US1733476A - Evaporation, distillation, or the like apparatus - Google Patents

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' 06h l929- w. VOGE/LBUSCH 1,733,476

EVAPORATION, DISTILLATION,0B THE LIKE APPARATUS Filed Feb. 17, 1927 v 2 Sheets-Sheet l Oct. 29, 1929. w. VOGELBUSCH 1,733,476

EVAPORATION, DISTILLATION, OR THE LIKE APPARATUS Filed Feb. 17. 1927 2 Sheets-She et 2 I I ig-- /6 20 E 1 m I a jig/we 1/6 Patented Oct. 29, 1929 UNITED STATES PATENT orrlcr.

EVAPORATION, DISTILLATION, on Tim LIKE arram'rn's Application filed February 17, 1927, Serial No. 168,918, and in the Netherlands April 14, 1826.

My invention concerns improvements in or relating to evaporation, distillation or the like apparatus.

It is well known that the efliciency of evaporating-de'vices in which vapourous or gaseous heating agent circulates around tubes or chambers containing liquid to be evaporated is subject to detriment due to various causes.

The transfer of heat from the heating agent to said liquid is impaired, for example, when materials which form crusts deposit from the liquid on to the walls of the tubes. It is also possible, however, for resistances to the heat transfer to be formed on the other side of the walls of the tubes, that is on the side in contact with the vapourous or gaseous heating agent. Such may be due to deposits from the heating agent, as for example, oil deposit which may occur when steam is employed which, exhaustingfrom an engine or engines, is not entirely free from oil.

The obstacles to heat transfer due to such circumstances may, however, be avoided comparatively simply by the employment of devices for the separation of the oil from the exhaust steam. It is, on the other hand, more difficult to obviate resistances due to condensate which deposits from the heating agent on the tubes and due to the separation of noncondensable or permanent gases which form a sheath over the said tubes. Both the condensed vapour and the permanent gases, being oor heat conductors, form obstacles to the lieat transfer and it is therefor necessary to remove the same.

In the case of eva orating devices with heating tubes the con ensate from the heating vapour surrounds the separate tubes in the form of a layer thereof which flows downwardly and which increases in thickness towards the bottom. Thepermanent gases, principall air, remain where the heating vapour whic had hitherto formed a carrier for the same disappears, that is also on the heating tubes, and thus hinder the access of fresh steam to the tubes. If provision is made for drawing oil? the permanent gases rapidly, then their detrimental actipn may be reduced, but a disproportionately large quantity of heating vapour is lost therewith, the. loss of heating vapour amounting to 15% or more. In banks of heating tubes which can be comparatively simply freed from air the heating vaour issubject to'pressure and temperature osses accompanied again by corresponding Eeduction in the efliciency of the heating surace.

The presentinvention relates to evaporating, distillation or the like devices wherein. provision is made not only for a high circuno latio'n velocity, at the walls in contact with the heating vapour, of the liquid or solution to be evaporated but also for a heating surface which, practically speaking, ofiers no resistance to heat-transfer.

Accordingly the invention residesin such an apparatus comprising one or more evaporation stages each of which has one or more heating elements, each of which elements on its side comprises in combination one or more comparatively large-bore, substantially horizontal circulation tubes communicating with the li uid space of an evaporating chamber,

a ban of mclined smaller-bore tubes oommunicating with the vapour space of the said chamber, a header space connecting the two sets of tubes and a jacket, through which flows a heating agent and which consists of two parts, each enclosing one of the sets of tubes and being in communication with each other so in the neighbourhood of the said header space.

