IMPROVEMENTS IN EVAPORATING APPARATUS
Year: 1888

page_text: 1, SAMUEL MORRIS LILLIE, of Philadelphia, State of Pennsylvania, U.S.A., Chemist,
do hereby declare the nature of my invention for IMPROVEMENTS IN EVAPORATING
APPARATUS and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
My invention has reference to evaporating apparatus especially adapted to sugar
refining; and consists in new means for feeding the evaporating tubes of the same
with the liquid to be evaporated, and in modifications in the arrangement of the
collecting chamber to make it more effective in collecting or separating the liquid from
the vapors which pass with it from the ends of the evaporating tubes into the collecting
chamber.
The former consists of means for feeding the evaporating tubes by overflowing the
upper edges of the same, or of feeding tubes leading to them with the liquid to be
evaporated, the said upper edges of the tubes being approximately in the same hori-
zontal plane, and as adjuncts to the same, of devices for facilitating an even distribution
of the liquid among the tubes and for compensating for any differences in level among
the said upper edges of the tubes. The latter consists in an annular chamber surround-
ing or partly surrounding the collecting chamber through which the vapors of
evaporation escape from the latter and in which particles of liquid held in mechanical
suspension by the vapor are separated from the same by the centrifugal force due to
the circular path of the vapors.
In the drawings :-
Fig. 1 is an elevation showing a multiple effect evaporating apparatus embodying
my invention.
Fig. 2 is a sectional elevation of one of my improved evaporators or pans with its
adjuncts.
Fig. 3 is a cross section of same on line y y.
Fig. 4 is a plan view of the lower head removed from the evaporator or pan.
Fig. 5 is an elevation of the regulator for controlling the supply of thin liquor to
the pan.
Fig. 6 is a sectional plan view similar to Fig. 3 showing a modified arrangement.
Price 8d.

page_text: Fig. 7 is a cross section showing an enlarged view of the construction for feeding the
evaporating tubes, and
Fig. 8 is an elevation with part in section of a modified form of my evaporator
or pan.
Referring to the drawings, E is a heating or steam chamber containing a battery
of vertical evaporating tubes, which open below through the tube plate p into the
collecting chamber P, and above through the tube plate into the feed chamber G,
into which they extend for a short distance and have their upper edges all lying in the
same horizontal plane as nearly as may be. A little above the upper ends of the
tube, is a plate having perforations g in it, and above which is the dome D.
Extending through or supported in or by the plate p² are tubes c, one for each
evaporating tubs b. Each tube is of larger diameter than its evaporating tube,
surrounds the latter and is concentric with it, thus forming between the two the
annular passage, which communicates below with the surrounding space in G. The
purpose of the feeding tubes c and their annular passages n is to insure an equal
supply of liquor to the several evaporating tubes irrespective of slight differences
in the level of the liquid in the feed chamber Gabove the evaporating tubes, which is
caused by the contracted passages n requiring a head of liquid above the tops of the
tubes to force the liquor through said passages. The section of each tube above
the evaporating tube, and by which it extends through the plate p if made as shown
in Fig. 7 is preferably of a reduced diameter as shown at c. The dome D has
approximately vertical side walls provided with a man hole or door, and is closed
above by the cap De bolted to flanges in the side walls of the dome. The dome has
a feed pipe U opening through it near the center and top and it supports directly
below the mouth of the said feed pipe a distributing plate or diaphragm which
may be perforated, as shown in Fig. 8, or not perforated as indicated in Fig. 2.
When perforated as shown in Fig. Sa portion of the liquor may pass through the
perforation and the remainder overflow the edges of the diaphragm onto and down
the side walls of the dome.
Any vapors which may be formed in the dome or which may escape into it from
the evaporating tubes may pass by a passage or pipe V communicating with the
interior of the dome below the diaphragm D, to the collecting chamber. The collecting
chamber is divided by the vertical cylindrical partition T which bends outward at T
to meet the outer wall T2 forming the curved, circular or annular surrounding
chamber which connects at one end with the compartment Pat P and at the other
end with the vapor outlet main B. In the outer wall opposite the passage between
the inner compariment and the annular chamber is a man hole P closed by a door
by opening which access may be had to the compartment into which the lower ends
of the evaporating tubes open.
