JP3305936B2 - Fan filter unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan filter unit used in, for example, a clean room, and more particularly to a novel structure of a fan casing located near a centrifugal blower used in a fan filter unit. Things.

[0002]

2. Description of the Related Art The present applicant has already disclosed Japanese Patent Publication No. 4-54140.
"Clean Room Construction System" and 1-1-1026
40 "clean room device", the casing has a suction port in the upper part and a blow port in the lower part, and the air sucked from the suction port is filtered through the filter by the action of the centrifugal fan driven by the motor. A fan filter unit that discharges from the outlet is proposed.

[0003] Referring specifically to the drawings, FIG.
9 shows an external view of the fan filter unit 101 according to the related art, FIG. 9 shows a plan view of the fan filter unit 101, and FIG. 10 shows a schematic side view of the fan filter unit 101. 103
Is formed with a suction port 104. This suction port 10
At the center of 4, a motor 106 for rotating a centrifugal fan type fan 105 is supported by a support bracket 107. On the other hand, for example, UL
A high-performance filter 108 such as a PA filter is mounted, and the lower surface side of the high-performance filter 108 located at the lower surface opening of the casing 102 forms an outlet 109.

[0004] Around the fan 105, a fan casing 110 for blowing the air blown by the fan 105 to the high-performance filter 108 is provided. Fig. 8-
The fan casing 110 of the fan filter unit 101 shown in FIG. 10 is of a so-called scroll type, and the wind from the fan 105 is spirally limited in two directions, and the cross-sectional area of the air passage gradually increases. It has a complicated shape in which a curved surface portion and a flat surface portion are continuously formed on at least these two side surfaces.

When the fan casing 110 having such a configuration is used, the blowing direction is limited to two directions (arrows in FIG. 11), but the dynamic pressure that increases when the fan 105 is rotated is efficiently reduced. Can be converted to static pressure. As a result, the efficiency of the fan 105 is improved, and the effect that the change in the air volume due to the change in the external static pressure applied to the fan 105 is small is obtained.

There are other types of fan casings for guiding the wind blown out by the fan 105 to the high-performance filter 108 and blowing it out, as shown in FIGS. 11 and 12. That is, FIG.
The fan casing 111 shown in FIG. 2 forms inclined surfaces 111a and 111b by appropriately bending both ends in the longitudinal direction of the plate material, and also has a gap for blowing out between the two ends 111c and 111d and the casing 102. In a simple form.

[0007]

However, first, since the scroll type fan casing 110 has a complicated shape as described above, its manufacture is not easy and the cost is high.

On the other hand, the fan casing 111 in which both ends in the longitudinal direction of the plate material are appropriately bent is extremely simple to manufacture, but since there is no scroll portion, the region where the wind flows is turbulent (for example, FIG. 11). There is a problem that the air volume is small under the same external static pressure as compared with the scroll type, which is inferior to the scroll type in performance. The noise was also loud.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a fan filter unit which employs a fan casing which is easy to manufacture and has the advantages of the scroll type to solve the above-mentioned problems. With the goal.

[0010]

According to a first aspect of the present invention, there is provided a fan filter unit having a suction port at an upper portion of a casing having a side surface formed by four side plates, for example, a top plate. An air outlet is provided below the casing, and by the action of a centrifugal blower provided in the casing, the air sucked from the suction port is guided and blown out by a fan casing located near the centrifugal blower. Specifically, in a fan filter unit configured to discharge from the outlet through a filter, the fan casing is provided on a bottom portion located below the centrifugal blower and on the bottom portion, and sandwiches the centrifugal blower. Consisting of two facing side portions, the bottom portion is a rectangular flat plate, and the front and rear ends of the bottom portion are A pair of opposed side plates in the casing are in contact with each other, and the left and right ends of the bottom portion are each provided with a gap between the pair of opposed side plates of the casing, that is, one set of bottom portions. Both ends are in contact with a pair of opposing side plates of the casing, respectively, and the other end of the other pair of bottom surfaces has a gap between the pair of opposing side plates of the casing. ing.

