Improvements in Evaporating Apparatus.
Year: 1892

page_text: Date of Application, 4th Apr., 1892
Complete Specification Left, 22nd Dec., 1892-Accepted, 4th Feb., 1893
PROVISIONAL SPECIFICATION.
Improvements in Evaporating Apparatus.
We, FRANK WALTER SCOTT, of 44, Christian Street, Commercial Road, in the
County of London, Engineer, ERNEST GEORGE SCOTT, of Lord Street, Liverpool,
in the County of Lancaster, Consulting Chemist, and FRANK WALTER SCOTT
Junior, of 44, Christian Street aforesaid, Engineer, do hereby declare the nature
of this invention to be as follows :-
Our invention relates to apparatus for evaporating saccharine juices, brine and
other liquids.
In carrying out our invention we employ a pan containing a series of tubes
through which the liquids to be evaporated circulate and around which the heating
medium such as steam is caused to circulate, the part of the said pan below the heating
tubes being provided with jacketted walls through which steam and also, if desired, the
water of condensation from the space between the heating tubes are caused to flow.
We make the lower part of the said pan with inclined sides and at the bottom of the
same we place a kind of valve having recesses and adapted to be rotated in order to
effect the removal of the substances deposited during the evaporation.
We find it advantageous to arrange in conjunction with the heating tubes
an agitator which will during its rotation promote the circulation of the liquid.
We sometimes pass the liquids to be evaporated through a condenser in which
the steam escaping from the evaporator is condensed, whereby the liquid is more or
less heated before entering the evaporating pan.
It is to be understood that our improvements are applicable either to a single pan
or to a series of pans working with multiple effect.
...
A: 1000
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.
COMPLETE SPECIFICATION..
Improvements in Evaporating Apparatus.
We, FRANK WALTER SCOTT, of 44, Christian Street, Commercial Road, in the
County of London, Engineer, ERNEST GEORGE SCOTT, of Lord Street, Liverpool,
in the County of Lancaster, Consulting Chemist, and FRANK WALTER SCOTT,
Junior, of 44, Christian Street aforesaid, 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 :-
Our invention relates to apparatus for evaporating saccharine juices, brine and
other liquids, and to that class of such apparatus designed to work with a vacuum,
and which is provided with a system of heating tubes and with inclined lower walls,
and the chief object of our invention is to effect the continuous removal of the
substances deposited in order that the evaporating operation may be carried on
continuously, without destroying the vacuum.
In carrying out our invention we place at the bottom of the pan a kind of valve
for effecting the removal of the substances deposited during the evaporation, the said
valve being so constructed that at no time is direct communication established
between the atmosphere and the interior of the vacuum pan or vessel.
To enable our invention to be fully understood we will describe the same by
reference to the accompanying drawings, in which :-
Figure 1 is a sectional elevation of evaporating apparatus provided with our
improvements:

page_text: Figure 2 is an elevation of the valve for effecting the removal of the deposited
substances; and,
Figure 3 is a section of the said valve. on the lines 3-3 Figures 1 and 2:
Figures 4, 5 and 6 are views drawn to an enlarged scale illustrating the
construction of the valve, Figure 4 being a sectional plan, Figure 5 a section on the
line 5-5 Figure 4; and Figure 6 a section on the line 6-6 Figure 4.
Similar letters of reference indicate corresponding parts in the several figures.
a indicates the evaporating vessel having the inclined or conical bottom & and
containing a series of circulating tubes c and the large central tubes d, all as
well known.
e is the valve by means of which the deposited substances are removed from the
vessel a without necessitating the stoppage of the same. This valve, as shewn, is
provided with a plug f having in it two recesses g, g, the said recesses serving
to receive the deposited substances and being of such size that during the rotation
of the plug they will be completely cut off from communication with the vessel a
before being placed in communication with the discharge opening h. The said plug
is also made conical as we have found in practice that it is necessary to provide
a discharge valve of a construction in which wear can be readily compensated
for as otherwise after being in use a short time air would pass the valve and enter
the pan under the action of the vacuum.
We advantageously rotate the plug by means of a worm i and a worm-wheel j,
the said wheel j being carried upon a shaft k which extends through the plug
and which is connected with the same by means of a feather 1, so that the said plug
may be adjusted without interfering with the proper operation of the worm-gearing.
m, ml are fast and loose pulleys mounted upon the shaft carrying the worm i.
During the time that the evaporation of liquids is proceeding the said valve
may be caused to continuously rotate so that there shall be a constant discharge
of the solid substances as they are deposited or it may be intermittently rotated.
As in using a valve for discharging the deposited substances as hereinbefore
described, it is found that the air carried back in the recesses g, g into the pan has
an injurious effect upon the vacuum and thus upon the efficiency of the apparatus,
we provide for exhausting the air from the said recesses after they have discharged
their contents and moved out of communication with the atmosphere but before
moving into communication with the interior of the pan. This we advantageously
accomplish as follows:-
In connection with the casing of the valve e we arrange a valve-box n, one end o
of which communicates by a pipe o' with an opening in the valve casing in such a
manner that when either of the recesses g is empty and out of communication with
both the atmosphere and the interior of the pan it is in communication with the said
pipe, as shewn most clearly in Figure 6. The other end p of the said valve-box
is in connection through the nozzle p¹ with the ordinary exhaust pump used in
conjunction with vacuum evaporating apparatus. Between the two parts o, p of
the valve-box n is a valve 9 which is normally closed against its seat by a spring q
and the stem of which extends through a stuffing-box. Upon the shaft k of the
valve e and attached to the worm-wheel j is a cam having two projections 1, 1
which act against the valve stem to open the valve ? when the plug f of the valve e
is in the position shewn in Figure 6, thereby placing the one or the other of
the recesses g in communication with the exhaust pump.
It is to be understood that we make no claim to our improvements relating to the
exhaustion of the air from the recesses g, g of the discharge valve in the present
application as they form the subject matter of an application No. 20595 of 1892.
In order that the solid substances shall not deposit upon the inclined sides b, b of
the pan we preferably surround these inclined sides with a jackets, as shewn in
Figure 1, through which steam is passed to keep the liquid against the said walls
circulating so that the solid substances will fall to the bottom.
It is to be understood that our improvements are applicable either to a single pan
or to a series of paus working with multiple effect.

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The combination with an evaporating pan or apparatus working with a vacuum,
of a valve placed at the bottom thereof and having a recess or recesses designed to
be placed alternately in communication with the interior of the pan and with
a discharge opening to effect the removal of the solid substances deposited in such
recess or recesses during the operation of the apparatus, the said valve being provided
with a conical plug so that wear is compensated for to prevent leakage of air,
substantially as described.
2. In an evaporating pan or apparatus having a valve of the kind hereinbefore
described at its lower part for effecting the continuous removal of the solid
substances deposited, a jacket surrounding the lower part of the said pan or
apparatus, substantially as described.
Duted this 22nd dow of December 1892
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.