JP3533649B2 - Safety cabinet - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety cabinet used for experiments and work dealing with pathogenic bacteria and chemical substances harmful to humans and the environment.

[0002]

2. Description of the Related Art A safety cabinet forms a semi-closed working chamber inside a cabinet body except for a working opening and sucks polluted aerosol generated in the working chamber so as not to flow out to a worker side. On the other hand, the contaminated air collected by suction has a function of being sterilized and cleaned by a HEPA filter and exhausted, and classified into Class I, II, and III depending on the level of pathogens that can be handled.

The class I type is an exhaust type as shown in FIG. 7 (g), and although it is possible to prevent the diffusion of dangerous bacteria to the surrounding environment, the outside air flows into the work table from the work opening. ,
Sterility on the workbench cannot be ensured. The class III type is a completely sealed type as shown in FIG. 7 (h) and can handle the bacteria with the highest risk, but the workability is not good because the work is performed through gloves.

Class II type is generally widely used. Class II type is classified into A type of indoor exhaust and B type of outdoor exhaust, and B type is B1 and B according to the airflow method.
It is classified into 2 and B3 type. The features of each are shown in the tables of FIGS. 7A to 7F and FIG. 7 (b) to (d),
Type A for indoor exhaust and type B for outdoor exhaust.
Class II is more expensive than Class I at the cost of high performance.

The basic performance of the class II type is the following three points. (1) Aerosol on the workbench does not flow out. (Protection of workers, Fig. 9 (a)) (2) Contaminated aerosol does not flow into the workbench. (Sample protection, Figure 9 (b)) (3) Left and right air is not mixed on the workbench. (Prevention of cross-contamination of samples, Fig. 9 (c)) In the pharmaceutical industry, hospitals, etc., the functions up to Class IIA type satisfying all of the above items are not necessary, but the class I type satisfying only (1) above is Addition of a cleaning function (2) above
There are many demands for an aseptic safety cabinet that can protect the sample.

[0006]

In view of the above-mentioned problems of the prior art, the present invention not only protects workers by preventing the outflow of contaminated aerosol to the outside, but also prevents the inflow of contaminated aerosol from the outside and supplies water. The purpose of the invention is to provide a biosafety and chemical hazard countermeasure aseptic safety cabinet that can reduce the size and weight, simplify the structure, and reduce the manufacturing cost while realizing the sample protection by cleaning the air. .

[0007]

In order to achieve the above object, the safety cabinet of the present invention uses a clean air blowout portion on the back surface of the working chamber to reduce the size and weight and simplify the structure. By making the front surface a forward inclined surface, the clean air blown horizontally is formed so as to form a vertical air flow that flows down toward the workbench, and is installed along the joint edge between the shutter on the front of the work chamber and the work chamber frame. A sub-air flow is formed from the slit to the suction side of the air blower to ensure aseptic performance on the workbench.

That is, in the safety cabinet of the present invention, a work chamber is formed on the upper side of the work table, and the work chamber has a small opening for work in the lower front portion, and the upper front portion that can be opened and closed by a shutter is inclined forward. On the other hand, the air supply filter is provided on the back surface to serve as a clean air blowing section, and further, a suction port is provided along the front end edge and the rear end edge of the work table, and the air sucked and collected from the suction port is cleaned air. The working chamber is provided with an air flow path for supplying air to the blowout part and an air blowing means, and is provided with an exhaust port and an exhaust filter for cleaning a part of the air on the discharge side of the air blowing means and discharging the air to the outside. A suction slit was provided along the joining edge between the front shutter and the work chamber frame, and a sub-air flow passage was formed that communicates from the suction slit to the suction side of the air passage of the air blower.

Further, in the cabinet of the present invention, a work chamber is formed on the upper side of the work table, and the work chamber has a small opening for work in the lower part of the front surface, and the upper front part that can be opened and closed by the shutter is a forward inclined surface. On the other hand, an air supply filter is provided on the back side to serve as a clean air blowing section, and a suction port is further provided along the front edge and the rear edge of the work table, and the air sucked and collected from the suction port is cleaned as a clean air blowing section. A positive pressure portion is formed by partitioning the clean air blowing portion on the back of the working chamber and the back of the air supply filter inside the air passage to form a positive pressure portion. A turbofan is provided as a blower in the section, the positive pressure section is surrounded by the negative pressure section of the air flow path, and a part of the positive pressure air on the discharge side of the blower is cleaned to external The exhaust port and the exhaust filter are installed to The suction slit is provided along the joint edge of the working chamber frame and the working chamber front of the shutter, to form a secondary air passage which communicates with the blowing means suction side of the air passage from the suction write slit.

