US1878317A

US1878317A - Apparatus for conserving and vaporizing liquefied gases

Info

Publication number: US1878317A
Application number: US381958A
Authority: US
Inventors: Picard Charles
Original assignee: Air Liquide SA
Current assignee: Air Liquide SA; LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Priority date: 1928-07-31
Filing date: 1929-07-29
Publication date: 1932-09-20
Anticipated expiration: 1949-09-20
Also published as: BE362625A

Description

Sept. 20, 1932 HCARD 1,878,317

APPARATUS FOR CONSERVING AND VAPORIZING LIQUEFIED GASES Filed July 29. 1929 Inventor maid/Fwd Attorney;

Patented Sept. 20, 1932 UNITED STATES PATENT OFFICE- CHARLES IPICARD, OF JOINV'ILLE FONT, FRANCE, ASSIGNOR TO I JAIR LIQUIDE, SOCIETE ANONYME POUR LETUDE ET LEXPLOITATION IDES PROCEDES GEORGES CLAUDE, OF PARIS, FRANCE APPARATUS FOR CONSEBVING AND VAIPOBIZTNG LIQUEFIED GASES Application filed July 29, 1929, Serial No. 381,958, and in France July 31, 1928.

The present invention relates to improvements in storing and vaporizing apparatus for liquefied gases and more particularly to devices for storing and transporting gases to at low temperature and to apparatus for vaporizing said gases, under pressure, by means of a liquid pump and a vaporizer for the' liquefied gases.

One of the objects of the invention com- 1 prises means to maintain automatically within the insulating covering surrounding the liquefied gases, an atmosphere excluding the outside air and dampness and the pressure of which is comprised within predetermined limits.

Another object of the invention resides in the provision of means to insure the correct functioning of the liquid pump while preventing, during idle periods, the condensation of the outside air humidity upon the parts in contact therewith and also upon the walls of the tank wherein the pump is disposed.

The invention has for an object also to improve the working of the vaporizer wherein the liquefied gas is vaporized by means of a pump circulating the liquefied gas upwardly therein and insuring an eflicient exchange of heat between the liquefied gas and the fluid adapted to vaporize the same.

Other objects of the invention will be apparent and described in the following specification and drawing, wherein a schematic representation of an insulation is shown particularly adapted to the vaporization of liquefied oxygen.

The liquefied gas is contained in container 8 insulated from the outside envelope 9 by a lining 10, for example, magnesium carbonate. Said container 8 is secured to the outside envelope 9 by means of suspension chains 3 and 3 (for purposes of clarity, only one chain of each kind has been shown on the drawing). The chains 3', the supports of which to the envelope 9 are situated below the securing points on the container 8 have for an object to prevent that the same be lifted by the extreme fluidity of the insulating matter when said container is empty. The envelope 9 is provided with a safety valve 30 and a metal-foil disk 31 adapted to be fractured when the internal pressure reaches a given limit. Furthermore, part of the envelope, at the top thereof, affects the shape of a disk 1; said disk being attached to the sheet metal constituting the envelope 9 by -a thin rubber diaphragm 32. When, due to an accident,.a leak occurs in the receiver 8 whereby the liquefied gas is absorbed by the insulating matter and vaporized thereby, the pressure quickly rises inside the envelope 9. Accordingly, the diaphragm 32 is torn and the disk 31 is free to rise and permit the escape of a great quantity of the imprisoned gas and also of part of the insulating material as the case may be.

A duct 11 feeds into the insulating matter a certain quantity of the gas evaporated in the liquid container whereby a certain pressure always exists therein. In said duct, a valve 2 is inserted which is regulated to be open when the pressure of the gas within the insulating lining is below a given limit, 5 cm. of water for example. Whenever the pressure in the insulating lining rises above this value, the valve is closed and the circulation of gas interrupted. Therefore, there is always tolerated in the lining a very light pressure.

On the duct 11, after the valve 2, a branch 12 is connected whereupon a. second valve 2 is inserted and which is regulated up to 10 cm. of water. If the pressure increases over this value, the valve 2' opens and the gas contained in the lining escapes to the atmosphere through 13, whenever this is produced for different reas0ns,.for instance, when the receiver 8 is empty of liquid.

It follows, therefore, that due to the use of the valves 2 and 2' a pressure is always maintained in the insulating lining and which is automatically maintained between 5 and 10 cm. of water. Of course, the valve 2' can be replaced by a mercury valve;

The liquefied gas pump 14.- is situated in a tank 15 lined also with insulating material and connected to the liquefied gas receiver by the pipe 16; the inlet being through a port 35 and the exhaust through a ball valve 36. There is maintained in the tank 15, during operation of the pum p,-a constant level by t e" following' means: At a certain height below the-lowestlevel to be maintained, a

certain part of the liquid is branched at 17 5 which'upon being heated by the surrounding sure.

