US3097499A - rodgers - Google Patents

Description

A y 16, 1963 F. c. RODGERS 3,097,499

METHOD AND APPARATUS FOR PRESERVING AN ADEQUATE 2 Sheets-Sheet 1 SUPPLY 0F CO FOR FIRE PROTECTION Filed Dec. 1, 1960 in 8 s8: m. t w 11 DJ... m m mm wF A A m) \3 M1 m m, ANT Q & I C m A a w G \Y m I .X A n Vl.| llll II M M!\ [M I M w \m Es E m N A 35 6, 4 47 OH /CZ i W e A A A A A A g T vm mm 2 N R nu Q As: Em F isw s H 2 mm 9 u G m lllli alllll q JEQ A e N 6? July 16, 1963 F. c. RODGERS 3,097,499

METHOD AND APPARATUS FOR PRESERVING AN ADEQUATE SUPPLY OF C02 FOR FIRE PROTECTION Filed Dec. 1, 1960 2 Sheets-Sheet 2 FIG. 3

INVENTOR.

Pal/X C. Rodgers BY METHOD AND APPARATUS FOR PRESERVING AN ADEQUATE SUPPLY OF C FQR FIRE PROTEC- TION Felix C. Rodgers, Evanston, Ill., assignor to Chemetron Corporation, Chicago, 111., a corporation of Delaware Filed Dec. 1, 1960, Ser. No. 72,937 8 (Jlaims. (Cl. 62-55) This invention relates in general to the storage of liquified gas materials adapted for dual uses, such as fire extinguishing and industrial purposes. More particularly, this invention relates to a method of preserving an adequate supply of the liquified gas materials necessary for fire protection. This invention entails a shut-off device in the form of a tamper-proof valve preferably housed within a low pressure CO refrigerated storage tank or enclosed receptacle for preventing withdrawals of CO when the supply is depleted to a predetermined level, to insure that a certain amount of CO for fire protection equipment is not used for other purposes.

It is often desirable to use only a single refrigerated low pressure liquid CO storage unit as a supply for various purposes. A storage unit serving such purposes is disclosed in US. Letters Patent 2,356,990 issued August 29, 1944 to Charles A. Getz. In industry, where liquid CO serves numerous purposes from low temperature cooling operations, such as rubber tumbling or instrument testing purposes, to fire protection operations, the CO is supplied to points of use via piping from a main source, the storage unit. Rubber tumbling apparatus utilizing CO for instance, is described in US. Letters Patent 2,682,732 issued July 6, 1954 to W. I. Hanrahan et al., and CO fire fighting methods and apparatus are described in US. Letters Patent 2,452,348 issued October 26, 1948 to W.A. Beach as well as in the Getz patent. The storage unit or tank in turn, is refilled when required from a bulk transport means such as a truck or railroad tank car. Thus, when the supply of CO in the storage tank has diminished to the point where only a minimum supply necessary for fire protection remains, a shut-01f device preserves this condition until the supply can be augmented. Another use for a shut-01f device according to this invention occurs where a C0 bulk supply is used for fixed and regulated CO fire protection equipment, and also where used for putting out small fires with hand CO equipment attached to connected hoselines. It is imperative that the regulated or fixed fire equipment has a minimum necessary supply of CO available to put out fires at critical areas which the regulated fire equipment covers, such as oil-soaked machinery and other locations of such fire hazardous nature as are highly susceptible to combustion. Furthermore, it is essential that hand equipment is not used without regard to providing means for insuring an adequate supply of CO for the regulated or fixed fire equipment.

To properly serve the above requirements, the control device must be tamper proof so that its proper function cannot be tampered with easily by personnel using the liquid CO for other purposes, thus maintaining the minimum required supply available at all times for fire protection.

Accordingly, it is a primary object of this invention to provide a method of preserving a minimum supply of liquid CO within a low pressure storage unit for emergency purposes while limiting the amount of liquid CO that may be discharged for other purposes.

It is another object of this invention to provide immersed in carbon dioxide within an enclosed receptacle or tank a tamper-proof liquid CO shut-ofi device that is capable of limiting withdrawal of liquid CO when the liquid in the tank reaches a predetermined level, resulting from a maximum permissible discharge of CO for various purposes, and for insuring that an adequate minimum supply for fire fighting is maintained available to essential fire extinguishing equipment.

