US2855756A - Apparatus for the control of vapor temperature - Google Patents

Description

ot. 14, I1953 Filed Oct. '7. 1955 Eff R. L. J. HAYDEN I'AL APPARATUS FOR THE CONTROL OF VAPOR TEMPERATURE 2 Sheets-Shea?I 1 05AM/a roR INVENTOR *Qua/Aka Juifs bu/ER AIrToRNEY Oct. 14, 1958 R. l.. J. HAYDEN ETAL 2,855,755

APPARATUS FOR THE CONTROL OF VAPOR TEMPERATURE Filed Oct. '1. 1955 2 Sheets-Sheet 2 'INV NfroR san/.4R0 /wfs CULI/ER Raaf/Pr BQEsL/E Jn/fs f/Awf/v C. ff

ATTORNEY United States Patent O APPARATUS FOR THE CONTROL OF VAPOR TEMPERATURE Robert Leslie James Hayden, Coulsdon, and Leonard James Culver, Purley, England, assignors to Foster Wheeler Corporation, New York, N. Y., a corporation This invention relates to apparatus for the control of vapor temperature and more particularly to boiler installations for alternately operating a pair of power generators.

In some marine boiler installations vapor, or steam, is provided for operating the ships propulsion apparatus which comprises a pair of power generating elements, as for example, vapor or steam operated turbines. The turbines are drivably connected to the ships propeller or propellers and one turbine is employed for effecting movement of the vessel ina forward or ahead direction while the other turbine operates to effect movement of the vessel in a rearwardly or astern direction; the turbines being generally referred to as the ahead turbine and the` astern turbine, respectively. It is customary to desuperheat the superheated steam in the boiler and to supply the astern turbine with desuperheated steam while the ahead turbine is provided with superheated steam. With the desuperheater in the boiler, it is necessary to stop and restart the ilow of desuperheating medium, or alternatively, alter the path of flow of the superheated steam when switching operation of the ahead and astern turbines.

The present invention contemplates a novel boiler installation which comprises an ahead turbine and an astern `turbine and means outside the boiler for desuperheating the superheated steam owing to the astern turbine. The superheated steam from the boiler ows through a tubular member which is connected to a juncture of conduits outside the boiler leading to the ahead turbine and the astern turbine, respectively. heater is arranged in the conduit leading to the astern turbine to desuperheat or temper the steam flowing thereto. In one embodiment of the present invention, feed water is employed in a tube and shell heat exchanger for desuperheating the steam, and in a second embodiment, condensate from a main condenser is used to condsense steam which is then sprayed into the steam supplied to` the astern turbine.

The invention will be understood from the following description when considered in connection with the accompanying drawings in which: t

Fig. l is a schematic illustration of a marine boiler installation constituting one embodiment of the present invention; and

Fig 2 is a schematic illustration of a marine boiler installation constituting a second embodiment of the invention.

Referring now to the drawings for a more detailed description of the present invention and more particularly to Fig. lv wherein one embodiment hereof is schematically illustrated, a marine boiler installation generally designated by the numeral 11, includes a casing or euclosure 12. Boiler installation 11, comprises a pair of water tube boilers 13 and 15 which include upper steam and water vessels 16 and 17, respectively, and lower water drums 18 and 19, respectively. Superheaters 20 and 21are providedr in boilers 13 and 15, respectively, and are connected by steam olf-take conduits 22 and A desuperfifiice 23, respectively, to the upper steam spaces of vessels 16 and 17. superheated steam ows from super heater 20 through a main stop valve 24 in a conduit 25 and superheated steam ows from superheater 21 through a main stop valve 26 in a conduit 27. A common steam pipe 28 is connected to conduits 25 and 27 and extends outside of the boilers where it is connected to a juncture of two conduits 29 and 30.

An ahead control valve 31 is disposed in conduit 29 for regulating the ow of steam to an ahead or main steam operated turbine 32 which is drivably connected by means, not shown, for effecting movement of a ship (not shown) in a forward direction, or ahead. An astern" control valve 33 is disposed in conduit 30 for regulating the tlow of steam to an astern turbine 34 by way of a desuperheater 35, to be more fully described hereinafter, disposed for cooperation with and in conduit 30. Astern turbine 34 is drivably connected by means, not shown, for effecting movement of the ship in a rearwardly direction, or astern. The steam discharged from turbines 32 andv34 is conducted to a main condenser 37 which changes the steam to Water and the latter passes through a pump 38 to a direct contact heater or deaerator 39. The water in deaerator 39 is heated to a temperature above 212 F., for a reason to be set forth, and the water is fed through a conduit 40 by a feed water pump 41. Conduit 40 is connected to the interior of a` shell 42 of desuperheater 35 which includes tubular means 43 connected in conduit 30. The feed water entering shell 42 ows in heat exchange relationship with the steam flowing through tubular means 43 to'provide for desuperheating of the steam prior to passage to astern turbine 34. The feed water leaves shell 42 through a conduit 45 whence it ows into economizers 46 and 48 of boilers 13 and 15, respectively. Economizers 46 and 48 communicate with vessels 16 and 17, respectively, to provide the latter with feed water. A by-pass valve 50 is disposed in conduit 40 and communicates with a by-pass conduit 51 connected to conduit 45 to vary the proportion of total ow' of feed water passing through the desuperheater.

