US2946571A - Condensers - Google Patents

Description

y 1960 LE ROY A. .DROESCHER 2,946,571

I CONDENSERS Filed June 26, 1959 INVENTOR 43 LEROY A. DROESCHER ATTORNEY.

' associated compartment.

tates Patent CONDENSERS Le Roy A. Droescher, Bala-Cynwyd, Pa., assignor to C. H. Wheeler Manufacturing Company, Lehigh, Pa., a corporation of Pennsylvania Filed June 26, 1959, Ser. No. 823,148

7 Claims. (Cl. 257-43) This invention relates to condensers, and it is among the objects of the invention to provide a condenser having a hot well adapted to store condensate during shutdown periods of a turbine in a manner to prevent absorption of non-condensable gases by the condensate.

The condenser of the present invention is provided with a hot well of the storage type separated and sealed from the steam space of the condenser except for conduits and valves permitting communication between the steam and condensate storage spaces during the operation of the condenser. The communicating means include a drain comprising one or more down pipes with discharge connections for conducting condensate into the storage space, and valve means for shutting off the flow of condensate from the down pipes and for closing an equalizing vent opening between the storage space and the steam space. The arrangement is such that by closing valves the stored condensate is completely isolated in a manner to prevent the absorption of air and non-condensable gases from the steam space when the operation of the turbine and the condenser is shut down.

With large condensers having a great number of condensing tubes several down pipes at each end of a condenser are connected to a manifold having a single conduit which discharges short of the bottom of the hot well. A valve located in the discharge conduit of each manifold affords means for shutting off the flow of condensate through all the down pipes connected with a common manifold. The several down pipes, receive condensate from different collecting areas in the steam space. These areas are formed as compartments or collecting trays separated from one another by dividing strips. The compartments are so arranged as to segregate the condensate received from different groups of condensing tubes, as well as from different longitudinally displaced portions of each group of condensing tubes.

Each down pipe contains a conductivity or purity cell and an instrument adapted to determine and indicate the degree of contamination of the water draining from its The instruments and purity cells aiiord means for determining and measuring the degree of pollution of the Water draining into each compartment and hence the field of search for leaks is reduced to restricted locations among the large number of tubes contained in a condenser. When divided water boxes are employed the arrangement serves to indicate which bank of tubes is leaking and discloses to the operator which bank of tubes to'remove from service to avoid further contamination.

Other objects and advantages of the invention will appear from a detailed description of the same, which consists in the features of construction and combinations of parts hereinafter described and claimed.

A full understanding of the invention may be had from the following description of an application of the invention, and from the annexed drawing, in which:

Fig. 1 shows an end elevation of a condenser with the lower portion thereof shown in section in the-plane 1--1 of Fig. 2; and

Fig. 2 is a horizontal sectional view on a reduced scale on line 2--2 of Fig. 1.

While the invention is applicable to a condenser of any desired construction having either a single cluster of condensing tubes, or condensing tubes arranged in banks or groups, its principle may be easily understood as described with reference to a condenser having two banks or groups of tubes. The condenser shown in the drawing includes a fluid-tight shell 10 open at its upper end to provide a steam inlet 11 adapted to receive exhaust steam from a turbine. The shell encloses a substantially rectangular steam space or chamber 12 containing two groups of condensing tubes 13, 14. Air-cooling tubes, baffies, air-evacuating conduits and other structures generally contained within a shell are omitted from the drawing in the interest of clarity.

The steam space and the condensing tubes extend to two tube sheets 15 and 16, Fig. 2, one adjacent either end of the condenser. These tubes open into water boxes at either end of the condenser from and to which cooling water is flowed through the tubes. Two of the water boxes are generally shown at 17 and 18 in Fig. 2. Noncondensable gases which are liberated from the steam and the condensate are withdrawn from the condenser through an offtake 19 by well-known means.

The hot well 20 is of the storage type and has sufiicient capacity to store a substantial quantity of condensed steam for use in the normal operation of a complete installation. In the illustrated condenser the width of the hot well is substantially coextensive with the width of the steam space 12 and its length is but little short of the length of the steam space, but it will be appreciated that these proportions are variable as required to satisfy the requirements of a particular condenser.

While the floor of the steam space and the roof of the hot well may be provided by ditferent walls, in many cases'a common separating wall 21 will serve the purpose of separating the steam space from the storage space in the hot well. A number of strips 22, 23 divide the bottom floor area of the steam space into a plurality of areas equal in number to the number of areas desired for segregating the condensate draining from the condensing tubes.

