US1198629A - Condenser. - Google Patents

Description

R. N. EHRHA M. cowogysm. APPHCATION F-HLED SEF'T- 4. 193.

Pgltnted Sm. 19,1916.

INVENTOR.

. 6 WITNESSES: Q i BY gig Q I H ATTORNEY IN FACT UNITED STATES Parana critics.

RAYMOND N. EHRHART, OF EDGEWOOD, PENNSYLVANIA, ASSIGNOR TO THE WEST- INGHOUSE MACHINE COMPANY, A

CORPORATION OF PENNSYLVANIA.

CONDENSER.

Application filed September 1913.

Be it known that l. Harmon!) N. Enuuur'r. a citizen of the United States. and a I resident of lldg'ewood, 1n the county of Allegheny and State of Pennsylvania, have made a new and useful Invention ip Gimdcnsers. of which the following is a specification. a

This invention relates to surface condensers and has for an object to produce an improved condenser which is well adapted to be constructed in relatively large sizes and is more efiicient, and smaller in proportion to its condensing capacity, than oiner large size surface condensers now in use and known to me.

The variation in pressure orlossin :acuum, within a small size surface condenser for example, a condenser having a shell diameter of not more than 30 inches, is so small that it is negligible; but this is not true of re atively large condensers which are, for example, 10 or 12 feet in diameter. In such condensers the path between the condensing tubes along which the steam or fluid to be condensed must flow in being fully condensed is relatively long, and, while the condensation may be complete and the vacuum relatively high at some point within the nest of tubes, it will beapparent that there will be an appreciable variation or difference in pressure between that existing in the vicinity of the fluid inlet of. the condenser and that existing at the point of complete condensation Within-the tubes, unless the tubes of the condenser are spaced relatively far apart in the region where the incoming steam first strikes the tubes, or unless ade quate steam lanes are provided through the tub es to facilitate the admission of steam to the condensing surfaces and to insure a quick dissemination of the large volume of fluid throughout the nest of condenser tubes. This variation or difference in pressure is ordinarily termed loss in vacuum. Condensers having relatively wide spacing of tubes or ample steam lanes are relatively large, in proportion to their condensing capacity, 'is compared with the small size condensers, and they are also proportionately expensive to manufacture. On the other hand, while a relatively large condenser of the ordinary or usualconstruction and havin a tube spacing comparable to the spac- Specification of Letters E'atent.

Patented acpt. 19, 1916. Serial No. 788,139.

ing in a small condenser might compare tavorably with a small condenser both in condensing capacity, per unit of volume, and in proportionate cost of construction, it would occasion such a loss in vacuum Within the shell and in the vicinity of the fluid inlet that the beneficial effect of the high vacuum, which possibly would exist at some point within the nest of tubes, would be almost entirely lost, due to the fact that the paths of'steam flow throughthe tubes would he relatively long and the admission space dietween the tubes relatively small as corn pared with the volume of steam delivered to the condenser and the amount of condensing surface required to condense it.

One of the objects of my invention is to produce a relatively largesurface condenser in which means are employed for reducing the loss in vacuum without greatly increasingthe size ofthe condenser proportionately to its condensing capacity as compared with small size condensers.

'A further object is to produce a surface condenser in which an improved arrange.- ment of tubes is employed such that the cooling: water is more effectively circulated.

These and other objects I attain in a condenser embodying the features herein described and illustrated in the drawings acconmanying a'nd 'forming a part of this application.

In the drawings: Figure 1 is a transverse sectional View along the line 1-1 of Fig. 2 and illustrates somewhat conventionally a condenser embodying my invention. I 2 is a fragmental sectional view along the line 2-2 oi Fig. 1.

The condenser illustrated as an embodiment of my invention includes a casing or shell 3 which is traversed by longitudinally extending tubes 4 and provided with a fluid inlet port 5, non-coiulensable fluid or gas outlet ports 6, and the usual port 10 for delivering products of condensation. As illustrated, the tubes 4 are arranged in three separate sets or nests 7, 8, and S), and each nest is so located in the shell that the steam or other fluid to be condensed can enter it at substantially any point of its perimeter. This is accomplished, in the illustrated embodiment of the invention, by so locating the tubes of each nest that there is an adequate steam space between them and the the steam in the condenser.

longitudinally extending walls of the casing, and by so spacing the nests across'the shell that an adequate steam space is provided between eacl The tubes of each set are shown arranged in two series, an inner series 11 and. an outer series 12, which surrounds the inner series and is so located that it is substantially surrounded by a 'free steamspare 13. Each steam space 13 is in free communication with an equilibrium space 13, which is in direct communication with the inlet ort 5. l he'stcam space is so proportioned with relation to the distribution the condensing sur'ace that each molecule of steam entering the condenser may readily find its way to the condensing surface without being appreciably impeded or checked in its flow by the remainder of This may be accomplished in various ways, for example, each steam space 13 may be progressively decreased in cross-sectional area from the top to "he bottom of the condenser so that each st of tubes is wider at the bottom than a; the top, or the passages 13 may be of any desired shape which will not re strict the liow of steam to the condensing surfaces and which will conserve space within the sl'iell.

