US2562930A

US2562930A - Dry powder fire-extinguishing medium discharge and directing apparatus

Info

Publication number: US2562930A
Application number: US99373A
Authority: US
Inventors: Mapes Doniel
Original assignee: Specialties Development Corp
Current assignee: Specialties Development Corp
Priority date: 1949-06-09
Filing date: 1949-06-09
Publication date: 1951-08-07
Anticipated expiration: 1968-08-07

Description

Aug. 7, 1951 D. MAPES 2, 6

DRY POWDER FIRE EXTINGUISHING MEDIUM DISCHARGE AND DIRECTING APPARATUS Filed June 9, 1949 INVENTOR. Daniel Ma oes BY ATTORNEY Patented Aug. 7, 1951 DRY POWDER FIRE-EXTINGUISHING I MEDIUM DISCHARGE AND DIRECT- ING APPARATUS D'niei Mapes, West Caldwell, N. L'assignor to specialties Development Corporation, Belleville, N. 1., a corporation of New Jersey Application June 9, 1949,- Serial No. 99,373 13 Claims; (Cl. 169-1) The present invention relates to fire extinguishing, and more particularly to improvements in apparatus for discharging and directing dry powder fire extinguishing medium.

Heretofore dry powders have been discharged from receptacles by establishing pressure in the receptacle by means of a fluid pressure medium and causing the pressure medium to expel the powder through a discharge nozzle. One of the difllculties in carrying out the foregoing has been that the powder was projected from the nozzle at a high velocity, thereby entraining a substantial volume of the laterally adjacent air. This has been highly objectionable and undesirable in practically all instances where powder has been so dispensed, particularly where the powder has been-utilized for extinguishing fires.

Where such powders have been used for extinguishing fires, it has been found that, if the nozzle is held close to the fire, considerable fanning of the fire due to the velocity of th stream and air entrainment thereby makes extinguishment difiicult, and, if the nozzle is held at a distance away from the fire to reduce tanning. the projected powder scatters to an extent whereby only a small portion thereof is effectively applied to the fire, thereby requiring wasteful discharge of a large amount of powder in' extinguishing the Accordinglvan object of the present invention is to provide dry powder fire extinguishinfgflapparatus adapted to produce a cloud of powder having a low velocity and a dense pattern.

Another object is to provide such apparatus which is adapted to produce a dense 'cloud of powder for application on fires of considerable area.

A further object is to provide such apparatus which is simple in construction and is economical to manufacture. ,l

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

In accordance with the invention, the foregoing objects are accomplished by projecting a stream of dry powder at a high velocity while shielding the stream from the laterally adjacent atmospheric air for a sufiicient distance to reduce the velocity of the stream to a value to prevent substantial entrainment of air, subjecting the stream to mixing action and causing portions thereof to diverge while shielded to further reduce its velocity and to produce a cloud of powder having a substantially uniform dense pattern, and directing the cloud on a fire.

The apparatus for accomplishing the foregoing generally comprises a tubular shield member of suitable shape having an inlet at one end through which the powder is projected and having an outlet at the other end from which the cloud of powder is directed, and a fiow diverging bafiie member in the shield member intermediate the inlet and outlet. t

A preferred embodiment of the invention has been chosen for purposes of illustration and description, and is shown in the accompanying drawing, forming a part of the specification, wherein:

Figure l is a schematic view, partly'in section, illustrating apparatus in accordance with the invention.

Figure 2 is an enlarged longitudinal sectional view of a dry powder discharge directing shield embodying the present invention.

3-3 on Figure l. I

Figure 4 is a sectional view similar to Figure 3, illustrating the invention applied to a shield which is generally oval in cross-section.

Referring more particularly to Figure 1 of the drawing, there is shown dry powder discharging and directing apparatus generally comprising a receptacle l for storing dry powder, a tube 2 ex-= tending from the lower interior portion of the receptacle to the upper exterior portion of the receptacle, which tube serves to conduct the powder from the receptacle, conduit means, such as a hose 3 having one end connected to the upper end of the tube and having its other end connected to powder dispensing and directing apparatus, such as a shield or horn 4, and a cartridge 5 for storing a pressure medium adapted to be released upon operation of a valve 6 to produce a pressure head H above the powder which serves to force the powder out of the receptacle by -way of the tube 2.