The .part of the jacket enclosing the inclined tubes i" furnished with bafiles which constrain the heating agent to flow in a tortuous manner between the-said tubes, so that, with a suitable velocity of flow of the heating agent, condensed liquid and permanent gases are forced towards the other part of the jacket, en closing the horizontal tube or tubes, whence they may be removed.

wo embodiments of the invention are illustrated by way of example in the accompanying drawings, wherein 1 Flg. 1 is a vertical section of one form of eva orating device, ig. 2 is a vertical cross section accordin to line 1-1 of Fig. 1, Fig. 3 is a view of the left side of Fig. 1,

gig. 4 shows a further form of execution an Fig. 5 a detail of this construction in a view from below,

Fig. 6 is 'a view similar to Fig. 2 showing a modified form of construction,

Fig. 7 is a cross sectional view of the construction shown in Fig. 6.

In the case of the construction illustrated in Fig. 1 the heating element consists of one the lower part of which communicates with the tube 3. The jacket of the heating element is composed of a part 5 enclosing the tube 3, a part 6 enclosing the bank of tubes 4 and a cover 8 which closes the header 7 The two parts 5 and 6 of the jacket of the heating member communicate with one another only in the neighbourhood of the header 7. Deflecting walls or bafiies 9 are arranged in the part 6 of the jacket to constrain the heating vapour, which enters through an inlet 10, to follow a tortuous course inside the jacket 6 so that it flows between the tubes 4 in a direction which is always more or less perpendicular to the longitudinal dir"ction of the said tubes. The heating vapour, after entering the jacket 6-by the inlet 10, fio-ws therefore, in a zigzag course through the said jacket and asses finally into the part 5 of the jacket w ence it emerges through an outlet 11.

The liquid in the chamber 1 fills also the tube 3, the header 7 and the tubes 4 in which it is heated bythe heating agent which circulates around said tubes. Due to the heating the liquid in the tubes 4 is forced upwardly, while the cooler liquid in the chamber 1 is caused to move downwardly, thus maintaining a circulation. I

The point atwhich the tube 3 communicates with the chamber 1 may be so disposed that there is always a portion of the liquid at rest in said chamber 1. This is of advantage when solutions are to be evaporated which deposit salts.

By suitably arranging and distributing the bafiies 9 in the jacket portion 6 it is possible to obtain any desired or necessary velocityof the heating vapour and to maintain the same constant over the entire course thereof in spite of the fact that the quantity of vapour may continuously decrease. It is also possible, however, to make the velocity of the heating vapour larger or smaller at will. In flowing through the jacket the heating vapour drives before it not only any condensate present but also the permanent gases, usually air, into the part 5 thereof whence the said substances, which would otherwise impair the heat-transfer, may be removed. The condensate flows out through the outlet 11 and the permanent gases may be drawn off through a separate outlet 12. It is possible in this manner to ensure that the heating surfaces of the tubes 4 remain free from condensate and permanent gases so that the heat transfer is not hindered.

It is naturally possible to provide a plurality of stages each with ,two or more heating elements of the type described and to arrange them' one beside the other or one above the other in any suitable manner, the acket surrounding the large circulation tube 3 of each stage being combined, if desired, to form a single jacket common to all stages. It is, moreover, not only possible to employ such heating elements in various ways in an evaporating device but also to construct the heating element itself in various ways within the scope of the invention. The overall height of the device may, for example, be reduced by disposing the horizontal tube 3, not below the inclined boiler tubes 4, but beside the same and it is clear that it is not fundamentally important that the tube 3 should be exactly horizontal and it may be somewhat inclined.

The construction according to Fig. 4 differs from that according to Figs. 1-3 in that the liquid circulating through the tubes 3 and 4 and through the chamber 1 is compelled to pass also through the pipe-shaped device 13 inserted into the chamber 1, the upper end of this pipe being connected to the wall of the chamber 1 and the width of this tube being dimensioned in such a manner that there is an annular space around this pipe in the chamber 1. The liquid coming from the upper end of the tubes 4 flows downwards through the interior of the inserted pipe 13 and as the lower end of this pipe 13 lies at a level lower than the place where the tube 3 is branched oft, the liquid is compelled to flow around the lower edge of the pipe 13 and to ascend in the annular space 14 in order to arrive at the tube 3. In consequence of the sharp curvature of the way of the liquid at the lower end of the pipe 13 and in consequence of the small speed of the liquid at this place solid substances .(e. g. salts) contained in the liquid are separated from the liquid and deposited on the bottom of the chamber 1. From here these said substances may be removed from time to time so that the liquid flowing through the heating tubes gets liberated from such substances.

