US1845547A

US1845547A - Condenser circulating system

Info

Publication number: US1845547A
Application number: US515759A
Authority: US
Inventors: Henry F Schmidt
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1931-02-14
Filing date: 1931-02-14
Publication date: 1932-02-16
Anticipated expiration: 1949-02-16

Description

1932. H. F. SCHMIDT CONDENS ER C IRCULATING SYSTEM Filed Feb. 14, 1931 4 Sheets-Sheet ATTORNEY Feb. 16, 1932. H. F. SCHMIDT CONDENSER CIRCULATING SYSTEM Filed Feb. 14, 1931 4 heets-Shee 2 BY 'lM WITNESSES:

ATTORNEY Feb. 16, 1932. sc D 1,845,547

CONDENSER CIRCULATING SYSTEM Filed Feb. 14, 1931 4 heets-Sheet 5 L Ill p INVENTOR H. F. 5HM\DT.

ATTORNEY Feb. 16, 1932. .H. F. SCHMIDT CONDENSER CIRCULATING SYSTEM Filed Feb. 14, 1931 4 Sheets-Sheet 'F'wa. 1.

Fxe. 6.

E. E L m 6% .W w... 0 ml fi w M w? D A o E M H n w J 5 3 w L G O O INVENTOR H. F. 5CHMVDT.

WITNESSES:

b, AIM

ATTORNEY scoop. Such a scoop, for a given capacity, ,can be made materially smaller than the Patented Feb. 16, 1932 UNITEDSTATES PATENT oFFIca HENRY F. SCHMID T, OF LANSDOWNE, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELEOTRIO & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA CONDENSER OIROULATING SYSTEM I Application filed February 14,1931. Serial No. 515,?59.

This application is a continuation in part of subject matter divided from my copending application, Serial N 0. 281,983, filed May 21, 1929 and entitled Scoop condenser apparatus.

This invention relates to steam condensing systems and particularly to steam condensing systems for marine power plants and still more particularly to circulating water apparatus for such steam condensing systems and it has for an object to provide apparatus of the character .designated which shall be capable of operating more eificiently and which shall, at the same time, occupy less space and entail less weight of material than the systems heretofore provided.

In marine power installations of the type installed in high speed vessels, it is customary to provide a condenser with a scoop system of circulation in order that the movement of the vessel through the water may be utilized to'cireulate the required amount of cooling water through the condenser. By utilizing the movement of the vessel to circulate the cooling water through the condenser, the requirement for a large circulating pump 1s dispensed with and considerable savings 1n weight and operating economy are effected.

However, during periods when the vessel is maneuveringor standing by, a scoop system is inefi'ective to circulate the required amount of cooling water through the condenser and it has, therefore, been the general praeice to provide, in addition to the scoop system, a relatively small capacity auxiliary circulating pump which is located-apartfrorn the condenser and the scoop system and which is connected; thereto by suitable, piping and valves. I

In my copending applieation,*Serial No. 382,456 filed July 31, 1929 for condenser scoop and assigned to the Westinghouse Electric and ManufacturingCompany, I disclose and claim a new form of scoop which is so arranged as to efiect a velocity-pressureconversionof the water passing through the scoops heretofore in vogue and,consequently, the weight as well as the space occupied by this portion of the water circulating system is materially reduced.

In the present application, I efi'ect further savings in the weight and the'space occupied by scoop systems of circulation by embodying in the system, in addition to a scoop such as disclosed and claimed in the aforesaid copending application, an auxiliary circulating pump of the propeller type. I have found that an auxiliary circulating pump of this type has exceptional application to a scoop system of circulation in that the propeller may be located directly in the circulating passage of the scoop system supplying I the condenser. Inaddition, such a type of pump is readily reversible.

