JPH09159240A - Clean bench - Google Patents

Abstract

(57) [PROBLEMS] To provide a clean bench that facilitates work and loading and unloading of equipment into and from a work space, and can improve cleanliness and cleaning ability in the work space. SOLUTION: A working space is formed above a workbench with both side surfaces, an upper surface, and a back surface hermetically closed, and a front surface serves as an opening for working, and a main filter is entirely provided on a back surface part of the working space. Is provided as a clean air blowing surface, the air taken in from the outside of the working space is pressure-fed to the main filter by a blower, and the cleaned air is blown into the working space through the main filter to cross the working space. In a clean bench designed to generate a horizontal airflow that flows out from the front opening, the reinforcing columns supporting the ceiling part of the working space are extended from the front edges of both sides of the working space into the front opening. The width of the front opening was made narrower than the width of the clean air blowing surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clean bench.

[0002]

2. Description of the Related Art A clean bench, which is a workbench for conducting experiments and work requiring a dust-free and aseptic condition in a normal environment that is not a clean room, is located above the workbench.
It has a working opening only on the front surface, forms a working space that is closed to the other, provides a main filter on the entire side of the working space, and constantly purifies air that has been cleaned through the main filter. The work space is kept clean by blowing the air into the work space and flowing out from the work opening.

In this clean bench, a main filter is provided on a ceiling portion of a work space, and a vertical airflow type main filter is provided at a rear portion of the work space so that clean air is blown down toward a work table. There is a horizontal airflow type in which air is blown out of an opening as it is across a work space. In the former, a tempered glass shutter is provided at the work opening to ensure cleanliness in the work space, and during normal work, the shutter is lowered to minimize the opening of the work space. It is necessary to open and close the shutter when carrying out the work through the glass and carrying the equipment for experiments and work into the work space.

[0004] On the other hand, the latter horizontal airflow type clean bench generates a parallel airflow directed directly to the work opening in the entire work space, thereby maintaining cleanliness in the work space. For this reason, as shown in FIG. 3, the work opening 31 is completely open, which is advantageous in that work and equipment can be easily carried in.

However, since the area of the outlet surface 30 and the area of the working opening 31 are equal to each other, the positive pressure in the working space 32 is not sufficiently maintained, and the main space is usually divided into two parts corresponding to the width of the working table. A dead space 34 having no blown air is generated at the center of the filters 33, 33, and the blown air is diffused and the blown air velocity is reduced, so that the pressure in the working space 32 is almost equal to the atmospheric pressure. In such a situation,
Temporary dust generation in the work space 32 due to experiments and work,
When entrained particles are generated from the outside, the recovery of cleanliness is delayed due to turbulence due to lack of positive pressure in the working space 32, or the cleanliness is reduced due to permanent entrainment 35 from outside. There was a problem.

[0006]

SUMMARY OF THE INVENTION In view of the above points of the conventional clean bench, the present invention makes it easy to carry out work and to carry equipment in and out of the work space, and also to improve the cleanliness in the work space. An object of the present invention is to provide a clean bench capable of improving the cleaning ability.

[0007]

Means for Solving the Problems A work space is formed above a work table, the work space having both sides, the upper surface and the back surface sealed, and the front surface serving as an opening for work. By providing a main filter on the entire surface and providing a clean air blowing surface, air taken in from the outside of the working space is pressure-fed to the main filter by a blower, and the purified air is blown into the working space through the main filter, thereby In a clean bench adapted to generate a horizontal airflow that traverses the working space and flows out of the front opening to the outside, reinforcing columns supporting the ceiling portion of the working space are provided from front edges of both sides of the working space to the inside of the front opening. The width of the front opening is narrower than the width of the clean air blowing surface.

[0008]

1 and 2 show an embodiment of a clean bench according to the present invention. In the figure, a clean bench according to the present invention has a work opening
A work space 6 in which both sides are surrounded by tempered glass 3 and 3, the upper surface is surrounded by a ceiling case 4, and the back surface facing the front opening 2 is entirely a clean air blowing surface 5. Is formed.

The clean air blowing surface 5 is provided with a perforated plate 7 on the surface and a main filter 8 made of a HEPA filter behind the perforated plate 7. Further, a positive pressure chamber 10 is formed inside the main body casing 9 from the lower portion of the work table 1 to behind the main filter 8.
The outlet 12 of the blower 11 is connected to the lower end of the blower.
Further, a negative pressure chamber 13 is formed inside the main body casing 9 so as to surround the blower 11, and a prefilter 14 is provided in an air intake section on a lower surface of the negative pressure chamber 13.