In operation, when it is desired to change the direction of the ship from forward to astern, valve 31 is closed to stop ow of steam to main turbine 32. Thereafter, valve 33 is opened to provide ow of steam through conduit 30 into tubularmeans 43 of desuperheater 35 and in indirect heat exchange with boiler feed water condensate in main condenser 37 from turbines 32 and 34; the feed water being conducted to the desuperheater through conduit 40. It is to be noted that when astern valve 33 is opened, moderation of the temperature of the steam 'supplied to astern turbine 34 through desuperheater 35 automatically takes place and is largely self-regulating since the volume of water passing through shell 43 is determined by the volume of steam condensed from turbine 34. When it is desired to resume operation of ahead turbine 32, astern valve 33 is closed and ahead valve 31` is opened. As soon as valve 33 is closed, the pressure in tubular means 43 decreases to a value corresponding to that of the astern turbine outlet. The saturation temperature'of the steam at this pressure is lower than that of the feed water (above 212) circulating within the shell, wherebyno condensation takes place when the desuperheater isnot in use. Consequently, there is no risk of water being passed into astern turbine 34 whenA Fig. l and only-.those parts necessary to an understanding of the second embodiment are disclosed in Fig. 2; the

reference characters of `Pig. 'l -designating parts identical with `those of Fig. 2, -being retained. In Fig. 2, aconduit 55 having a regulating valveSSA is connected to common steam pipe 28 and communicates with the interior of a shell 56 ofa heat exchanger V57 to provide for ow of steam into shell 56. 'Heat exchanger V57 Vincludes tubular means -59 having an inlet `communicating with the discharge :side of pump 38 through -a conduit 60 and anl outlet communicating with main ycondenser 37 by Way of -a-conduit 61. By reason ofthe foregoing arrangement, the -supcrheated steam entering shell ``56 by way of conduit 55 passes in heat exchange with 'the feed water in tubular means 59 and lis condensed. The condensate leaves Vthe heat exchanger through a conduit 62 while the feed water, heated in the tubular lmeans, is returned to the-,main condenser 37 =by way of conduit 61. 'If desired, the feed water may be fed to a feed water conduit 63 Which'has one end connected to feed water pump 40 and the other end connected to economizers l46 and 48 (not shown in Fig. 2').

Conduit 62 has another end 65 which extends into a spray type desuperheater 66 and the end is provided with means (not shown) for spraying pure water into the desuperheater. Desuperheater 66 simply comprises a large pipe to accommodate the spray and is connected in conduit 30 leading to astern turbine 34. The necessary pressure differential in desuperheater 66 is obtained by throttling the steam entering the latter by a throttle 67. Astern valve 33, in conduit 3.0, is coupled to regulating valve 55A by ya mechanical connection 68, shown `as a broken line, to provide for .simultaneous operation of both valves. The steam is desuperheated in desuperheater 66 and is fed to astern turbine 34.

In operation', when it is desired to commence operation of astern turbine 34, valve 31 in conduit 29 is closed andv thereafter, valve 33 in conduit 30 is opened to provide flow of steam in the latter. Simultaneous with the opening of valve 33. regulating valve 55A also is opened through mechanical connection 68 to provideow of steam in conduit 55 and in shell 56 of heat exchanger 57. The steam passes in heat exchange with the feed water in tubular means 59 where it is condensed and drawn off through conduit. 62: for spraying in desuperheater 66. The Steam in desuperheater 66 is thus desuperheated and `conducted to astern turbine 34 whence it is discharged for delivery to main condenser 37,. It will be apparent that automatic control ofi the condensate rate is achieved in heat exchanger 57. The covering of tubular means S9 by any excess condensate controls the effectiveness thereof and in this way the rate of admission of. steam to ex.- changer 57 is automatically controlled by the rate at which the condensate is drawn-off. The rate at which condensate is drawn-off automatically increases and decreases as the rate of steam flow to the astern. turbine 34 is raised or lowered. Shell 56 provides a reserve of condensate for the spray which 33 is first opened.

An advantage of the boiler installation of Fig. 2 is that there is no danger of feed water, which may contain solids, being admitted to the conduit 30 in the event of.

