Improvements in Apparatus for Evaporating or Concentrating Saccharine or other Crystallizable Liquids.
Year: 1899

page_text: Date of Application, 21st Nav., 1899-Accepted, 23rd Dec., 1899
Improvements in Apparatus for Evaporating or Concentrating
Saccharine or other Crystallizable Liquids.
We, Jons MCNEIL and CHARLES MCNEIL, both of the Colonial Iron Works,
Helen Street, Gova, in the County of Lanark, North Britain, Engineers, 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 follow-
ing statement, that is to say:-
Our said invention comprises certain improvements in the construction and
operation of apparatus for evaporating or concentrating saccharine or other
crystallizable liquids.
"Our invention has for its object the production of a better quality of sugar, a
higher yield of crystals, and the reduction of time taken to complete a charge.
This object is attained by having rotating heating surfaces at different levels,
and arranging that during the earlier stage of operation when the liquid forming
a charge is being filled in gradually and before crystallization takes place, to
mechanically assist the circulation of the liquid by means of a pump. In this
way the whole of the heating surface is continually in use, thereby effecting a
saving in time. In the final stage when the heating surfaces are fully immersed
by the liquid their rotation directs the path and causes a constant motion of the
crystals through the mother liquid, thus ensuring a more regular and uniform
crystal, as well as reducing the risk of the formation of false grain.
And in order that our said invention and the manner of performing the same
may be properly understood, we hereunto append three sheets of explanatory
drawings to be hereinafter referred to in describing our improvements.
Figure, 1, on Sheet, 1, of the drawings is a side elevation and Figure, 2, on
Sheet, 2, a front elevation of the improved apparatus. Figure, 3, on Sheet, 3,
is a longitudinal vertical section, and Figure, 4, a transverse vertical section of
a part of the improved apparatus. Figure, 5, is a side elevation, partly in
section, and Figure, 6, a transverse vertical section of details in connection
therewith. In these drawings the same reference letters and numerals are used
to mark the same or like parts wherever they are repeated.
In carrying out the invention the evaporating vessel, A, is made with a semi-
cylindrical upper part, with a curved lower part, and with flat vertical ends, A 1,
and it is supported on a framing A 2, fixed to the pillars, A 3. The requisite
heat for the process of evaporation, is applied by means of steam admitted to
hollow lens-shaped disks, B, shown on Sheet, 3, of which disks there are three
The
sets on three separate hollow shafts, C, two upper ones and one lower one.
shafts, C, are arranged in stuffing box bearings, C1, fixed or formed on the
end plates, C1, of the vessel, A, to which are externally connected pipes, D,
with stop valves, D1, for admitting steam, similar pipe connections D2, for
drawing off water of condensation being provided at the other ends of the
shafts. The steam on entering each hollow shaft, C, passes into a compart-
ment, D3, (Figures, 5, and 6) formed within the shaft and then enters by

page_text: ports, D4, compartments, B 1, formed within each disk by partitions B2. The
water of condensation passes out of each disk into the hollow shaft by ports, D 5,
and is thereafter discharged by a drain pipe, D2, fixed to the stuffing gland.
The hollow disks, B, for each shaft, C, are formed to fit a key or feather, E,
(Figure, 6) fixed to the shaft and they are firmly jointed together by nuts, E 1,
working on a screwed part of the shaft, the nuts pressing the disks as a whole
against a shoulder, E2, formed on the shaft. The disks are suitably
strengthened with internal ribs, 133, to prevent any tendency to buckling.
whilst the form of joint between each disk is such as to prevent the slightest
liability to leakage. The hollow shafts, C, are driven by means of spur-
wheels, C2, with one of which there gears a pinion F, on a shaft, G, having
also on it fast and loose pulleys, G1, driven by a belt, G2, from a steam
engine, H.
The juice or saccharine liquid to be evaported is supplied to the vessel, A,
by a pipe, J, proceeding from a direct-acting steam pump, K, and enters the
'vessel by two branch pipes, J 1, which cross the vessel and have a number of
small tubes, J2, projecting downwards for pouring the liquid over the two
upper sets of rotating hollow heating disks, B. The juice forming one charge
of the vessel, A, is filled in gradually, the lower heating disks, B, being first
partly immersed and then wholly immersed; the juice in rising next gradually
immersing the upper two sets of disks, 33, this mode of working making the
evaporating action expeditious. During the first stage of an operation and whilst
the juice or saccharine liquid is being filled in, it is made to circulate; and for
this purpose the juice is continually withdrawn from the lower part of the
vessel, A, by a pipe, L, (which has the supply pipe, L1, connected to it at the
stop valve, L2) which is connected to the inlet or suction part of the steam
pump, K, the pump forcing the liquid up through the pipes, J, J1, J2, so
as to descend in a number of small jets upon the hollow rotating heating
disks, B. At the same time the liquid is being kept thoroughly mixed by
mixers or blades, B4, fixed to angle iron bars or frames, B5, helically fixed
to the rotating disks, B.
In the final stage and after crystallization has taken place the mechanicai
_circulation of the liquid by means of the pump, K, is discontinued and the
further supply of the liquid for building up the grains is carried on in the usual
way.
The circulation and mixing of the liquid in the manner described, produces
many important and advantageous results, principal among which are that the
quantity of first sugars obtainable from a given initial volume of syrup is much
increased, the quality of the sugar is improved, the crystals being more regular,
while one of the principal causes of the formation of false grain" is to a great
extent eliminated, and also violent ebullition which causes suspension of liquid
particles in the vapor is prevented. When a charge of the liquid has become
sufficiently concentrated it is emptied from the vessel, A, through a discharge
valve, A4, fitted at the bottom of that vessel, into a receptacle (not shown) then
placed below to receive it.
The top of the vessel, A, is connected with vacuum producing apparatus by
a large pipe, M, but before entering this pipe the vapor passes through appliances
for separating particles of liquid carried up in suspension in the vapor. The
lower end of the pipe, M, communicates with a box, M1, (Figures, 3, and 4)
occupying a middle part across the space at the upper part of the vessel, A,
and this box has extending through it and entirely across the vessel, A, two
tubes, M2, which within the box have openings, M3, at their inner sides,
.whilst between the box and the end plates of the vessel they have openings, M 4,
at their tops. Below the box, M 1, a dished plate, M5, fixed to snugs, M6,
. on the end plates, A 1, extends angularly across the vessel, but with spaces at
the sides for the passage of the vapor, and there are central vertical plates, M7,
in the spaces between the box, M1, and the end plates. With this arrangement

