JPH11332550A - Safety cabinet - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the sterilization effect by equalizing the formaldehyde concentration during sterilization, and to improve the sterilization workability, labor saving,
To provide an automated safety cabinet. A laboratory (2) and an outlet (12) at the upper part of the laboratory (2).
, A blower 6 disposed close to the air supply filter 4, and a laboratory 2
, An intake port 15 provided in the vicinity of the experimental table 3 for exhausting the air in the laboratory 2, and at least a part of the air sucked from the intake port 15 Flow path 16 for returning the air to the air filtration means 4, exhaust air filtration means 5 disposed close to the flow path 16, and an exhaust chamber provided on the secondary side of the exhaust air filtration means 5 9, a circulation channel 7 is provided which communicates with the exhaust chamber 9 on the secondary side of the exhaust air filtering means 5 and the primary side of the exhaust air filtering means 5 and is exposed outside the casing. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety cabinet for preventing contamination of an experimenter in a bacterial experiment, a genetic modification experiment, and the like. It is about the cabinet.

[0002]

2. Description of the Related Art Formalin sterilization of a cabinet, which is used as a laboratory for a bacterial experiment, a genetic modification experiment, and the like, is performed by filling a machine with formaldehyde. But,
When the area to be sterilized in the machine is sealed, the exhaust HEPA filter section is in the form of a dead end to block the exhaust port, and the formaldehyde generated on the laboratory bench is less likely to fill the inside of the machine and has a low concentration. Tended to be.
Therefore, a long sterilization operation was required to ensure the reliability of sterilization.

[0003] This sterilization operation has to be performed every time the experiment is completed. However, it takes time and labor to generate formaldehyde gas and exhaust after 5 to 6 hours for sterilization. The formaldehyde gas to be exhausted is harmful and has a pungent odor, necessitates a neutralization treatment, and involves problems such as equipment cost and labor. Further, at the time of sterilization, the front opening and the exhaust port must be sealed with a policy and a tape or the like.

Further, when the air is dry, such as in winter, the humidity is low. However, when the humidity is low, there are two problems that the sterilizing effect of formaldehyde is reduced and the risk of explosion of formaldehyde is increased. I do. In order to avoid these problems, it is generally said that it is necessary to secure a humidity of 50% or more. For this reason, it has been necessary to take measures such as evaporating water with a heater or spraying water in the apparatus.

[0005]

Today, there is a strong demand for ensuring the safety of the experimenter and saving labor for the experimenter, and there is a need for the development of equipment to meet these needs. The present invention has been made in order to solve the above-mentioned problems of the prior art and to respond to social needs, to enhance the sterilization effect by uniformizing the formaldehyde concentration during sterilization, and to improve the sterilization workability. Its purpose is to provide a labor-saving and automated safety cabinet.

[0006]

In order to achieve the above object, a safety cabinet according to the present invention has a work opening having a door on a front surface thereof, and allows air containing at least formaldehyde to flow therethrough. A laboratory, an air supply means for air supply disposed close to the upper outlet of the laboratory, an air supply means disposed close to the air supply means for air supply, and a lower part of the laboratory And an intake port provided near the experimental table for exhausting air in the laboratory, and at least a part of the air sucked from the intake port is returned to the air supply air filtering means. A gas flow path for recirculation, exhaust air filtration means disposed in close proximity to the gas flow path for recirculation, the laboratory, the air filtration means for air supply, the air blowing means, the laboratory bench, and the intake port , The reflux gas flow path, and the exhaust gas flow path. A housing for storing the air filtration means, an exhaust chamber provided on the secondary side of the exhaust air filtration means, and a formaldehyde generator having a heater and a humidifier provided in the gas flow path for recirculation. A formaldehyde neutralizing device having a heater provided in the reflux gas flow path, and a gas circulation path provided to be exposed outside the housing so as to communicate the inside of the exhaust chamber with a suction port of the blowing means. A control unit for controlling the formaldehyde concentration detecting device, the formaldehyde generating device, the formaldehyde neutralizing device, and the air blowing device, and the gas circulating passage is provided at a portion exposed outside the housing. A valve for shutting off, wherein the control unit is configured to output the formaldehyde generator and the hose based on an output of the formaldehyde detecting means. Formaldehyde neutralizer, and each of the ON · OF of said blowing means
F is instructed.