The propeller may be located directly in the conduit through which the water flows from the scoop inlet to the tube nest of the condenser because it is a pump of such a character that, when not in use, it will not interfere withthe circulationof sea water from the scoop to the condenser as it will merely turn over idly. In accordance with my invention, I propose to provide a separate and independent primemover for driving the propeller and to mount the prime mover directly upon the exterior of the conduit in which the propeller is disposed. In this way, all water connecting valves and pipingfor the auxiliary circulating pump are dispensed with and, inasmuch as the auxiliafi y circulating pump becomes a" unitary part of the scoop system, the requirement for independent foundations for the auxiliary circulating pump is entirely dispensed with. Furthermore, inasmuch. as the propel- .ler is driven by its own independent prime mover, the propeller and the rotating element of its prime mover are free to turn over idly when the scoop alone is being utilized to effect the required circulation.

It is, therefore, a more particular object of my invention to provide an auxiliary circulating pump of the propeller type and to locate the propeller of the pump directly in the scoop system, as well as to provide an 1 independent prime mover for driving the propeller, which prime mover shall be lo-"ioo' cated exteriorly of and adjacent to the conduit formed by the scoop system.

It .is a still more partlcular object of my invention to provide a propeller for the auxiliary circulating pump which shall be so formed as to offer a minimum amount of resistance to the flow of the cooling water through the scoop system of circulation at such times as the auxiliary pump is not being operated.-

These and other objects are effected by my invention, as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. l is a diagrammatic view showing one form of condenser circulating system arranged in accordance with my invention;

Fig. 2 is a view, in longitudinal elevation, showlng a more practical form of condenser circulating system arranged in accordance with my invention;

Fig. 3 is a detail view, in section, of the arrangement of the scoop and circulating pump embodied in the system shown in Fig.

Fig. 4 is a view looking into the scoop from outside the hull of the ship;

Fig. '5 is a view in cross-section, taken on the line V-V of Fig. 3;

Fig. 6 is a plan view of the propeller utilized in the auxiliary circulating pump;

Fig. 7 is a view, in end elevation, of the propeller shown in Fig. 6; and,

Fig. 8 is a graph showing the resistance offered by different forms of propellers to the flow of cooling water through the scoop system. b

Referrin now to Fig. 1, I show a ships hull 1O havlng a bottomll and a condenser 12 supported in any suitable manner upon the ships hull. The condenser is of the scoop type and it has conduit or scoop portions 13 and 14 arranged at its forward and astern ends, respectively, the conduit portion 13 terminating at its forward end in'a projecting lip 15 of any suitable design.

Disposed in the forwardconduit13, is a reversible propeller 17 carried by a shaft 18 whose outer end is connected to a suitable motor, at 20. In the form shown, the motor at 20, takes the. form' of a reversible steam turbine, although any reversible motor may be used for this purpose. The casing of the motor is provided with respective ahead and astern steam inlet passages, 22 and 23, adapted to be alternately connected, by way'of the

valves

24 and 25, to the steam su ply line 26. In my copending application, erial No. 281,983, filedMay 31, 1928, of which this application is a continuation in part, I disclose and claim apparatus for automatically con trolling the operation of the

steam valves

24 and 25 alternately in response to a char- 65 acteristie-of the water of circulation and, for

a detail description of the construction and operation of such control apparatus, reference may be had to that application.

From the foregoing, the operation of my invention will be apparent. Assuming that the ship is moving in a forward direction under full speed conditions, sea water is taken in by the conduit portion 13,-Which conduit portion includes the lip 15, and is conveyed .to the condenser 12. After passing through thecondenser 12, the cooling water is returned to the seat through the conduit portion 14 which is located astern of the conduit portion 13, all as is well understood in the art. During such operation, the

steam valves

24 and 25 are closed and the propeller 17 is not being motivated by the prime mover 2O inasmuch as the speed of the ship is suflicient to effect the required circulation of cooling water through the condenser 12. At such times, the water from the scoop 13 passes between the blades of the propeller 17 to the condenser, this circulation of the water through the propeller causing the latter, together with the rotor element of its turbine prime mover 20, to turn over idly. However, the propeller in no way interferes with the effective operation of the scoop system.

