My said improvements relate to that, part of the apparatus used in the
manufacture of sugar which is commonly called sugar pans or coppers, whereof
several are disposed in a row or series, and heated by fire applied beneath, or
nearly beneath, one or more of them, and the flame and smoke from the fire.
is conducted beneath all the other pans or coppers, so as to give heat to the
whole series. And they are used for evaporating the aqueous portion of cane
juice, by boiling such juice within all the pans or coppers of the series, and
transferring the juice from one to another in succession as the waste occasioned
by the evaporation may require for keeping all the pans or coppers properly.
filled. Such cane juice is obtained from sugar canes by passing them through
between the revolving rollers of a sugar mill (or otherwise), and the juice as in
some cases clarified in a distinct vessel heated by fire (but not to boiling);
and then, by such evaporation as aforesaid, by boiling within a series of such
pans or coppers, the said clarified cane juice, after having been transferred from
one to another and arrived in the last pan or copper of the series, is finally.
boiled therein until it becomes syrup sufficiently concentrated for crystallizing,
when it is afterwards allowed to cool within a shallow cooler. But note, the.
aforesaid preliminary clarifying operation is not always practised, for the boil-
ing is sometimes begun with the cane juice as it comes from the sugar mill.
Such pans or coppers are commonly of a circular concave form, like large.

page_text: L
shallow basins, made of copper or of cast iron, and several such sugar pans or
coppers are placed in a row, side.by.side, being set or hung in brickwork, so as
to receive heat from fire applied beneath (or nearly beneath) i one..or more of
them; and a current of flame, heated air, or gas and smoke. passing away from
such fire acts beneath the bottoms of all the other pans or coppers of the series
in succession in passing along a flue or passage which extends: beneath them
all. The fire is made on a fire grate situated beneath. (or nearly beneath): one
of the pans or coppers as aforesaid at one end of the row or series, which one
is called the teache, so that the fire acts with full force beneath that one,
and then the flame, smoke, heated air; and gas which proceeds from the fires
passes onwards beneath all the other pans or coppers of the same series: in it's
way from the fireplace along a flue or passage beneath them all to the vertical
chimney stack, which causes the draft or current, so. that the same fire gives
heat to all the pans or coppers of the series. That copper or pan.which is the
last of the series; and the most remote from the fireplace and nearest to the
chimney, is called the grand pan or copper. During the operation of boiling
and evaporating the cane juice in the series of sugar pans or coppers, as afore-
said, they are all kept filled up with the juice; and besides the evaporation of
the aqueous portion of the juice there are impurities contained in the juice,
which arise in scum to the surface as the boiling and evaporation goes on, and
are removed from time to time by skimming such scum from off that surface.
And whenever the evaporation of the aqueous portion of the juice has caused
deficiency in the contents of the pans. or coppers, or any of them, such de-
ficiency is supplied by transferring as much juice as may be requisite from
one pan or copper to the next in succession in the direction from the grand
pan or copper, towards the teache. And the said grand pan or copper is kept
filled by replenishing it, when requisite, with fresh cane juice, either clarified
cane juice or cane juice as it comes from the sugar mill, according as the
clarifying vessel is used or not. In this manner of proceeding the juice con-
_tained in each pan or copper which is farther along in the series from the
grand copper, and nearer to the teache, will be more and more concentrated
or freed from the aqueous part which has been evaporated in steam, and from
other impurities which have been thrown up in scum and been removed by the
skimming, and in supplying deficiencies in the several pans or coppers.by
transferring from one to the next in succession, as aforesaid. The juice which is
so supplied to each pan or.copper, when requisite, will have been duly prepared
by a previous course of boiling and skimming in all the preceding pans or
coppers of the series. And the heat which is applied to the several pans
or coppers of the series will be the strongest heat to the teache, and' progres-

page_text: sively less and less to each of the pans or coppers in the series, and the spent
heat to the grand copper. And in this manner the cane juice having been
evaporated, boiled, and skimmed in all the pans or coppers of the series in
succession, by transferring from one to another until it comes into the teache
aforesaid, wherein the boiling and evaporation and skimming is continued
.until it is completed, and then the concentrated juice or syrup is removed from
the teache into a cooler, where it is left to cool and crystallize into, sugar.
