US2819882A

US2819882A - Heat exchange apparatus

Info

Publication number: US2819882A
Application number: US383550A
Authority: US
Inventors: Richard M Stephani
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1953-10-01
Filing date: 1953-10-01
Publication date: 1958-01-14
Anticipated expiration: 1975-01-14

Description

Jan. 14, 1958 R. M. STEPHANI HEAT EXCHANGE APPARATUS Filed Oct INVENTOR RICHARD M.STEPHANI ATTORNEY HEAT EXCHANGE APPARATUS Richard M. Stephani, Crum Lynne, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application October 1, 1953, Serial No. 383,550

4 Claims. (Cl. 257-239) This invention relates to heat exchangers, more particularly to an arrangement in which a plurality of heat exchangers are included in a common shell, and it has for an object the provision of improved apparatus of this character.

in present day power plant design, it is often desirable to arrange a plurality of feedwater heaters having U- shaped tube bundles of difierent lengths in a common shell in order to save space and to reduce expense in manufacture. It has been proposed to arrange a plurality of such feedwater heaters in a common shell in such a manner that the water boxes are all disposed at one end of the shell. Since the tube lengths of the feedwater heaters are not the same, this arrangement results in considerable wasted space for the shell must necessarily belong enough to accommodate the longest heater. Also, the diameter of the shell assumes large proportions in order to accommodate the tube bundles of all the feedwater heaters. It is desirable to obviate a shell of large diameter for economic reasons, since a large diameter shell is more costly to manufacture. Also, it is desirable to maintain the diameter of the shell at a minimum, since a heat exchanger structure of this type is often installed in the inlet neck of a condenser for a steam turbine. The steam flow area in the neck of the condenser is critical and excessive restriction of the of the flow area by a large diameter heat exchanger shell is highly undesirable.

In view of the above, it is a further object of the invention to provide a structure having disposed therein a plurality of heat exchangers utilizing tube bundles of different lengths and arranged to reduce unnecessary space to a minimum.

A more specific object is to provide a structure having three heat exchangers of the above type disposed therein in a simple and compact arrangement, each of said heat exchangers having a steam inlet and a condensate discharge outlet and one of said heat exchangers having a tube length approximately equal to the sum of the tube lengths of the remaining heat exchangers.

A still further object is to provide elongated tubular shell having a long tube bundle and water boxes may be readily demounted for servicing.

In accordance with the invention, there is provided an elongated tubular shell having a long tube bundle and a somewhat shorter tube bundle extending into the shell from one end, the tube bundles being supported by a common tube plate and having a unitary water box. A third tube bundle having a length approximately equal to the difierence in length of the two first-mentioned tube bundles, extends into the shell from a tube plate and water box structure disposed at the opposite end and takes up the space beyond the second-mentioned above tube bundle. The shell is divided into three vapor-tight compartments, one for each tube bundle, and is provided with steam inlet and condensate outlet connections for each of the compartments.

heat exchange ap- St tes Patent The above and other objects are efiected by the invention as will be apparent from the following description taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is a vertical longitudinal sectional view of a structure embodying the invention;

Fig. 2 is a cross-sectional view taken on line 11-11 of Fig. 1; and

Fig. 3 is a longitudinal elevational view of the structure shown in Fig. 1, with parts thereof partially exploded or demounted.

In the drawing, there is shown heat exchange apparatus comprising a tubular shell 10 having a substantially centrally disposed longitudinal partition 11 and a transverse partition 12 connected to a substantially median portion of the longitudinal partition 11 and extending therefrom to the wall of the shell, thereby dividing the shell into three separate compartments a, b and c. It will be noted that the compartment a extends from one end of the shell to the other and is the largest, while the compartments b and c extend from the transverse partition 12 in opposite directions to the ends of the shell and are substantially half the size of the compartment a.

A plurality of

U-shaped tube bundles

13, 14 and 15 are disposed within the shell. The tube bundle 13 is the longest and is disposed longitudinally in compartment :1. The

tube bundles

13 and 14 are supported in side-by-side relation by a tube plate 16, while the tube bundle 15 is supported by a tube plate 17. The

tube plates

16 and 17 overlie the openings in the opposite ends of the shell 10 and serve to assist in isolating the compartments a, b and c from each other.