Should the speed of the ship be so reduced or should'th-e ship be so maneuvered as to render the scoop system of circulation ineflective to circulate the required amount of water through the condenser, then, one of the

steam valves

24 or 25 may be opened and the prime mover 20 energized to cause the propeller 17 to rotate and to pump water through the scoop system. If the ship is moving ahead, thesteam valve 24 may be opened to cause the propeller to circulate water from the conduit portion 13 in a direction toward the con- 05 'duit portion 14 while, if the ship is moving astern, the Valve- 24 may be closed'and the valve 25 opened to cause the propeller to circulate cooling water inthe reverse direction, that is, from the conduit portion'14 toward 11 the conduit portion 13. It will, therefore, be apparent thatthe auxiliary-circulating pump 17 is effective to I circulate ,cooling water through the condenser in an astern direction when the ship is moving ahead and inan ahead direction when the ship is moving astern. Then again,.should it be desired to operate the ship at the highest maximum speed obtainable, both the scoop system and the auxiliary pump 17 may be utilized. At such times, the turbine 20 is energized and the propeller 17 serves to effect more rapid flow of water through the scoop system than would be the case if only the scoop were relied upon.

Inasmuch as a pump of the propeller t pc is readily reversible, my arrangement has still another advantage when applied'to a scoop system of circulation in that it may be utilized to cleanse the condenser. Ordinarily, most high speed vessels steam nearly all of the time in an ahead direction with the result that the tubes and the forward tube sheet of the condenser become fouledwith sea-weed and other dbris. By periodically reversing the auxiliary propeller 17, the condenser may be backwashed, that is, a circulation of cooling water through the condenser in a direction which is the reverse of that normally prevailing is effected. Such reversal of circulation results in effectively removing a considerable portion of the foreign matter.

Referring now to the more practical ar rangem'ent of my apparatus shown in Fig. 2, I show a ships hull structure indicated generally at 31, having a shell 32, an inner plating structure 33 and a plurality of lon gitudinally-spaced,- transversely-extending frame members 34. Supported upon the ships structure 31, in any suitable manner, is a condenser 35 which has, in turn, supported thereon a prime mover or turbine 36 for propelling the vessel, the turbine 36' ordinarily exhausting into the condenser 35. The condenser 35 is provided with a forward water box 37 and an astern water box 38. Sea water is supplied to the forward water box 37 by a scoop 39 connecting through a gate-valve 41 to a fitting 42 which also serves as a pump casing. The latter has an outlet 43 connecting with the water box 37 through a suitable expansion joint 44. Supported upon the fitting 42 is an independent prime mover 45 for driving an auxiliary circulating pump. Tn this embodiment, a prime mover rotatable in only one direction is shown. The water discharged from the astern water box 38 is conveyed to the sea through an overboard discharge chest 46, the chest 46 being connected to the water box 38 through a suitable gate valve 47.

Referring now to Figs. 3, 4, and 5, it will be noted that the scoop 39 is composed of an inlet portion 48 and an outlet portion 49. The inlet portion 48 is rigidly secured to the shell of the ship by a suitable flange 51, while the outlet portion 49 is secured to the inner plating structure 33 by a suitable flange 52. In order to compensate for weaving of the hull structure, the inlet and outlet portions are joined by a suitable slip joint 53 equipped with a stuffing box 54 for effecting a fluid-tight join-t therebetween. As specifically disclosed and claimed in my aforesaid copending application, Serial No. 382,456, the flow-area of the inlet portion 48 of the scoop 39 increases, as shown in Fig. 3, in the direction of the normal flow of the Water, the direction of normal flow being indicated by the arrow. Consequently, as the water passes through the scoop, it assumes a gradually decreasing velocity and some of its kinetic energy isthus given up and transformed into energy in the form of increased static pressure. Hence, the static pressure atthe exit end of the scoop, the end 55, is

greater than at the entrant end, the end 56,

condenser 35 and, consequently, the circulation of sea water through the condenser is facilitated. I

In the system shown in Fig. 1, I embody a scoop of the prior art, which scoops are generally provided with a protruding lip 15. However, I have found that, with scoops arranged in accordance with the principles disclosed in my aforesaid copending application, Serial No..382,456, the protruding lip may be dispensed with and, as shown in Fig. 3, the inlet portion ofthe scoop made substantially flush with the hull of the ship. As a result, the scoop does not increase the resistance to the passage of the hull through the water.

