US1578058A - Condenser - Google Patents

Description

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UNITED STATES 1,578,058 PATENT OFFICE.

DAVID W. R. MORGAN, OF SWARTHMOBE, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIO AND MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLV AN IA.

CONDENSER.

Application filed September 28, 1923. Serial No. 665,418.

To all whom it may concern:

Be it known that I, DAVID V. R. MORGAN, a citizen of the United States, and a resident of Swarthmore, in the county of Delaware and State of Pennsylvania, have invented a new ancl'useful Improvement in Condensers, of which the following is a specification.

My invention relates to surface condensers and it has for an object the pro vision of apparatus of the character designated which shall deliver condensate to the hotwell at a high temperature, and which shall at the same time eliminate entrainment of air and non-condensable gases in the condensate removed therefrom.

These and other objects. and advantages of my invention are attained by the structure hereinafter described and illustrated in the accompanying drawing, in which Fig. 1 is a transverse sectional elevation of a condenser takenon the line 1-1 of Fig. 2; Fig. 2 is a longitudinal sectional view of the condenser taken on the line IIII of Fig. 1 andFig. 3 is a plan view in section of the condenser hotwell taken on the line IIIIII of Fig. 1.

Surface condensers of the so-called radial-flow type, such as are shown and claimed in U. S. Patent No. 1,142,784, issued to Westinghouse Machine Company on June 8, 1915, on application filed by Raymond N. Ehrhart. have the distinct advantage of providing a heat-transmitting surface of high efiiciency by reason of the large entrance area presented to the steam entering the tube nest. and the short path of travel of the air to the air ofi'-take. This arrangement insures that there will be no appreciable drop in pressure between the steam inlet and the point of complete condensation. condensers demands. in addition, that the energy expended in the withdrawal of the non-condensable fluids should be reduced to a minimum. This result is most readily accomplished by reducing the volume of fluids necessary to be handled by the air removing means prior to the delivery thereto, as disclosed in a copending application of Francis Hodgkinson, Serial No. 489893, filed August 4, 1921, and assigned to Westinghouse Electric and Manufactuiing Company.

Efficiency in the operation of In the above application, a separate bank of cooling tubes within the condenser shell is partitioned oil for the cooling and drying of the non-condensable gases. This portion of. the condenser comprises an aircooling and drying chamber, While the remaining portion comprises a condensing chamber. Air passages are provided in the' partition separating the air cooling chamber and the condensing chamber, which passages connect the two chambers in series. The temperature and pressure maintained within the air-cooling and drying chamber are relatively lower than those within the condensing chamber, due partly to the additional cooling effect produced therein and partly to its closer proximity to the air removal means.

Heretofore in condensers of the above type, it has notbeen customary to provide adequate sealing means between the condenser and the condensate pump, such as would prevent the passage of steam, air and vapor thereto. As at present constructed, a water or hydrostatic seal is provided in the condensate removal means from either the condensing chamber or the airrcooling chamber for preventing passage, through the hotwell, of air and vapor from the condensing chamber to the air-cooling chamber, because of the relatively lower pressure prevailing therein. As the suction pipe of the condensate pump is connected to the hotwell of the condenser, it follows that communication between the pump and one of the chambers is through a Water seal, while communication between the pump and the remaining chamber is open, free or direct.

\Vhen operat ng under full load conditions, the suction pipe leading from the hotwell of the condenser to the pump disposed below is continually flooded with condensate, and there is very little tendency to entrain air. Under operating conditions such as these, the sealing means interposed between the condenser and the pump, as heretofore described, is entirely adequate. However, when operating at partial load, the

pump being designed for a larger capacity, removes the condensate intermittently, at times scavenging the suction. pipe and hotwell entirely free of water. At such times, the condensate pump functions as an air pump, drawing in vapors and an from the chamber or chambers of the condenser which are in open communication with the hotwell. As the condensate discharged by the condensate pump is usually employed as feed water for the boilers, the air entrained therein has a corrosive effect upon the boilers and other apparatus, resulting in a reduction in efficiency and life of the parts. In some installations, the extent of this cor rosion has made it advisable to install deaerators in the system, involving considerable expense and expenditure of heat energy. 4

In my improved apparatus, I inter-pose separate sealing means in the condensate outlets. This arrangement not. only prevents a passage or short cireuiting of the uncondensed gases from one chamber of the condenser to another, but, under any condition of operation, insures against the passage of air and non-eondensable gases from either chamber to the pump. The condensate discharged by the condensate pump is therefore substantially free of entrained air, and, where the condensate is employed for boiler feed water, considerable reduction may be effected in the amount of corrosion taking place in the machinery and piping, resulting in a longer life of the apparatus and an increase in general efiicienoy of the entire power plant.

