US2450537A

US2450537A - Apparatus for extinguishing fires

Info

Publication number: US2450537A
Application number: US611009A
Authority: US
Inventors: Hilding V Williamson
Original assignee: Cardox Corp
Current assignee: Cardox Corp
Priority date: 1945-08-17
Filing date: 1945-08-17
Publication date: 1948-10-05
Anticipated expiration: 1965-10-05

Description

Oct. 5, 1948. H. v WILLIAMSON v APPARATUS FOR EXTINGUISHING FIRES 2 Shegts-$heet 1 mRNEY Filed Aug. 17, 1945 Oct. 5, 1948. H. v. WILLIAMSON 2,450,537

APPARATUS FOR EXTINGUISHING FIRES Filed Aug. 17, 1945 2 shee s-sham 2 INVENTOR.

Patented Oct. 1948 meas'rus ron ex'rmomsnmc mas Hiidlng V. Williamson. Chicago. IlL, auignor to Cardox Corporation, Chicago, 111.. a corporation of Illinois Application August 1'7, 1945, Serial No. 611,009

11 Claims.

This invention relates to apparatus for extinguishing fires, and deals more particularly with inerting the atmosphere surrounding the fires to effect such extinguishments.

This use of liquid carbon dioxide to put out fires has had recent wide spread development. The equipment includes a container for the carbon dioxide and a conduit extending from this container to the place of use. tical to store the liquid carbon dioxide under refrigerated conditions because of the correspondingly reduced vapor pressure. This makes it possible to utilize containers having walls.

When discharging liquid'carbon dioxide from a nozzle to atmospheric pressure, the carbon dioxide is discharged in the form of carbon dioxide snow and vapor, the temperature of which'is approximately -i F. This extreme cold causes water vapor to be condensed from the surrounding and'entrained air. This condensed water vapor appears in the form of a dense fog of water ice particles and water droplets, which reduce visibility to nearly zero. It the discharge takes place outdoors train a direct application type nozzle, the fog produced, although it reduces visibility, is not too much of a handicap since it readily disperses. If the discharge takes place indoors from a total flooding nozzle, the fog does not disperse readily and visibility remains reduced. If the discharge takes place as the result of the automatic or manual operation of a fixed fire extinguishing system with the usual alarm.

period preceding the discharge, the lack of visibility is not too detrimental although better visi- It is most pracrelatively thin bility would be advantageous. However, if the discharge is from a playpipe or nozzle from a mobile fire fighting, apparatus, the lack of visibility is critical.

For instance, when a mobile fire fighting unit is used to totally flood a room in a building with carbon dioxide in order to extinguish a flre, the exact location of the fire is not usually known and whether or not there are persons in the room is also not usually known. The visibility is usually initially bad, due to the smoke and other fumes, from the fire and ii the room is flooded with carbon dioxide from the usual discharge, ,the resulting low visibility makes it nearly impossible to see the location oi the fire, possible asphyxiated persons, and other objects.

The apparatus of this invention has been developed in order to reduce the above fogging difl'iculties and to get greater inerting benefits from a given amount of carbon dioxide. i i.

When carbon dioxide is discharged in the usual way from a storage tank directly to a place to be inerted, the resultant carbon dioxide snow is not effective in helping to create a flre extinguishing atmosphere until after it sublimes. It is important, therefore, that this snow be converted to vapor as soon as possible, and that all or the carbon dioxide vapor be heated so'that it occupies a greater volume, that is, is less dense, and will inert more space.

It is an object of the invention to elevate the temperature of the carbon dioxide being delivered through a conduit from a container. so that the carbon dioxide discharging from the open end of the conduit will be at such a high temperature that it will not lower the temperature of the surrounding atmosphere below its dew point. In accordance with this feature of the invention, a heater is provided in the conduit line to elevate the temperature of the flowing carbon dioxide.

The heating of the carbon dioxide before it is discharged from the delivery conduit has the important effect of making sure that it is fully vaporized. It therefore occupies a greater volume in the space to be inerted and is more eflective in extinguishing the fire.

As a further feature of the invention, the flowing carbon dioxide is caused by a jet action to draw into the conduit, hot combustion gases to more rapidly increase the temperature of the flowing carbon dioxide. This is of additional benefit because the ,inerting effect of the carbon dioxide is supplemented by the products of com bustion since they give an increased volume and, hence, ability to inert a greater space.

