CERTAIN IMPROVEMENTS IN THE CON- CENTRATING AND EVAPORATING OF CANE JUICE, SOLUTIONS OF SUGAR, AND OTHER FLUIDS
Year: 1829

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
AITCHISON, of. Clyde Buildings, in the City of Glasgow, and County of
Lanark, North Britain, Merchant, send greeting.
WHEREAS His most Gracious Majesty King George the Fourth, by His
Letters Patent under the Great Seal of that part of the United Kingdom of
Great Britain and Ireland called England, bearing date at Westminster, the
Fifteenth day of September, in the year of our Lord One thousand eight hundred.
and twenty-nine, and the tenth of His reign, did, for Himself, His heirs and
successors, give and grant unto me, the said John Aitchison, my executors;
administrators, and assigns, and no others, His especial licence, full power, sole.
privilege and authority, that I, the said John Aitchison, my executors, admi-
nistrators, and assigns, during the term of fourteen 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 our Colonies
and Plantations abroad, my Invention of "CERTAIN IMPROVEMENTS IN THE CON-
CENTRATING AND EVAPORATING OF CANE JUICE, SOLUTIONS OF SUGAR, AND OTHER
FLUIDS;" in which said Letters Patent there is contained a proviso, obliging
me, the said John Aitchison, by an instrument in writing under my hand
and seal, particularly to describe and make known the nature of my said
Invention, and in what manner the same is to be performed, and to cause the

page_text: same to be enrolled in His Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the above in part
recited Letters Patent, and in default of which, all liberties, privileges, and
advantages whatsoever therein granted should utterly cease, determine, and
become void, as, by reference thereto, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, to the said
John Aitchison, do hereby declare that the nature of my said Invention, and
the manner in which--the-same-is-to-be-performed, is particulary set forth and
explained by the following: description, reference being made to the Drawing
hereto annexed, that is to say:-
My improvements in concentrating and evaporating of cane juice, solution of
sugar, and other fluids, consist in the employment of an apparatus of a peculiar
and novel construction, by means of which the process of evaporation is more
conveniently and economically effected and-carbonization prevented than by
any other means heretofore used for that purpose. The apparatus may be
made of any dimensions, according-to-the-quantity of liquors required to be
evaporated, and may be slightly varied in form from that represented in the
accompanying Drawing without materially altering rits effect. Fig. 1 is a
horizontal view of the apparatus, the covering being removed in order to show
the construction of the parts within; Fig. 2-isa side-elevation of the same,
the cover being shown in section; Fig. 3 is an end view of the apparatus,
with the cover attached to it; Fig. 4 is a longitudinal section of the whole
apparatus, taken through the middle as it would appear when charged with
the liquor and in operation; and Fig. 5-is a transverse section of the samė ;
similar letters referring to corresponding parts in all the Figures. a‚ ã‚‹ã‚ª‚
is a square or oblong framing or standard, of iron or wood, supporting
the pan b, b, which I propose to be made of stout: sheet copper, and..in
the form of the segment of a cylinder. On the outside of the pan there
is another corresponding segment of a cylinder cattached to the pan
by flanges and rivets, or by "other" means, liaving steamtight joints, which
constitutes' a jacket or casing, and by these means a space d, d, is formed-
for the reception of steamy for the purpose of heating the syrup or other
fluids contained in the pan: A-hollow drum 'or cylinder e, e, e, suspended
upon an axle, is mounted in plummer blocks, fixed on the rim of the
standard or frame, and is made to revolve by means of tooth gear, as shewn in
the end view, Fig. 3, the cylinder dipping into the pan to within about two or
three inches of the bottom; this drum is formed by two concentric cylinders
of sheet copper, attached together by rings or flanges at the ends; which are
revited or soldered, so as to render the joints steam-tight; leaving a space