As illustrated, the inner series 11 of each nest of tubes is adapted to pass the coolest or incon' ng condensing liquid, while the outer series of each nest is adapted to pass fliquid which. has once traversed inner tubes of the condenser and consequently the inner s of tubes is the colder and fluid to be conoensed' ent ring each nest of tubes encounters progressively coldcr surfaces as it passes toward the center of the nest. This is accomplished in the apparatus illus trated by providing a water box ll at one end of the shell 3, which is provided with a set of passages 15 communicating with a port 16 through a passage 17, and a passage 18, which communicates with a port 19. As is customary, the water box is bolted or otherwise secured to the shell so that the open ends of the tubes communicate with its liquid circulating passages. The water, or condeuf liquid, employed in the condenser delivered to the water box 14: thrrmgh me port 16, and each passage 15 eonnuunic: with and delivers water, from the po t it to the inner series of one of the i 5, while the passage 18 communicat and receives water from the outer seies of all of the nests of tubes and delivers the water so received tothe dis charge port 19. It will beunderstood that the opposite end of the condenser, which is .not shown, is provided with a water box or cover capable of receiving liquid discharged from all of the inner series of tubes and of directing it into the outer series of tubes. Such covers are ordinarily employed in surface condensers and since they are familiar to those skilled in the art, illustration is deemed unnecessary.

One of the air or non-condensable fluid off-take ports 6 communicates with eachhest of tubes through a passage 20 which extends upwardly from the bottom of theshell to a point well within the nest of tubes, so that air or non-condensable fluid is withdrawn from the condenser at the innermost point of the nests of tubes. As shown, each air off-take passage 20 consists of two parallel plates which are mounted on the bottom of the shell andextend longitudinally of the condenser the entire length of the shell.

The ports 6 of the shell communicate with.

a manifold 21, which is located at some con venient point intermediate the ends of the condenser and may communicate with an air pump (not shown) or any other suitable apparatus for removing attenuated air or fluid. Any suitable means may be provided for removing liquid whiclrmay collect in themanifold, and, if desired, several manifolds may be employed so that each passage 20 may communicate with one or more ports fi. It will be understood that the construction of the passages 19 is merely illustrative and that they may be formed in any desired manner.

The principal advantage of my invention is that it eliminates or minimizes the loss in vacuum encountered in large size condensers and at the same time, permits a reduction in the size of the condenser, per unit of condensing capacity, over other large size condensers of the usual or ordinary construction, and consequently reduces the cost of constructing large size condensers. I

The ordinary form of condenser admits steam at the top to an equalizing space or passage, from which it flows downwardly through the condensing tubes toward the bottom of the condenser. Vith such an arrangement the area of the steam admission spaceof the nest of tubes is equal to the width of the condenser times its length (not deducting the space occupied by the tubes),

and the path of steam flow through the tubes is not less than the depth of the con'denser. It'will be apparent that, with such a construction, the size of the condenser is deter: mined in large measure by the, necessary steam admission space to the tubes, since the path of flow through the tubes cannot be arbitrarily without jeopardizing the efficiency of the condenser, as a condensing agent, or creating an objectionable loss in vacuum. In condensers, embodying my invention an admission space of maximum area anda'path of flow of minimum length are obtained. This results from the fact that steam is admitted to each host of tubes sab-' stantially around the entire perimeter of creases the admission space, the lineal flow through the tubes, which is radial or toward the air ofi'-take, can also be materially reduced in length without reducing the efficiency of the condenser as a condensing agent. This roduction in the length of the path of flow, in conjunction with the increased inlet area to the tubes, permits of a relatively close spacing of the tubes, and I have found. that the spacing of the tubes may be reduced to such an extent that a condenser embodying my invention and giving the same vacuum, other conditions being equal, may be reduced in size about 10 per cent. without occasioning an objectionable loss in vacuum within the conrlenseshell.