It is to e understood that my invention does not relate solely to radial-flow condensers, nor does itrelate solely to condensers having separate condensing and aircooling chambers, but may be adapted to be employed with steam condensers of any type or design in which one or more condensate outlets are provided.

Referring to the drawing for a more detailed understanding of an apparatus em- "bodying my invention, 1 have indicated at a condenser, having a shell 11 in which there is a steam inlet 12, a hotwell 13, tube sheets 14 secured to the shell, and an eccentrically arranged nest of tubes 15 withinthe shell and secured to the tube sheets. lVater boxes 17, joined to the tube sheets and shell, are provided in the usual manner.

The tube nest is divided into two groups of tubes, which, for d stinction and convenience in description, are hereinafter des ignated as condensing tubes and aircooling tubes 21. The air-cooling tubes 21 constitute a wedge-shaped group rising from the bottom of the she I and having its base adjacent to the shell and above the hotwell. The edge of the wedge-shaped group is located well within the tube nest. The condensing tubes 20 surround the air-cooling tubes except where the latter are adjacent to the shell 11.

The two groups of tubes are separated by suitable partitions or wall-constructions extending the length of the condenser. h s

shown, these partitions are formed of inclined hollow wall members 22 and 23 comprising outer plate members 24, supported by means of continuous lugs 27 cast integral with the condenser shell, and inner plate members secured to and spaced from the outer members 24 by suitable spacers 26. The inner plate members 25are spaced at their lower edges from the shell to form outlet passagesand extend upwardly beyond the outer members 24. An a1r off-take 28 is carried by the inner plate member 25 and extends throughout the longitudinal length of the shell. It comprises a horizontal baffie portion29 which covers the top of the aircooling chamber and a hollow rectangular portion 31 having disposed therein a plurality of rectangular openings 32 for the admission. of the non-condensable gases. The non-condensable gases are removed from the air off-take by means of a plurality of conduits 33 which in turn communicate through -transformation pieces 34 with the air outlet flanges 35. The air outlet flange 35 is so designed as to make a fluid-tight joint with the condenser shell 11 and, at the same time, make a gas-tight joint with the transformation piece 34, thereby insuring complete separation of the air and condensate. A bafiie 36 is disposed horizontally above the air off-take 28 and extends throughout the longitudinal length of the condenser shell. It prevents condensed fluid or rain from falling into the hollow wall members 22 and 23 and being thereby conveyed to the air-cooling chamber.

The hotwell 13 is bolted to a supporting flange 37 cast integral with the condenser shell 11. It comprises a circular or some other suitable form of collection chamber 38 having cast concentrically therein a cup 39. Extending into the cup 39 is a conduit 41 for conveying drainage or condensate from the air-cooling and drying chamber to the hotwell. The conduit 41.has an extended flange portion 42 which is bolted to the upper face of the hotwell and makes a gas-tight joint therewith. The conduit 41 and the cup 39 form a water seal through which all condensate discharged from the air-cooling and drying chamber must pass. Disposed oppositely on each side of the collection chamber 38 and transversely to the longitudinal axis of the condenser are pockets 43 cast integral therewith. These pockets 43 extend the full depth of the hotwell and have their upper portion formed into aflange continuous with "the flange of the collection chamber. Disposed in each of the pockets 43 is an inverted L-shaped bafile 44. The vertical leg of the baffle 44 extends transversely across the pocket 43 and has its lower portion spaced from the bottom of the pocket. It forms with the pocket a water seal. communicating at its inlet end with the condensing chamber of the condenser and at its outlet end with the collection chamber 38. The horizontal leg of the Lshaped batlle 44 makes a tight joint with an extended flangeportion of the continuous lugs 27, whereby condensate discharged from the condensing chamber is compelled to' pass through one'of the seals formed by the' pockets 43 and the baffles 44 before passing into the collection chamber 38. Condensate which accumulates in the collection chamber 38 is'discharged through an outlet port 45 provided in the bottom of the hotwell.

