mc kee - thermosiphon reboileres a review
TRANSCRIPT
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HUGH
R. McKEE
latest holdup correlation proposed is the model of Levy
55) with additional empirical relationships between
variables established from actual data applicable to
thermosiphons. Pressure-drop calculations follow the
recommendations of Collier and He witt
14)
who found
agreement with the Lockhart-Martinelli correlation
below a liquid Reynolds number of 2100, and Cheno-
weth-Martin ( 73) above 2100.
Nucleation effects are
considered as a function of liquid film thickness in the
calculation of a maximum flux, thus relating these two
design features to experimental d ata.
A
recent study by Tripathy
(73)
compared the pres-
sure-drop calculation methods of Fair, Hughmark, and
a shortcut method based on an overall average two-
phase density, using data obtained on a 5/8 in., 1 6
gauge, 4.5-ft tube, with w ater as the process fluid.
Agreement was found best using Fair's method, ac-
ceptable for Hughmark's method, a nd rather poor for
the shortcut method. It was recommended tha t the
designer follow the more sophisticated methods for
other than very approximate work.
Design Data Sources
Overall design data, including both local heat-transfer
coefficients and pressure-drop values, started appearing in
the mid-fifties. Piret and Isbin (67) investigated six fluids :
water, carbon tetrachloride, normal butyl alcohol,
isopropyl alcohol, 35 wt
%
KzCOa, and 50 wt %
KzCOa
at atmospheric pressure in a 1-in. nominal copper tube
with a heated length of 46.5 in. Th ey correlated th e
inside heat-transfer coefficient by using a modified
Dittus-Boelter equation
where ha, is the inside average boiling coefficient,
Urn is a log mean velocity assuming homogeneous
flow equals (U mixture outlet
-
U liquid inlet)/ln
erties (surface tension, viscosity, thermal conductivity,
hea t capacity, a nd density, respectively), ur s the surface
tension of water, and D is the characteristic length.
Th e authors also correlated their dat a using t he superpo-
sition technique of convection and pool boiling.
Guerrieri and Talty
(36)
employed a light oil as a
heating medium around a 0.75 in. i.d. by 6-ft long tube
an d a 1.0 in. i.d. by 6.5-ft long tube. Inside wall an d
boiling stream temperatures were measured at 6-in.
intervals along the tubes. Film coefficients ar e pre-
sented for methanol, cyclohexane, benzene, pentane,
an d heptane atmospheric pressure as a function of the
Lockhart-Martinelli parameter X t t . Wall tempera-
tures were found generally to decrease from the bottom
to the top of the tube. Stream- tempera ture distribu-
tions displayed the expected maximum at some inter-
media te point. Th e boiling film coefficient is also pre-
sented in terms of a nucleate boiling correction factor.
Dengler and Addoms
18)
used a
1
in. i.d. by 20-ft
long copper tube in a forced convection study on water,
using radioactive tracers to measure liquid fractions
along the tube. The y present the ratio of the local co-
efficient to the liquid-phase coefficient as a function of
the reciprocal of the Lockhart-Martinelli parameter.
The y observe an d discuss the suppression of nucleate
boiling by forced convection either externally induced
or
vapor induced.
Beaver and Hughniark (8) used an electrically heated
3 4
in. by 8-ft long carbon steel tube to investigate the
reliability of using developed correlations in vacuum
operations. Th e authors decided tha t for wall minus
saturation temperature differences less than 15°F single
phase coefficients dominate and can be predicted by a
modified Dittus-Boelter equation (Sieder-Tate modifica-
tion)
[ u o u t / u i n l ,
UL PL kz , Cz, PL are liquid phase prop-
Nu
=
0.023
(Re)'J.*
(Pr)0.4
[ . 1 4
Steam
Thermosiphon
Reboi ler
Tubes
Figure
7. Vertical thermosiphon
reboiler
VO L 6 2
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D E C E M B E R
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Nucleation occurs for temperature differences greater
than 15°F and local inside coefficients can be predicted
by existing two-phase correlations. Investigations
covered a total of twelve fluids, and the observed liquid
circulation rates are presented ; this allows the designer
to compare calculated an d experimental liquid rates.