Another feature of the invention is the provision of means for removing from the combustion gases the moisture therein as a product of combustion. This removal of this moisture, which would otherwise enter the space to beinerted, is important to maintain a low dew point in the space to be inerted.

Another feature of the invention involves the use of the flowing carbon dioxide to create a suction which will draw a fuel mixture into a combustion space so that heat will be generated for elevating the temperature of the flowing carbon dioxide.

A still further feature of the invention involves the use of a thermostat to control the delivery of combustible fuel which is used to heat the flowing carbon dioxide.

Other features oi the invention will appear from the following description when considered in connection with the accompanying drawings.

tion

Figure 2 is a vertical section through the heater of the invention,

Figure 8 is a vertical section through a modified heater contemplated by the invention, and

Figure 4 is a vertical section through a different type of fuel mixer which may be utilized in practicing the invention.

Referring mat to Figure 1,-this shows at 8 a container for the liquid carbon dioxide. As is here shown, this containeris within a truck I for mobile purposes, but the container 8 may as well be stationarily mounted. Associated with the container 8 may be a refrigerating apparatus to maintain the carbon dioxide at a low temperature and at a corresponding vapor pressure, but the invention contemplates the possibility of using carbon dioxide from a container which is not refrigerated. The carbon dioxide is delivered to the place where it is to be used through a conduit 8 having a communication with the interior of the container 8. A valve 8 in the conduit 8 controls the delivery of carbon dioxide therethrough.

In the drawings, the carbon dioxide is shown delivered to the interior of a room- 9' within a building ill. The discharge end of the conduit 8 extends through the window I I so that the escaping carbon dioxide will pass into the room and inert the atmosphere therein. As here shown, the discharge end of conduit 8 is close to the floor and this has the advantage of delivering the carbon dioxide upon the floor so that it will rise and displace the smoke upwardly. This will resuit in greater visibility near the floor and will also inert the atmosphere upon the floor where the flre may be. However, in some cases, it may be desirable to direct the conduit 8 toward some other location, as the ceiling, if it is desired that better visibility be attained there.

As has been explained, if this carbon dioxide which is escaping into the room is delivered directly from the container 8 as has heretofore been the general practice, it will be so cold that it will lower the temperature of the air within the room below its dew point and the resulting condensed moisture from the air will create a fog. This fog may be so thick that it will be impossible for the operator to direct the escaping stream of carbon dioxide to the desired point, and moreover it may portion thereof. Within the heater II the conduit is broken and the ends are shaped to form an aspirator Jet. This includes the formation of a nozzle l8 at the end of the conduit leading from the container 8 and the formation of a widened Venturi portion 20 at the end of the conduit leading to the discharge end. Inasmuch as there will be a marked expansion of the carbon dioxide ai'ter it escapes from the nozzle l8, it is preferable that the portion of the conduit 8 between the heater i8 and the discharge end of the conduit be of larger diameter.

When the valve 8 is turned on, the carbon dioxide directed through the nozzle l8 will have an aspirator effect within the Venturi 20 to withdraw the contents from the space within the heater. As a feature of the invention, combustible fuel is burned within this space and the combustion gases are drawn into the Venturi 20 to mix with the carbon dioxide vapors. The heat from these combustion gases raises the temperature of the carbon dioxide so that when the vapors escape from the open end of the conduit 8 beyond the heater i5, they are at a sufficiently high temperature that they will not lower the temperature of the air .within the room 8 below the dew point. As a consequence, there will be no fog formed with the room 8 which will obstruct visibility. Moreover, the intermingling with these hot combustion gases will make sure that all the carbon dioxide is vaporized.

To supply fuel to the interior of the heater II, a duct 2| extends therein through the bottom of the heater. At the upper end of this duct 2| is a cap 22 spaced from the end of the duct and it is of concave under formation to direct the fuel downwardly. This downwardly directed fuel impinges upon a ceramic block 23 supported on the duct 2i and having a circular groove 24 therein. This groove serves to redirect the burning fuel and gases upwardly into the combustion space.