More specifically, a pressure detector is provided in the laboratory table or the laboratory, and the control means detects the hermetic sealing of the working opening by detecting the pressure at the start of operation, and judges the start of sterilization operation. It is like that.

The operation of the above technical means is as follows. The present invention provides a gas circulation path communicating the secondary side and the primary side of the exhaust air filtering means, and by operating a blower, it is possible to circulate formaldehyde gas to the exhaust air filtering means. It is possible to make the formaldehyde concentration uniform in the machine (in the safety cabinet) including the air filtration means, and it is possible to more reliably sterilize the entire flow path in the device.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. [Embodiment 1] FIGS. 1A and 1B are diagrams showing a configuration of a safety cabinet according to a first embodiment of the present invention, wherein FIG. 1A is a schematic front view, FIG. 1B is a schematic side view, and FIG. FIG. 3A is a diagram illustrating a main part of a circulation flow path of a 2A type safety cabinet according to the first embodiment, where FIG. 4A is a schematic front view and FIG.
It is sectional drawing in the -A arrow direction.

First, referring to FIG.
Will be described. In FIG. 1, reference numeral 2 denotes a laboratory for performing, for example, a bacterial experiment or a genetic modification experiment,
Denotes an experimental table provided at the lower part of the experimental room 2, 3 a denotes an inside of the experimental table, and 3 b denotes a bottom plate of the experimental table 3. 4 is the laboratory 3
The air supply air filtering means 5 disposed close to the upper air outlet 12 is located above the air supply air filtering means 4 with a space region (where a pressurized chamber described later exists). The exhaust air filtering means 6 is a blower that is related to a blowing means disposed near the upper part of the supply air filtering means 4 and adjacent to the exhaust air filtering means 5. Here, as the supply air filtration means 4 and the exhaust air filtration means 5, a filter called a HEPA filter suitable for removing fine particles such as microorganisms and fine dust is generally employed.

Reference numeral 9 denotes an exhaust chamber which is a space area on the secondary side (exhaust side) of the exhaust air filtering means 5, and reference numeral 10 denotes an openable / closable exhaust port provided at an upper portion of the exhaust chamber 9. Are connected to an exhaust duct or the like (not shown).
Reference numeral 11 denotes an outside air inlet serving as a working opening;
Is an upper outlet of the laboratory room 3, 13 is a pressurized chamber which is an upper space area of the air supply air filtering means 4, and 14 is a front door for sealing the working opening (suction port 11). It is.

Reference numeral 15 denotes an intake port provided near the laboratory table 3 for exhausting air in the laboratory room 2, and 16 denotes at least a part of the air sucked from the intake port 15 to the air supply means 4. The reflux channel 16 is a channel including the inside of the experimental table 3a described above. Reference numeral 17 denotes a storage section of the blower 6. further,
Reference numeral 7 denotes a circulation passage relating to a gas circulation passage that communicates the exhaust chamber 9 with the primary side (intake side) of the exhaust air filtration means 5, and reference numeral 8 denotes a valve provided in the circulation passage 7. The circulation channel 7 and the valve 8 are connected to the above-described laboratory 2, the laboratory table 3, the air supply air filtration unit 4, the exhaust air filtration unit 5,
The blower 6, the recirculation flow path 16, and the like are disposed so as to be exposed outside the housing.

