Improvements in Vacuum Evaporating and Distilling Apparatus.
Year: 1888

page_text: Jate of Application, 5th Jan., 1888
Specification Accepted. 10th Feb.. 1888
COMPLETE SPECIFICATION.
Improvements in Vacuum Evaporating and Distilling Apparatus.
I, HOMER TAYLOR YARYAN, residing in the City of Toledo, County of Lucas, State
of Ohio, United States of America, Manufacturer, ilo 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 an improved evaporating and distilling apparatus operated
in multiple effects, in which the evaporation takes place while the liquid is flowing
through heated coils of pipe or conduits, and in which the vapor is separated from the
liquid in a chamber at the discharge end of the coils and is conducted to the heating
cylinder surrounding the evaporating coils of the next effect, from the first to the
last effect.
The objects of the invention are:
First. To provide extended vaporizing coils or conduits and increased heating
surface for each liquid feed supply in the heating cylinders, and provide improved
means for feeding the liquid, whereby each set or coil of vaporizing tubes, will receive
a positive and uniform supply of liquid without danger of the feed ducts being clogged.
by extraneous matter.
Second. To positively control the amount of liquid fed by the pump to the
evaporating coils and make it more uniform than heretofore, regardless of the speed
of the pump.
Third. To provide improved separating chambers at the discharge ends of the
vaporizing coils, so as to better free liquid and solid particles from the vapors...
Fourth. To provide for the successful and economical treatment of the most frothy
liquids, such as cause much trouble by excessive priming, by causing the vapors
carrying solid and liquid particles to pass through catch-all chambers, where such
particles are arrested and precipitated, and then returned to the evaporating coils..
Fifth. To secure a more positive flow and circulation of liquid from the evaporating
cylinder of one effect to another, under the influence of a better vacuumi
than
heretofore in multiple effect vacuum evaporating and distilling apparatus....
Sixth. To provide for transferring a hotter concentrated liquid into the separating
chamber containing a cooler concentrated liquid in direct connection with the condenser

page_text: and vacuum pump, so as to equalize the temperature of the two liquids, and then draw
off both by one tail pump.
My present invention comprises more particularly, improvements on the apparatus
described and shown in my British Patent, No. 14,162, A.D. 1886, and covers a
number of important modifications in construction, whereby improved results are
secured, as follows:-
In practical working it has been demonstrated that where the liquid to be evaporated
is fed into each tube having but a small extent of heating surface, a relatively small
feed is required. Where the copper vaporizing tubes are three inches in diameter
and sixteen feet long, this feed cannot be more than three-sixteenths of an inch within
which a taper pin must be worked according to the construction of my above-mentioned
patent. When it is desired to decrease the amount of feed by reducing the size of the
opening, the entering pin forms a thin annular opening through which the liquid must
pass. With a perfectly pure liquid, the feed can be adjusted to a nice point by the
withdrawal or insertion of the taper pins; but when a material is to be worked which
contains impurities, these annular openings are constantly being closed by obstructions
to the feed, and the particular tubes thus closed, are consequently thrown out of use.
To avoid this difficulty and to facilitate the means of cleaning the tubes, I have devised
a solid metal head, so constructed with partitions, that when they are fitted in position
against the tube sheet, they form the equivalents of return bends and throw the tubes
into sets of five, forming practically a coil of three inch pipe, sixty feet long. This
allows me to feed five times the quantity, as by the old plan, of liquid to be evaporated
since I have five times the extent of heating surface, and as a consequence,
the area of the opening to each set of tubes can be enlarged five times. In
order to feed each set of tubes contained within the cylinder, I construct a manifold
which allows of a distinct feed duct to each set of tubes, and the area in cross section
of this feed may be one-half inch, which is sufficiently large to prevent its being closed
by ordinary impurities. In the triple effect apparatus, which will evaporate say
sixty thousand gallons in twenty-four hours, it requires twelve sets of these tubes (five
tubes in a set) to each cylinder, and as each effect has the same number of tubes, the
manifolds are all alike and similar to the one just described. The head with partitions
which is inside the separating chamber against the flue sheet, covering the inner ends
of the tubes, has an opening of full size of the tube, from each sixth tube, to permit
the vapor and condensed liquid to be discharged into the separating chamber.
