Information
-
Patent Grant
-
6446716
-
Patent Number
6,446,716
-
Date Filed
Wednesday, July 5, 200024 years ago
-
Date Issued
Tuesday, September 10, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Bennett; Henry
- McKinnon; Terrell
Agents
-
CPC
-
US Classifications
Field of Search
US
- 165 74
- 165 75
- 165 86
- 165 122
- 165 253
- 454 184
- 361 605
- 361 613
- 361 616
- 361 690
- 361 676
- 361 677
- 361 678
- 422 109
- 219 408
- 219 522
- 219 520
- 055 3852
- 055 3854
-
International Classifications
-
Abstract
A working enclosure includes a working chamber whose walls delimit a confinement space for working in and an exterior branch loop for recycling the atmosphere of the confinement space. The branch loop opens at each end into the confinement space and includes means for circulating the atmosphere in the branch loop. The working enclosure includes filter members at each end of the branch loop.
Description
FIELD OF THE INVENTION
The present invention relates to a working enclosure of the type including a working chamber whose walls delimit a confinement space for working in and an external branch loop for recycling the atmosphere of the confinement space and which opens into the confinement space at both ends and includes means for circulating the atmosphere in the branch loop.
BACKGROUND OF THE INVENTION
Conventional working enclosures of the above kind are routinely thermostatically controlled so that the confinement space is maintained at constant temperature and auxiliary systems are routinely used to procure a high relative humidity.
Enclosures of the above kind are used for working in a controlled atmosphere, for example. One example of such work is the culture of animal cells or embryos. In this case the CO
2
and water vapour content of the atmosphere in the confinement space in particular are monitored.
Depending on the use to which the enclosure is put, it can be contaminated by undesirable germs which develop in the confinement space.
Recycling the atmosphere of the enclosure via an external branch loop provided for this purpose enables continuous treatment, and in particular filtering, of the atmosphere of the enclosure.
A fan or a pump is mounted in the branch to circulate the atmosphere.
A filter is provided at the entry end of the pipe constituting the branch loop relative to the normal direction of flow of the atmosphere in the loop. It holds back contaminating elements when the atmosphere of the enclosure is circulated.
An enclosure of the above kind works well if the fan or the pump is not stopped and the atmosphere circulates through the branch loop.
Contamination of the branch loop is possible if the operation of the pump is interrupted. It is then necessary to decontaminate the whole of the branch loop before restarting the enclosure, which necessitates a great deal of work.
Also, if work on the branch loop necessitates stopping the pump, it is necessary to decontaminate both the confinement space and the branch loop before returning the enclosure to service.
SUMMARY OF THE INVENTION
An object of the invention is to propose a working enclosure which limits the need for manual decontamination of the confinement space and the branch loop.
To this end, the invention provides a working enclosure of the above type characterized in that it includes filter members at each end of said branch loop.
Particular embodiments of the enclosure have one or more of the following features:
the filtration members at each end of the branch loop extend the wall of the chamber through which the branch loop opens;
the working chamber includes a containment vessel and a door mobile relative to the containment vessel and shutting off an access to said containment space and the branch loop is carried by the door, each end of the branch loop opens via the door, and the filter members are carried by the door at each end of the branch loop;
the door has over most of its surface a thermostatically controlled box-section and said branch loop extends over most of its length inside said thermostatically controlled box-section;
the working chamber includes a containment vessel and a door mobile relative to the containment vessel and shutting off an access to said confinement space and each end of the branch loop opens through walls of the containment vessel;
the containment vessel is at least partly surrounded by a thermostatically controlled jacket and said branch loop extends over most of its length inside said thermostatically controlled jacket; and
the containment vessel is at least partly surrounded by a thermostatically controlled jacket filled with a heat-conducting liquid and said branch loop passes through said jacket and extends over the greater part of its length in a thermostatically controlled box-section adjacent said jacket, which box-section contains a gas.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood after reading the following description, which is given by way of example only and with reference to the accompanying drawings, in which:
FIG. 1
is a diagrammatic view of an enclosure according to the invention in cross section in a vertical plane passing through the entry opening of the enclosure, and
FIGS. 2 and 3
are diagrammatic views of two embodiments of working enclosure according to the invention in cross section in vertical section planes parallel to the entry opening of the enclosure.
DETAILED DESCRIPTION OF THE INVENTION
The working enclosure
10
shown in
FIG. 1
includes a working chamber
12
inside a thermostatically controlled box
14
. The working chamber delimits a confinement space
16
for working in, for example for incubating cells or embryos. In the conventional way, the enclosure
10
is equipped with means for monitoring the atmosphere of the confinement space and in particular its CO
2
and water vapour content.
