US2209264A - Method of and apparatus for discharging fire extinguishing mediums - Google Patents

Description

E. GEERTZ July 23, 1940.

METHOD OF AND APPARATUS FOR DISCHARGING- FIRE EXTINGUISHING MEDIUMS Filed April 27, 1958 gwucnton Z1 76 flail? 3 if P H Patented July 23, 1940 UNITED STATES PATENT OFFICE METHOD OF AND APPARATUS FOR DIS- CHARGING FIRE EXTINGUISHING LIE- DIUMS Eric Geertz, Aurora, 11].,

assignor to Cardox Cor- 17 Claims.

This invention relates to new and useful improvements in a method of and apparatus for employing carbon dioxide as a fire extinguishing medium.

Fire extinguishing systems which are intended to have available for use large quantities of carbon dioxide as an extinguishing medium store the carbon dioxide as a liquid in a bank or battery of cylinders. These cylinders are connected in parallel to a common 'header or header arrangement so that the carbon dioxide may be discharged as desired from the various cylinders. The temperature of the liquid carbon dioxide stored in the cylinders is permitted to vary in accordance with variations in the temperature of the surrounding atmosphere. The carbon dioxide is discharged from the tops of the several cylinders through the pipes of the system in the form of gas and is thus released at the location of the fire.

It is a well known fact that the discharge of carbon dioxide gas from the top of a container will cause vaporization of a like amount of liquid remaining in the container. This vaporization within the container effects refrigeration of the.

remaining liquid. If the discharge of gas from the top of the container is continued for a sufficient length of time to lower the temperature of the remaining liquid to the point at which solid carbon dioxide is formed, --'70 F., the remaining liquid will solidify and discharge must cease. Continuous discharge of approximately threequarters of the original quantity of liquid carbon dioxide will produce a temperature drop of the character referred to above so that the remaining one quarter will not be available for use.-

It has been determined that liquid carbon dioxide discharged at a sub-atmospheric temperature is much more effective and possesses many advantages over carbon dioxide discharged as a" gas from liquid stored at atmospheric temperature.

much higher percentage of yieldof snow when discharged to the atmosphere than will gas discharged at atmospheric temperature. Theoretically, gas released at 70 F. canproduce 29% snow, while-liquid released at 0 F. can produce 60% snow. Lower temperatures, of course, can produce even higher percentages of snow. It will be appreciated that this increased yield of snow will provide a heavier blanket over the For example, liquid carbon dioxide dis- T charged at from 0 F. to 50 F. will afford a the fire. The increased yield of snow also will provide greater mass which permits the discharge to be directed at the fire with greater velocity for penetrating rising air currents and projected greater distances. ,The lower temperature of the liquid carbon dioxide has a much greater cooling effect on the material being consumed by the fire and thereby is more effective in preventing re-fiash and will permit the fire fighters to more closely approach the fire.

It is the primary object'of this invention to provide a method of and apparatus for materially improving the total effectiveness of a quantity of carbon dioxide as a fire extinguishing medium when stored at atmospheric temperature and its 1 corresponding vapor pressure. 1

A further object of the invention is to provide an improved method of and apparatus for releasing carbon dioxide from one or more cylinders in which it is stored at atmospheric temgo perature for fire extinguishing purposes. t Other objects and advantages of the invention will be apparentxduring the course or the following description.

1n the accompanying drawing forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a diagrammatic vlew'oi' a fire extinguishing system embodying this invention, q.

and

Figure 2 is a similar view toFig. 1, but illustrates, a form of automatic control which has beein 'added to the system of Fig. 1.

In the drawing, wherein for the purpose of u illustration are shown the preferred embodiments of this invention, and particularly referring to Fig. 1, the reference character 5 designates the cylinders, or other containers, which are arranged in. a bank or battery in any desired 0 and' most suitable manner. These cylinders 5 are intended to be charged with liquid carbon dioxide. They are intended to form a part of and constitute a source of supply for a fire extinguishing system which affords protection for a anyand all types of articles, apparatus and enclosed spaces in connection with which a fire hazard may exist. The cylinders and the liquid carbon dioxide stored therein are directly subjected to changes in temperature of the surso rounding atmosphere and for that reason, the liquid carbon dioxide is stored at atmospheric temperature and its corresponding vapor pressure.