It has also been found by experience, that the float chamber described in my former
patent, is not necessary in connection with my new construction, and is really an
objection as the passage of a small quantity of vapor through the manifold causes a
more equal distribution of the feed, owing to the varying height of the several feed
pipes for each set or coil of vaporizing tubes.
It has also been found in working frothy liquids, such as the waste alkali from wood
pulp, that the separating chambers fill with froth and have a tendency to prime. To
avoid this difficulty, I have introduced catch-all chambers through which all the
vapors must pass from the separating chamber of one effect to the heating cylinder of
the next effect. It consists of a cylinder which has an interposed plate, and into this
plate are expanded a number of small tubes through which the vapor must pass to the
opposite end of the cylinder and impinge against another plate, which has the effect of
precipitating and accumulating the solid and liquid matters so that they can return to
the original liquid in the coils. The principle involved in the action of this catch-all,
is the use of small tubes which permit the ends to be approached near to the plate so
that the momentum which the liquid or solid matter in the vapor has attained will
carry it forward against the impinging plate where it adheres and runs out of the
drip pipe.
Sometimes small tubes and the impinging plate are arranged within the separating
chamber in place of making a separate catch-all. When arranged in this way, the
first dash-plate acts as a flue sheet, into which a number of one inch tubes about six
inches long are expanded and extend to within one inch of the second dash plate, care
being used not to place any tubes opposite the opening of the second dash plate,

page_text: 1
Any entangled liquid which is not precipitated as it discharges from the fifth pipe
of the evaporating coil will be effectually separated by this arrangement.
The next modification and improvement in this apparatus, as compared with the
patent No. 14,162, A.D. 1886, is the arrangements for feeding the liquid through
the separate effects, and consists in so arranging the pipes as to make a more
positive circulation. Where exhaust steam with five pounds pressure is used as
the heating medium in the first effect, and where the number of effects are
increased to four, the vacuums on the separate effects would read about as follows:
On the first effect three inches; second, eleven inches; third, nineteen inches;
fourth, twenty-six inches. In constructing very large apparatus, and where the
cylinders containing the coils are six feet in diameter, the difference in vacuum
between the first and second effect is not sufficient to get a reliable feed to the upper
coils. In order to remedy this difficulty, I provide a feed direct from the liquid
supply pump to coils in the cylinders of both the first and second effects, and run the
liquid discharge pipe from the separating chamber of the first effect to the manifold
and feed ducts of the third effect, and from the separating chamber of the second
effect to the manifold and feed ducts of the fourth effect, thereby securing the advan-
tages of the superior vacuums in the cylinders nearer the exhaust pump and
consequently a better and more positive circulation of liquid through the coils and
from one effect to another throughout the series. As the evaporating surfaces in all
the effects are alike, and as the amount of liquor pumped to the first and second
effects is equal, it results that the liquor finished in the third effect will be of the
same gravity as that finished in the fourth effect, but the temperature of the liquor
in the third effect will be higher than that in the fourth effect, and hence it is
impractical for one tail pump to remove the liquor from the third and fourth effects
by direct connection. I obviate this difficulty by making a cross connection from
the separating chamber of the third to that of the fourth effect, and passing the
liquor through this connection from the third to the fourth effect, where the latent
heat escapes with the vapor to the condenser, cooling the liquid down to the tempera-
ture of that in the fourth effect, which will then allow of removal by the tail pump of
the fourth effect. This arrangement of allowing the liquid from the third effect to
pass over to the fourth. has two advantages, one of which is to save an extra pump
for the third effect and the second is to remove the excessive heat held by the liquid.
In the patent No. 14, 162, A.D. 1886, no arrangement was shown for regulating
the amount of feed except by the speed of the feed pump, which is found by experience
not to be reliable. In order to make the supply absolutely uniform, regardless of the
speed of the pump, a feed regulator consisting of a float and valve is arranged in the
liquid supply box with which the suction pipe of the pump is connected, and as a
given amount of liquid is constantly running into the box should the pump run too
fast, the float lowers and prevents air from being drawn into the apparatus through
the pump, and also prevents an excess of liquid from being forced into the evaporating
coils.
