U.S. patent application number 10/141884 was filed with the patent office on 2002-09-12 for fluid control device.
This patent application is currently assigned to Tadahiro Ohmi. Invention is credited to Hirao, Keiji, Hirose, Takashi, Ikeda, Nobukazu, Minami, Yukio, Morimoto, Akihiro, Ohmi, Tadahiro, Yamaji, Michio, Yoshikawa, Kazuhiro.
Application Number | 20020124894 10/141884 |
Document ID | / |
Family ID | 16586346 |
Filed Date | 2002-09-12 |
United States Patent
Application |
20020124894 |
Kind Code |
A1 |
Ohmi, Tadahiro ; et
al. |
September 12, 2002 |
Fluid control device
Abstract
A fluid control device comprises a first passageway, and a
second passageway communicating therewith and having a terminating
end closed with a fluid control unit or instrument. The first
passageway is adapted to pass a fluid therethrough with a different
fluid remaining in the second passageway. The first passageway
comprises an upstream portion and a downstream portion
communicating with the upstream portion at an approximate right
angle therewith. The second passageway extends from a terminating
end of the upstream portion of the first passageway in alignment
with the upstream portion.
Inventors: |
Ohmi, Tadahiro; (Sendai-Shi,
JP) ; Minami, Yukio; (Osaka-shi, JP) ;
Morimoto, Akihiro; (Osaka-shi, JP) ; Ikeda,
Nobukazu; (Osaka-shi, JP) ; Hirao, Keiji;
(Osaka-shi, JP) ; Hirose, Takashi; (Osaka-shi,
JP) ; Yamaji, Michio; (Osaka-shi, JP) ;
Yoshikawa, Kazuhiro; (Osaka-shi, JP) |
Correspondence
Address: |
ARMSTRONG,WESTERMAN & HATTORI, LLP
1725 K STREET, NW.
SUITE 1000
WASHINGTON
DC
20006
US
|
Assignee: |
Tadahiro Ohmi
Miyagi
JP
|
Family ID: |
16586346 |
Appl. No.: |
10/141884 |
Filed: |
May 10, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10141884 |
May 10, 2002 |
|
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|
09127817 |
Aug 3, 1998 |
|
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6408879 |
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Current U.S.
Class: |
137/606 |
Current CPC
Class: |
Y10T 137/87684 20150401;
F16K 27/003 20130101 |
Class at
Publication: |
137/606 |
International
Class: |
E03B 001/00; E03C
001/00; F17D 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 5, 1997 |
JP |
9-210254 |
Claims
What is claimed is:
1. A fluid control device comprising a first passageway, and a
second passageway communicating therewith and having a terminating
end closed with fluid control means, the first passageway being
adapted to pass a fluid therethrough with a different fluid
remaining in the second passageway, the fluid control device being
characterized in that the first passageway comprises an upstream
portion and a downstream portion communicating with the upstream
portion at an approximate right angle therewith, the second
passageway extending from a terminating end of the upstream portion
of the first passageway in alignment with the upstream portion.
2. A fluid control device according to claim 1 wherein the fluid
control means is a pressure measuring instrument closing the
terminating end of the second passageway at all times.
3. A fluid control device according to claim 1 wherein the fluid
control means is a channel opening-closing device for temporarily
closing the terminating end of the second passageway.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to fluid control devices which
are adapted, for example, for use in apparatus for manufacturing
semiconductors and which require passage of a first fluid
therethrough and subsequent replacement of this fluid by a second
fluid.
[0002] Fluid control devices comprise various components, such as
filters, pressure regulators, various kinds of valves, massflow
controllers, pressure gauges and pressure sensors, which are
connected together. For example as shown in FIG. 5, a pressure
gauge 40 is provided generally at the terminating end of a branch
channel 42 extending from a main passageway 41 at right angles
therewith.
[0003] With this conventional fluid control device, the branch
channel having its terminating end closed with the pressure gauge
provides a so-called dead volume, and with a fluid remaining in
this portion of dead volume, another fluid is subsequently passed
through the passageway. It is an important problem to reduce the
replacement time involved in this procedure and taken for the
purity of the subsequent fluid to reach a required value.
Consideration is therefore given to how to diminish the dead
volume. However, no consideration whatever has been given to the
relation between the main passageway and the branch channel
relative to each other.
SUMMARY OF THE INVENTION
[0004] An object of the present invention is to provide a fluid
control device wherein consideration is given to the position of
passageways relative to each other so that one fluid can be
replaced by another within a shortened period of time.
[0005] The present invention provides a fluid control device
comprising a first passageway, and a second passageway
communicating therewith and having a terminating end closed with
fluid control means, the first passageway being adapted to pass a
fluid therethrough with a different fluid remaining in the second
passageway, the fluid control device being characterized in that
the first passageway comprises an upstream portion and a downstream
portion communicating with the upstream portion at an approximate
right angle therewith, the second passageway extending from a
terminating end of the upstream portion of the first passageway in
alignment with the upstream portion.
[0006] Useful fluid control means include a measuring instrument,
such as a pressure gauge or pressure sensor, closing the
terminating end of the second passageway at all times, and a
channel opening-closing device, such as a valve, for temporarily
closing the terminating end of the second passageway.
