US1578031A - Condenser - Google Patents

Description

March 23 19 26.

F. HODGKINSON CONDENSER Original Filed August 4, 1921 OOOQOOOOOO (gun I E TOR If [lady by g I BY ATTORNEY Patented Mar. 23, 1926.-

UNITED STATES PATENT OFFICE.

CIS HODGKINSON, OF SWARTHMORE, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC ANTD MANUFACTURING COMPANYfiA CORPORATION OF PENNSYL- VANIA.

Application filed August 4, 1921, Serial To all whom it may concern:

Be it known that I, FRANCIS HODGKINBON, a subject of the King of Great Britain and Ireland, and a resident of Swarthmore, Pennsylvania, in the county of Delaware and State of Pennsylvania, have invented a new and useful Improvement in Condensers, of which the following is a specification.

My invention relates to surface condensers of the horizontal tube type and it has for an object the provision of a condenser of the character designated which shall z'eflectively separate the condensable from the non-condensable fluids and deliver the non-condensable fluids to a removal pump at as low a temperature and specific volume as possible. These and other objects and advantages of my invention are obtained by the structure hereinafter described and illustrated in the accompanying drawings in which Fig. 1 is a transverse sectional view of a preferred embodiment of my invention on line II of Fig. 2; Fig. 2 is a longitudinal sectional view thereof on line II-II of Fig. 1; and Fig. 3 is a fragmentary detailed sectional view taken on line III-III of Fig. 2.

It is a well known principle in surface condenser construction that heat transfer from the exhaust entering a condenser to the water in the cooling tubes is best effected by the gradual absorption of the heat of the exhaust fluids from the inlet to the point at which the non-condensable fluids are withdrawn and that the temperature of the non-condensable fluids should be as low as possible to secure a maximum efficiency in the operation of the non-condensable gas removing apparatus.

It is also an established practice in surface condenser constructions to proportion the compartments of multiple compartment condensers so as to provide constantly decreasing cross-sectional flow areas for the passage of the exhaust fluids, since the gradual condensation of the vapor by reason of contact with the cooling tubes causes a constantly decreasing volume ofuncondensed fluids.

I have embodied these essential characteristics in my novel condenser construction in such a manner as to produce highly satisfactory results. In a two-pass condenser in which the cooling water makes a first CONDENSER.

No. 489,892. Renewed February 2, 1926.

pass through a lower bank of tubes and a second pass through an upper bank of tubes, I dispose baffles in such a manner as to divide the tubes of" the lower bank into three wedge-shaped groups horizontally disposed with respect to each other, and connected near the bottom of the condenser, the two outer'groups having the thin edge of wedge disposed adjacent the bottom of the condenser, and the middle group having the edge of-the wedge adjacent the central portion of the uppermost rows of first pass tubes. A longitudinally disposed non-conden'sable gas off-take conduit communicates with the converging portion of the middle tube group and extends upwardly into the upper bank, dividing the flow of steam therethrough into two substantially parallel streams. This arrangement provides two condensing compartments of generally decreasing flow area through which the steam passes downwardly, and a middle condens ing and non-condensable fluid cooling compartment through which the uncondensed fluids pass upwardly to the non-condensable fluid off-take conduit. Under normal conditions of operation, the middle group of tubes serves primarily as a cooler for the non-condensable fluids. The heat transfer capacity .of the middle group of tubes is, however, relatively large and may serve as an active condensing surface during periods of overload and secure a high condenser vacuum at times of low air leakage.

For a fuller understanding of an apparatus embodying my invention, reference is to be had tothe drawing in which I represents a condenser 10 comprising a shell 11, having a steam inlet 12 in the upper por- -tion thereof, and provided with tube plates 13 and water box casing 14. The shell 11 and tube plates 13 define a condensing space which is traversed by tubes 15 which aresuitably secured to the tube plates. The tubes are preferably arranged in two banks, a lower gfiI'St pass bank 16 and an upper second'pass bank 17.

Oppositely inclined baflles 20, 21 extend from the-middle portion of the upper rows of the first pass'tubes downwardly toward the bottom of the condenser, passages 22, 23 of suitable size being'provided between fthe lower edges of the baflies and the condenser shell; lower bank of tubes into three wedgeshaped groups of tubes of decreasing crosssectional area, two outer groups 24, 25 and a middle group 26. Joined to the upper edges of the baffles 20, 21 is an air off-take conduit 27 which communicates with the middle compartment and which, as shown, is located within the upper bank of tubes. A roof member 28, spaced from and conforming to the shape of the air off-take, protects the air off-take from the heat of the incoming steam and of condensate dripping from the tubes located thereabove. A conduit 29 leads non-condensable fluids from the off-take 27 through the water box to an air removal pump (not shown) of any suitable type.

On the lower edges of the baflles 20, 21 are formed troughs 30 which catch the condensate falling upon the baffles. The troughs 30 are provided at each end with spouts 31, through which the collected condensate flows into the bottom of the condenser, whence the condensate passes to a hot well 32 which is provided with a discharge conduit 33 leading to a condensate pump.

Having described the arrangement of an apparatus embodying my invention the op eration thereof is as follows: Exhaust steam from a turbine, or other prime mover, enters through the inlet 12 and passes downwardly through the upper bank of cooling tubes where it is divided into two parallel streams by the roof member 28. The streams continue their downward flow through the outer group of cooling tubes 24, 25 toward the passages 22, 23. Normally, the condens ble vapors of the exhaust steam are practically condensed before reaching the passages 22, 23 so that air and non-condensable fluids, carrying a small quantity of vapors, pass through these passages and flow upwardly through the middle compartment 26, where the condensable vapors are largely separated from the non-condensable fluids. The latter are also cooled and their volume greatly reduced during the passage through the compartment and are deliveredto the conduit 27 at a temperature approximating that of the coolin water in the first pass. The noncondensable fluids are drawn through the off-take 27 into the conduit 29, which passes through the water box, where the gases are further cooled, and leads to an air removal I have provided means for preventing the condensate from raining down in a sheet from the lower edges of the baflles 20, 21, and hence from being entrained and carried mechanically in fine drops or a spray into the middle tube group 26, where the condensate would collect upon the tubes, cut .down their cooling eflect upon the noncondensable fluids apd lower the temperature of the condensate. This I accomplish by providing a trough upon the lower edge of the baflies and providing one or more spouts 31 from which the collected condensate flows out of contact with the fluid entering the central compartment into the bottom of the condenser.