Lee et
al. 53)
sed a reboiler consisting of se\wi tubes
in a bundle. Th e tubes \ve x 1 in. o.d., 14 gauge, 10-ft
long Admiralty metal. Dat a for a total of s e ~ e niquids
are presented for pressure ranges of approxiniatcly 2
to
120 psia. T h e authors present overall coefficients
as
functions of overall temperature differences. The aver-
age inside-film coefficient and tlie niaxiriiuiii flux are
presented in terms of dimensionless groups. The niaxi-
mu m flux
vas
found for each fluid and system pressure.
Above the niaximuni flux, vapor lock occurred; it \vas
the departure from smooth cocurrent
f low
of the two
phases through tlie equipment. Recoininendations
include a inaximurii overall coefficient of 500 Btu jh r
s q f t O F , an d the need for giving particular atrention to
reboiler entrance an d exit piping.
Johnson (46) measured circulation rates and overall
temperature driving forces for a 15-in. shell reboiler
con-
taining 96
1
in., 1 2 gauge, 8-ft long tubes. One tube was
equipped with a temperature probe
to
obtain local boil-
iiig stream temperatu res. Circulation rates wer e pre-
dicted by Kern's method. This method assumes a linear
variation of specific volume Tvith leng th in
the
vapor-
ization zone, and that heat transfer proceeds from
the
wall
to
the liquid and then
to
the vapor ca\.ities. T he
Lockhart-h,lartinelli parame ter is used in t h e calculation
of friction and expansion losses for the two-phase zonc.
Overall coefficients, driving forces, fluxes, flow, and
vaporization rates are tabulated for water and a hydro-
carbon having a normal boiling point of
80. 8 C.
Typ-
ical temperature profiles are show711 for six runs on the
hydrocarbon. Overall temperature differcncc predic-
tions are compared to the work of Piret and Isbin (67).
Data on 44 runs are included.
Shelleiie et
al. (69)
also used an industrial-size reboiler
having a 14-in. shell, containing 70 3/4 in., 13 gauge, and
3 7/ 8 in., 12 gauge, 8-ft long tubes, providing 110 s q
f t
of area . The reboiler was connected to
an
existing dis-
tillation column and, except for instrunlentation, was
identical to a typical coriiniercial unit. The hcat sourcc
was steam, and the process fluids \vex benzene, water,
isopropyl alcohol, methyl ethyl ketone, glycerine, and
various aqueous solutions of the alcohol, ketone, and
glycerine. Of parti cular interest in the work was the
exploration
of
the onset of unstable operation. Th e
authors found t ha t rhe addit ion of flow resistance
to
the
inlet line extended the srable operating range and: as
might be expected, the allowable pressure drop across
the tubes decreases as the heat flux increases. Resis-
tances were also added to the vapor return line, which
resulted in a decrease in the niaxirnuni flux as the resis-
AUTHOR Hugh R. McKee
is with
Born Engineering Co mp an y,
P.0 ox 102, Tu l sa , Okla . 74101.
tance increased. The resulting rccoiiiiiiciidation o
keeping
t h e
return line flow area cqual
to
the tubc fl o
area was consistent with t ha t of Giliiiorc
(L31) .
Max
imum lieat fluxes are tabulated for the various fluids with
accoiiipanying ie inper ature differences and
c;/c
17aporiza
tion. Other data are prescntcd as
flux
us. log nieai
temperature differciic,e and mass x-clocity us. pressur
drop. This work will be invaluable for design and
coin
parison purposes, an d it
shows
that an opportunily cxist
for a n experi inen talist to iiivestiga tc the contribution o
the various componcnis in the flow loop to stablc opcra
rion. Emphasis to da te has
been
placed on
the
hcat.cd
elenient of the loop, ivhicli
is
certainly justified. Th e
designer also needs to be sure that his filial proposal wil
meet both heat transfer
arid
stable operation rcquirc
men s.