Although two embodiments of theV invention have been illustrated and described in detail, it is to be expressly understood that thel invention, is not limited thereto..

Various changes can be made in the design and an'angementof parts without departing from the spirit and scope of the invention as the same will now be understood*V byl those skilled in the art.

What is claimed is: l. In a boiler installation of the class described, a

is useful when astern valve boiler for producing a vapor and having an enclosure, a -superheater lin -said venclosure connected for superheating vapor, conduit means connected to the superheater and extending outside said boiler, a first turbine, a second turbine, a second conduit means in communication with said first mentioned conduit means and with said first turbine for delivering vapor to the latter to provide operation thereof, third conduit means communicating with said first conduit means and with said second turbine for delivering vapor to the latter to provide operation thereof, means for regulating the flow of vapor in said second and ysaid third conduit means, cooling means -communicating with the first conduit means for receiving a portion of vapor therefrom and condensing the latter to a liquid, a desuperheater arranged in communication with said third conduit means and receiving vapor therefrom prior to passage of the vapor to said second turbine, said desuperheater being connected to said cooling means for receiving the liquid therefrom in direct contact with the vapor within the desuperheater, a condenser connected to receive vapor discharged from said first and said second turbines for condensing the vapor, and means communicating with the condenser and with the boiler for delivering condensate to the latter.

2. In a boiler installation of the class described, a boiler for producing vapor and having an enclosure, a superheater connected for superheating the vapor, first conduit means connected to the superheater and extending outside said boiler, a first turbine, a second turbine, a second conduit means in communication With the first conduit means and with the first turbine for delivering vapor to the latter to provide operation thereof, third conduit means in communication with the first conduit means and with the second turbine for delivering vapor thereto to provide operation thereof, means for regulating the ow of vapor within the second and the third conduit means, a condenser connected to receive discharged vapor from both said first and said second turbines, a heat exchanger communicating with the first conduit means for receiving a portion of vapor therefrom, said yheat exchanger being also in communication with said condenser for receiving condensate therefrom in indirect heat exchange relationship with the vapor to effect condensation of the latter to a liquid, a desuperheater arranged in communication with said third conduit means and receiving vapor therefrom prior to passage of the vapor to said second turbine, said desuperheater being connected to said. heat exchanger for receiving liquid therefrom in direct contact with the vapor within the desuperheater and means in communication with the Icondenser and with the boiler for delivering condensate to the latter.

3. The boiler installation of claim 2 wherein the heat exchanger is a tube and shell exchanger wherein the vaporl passes on the outside of the tubes and the condensate flows through the tubes.

4. The boiler installation of claim 3 wherein means are provided in communication with tubes in said exchanger and with the condenser for returning condensate leaving the exchanger to the condenser.

5. In a marine boiler installation of the class described and having an enclosure, a boiler for producing vapor, a superheater connected for superheating the vapor, .first conduit means communicating with the superheater for receiving superheated vapor therefrom for passage therein, said conduit means having an outlet portion extending outside said boiler enclosure, an ahead turbine, an astern turbine, second conduit means in communication with the outlet portion of the rst conduit means and with said ahead turbine for delivering vapor to the latter to provideoperation thereof, third conduit means in cornmunication with the outlet portion of the first conduit means and with said astern turbine for delivering vapor to the latter to provide operation thereof, a condenser connected for receiving and condensing. vapor discharged from both said turbines, a valve arranged in said second 5 conduit means for regulating ow of vapor therein, a second valve arranged in said third conduit means for regulating ow of vapor therein, a neat exchanger, fourth conduit means having one end connected to the outlet portion of the first conduit means for receiving a portion of the vapor therein prior to passage of the vapor to the second and the third conduit means, said fourth conduit means having another end connected to said heat exchanger for delivering vapor thereto, a third valve in said fourth conduit means for regulating ow of vapor therein, means connecting said second and said third valves for conjoined operation, said heat exchanger being connected to said condenser to receive condensate therefrom for indirect heat exchange relationship with the vapor therein to provide a liquid, a desuperheater arranged in said 15 third conduit means and receiving vapor therefrom prior to passage of the vapor to said astern turbine, said desuperheater being connected to said heat exchanger for 6 receiving the liquid therefrom in direct contact `with the vapor within the desuperheater, a throttle valve in said third conduit means between said second valve and said desuperheater for reducing the pressure of the vapor entering the desuperheater, and means for returning the condensate from said condenser to the boiler.

References Cited in the file of this patent UNITED STATES PATENTS 2,024,761 Fraser Dec. 17, 1935 2,103,685 Kuhner Dec. 28, 1937 2,431,177 Iager et al. Nov. 18, 1947 FOREIGN PATENTS 210,051 Great Britain Aug; 14, 1924 416,091 Great Britain Sept. 10, 1934

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