US1338848A - Liquid-evaporator - Google Patents

Description

R. T.-'WH|TE LIQUID EVAPORATOR.

APPLICATION man mm, 1919.

Patented May 4, 1920.

Q Q Q Q JO IIIIIIOIIIHJII RICHARD 1. WHITE, or cnrcaco, ILLINOIS.

LIQUID-EVAPOBATOR' Specification of Letters Patent.

Patented May 4, 1920.

Application filed p il 7, 1919. Ser1a1No.288,423.

To all whom it may concern:

Be it known that I, RICHARD T. WHITE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Liquid-Evaporators, of which the following is a specification.

My invention relates to heat exchange apparatus and more particularly to liquid 'evaporators such as are employed to vaporize and evaporate various ,liquorsfor distilling purposes and the like.

The practice prior to my invention has become rather firmly settled and little improvement has recently been made along this line. I have observed the action of previous types of evaporators and have noticed, a number of defects which I have cured in the construction of my invention.

I have observed that for a given tube area the e'lliciency of previous evaporators has been unnecessarily low. This defect I have corrected. by the unique arrangement of tubes which I shall later describe. Heretoiore it has been customary to give the tubes through which the steam flows very little or no inclination. The result has been that due to repeated contraction and expansion the tubes sag down and trap the moisture in the sagged portions. This gives an irregular action of a, flow of steam therethrough and greatly lowers. the e'fliciency of the tubes for heat exchange or transfer. I also make the aggregate tube opening relatively small so that a rapid flow will result. This has the desirable result of sweeping the moisture out of the tubes and permits of a smaller number of tubes to produce a given effect. A further result of using the tubes in an inclined position is the ability to use longer tubes within a given space. Another striking defeet which I have observed in former types of evaporators is the defective circulation of the liquor which is being treated. Numerous schemes for controlling the circulation by battles have been proposed, but

they are far inferior to the scheme of my invention. I arrange the tubes in alternate and crossed relation half of the tubes being inclined in one direction and half in the opposite direction. The two sets or groups of tubes thus cross each other at substantially the center otthe liquid chamber and produce an inherently correct condition govwhere the tubes cross each other.

erning the circulation, which is of great practical value. Thereis a tendency for the liquor or liquid around each tube to become heated and to rise along the tube. The result of the alternate cross tubes is to bring these two tendencies into opposition at the center so that the maximum effeet is exerted at the center causing vigorous upward movement of the liquid at the center. It will also be appreciated that the concentration of heat is greater at the center The re sult is that the liquid starts to boil at that point, first, invariably starting the circulation properly and maintaining it properly at all times.

In order to produce a rapid flow through all the tubes and to distribute the heat properly I provide means for causing the steam to flow downwardly in each group of tubes. This may be accomplished by putting the two setsof tubes in series or it maybe accomplished by admitting live steam to the upper ends of each set of tubes.

Proper drainage of the tubes is enhanced by the inclined arrangement of the tubes and also by the provision of a drainage connection at the lower ends of the tubes of each set or group.

The alternate crossed arrangement of the tubes is highly advantageous in a number of other ways. As it inherently corrects the circulation, I am able to govern the feeding of the liquid toand the passage of the same from the evaporator in a highly I providea feeding advantageous manner. connection which introduces the liquid at a point just below the point of violent ebullition and above the point of withdrawal of the concentrated liquor. Thus the specific gravity of the two liquors as well as the natural current due to the temperature keeps the two streams of liquor apart. This speeds up the action decidedly and makes for much greater efiiciency.

A. further advantage of the arrangement of the tubes resides inv the space which is left for cleaning the bottom of the evaporator. Heretofore the bottom ofthe evaporator has been peculiarly inaccessible for cleaning and has required practically a total dismantling of the device to be able .to

clean the bottom of the same. The accumulation of sediment has also heretofore im-- paired the efliciency of the lower tubes, but the accumulation of any sediment on the tubes is prevented in my construction both because of the rapid circulation of the liquor and also because of the space between the cross portions of the tubes and the bottom of the liquid chamber.

