Venting device for liquid propellant storage tank using magnetic field to separate liquid and gaseous phase

Graham, R. W.

Papell, S. S.

English

NASA Technical Reports Server

S. S. PAPELL ETAL 3,295,545 
LIQUID STORAGE TANK VENTING DEVICE FOR ZERO 
3, 196 
GRAVITY ENVIRONMENT 
Filed Dec. 13, 1963 
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FIG. 3 FIG. 4 
BY 
INVENTORS 
ROBERT W. GRAMAM 
A&?& 
ATTORNEYS 
A- 
https://ntrs.nasa.gov/search.jsp?R=19700032330 2020-03-17T02:12:09+00:00Z
tates Patent ffice 
1 2 
3,295,545 
Solomon Stephen Papell, Beres, and Robert W. Graham, 
Parkview, Ohio, assignors to the United States of 
Ameriea as represented by the Administrator of the 
Nati0n.a Aeronautics and §pace Administration 
CE FO 
Filed Dec. 13,1963, Ser. No. 330,209 
1 Claim. (CL 137-197) 
The invention described herein may be manufactured 
and used by or for the Government of the United States 
without the payment of any royalties thereon or therefor. 
The present invention relates, generally, to a venting 
device and, more particularly, to a zero-gravity venting 
device for vessels or tanks storing magnetic fluids such 
as those disclosed in co-pending application Serial No. 
315,096 filed October 9, 1963 now Patent No. 3,215,572, 
issued November 2, 1965, and having a common assignee. 
Under the zero-gravity environment of outer space, 
fluids such as cryogenic fluids or liquid propellants be- 
come disoriented with the result that, the liquid and 
vaporous phases of the fluid are free to disperse and 
intermix throughout the storage tank. From this condi- 
tion ensues the problem of proper tank venting since 
radiant heat gain to the storage tank from space causes 
a dangesous pressure bvild-up within the tank which must 
be compensated for in I der to prevent tank rupture and 
to insure that pump bdet pressures are within design 
limitations so that pua,ping may be successfully carried 
out. Of course, the storage tank or pump could be built 
with thickened containing walls and heavier moving parts, 
but the excessive weight caused thereby would engender 
a large energy penalty, necessitating heavier and more 
cumbersome lower stage boosters or lowered payload. 
A more advantageous solution to this problem would 
seem to be the use of a tank venting device to bleed off 
excess pressure. However, since the gaseous and liquid 
phases of fluid are intermixed, the use of normal venting 
devices would result in the loss of large amounts of 
usable liquid. 
Accordingly, it is an object of the invention to provide 
a venting device which is operative under zero-gravity 
conditions. 
It is another object of the invention to provide a 
venting device which orients the fluid by magnetic force. 
I t  is still another object of the invention to provide a 
venting device which selectively vents only the gaseous 
phase of fluid from the storage tank. 
It is yet another object of the invention to provide 
a venting device for use with a magnetic propellant such 
as disclosed in the aforementioned co-pending application. 
A more complete appreciation of the invention and 
many attendant advantages thereof will be more readily 
appreciated as the same becomes better understood by 
reference to the following detailed description when con- 
sidered in connection with the accompanying drawing 
wherein like numerals are used to identify like parts in 
both embodiments. 
In the drawings: 
FIG. 1 is an elevation view in section of one embodi- 
ment of the invention showing the vent port closed. 
FIG. 2 is a view of the venting device of FIG. 1 in 
larger scale showing the vent port open. 
FIG. 3 is an elevation new partly in cross section of 
an alternate embodiment of the invention showing the 
vent port in closed position. 
FIG. 4 is a view of the venting device of FIG. 3 with 
the vent port open. 
According to the present invention, the foregoing and 
other objects are obtained by providing a novel venting 
device for a fluid storage means in which the liquid and 
vaporous phases of the fluid are selectively separated and 
the gaseous phase vented to space. A magnet is utilized 
