IMPROVEMENTS IN APPARATUS FOR CONCENTRATING SACCHARINE FLUIDS
Year: 1852

page_text: LETTERS PATENT to Henry Bessemer, of Baxter House, Old Saint
Pancras Road, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN APPARATUS FOR CONCENTRATING SACCHARINE
FLUIDS."
Sealed the 4th May 1853, and dated the 19th November 1852.
PROVISIONAL SPECIFICATION left by the said Henry Bessemer at
the Office of the Commissioners of Patents, with his Petition,
on the 19th November 1852.
I, HENRY BESSEMER, of Baxter House, Old St. Pancras Road,
in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR CONCENTRATING SACCHA-
RINE FLUIDS" to be as follows:-
This Invention is intended to prevent the injurious effects of high
temperatures on saccharine fluids while undergoing the process of
evaporation in vacuum pans; for which purpose I use hot water as a
means of transmitting heat to the fluid under operation, although
other hot fluids may be used in lieu thereof, all such fluids being at
or lower than the ordinary boiling temperature of water, or 212
degrees Fahrenheit; warm air may also be used, or steam, at a
pressure not exceeding that of the atmosphere, may also be subşti-

page_text: tuted, as a means of transmitting the requisite low degree of heat,
although liquids will be found preferable, on account of the absence
of that amount of latent heat which steam contains. In consequence
of this reduction in the ordinary temperature applied to the fluid
inatters in vacuum pans, a much larger extent of heating surface
will be found necessary, in order not to lessen the evapora-
tive power of the pan; but as this augmentation of surface, if con-
sisting simply of additions to the usual horizontal pipe or worm
within the pan, would be apt to become clogged with the granulated
sugar, and would also impede the free circulation of the fluid, I
therefore prefer to use a series of vertical heating pipes suspended
from above and passing through the charge of liquor to within a
short distance of the bottom of the pan; these pipes are fixed to a
large circular plate, which is attached to a hollow central shaft, which
communicates by suitable passages with the vertical heating pipes
through which the hot fluid is made to circulate, and then return
through the other passage in the shaft. In order to facilitate the eva-
poration of the syrup, and to bring all parts of it into contact with
the heating pipes, the vertical central shaft and heating pipes are
made to revolve by suitable gearing acting on the outside of the pan,
the shaft working through a stuffing box. To prevent the access of
air to the interior of it, the central shaft is so constructed as to
admit of a vertical movement being given to it, which may be ef-
fected by hydraulic pressure or by a screw, or other convenient mode.
When the central shaft is lifted up, it carries with it the heating
pipes, which are fitted into a guide plate, through which they pass in
such a manner that in moving upwards through the plate the viscid
matter is scraped off from their surfaces and falls into the mass
below; a scraper is also fitted to the central shaft in such a manner
as to cleanse the bottom and sides of the pan, and thus deliver the
whole charge of concentrated matter to a suitable opening in the
bottom of the pan, which I prefer to construct of cast iron, or cast
yellow metal turned true on the inside, the body of the pan being cylin-
drical with a conical bottom, the whole being jacketted and heated
by a warm fluid.
To prevent corrosion of the interior, when made

page_text: of iron, it may be tinned, galvanized, or enamelled. The heating pipes
are to be placed a few inches only apart from each other, so as to
give a very large amount of heating surface equally distributed
throughout the whole bulk of fluid. The mode of forming the
vacuum and supplying the syrup from time to time is the same as
that usually employed in vacuum pans.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Bessemer in the Great Seal Patent Office
on the 19th May 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
HENRY BESSEMER, of Baxter House, Old Saint Pancras Road, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date the Nineteenth day of November, in the
year of our Lord One thousand eight hundred and fifty-two, in the
sixteenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Henry Bessemer, Her special licence
that I, the said Henry Bessemer, my executors, administrators, and
assigns, or such others as I, the said Henry Bessemer, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter 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 APPARATUS FOR CONCENTRATING SACCHARINE FLUIDS," upon the
condition (amongst others) that I, the said Henry Bessemer, by an
instrument in writing under my hand and seal, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the saine to be
filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Henry Bessemer, do hereby de-
clare the nature of the said Invention, and in what manner the same

page_text: is to be performed, to be particularly described and ascertained in
and by the following statement thereof (that is to say):-
This Invention is intended to prevent the injurious effects of high
temperatures on saccharine fluids while undergoing the process of
evaporation in vacuum pans; for which purpose I use hot water as
a means of transmitting heat to the fluid under operation, although
other hot fluids may be used in lieu thereof, all such fluids being
at or lower than the ordinary boiling temperature of water, or 212
degrees Fahrenheit; warm air may also be used, or steam at a pres-
sure not exceeding that of the atmosphere may also be substituted,
as a means of transmitting the requisite low degree of heat, although
liquids will be found preferable, on account of the absence of that
amount of latent heat which steam contains. In consequence of this
reduction in the ordinary temperature applied to the fluid matters
in vacuum pans, a much larger extent of heating surface will be
found necessary, in order not to lessen the evaporative power of a
pan;
but as this augmentation of surface, if consisting simply of ad-
ditions to the usual horizontal pipe or worm within the pan, would
be apt to become clogged with the granulated sugar, and would also
impede the free circulation of the fluid, a double or treble coil of
pipes may be used in lieu of the single coil now in general use; and
to avoid the clogging referred to, it will be found desirable so to
construct the said coils of pipe, that each portion thereof may be
placed vertically over the corresponding portion of the other coils,
whereby a free space will be left between them for a circulation of
the fluid to be carried on in a vertical direction; and by this simple
ineans a sufficient amount of heating surface and freedom of motion
may be obtained at a less cost, and with less complication, than an
arrangement of vertical heating pipes, which I thought preferable in
the early stage of the Invention; at the same time, such arrange-
ment may be resorted to if preferred: and here I would remark, that
neither arrangement of the heating surfaces forms any part of the
Invention which I desire to secure by these Letters Patent, and I
may state that the same beneficial results may be effectively (though
more slowly) obtained by the use of hot water or other fluid in the