Reference numeral 19 denotes an exhaust chamber 9 and a reflux channel 1.
6 is a density sensor provided in the apparatus. Reference numeral 20 denotes a formaldehyde generator disposed in the reflux channel 16 (in the embodiment of FIG. 1, inside the experimental table 3a), and reference numeral 21 denotes a formaldehyde generator in the reflux channel 16 (FIG. 1).
In the embodiment of the present invention, the formaldehyde neutralizing device 22 arranged in the inside of the laboratory table 3a) has an outlet for the laboratory table 3, 2
Reference numeral 3 denotes a gas burner take-out unit for the laboratory bench 3, 24 denotes a drain water discharge unit for the laboratory bench 3, and 30 denotes a control unit including a control panel and the like.

FIG. 2 shows a main part of a circulation channel of a safety cabinet called a 2A type, which is essentially the same type as the safety cabinet 1 shown in FIG.
The shapes of the exhaust chamber 9 and the circulation channel 7 are different. The + mark shown in FIG. 2 indicates that the primary side of the air filtering means (HEPA filter) is on the positive pressure side, and the-mark indicates
Indicates that the secondary side of the air filtering means (HEPA filter) is on the negative pressure side. The function and control of the safety cabinet 1 will be described with reference to FIGS.

The safety cabinet 1 shown in FIGS. 1 and 2 is provided with a circulation channel 7 for communicating the exhaust chamber 9 on the secondary side (negative pressure side) of the exhaust air filtering means 5 with the blower housing 17. During the sterilization operation, by operating the blower 6, the airflow flows in the direction of the blower storage unit 17 as indicated by the solid arrow. The air flow pressurized by the blower 6 passes through the air supply air filtering means 4 as shown by the thick arrow in FIG.
Laboratory 2, inlet 15, laboratory bench interior 3a, reflux channel 16
And circulates to the blower 6.

For this reason, the formaldehyde gas generated from the formaldehyde generator 20 inside the laboratory table 3a fills the entire flow path in the machine with a uniform concentration over time by the circulation of the air flow. Valve 8 provided in circulation channel 7
Is opened during sterilization, but serves to close the primary and secondary sides of the exhaust air filtering means 5 in a normal experiment so as to prevent bacteria used in the experiment from leaking. Here, the circulation flow path 7 is provided to be exposed outside the housing, and a valve 8 for closing the circulation path is provided in a portion exposed to the outside of the housing. 8 can be easily checked from the outside from outside, and safety can be enhanced.

The formaldehyde neutralizing device 21 housed in the laboratory bench 3a operates after sterilization inside the machine, and neutralizes formaldehyde to a concentration that can be exhausted outdoors. Here, the formaldehyde generator 20 and the formaldehyde neutralizer 21 will be described with reference to FIGS. FIG.
Is a detailed view of a formaldehyde generator with a built-in heater, (a) is a front view, (b) is a side view, FIG. 6 is a detailed view of a formaldehyde neutralizing apparatus with a built-in heater, (a) is a front view, (B) is a side view.

A formaldehyde generator 20 shown in FIG.
Is a tray 20a for generating formaldehyde, and a small fan 2 for diffusing formaldehyde into the reflux channel 16.
0b, a mounting table 20c, and a heater 20d is provided in the mounting table 20c below the tray 20a. Although not shown in FIG. 5, a humidifier may be provided. The formaldehyde neutralizing device 2 shown in FIG.
Reference numeral 1 denotes a catalyst housing 21a, a small fan 21b, and an end net 21c, and a heater 21d is provided in a part of the catalyst housing 21a.

The formaldehyde neutralizing device 21 has a structure in which a catalyst is filled in a catalyst accommodating portion 21a and surrounding formaldehyde gas is passed through the catalyst. Examples of the catalyst used here include a sulfur-resistant nickel catalyst and a copper / chromium / manganese alumina catalyst. The former is commercially available with diatomaceous earth as a carrier and a small amount of a co-catalyst added, and the latter is commercially available with alumina as a carrier and added with copper, chromium and manganese. Formaldehyde generator 2
0 has a heater 20d and a humidifying unit, and the formaldehyde neutralizing device 21 has a heater 21d, so that the control unit 30 can control the heater.