As shown in both Figs. 3 and 4, the entrant portion of the scoop is preferably of rectangular formation and is provided with a suitable transverse guide vane 57 extending in the direction of the flow of the Water. The guide vane is effective to reduce turbulence in the scoop. Whilethe scoop is of rectangular formation near its entrant end, 9 I prefer to so form the same that it transforms into a circular cross-section as it approaches the slip joint 53, (see Fig. 5), so that the discharge section 49 of the scoop may be made entirely of circular cross-section.

The fitting or pump casing 42 embodies a screw propeller '58 located adjacent to the discharge end 55 of the scoop. The propeL ler 58 is connected by a drive shaft59 to a gear 61. The latter in turn meshes with a suitable pinion 62 connected through a pinion shaft 63 to a rotor 64 of the prime mover 45. Although any well-known form of prime mover may be employed, ll show, in the present embodiment, a steam turbine having a casing 65, a steam inlet 66 and an exhaust outlet 67. A throttle valve 70 controls the supply of steam to the turbine. The drive shaft 59 of the propeller is supported in suitable bearings 68 provided in the pump casmg.

The operation of this latter embodiment of myinvention is essentially the same as that set forth with reference to the embodiment shown in Fig. 1. However, in the second embodiment, the scoop 39, as stated heretofore, is capable of efiecting a velocity-pressure conversion of the sea water passing through the scoop so that the water at the discharge end 55 of the scoop has assumed a decreased velocity but an increased static pressure, which increased static pressure is available to overcome the resistance to flow offered by the condenser 35. When the propeller 58 is the freely supported drive shaft 59, the gear 61, the pmion 62, the pinion shaft 63 and the turbine rotor 64.

.When the velocity of the ship is such that the scoop is inefiective to create the required qc'irculation of water, the turbine 45 is energized and the propeller 58 circulates the water through the conduit, which conduit includesthe scoop 89, the valve 41, the fitting or pump casing 42, the expansion joint 44 and the forward water box 3'1. After circulating through the condenser, the water passes to the overboard discharge chest 46. Durin such times as it is desired to propel the ship at its highest maximum speed, the use of the scoop system of circulation as well as the propeller may be both resorted to in order to circulate the maximum amount of cooling water through the system.

Preferably, I employ a propeller of the type shown in Figs. 6 and 7, which propeller embodies a hub 71 and only two blades 7 2. ll also prefer to employ a propeller having an increasing axial pitch from the leading edge 73 to the trailing edge 74 of each blade. 'lhe radial pitch is constant. In my Unlted States Patent No. 1,596,459, issued August 17, 1926, for propeller pump and assigned to the Westinghouse Electric and Manufacturmg Company, I disclose and claim a form of propeller which, when used in a conventional pump or blower apparatus, is capable of c1rculating a fluid with maximum efficiency. In the aforesaid patent, 1 so proportion the propeller that the projected area thereof is approximately two-thirds of the disc area. In other words, the projected area to disc arearatio is about 66 per cent. However, in the present application, a form of propeller must be provided which is not only capable of C11- culating the water in the most efficient manner possible, but the propeller must be so proportioned that, when the auxiliary'pump 1s not in use and the propeller is merely idling owing to the circulation of water by the scoop, it offers a minimum amount of resistance to flow through the conduit.

