US2385984A - Method and apparatus for distributing liquefied gases - Google Patents

Description

3 Sheets-Sheet 1 y lNv NToRS @i im BY QJ r' a( m a v ATTORNEY Oct. 2, 1945.

o. A. lHANSEN ET A1.

METHOD AND APPARATUS FOR DISTRIBUTING LIQUEFIED GAS Filed Dec. e, 1941 vOct. 2, 1945. 'Q A, HANSEN ET AL 2,385,984

METHOD AND APPARATUS FOR DISTRIBUTING LIQUEFIED GAS Filed Dec. 6, 1941 3 Sheets-Sheet 2 INVENTORS W/m/ /zalflabgv am NEY Oct. 2, 1945. v o. A. HANSEN ET Al. 2,385,984

l METHOD AND APPARATUS FOR DISTRIBUTING LIQUEFIED GAS Filed Dec. 6, 1941 3 Sheets-Sheet 3 Patented Oct. 2, 1945 un'raon AND APPARATUS ron msrnm'un- :No uoUEnEn casas i Odd A. Hansen, Kenmore, and Peter M. Riede.

Builalo, N. Y., assignors to The Linde Air Products Company, New York, N. Y.

Application December 6, 1941, Serial No. 421,902

9 Claims.

This invention relates to an apparatus for and a method of transporting and dispensing gas material, such as oxygen, which has been liquefied. It is particularly concerned with providing with such gas, consumers whose demands are small relatively to that required by some of the large industrial plants. I

Heretofore in the case of such smaller consumers it has been common practice to deliver the material as a` gas under high pressure in steel cylinders which involves the transport back and forth of considerable dead weight in. the containers themselves, such dead weightv being high `in proportion to the amount of gas delivered.

On the other hand, in the case of larger consumers a common practice has been to deliver the gas material in the liquid phase in special transport trucks and tank cars with the liquid container mounted permanently thereon. This necessitates, however, that such large consumers have considerable equipment for storing the liquid and for converting it into gas as desired for use, including suitable controlstherefor,`the cost of which equipment would be prohibitively burdensome if the quantity oi. gas material used was small.

The present invention proposes an economical and simple way of supplying the demands of such smaller consumers. It contemplates the transport of the material to the consumer as a liquid and involves the provision and use of a novel combined container and converter of small capacity. The unit is self-contained and of a character and size such' that it may be readily transported ona normal truck and readily moved about manually at the plant where the gas is to 'be consumed. The unit is capable of generating and supplying gas under adequate pressure for general industrial uses and is provided with full controls to render it a complete independent container and source of gas supply. It is designed to withstand relatively high pressures and, in conjunction particularly with appropriate receivers which may readily be associated therewith, to take care of periods of non-use or shut-downs of fairly long duration. The connections are such as to enable it to be quickly connected for service or disconnected when exhausted of gas, and easily handled and recharged.

Other objects 0f the invention will in part be .obvious and will in part appear hereinafter.

The invention Aaccordingly comprises the several steps and the relation of one or more of such apparatus embodying features ot construction. combinations of elements and arrangement of partswhich are adapted to effect such steps, all as exemplified in the following detailed disclosure. and the scope of which invention will be indicated in the claims. n

For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

Fig. 1 is a view partly in section of a mobile unit illustrative of principles of the invention:

Fis. 2 is a diagrammatic showing of a typical installation of the unit including the circuits andJ connections of the unit; and

Fig. 3 is a unitsimilar to that of Fig. 1 but including gas receivers removably mounted on the common mobile support.

Referring now particularly to Fig. 1, there is depicted a portable vcold converter in which I U denotes an inner vessel adapted to contain lique` iied gas and the gas as evaporated, the walls of which are of aA thickness and strength' adapted to withstand substantial pressures such as 400 lbs. per square inch. The vessel IB is provided with an outer shell II spaced a substantial distance therefrom to provide an intermediate vacuum space Il. The container unit also includes an outer protective shell or casing I3. The container vessels Ill and Il are preferably spherical in shape. and the outer shell I3 may be of a generally cylindrical shape with a dome-shaped top Il as shown. The space I2 between the two ves.- sels may be filled with suitable insulating material such as magnesium carbonate, but inthe interests of maintaining the dead weight at as low a valueas reasonably practicable and thereby provide increased gas material capacity for a given size and total weight of charged container, it is preferred to employ a straight high vacuum. In that case the outer surface of the vessel IG and the inner surface of vessel II will preferablysecured in the upper end of the neck portion I'6 and has a counterbore Il into which extends the upper end of the neck portion I5 of the inner container. The joints between the plate Il and the neck portions vIt and I5 are of course made gas-tight, the Junctures being made by Vany convenient means as welding. A cap assemf bly indicated generally at I9 is adapted to be re-A movably secured to the top. as by stud bolts threaded into the plate I1, including nuts 2| threaded on the upper end of the stud bolts. The

assembly I9 includes various elements. some of which project down into the interior of the container Il), as will be .described more in detail shortly.

