IMPROVEMENTS IN OR APPERTAINING TO PROCESSES " FOR EVAPORATING OR CONCENTRATING SACCHARINE, SALINE, OR OTHER SOLUTIONS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by William Phillips Thompson at the
Office of the Commissioners of Patents on the 21st December 1882.
A communication to him from Monsieur Achille Gilain a person resident at
Embresin in the Kingdom of Belgium
WILLIAM PHILLIPS THOMPSON Fel. Inst. P.A. of the Liverpool and London
Agency for Foreign Patent Solicitors 6 Lord Street Liverpool in the County of
Lancaster, Civil Engineer "IMPROVEMENTS IN OR APPERTAINING TO PROCESSES
"
FOR EVAPORATING OR CONCENTRATING SACCHARINE, SALINE, OR OTHER SOLUTIONS
a communication to me from Monsieur Achille Gilain a person resident at Embresin
in the Kingdom of Belgium
(The following being the description of the invention substantially as communi-
cated to me in French by my foreign correspondent.)
For many years the problem of the evaporation of liquids has occupied attention;
the numerous researches made to arrive at a practical and economical result testify
to the importance of this question. Already the invention of apparatus for
evaporating in vacuo has made great progress and the continued efforts of industry
tend every day towards its establishment.
In the vacuum evaporating apparatus at present employed, steam has always
been utilized as the source of heat either direct from the generators or the exhaust
steam from engines.
The present invention consists in employing for the evaporation and concentration
of saccharine, saline, or other solutions, of vacuum apparatus in single double or
multiple effect, in which steam is no longer introduced into the pan (or into the
first one, if there be a series), but in which the pan is subjected to the action of
furnace gases, and consists more especially in placing the pan in that part of the
course of the gases comprised between the last Hue of one or more generators, and
the chimney, so as to recover the waste heat escaping from the boilers.
These hot gases traversing the tubular system of the apparatus evaporate the
liquor contained therein and the vapours produced pass to the condenser and air
pump if there be only a single pan or to the vapour space of the second pan if
there be a series where they serve afresh as a source of hent. In this latter case,
the remainder of the apparatus is exactly similar to the vacuum evaporating
apparatus in multiple effect, described in all the works treating of the subject. It
is this last arrangement with the utilization of the waste furnace gases from the
boilers which will be most often applied in practice.

page_text: In order to come as near as possible to the arrangement which will be most
frequently employed in practice, we will suppose the tubular pan fixed in the rear
of a group of generators and connected directly to another pan which receives the
vapours and liquor from the first and which is itself connected to a third pan which
sends its vapours to a condenser and air pump; the whole forms an apparatus for
the circulation of liquor and vapours analogous to vacuum evaporating apparatus
in triple effect. It is evident that the pan in the flue can if desired be connected
directly to an air pump or to another pan or group of evaporating pans.
The tubular pan is constructed of iron plates with bronze or cast or wrought iron
tube plates fitted with iron or brass tubes (the sum of the tube sections can ho
equal to or even less than the section of the chimney); it is also provided with all
the appliances for the introduction and withdrawal of liquor besides the usual
accessories of a vacuum pan, such as a manometer, thermometer, glass sight-holes,
"robinets à beurre" et cetera. A flue is formed under the pan provided with
dampers, by regulating which the furnace gases may be passer direct up the
chimney without passing through the tubes, and the amount of gas passing through
the tubes may be increased or diminished as desired. A door is also provided for
cleaning the tubes when the gases are shut off. The vapours pass from the top of
one pan to the vapour space of the next by a pipe leading through a safe, for
catching any liquid primed over, and from the last pan they pass to the condenser
and air pump. The charging and discharging of the liquor and the production of
the vacuum are effected as in ordinary apparatus in triple effect.
In short the present invention permits of the direct utilization of the waste
gases from a furnace or in the flues of generators, for evaporation in vacuo by
means of tubular apparatus in single or multiple effect. This evaporation and
waters,
concentration can be applied to saccharine and vinous solutions, "osmose
the liquids obtained in the processes of lixiviation and chemical substitution, saline
and other solutions, and can be continued to the point of crystallization. The
description of the invention demonstrates the economy of fuel which it will effect
and the services which it will render to works already established the evaporating
power of which it permits of increasing at small expense.
The advantages claimed for this invention are as follows:
First. The employment of the direct heat of the flames gives a considerable
economy in fuel over that in the case of steam, in which the waste due to
production is increased by that due to condensation in the tubes, and leaks aro
inevitable
Second. The employment of the tubular pan placed at the back of the boilers
permits of the recovery of the heat wasted by the chimney and which in most works
far exceeds what is necessitated by the draught.
Third. The employment of the tubular pan placed as just indicated permits for
the cost of fixing alone, of increasing without extra consumption of fuel, the
evaporating power of vacuum apparatus which in the majority of cases, notably in
sugar works, have not nearly sufficient power.
Fourth. The employment of this pan permits of adling if required to the
vapoure produced in it and which pass to the next pan, exhaust steam from engines,
which correspondingly increases the power of the following pans.
Fifth. The employment of the process permits of passing in exhaust steam from
engines and thus permits of using engines of the most improved kind with variablo
expansion and of the condensing type from which a considerable economy in fuel
results: