Improvement in Vacuum Distillation Apparatus.
Year: 1886

page_text: Improvement in Vacuum Distillation Apparatus.
I, HOMER T. YARYAN, of Toledo, in the County of Lucas and State of Ohio,
United States of America, Manufacturer, do hereby declare the nature of this
invention 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 improved methods of constructing apparatus for the
distillation of liquids, in which the evaporation takes place while the liquid is in
transit through coils of pipe and the objects of my invention are to provide, first, a
compact and easily constructed apparatus which will operate upon large quantities
of liquid; second, to provide apparatus which is adapted to be arranged in systems
of double and triple effects; and further objects are, to increase the efficiency,
capacity, facility of regulation, uniformity of product, and economy of construction
and operation of vacuum distilling and evaporating apparatus, as hereinafter
described.
For the purpose of giving a better and clearer understanding of my invention, I
will describe it under two principal heads or divisions. The apparatus described
and illustrated in both divisions, embrace the same general principles of construction
and operation, but each contains modified forms of some of the parts or devices, by
which the details of construction only are varied.
The first division is illustrated on Sheet 1, in figures 1 to 9 inclusive, in which,
Figure 1, represents a right-hand side elevation of my invention as applied to a
"double effect" apparatus; figure 2, an end elevation of the same; figure 3, a plan
view of the same: figure 4, a left-band side elevation of part of the same, partly in
section; figure 5, a side elevation of automatic feed device; figure 6, a plan of the
same; figure 7, a central vertical section of the tail-pipe and trap; figure 8, a
sectional horizontal plan of separating chamber showing dash-plates; and figure 9,
a transverse vertical section of the same.
Like letters refer to like parts throughout the several views.
When it is desired to increase the capacity of my apparatus, so as to treat fluids
in large quantities, I find that it is not practicable to do so by increasing, to any
considerable extent, either the diameter or the length of the pipe constituting my
evaporating coils, for the following reasons:
1st. The coils, being usually of copper, the increase of thickness and weight of
metal requisite as the diameter of the pipe is increased, renders the cost as well as
the bulk and weight of the enlarged coil, entirely disproportionate to the increase

page_text: of capacity. 2d. Unless the diameter or area of the pipe is restricted, a sufficient
current of vapor will not he formed to throw the liquid being evaporated into
commotion, so as to constantly bathe the whole inner surface of the coil, which is
absolutely necessary to ensure the greatest efficiency of heating surface and to
prevent coating and clogging of the coil. 3d. In coils composed of pipe of uniform
diameter, a uniform degree of vacuum and heat cannot be maintained throughout
the coil, owing to the constantly increasing volume, pressure, and friction of the
vapor, as it progresses toward the separating chamber. 4th. When the coil is of
too great length, the friction of the contained fluid and vapor amounts to several
inches of mercury, or, in other words, a vacuum guage connected with the outlet,
will mark some inches higher than one connected with the inlet, which results in
unduly heating the substance contained in the inferior vacuum; and in consequent
injury to the products. To overcome the difficulties here explained, I adopt as a
standard vaporizing coil, one of about seventy-five feet in length of pipe, starting
at the inlet with a diameter of about two and one-half inches, increasing gradually
to correspond with the increasing volume of vapor formed, to about four inches at
outlet. I do not, however, limit my vaporizing coils to these dimensions, though I
find that, in a single coil, they give entirely satisfactory results giving substantially,
n uniform degree of vacuum and heat throughout the length of the pipe and keeping
its interior bathed, so as to prevent coating.
As above indicated, the capacity of a single coil is in practice, limited, and by
multiplying these coils of uniform size and capacity, and connecting their outlets
with a separating chamber common to all,. the capacity of the apparatus may be
increased to any desired extent.
In the drawings, A, is the outer and a, (Figure 4) the inner pipe of my coils.