Research into boiling heat-transfer cocf-licients ha
been rather recent, and a s
y e t
no coiiiplctcly reliable
correlation h a s evolved, a s it has for single p h a s e flow fo
various geometries.
Table I is a brief suiiiiiiary
of
typical boiling data in
tcrnis of the more coiniiionly investigated fluids. W h e n
lack of a siinilar fluid-surface coiiibination
is
encountered
particular attention should be givcn in riiatchiny sur
faces when using a generalized correlation. Fluid prop-
erty variations are adequately described in inost cor
relations, the surface characteristic remaining inde
pendent. Unfortunately, the best one can do is
rc i i ic i i i
ber that the type
of
surface is iiiiportant i n boiling hea
transfer, and remain alert to clcvelopinents in this arca.
Schrock aiid Grossman (68) correlated local hcat
Lransfer cocfficients for the
lorccd
f l ow of water in the
wettcd-wall rcgion---i.e., between subcoolcd boiling and
the traiisition to dry wall conditions-in tcrnis of the
Lockhart-hlartin elli parameter and the boiling nuliibcr
The boiling num ber is the hcat flux cli\rided by the prod
uct of
the
m a s s flux aiid rhc latent heat of vaporization
Local pressure gradients are presented
as
functions of a
niodified Lockhart-hlartinclli parameter
where p is the viscosity. 17 is the specific volume. x is the
fraction vapor. and F efers to saturatcd liquid.
Experiinents \ \ere perforiiied on tubes 0.116 2 to
0.4317 in. i.d
,
15-
to 40-111.
long, Tlith hcat fluxcs of
6 X
l o 4 to 1 . 4 5
X
l o GBtu/lir
f t 2 .
inav fluxes
of
49 to
911
lb/sec f t L , and system pressures from 42 to
505
psia
The authors rccornrriend their correlation for cxit qual-
ities up to
50%
A niax imuni coefficient was observed by Groothius an d
Hendal (35) a t the suspected transition from slug to
niist-annular flow. Th e authors were in\-estigating two-
phase heat transfer in air-water and air-gas oil mixtures.
Th e conditions for the riiaxirnurn coefficient arc related
to a dimensionless group deri\-ed from the IVeber nuiii-
ber . Local coefficients are presented in terms of
S u ,
Re
Pr, and viscosity rati o.
The concept of superposition of heat-transfer inecha-
78 I N D U S T R I A L A N D E N G I N E E R I N G C H EM IS T RY
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TABLE I NUCLEATE B OIL ING CORRELATIONS
Surface
Stainless steel
Comments
low
pattern
Inside horizontal, vertical
Fluid
Aniline
Aniline
Generalized correlation
independent of flow pat-
tern
Brass
Chromium
304 Stainless
Stainless steel
Copper
Annular
Pool boiling
Pool boiling
Inside horizontal, vertical
Benzene
13.5 to 48.8 psia
Data from 14 runs
-Butyl alcohol
Alcohol, n butyl
Data from 15 runs
arbon tetrachloride
Cyclohexane
Diphenyl
Copper
Brass
304 Stainless
Annular
Pool boiling
Pool boiling
Pool boiling, axial, and
twisted tape swirl flow
Alcohol, ethyl ethanol
Ethylene glycol
Copper
347 Stainless
A-nickel
Copper and stainless steel
Atmospheric pressure
Burnout data included
Freon 11, 113
Heptane
Inside horizontal
Annular
Pool boiling
Pressure drop da ta included
Polished chromium
Hydrogen
Isopropyl alcohol
Alcohol, isopropyl
Methyl alcohol
Alcohol, methy l
Mercury
11 correlations
Data from
1 4
runs
opper
Annular
Inside tubes, across flat
plate
Annular
1 and
3
atm
30"-78"K temperature
range
30'-78 OK tempe rature
range
Neon
Copper, nickel, cadmium
Copper, nickel, cadmium
Pool boiling
Annular
Pool boiling
Annular
Inside horizontal and
vertical
Nitrogen
Pentane
Potassium carbonate,
35% and 50%
Stainless steel
Nickel
Data from 15 runs length-
wise temperature profile
included
65-400 mm Hg abs
1200°-15000F
Sodium Horizontal disk
Pool boiling
Pool boilingeta-terphenyl, ortho-
terphenyl, 4.35y0 pura-
terphenyl in meta-ter-
phenyl (Santowax-
Monsan o)
Water
Inside vertical tubesopper
Oth er correlations Boiling
Two-phases (gas-liquid)
Review
22,
23,
24,
71)
69)
66)
nisms was modified by Chen (72) to account for the sup-
pression effect of the moving fluid on the boiling rate.