On the other hand, each of the side portions is formed by three side plates of a first side plate, a second side plate, and a third side plate, and the first side plate is formed of the pair of side plates of the casing. One side plate of the casing, the second side plate faces one side plate of the other set of side plates of the casing (it is better not to face in parallel), and the third side plate faces the centrifugal blower. The third side plate has a shape curved concavely toward the centrifugal blower.

Since the fan casing having the above-described features is composed of a plate-shaped bottom portion and two side portions having an outer shape of a substantially triangular prism, it is very easy to manufacture first. The air blown in the radial direction of the centrifugal blower flows along the third side plate on the side surface between the other pair of side plates of the casing located outside the left and right ends of the bottom surface portion. The air is blown out in a substantially scroll shape toward the casing, and is guided downward from the gap to the casing, that is, to the filter and the outlet. That is, the scroll part is arranged in a manner limited to the disturbance area of the flow field,
The fan efficiency will be improved. Therefore, fan efficiency is good and noise is small.

The upper and lower surfaces of the side portions may be set so as to be in contact with the top plate of the casing and the bottom portion, respectively.
In this case, the upper and lower surfaces may be made of independent plate materials. Then, the number of members and the weight can be reduced. Of course, the top plate and the bottom plate may be individually joined to the upper and lower surfaces of the side surface.

According to the findings of the inventors, the curved portion of the third side plate of the side surface portion of the fan casing in the fan filter unit has an arc shape as viewed from a plane, as described in claim 2. If the center angle of the circular arc portion is set to be 60 ° to 90 °, the side surface portion can be installed more adaptively in the turbulence region of the flow field of the wind, which is more preferable.

[0015] Note that the curved portion of the third side plate of the side surface portion in the fan casing, gradually different curved shape curvature as viewed from the plane may be configured to exhibit for example a cycloid. In this case, the width of the portion facing the fan is preferably set so that the central angle of the fan corresponds to 60 ° to 90 °.

[0016] Furthermore, the first side plate of the side surface portion of the fan casing may be configured as being formed by the side plate of the casing. That is, since the first side plate of the side surface portion is in contact with a pair of side plates of the casing,
The side plate of the casing may also serve as the first side plate of the side surface portion. Then, the number of members constituting the side portion of the fan casing can be reduced (as a result, the side portion is formed by the first and second side plates as components), and the fan filter unit itself is formed. Weight can be reduced.

In the present invention, the slope portion approaching the upper portion of the casing is formed near the left and right ends of the bottom portion .
Thus, the efficiency of converting dynamic pressure, which increases when the centrifugal blower is operated, to static pressure can be further increased.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a fan filter unit according to an embodiment of the present invention; FIG. This fan filter unit 1 is
The lower part of the substantially rectangular parallelepiped casing 2 has the ULPA filter 3 housed in the horizontal direction so as to close the lower surface opening, and the lower surface of the ULPA filter 3 forms the outlet 4. A top plate 5 is provided at an upper portion of the casing 2, and a suction opening 6 which is opened in a circular shape is formed at a substantially central portion of the top plate 5.

At the center of the suction port 6, four support pieces 7
The fan motor 8 supported by the top plate 5 is located. Note that the fan motor 8 may be located below the fan 9. That is, the motor 8 may be supported on the fan casing 11 and the fan 9 may be provided thereon. A centrifugal blower type fan 9 rotated by the fan motor 8 is located at a lower portion of the suction port 6, and a fan casing 11 whose outline is shown in FIG. I have.

The fan casing 11 is shown in FIGS.
As shown in the figure, the plane is constituted by a rectangular bottom portion 12 and two side portions 13 and 14.

The bottom portion 12 is made of a rectangular thin plate,
Each of the left and right ends 12a and 12b has a form bent at two places, thereby forming the slope 12
c and 12d are formed near the left and right ends 12a and 12b. The presence of the slopes 12c and 12d allows the vertical cross-sectional area to be gradually increased, and the increased dynamic pressure to be efficiently converted to static pressure.