[0010]

1 to 3 show a typical embodiment of a safety cabinet according to the present invention. In the figure, a safety cabinet 1 includes a work table 2, a work chamber 3 formed above the work table 2, and a cabinet body 11 including a body case 4 supported on a leg frame 12.

The working chamber 3 is a side plate 3 made of tempered glass on both side surfaces and a ceiling surface of a working chamber frame 31 made of a square steel pipe.
2, 32 and the top plate 33 are shielded, and a front panel 34 made of transparent resin (UV polycarbonate) is provided on the lower front portion, while a shutter 35 made of tempered glass is provided on the forward inclined upper portion to open and close. It is possible.

The shutter 35 in the illustrated example is of a flip-up type which is attached to the work chamber frame 31 at the upper end of the front face by a hinge or the like, but may be of a slide type which can be moved up and down along the inclined portion of the work chamber frame 31. . In addition, the front panel 34 has two small openings 37, 37 for working at the left and right sides, and a slide cover 38,
38 is provided so that it can be opened and closed. The slide cover 3
8 may be omitted.

The body case 4 is provided at the rear of the work chamber frame 31, and the air supply filter 5 composed of a HEPA filter is provided at the center of the partition wall 41 of the body case 4 which constitutes the back surface of the work chamber 3. An air flow diffusion member made of a perforated plate (punch metal) is provided on the front surface of the air supply filter 5,
The clean air blowing section 42 is configured.

The inside of the main body case 4 is partitioned by a partition wall 43 into a positive pressure portion 44 and a negative pressure portion 45. Inside the positive pressure portion 44, a turbo fan 6 and a fan motor 7 are provided as a blowing means. An exhaust filter 8 is provided above the positive pressure portion 44, and an exhaust port 9 is formed. In addition, 13 is an illuminating lamp, 14 is a germicidal lamp, and 15 is a control unit.

The workbench 2 is provided with suction ports 21 and 22 along its front and rear edges, and the lower part of the workbench 2 is hollow to form a negative pressure portion 23. The negative pressure portion 23 communicates with the negative pressure portion 45 of the main body case 4, and the suction port 21,
An air passage is formed from 22 to the negative pressure portions 23 and 45 and the positive pressure portion 44 to the air supply filter 5 and the clean air blowing portion 42.

Further, the shutters 3 on both front sides of the work chamber 3
5 and the front panel 34, and the suction slit 2 penetrating the inside of the work chamber frame 31 along the joint edge of the work chamber frame 31.
4 and 25 are provided. As described above, the work chamber frame 31 is composed of a hollow square pipe, and the negative pressure portion 26 is formed by communicating the inner cavity with the negative pressure portion 23 at the lower portion of the work bench 2 at the joint portion with the work bench 2. And suction slits 24, 2
An auxiliary air flow path from 5 to the negative pressure portion 23 via the negative pressure portion 26 is formed.

When the suction slit 24 is provided outside the door stop member 39 that abuts the shutter 35 as shown in FIG. 4A, the shutter 35 and the work chamber frame 31 are provided as shown in FIG. 4B. May be provided in the joint surface of.
Further, as shown in FIG. 4C, it may be provided inside the door-stop member 39. In addition, each suction slit 24, 25
May be further divided into a plurality in the longitudinal direction.

In the safety cabinet 1 constructed as described above, the air in the negative pressure portions 23 and 45 is pressure-fed to the positive pressure portion 44 by the turbofan 6, and is cleaned by the air supply filter 5 to be a clean air blowing portion. Although it is blown into the working chamber 3 from 42, the clean air is blown horizontally into the working chamber 3 by providing the air supply filter 5 and the clean air blowing portion 42 on the back surface of the working chamber 3.

However, the shutter 3 on the upper front of the working chamber 3
Since 5 has a forward inclined surface, the airflow blown horizontally is guided downward by the shutter 35 to form a vertical airflow on the workbench 2 (FIG. 5). As a result, the work room 3
The sterilization performance on the workbench 2 is ensured without generating vortices even on the upper part of the front surface of the workbench, and the air on the left and right on the workbench 2 is not mixed with each other, so that the sample mutual contamination can be prevented.

The air reaching the workbench 2 is sucked and collected from the suction ports 21 and 22 in the front and rear of the workbench 2 into the negative pressure part 23, and the negative pressure part 45, the positive pressure part 44 and the air supply filter 5 are collected. After being cleaned, the air is cleaned and circulated in the working chamber 3, but a part of the air is cleaned by the exhaust filter 8 above the positive pressure portion 44 and discharged from the exhaust port 9 to the outside.