' As shown in Fig. 2, the dividing strips 22 and 23 are arranged to separate the floor of the steam space into four compartments 24, 25, 26 and 27. The compartments 24 and 25 receive the drainage from the group of the condensing tubes 13 with the compartment 24 receiving the drainage from the front half of the same group of tubes and the compartment 25 receiving the drainage from the rear half. The compartments 26 and 27 likewise segregate the drainage from the two half portions of the group of condensing tubes 14. Each compartment is provided with one of several drains or down pipes 28, 29, 30 and 31.

The two down pipes 28 and 29 at one end of the condenser are connected to a common manifold 32 and this manifold discharges the condensate received from the compartments 24 and 26 through a single discharge pipe 33 opening short of the bottom of the hot well. A suitable valve 34 is provided for closing the discharge pipe 33 when the operation of the condenser is discontinued. The valve may be operated automatically or manually by ahandwheel 35, Fig. 2.

. roof 21 of the hot well is provided with an equalizing vent opening therethrough, a conduit 39 and a valve 40 through which air and steam may be vented to the steam space of the condenser. A shaft 41 extends from the valve and through a side wall of the hot well and is provided with a handwheel 42 for operating the valve.

Water is normally withdrawn from the hot well by a pump 43 through a take-off connection 44 and a valve 45. A pipe 46 is connected through a side wall of the hot well close to the roof 21. This pipe is connected to an air-evacuating pump 47 through a valve 48 which is operable to seal the connection during the normal operation of the installation.

When the installation is in operation, the condensate valves 34 and 37 and the vent valve 40 are open so that the storage space in the hot well is subjected to substantially the same vacuum pressure as that which obtains in the steam space. When the installation is shut down the valves 34, 37 and 40 are closed, thereby sealing off the storage space in the hot well from the steam space, and the vacuum pressure is maintained in the storage space by the operation of the air-evacuating pump 47. The roof 21 of the storage space may be reinforced in any suitable manner, such as by the columns 49.

Each of the down pipes is provided with a sleeve 50 which extends through the adjacent side wall of the storage space and into a down pipe at a point slightly below the minimum water level usually carried during operation of the equipment, as illustrated in Fig. 1. This sleeve is adapted to receive a conductivity cell 51 which is inserted through a valve 52. The conductivity cell may be of any standard type responsive to changes in the conductivity of a liquid to which it is exposed. Spaced electrodes in the cell connect with an instrument 53 responsive to current flow and adapted to indicate and record changes in the conductivity of the condensate flowing over the electrodes. There is a conductivity cell 51 and an indicating instrument 53 for each of the down pipes 28, 29, 30 and 31, so that the degree of salinity or pollution of the water which is collected by each of the various compartments 24, 25, 26 and 27 is continuously recorded. So long as no leakage occurs from any of the condensing tubes, these conductivity cells indicate the purity of the condensate passing through the condenser, but when the purity changes, an alarm device warns the operator that cooling water is leaking into the steam space. The recording and indicating mechanism of the warning instrument discloses the degree of impurity resulting from the leak.

Should there be leakage from either of the groups of tubes 13 and 14 it would be manifest from the indicated change in purity of the condensate draining through either one or both of the down pipes 28 and 30, or through either one or both of the down pipes 29 and 31. Should the conductivity cell in only one of these down pipes indicate pollution, the search for the leak would be restricted to the front or rear portion of the tubes which drain to the compartment feeding into the particular down pipe where pollution is indicated and to the half of the tube sheet in which these tubes are fitted.

It is evident that the search for leaks can be further narrowed simply by increasing the number of condensate collecting compartments or trays and associated down pipes and purity cells and their respective indicating instruments. This may be accomplished in the form of condenser illustrated, for example, by placing a dividing strip at either side of the dividing strip 22, midway between the dividing strip and each of the side walls of the steam space, and by providing two additional down pipes to each of the manifolds 32 and 36. By so doing each of the banks of tubes 13 and 14 would be subdivided in the two groups, with the result that if contamination is indicated in the water descending in only one of the eight down pipes, the search for the leakage would be restricted to a group of tubes constituting approximately one-fourth of the total number of condensing tubes and to only the front or rear portion thereof which drains into the down pipe showing that contamination is present.

While the form of apparatus herein shown and described is admirably adaptcd to fulfill the objects primarily stated, it is to be understood that it is not intended to confine the invention to the one form of embodiment herein disclosed, for it is susceptible of embodiment in various forms all coming within the scope of the claims which follow.

