US1142784A - Condenser. - Google Patents

Description

R. N. EHRHART.

CONDENSER.

APPLICATION FILED JULY 2,1913.

Patented June 8,1915.

HIS ATT RNEY IN FACT RAYMOND N. EHRHART, OF EDGEWOOD, PENNSYLVANIA, ASSIGNOR TO THE WESTING- HOUSE MACHINE COMPANY, ACORPORATION OF PENNSYLVANIA.

CONDENSER.

Specification of Letters Patent.

Patented.- June 8, 1915.

Application filed July 2, 1913. Serial No. 776,966.

size condensers now in use and known to me.

The pressure variation, or, as it is termed, loss 111 vacuum within the shell of a small size surface condenser, for example, a condenser having a diameter of not more than N in condensing capacity, per unit of volume, and in the proportionate cost of manufac- 30, is so small that it is negligible; this, however, is not true of relatively large condensers having a shell diameter of 10 or 12 feet: In such condensers the path along which the fluid or steam to be condensed must flow before it is fully condensed, is relatively long. and, while, the condensation may be complete and the vacuum relatively high at some point within the shell, it will be apparent that there will be a loss in vacuum in the vicinity of the inlet of the condenser, or, in other words, there will be an appreciable variation in pressure between the point of complete condensation and the fluid inlet of the condenser, unless the tubes of the condenser are spaced relatively far apart in the region Where the incoming fluid or steam first encounters the cooling or condensing tubes, or unless adequate steam lanes are provided through the tubes to facilitate the admission of fluid or steam to the condensing surfaces and to insure a quick dissemination of the large volume of fluid throughout the nest of condenser tubes.

Condensers having relatively wide spacing of'tubes or ample steam lanes are relatively large, in proportion to their condensmg capacity, as compared with small size condensers and they are also proportionately expensive to manufacture. On the other hand, while a relatively large condenser of ordinary or usual construction, and having a tube spacing comparable to the spacing in a small condenser, might compare favorably with a small condenser both ture, it would occasion such a loss in vacuum; that is, such a variation of pressure within the shell, that the beneficial effect of the high vacuum attained by the complete condensation of the steam or fluid at some point within the nest of tubes, would be almost entirely lost, due to the fact that the paths of steam flow through the tubes would be relatively long and the admission space be-- tween the tubes relatively small as compared with the "volume of steam delivered to the condenser and the amount of surface required to condense it.

One of the objects of my invention is to produce a relatively large surface condenser the loss in vacuum or the pressure variations throughout the interior of the condenser shell I without greatly increasing the size of the condenser proportionately to its condensing capacity as compared with condensers of relatively small size, and afurther object is to produce a surface condenser in which an improved arrangement of tubes is employed, such that the cooling water is more effecin which means are employed for reducing tively circulated. These and other objects are attained by meansof a condenserembodying the features herein described and illustrated in the drawings accompanying and forming a part of this application.

In the drawings: Figure 1 is a longitudinal sectional view of a condenser taken along the line 1'1 of Fig. 2 and looking in the direction of the dotted arrows; Fig. 2 is a cross-sectional view on the line 22 of Fig. 1; and Fig.3 isan end view of a condenser constructed in accordance with my invention. a The condenser illustrated as anembodiment of my invention lncludes a casing or shell 1 through which tubes 4 extend longitudinally and which is provided with a fluid inlet 6-, a non-condensable fluid or gas outlet port 8, and the usual port 9 for the delivery of produetsof condensation.

As illustrated, the tubes 4 are arranged ina substantially cylindrical nest, which is so located within the shell that the steam or fluid to be condensed can enter it at substantially any point around its perimeter. Th s is accomplished in the illustrated embodlment of the invention by so locating the tubes that the nest is located eccentrically with relation to the cylindrical shell 1, or 1S so located that there is an adequate steam space 5 between the tubes and the longitudina-lly extending wall of the shell, 'which space communicates with the inlet port 6 of the shell and almost entirely surrounds the nest of tubes.

The tubes 4 of the nest are arranged in two series,an inner series 20, and an outer series 21 which surrounds the inner series and is so located that it is substantially surreaching the lower portion of the condenser must traverse in close proximity to and eventually enter the nest of tubes.