•
In the annular compartment may be placed one or more concentric partitions T
which may rest on the false bottom K with which the annular chamber is provided;
the inner face of the outer wall T2, and also of each of the concentric partitions T',
bas on its face the ribs or ledges t¹ inclining from the face of the wall towards the
passages from the annular chamber to the inner or collecting chamber P. At the lower
end of each ledge there is a perforation; through the false bottom into the gutter J
below it, which gutter J leads into a passage which delivers from the collecting
chamber into the float chamber F by the inclined floor A' of the lower head A of
the evaporator.
A float in the float chamber F arises and falls with the level of the liquid
in the chamber, and through the lever F2 and connecting mechanism f¹ a butterfly
valve Fs in the pipe e which brings the liquid to be evaporated to the pan is operated
in such manner that as the float arises the valve closes, and as it falls the valve opens
in proportion.
A discharge pipe d leads from the float chamber to the pump C, which delivers
through the pipe into the dome D of the pan, or through the branch away
from the pan, in a multiple effect, for example, to the next pan of the series as shown
in Fig 1

page_text: The operation of this pan in evaporating or concentrating a liquid is as follows.
The liquid to be concentrated flows by the supply pipe and the pipe through
the cap of the dome upon the distributing plate or diaphragm, thence onto and
down the side walls of the dome upon and over the perforated plate through
whose perforations it flows into the feed chamber G, whence it overflows the upper
edges of the evaporating tubes b, which edges lie all in the same horizontal plane.
The liquid then flows in thin films down the inner surfaces of the tubes suffering
evaporation in its course due to a heating agent, as steam, supplied to the heating
chamber E, by the main S. The unevaporated concentrated liquid falls from the
bottoms of the tubes, together with vapor formed by the evaporation, into the
interior chamber of the separating chamber P and Hows by the passage f into
the float chamber, whence it is drawn by the pump C and is delivered away from
the pan (see arrows Fig. 2) by the discharge pipe which is the supply pipe of
the next cooler pan in the case of a multiple effect.
The rate of feed of the thin liquid from the supply pipe to the pan is governed
by flow of concentrated liquid from the discharge pipe and the automatic action
of the float. If the discharge is increased by opening wide the valves (see right
hand side of Fig. 1) the level of the liquid in the float chamber and consequently
the float itself will fall until the butterfly valve in the supply pipe is opened
sufficiently to correspondingly increase the feed of the thin liquid to the pan. If
the flow from the discharge is diminished by partially closing its valves the level
of the liquid in the float chamber and also the float rises and the feed from the
supply pipe is correspondingly diminished, which is the case until the float ceases
to rise at which time all supply of liquid is cut off.
Other things remaining equal the density of the finished product diminishes in
proportion as the valves in the final discharge pipe S2, is opened and increased
in proportion as it is closed, and to regulate its density it is only necessary to
open or close the valve, as the case may be until the thickened material leaves the
final discharge pipe at the desired density. The function of the pump in addition
to that of supplying liquor to the next evaporating pan, is to return a portion of
the liquor to the dome of its pan which will assist the feed liquor in keeping the
surfaces of the tubes well covered. The vapors resulting from the evaporation pass
from the tubes into the chamber P and thence through the annular chamber and
away from the pan by the vapor main B. During its rapid passage along this
annular chamber, any drops or particles of liquid that may be carried along by it are
projected by centrifugal force against the inner surface of the walls T T to which
they adhere, while the vapor passes on and away from the pan perfectly freed
of all particles of liquid which would otherwise be held in suspension. The
separated liquid adhereing to the surfaces of the walls flow down the same to the
gutter along which it Hows into the passage f, and float chamber. The ledges t'
on the inner faces of the walls T T serve to prevent liquid being drawn along
the said surfaces and out of the vapor discharge by the rushing vapors.
The concentric partitions or diaphragms T are placed in the annular chamber to
lessen the radial distance through which the particles of liquid held in the escaping
vapors will have to be moved before coming in contact with a surface to which they
can adhere. This combination of collecting chamber and annular vapor passages may
be used with pans operating on the principle common to the apparatus described in
this application whatever may be the construction of the feeding devices for the
evaporating tubes.
In Fig. 8 is shown a modification of this overflow system of feeding the evaporating
tubes with liquor. In this arrangement the upper edges of the evaporating tubes all
lie approximately in the same horizontal plane a short distance above the tube plate pl
as in Fig. 2, the feeding tubes are dispensed with, and the liquid having fallen
through the perforations in the perforated plate p², at once overflow the edges of the
evaporating tubes.
