US2375297A

US2375297A - Apparatus for extinguishing fires

Info

Publication number: US2375297A
Application number: US406450A
Authority: US
Inventors: Howard G Freeman
Original assignee: Rockwood Sprinkler Co
Current assignee: Rockwood Sprinkler Co
Priority date: 1941-08-12
Filing date: 1941-08-12
Publication date: 1945-05-08
Anticipated expiration: 1962-05-08

Description

'May 8, 1945!; H. G. FREEMAN 2,375,297

' 'Y APPARATUS FOR EXTINGUISHIRG FIRES Filed Aug. 1:2, 1941 Patented May 8, 1945 g Howard G. Freeman, WoroestenMass., assigner to .Ruck-wood Sprinkler Company, Worcester, Massga corporation of Massachusetts Application August 12, 194 1,'SeralNo. l406,450

(ci. 16s- 4i Claims.

The `preset-1t Ainvention relates toapparatus for extinguishing fires, and-:more 1particularly Vfor extinduishi-ng oil fires occurring in-vessels such as transformerscpen quenching vats, and the like.

The extinguishment of fires under'such circumstances has presen-ted a number of diflicult problems. In the case of a transformer, for example, the lire often follows a Short-circuit, the heat of which causes a hole to be'fcrmed in Athe `too of the transformer by rupturing, cracking, or

even melting `the metal. Or an explosion vmay occur. which'blows oif the manhole cover. `In

any such case, the conditions are favorable for ignition l*of the oil vapors dwhich rush out 'through the opening. Burning oil may rise over 'the top and run down the sidewalls, thus contributing to the difliculties by maintaining the contents of the transformer in a heated condition. Such burning oil prevents effective action byiire-i'lght- L ing crews and also endangers adjoining struc tures. l j

According to the present'invention, water in the form of line sprays or mists is directed across the top of the vessel, but yout of contact with the contents thereof, and also in a .vertical direction to envelop the flaming oil which runsf down-the wal-ls. The mist or .spray in finely divided form lowers, the temperature of the vapors by the vaporization of the water. The entire structure is blanketed over the top and around the sides by a dense mist or fog, through which the radiant heat cannot penetrate, and thus adjoining structures are satisfactorily protected.

In the accompanying drawing, Fig. 1 is a diagrammatic plan view of a fire protection installation for a large transformer; Fig. 2 is an elevation of the installation shown in Fig. 1; Fig. 3 is a sectional detail view of the preferred form of nozzle; and Fig. 4 is a bottom plan view of the nozzle shown in Fig. 3.

As shown in Fig. 2, a transformer 6 is mounted on conventional supports 8 on a base I0. The

transformer is protected by a series of nozzlev heads indicated generally at I2 in Fig. 1, and'of a construction to be described later in detail. Around thevbase of the transformer is preferably arranged another series of somewhat similar heads I4. 'I'he heads I2 and I4 are connected Aby piping IB, through a supply pipe I8 and deluge valve 20, with a suitable source. y

Each of the nozzle heads I2 is arranged to deliver a ne fan-shaped spray across the top Aof the transformer, and also a vertical spray which envelopes the side walls thereof. As shown in Fig.

l, the horizontal spray from each nozzle 'head is of a patterrr-indicated'by the dotted lines. The patterns of the ,several horizontal spraysoverlap labove the transformer to produce adense mist or' fog directly over, the burning oil. .Als

ys'hovs'zn in Fig. 2 .the heads Q'I'Z are disposed only slightly above the top of thetransformer, where- 'by substantially no "Water is actually directed into the v'interior' of the transformer itself. The effectiveness of the installation depends on the ac- `tion ofthe fine particles of water on the ignited l vapors.

JI'henozzle heads I4, which are arranged around the. base of the transformer in a manner similar to the heaclsIZ, direct a horizontal spray against the base, to protect ragainst the .spread of burning oil from the base. y

,The main purpose of the vertical sprays is to heid the fire in .check and to forma 'blanket which protects reghting crews and also any structures in the neighborhood. The horizontal sprays which play across the top constitute the .chief D These sprays water are quickly vaporized, and because of the high latent heat of water, act to carry the heat away rapidly. When the rate of absorption of heat by Avaporization -is faster than the rate of oxidationA of the vapors, the fire is extinguished. Without the horizontal sprays, therefore, the vertical sprays would not be completely effective. On the other hand, the horizontally projected sprays should not in themselves be relied upon, since, if the re has attained some headway before the spray is turned on, the presence of the burning oil on the side walls might be sufficient to keep the contents of the transformer at a Vsuiciently high temperature to maintain the re.