I have found by experiment that the loss in vacuum within a condenser is decreased by raving the areas of flow gradually diminishing om the inlet of the condenser to the air otltake. This diminution of area should be inversely proportional to the condensation taking place along the paths of flow, so that the velocity of the fluid is maintained at an amnroximately constant value. In the illustrated embodiment of the'iuven tion. this is accomplished by the fact that thepaths of fluid flow converge toward the center of the nest or at the point of air otftake.

Another feature of my invention is that the water of condensation may be withrawn at a higher temperature, for the same vacu in, than in ordinary con- .ln the ordinary condenser the temc s e of the water of condensation canot possibly be greater than the temperature of the steam or vapor in the lowest portion o the condenser, which is normally the mint of lowest temperature, and conseguently thcrc is a loss in vacuum, the eflicicncy' of the organized apparatus, of which the condenser corms a part, is reduced not only by the loss in \acuuni in the condenser, but also by the delivery oi water of condensation at a lower temperature than the temperature of the steam existing at the effective vacuum pressure, by which I mean the vacuum at the inlet 5 of the condenser. In condensers embodying my invention each nest of tubes is practically surrounded by steam, or other fluid to be condensed, at substantially the temperature at which it enters the condenser, and consequently any liquid of condensation falling from the nest of tubes will pass through this uncondensed steam, or fluid, in dropping from the condenser tubes, and will therefore take up heat from the steam or fluid and be delivered at approximately the temperature of the steam or fluid through which it falls. Condensers embodying my invention, therefore, have the advantage of operating w th a lower loss in acuum, within the condenser shell, and in delivering liquid of condensation at a higher temperature, other conditions being equal, than other condensers now in use and known to me[ In accordance with the patent statutes I have illustrated and described one form of a condenser embodying my invention. It will, however, be understood that various changes, modifications, substitutions and omissions may be made in the condenser without departing from the spirit and scope of my invention as set forth in the appended claims.

Having thus described my invention, what I claim is:

1. A condenser comprising a shell, a plurality of separate sets of condensing tubes inclosed within the shell, and a non-condensable fluid oil-take passage extending into each set of tubes.

2. A condenser comprising an inclosing casing, condensing tubes extending across and located within the casing and so arranged in separate nests that a fluid delivery space extends substantially around each nest.

A condenser comprising an inclosing casing, condensing tubes extending across and loaded within the casing and so arranged in separate nests that a fluid delivery space extends substantially around each nest, and a separate non-condensable fluid oft-take located substantially centrally with relation to each nest.

l:- A (.ondenser comprising an inclosing shell, condensing tubes located within the shell and arranged in separate nests with a fluid delivery passage substantially surrounding each nest, a separate non-coirdensable fluid oft-take located within each nest, and means for delivering condensing liquid to the tubes so that the coldest liquid delivered to the inner tubes of each nest. A condenser comprising an inclosing casing having a fluid inlet formed therein, condensing tubes located within said casing and arranged in a plurality of substantially cylindrical nests with a fluid delivery space extending between each nest and the bottom of the casing and communiaiting with Said fluid inlet.

i l. A condenser comprising an inclosing casing having a fluid inlet and a condensation liquid outlet formed therein, tubes ex tending across the shell and arranged in separate nests with a fluid delivery passage located between adjacent nests and extending betwcen each nest and said outlet, and means for circulating condensing liquid through the inner and then through the outer tubes of each nest.

7. A condenser comprising an inclosing shell, a. plurality of substantially cylindrical nests of tubes located Within'the shell, and means for circulating condensing liquid through the inner and then through the outer tubes of each nest.

8. A condenser comprising a shell having an inlet port formed therein, a plurality of separate sets of condensing tubes located within the shell, each set being substantially surrounded by a fluid delivery space communicating with the inlet, and a separate noncondensable fluid outlet located well within each set of tubes.

5). A condenser comprising-a shell having a fluid inlet port formed therein, a plurality of nests of tubes inclosed Within the shell, and so arranged that the fluid admission space to each nest of tubes is greater in circun'it'erential Width than the length of the path of flow through the tubes, and a separate non-eondensable fluid outlet located Well within each nest of tubes.

10. In a condenser, a plurality of nests of tubes, each having converging fluid passages between the tubes, a shell inclosing the nests of tubes and providing fluid passages substantially surrounding each nest and communicating with the inlet port formed therein, and a separate nonrconden'sable fluid outlet located Well Within each nest of tubes at the point of convergence of the fluid passages of the nest.

In testimony whereof, I have hereunto subscribed my name this 30th day of August,

RAYMOND N. EHRHART.

lVitnesses:

C. W. McGri-mn, E. W. IVIGCALLISTER.

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