The tops of all of the cylinders 5 are suitably I connected with and in communication with a common header 6 which extends to and communicates with the interior of the casing 1 of a suitable three-way valve which further includes the rotatable plug 8 having formed therein the right angularly arranged passageway 9.

A second header I is connected with and placed in communication with the bottom portions of all of the cylinders by means of the couplings or attaching devices II. This header III also extends to and is placed in communication with the interior of the valve casing -'l.

A pressure indicating gauge I2 is placed in communication with the header 6 so thatthe person in charge of this fire extinguishing system may determine at a11times the vapor pressure of the carbon dioxide within the cylinders 5 and the header 6. A manually operable valve I3 is positioned within the header I0 between the battery of cylinders 5 and the valve 1. This manually operable valve I3 is employed for varying the rate of discharge through this header. In other words, this valve I3 may be manipulated to provide a maximum fiow through the header III, which will correspond with the flow through the header 6. or the valve I3 may be manipulated to restrict or retard the jflow I through the header III so that it will be less than the iiow through thefheader 6.

The reference character I4 is intended to 'designate diagrammatically any space, article, apparatus'or 'the like which requires fire protection. 'A common discharge line I5 extends from the valve I to the space, etc., I4, and discharges 'thereinto through the diagrammatically illustrated nozzle, or the like, I6.

The mode of operation of this fire extinguishing system will be described as follows:

When a hostile fire exists in space I4 which must be extinguished by means of this system, the operator or attendant adjuststhe plug 8 of the valve 1 intothe position shown in Fig.1, from a position, not shown, where the terminals of the passageway 9 are placed out of communication with any two of the lines 6, III and I5.

,This positioning "of the valve plug 8 brings about discharge of carbon dioxide gas through the header 6 and the discharge line I5 to the nozzle f I6 by means of which it is directed onto the fire.

Forevery pound of gas which is discharged from thecylinders through the header 6, a pound of carbon dioxide will evaporate in the cylinders? This evaporation of liquid carbon dioxide in the cylinders occurs as a result of absorption of heat from the liquid carbon dioxide remainingin the cylinders ,and from the walls of the cylinders. This absorption of heat from the remaining liquid carbon dioxide functions to temperature of the remaining liquid carbon dioxide by watching the pressure gauge I2 which will indicate the drop in vapor pressure within the cylinders. When the pressure drops to the desired value, which corresponds with the desired sub-atmospheric temperatureythe attend- The attendant of the "system, therefore, can determine the drop in ant will manipulate the piugJ of the valve 1 for moving the passage-way 3 out of communication with the header 6 and into a position, not illustrated, which will establish communication between the header I6 and the common discharge llne I5. In this position, the discharge of carbon dioxide gas from the tops of the cylinders 5 will cease and liquid carbon dioxide at the desired sub-atmospheric temperature will be discharged from the bottom portions of the cylinders through the header land the common least two different rates of discharge of the fire extinguishing medium. It frequently isvery desirable to rapidly discharge the medium to flood the area attacked by fire in order to promptly extinguish the flame and superficial burning and to then materially reduce the flow of the fire extinguishing medium in order to keep the percentage of medium high enough to extinguish glowing and smoldering. fire. The valve I3 is provided in the header III for this purpose. This valve may be adiustedand left in a. condition which will bring about a delay or reduction in the discharge of liquid carbon dioxide through the header It as compared to the rate desirable to operate the system in this manner, the valve 13 normally may be set to provide a maximum rate of discharge through the header III which will correspond with thevrate of disof discharge through the header 6. If it isnot charge through the header 6. At a proper time,

in the space I4, the valve I3 may be manipulated to retard the rate of flow of liquid carbon dioxide at a sub-atmospheric temperature through the header I0. V

The fire extinguishing system disclosed in Fig. 2 differs from the system disclosed in- .Fig. 1 only to 'the extent .thatan automatic valve is provided for the valve I in the first described system.