The shield 4. as shown in Figures 2 and 3, comprises a tubular member it having an outlet opening l2 and an inlet end ll formed with an aperture ii, a nipple or nozzle It in the aperture l5 extending into the shield member at the inlet end thereof for directing a stream of dry powder through the shield, and a bafile member H in the shield member intermediate the outlet l2 and the inlet end ll.

The shield 1 may be flared outwardly or may be aseaeso 3 generally conical in shape, and, if desired may be cylindrical or of any other suitable shape for directing a cloud of powder.

As shown, the outlet l2 of the shield member is unobstructed and the length of the shield member is greater than the diameter of the outlet, whereby the shield member H is proportioned to shield the stream of powder from the laterally adjacent atmospheric air for a sumcient distance while the velocity of the stream is reduced.

The bafiie member ll may be spaced a sufficient distance from the inlet end ll of the shield to enable the velocity of the powder stream to be somewhat reduced before the stream is diverted. It has been found that excellent results are obtained by positioning the baille member closer, to the outlet opening I2 than to the inlet end, and

that the characteristics of the cloud of powdermay be varied by mounting the baflle member at different distances from the outlet opening.

The nozzle l6 has an unrestricted bore of an area approximately equal to the area of the passage of the hose 3, whereby powder may be introduced into the shield at a high rate but without increasing the velocity of its flow. Preferably,

the area of the outlet 12 of the shield is much greater than the area of the bore of the nozzle, for example, about twenty-five times greater, thereby allowing for considerable expansion of the powder stream within the shield.

The baille member H in accordance with the illustrative embodiment comprises a conical body IS, the apex of which faces the nozzle l6, and legs 20 or the like extending radially outwardly from the body at the downstream or base end of the body. The ends of the legs are connected to the shield member II in a suitable manner, for example, by forming projections 2| thereon which extend into apertures 22 formed in the shield member. The legs preferably are of streamline configuration, as shown in Figure 2, to offer a minimum resistance to the flow of powder .through the shield. It will be appreciated that the shape of the conical body may be varied to vary the manner in which the powder stream is caused to diverge.

In accordance with one of the features of the present invention, the cone-shaped body of the .baflle member is coaxially positioned in the shield member with respect to the longitudinal axes thereof, whereby the body serves to diverge the central portion of the stream outwardly. The effective flow diverting cross-sectional area of the baille member body is such that between about 20% and 40% of the cross-sectional area of the shield member is obstructed at the section where 'the base of the baifle member is located, thereby nozzle, turbulence is imparted to the stream of effect a further reduction in its velocity, while the shield tends to fill somewhat with powder and thereby produces a denser cloud of powder issuing from the outlet of the shield. It is believed that portions of the outwardly diverted stream strike the inner wall of the shield intermediate the baffle member and the outlet opening in a manner to cause such portions of the stream to rebound and be redirected inwardly to prevent undue scattering and thereby produce a dense cloud.

Numerous tests indicated that this dense slow moving cloud of powder is highly effective in economical shield. The bafile fills the shield to rapidly extinguishing gasoline fires, standard tub fires having been knocked out completely in as little time as one second. Also, the cloud produced by the shield is particularly effective when the fire is fanned by wind, because the cloud is not dispersed by the wind and maintains its dense pattern.

In Figure 4, the present invention is illustrated as being applied to a shield H! which is generally oval in cross-section. To accomplish this, the baiile member H has an oval conical body 19' of the same general cross-sectional shape as the tubular shield member II and is arranged and secured therein by means of legs 20' to provide an annular passage of oval shape and an area between 20% and 40% less than the cross-sectional area of the tubular member I l at the base ofthe body member 19'. s

This modified shield produces a dense cloud of powder comparable to the cloud described in connection with Figures 1 and 2.

In operation, when utilizing either the round or oval shield, dry powder under the influence of a gaseous pressure medium and traveling at a relatively high velocity is delivered to the nozzle I6 by the hose 3. The nozzle projects a stream of powder into the shield along the longitudinal axis thereof, whereby the stream is shielded from the laterally adjacent atmospheric air for a sufficient distance while reducing the velocity of the stream to prevent substantial entrainment of air. The center portion of the stream is deflected outwardly by the baflle member and is caused to diverge while shielded to further reduce the velocity of the stream and to produce a cloud of powder having a dense pattern. This cloud is then directed on the fire.