The conditions of convective heat transfer are met at the
limits of 0% and
1 0 0 %
quality, and in the boiling, two-
phase region the interaction between the mechanisms
is accounted for. I t
is
at this point that empiricism
enters the model, that is, in the determination of the
interaction effect. Chen's appr oac h provides the de-
signer with a method of obtaining a forced con-
vection boiling coefficient with a min imum of model
detail considerations.
Other generalized boiling correlations have been pre-
sented by Levy 54, Gilmore (31), and Forster and
Greif
(25).
Boiling curves and correlations are also to
be found in the general review
of
boiling by Westwater
(79,
80).
Pressure effects on boiling curves have been
studied by Mendler
e t
al . (63).
For those
who
insist on climbing the nucleate boiling
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curve as far
as
possible, a grea t deal of attention has been
given to the critical flux, first boiling crisis or burnout
point. This riiaxiiiiuiii nucleate boiling flux is slightly
above the DNB (departure from nucleate boiliiig) point.
The area
is
unreliable in ternis of stability and repro-
ducibility. On e easily slips over into either the transi-
tion region or the film-boiling region, with a resultant
decrease in the flux. Thi s critical flux
is a
point the
designer should respect enough
to
check a nd avoid.
Bergles et a l . ( 9 ) investigated the critical hcat flux for
water at low pressures (below 100 psia ). They iiivesti-
gated the effects of tube lengt h, inler temperature , tube
diameter, and pressure on the critical heat flux. Th c
authors relate their results
to
the instabilities of th e slug-
flow regime. Critical heat fluxes for water a re normally
considered to start around 0 . 4
X
l o 6
Btulhr ft’;
ho\v-
ever, the authors have shown values of half this amount
und er low pressure conditions.
Gaiiibill
(28)
has kept abreast of the critical flux liter-
ature in ternis of general rcvie\vs (27) , aiid in the prc-
sentation of a corrclation. Th e latter correlation
is
based
on
two
ternis,
a
forced convection term and
a
boil-
ing term. Gaiiibill has also demonstra ted the uncer-
tainty i n predicting the critical flux ( 2 9 ) . If one needs
to be impressed xvith the magnitude of the problem, the
latte r reference is suggested.
Boiliiig curves and critical fluxes for some binary
liquids have been presented by
van
tVijk
t al.
75) or
benzene, toluene, and acetone for both pool boiliiig, aiid
for forced convection lengthwisc outsidc tubes by Carne
I ). Pressure effects on the critical flux have been in-
\-cstigated by Hoxvell and Bell
(37) .
Th e designer then
h a s
the usual problem of selecling
which approach to utilize, empirical or theoretical.
Fair
(22)
describes these approaches as the statistical
approach of Iliighniark, arid his o i vn riiechanistic ap-
proach. Th e former presents sccurity to the, dcsigner,
if
siiiiilar coiidir ioiis can be found betwxen his prob lem
and the contributing data . T he advaiitage of the rnech-
anistic approach lies
in
extrapolation into the unknown.
Th e soft spot in Fair’s nierhod is in
the
selection of a boil-
TABLE
I I .