As illustrated, the inner series 20 of the nest of tubes is adapted to pass 'the coolest or incoming condensing liquid, while the outer series 21 is adapted to pass condensing liquid which has traversed the inner tubes of the condenser, and consequently fluid entering the nest of tubes encounters progressively colder surfaces as it passes toward the center ofthe nest. This is accomplished in the apparatus illustrated by providing a 'water' or liquidbox 2 at one end of the shell 1, which is rovided with a passage 17 communicating with the inlet port of the water boxthrough a passage '15 and an annular passage 22 which communicates with the outlet passage 14 of the water box. The two passages 17 and 22 are separated from each other by means of ,an annular flange or partition 12 and the passage22 which is annular in shape surrounds the passage 17. 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 passage. Water, en-

tering the water box, through the inlet port thereof, traverses the passage 15 and enters the passage 17 with which the inner series 20 of the tubes communicate. After having traversed the tubes, it is delivered to a water box, 3, from which it is delivered to the outer series of tubes 21. These tubes communicate with the annular passage 22 and after the water has traversed them, it is delivered from the passage 22 through the outlet 14.

The air or'non-condensable fluid ofl'take port 8 communicates with the interior of the nest of tubes through a passage 7 which extends upwardly from the bottom of the shell to a substantially central point within the cylindrical nest of tubes. As shown, the ofltake'passage 7 is formed by two parallel plates or partitions which are mounted on the bottom of the shell and which extend longitudinally of the condenser the entire length of the shell. The port 8.may communicate with an air pump (not shown), or any other suitable apparatus for removing attenuated'air or fluid and this port may be located at any suitable point within the condenser shell.

Any suitable means may be provided for removing the liquid of condensation which may collect in the air outlet passage, but in the drawings I have provided an entrainer 10 which will deliver the liquid collected in the air passage to the liquid delivery port 9 or to the hot wells; without creating a direct passage from the interior of the shell to the pump employed. It will be understood that the construction of the passage 7 is merely illustra tire and that the air or noncondcnsable fluid may be taken toward the top or even out through the end of .the condenser, if desired. The water of condensation accumulating in the bottom of the condenser shell is delivered in the usual manner to the port 9.

The principal advantage of my invention is that it eliminates or minimizes .theloss in vacuum or the variations'in pressure ordinarily encountered within the shell of large size condensers, and it, 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. sults in a reduction'of the cost of construction of large sizecondensers. j

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. With such an arrangement the area of the steam admission space of 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 condenser.

It will be apparent that, with such a construction, the size of the condenser is determined in large measure by the necessary steam admission space to the tubes, since the path of flow through the tubes cannot be arbitrarily fixed without jeopardizing the the nest, and, inasmuch as this greatly in- This consequently recreasas the admission space,

through the tubes, which is radial or toward the air oif-take, can also be materially reduced in length without reducing the efiiciency of the condenser as a condensing agent. This reduction in the length of thepath of flow, in combination with the increased inlet area to the tubes, permits ofa 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 condenser'shell.

I have found by experiment that the loss in vacuum within a condenser is decreased by having the areas of flow gradually diminishing from the inlet of the condenser to the air oiftake. This diminution of area should be inversely proportional to the condensation taking place along the paths of flow, so

I that the velocity of the fluid is maintained at an approximately constant value. In the illustrated embodiment of the invention this is accomplished by the fact that the paths of fluid flow converge toward the center of the nest orat the point of air ofltake.

I Another feature of my invention is that the water of condensation may be withdrawnata higher temperature, for the same I eflective vacuum, than in ordinary condensers. In the ordinary condenser'the temperature of thewaterof condensation can not possibly be greaterthan the temperature of the steam or vapor in, the lowest portion of the condenser, which is normally the point of lowest temperature, and consequently if there is a loss in vacuum, the eflithe condenser forms a part, is reduced not only by the loss in vacuum in'the condenser, but also by the delivery of water of condensation atia lower temperature than the temperature of the steam existing at the effectlve vacuum pressure, by which I mean the vacuum at the inlet 6 of the condenser.

In condensers embodying my invention the 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 vfrom 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 with a smaller loss in vacuum, within the condenser shell, and

' in delivering liquid of condensation at a higher. temperature,'other conditions being now in use and will, however, be understood that various changes, modifications, substitutions, and omissions may be madev 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 claimis: 1. In a condenser, a cylindrical shell, a substantially cylindrical nest 'of tubes located eccentrically within the shell' and forming a steam delivery space substantially surrounding the nest of tubes and in direct communication with the steam inlet port to the condenser, an air offtake having its inlet well within the nest of tubes and extending longitudinally with relation to the tubes of, the nest, and means for directing a flow of cooling liquid through the tubes .so that the coldest liquid traverses the tubes located adjacent to the inlet of the .take.

