US2347062A - Generator protection against leakage of cooler tubes - Google Patents

Description

April 18, 1944. PQLLARD 2,347,962

GENERATOR-PROTECTION AGAINST LEAKAGE OF COOLER-TUBES Filed April 29, 1942 Fig; 2

\ WITNESSES: INVENTOR 4M r'flasz Paflard I BY 1 74a. 7ZWZJZIOQL- ATTORNEY Patented Apr. 18, 1944 UNITED STATES PATENT OFFICE GENERATOR PROTECTION AGAINST LEAKAGE-OF COOLER TUBES Pennsylvania Application April 29, 1942, Serial No. 441,051

(Cl. lib-252) 3 Claims.

My invention relates to ventilated dynamoelectric machines, and ithas particular relation to marine electrical equipments (generators or motors), which are cooled by a recirculating-gaseous cooling-medium, such as air, which passes over water-coolers which circulate sea-water through the tubes of the coolers. The fact that sea-water is salt makes it particularly necessary to safeguard against any possibility of waterleakage into the vital parts of the machine, and on vessels where the utmost reliability of the electrical equipment is required, precautions must be taken .to prevent any possibility of the entrance of sea-water into .the machine in the event of corrosion or breakage of the pipes of the cooler.

Heretofore, the above-mentioned problem has been solved, at very considerable expense, by the use of double-tube coolers, arranged with the water-tubes inside .of other tubes which collect the water which would otherwise drip into the machine in the event ofafailure of an inner tube asa result of corrosion or breakage from shellshock or other cause, an alarm being sounded when the water'leaks into the outer tubes. This construction is obviously expensive, of poor heattransfer efiiciency, and of poor space-economy, allof which considerably increases the expense, but heretoforeit ihas'been the only solution to theproblem in question.

According to myinvention, Iutilize standard coolers, thatis, coolers'having singletubes, or just the tubes carrying the cooling water, and I provide a system of bai'lles for "draining'away'any leakage-water from the vital parts of the machine, while permitting the recirculated coolingair to pass moderately 'freely'through the system of bafiles. This construction is not only very much less expensive than the double-tube coolerarrangement, saving over one hundred thousand dollars on a single years business, but it also has the advantage of being .more rugged, from the standpoint of shell-shock, which is .very important on naval vessels.

'Withthe foregoing and other objects'in view, my invention consists in the apparatus, combinations, parts and methods hereinafter described and claimed, and illustrated in the accompanying drawing, wherein Figure 1 is an end-view, partly in section, showing an alternating-current turbine-generator utilizing my invention;

Fig. 2 is a side-view, partly in section, of the same machine; and

Figs. 3 and 4 are similar views of an alternating-current motor utilizing a diiierent form of embodiment of-my invention.

Figures 1 and 2 illustrate the application of my invention to a very common type of coolercooled dynamo-electric machine in which the water-cooler is disposed above the machine. The stator of the machine-is shownat '5, consisting of a core having a plurality of radial ventilatingducts 6, and a stator-winding l. Separated from the stator by an air-gap 8, is the rotor 9 of the machine. In-theform of'embodiment of the invention shown .inFigs. l and 2:,the rotor 9 carries a fan or blower-member H at each end thereof, and the end-bell space 12, at each end, is provided with air-baffles 1.3 for directing the return-air into theentrance-portion of the blower II, and thence into the air-gap 8, and on through the radial vents 6,,from which the air is discharged out of the vital electrical parts of the machine.

Disposed on top .of the stator-member 5 is a water-cooler 15, illustrated as comprising a series of pipes :16 extending horizontally between headers 11 and ill, with inlet and outlet pipes t9 and 20 for the cooling water, usually sea-water on marine applications. An outer housing-structure 22 is provided for taking the air, which is discharged radially outwardly fromthe machine, and passing it upwardly through the tubes 16 of the cooler 5, and then bringing the air back, through the two end-bell spaces l2 of the machine, into the respective blowers ll, thus completing the recirculating path for the air.

In accordance with my invention, as shown in Figs. 1 and ,2, I provide bathe-means for preventing any accidental leakage of water from the cooler-tubes 16 from flowing back through the radial ventilating ducts'fiof the machine, and on into the vital parts of the machine, producing corrosion and short-circuits. I accomplish this function by suitable .bafile-means disposed so as to catch any water leaking from the cooler 15, and draining it away from the vital parts of the machine, as into a trough 24 which is shown in Fig. 1. vThe particular baffle-means, which is shown in Figs. 1 and 2, vfor the purposejust mentioned, consists of.a series of baflles illustrated as comprisinga-centralconvex or inclined bafiie 26, disposed above the stator-member 5 and below the cooler 15, for draining the water to either side of the machine, and an inclined system of louvers, comprising vertically spaced and overlapping slats or other short bafiies 21, at each side of the machine, for catching the water which drains off of the ends of the central baffle 26, and

carrying it far enough to the side, or horizontally, so that the water will finally drip into the draining-trough 24. While the inclined baffle-means 26 1 thus effectively drains any downwardly dripping leakage-water horizontally away from the vital parts of the'machine, the system of louvered baflles is at the same time sufficiently open, vertically, to permit a moderately free passage of the recirculated cooling-air in an approximately horizontal direction through the louvered baffle-means, the air-circulating path being indicated by arrows in Figs. 1 and 2.