These pipes, I prefer to arrange as shown in Figs. 1 and 4, instead of spirally, as
being more economical of space, less expensive, more easily put together, providing
convenient means of enlarging the area of the pipes progressively, and affording
ready access to the interior of the coils for inspection and cleansing. For convenience
in building up my coils, one pipe within another, I employ straight pipes of proper
diameter and suitable lengths, placed horizontally and arranged in series in a vertical
plane, so that the pipe of smallest area shall be at top; that of the next to the smallest
area immediately beneath it, and so on, the pipe or section of pipe of largest area
being at the bottom of the coil. The lengths composing the inner or vaporizing
pipe or coil a, are threaded at each end, one end being screwed into return bend a¹,
the other end having screwed upon it, the T (tee) coupling all. The first and
second sections of pipe a, (commencing at top) are connected by a right and left
nipple a³ (fig. 4) screwed into T (tee) couplings a²; the second and third lengths
are united by a return bend a', the third and fourth lengths of said pipe a, are
connected in the same manner as the first and second; and the fourth and fifth
lengths, in the same manner as the second and third, and so on. The sections of
the outer pipe A, are at one end threaded and screwed into return bend A¹, and at
the opposite end, flanged and bolted to corresponding flanges on steam box or
head A2; and said box or head is provided with a plate or door A³ upon the inner
side of which are projecting horizontal plates A* which, when the door is closed,
form partitions causing steam, or other heating medium contained in coil A, to
follow its meanderings to and fro from inlet to outlet. As many other methods of
building up flat coils one pipe within another, will readily suggest themselves I do
not limit the coils in question to the construction here shown, though I prefer this
form for its convenience for inspection and cleansing.
As the degree of the concentration of the fluid under treatment depends upon the
amount of fluid supplied to the coils within a given time, and as a uniform product
is essential, it is necessary that the quantity of fluid supplied to each of the several
series of coils, shall be the same, and that such quantity shall be constant and
unvarying, and that when any change in the feed occurs, each series of coils shall
be affected alike. To attain this regular.and uniform feed, I provide the mechanism
shown on an enlarged scale in Figures 5 and 6, in which, F, is the supply-tank
с

page_text: containing the liquid to be evaporated, from which leads pipe f, to stand-pipe G,
the bottom of which is below the bottom of tank F. In f, is a butterfly valve g,
controlled by a lever. A cord or chain passing over vertically adjustable pulley i,
is attached at one end to said lever, and has suspended from its other end and
within stand-pipe G, a float k. From the bottom of stand-pipe G, nozzles l, of
uniform opening discharge into separate compartments of feed-box L, there being
a nozzle and a compartment for each coil to be fed. From each compartment of
feed-box L, leads pipe m, to its proper coil; a, leading into the top outer coil A,
of the series marked Y, Z, as shown in figures 2 and 3. In pipe m, is a butterfly
valve n, controlled by lever and float o, fig. 6. The pulley and cord i, suspended
float k, and lever to valve g, being adjusted in proper position, the fluid to be
treated is admitted to stand-pipe G where the column of fluid is automatically
maintained at any desired height and consequent pressure, regardless of the
quantity in the supply-tank, by means of float k, which, as it rises, closes valve g,
and as it falls, opens said valve. The feed to each of the compartments of feed-
box L, through nozzles, is the same. By means of valves n, and float and
levers o, all the fluid fed in to said compartments is permitted to be drawn into the
coils, but if either of the compartiments runs empty, the float and lever o fall,
closing the valve, thus maintaining the vacuum in the coils. In treating fluids
containing foreign substances, valves and pipes of the feeding apparatus sometimes
become clogged and one of the advantages of having nozzles l, empty into feed-
box L, instead of leading directly to the coils, is that the streams from the nozzles
into the box may be seen, thus furnishing a sight-feed. When these streams flow
smooth shining and cylindrical, the operator knows that each coil is receiving its
proper supply; when a stream flows rough and ragged, attention is directed to an
obstruction to be removed.
It sometimes happens that by means of obstruction in the feeding apparatus, or
improper regulation of the supply to tank F, said tanks will run over. To obviate
this; I provide said tank with float p, Fig. 5, attached to arm of valve q, in over-
flow pipe ql, so arranged that when the fluid in the tank reaches a given height, said
valve is opened and the excess of fluid is drawn through said valve and pipe q', to
the supply pump H, (Fig. 4) to be returned to the tank either directly, or through
the primary coil of a double effect apparatus (in the latter manner in the apparatus
illustrated in the drawing). When float p falls, valve q, is closed, preventing the
supply-pump from taking air through said overflow pipe.