Having stated the object of my invention, I will describe it detail with reference to
the accompanying drawings in which :-
Figure 1, represents a side elevation of the apparatus.
Figure 2, represents a front end elevation.
Figure 3, represents a top plan view.
Figure 4, represents a vertical section of a cylinder showing the evaporating coils
and separating chamber.
Figure 5, represents a horizontal section and Figure 6, a vertical section of the
separating chainber shown in Figure 4, both on reduced scale.
Figure 7, represents a broken section of the cylinders for showing the connections
of the liquid pipe from the first to the third effect evaporator.
Figure 8, represents a rear end view of a cylinder with manifold, the feed pump
and a sectional view of the feed box and supply devices.
Figure 9, represents a sectional view on enlarged scale, of the manifold and a feed
duct.

page_text: Figure 10, represents an inside view of a return bend head.
Figure 11, represents an inside view of a section of the head.
Figure 12, represents a vertical cross section thereof on enlarged scale, and
showing the partitions forming cells for connecting the ends of the evaporating tubes.
Figure 13, represents a vertical longitudinal section of a catch-all chamber.
Figure 14, represents a cross section thereof.
Figure 15, represents a vertical longitudinal section of my new form of separating
chamber..
Figure 16, represents an end view, and Figure 17, represents a side view of the
cylinders for showing the pipe connection between the separating chambers of the
third and fourth effect evaporators.
The evaporating cylinders are mounted upon a framework Y, supported upon
columns. X, X. or other suitable, supports. I have shown the apparatus arranged as
quadruple effect,, with four connected cylinders but I construct multiple effect
apparatus with an increased number of cylinders up to ten or twelve. The heating
cylinders B, B; B³, .B, containing the evaporating tubes or coils are preferably
arranged in the same horizontal plane and are provided at the discharge ends of the
evaporating coils, with separating chambers A¹, A2, A3, A4, of enlarged diameter, and
at the supply.ends of the coils with return-bend ends C. C2, C3, C. From each
separating chamber A1, A2, A3, valve pipe D1, D2, D3, leads into the shell of the next
heating cylinder, as B2, B3, B4, and vapor pipe D leads from the last separator A* to
the condenser H; and the vacuum pump H. A cylindrical catch-all chamber E¹ E
EE, is connected in each vapor pipe between each separator and each successive
heating cylinder, as shown in figures 1, 2, and 3, and in detail in figure 13. Gange
glass and liquid receiving chambers G¹ G² G³ G¹ connect with the bottom of each
separating chamber, for receiving the liquid as it is separated from the vapor, and a
gauge glass g, is applied to each of such chambers. Liquid discharge and transfer
pipes t, having valves h. ' as best shown in figures 1, 3, and 7, lead respectively
from chambers G1 G2 of the first and second effect, to the manifold feed pipes leading
into the cylinders B3 B. of the third and fourth effect, for the purpose hereinafter
fully described. The main steam supply pipe F, having safety valve, and stop-valve f",
figures 1, 2, and 3, connects with the heating cylinder B of the first effect. The
evaporating tubes 1, 2, 3, 4; 5, are expanded or otherwise secured in the tube sheets d
and e, at opposite ends of the cylinders, and are properly connected at the ends in
sets of five, to form coils. The outer rear return-bend heads CC, etc., are provided
on their insides with numerous short intersecting partition plates c, forming single
and double cells, properly arranged for connecting the evaporating tubes in sets of
five, as illustrated in figures 10, 11, 12. The inner face of the heads and the edges of
the partitions c, are ground so as to make a tight joint with the tube sheet e" and the
two are drawn together by bolts.
The heads, are pierced with holes e' for connecting the liquid supply pipes M, of the
manifolds L. The inner return-bend head T, in the separating chambers are formed
like, heads CC etc., with intersecting partition plates, and are provided with
discharge openings for every fifth tube, as shown in figure 4. Tube sheet d, is
made of considerably larger diameter than cylinders B1 B2 etc., and acts as a vibrating
diaphragm, to accommodate the expansion and contraction of the tubes.