The system of Fig. 2, therefore, includes a suitable bank or battery of cylinders 5 with a common header 6 connected to the tops of all of the cylinders and a common header I0 connected to the bottom portions of all of the cylinduring the procedure of extinguishing the tire ders by means of the connection I I. The header 6 is provided with a pressure gauge I2 to enable an attendant to determine at all times the vapor pressure of the carbon dioxide stored in the cylinders 5. The headers 6 and I0 extend to branches I1 and I8, respectively, of a valve casing IS. A common discharge line 20, having a manual control valve 2|, extendsto the location which is to be protected from fire by the system.

The automatic control feature of the system includes a cylinder 22 which has positioned there-' in a suitably packed piston .23 which is loaded or normally urged in one direction by means oi the spring .24. The piston rod 26 projects outwardly of the cylinder 22 and has a rack 26 formed on its projecting portion. This .rack 26 meshes with the teeth of a pinion 2'! which is suitably secured to the stem 26 of the rotatable character disclosed in Fig. 1 and designated by the reference character 8. This is a conventional form of rotary plug valve construction and for that reason, need not be specifically illustrated with reference to its details. The valve plug in Fig. 2 is normally positioned so that its angular passage-way. will establish communication between the top header 6 and the common discharge line 20. The valve 2i, which may be manually controlled as illustrated or which may be automatically controlled in any desired manner, is manipulated when a hostile fire occurs to permit flow of carbon dioxide through the discharge line 20.

The vapor pressure normally existing in the cylinders 5 and the top header 8 will also exist in the cylinder 22 and will be high enough, at atmospheric temperature, to oppose the action of the spring 24 tending to move the piston 23 toward the left-hand end of the cylinder 22. After the valve 2| is opened, carbon dioxide gas will be discharged from the tops of the several cylinders 5 through the top header 6 and the valve is to the discharge line 20. This discharge of carbon dioxide gas will continue until vaporization of liquid carbon dioxide'has lowered the temperature of the remaining liquid carbon dioxide to a value where the vapor-pressure existing in the cylinder 22 will no longer be eifective to oppose action of the spring 24. The spring, then, will move the piston 22 and its rod 25 with the result that the rack 26 will cause a 90 adjustment of the plug for the valve l9. This manipulation of the valve I! will bring about a discontinuation of discharge of carbon dioxide gas from the cylinders 5 through the header 8 and will initiate a discharge of liquid carbon dioxide at the desired sub-atmospheric temperature through the header Ill and the valve I 9 to the main discharge line 20. It will be appreciated that with this type of automatic control, carbon dioxide gas will be discharged through the main line until the temperature of the liquid remaining in the cylinders 5 has dropped to the desired sub-atmospheric temperature and its corresponding vapor pressure, at which time the valve IE will be manipulated to automatically effect change of discharge from gas to low temperature liquid. may be manipulated in the same manner as that described in connection with the system illustrated in Fig. 1.

As has been explained above, liquid carbon dioxide released to the atmoshpere at a low temperature will produce a considerably higher percentage of snow than will be produced by carbon dioxide gas when released tothe atmosphere at atmospheric temperature. The lower the temperature at which the liquid carbon dioxide is re-,- leased, the greater the percentage of yield of snow. The spring 24, which loads the piston 22 against the force of the vapor pressure within the cylinder, may be of any desired strength so that the piston 23 will be actuated to adjust the valve is at any desired vapor pressure value. The

The valve I3, shown in Fig. 2,

selected vapor pressure value, of course, will correspond with the desired sub- -atmospheric temperature at which the liquid carbon dioxide is to be discharged.

It is to be understood that the forms of this invention herewith shown and described are to be taken as preferred examples of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the sub-joined claims.

Having thus described the invention, I claim:

1. A method of employing carbon dioxide as a fire extinguishing medium which comprises storing liquid carbon dioxide at atmospheric tem- .perature and its corresponding vapor pressure, effecting discharge of carbon dioxide gas from storage until the vaporization caused by such gaseous discharge has lowered the temperature of the remaining liquid to a desired sub-atmospheric temperature, and then efiecting discharge of the carbon dioxide as a low temperature liquid.