Another feature of value is the enlarged vapor releasing chamber. It is desirable that the body of liquor to which heat is applied be relatively small and the vapor releasing surface relatively large to provide an efficient device. The liquid container is made rectangular to provide proper space for the tubes and the heads 'or' boxes in which the tubes are fastened. The upper part of'the device is provided with a vapor dome in which separation of the liquid from the vapor may occur because of the relative slowness of motion of the vapor, even though the device is vigorously operating and vapor is being rapidly released and withdrawn. V

In order to acquaint those skilled in the art with the manner of constructing and numbered respectively 3, 4 and 5 in their entirety. The section or unit 3 may be termed the lower or evaporating section; the section or unit 4 may be termed the intermediate section; and the'section or unit 5 may be termed the upper or vapor chamber or section. V V V The evaporating section 3 is of generally rectangular form, as will be clearly evident from Fig. 2. Its bottom is closed by means i ofa plate or casting 6, which may be bolted or otherwise secured to the flange 7 on the lower portion of the section 3. The upper portion of the evaporating section 3 is provided with a flange 8, on which may rest and to which may be secured the lower flange 9 of the intermediate section 4:. The lower portion of this intermediate section a is of rectangular form to correspond with the evaporating section 3, but the upper portion of the intermediate section 4 is circular in form, being peculiarly shaped in order to secure this result. The intermediate section l has a circular flange 10 on its upper por tion, and may be provided with a' 'plurality of reinforcing ribs or Webs 11.

The upper or vapor section 5 is circular in form and has a flange 12 on its lower edge,

The lower or evaporating section 3 is provided on one side with an upper steam chest 17 and a lower steam chest 18. On its opposite side the evaporating section is provided with an intermediate or connecting steam chest 19. These various steam chests may be removably connected to said portions of the lower evaporating section 3, and may be provided with removable cover plates20, 21 and 22, as illustrated. Extending from the upper steam chest 17 to the intermediate steam chest 19 is a series of downwardly sloping tubes 23, and extending from the upper portion of the intermediate chest 19 to the lower steam chest 18 is another series of downwardly sloping tubes 24.

The steam isintroduced into the upper chest 17 in the first instance through the steam connection 25. It then flows from the chest 17 to the intermediate chest 19 through the downwardly sloping tubes 23, and any condensation formed in these. tubes will naturally drain into the chest 19, the un condensed steam entering the chest 19 goes to the top' thereof, and then flows through the downwardly sloping tubes 24 to the.

lower chest 18. Any condensation formed in these tubes will naturally drain into the chest 18.

A. condensation pipe 26 connects the lower portion of the intermediate chest 19 with the lower steam' chest 18, so that the condensation from the tubes 23'will drain through said pipe 26 into the lower end of the chest 1.8. This pipe 26 is of U-shape form, as is clearly evident from Fig. 1, so that as soon as it fills with condensation it acts as a steam trap orseal and prevents any steam from returning directly from the chest 19 to the chest 18. This compels such steam to flow to the chest 18 by way of the tubes 24, thus insuring additional heating service and benefit from the steam. Examination of Fig. 2 of the drawing shows the presence of a central connection 30, to which is attached the drain pipe 31 shown in Fig. 1. The con densate from the chest 18 is drained through this connection, and since the condensate from the chest 19 reaches the chest 18 through the connection 26 it follows that all of the condensate is removed through the connection 31.

The fresh liquor is introduced into the,

evaporating section 3 through a connection 27 somewhat below the elevation of the tubes 23 and 24-, and a tray or pan 28 communi cates directly with the opening 27, so that the liquor so introduced is distributed throughout the entire width of the evaporating section 3, and the action is accordingly improved; Ordinarily the liquor will stand at an elevation in section 3 somewhere between the pan 28 and the upper portion of the tubes 23 and 24;, but the liquor will at all times be distributed more or less by the presence of this pan 28.