The separating chambers may be constructed with dash plates b, b, two or more in
number; having openings g g alternately upon opposite sides for the passage of vapor
and opening a¹ at the bottom, for the passage of liquid, as in my former patent, or
with my improved arrangement of tubes and plate, shown in figure 15; here a tube
sheet is provided near the openings of the evaporating tubes and in such sheet are
set numerous small horizontal tubes n, which discharge against a vertical arresting
plate b set near their open ends. Watery and solid matter are impelled against the
plate and thereby arrested, and caused to flow down to the bottom of "the "chamber.
A vacuum gauge a, is applied to the end of each separating chamber. The liquid
feed apparatus consists of supply tank K, placed at suitable elevation, stand-pipe J,
feed-box K double pump 1, manifold L, and connecting pipes and valves.
The

page_text: liquid to be evaporated flows from tank K, through pipe k, to stand-pipe J, and box
K, the flow being made constant and uniform and of the desired quantity by means
of a valve k, having a connected lever handle, which is connected by a cord or
chain, passing over pulley j, with float q, in stand-pipe J. The valve opening in pipe k
being properly adjusted by means of float q lever r, and the connecting cord, the
liquid is admitted to stand-pipe J, while the column of liquid is automatically
maintained at any desired height and consequent pressure, regardless of the quantity
in the supply tank, by means of float 42. which, as it rises, tends to close valve and
as it falls tends to open said valve. From the bottom of stand-pipe J, nozzle
discharges a constant and uniform stream of liquid into feed-box K'. The suction
pipe I of pump I, extends into box K' where it terminates in a turned down nozzle,
provided with valve i, having a lever handle and float =. By means of this valve and
Hoat, the amount of liquid drawn by the pump and forced to the evaporating coils, is
made absolutely uniform, regardless of the speed of the pump, which is apt to vary.
As a given amount of liquid is constantly running into the box, should the pump run
too fast, the float lowers, partially closing the valve, and lessening the amount of
liquid drawn at each stroke of the pump and preventing air from being drawn in,
since the end of the suction pipe is always scaled by the liquid. The liquid is forced
by pump I, into the manifolds L, from which it flows through the contracted ducts 1,
into the enlarged feed pipes m, as shown in figure 8 and 9. Ducts, are of about
one half-inch diameter and the upper and lower sections thereof, are connected by a
union coupling one portion of which ', has a reducer with opening of one quarter
inch diameter, more or less, according to the amount of liquid it is desired to feed.
Pipes m, are of one and a quarter inch diameter, and are connected to ducts 1, by
reducers m¹.
The liquid being forced under pressure by the pump, it will flow, in approximately
uniform quantities through all the contracted ducts, to the evaporating tubes at
varying heights in the cylinders. As soon as the liquid enters the enlarged pipes m,
it is favorably affected by the vacuum of the evaporating coils and the flow
accelerated, particularly to the upper coils. A double feed pump being used, the
liquid is forced thereby positively into cylinders B B², of the first and second effects,
as shown in figures 2 and 3. For convenience of illustration, but four feed-pipes m,
are shown feeding into four sets of evaporating coils, yet in practice, I arrange twelve
or more sets of coils in the cylinders, and provide a corresponding number of feed
pipes. The heating surface for each feed supply being much increased by the
extended pipe, in the form of a coil, the feed openings can he advantageously enlarged
to one-half inch, as in ducts l, and clogging and obstructions with impurities thereby
avoided, and greatly improved results secured, since every set of tubes certain to
have its supply of liquid and thus perform its required duty.
The catch-all chambers E¹ E², etc., figures 1, 13, and 14, are provided each at its
inlet end e, with tube sheet o, extending across its diameter a short distance in front
of the opening of vapor pipe D', and in such sheet are fixed numerous longitudinal
tubes p, extending to near the opposite head el, so that the vapors carrying watery or
solid particles, are impelled against the head and arrested. The inwardly extending
escape pipe d', is cast with or otherwise secured to head e¹, and causes a return of the
vapors, preventing any watery or solid particles from being blown directly into the
vapor pipe D. Liquid and solid matter, arrested in the catch-all chambers, flow
through pipes e, all down into the fluid transfer pipe t, t', as shown in figures 2, 3,
and 7, and thence into the evaporating coils, and through pipe o directly to the tail
pump W, figure 2. By use of the catch-all chambers, the most frothy liquids can be
readily and economically managed. A liquid transfer pipe s, having valve h", leads
directly from receiving chamber G³, of the third effect, to separating chamber A* of
the fourth effect, as shown in figures 16 and 17, to conduct finished liquid into such
separator, where it is cooled to the same temperature as the liquid finished in the
fourth effect, the latent heat being carried off in the vapors drawn by the vacuum
pump H into the condenser H, and the finished liquid of both effects is drawn off
through pipe w, by one and the same tail pipe pamp W. The water of condensation

page_text: accumulating in the heating cylinders B B etc., is transferred from one to the other
through connecting pipes u, u having valves y, shown in figures 1, 2, and 3, and
finally from cylinder B, through pipe directly into condenser H.
