University of Southern California Dissertations and Theses

The construction and testing of a continuous equilibrium flash vaporization apparatus

(USC Thesis Other)

The construction and testing of a continuous equilibrium flash vaporization apparatus

PDF

Download

Open document

Flip pages

Download a page range

Download transcript

Copy asset link

Request this asset

Transcript (if available)

Content THE CONSTRUCTION AND TESTING OP A CONTINUOUS EQUILIBRIUM
PLASH VAPORIZATION APPARATUS
A Thesis
Presented to
the Faculty of the Department of Chemical Engineering
The University of Southern California
In Partial Fulfillment
of the Requirements for the Degree
Master of Science in Chemical Engineering
by
Abraham Charles Goodman
June 1950
UMI Number: EP41726
All rights reserved
INFORMATION TO ALL USERS
The quality of this reproduction is dependent upon the quality of the copy submitted.
In the unlikely event that the author did not send a complete manuscript
and there are missing pages, these will be noted. Also, if material had to be removed,
a note will indicate the deletion.
Published by ProQuest LLC (2014). Copyright in the Dissertation held by the Author.
Dissertation Publishing
UMI EP41726
Microform Edition © ProQuest LLC.
All rights reserved. This work is protected against
unauthorized copying under Title 17, United States Code
ProQuest LLC.
789 East Eisenhower Parkway
P.O. Box 1346
Ann Arbor, Ml 48106- 1346
This thesis, w ritte n by
....
' Chairman
..
%<#
, 4
v
\ I * -
* 1
A f r X £ & ^ . . Q t a £ & ^ ^ ........
under the guidance of h.X.S.. F a c u lty Com m ittee,
and approved by a ll its members, has been
presented to and accepted by the C o u n cil on X ^
G raduate S tudy and Research in p a rtia l f u lf il l
ment of the requirements fo r the degree o f
..... M a s t e r . . ^ .................
in....Gh©mlc.al„ ........
Date : . S T ? . .......
Faculty Committee
t
^ 0
TABLE OF CONTENTS
CHAPTER PAGE
I. INTRODUCTION..................... . . . . I
II. PREVIOUS APPARATUS ....................... 3
III. DESIGN AND CONSTRUCTION OF APPARATUS .... k
Feed tanks ••••• .................. i f .
Feed pumps I f
Heater......... 7
Equilibrium flash separator ....... 7
Control valves ..... ............... 12
Thermocouples ....... ••••••••• 12
Vapor condenser and liquid cooler • • • • • 13
Receiver tanks ••••.. ........... • 13
Miscellaneous ..................•••• 13
IV. TEST OP APPARATUS ....................... l6
Physical tests.................... l6
Operational tests ............... ... 17
Experimental data ............ 21
V. RESULTS OP TEST R U N S..................... 25
VI. OPERATING CHARACTERISTICS OP APPARATUS ... 29
VII. CONCLUSIONS.............................. 3k
LITERATURE CITED .............................. 35
APPENDIX..................................... 37
LIST OP TABLES
TABLE PAGE
I. Specific Gravity of Benzol-Toluol Mixtures . • 18
II. Experimental Data--Flash Vaporization of
Benzol-Toluol Mixtures • 23
III. Comparison of Vapor-Liquid Equilibria at
115 Pounds per Square Inch ••••«•••• 28
IV. Operating Log-Sheet, Run H ............. 39
V* Successive Observations at Steady State • * • • 1 ^ . 0
LIST OP FIGURES
FIGURE PAGE
1. Flow Diagram, Equilibrium Flash. Vaporization
Equipment * . .......................... 5
2. Component Parts, Equilibrium Flash Vaporization
Equipment • 6
Electrical Diagram, Equilibrium Flash
Vaporization Equipment ................ 8
I j . * Equilibrium Flash Separator............ . . 10
5. Equilibrium Flash Separator.............. 11
6. Continuous Equilibrium Flash Vaporization
Apparatus........................... . . 1 ! { .
7. Specific Gravity of Benzol-Toluol Mixture
@ 2 5. 5° c ..... 19
8. Temperature Curves for Run H ......... 2 i j .
9* Deviation of Steady State Observations from
True Equilibrium Values................. 26
10. Thermal Efficiency of Heater ........... 32
11. Vapor-condensate Rate as a Function of
Manometer Reading ............ 33
CHAPTER I
INTRODUCTION
Vapor-liquid phase equilibrium data, at various con
ditions of temperature and pressure, are fundamental require
ments in the design of equipment for the separation of mater
ials by distillation processes.
In the past, such methods as those used by Rosanoff
et al (l i | ) have produced satisfactory data, especially in
the case of binary mixtures. The method using the still de
veloped by Othmer (13) was an improvement on previous methods
in that equilibrium data could be determined accurately and
did not involve any extrapolation of data; It did, however,
involve a recirculation of material. The method developed
by Stockhardt and Hull (15) eliminated the recirculation
feature of the Othmer type still, but, in doing so, intro
duced a differential condenser hold-up leading to erroneous