The said pans or coppers, which are set in a row or series, are commonly of
different sizes; the first of the series (called the grand copper) which, as afore-
said, is the most remote from the fireplace and nearest to the chimney, and
into which the clarified juice is first introduced, is the largest, and the others
of the series diminishing gradually therefrom in size, until the teache aforesaid,
which is over or nearly over the fire, and that teach is the smallest pan or
copper of all the others in the series. But that is not always the case, for all
the pans or coppers of a series :(except the teache and the copper or pan next
to it) are sometimes of the same size; and in some cases two small-sized pans
or coppers are set side by side, or abreast, to serve for teaches at one end of
the row or series of large pans; or coppers, with a fireplace beneath (or nearly
beneath), each such small teaches, and the currents from both those two fire-
places conjoining and proceeding. onwards as one broad current beneath
the other larger pans or coppers, which are disposed one after another in a
row beyond the two teaches, to complete the row or series. And the passage
or flue which is left between the brickwork beneath the pans or coppers
such a series and the bottoms thereof, for the current of flame, heated air, gas or
smoke to.
.pass beneath them all, is sometimes a continuous concave channel
like the inside of a boat, with the series of pans or coppers placed therein,
without any other checks to the passage of the current than is occasioned by
the bottoms of those pan or coppers.
But in other cases the said brick work is
made somewhat more conformable with the bottoms of the several pans,
by rising up in the intervals between the several bottoms, so as that the current
in passing along beneath the whole series may be an undulating course,
ascending in the space between each pan or copper and the next, and then
descending again beneath that next. pan or copper and spreading round
beneath the bottom thereof, and then ascending again, in order by that means
to check the current and detain the same beneath and around the bottom part
of each pan or copper so as more effectually to apply the heat thereto. And,
owing to the circular form of the pans or coppers herein-before used as afore-
said, they require brickwork to be built between each one and the next one in
the row, for arching over such flue or passage as aforesaid in the intervals which
in

page_text: are left between the several pans owing to their circular forms, which brick-
work arching, owing to the intense heat to which it is subjected, requires
frequent repairing.
And part of my said improvements is to construct such pans or coppers in
the new form shewn at Figures 1 and 2 of the Drawing hereunto annexed,
Figure 1 being a side elevation taken laterally in respect to the row, in which
several such pans or coppers are to be arranged in a series; and Figure 2 is
an end elevation taken crossways of such row. The bottom or lowest
part A, A, of the pan or copper is formed to the concavity of a semicylinder (or
nearly such a portion of a cylinder), the imaginary axis or central line of which
is horizontal, and across the direction of the row in which the series of such
pans or coppers are to be arranged. And as to the two side portions B, B, of.