It is another object of this invention to provide immersed in liquid carbon dioxide within a storage tank a tamper-proof liquid CO device having a float supporting open the weight of a shut-off valve, when the float is fully or partially immersed in liquid carbon dioxide.

It is yet another object of this invention in conjunction with the last mentioned object, to insure when the liquid CO decreases to a predetermined level within said pressurized tank after having discharged a maximum amount to an outlet, that the fioat is lowered sealing the valve disc against the outlet to positively hold the valve assembly sealed against the outlet with a force equal to the internal pressure of the storage tank.

It is still another object of this invention to provide a storage system for supplying liquid CO to both industrial equipment and fire protection equipment from separate outlets of the same source, while limiting the supply to the industrial equipment and preserving an adequate supply to the fire protection equipment.

These and other objects and advantages of this invention will more fully appear from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a storage system comprising a low pressure storage unit containing liquid CO for supplying through different pipelines the CO to various equipment, and a shut-off device immersed in liquid CO Within the storage unit for controlling the permissible amount of CO to the pipelines;

FIG. 2 is a sectional view of the shut-off device shown with its valve assembly in the open position;

FIG. 3 is a sectional view of the shut-ofi device shown with its valve assembly in the closed position; and

FIG. 4 is a sectional view looking downward on the shut-oft device from a point below the raised valve disc.

The development of practical means for transporting in bulk low pressure CO has made it possible to enlarge the fields in which CO in such condition can be efiectively used. There are many advantages which make use of low pressure CO practical. These advantages pertain both to the material itself and to the ease with which it can be transported. For instance, it is common for a limited user of liquid CO to have one storage unit for dispensing CO to various pipe lines, and consequently, to various types of equipment. It is often desirable to utilize a single storage unit not only for various industrial types of equipment, but also to include fire fighting equipment. Such dual use however, poses the problem whether or not there will always be available an adequate supply of liquid CO for the fire extinguishing equipment. Controls must be arranged so that personnel cannot tamper with these controls to increase withdrawal of CO for non-fire equipment.

Unless these controls are tamper-proof, two separate sources of liquid CO which may not always be practical, must be provided.

The present invention overcomes the above problem by providing for the immersion of a control in the form of a valve assembly into the liquid CO within the storage unit so that it is practically impossible to tamper with it to alter its intended function.

A typical stationary low pressure CO storage unit It) for industrial use, or the like, is illustrated in FIG. 1 and described in greater detail in' the referenced Getz patent. Briefly, the storage unit 10 is usually constructed for a working pressure of 325 lbs. p.s.i. in accordance with the A.'S.M.E. code. Since the temperature corresponding to such pressure is substantially below (about F.) normal ambient temperature, the tank 11 is provided with insulationlZ of cork or other type of insulation in conjunction with' an outer cover or shell 13 which may be hermetically sealed. The insulation 12 furnishes an effective vapor barrier preventing the accumulation of water which would reduce thermal eificiency. A pressure gauge and a liquid valve gauge (not shown) which indicate the internal pressure and the quantity of liquid CO in the tank are also part of the unit, together with other equipment, such as cooling coils 14 extending from an automatic refrigeration unit, more particularly illustrated and described in the Getzpatent. The cooling coils 14 are preferably mounted in the vapor space above the liquid CO level for maximum efficiency, and with the automatically controlled refrigeration equipment the required low temperature and corresponding pressure can be maintained indefinitely. A vapor vent pipe 7 is utilized for equalizing the pressure in the storage unit during the refilling opera tion of the storage unit 10.

Afloat valve'assembly 20 is anchored to one end of a C0 outlet pipe 19 adapted for feeding CO to a pipe lineS aswell as feeding liquid CO to the storage unit during refilling. A feed pipe 8 interconnects the outlet pipe -19 and the pipeline 5. It will be noted that feed pipe-8- is curved to form a vapor trap. The cold liquid remaining in the trap after valve 17 is closed following a refilling operation of the feed pipe 8 will begin to vapor ize forcing the liquid back into the insulated section next to thepressure tank 11. The pipe line may extend to further pipe lines in industrial areas where equipment utilizing the liquid CO are located, such as rubber tumbling'apparatus described in the Hanrahan et a1. patent, and/or to manual fire fighting equipment such as the fire hose 18 forextinguishing small fires.