The operation of the apparatus is as follows
The feed pump I, having its suction pipe in connection with the feed box; is
started at the same time as vacuum pump H¹, which produces a partial vacuum
throughout the apparatus. As soon as liquid appears in glass gauge g, of receiving
chamber G, figure 2, the tail pump W, is started, and steam is admitted by pipe F,
into cylinder B of the first effec" and the pressure properly regulated. The liquid
flows uniformly into the evaporating coils of cylinders B₁ B² in properly regulated
quantities as heretofore described. The liquid is first partially evaporated in the coils
of cylinder B, and the vapor and reduced liquid are discharged into separating
chamber A', where, under the influence of enlarged area, and the mechanical effects
of the dash-plates or short tubes and arresting plate, the liquid and vapors are
separated, the hot vapor passing off through vapor pipe D', into heating cylinder B²
of the second effect, in contact with the evaporating coils for heating and evaporating
the liquid passing through them. The partially reduced liquid passes through the
bottom opening a¹ of the dash plates and flows into receiving chamber G, and thence
through pipes t, figures 3 and 7, into the manifold L, and feed pipes supplying the
evaporating coils of cylinder B3 of the third effect, in which coils are maintained a
better vacuum than in the coils of cylinder B2 whereby the flow and transfer of the
liquid is more positively and rapidly accomplished than would be the case if the liquid
pipe connected the first with the second effect evaporator. Liquid is supplied by
pump I, to the coils of the second effect in cylinder B2, the partially reduced liquid
and hot vapors are separated in chamber A as before explained, and the hot vapor or
steam is conducted, by vapor pipe D², into cylinder B³, around the contained evapo-
rating coils. The partially reduced liquid flows into the receiving chamber G³, and
thence by transfer pipe t, into the manifold. and feed pipes supplying the evaporating
coils of cylinder B₁ of fourth effect, where a superior vacuum is maintained. In case
exhaust steam at five pounds pressure is used as the heating medium in cylinder A, of
the first effect, the vacuum gauges of the separate effects would indicate about as
follows: On the first effect, three inches second effect, eleven inches; third effect,
nineteen inches; and fourth effect, twenty-six inches. It is thus seen that in skipping
one effect, evaporator, in making connections of the liquid transfer pipes, as from the
first to the third effect, and from the second to the fourth effect, the advantages of an
increased vacuum are obtained for causing better transfer, feed and circulation of
liquid to and through the evaporating coils."
With my improved method of transferring and feeding the liquid, the number of
evaporators or effects can be increased to twelve or more and economically and
successfully worked. The hot vapors separated in chamber A³ pass by pipe D³ into
the cylinder B around the contained evaporating coils and the vapor arising in
chamber A passes by pipe D directly to condenser H. Liquid from separating
chambers A¹ A, is finished in the evaporating coils of cylinders B³ B₁, and is of the
same gravity in both, but that finished in coils B and entering separating chamber A³,
is of a higher temperature, and before removal by the tail pump, is preferably reduced
to the same temperature as that finished in the coils of the fourth effect, and to
accomplish this result, it is transferred by pipe S, from receiving chamber G³ directly
into separating chamber A', where the latent heat escapes with the vapor to the
condenser, and the liquid is cooled to the same temperature as that finished in the coils
of cylinder B. The concentrated liquid is then drawn off through tail pipe w, by
pump W. Two advantageous results are thus effected, the first of which is to save.an
extra pump for the third effect evaporator and the second is to remove the excess of
heat held by the liquid. The water of condensation is conducted from one cylinder to
another, and finally to the condenser, by pipes u, u₁ u ulas before explained.