Some catalysts work without heating, but in general, heating often increases the effect. By using this heated catalyst and providing a heater 21d in the catalyst accommodating portion 21a, the heater 21d is heated by the heater 21d when the formaldehyde neutralizing device 21 is operated.
Since the temperature inside the machine rises, formaldehyde that has adhered to the machine disperses in the air again, which promotes the effect of neutralization, shortens the neutralization time, and lowers the concentration at the end of neutralization. Can and is effective.

The formaldehyde generator 20 shown in FIGS. 1 and 5 is arranged on the bottom plate 3b inside the laboratory bench 3a. However, the present invention is not limited to this, and although not particularly shown, the formaldehyde generator is suspended and housed in the inside of the laboratory table 3a which is a gas flow path for reflux, and the bottom plate 3 is housed.
b. In this case, the heat of formaldehyde generation is not easily transmitted to the bottom plate 3b, and there is an effect that the rise in surface temperature of the safety cabinet can be suppressed to some extent.

The concentration sensor 19 detects the formaldehyde concentration in the apparatus such as the exhaust chamber 9 and the reflux passage 16, and by monitoring this concentration data by the control unit 30, the formaldehyde concentration in the apparatus can be sterilized after the formaldehyde generation. That the concentration has decreased over time due to the deposition of formaldehyde,
Further, automatic control from the start of the operation of the formaldehyde neutralizer 21 to the end of the neutralization can be performed.

By the way, when performing a normal experiment, the laboratory 2 is opened, and at the time of sterilization after the normal experiment, the front door 14 of the laboratory 2 must be closed to ensure airtightness.
The opening and closing structure of the front door will now be described with reference to FIG.
FIG. 7 is an exploded view of a main part showing a structure of a front door in the safety cabinet of FIG.

The front door 14 shown in FIG. 7 is provided at a front opening (suction port 11) of the laboratory 2 and has a packing 14a facing the main body of the safety cabinet 1. On the other hand, the rail 18 for guiding the front door 14 has a bent portion 18a in which the lower part is divided into upper and lower parts and is inclined downward toward the cabinet body. When the front door 14 is lowered to the lower end along the rail 18, The packing 14 a of the door 14 is configured to contact the front surface of the main body of the safety cabinet 1.

FIG. 8 is a flowchart showing one embodiment of the automatic sterilization operation according to the present invention. This flowchart schematically shows the flow of control described below. Laboratory bench 3
Alternatively, a pressure detecting unit (not shown) is provided in the laboratory 2,
The pressure at the start of operation detects the tightness of the front opening (airtightness check). The airtightness of the laboratory 2 is confirmed, and the start of the sterilization operation is determined based on the detection results of the formaldehyde gas concentration, temperature, humidity, and the like.

When the formaldehyde gas concentration detection data is low, the sterilization operation is ON, and the formaldehyde generator 20 is operated to generate formaldehyde (CHCO) gas. A sterilization timer is set and sterilization is continued for the set time (for example, 5 hours). The formaldehyde gas generated from the formaldehyde generator 20 fills the entire flow path in the machine with a uniform concentration over time by circulation of the air flow. When the sterilization for a predetermined time is completed and the detection data of the formaldehyde gas concentration is high, the formaldehyde generator 20 is turned off, and the formaldehyde neutralizer 21 is operated to perform the neutralization of the formaldehyde (CHCO) gas.

When the detection data of the formaldehyde gas concentration decreases and it is determined that the formaldehyde has been neutralized to a concentration that can be exhausted outdoors, the valve 8 of the circulation flow path 7
Is closed, the exhaust port 10 of the exhaust chamber 9 is switched, and the neutralized gas is discharged outside from the exhaust duct. After that, the front door 14 is opened and the refresh air is circulated in the machine. These series of operations are automatically performed by a command from the control unit 30.

