US1591825A - Fluid condenser - Google Patents

Description

July 6,1926.

1,591,825 F. HODGKINSON FLUID CONDENSER Filed July 2, 1921 INVENTOR III! av W ATTORNEY Patented July 6, 1926.

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FRANCIS HODGKINSON, O F S'WARTHMORE, FENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVANIA.

FLUID CONDENSER.

Application filed July 2,

My invention relates to surface condensers of the radial flow type and it has for an object the provision of an apparatus which shall increase the general overall eificiency of a condenser of the type designated. It

is a further object of my invention to provide an improved means for reducing the specific volume of the non-condensable gases 5 withdrawn from a condenser prior to the de- 1 livery of the gases to a withdrawal mechanism. These and other objects of my invention, which will be made manifest throughout the further description thereof, may be attained by the employment of the apparatus illustrated in the accompanying drawing in which-- 7 Fig. 1 is a transverse sectional view of a condenser embodying my invention;

Fig. 2 is a fragmentary view in longitudinal section disclosing the construction of the inlet water box of the condenser illus trated in Fig. 1;

Fig. 3 is a transverse sectional View of a modified form of the condenser illustrated in Figs. 1 and 2; and

Fig. 4 is a transverse sectional View taken on line IV-IV of Fig. 3.

In radial flow condensers as commonly constructed the nest of cooling tubes is so 30 disposed with respect to the condenser shell that there is an adequate space between the tube nest and the longitudinally extending walls of the shell for the flow of the incoming gas and vapor. The fluidto be condensed, hereinafter, for brevity and convenience of description, called steam, usually en ters at the upper portion of the shell and flows radially through the nest of cooling tubes from the surrounding steam space.

40 The condensate collects in the hot well at the bottom of the shell and thenon-condensable fluids, hereinafter for distinction and brevity called air, which appears in the condenswithin the nest of tubes. The large entrance area presented by the tube nest to the-entering steam and the short path of travel of the steam through the cooling tubes combine to produce a condenser of large capacity com pared to its size and of high vacuum-producing qualities. It is the purpose of my present invention to further increase the efficiencyof this type er, are withdrawn through an air ofltake member, the inlet to which is disposed well 1921. Serial No. 482,285.

of condenser by reducing the energy re- 'quired for the withdrawal of the non-condensable fluids from the condenser. this result by reducing the volume of the fluids necessary to be handled by the air removal means prior to its delivery thereto. To accomplish this I provide an enlarged air oif-take chamber and associate therewith means for reducing the temperature and the specific volume of the air passing therethrough to approximately the temperature and volume corresponding to the temperature of the first-pass cooling water. 7

Referring to the drawings for a more detailed understanding of an apparatus embodying my invention, I have indicated at 10 a condenser shell or casing through which a nest of tubes 11 extends longitudinally and which is provided with a fluid inlet 12, a hot well 13, and an air oif-takechamber 14, the latter having inlet ports 15 located well Within the nest of tubes. The tubes 11 are arranged in a substantially cylindrical nest and are so disposed within the shell that there is an adequate steam space 16 between the tubes and the longitudinally extending wall of the shell, which space communicates with the inlet port 12 and almost entirely surrounds the nest of tubes.

The tubes 11 are arranged in two groups, an inner group .20 and an outer group 21 which surrounds the inner group and is so disposed that it is substantially surrounded by the steam space 16. The inner group of tubes '20 is arranged to receive the coldest or incoming cooling water while the outer group 21 receives the cooling water which has traversed the inner tubes of the condenser. Consequently, the steam entering the nest of tubes encounters progressively colder surfaces as it passes toward the inlet ports 15 of the off-take chamber 14. This flow of cooling water through the tubes is accom-. plished by providing a water box 24 at one end of the shell which is provided with a passage 25 communicating with the inlet port 26 through a-passage 27 and an annular passage 28 which communicates with an outlet passage 29 of the water box. The two passages 25 and 28 are separated from each other by an annular flange or partition 30, the passage 28, which is annular in shape, surrounding the passage 25. As is customary, the water box is bolted or otherwise se- I effect cured to the shell so that the open ends of the tubes communicate with its liquid circulating chambers. The water box at the other end of the condenser shell is of the usual return box construction.

The air oft-take chamber 14, communicating with the interior of the inner group of cooling tubes through the inlet passages 15, extends downwardly from a substantially central point within the inner group of cooling tubes through the tube nest to the bottom of the condenser. As shown, the offtake chamber 14 is formed of two plates or partitions 30. 31 which extend longitudinally of the condenser the entire length of the shell. The plates 30, 31 deline a chamber of considerable width within the inner group or" cooling tubes, some of the cooling tubes 22 of the inner group 20 traversing this portion of the oft-take chamber. The oft-take chamber is of limited width in the portion which passes through the outer group of cooling tubes 21. The plates 30. 31 may extend downwardly into the hot well of the condenser and form with a conduit 32 a discharge means for the air withdrawn through the chamber 14. Any suitable means may be provided for removing the water of condensation which may collect in the air oft-take chamber. As shown, I have provided a U- tube 33 which delivers the condensate into the hot well 13. The water of condensation accumulating in the hot well is delivered in the usual manner through a port 84.

It will be understood that the construction of air-withdrawal conduits is merely illustrative and that the air may be taken out through the bottom or end of the con denser if desired.

