Improved Method and Apparatus for the Treatment of Bagasse.
Year: 1896

page_text: Date of Application, 4th Apr., 1896-Accepted, 9th May, 1896
COMPLETE SPECIFICATION.
Improved Method and Apparatus for the Treatment of Bagasse.
I, JEAN PÉRICHON, of 15 Rue des Halles, Paris, France, Engineer, do hereby
declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement :-
This invention relates to improvements in the treatment of bagasse and its
object is to extract therefrom, by washing after the first or second passage through
the roller-mills, the largest possible amount of juice of the greatest possible
density.
The method I adopt for this purpose unlike the diffusion-process commonly
employed, enables the roller-mills to be made use of, and the apparatus and its
operation to be simplified, and, whilst enabling working to be conducted with
economy, ensures a high yield.
In the accompanying drawings,
Fig. 1 is a front elevation, Fig. 2 an end elevation, and Fig. 3 a plan, of
apparatus arranged in a special building, for carrying out my invention.
A and A' are heating-tanks containing pure water heated to about 97° C. or
water mixed with a certain amount of normal juice that is to say juice extracted
by the first pressing or of juice resulting from one of the subsequent pressings.
B1, B2, B,.... B' and 1, 3, 3....67 are washing vats, preferably mounted on
wheels, and each capable of being tipped on trunnions for the purpose of being
completely emptied; they are mounted on two parallel tracks in two series or rows
each containing a suitable number of vats. The vats are charged with bagasse
that bas been more or less crushed and which is brought and discharged into them
by a conveyor, which may be in the form of an endless jointed apron acting as a
large horizontal belt. The bagasse may have been saturated with juice on its passage
from the rolls, but it is usually in the ordinary condition of crushed or recrushed
bagasse. This bagasse is allowed to soak in liquid in the vats during a sufficient
period of time, such soaking being repeated a suitable number of times with fresh
liquid for each soaking operation. A device M arranged at the lower part and at
the side of each vat enables the liquid to be run off. Above the washing-vats
there are arranged heating-tanks C, C, C. C in which juice supplied
thereto is heated by means of coils or bundles of pipes or tubing through which
steam is caused to pass, after which the juice is discharged from the said vats.
Below the washing-vats there are arranged discharging-troughs O', 02, 0³.....07
and o¹, 02, 03. o corresponding to the vats B', B6, B ..... B and b', 66,
666 P1, P2, P3
P are pumps that serve to draw liquid from the
troughs 0, 02, 03... O and o', 02, 03.... o alternately and lift it into the
beating-tanks C, C², C³... C. The pump P' draws liquid from the troughs O'
and o alternately and delivers it to the defecating-apparatus in the factory.
Above the washing-vats there are also arranged spraying-devices R, which serve
to distribute the soaking-liquid in a uniform manner over the bagasse contained in
the vats.
The washing-vats have false bottoms of perforated sheet metal, and each is
provided in its upper part with a perforated or reticulated cover, which enables the
bagasse to be kept at a constant level, whilst pressing it gently upon the false
bottom during the washing. Each cover may be movable so that it may enable