[Embodiment 2] FIGS. 3A and 3B are views showing a main part of a circulation flow path of a 2B type safety cabinet according to a second embodiment of the present invention. FIG. 3A is a schematic front view, and FIG. () Is a sectional view taken along the line BB in (a). In the figure, components having the same reference numerals as those in FIG. 2 are the same as those in the first embodiment, and the overall configuration of the safety cabinet is in accordance with FIG.

The 2B type shown in FIG. 3 corresponds to the 2B type shown in FIG.
The difference from the A type safety cabinet is that a partition plate 28 is provided between the air supply air filtering means 4 and the exhaust air filtering means 5, and a small blower 27 is provided in the circulation flow path 7A. Gas circulation in the circulation channel 7A can be forcibly performed by the small blower 27. In the embodiment shown in FIG. 3, the same operation and effect as those in the embodiment shown in FIGS.

[Embodiment 3] FIGS. 4A and 4B are diagrams showing a main part of a circulation flow path of a 2B type safety cabinet according to a third embodiment of the present invention. FIG. 4A is a schematic front view, and FIG. () Is a cross-sectional view taken along the line CC of (a). In the figure, components having the same reference numerals as those in FIG. 3 are the same as those in the second embodiment, and the entire configuration of the safety cabinet is in accordance with FIG.

The 2B type shown in FIG. 4 corresponds to the 2B type shown in FIG.
The difference from the B type safety cabinet is that the circulation channel 7 </ b> B is arranged so as to communicate the exhaust chamber 9 and the pressurizing chamber 13. Accordingly, when the blower 6 is operated during sterilization, the gas circulates from the positive pressure pressurizing chamber 13 side to the negative pressure exhaust chamber 9 as indicated by the solid line arrow, thereby achieving a uniform formaldehyde gas concentration. be able to. Therefore, in the embodiment shown in FIG. 4, the same operation and effect as those in the embodiment shown in FIGS.

[0032]

As explained in detail above, the present invention has the following effects. (1) Since the formaldehyde generator has a heater and a humidifying unit, and the formaldehyde neutralizer has a heater, it can be controlled by the control unit. (2) Since the gas circulation passage is provided outside the housing and a valve for closing the circulation passage is provided in the portion exposed outside the housing, the valve can be easily operated and the opening and closing of the valve can be checked externally. Can be easily done and safety can be improved.

(3) Based on the output of the formaldehyde detecting means, the control section turns on / off each of the formaldehyde generating device, formaldehyde neutralizing device, and blowing means.
Since the FF is instructed, the sterilization operation can be automated, and the workability during sterilization can be improved.

Taken together, according to the present invention, it is possible to provide a safety cabinet which enhances the sterilization effect by making the formaldehyde concentration uniform during sterilization, and which improves sterilization workability, labor saving and automation. it can.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a safety cabinet according to a first embodiment of the present invention, where (a) is a schematic front view and (b) is a schematic side view.

FIGS. 2A and 2B are diagrams showing a main part of a circulation flow path of a 2A type safety cabinet according to the first embodiment, wherein FIG. 2A is a schematic front view, and FIG. 2B is a sectional view taken along the line AA of FIG. It is.

FIGS. 3A and 3B are views showing a main part of a circulation flow path of a 2B type safety cabinet according to a second embodiment of the present invention, wherein FIG. 3A is a schematic front view, and FIG. It is arrow sectional drawing.

4A and 4B are diagrams showing a main part of a circulation flow path of a 2B type safety cabinet showing a third embodiment of the present invention, wherein FIG. 4A is a schematic front view, and FIG. It is arrow sectional drawing.

FIG. 5 is a detailed view of a formaldehyde generator with a built-in heater, wherein (a) is a front view and (b) is a side view.

FIG. 6 is a detailed view of a formaldehyde neutralizing device with a built-in heater, wherein (a) is a front view and (b) is a side view.

FIG. 7 is an exploded view of a main part showing a structure of a front door in the safety cabinet of FIG. 1;

FIG. 8 is a flowchart showing an embodiment of the automatic sterilization operation according to the present invention.

