US1721251A

US1721251A - Condenser preheater

Info

Publication number: US1721251A
Application number: US151127A
Authority: US
Inventors: Hodgkinson Francis
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1926-11-27
Filing date: 1926-11-27
Publication date: 1929-07-16
Anticipated expiration: 1946-07-16

Description

y 16, F. HODGKINSON l.721,251

CONDENSER PREHEATER Filed Nov. 27, 1926 F. 'H5cl9kinson lNVENTOR ATTORNEY WITNESSES Patented July 16, 1929.

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FRANCIS HODGKIN SON, OF SW'ARTHMORE, EENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTBIO & MANUFACTURING COMPANY, A. CORPORATION OF PENNSYL- VANIA.

CONDENSER PREHEATER.

My invention relates to power plant apparatus and it has for an object to provide means for preheating condensate to or near to the temperature of exhaust steam.

A further object of my invention is to provide power plant apparatus including heatexchange devices or condensers arranged in series, both receiving exhaust steam from a prime mover, such as a turbine, the surface condenser or heat exchange device condensing the major portion of the exhaust and discharging the condensate into the ct heat exchange device or condenser wherein the temperature of the condensate is raised and a portion of the exhaust steam supplied to the jet heat exchange device or condenser is con densed.

In many condenser installations, condensate is discharged at a temperature much below that of the exhaust steam. This is particularly true of the vertical type condenser where.

the condensate trickles over a cold tube plate at the bottom. Accordingly, therefore, 1 provide a heating hotwell, or heat exchange device, into which condensate drains from the condenser by gravity and comes into direct contact with a stream of exhaust steam, the exhaust steam serving to raise the temperature of the condensate and being partially condensed by the latter.

Another purpose of my invention is to provide a condenser of the type designated in which means are provided for withdrawing dissolved and non-condensable gases from the condensate, either by raising the temperature of the condensate, or by actually producing some degree of evaporation. This is accomplished by providing means for reducing the pressure which would normally prevail within the hotwell.

These and other objects are effected by my invention as will be apparent from the following description andclaims taken in connection with the accompanying drawings.

forming a part of this application, in which Fig. 1 is a view partially in section and partially in elevation showing my improvement applied to a vertical condenser installation; and I Fig. 2 is a view, partially in section, showing my improvement applied to a power in stallaton having a horizontal condenser;

Fig. 3 is a partial view on a somewhat larger scale of the tubular member 16 shown in Fig. 1.

Referring now to the drawings more in detail, in Fig. 1, I show a turbine having an exhaust end 10 from which steam is discharged through suitable passages 11 to vertical condensers 12'. Condensate drains from the bottoms of these condensers through suitable conduit connections 13 to'my improved heat exchange device or heating hotwell at 14, wherein the condensate has its tempera-v ture raised and the heating exhaust steam supplied thereto is partially condensed. This arrangement of heat exchange device or heating hotwell is particularly useful in connection with vertical condensers for the reason that condensate therein comes in contact with cold tube plates and thereby has its temperature lowered, causing a thermal loss.

Referring to the heat exchange device, heating condenser, or heating hotwell at 14 more in detail, it will be seen that this device is provided with an inlet chamber 15 for receiving condensate from the conduits 13, this condensate entering the concentric member 16 through jet passages 17, the 'concentric m ember 16 having a convergent lower discharge portion 18 which depends within the receptacle 19 and condensate is discharged through a suitable outlet 20. The upper end of the concentric tubular member 16 is open and communicates with the space or passage 22 leading to the exhaust chamber of the turbine. 7

It will, therefore, be seen that a stream-of exhaust steam passes downwardly through the tubular member 16 and that jets of condensate enter such stream from the jet passages 17. In this way, the condensate is caused to present a high ratio of exposed surface to direct contact with exhaust steam, thereby effecting exchange of heat from the steam tot-he condensate quite efliciently, resulting in the temperature of the condensate being increased'and in a portion of the exhaust steam being condensed. In addition to the thorough inter-mixture of condensate and exhuast steam provided by the jets to promote heat exchange, the condensate drains down in a sheet over the converging surface 18, thereby presenting further opportunity for direct contact of exhaust steam therewith to secure further heating andcondensation.

In order that a suitable draft may exist to assure the passage of the stream of exhaust steam through the member 16 in the manner referred to and in order that the effectiveness of the apparatus will not be impaired by the accumulation of non-condensable gas coming from the exhaust of the turbine, I provide connections 23 leading to points in the surface conoensers adjacent to the air offtalre portions of the condensers and connected to the chamber 19 near to the top thereof.

Referring to the embodiment of my invention applied to a horizontal condenser, in Fig. 2, I show a turbine 25 having an exhaust connection 26 leading to a horizontal surface condenser 27, the latter being provided with suitable condensate outlet 28 and air and noncondensable gas offtalre 29. Condensate from the outlet 28 is supplied to the heat exchange device or hotwell, at 29, somewhat similar to the one already described.

The heat exchange device, heating hotwell, or jet condenser at 29, receives oondensate from the heat exchange device or sur face condenser 27 and exhaust steam by way of the conduit 30, which is connected to the exhaust connection 26, the heat exchange device heating hotwell or et condenser at 29 serving to intermix the received media resulting in the temperature of the condensate being increased and a portion of the received exhaust steam being condensed.