Vacuum or vaporizing coil a, connects by means of pipes 63 (figures 1 and 3)
with separating chamber B or B2, as the case may he, provided with. dash-plates b²
(see figures 8 and 9) arranged and operating in the manner described under the
second division of my invention with reference to figures 13, 14, and 15.
The apparatus shown in the drawing, employing three vaporizing coils, is so
arranged that the first coil, marked X, receives the fluid to be evaporated from
force-pump H, through pipe h, under a pressure of one or more atmospheres,
and so that the second and third coils, marked Y and Z, terminating in common
separating chamber B, work under a partial vacuum, the heating medium in coils Y
and Z being the hot vapor from the separating chamber of coil X. The application
of the "double" and "triple effect" method to my system of continuous vacuum
distillation (that is, utilizing the heat of the vapor released from the contents
of one coil in heating the contents of the next succeeding coil) is also described
herein, under the second head or division of my invention. In the apparatus there
shown, however, all of the evaporation takes place under partial vacuum, which
is necessary in the treatment of some solutions which would be injured by
heat of more than 212 degrees F., while in the apparatus here described, designed
for the treatment of liquids which such a degree of heat would not injure, the
first coil X, is not provided with any means for producing a vacuum therein, and
I am not aware that the vapor from fluids evaporated under pressure of one or
more atmospheres has heretofore been utilized in heating other evaporators either
under pressure, or in vacuo.

page_text: The further principal parts of my apparatus may be pointed out in describing
its operation, which is as follows:
The fluid to be treated is taken from vat r (fig. 2) by feed-pump H, and forced
through pipes h and a of coil X. being heated in its course by live steam from
supply pipe S, (figures 2 and 3)—the pressure of which is controlled by regulating
valve v) in the surrounding pipe A, and discharging with the vapor generated,
into separating chamber B where the vapor and fluid are separated in their
sinuous course between dash-plates 6', the reduced liquid passing out of separating
chamber down through interior pipe c, and up through exterior pipe d, (figures 1
and 7) discharging into tank F. This arrangement of pipes c, d, forms a trap
which prevents the vapor in separating chamber B' from blowing out with the
liquid and compelling the vapor from chamber B¹ to seek egress through pipe
and branches 61.61 6. (figure 3) into exterior pipes A, of coils Y and Z, to be
utilized in heating their interior pipes and contents. In vaporizing pipes a, of
coils Y and Z, and the common separating chamber B, of said coils, a vacuum is
maintained by exhaust pump D, and by means of this vacuum, liquid is drawn
from feed-box L, through pipes m, into each of said pipes a of coils Y and Z, in
equal quantities. In its course through said pipes a, in vacuo, the volatile
constituents of the liquid are further vaporized and the vapor and remaining
liquid of both coils are discharged into their common separating chamber B, the
vapor being carried over through pipe b, to exhaust pump D, while the reduced
fluid is trapped or pumped away from tail pipe e, ly tail-pump E, in such manner
as not to break the vacuum in coil and chamber.
In the device shown, the several pumps are arranged so to exhaust their steam
as to utilize the same for heating, into outer pipe A of the coils.
I will now further describe my invention under the second division thereof, as
illustrated in the modified form of apparatus represented on sheet 2, in figures 10
to 20, inclusive, in which:
Figure 10, represents a side elevation of the vacuum distilling apparatus in
modified form; figure 11, a plan; figure 12, a front elevation; figure 13, a
longitudinal vertical section of separating chamber A, showing dash-plates A¹,
float chamber E, with float a, and butterfly valve b, and diaphragm plate B¹ to
receive and support tubes T; figure 14, is a transverse section of separating
chamber, showing construction of dash-plates A'; figure 15, is a sectional plan of
separating chamber A, showing arrangement of dash-plates A¹; figure 16, is a
longitudinal section on enlarged scale, of distributing chamber L" and a portion
of cylinder H" showing manner in which tubes T are partially closed with
plugs K¹, pin-plate H¹ holding taper pins I¹, shaft L' and lever M₁ for adjusting
feed, water seal S, with stuffing boxes d, and inlet pipes O¹, for liquid to be
evaporated; figure 17, is a plan of pin plate H₁, showing spider R, to stiffen the
same; figure 18, is a plan of water seal S; figure 19, is a longitudinal section, on
enlarged scale, of a tube T, showing plug K¹ with opening e, and pin I¹ withdrawn ;
figure 20, is a view of the same with pin I' inserted.