VERTICAL FLOW TWO-PHASE
CORRELATIONS
jsteni
Comments Rejerence
Introductory survcy ( 7 7 )
Survcy advocating
Dukler’s
Energy equation discussion
Film thickncss, film
f low
rate
Air-lvat er Pressure drop and holdup
study comparison with ex-
Pressure drop in slug flow, ex-
Elevated pressure effects, cx-
(20, 21)
approach (76)
(theory) (76, 74)
.lir-Water
study 30.1
perimcntal dat a 1 7
perimciital study (33)
perimeiital study 1631
.\ir-\Vater
Boiling water
-
ing coefficient, which places one in the wonderland o
boiling da ta . The most benevolent advice to the d
signer in selecting a boiling coefficient is to adopt Hug
mark’s attitude and search for an appropriate boilin
curve that represents identical fluid propcrties
and
su
face characterisLics.
Pressu re Drop
Calcu la t i ons
First, it should be mentioned that several valuab
works are available for reference purposes in tkvo-pha
flow. Kepple an d Tun g
(47)
have absrracted the lite
ature for the period 1950- 1962. Grouse (34) has als
classified a large amo unt of the tLvo-phase lit era ture.
Anderson and Russell (2, 3,
4 )
present
a
thrce-pa
survey of nvo-phase floxv. Parr I deals with
f l ow
pattern
encountered in two-phase flo\v, an d how to predict thes
floiv pat terns for horizontal and \,ertical
f l ow
For ve
tical
f l o ~ ,
he slug-flow regime envelope (between bubb
and annular mist), is presented as thc voluiiietric g
fraction of
the
entering fuel streaiii ZJS. a gas-liqu
Froude nuniber. 4 econd correlation is also presente
a s
the liquid superficial velocity
us.
the gas-liquid vol
iiictric ratio at input, which
is
divided into the bubbl
slug, fro th, ripple, an d film-flow regimes.
Part I1 considers the prediction of pressure drop
two-phase f l ow. The authors recommend Dukler’s (2
27) method as a general approach
and
they also fin
favor in Hughmark’s 43) ethod
as
applied to eith
horizontal o r vertical f l ow.
Part
I11
coiicerns itself with a review of the status
inass transfer, heat transfer, and clieinical reaction
tlvo-phase f l ow (Other pertinent references arc pre
scntcd in Table 11.)
Hsu and Graham (38) forced water through
13-
an
1~-11111i ubes Lvith boiling in an effort to gain soiiie insig
into the niechaiiisiri of boiling inside tubes. Th e force
floiv produces a scarcity of nucleation sites and a co
responding small bubbly f l ow region. Coiivcciioii slu
f l o ~ v a large hot layer forining vapor instead of bubb
coalescence
to
form slugs) occurs rapidly, forming a lon
Tay lor bubble. Bubble trajectories into the stream ar
compared
to
jet rrajectories, aiid an actual trajector
from high-spced motion picture studies
is
shown. T h
change from bubble to slug aiid ann ula r flow is compare
to the adiabatic map : ( r7,j
(
JTL+ V , )
ZJS.
Fr, whe
Fr
=
( V ~ + V J 2 / ( D g ) ,V is velocity, D is characteristi
leng th, an dg is acceleration of gravity), not too favorabl
Th e slug to annular
f l ow
transition occurred ax
a
dinien
sionless vapor velocity Ut*
=
0.417 M-hich, according
Wallis (78) should take place at
G,*
= 0.525, (U,*
U / d G where
U
equals superficial vapor velocity).
The calculation of the void fraction is dependent up01
the relative velocity ratio between the phases (velocit
slip rat io) , which is unknown. Von Glahn (77) corrc
lated all xhe available steam-water data froin th e literatur
in the form of an empirical equation that needs
to
b
tested on other s>-stems. Hughmark (47, 42) also h
been busy in the holdup correlation area. Xicklin e t a
(65) investigated the rise velocity of bubbles in a one-in
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tube . Equa tions are presented for the velocities in slug
flow as approximations below Re
=
8000, and accurate
above Re
=
8000.
