Improvements in or relating to Evaporating Apparatus.
Year: 1893

page_text: Date of Application, 13th Mar., 1893-Accepted, 27th May, 1893
COMPLETE SPECIFICATION.
Improvements in or relating to Evaporating Apparatus.
I REGINALD HADDAN of the firm of Herbert Haddan & Co., of 18 Buckingham
Street, Strand W.C. London, Patent Agent do hereby declare the nature of this
invention a communication to me from abroad by Emit Passburg, of Kronprinzen-
strasse 49, Breslau, in the Empire of Germany, Engineer, and in what manner the
same is to be performed to be particularly described and ascertained in and by,
the following statement:-
This invention relates to apparatus for evaporating the lighter or more volatile
constituents from a liquid of any kind by employment of fat, corrugated or other
heaters within a closed chamber more or less exhausted of air and maintained
under reduced atmospheric pressure, the liquid to be evaporated and reduced to a
greater density being caused to flow in a film down the surfaces of the said heaters.
The purpose of the present invention is to improve this kind of evaporator in
certain modifications and additional features of its construction so that its utility in
evaporating power may be increased, and consequently the cost of an evaporating
plant for a desired output correspondingly diminished.
These improvements will be hereinafter described and pointed out in the claims.
Reference being made to the annexed drawings
Fig. 1 is a cross section on line 1, 1 of Fig. 3.
Figs. 2, 24, 2B 2C and 2D are alternative constructions of heater for use in the
evaporating chamber, all shown in vertical cross section.
Fig. 3 is a section on line 22 of Fig. 1 showing the evaporator.
Fig. 4 is a horizontal section on line 4 4, Figs. 1 and 3.
Figs. 5 are sections on lines 5, 5, and 54, 54 respectively in Fig. G.
Fig. 6 is an elevation partly in section of another modified form of heater and of
the framework thereof.
Fig. 7 is an elevation of a complete evaporating plant.
The evaporator consists of a chamber A preferably rectangular in form, of
considerable height and ending above in the flange A onto which the corre-
sponding flange B₁ of the cover B may be bolted so as to secure an airtight joint.
The cap B has an outlet C to which the exhaust pipe may be connected.
bare the heaters vertically arranged in the chamber A for evaporation of the
liquid flowing down their surfaces.
It has been found that if the liquid to be evaporated is subjected to a pre-
liminary heating and while in a state of any considerable heat is brought in contact
with the surface of the heaters b b, it splutters and refuses to flow evenly down
the surface of the heaters, much of it being projected and falling into the base
of the chamber without flowing down the heater. If on the contrary the liquid
be not previously heated a considerable portion of its travel over the surface of
the heater is occupied in bringing up the liquid to the temperature at which the
evaporation will commence so that a proportionate superficial length of the heater
is as regards evaporation itself wasted.
The purpose of the first improvement is to obviate all difficulties connected with
an exact regulation of the temperature of the incoming liquid by affording means
whereby liquid heated above the temperature required may be automatically
reduced to the desired temperature, that is attemperated to the heat prevailing
in the apparatus. For this purpose the incoming liquid arriving through pipe
and having its rate of inflow controlled by cock h with indicator of its amount of
open passage way, is first caused to circulate around the side walls of the cover B
within spate R partitioned oft by a side wall R' cast with the cover and

page_text: strengthened by cross partitions f so made as to leave spaces f¹ at the base for free
passage of the liquid and at the top at f2, the interior partition R' having also
holes at the top at f³ so that the pressure in the evaporator may be always the
same as in the chamber R. The liquid in the chamber R is attemperated to the
heat prevailing in the evaporator and passes out at the several outlets R³ through
return bend pipes S connected at their ends respectively to the cover B and the
lower chamber A in which latter chamber the pipes S lead direct into horizontal
troughs u one into each, the said troughs being located one on each side of each of
the heaters in the chamber A and revolvable on their horizontal longitudinal axes
so as to supply the liquid evenly and properly along each face of the heater.
troughs are preferably supplied through hollow trunnions aligned with the pipes S
respectively and are rotated by handles e fitted with indicators of their positions
and secured to the ends of the trunnions of the troughs u projecting through stuffing
boxes at the ends opposite the pipes S.
The
Further improvement relates to the construction of the heaters band of the
supply conduits thereto. In the base of the cover B and extending across the same
are a series of closed chambers or pipes k continued at one end outside the cover
and terminating in short lengths of pipe with flanges for the connection of the steam
supply pipes from the steam main L, or with supply pipes for passage of any
heating medium to the interior of the heaters. Along the floors of these pipe like
chambers k are slits s and the outer and under face of the floor of each chamber k
is made of suitable shape for attachment of the heater proper which is made by
rivetting two flat or corrugated or other sheets of metal bb upon the respective
faces of a rectangular three sided framer (Fig. 3). The only opening left unclosed
by the absence of the fourth side of the frame corresponds in breadth and extent
to the slits so that when each heater is soldered or otherwise fixed on the under
face of the floor of the respective chamber k the slits affords unrestricted access to
the interior of the heater for the steam or equivalent heating vapour; and the
heater is suspended by means of the cover B (the chambers k being part of said
cover) within the chamber A without contact with the walls or floor of the latter.
The pipe m leading to the wall of the chamber A and communicating with the
exterior pipe m¹ affords outlet for condensed water or liquid from the bottom of the
interior of each heater. nis a syphon outlet pipe for the denser liquid which flows
off the heater and collects in the bottom of the chamber A.
(
In the modification shown in Figs. 5 and 6 the heater 6 is constructed upon a
four sided instead of a three sided frame, but the fourth side of this frame
corresponding to the open side of the three sided frame is provided with a number
of passage ways o Fig. 6 of collectively as great a cross sectional area as the
aforesaid slit s or the general average area of a cross section through the heater.
To enable this area to be attained, this side of the frame must be made thicker aud
the cross area of the heater gradually reduced from the extra breadth needed to
the ordinary breadth between the plates within a short distance below the upper
end of the heater. A flat form of heater is shown in Fig. 2. Alternative forms of
corrugated heaters in Figs. 2A, 2B, 20, 2D and in Fig. 5.
The complete plant for evaporating is shown in Figure 7 there being any desired
number of evaporators A connected in the same manner as the four shown. R³ is
the tank containing liquid to be subjected to evaporation.
liquid to the boiler or heater V of any convenient kind and pipe R5 carries the
Pipe R carries this
heated liquid to the several evaporators. The air pump P draws off the vapours
through pipes L and causes them to be condensed in any convenient condenser C¹.
In the arrangement shown the vapours from each evaporator are made to do duty
as evaporating medium in the heaters of the next evaporator in series and their
condensed liquid consequently runs out at the pipes m³ to any convenient receivers.
The denser liquors from the pipes are received in vessels D D.
For control of the process, thermometers t are placed in the pipes L. Gauge
glasses for ascertaining the level of the liquid are used in connection with the
chambers R and A as shown at ii and pressure gauges for the chambers A at v v.