As a result, the working chamber 3 is constantly kept at a low negative pressure, and external air corresponding to the amount of air discharged to the outside flows in from the small opening 37 at the lower front of the working chamber 3.
The inflowing air is sucked and collected directly from the suction port 21 at the front end of the workbench 2 into the negative pressure portion 23 to prevent the workbench 2 from being contaminated by the inflowing outside air, while being generated on the workbench 2 by the inflow air flow. Outflow of contaminated aerosol is prevented.

The upper opening of the front surface is closed as much as possible by the shutter 35. However, if the shutter 35 is completely closed, the convenience of the device may be impaired. In some cases, it cannot be said that it is completely sealed due to the opening degree. In the safety cabinet 1 of the embodiment, the front panel 34 is provided to limit the inflow amount of outside air. Therefore, if the opening degree of the small opening 37 is reduced and the negative pressure inside the working chamber 3 is increased, the shutter 35 is opened.
It is conceivable that outside air may be attracted from the gap around the.

However, in the safety cabinet 1 of the embodiment, the outside air drawn from the gap around the shutter 35 is sucked and collected by the suction slits 24, 25 provided along the joint edge between the shutter 35 and the work chamber frame 31. To be done.
When the suction slit 24 is provided outside the door stop member 39 that abuts the shutter 35, the arrow a in FIG.
Then, the suction slit 24 is connected to the shutter 35 and the work chamber frame 31.
When it is provided in the joint surface with, the arrow b in FIG.
When the suction slit 24 is provided inside the door stop member 39, the suction slit 24 is sucked by the negative pressure portion 26 inside the working chamber frame 31 as shown by an arrow c in FIG. It is possible to prevent the intrusion of the work room 3 into the work room 3. As a result of the particle counter scanning test,
There was no gap around the shutter 35, no attraction from the outside near the upper end, and no leakage from the inside.

FIG. 6 compares the performance of the safety cabinet of the present invention with the class I and class IIA safety cabinets. As shown in the table, the safety cabinet of the present invention has performance comparable to Class IIA type. In addition, compared to the Class I and Class IIA safety cabinets, the exhaust air volume is small and the circulating air ratio is 87% (when the slide cover is fully opened), which is extremely high. This is because the amount of inflowing air is reduced by the front panel 34, but a small amount of exhaust air is advantageous in performing indoor exhaust and also has an advantage that the exhaust filter 8 can be made compact.

Therefore, in the safety cabinet 1 according to the embodiment of the present invention, the exhaust filter 8 is embedded in the main body case 4, the turbo fan 7 and the air supply filter 5 are arranged on the back surface of the working chamber 3, and the ceiling portion is provided. Due to the flat structure, the height dimension of the safety cabinet 1 is kept small.

Further, the turbo fan 7, the air supply filter 5, and the exhaust filter 8 are arranged on the back surface of the working chamber 3, so that the air supply filter is passed from the suction ports 21 and 22 to the negative pressure portions 23 and 45 and the positive pressure portion 44. 5. The air flow path to the clean air outlet 42 is greatly shortened compared to class IIA, which contributes to simplification of the structure and reduction in size and weight.

In the above embodiment, the case where the thin turbofan 7 is used as the air blower and the turbofan 7 is arranged on the back surface of the work chamber 3 is shown, but the air blower may be arranged below the workbench. Further, the air supply filter may be arranged on the lower side of the workbench on the suction side of the air blowing means to form a negative pressure type, in which case the exhaust filter may be omitted.

Further, in the above embodiment, the left and right small openings 37 of the front panel 34 at the lower part of the front surface can be formed in another shape (such as a quadrangle) or can be integrated into one shape, and the circulating air ratio is lowered. However, the front panel 34 itself can be omitted.

[0029]

The safety cabinet of the present invention according to claim 1 is
As detailed above, a work chamber is formed above the work table,
The work chamber has a small opening for work at the lower front surface, and the upper front surface that can be opened and closed by a shutter is a forward inclined surface,
An air supply filter is provided on the back side to serve as a clean air blowing section, and a suction port is further provided along the front edge and the rear edge of the work table, and the air sucked and collected from the suction port is fed to the clean air blowing section. An air flow path and an air blower for removing air, and an exhaust port and an exhaust filter for cleaning a part of the air on the discharge side of the blower and discharging the air to the outside. Since a suction slit is provided along the joint edge with the chamber frame, and a sub-air flow path communicating from the suction slit to the suction side of the air flow path of the air blower is formed, an operator by preventing outflow of contaminated aerosol to the outside In addition to protection, it prevents the inflow of contaminated aerosols from the outside and protects the sample by cleaning the air supply.Especially, even if the negative pressure inside the working space is increased by the configuration of the auxiliary air flow path, it can be protected from the surroundings of the shutter. Outside air and pollutant particles Intrusion together can be prevented, the structure of the shutter can also be what simple with excellent convenience.