equilibria where high relative volatilities were prevalent.
The recirculation feature of the Othmer type still
renders it unsuitable for mixtures which are only partially
miscible under operating conditions.
A suitable apparatus for the accurate determination
Numbers refer to bibliography, page 35♦
2
of vapor-liquid phase equilibria, for all types of mixtures,
is one in which the feed, vaporization, and take-off are con
tinuous, namely, a continuous equilibrium flash vaporization
apparatus•
CHAPTER II
PREVIOUS APPARATUS
The continuous equilibrium flash vaporization appar
atus introduced by Leslie and Good (10) has been used exten
sively for vaporization at atmospheric pressure* Pancher
(4) and many others used equipment of this type*
Colburn et al (1) used a continuous apparatus in
which two pure components were separately vaporized and then
fed Into liquid in an equilibrium chamber* This apparatus
was designed for operation at low pressures only.
Nelson (12) describes apparatus, suitable for use in
vacuum and low pressure vaporizations, employing a heating
coil cast into an electrically heated aluminum block.
Penske (5) refers to continuous equilibrium vaporiza
tion equipment utilizing Dowtherm as a heating medium*
The apparatus used by Edmister, Reidel, and Merwin
( 2) employed a heating coil immersed in a lead bath which
was heated electrically. The equipment incorporated the
better features of previous equipment and, in addition, was
designed for operation at moderately high pressures. Simi
lar apparatus was used by Edmister and Pollock (3), their
heating baths, however, being gas fired.
A critical study of the construction and operation of
these above apparatus lead to the design of the apparatus
described in Chapter III.
CHAPTER III
DESIGN AND CONSTRUCTION OP APPARATUS
The continuous equilibrium flash vaporization appar
atus constructed contained many of the features of that used
by Edmister, Reidel, and Merwin (2)* The apparatus, a flow
diagram of which is shown in Figure 1, was designed for op
eration at pressures between atmospheric and 375 pounds per
square inch, gauge. As constructed, the apparatus comprised
the equipment described below*
Feed Tanks:- Two seventeen gallon, vertical, cylin
drical tanks fabricated of l6 gauge sheet steel* Each tank
was provided with a "milk-can1 * type lid, a one-half inch
drain cock, a liquid-level gauge glass, a suction connection
that permitted one gallon of stagnant liquid at the tank
bottom, and four one inch angle-iron legs that raised the
tank six Inches off the ground. Details of the feed tanks
are shown on Figure 2.
Feed Pumps:- The pumps used were Hills-McCanna Pro
portioning Pumps, Type UM-2F. The pumps each had a maximum
capacity of 7*80 gallons per hour and were equipped with
one-quarter Inch Verquad cone type check valves containing
Durimet seats and cones of Hastelloy , f D, ! * The pumps were
driven at a rate of 6J L | _ strokes per minute, through a speed
H
r >
I
I
a
I
£
I
I
I
V J l
/ fb Gaaye !
% P i p e
Coup/rry
A il Openings , p Pipe C oupiinys
< i Z ^ W .
1
!
j ^ > - - / / ^ o . £
C o /io E M S E ft f i C o o l e r
Sca/e / /# ^
CoMPOA/EiiT P a r t s
E q u e u e w u M Fl a s h Vapor tx a t ic ^P E q u i p m e n t
U n iv e r s ity o f Southern California Pj,C. G o o d 'm a n
Los A ny ties ,C o /i/o r n la S eptem ber 1949
Figure 2c
7
reducer, by a one-quarter horsepower, 110 volt, single
phase, 60 cycle, explosion-proof motor.
Heater:- The heater consisted of a heater pot, the
details of which are shown in Figure 2, fabricated of one-
quarter inch steel plate, in the annular space of which was
placed twenty feet of coiled one-quarter inch extra-heavy
seamless steel tubing. The coil of steel tubing was im
mersed in a bath of l i | . 0 pounds of lead. Around the heater
pot were wound six coils of #l6 nichrome wire, each coil
consisting of seventy feet of wire. The wire coils were
threaded through separators of one-quarter inch thick tran
sits boards in order to prevent them from contacting each
other and the heater pot itself. The nichrome coils were
connected to a 220 volt alternating current source through a
switching arrangement capable of energizing any desired com
bination of the coils. The electrical connection of the
heater elements is shown in Figure 3* Lead in wires to the
heater elements were of #10 stranded copper wire with asbes
tos insulation and were connected to the nichrome elements
with copper, screw-type, solderless connectors. The entire
heater assembly was surrounded and insulated with a housing
constructed of firebrick and fireclay cement.
Equilibrium Flash Separator:- The flash separator
was fabricated from two inch extra-heavy steel pipe. Inlet
220-
Y B .C .
E l e c t r ic a l D ia g r a m
