Improvements in Apparatus for Evaporating Saccharine or other Solutions or Liquids.
Year: 1888

page_text: Date of Application, 6th Feb., 1888
Complete Specification Left, 16th Oct., 1888
Complete Specification Accepted, 16th Nov., 188
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Evaporating Saccharine or other
Solutions or Liquids.
I ALFRED CHAPMAN, of the firm of Fawcett Preston and Company, of 17 York
Street, Liverpool, Engineers, do hereby declare the nature of this invention to be as
follows:-
The efficiency of apparatus such as is generally employed for the evaporation of
saccharine or saline solutions whether by simple, double or multiple effect depends in
a great measure upon the circulation maintained in them of the liquid to be treated.
With the ordinary construction in which a number of vertical tubes pass through a
steam drum in the evaporating pan or vessel the liquid is delivered to the pan at the
part thereof which is below the drum then rises through some of the tubes, descends
through others of the tubes and then leaves the pan by an outlet at the lower part, the
vapour which is given off rising to the upper part of the pan and being conveyed to
the steam drum of the next pan of the series or to a condenser. Various arrangements
have been proposed for ensuring a good circulation of the liquid through the tubes
which pass through the steam drum, such for example as making some of these tubes
larger than the others, or by employing tubes within tubes in a manner resembling
Field boiler tubes so that the liquid may travel in the one direction through the inner
tubes and in the other direction through the annular spaces between the inner and
outer tubes. But these arrangements have not always proved satisfactory in working.
Further, in the arrangements hitherto employed there is a tendency for some of the
liquid to flow from the inlet to the outlet of the pan without any portion of it being
evaporated.
Now according to my invention I construct the pan with a steam drum as usual and
in this drum I fit a number of vertical tubes through which the liquid under treatment
will flow or circulate upwards as in an ordinary evaporating pan, but for the down-
ward flow of the liquid I provide one large tube which is preferably in the form of an
inverted cone though a cylindrical tube will answer. This tube is placed within
another tube an annular space being left between them which will serve as one of the

page_text: channels for the upward flow of the liquid. The exterior of the tube for the down-
ward flow of the liquid is thus not in contact with the steam in the drum. Instead of
allowing-this tube to discharge the liquid into the lower part of the pan as usual I
continue it to the outlet from the pan and I do not otherwise normally connect the
outlet with the liquid space of the pan. Thus while a good circulation of the liquid is
ensured none of it can reach the outlet without having first passed up through the
tubes in the steam drum and then down the large tube which is connected with the
outlet. In order to be able to run the liquid in case of need from the bottom of
the pan direct to the outlet or from the bottom of the large tube into the bottom
of the pan, I fit the connection between the large tubo and the outlet with a cock
which can be operated from the exterior of the pan so as to open a direct communica-
tion between the bottom of the pan, the large tube and the outlet.
Another part of my invention consists in vertically dividing the portion of the pan
which is below the steam drum into two or more parts, the division or divisions being
extended above the drum to a certain extent. The drum is fitted with as many of my
large tubes for the downward flow of the liquid as there are divisions, that is to say,
one such tube for every such division; the lower end of the large tube of the first
division is in communication with the second division, the lower end of the large tube
of the second division is in communication with the third division and so on, the
lower end of the large tube of the last division being in communication with the
outlet from the pan. The liquid rises up the small tubes of the first division then
descends the large tube of sane, next goes to the second division, rises and descends
as before and so on until it reaches the outlet. All the vapor given off from the
several divisions collects as usual at the upper part of the pan which is not divided
except to a sufficient extent to ensure that the liquid which has ascended the tubes of
one division shall descend the large tube of the same division.
Dabad thin th
1000

page_text: 1st division runs over into the vertical channel or way d which conducts it to the
bottom of the 2nd division and so on as indicated by the arrows; the channel d of
the last division is connected with the next pan of the series or with the extracting
pump when there is not a further pan. Figure 12 is a vertical section on a larger
scale of a cylindrical pan formed into divisions by partitions and m as hereinbefore
described and fitted with a valve which can be operated from the exterior of the pan
so as to open a direct communication between the bottom of the pan, the large tube d
and the outlet whether such outlet be that communicating with the next division of
the pan or with the next pan of the series or with the extracting pump. n is the valve
having its seat in the bottom of the pan; it carries a tube p the upper end of which
fits the large tube d which is cylindrical. The valve and its tube are supported by a
screw spindlog fitted with a hand wheel r outside the pan. By turning the spindle
the valve n and its tube p are lifted so as to open direct communication between the
tube d (through the tube p) the bottom of the pan and the outlet f.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
1 claim, in respect of apparatus for evaporating saccharine or other solutions or
liquids, is :-
1. Constructing evaporating pans which have tubes passing through a steam drum
for the upward flow of the liquid under treatment with a tube or way for the down-
ward flow of the liquid from the upper part of the pan, the said tube or way and its
outlet not being in direct communication with the part or space of the pan below the
drum but in communication with the part or space above the drum, whereby no
liquid can reach the said tube or way or its outlet without having passed up through
the tubes in the drum, so that a good circulation is onsured, substantially as herein-
before described.
2. Constructing evaporating pans which have tubes passing through a steam drum
for the upward How of the liquid under treatment, with one or more partitions
separating the pan into 2 or more divisions which so far as the liquid is concerned
have no communication with each other except by a tube or way which conveys the
liquid from the part or space above the drum in one division direct to the part or
space below the drum in the next following division, substantially as hereinbefore
described.
3. In evaporating pans which have tubes passing through a steam drum for the
upward flow of the liquid under treatment and in which there is a tube or way for the
downward flow of the liquid from the upper part of the pan which tube with its outlet
is not normally in direct communication with the part or space of the pan below the
druin, I claim a valve which can be operated from the exterior of the pan so as when
required to open direct communication between the bottom of the pan, the down-flow
tube, and the outlet, substantially as hereinbefore described.
4. The several arrangements of evaporating pans herein before described and
represented in the annexed drawings.
1000
J. C. MEWBURN,
169, Fleet Street, London,
Agent.