It is to be observed that by combining together the three sections in the manners plained, the evaporating section being of smaller size than the vapor section, the vapor is enabled to very rapidly expand and fill the entire upper portion ofthe device, thus insuring a rapid and complete removal of the vapor from the surface of the liquid at all times. This will enhance or improve the boiling of the liquor and will to a large extent prevent foaming or other undesirable actions. A connection 29' is provided in the bottom section 6 for the removal of concentrated liquor if such removal should be desired.

The operation ofthe device is as follows: The liquid chamber or receptacle 3 is filled with liquor by way of the inlet connection 27. Steam is turned into the heating tubes by way of the connection 25. The steam first flowing into the header or box 17 and then downwardly through the inclined tubes 23 of one group. As the steam loses heat in the tubes 28, condensation will gather in the bottoms of these tubes and run down into the bottom of the header or box 19 at the opposite end of the liquor chamber 8. The movement of the steam in the tubes 23 aids in sweeping the tubes clean of moisture and the action of gravity aids in the same. The steam after passing through the tubes 23 enters the header 19 and then passes downwardly througl'i the tubes 24: toward the header 18. Again the condensation is swept onward by the motion of the steam in the tubes, being aided by gravity. The moisture is trapped in the connection 26 preventing the transfer of steam from the header 19 to the header 18except through the tubes 24 and such moisture as is in excess of that required to form the trap is withdrawn from the condensation outlet 31.

The liquor chamber 3 being relatively small can be heated up quite rapidly with the result that the action is promptly started and readily maintained. At the central part of the liquor chamber where the two groups of tubes are crossed there is the greatest concentration of heat upon the relatively small body of the liquor with the result that circulation is started in the proper direction and always maintained properly. There is a natural tendency for the heated liquor around each tube-to rise and the tendency of the same is to rise along the tube. As the two sets of tubes are inclined oppositely the tendency of the liquor at one tube will thus be met by the tendency of the liquor at a tube of the opposite set to rise with the result that vigorous action occurs at the central part of the liquor chamber. The liquor rises at the center of the chamber and passes up and releases the vapor and then drops down along the ends of the tubes either again entering the circulation or passing off through the outlet 29. The feeding connection 2 7 -28 is placed so that the circulation of liquor will pick up the liquor which is introduced and immediately passthe same through the point of greatest heat and do this without mixing the same with the concentrated liquor. The result is that both the density due to concentration and the density dueto temperature conditions keepthe two streams of liquor apart' insuring proper operation. The space between the crossed portions of the tubes 232& and the bottom part 6 prevents any sediment from settling on the lower tubes and gives ample space for cleaning of the bottom of the liquid chamber. The provision of the round cylindrical vapor drum 5 and its connection to the rectangular box 3 by the intermediate section 4 is highly advantageous, primarily because of the separating efi'ect which is thus secured by the relatively large vapor dome and second the increase in diameter tends to free the vapor from the liquor in case the same boils up above the top of the box of chamber 3. The liquid chamber 3 can most advantageously be made in rectangular form because of the requirement to mount the tubes 23 and 24. The steam dome 5, can be made most advantageously in round cylindrical form because it will best withstand pressure and can most cheaply be made in that form. The flaring section 4 provides, as I have above mentioned, an increased vapor releasing area for a greater height of liquor and also serves to join the steam dome section 5 with the liquid chamber 3 in advantageous manner.

I do not intend to be confinedv to the precise details of construction shown and described.

I claim:

. 1. In an evaporator, the'combination with a rectangular chamber having a side liquor inlet connection and a bottom liquor discharge connection, of upper and lower steam chests on one side of said section, and an intermediate steam chest on the other side of said section, a steam inlet connection into the upper steam chest, a condensation connection from the lower portion of the lower steam chest, a water seal connection joining the intermediate steam chest with the lower steam chest, a series of downwardly sloping steam tubes extending across the interior of the chamber from the upper steam chest to nection, of a series of steam tubes slanting downwardly across the lnterior of sald chamber from the upper portion of one side to the lower portion of the other side, an-

other series of steam tubes slanting downwardly across said chamber from the upper portion of the last mentioned side to the lower portion of the first mentioned side of the chamber, a connection joining the lower ends of the first mentioned tubes to the upper ends of the last mentioned tubes, and a water seal joining together the lower ends of both sets of tubes, substantially as described.