Referring to the heat exchange device, jet condenser, or heating hotwell 29 more in detail, it will be seen that it comprises a receptacle 31 having its upper end connected to the exhaust steam conduit 30 and having the condensate'outlet 28 entering through the top thereof and depending therein. The lower end of the condensate outlet within the receptacle has a convergent portion 82 having jet passages 33 arranged to discharge condensate outwardly therefrom. Arranged below the outlet of the conduit 30 and about and below the convergent jet passage portion of the condensate outlet 32, there is an inverted bellshaped or convergent partition 34 connected circumferentially to the wall of the receptacle and having an exit or throat portion 35 arranged below the lower end of the condensate outlet portion 32. Heated condensate is removed through the outlet 36 from the lower portion of the receptacle 81 by any suitable means not shown.

To assure the passage of a current of steam from the conduit 30 and through the converging passage provided by the member 34, I provide means to effect a draft through these passages, or means to produce a zone of lower pressure below the discharge end 35. To this end, I show a conduit 37 connected to the receptacle 31 above the throat portion 35 and to the air and non-condensable gas offtake space 38 between the partition 39 and the shell 4:0 of the condenser 27. In View of the fact that the pressure at the region where the conduit 37 enters the condenser 27 is lower than that of the exhaust steam supplied to the conduit 30, and, for that matter, is also lower than the pressure corresponding to the temperature of condensate entering the outlet 28, it is assured that a draft shall be -maintained tending to produce a suitable current of steam for the purpose stated and precluding the accumulation of any non-condensable gas.

Furthermore, in the construction shown by Fig. 2, with connection 37 admitted to condenser 27 at a point where the pressure is slightly less than at the connection 28, and because of the ample steam flow and intimate mixing, the condensate at 35 will be at a temperature higher than that of evaporation at the pressure in the conduit 37, thereby producing boiling or evaporation within the hotwell, and, consequently, deaeration and the withdrawal of dissolved gases.

From the foregoing, it will be apparent that I have devised an arrangement of heat exchange devices, one being of the surface type, and the other being of the ct type, both devices receiving exhaust steam from a suitable prime mover, such as a steam turbine, and condensate from the surface heat exchange device beingsupplied to the jet heat exchange device, such condensate constituting the media of the jets and the jet heat exchange device serving to increase the temperature of condensate and to condense some of the exhaust steam supplied thereto. More particularly, I have provideda heater hotwell which receives condensate from a suitable condenser and raises its temperature by bringing exhaust steam into direct contact therewith. This arrangement of heater hotwell is particularly useful wherever the condensate of a condenser attains a temperature somewhat lower than the temperature of exhaust steam, as is the case with a surface condenser of the vertical type where the condensate trickles over cold tube plates or with cone densers of the simple down-flow type.

While I have shoWn my invention in several forms, it will be obvious tothose 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 power plant installation including a turbine and surface condensing means for condensing exhaust from the turbine, said surface condensing means having anoutlet for air and non-condensable gases, the combination of heat exchanging means for effecting a heat transfer between exhaustfrom the turbine and condensate discharged from the surface condensing means, a direct connection between the turbine exhaust and said heat exchanging means, a direct connection between the condensing compartment of the surface condensing means and said heat exchanging means, and means communicating with the surface condensing means in the vicinity of the air and non-condensable gas outlet thereof for producing a pressurein said heat exchanging means below that of the temperature of evaporation of the media therein.

2. In a power plant installation including a turbine and surface condensing means for condensing exhaust from the turbine, said surface condensing means having an outlet for air and non-condensable gases, the combination of heat exchanging means for of fecting a heat transfer between exhaust from the turbine and condensate discharged from the surface condensing means, a direct con nection between the turbine exhaust and said heat exchanging means, a direct connection between the condensing compartment of the surface condensing means and said heat exchanging means, and means associated with the surface condensing means in the vicinity of the air and non-condensable gas outlet thereof for producing a pressure in said heat exchanging means lower than the higher pressures in the surface condensing means.

3. In a power plant installation including a turbine and surface condensing means for condensing exhaust from the turbine, said surface condensing means having an outlet for air and non-condensable gases, the combination of heat exchanging means for effecting a heat transfer between exhaust from the turbine and condensate discharged from the surface condensing means, a direct connection between the turbine exhaust and said heat exchanging means, a direct connection between the condensing comparte ment of the surface condensing means and said heat exchanging means, and means for producing a pressure in said heat exchanging means corresponding approximately to that in the vicinity of the air and non-condensable gas outlet of the surface condensing meansceive condensate from the surface condensing means, means for passing steam directly from the turbine to the hotwell for heating the condensate, and means for venting air and other non-condensable gases from the hotwell to the surface condensing means in the vicinity of the air and non-condensable gas outlet of the latter.

5. In a power plant installation, including a turbine and surface condensing means for condensing exhaust. from the turbine, said surface condensing means having an outlet for air and other non-condensable gases, the combination of a hotwell, means for spraying condensate from the surface condensing means into the hotwell, means for passing steam direct from the turbine into contact with the condensate in the hotwell, and means for venting air and non-condensable gases from the hotwell to the surface condensing means in the vicinity of the air and non-condensable gas outlet thereof.

In testimony whereof, I have hereunto sub-- scribed my name this fifteenth day of November, 1926.

FRANCIS HODGKINSON