US3369372A - Liquid helium distribution system - Google Patents

Description

Feb. 20, 1968 J. KLEINHAUT ET AL Original Filed May IL 1966 L/QU/D HEL lUM a a i k/ v PS I F' 20 8 (22 0 [VAPOR/25R ICOMPRESSOR' L/QU/D A 2 CYLINDER I 5 6 F/LL i V d TO 40 CUSTOMER INVENTORS JOSEPH KLElNHAUT MARK M. LEE ARNO RA AG ATTORNEY United States Patent OfiFice 3,369,372 Patented F ab. 20, 1968 3,369,372 LIQUID HELIUM DISTRIBUTION SYSTEM Joseph Kleinhaut, Livingston, Mark M. Lee, North Bergen, and Arno Raag, West New York, N.J.,

assignors to Air Reduction Company, Incorporated, New York, N.Y., a corporation of New York Continuation of application Ser. No. 550,751, May 17, 1966. This application Apr. 17, 1967, Ser. No. 631,550 14 Claims. (Cl. 62--52) ABSTRACT OF THE DISCLOSURE An apparatus and process for the eflicient handling of liquid helium supplied to a demand in either liquid or gaseous form through a simple and efiicient distribution system in a manner so as to minimize losses.

This application is a continuation of application No. 550,751, filed May 17, 1966, now abandoned.

The present invention relates to the eflicient handling and delivery of helium.

More particularly, the present invention relates to the efficient handling of liquid helium supplied to a customer in either liquid or gas form through a unique distribution system in a manner so as to minimize losses.

Helium is a relatively expensive. product. In the past, when it has had to be distributed over relatively long distances, it has been transported in gaseous form. Transportation of helium in liquid form has necessitated an elaborate and expensive recovery system. However, it is advantageous to transport helium in liquid form since larger quantities can be transported per truck full of liquid than gas, making transportation of this rare gas more economical, especially since the liquid can easily be transformed into gas while still having a capability of supplying the liquid user with his requirements.

The difiiculty in the past has been in designing an efficient system for distributing the helium so that losses of helium in the handling of the helium would be substantially eliminated, while not requiring encumbering capital investment for complicated apparatus to insure maximum recovery of the helium. Contamination of the helium liquid or gas to which it is transformed also must be insured against.

It is therefore an object of this invention to design a distribution system for use with a liquid helium transport and/or storage container which allows for both helium liquid and helium gas recovery with a minimum of losses in handling.

It is a further object of this invention to provide a simple and eflicient system for supplying helium from a vessel. 7

More specifically, it is further an object of this invention to provide a simple and efficient system for supply- I ing, with minimum losses, either liquid or gaseous helium from a movable liquid helium trailer source to a customer.

Other objects and advantages of this invention will become more apparent upon reading the following more detailed disclosure.

As previously stated, helium is a relatively expensive product. The philosophy in setting up a helium distribution system is at all times to minimize helium losses in handling. Helium is produced in relatively few locations spread relatively far apart. It is not uncommon to transport helium many hundreds of miles before it is supplied to the customer.

The system for supplying helium to be described hereinafter is to be used, for example, with a liquid helium trailer source, usually one that has transported the helium to the point of distribution. It is emphasized that it is intended that said system may be utilized with stationary liquid helium tanks as well as transportable trailers. The trailer vessel carrying the liquid helium may be used for example both for transport of the liquid helium and to store it at a distribution terminal.

Throughout the specification which follows, applicants will refer to liquid helium storage with a liquid and gas phase. It is understood, however, that this terminology embraces storage in the trailer or storage vessel of helium under pressure conditions which either (1) make the helium contained therein of a single phase; or (2) allow helium contained therein to be in the two-phase condition.

Generally speaking, the distribution system which is the subject of our invention provides for liquid filling from the trailer or storage vessel to a smaller (as compared to the trailer) customer liquid storage container, sometimes called a dewar. That liquid filling and gas supply, which is believed to be the major customer consideration, is supplied generally in the following manner.

Gas (or single phase helium, in the case of single phase storage) supplied from the upper portion of the liquid helium trailer or storage vessel is supplied through a vaporizer and compressor to the gas customer. At times, liquid is withdrawn from the trailer or storagevessel, vaporized to gas, and then compressed before being supplied to a customer. Flash gas evolving from the liquid filling of said smaller liquid container combines with the helium supplied from the trailer or storage vessel for compression into warm helium gas containers or supply of other customer demand. If the pressure in theliquid helium storage container falls below a certain pressure limit, then liquid helium is withdrawn from the trailer or vessel and efiiciently vaporized and supplied back as gas into the liquid helium trailer or vessel in order to raise the pressure.