Th e dimensionless group approach as employed by the
petroleum industry in two-phase flow problems has been
discussed by Baker
(5).
Th e work of Lockhart and Martinelli (56) has been
modified innumerable times, which only seems to attest
to its utility. Chenoweth and Marti n
(73)
extended the
Lockhart-Martinelli work to larger straight pipes and
included flow through some fittings.
Dukler et a l . (20, 27) have presented a review of two-
phase pressure drop. The conclusion of (20)was that the
Lockhart-Martinelli correlation showed the best agree-
men t with reality of t he pressure-drop correlations tested,
and the holdup correlation of Hughmark (42) or holdup
calculations was best. Hughmark's correlation
is
a
modifica tion of one proposed by Bankoff 6),which as-
sumes a high bubble concentration at the center of the
stream, decreasing to zero at the wall for bubble flow.
The slippage between the phases also is assumed zero,
which is the single fluid model assumption. Th e model
is applied to stream qualities for zero
to
60%.
Following the work of Bankoff, we have the salvation
of two-phase flow by Zuber and Findlay (87). They
considered both the velocity and concentration profiles
across the duct, along with the relative velocity between
the phases in arriving at a holdup correlation.
The
result
is
a correlation that
is
independent of flow regime;
however, it is limited to two-phase systems in which no
phase change occurs by evaporation, condensaiion, boil-
ing, or chemical reaction.
Davis
( 7 5 )
modified the Lockhart-Martinelli param-
eter using the Froude number to accommodate the hori-
zontal to vertical flow geometry change. Lockhart-
Martinelli :
Revised Lockhart-Martinelli parameter by Davis :
where V, is the mean velocity of the liquid-vapor mix-
ture, D s the diameter, and g c is the gravitational con-
stant.
The Davis correlation for pressure drop ( 0%)
is
applicable to the same pressure range as the Lockhart-
Martinelli correlation : for the turbulent-turbulent flow
regime with liquid Reynolds numbers above 8000, and
the vapor Reynolds numbers above 2100 ; for liquid Reyn-
olds numbers between 6000 and 8000, providing the
vapor flow rate is great enough to obtain a Froude num-
ber above 100.
The inclusion of interfacial roughness considerations
into the Lockhart-Martinelli correlation improved the
pressure-drop prediction, as shown by McMillan et
al .
(62). Among the fluids used in horizontal systems was
trichloromonofluoromethane.
Baroczy (7) modified the Lockhart-Martinelli two-
phase pressure drop gradient ratio,
r li2,by
considering
the ratio of the two-phase gradient
to
the total liquid
gradient
In terms of the mass fraction (quality) vapor or gas
This two-phase friction multiplier has been correlated
for substances of a wide range of properties, in terms of
a property index
p
and p are viscosity and density,
respectively)
with quality as the correlating parame ter. Th e autho r
also presents a method for finding the two-phase pressure
drop for changes in flow geometry, such as contraction-
expansion, sharp-edged orifices, and other velocity-head
related elements.
Entrance effects and flow-transition effects for the slug-
flow regime were considered by Moissis and Griffith 64
in their description of the density distribution. Th e
pressure drop is calculated
to
a first approximation for
the final 20 pipe diameters.
For work in which the critical pressure or above is
liable to be encountered for homogeneous, two-phase
flow, for appreciable AP, Paige
(66)
has presented three
methods of calculating the pressure drop with a flashing
liquid. Based on the use of average mixture densities
and starting with the mechanical energy equation, the
prediction of the pressure profile along the line is possible.
The amount
of
effort being expended on two-phase
flow is of an order of magnitude that allows
us
only to
indulge in a selected bibliography. Th e game of com-
parison quickly gets to be an infini tum of cornbinat ions.
For example, Hughmark (43) has shown the similarity
of form between the work of Lamb a nd White (57) and
Hughmark and Pressburg (47). Pressure-drop expres-
sions derived from a momentum balance result in a drag
coefficient form. Energy balance derived expressions
take on the lost work form.
