This experimental investigation concerns the hydraulic transport of a spherical capsule train, whose density is equal to that of water (relative density; $s=1$), in horizontal pipes. In a system where the carrier fluid is water, pressure drops of two phase flow and capsule velocities were measured at 0.2–1.0 m/s bulk velocities and 5–20% capsule transport concentrations. The results found were compared with the pressure gradient (pressure drops per unit length) ratios $((ΔP/L)m/(ΔP/L)w)$ measured for less dense capsules. The capsule velocity and the velocity ratio $(Vc/Vb)$ increased with increasing the bulk velocity. As concentration increases, the pressure gradient of the capsule-water mixture increases. For all concentrations, the pressure gradient ratio decreases (getting closer to 1) with increasing bulk velocity. This result is similar to that of capsules with less relative density. However, the pressure gradient ratio of the capsule flow with less density is higher than that of capsules with equal density at constant transport concentrations. The reason for this difference is that the capsules with a density equal to that of water move along the axis of the pipe for a longer time. When capsules with equal density are used, the mass flow rate will remain the same, but energy consumption will decrease.

1.
,
Y.
,
Shirakashi
,
M.
, and
,
S.
, 1999, “
Flow Characteristics of Ice-Water Slurry in a Horizontal Circular Pipe
,”
Proceedings of the Third ASME-JSME Joint Fluids Engineering Conference
, July 18–23, San Francisco, CA, pp.
1
5
.
2.
Snoek
,
C. W.
,
Walosik
,
S.
, and
Gupta
,
R. P.
, 1993, “
Ice Slurry Transport for District Cooling Networks
,”
Hydrotransport 12
,
Proceedings of the 12th International Conference on Slurry Handling and Pipeline Transport
, Brugge, Belgium,
Mechanical Engineering Publications
,
London
, 28–30 September, pp.
511
524
.
3.
Takahashi
,
H.
,
Masuyama
,
T.
, and
Kawashima
,
T.
, 1991, “
Flow Properties for Slurries of Particles With Densities Close to That of Water
,”
Proceedings of the First ASME-JSME Fluid Engineering Conference
, Liquid-Solid Flows, FED, Vol.
118
, pp.
103
108
.
4.
,
Y.
,
,
Y.
,
Kobayashi
,
M.
, and
Shirakashi
,
M.
, 1998, “
Measurement of Properties of Ice Particles in Water Affecting Ice-Water Mixture Flow in Pipes
,”
Proceedings of Fourth KSME-JSME Liquids Engineering Conference
, Oct. 18–21, Pusan, Korea (South), pp.
373
376
.
5.
Ulusarslan
,
D.
, and
Teke
,
I.
, 2005, “
An Experimental Investigation of the Capsule Velocity, Concentration Rate and the Spacing Between the Capsules for Spherical Capsule Train Flow in a Horizontal Circular Pipe
,”
Powder Technol.
0032-5910,
159
, pp.
27
34
.
6.
Ulusarslan
,
D.
, and
Teke
,
I.
, 2006, “
An Experimental Determination of Pressure Drops in the Flow of Low Density Spherical Capsule Train Inside Horizontal Pipes
,”
Exp. Therm. Fluid Sci.
0894-1777,
30
, pp.
233
241
.
7.
Button
,
B. L.
, and
Ma
,
T. H.
, 1975, “
Hydraulic Transport of Single Spheres in a Horizontal Pipe
,”
ASME J. Fluids Eng.
0098-2202,
97
, pp.
243
245
.
8.
Garg
,
V. K.
, 1977, “
Capsule Pipelining—An Improved Theoretical Analysis
,”
ASME J. Fluids Eng.
0098-2202,
99
, pp.
763
771
.
9.
Ellis
,
H. S.
,
Kruyer
,
J.
, and
Roehl
,
A. A.
, 1975, “
The Hydrodynamics of Spherical Capsules
,”
Can. J. Chem. Eng.
0008-4034,
53
, pp.
119
125
.
10.
Kruyer
,
J.
, and
Ellis
,
H. S.
, 1974, “
Predicting the Required Liquid Throughput From the Capsule Velocity and Capsule Pressure Gradient in Capsule Pipelines
,”
Can. J. Chem. Eng.
0008-4034,
52
, pp.
215
221
.
11.
Round
,
G. F.
, and
Bolt
,
L. H.
, 1965, “
The Pipeline Flow of Capsules—Part 8—An Experimental Investigation of the Transport in Oil of Single, Denser Than Oil, Spherical and Cylindrical Capsules
,”
Can. J. Chem. Eng.
0008-4034,
43
, pp.
197
205
.
12.
Vlasak
,
P.
, 1995, “
The Toms Effect in Capsule-Liquid Flows
,”
Proceedings of the Eight International Freight Pipeline Society Symposium
, Pittsburgh, PA, pp.
93
98
.
13.
Seaba
,
J.
, and
Xu
,
G.
, 1995, “
Capsule Transport in Coal Slurry Medium
,”
ASME J. Fluids Eng.
0098-2202,
117
, pp.
691
695
.
14.
Seaba
,
J.
, and
Xu
,
G.
, 1996, “
A Novel Method to Measure Capsule Pressure Gradient in a Pipeline
,”
ASME J. Fluids Eng.
0098-2202,
118
, pp.
867
870
.
15.
Vlasak
,
P.
, 1999, “
An Experimental Investigation of Capsules of Anomalous Shape Conveyed by Liquid in a Pipe
,”
Powder Technol.
0032-5910,
104
, pp.
207
213
.
16.
Feng
,
J.
,
Huang
,
P. Y.
, and
Joseph
,
D. D.
, 1995, “
Dynamic Simulation of the Motion of Capsules in Pipelines
,”
J. Fluid Mech.
0022-1120,
286
, pp.
201
227
.
17.
Ellis
,
H. S.
, 1964, “
The Pipeline Flow of Capsules—Part 3—An Experimental Investigation of the Transport by Water of Single Cylindrical and Spherical Capsules With Density Equal to That of the Water
,”
Can. J. Chem. Eng.
0008-4034,
42
, pp.
1
8
.
18.
Ellis
,
H. S.
, and
Bolt
,
L. H.
, 1964, “
The Pipeline Flow of Capsules—Part 7—An Experimental Investigation of the Transport by Two Oils of Single Cylindrical and Spherical Capsules With Density Equal to That of the Oil
,”
Can. J. Chem. Eng.
0008-4034,
42
, pp.
201
210
.