What is claimed is:

1. In a condenser, a shell having an opening for the admission of exhaust steam to a steam-condensing space within said shell, condensing tubes in said steam space, a hot well for storing condensate received from said steam space, said hot well having a roof wall separating said hot well from said steam space, means normally communicating between said steam space and said hot well, said communicating means comprising a vent to allow non-condensable gases and steam to escape from said hot well to said steam space, and a drain terminating short of the bottom of said hot well for conducting condensate from said steam space into said hot well, and valve means for closing said vent and drain whereby the condensate contained in said storage hot well is isolated from said steam space when said valve means are closed.

2. In a condenser, a shell having an opening for the admission of exhaust steam to a steam-condensing space within said shell, groups of condensing tubes in said steam space, a storage hot well below said steam space, said storage hot well having a roof wall separating said storage hot well from said steam space, means for segregating condensate draining from different groups of said condensing tubes, said segregating means comprising compartments and down pipes opening through said roof wall, said down pipes respectively draining condensate from a compartment receiving condensate draining from one group of said groups of condensing tubes, a plurality of said down pipes connecting with a manifold having a discharge passage for conducting condensate to said storage hot well, a conduit for providing communication for non-condensable gases and steam between said steam space and said storage hot well, and valve means in said conduit and in said discharge passage to enable isolation of said storage hot well from said steam space to avoid absorption of non-condensable gases in said steam space by the condensate in said storage hot well whenever the operation of the condenser is shut down and said valve means are closed.

3. 'In a condenser, a shell having an opening for the admission of exhaust steam to a steam-condensing space within said shell, groups of condensing tubes in said steam space, means for receiving condensate streaming from said condensing tubes, said condensate-receiving means comprising a plurality of compartments constructed and arranged to collect in separate compartments the condensate streaming from each group of said groups of condensing tubes, a condensate storage hot well, a down pipe extending into said storage hot well from each of said compartments, said down pipes allocated in separate and distinct groups, a manifold connecting the discharge ends of the down pipes of one of said groups of down pipes, a second manifold connecting the discharge ends of the down pipes of the other of said groups of down pipes, each of said manifolds having an opening for discharging condensate to said storage hot well, valve means for closing said openings, and a vent valve in an opening between said steam space and said storage hot well.

4. In a condenser, a shell having an opening for the admission of exhaust steam to a steam-condensing space within said shell, groups of condensing tubes in said steam space, means for receiving condensate streaming from said condensing tubes, said condensate-receiving means comprising a plurality of compartments arranged to receive and segregate condensate streaming from front and rear portions of each group of said condensing tubes,

a drain for each of said compartments, a hot well, a

manifold connecting the discharge ends of said drains which receive condensate from the front portions of said condensing tubes, a second manifold connecting the discharge ends of said drains which receive condensate from the rear portions of said condensing tubes, each of said manifolds having an opening for discharging condensate to said storage hot well, valve means for closing said openings, and a vent valve for closing a vent opening between said steam space and said storage hot well.

5. In a condenser, a shell having an opening for the admission of exhaust steam to a steam-condensing space within said shell, groups of condensing tubes in said steam space, means for receiving condensate streaming from said condensing tubes, said condensate-receiving means comprising a plurality of juxtaposed compartments disposed below said groups of condensing tubes to receive and segregate condensate streaming from different portions of each group of said condensing tubes, a hot well, a down pipe depending from each of said compartments into said storage hot well, means in each of said down pipes for determining the purity or contamination of the condensate entering the respective down pipes from difierent portions of the condenser, a plurality of manifolds in said hot well, each of said manifolds connecting with a diiferent group of said down pipes and having a discharge conduit terminating short of the bottom of said hot well, and valve means for shutting ofi the flow of condensate from said manifolds into said storage hot G well, and a valve adapted to close a vent passage between said steam space and said storage hot well.

6. In a condenser, a shell having an opening for the admission of exhaust steam to a steam-condensing space within said shell, condensing tubes in said steam space, a condensate storage hot well below said steam space, said hot well having a roof wall separating said hot well from said steam space, means normally open for communicating between said steam space and said hot well, said communicating means comprising a vent through said roof wall and a down pipe opening through said roof wall and terminating short of the bottom of said hot well for conducting condensate from said steam space to said hot well, means in said down pipe for determining the purity or contamination of the condensate flowing through said down pipe, means for closing 01f communication through said vent and said down pipe to enable the isolation of the condensate in said hot well when the operation of the condenser is discontinued.

7. The combination set forth in claim 3 in which means are provided for determining the purity of the condensate collected by the respective compartments.

References Cited in the file of this patent UNITED STATES PATENTS 1,102,071 Parsons et a1. June 30, 1914 2,499,169 Sebald Feb. 28, 1950 2,658,728 Evans Nov. 10, 1953 2.663.547 Evans et al. Dec. 22. 1953

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