Another feature of the modification shown in Fig. 8 is that the evaporating tubes,

page_text: heating chamber E and collecting chamber are arranged horizontally while the dome
and feeding device is horizonial as before.
Other modifications of this overflow feeding system for the evaporating tubes of
pans operating substantially as set forth, will readily present themselves to those
skilled in the art, for example in the modification shown in Fig. 8, the evaporating
tubes, or more strictly speaking the curved tubes leading to the same, might open
horizontally through the side walls of the feeding chamber as shown in dotted lines,
but all at the same level, in which case also the rising liquid in the feed chamber
would overflow into the several tubes at approximately the same rate, and I do not
wish to limit myself to any particular form or arrangement of the devices for
practising this overflow system of feeding limited quantities of liquid to the
evaporating tubes of apparatus operating on the principal of that described in this
application.
In the modification shown in Fig. 6 we have the curved or annular passages t
formed with two inlets P and one outlet requiring the vapors to travel only half the
distance. A pipe with a valve d² may be used to drain the float tank F when
desired (see Fig. 5).
The evaporating pans E E and E³ may be combined to form a multiple effect in
the manner shown in Fig. 1 in which the vapor main B of one evaporator connects with
the heating chamber E of the next pan or evaporator, and the main B of the last pan or
evaporator connects with the vacuum pump M..
The domes of the several pans may
"
be connected by pipes H having valves me which could be used in starting the plant to
exhaust the air from the pans. Drain pipes n may connect the bottom of each of the
heating chambers so that the condensed liquid may pass from chamber to chamber
and finally be discharged into the condenser of the vacuum pump. The supply pipe
for pans and E3 connect with the discharge side of the pump C of the preceding
pan by pipe. The fresh or thin liquor enters the first pipe at S₁ and the
concentrated liquor passes out by the final discharge pipe S and its flow is regulated
by valve s. In a multiple effect like this the valve s controls the operation of the
Hoats and their valves F and hence the supply of liquor by the pipes to the various
pans, and it is also evident that the float and its valve for pan E3 controls the supply of
liquor to pan E, and likewise the float and its valve to pan E2 controls the supply and
height of liquor in the pan E', and the float and its valve to pan E' controls the flow
of this liquor from S¹.
Any number of pans may be combined to form a multiple effect, and the details
may be modified in various ways without departing from my invention. The details
here shown are those preferred but other equivalents may be substituted in lieu thereof
without changing the principles involved or the operation of the apparatus in carrying
out my invention.
Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1st. In an evaporating pan the combination of the evaporating tubes and enclosing
heating chamber, liquid feeding devices for the tubes at one end of the same, a
collecting chamber into which the tubes open at their other ends, and one or more
annular vapor passages, approximately concentric with the collecting chamber, leading
from the said collecting chamber to a vapor escape for the pan.
2nd. In an evaporating pan the combination of the evaporating tubes and enclosing
heating chamber, a dome at one end of the tubes and heating chamber, having liquid
supply openings leading to the tubes, an inlet for the liquid to be evaporated opening
into said dome, a collecting chamber at the other end of the tubes and beating
chamber, a vapor passage opening from the dome above the liquid level and communi-
cating with the collecting chamber, and a vapor escape conduit leading from the
collecting chamber.
3rd. In an evaporating pan the combination of the evaporating tubes and enclosings

page_text: heating chamber, feeding devices for the tubes at one end of the same, a collecting
chamber at the other end of the tubes and heating chamber, one or more annular
vapor passages approximately concentric with the collecting chamber opening from
said collecting chamber and leading to the vapor outlet pipe and drainage passages
leading from the bottom of the collecting chamber and from the circular passages to
the outside of the pan.
4th. In an evaporating pan the combination of the evaporating tubes and enclosing
heating chamber, feeding devices for the tubes at one end of same, a collecting chamber
at the other ends of the tubes into which the tubes discharge, a vapor escape pipe or
passage leading from the collecting chamber, drainage passage leading from the
collecting chamber to the outside of the pan, and connecting to a pump, a pipe from
the pump leading to the feeding devices for the tubes, and also having a valved
discharge pipe, a supply pipe for liquor connecting with said pipe leading to the said
feeding devices and a valve in said supply pipe to control the supply of liquor.