Hughma rk applies the latter
to data for horizontal,
vertical upward, and vertical
downward flow for isothermal systems.
Gill
e t
al . (30
compare favorably with Lockhart-Martinelli for vertical
upward flow of air-water.
Conclus ions
Th e standard of comparison seems to have been estab-
lished by Lockhart -Martinelli. There must be some
satisfaction in having produced the most often quoted,
compared, an d modified work in the field. Th e Lock-
hart-Martinelli standard appears not only in pressure-
drop correlations, but also in two-phase coefficient cor-
relations.
There are several design methods currently available
the classic local coefficient approach utilizing average
conditions and properties in the two-phase region, the
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statistical or empirical approach, and the more sophis-
ticated method of Fai r. T he first
is
dangerous for the
serious designer. Realistically a nd traditionally, the
designer has functioned in the realm of experience and
expedience. He, therefore, tends toward the second or
empirical approach, which is highly useful for repeat
rout ine work, b ut suffers from the limitation
of
producing
questionable results when extrapolated beyond the con-
ditions of the original da ta . Sufficient mater ial is now
available to produce a satisfactory iriethod of design, if
one remembers that investigations into areas such as f low
control are still incomplete.
The
more theoretical ap-
proach overcoines the extrapolation limitation, but
d e -
mands more effort to successfully set up the calculating
procedure. The ubiquitous piper seems
to
be demand-
ing his due for the pleasure of flexibility.
REF
E
R ENCES
1 j
Anderson, G. H.
and hl antzourdni s,
B. G.. "T>\o-Ph;isc (G'is-Liquid)
I'low
( 2 )
hndcrson:
R.
J . and Russcll, T . IV. F., "Dcsigning for Tso-Phab c Floi*," Pa rt
ind
Russcl l ,
T .
IV. F..
"Dcsigning
l or
Tuo-I'hdsc
Florc,
I'.iri
(4)
Anderson,
R .
J . and
Russcll, T.
I V . F., "Designing for 'Two-l'htiic Flow," P x t
(5)
Bakcr.
O. ,
Design of Pipclincs for Simultaneous Flow
of
Oil
and
Gas," 011 Gas
(6)
Bankoff.
S. G . : \ ari,rble Density Sing le Fluid
h l od r l for
T\r.o-l'h,tic Flov with
( 7 ) Barocrv C. J.,
A
Syatem,itic Corrcl.ition for Two-Ph.ise I'ressurc Drop,"
(8)
Bcaver, P. R. . ind Hughm,irk. G . I,,lIC/ii:
J . >
4
j), 46- 749
(Scpt.
1968).
9) Berglcs. :\.
E.,
LopinSi: I . cr. l i ,
52,
37-46
(1956).
-Liquid) Systems: Hc. r
Transfer
a nd
Hydraulics, An
Annotntcd
Bibliogr.ip
,lrgonne .Vul. Lair . , 67311
July
1964.
(48) Krcith, I'. m i l Summcrficld, M , , "Presaurc Drop
and Cun\cct icc
Hea
rr,insfer with
Surf,icc
Boiling
'it
Hiqh Hcat
F l ux ; D . R-742
(Fcb
1 9 6 2 ) .
(79) \Veitwatcr, J. I ',, "Boiling of Liquids,"
n
hdvanccr in Ch cmicd I,nginecring,
Vol.
I ,
Academic Prcss lnc ., Kew
York, 1956.
(80)
\Vest\\.atcr: J. W.,bid.,Vol.
11,
1958.
(81)
Zubcr, N. and
Findlay,
J
Phase
Flow Systems,"
.J .
Hea
T h e s i a , Dcpt. of Chem. Cng., Th e Univcrsity of Tuls .~, 'ulsa, Okl.i., 1967.
"A\-cragc Volumetric Conccntration in T wo-
n s j c r ,
87C ( 4) , 453-468
(Nov.
1965) .
82 I N D U S T R I A L A N D E N G I N E E R I N G C H EM I ST R Y