A study of porous plug use for vapor-liquid phase seperation in spaceborne cryogenic systems was conducted. The three main topics addressed were: (1) the usefulness of porous media in designs that call for variable areas and flow rates; (2) the possibility of prediction of main parameters of porous plugs for a given material; and (3) prediction of all parameters of the plug, including secondary parameters

Frederking, T. H. K.

Hepler, W. A.

Yuan, S. W. K.

English

NASA Technical Reports Server

VAPOR-LIQtJID PHASE SEPAPATOcl STUDIES 
-TRACT NCC 2-64 
~ugust 1985 
https://ntrs.nasa.gov/search.jsp?R=19850023959 2020-03-20T18:12:55+00:00Z
NASA CONTRACTOR REPORT 166545 
VAPOR-LI QUI D PHASE SEPARATOR STJBI ES 
S.U.K.Yuan 
b.A.Hepler 
T.H.K.Frederking 
School of Engineering and Applied Science 
University of California a t  Los Angeles 
Los Angeles, CA 99024 
Prepared foe 
Arnes Research Center 
Under Contract NCC 2-64 
h g u s t  1985 
4atiorial Aerwrautics and 
SWce Admintslntion 
FINAL REPORT - NASA GRANT 2-64, Suppl. No.1 * 
1. General S r y  
2. Bibliographical References 
3. dditional References 
4. Thesis Abstra-ts 
5 .  Abstracts of Porous Xedia Papers 
PAGE 
1 
3 
4 
6 
8 
*)The NASA Technical Officer for this grant i s  Dr. Peter Kittel, 
NASA AWES RESEARCH CEKTER. 
1. General Sumnary 
Vapor-liquid phasz separation by means of porous plugs 
("Fairbank plugsw') has been explored siuce the  Seventies in pre - 
paration fo r  f l i g h t  demonstration. The l a t t e r  has been i n i t i a t e d  
in 1983. Tnis year provided data  of the  TIUS system. The r e su l t s  
include ac tual  performance data of porous plugs in  space acting 
a s  important subsystem ~~~~~~ts f o r  the  cryogenic liquid. 
NASA Grant NCC 2-64 i n  pa r t i cu la r  had the  purpose of pro- 
viding answers i n  three  m a i n  a reas  re la ted  t o  porous plug use 
fo r  phase separation. These points  a re  expressed a s  three main 
questions: 
i. Are porous media useful  ev- when design specif icat ions 
c a l l  fo r  variable areas and flaw r a t e s  respectively ? ; 
2. Is it possible t o  predict  main parameters of norous 
plugz f o r  a pa r t i cu la r  material  selected ? ; 
3. Is it possible t o  predic t  all parameters of the  plugs 
including secondary ones ? . 
Area 1 is a l s o  referred t o  a s  flow m~dulet ion R & D work 
based on porous media, and this question has been answered by a 
pa r t i c s l a r  demonstration of a device using a s t a i n l e s s  s t e e l  
plug. This work is described i n  the CEC paper l i s t e d  i n  Section 2. 
Area 2 is i n  between the  simple packed bed system of spheres 
and the  conplex s i tua t ion  delineated as  area 3. The  l a t t e r  has 
been found t o b e  qui te  complicated.?hts,partial progress has been 
achieved re la ted  primarily t o  questions of area 2 .In par t icular ,  
there has been a lengthy search fo r  charac ter is t ic  lengths de- 
termining the throughput. This e f f o r t  led t o  the  proposal t o  emplop 
a s ing le  cha rac te r i s t i c  length LC which i s  the square root of the  
pemeabi l i ty  of the  plug. The r e s u l t s  obtained , l i s t e d  i n  Section 2, 
so f a r  show tha t  indeed LC is a very useful  pzrameter . Throughput- 
pressure drop functions a r e  conveniently combined i n  dimensionless 
form. The dimensionless groups studied include LC . Srarting from 
Stokes - Darcy solut ions i t  has been possible t o  place upper bounds on 
the  functional range of transport covered by porous p h g  phase separators. 
The studies have been complex because of the  use of d i f ferent  sets of 
parameters by plug manufacturers. The latter deal  primarily with solid- 
f lu id  separatioa, and the  characterizat ion e f f o r t s  a re  directed tclvard 
infcrmation about the so l ids  t o  te f i l t e r e d  out. 