5th. In an evaporating pan the combination of the evaporating tubes and enclosing
heating chamber, feeding devices for the tubes at one end of the same, a vapor
escape conduit leading from the collecting chamber, liquid drainage passages leading
from the collecting chamber to the outside of the pan, and connecting with a pump,
a pipe from the pump leading to the feeding devices for the tubes, and also having a
valved discharge pipe, a supply pipe for liquor connecting with said pipe leading to
the feeding device for the tubes, a valve in said supply pipe to control the supply of
liquor, and an automatic device operated by variations in the level of the liquid
flowing out of the collecting chamber to control said valve in the supply pipe.
6th. In an evaporating pan the combination of the evaporating tubes and enclosing
heating chamber, feeding devices for the tubes at one end of the same, a collecting
chamber into which the other ends of the tubes open, a vapor escape conduit leading
from the collecting chamber a liquid discharge passage leading from the collecting
chamber, a supply pipe for leading liquid to the pan, a valve in said supply pipe to
control the supply of liquid and an automatic device operated by variations in the
level of the liquid flowing away from the collecting chamber to actuate said valve in
the supply pipe.
7th. In an evaporator (operating substantially as set forth) the combination with
the collecting chamber of an annular vapor outlet passage approximately concentric
with the said chamber and transverse ribs on the inner face of the outer walls of said
passage, whereby particles of liquid separated from the circling vapors and thrown
against the said outer walls by centrifugal force are arrested and permanently separated
from the vapors.
Sth. In an evaporator the combination of the evaporating tubes, the collecting
chamber P having curved partitions or walls T T T', the inclined floor A¹ for the
chamber P, and inclined gutter J for the curved passage-ways formed by the walls or
partitions.
9th. In an evaporator the combination with the evaporating tubes of a collecting
chamber, encircled by an annular vapor escape passage, and approximately concentric
partitions in the said vapor escape passage sub-dividing the said vapor escape passage
into a number of narrower passages, substantially as and for the purpose specified.
10th. In an evaporator the combination of the evaporating tubes, the collecting
chamber with an annular vapor escape passage encircling and leading from the same,
a false bottom K in the annular vapor passage having passages or perforations through
it leading into the space below the same.
11th. In an evaporator the combination of the evaporating tubes, the collecting
chamber having curved partitions or walls T, T¹, T, the inclined floor A' for the
chamber P, inclined gutter J for the curved passageway formed by the walls or
partitions, and the curved inclined floor K having communicating passages for liquid
from the compartment between walls T T and the gutter.
12th. In an evaporator the combination of the evaporating tubes, the collecting
chamber and the vapor escape passage encircling it and the gutter J at the bottom of
the vapor passage and leading to the liquid discharge passage of the pan.

page_text: 13th. In an evaporator the combination of the evaporating tubes having their ends
extending into a feed chamber, a dome arranged above the feed chamber and having
a perforated bottom separating it from the feed chamber, a liquid distributing
diaphragm supported within the dome and above the perforated floor, and a liquid
supply pipe opening into said dome above the diaphragin.
14th. In an evaporator the combination of the evaporating tubes having their ends
extending into a feed chamber, a dome arranged above the feed chamber and having
a perforated bottom separating it from the feed chamber, a liquid distributing
diaphragm supported within the dome and above the perforated floor, a liquid supply
pipe opening into said dome above the diaphragm, a collecting chamber at the other
end of the tubes, and a vapor passage connecting the collecting chamber with the
dome and opening into the latter below the diaphragm.
15th. In an evaporator the combination of a heating chamber and a horizontal feed
chamber evaporating tubes arranged within the heating chamber and projecting some
distance into the feed chamber and having their ends in the said feed chamber on the
same or substantially the same horizontal plane.
16th. In an evaporator the combination of a heating chamber and a horizontal liquid
feed chamber, evaporating tubes arranged within the heating chamber with their feed
ends opening into the feed chamber, and with the said openings at approximately the
same elevation, with a perforated plate p² above the openings in the tubes and means
for delivering the liquid upon the perforated plate.
17th. In an evaporator the combination of a heating chamber and a horizontal
liquid feed chamber evaporating tubes arranged within the heating chamber with
their feed ends opening into the feed chamber and a short distance above the bottom
of same, and with the said openings at approximately the same elevation, and means
for delivering the liquid to be evaporated into the feed chamber.