As for this result it is necessary that the I liquid flows through a sharp curvature before it arrives at the tube 4 also other means securing the same efiect may be used. For

instance a vertical wall may be arranged in the chamber 1 around the lower edge of which the liquid would flow before it arrives at the tube 3. It is also possible to give the chamber 1 itself such a shape that it forms a way for the flowing liquid with a sharp curvature before its entrance into the tube 3. The sharp curvature of the course of the liquid need not in all cases be directed downwards; this curvature may also be directed otherwise.-

Fig. 4 shows further the space 15 for the vapour subdivided by a partition 16 into two chambers 17 and 18 communicating with each other by means of a tube 19. A mixture of vapour and li uid leaving the upper ends of the heating tu es 4 enters the chamber 17 and whilst the particles of the liquid collect and flow downwards into the chamber 1, whcrefrom the liquid begins again its circulation through the heating device, the vapour escapes upwards in order to be used for heating or other purposes or to be condensed.

In order to prevent the particles of liquid from being carried away together with the vapour through the tube 19, a hollow cylindrical screen 21 is fixed to the bottom 16 (Fig. 5 shows this screen as seen from below), the inner space of this screen being open at both ends. Therefore the vapour may enter the innner space of the screen through both open ends and escape into the chamber 18 through the tube 19. The liquid collecting on the outside of the screen 21 drops down and assembles with the liquid in the chamber 1. The inner space of the screen 21 may also be open only on'one side or on more than two sides.

Abovethe tube 19 there is arranged a device 20 for destroying the foam producedby the liquid; this device may be of a well known construction.

From a constructional point of view, it is quite possible to realize the invention in a somewhat different way, that is, instead of employing a single tube 3, two or more such tubes may be provided within the jacket 5. Fig. 6 is a fragmentary end view showing three tubes 3 located within the jacket 5 and Fig. 7 is a cross sectional view showing the arrangement when more than a single tube 3 is used.

What I claim is 1. In an apparatus for evaporation, distillation or the like, the combination of at least one chamber for the liquid to be evaporated, this chamber having at its lower part a liquid space and above this spacea vapour-space for the vapour produced of the liquid, with at the first named tube or tubes and with the 7 other ends with the vapour space ofthe said chamber, the firstnamed tube or tubes being of a larger diameter than the second named tubes, and a jacket consisting of two parts, one of which encloses the first named tube or tubes and the other part encloses the second named tubes, these two parts of the jacket communicating with-one another only in the neighbourhood of the outer ends of the said tubes, the second named part of the jacket being provided with an inlet for a condensable heating agent and the first named part of the jacket being provided with an outlet for the non-condensable portion of said heating agent, and an outlet for products of condensation.

2. In an apparatus for evaporation, distillation or the like, the combination of at least one chamber for the liquid to be evaporated, this chamber having at its lower part a liquid space and above this space a vapour space for the vapour produced of the liquid, with at least one heating device arranged beside the said chamber, this heating device consisting of one 'or more horizontal tubes branched oil from the liquid space of the said chamber, a bank of inclined tubes communicating at their outer, lower ends with the first'named tube or tubes and at their other higher ends with the vapour space of the said chamber,

the first'named tube or tubes'being of a larger diameter than the second named tubes, and a jacket consisting of two parts, one of which encloses the first named tube or tubes and the other part encloses the second named tubes, these two parts of the jacket communicating with one another only in the neighbourhood of the outer ends of the said tubes, the second named part of the jacket being provided with an inlet for a condensable heating agent and the first named part of the jacket being provided with an outlet for the non-condensable portion of said heating agent, and an outlet for the products of condensation.

In testimony whereof I aflix my signature.

WILHELM VOGELBUSCH.

least one heating device arranged beside the

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