the same bottom (in continuation' upwards on each side from the said por-
tion A, A,) those portions B, B, are formed to the convexties of portions of
two other cylinders, whereof the imaginary axes are horizontal and parallel
to the aforesaid imaginary axis of the cylinder to which the bottom portion A, A,
is formed; and the said two side portions B, B, of the bottom' are conjoined to
two flat vertical sides b, b, Figure 1. The ends D, D, Figure 2, of the same
pan or copper are flat-surfaces, but somewhat inclined from vertical, as is clearly
shewn in that Figure; and the upper parts d, of the said ends are consider-
ably inclined outwards from the interior of the pan or copper. The middle
part of the bottom A is bended downwards, as seen at a, Figure 2, to
form a lowest place of all, from which the last remaining portion of the syrup
can be ladled out, so as to empty the pan or copper completely. The form
of the said pan or copper in its horizontal plan is rectangular, as is
shewn in Figure 4, which is a horizontal plan, and Figure 3 is a corresponding
longitudinal vertical section of a series of seven such pans or coppers F, F, G;
H, I, J, K, put together and set or hung in brickwork, according to another
part of my said improvements, ready for use; two of the said seven (marked
F, F,) being of smaller size for teaches, and they are set side by side at the
end of the row of larger pans or coppers. Figure 5 is a transverse vertical
section. L, L, in Figures 3 and 4, are the fire-grates, situated side by side;
upon which the fuel is burned; kis the entrance for putting in the fuel,
which may be cane trash, as usual; M, M, Figure 2, are the fireplaces arched
over the fire-grates. The teaches F, F, are not immediately over the fire-
grates L, L, but somewat beyond, so that the flame proceeding from each of
the fires passes over the fire-bridge at the farther end of the fireplace M, M,
and striking laterally against the bottoms of the teaches F, F, then descends
in the curved course that is left between the lower parts of those teaches and

page_text: the brickwork beneath, which brickwork conforms to the cylindrical curvature
of the said lower parts of the two teaches F, F, and, therefore, rises up in the
space between the teaches F, F, and the next pan or copper G, so as to form
an undulating course l, f, f, g, h, i, j, k, Figure 3, for the current of flame,
heated air, or gas and smoke proceeding from the fireplaces M, M, to pass
along and act beneath the bottoms of all the several pans or coppers in the
series. And every portion of the upper part. of such undulating course is
covered over with the said bottoms of the several pans or coppers, so as to
receive heat from the said current of flame, heated air, or gas and smoke
which is proceeding rapidly along in such undulating course. Wherefore a
very extensive heating surface is obtained for boiling and evaporating the cane
juice contained in all the said pans or coppers; and no portion of the said
upper part of the said undulating course beneath the pans or coppers is
covered over with brickwork arching, such as must be built in the ordinary
mode of setting circular pans in a row or series, and some part of which
brickwork is of necessity interposed between one circular pan or copper and the
next; whereas, according to my improvements, the two flat vertical sides b, b,
Figures 1 and 2 of each pan or copper are applied in close contact with the
corresponding vertical sides of the next adjacent pan or copper on each side of
it, and all the sides which are so in contact one with another are united
together by revits, or otherwise, so that all the pans or coppers of the series
become united together as is shewn in Figures. 3 and 4, and form as it were
one long boiling vessel having an undulating or waved bottom and parallel
sides, and with partitions across its width at the highest parts of the undu-
lations of the bottom, so as to divide its capacity into compartments, and, with
the whole of the said undulating bottom, covering over and forming the upper
part of the flue or passage from the fireplaces to the chimney, in order to
receive heat from the current of flame, heated air, or gas and smoke which is pro-
ceeding along within such flue, the brickwork which forms the lower part of the
said flue or passage conforming with a parallel curvature to the said undulating
bottoms of the series of vessels in a suitable manner for leaving a broad undu-
lating flue or passage for the flame, heated air, or gas and smoke to pass along
and spread itself out in a broad thin sheet beneath the undulating bottom.