' 3. In an evaporator, the combination with an evaporating chamber, of a series of steam tubes extending downwardly across said chamber from the upper portion of one side to the lower portion of the other side, another series of tubes extending across said chamber from the upper portion of the second mentioned side to the lower portion of the first mentioned side, the upper ends of the second series of tubes being at greater elevation than. the lower ends of the first series of tubes, a steam passage joining together the lowerends of the first mentioned tubes and the upper ends of the last mentioned tubes, and means for removing water of condensation from the lower ends of both sets of tubes, substantially as described.

4. In an evaporator, the combination of an evaporating chamber, of two series of downwardly sloping tubes extending across said chamber between two of its sides, the upper ends of both series being at substantially the same elevation, means for introducing steam into the upper ends of one series of tubes, means for joining together the lower ends of said last mentioned tubes and the upper ends of the other series of tubes, and means for removing water of condensation from the lower ends of both series of tubes, substantially as described.

5. In an evaporator, the combination with an evaporating chamber, of a steam tube extending across said chamber from the upper portion of one side to the lower portion of another side, another steam tube extending across said chamber from the upper portion of said other side to the lower portion of the said one side, the upper end of the second tube being at a greater elevation than the lower ends ofthe first tubes, means for introducing steam 1nto the upper end of the first mentioned tube, means for joining together the lower end of said tube and the upper end of the second mentioned tube, and means for removing water of condensation from the lower ends of both tubes, substantially as described.

6. In an evaporator the combination of a liquid chamber, of heating pipes arranged in the chamber in two groups, one group being inclined in one direction and the other group being inclined in the opposite direc' tion, the pipes of one group being placed alternately with the pipes of the other group and crossing substantially at the center of the chamber. 7

7. In an evaporator the combination of a liquid chamber, heating pipes arranged in the chamber in two groups, one groupbeing inclined in one direction and the other group being inclined in the opposite direction, the pipes of one group being placed alternately with the pipes of the other group and crossing substantially at the center and fluid connections for causing heating fluid to flow downwardly in each group of pipes.

8. In an evaporator the combination of a liquid chamber, heating pipes arranged in the chamber in two groups, one group being inclined in one direction the other group being inclined in the opposite direction, the pipes of one group being placed alternately with the pipes of the other group and crossing substantially at the center and fluid con nections for causing heating fluid to flow downwardly in each group of pipes, and draining means at the lower ends of the pipes of each group.

9. In combination a liquid chamber having two groups of heating pipes passing therethrough. The pipes of the two groups alternating in position horizontally, the pipesof one group being inclined in one direction and the pipes of the other group being inclined in the opposite direction, said pipes crossing each other substantially at the center, and leaving a clear space between said crossed. portions of the pipes and the bottom of the chamber to permit of cleaning of the lower part of the chamber.

10. In combination a liquid chamber having two groups of heating pipes passing therethrough, the pipes of the two groups alternating in position horizontally, the pipes of one group being inclined in one direction and the pipes of the other group being inclined in the opposite direction, said pipes crossing each other substantially at the center and leaving a clear space between the crossed portions of the pipes and the bottom of the chamber, a liquid outlet in the bottom of the chamber and a liquid feed inlet above the outlet and below said crossed portion of the tubes.

11. In combination a liquid chamber having two groups of heating pipes passing therethrough, the pipes of the two groups alternating in position horizontally, the pipes of one group being inclined in one direction and the pipes of the other group being in clined in the opposite direction, said pipes crossing each other substantially at the center, a liquid outlet in the bottom of the chamber and a liquid feed inlet above the outlet and below said crossed portions of the tubes, said liquid inlet comprising a conduit having an opening or openings facing upwardly and lying below the crossed portions of the tubes.

RICHARD T. WHITE.

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