The working chamber
12
consists of a substantially parallelepiped-shaped containment vessel
17
one face
18
of which is open. That face is closed by an articulated door
20
adapted to seal an access opening to the confinement space
16
.
The containment vessel
17
which partly delimits the working chamber
12
is accommodated entirely within the thermostatically controlled box
14
. The latter forms a jacket
22
all around the working chamber
12
, except for its open face
18
. The jacket
22
formed in this way is filled with a heat-conducting liquids such as water. The solid walls of the containment vessel
17
are in contact with the heat-conducting liquid.
Means
24
for regulating the temperature of the heat-conducting liquid, such as resistive heating elements, are installed in the thermostatically controlled box
14
.
The door
20
is articulated to the thermostatically controlled box
14
by means of hinges
26
. The door can be moved between a position allowing access to the confinement space
16
via the open face
18
of the working chamber and a position closing the face
18
.
The door
20
has a frame delimited by a sealed box-section
28
filled with a heat-conducting fluid such as water. Means
30
for regulating the temperature of the heat-conducting fluid, such as resistive heating elements, are provided inside the box-section
28
. The box-section
28
is therefore thermostatically controlled and can advantageously be maintained at the same temperature as the jacket
22
.
The face of the door
20
facing the chamber
12
incorporates a plate
32
for sealing off the confinement space
16
. The plate
32
is slightly larger than the open face
18
of the containment vessel. It is adapted to be applied to the edges of the containment vessel in order to seal it hermetically. A peripheral seal is advantageously provided for this purpose.
A branch loop
40
for recycling the atmosphere in the confinement space
16
is integrated into the interior of the door
20
. The branch loop opens at both ends into the interior of the working chamber
12
via the open face
18
thereof.
The branch loop
40
extends from an entry opening
42
to an exit opening
44
, both of which are formed in the closure plate
32
. A suction intake
46
is provided to the rear of the entry opening
42
, which is extended by a duct
48
extending the length of the door inside the box-section
28
. The duct
48
is therefore immersed in the heat-conducting fluid.
The branch loop opens at the exit end
44
via a vent
50
.
A ventilator
52
or a compressor a pump is mounted inside the suction intake
46
to circulate the atmosphere through the branch loop
40
.
According to the invention, respective filter units
54
,
56
are provided at the entry and exit ends of the branch loop
40
. The filter units are identical and are high-efficiency particle air (HEPA) filters, for example. The filters have a mesh diameter of 0.2 μm, for example.
The filter units
54
and
56
are contained within the thickness of the plate
32
and therefore ensure the continuity of this wall of the chamber.
Clearly the branch loop
40
equipped with the fan
52
enables continuous circulation of the atmosphere in the confinement space. Contaminating particles contained in the atmosphere are held back by the filter unit
54
mounted at the entry
42
of the branch loop.
When the enclosure is operating normally, i.e. when the fan
52
is running, the filter unit
56
does not as such contribute to filtering the atmosphere of the enclosure.
On the other hand, if the fan
52
is stopped, with no flow in the branch loop
40
, the filter unit
56
prevents contaminants entering the branch loop
40
via the exit opening
44
.
Likewise, if the door
20
is opened, the two filters
54
and
56
prevent any contamination of the interior of the branch loop
40
.
Most of the length of the branch loop
40
is inside the thermostatically controlled box-section
28
and the atmosphere is therefore not subjected to any variation of temperature as it passes through the loop
40
.
In the embodiments of the invention shown in
FIGS. 2 and 3
elements identical or similar to those shown in
FIG. 1
are designated by the same reference numbers.
In the
FIG. 2
embodiment of the invention the branch loop
70
is not in the door for closing off the confinement space
16
. That door is not shown, but is parallel to and in front of the plane of the figure. The branch loop
70
is inside the jacket
22
delimited by the box
14
and the working chamber
12
.
To be more precise, the branch loop
70
extends along an exterior lateral wall
72
of the box. The branch loop
70
opens via a lateral wall
73
of the containment vessel. To this end, that wall has an entry opening
74
in it through which the atmosphere in the confinement space is collected and an exit opening
76
in it through which the filtered atmosphere is returned.
Each opening
74
and
76
is fitted with a respective filter unit
78
and
80
. The filter units are integrated into the thickness of the wall
73
and have a mesh diameter of 0.2 μm, for example.
As in the previous embodiment, the branch loop includes a suction intake
82
downstream of the filter
78
, a duct
84
and a vent
86
opening into the confinement space
16
via the filter
76
.
A fan is mounted in the branch loop. It has a rotor
88
in the duct
84
downstream of the suction intake
82
. The rotor
88
is rotated by an electric motor
90
which is outside the thermostatically controlled box
14
and inside an auxiliary cabinet
92
.