Another feed pipe line 9 extending through the top of the storage unit .10 and downward adjacent to the bottom of the pressure tank 11 is adapted for withdrawing liquid CO from the tank and feeding it to pipe line 35 extending to fixed or automaticfire extinguishing equipment; This pipeline 35 is preferably utilized only for emergency purposes arising from fires, and therefore has a master valve 15 which opens for permitting withdrawalof the liquid CO2 from the stonage unit only during such emergencies; A solenoid 16 electrically energized responsive to a fire condition may be utilized for controlling the opening and closing of the master valve 15. However, other suitable means for controlling-the valve 15 may' also be employed.

An automatic fire extinguishing system, a part of which or its entirety is illustrated in FIG. 1 is connected to the pipeline 35. The size of the system is dependent upon the area to be protected. For instance, a plurality of fire hazardous articles 36, such as oil laden machinery, fuel storage, or other combustible articles, have standard liquid CO dispensing nozzles 34 trained on them from various angles. By means of thermostatic controls (not shown), or by-depressing-ra manual push button PB, an electrical circuit is closed to solenoid 16 for initiating the opening of the master valve 15, and consequently, withdrawing liquid CO from the storage unit for-dispensing on the localized fire via the nozzles 34. A relay cabinet 31 having a plurality of relays (not shown) responds to the manual depression of the push button PB for maintaining the electrical circuit closed to the solenoid 16 as well as to initiate an alarm 32 for audibly warning all persons within the hazardous area that fire has broken out. An electrical conductor or wire 33 connected to a suitable power supply interconnects these components and is also branched to other interconnected components (not shown). Various other fire equipment may also be employed as well as other types of regulated systems. For instance, the apparatus disclosed in the referenced Getz patent and the Beach patents may also be utilized.

Thus, it becomes apparent that safety requires at-all times a sufiicient supply of liquid CO within the storage unit M to cope with any fire by providing enough liquid CO for the fixed fire equipment. The shut-off device 20 illustrated in FIGS. 1 to 4 inclusive, is utilized for insuring that a sufiicient supply of liquid CO is available to the fire equipment at all times via the pipeline 35.

The shut-off device 20 is adapted to be immersed in liquid CO as shown in FIG. 1. The shut-ofl? device -20 has a main frame or casing 26in the shape of a cylinder with two cut-away sections or ports 27, more clearly seen in FIG. 4, for permitting liquid CO to freely enter within the casing. In addition, casing 26 is secured to a base28, and a bonnet 29 is secured to the upper end of the casing; The base 28 has a threaded portion forming an openingfor securing the shut-off device to a correspondingly threaded portion on the outlet pipe '19. Thus, the shut oif device is anchored within the tank 10 belowthe sur-" face of'the liquid CO directly above the outlet pipe extending to the pipeline 5. The casing 26 forms a guide for a valve disc 24. The valve disc 24 has a flat bottom surface 39" adapted for being lowered onto a flat surface 2811 which forms a valve seat on the base 28. In

addition, the valve disc 24 Mean opening 24a for receiv-' ing a stem 22 which also extends through an opening 29a in the bonnet 29. A pin 25 is tightly fitted through an opening 24b in the'valve disc in alignment through a wider hole 22a in the stem 22. The stem 22 which may take the form of a tube, is in turn, by means of upper threads secured to a nut 23 connected to a float 21. The float 21 which may take the'form of a hollow sphere is adapted to buoyantly support the valve disc- 24 in the liquid C0 The float '21 is preferably made of stainless steel or other suitable material, capable of withstand ing the low temperature and changing pressures of the liquid C0 The diameter of the circular opening29a is much smaller than the diameter of the upper cylindrical portion of the valve disc 24, therefore, confining the valve disc 24 within the casing 26. The opening29a in the bonnet and the annulus 222a circumscribing the roll pin 25 permits a limited amount of play for both the stem 22 and the valve disc 24 during longitudinal movement. This limited amount of play permits the valve disc'to selfalign its bottom fiat surface 29-with the flat surface seat 28a of the base'28. The surface 28a and the correspond ing flat surface 29 of the valve disc 24'are preferablypolished and of a hard metal, such as stainless steel, providing a close fit and seal of the port 30, when the valve disc is lowered onto the valve seat, as" illustrated in FIG. 3.

The length of the outlet pipe 19 extending into tank .10 determines the level at which the shut-off'device 20 is'adapted to be immersed in the liquid CO within the storage unit, and consequently determines the level of CO below which withdrawal will be permitted to pipeline 9 only. :For instance, when the float 21 follows the liquid level to the level shown in phantom lines (FIG. 1) resulting from the withdrawal of a predetermined amount of CO the valve disc moves correspondingly to close the port 30, thus preventing further withdrawal of liquid CO to the pipe line 5. Therefore, the precise position in the tank at which it is desirable to anchor the shut-01f de vice, depends upon the amount of liquid CO calculated for an adequate reserve for fighting fires.