The tank is adapted to be emptied during the idle periods of the pump. It has been found that condensation of moisture inside said tank should be prevented at all 15 cost together with all the, cold parts of the apparatus in contact with the outside atmosphere. To that end, a duct 5 is provided which feeds a part of the evaporated gas from the receiver 8 to the bottom of the tank 15 and aroulfd the ump 14; more particularly,

it is necessary t at the gas be circulated in the space 33 around the piston rod to prevent the condensation of dampness upon said parts. In the event said circulation of as be prevented due to the absence of lique ed gas in the receiver 8, the various parts which are in contact with the outside atmosphere are treated or made of rustless metal or steel, Monel metal or any other metals which 0 are rendered rustless by known treatments,

14 through a conduit 20 into a vaporizer which is submerged in the water of a container 21 and which is constituted by a bunch of coils 7 connected in parallel. The liquevfied gas travels through said coils downwardly and absorbs the heat of the water whereby the gas is va orized. This system of circulation of the iquefied gas enables one to use the minimum amount of water to vaporize a given amount of liquid. As the coldest portions of the water in the vessel which contains the vaporizing coil are at the upper part of this vessel and as they are simultaneously the lightest portions, no circulation of water from the to to the bottom of the vessel is 5 caused by t e difference in the density of said water; consequently, a total and rapid freezin of the water contained in the vessel is 'avoi ed and, therefore the efficiency of the apparatus is not diminished, whilst such efii- 9- clency would be diminished in the case of total and rapid freezing of water, since in. this latter case the vaporized gas would leave the vaporizer in a too cold state. Onthe contrary, the ice which surrounds the up er part of the spires of the vaporizing coils ecomes cooled by the very cold liquefied gas apparatus at the temperature of the water situated in the bottom of the vessel, about +4 C. n. y

The produced gas under pressure reaches the apparatus of consumption through 22 and the branch 23 opening at the bottom of the container 21 whereby part of the gas is fed into said container to agitate the water thereof in order that the temperature throughout its mass be adjusted at a constant level; the said gas necessary to agitate the water is regulated by a valve 24 which, by the way, may be replaced by anexpansion valve.

Finally, at the start of the conduit 20, near the pump, a coil 6 is mounted having a single tube ofl copper of internal diameter as large as the mechanical resistance and manufacturing limitations permit. This coil is placed in contact with the atmosphere and closed at 34; later, the volume of said coil is gradually filled by compressed gas resultin from the vaporization ofthe liquid occupym a good portion of said coil 6. The object o the coil is to provide a gas cushion to dampen the working of the pump.

What I claim is:

1. An apparatus for conserving liquefied gases, which comprises a liquid container, an exterior sheath and insulating material there between, means for automatlcally admitting up to a predetermined pressure a part of the evaporated gas to the space between the container and exterior sheath and means for preventing the gas pressure in the insulating material to exceed a certain limit and for allowing the gas in the insulating material to escape outwards, when the pressure of this gas has reached the said limit.

2. An apparatus for delivering liquefied 1 gases which comprises a liquid container, a

pump, an intermediate vat, means for conducting a part of the liquid from said vat in relatively warm zones and for vaporizing it under pressure and means for controlling by said pressure the arrival of liquid to the said vat. I

3. An apparatus for delivering liquefied gases which comprises a pump, a vat and means for sweeping the parts of apparatus liable to be in contact with the atmospheric air by a flow of evaporated gas.

4. An apparatus for containing liquefied gases which comprises an internal liquid container, an outer sheath, insulating material therebetween, a separate member forming a part of the outer sheath and frangible means for attaching said member to said sheath.

5. An apparatus for vaporizing under pressure liquefied gases which comprises a pump for liquefied gases, a container for a heating medium, heat exchange means submerged in the said heating medium and in which the liquefied gas forced by the said pump becomes vaporized under pressure, v means for diverting a part of this gas under pressure and for conducting it into the heatingmedium which surrounds the said heat exchange means. i

6. An apparatus for delivering liquefied ases which comprises a' pump, a conduit 10 eriving a part of the delivered liquefied gas branched off on the delivery pipe of the pump between the pump and the vaporizer, a closed vessel in connection with said conduit and situated in relatively warm zones in order to vaporize under pressure the derived part of theliquefied gas, the gas under pressure in said closedvessel constituting a gas cushion damping the Workin of the ump.

apparatus or vaporizing liquefied go gases which. comprises a container, 9, determined bulk .of noncirculating water enclosed in said container, exchange means immersed in the said bulk of water and connected at their upper end to a distributing pipe for 55 liquefied gas and at their lower end to a discharge pipe for vaporized gas.

apparatus for vaporizing liquefied gases which comprises a container, a determined bulk of noncirculating water enclosed so in said container, several slnuous tubes in parallel situated in vertical planes, immersed in the said bulk of water and simultaneously traversed by the liquefied gas from their upper end connected to a distributing pipe for as liquefied gas to their lower end connected to a discharge pipe for va mind as.

In witness whereof l have ereunto set i my hand.

- CHARLES PICARD. 40