Improvements in Evaporating Apparatus.
Year: 1893

page_text: Date of Application, 6th June, 1893-Accepted, 8th July, 1893
COMPLETE SPECIFICATION.
Improvements in Evaporating Apparatus.
I, SAMUEL MORRIS LILLIE, of 328 Chestnut Street Philadelphia, in the County
of Philadelphia, State of Pennsylvania, United States of America, Mechanical
Engineer, do hereby declare the nature of my invention, and in what manner the
same is to be performed to be particularly described and ascertained in and by
the following statements :-
My invention relates more particularly to a class of evaporating apparatus in
which the liquid to be evaporated is discharged from above by suitable devices
over the exterior surfaces of internally heated tubes contained in a chamber.
The object of my invention is to provide means for separating suspended particles
of liquid from the vapors evolved during evaporation before they pass from the
apparatus, and therefore prevent loss of liquor by suspension in the escaping vapors,
and it consists in lengthening the chamber containing the evaporating tubes in the
direction of the length of the tubes to form a large subsiding chamber into which
the vapors of evaporation pass and in which suspended particles of liquid may
settle from the vapors, and from which the latter escape through an outlet provided'
for the purpose.
In the drawings:
:-
Fig. 1 is a longitudinal view of an evaporator embodying my invention;
Fig. 2 is an end view of Fig. 1 with the plate R and baffle plate N removed to
expose the interior to view, the position of the baffle plate, if not removed, being
indicated by the dotted lines;
Fig. 3 is a portion of a longitudinal section of an evaporator showing a second
construction of the baffle plate.
Above
Referring to the drawings, Figs. 1 and 2, E is a chamber containing a battery
of horizontal and parallel evaporating tubes s, s, &c., which are supported in, and
open through the heavy tube plate G closing one end of the chamber, into the
chamber S, which is supplied with steam through the main B and in turn supplies
steam, the heating agent, to the interiors of the evaporating tubes, s, s, &c. At
their ends opposite the steam chamber S the evaporating tubes are closed.
the evaporating tubes are a series of perforated distributing plates F, upon which,
during the operation of the apparatus, the liquid to be evaporated is delivered
through the main A, and which in turn shower it upon the evaporating tubes s, s,
down over whose surfaces the liquid trickles and finally falls upon the bottom of
the chamber and flows away by the main L. The evaporating chamber E is
extended in the direction of the length of the evaporating tubes to form the large
subsiding chamber E', which is made preferably somewhat larger in cross section
than the evaporating chamber so as to form the shoulder e, against which may rest
baffle plates hereinafter to be described. The subsiding chamber E' has its end
opposite the chamber E formed with a vapor escape main H, and a drain pipe o,
which may lead into the pipe L. Unless the liquid to be evaporated boils very
gently, a baffle plate of some suitable construction as N, Fig. 1, or N, Fig. 3, is
placed in the subsiding chamber E¹ to assist in separating suspended particles of
liquid from the vapors of evaporation. In Fig. 1, and as indicated by dotted lines
in Fig. 2, the baffle plate is a simple plate resting against the shoulder e and
extending across the chambers and from the top partway towards the bottom, the
vapors issuing from the chamber E being deflected by it towards the bottom of the
chamber E. In Fig. 3, the baffle plate is shown of the construction I prefer to
It consists of a
use when the liquid to be evaporated is of a foamy nature.
perforated plate N₁ resting against the shoulder e on all four sides of the apparatus
and completely closing, save for its perforations, communication between the