page_text: The level gauges i may contain hydrometers as at ¹Fig. 1 for indication of the
density of the resultant liquid.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed 1 declare that what
I claim is.
1. In an evaporator adapted to treat liquid under pressure less than the usual
atmospheric pressure, a preliminary channel or chamber R within the evaporator
and in communication therewith for equalization of pressure, the said chamber
being intended for reception of the liquid to be treated for its attemperation prior
to contact with the evaporating surfaces substantially as set forth.
2. The construction of heater of flat, corrugated, or other plates fixed on three
sided frames adapted to be affixed to the face of a feed chamber such as k with
slits for communication with the heater.
3. The construction of heater on a four sided frame with passages in one of
its sides of collective extent equal to the cross sectional area of the interior of the
heater and adapted to be fixed to the face of a feed chamber such as H as and
for the purpose described.
4. In an evaporator the combination of a chamber A, a cover B thereto, cross
pipes in the base of said cover, hollow heaters b depending severally from said
cross pipes and communicating therewith, troughs for supply of liquid to be
evaporated onto the surface of said heaters, a surrounding compartment R in said
cover, an inlet for liquid thereto and outlets for same therefrom, and pipes S
severally connecting said outlets and troughs for the purpose set forth.
5. In an evaporator the combination of a chamber A, a cover B thereto cross
pipes in the base of said cover, hollow heaters depending severally from the
said cross pipes and communicating therewith, troughs for supply of liquid to be
evaporated onto the surface of said heaters, said troughs being journalled to revolve
on their longitudinal horizontal axes a surrounding compartment R in said cover
an inlet for liquid thereto and outlets for same therefrom and pipes S severally
connecting said outlets and troughs, for the purpose set forth.
6. In an evaporator the combination with a heater b adapted to treat liquid
flowing down the surface thereof in a film, of a trough horizontal and parallel to
the surface of the heater and revolvable about its longitudinal axis for the supply
of liquid to said surface.
7. In an evaporator the combination of a case, a heater b suspended therein
adapted to treat liquid flowing down the surface thereof in a film, and a trough,
horizontal and parallel to the surface of the heater, a hollow trunnion for supply of
liquid to said trough at one end, and a projecting trunnion for revolving the trough
at the other end.
8. In an evaporator the combination of a chamber A, a cover B thereto, cross
pipes in said cover and heaters composed each of a rectangular frame and two
surface plates attached along the lower faces of pipes & respectively and having
communication therewith equal in cross sectional area to the cross sectional area of
the heater.
9. In an evaporator the combination of a chamber A, a cover B thereto, cross
pipes in said cover, longitudinal slits s in said cross pipes and heaters composed
each of a rectangular three sided frame and two surface plates attached along the
lower faces of said pipes k respectively and having uninterrupted communication
therewith through slits s.
10. In an evaporator the combination of a chamber A, a cover B adapted to be
fixed airtight thereon, an outlet C in said cover, a surrounding passage R therein,
an inlet for liquid thereto, and a series of outlets from said passage, horizontal
cross pipes in said cover, heaters composed each of a rectangular frame and two
facing plates connected respectively to said cross pipes and suspended thereby in
the chamber A, a series of troughs u one on each side of each heater and revolvable

page_text: on their longitudinal axes, hollow trunnions to said troughs at one end and pipes S,
exterior of the chamber A and cover B connecting the hollow trunnions and outlets
of passage R, the whole substantiailly as set forth.
11. In an evaporating plant, a tank R³ heater V, a series of evaporators each
having in the cover thereof an attemperating chamber R, pipes L adapted to
carry the evaporated vapours from each evaporator to the heaters of the next
evaporator in series, an air exhaust pump, a condenser in communication with the
last pipe L of the series, the whole in combination substantially as set forth.
Dated this 13th day of March 1893.
K. HADDAN.
Herbert Haddan & Co.,
18, Buckingham Street, Strand, London, Agent for Applicant.