page_text: ordinary coil of pipes now in general use. I have, however, pointed
out the mode which, according to my present knowledge, I consider
the most efficient and economical way of arranging the heating sur-
faces required in carrying out my Invention.
any
I have before stated, that hot fluids of various kinds may be em-
ployed for the purposes of this Invention, but I prefer water to any
fluid, and to use it at a temperature of about 130 to 140 degrees
Fahrenheit at the commencement of the process of concentration;
which temperature may be gradually increased to about 160 to 170
degrees Fahrenheit towards the close of the operation, because the
aqueous parts of the fluid are less easily separated as the syrups
increase in density.. The mode of heating the water, and causing
the same to circulate in pipes, is so well known, and so generally
practised for other purposes, that I do not consider detailed
account of such methods necessary, as any means by which the
temperature can be controuled and applied with facility and
economy, may be used both to the heating of water, or whatever
other fluids may be substituted or used in lieu thereof; with
regard to the use of steam at a pressure exceeding that of the
atmosphere, which is now used to transmit heat to saccharine fluids
in vacuum pans, I desire it to be distinctly understood that I
have discovered that an injurious chemical change is effected in
such syrups as are brought in contact with pipes in which there is
steam at a pressure exceeding that of the atmosphere, and con-
sequently of a temperature exceeding 212 degrees Fahrenheit, and
also that such injurious action is greatly reduced by lessening the
temperature of the heating media to points ranging from 130 to
170 degrees Fahrenheit or thereabout. But if, from any local or
other circumstance, it is desired to effect the concentration of
saccharine solutions in vacuum pans by the use of steam instead of
hot water, care should be taken that the pressure thereof be less
than that of the external atmosphere. And in order that steam'
may be kept at the low and requisite pressure, I establish a
communication between the discharge end of the steam coil and the
condensor of the vacuum pan; and upon the pipe which forms this

page_text: communication I place a loaded valve similar to an ordinary safety
valve, one side of which valve will be pressed upon by the steam in
the coil, while on the opposite side of it there will exist a vacuum
or nearly so; if, for example, we assume the atmospheric pressure
to be equal to 15 lbs. on each superficial square inch, and the valve
to be loaded to 9 lbs. per square inch, then, whenever the pressure
of the steam in the coil approached the pressure of the external
atmosphere within 6 lbs. per square inch, it will balance the loaded
valve, and any excess of pressure beyond that amount will raise the
valve and allow the steam to escape into the condensor, and thus
prevent any increase of pressure beyond that which is desired,
and which may be regulated by the weight applied to the loaded
valve.
The outside of the pan may be jacketed in the usual way, and if
steam at a pressure not exceeding that of the atmosphere be cm-
ployed, the same means may be used for securing the requisite low
temperature as before described, in reference to the coil of pipes
occupying the interior of the pan; so also, when water or other
heated fluids are used in lieu of steam, the jacket of the pan may be
used to assist in the transmission of heat to the saccharine fluid
therein contained. The mode of supplying the syrup from time
to time, the valve for discharging it, and the proof stick eye-hole,
and other general fittings of the pan, are constructed and used in
the ordinary manner.
The vacuum pans in general use are constructed of
copper, and
are very expensive, both on account of the material and the labor
entailed in their construction; I therefore prefer to construct the
pan of cast iron, the central or body part of the pan being of a
cylindrical form, and the upper and lower sides being cast
separately, and bolted by flanges to the cylindrical part. All
the joints should be turned truc, and the whole either galvanized
or tinned, to prevent the rusting of the iron; or the interior. may be
enamelled or coated with glass or other vitrious compound, after
the manner usually practised in such manufactures. This last-

page_text: named mode of protecting the surface of the iron will be found to
affect the sugar less than any metallic surface heretofore used.
Having now described the nature of my said Invention, and the
inanner in which the same is to be performed, I would have it
understood, what I claim is,-
Firstly, The use of hot water, or other heated fluids, at a tem-
perature not exceeding 212 degrees Fahrenheit, for the purpose
of transmitting heat to saccharine fluids contained in vacuum
pans.
Secondly, I claim the use of steam at a pressure not exceeding
that of the atmosphere, or below a temperature of 212 degrees
Fahrenheit, for.the purpose of transmitting heat to saccharine fluids
contained in "vacuum pans."
Thirdly, I claim the use of air or other aëriform fluids at a tem-
perature below 212 degrees of Fahrenheit, for the purpose of trans-
mitting heat to saccharine fluids contained in "vacuum pans;"
and I claim the mode herein described of regulating the pressure
of steam when used at a pressure below that of the atmosphere.
Lastly, I claim the construction of galvanized, tinned, or ena-
melled cast iron vacuum pans as herein described.
In witness whereof, I, the said Henry Bessemer, have hereunto
set my hand and seal, this Nineteenth day of May, in the
year of our Lord One thousand eight hundred and fifty-
three.
Witness,
FRANCIS HARRIS.
HENRY BESSEMER. (L.S.)