Left and right ends 12a, 12a of the bottom 12
A gap W for blowing out the wind is secured between b and the side plates 2a and 2b of the casing 2. On the other hand, front and rear ends 12e and 12f of the bottom surface portion 12 are in contact with the inner surfaces of the other side plates 2c and 2d of the casing 2, respectively.
The lower surface of the fan 9, that is, the fan runner is in contact with the bottom surface 12. Needless to say, the lower surface of the fan 9 and the upper surface of the bottom portion 12 do not necessarily have to be at the same level, and the lower surface of the fan 9 may be at a position higher than the upper surface of the bottom portion 12.

On the other hand, the side portions 13 and 14 have the same shape and the same size. For example, taking the side portion 14 as an example, this side portion has three side plates, that is, a first side plate 14a and a second side plate 14a.
The side plate is formed by the side plate 14b and the third side plate 14c, and the upper and lower surfaces are formed by the top plate 14d and the bottom plate 14e. The top plate 14d is in close contact with the inner side surface of the top plate 5 of the casing 2, and the bottom plate 14e is in close contact with the surface of the bottom portion 12. Therefore, these top plates 1
4d and the bottom plate 14e may be formed by the top plate of the casing 2 and the flat portion 12, respectively. That is, it may be omitted.

The first side plate 14a is formed of a rectangular thin plate, and is in close contact with the side plate 2c of the casing 2. Therefore, the first side plate 14a may also be used as the side plate 2c of the casing 2. That is, as a result, the first side plate 1
4a can be omitted.

Although the second side plate 14b is also basically formed of a rectangular thin plate, the boundary with the third side plate 14c is as follows.
It has a shape that is curved convexly outward. And this second
The side plate 14b faces the side plate 2b of the casing 2. In this case, as shown in FIG. 5, the second side plate 14b is set so as to face a certain angle when viewed from a plane, so that occurrence of disturbance can be suppressed. Specifically, it is preferable to set the angle between the second side plate 14b and the side plate 2b of the casing 2 to be about 15 ° to 45 °.

Although the third side plate 14c is also formed of a rectangular thin plate, the third side plate 14c is formed in an arc shape as viewed from a plane, and has a form curved concavely toward the fan 9. , The center angle θ of the arc portion as shown in FIG.
Is set to 90 ° in the present embodiment, and the radius of curvature thereof is larger than that of the outer periphery of the fan 9.

The length of the third side plate 14c, that is, the radius of curvature and the central angle θ can be changed as required. For example, the central angle θ can be set to any angle between 60 ° and 90 °. The center P, which is the base of the central angle θ, is shifted from the center of the fan 9, and as a result, the gap between the third side plate 14 c and the fan 9 becomes larger toward the side plate 2 b of the casing 2. ing.

The three side plates of the side portion 14 having the above structure, namely, a first side plate 14a, a second side plate 14b and a third side plate 14b.
The side plate 14c can be easily formed by appropriately bending one long rectangular thin plate. Therefore, its manufacture is very simple.

The side portion 14 and the fan 9 having the above-described structure are provided.
The remaining side portions 13 facing each other have the same configuration as this side portion 14, and the first side plate 13
a, the second side plate 13b and the third side plate 13c, and the top plate 1
3d and a bottom plate 13e.

The bottom part 12 and the above-mentioned ULPA filter 3
And a guide plate 16 which forms an air flow path.
Are provided horizontally, and a sound absorbing material 17 is provided on the upper surface of the guide plate 16. A diffusion plate 18 is provided on the outlet side of the flow path. An auxiliary terminal block 19 and a terminal unit 20 serving as an operation terminal are provided on one upper surface of the top panel 5.

The fan filter unit 1 according to the present embodiment has the above configuration. When the fan motor 8 is driven to rotate the fan 9, the air sucked from the suction port 6 is changed to the state shown in FIG. After being blown out along the flow indicated by the arrow and cleaned by the ULPA filter 3, it is discharged downward from the lower outlet 4.

At this time, the wind from the fan 9 is basically blown out in the radial direction. However, as shown in FIG. 5 viewed from a plane and FIG. The wind coming out of the fan 9 by the side plates 13c and 14d is as follows.
Guided substantially in a scroll shape, the end 1 of the bottom portion 12
The air is blown out through a gap W between the side plates 2a and 2b of the casing 2 and reaches the guide plate 16.