Figure 6 is another transverse vertical section, shewing how the pans or coppers
are set or hung in the brickwork, which is built along each side in two parallel
vertical walls N, N, in order to include the ends D, D, Figure 2, of the
several pans or coppers between those walls N, N, but leaving sufficient
intervals between each of those ends D, D, and the said vertical walls N, N,
for the passage of a portion of the current of flame, heated air, or gas and

page_text: smoke, in order to give heat to the said ends, D, D, which, being (as already
mentioned) somewhat inclined from the vertical, the said intervals are rather
narrower at their upper than at their lower parts, which lower parts commu-
nicate with the space beneath the bottoms of the pans or coppers, in order to
allow a portion of the aforesaid current which is proceeding along in the undu-
lating course beneath the said bottoms to act against the ends D, D. The
weight of each pan or copper is sustained by the two side walls N, N, the
upper inclined parts d, d, Figure 2, of the ends of the pans or coppers reaching
over the upper edges of those walls, as is shewn in Figure 6, and suitable
pieces of metal, which are united to the ends of each pan or copper project out
horizontally therefrom, and are built into the two side walls N, N. The
manner whereby the extremity of the flue or undulating passage f, f, g, h, i, j, k,
Figure 3, beneath the bottoms of all the pans or coppers F; F, G, H, I, J, K,
joins to the base of the vertical chimney stack O is sufficiently explained in
Figures 3 and 4; and owing to the rectangular form of the several pans or
coppers, and to their being, in consequence, brought into close contact one
with another at their flat vertical sides d, d. The length of the undulating course
ff, g, h, i, j, k, through the flue beneath the bottoms of all the series of pans
or coppers is a much shorter length from the fireplaces M, M, to the base of
the vertical chimney stack than could be the case with a series of the same
number of circular pans or coppers, which could be capable of containing the
same quantity of cane juice; and the heating surface which is exposed by.
the bottoms of all the pans or coppers to the current which is passing along..
the said undulating course of the flue is greater than would be exposed by the
5 bottoms of as many circular pans or coppers which could be capable of con-
taining the same quantity of cane juice; and not only is a greater extent of
heating surface exposed, but the said greater extent is more advantageously
exposed for absorbing heat; also the space occupied by the series of pans or
coppers is less. And-note, the undulating course f, f, g, h, i, j, and k of the
flue may be prolonged in order to conduct the current of flame, heated air, or
gas and smoke beneath the steam boiler of a steam engine for working a sugar
mill before that current begins to ascend the vertical chimney stack O, which
must in such case be situated at a sufficient distance beyond the grand:
copper K, to leave room for the said boiler between the wall at the end of the
5 boiling house and the chimney. Such an arrangement has been practised with
a series of common circular páns or coppers, and would be applicable with pans
or coppers constructed and set according to my improvements. And note,
the flat vertical sides b, b, of the several pans or coppers, where they are
applied in contact one with another as before mentioned, should be cut down

page_text: with notches to a lower level than the ends d; d, for the facility of transferring
the juice from one to another when required, and also for the skimming. As
the surface of the juice is liable at times to boil up, the inclined ends d, d, of
the several pans or coppers must be so much higher than the level to which
the juice is kept in them as to avoid any risk of boiling over; but the vertical
sides b; b, of the several pans or coppers being in contact one with another
may be lower, because in case of boiling over it would only be from one pan
or copper into the next one. The level to which the said notches in the several
vertical sides b, b, of the series of pans or coppers may be cut down, is desig-
nated by the dotted line w, w, Figure 3, that level being lowest at the grand
copper and highest at the teache; and, if the several pans are all kept filled
with juice to a suitable level for each one, the scum which rises upon the
surface of the boiling juice-will be very easily removed by skimming it over the
said notches from one pán or copper into the next from the teach towards the
grand pan or copper, and can be laded out from off the surface of the juice in
the grand pan or copper, or any other one of the series as may be most con-
venient. Figure 5 shews how the two teaches F, F, are disposed side by side
with a middle wall of brickwork m between them, which wall separates the two-
fireplaces M, M. Each of the teaches F, F, is of the same form as the other
pans or coppers, and as represented in Figures 1 and 2, and already described,
but smaller in size; the inclining upper parts, such as d, d, of each teach are
sustained by the two side walls N, N, and the middle wall m in the same
manner as the other pans or coppers are sustained by the two side walls N, N,