E o w t / a f f u t f T l a s * Y a p o p / z a r t o t f T q u / p m M t
U fj 't tfc r$ !ty o f Sexft& em C o /t& rn t*-
L o s A 'fy o /e .s , C a /S /b rn to L
Figure 3
9
to the separator, which was twenty-four inches in length,
was located eight inches above the bottom, thus leaving six
teen inches for liquid disengaging space. The inlet was
installed such as to permit the incoming fluid to enter tan-
gentially to the separator wall, thus inducing a spin to the
fluid with consequent separation of liquid from vapor due to
centrifugal forces. As an additional inducement for liquid-
vapor separation, entrainment removal baffles, introducing a
double reversal in the direction of flow, were installed in
the upper four inches of the separator. Complete construc
tion details of the separator are shown in Figure .
Provisions were made for a liquid-level gauge glass
in the lower eight inches of the separator; high pressure,
high temperature gauge glass, one-half inch in diameter, was
installed for liquid-level visual indication. A thermowell
of three-eighths inch pipe was installed four inches from
the bottom of the separator and a fitting installed at the
top of the separator for both a copper-tubing thermowell
and for a pressure gauge connection; either a pressure
gauge of the Bourdon type or a mercury manometer was used
for pressure measurement. Figure 5 is a composite picture
with both pressure gauge and manometer apparently connected.
The separator was completely insulated with standard
two inch eighty-five per cent magnesia pipe insulation and
then a coil of thirty feet of #16 nichrome wire wound around
10
Section 8'8
x ~1
-jL__ jr_
Removal
Baffles
Sco/c / £ "
E q u il ib r iu m F l a s h S e p a r a t o r
Sca/c / " ■ 4 “
£*ccf>t as Fotee/
U F / e r s i t y o f S o u t h e r n C a F / o m i a
£ . o s E ) n e r c / e s , C a / / / o r n / ( 7
Section C-C
Figure
Figure 5* - Equilibrium Flash Separator
12
the insulation, an additional amount of eighty-five per cent
magnesia insulation was then built up to a thickness of one-
half inch completely covering the separator* A coil of two
and three-quarters feet of #l6 nichrome wire was wound
around the liquid-level sight glass. Each of the latter
coils was connected to a separate 110 volt Variac, the for
mer coil being used to maintain the temperature of the insu
lation at a definite temperature approximately the same as
the vapor temperature in the separator, and the latter coil
being used to offset the radiation and convection heat
losses from the liquid-level sight glass. Electrical con
nection of these coils is shown on Figure 3> page 8.
Control Valves:- Both the liquid-level control valve
below the separator and the throttling valve for the vapor
leaving the separator were of the same design. They were
forged steel globe valves with chromium plated cone-shaped
seats and discs; the valves were designed for service with
two thousand pounds of water or gas, or, oil at six hundred
pounds per square inch at nine hundred degrees Fahrenheit.
Thermocouples:- Twenty gauge iron-constantan, glass
insulated, thermocouple wire was used. Thermowells into
which the thermocouples were inserted were installed in the
liquid space of the separator, in the vapor space of the
separator, and two in the lead bath of the heater pot. A
13
thermocouple also was inserted into the insulation surround
ing the separator* The thermocouples were connected to a
type ! , K" portable potentiometer, through a ten-point rotary
switch, for temperature observations. Location of the
thermocouples is indicated on Figure 3» page B.
Vapor Condenser and Liquid Cooler:- The condenser
and cooler were fabricated of six inch standard iron pipe
and three-eighths standard copper tubing. The condenser
contained twenty feet of coiled copper tubing and the cooler
contained eight and one-half feet of coiled copper tubing;
the coils of both were wound to four inch diameters.
Details of the condenser and the cooler are shown in Figure
2, page 6.
Receiver Tanks:- The receiver tanks, of approx
imately ten gallons capacity each, were connected, one to
the condenser and the other to the cooler, by sloping pipes
leading from tee pipe-fittings just below the condenser and
cooler, respectively. The tanks were provided with liquid-
level gauge glasses and with bottom drain valves. The tanks
were set horizontally in pipe-framed cradles and are shown
in Figure 6.
Miscellaneous:- Provisions for sampling cooled
liquid and vapor-condensate from the separator were made by
Figure 6* - Continuous Equilibrium Flash. Vaporization Apparatus
15
installing sampling valves directly below the cooler and the
condenser at the tees leading to the reooxver tanks•
A spring-loaded safety relief valve, set at a gauge
pressure of 250 pounds per square inch, was installed in the