The ceiling case 4 of the work space 6 has an illuminating lamp 15 inside and a cover 16 provided on the lower surface. The rear side of the ceiling case 4 is a positive pressure chamber 10.
Part of the main body casing 9 and, on the front side, the workbench 1
Are supported by reinforcing columns 17, 17 provided along the front edges of the tempered glass 3, 3 on both sides of the front opening 2 of the work space, and a height H from the work space 6 to the front opening 2 is one. It is like.

As shown in FIG. 2, the reinforcing pillars 17, 17 project inward from the side surface of the work space 6, ie, toward the front opening 2, and the front opening 2 is extended by an amount u. The opening width Wb of No. 2 is smaller than the blowing surface width (work space width) Wa.

In the clean bench constructed as described above, external air sucked through the pre-filter 14 into the negative pressure chamber 13, which has been depressurized by the blower 11, is fed into the positive pressure chamber 10 by pressure, and The pressure in the pressure chamber 10 increases the pressure of the main filter 8.
The clean air is blown out from the blowing surface 5 into the working space 6, and a horizontal clean air flow is blown out from the opening 2 across the working space 6 in the working space 6. Is done.

At this time, as described above, since the opening width Wb is smaller than the blowing surface width (working space width) Wa, the wind speed in the vicinity of the opening 6a becomes higher than the blowing side 6a in the working space 6, and the working space 6 The internal pressure is maintained at a positive pressure higher than the atmospheric pressure.

Therefore, it is possible to prevent the constant entrainment of outside air and the resulting decrease in cleanliness, and also to prevent the entrainment of particles from outside due to experiments and operations. Work space 6 for temporary dust generation
The cleanliness inside is restored.

[0015] Even in the case of the main filter 8, 8 of the central two-partition type as shown in the figure, diffusion of the blown air flow in the central part 6c of the work space, and the lack of positive pressure and the internal cleanliness due to the diffusion. Since the decrease is suppressed, the main filter 8,
8 is also advantageous in terms of structural design.

Regarding the overhang amount u of the reinforcing columns 17, 17,
Although it is not particularly limited, if it is extremely small,
It cannot affect the positive pressure in the working space 6. Further, if the amount of overhang u is too large, the pressure loss due to a sudden change in the opening cross section increases and the positive pressure is not necessarily improved, and the workability through the opening 2 is deteriorated, and the horizontal airflow type clean bench is used. The advantage of is not utilized. For these reasons, the overhang amount u is 1 to 1 of the blowing surface width Wa.
About 6% (the opening area Wb × H is 98% of the blowing area Wa × H)
Is preferably about 88%).

In the above embodiment, the back surface of the reinforcing pillars 17, that is, the surface facing the blowout surface 5 is parallel to the blowout surface 5 and perpendicular to the direction of the blown airflow. Alternatively, it may be inclined along the airflow direction in the vicinity thereof, or may be chamfered in an arc-shaped cross section. Further, by adopting the structure of the reinforcing pillars 17 and 17 in a vertical airflow type clean bench provided with an air curtain instead of providing a shutter at the front opening portion, the cleanness and cleanliness of the clean bench of this type are improved. Ability can be improved.

[0018]

As described above, the clean bench of the present invention forms a work space above the workbench, in which both side surfaces, the top surface, and the back surface are hermetically sealed, and the front surface serves as an opening for work. A main filter is provided on the back surface of the space as a clean air blowing surface, and the air taken in from the outside of the working space is pressure-fed to the main filter by a blower, and the cleaned air is passed through the main filter into the working space. In a clean bench configured to generate a horizontal airflow that blows out and crosses the inside of the work space and flows out to the outside from the front opening, a reinforcing column that supports the ceiling portion of the work space is provided in front of both side surfaces of the work space. There is no shutter in the front opening because it is provided so as to project from the edge into the front opening and the front opening width is narrower than the clean air blowing surface width. Is intact advantages of conventional horizontal air flow type clean bench that loading and unloading of the vessel can be easily, can be greatly improved cleanliness of the work space, and the cleaning capability.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a clean bench according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a horizontal sectional view showing a conventional clean bench.

[Explanation of symbols]

 Reference Signs List 1 work table 2 opening 3 tempered glass 4 ceiling case 5 blowing surface 6 working space 8 main filter 10 positive pressure chamber 11 blower 13 negative pressure chamber 14 pre-filter 17 reinforcing column

Claims (1)

[Claims] 1. A work space in which both sides, an upper surface, and a back surface are hermetically sealed and a front surface is an opening for work is formed above a work table. A filter is provided as a clean air blowing surface, and air taken in from the outside of the working space is pressure-fed to a main filter by a blower, and the purified air is blown into the working space through the main filter, so that the inside of the working space is reduced. In a clean bench adapted to generate a horizontal air flow that traverses and flows out of the front opening to the outside, reinforcing columns supporting a ceiling portion of the working space are extended from front edges of both sides of the working space into the front opening. A clean bench characterized in that the width of the front opening is narrower than the width of the clean air outlet surface.