[0007] The fluid control device of the present invention has the
feature that the second passageway providing a dead volume in
replacing one fluid by another extends from the terminating end of
upstream portion of the first passageway in alignment with the
upstream portion, whereby the time required for the replacement of
fluid can be shortened without diminishing the dead volume.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a view in vertical section showing a fluid control
device embodying the invention;
[0009] FIG. 2 is a view in vertical section showing a fluid control
device for comparison;
[0010] FIG. 3 is a graph showing replacement characteristics of the
fluid control devices shown in FIGS. 1 and 2;
[0011] FIG. 4 is a piping diagram showing another embodiment of
fluid control device of the invention; and
[0012] FIG. 5 is a piping diagram showing a prior-art device
corresponding to the device shown in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] Embodiments of the invention will be described below with
reference to the drawings.
[0014] FIG. 1 shows a fluid control device embodying the invention.
The device includes two on-off valves 2, 3 vertically opposed to
each other and arranged at the inlet side of a massflow controller
1. Although not shown, the outlet side of the controller is also
provided with two on-off valves vertically opposed to each other.
The upper on-off valve 2 and the lower on-off valve 3 have their
bodies 4, 5 joined to each other. The upper valve 2 has an actuator
6 mounted on the top side of the valve body 4, while the lower
valve 3 has an actuator 7 attached to the bottom side of the valve
body 5. The body 5 of the lower valve 3 is joined to a channel
block 8 provided at the inlet side of the massflow controller 1.
The upper and lower valve bodies 4, 5 are provided with respective
inlet pipe connecting couplings 9, 10. The upper valve body 4 is
formed with an L-shaped inflow channel 11 and an I-shaped outflow
channel 12. The outflow channel 12 is open downward. The lower
valve body 5 is formed with an inverted L-shaped inflow channel 13
symmetric with the L-shaped inflow channel 11 of the upper valve
body 4, an inverted L-shaped outflow channel 14 generally symmetric
with this inflow channel 11, and a bypass channel 15 holding the
outflow channel 14 in communication with the outflow channel 12 of
the upper valve body 4. The inverted L-shaped outflow channel 14 of
the lower valve body 5 comprises a main passageway (downstream
portion) 16 communicating with the massflow controller 1, and a
first fluid subpassageway (upstream portion) 17 communicating with
the main passageway 16 at an approximate right angle therewith. The
main passageway 16 is used not only for the outflow of a fluid
flowing, in through the lower inlet pipe coupling 10 but also for
the outflow of a fluid flowing in through the upper inlet pipe
coupling 9. The combination of the outflow channel 12 of the upper
valve body 4 and the bypass channel 15 of the lower valve body 5
provides a second fluid subpassageway 18.
[0015] FIG. 2 shows a fluid control device used for comparison with
the fluid control device shown in FIG. 1. The body 22 of a lower
on-off valve 21 has a fluid passage different from the
corresponding passage of FIG. 1. More specifically stated, the
valve body 22 has an inlet pipe connecting coupling 10' attached to
the bottom side thereof and an actuator 7' mounted on the left side
thereof. An outflow channel 23 is I-shaped and comprises a main
passageway (downstream portion) 16 having the same size as the
corresponding passageway of FIG. 1 and communicating with a
massflow controller 1, and a first fluid subpassageway (upstream
portion) 24 substantially in alignment with the main passageway 16.
The outflow channel 23 is held in communication with an outflow
channel 12 in an upper valve body 4 by a bypass channel 15, which
has the same size as that of FIG. 1.
[0016] FIG. 3 shows variations in the purity of a process gas after
the start of passage of the process gas through the fluid control
devices shown in FIGS. 1 and 2. The purity of the process gas was
measured by checking the concentration of N.sub.2 serving as a
purge gag. The dead volume was 0.7 cc. FIG. 3 reveals that with the
device shown in FIG. 1, the concentration of nitrogen gas decreases
to less than 1 ppb upon lapse of 250 seconds, and that with the
device shown in FIG. 2, the nitrogen gas concentration is higher
than 1 ppm 250 seconds later, failing to decrease to not higher
than 1 ppb despite the lapse of 500 seconds.
[0017] Although the two devices are the same in the size of the
second fluid subpassageway 18 providing a dead volume, the device
wherein the subpassageway 18 closed by the actuator 6 and the first
fluid subpassageway 17 are generally aligned with each other and
communicate with the main passageway 16 nearly at a right angle
therewith (see FIG. 1) exhibits higher replacement characteristics
than the other device wherein the second fluid subpassageway 18
communicates with the first fluid subpassageway 24 nearly at a
right angle therewith (see FIG. 2).
[0018] The above result is usable as a criterion in evaluating
passages formed not only in fluid control devices of the type shown
in FIG. 1 and also in any other fluid control devices.
[0019] FIG. 4 shows an optimum passageway for use with a pressure
gauge or other measuring instrument. A main passageway 31 comprises
an upstream portion 32 and a downstream portion 33 communicating
therewith nearly at a right angle therewith. A branch channel 34
having a terminating end closed with a pressure gauge 40 extends
from the terminating end of the upstream portion 32 of the main
passageway 31 in alignment with this portion 32. This arrangement
produces the same effect as is shown in the graph of FIG. 3, when
compared with a conventional arrangement shown in FIG. 5,
consequently shortening the replacement time although the two
arrangements have branch channels 34, 42 of the same volume.
[0020] Although the foregoing devices have been described for use
with gases useful for producing semiconductors, the same advantage
as described above can be obtained with devices of similar
construction for other uses or for use with liquids instead of
gases.
* * * * *