In this embodiment the filter
78
captures contaminants during continuous circulation of the atmosphere of the working space through the branch loop
70
.
If the fan is stopped, the filter
80
prevents contaminants entering the branch loop
70
, so avoiding the need to decontaminate the branch loop
70
before the enclosure is used again.
In the
FIG. 3
embodiment of the invention the branch loop
100
includes a duct
102
which connects a suction intake
104
to a vent
106
. The intake and the vent open into the space
16
via a lateral wall
108
in which openings
110
,
112
are formed. Each opening is equipped with a filter
114
,
116
. The duct
102
is no longer inside the jacket
22
filled with heat-conducting fluid, but instead in an adjacent thermostatically controlled area
120
. The area
120
is delimited by a cabinet
122
and is filled with air. Resistive heating elements
124
are placed inside the cabinet
122
to maintain the temperature in the area
120
substantially equal to that of the jacket
22
.
A fan rotor
130
is mounted in the branch loop
100
. Its drive motor
132
is inside the thermostatically controlled area
120
.
In this embodiment the filter
116
prevents contaminants entering the branch loop
100
if the fan is stopped.
Maintenance of the branch loop is facilitated because the duct
102
is no longer inside the jacket
22
filled with heat-conducting liquid, but instead in an adjacent thermostatically controlled area which is open to the atmosphere. However, transportation of the atmosphere from the confinement space through the duct
102
while it is being filtered does not vary its temperature, because the area
120
is also thermostatically controlled. This reduces the risk of condensation.
Whichever embodiment of the invention is used, if work has to be carried out on the branch loop, in particular on the fan, it is not necessary to decontaminate the working enclosure when work resumes because the enclosure is protected from contaminants introduced into the branch loop by the filters at both ends thereof.
Claims
- 1. A working enclosure comprising a working chamber whose walls delimit a confinement space for working in and an exterior branch loop for recycling the atmosphere of the confinement space, which branch loop opens at each end into the confinement space and includes means for circulating the atmosphere in the branch loop, wherein the working enclosure includes filter members at each end of said branch loop,wherein the working chamber includes a containment vessel and a door mobile relative to the containment vessel and shutting off an access to said confinement space and wherein each end of the branch loop opens through walls of the containment vessel, the containment vessel being at least partly surrounded by a thermostatically controlled jacket filled with a heat-conducting liquid and wherein said branch loop passes through said jacket and extends over the greater part of its length in a thermostatically controlled box-section adjacent said jacket, which box-section contains a gas.
- 2. The working enclosure according to claim 1, wherein the filter members at each end of the branch loop extend the wall of the chamber through which the branch loop opens.
- 3. A working enclosure comprising a working chamber whose walls delimit a confinement space for working in and an exterior branch loop for recycling the atmosphere of the confinement space, which branch loop opens at each end into the confinement space and includes means for circulating the atmosphere in the branch loop, wherein the working enclosure includes filter members at each end of said branch loop,wherein the working chamber includes a containment vessel and a door mobile relative to the containment vessel and shutting off an access to said confinement space and wherein each end of the branch loop opens through walls of the containment vessel, the containment vessel being at least partly surrounded by a thermostatically controlled jacket and wherein said branch loop extends over most of its length inside said thermostatically controlled jacket.
- 4. The working enclosure according to claim 3, wherein the filter members at each end of the branch loop extend the wall of the chamber through which the branch loop opens.
- 5. A working enclosure comprising a working chamber whose walls delimit a confinement space for working in and an exterior branch loop for recycling the atmosphere of the confinement space, which branch loop opens at each end into the confinement space and includes means for circulating the atmosphere in the branch loop, wherein the working enclosure includes filter members at each end of said branch loop,wherein the working chamber includes a containment vessel and a door mobile relative to the containment vessel and shutting off an access to said containment space and wherein the branch loop is carried by the door, each end of the branch loop opens via the door, and the filter members are carried by the door at each end of the branch loop.
- 6. The working enclosure according to claim 5, wherein the filter members at each end of the branch loop extend the wall of the chamber through which the branch loop opens.
- 7. The working enclosure according to claim 5, wherein the door has over most of its surface a thermostatically controlled box-section and wherein said branch loop extends over most of its length inside said thermostatically controlled box-section.
Priority Claims (1)
Number |
Date |
Country |
Kind |
99 08716 |
Jul 1999 |
FR |
|
US Referenced Citations (7)
Foreign Referenced Citations (5)
Number |
Date |
Country |
296 22 079 |
Aug 1997 |
DE |
0 195 703 |
Sep 1986 |
EP |
1 396 883 |
Jun 1975 |
GB |
WO 9005549 |
May 1990 |
WO |
WO 9534078 |
May 1995 |
WO |