page_text: the rising vapor passing the edges of the dished plate, M 5, strikes the plates, M 7,
and then finds its way by the tubes, M2, into the box, M 1, and thence into
the ascending pipe, M, the effect being, by the baffling of the currents of vapor
to promote the separation from it of suspended particles of liquid. Draining
holes, M3, are formed in the box, M1, and the tubes, M2, to allow the separated
particles of liquid collecting in the box and the tubes to fall onto the dished
plate, M5, from which the liquid is drained back again into the vessel over the
lower end of the plate and small draining holes may also be formed in the plate
at suitable parts to further quicken the draining action.
The ascending vapor pipe, M, is connected to a jet condenser, N, supplied
with cold water by a pipe, N 1, and connected by a pipe, N 2, to an air pump, P.
From the bottom of the condenser, N, a pipe, N3, for the discharge of water,
descends sufficiently far down to form a Torricellian vacuum column. The
water as well as the air might, however, be withdrawn from the condenser by
means of pumps.
The discharge pipe, P1, of the air pump, P, is by branch pipes P2, and
stop valves, P3, connected to the suction pipe, N 2, so that the pump may be
made to pump air through the condenser, N, and pipe, M, into the vessel, A, in
order to apply pressure in that vessel when discharging a charge of concentrated
juice or liquid from it, a valve, N 4, on the pipe, N3, being then closed.
Pressure gauges, Q, safety valves, R, and other appliances are provided as
is usual with apparatus for evaporating or concentrating juices or saccharine
liquids.
Instead of there being within the vessel three heaters as in the example
herein before described and shown in the accompanying drawings there may be
five arranged with two at the lower level and three at the upper level. And
instead of external pumps being used for producing circulation, as herein before
described, a centrifugal or other suitable pump may be arranged within the
vessel, with a shaft extending out through a stuffing box to be driven externally;
or combined with a rotatory or other suitable motor placed within the vessel.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
: -
1. In apparatus for evaporating or concentrating saccharine or other crystal-
lizable liquids, a series of hollow lens-shaped disks, fixed upon a hollow shaft,
with means for admitting steam thereto and withdrawing water of condensation
therefrom, substantially as hereinbefore described with reference to the accom-
panying drawings.
2. In apparatus for evaporating or concentrating saccharine or other crystal-
lizable liquids, the combination in one vessel of two or more heaters, such as
are claimed in the preceding claim, substantially as herein before described with
reference to the accompanying drawings.
3. In apparatus for evaporating or concentrating saccharine or other crystalliz-
able liquids, and in combination with rotating heaters, a pump for causing the
juice or liquid to circulate by withdrawing it from one part of the evaporating
vessel, and reintroducing it at another part substantially as herein before described
with reference to the accompanying drawings.
4. In apparatus for evaporating or concentrating saccharine or other crystalliz-
able liquids, pipes fixed across the upper part of the evaporating vessel, having
downwardly projecting tubes, for pouring or distributing the circulating juice
down on the rotating disks or heaters, substantially as herein before described
with reference to the accompanying drawings.
5. In apparatus for evaporating or concentrating saccharine or other crystalliz-
able liquids, mixers or blades fixed to frames helically fixed to the rotating disks
or heaters, substantially as and for the purposes herein before described with
reference to the accompanying drawings.

page_text: 6. In apparatus for evaporating or concentrating saccharine or other crystalliz-
able liquids a box fixed to the upper part of the evaporating vessel having tubes
passing through the box, and extending out from it entirely across the vessel,
the portions of the tubes within the box and outside of it, being formed respec-
tively with side and top ports or openings, a curved plate being fixed under the
box, and vertical plates to the sides of the box for the purpose of baffling the
currents of vapor, and effecting the separation from it of suspended particles
of liquid before entering the pipe leading to the vacuum producing apparatus,
substantially as herein before described with reference to the accompanying
drawings.
Dated this Twentieth day of November 1899.
EDMUND HUNT,
Applicants' Agent.