The vapor pressure in the storage unit further insures that the outlet is sealed when the valve disc lies on the valve seat 28a. The liquid CO which has been used by the equipment on pipeline 5 after the valve has closed gradually decreases in pressure to atmospheric, thus, the two polished surfaces v2.8a and 29 which are self-aligned by the limited play of the stem 22 and disc 24, and the higher pressure above the closed valve disc hold the valve closed insuring that no further liquid CO may be withdrawn through the pipeline 5.

The infeed pipe 8 together with the vapor pipe 7, are utilized to equalize the pressure between the storage unit 10, and the delivery unit or truck during the refilling of the storage unit so that the valve disc 24 may rise and permit the flow of the liquid CO into the storage unit. The refilling operation comprises connecting a convenient length of flexible hose between the vapor pipe 7 and a similar vapor pipe (not shown) on a bulk liquid CO transport truck or railroad tank car. This connection is utilized to equalize the pressure between the two units upon opening of the hand valve 6. A rotary type liquid pump mounted on the delivery truck (not shown) is connected by a suitable length of flexible hose to the infeed pipe 511. Liquid CO is then pumped from the transport truck into the port 30 which causes the valve disc 24 to rise. The ball float 21 follows the rising level of liquid CO to further raise the valve disc to its fully open position as the tank is filled.

According to various automatic fire extinghishing systems that may be utilized incorporating the shut-off device, it may be essential only to maintain an adequate supply of CO for the large or extra hazardous locations being protected. Therefore, for less critical areas fire fighting hose, such as 18, may be connected to the industrial pipeline 5 for extinguishing small fires that may break out. Thus, the pipeline 35 may not have to be utilized. Moreover, in certain areas to be protected a fire protection hoseline may be preferable, and of equally critical importance as the automatic fire extinguishing system, especially in locations where the automatic system would be impractical. Therefore, such a hoseline would be connected to the pipeline 35 at a point between master valve of the automatic fire extinguishing system and the feed pipe line 9, so as not to aifect the automatic system during emergencies requiring the need for the hoseline only.

The shut-oif device being immersed in the liquid CO makes it practically impossible for personnel to tamper with the device. The storage unit would virtually require dismantling to do so, which would afiect the refrigeration and consequently the pressure and temperature of the CO Such dismantling would also cause considerable loss of the CO in the storage unit. There is thus provided a liquid CO shut-off device for permitting only a predetermined amount of liquid to be withdrawn to a first outlet and closing the outlet to maintain an adequate supply of liquid for fire extinguishing, While being tamper-proof so that its proper function cannot be altered. Furthermore, there is provided a tamper-proof shut-ofi device constructed to withstand the temperatures and the changing pressures of liquid CO within the storage unit.

It will be understood that various changes in the form, details, arrangement and proportions of the different parts of the apparatus will be suggested to those skilled in the art and all such changes as may be made without departure from the spirit of the present invention are intended to fall within its scope as best defined in the appended claims in which there is claimed:

1. A method of reserving a minimum supply of liquid gas material in a storage unit for an emergency purpose, comprising the steps of connecting a first outlet to said unit for withdrawal of said liquid gas therefrom, limiting the withdrawal of the liquid gas material from the first outlet for any purpose by closing the outlet when the gas material reaches a predetermined level, connecting a second outlet to emergency use equipment and to said unit, maintaining said outlet in continuous open communication with said storage unit and said emergency equipment at all times, and reserving all liquidl gas material below said predetermined level for Withdrawal through said second outlet.

2. A method of reserving a minimum supply of liquid gas material in a storage unit for an emergency purpose, comprising the steps of connecting a first outlet to said unit for Withdrawal of said liquid gas therefrom, limiting the withdrawal of the liquid gas material from the first outlet for any purpose by closing the outlet when the liquid gas material reaches a predetermined level, connecting a second outlet to emergency use equipment, exerting the pressure of the vapor phase above said liquid gas material to maintain said first outlet closed, openly accessing said second outlet to all liquid gas material in said storage unit, and reserving all liquid gas material below said predetermined level for Withdrawal through said second outlet.