The unit, as a whole, is made mobile through suitable means. In the particular construction disclosed this is accomplished through a supporting base upon which the unit is secured, the base being provided with a pair of wheels 3l permanently attached thereto and an attachable truck jack 32 provided with a pair of wheels is provided having a shut-od valve 8| and couvprox'imately the bottom of the neck portion.

33. The truck jack may be of any well known l type suitable to be wheeled into place and operated to elevate the unit of! the legs 34 when the mal individual. As an example, it has been found F'that a unit employing an inner liquid containing vessel comprising a sphere about two feet in diameter is well within that range and at the same time provides a considerable capacity for gas material.

Returning now to the cover assembly I9 and referring also to Fig. 2, which shows the connections diagrammatically, it will be seen that this assembly unit includes an upper sleeve 40 from which projects down into the liquid container a supporting rod 40a, carrying a suitable oat means 4I at the lower end suitably con'iected to operate a rod 42 which in turn operates through a suitable mechanism a liquid level indicator 43. Secured also in the assembly I8 and projecting down into the liquid container III is a second tube 44 containing electric wire connections to an electrical heater unit 45. In duid communication with the interior of sleeve 40 and thereby with the interior of container I0 is a pressure responsive device 46 comprising a switch adapted to control the electrical heater circuit to maintain a predetermined pressure within container I0. This may be adjusted to maintain any desired pressure within the capacity of the container, as, for example, to open the circuit when a pressure of l110 lbs. per sq. inch is reached and to close the switch when the pressure drops to` 100 lbs. There is also provided la. safety release valve 41 and, if desired, a bursting disk 48. The circuit to the electrical heater may be plugged into a suitable source of electric energy through the conveniently arranged socket 49, an electric cord 50 so connected being shown in Fig. 2 at the left. The electrical heater circuit also includes a thermostatically operated switch il exposed to the temperature within the cohtainer I0 so that when the latter becomes exhausted of liquid the circuit to the heater will be broken automatically. Both the electrical heater and the thermostat are enclosed in a suitable sheath, and the tube. is suitab1y sealed so that none of the gas material comes in direct contact with the electric units or connections. A gas outlet line is shown at 52 communicating with the interior of the container in any suitable manner as through the interior of sleeve 4i).l This outlet includesa shut-off valve 53 and suitable coupling 54. A main filling and withdrawal line $0 This prevents liquid entering through 60 from being blown out with gases escaping through pipe 52 in cases where the gases are vented oi during -filling. The assembly I9 is provided with an outer shell 64 which may be removed independently for access to the nuts 2l to removethe assembly as a whole when desired.

As illustrative of the advantages of the type of unit comprised in this invention and of the method of employing it, the following example is given. Assuming that there is a unit to be charged with liquid oxygen at the manufacturing plant, the unit will be connected to the source of supply through the coupling 62 and line 60. If the container is cold it can be filledA by pressure means, as through a pump, without venting gas which may remain or be formed in the con tainer since the incoming cold liquid will tend to condense any such gas. If, however, the container is warm or because of any other circumstances it is desired to vent oil! the gases, this may be done through the line B2 and the discharged gas taken to a holder for compression into cylinders. After the container I0 has been fully charged, the valve 8| may be closed and the container preferably maintained sealed during subsequent transportation. Some heat leakage into thecontainer contents will occur during transport, but ordinarily tris will not be suilicient to produce a pressure in excess of the service pressure. and therefore no loss will occur. The unit will be loaded on a suitable automotive truck which may be of an ordinary plain platform type along with, if desired, other like units or other equipment such as the high pressure cylinders of gas heretofore referred to in the,

plied under the unit and the unit manually wheeled oi! the truck and positioned as desired.