page_text: chambers E and E'. A little in front of the perforated plate N¹, i.e. on the
chamber E¹ side, a solid baffle plate. No parallel to plate N₁ is suitably sup
ported, as by studs i extending between it and the plate N¹. The plate No should
extend far enough towards the four sides of the chamber E¹ to cover all the
perforations in the plate N¹. The space between the two plates N1 and N°
communicate with the subsiding chamber E' by passages n around the edges of the
plate No, the edges of the plate being near enough to the walls of the chamber so
that the vapors escaping, as hereinafter described, will be compelled to impinge
against the walls of the chamber.
The plate R is made easily removable, and also the baffle plates when used, in
order that easy access may be had to the interior of the evaporating chamber E.
The operation of this apparatus is as follows: The liquid to be evaporated is
delivered by the pipe A upon the distributing plates F, and by them is showered
upon the battery of heated evaporating tubes s, s, &c. below, down over whose
surface it trickles, suffering evaporation in its course, and falls concentrated upon
the bottom of the evaporating chamber and thence flows away by the pipe L.
The vapors resulting from the evaporation escape from the longitudinal spaces c
between the tubes, and pass into the subsiding chamber E' in which any particles
of liquor which may be suspended in the vapors subside, and from which the vapors
escape by the main H, comparatively free from the liquid in suspension. Steam
to produce the evaporation is supplied through the nozzle B to the chamber S,
whence it passes into the interior of the evaporating tubes s, s, on whose surfaces it
condenses, its latent heat passing by conduction through the walls of the tubes,
causing evaporation from the liquid in contact with their outer surfaces, while the
water of condensation flows back from the tubes into the chamber S, and away from
the latter by the drip pipe a.
The baffle plates, when used, assist to a greater or less extent the separation of
suspended particles of liquid from the vapors. The baffle plate N, shown in
Fig. 1, assists to a considerable extent by deflecting the vapors downward into the
subsiding chamber E', i.e. away from the vapor escape main H, so that they may
have a longer distance to travel in the subsiding chamber, and a greater opportunity
of depositing the suspended liquid they may contain before passing out through the
vapor escape. Baffle plates of the type N', shown in Fig. 3, give most effective
assistance. They are of a type that I have found very effective when strongly
foaming liquids are to be evaporated. As herein before stated the baffle plate N¹
completely separates the chamber E from the subsiding chamber E', save for the
perforations or passages through it, which in the drawings, it will be observed, are
opposite the ends of the evaporating tubes instead of the longitudinal spaces c
between the tubes. The vapors generated in the evaporating chamber E, from the
surface of the evaporating tubes, move along the longitudinal spaces e between the
evaporating tubes and impinge against the inner face of the plate N' by whose
surface much of the liquid which is drawn along by the vapors is stopped and
separated from the latter. The vapors then pass through the perforations in the
plate and impinge against the inner surface of the plate N°, by which another
portion of suspended liquid is separated from the vapors, and by which the latter
are deflected along the space between the two plates whence they merge into the
subsiding chamber E' through the passages n after impinging against and being
deflected by the walls of said chamber. At each impinging and deflecting the
vapors give up some of their suspended liquor and the result is they enter the sub-
siding chamber E' comparatively free of liquid in suspension. When this form of
baffle plate is used, the pipe o serves to drain the subsiding chamber E' of whatever
liquid there may be carried into it by the vapors.
it
may
be
If this apparatus is stood vertically with the settling chamber E¹ up,
used for evaporating liquids "en masse" instead of in thin films. The dilute liquid
would be fed to the evaporating chamber by the pipe A, the thickened liquid would
be drawn away through the pipe L, and the liquid in the evaporating chamber
would be kept at a level of say the dotted lines x, x. The vapors resulting from

page_text: evaporation would pass upward, around or through the baffle plates if used, into the
subsiding chamber E' and then away by the vapor main H.
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 I
claim is :-
1. The combination in an evaporating apparatus of an evaporating chamber, a
battery of horizontal evaporating tubes contained therein opening at one end
through a tube plate into a steam supply chamber and having their other ends
closed, a subsiding chamber consisting of an elongation of the evaporating chamber
beyond the closed ends of the tubes, a vapor escape main leading from the subsiding
chamber, suitable pipes for leading the liquid to be concentrated by evaporation into
the evaporating chamber and the concentrated liquid away from the evaporating
chamber, and means for causing the liquid entering the evaporating chamber to
flow in thin films over the exterior surfaces of the evaporating tubes, substantially
as specified.
2. The combination in an evaporating apparatus of an evaporating chamber, a
battery of evaporating tubes contained therein opening at one end through a tube
plate into a steam supply chamber and having their other ends closed, a subsiding
chamber consisting of an elongation of the evaporating chamber beyond the closed
ends of the tubes, a vapor escape main leading from the subsiding chamber, baffle
plates located in the subsiding chamber and suitable liquid induction and eduction
pipes for the evaporating chamber substantially as and for the purpose specified.
3. The combination in an evaporating apparatus having evaporating chamber,.
evaporating tubes and subsiding chamber substantially as described, of a transverse
plate with vapor escape holes through it, dividing the evaporating chamber from
the settling chamber, and a baffle plate in the settling chamber in front of the said
perforated dividing plate, substantially as and for the purpose specified.
4. In an evaporating apparatus constructed substantially as described, a shoulder
formed between the evaporating chamber and the subsiding chamber by making the
subsiding chamber of greater cross section than the evaporating chamber, and
baffle plates supported against the said shoulder substantially as and for the purpose.
specified.
תו.
L
CM 1000
SAMUEL MORRIS LILLIE.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.