to orient and separate the two phases of the fluid while a 
6 movable valve element mounted in the venting device 
permits the separated vaporous phase to exhaust to  space. 
Additionally, a pressure sensitive means is provided to  
control operation of the valve element. In a further re- 
finement of the invention, the movable valve element is 
10 solenoid operated and is disposed as to clear the venting 
device of entrained liquid, returning it to the storage 
tank by a piston-like motion. In this embodiment a 
timing means is also provided to regulate the time se- 
quencing operation of the solenoid. 
Referring now to the drawings, where throughout like 
numerals are used to indicate like elements, there is 
shown in FIGS. 1 and 2 one embodiment of the invention 
wherein a tank and venting assembly 10 is provided with 
a storage tank 12 in which the liquidous phase 14 and 
20 gaseous phase 16 of the fluid 17 are stored. Because of 
the absence of any gravitational force on these phases, 
they are randomly dispersed and intermixed throughout 
the tank 12 (as best seen in FIG. 1).  Venting device 18, 
fixed to the tank, provides an exit flow passageway from 
25 the tank interior 20 to control excess pressure build-up 
caused by the boil-off of the stored fluid. 
This venting device is sealingly attached to tank wall 
22 by welding or the like to insure that there is no un- 
wanted leakage of the stored fluid to space, and is formed 
30 from a pipe 24 having an inner portion 26, an inter- 
mediate port portion 28, and an end portion 32. The 
inner portion 26 of the vent pipe 24 extends into the 
tank interior 20 and is open thereto to  provide com- 
munication for the gaseous phase of the fluid to the vent- 
35 ing device, while the ports 30 in the intermediate portion 
28 are capable of being alternately opened and closed 
by valve element 36 to permit exhaust of this vaporous 
phase to space. End portion 32 made integral or separate 
from the remainder of the vent pipe closes the end of 
*O the pipe 24 to seal the tank and venting assembly from 
space. Attached between the end portion 32 and the 
valve element 36 is compressed spring 34, this sp&g 
being preloaded tu resist a selected pressure safely with 
45 the design limitations of the tank 12. On the h e r  pOr- 
tion 26 of the vent pipe 24, magnet 38 is mounted so 
as to surround the vent pipe and trap the magnetized 
liquid and prevent its escape to space. 
In operation, as boil-off of the fluid progresses, pres- 
5o sure increases in tank 12 forcing the valve element 36 
against the preloaded spring 34. As the spring com- 
presses, the valve element 36, within the vent pipe 24, 
moves away from sealing engagement with ports 30 to- 
wards the end portion 32 to thereby permit the gaseous 
55 phase 16 of the fluid to escape from the tank in sufficient 
amounts to permit the valve element to again seal the 
ports 30. As set out in the aforementioned co-pending 
applications, the liquidous phase of the fluid 17 has col- 
loidally suspended therein metal particles having magnetic 
Magnet 38 attracts and holds this liquidous 
phase to form a slug which by a process of adhesion or 
surface tension remains held adjacent to the magnet while 
the non-magnetic gaseous phase bubbles through the slug 
and passes out the exit ports. 
Referring now to the embodiment of the invention 
65 illustrated in FIGS. 3 and 4, wherein the venting device 
includes a valve element having solenoid actuation. 
The tank and vent assembly, indicated generally by 
the numeral 40, is provided with a venting device 42, 
70 similar in many respects to the venting device of the first 
embodiment. It includes a vent pipe 44 having an inner 
portion 46 in sealing communication with the tank in- 
15 
6o properties. 
3,295,545 
terior 20 and port and end portions 48, 50, respectively, 
extending outwardly from the tank 112. The vent portion 
48, similarly to the first embodiment, is provided with 
ports 30 through which the gaseous phase of the fluid 
exhausts to atmosphere. 
End portion 50 made either integral or separate from 
the remainder of the vent pipe seals the end of the pipe 