In Fig. 2 there is shown a typical illustrative arrangement which may be employed at the consumers. It may be assumed that the unitA at the left in Fig. 2 is in use and is connected to one or more gas cylinders l5 by means of suitable piping as the flexible hose connection 66 having couplings 68' and 8l". 'I'he line will have a valve B1 therein adjacent the receiver. As shown, a service line BI having therein a valve 69 leads from the receivers 85. It may be assumed also, for example, that the unit B at the right has been in previous service and the contents exhausted. The unit B therefore will be disconnected and replaced by a new charged unit, and the valves 6I andl t1 to the newly attached unit opened. As soon 4as the unit A is exhausted the new unit at B is placed into active operation, which requires merely the plugging in of the electrical heater connection.

The exhausted unit B which had been disconnected is loaded onto the truck and returned for reilling to the manufacturing plant. The empty units may, of course,v becpen to the atmosphere and the pressure released therefrom, but in accordanc'e with the principles of the present proassunse posed method and the character of unit provided, the valve may remain closed and the unit returned to the manufacturing plant and the gas remaining withdrawn and conserved prior to recharging. 'I'he amount of oxygen delivered to a customer in any case maybe readily determined and kept account of by weighing of the charged container as it leaves the plant and reweighing the container as returnedfrom the customer.

Referring again to the operation at the consumers. the construction and arrangement permit intermittent withdrawal and shutdowns without loss of gas, except perhaps when the shutdown is unusually long. This advantage results from the fact that the liquid container is well insulated and is capable of withstanding an interna! pressure of approximately 400 lbs. per sq. in., which is considerably in excess of the 100 lbs. per sq. in. normal working pressure. Thus if a shutdown occurs, normal heat leak to the container will cause the pressure to rise rather than the safety device to blow with an accompanying loss of gas. Upon resumption of withdrawal the N'pressure will gradually drop until it returns to the normal working pressure where it is maintained by the electrical heater means. 'I'he capacity to permit long shutdown periods without loss is increased Iby the receivers 85 which hold some of the gas generated by heat leak during the period. lHy adding receiver capacity, as by increasing the number, the permissible shutdown period without loss of gas can be extended as desired.

The receivers perform an additional function which is to act as an atmospheric type superheater when the unit is in operation. The gas issuing' from the converter is very cold having been vaporized directly from the liquefied gas. It is noted that the boiling point of liquid oxygen at 100 lbs. per sq. in. gauge is 157 C. Before feeding the gas to the oxygen consuming equipment it should -be heated to approximately room temperature. This is conveniently done by passing the gas through the receivers. The large surface area and high heat capacity supply the necessary heat transfer picking up the heat from the surrounding atmosphere. l

It will be understood that the description as to the units is merely illustrative and that the units disclosed are capableof use in many dierent ways appropriate to the'conditions encountered at various consumers. The unit, for example, 4may be moved aroundthe consumers plant from one location toanother and be brought closely adjacent the point, where gas is to be consumed, thereby eliminating in such cases any need for extensive pipe connections but at the same time making readily and quickly available at various points quite remote from each other a source of gas under pressure adequate or'normal industrial use. the consumers plant and the liquid brought to it and transferred thereto at any convenient point. y In Fig. 3 there is shown another unit similar in general to that of Fig. 1 but in which there is directly mounted thereon one or more gas cylinders 8,0, two such being Shown, the one in the foreground being partly broken away. The cylinders arepreferably removable, being held in place normally by anysuitable meansI which in the present case includes a pair of chains 8l, one hooked to each of a pair of handles 82 arranged on opposite sides ofthe container shell. Such handles preferably form a part also of the unit If desired, the units may remain at shown in Fig. l and may serve as a means to which a chain fall may be readily attached for lifting the unit by a small den'ick, as on and oir a truck. The coupling 62 enables the gas dis- 'charge line from the container to be quickly coners in the line and may be maintained intact as such if desired. It will be advantageous in some cases, however, when the liquid in a unit is exhausted to remove the gas receivers therefrom and assemble them on a freshly charged container, which may be accomplished, of course, without releasing the gas from the receivers. This manner of operation requires less equipment.

Since certain changes in carrying out the above method and in the constructions set forth, which embody the invention may be made without departing from its scope, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having described our invention, what We claim as new and desire to secure by 'Letters Patent, is:

1. A portable apparatus for containing liquefied gases and-for generating and supplying gas under pressure directlytherefrom, comprising an insulated pressure container, a mobile support therefor forming a unitary part of said apparatus, an electrical heating means in p s'aid container for conveying heat to the liquid togasify same as desired for industrial use. a controlling device for said electrical heating means responsive to the pressure in said container for maintaining a predetermined pressure therein, a thermostatic device exposed to the temperature within said con-- tainer and adapted to control said heating means to preventan -excessive temperature, and valved supply and withdrawal connections for said container.