Having described the arrangement of an apparatus embodying my invention, the operation thereof is as follows. Steam, or other fluid to be condensed, enters the condenser through the inlet 12 and passes downwardly therein through the passages 16 so as to surround the tube nest. The steam enters throughout the entire periphery of thetube nest and passes radially over the cooling tubes to the substantially centrally located inlets 15 of the chamber 14. In passing over the tubes. the condensable portion of the steam is almost completely condensed so that practically only the non-condensable gases enter through the inlet 15 into the chamber 14. The air flows downwardly through the tubes 22 which are embraced by the walls 30, 31 of the chamber 14 where the temperature and volume of the air is lowered and where the vapors carried over in the air are condensed. The air is withdrawn through the pipe 32 by av suitable air pump (not shown). The water of condensation which collects in the bottom of the chamber 14 is drained into the hot well 13 through the pipes 32 and 33.

The cooling tubes of the condenser are arranged with respect to the flow of the steam therethrough so as to secure the benefits of a counterflow of steam and water, that is, the steam at highest temperature first contacts with the cooling tubes containing water at highest temperature and then contacts with the tubes of lower temperature. The circulation of the water through the cooling tubes is directed to pro-- duce this result. lVater entering the water box 24 through the inlet port 26 traverses the passage 27 and enters the passage with which the inner tubes 20 communicate. After having traversed the tubes 20 the water is delivered to the water box at the opposite end of the condenser shell, from which it is delivered to the outer group of tubes 21. These tubes communicate with the annular passage 28 and after the water has traversed them it is delivered from the passage 28 through the outlet 2.). The hea of the exhaust steam entering the condenser is thus gradually absorbed and its volume reduced during its passage through the tube nest and oft-take chamber, and the air, or non-condensable portions, which is finally delivered to the air-removal pump has an extremely low temperature and volume. Since the energy required to operate an air pump is substantially proportional to the volume of the air handled. it is apparent that the best economy in the operation of the air pump is obtained in connection with the condenser above described.

In some condenser installations. it is preferable to withdraw the air from the otl-tal-re chamber through an upper portion of the condenser shell. In Fig. 3, I have shown an arrangement in which the air off-take chamber 14 has an inlet disposed at the lower end thereof and substantially centrally of the inner group of tubes 20. The off-take chamber 14 extending upwardly through the tube nest 20, 21 and into the steam passage 12, which is, of course, the hottest part of the condenser. In order to prevent the air in the oft-take chamber from being heated. a jacket 41 is spaced from and surrounds the upper portion of the chamber 14. An offtake pipe 42 connects with the upper portion of the chamber 14 and extends laterally through the side of the condenser shell as at 43. The conduit 42 is also provided with a jacket 45 which is spaced from and surrounds the conduit 42. The hollow spaces 46, formed by the jackets, may be filled with any kind of insulating material, as for example, dead air or asbestos. It is preferable, however, to circulate water through the spaces 46, since the cooling effectof the water not only prevents a heat transfer of the condenser fluids to the air being withdrawn but also further cools the air before it is delivered to the air pump. As shown, water may be admitted to the space 46 through an inlet 47, flow about the pipe 42 and be with drawn through the conduit 48 which is arranged to discharge the cooling water into the space 46 surrounding the chamber 14. A web 49 unites the jacket 41 and chamber 14 at its upper portion and divides the space 46 into two chambers, which chambers are united near the base thereof by one or more pipes 50. vAn outlet connection 51 is provided for the discharge of the water from the jacket 46. Piping communicating with the inlet 47 and the outlet 51 may conveniently be connected with the water boxes of the condenser so that water is delivered to the inlet 47 from an inlet passage of the water box and'delivered from the outlet 51 to a discharge passage of the water box.

The operation of the apparatusdisclosed in Fig. 3 is in all essential respects similar to that described above in relation to Fig. 1. The air entering'the chamber 14 through the inlet 40 is cooled and reduced in volume by contact of the tubes 22 and passes upwardly through the jacketed portion of the casing 14 and off-take pipe 42 to a suitable air withdrawal means. It will be noted that the air in passing through the jacketed portion of the chamber 14 and conduit 42 is further cooled. No provision need be made for withdrawing condensate from the otftake passages since it is obvious that the passages are self draining, the water of condensation falling downwardly through the tube nest and collecting in the hot well.

A radial flow condenser equipped with the air cooling oft-take chambers, as illustrated in either Figures 1 or 3, may be operated with a high degree of economy because of the reduction in the volume of the fluids which it is necessary for the air pump to handle. This economy in the operation of the air pump combined with the economies inherent in the radial flow condenser utillzing a counterflow of steam and water serves to provide a condenser construction which maintains high vacuum conditions with a minimum expenditure of energy.

While I have shown my invention in but two forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is 1. In combination in a condenser, a shell a nest of cooling tubes in the shell, an air elf-take extending through the steam space into the nest of cooling tubes, said off-take comprising two Vertically and parallelly disposed walls, the upper portions of said walls being hollow, the lower portions of said walls extending downwardly below said hollow portions, and means for serially passing water through the hollow portions of the walls.

2. In combination in a condenser, a shell, a nest of cooling tubes in the shell through which cooling water flows in a first and a second pass, an air off-take extending clownwardly through the steam space into the nest of cooling tubes, first through a portion of the tube nest traversed by second-pass cooling water, and then into a portion of the tube nest traversed by first-pass cooling water, said elf-take comprising two parallelly disposed walls, the portions of the walls above the first-pass tubes being hollow, and the portions of the walls below the secondpass tubes embracing first-class tubes, and means for passing water through the hollow portions of the walls.

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

FRANCIS HODGKINSON.

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