Similar letters refer to similar parts throughout the several views of the above
figures 10 to 20 inclusive.
In operating distilling and evaporating apparatus having spiral or helical coils,
where large quantities of liquids are to be operated upon, it has been found
necessary to multiply the number of coils, in order to obtain the requisite amount
of heating surface. To a certain limit, this is practicable, beyond which, and
especially when used as multiple effects, there aro serious objections, among which
are cost, space occupied, and the large number of joints expose to the atmosphere
to be kept tight.
In the apparatus and by the methods constituting the subject of my invention,
and particularly described under this second head thereof, these difficulties are
overcome and to this end I employ a cylinder containing a large number of
tubes, each tube being the equivalent of a coil, and so arranged in connection with

page_text: distributing mechanism as to receive an equal feed of liquid, and to discharge into
a common separating chamber.
In the accompanying drawing, I have shown the apparatus arranged in the form
of triple effect, because the operation and construction of this form include the
principles involved in single and double effects.
The connecting pipes and valves will be alluded to and their functions pointed
out in the description setting forth the operation of the apparatus.
The operation is as follows:-
The pump Q, having its suction end connected with the supply tank, is started,
and at the same time the vacuum pump O, which produces a partial vacuum
throughout the apparatus. As soon as liquid shows in glass gauge f, of small
chamber G, the pump P is started and steam is admitted to the first cylinder H",
through steam pipe K, and the pressure regulated by the reducing valve L. The
liquid entering the distributing chamber L", would have a tendency to feed
entirely through openings of lower tubes, and to prevent which the lever M₁ is
moved until the taper pins I¹ enter openings e, in plugs K', and partially close the
same, which is indicated by a little back pressure on the liquid entering through
pipe 01. By this means the liquid is caused to rise in chamber L¹¹ to the level of
the upper tubes and is equally distributed to all the tubes and in passing through
the same is partially evaporated. The vapor and reduced liquid are discharged
into separating chamber A, where, under the influence of enlarged area and
mechanical effects of dash-plates A¹, the liquid and vapor become separated, the
vapors passing through side openings g, of dash-plates, to vapor pipe H, through
which it is conducted to inside of adjacent cylinder H", which belongs to second
effect. The partially reduced liquid passes through bottom openings h, (figures 13
and 14) of dash-plates in separating chamber A, and finds its way by gravity,
within the float chamber E, and from this through pipe U, to the distributing
chamber of second effect, where the operation of first effect is repeated and so on
to the third effect. In the last effect, the vapor passes to condenser W, of vacuum
pump O, and the reduced liquid is discharged by the pump P. As soon as the
apparatus is started, the vacuums in the several parts will seek an equilibrium and
will be constant so long as the steam pressure on first effect and vacuum on last
effect do not vary. In ordinary practice, with 15 lbs. of steam pressure within
cylinder of first effect, and 28 inches of vacuum on third effect, the vacuum on
first effect will equal about five inches of mercury, and on the second effect abont
15 inches. I do not claim as new, utilizing the latent heat of vapor given off
under a low vacuum, to boil a second body of liquid under a higher vacuum, as
this a well-known and common physical law as applied to multiple effects.
Referring now to the details of my apparatus, the several improvements will be
taken up in their order.
The functions of distributing chambers, pin plates, taper pins and dash-plates,
have already been described and their arrangement is plainly shown in figures 13,
14, 15, 16, 17, 18, 19, and 20.
