US 2006/0231963 A1 · Method and apparatus for producing fine particles

Abstract

A producing apparatus (1) of fine particles includes two pipes constructed by an outer pipe (11) and an inner pipe (21) arranged in a concentric shape. The tip (21a) of the inner pipe (21) is spaced from the tip (11b) of the outer pipe (11) by a comparatively long distance. Fluid II is flowed toward the tip (21a) of the inner pipe (21) within the inner pipe (21). Fluid I is flowed toward the tip of the outer pipe (11) as a continuous phase within the outer pipe (11). The flow velocities of the fluid I and the fluid II within the outer pipe (11) and the inner pipe (21) are set to appropriate values by controlling the operations of respective pumps (14, 24) by commands from a controller (31). Thus, the fluid II exhausted from the tip (21a) of the inner pipe (21) becomes a droplet (3) having a in approximately spherical shape surrounded by the fluid I within the outer pipe (11) and having a predetermined desirable diameter.

Claims18

Dependent claims

A method for producing fine particles by using a first pipe for flowing fluid I therethrough, and a second pipe for flowing fluid II therethrough and arranged such that one end of the second pipe exists within said first pipe and the vicinity of said one end is extended substantially in parallel with the axial direction of said first pipe;

wherein the fluid I and the fluid II are respectively flowed to said first and second pipes by selecting flow velocities and physical property values of the fluid I and the fluid II and the sizes of said first and second pipes satisfying the following formula (1) such that the fluid II exhausted from said one end of said second pipe becomes fine particles surrounded by the fluid I within said first pipe,
FS=FB+FK+FD (1)
where
FS=πγDii—interfacial tension (N) between the fine particles and the second pipe,
F
B
=
λ
⁢
4
3
⁢
π
⁡
(
D
2
)
3
⁢
g
⁢
⁢
Δ
⁢
⁢
ρ
—buoyant force (N) of the fine particles,
FK=ρ′UiQi—inertial force (N) of the fluid II, and
F
D
=
C
D
2
⁢
ρ
⁢
⁢
U
e
2
⁢
π
4
⁢
(
D
2
-
D
ii
2
)
—fluid force (N) of the fluid I affecting the fine particles,
γ:
interfacial tension coefficient (N/m),
g:
acceleration of gravity,
λ:
coefficient,
D:
diameter (m) of the fine particle,
Δρ=ρ−ρ′ (ρ:
density (kg/m3) of the fluid I, ρ′:
density (kg/m3) of the fluid II),
Ui:
average flow velocity (m/s) of the fluid II,
Ue:
average flow velocity (m/s) of the fluid I around the fine particles,
Q
i
=
π
4
⁢
D
ii
2
⁢
U
i
⁢
:
flow rate (m3/s) of the fluid II (Dii:
inner diameter of the second pipe), and
CD:
flow resistance coefficient of the fine particles,
C
D
=
κ
Re
=
κ
U
e
⁢
D
⁢
⁢
ρ
′
⁢
μ
(Re:
Reynolds number, κ:
constant, μ:
viscosity coefficient of the fluid I).

106 more elements

A producing apparatus of fine particles comprising:

a first pipe for flowing fluid I therethrough;
a second pipe for flowing fluid II therethrough and arranged such that one end of the second pipe exists within said first pipe and the vicinity of said one end is extended substantially in parallel with the axial direction of said first pipe;
and
flow velocity control means for controlling the flow velocities of the fluid I and the fluid II on the basis of physical property values of the fluid I and the fluid II and the sizes of said first and second pipes such that the fluid II exhausted from said one end of said second pipe becomes fine particles surrounded by the fluid I within said first pipe;
wherein said flow velocity control means controls the flow velocities of the fluid I and the fluid II so as to satisfy the following formula (1),
FS=FB+FK+FD (1)
where
FS=πγDii—interfacial tension (N) between the fine particles and the second pipe,
F
B
=
λ
⁢
⁢
4
3
⁢
π
⁡
(
D
2
)
3
⁢
g
⁢
⁢
Δ
⁢
⁢
ρ
—buoyant force (N) of the fine particles,
FK=ρ′UiQi—inertial force (N) of the fluid II, and
F
D
=
C
D
2
⁢
ρ
⁢
⁢
U
e
2
⁢
π
4
⁢
(
D
2
-
D
ii
2
)
—fluid force (N) of the fluid I affecting the fine particles,
γ:
interfacial tension coefficient (N/m),
g:
acceleration of gravity,
λ:
coefficient,
D:
diameter (m) of the fine particle,
Δρ=ρ−ρ′ (ρ:
density (kg/m3) of the fluid I, ρ′:
density (kg/m3) of the fluid II),
Ui:
average flow velocity (m/s) of the fluid II,
Ue:
average flow velocity (m/s) of the fluid I around the fine particles,
Q
i
=
π
4
⁢
D
ii
2
⁢
U
i
:
flow rate (m3/s) of the fluid II (Dii:
inner diameter of the second pipe), and
CD:
flow resistance coefficient of the fine particles,
C
D
=
κ
Re
=
κ
U
e
⁢
D
⁢
⁢
ρ
′
⁢
μ
(Re:
Reynolds number, κ:
constant, μ:
viscosity coefficient of the fluid I).

110 more elements

Dependencies are inferred from the claim text.

Method and apparatus for producing fine particles

Life of this patent

Method and apparatus for producing fine particles

Life of this patent

Abstract

Claims18