line between the pumps and the heater.
All of the piping of the system was of three-eighths
inch standard galvanized steel pipe. All of the pipe fit
tings in the pressurized section of the system (from the
pumps to the control valves) were high pressure fittings.
All of the valves used in the system, with the ex
ception of the two control valves, were stainless steel
globe valves.
CHAPTER IV
TEST OF APPARATUS
I. PHYSICAL TESTS
The assembled apparatus, with the safety relief valve
plugged, was subjected to a cold hydraulic test at a gauge
pressure of 375 pounds per square inch and was found to be
satisfactorily tight. The apparatus was then operated with
water as feed and with all of the heater coils energized;
the resulting steam test at a gauge pressure of 375 pounds
per square inch proved satisfactory. The safety relief
valve was then tested and found to perform satisfactorily at
its rated gauge pressure of 250 pounds per square inch. The
pressure gauge had previously been calibrated on a dead
weight tester.
The thermocouples were calibrated in boiling water
and found to be accurate within three tenths of a degree,
Centigrade. The same degree of accuracy was experienced
when the thermocouples, in the separator thermowells, were
calibrated in place when operating with steam under approx
imately atmospheric pressure.
II. OPERATIONAL TESTS
17
In order to prove the attainment or true equilibrium
separation and to determine the operating features of the
apparatus, tests were made using mixtures of commercial
benzol and commercial toluol. The benzol and toluol used
o
were specified to have 2.0 C. boiling range purities and
were found to contain a maximum of 0.1 mol per cent impur-
. o
ities by freezing point depression tests. At 25.5 C. the
specific gravity of the benzol was measured as 0.8722 and
that of the toluol as 0.86ll as compared to the accepted
values (7) for benzene and toluene of 0.8728 and O.8606,
respectively.
Analysis of the products from the separator was made
through specific gravity measurements on the products. Pyc-
nometers similar to the type reported by Lipkin et al (11)
and made from 0.1 ml. pyrex urological pipettes were used in
conjunction with a constant temperature bath for the speci
fic gravity measurements.
The specific gravities of various known mixtures of
pure benzol and pure toluol were determined (Table I) and
from those data the plot of specific gravity versus mol per
cent benzol, shown on Figure 7» was prepared in order to
facilitate the analysis of the benzol-toluol mixtures re
sulting from the separator.
18
TABLE I
SPECIFIC GRAVITY OF BENZOL-TOLUOL MIXTURES
Mol % Benzol Specific Gravity @ 25*5° C.
0 0 .8 6 1 1
11.7
0.8619
2 3 .0 0 .8 6 2 8
28.5 0.8633
37.4
O.8641
Wt- 3
0 .8 6 4 8
54*4
0.8 65 9
6 4 .2 0 .8 6 7 1
70.5
0 .8 6 7 8
7 8 .2
0 .8 6 8 9
82.7
0.8 6 9 5
91-5
0 .8 7 0 8
100
0 .8 7 2 2
8750
871Q
.8660
■ 8640
M 10
60 20 40 10 30 50 0
70 80 90
100
Mol Per Cent Benzol
Figure 7* - Specific Gravity of Benzol-Toluol Mixture ft 25.5° C.
20
In general, the test runs were conducted as follows:
(a) The pumps were set at the desired feed rate and
switched on simultaneously with the energizing of sufficient
heater coils to result in approximately fifty per cent
vaporization when at steady state.
(b) The heating coil in the insulation around the
equilibrium flash separator was energized and the control
ling Variac adjusted to deliver sufficient current to bring
the insulation to approximately steady-state temperature.
(c) The throttling valve in the vapor line was ad
justed continuously so as to maintain the desired operating
pressure in the separator.
(d) The liquid-level control valve was adjusted con
tinuously so as to maintain a constant liquid level In the
separator.
(e) The heating coil around the liquid-level gauge
glass was energized and the controlling Variac adjusted con
tinuously so as to maintain a minute amount of visible bubb
ling in the sight glass.
(f) Temperature measurements of all of the thermo
couples were made periodically, at Intervals of about ten
minutes•
(g) Current readings were observed periodically, at
intervals of about ten minutes, for all energized heating
coils, by means of a clamp ammeter.
21
(h) Liquid and vapor-condensate rates were deter
mined periodically, at intervals of about ten minutes, by
means of timed volumetric sampling.
(i) Pressure readings were observed periodically, at
intervals of about ten minutes.
(j) When all observations of temperature, pressure,
liquid-level, and flow rate were found to be unchanged over
several successive periods, small samples of liquid and va
por condensate were taken and retained for analysis. Three
sets of samples were taken at five minute intervals and all