After the partially reduced liquid passes out of separating chambers A, B,
and C, and into float chambers E, F, and G, it is necessary to arrange an automatic
device by which the liquid may be fed continuously to the distributing chamber of
next effect, without the passage of any vapor. This is important, since the passage
of any vapor would disturb the homogeneity of the body of liquid in distributing
chambers L", thus allowing vapor to pass through some of the openings e, and
affecting the uniformity of the feed. To prevent the passage of vapor, I employ a
butterfly valve b, operated by the float a, as plainly shown in figure 13. The
superior vacuum in the tubes to which the liquid is being fed, draws all the liquid
that the butterfly valve b, actuated by the float a, will permit to pass. It is quite
evident that the effect of liquid entering chamber E, would be to raise the level
and by operating the float a, would open the butterfly valve b, and permit liquid
to pass equal to the amount run in.

page_text: As usually constructed, the shells of cylinders H H and H are made of iron
and the tubes T, of copper, hence some provision must be made for the difference
in contraction and expansion of the two metals. This is accomplished by making
the plate B¹ of such diameter that the circumferential portion outside of the area
occupied by tubes, shall act as a vibrating diaphragm, and thus accommodate the
expansion and contraction of the tubes without strain.
The condensation within the cylinders H H H is removed through pipes V,
and is finally discharged through the vacuum pump O. It is quite evident that
other means of removing it may be adopted, as by a pump attached to the drip of
each cylinder, but the manner described is probably the simplest.
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. In a vacuum distillation apparatus the pipe or coil a, having progressively
increasing area from inlet to outlet, substantially as shown and described, for the
purpose specified.
2. In a vacuum distillation apparatus, two or more vaporizing coils a, of
gradually increasing area, discharging into a common separating chamber, substan-
tially as shown and described for the purpose specified.
3. In a vacuum distillation apparatus, the herein described combination and
arrangement of sections of pipe and their connections constituting vaporizing
coils a, and outer coil A, with head A2 having division plates A substantially as
shown and described and for the purpose set forth.
4. Tie herein described method of utilizing the latent heat of vapor generated
within coils under pressure of one or more atmospheres, to evaporate a second
body of liquid, under a less pressure, substantially as shown and described, for the
purpose set forth.
5. One or more vaporizing coils a, surrounded by a heating medium and
discharging into separating chamber B¹ provided with means for forcing the fluid
to be evaporated through such coil or coils, in combination with one or more
additional vaporizing coils a, surrounded by a heating medium and discharging
into separating chamber B, provided with means for producing a vacuum within
said latter coils and chamber B, the space surrounding said latter coil or coils
being connected with said chamber B by suitable pipe connections, substantially
as shown and described, for the purposes specified.
6. One or more vaporizing coils a, surrounded by a heating medium and
discharging into a separating chamber B¹, provided with means for forcing the
tuid to be evaporated through said coil or coils, and means for withdrawing the
reduced fluid from said chamber B₁ without permitting the escape of the vapor
therefrom, in combination with one or more coils a, heated by vapor from said
chamber B¹, said latter coil or coils and chamber B being provided with means for
producing a vacuum therein and means for withdrawing the reduced fluid from
said chamber B, substantially as shown and described, for the purpose set forth.
7. In a vacuum distillation apparatus, in combination with separating chamber B¹,
the trap c, d, substantially as shown and described and for the purpose set forth.
8. In a vacuum distillation apparatus, the combination of force pump H, coil X,
separating chamber B¹, trap c, d, vapor pipe b¹, coils Y, Z, separating chamber B,
tail-pipe pump E, vapor pipe b, and exhaust pump D, substantially as shown and
described, for the purpose set forth.
9. In a vacuum distillation apparatus, stand-pipe G, provided with means for
maintaining the liquid therein at a uniform height, in combination with discharge
nozzles, and open feed-box L, whereby a sight feed is provided, substantially as
shown and described, for the purpose specified.
10. In a vacuum distillation apparatus, in combination with means, substantially
as described, for delivering a regular and c.nstant supply of liquid to be evaporated,

page_text: the nozzles as a sight feed, substantially as shown and described, for the purpose
set forth.
11. In a vacuum distillation apparatus, feed-box L having for each vacuum coil
to be fed, a separate compartment provided with float and lever o, and valve n,
substantially as shown and described, for the purpose specified.
12. In a vacuum distillation apparatus, the combination of supply pipe f, valve
and lever g, connected to float k, adjustable pulley i, stand-pipe G, and nozzles
with feed-box L, floats and levers o, valves n, and feed pipes m, substantially as
shown and described, for the purpose specified.