In Figs. 3 and 4, I have illustrated the application of my invention to a somewhat different cooler-arrangement which is also commonly used, in which the cooler is disposed at one side of the dynamo-electric machine which is being cooled. In this form of embodiment of my invention, the machine is illustrated as a large synchronous motor, comprising a stator-core 33 having a plurality of radial ventilating-ducts 3i therein, and an armature-winding 32 carried by said statorcore. The rotor-member 33 is separated from the stator-member 30 by a small air-gap 34, and the rotor-member is illustrated as comprising a spider 35 carrying a rim-member 36 having a plurality of pole-pieces 31 disposed around its circumference, said pole-pieces terminating at the airgap 34.

The rotation of the rotor-member 33 in Fig. 4 causes a radial flow of air radially outwardly through the radial vents 3| of the stator-core 38, after which the air flows into annular passages 38 which are provided in the supporting framestructure 39 of the stator-member. At the top of this supporting frame-structure as, there is provided a rectangular air-housing i I, into which all of the air which is discharged from the statorducts 3|, all the way around the machine, is discharged, as indicated by the arrows 32. The airhousing 4! carries this air laterally or" the machine, and discharges it down through a watercooler l, which may be more or less similar to the water-cooler of Figs. 1 and 2, after which the cooled air continues to move downwardly into an air-chamber M which contains a series of vertically spaced or louvered baffles 155, an air-blower 46, and suitable ducts or guides 58 for directing the air again into the rotor-member thus completing the recirculating air-system of the motor. The baffles 45 are disposed in a position beneath the cooler l5 and above the blower 38, in such manner as to cause the approximately horizontally moving air to enter the blower through the spaces between the verticallyspaced bafiles, in a tortuous path which does not greatly impede the air-flow, while effectively draining all downwardly dropping water horizontally away from the blower 46, and thence horizontally away from the duct-system 48 which leads into the vital parts of the electric machine.

While I have described my invention in two specific forms of embodiment, which at present appear to be preferable, it will be readily understood, by those skilled in the art, that many changes may be adopted without departing from the essential spirit of my invention. 1 desire, therefore, that the appended claims be accorded the broadest construction consistent with their language.

I claim as my invention:

1. A ventilated dynamo-electric machine comprising, in combination with the machine, means for providing a closed recirculating path for a recirculated gaseous cooling-medium for cooling themachine, a cooler of a-type using a liquid cooling-medium and conduit-means for said liquid cooling-medium separate from the gaseous cooling-medium, said cooler being disposed above a vital part of the machine and in the path of said recirculated gaseous cooling-medium, and baffle-means disposed underneath said cooler and including an inclined system of louvers comprising vertically spaced and overlapping slats, said inclined system of louvers being disposed in the path of said recirculated gaseous cooling-medium in a position below said cooler in such manner as to permit a moderately free passage of the gaseous cooling-medium in a substantially horizontal direction through the louvers, while draining any downwardly dropping leakage-liquid from the cooler horizontally away from the vital parts of the machine.

2. In combination, a dynamo-electric machine having a gaseous cooling-medium, an enclosure therefor, and a recirculating and cooling means for said gaseous coolingemedium, said recirculating and cooling means including a cooler having a liquid cooling-medium therein, said cooler being located in such elevated position adjacent to the machine that any leakage of liquid therefrom would tend to flow into a vital part of the machine, said recirculating and cooling means causing the gaseous cooling-medium to leave the machine and then pass over said cooler and subsequently return to the machine, said recirculating and cooling means also including a system of vertically spaced, louvered draining-bafiies disposed under the cooler in such manner as to permit a moderately free passage of the gaseous cooling-medium in an approximately horizontal direction away from the machine and thence upwardly into the cooler after passing through said bafiles, while draining any downwardly dropping leakage-liquid from the cooler horizontally away from possible leakage into the vital parts of the machine.

3. In combination, a dynamo-electric machine having a gaseous cooling-medium, an enclosure therefor, and a recirculating and cooling means for said gaseous cooling-medium, said recirculating and cooling means including a. cooler having a liquid cooling-medium therein, said cooler being located over the machine, said recirculating and cooling means causing the gaseous coolingmedium to leave the machine and then pass over said cooler and subsequently return to the machine, said recirculating'and cooling means also including a system of vertically spaced, louvered

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