of the above observations taken simultaneously with each set
of samples. If any of the conditions had changed, the sam
ples were discarded and a resampling carried out when true
steady-state conditions had been reached.
(k) Each sample was analyzed by use of three meas
urements of its specific gravity, and the compositions of
the liquid and the vapor from the separator obtained, each
as the average of nine determinations.
In several runs, In order to determine the effect on
the overall time for a run, the pumps were not started until
the heater pot and the Insulation around the separator were
at approximately the desired steady-state temperatures.
III. EXPERIMENTAL DATA
The majority of the test runs were conducted with the
throttling valve in the vapor line wide open, that is, at
essentially atmospheric pressure* Two runs were conducted
at a gauge pressure of approximately 100 pounds per square
inch. A condensation of experimental steady-state data for
all of the test runs is presented in Table II. A compila
tion of the successive observations taken at steady state
for a number of the runs is presented in the Appendix
(Table V).
Plots of the temperatures at the various thermo
couples throughout the duration of a typical run are shown
in Figure 8. The operating log-sheet for this run is pre
sented in the Appendix (Table IV).
23
TABLE II
EXPERIMENTAL DATA
FLASH VAPORIZATION OF BENZOL-TOLUOL MIXTURES
Run
Feed
rate
gal./hr.
Vapor
rate
gal./hr.
Temp.
0 C.
Press.
In.Hg.
Liquid Vapor
comp. comp,
mol % Benzol
Time
required
hr.
A 4 .3 6 2 .0 6
9 5 .0
29.92
4 0 .5 6 2 .5 2.3
B
2.71 1 .3 5 9 5 .0 29 .83 4 0 .3 6 2 .3 2.5
Cb 9.08 4 .1 2 9 1 .2 30 .72 5 0 .4 7 2 .0
1.3a
D-lb
6.31 94*4
3 0 .6 0
4 1 .7 6 2 .5 2 .7 5
D-2b
6.31 3.i f - l 93.4 30.35
4 5 .2 6 6 .2 1.0a
D-3b
6.31 2.74
9 3 .0
30 .15
---- ----
1.0a
Eb
6.79
H
HI
0
C V J
9 1 .5 2 9 .9 4 4 9 .1
7 1 .6
2.5
F
8.74
4.28 93.8 30 .80
4 6 .3
68.8 2 .2
G
Xl.7
5 .6 0
94*4
31 .2 8
46.5
68.0 2 .6
H 6.11
3.33 93.3 30.15
46.8
6 8 .3
2 .2
Ic 7.80 6.02
99.1
31.68
35.5 53.5
2 .2
J 1 6 .2
7.1*1
100.2 32.65
35.3
57-0 2 .0
K 7.42
3.17
180 (1 1 5 psl)
50.4
65.2
2.75
L 11.56 6.3^ 182 (115 psl)
49-1
64.0 1.3a
a - Run started with apparatus hot.
b - Run discarded; feed saturated with water.
c - Run discarded; non-volatile material dissolved
In feed.
Temperature
200
180
* 120
o
o
100
Hwtcr (Lead bate)
Heater (Lead bath)
Separator (Vapor)—
separator (Liquid)
20
o.5
T im e - Hours
Figure 8. - Temperature Curres for Run H
CHAPTER V
RESULTS OP TEST RUNS
For the runs made at essentially atmospheric pressure,
ascertainment of the closeness of approach to equilibrium
was made by the use of the nomograph presented by Griswold,
Andres, and Klein ( 6)* The deviation from equilibrium at
steady-state conditions is shown by the three point-to-point
curves of Figure 9« 0ne curve indicates the deviation, in
degrees Centigrade, of steady-state temperature from the
true equilibrium temperature on the assumption that the ob
served pressure and the compositions of the liquid and the
vapor from the separator were true equilibrium values;
another curve indicates the deviation, in inches of mercury,
of the steady-state pressure from the true equilibrium pres
sure on the assumption that the observed temperature and
compositions of the liquid and the vapor from the separator
were true equilibrium values; and the other curve indicates
the deviation, in mol per cent benzol, of the steady-state
compositions of the liquid and the vapor from the separator
from true equilibrium compositions on the assumption that
the observed pressure and temperature were true equilibrium
values.
For the runs conducted at elevated pressure, ascer
tainment of the closeness of approach to equilibrium could
(Assume Temperature and
____________ Preaeure Ocrraoll)
(Assume Compoiltlori and
Treasure Ccrrtot)
• (Assume Composition and
_________ T— paratura Ccrraal)
Mol Per Cent Benzol
Temperature -
Inc he e H Preieure
0 1 2 3 4 5 6 7 6 9 10 11 12 13 14 15 16 17 18 19
Feed Rate - Oal./Hr.
Figure 9. - Deviation of Steady State Observations from True Equilibrium Values
27
not be as conclusively made as in the case of the runs at
essentially atmospheric pressure; however, a comparison of
the steady-state data with the supposedly equilibrium data
represented by the curves of Griswold et al ( 6) was made.
Table III lists the deviations of the observed steady-
state data from the data of Griswold et al ( 6) on the same
assumptions as stated above for the runs at atmospheric
pressure, and, in addition, lists the deviations from
Raoult*s Law and from Dalton* s Law for both the observed
steady-state data and values at the same pressure and tem
peratures presented by Griswold et al ( 6).
Vapor pressures of benzene and toluene, at the re
quired temperatures for the above comparisons, were obtained