13. In a vacuum distillation apparatus, tank F, provided with float and lever p,
valves 9, and overflow pipe ql, in combination with force pump H, and coil ✗,
substantially as shown and described, for the purpose set forth.
14. In a vacuum distillation apparatus, tank F, provided with float and lever p,
valve q, and overflow pipe q', in combination with means for delivering a regular
and constant supply of liquid to the evaporating coils, substantially as shown and
described, for the purpose set forth.
15. In a vacuum distillation apparatus, coils Y, Z, in combination with means
for delivering to each of said coils an equal, regular, and constant supply of the
fluid to be evaporated, substantially as shown and described, for the purpose
set forth.
16. In a vacuum distillation apparatus, coils Y, Z, in combination with stand-
pipe G, valve g, float k, cord and adjustable pulley i, nozzles L, feed-box L, and
valve o, n, and feed pipes m, substantially as shown and described, for the purpose
set forth.
17. In a vacuum distillation apparatus, the combination of a shell to contain
steam or other heating medium, surrounding vaporizing tubes passing through the
shell and terminating at one end within a common separating chamber, and device
for supplying a uniform quantity of liquid to be evaporated to each of the tubes,
at the end of said tubes opposite the separating chamber, substantially as described.
18. In a vacuum distillation apparatus, the combination of a shell or its equiva-
lent, so constructed as to act as a jacket, to contain steam or other heating medium,
surrounding tubes discharging at one end only, into a common separating chamber,
the opposite ends of each tube terminating in a common distributing chamber, and
means for supplying said distributing chamber with a regulated amount of liquid,
substantially as described.
19. The combination in a vacuum distillation apparatus, of a shell to contain
steam or other heating medium, parallel tubes passing through said shell and
terminating at one end in a common separating chamber, a distributing chamber
covering the opposite ends of said tubes, and any means of varying the size of
openings to tubes within the distributing chamber, substantially as described.
20. In a vacuum distillation apparatus having a shell to contain steam or other
heating medium, surrounding vaporizing tubes terminating in a common separating
chamber, and receiving their supply of liquid to be evaporated from a cominon
distributing chamber, the plugs K' with openings, taper pins I, pin plate H³,
operated by rod L', through stuffing box d, for the purpose described.
21. In a vacuum distillation apparatus, arranged as multiple effects, the float
chamber E, and any means of delivering the liquid flowing into said chamber
continuously to the distributing chamber of next effect, and preventing the flow
of vapor, when operated by the varying height of liquid in said chamber, for the
purpose set forth.
22. In a vacuum distillation apparatus, two or more evaporators and a connected
separating chamber in combination with the float chamber E, a discharge pipe
having a seal or trap and leading therefrom to the second evaporator, and a valve
and float operated by the varying height of liquid in said float chamber, whereby
the flow of vapor is prevented and the flow of liquid is regulated, substantially
as described.

page_text: 23. In a vacuum distillation apparatus, in combination with the heating shell
and separator, the plate B¹ supporting the ends of the vaporizing tubes and having
an extended circumferential portion to act as a vibrating diaphragm, to permit
expansion and contraction of the tubes without strain, substantially as shown and
described.
24. In a vacuum distillation apparatus, the combination of vibrating diaphragm
plate B¹ with vaporizing tubes surrounded by a heating medium and terminating
in a common separating chamber, substantially as shown and for the purpose
described.
25. In a vacuum distillation apparatus, the steam heating shell containing
vaporizing tubes, in combination with a separating chamber provided with dash-
plates having openings alternately on opposite sides, for the passage of vapor and
openings at the bottom for the passage of liquid, substantially as described.
26. In a vacuum distillation apparatus, dash-plates A¹ in combination with a
separating chamber and a shell to contain steam, or other heating medium,
surrounding the vaporizing tubes, terminating in the common separating chamber,
each of said tubes receiving a regulated supply of fluid to be evaporated, substan-
tially as shown and described.
27. In a vacuum distillation apparatus, the combination of two or more evapo-
rators, and separators with a vapor pipe H leading from the separating chamber of
one evaporator to the space in shell surrounding the tubes in the next evaporator,
so as to produce multiple effects as set forth.