and already described; but in some cases only one teach will be used, as the
manufacturer may prefer. Also in some cases the ends D, D, Figure 2, of
each pan or copper, may have the brickwork of the side walls N, N, Figure 6,
built in close contact with those ends, and in such case the said ends D, D,
may be flat vertical instead of being inclined to vertical. And as to the mode of
making such pans or coppers, Figures 1 and 2, according to my improvements,
they may be made of sheet copper or of sheet iron rivetted together into the
form shewn in those Figures. The bottom B, B, A, A, may be made in three
plates (or two if of sufficient size). In the Figure four plates are represented,
two for the lower part A, A, and two more for the two parts B, B. In order
to render the interior surface even, and free from projections of rivets and over-
lapping edges of the plates, they may be fitted edge to edge and united by
bands of iron plate applied externally over the edge to edge joints and fastened
with two rows of revets, which may be countersunk on the inside so as to be
flush with the surface of the pan or copper. The ends D, D, may each be
formed of one large plate, bended at the upper parts d, d, to suit the inclination

page_text: of those parts, and with the border edges of the said plates D, D, turned up all
round like rims to include the border edges of the plates B, A, B, from the
bottom, in order to be united thereto with rivets. The two flat vertical sides
b, b, are two distinct plates turned at their lower border edges to go beneath
the border edges of the plates B, B, in order to be united thereto with rivets,
and also turned at their ends so as to go round the upper parts of the plates
for the two ends. D, D, and be rivetted thereto. In that way the interior of
the, pan or copper will have smooth and even surfaces, and the flat vertical
sides b, b, will be capable of applying in close contact one with the other, as
already explained; but the manner of putting the plates together may be left
to the skill and discretion of the workmen who is to construct the same, or
such pans or coppers might be cast. in iron if that were desirable. And the
manner of using a series of sugar pans or coppers which are constructed and
set in brickwork according to my said improvements, as herein-before de-
scribed, may be the same as is commonly practised for boiling and evaporating
cane juice in a set of ordinary circular pans or coppers, as heretofore used for
such purpose, with all the variations in such mode of using as have been or
may be practised according to the skill, experience, and discretion of the
manufacturer. And note, the form of each of the pans or coppers as it
appears in Figures 1 and 2 is symetrical, and, therefore, if the plates at the
bottom B become warm by the heat acting more ou that side of such bottom
which is towards the fireplaces than on the other side, the pans or copper may
be turned end for end when the brickwork requires renewal and rebuilding.
Having now described my said improvements,. I, the said Robert Barr
Purbrick, do hereby declare that the new Invention whereof the exclusive use
is granted to me by the Letters Patent herein-before recited, consists in the
form of the pans or coppers (as herein-before described), being rectangular in
their horizontal plan (instead of circular as in the common sugar pans or
coppers heretofore commonly used), and their bottoms being portions of cylin-
drical surfaces, concave and convex, combined as herein-before described (instead
of being portions of spherical concave surfaces, as in the said common sugar.
pans or coppers), and with flat vertical surfaces at those parts which will be
adjacent when a number of such pans or coppers are set in a row or series
suitably for joining one to another at such flat vertical surfaces, as herein-
before described, without leaving any interval between the several pans or
coppers. Also in combining a number of such pans or coppers together in a
series and setting them in brickwork, as herein-before described, whereby such
series of pans or coppers so combined will become as it were one long vessel
with parallel sides and an undulating bottom, and having partitions across its

page_text: width at the highest parts of the undulations of the bottom, so as to divide its
interior capacity into compartments, and with the whole of the said undulating
bottom covering over and forming the upper part of the flue or passage from
the fireplaces to the chimney, as herein-before described.
In witness whereof, I, the said Robert Barr Purbrick, have hereunto set
my hand and seal, this Twelfth day of September, One thousand eight
hundred and forty-five.
AND BE IT REMEMBERED, that on the Twelfth day of September, in
the ninth year of the reign of Her Majesty Queen Victoria, the said Robert
Barr Purbrick came before our said Lady the Queen in Her Chancery, and
acknowledged the Instrument aforesaid, and all and every thing therein con-
tained and specified, in form above written. And also the Instrument
aforesaid was stamped according to the tenor of the Statute made in the fifty-
fifth year of the reign of His late Majesty King George the Third.
Inrolled the Thirteenth day of September, One thousand eight hundred
and forty-five.