and provides one of the connections for a spring 52. The 
opposite end of this spring is connected to a valve element 
60 and is always under slight compression so as to urge 
the valve element into sealing engagement with the ports 
30. A pressure tap 54 which is sealingly affixed to the 
tank 12 at one end, adjacent to the vent pipe 44, has 
its opposite end connected to a pressure transducer 56 
set for a predetermined pressure safely within the design 
limitations of the tank 112. Leads 57 provide connection 
to an outside power source (not shown) while leads 58 
connect the transducer 56 to a timer 59, for example, a 
time delay relay, which actuates the valve element 60 
through solenoid 62 having windings 64. The timer 59 
holds the valve element open a predetermined time to 
permit exhaust of the gaseous propellant 116 and to pre- 
vent too rapid sequencing of the valve element and then 
switches off the solenoid to permit the valve element 6Q 
to return to the closed position illustrated in FIG. 3. As 
can be easily seen in this figure, this position of the valve 
element 60 discharges any liquid phase 14 of the mag- 
netic fluid back into the tank to prevent a large build-up 
of liquid in the venting device itself. 
The operation of this embodiment of the invention is 
similar to that of the embodiment illustrated in FIGS. 
1 and 2 but, because of the positive solenoid actuation 
and consequent purging of the venting device by the 
valve element, provides somewhat better control over ex- 
tended periods of operation. 
It is clear from the foregoing that the present invention 
may be effectively utilized for venting any stored magnetic 
fluid, and that, obviously, many modifications and varia- 
tions of the present invention are possible in the light of 
the above teachings. It is to be understood, therefore, 
that within the scope of the appended claims, the inven- 
tion may be practiced other than as specifically described. 
What is claimed is: 
5 
10 
15 
20 
25 
30 
35 
40 
b ' 2 &  4 
A venting device for pse with a storage tank adapted 
to contain a magnetic fluid having a liquid phase and 
a gas phase and subject to zero gravity conditions, said 
venting device comprising a vent pipe connected to said 
tank in sealing communication therewith, said vent pipe 
having an inner portion extending into said tank and 
outer portion disposed outwardly of said tank, said inner 
portion having an, open end and said outer portion having 
a closed end; port means in said outer portion of said 
vent pipe; magnetic means disposed around said inner 
portion of said vent pipe to prevent passage of the liquid 
phase of said magnetic fluid from said tank to said port 
means; a plunger-like valve element slidably disposed in 
said vent pipe and having sufficient travel so that the 
end of said valve means facing the interior of said tank 
can move between a point inward of said magnetic means 
and a point outward of said port means; a preloaded 
spring means disposed between said valve element and 
said closed end of said outer portion of said vent pipe, 
said valve means compressing said spring means to un- 
block said port means thereby venting a portion of the 
gas, phase of said magnetic fluid when pressure in said 
tank exceeds a predetermined magnitude, said spring 
means biasing said valve means to a position at which the 
end of said valve means facing said interior of said tank 
is normally positioned inwardly of said magnetic means 
whereby after each venting action, said valve means forces 
magnetic liquid from said vent pipe into said tank thereby 
preventing a build-up of magnetic liquid in said vent pipe. 
References Cited by the Examiner 
UNITED STATES PATENTS 
1,553,737 9/1925 Allingham _ _ _ _ _ _ _ _ _ _ _ _  55-3 
2,305,519 12/1942 Dunmire _ _ _ _ _ _ _ _ _ _ _  137-538 
2,556,906 6/1951 Del Mar _ _ _ _ _ _  137-487.5 XR 
2,575,906 11/1951 Bullard _ _ _ _ _ _ _ _ _  251-65 XR 
FOREIGN PATENTS 
561,861 4/1957 Italy. 
ALAN COHAN, Primary Examiner. 
WILLIAM F. O'DEA, Assistant Examiner. 


Liquid storage tank venting device for zero gravity environment Patent

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