2. A method of employing carbon dioxide as a fire extinguishing medium which comprises'storing liquid carbon dioxide at atmospheric temperature and its corresponding vapor pressure, effecting discharge of carbon dioxide gas from storage until the vaporization caused by such gaseous discharge has lowered the temperature of the remaining liquid to a desired sub-atmospheric temperature, and then effecting discharge of all of the remaining carbon dioxide as a liquid at the sub-atmospheric temperature obtained by said vaporization.

3. Carbon dioxide fire extinguishing apparatus comprising a battery of cylinders for receiving liquid carbon dioxide at atmospheric temperature and its corresponding vapor pressure, means for discharging carbon dioxide gas' from said battery of cylinders to the atmosphere until the vaporization caused by said gaseous discharge has lowered the temperature of the liquid remaining in the cylinders to a desired sub-atmospheric temperature, and means for automatically effecting discharge of carbon dioxide liquid from said battery .of'cylinders to the atmosphere at said sub-atmospheric temperature.

4. Carbon dioxide fire extinguishing apparatus comprising a container for liquid carbon dioxide at atmospheric temperature and its corresponding vapor pressure, means for discharging carbon dioxide gas from saidcontainer to the atmosphere until the vaporization caused by such gaseous discharge has lowered the temperature of the liquid remaining in the container to a desired sub-atmospheric temperature, and means for automatically effectingv discharge of carbon dioxide liquid from said container to the atmosphere at said sub-atmospheric temperature.

5. Carbon dioxide fire extinguishing apparatus comprising a battery of cylinders for receiving liquid carbon dioxide at atmospheric temperature and its corresponding vapor pressure, a

header connected to the tops of all ofsaid. cylin.-.

ders of the battery, a second header connected to the bottom portions of all of said cylinders, a common discharge line for both of said headers, means for effecting discharge of carbon dioxide gas from said battery of cylinders through the top header and the common discharge line, and means automatically operating, as a result of refrigeration of the liquid remaining in said bank of cylinders to a desired sub-atmospheric temperature and corresponding vapor pressure by the vaporization of liquid during the discharge of gas, to discontinue discharge of gas and to effect discharge of liquid carbon dioxide from said bank of cylindersthrough the bottom header and said common discharge line.

charge of carbon dioxide gas from said container,

throughthe gas discharge line and the common dischargeline, and means automatically operating, as a-result of refrigeration of liquidremaining in said container to a desired sub-atmospheric temperature and corresponding vapor pressure by the vaporization of liquid during the discharge of gas, to discontinue discharge of gas and to effect discharge of liquid carbon dioxide from said container through the liquid discharge line and said common, discharge line.

7. A method of employing carbon dioxide as a fire-extinguishing medium which comprises the steps of discharging to the atmosphere carbon dioxide gas from a confined quantity of both liquid and gaseous carbon dioxide, continuing said discharge until the vaporization of liquid resulting from said gaseous discharge has lowered,

the temperature of the remaining liquid to a: desired sub-atmospheric temperature, and then effecting discharge to the atmosphere of the carbon dioxide as a low temperature liquid.

8.:A method of employing carbon dioxide as a fire extinguishing medium which compriseslthe steps of discharging to the atmosphere carbon dioxide gas from a confined quantity of both liquid and gaseous carbon dioxide, continuing said dischargeuntil the vaporization of liquid resulting from said gaseous discharge has-loweredthe temperature of the remaining liquid to a desired subatmospheric temperature, and then effecting discharge to the atmosphere of all of the remaining carbon dioxide as-a liquid at the subatmospheric temperatureobtained by said vaporization.

9. A methodof employing carbon dioxide as a fire extinguishing medium which comprises the steps of discharging to the atmosphere carbondioxide gas from a confined quantity of both liquid and gaseous carbon dioxide, continuing said dis- 1 charge until the vaporization of liquid resulting from said gaseous discharge has lowered the temperature of the remainingliquid to from F; to -50 F., and then efi'ecting discharge to the atmosphere of the carbon dioxide as a liquid, at

the temperature obtained by said vaporization.