Referring now to Fig. 8, I show a graph which indicates that, as the projected area to disc area ratio is increased, the resistance offered by the propeller, arranged as shown in Fig. 3, that is, with the elbow 71, increases. The graph-embodies two curves, one showing the resistance when the propeller is idling and the other when the propeller is fixed, that is, held stationary. From the foregoing raph, it will be apparent that, if a projected area to disc area ratio of about 66% is employed, the resistance offered by the propeller, when idling, will be approximately 450% or equivalent to about four and onehalf times the head corresponding to the velocity of flow of the water circulatmg through the conduit. ll, therefore, prefer to make the projected area to disc area ratio of the propeller not greater than 40% or, specifically, about 22 or 23%, as it will be apparent from 'Fig. 8 that a propeller formed with the lat ter ratio offers a resistance of only about 70% of the head corresponding to the velocity of flow of the Water circulating through the conduit. At the same time, a propeller so proportioned acts as a pump with quite good efficiency. While I show a propeller having only two blades, this illustrates a preferred form of my invention inasmuch as my invention contemplates, in its broader aspects, the provision of a propeller having a plurality of blades but wherein the projected area to disc area ratio does not exceed 40%.

v From the foregoing, it will be apparent that I have evolved a novel form of system for circulating cooling water through a ma rine condenser. It Will be noted that I have embodied in this system a novel form of scoop which is capable of efiecting a velocity-pressure conversion of the water circulating through the system in order that circulation of cooling water may be facilitated. In addition, by utilizing an auxiliary pump of the propeller type, having its own independent prime mover, the propeller may be located directly in the conduit connecting the scoop with the condenser, the propeller and its prime mover may rotate idly when the scoop is efiecting the required circulation and the prime mover for driving the propeller may be mounted and supported directly upon the conduit. in this way, an extremely compact arrangement is afforded and the weight of the condenser circulating system is very materially reduced, a fact that is of utmost importance in the design of propelling ma chinery for high speed vessels.

While I have shown my invention in but two forms, it will be obvious to those skilled in the art that it is not so limited but is susceptible ofvarious other changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be imposed thereon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. The combination with a condenser for eluding a scoop for effecting the required circulation, additional means for circulating cooling water through the condenser including a propeller disposed in said first-named means, and means for driving said propeller.

3. The combination with a marine condenser, of means providin for the passage of cooling water through t e condenser and including a scoop for eiiecting the required circulation, additional means for circulating cooling Waterthrough the condenser includling a propeller disposed in said first-named iii means, and reversible means for driving said propeller. I

4. The combination with a marine condenser, of means providing for the passage of cooling water through the condenser and including a scoop for efiecting the required circulation, additional means for circulating cooling water through the condenser including a propeller disposed in said first-named means, and means disposed exteriorly of said first-named means for driving the propeller.

5. The combination with a marine condenser installation including means for circulating water through the condenser in one direction when the ship is moving ahead and in another direction when the ship is moving astermsaid means including a scoop communicating with the forward end of thecondenser and a conduit communicating with the after endot the condenser, of additional means for supplying water to the condenser and including a propeller disposed in said water circulating means, and means for drivmg said propeller in either direction so as to effect a direction of circulation in accordance with the direction of movement of the ship.

6. The combination with a ships condenser, of a scoop system for circulating cooling water through the condenser by movement of the ship, said scoop system including a conduit having its after end portion connecting with and including the inlet water box of the condenser and having its forward end portion communicating with the exterior of the ships hull, and a pump for also circulating cooling water through the condenser, said pump embodying a propeller disposed in the conduit of the scoop system and also embodying a. prime mover connected solely to the propeller for driving the latter.

7. The combination as claimed in claim 6 wherein theprime mover for driving the propeller is disposed exteriorly of the conduit and is mounted thereupon.

8. The combination with a ships pondenser, of a scoop system for circulating cooling' water through the condenser by movement of the ship, said scoop system including a conduit having its after end portion connecting with and including the inlet water box of the condenser and having its forward end portion communicating with the exterior of the shipshull, an auxiliary pump for also circulating cooling water through the condenser,

said auxiliary pump embodying a propeller disposed in the conduit and a prime mover for driving the propeller, and means for energizing and deenergizing the prime mover, said prime mover embodying rotor and stator elements and said rotor element being arranged to be rotated idly by the propeller at such times as the prime mover is deenergized and cooling water is being circulated through the condenser by action of the scoop system alone.