Each of the compartments a, b and c is provided with separate steam inlet connections 18, 19 and 20, respectively, connectible to any suitable steam supply (not shown) and

discharge outlet connections

21, 22 and 23, respectively, connectible to any suitable water utilizing or storage device (not shown).

A water box structure 25 having a water inlet connection 26 and a water outlet connection 27 is mounted on the tube plate 16 and is provided with partitions 25a:

and 25b for directing the flow of water through the U-shaped

tube bundles

13 and 14 in a series How arrangement. A second water box 28 having a water inlet connection 29 and a water outlet connection 30 is mounted to the tube plate 17 and is provided with a horizontal partition 28a which directs flow of water through the tube bundle 15.

The water outlet connection 27 of the water box 25 is preferably connected to the water inlet connection 29 of the water box 28 by a conduit indicated by the dotand-dash arrows 31, so that the water which flows into the box 25 through the inlet connection 26 flows through 14 and 15 in a series circuit followthe tube bundles 13, ing the path shown by the arrows 32 and is then discharged through the water outlet connection 30 at a higher temperature than when it is admitted through the inlet 26.

The tube bundle 13 may be provided with the usual transverse bafiies 33a and 33b to provide a tortuous path for the steam flowing through the compartment a and across the surfaces of the tubes contained therein, as well understood in the art. Similarly, the tube bundles 14 and 15 may be provided with transverse baflles 34a and 3412.

Although the

water boxes

25 and 28 have been shown bolts 39 and clamp the

tube plates

16 and 17 therebetween to close the ends of the shell against leakage of steam to the atmosphere. When in the above clamped relation, the

tube plates

16 and 17 abut the ends of the longitudinal baffle 11 to prevent flow of steam between compartment at and compartments b and c. p

The

tube bundles

13, 14 and 15 may be arranged in their compartments, a, b and c, respectively, in such a manner that steam entering by the inlets may expand before contacting the surfaces of the tubes. For example, as shown in Figs. 1 and 2, the tube bundle 13 is disposed in the lower portion of the compartment a, while the upper portion of the compartment contains no tubes and forms a steam expansion space. Similarly, as best shown in Fig. 2, the tube bundle 15 is disposed in the compartment c in such a manner that the proportion of the compartment adjacent theinlet connection 20 is devoid of tubes.

When it is desired to demount the

water boxes

25 and 28 and the tube bundles 13, 1 and 15 for servicing, the conduit 31 may be disconnected and the bolts 39 may be removed whereby, as indicated in Fig. 3, after the water box is removed, the

tube bundles

13 and 14 may be withdrawn from the shell to the right as viewed in Fig. 1, together with their tube plate 16 as a unit. Similarly, after the water box 28 is removed, the tube bundle may be withdrawn from the shell to the left together with its tube plate 17 as a unit.

It will be noted that the tube bundle 13 is approximately of a length equal to the sum of the lengths of tube bundles 14 and 15 and that it extends substantially from one end of the shell 10 to the other, while the tube bundles 14 and 15 extend from the opposite ends of the shell inwardly towards each other and terminate adjacent the transverse partition 12. Thus, the space within the shell is utilized to the fullest, while the compartments a, b and 0 together with their

tube bundles

13, 14 and 15, respectively, retain their separate identity and may be heated by steam at different temperatures and pressures.

Also, with the above arrangement, the heat exchange may be effected in a highly efiicient manner and linear expansion of the tube bundles is free to occur without stressing of adjacent parts.

By utilizing steam in the compartments a, b and c, at successively higher temperatures and pressures, the water may be heated in steps, that is, the incoming water passing through tube bundle 13 is heated to one tempera ture, is then heated to a higher temperature while passing through tube bundle 14 and is finally heated to its highest temperature while passing through tube bundle 15.