In some instances, circulation of condensate through the hotwell may be facilitated by venting the collection chamber of the hotwell into the air-cooling and drying chamber. This can be accomplished by providing a small hole or restricted opening 48 between the two chambers. Since the opening 48 communicates with the air off-take chamber in which the pressure is low, entrained gases in the (ondensate are liberated upon passing through the region of reduced pressure and are drawn through the opening48 and discharged through the airofl-take 28.

Having thus described the arrangement of an apparatus embodying my invention, the operation thereof is as follows: Steam from a turbine, or other prime mover, is admitted info the condensing chamber through the steam inlet 12 and passes within the shell in such manneras to substantially surround 'the cooling tubes within the condensing chamber. The cylindrical entrance area to the tube nest is enabled to accommodate large volumes of steam readily and the steam passes radially through the nest of tubes toward the inlet ends of. the passages 22 and 23, which are disposed at approximately a central point within the tube nest. The steam is substantially condensed in the passage over the tubes so that non-condensable gases having a very small'condensable fluid content pass between the walls 24 and 25 to the lower portion of the air-cooling chamber. The air flows upwardly through the air-cooling chamber over the cooling tubes, which contain first-pass cooling water, and is further dried and cooled. The condensate dripping from the cooling tubes of the chamber falls into the hotwell, wherein it mingles with the condensate from the condensing chamber as will be hereinafter more fully described. The air then enters the inlet ports 32 of the air otl-take 28, passes through the conduits 33 and is withdrawn through the air outlet flanges 35 by means of any cellett ench m efr 35 Two bodit of liquidhaving levels, such as indicated in Fig. 1 of the drawing, will be maintained during operation of the apparatus, which bodies of liquid form seals whereby air and other non-condensable gases are substantially prevented from passing from the condensing chamber to the collection chamber of the hotwell and thence to thepump. Condensate within the air-cooling chamber falls into the conduit 41 and passes through the seal formed by the conduit and the cup 39, and thence into the collection chamber 38, wherein it mingles with the condensate from the condensing chamber. T he cup 39 is filled with condensate at all times during operation, and, as indicated on the drawing, a leg of water having slightly higher level than the top of the cup will be maintained in the conduit 41 because of the relatively higher pressure prevailing within the condensing chamber.

This liquid seal prevents air and other non-condensable gases from passing from the air-cooling chamber to the collection chamber 38 and thence to the pump, as well as insuring that the temperature and pressure prevailing within the collection chamber 38 will be substantially that of the condensing chamber, which temperature and pressure is the higher of the two. Furthermore, this construction insures there will be substantially no re-evaporation of condensate in the hotwell, as the condensate from the air-cooling chamber passes into a region of relatively higher pressure. I

The condensate discharged from the condensing chamber and the condensate discharged from the air-cooling chamber mingle in the collection chamber 38 of the hotwell and are removedthrough the outlet 45 by the condensate pump. The temperature and pressure prevailing within the collection chamber 38 being substantially equal to that of the condensing chamber, the temperature of the condensate removed by the pump is consequently of the highest possible temperature consistent with that of the en tering steam.

,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: I

1. In condensing apparatus, the combination of a condensing chamber, an air-cooling chamber, means for passing steam successively through the chambers. a condensate collection chamber. means for withdrawing condensate from the cond g cham er to said condensate collecting chamber and means for withdrawing condensate from the air-cooling chamber to said condensate collection chamber each of said condensate withdrawal means including water sealing means to prevent the passage of non-condensable gases tlierethrough.

2. In a condenser, the combination with a shell having a fluid inlet port, of a nest of condensing tubes within the shell,a nest of cooling tubes within,the shell, means for removing condensate from the condensing tube nest including a liquid seal, means for removing condensate from the cooling tube nest including a liquid seal, and a common means for receiving the condensate removed from the condensing tube nest and from the cooling tube nest.

3. In a condenser, the combination with a shell having a fluid inlet port, of a nest of condensing tubes Within the shell, a nest of cooling tubes within the shell, a hotwell, means provided in the hotwell for receiving condensate from the condensing tube nest, said means including a liquid seal, means provided in the hotwell for receiving condensate from the air-cooling tube nest, said means including a liquid seal, and .condensate outlet means provided in the hotwell.

4. In a condenser, the combination with a shell having a fluid inlet port and a hotwell, of a condensing chamber and an a rcooling chamber within the shell, means including a liquid seal for conveying condensate from the condensing chamber to the hotwell, means including a liquid seal for conveying condensate from the air-coohng chamber to the hotwell, whereby the pressure prevailing within the hotwell is substantially equal to that of the condens ng chamber. and outlet means for withdrawing the condensate from the hotwell.