Therefore, the efficiency of the fan 9 is good. When actually comparing the fan filter unit 1 according to the present embodiment with the fan filter unit of the type shown in FIGS. 11 and 12 (using the same fan and the same fan motor), when the external static pressure is 10 mmAq, 0.8 m ³ / min for the fan filter unit 1 according to the present embodiment.
High airflow was observed. In addition, the fan filter unit 1 according to the present embodiment also consumed less power by up to 16 W at maximum. The noise was also small.

In addition, the bottom 1 of the fan casing 11
2. The production of the side portions 13 and 14 is extremely simple as described above, and the production cost is much lower than that of the conventional scroll type.

Note that the third side plate 14 in the above embodiment is used.
Although c is formed in an arc shape when viewed from a plane, it is not limited to this, and may be constituted by a curve having a gradually different curvature, for example, a cycloid curve.

[0036]

According to the fan filter unit of the present invention, the scroll portion is arranged in a manner limited to the turbulence region of the flow field, and its manufacture is much more difficult than the conventional scroll type fan casing described above. Easy to be. Moreover, the fan efficiency is better and the noise is less than that of a conventional thin plate in which only both ends are bent.

[0037]

[0038]

[0039] Moreover it is possible to further increase the conversion efficiency to the static pressure of the dynamic pressure increases when operated centrifugal blower.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overview of a fan filter unit according to an embodiment of the present invention.

FIG. 2 is a plan view of the fan filter unit of FIG.

FIG. 3 is a longitudinal sectional view of the fan filter unit of FIG. 1;

FIG. 4 is a perspective view of a fan casing in the fan filter unit of FIG. 1;

FIG. 5 is a plan view of the fan casing of FIG. 4;

FIG. 6 is a front view of the fan casing of FIG. 4;

FIG. 7 is a plan view of a side surface portion of the fan casing of FIG. 4;

FIG. 8 is a perspective view of a fan filter unit according to the related art.

FIG. 9 is a cross-sectional view showing a scroll type fan casing in the fan filter unit of FIG. 8 and a flow of wind therethrough.

FIG. 10 is a vertical cross-sectional view showing a flow of wind by a fan casing of the fan filter unit of FIG.

FIG. 11 is a cross-sectional view showing a fan casing of a fan filter unit according to another related art and a flow of wind therethrough.

FIG. 12 is a vertical cross-sectional view illustrating a flow of wind by a fan casing of the fan filter unit of FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fan filter unit 2 Casing 2a, 2b, 2c, 2d Side plate 3 ULPA filter 4 Outlet 5 Top plate 6 Inlet 9 Fan 11 Fan casing 12 Bottom part 12a, 12b End part 12c, 12d Slope part 13, 14 Side part 13a , 14a First side plate 13b, 14b Second side plate 13c, 14c Third side plate W Air gap

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuichi Misawa 2-15-19-402 Higashihashimoto, Sagamihara City, Kanagawa Prefecture (72) Inventor Tomoyoshi Noda 4-4-13-903 Nagayama, Tama City, Tokyo (56) References 6-57416 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 46/00-46/54 F24F 7/06

Claims (1)

(57) [Claims] 1. A suction port is provided at an upper portion of a casing having a side surface formed by four side plates, an outlet is provided below the casing, and the suction is performed by a centrifugal blower provided in the casing. In a fan filter unit configured to guide air blown out from a mouth by a fan casing located near the centrifugal blower and discharge the air from the outlet through a filter, A bottom surface located below the centrifugal blower, and two side surfaces provided on the bottom surface and facing each other with the centrifugal blower interposed therebetween, wherein the bottom surface has a rectangular flat plate shape, Front and rear ends of the casing are in contact with a pair of opposed side plates of the casing, respectively. A gap is secured between each of the other set of side plates facing each other, and each of the side portions is formed by three side plates of a first side plate, a second side plate, and a third side plate, respectively. One side plate contacts one side plate of the set of side plates of the casing, a second side plate faces one side plate of the other set of side plates of the casing, and a third side plate is centrifugal. Facing the blower, the third side plate is concavely curved toward the centrifugal blower, and near the left and right ends of the bottom surface, near the upper part of the casing.
A fan filter unit, characterized in that a slope portion is formed .