This system will now be described in more detail in relation to the accompanying drawing, which shows in schematic form the distribution system which is the subject of this invention.

Referring to the drawing, a helium source, hereafter called a vessel, which may be, for example, a transportable trailer or a storage vessel, is shown at 1. That vessel 1 supplies liquid helium through a liquid discharge line 3 to smaller containers for customer use, said smaller containers being shown at 2. A second liquid discharge line 4 directs liquid helium from the vessel 1 through a helium discharge line 40, and then to a vaporizer 5 (to superheat it) and a compressor 6, and then to a customer as shown in the drawing. A third discharge line 7 extends from the upper part of the helium vessel ii and is in con nection with the discharge line 40 previously described, and then to the vaporizer 5, compressor 6, and customer. The discharge line 7 conducts gas (or high density single phase cold helium if that is in fact what the helium source contains, as discussed previously) from the upper part of the vessel 1 to the discharge line 40 and then to the vaporizer. A connecting line 8 transports flash vapor evolved from the filling of the liquid cylinders 2 to the discharge line 4 (or alternatively, but not shown, directly to the discharge line 40) for supply to the customer.

The pressure in vessel 1, for example about 3 to 5 p.s.i.g., will supply liquid to the liquid cylinder 2 when valve 20 is open. The higher the trailer pressure, the more flash vapor will be generated for a given transfer of helium liquid from the vessel 1 to the cylinder 2. The compressor 6 is maintained at a compressor suction of only a few inches of water above the atmospheric so as not to create an excessive back pressure in the smaller liquid helium cylinders 2. This compressor suction pressure, however, will insure against air leakage into the system. Flash vapor which does evolve from the filling of the cylinder 2 is recovered through line 8.

Gas will be withdrawn from the vessel 1 through a valve 11. The action of the valve 11 may be manually controlled or alternatively controlled by a pressure control device 21. Upon the opening of valve 11, gas from the vessel 1 is supplied through the line 7 to the supply line 40, the vaporizer 5, the compressor 6, and then to the customer demand. A second gas removal line 9 from the container 1 is provided only to be utilized in emergency situations to keep the trailer 1 within the maximum pressure safety limit prescribed. Flow through said line 9 may be controlled through a standard safety valve shown, for example, at 22.

If vapor flow through line 7 and/or line 8, while the liquid is being supplied to the cylinder 2, is not suflrcient to supply the compressor suction, then a pressure control mechanism 10 monitoring the flow in line 40 will operate to open line 4 through the valve 12 in order to augment the flow requirement. Again, the operation of valve 12 may alternatively be manual. Liquid supplied through valve 12 is vaporized in the line or in the vaporizer (depending on conditions) compressed to, for example, about 3000 psig. in the compressor 6, and supplied to the customer.

If the pressure in the vessel 1 falls below a certain minimum limit, for example about 3 p.s.i.g., below which the flow rate in the system is diminished, a valve 13 responsive to a pressure control device 14, monitoring pressure conditions within the trailer (valve 13 alternatively may be manually controlled) will open in order to reroute at least a portion of the helium in line 4 derived from the trailer back through the line 7 into the vessel 1 as a gas, in order to raise the pressure above the minimum level. The helium will vaporize before reaching the vessel 1, and such vaporization can be abetted by the use of a heat exchanger, not shown.

The vaporizer 5 may be of any chosen design, for ex- :ample a hot Water vaporizer with an electric heater used .as the heat source. The compressor 6 may also be of any desired design, preferably a nonlubricating machine capable of compressing helium gas from atmospheric pres- ;sure to at least 3000 p.s.i.g.

None of the details of the process or apparatus described above or shown in the drawing should be construed so as to limit applicants invention. Rather applicants invention should be limited only by the scope of the following claims.

We claim:

1. A process for the eflicient supply of helium from a vessel to meet a demand comprising the steps of supplying helium in gaseous form from said vessel, supplying liquid helium from said vessel when the gas supplied does not satisfy said demand, passing said helium supplied through a vaporizer to vaporize and superheat it, compressing the helium after passing it through the vaporizer, directing the compressed, vaporized heated helium to the demand, and returning helium supplied from the vessel in liquid form back to the vessel in gaseous form when the pressure in the vessel falls below a minimum pressure limit.