Concerning material  select ion i t  is noted tha t  s t a i n l e s s  s t e e l  
has been preferred . Rovever , the use of a lubricant  during pre- 
s intering operations jntroduces more complicated conditions than in 
near-spherical p a r t i c l e  beds . Examples of the l a t t e r  a r e  Imam from 
basic s tudies,  and bronze plugs and tungsten plugs have been found t o  
be re la t ive ly  c lose  t o  packed beds of near-spherical par t ic les .  In  
part icular ,  experiments have been run on the sleallest bronze plug 
ccmmercialiy available . It turns out t h a t  the  zero net  mass flow 
mode const i tu tes  an asymptote ro  the  phase separation mode when 
the temperature is lowereC. 
Concerning area  3 , the  s tudies  so f a r  have indicated tha t  there 
exis t  secondary parameters fo r  each type of plug. They a re  modifying 
the length Lc,to some extent,along with the  flow charac ter is t ics  of 
laminar and turbulent flow. Thus, a basic frame of reference has 
been achieved up t o  t h i s  point,  and more detai led work concerning 
the usefulness of the  frame fo r  d i f f e ren t  classes of plugs appears 
t o  be the next step. 
Detai ls  of the  work carr ied out a r e  l i s t e d  i n  the subsequent 
bibliographical data sections. 
* 
2. BIBLIOGRAPHIC& REFERENCES 
a. Paper Presentations at Conferences 
"Sintered Plug F l w  Modulation of a Vapor-Liquid Phase Separator 
For a Helim I1 Vessel ", T.H.K. Frederklng, C. Cinuang, Y. Kamioka, 
J.H. Lee and S.W.K. Yuan , Paper CB-3 , presented at Cryogenic Enpg. 
Conference, Colorado Springs, Aug. 1983; 
"Plug Flaw Comparison", S.W.K. Yuan, J.M. Lee and T.H.K. Frederkicg, 
Paper presented at Space Helium Dewar Conference and Workshop, sponsored 
by NASA, Marshall Space Flight Center and Organized by the University of 
Alabama in Huntsville, Alabama 35899 ; 
b. Publications 
"Sintered Plug Flow Modulation of a Vapor-Liquid Phase Separator 
for a Helium I1 Vessel" , T.H.K. Frederking, C. Chuang, Y. Kamioka, 
J.M. Lee and S.W.K. Yuan, accepted for publication in Volume 29, Advances 
in Cryogenic Engineering, (expecced to be publish& in 19P4). 
"Plug Flow Comparison" , listed under (a) is expected to be published 
by the organizers in 1984. 
c. Thesis Work 
Sidney W. Yuan, The Characterization of Sintered Stainless Steel 
Porous Plugs for Vapor-Liquid Phase Separetim of Re I1 , M. Sc. thesis, 
University of California , Los ageles 1981 . 
Jeffrey Marshall Lee, Permeabilities of Sintered Porous Metal Plugs 
and Transport Rates of Vapor-Liquid Phase Separators for Helium I1 
Vessels, M. Sc. thesis, University of California, Los Angeles 1983. 
*I 
Additional work related Cu part to these topics is compiled in Section 3. 
3. ADDITIONAL REFERENCES RELATED I N  PART 
TO NASA GRANT NCC 2-64 
There has been preceding work on porous plugs l i s t e d  be lw .  
I n  addi t ion,  an NSP Grant has  been concerned with thermo-osmotic 
t ransport  phenomena. In  general ,  porous plugs w i l l  be subject  t o  
thermal boundary condit ions of a non-adiabatic na ture  (diatherraall 
diathermic boundaries with f i n i t e  heat t r a n s f e r  r a t e s ) .  This 
point has been ~ a d e  by U. Schotte  ( Physlca 107B, 1981,577-578 ) 
f o r  w a l l  e f f e c t s  of non-isothermal p in  devices used f o r  phase 
separation. I n  addi t ion  the re  may be t r ans i en t  e f f ec t s .  Thus, there  
may be an ind i r ec t  r e l a t i o n  t o  sol id-  He I1 in t e rac t ion  , i n  
pa r t i cu l a r  during acc identa l  anomalies of system operation. The 
f l w  modulator l i s t e d  i n  Section 2 incorporates  a ro t a t ab l e  shut ter .  
There has been a previous phase of ro t a t ing  I?e4 research (supported 
by an NSF Grant). I n  l i n e  with these addi t iona l  top ics ,  papers 
i n  those ca tegor ies  a r e  l i s t e d  below. 