2. In acondenserpa nest of tubes located within the condenser shell and substantially surrounded by a fluid delivery space which communicates with the fluid inlet of the shell, said nest having converging fluid passages which communicate with saidvspace,

ne'st of tubes "and communicating with an ofl'take port formed in said shell. I

4. -In a condenser, a shell having a fluid inlet and a condensate outlet port, a nest of tubes located within the shell and spaced therefrom so that the condensate dropping from the tubes and passing to said outlet 7 port is surrounded by uncondensed fluid, and a noncondensable-fiuid ofi'take" having an inlet located well within the nest of tubes. 5. In a-condenser, a shell, anestof tubes therein, a non-condensable vapor ofltake 10- dated well within said nest'ofl tubes-in com bination with means'for directing the flow of water through the tubes so that the inner portion ofthe' nest of tubes surrounding the ofl'take will be supplied with the coldest tubes in combination with means for directing the flow of water through the tubes so that the temperature of the water in the tubes in proximity to the ofltake will be diflerent from that in .the tubes in proximity to the perimeter.

7 In a condenser, a shell having a fluid inlet port and an outlet port for the condensate, a nest of tubes arranged eccentrically within the shell so that a fluid delivery space communicating with said inlet port substantially surrounds the nest, and a noncondensable-fluid ofltake extending into said a shell and having an inlet located well within port, acylindrical nest of tubes located eecentrically within-said shell whereby a fluid space communicating with the inlet port substantially, surrounds the nest, a noncondensable-fiuid ofltake vcommunicating with i said offtake port and extending well within the nest of tubes, and means for directing a flow of liquid through said tubes so that the temperature of the liquid within the tubes located adjacent to 'the inlet otthe offtake 1 toward the condensate outlet and in openis below that of the liquid traversing the outer tubes of'the nest. i

10. In a condenser, a condenser shell having a fluid inlet port and an outlet port for the products of condensation, a nest of tubes located within said shell and having a fluid space communicating with the inlet port and extending between the nest of tubes and the shell, and a noncondensable-fluid ofitake ex tending into the nest of tubes and having an inlet located well within the nestof tubes and at which the fluid passages throughthe nest of tubes converge.

11. Ina condenser, a nest of tubes havingconverging fluid passages between the tubes,

a shell havingoppositely disposed steam inlet and condensate .outlet ports, said shell surrounding the nest of tubes and so located as to provide a steam space of gradually decreasing cross sectional area from the inlet and free communication with the ,inlet and the converging fluid passages of-the nest, a non-condensable fluid outlet extendlng longitudinally of the nest of tubes and having its inlet located well within the nest of tubes and at the point of convergence of said converging fluid passages, and means for delivering cooling liquid to the tubes so that livery port, a substantially cylindrical nest of tubes locatedv eccentrically within the shell and forming a' steam delivery space substantially surrounding the nest of tubes and in direct and free communication with the steam inlet port to the condenser, and an air ofltake having its inlet well within the nest of tubes and extending longitudinally withrelation tothe tubes of the nest.

13. In a condenser, a shell having a steam inlet and a condensate delivery port formed in opposite sides thereof, a nest of tubes located within the shell and substantially surrounded by a steam delivery space in open and free communication with the steam inlet of the shell and the steam passages between 3 the tubes of the nest of tubes, and in communication with the condensate offtake, an airofltake located well within the nest of tubes, and means for delivering condensing water to said tubes of said nest.

1 1. In a condenser, a shell having a steam inlet formed in one side thereof, and a condensate outlet formed in the opposite side thereof, a nest of tubes having converging steam passages located between the tubes thereof, said nest being solocated within the shell as to provide a steam space substantially surrounding the nest and in open communication with the steam inlet, the condensate outlet and the converging passages of the nest, an air ofltake located well within the nest at the point of convergence of the passages, and means for delivering condensing water to the tubes in such manner that the water is first passed through the innermost tubes of the nest in onedirection and then passed through the outer tubes of the nest in the opposite direction.

In testimony whereof, I have hereunto subscribed my name this 30th day of June, 1913.

RAYMOND N. EHRHART.

Witnesses:

C. IV. MCGHEE,

- ANNA CLOHERTY.

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