5. In a condenser, the combination with a shell having a fluid inlet port, of a nest of air-coolingtubes rising from the bottom of the condenser, a nest of condensing tubes at the sides of and above said air-cooling tubes, partition means defining air passages between said groups of tubes, a hotwell associated with the shell, means including a liquid seal for conveying condensate from the nest of air-cooling tubes to the hotwell, means disposed 011 each side of the nest of air-cooling tubes for conveying condensate from the nest of condensing tubes to the hotwell, each of said last-mentioned means including a liquid seal, and outlet means for withdrawing the condensate from the hotwell. I

6. In a condenser, the combination of a shell having a fluid inlet port, of a nest of air-cooling tubes rising from the bottom of the condenser, a nest of condensing tubes at the sides of and above said air-cooling tubes and arranged within the shell so that a fluid delivery space communicating with said inlet port substantially surrounds the nest of condensing tubes, partition means defining air passages between said groups of tubes, a hotwell having a plurality of condensate inlets and a condensate outlet, liquid seals interposed between the outlet and each of the inlets of said hotwell, means for conveying condensate from the air-coollng tube nest to one of the inlets of said hotwell, means for conveying condensate from the condensin tube nest to the other inlets of said hotwel and means for withdrawing condensate from the hotwell.

7. In a condenser, the combination with a shell having a fluid inlet port, of a nest of air-cooling tubes rising from the bottom of the condenser, a nest of condensing tubes at the sides of and above said air-cooling tubes, dividing means between said groups of tubes comprising passages through which the uncondensed fluids pass from the condensing tubes to the air-cooling tubes, a hotwell associated with the shell, said hotwell having a plurality of condensate inlets and a condensate outlet, liquid seals interposed be tween the outlet and each of the inlets of said hotwell, means for conveying condensate from the space traversed by the condensing tubes to two of the inlets of said hotwell, and means for withdrawing condensate from the space traversed by the aircooling tubes to the remaining inlet of said hotwell.

8. In a condenser, the combination with a shell having a fluid inlet port, of a nestof cooling tubes within the shell, of a wedgeshaped air-cooling and drying chamber in the shell through which a portion of the cooling tubes extend, the remainingtubes traversing a condensing chamber, partition means between the chambers comprising passages through which the uncondensed fluids pass from the condensing to the aircooling chamber, a hotwell, said hotwell comprising a plurality of liquid seals and a collection chamber communicating therewith, means for passing condensate discharged from the air-cooling and drying chamber through one of the seals prior to its delivery to the collection chamber of said hotwell, means for conveying condensate discharged from the condensing chamber through the remainder ofthe liquid seals prior to its delivery to the collection chamber of said hotwell, and condensate outlet means provided in the hotwell.

9. In combination with a condenser, a hotwell comprising a condensate inlet chamher, a condensate collection chamber communicating therewith at its upper portion, means dividing the said condensate inlet chamber into two compartments communicatin at the bottom, said condensate inlet ment remotely disposed from the condensate collection chamber, said condensate collection chamber having an opening in the upper portion thereof, means constituting a hydrostatic seal closing said opening, and means for withdrawing condensate from the collection chamber.

' of the web remote from the condensate coldensate collecting chamber, means for with-,

drawing condensate from the condensin chamber and the air cooling chamber to sai condensate collection chamber including liquid sealing means to prevent the passage of noncondensible gases therethrough, and a vent between said condensate collection chamber and said air cooling chamber.

12. In a condenser, the combination with a shell having a fluid inlet ort, of a nest of condensin tubes within t e shell, a nest of cooling tu es within the shell, means for removing condensate from the condensing tube nest including liquid seals, means for removing condensate from the cooling tube nest including a liquid seal, a common means for receiving the condensate removed from the condensing tube nest and from the cooling tube nest, and a vent between the 'common receiving nest.

13. In a condenser, the combination with a shell having a fluid inlet port, of a nest of means and the cooling tube condensing tubes within the shell, a nest of cooling tubes within the shell, a hotwell, means provided in the hotwell for receiving condensate from the condensing tube nest,

said means including aliquid seal, means provided in the hotwell for receivings-tcondensate from the air cooling tube nest, said means including a fluid seal, and condensate outlet means provided in the hotwell, said shell having an aperture communicating with the condensate outlet means.

In testimony whereof, I have hereunto subscribed my name this 25th day of September, 1923.

DAVID W. R. MORGAN.

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