Accordingly, the combination of the horizontally projected sprays with the vertically projected cof to the maximum extent. Introduction of any considerable quantity of Water into the liquid itself is not desirable, not only because of inefground.

2h .Ivi ti cient use of the water, but also because increase in volume of the contents of the vessel may contribute to the spilling over of burning oil.

The preferred form of nozzle head l2 is shown in Figs. 3 and 4. This head comprises a fitting 22, having coupling threads 24 for attachment to the piping. A thick disc forming a nozzle member 26 is threaded into the end of the head,

' and a. second nozzle member 28 is inserted in the bottom wall of the head. The nozzle members 26 and 2,8 are identical, and the description of one only Will suiiice. Each is provided with a, milledl internal slot 30 and an external slot 32 at right angles t0 the slot 30. The slotsare cut'approximately half Way through the disc so that they intersect to form a rectangular oriceishown at 34 in Fig. 4. The Water flows along the internal slot 30 toward the central orifice in streams indicated by the arrows in Fig. 3. The streams meet forcibly at rthe center of the slot, and the` Wateris broken upinto a ne mist or fog, which is projected `outwardly through the central orice, mainly in .a, plane perpendicular kto the inner slot.. From i. the nozzle 2E, the spray is projected in a horizontal plane. As viewed in Fig. 3, the pattern is relatively narrow, but as viewed from below, as shown in Fig. e, itfans out sufficiently to cover the top of the vessel, (see Fig. 1). The vertically projected sprays from the nozzles 28 are similar in shape, as indicated in Figs. 2 and 3, and are arranged so that the individual spray patterns overlap to vproduce, a dense fog blanket surrounding the .'transformer.

Although the vertical spray patterns in Fig. 2 donot indicate actual contact of the water with the side walls, it will be understood that a considerable volume of whatvmay be called drift fog moves intodirect contact with the names., Actual contact of all the vWater .with the walls is not necessary, and in fact is not desirable, since the surrounding blanket of ne water particles is most effective for preventing transmission of radiant heat tothe surroundings.

The heads I4 around the base preferably include the end nozzles 2B only, to direct horizontal sprays to act on burning oil which may have run down the side Walls and started to spread over the 2,375,297 if -I For the nozzle head shown in Figs. 3 and 4, other types of nozzles capable of producing a, projected fog may be substituted.

Although the invention has been described as employed in installations for transformer protection, it is equally suitable for other installations where oil iires in open vessels are likely to occur.

'For eitample, `rires in large quenching vats present substantially the same problems as in the case of transformers, and it has been found that the present invention is equally effective therewith.

Having described my invention, I claim: 1. Apparatus for extinguishing oil fires in vessels n comprisinga fram'eof piping surrounding the vessel, means for supplying Water to said piping, and a plurality of nozzle heads connected to said piping, veach head having a nozzle member to project a fanshaped fog substantially in a horizontal plane above the vessel, and a second nozzle member to direct a fan-shaped yfog in a generally vertical plane,y the fogs projected from the several ynozzles overlapping to cause the vessel to be sublstantially completely enveloped by fog.

vnozzles being disposed to project a finemist of .water substantially in a horizontal plane above the vessel, others of said nozzles being disposed to `4direct a ne mist of Water over the Walls of said vessel, and the remainder of said nozzles being disposed to direct a iine mist of Water over a sublstantial area surrounding the base of the vessel.

3. Apparatus for extinguishing fires in vessels containing highly flammable uids, comprising a frame of piping surrounding the vessel, means for supplying Water to said piping, and a plurality of nozzle heads connected to said piping, certain of said heads being disposed in the vicinity of the top .of l the vessel vto project a iine mist of water across the top and over the Walls of the vessel, and other heads being disposed adjacent the base of the vessel to envelop the base and' to blanket an area surrounding said base with a line mist of Water.

' HOWARD G. FREEMAN.