2. A process as set forth in claim 1, further comprising the steps of filling a small container with liquid helium supplied from the vessel, drawing flashed vapor from said liquid filling, and combining said flashed vapor with said helium to be passed through said vaporizer.

3. A process as set forth in claim 2, further comprising the steps of controlling the quantity of supply of liquid helium from the vessel directed to the vaporizer in relation to the quantity of vapor contemporaneously drawn from the filling of the container and supplied from the vessel.

4. A process as set forth in claim 3, the minimum pressure limit being about 3 p.s.i.g.

5. Apparatus for the eflicient supply of helium from a vessel comprising vaporizing means, compressing means, means connecting the vaporizing means to the compressing means, means for supplying helium as a gas from the compressing means to meet a demand, means connecting said vessel to means leading to said vaporizing means for directing liquid from said vessel to said vaporizing means, additional means connecting said vessel to said means leading to said vaporizing means for directing gas from said vessel to said vaporizing means, valve means for controlling movement of gas from said vessel into said means for directing gas, and additional valve means for directing liquid, taken from the vessel in the means for directing liquid, back to the vessel in the form of gas when the pressure within the vessel falls below a minimum pressure limit.

6. Apparatus as claimed in claim 5, further comprising pressure responsive means responsive to the pressure within the vessel to open said additional valve means when said pressure falls below said minimum pressure limit.

7. Apparatus as claimed in claim 6, further comprising means for delivering liquid from said vessel to a container, means for transporting substantially all flashed vapor from said last-mentioned liquid delivery means and said container to said means leading to said vaporizing means.

8. Apparatus as claimed in claim 7, further comprising still additional valve means for controlling the quantity of liquid directed from the vessel to the means leading to the vaporizer, and pressure responsive means for actuating said last-mentioned valve means upon monitoring the supply of flashed vapor from the small container plus from the gas directing means.

9. Apparatus as claimed in claim 5, further comprising additional pressure responsive means dependent on the pressure in said vessel for actuating the first-mentioned valve means.

19. Apparatus as claimed in claim 6, the minimum pressure limit being about 3 p.s.i.g.

11. A process for the eflicient supply of helium from a vessel to meet a demand comprising the steps of supplying helium in gaseous form from said vessel, supplying liquid helium from said vessel when the gas supplied does not satisfy said demand, passing said helium supplied through a vaporizer to vaporize and superheat it, compressing the helium after passing it through the vaporizer, directing the compressed, vaporized heated helium to the demand, filling a container with liquid helium supplied from the vessel, drawing flashed vapor from said liquid filling, and combining said flashed vapor with said helium to be passed through said vaporizer and controlling the euantity of liquid helium supplied from the vessel and directed to the vaporizer in relation to the quantity of vapor contemporaneously drawn from the filling of the container and supplied from the vessel.

12. Apparatus for the efficient supply of helium from a vessel comprising vaporizing means, compressing means, means connecting the vaporizing means to the compressing means, means for supplying helium as a gas from the compressing means to meet a demand, means connecting said vessel to means leading to said vaporizing means for directing liquid from said vessel to said vaporizing means, additional means connecting said vessel to said means leading to said vaporizing means for directing gas from said vessel to said vaporizing means, valve means for controlling movement of gas from said vessel into said additional means, means for delivering liquid from said vessel to a container, means for transporting substantially all flashed vapor from said last-mentioned liquid delivery means and said container to said means leading to said vaporizing means, valve means for controlling the quantity of liquid directed from the vessel to the means leading to the vaporizing means, and pressure responsive means for actuating said last-mentioned valve means when the pressure in the means leading to the vaporizing means drops below a desired minimum pressure.

13. A process for the efficient supply of helium from a vessel to meet a demand comprising the steps of supplying helium in gaseous form from said vessel, supplying liquid helium from said vessel when the gas supplied does not satisfy said demand, passing said helium supplied through a vaporizer to vaporize and superheat it, compressing the helium after passing it through the vaporizer, directing the compressed, vaporized heated helium to the demand, filling a container With liquid helium supplied from the vessel, drawing flashed vapor from said liquid filling, utilizing said flashed vapor to at least partially meet the demand.

14. A process as set forth in claim 11, further comprising, maintaining the pressure in the vessel above a minimum pressure limit by returning gaseous helium to the vessel When the pressure in the vessel falls below the minimum pressure limit.

References Cited LLOYD L. KING, Primary Examiner.

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