3a. Preceding work 
"Vapor-Liquid Phase Separation of Cryogenic Liquid Storage 
4 Systems Below the  Lambda Point (He 1, C. Chuang, Y.I. K i m  
and T.H.K. Frederking, Cryog. Proc. Equipment, ASME Publ. No. 
800164, pp. 135-140, 1980. 
3b. Thermo-Osmctic Transport Phenomena 
"Darcy Law of Thermo-Osmosis f o r  Zero Net Mass Flow a t  Low 
Temperatures", S.W. K. Yuan and T.H.K. Frederking, Proc. - ASME- 
JSME J o i n t  Thermal Engng. Conf., Eonolulu, March 1983, Vo1.2, 
pp. 191-197 (1983). 
3c. Thennal Boundary Conditions Including T r a s l e n t s  
"Transient Triple-Phase Transi t ions i n  Superfluid Liquid 
Helium 11, C. Chuang, Y. Kamioka and T.H.K. Frederking, Adv. 
Cryog. Engng. 27, 1982,pp. 493-500. 
3c. Thermal Boundary Conditions (contin.) 
"Formvar Coating Effects on Heat Transfer from NbTiICu to 
Liquid Helium: Dynamic Evaluation of the Formvar Thermal Con- 
ductivity, L.H. Lin, C. Chuang and T.H.K. Frederking, ICEC-9, 
Proc. 9th Int. Cryogenic Eng. Conf., Kobe, pp. 57-60, 1982. 
"Influence of the Kapitza Resistance on Nucleate Boiling 
of Liquid Helium" L.H. Lin and T.H.K.  Frederking, Letters in 
Beat and Mass Transfer 9, pp. 473-478, 1982. 
"Transient Superconductor (NbTi/Cu)- He I1 Heat Transfer 
Rates to Pressurized Superfluid During Step Input in Power, 
C. Chuang, Y. Kantioka and T. H. K. Frederking , Ref rigeration 
Science and Technology, Int. Inst. Ref rig. , Vol. 1981-6,pp. 
63-68, 1981. 
"Quenches of Formvar-Coated NbTiICu Caused by Step Input in 
Power", L.H. Lin, C. Chuang, Y.I. Kim and T.H.K. Frederking, 
IEEE Trans. Magnetics , Vol. HAG-19, pp. 212 - 215, 1983. 
3d. Rotating Helium at Low Temperatures 
"Axial Transfer Tube Heat Leak of Rotating Superconducting 
Machines: Fluid Contribution, 'f.1. Kim, C. C 5 r .  -I-- and T.H.K. 
Frederking, IEEE Trans. Magnetics, Vol. HAG-17, pp. ,?O - 133, 
1981. 
"Irreversible Thermodynamics of Cryo-Fluid Convection 
(Newtonian Fluid Convection), Y.I. Kim and T.H.K. Frederking, 
AIChE Symposium Series No. 224, Vol. 79, pp. 114 -119, 1983. 
3e. He I1 Convection 
"Influence of Forced Flow on the He I1 - He I Transition 
in the Presence of Heat Flow", S. Caspi and T.H.K. Frederking, 
J.  Heat Transfer, Vol. 105, pp.846 - 850, 1983. 
A B S T R A C T  0 F T H E S I S  
The Characterization of Sintered 
Stainless Steel Porous Plugs for 
Vapor-Liquid Phase Separation of He 11 
Sidney U. Yuan 
Master of Science in Engineering 
University of California, U s  Angeles, 1981 
Professor Traugott H. K. Prederking, Chairman 
The vapor-liquid phase separation of Re I1 by means 
of porous plugs has been of great importance in long-term 
storage of cryogenic liquid for space equipments. It is 
the purpose of this vork to study the properties of sintered 
stainless steel porous plug with a nominal pore sisd of 
2 PI. The pemeability (K ) at various temperatures wzs P 
4 measured by passing 9e gas through the porous plug at 
room tempe~ature, liquid nitrogen temperature and liquid 
helium temperature. In agreement with Darcygs law Z was 3 
2 found to be 5.65 X lo-' cm at room teaperatwe and 
2 L = 4.9 X 10" crn at 77.4 X. The decrease in perme- 
P 
ability found e-xperinentally was larger than the contractioa 
rate of bulk stainless steel. Using the assumption that 
the pores of the plug are o2de of capillary ducts or slits, 
a hydraulic radius of 1.33 X cn was found. In fitting 
the experimental datz by 3r,pn1s equation for gacked beds, 
a particle diaceter of 3.3 X lo-' cam was evaluated. The 
porous plug was further ch~xacterized by studying the flow 
of He I1 in the plug. The normal fluid permeability (K?), 
was calculated. It was found that (K ) was lower than 
P n  
the classical permeability. As temperature was lowered, 
(K ) increased and a~proached the order of magnitude of P n  
the classical value. Therzal circulation convection m s  
found to occur in the porous plug. 