from a standard reference (8) and from Krase and Goodman (9)»
respectively.
28
TABLE III
COMPARISON OF VAPOR-LIQUID EQUILIBRIA
AT 115 POUNDS PER SQUARE INCH
Deviation of Observed Results from those of
___________Griswold et al ( 6) _________________
Deviationfrom Griswold et al ( 8 )
Liquid Vapor ___________assuming:___________
Run Temp. comp. comp. t & P t & comp. P & comp.
° C. mol % Benzol same same same
mol^ C&H6 psi._______ ° C.
K 180 50.1*. 65.2 - 2 .6 2 - 2.5
L 182 q-9.1 64.0 - 2.9 2 - 1.5
Deviation of Total Pressure from that calculated by
Raoult’s Law assuming Temperature and Composition correct
Liquid comp. Press# by Raoult’s Law'< f
Source Temp. mol % Partial Total Deviation
0 C. Benzol Benzol Toluol psi.
psi. psi. psi.
Run K 180
S o .4
7 3 .1 3 5 .2 1 0 8 .3 6 .7
Griswold 180 5 3 .0 7 6 .8 3 3 .4 11 0 .2 4 -8
Run L 182
4 9 -1
7 3 .6 3 7 .7
111.3 3 .7
Griswold 182 5 2 .0 7 8 .0 3 5 .5
1 1 3 .5 1 .5
Deviation of Vapor Composition from that calculated
by Dalton’s Law
using Partial Pressures calculated by Raoult * s Law
Vapor comp. Press, by Raoult1 s Law Vapor Comp* .
Source mol % Partial Total mol % Deviation
Benzol Benzol Benzol mol %
(observed) psi.
...psi. (calc.) Benzol
Run K 6 5 .2
7 3 .1
10 8.3 6 7 .8
- 2.3
Griswold 6 6 .0 7 6 .8 110.2
6 9 .7 - 3.7
Run L 64* 0 7 3 .6
111.3
6 5 .8 - 2 .1
Griswold 6 5 .0 7 8 .0
113.5
6 8 .6 - 3 .6
Vapor pressure of benzol— l45 and 150 psi. at 180
and 182° C., respectively, ( 8)5 of toluol— 71 an(i I k - psi.
at 180 and 182° C., respectively, (9)*
CHAPTER VI
OPERATING CHARACTERISTICS OP APPARATUS
Feed Rate:- Examination of Figure 9> Page 26, leads
to the conclusion that the most accurate results are obtain
able with a feed rate between two and six gallons per hour;
it can also be concluded that satisfactory results can be
obtained with feed rates greater than these even up to the
maximum possible* This latter conclusion leads to the de
duction that there is very little, if any, entrained liquid
passing out in the vapor even at vapor rates as high as 7 *4
gallons per hour (on condensed basis). Feed rates less than
two gallons per hour incur difficulty in control due to the
large time lag between changes in valve settings and result
ant re spons e s•
Examination of Table III shows the results obtained
at a pressure of 115 pounds per square inch to compare fa
vorably with those of Griswold et al ( 6). The results of
this experimenter show a slightly greater deviation from
Raoult*s Law but a slightly lesser deviation from Dalton*s
Law than the reference data indicates. It can be concluded,
however, that the apparatus is capable of producing satis
factory equilibrium data for moderately high pressures over
the feed range given above.
30
Time Requirements:- Examination of Table II, page
23, indicates that, when starting with all of the apparatus
cold, approximately two to two and three-quarters hours are
required to attain steady-state condition and complete a
run; when the apparatus is hot, approximately one to one
and three-tenths hours are required. These figures, of
course, are exclusive of the time required for analysis of
the liquid and vapor samples.
Thermal Efficiency of Heater:- The curve shown on
Figure 10 indicates a rising thermal efficiency with in
crease in the feed rate. This fact is to be expected, and
merely indicates a minimization of the heat losses from the
heater with an increase of the heater output. The thermal
efficiencies were calculated from the current input to the
heater elements and the sensible heat and heat for vapor
ization picked up by the fluid flowing through the heater.
The latter heats were computed using a constant specific
heat of 0.5 B.T.U. per pound per degree Fahrenheit and a
constant latent heat of vaporization of 150 B.T.U. per pound
for all except the runs made at high pressure; for these
runs, the same specific heat was used but a latent heat of
vaporization of 102 B.T.U. per pound was used.
Miscellaneous:- When operating at approximately at
mospheric pressure, the rate of flow of vapor-condensate is
indicated by the manometric pressure; this fact is to be
expected and is merely an indication of the resistance to
fluid flow in the piping between the top of the separator
and the receiver tank, which is at atmospheric pressure*
curve showing the above is presented in Figure !!♦
Thermal Efficiency o f Heater - Per Cent
30
20
o Runs at atmospheric
— ; j _J pressure
• Runs at 115 p*s*i. j
10
Feed Rate - Gal«/Hr*
Figure 10.- Thermal Efficiency of Heater
Manometer Heading - Inches of Mercury
10
0*1
5
i 2 10
Vapor-condensate Rate - Gal./Hr*
Figure 11*- Vapor-condensate Rate as a Function or Manometer Heading
CHAPTER VII
CONCLUSIONS
A continuous equilibrium flash vaporization apparatus