To ignite this fuel, any suitable means may be employed, but as here shown, this may be accomplished by forming a port 25 through the side wall of the heater through which a match may be inserted. This match preferably should be made be impossible for a searcher to find persons who i may have become asphyxi-ated within the room.

The gas delivered from the open end of conduit 8 may be raised to such a high temperature that it will not lower the air temperature below the dew point, by means of a heater, generally indicated at ll. As is shown in detail in Figure 2, the heater I! includes an outer shell i8 which, preferably, will be of metal. Within shell i8 are layers ll of insulating material and innermost thereof is a lining l8 preferably of a ceramic material. The shell i8 is preferably of cylindrical shape in cross section and has a flat bottom and a dome-shaped top, but it is by no means required that the heater have this particular formation.

As is shown in Figure 2, the conduit 8 passes through the heater ll, preferably, at the upper of a burning material, similar to that in sparklers, so that it will not be blown out by the strong draft through the burner. The match preferably should have a handle part which will plug hole 28 to prevent entrance of air which might blow out the match or dilute the fuel mixture within the burner.-

To the lower end of the duct 2| is affixed a charge forming device which is here shown to be a carburetor 28. This includes a float chamber 21 which receives liquid fuel from a receptacle 28 carried by the heater I8 in any suitable manner. A float 28 within the chamber 21 maintains a constant liquid level within this chamber.

The carburetor 26 also includes a duct 3| attached at its upper portion to the lower part of duct 2!, and the lower portion of duct 8! has an extension 82 through which air may-be delivered tothe duct 3|. A Jet 38 extends from the float chamber 21 into the ductil to deliver the liquid fuel into admixture with the air flowing upwardit? through the duct 3|.

The suction eflect created by the nozzle l8 and Venturi 20 draws air into the inlet 82 and upwardly through the ducts 8i and 2| and draws with it liquid fuel from the jet 88. The combustible mixture which is so formed burns within the combustion space within the heater l8 and, as has been stated, the combustion gases which are so formed are drawn into the Venturi 20 to mix with the carbon dioxide vapor and elevate its temperature. In addition, the high temperature within the combustion space heats the nozzle l9 andVenturi 20 so that the carbon dioxide vapor is heated by conduction through these walls.

A valve 36. here shown to be of the butterfly type, is located in the duct H to regulate the flow of the combustible mixture into the combustion space in the heater. This valve u may be manipulated manually, but the invention contemplates its movement in response to a thermostat, shown at tit, in duit a from the heater iii. The thermostat I is oi the type which contains a fluid which expands under an increase in temperature and this expanding fluid is conducted through a pipe 36 to a bellows s'i carried by an arm 38 on the exterior of duct 86. The upper movable end of bellows 31 is pivoted to an arm 39 which is connected to the valve shaft of the butterfly valve as.

During operation, the thermostat 38 will serve to maintain a constant temperature of the escaping carbon dioxide vapor because if it becomes too hot, the thermostat 35 will operate to close the valve as and reduce the amount of fuel supplied to the heater. If, on the other hand, the temperature of the escaping vapor from heater is drops too low, the thermostat as will function to open the valve is and cause a greater combustion within the chamber of heater it.

In the modification shown in Figure 3, the carbon dioxide is heated within the heater before it reaches the nozzle. In this embodiment, the heater includes a shell Mi, the interior wall of which is insulated in the same manner that shell is is internally insulated. This shell to, however, is formed with a lateral extension ti which serves as a flue portion and which terminates in a Venturi portion as. The nozzle 83 is directed into the Venturi t2 and the conduit from the supply tank to this nozzle is coiled within the interior of the heater, as shown at M and it. The coils to are subiected to the direct flame of the burnng fuel and the coils to are exposed to the combustion gases by being located in the flue portion ii of the shell til.

As the incoming carbon dioxide initially passes through the coils as in the flue portion ll of shell 80, and as this carbondloxide is cold, it will cool the combustion gases and cause condensation of the moisture which is in the combustion gas'as a product of combustion. This moisture condensed from the combustion gases drops to the lower part of the extension ii of the heater shell, where it collects and is conducted downwardly through a pipe 68 to a valve controlled trap. M.