A B S T R A C T  O F  T H E S I S  
Penreabilities of Sintered Porous Petal Plugs and Transport Raks 
of Vapor-Liquid Phase Separators for  He1 ium 11 Vessels 
by 
Jeffrey Harshall Lee 
Master of Science f n Engineering 
llnivcrsity of California, Los Angeles, 1983 
Professor Traugott H. K. Frederking, Chair 
Sinteted stainless steel and bronze porcus plugs (pore size fm 
2 t o  10 w) have been characterized for  cryogenic liquid-vapor phase 
separation in dewars, i n  particular l iquid He 11 vessels. k s u r e d  
permeabilities (K of Darcy's law) o f  the 2 s ta inless  steel p l u ~ s  P 
sha. a 10: mduction f n n  300 K t o  77 K with 5 = (5.03=CI.3)~10-~ d 
and 5 = (3.2dl.3)xl0-~ anZ . Plugs of pore s i ze  greater than 5 rmr 
- 
she* "p (3.01~).03)~10'~ a? (5  w stainless  s t e e l ) ,  and 5 = (1.016 
d.045jx10" d (5 to  15 w f i l t r a t i on  sire, bronze). 
Oata far zero net mass flow through an insulated 2 urn plug i n  
He I1 agree w i t h  a modified Darcy equation of theno-osmsis based on 
n o m l  f luid properties, and with related l i t e ra ture  values. The vis- 
cosi ty fs re?laced by the nonral f luid viscosity %, and the driving 
Pressure gradient is  the them-osmotic (thennomechanical) gradient, 
9. me superficial flo* saeed of n o w 1  f lu id  f l o w  i s  ;no = K ~ ) ~  
vP,hn (supe*icial heat flux density go = P ~ ~ ; n o ,  (pST) thermal 
- 
energy density). A t  large OPT, vno-data are below the Oarcy value 
due to  turbulence, In the turbulent range, a modified Gorter-Hellink 
(M) equation i s  proposed for  4, with an aeus tab le  parameter (KM). 
is found to be a monotonically increasing function of the Don 
size (within the precision of plug definition) for  zero net ;nass flow 
and phase separation. In addition, a phase separation device with 
variable cross section has been successfully tested w i t h  f l  an changes 
of up t o  260% of .the mean value. 
5. Abstracts of Porous Media Papers 
C. Chuang e t  a l .  (1980). 'Vapor-Liquid Phase Separation.. " 
I n  cry-vessels f o r  space equipment , vapor-liquid phase 
separat ion by means of porous plugs has been of in te res t  i n  
severa l  advanced systems (e.g. i n f r a r ed  telescopes).  Plug operat ion 
is character ized by coupling of t h e  mass throug.,put t o  t h e  entropy 
r e j ec t i on  r a t e  required f o r  cont ro l led  vaporization. The l a t t e r  i s  
accomplished by u t i l i z a t i o n  of t h e  l a t e n t  heat  of vaporizat ion on 
the  vent s ide.  For defined entropy r e j e c t i o n  a most usefu l  quant i ty  is 
the  nonaal f l u i d  f l w  r a t e  which has t o  be known f o r  t he  thermo- 
osmotic conditions of t he  plug. Porous media concepts have been 
applied i n  a parametric study of var ious  quan t i t i e s  of i n t e r e s t  
fcr the  flow ra te .  This approach leads  t o  r e l a t i v e l y  simple so lu t ions  
f o r  small t ranspor t  ra tes .  A comparison of t h e  l imited da ta  ava i l ab l e  
with pred ic t ion  shows p a r t i a l  agreement i n  t he  conductance r a t i o  of 
phase separat ion expressed a s  entropy t ranspor t  r a t i o .  
T.H.K. Frederking e t  a l .  (1983) ,I1 S intered Plug Flow Modulation . . " 
A s in t e r ed  s t a i n l e s s  s t e e l  system is described which has the  
purpose of ac t ing  a s  a vapor-liquid phase separator  between a l i qu id  
H e  I1 bath and the  vapor vent  l i ne .  A va r i ab l e  c ross  s ec t i ona l  a rea  
component is incorporated i n  order  t o  modulate t he  mass flow r a t e  
through the  separator .  System d e t a i l s  and da ta  a r e  presented. 