page_text: the bagasse to be alternately compressed and allowed to expand in a vertical
direction for the purpose of promoting the mixing of the liquids by absorption
and re-absorption. The number of washing-vats to be used is determined by the
degree of density which it is desired that the juice shall have after the washing is
completed.
It will be seen from the drawings that the same heating-tank and the same
pump are employed for a vat of the series B and the corresponding vat of the
series b alternately. This constitutes a considerable improvement in the plant.
The washing-vats having been charged and being in the positions shown in the
drawings, soaking first takes place, as regards the series B, in the vat B' and with
pure water heated to 97° C. and supplied from the heating tank A. The liquid
run off from this vat and drawn up by the corresponding pump serves for soaking
the bagasse in the vat B6, and so on. The same takes place with the series of
vats 6 which is supplied from the heating tank A'. Or one tank may be used for
delivering liquid to the tanks, whilst the liquid in the other is being heated in
readiness for subsequent use. When the liquid of the vat B' runs off into the
lower trough 07, the apparatus is in full operation; and as soon as the liquid in
this vat has been completely run off, a fresh vat B is coupled up in the position
indicated by dotted lines, and the row of travelling vats is caused to move foward
through the length of a vat; and so on. The apparatus will be in full continual
and intermittent operation as soon as the vat B has arrived in the position of the
vat B'; and the contents of every vat that is uncoupled and moved out of the
building will thenceforth have been subjected to seven successive washings. The
same operation takes place with the series of vats b, so that the plant is double-
acting. The period during which the washing-liquid remains in contact with the
bagasse in each vat is longer or shorter according to the capacity of the vats; but
this period should never be less than six minutes.
I shall now proceed to describe the progress of the liquid when the apparatus is
in full operation.
The washing-liquid in the vat B' having been run off into the trough O¹, the
pump Praises it into the heater C' wherein it is heated again before being
discharged over the bagasse in the vat B6, with which it remains in contact for six
minutes at least; after this time the soaking-liquid is run off into the trough 02
whence it is delivered by the pump P2 into the heating-tank C, wherein it is
heated, and then discharged over the bagasse in the vat B; and so on until it
reaches the pump P', which finally delivers the washed-out juice from the vat B'
to the factory, where it undergoes defecation. The defecation may, however, be
begun or carried out in the washing-vats or in the heaters.
It will be noted that whilst the liquid is travelling from A B O¹ P' to B' O'P',
the washing-vats are travelling in the contrary direction-namely, from B' to B
the train of seven vats of each of the series B and moving forward through
exactly the length of a washing-vat after each washing. Hence, in order to ensure
the perfect working of the process, the work of the two series of vats must
alternate. That is to say whilst liquid is being delivered to the vats of one series,
and bagasse is being soaked therein in the liquids of various degrees of richness in
syrup, the other series of vats is draining; at the same time each pump is drawing
the liquid drained off alternately into the trough 01 02 etc. of the series B, the
troughs o' o* etc. of the series b, and delivering it to the heating tanks C¹ C³ etc.
above.
When the bagasse in the vat B' has received its seventh and last washing, which
is generally effected with pure water heated to 97° C., and when the washing
liquid has been run off into the trough O', the train of washing vats is caused to
move forward through the length of a vat, after having had coupled to it a vat B
filled with bagasse supplied by the conveyor. The vat B' then moves into the
exit-position B'; and it is now uncoupled from the train, and sent to a conveyor
or other discharging-apparatus, where the bagasse is preferably discharged by
tipping to be again sent to the crushing-mill.

page_text: With the object of increasing the density of the washed-out juice, I may
employ a certain quantity of ordinary defecated or undefecated juice coming from
the mills, to fill up the first washing-vats B1, and 6, this mixing of ordinary juice
with the washing-liquid being effected either in the washing-vats or in their
heaters.
I may likewise use the liquid produced by the mill that recrushes the washed
bagasse and I may cause it to enter at any point or at any time during the washing
of the bagasse, by mixing it or not, with the washing-liquid. This return-juice
may, moreover, he extracted from the washed bagasse by centrifugal separation or
by means of a slight pressure produced by a suitable apparatus.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The hereinabove described method of washing bagasse consisting in placing
the bagasse in two parallel series of vats B¹, B',...... B' and b, b,.... b,
running the said vats under two series of spraying-devices R and soaking the
bagasse contained in the series of vats in the liquid supplied thereto, by the
spraying devices, running off the liquid from each series of vats in turn into corre-
ponding lower troughs and pumping it into the heating-tanks whilst bagasse is
undergoing soaking treatment in the other series of vats, so that each pump will
deliver liquid from a vat of each series alternately into the corresponding heating
tank, moving forward each series of vats, after the liquid has been run off there-
from, to a sufficient extent to bring each vat of the series, except the front one,
into the place previously occupied by the adjacent forward vat and then supplying
fresh liquid thereto for effecting a further soaking of the bagasse, these operations
being repeated intermittently, the front washing vat of each series being removed
and a fresh washing vat being put into place at the rear of each series of vats, at
each forward movement thereof, substantially as hereinbefore described.
2. For carrying out the method referred to in the preceding claim, apparatus
constructed and operating substantially as described and shown."
Dated this 4th day of April 1896.
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.