The moisture which is i'ormed as a product of combust on is therefore removed from the gases before they enter the Venturi 42 for delivery to the d scharge end 01' the conduit 8. This is of importance because this removes moisture from the system which would tend to elevate the dew point of the air w thin the room 9. In passing through the coils M. the carbon diox de is heated by conduct on of heat through the coil walls.

The heater shown in Figure 3 is sup lied w th fuel in the same manner that the heater of F gure 2 is sup lied. Th s includes the duct 48 which extends upwardly into the combust on space and wh ch corresponds to the duct 2! in Figure 2.

Figure 4 shows a d fferent type of device for supplying a combustible mixture to the combustion space. The duct 50 there shown correthe outlet portion of consponds to either the duct 2i 0! Figure 2, or the duct I! of Figure 3, since this charge iorming device may be used with either heater. To the lower end of duct 50 is attached a duct 5| which is of T-tormatlon so that it has the inlet portions 52 and 53. The branch duct or is intended to deliver air to the upwardly rising duct 5i and a disc 54 interposed therein has an orifice therethrough of a size to determine the amount of air which will be supplied. The branch duct 53 is intended to be connected to a source of gaseous fuel, as for example, ordinary illuminating gas. Interposed in branch at is a disc be having an orifice therethrough of a size to determine the volume of flowing gas. A gas supply line be is connected to the branch duct 58 through a pressure reducing valve o'i which preferably atmospheric pressure.

By appropriately regulating the pressure reducing valve ti and employing discs tit and as having the proper sized orifices therethrough, a mixture of the correct proportions for combustion will be supplied upwardly through the ducts be and Bi for delivery into the combustion space. The voiurne of this mixture which is supplied will be limited by a valve at corresponding to valve 321 and preferably operated by a bellows as under thermostat control, as has been described. If desired, the heater may be a built-in part of the fire truck so that it need not be positioned apart from the truck when it is to be put in use as shown in Figure 1. In the case of a nonmobile fire extinguishing equipment, the heater may, in similar manner, be either movable as shown, or fixed in position. In operation, the valve ii is first turned on so as to create a suction todraw fuel into the combustion space of the heater and then the fuel mixture in this space is ignited.

What I claim is:

1. Apparatus for extinguishing fires comprisa container for storing liquid carbon dioxide, a conduit for conducting the carbon dioxide from the container to a place of use, means providing a closed combustion space, and means for deliverin fuel to said space for combustion therein, said conduit having a portion thereof passing through said combustion space and including an aspirator jet within the combustion space to draw the products of combustion into the conduit to elevate the temperature of the flowing carbon dioxide.

2. Apparatus for extinguishing fires comprising a container for storing liquid carbon dioxide, a conduit for conducting the carbon dioxide from the container to a place of use, a shell having thermally insulated walls, means for delivering fuel to the lower part of the shell for combustion therein. said conduit having a portion thereof passing through the upper part of the combustion space and including an aspirator jet within the combustion space to draw the products of combustion into the conduit to elevate the temperature of the flowing carbon dioxide.

3. Apparatus for extinguishing fires comprising a container for storing liquid carbon dioxide. a conduit for conducting the carbon dioxide from the container to a place of use, a shell having thermally insulated walls, means for delivering fuel to the lower part of the shell for combustion therein, said conduit having a portion thereof passing through the upper part of the combustion space and including an aspirator jet within the combustion space to. draw the products of combustion into the conduit to elevate the temperature of the flowing carbon dioxide, said fuel delivreduces the gas to ering means being subjected to atmospheric pressure whereby the aspirator jet serves to draw the fuel into the shell.

4. Apparatus for extinguishing tires comprising a container for storing liquid carbon dioxide, a conduit for conducting the carbcn dioxide from the container to a place of use, a shell having thermally insulated walls, and providing a combustion space therein a duct entering into said combustion space and having connected to its exterior an air and fuei'mixing device, said conduit having a portion thereoi' passing through the combustion space and including an aspirator jet within the combustion space to draw the products of combustion into the conduit to elevate the temperature oi the flowing carbon dioxide, said aspirator Jet also serving to draw said mixture irom said device and into the combustion chamber.