2. A portable unit for containing andv transporting liquefied gases and for supplyingdirectly gas under pressure, said unit vbeing of a size adapted to be carried on a transport means and provided with means for readily moving it at the consumers independently of such transport means, and said unit comprising an insulated pressure container for the liquefied gases'a supporting base therefor, valved supply and withdrawal connections for said container, electrical heating means for supplying heat directly to the liquid to gasify the liquid and supply gas as required for use, means for automatically -controlling thesupply of heat to maintain a predetermined maximum gas pressure, and means for controlling said heating means to prevent excessive tempe'rature.

3. A portable unit for containing `and transporting liqueed gases and for supplying directly gas under pressure, said unit being 'of a size adapted to be carried on a transport truck and provided with means for readily moving it at the consumers independently of such transport truck, and said unit comprising an insulated pressure container for the liquefied gases, a wheeled supporting base therefor forming a permanent part of said unit, a gas receiver mountedon said base, valved supply and withdrawal connections for said container including a gas connection to said receiver, electrical heating means for supplying heat directly to the liquid to gasify the liquid and supply gas as required for use. means for automatically controlling the supply of heat to maintain a predetermined maximum gas pressure, and means for readily connecting said electrical heating means to a source of power at the selected place of use.

4. A portable unit for containing liquefied gases and for supplying gas under pressure directly therefrom for industrial use, said unit being of a size and character adapted to be carried on a transport truck and provided with means for readily moving it at the consumers independently of said transport and comprising an insulated pressure container for the liqueiled gases, valved supply and withdrawal connections for said container, electrical heating means for supplying heat directly to the liquid to gasify the liquid and supply gas under pressure suitable for industrial use as required, means 4for automatically controlling the supply of heat to maintain a predetermined pressure, and a thermostatic control in the circuit to said electrical heater exposed to the temperature within said container.

5. A. portable apparatus for containing liquefied gas and supplying gas under pressure directly therefrom, comprising an insulated container adapted to withstand substantial pressures suitable for general-industrial use having an opening for theinsertion ,of associated equipment, and a closure assembly for said opening adapted to be applied or removed as a unit including an electrical heater adaptedto project into the interior o! said container, a control device therefor connected to control said heater to maintain a predetermined gas pressure, a liquid level indicator and valved conduit connections for the supply or withdrawal of fluid all forming part of said unit, and means i'or releasably securing said closure assembly in place against the pressure maintained in said container.

6. gA portable unit for containing liquefied gasesv andgi'or supplying gas under pressure directly therefrom, comprising a. supporting frame, an insulated pressure container mounted thereon, automatically controlled electrical heating means within said container ior conveying heat to the liquid in said container to gasify the liquid as required, a gas receiver removably mounted on said Supporting frame, and valved gas connectionsl from said container to said receiver readily releasable to permit the easy removal of said receiver.

7. A portable unit for containing -liquefled gases and i'or supplying gas under pressure directly therefrom, comprising a mobile supporting frame, an insulated pressure container mounted thereon, automatically controlled means for conveying heat to the liquid in said container to gasify wit L in said container the liquidas required, a gas receiver removably mounted' on said supporting frame. and valved gas connections from said container to said receiver readily releasable to permit the easy removal oi' said receiver. said unit not exceeding a size such that it may be readily moved about manually on said mobile supporting frame.

8. A portable apparatus for containing liquid oxygen and for generating and supplying oxygen gas under pressure directly therefrom, comprising an insulated pressure container, a mobile support therefor forming a unitary part of said apparatus, an electrical heating means in said container for conveying heat-to the liquid to gasify same asdesired for use. means responsive to pressure in said container connected to control said heating means for maintaining a predetermined pressure in said container, a thermostatic device exposed to the temperature within saidcontainer and adapted to control said heating means to prevent an excessive temperature, and a valved withdrawal connection and means for illling said container with said liquid oxygen.

9. A unit for holding highly volatile liquefied gas and for generating and supplying gas under pressure directly therefrom comprising an insu-` lated pressure container. an electrical heating means in said chamber for conveying heat to the liquefied gas to gasify same, means responsive to pressure in said container connected to control said heating means to maintain automatically a predetermined pressure in said container, a thermostatic device exposed to the temperature within said container and connected to render said heating means inoperative when the temperature rises to a predetermined limit, a valved gas withdrawal connection, and means for filling said container with the iiqueed material.

oDD A. HANSEN. PETER M. RIEDE.

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