IMPROVED APPARATUS OR APPLIANCES FOR OBTAINING AND APPLYING AIR TO THE EVAPORATION OF SUGAR CANE JUICE, BEET ROOT JUICE, SYRUPS, OR OTHER LIQUIDS, AND TO THE DRYING OF SOLID OR PASTY SUBSTANCES
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Washington Hume at the Office of
the Commissioners of Patents on the 7th June 1881.
WASHINGTON HUME, of Buenos Ayres, South America, Associate Member of the
Institution of Civil Engineers.
"IMPROVED APPARATUS OR APPLIANCES FOR
OBTAINING AND APPLYING AIR TO THE EVAPORATION OF SUGAR CANE JUICE,
BEET ROOT JUICE, SYRUPS, OR OTHER LIQUIDS, AND TO THE DRYING OF SOLID
OR PASTY SUBSTANCES."
This Invention consists mainly in the particulars hereinafter set forth.
'The air to be used for the purpose, more or less dry, will be obtained by the
expansion into suitable passages or chambers of compressed atmospheric air which
has been previously cooled down while under compression by the several cooling
mediums mentioned further on. The amount of compression, cooling, and expansion
of said air being so proportioned one to the other that the temperature of the
expanded air may fall to a point somewhere below thirty-two degrees Fahrenheit
(32° F.), causing the contained moisture to freeze and be deposited in the shape of
snow or ice. The air, after having been freed from its moisture by this process,
will be used firstly to cool down the compressed air already mentioned, at the same
time becoming heated itself, then, after having its temperature still further raised
(if desired) by passing through an apparatus heated by direct fire or waste heat, it
will be brought into immediate contact and be mixed with the liquid which it is
sought to evaporate, and will then be allowed to escape into the atmosphere. The
compressed atmospheric air already mentioned being still under compression will
pass in succession through one, two, three, or more separate cooling vessels, in each
of which it will give up successive portions of its heat to the cooling mediums
contained in them, and from which it will be separated by conducting surfaces.
All these vessels will be in communication with one another by suitable passages
for the compressed air, so arranged however that any one or more of the series can
be cut off and the operation of cooling be continued in the remainder.
The cooling
mediums mentioned further on will be preferably different in each vessel and will be
kept entirely separate from one another. The order in which they will be used will
bo preferably as follows, but may be varied or reversed as desired, and one or
D971

page_text: more of the cooling mediums be dispensed with, the process being carried on with
the remainder, viz. :-
The hot compressed air in passing through the first cooling vessel or series of
vessels will give out a portion of its heat to the liquid contained therein, which it
will be the object afterwards to evaporate. In the second cooling vessel or vessels
it will give out a second portion of its heat to the cold dry air obtained in the
manner already described. In the third vessel or series of vessels (if it is desired to
still farther cool it) it will give out another portion of its heat to cold water or
other liquid, which; if water, can be afterwards used to feed-steam boilers, or for
other purposes. The liquid which it is. desired to evaporate, after having been
used in the first cooling vessel to partially cool down the hot compressed atmo-
spheric air as already described, will now be subjected to any intermediate
treatment which may be requisite before evaporation, and will then be passed on to
the evaporating pan where it will come into direct and intimate contact with the
dry air already described, and will be concentrated to any desired point, the
moisture being carried off into the atmosphere by said dry air.
: For drying solid or pasty substances the hot compressed air already mentioned
will be cooled down, first, by the cold dry expanded air, also already described,
and, secondly, by water or other liquid if it is desired to cool it still further, or
vice versa, or one or other of these cooling mediums may be omitted. The dry air
obtained as described for evaporating liquids after having been heated first by the
hot compressed air, and still further by passing through an apparatus heated by
direct fire or waste heat, will be passed backwards and forwards through closed
chambers in which the solid or pasty substances which it is desired to dry are
placed, after which it will be allowed to escape into the atmosphere.