10. A method of employing carbon dioxide as a fire extinguishing medium which comprises the steps of discharging to the atmosphere carbon dioxide gas from a confined quantity of both liquid and gaseous carbon dioxide, and with the rate of fiow of the discharging gas being sufficiently rapid to quickly extinguish the flame and superficial burning of the fire to be extinguished, continuing said discharge until the vaporization oi liquid resulting from said gaseous discharge has lowered the temperature of 'the remaining liquid to a desired'subatmospheric temperature, and then eflecting discharge to the atmosphere of the carbon dioxide as a low temperature liquid at a rate of flow which is reduced sufiiciently to materially prolong the period of discharge.

11. A method of employing carbon dioxide as a fireextinguishing medium which comprises the steps of discharging to the atmosphere carbon,

dioxide gas from a confined quantity of both liquid and gaseous carbon dioxide, continuing said discharge until the vaporization of liquid resulting from said gaseous discharge has lowered the temperature of the remaining liquid to a desired subatmospheric temperature with its correspondingly low vapor pressure, and as aresult of said lowering of the vapor pressure effecting discharge to the atmosphere of the carbon dioxide as a low temperature liquid. 12. Carbon dioxide fire extinguishing appa ratus comprising a container for both liquid and gaseous carbon dioxide, a first discharge line connected to the normal vapor space of .the container, 3. second discharge line connected to v the normal liquid space of the container, means for effecting discharge oi carbon dioxide gas through the first mentioned line, and means automatically operating, as a result of refrigeration of liquid remaining in said container to a' desired subatmospheric temperature and corresponding vapor pressure by the vaporization of liquid during the discharge of gas, 'to discontinue discharge 01' gas through said first line and to efi'ect discharge of liquid carbon dioxide from said container through the said second line.

13. Carbon dioxide fire extinguishing apparatus comprising a container for both liquid and gaseous carbon dioxide, a first discharge line connected to the normal vapor space of thecontainer, a second discharge line connected to'the normal liquid space of the container, means for effecting discharge of carbon dioxide gas through the first, mentioned line, means ,automatically operating, as a result of refrigeration of liquid remaining in said container to' a desired subatmospheric temperature and corresponding vapor pressure bythe vaporization of liquid during. the discharge of the gas, to discontinue discharge of gas through said first line and to effect discharge of liquid carbon dioxide from said container through the said second line,

and means in said second line for varying the rate of flow of the liquid carbon dioxide therethrough relative to the rate of fiow of the gaseous carbon dioxide through the said first line.

14. Carbon dioxide fire extinguishing apparatus comprising a container for both liquid and gaseous carbon dioxide, a first discharge line connected to the normal vapor space of the container, a second discharge line connected to the normalliquid space of the container, means for eilfecting discharge of carbon dioxide gas through V the first mentioned line, means automatically operating, as a result of refrigeration .of liquid remaining in said container to a desired subatmospheric temperature and corresponding vapor pressure by the vaporization of liquid during the discharge of gas, to discontinue discharge of gas through said first line and to eilfect discharge of liquid carbon dioxide from, said container through the said second line, and means operating independently of either of the aforementioned means for varying the rate of fiow of liquid carbon dioxide through the second mentioned line. i

15. Carbon dioxide fire extinguishing apparatus ,comprising a container for both-liquid and gaseous carbon dioxide, a first discharge line connected to the normal vapor space 01' 'the'container, a second discharge line connectedto the normal liquid space of the container, means for effecting discharge of carbon dioxide gas through the first mentioned line and thereby causing refrigeration of liquid remaining in said container to a desired subatmospheric temperature and corresponding vapor pressure, and means automati-- cally operating, as a result of reduction in pressure in the said first line, to discontinue discharge of gas through said first line and to'eflect discharge of liquid carbon dioxide from said container through said second line.

16. A method of employing carbon dioxide as a iire extingushing medium which comprises maintaining a plurality of independently conflned charges of liquid carbon dioxide at atmos pheric temperature and its corresponding vapor pressure, eflecting discharge of carbon dioxide gas from each one of said charges until the vaporiaation caused by such gaseous discharges has lowered the temperature of the liquid remaining in each charge to a desired subatmospheric temthe vaporization caused by said gaseous discharge has lowered the temperature of the liquid remaining in all of said charges to a desired subatmospheric temperature, and then simultaneously eflecting discharge of all of the remaining carbon dioxide of all of said charges as a low temperature liquid.

ERIC GEER'IZ.

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