18th. In an evaporator the combination of a heating chamber and a horizontal
liquid feed chamber, evaporating tubes arranged within the heating chamber and
projecting some distance into the feed chamber and in which the ends of said tubes
are on the same or substantially the same horizontal plane, and feeding tubes c
arranged concentrically about the ends of the ovaporating tubes respectively and
forming the annular passages n.
19th. The combination of the heating chamber and tubes b, the dome D having
peforations in its bottom, the feed chamber G below the dome into which feed
chamber the tubes project, and concentric tubular portions e arranged about the ends
of the tubes and forming annular passages n for the liquid.
༡
20th. The combination of the heating chamber and tubes 6, the dome 1 having
perforations in its bottom, the feed chamber G below the dome and into which the
tubes project concentric tubular portions c arranged about the ends of the tubes and
forming annular passages n for the liquid and one or more of which tubular portions
extend as at above the perforated bottom of the dome.
21st. The combination of two evaporating pans arranged to form a multiple effect,
with a
liquid passage between the collecting chamber of first pan and the feeding
devices for the tubes of both pans, a pump in said liquid passage to positively
circulate the liquid, a liquid supply pipe connecting with the passage or pipe leading
to the feeding device of the first pan, an automatic valve controlled by the level of
the liquids in the first pan to control the supply of liquid to the same, a liquid passage
connecting the collecting chamber of the second pan with the feeding devices for
its tubes, a pump in said passage to circulate the liquid, an automatic valve controlled
by the level of the liquid in the last pan to control the flow of liquid from the first
pan to the second, and a valved outlet or discharge from the discharge end of the
pump of the second pan.
22nd. In a combination of two evaporating pans to form a multiple effect, a liquid
supply pipe leading to the first pan a valve in the said supply pipe automatically
operated by the lever of the liquid in the first pan to control the supply of liquid to 5
the same, a liquid discharge pipe leading from the collecting chamber of the first pan
to the second pan, a valve automatically operated by the level of the liquid in the

page_text: second pan to regulate the flow of liquid from the first pan to the second and a valved
liquid discharge pipe for the collecting chamber of the second pan.
23rd. The combination of two pans operating substantially as described to form a
multiple effect, with a liquid discharge pipe leading from the collecting chamber of
the first to the second pan, a valve automatically operated by the level of the liquid
in the second pan to regulate the flow of liquid from the first pan to the second,
and a liquid discharge pipe for the collecting chamber of the second pan.
24th. The combination of two or more evaporating pans arranged to form a multiple
effect, a supply pipe to supply thin liquid to the pans a valve in said supply pipe,
automatic mechanism substantially as set out to automatically actuate said supply pipe
valve, a discharge pipe to discharge the concentrated liquor from the last pan, a
valve in said discharge pipe to control the discharge of concentrated liquor and
indirectly to control the supply of thin liquor to the first pan.
25th. The combination of two or more evaporating pans arranged to form a multiple
effect, a pump and pipe for circulating the liquor through each of the pans, a supply
pipe for supplying fresh liquor to the first pan, a supply pipe for supplying a portion
of the liquor from each pan excepting the last to the next pan, antomatic valve
mechanisms controlled by the level of the liquid in the last pan to regulate the passage
of liquor through the supply pipes, to each pan and a valved discharge pipe from the
lasi pan which controls the level of the liquid in the last pan and thereby the passage
of the liquor into and through all of the pans.
26th. In a multiple effect the combination of liquor supply and discharge pipes for
each pan, a valve in the supply pipe for each pan, and automatic valve actuating
mechanism substantially as set out controlled by the level of liquid in each pan to
regulate the valve in the supply pipe to the same pan.
27th. In a combination of two or more pans operating substantially as described to
form a multiple effect a liquid discharge pipe for each pan excepting the last pan
leading from the said pan to the next cooler pan in the series, and containing an
automatic valve operated to regulate the flow of liquid through the pipe by the level
of the liquid in the said next pan, a liquid discharge pipe for the last pan, and a hand
valve in the same to control the flow of liquid through all the pans.
28th. In an evaporating pan operating substantially as described, the within described
method of feeding limited and approximately equal quantities of liquid to the several
evaporating tubes having their feed openings in the same horizontal plane, consisting
in causing the liquid to rise to the said openings and overflow the same.
Dated this 10th day of August 188S.
Dated this 10th day of August 1888.
SAMUEL MORRIS LILLIE.
Haseltine Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.