Further, in the above safety cabinet, since the front panel is provided at the lower part of the front of the work chamber, the small opening for work is opened in the front panel, and the cover for opening and closing the small opening for work is provided. The amount of inflow air and exhaust air can be reduced to increase the air circulation rate, the exhaust filter can be downsized, the overall height of the device can be kept low, and the device itself can be downsized, and the airflow to the installation space can be reduced. The impact can be reduced.

In the safety cabinet of the present invention as defined in claim 2, the clean air blow-out portion on the rear surface of the working chamber and the back of the air supply filter are partitioned within the air flow passage to form a positive pressure portion, and a blowing means is provided in the positive pressure portion. As a turbo fan, the positive pressure part is surrounded by the negative pressure part of the air flow path. Therefore, the suction filter, the positive pressure part, the air supply filter, the clean The air flow path to the air blowing section becomes the shortest, which is advantageous in reducing the size and weight of the device, simplifying the structure, and reducing the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a safety cabinet according to an embodiment of the present invention.

FIG. 2 is a partially cutaway front view showing the safety cabinet of the embodiment of the present invention.

FIG. 3 is a perspective view showing a safety cabinet according to an embodiment of the present invention.

4A is a sectional view taken along line XX of FIG. 2, and FIGS. 4B and 4C are sectional views taken along line XX of different embodiments.

FIG. 5 is a vertical cross-sectional view showing an air flow and internal air pressure in the safety cabinet according to the embodiment of the present invention.

FIG. 6 is a table comparing the performances of the safety cabinet according to the embodiment of the present invention and the conventional safety cabinet.

FIG. 7 is a vertical cross-sectional view showing a form of each class in a conventional safety cabinet.

FIG. 8 is a table showing characteristics of each class in the conventional safety cabinet.

FIG. 9 is a schematic diagram showing main performance of a conventional class II type safety cabinet.

[Explanation of symbols]

1 safety cabinet 2 workbench 3 workspace 4 body case 5 Air supply filter 6 Turbo fan (air blower) 8 exhaust filter 9 exhaust port 21,22 Suction port 23, 45, negative pressure part (air flow path) 24, 25 suction slit 26 Negative pressure part (sub air passage) 31 Working room frame 32 side plate 33 Top plate 34 Front panel 35 shutter 41, 43 partition walls 42 Clean air outlet 44 Positive pressure part

Continuation of the front page (56) Reference JP 2001-141273 (JP, A) JP 6-241519 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F24F 7/04 -7/06

Claims (2)

(57) [Claims] 1. A work chamber is formed on an upper side of a work table, and the work chamber has a small opening for work in a lower portion of a front surface, and a front upper portion which can be opened and closed by a shutter is a forward inclined surface, while a rear portion is formed on a rear surface. To provide a clean air blower with an air supply filter, and further to provide a suction port along the front edge and the rear edge of the work table, and to feed the air sucked and collected from the suction port to the clean air blower. And an exhaust filter for cleaning a part of the air on the discharge side of the blower and discharging it to the outside, the shutter on the front of the work chamber and the work chamber frame. A safety cabinet characterized in that a suction slit is provided along a joining edge with the sub slit, and a sub air passage communicating from the suction slit to a suction side of the air passage of the air blower is formed. 2. A work chamber is formed on the upper side of the work table, and the work chamber has a small opening for work in the lower part of the front surface. To provide a clean air blower with an air supply filter, and further to provide a suction port along the front edge and the rear edge of the work table, and to feed the air sucked and collected from the suction port to the clean air blower. The air flow path and the air blowing means, and the positive pressure portion is formed by partitioning the clean air blowing portion on the back surface of the working chamber and the back of the air supply filter inside the air flow passage, and as the air blowing means in the positive pressure portion. An exhaust port provided with a turbo fan, configured such that the positive pressure part is surrounded by the negative pressure part of the air flow path, and cleaning a part of the positive pressure air on the discharge side of the blower means and discharging it to the outside. And an exhaust filter are installed to work with the shutter on the front of the work room. A safety cabinet characterized in that a suction slit is provided along a joint edge with a business chamber frame, and a sub-air flow passage is formed so as to communicate from the suction slit to a blower suction side of the air flow passage.