Improvements in Evaporators.
Year: 1891

page_text: Date of Application, 31st Mar., 1891-Accepted, 2nd May, 1891
COMPLETE SPECIFICATION.
Improvements in Evaporators.
I, REGINALD HADDAN of the firm of Herbert & Co. Patent Agents of
18 Buckingham Street Strand W.C. London Civil Engineer do hereby declare
the nature of this invention a communication from abroad by John William Evans
of Cleveland, Ohio, United States of America Manufacturer 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 improvements in evaporators designed more especially
for evaporating naphtha from oil and it consists in certain features of con-
struction and in combination of parts hereinafter described and pointed out in
the claims.
In the naphtha process of extracting oil, for instance from seeds, the seeds are
ground and placed in large percolators and the latter are then filled with hot
naphtha for extracting the oil. At the end of this process the united oil and
naphtha are drawn from a percolator into an evaporator where the naphtha is
evaporated and the vapour thereof passes to a condenser from whence the liquid
naphtha is returned to its tank to be again used for the same purpose. As the
percolator is likely to hold say a thousand bushels of meal, more or less and at the
same time to be charged with say a hundred and fifty barrels, more or less of
naphtha, and as there are likely to be a number of such percolators in constant
operation it is evident that the evaporator must be of large size and construction so
as to do its work with despatch.
In evaporating the naphtha, only a moderate heat should be applied for the
reason first, that too much heat will scorch and injure the oil, and second that
it is not desirable or prudent to heat naphtha to a high degree. It will therefore
be understood that the evaporator should be so arranged and be provided with such
appliances that the naphtha may be quickly evaporated with the minimum degree
of heat. To this end I have devised the evaporator and connected mechanism
illustrated in the accompanying drawings.
Fig. 1 is a view in perspective.
Fig. 2 is an elevation in longitudinal section on line xx Fig. 3.
Fig. 3 is an elevation in transverse section on line Y Y Fig. 2.
A represents the container constructed preferably of boiler iron and of
approximately the form shown and of such size as will have the necessary capacity
for holding a batch of oil and naphtha from at least one percolator. At the top of the
evaporator the walls thereof are extended laterally in one direction, the one above
the other as shown at A¹ A2, these walls connecting with a semi circular plate A³.
The end walls and plate A³ are provided with flanged openings at a leading into
eduction pipes a' that may be attached at either or both ends of the evaporator and
at the side for conducting the naphtha vapour to a condenser (not shown). With
such construction it is evident that the naphtha vapour may have free passage to
the eduction pipe or pipes a¹ and has not to travel lengthwise of the evaporator to
find an outlet, as would be the case were there one or more eduction pipes connected
with the top of the evaporator. On the inside of the evaporator, and located near the
bottom thereof is a coil of steam pipes B, and just above this coil is located a series
of perforated steam pipes B' for admitting live steam into the liquid in the
evaporator. Pipes B usually connect with the coil B with valves B2 to control or
shut off the steam to or from pipes B¹. Located above pipes B¹ are agitators each
comprising a large heavy axial tube C bearing a series of hollow radial arms C¹,
these arms consisting preferably of tubes with caps to close the outer ends these

page_text: arms being screwed into threaded holes in tubes C. Tubes C extend out through
suitable boxes and stuffing boxes at the ends of the evaporator, the two tubes C
being intergeared preferably as shown at cc so as to turn in opposite directions,
and on one of these tubes is mounted a driving pulley C². The one end of each
tube C connects with a steam pipe, and the other end is usually reduced in size
and provided with a cock as shown at C3 by manipulating which cock a slight
discharge of steam is had to give circulation of steam through the agitators to
keep them heated.
DD are troughs extending approximately the internal length of the evaporator
these troughs being arranged preferably substantially as shown each trough being
heated by steam for the purpose of heating the upper section of the evaporator
of the enclosed chamber to prevent as far as possible the condensation of the
naphtha vapour and to catch any condensed naphtha that there may be and
revaporize the same by means of the heat of the troughs. These troughs are
preferably constructed with double walls, as shown more clearly in Fig. 2 so that
steam may be admitted into the chambers of each trough. The troughs are located
as shown, some distance apart so that the vapour may have free passage between
the troughs and so that the troughs will catch any condensed naphtha from above.
A system of pipes and return bends connect the different troughs and these are
supplied with steam through pipe d leading preferably to and connecting with
the coil of pipe B although these troughs may be supplied with steam from other
source if for any reason it is found more convenient to do so. The last trough of
the series should be provided with a bent cock as shown at d¹ to give circulation
of steam through the troughs. A trough constructed with a single wall, and having
a steam pipe extending lengthwise and resting on the internal bottom thereof
would answer fairly well but would not be so effective in heating the upper
section of the evaporator, hence, the construction shown although more costly is
preferred.
E is a vacuum valve opening inward to prevent the evaporator from collapsing
in case of a partial vacuum being formed therein by the vapours being condensed
too suddenly in the condenser.
F is a glass gage of ordinary construction for showing the depth of liquid in the
evaporator. There is a large opening at one end of the evaporator for introducing
the coils of pipe and this opening being closed by removable plate G portions
of which may be seen in Fig. 1. Also is provided a man-hole and plate
shown at H. Large sight holes are provided at on either end of the evaporator,
these orifices being closed by glass plates that admit light inside the evaporators
and through which the operation going on inside the evaporator may be
inspected.
J is a pipe for admitting the material to the evaporator, and K is a pipe for
drawing off the oil.
L is an oil well of ordinary construction consisting of outer and inner tubes
jointed at the outer ends, the inner end of the inner tube being closed and
the inner end of the outer tube extending into the container. A thermometer
is inserted in the inner tube to determine the temperature of the liquid in
the still.
This is
In operating the device, the evaporator having been charged with a mixture
of oil and naphtha say to near the line of the bottom troughs first steam is
admitted to coil B to heat the liquid. A large per cent. of the naphtha is readily
evaporated by this means. Next steam is admitted to the perforated pipes and
the agitator is also set in motion, being heated meantime with steam."
continued until the naphtha is entirely evaporated from the oil which will be
readily determined by observing the discharge of the condenser to see when the
condensed naphtha ceases to flow from the condenser, leaving a discharge
only of water from the condensed steam. The oil is then drawn off through
pipe K and the evaporator is again charged through pipe J and is ready for another
operation.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is
-
1. The combination with an evaporator of the class indicated and having a
lateral chamber at the top, opening into the body of the evaporator and extending
lengthwise thereof of one or more eduction pipes, connected and in open relation
with such lateral chamber, substantially as set forth.
2. The combination with an evaporator of one or more steam heated troughs.
located internally along the upper section of the evaporator substantially as set
forth.
3. The combination with an evaporator of troughs located in the evaporator
substantially as indicated such troughs having double walls enclosing steam
chambers, pipes connected with these chambers for supplying steam thereto.
substantially as set forth.
4. An evaporator the walls whereof at the top are extended laterally in the one.
direction, the one wall above the other so as to enclose a chamber lengthwise the
evaporator, one or more eduction vapour pipes connecting with such chamber,
substantially as set forth.
5. The combination, with an evaporator having a heating coil and perforated
steam pipes arranged substantially as indicated, of agitators comprising axial
pipes having attached hollow radial arms with appliances for introducing steam to
such agitators the latter being intergeared to turn in opposite directions substantially
as set forth.
6. An evaporator of the variety indicated substantially as shown and described.
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3003
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C.,.
Agents to Applicant.