For some purposes, that is, the evaporation of liquids not particularly frothy, the
catchall chambers are dispensed with, but for frothy liquids that give trouble by
priming, they perform an economical and important function, as heretofore explained,

page_text: and the liquid and solid matter collected in them is conducted by pipes,
transfer pipes, t, and thence into evaporating coils and by pipe
the last one directly to the tail pump W.
vl, into
leading from
Having now particularly described and ascertained the nature of my said Inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. In a vacuum evaporating apparatus the herein described method of transferring
and feeding liquid from any one effect evaporator, past the next succeeding effect.
evaporator into the third effect from the starting point whereby the advantages of a
superior vacuum, and consequently better transfer and circulation of liquid through
the different effects of the series are secured, and an increased number of effects may
bo used.
2. In a vacuum evaporating apparatus, the herein described method of feeding
directly with a pump, the first two or more evaporators and transferring the partially
reduced liquid from any one effect evaporator past one or more succeeding effect
evaporators into the third or fourth effect evaporator from the starting point where by
the advantages of a superior vacuum, and consequently better transfer and circulation
through the different effects of the series are secured and an increased number of
effects or evaporators may be economically used.
3. In combination with a heating cylinder of an evaporating apparatus, the
evaporating tubes enclosed within such cylinder, and connected at their ends to form
any desired number of sets of coils containing two or more tubes each for the purpose
described.
4. In combination with the heating cylinder, the evaporating tubes enclosed within
such cylinder, and connected at their ends to form sets of coils containing two or more
tubes each, and a feed supply pipe connecting with each coil, for the purpose
described.
5. In combination with the heating cylinder, the enclosed sets of coils, each opening
into the separating chamber, and a feed supply pipe connecting with the inlet end of
each coil, for the purpose described.
6. In combination with the heating cylinder containing evaporating tubes set in
the tube sheets at each end, the return bend heads provided with intersecting partitions
forming cells to connect the ends of the tubes and form sets of coils, for the purpose
described.
7. In combination with a heating cylinder containing evaporating tubes set in the
tube sheets, the return bend head C provided with intersecting partitions c, forming
cells and openings e¹ for connecting the supply pipes, and the return bend head T,
having partitions, and outlet openings t", for the discharge of liquid.
8. In combination with the evaporating coils, a manifold, and contracted liquid
ducts connecting it with the enlarged feed pipes of the coils, for the purpose
described.
9. In combination with an evaporator and feed pipe the supply pump and connected
feed box, the connecting suction pipe being provided with a valve and connected float
resting on the liquid in said feed box, for controlling the supply of liquid independent
of the speed of the pump.
10. In a vacuum evaporating apparatus, the combination with an evaporator of any
one effect of a liquid transfer pipe leading therefrom, past one or more of the successive
effects to an evaporator beyond, for securing the advantage of a better vacuum to
facilitate the transfer and circulation of liquid.
11. In a vacuum evaporating apparatus, an evaporator and a connecting feed puun
in combination with a transfer pipe for partially reduced liquid leading from such
evaporator past one or more of the succeeding evaporators to the feed pipe of an
evaporator beyond, whereby improved feed and circulation of liquid is secured.
12. A separating or catch-all chamber provided with numerous small open ended
tubes and an arresting plate placed near their discharge ends for separating liquid
or solid matter from the vapor arising from the liquid being evaporated.

page_text: "
13. In combination with separating chamber A' having the evaporating coils
discharging into one end, the tube sheet, placed near such end, and carrying open
tubes n, and arresting plate 6', placed in front of the discharging ends of tubes n, for
the purpose described.
14. A catch-all chamber E¹ having tube sheet o, placed near its vapor inlet end
and extending to near its opposite end plate, and outlet pipe d' extending back from
the rear end plate and connecting with outlet vapor pipe D', for the purpose
described.
15. In combination with the separating chambers of the last two effects, as A³
and A', the direct connecting pipe S, for the purpose described.
16. In combination with separating chambers of the last two effects, as A³ and A*,
the connecting liquid transfer pipe S, tail pipe w, connecting with chamber A₁ and
tail pump W, for the purpose described.
Dated thi al L
CT
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.