was designed, constructed and tested.
Operational tests of the apparatus proved it capable
of effecting liquid-vapor equilibrium and separation at
pressures in the vicinity of atmospheric pressure and 115
pounds per square inch.
Test of the apparatus proved that steady-state opera
tion could be obtained in about two and one-half hours when
starting cold and in about one hour when starting hot.
LITERATURE CITED
1. Colburn, A. P., Schoenburn, E. M., and Schilling, D.,
Ind* Eng* Chem., 35* 1250 (19^-3) •
2* Edmister, W. C., Reidel, J. C., and Merwin, W. J.,
Trans * Am* Inst* Chem* Engrs *, 39» k5l (19^-3) •
3* Edmister, W* C*, and Pollock, D. H*, Chem* Eng* Prog*,
Mt, 905 (1948).
4» Fanoher, G. H., Pet, Eng,. 2, No. 6, 176 (1931).
5* Penske, M. R*, in t f Science of Petroleum’ 1, Vol. II,
p. l6?7, Oxford University Press, London, 1938.
6* Griswold, J., Andres, D., and Klein, V. A., Trans * Am*
Inst* Chem* Engrs *, 39* 223 (19^-3) •
7* "International Critical Tables” 1st ed*, Vol. Ill,
p. 29, McGraw-Hill, New York, 1928*
8* ’ ’ International Critical Tables" 1st ed., Vol. Ill,
p. 2 l \ l ± , McGraw-Hill, New York, I9 2 8*
9* Krase, N* W., and Goodman, J. B,, Ind* Eng* Chem., 22,
13 (1930).
10* Leslie, E. H., and Good, A. J., Ind* Eng* Chem*, 19*
1 +5 3 (1927).
11. Lipkin, M. R., Davison, S. A., Harvey, W. T., and Kurtz,
S. S. Jr*, Ind* Eng. Chem* (Anal* Ed.), l6, 55 (19W4-)*
12* Nelson, W. L., "Petroleum Refinery Engineering” 2nd ed.,
PP* 59f 2ii . 2 , McGraw-Hill, New York, 19ij.l*
Othmer, D. F., Ind. Eng* Chem*» 20* 7 i j _ 3 (1928).
Rosanoff, M. A., Bacon, C. W., and White, H. H.,
J. Am. Chem. Soc., 2k, 1803 (191ii-).
Stoekhardt, J. S., and Hull, C. M., Ind. Eng. Chem.
22, 3438 (1931).
APPENDIX
SAMPLE CALCULATIONS
38
Peed Rate— Rum H
(10.6 - 5,0 Mip-9-- - J l - 2 1 « 6.11 gallons/hr.
1 +
► 0
Vapor-condensate Rate--Run H
, ml. s,min. x, cu. In. w gal. x_ gal.
(HK7)(-EF:)(-Ku— )(cu.in.>= hF7
( 2 1 0 ) ( 6o ) ( # 3Y) (2 3 1) s 3*33 gallons/in*.
Thermal Efficiency or Heater—-Rim H
Input * (amps.)(volts)(BTU/watt-hr.) s BTU/hr.
r (2 7 .0 ) (2 2 0 ) (3,1*15) = 20,25 0 BTU/hr.
Output = Sensible heat + Heat of Vaporization
Sensible W°F.BTU *,lb. gal.
heat = (Temp.rise °C.) (t5^) ('ibW.} ( iiJ7) (h?T)
= (9 3 .3 - 25) ( 1 . 8 ) ( 0. $ ) ( 8 . 33* 0 . 8 6 5) ( 6 . 1 1 )
= 2,720 BTU/hr.
Heat of _ , BTU____ % , Ib.v,gal. vaporized,
Vap. * 'lb. vapori zed * * gal.'' hr. *
= ( 1 5 0 ) ( 8 . 33x 0.865)(3*33)
= 3 ,6 0 0 BTU/hr.
Output = 2,720 + 3,600 = 6,320 BTU/hr.
Thermal Efficiency = Output x ; j _ qo
Input
- - 6 iu?gS x 100 = 31, 25s
20,25 0
TABLE IV
OPERATING- LOG-SHEET, RUN H
Heater Insulation Sight glass Gauge
Product rates
Time current heater heater Temperature, °C. press. ml./min.
amps* current current Thermocouple no. in.Hg. Liquid Vapor
amps. amps. 1 2 3 4 5 cond.
3 00*
22.6 4.8 3.6 25 25 25 25 25
3
16
3 20 25.2 4*7 3.0 80 159 84 105 89 0.13 60
3 25 27.0
161
3 40 27.0 4.7 3.0 89.8 165 89 109 90 0.20 260 105
3 47 27.0
169 112
3 58 27.0
4.7 3.0 91 173 91 114 92 0.23 210 145
4 12 27*0 178 0.32 190 160
4 22 27.0 4.7 3.0
92.6 182 92.6
118 92.6 0.34 175
4 30 27.0
184
4 40 27.0 4.7 3.0 93.3
186
93.3 119 93.3
4 52 27*0
93.3 189 120 93.3
4 58 27.0
4.7 3.0 93.3 190 93.3 121 93.3 0.48 150 210
5 03 27.0
4.7 3.0 93.3 190 93.3 121 93.3 0.49 150 210
5
10
27.0
4.7 3.0 93.3 190 93.3 121 93.3 0.50 150 210
5 0 0 0
Start Finish
Room temperature - 25° C. Feed tank readings) Left 10*6 5*0
Atmospheric pressure - 29*66 in*Hg* gallons )Right 10.9 4*9
** Pumps on
Pumps and power off
Pump piston stroke) Left 3/8
inches )Right 3/8
Vo
vO
ko
TABLE V
SUCCESSIVE OBSERVATIONS AT STEADY STATE
Gauge Liquid Vapor-condensate
Run Time Temp.
°C.
press.
in.Hg.
Sp.gr.
mo
Comp.
< 1 % CfcHfc
Sp.gr. Comp.
mol% C&H6
A
12:15
95.0
0.15 0 .8 6 4 4 40.5 O.8669 6 2 .5
B
3:26
3:33
3:4-0
95.0
95.0
95.0
0.10
0.10
0.10
0 .8 6 4 4
0.8644
0.8643
4 °.5
40.5
4o.o
0.8668
0.8 66 9
0.8 66 9
6 2 .0
6 2 .5
6 2 .5
P 12:20
12:25
12:30
93.8
93.8
93.8
1.00
1.00
1.00
0.8649
0.8 6 5 0
0.8651
4 5 .2
4 ° . 3
4 7.0
O.8676
0 .8 6 7 6
O.8676
68.8
68.8
68.8
G
11:35
11:42
11:47
94*4
94.4
9 4.4
1.54
1.55
1.55
0.8650
0.8651
0.8650
46.3
f c °
O.8676
O.8 6 7 4
0.8675
68.8
6 7 .2
■ 68.0
H 4:58
5:03
5:08
93.3
93.3
93.3
0 .4 8
0.49
o.5o
0.8651
0.8651
0.8650
4 7.0
m
O .8 6 7 6
0.8675
0.8675
68.8
68.0
68.0
J 2:00
2:05
2:10
100.2
100.2
100.2
2 .8 0
2.85
2 .9 0
0.8639
0.8639
0.8638
3 5 .5
3 5 .5
3 4 .9
0 .8 6 6 2
0 .8 6 6 2
0 .8 6 6 2
5 7.0
5 7.0
57.0
K
4:30
4:35
4:4-0
180
18 o
180
100.3*
100.3*
100.3*
0.8654
0.8654
0.8656
4 9 .7
4 9 .7
5 1 .7
0 .8 6 7 2
O.8672
0.8672
6 5 .2
6 5 .2
65.2
L 11:30
11:35
ll: 4 o
182
182
182
100. 3*
100. 3*
100.3*
0.8653
0.8653
0.8654
48.8
48.8
49.6
0.8670
0 .8 6 7 1
O .8671
63.5
64.2
6 4 .2
Each value the average of three determinations.
w Pounds per square inch.