page_text: :
between them of about two inches for a steam chamber. A small-rib or feather
of thin.copper is attached to the inside of the external cylinder, winding round
it in a helical curve, for the purpose of conducting any water which may form
within the chamber by the condensation of steam; and a.receptical or cup is
placed at the end of the channel; for the purpose. of receiving the water and
.conducting it through the hollow arm into the axle, from whence it flows
away by the bent pipe. Steam from an ordinary boiler, situate at any con-
venient distance, is made to enter the apparatus through the hollow axle at the
stuffing box f (as will be best seen at Fig. 4); and having reached the box g,
proceeds through one of the hollow arms h into the space or chamber of the
'double.cylinder, from thence the steam passes off by the hollow arm i to the
box k, and through the vent pipe to the space or chamber below, formed
between the pan 6 and its jacket c, for the purpose of heating the pan, as above
described, and ultimately the steam escapes with the air and condensed water
by an open cock m at bottom. The cane juice, syrup, or other fluid intended to
be evaporated having been first properly prepared and clarified; is. to be intro-
duced into the pan b, b, filling the pan to within three or four inches of the
rim, which will cause about three-eights of the' diameter of the drum to be
immersed in the fluid. The apparatus is now ready to be put in operation, by
introducing the steam, as above 'described, and by giving to the drum 'rotatory
motion from any first mover, or by manual power. In order to keep the
surfaces of the pan and of the drum free from incrustation, I have introduced
three scrapers, made of wood, and covered with woollen cloth, which act in
close contact with these surfaces, and scrape off the syrup or other fluids as
they begin to thicken or concentrate. The scraper intended to act against
the bottom of the pan is shewn at n in Figs. 1 and 5, which is formed by a
straight bar of wood 'extending along the bottom of the pan, its extremities.
are connected by joints to two crank rods o; o, which rods are attached to the
crank shaft p; Fig. 1: hence as the winch vis turned, the crank shaft révolyes
also by means of the toothed gear; and gives to the scraper the reciprocating
action required, which agitates the thick parts of the material at bottom of
the pan
and prevents it from adhering The scraper intended to act against
the external surface of the drum is a straight thin bar of wood q, Eigs: 1 and
5, supported by a pivot at each end, bearing on blocks, which rest on the
Hanges of the pan. These pivots are so placed that the front edge of the wooden
bar bears against the periphery of the drum, and the edge, being bevelled,
illows the syrup as it is scraped off to run over it' and fall down into the pan.
The scraper which acts against the internal surface of the drum is a bar of
vood 7, extending along the drum'in.the inside, which is suspended by two

page_text: arms from the central part of the axle of the drum, and, falling by its own
gravity, continues scraping the surface as the drum revolves under it. A cover
or casing of wood s, s, is placed on the upper rim of the standard, and fitted
close, for the purpose of enclosing the mouth of the pan of the drum, which
casing has doors or flaps on the sides in order to give access to the interior.
In the upper part of the cover, at the end, an aperture is made, leading to a
ventilating box t, in which a revolving fan is mounted upon a horizontal axle,
having a pully at its extremity for the purpose of driving it, and a very rapid
rotatory motion is given to this fan by a band leading from a rigger j, fixed
upon the end of the crank- shaft p, and passing over this pully, as shown in
Fig. 2. The syrup or other fluid to be evaporated having. been introduced
into the pan, as before mentioned, and the steam admitted into the chambers
of the drum and the pan, in the manner above, explained, the flaps or doors of
the cover are to be shut down close in order to exclude the external air.
The moving power is now to be applied, by means of the winch v, or by any
other convenient means, through the train of toothed gear to the toothed
wheel u, fixed on the axle of the drum on the outside of the. framework.
Rotatory motion being by these means given to the drum, the hot syrup
becomes agitated, and a thin stratum of the syrup attaching itself to the
external and internal surfices of the drum, it is carried round as the drum
revolves, and the aqueous parts evaporated by the heat of the steam within,
which operation is greatly assisted by the action of the rotatory fan in the
box t. The fan is formed by four or more oblong blades, affixed to radial
arms extending from the horizontal axle, which blades fit closely to the interior
of the ventilating box, and by the rapidity of their motion when driven, produce
an exhaustion of the air within the box, which causes the vapour to rise
rapidly from the surface of the drum and from the liquor in the pan, and which
is thrown out through an opening in the side of the box at w by the centri-
fugal force of the fan. When the process of corporation is finished, the syrup is
drawn off through the valve x at the bottom of the pan, which is opened by
raising the weighted lever y, from whence it is carried to coolers, as usual.
Though I have described in the performance of this my improved process for
evaporating and concentrating of cane juice, solutions of sugar, and other fluids,
only one rotatory drum partially immersed in the pan, yet I do not mean to
confine myself to the employment of the particular construction of the appa
ratus set out in the Drawing, as I contemplate, under some circumstances,
when performing the operation of evaporation and concentration upon a large
scale, to introduce two, three, or more revolving drums into one pan, their
construction and mode operating being the sum as above described. And

page_text: further, I sometimes construct my drums or rotatory cylinders with four, six, or
more surfaces, by connecting several concentric cylinders one within the other,
and conducting the steam into their several chambers by hollow arms leading
from the central shaft, similar to those already described. And, lastly, I
desire it to be understood that my Invention of improvements in concentrating
and evaporating cane juice, solutions of sugar, and other fluids, consist in the
employment of the means and apparatus above described.
In witness whereof, I, the said John Aitchison, have hereunto set my
hand and seal, this Fifteenth day of March, in the year of our Lord
One thousand eight hundred and thirty.