S.W.K. Yuan et  a l .  (1983) ," Plug Flow  omp par is on". 
Flow through porous media tncluding s in te red  phase separa tors  
plugs at low temperatures has been invest igated f o r  plugs i n  t he  pore 
s i z e  range from 1 t o  1 0  pm. Experiments have been conducted i n  t he  
l i qu id  Helium 11 range with 2 p s t a i n l e s s  s t e e l  plugs (nominal 
re ten t ion  s i z e  of f i l t r a t i o n ) .  It i s  proposed t o  provide a common 
frame of reference f o r  t h i s  type of plugs by means of t h e  m o d i f i ~ d  
Darcy flow permeabili ty of normal f l u i d  t ransport .  
5. Abstracts of Porous Plug Papers (contin.) 
S.W.K. Yuan et al. (1983), I' Darcy Law of ~hermo-~smosis.." 
In frequently used solid-fluid material combinations of 
porous media systms, the thermal conductivity of the solid is 
significantly larger than the fluid values. In contrast, at low 
* temperatures the solid k-value may be quite small, and thr 
fluid may reach high k-values locally cr over an extended 
temperature range. In Helium-4 below the lambda temperature (= 
superfluid He 11) thermo-osmotic forces dominate transport 
phenomena. Darcy transport at low speeds in the laminar range is 
studied for the material combination of low conductivity solids 
and He 11. The continuum conditions of the two-fluid model 
are considered. The resulting thenno-osm~tic equation does not 
depend on the superfluid density ratio explicitly. The theoretical 
results obtained are compared with various data for different 
types of porous media. Good agreement with prediction is found 
within uncertainty limits associated with porous meJia 
characterization. 
* 
k thermal conductivity and apparent value associated with con- 
vection respectively. 
NASA CR 166545 I 1 
- 
4. fith .nd aubt~w 1 a t w m b m  1 
I Vapor-Li qu i  d Phase Seoarator Studies 
Sihl.KYu~n, W.A.Hepler and T.H.K.Frederking 
- , 
9 i%fomkg o~~rua.ran ~ ( m  nd ~edrml  
15 su-v Notn 
Poin t  o f  Contact: Teck?ical Yoni t o r ,  Peter Ki t t e l ;  Y/S 244-10 1 
10 W u k  W No. 
T6624 
School o f  E n g i n ~ e r i  nq and Appl i e d  Science 
IJniversi t y  o f  C a l i f o r n i a  a t  Los Angeles 
Los Anseles, Ck 90024 
- 
12 konronnp-rNmmdAddrra 
Natioaal  Aeronautics and Space Administratio11 
Washington DC 20546 
Ames Research Center, n o f f e t t  F:el d ,  CA 94035 
41 5-694-6525 o r  n S  464-6525 
- 
11. Comnec or GnM No. 
YCC 2-64 - 1. NO. 1 
13. TVP of R* rd hid t h m d  
F ina l  repor t  ,1980-:993 
14. Soormring hgmq codr 
506-54-21 
16. Abm.cl 
Compi l a t i o n  o f  pub1 i ca t i ons  and tbes i s  tha t  resv l  ted from t h i s  cont ract .  
These references addressed the f o l  lw i  ng quest ions: 
1. Are porous media usefu l  even when design speci5icaions c a l l  f o r  
va r iab le  areas and f low ra tes respect ive ly? 
2. I s  i t  poss ib le  t o  p r e d i c t  main parameters o f  porous plugs f o r  a 
p a r t i c u l a r  mate r ia l  selected? 
3. I s  i t  poss ib le  t o  p red i c t  a l l  parameters o f  the plugs inc lud ing  
secondary ones? 
porous plugs 
supe r f l u i d  he1 ium 
space cryogen i cs 
UNCLASSI FIED-UNLIMITED 
STAR Category - 34 
'For ulr by t h  Nctio:d T c h i  Informotion Sllwcr. wn#i.ld. V i v n ~ u  22181 
I 
19. Srvi* Orit. (ol thm npwt) 
UNCLASS l Fl ED 
22.w0 20. Scuiw W t .  toa mi# -1 
UNCLASS l F l  ED 
2 1 . I Y o . o f ~  
1 1  


Vapor-liquid phase separator studies

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server