9. The combination with a ship s condenser, of a scoop system for circulating cooling water through the condenser by movement of the ship and including a conduit having its after end portion connecting with and including the inlet water box of-the condenser and having its forward end portion communicating with the exterior of the ships hull, said conduit having a portion thereof so increasing in flow-area in the direction of the flow of the water as to efiect a velocity-pressure conversion of the water passing through the conduit in order to provide added pressure head for overcoming the resistance of the condenser, and a pump for also circulating cooling water through the condenser, said pump embodying a propeller disposed in the conduit and on the discharge side of the portion which increases in flow-area and efi'ects the velocitypressure conversion of the water.

10. The combination with a ships condenser, of a scoop system for circulating cooling water, through the condenser by movement of the ship and including a conduit having its after end portion connecting with'and including the inlet water box of the condenser and having its forward end portion communicating with the exterior of the ships hull,.and a pump for also circulating cooling water through the condenser, said pump embodying a propeller disposed in the conduit and said propeller having a projected area to disc area ratio of not greater than 40 per cent.

11. The combination with a ships condenser, of a scoop system for circulating cooling water through the condenser by movement of the ship and including a conduit having its after end portion connecting with and including the inlet water box of the condenser and having its forward end portion communicating with the exterior of the ships hull, and a pump for also circulating cooling water through the condenser, said pump embodying a propeller disposed in the conduit and said propeller having a projected area to disc area ratio of approximately 23 per cent.

12; The combination with a ships condenser, of a scoop system for circulatingcooling water through the condenser by movement of the ship and including a conduit having its after end portion connecting with and including the inlet water box of the condenser and having its forward end portion communiciir with the exterior of the ships hull, I a propeller disposed in the conduit and having a projected area to disc area ratio of not greater'than 40 per cent and a prime mdver disposed exteriorly of the conduit, said prime mover embodying rotor and stator elements and said rotor element being so connected to the propeller as to be rotat able simultaneously therewith.

13. The combination with a ships condenser, of a scoop system for circulating cooling water through the condenser by movement of the ship and including a conduit having 1 its after endportion connecting with and including the inlet water box of the condenser and having its forward end portion communicating with the exterior of the ships hull, said conduit having a portion thereof inc easing in flow-area in the direction of the L ow of the water so as to efiect a velocity-pressure conversion of the water pass.- ing through the conduit, a propeller disposed 'inthe conduit between the condenser and the portion of the conduit which increases in flow-area, said propeller having a projected area to disc area ratio of not greater than 40 per cent, a prime mover for driving the propeller, and means for energizing and deenergizing the prime mover, said prime mover embodying rotor and stator elements and said rotor element being connected to the propeller and arranged to be rotated idly by the propeller when cooling water is circulated through the condenser solely by action of the conduit.

14. The combination with a ships condens- 'er, of a scoop system for circulating cooling water through the condenser by movement of the ship and including a conduit, said conduit embodying a curved inlet portion communicating at its entrant end with the exterior of the ships hull, a straight intermediate portion and an elbow discharge portion connecting with the condenser, said curved inlet portion so increasing in flow-area in the direction of flow of'the water as to effect a velocity-pressure conversion of the water passing through the conduit, a propeller disposed in the intermediate portion of the conduit, a drive shaft'connected to the propeller and projecting outwardly of the elbow portion of the conduit, a prime mover for driving the propeller, said prime mover embodying relatively rotatable rotor and stator elements, and means for operatively connecting the rotor element ofthe prime mover to the propeller.

15. A system as claimed in claim 14 wherein the means for connecting the rotor ele- 16. The combination with a ships condens 'er, of a conduit for circulating cooling water through the condenser by movement of the ship, said conduit having its after end portion connecting with and including the inlet water box of the condenser and having HENRY F. SCHMIDT.