Linked assets

University of Southern California Dissertations and Theses

Conceptually similar

PDF

A study of possible methods of separation of hydrocarbon isomers

PDF

A study of the heat transfer between a falling drop of liquid and a rising stream of gas

PDF

Construction of a laboratory distilation column

PDF

A study of a cross-flow, induced draft cooling tower

PDF

A study of the degree of mixing for liquids undergoing continuous dilution

PDF

Allowable vapor and liquid rates in bubble cap columns

PDF

A study of the condensation reaction of methylethyl ketone at elevated temperatures and pressures

PDF

The effect of sodium sulfate scale on heat transfer coefficients inside tubes

PDF

A new reduced equation of state for liquids and gases

PDF

An experimental study of batch distillation

PDF

A study of the flow paths of fluids in tanks

PDF

The preparation of sulfur dioxide by adsorption in and extraction from nitrobenzene

$Studies on association: Its correlation with ionization, refractive index and dielectric constant$

PDF

Studies on association: Its correlation with ionization, refractive index and dielectric constant

PDF

Variables of etching aluminum foil for use in electrolytic capacitors

PDF

Engineering properties of phosphorus thiotrichloride

PDF

Experimental investigation of an integrator based on pneumatic control instruments

PDF

An investigation of the effect of liquid surface tension on the operation of a bubble cap distillation column

PDF

The phase behavior of cyclohexane-rich mixtures with water

PDF

Investigation of surface tension decrements of polymer solutions, particularly as a function of concentration and molecular weight of the dissolved polymer

PDF

Prediction of viscosity of pure liquids, mixture of gases and mixture of liquids

Asset Metadata

Creator Goodman, Abraham Charles (author)

Core Title The construction and testing of a continuous equilibrium flash vaporization apparatus

Contributor Digitized by ProQuest (provenance)

Degree Master of Science

Degree Program Chemical Engineering

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag engineering, chemical,OAI-PMH Harvest

Language English

Advisor Lockhart, Frank J. (committee chair), Dodson, Charles R. (committee member), Landee, Franc A. (committee member)

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c20-305980

Unique identifier UC11259465

Identifier EP41726.pdf (filename),usctheses-c20-305980 (legacy record id)

Legacy Identifier EP41726.pdf

Dmrecord 305980

Document Type Thesis

Rights Goodman, Abraham Charles

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Access Conditions The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the au...

Repository Name University of Southern California Digital Library

Repository Location USC Digital Library, University of Southern California, University Park Campus, Los Angeles, California 90089, USA