A novel droplet imaging system (DIS) has been developed which, when interfaced with an electrodynamic balance (EDB), offers unique capabilities for characterizing size, mass, density, and composition of single, compositionally dynamic droplets. The DIS employs a standard closed‐circuit video camera as a droplet sensor. Real‐time hardware image processing techniques are employed to extract cross‐sectional area and position information from the video signals. The position information is used to generate a control signal which is proportional to the droplet mass. The DIS capabilities are demonstrated for evaporating water and coal‐water slurry droplets. The results presented clearly demonstrate that this system can be applied to easily detect compositional variations from one droplet to another. Accurate estimates of droplet composition can be obtained with little knowledge of the starting composition. The DIS has a wide range of applications and is particularly valuable when applied to the study of multicomponent droplets where the physical and chemical behavior often times depends on the droplet composition.

1.
E. J.
Davis
and
A. K.
Ray
,
J. Colloid Interface Sci.
75
,
566
(
1980
).
2.
M. A.
Philip
,
F.
Gelbard
, and
S.
Arnold
,
J. Colloid Interface Sci.
91
,
507
(
1983
).
3.
E. J.
Davis
,
P.
Ravindran
, and
A. K.
Ray
,
Adv. Colloid Interface Sci.
15
,
1
(
1981
).
4.
E. J.
Davis
,
Aerosol Sci. Tech.
2
,
121
(
1983
).
5.
C. B.
Richardson
and
J. F.
Spann
,
J. Aerosol Sci.
15
,
563
(
1984
).
6.
J. F.
Spann
and
C. B.
Richardson
,
Atmos. Environ.
19
,
819
(
1985
).
7.
G.
Sageev
,
R. C.
Flagan
,
J. H.
Seinfeld
, and
S.
Arnold
,
J. Colloid Interface Sci.
113
,
421
(
1987
).
8.
S.
Arnold
and
N.
Hessel
,
Rev. Sci. Instrum.
56
,
2066
(
1985
).
9.
S.
Arnold
,
M.
Neuman
, and
A. B.
Pluchino
,
Opt. Lett.
9
,
4
(
1984
).
10.
S.
Arnold
,
E. K.
Murphy
, and
G.
Sageev
,
Appl. Opt.
24
,
1048
(
1985
).
11.
S.
Arnold
and
L. M.
Folan
,
Rev. Sci. Instrum.
57
,
2250
(
1986
).
12.
G. S.
Grader
,
S.
Arnold
,
R. C.
Flagan
, and
J. H.
Seinfeld
,
J. Chem. Phys.
86
,
5897
(
1987
).
13.
R. E.
Spjut
,
E.
Bar‐Ziv
,
A. F.
Sarofim
, and
J. P.
Longwell
,
Rev. Sci. Instrum.
57
,
1604
(
1986
).
14.
R. E.
Spjut
,
A. F.
Sarofim
, and
J. P.
Longwell
,
Langmuir
1
,
355
(
1985
).
15.
E. J.
Davis
and
P.
Ravindran
,
Aerosol Sci. Tech.
1
,
337
(
1982
).
16.
R. H. Frickel, R. E. Shaffer, and J. B. Stamatoff, Report No. ARCSL‐TR‐77041, Chemical Systems Laboratory, Aberdeen Proving Ground, Maryland, 1978.
17.
E. J.
Davis
,
Langmuir
1
,
379
(
1985
).
18.
G.
Sageev
,
J. H.
Seinfeld
, and
R. C.
Flagan
,
Rev. Sci. Instrum.
57
,
933
(
1986
).
19.
R. F.
Wuerker
,
H.
Shelton
, and
R. V.
Langmuir
,
J. Appl. Phys.
30
,
342
(
1959
).
20.
D. J. Maloney, G. E. Fasching, L. A. McCarthy, W. F. Lawson, and K. H. Casleton, in Design and Operating Characteristics for a Laboratory Coal‐Water Fuel Droplet Generator, U.S. DOE Technical Note, DOE/METC‐87/4067, October 1986.
21.
D. G. Fink, Ed., Electrical Engineers Handbook (McGraw‐Hill, New York, 1975), Sec. 20.
22.
D. C.
Taflin
,
S. H.
Zhang
,
T.
Allen
, and
E. J.
Davis
,
AIChE J.
34
,
1310
(
1988
).
23.
D. J. Maloney and J. F. Spann, Twenty‐second (International) Symposium on Combustion (The Combustion Institute, in press).
This content is only available via PDF.
You do not currently have access to this content.