It will be apparent from the above description that the exhaust steam first passes in contact with the second pass tubes, in which the cooling water is at a higher temperature, then in contact with the first pass tubes through which the cold water flows. The heat of the exhaust fluids is thus gradually absorbed and the vapors for the mostpartcondensed. The uncondensed vapors are then caused to flow over the central portion of the cold first pass tubes, completing the condensation and coolin the gases and vapors prior to withdrawal t irough the noncondensable fiuid off-take conduit The ability of my condenser to handle over-loads is made possible because of the large cooling surface of the middle group of tubes 26. l/Vhen operating under overload conditions-uncondensed vapor will pass in considerable quantities through the passages 22, 28, and Wlll be condensed by the tubes 26, the condensate falling back into the bottom of the condenser.

While I have shown my invention 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 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 a surface condenser, the combination witha shell enclosing a condensing space and having a steam inlet at the upper portion thereof, and approximately horizontal condensing tubes traversing the said space, of means providing two passages of decreasing cross-sectional area at either side of the condensing space and extending from the top to adjacent the bottom thereof, and providing a third passage of decreasing crosssectional area between the said two passages and extending from the bottom of the space upwardly, and a non-condensable fluid oiftake means communicating only with the converging portion of the said third pas sage, whereby the vapors and non-condensible fluids pass downwardl through the said two passages and t en upwardly through the third passage to the off-take.

2. In a condenser, the combination with a shell enclosing a condensing space and having a steam inlet at the upper portion and approximately horizontal cooling tubes traversing the said space, of three groups of tubes, each of generally decreasing crosssectional flow area, and means for directing the flow of the vapors treated downwardly through two of the groups and upwardly through the third group of tubes.

3. In a condenser, the combination with a shell enclosing a condensing space and having a steam inlet at the upper portion and approximately horizontal cooling tubes traversing the said space, of two inclined baflles extending longitudinally the length of the condensing space and defining a central converging passageway from the bottom of the condensing space upwardly, and a non-condensable fluid off-take mounted upon the baffles at their upper edges and communicating only with the converging passage, whereby the vapors and non-condensable fluids pass downwardly on each side of the central converging passageway and then upwardly through the central converging passageway to the off-take.

4. In a condenser, the combination with a shell enclosing a condensing space and havapproximately horizontal ing a steam inlet at the upper portion and cooling tubes traversing the said space, of two inclined baflles extending longitudinally the length of the condensing space and defining a central converging passage from the bottom of the condensing space upwardly, a non-condensable fluid off-take mounted upon the batllcs at their upper edges and communicat ing with the converging passage and a shield above the said off-take for preventing the incoming steam and condensate from contacting with the said off-take.

5.- In a condenser, the combination with a shell enclosing a condensing space and having a steam inlet at the upper portion and approximately horizontal cooling tubes traversing the said space, of two inclined bailies extending longitudinally the length of the condensing space and defining a central converging. passage from the bottom of the condensing space upwardly, troughsformcd on the lower edges of the baffles to collect the condensate falling upon the baflies, spouts depending from the troughs to discharge the collected condensate, and a non-condensable fluid off-take mounted upon the battles and communicating with the converging passage.

G. In a condenser, the combination with a shell enclosing a condensing space and having a steam inlet at the upper portion and horizontal cooling tubes traversing the said space, of two inclined baffles extending longitiidinally the length of the condensing space and defining a central converging passage from the bottom of the condensing space upwardly, troughs formed on the lower edges of the baflies to collect the condensate falling upon the bafiies, spouts depending from the troughs to discharge the collected condensate, a non-condensable fluid oit-take mounted upon the battles and communicating with the converging passage and a shield above the said elf-take for preventing tlu incoming steam and condensate from contacting with the said oif-take.

7. In a condenser, the combination with a shell enclosing, a condensing space and having a steam inlet at the upper portion thereof, of approximately horizontal cooling tubes traversing said space and divided into a lower bank of first pass tubes and an upper bank of second pass tubes, two oppositely inclined bafiles among the first pass tubes, extending longitudinally of the length of thecondensing space, the upper edges of the battles being spaced to form an outlet passage of limited flow area adjacent the central portion of the uppermost rows oi tubes of the said lower bank, and extending downwardly to within a short distance of the bottom of the condensing space and a noncondensable fluid oft-take communicating through the said outlet passage, only with the space between said baflles, whereby the vapors and non-condensable fluids pass downwardly on each-side of the central converging .passageways and then upwardly through the central converging passageway to the ofi-take. I

8. In a condenser, the combination with a shell enclosing a condensing space and having an inlet for fluids to be treated at the upper portion thereof, of approximately horizontal cooling tubes traversing said space and divided into a lower bank of first pass tubes and an upper bank of second pass tubes, partition means dividing a group of the lower bank tubes, rising from the bottom of the central portion of the bank in the form of an inverted V, from the remainder of the tubes and spaced from the shell to provide a last upward passage for the fluids treated, and a non-condensable fluid oil-take communicating with the upper converging portion of the V-shaped bank.

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

FRANCIS HODGKINSON.

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