3. A method of reserving a minimum supply of liquid carbon dioxide in a storage unit for fighting fires, comprising the steps of connecting a first outlet to said unit for withdrawal of said liquid gas therefrom, limiting the withdrawal of the liquid carbon dioxide from the first outlet by closing the outlet when the carbon dioxide reaches a predetermined level, exerting the pressure of the vapor phase above said liquid carbon dioxide to maintain said first outlet closed, connecting a second outlet to emergency use equipment, openly accessing said second outlet to all liquid carbon dioxide in said storage unit, and reserving all carbon dioxide below this predetermined level for withdrawal from a second outlet for extinguishing fires.

4. A tamper-proof device for preventing withdrawal and reserving adequate amounts for certain uses of liquid carbon dioxide from a storage unit, comprising a storage tank, a valve assembly mounted within said storage tank to dispense liquid carbon dioxide from an outlet in the storage tank, a pipeline extending through the bottom of said storage tank to the internal end of which said valve assembly is anchored at a predetermined level Within said storage tank; said valve assembly having a valve disc adapted for closing said outlet, a perforate casing for guiding the movement of said valve disc, a float connected to said valve disc for following the diminishing level of liquid carbon dioxide resulting from the dispensing of liquid carbon dioxide for consequently moving said valve disc Within said casing toward said outlet and another outlet for withdrawing the reserve supply of said gas material below said predetermined level.

5. A device for stopping the withdrawal of liquid CO from a pressurized storage unit and for reserving adequate amounts therein comprising, a first outlet and a second outlet for dispensing liquid CO from said storage unit, said first outlet communicating with manual fire fighting equipment and for other purposes, said second outlet communicating with emergency regulated fire equipment, valve means regulating said first outlet and adapted to buoyantly follow a predetermined distance the diminishing level of liquid CO resulting from withdrawal of liquid CO through said first outlet for closing said outlet, and means operatively responsive to an emergency condition to withdraw liquid CO for said. emergency regulated fire equipment via said second outlet regardless of whether said first outlet has been closed.

6. A tamper proof device for insuring an adequate reserve of liquid gas material within a storage tank for a predetermined purpose, comprising an outlet for dispensing gas mate-rial from said tank, tamper proof means including a valve for closing said outlet when the gas material in the tank reaches a predetermined level, said valve being mounted internally of the-tank, and another outlet for withdrawing the remaining reserve supply of said gas material below said predetermined level.

7. A tamper proof device as claimed in claim 6 in which said predetermined level is determined by the location of saidtamper proof means including said valve.

8; A tamper proof device for insuring an adequate reserve of liquid gas material within a storage tank for a predetermined purpose, comprising an outlet for dispensing gasmaterial from said tank, tamper proof means including a valve for closing said outlet when the gas material' in the tank reaches a predetermined level, and a second outlet for withdrawing the remaining reserve supply of saidgas material below said predetermined level,- said second outlet being connected to firefighting equipment, and means responsive to a predetermined condition permitting withdrawal of said "liquid gas material through said second outlet) for said firefighfingjequipment.

References Cited in the file of this patent UNITED STATES PATENTS 1,397,523 Jerdone Nov;- 22, 192 1 2,290,461 Young July 21,1942- 2,3l4,l58 Peters Mar. 16, 1943" 2,346,253" De Motte Apr. 11, 1944 2,356,990 Getz Aug. 29, 1944' 2,532,379 Trom Dec. 5, 1950

Claims (1)

1. A METHOD OF RESERVING A MINIMUM SUPPLY OF LIQUID GAS MATERIAL IN A STORAGE UNIT FOR AN EMERGENCY PURPOSE, COMPRISING THE STEPS OF CONNECTING A FIRST OUTLET TO SAID UNIT FOR WITHDRAWAL OF SAID LIQUID GAS THEREFROM, LIMITING THE WITHDRAWAL OF SAID LIQUID GAS MATERIAL FROM THE FIRST OUTLET FOR ANY PURPOSE BY CLOSING THE OUTLET WHEN THE GAS MATERIAL REACHES A PREDETERMINED LEVEL, CONNECTING A SECOND OUTLET TO EMERGENCY USE EQUIPMENT AND TO SAID UNIT, MAINTAINING SAID OUTLET IN CONTINUOUS OPEN COMMUNICATION WITH SAID STORAGE UNIT AND SAID EMERGENCY EQUIPMENT AT ALL TIMES, AND REVERSING ALL LIQUID GAS MATE-

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