5. Apparatus for extinguishin fires comprising a container for storing liquid carbon dioxide, a conduit for conducting the carbon dioxide from the container to a place of use, means providing a closed combustion space, a duct entering into said combustion space for the delivery of fuel to said space for combustion therein, said conduit having a portion thereof passing through the combustion space and including an aspirator jet within the combustion space to draw the products of combustion into the conduit to elevate the temperature of the flowingv carbon dioxide, said aspiextending into the interior of said shell, means ior deliverin a combustible iuel to said duct for combustion inside the shell, and a valve in said duct tor regulating the rate of flow 01 fuel through the duct.

9. A heater for elevating the temperature or carbon dioxide being delivered through a conduit @rom a carbon dioxide container to a place of use, said heater comprising a shell having insulated walls, an aspirator jet therein including an inlet nozzle and an outlet Venturl for connection into the conduit with the nozzle disposed to receive carbon dioxide from the container, a duct extending into the interior or said shell, means for delivering a combustible fuel to said duct for combustion inside the shell, a valve in said duct, and

rator Jet also serving to draw i'uel through said duct into said space, and a valve in said duct to regulate the flow oi iuelto said combustion space.

6. Apparatus for extinguishing fires comprising a container for storing liquid carbon dioxide, a conduit for conducting the carbon dioxide from the container to a place of use, means providing a closed combustion space, a duct entering into said combustion space for the delivery of fuel to said space for. combustion therein, said conduit having a portion thereof passing through the combustion space and includin an asplrator iet within the combustion space to draw the products of combustion into the conduit to elevate the tem..

perature of the flowing carbon dioxide, said aspiratcr jet also serving to draw fuel through said duct into said space, a valve in said duct to regulate the flow oi fuel to said space, and a thermostat in the outlet of said conduit from the heater and having an operative connection to said valve.

7. A heater for elevating the temperature of carbon dioxide being delivered through a conduit from a carbon dioxide container to a place oi use, said. heater comprising a shell having insulated walls, an aspirator jet therein including an inlet nozzle and an outlet Venturi for connection into the conduit with the nozzle disposed to receive carbon dioxide irom the container, a duct extending into the interior of said shell, and means for delivering a combustible iuel to said duct for combustion inside the shell.

8. A heater for elevating the temperature of carbon dioxide being delivered through a conduit from a carbon dioxide container to a place of use, said heater comprising a shell having insu. lated walls, an aspirator Jet therein including an inlet nozzle and an outlet Venturli'or connection into the conduit with the nozzle disposed to receive carbon dioxide from the container, a duct a thermostat exposed to the delivery through the Venturi and having a connection to the valve to control its position.

10. A heater for elevating the temperature of carbon dioxide being delivered through a conduit from a carbon dioxide container to a place of use, said heater comprising a shell having insulated walls, an aspirator Jet in communication with the interiors! the shell and including an inlet nozzle and an outlet Venturi, a pipe within said shell and connected at one end to-said nozzle, the other end of the pipe being connectable to receive carbon dioxide from the container and the Venturl being connectlble to deliver the carbon dioxide to the place of use, a duct extending into the interior of saidshell ztcr delivering a combustible fuel to the interior of the shell, the entrance portion or said pipe being disposed out of the flame area from the duct but in the path oi the combustion gases to cause condensation of the moisture in said gases, and means for removing the condensed moisture from the shell.

11. A heater dor elevating the temperature oi. carbon dioxide being delivered through a conduit from a carbon dioxide container to a place oi use, said heater comprising a shell having insulated walls, an aspirator jet in communication with the interior of the shell and including an inlet nozzle and an outlet Venturi, a pipe within said shell and connected at one end to said nozzle, the other end of the pipe being connectavble to receive carbon F Number dioxide from the container and the Venturi being connectible to deliver the carbon dioxide to the place of use, a duct extending into the interior of said shell for delivering a combustible fuel to the interior of the shell, the entrance portion 0d! said pipe being disposed out of the flame area from the duct but in the path of the combustion gases to cause condensation of the moisture in said gases, and a liquid trap to receive the condensed moisture and remove it from the shell.

HILDING V. WILLIAMSON.

I file of this patent:

UNITED STATES PATENTS Name Date Connelly "Dec. 7, 1875 Rew June 25, 1389 Weidig Sept, 12, 1893 Osborne Oct. 15, 1908