In practicing the present invention, a 20 pound charge of powder in the receptacle was subjected,

to a pressure of about 200 pounds per square inch and was discharged through a nozzle having a circular orifice of about .4 inch in diameter into a shield 4 having a length of about inches and a circular opening of about'2 inches in diameter,

the shield being provided with a baffle H.

The stream of powder projected from the and passed through the nozzle bore at a rate of about 1.75 pounds per second. The cloud of powder issuing from the shield outlet l2 had a velocity of about 10 feet per second. The major portion of the cloud was deposited over an area of about 20 square feet, the center of the area being at a distance of about feet from the shield outlet.

It was found that for every pounds of powder directed from the shield about 15 pounds were deposited in the area, that isapproximately of the powder fell within this area, the average weight of powder for each square foot of area being about .75 pound. Thus at a discharge rate of about 1.75 pounds per second, about .065 pound per square foot can be efiectively applied per second. This high density rate coverage enables fires to be extinguished very rapidly, for example, in several seconds, while the operator stands at .a comfortable and safe distance from the fire.

From the foregoing description, it will be seen that the present invention provides improved apparatus for discharging and directing dry powder fire extinguishing medium. The cloud of powder is highly effective to rapidly extin uish fires and is produced by a simple, practical and provide a denser cloud of powder, increases turbulen'ce to reduce velocity, and gives the cloud of powder a better pattern.

As various changes may be made in the form, construction and arrangement of the parts herein, without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is'to be understood that all matter herein is to be interpreted as illustrative and not in any limiting sense.

I claim:

1. Dry powder discharge directing apparatus comprising a tubular shield member having an inlet at one end and an outlet at the other end, said shield member having a minimum crosssectional area substantially greater than the cross-sectional area of said inlet to provide for the expansion of the powder stream in said shield member, and a flow diverging bailie member in said shield member intermediate said inlet and said outlet, said baflle member obstructing between about 20% and 40% of the cross-sectional area of said shield member at said bame member,

said baiile member being spaced from the inner wall of said shield member to provide an annular passage having an area of between about 60% and 80% of the cross-sectional area of said shield member at said baille member.

2. Dry powder discharge directing apparatus comprising a tubular shield member having an inlet at one end and an outlet at the other end, said shield member having a minimum crosssectional area substantially greater than the cross-sectional area of said inlet to provide for.

the expansion of the powder stream in said shield member, and an imperforate conical flow diverging baflie member in said shield member intermediate said inlet and said outlet, said bafile member being spaced from the inner wall of said shield member to provide an annular passage.

3. Dry powder discharge directing apparatus comprising a tubular shield member having an unrestricted powder inlet at one end and having an unobstructed discharge outlet at the other end, said shield member having a minimum crosssectional area substantially greater than the cross-sectional area of said inlet to provide for the expansion of the powder stream in said shield member, and a flow diverging 'baille member coaxially positioned in said shield member with respect to the longitudinal axes thereof intermediate said inlet and said outlet but closer to said outlet, said baflie member being spaced from the inner wall of said shield member to provide an annular passage.

4. Dry powder discharge directing apparatus comprising a tubular shield member having an unrestricted powder inlet at one end and having an unobstructed discharge outlet at the other end, said member being flared outwardly in the direction from the inlet end to the outlet end and being of a length greater than its maximum internal cross-sectional dimension, said shield member having a minimum cross-sectional area substantially greater than the cross-sectional area of said inlet to provide for the expansion of the powder stream in said shield member, and a flow diverging baflle member coaxially positioned in said shield member with respect to the longitudinal axes thereof intermediate said inlet and said outlet but closer to said outlet, said baflle member being spaced from the inner wall of said shield member to provide an annular passage.