[Explanation of symbols]

1. Safety cabinet, 2. Laboratory, 3. Laboratory bench, 4.
Supply air filtering means, 5 ... Exhaust air filtering means, 6 ... Blower, 7, 7A, 7B ... Circulation flow path, 8 ... Valve, 9 ... Exhaust chamber, 10 ... Exhaust port, 11 ... Suction port, 12 ... Outlet, 13 ... Pressurized chamber, 14 ... Front door, 14a ... Packing, 15 ... Inlet, 16 ... Reflux channel, 17 ... Blower storage section, 18 ... Rail, 18a ... Bent section, 19 ... Concentration sensor, 20 ... formaldehyde generator, 21 ... formaldehyde neutralizer, 20d, 21d ... heater, 27 ... small blower.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Katsuaki Shinohara, Inventor Katsuaki Shinohara 2-4-4 Daimon-cho, Higashi-Kurume-shi, Tokyo 501-5 (72) Inventor Tetsuo Miyoshi 1-5-8 Kyobashi, Chuo-ku, Tokyo Stock Company Within Mershan Klintec (72) Inventor Atsuo Kitabayashi 1-2-23-2 Kandasuda-cho, Chiyoda-ku, Tokyo Within Hitachi Refrigerants Co., Ltd. (72) Inventor Mikio Suzuki 508-10, Kyushu-shi, Kashiwa-shi Chiba Pref. Inside the Environmental Technology Research Laboratory (72) Inventor Yuji Toyama 46-1 Tomioka, Nakajo-cho, Kitakanbara-gun, Niigata Prefecture Industrial Machinery Division, Hitachi, Ltd.

Claims (4)

[Claims] 1. A work opening having a door on a front surface,
A laboratory that allows the flow of at least air containing formaldehyde, an air supply air filtering means arranged near an upper outlet of the laboratory, and an air supply means arranged in close proximity to the air supply means Blower means, an experimental table provided at the lower part of the laboratory, an intake port provided near the experimental table for exhausting the air in the laboratory, and at least a part of the air sucked from the intake port. A recirculation gas flow path for recirculation to the air supply air filtration means, an exhaust air filtration means disposed in close proximity to the recirculation gas flow path, the laboratory, the air supply air filtration means, A housing for storing the blowing unit, the test bench, the intake port, the recirculating gas flow path, and the exhaust air filtering unit, an exhaust chamber provided on a secondary side of the exhaust air filtering unit, A heater and heating A formaldehyde generating device having a means, a formaldehyde neutralizing device having a heater provided in the reflux gas flow path, and a formaldehyde neutralizing device having a heater exposed outside the housing so as to communicate the inside of the exhaust chamber with a suction port of the blowing means. A gas circulation path, a formaldehyde concentration detection means, and a control unit for controlling the formaldehyde generation device, the formaldehyde neutralization device, and the air blowing means, wherein the gas circulation path is provided outside the housing. An exposed portion has a valve for shutting off this circulation path, and the control section turns on each of the formaldehyde generating device, the formaldehyde neutralizing device, and the blowing device based on an output of the formaldehyde detecting device.
-A safety cabinet characterized by being configured to command OFF. 2. A pressure detection unit is provided in the laboratory table or the laboratory, wherein the control means detects the hermetic sealing of the working opening by detecting pressure at the start of operation, and determines the start of sterilization operation. The safety cabinet according to claim 1, wherein the safety cabinet is provided. 3. The laboratory bench forms a part of the gas flow path for reflux, and the formaldehyde generator is suspended inside the laboratory bench and disposed separately from a bottom surface of the laboratory bench. The safety cabinet according to claim 1, wherein the safety cabinet is provided. 4. A front door provided at the work opening, a packing facing the cabinet body, and a front door left and right rail which is divided into upper and lower parts and inclined downward to the cabinet body side. 2. The safety cabinet according to claim 1, wherein the front door is attached so that the packing comes into contact with the front surface of the cabinet body when the lower end is lowered along the rail.