While the invention has been shown in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

What is claimed is:

l. A heat exchanger comprising a tubular shell having openings at opposite ends, a longitudinal imperforate partition mounted in said shell and extending to said opposite ends, a transverse imperforate partition extending from said longitudinal partition to said shell, said partitions dividing said shell into a large substantially fluid-tight compartment and a pair of substantially smaller substantially fluid-tight compartments, said smaller compartments being disposed in end-to-end relation and being accessible from the opposite ends of said shell, a bundle of U-shaped tubes disposed in each of said compartments, a first water box structure including a first tube plate associated with the tube bundle in said large compartment and one of the tube bundles in said smaller compartments and providing for circulation of water therethrough in a plurality of passes, a second water box structure including a second tube plate associated with the other of the tube bundles in said smaller compartments and providing for circulation of Water therethrough in a plurality of passes, said tube plates being demountably attached to said opposite ends of the shell and closing said openings, said shell having a steam inlet and a discharge outlet for each of said compartments, each of said tube plates being individually demountable from said shell together with its associated tube bundle or bundles as a unit.

2. A heat exchanger comprising a tubular shell having openings at opposite ends, a longitudinal imperforate partition mounted in said shell and extending to said opposite ends, a transverse imperforate partition extending from said longitudinal partition to said shell, said partitions dividing said shell into a large substantially fluid-tight compartment and a pair of substantially smaller substantially fluid-tight compartments, said smaller compartments being disposed in end-to-end relation and being accessible from the opposite ends of said shell, a bundle of U-shaped tubes disposed in each of said compartments, a first water box structure including a first tube plate associated with the tube bundle in said large compartment and one of the tube bundles in said smaller compartments and providing for circulation of water therethrough in a plurality of passes, a second water box structure including a second tube plate associated with the other of the tube bundles in said smaller compartments and providing for circulation of water therethrough in a plurality of passes, said tube plates being demountably attached to said opposite ends of the shell and closing said openings, said shell having a steam inlet and a discharge outlet for each of said compartments, each of said tube plates being individually demountable from said shell together with its associated tube bundle or bundles as a unit, the tube bundle in said large compartment having a longitudinal dimension substantially equaling the sum of the longitudinal dimensions of the tube bundles in said pair of smaller compartments.

3. A heat exchanger comprising a tubular shell having openings at opposite ends, a longitudinal imperforate partition mounted in said shell and extending to said opposite ends, a transvesre imperforate partition extending from said longitudinal partition to said shell, said partitions dividing said shell into a large substantially fluidtight compartment and a pair of substantially smaller substantially fluid-tight compartments, said smaller compartments being disposed in end-to-end relation and being accessible from the opposite ends of said shell, a bundle of U-shaped tubes disposed in each of said compartments, a first water box structure including a first tube plate associated with the tube bundle in said large compartment and one of the tube bundles in said smaller compartments and providing for circulation of water therethrough in a plurality of passes, a second water box structure including a second tube plate associated with the other of the tube bundles in said smaller compartments and providing for circulation of water therethrough in a plurality of passes, said tube plates being demountably attached to said oppositeends of the shell and closing said openings, said shell having a steam inlet and a dicharge outlet for each of said compartments, each of said tube plates being individually demountable from said shell together with its associated tube bundle or bundles as a unit, the tube bundle in said large compartment having a longitudinal dimension substantially equaling the sum of the longitudinal dimensions of the tube bundles in said pair of smaller compartments, and a conduit disposed externally of said shell and communicating with said water boxes, said conduit providing for flow of Water from one to the other of said water boxes.

4. A heat exchanger comprising a tubular shell having first and second openings at opposite ends, a longitudinal imperforate partition disposed in said shell and extending to said opposite ends, a substantially transversely disposed imperforate partition extending from a substantially median portion of said longitudinal partition to said shell, said partitions dividing said shell into a large compartment and first and second substantially smaller compartments, said smaller compartments being disposed in endto-end relation with each other, said first compartment being accessible from said first opening and said second compartment being accessible from said second opening, each of said compartments having a bundle of U-shaped tubes disposed therein, a first Water box structure including a first tube plate demountably attached to said shell and closing said first opening, the tube bundles disposed in said large compartment and said first compartment being supported by said first tube plate and having fluid communication with said first Water box, a second water box structure including a second tube plate demountably attached to said shell and closing said second opening, the tube bundle in said second compartment being supported by said second tube plate and having fluid communication with said second water box, each of said compart- 15 References Cited in the file of this patent UNITED STATES PATENTS 686,313 Mann NOV. 12, 1901 1,251,262 Maurice Dec. 25, 1917 2,049,748 Rathbun Aug. 4, 1936 2,360,408 Dunn et a1 Oct. 17, 1944 2,361,726 Weimar Oct. 31, 19