5. Dry powder discharge directing apparatus comprising a tubular shield member having an unrestricted powder inlet at one end and having an unobstructed discharge outlet at the other end, said member being flared outwardly in the direction from the inlet end to the outlet end and being of a length greater than its maximum internal cross-sectional dimension, said shield member having a minimum cross-sectional area substantially greater than the cross-sectional area of said inlet to provide for the expansion of the powder stream in said shield member, and a flow diverging baflle member coaxially positioned in said shield member with respect to the longitudinal axes thereof intermediate said inlet and said outlet but closer to said outlet, said bailie member having a substantially conical body,

the apex of which faces said inlet, and having outwardly extending legs for securement to said shield member.

6. Dry powder discharge directing apparatus comprising a tubular shield member having an unrestricted powder inlet at one end and having an unobstructed discharge outlet at the other end, said member being flared outwardly in the direction from the inlet end to the outlet end and being of a length greater than its maximum internal cross-sectional dimension, said shield member having a minimum cross-sectional area substantially greater than the cross-sectional area of said inlet to provide for the expansion of the powder stream in said shield member, and a how diverging baille member coaxially positioned in said shield member with respect to the longitudinal axes thereof intermediate said inlet and said outlet but closer to said outlet, said baflle member having a substantially conical body, the apex of which faces said inlet, and having outwardly extending legs for securement to said shield member, said baflie member obstructing between about 20% and 40% of the cross-sectional area of said shield member.

'1. Dry powder discharge directing apparatus comprising a tubular shield member having a powder inlet at one end and having a discharge outlet at the other end, said shield member having a minimum cross-sectional area substantially greater than the cross-sectional area of said inlet substantially conical body, the apex of which faces said inlet.

8. Dry powder discharge directing apparatus comprising a tubular shield member having a powder inlet at one end and having a discharge outlet at the other end, said member being substantially circular in cross-section, said shield member having a minimum cross-sectional area substantially greater than the cross-sectional area of said inlet to provide for the expansion of the powder stream in said shield member, and a flow diverging baille member coaxially positioned in said shield member with respect to the lo itudinal axes thereof intermediate said inlet and said outlet having a substantir 1y conical body circular in cross-section, the apex of which faces said inlet.

9. Dry powder discharge directing apparatus comprising a tubular shield member having a powder inlet at one end and having a discharge outlet at the other end, said member being substantiallv oval in cross-section, said shield member having a minimum cross-sectional area substantially greater than the cross-sectional area powder stream in said shield member, and a iiow diverging baiiie member coaxially positioned in said shield member with respect to the 1ongitudinal axes thereof intermediate said inlet and said outlet having a substantially conical body oval in cross-section, the apex of which'faces said inlet.

10. Dry powder discharge directing apparatus comprising a tubular shield member having an inlet end and an outlet end formed with an opening, and a nozzle at said inlet end having an unrestricted opening positioned to direct a stream a stream of powder from said inlet end to said outlet end opening, and conduit means connected to the other end of said nozzle, said nozzle and said conduit means having passageways of substantially equa1 areas extending therethrough;

said shield member having a minimum cross-sectional area substantially greater than the crosssectional area of said nozzle opening to provide for the expansion-of the powder stream in said sheld member.

12. Dry powder discharge directing apparatus comprising a tubular shield member having an inlet end and an outlet end formed with an opening, and a nozzle at said. inlet end having an unrestricted opening positioned to direct a stream of powder from said inlet end to said outlet end opening, the ratio of the area of said shield member outlet opening and said nozzle opening being on the order of about 25 to 1, said shield member having a minimum cross-sectional area substantially greater than the cross-sectional area of said nozzle opening to provide for the expansion of the powder stream in said shield member.

13. Dry powder discharge directing apparatus comprising a tubular shield member having an inlet end and an outlet end formed with an opening, a nozzle at said inlet end having an unrestricted opening at one end positioned to direct a stream of powder from said inlet end to said outlet end opening, and conduit means connected to the other end of said nozzle, said nozzle and said conduit means having passageways of substantially equal areas extending therethrough, the ratio of -the area of said shield member outlet opening and said nozzle passageway being on the order of about 25 to 1, said shield member having a minimum cross-sectional area substan tially greater than the cross-sectional area of said nozzle opening toprovide for the expansion of the powder stream in said shield member.

' I DANIEL MAPES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PA'I EN'I S