CN100444928C - Low energy consumption fan-filter unit - Google Patents

Abstract

A low power consumption fan-filter unit comprising: a nozzle portion having an inlet end and an outlet end; a fan connected to the air outlet end of the nozzle; a driving source for driving the fan to rotate, so that the ambient air enters the nozzle part from the air inlet end and is exhausted from the periphery of the fan through the air outlet end by virtue of the shape of the nozzle part; the invention achieves good effect of converting dynamic pressure into static pressure by the design of the special diffusion part, has ideal static pressure recovery and low total pressure loss, solves the problem of high power consumption of a dust-free chamber, and has the advantages of simple manufacture, low cost, low noise and good dust removal effect.

Description

Low energy consumption fan - filter unit

technical field

The invention relates to a low energy consumption fan-filter unit, in particular to a low energy consumption fan-filter unit which is used in dust removal in a clean room and has relatively high electrical efficiency

Background technique

A fan-filter unit (FFU, fan Filter Unit) is a dust removal device used in a highly clean space. It is generally placed in the clean room (Clean Room) of a semiconductor manufacturing plant. The airflow from top to bottom clears the air in the room, thereby discharging the polluted dust particles in the air to achieve a dust-free working environment with high cleanliness.

Figure 8A and Figure 8B are a sectional view and a top view of an existing blower-filter unit 50, comprising a bell-shaped (Bell) nozzle portion 51, having an air inlet 52 and an air outlet 53, and the air outlet 53 is configured There is a fan 55, which is arranged on a motor base 56, and is driven by the driving motor 57 under the motor base 56, and a partition plate 61 (Seperator) and a superstructure are arranged below the motor base 56. High filter screen 41 (ULPA), therefore, when this fan 55 is running, the surrounding air flow can be sucked in this nozzle portion 51 from this inlet end 52, then through the circle of this air outlet end 53 and this nozzle portion 51 The arc-shaped inner wall 51a is discharged from the outlet around the fan 55, forming a dust removal airflow from top to bottom.

However, according to the existing clean room energy consumption analysis, it is known that in the operation of the clean room, only the energy consumption of the air circulation part accounts for up to 14%. For the fan-filter unit 50, the main reason is When the fan 55 is in operation, the airflow blown by the impeller of the fan 55, in addition to flowing down along the motor frame 56, also has a part that will turn back up to the outside of the impeller, so that the upper space of the fan-filter unit 50 forms a Backflow causes partial energy loss, thereby reducing the overall electrical efficiency of the fan and increasing the operating cost of the clean room.

According to theoretical analysis, this reason is because after the air flow flows out from the outlet around the fan 55, its wind speed gradually decreases, and the air flow pressure gradually increases. At this time, the air flow pressure gradually converts the dynamic pressure of the fan 55 outlet into static pressure. If the airflow produces a backflow phenomenon during the flow process, an unnecessary vortex (Vortex) loss occurs in the overall energy, which greatly reduces the efficiency of converting the airflow pressure to the static pressure, resulting in poor recovery of the static pressure; therefore, if the automatic From the point of view of the overall airflow total pressure (total energy), in addition to the unavoidable friction loss, it also increases the above-mentioned eddy current loss caused by backflow, which greatly increases the airflow total pressure loss, resulting in high energy consumption in the clean room. serious problem of energy.

For example, the example shown in Fig. 9, it is simulated with the unit size shown in Fig. 8A, and the horizontal axis among the figure is the distance between the air flow measurement point and the fan 55 outlet, and the unit is meter (m), and the vertical axis then represents each respectively. The air pressure and wind speed of the airflow at the position can be seen from the curve in the figure that the wind speed (Speed) of the airflow is gradually decreasing, and the airflow pressure (Pv) will gradually decrease and be converted into static pressure (Ps). However, due to the backflow of the airflow Effect, it can be seen from the figure that the recovery efficiency of static pressure is not high, and its upward recovery trend is far less than the trend of dynamic pressure decrease, which is the energy loss caused by eddy current loss; if the total pressure of dynamic pressure and static pressure is (Pt) trend observation is just clearer, as can be seen from the figure, the total pressure loss of the airflow is up to more than 80Pa, which is the main cause of energy consumption of the existing blower-filter unit 50.

The fan-filter unit invented by U.S. Patent No. 6,030,186 and No. 6,174,342 is also difficult to solve this energy consumption problem. It can only reduce the noise in operation, and its improved structure is too complicated. As far as the fan-filter unit in the clean room is concerned (a wafer foundry equipped with a clean room will use at least thousands of fan-filter units), it is obviously difficult to manufacture and mass-produce, which will also lead to cost too high.

Therefore, how to develop a new type of fan-filter unit, which can reduce the overall power consumption and achieve the effect of improving electrical efficiency, while also taking into account the simplicity of structural design and improving the dust removal efficiency of the clean room, is indeed an urgent problem to be solved in the related research and development fields. .

Contents of the invention

In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a low-energy fan-filter unit that does not generate backflow due to air separation.

Another object of the present invention is to provide a low energy consumption fan-filter unit that can reduce the total pressure loss of the airflow.

Another object of the present invention is to provide a low energy consumption fan-filter unit with good static pressure recovery.

Another object of the present invention is to provide a low energy consumption fan-filter unit which is simple to manufacture and low in cost.

Another object of the present invention is to provide a fan-filter unit with low noise and low energy consumption.

Another object of the present invention is to provide a low energy consumption fan-filter unit with good dust removal effect.

In order to achieve the above and other objectives, the low energy consumption fan-filter unit proposed by the present invention includes: a nozzle portion with an arc-shaped inner wall, including an air inlet end and an air outlet end; a fan connected to the air outlet end of the nozzle portion; carrying the The base of the fan; the driving source for driving the fan to rotate, so that the surrounding air enters the nozzle part from the inlet end, and is discharged from around the fan through the air outlet end through the arc-shaped inner wall of the nozzle part; and the diffuser part , has a hole, and is arranged around the fan, so that the fan is accommodated in the hole, and the air inlet and the air outlet are defined by the base and the fan, so that the air discharged from the surrounding of the fan enters the inlet The air outlet diffuses evenly and decelerates, and then passes through the downstream ultra-high filter from the air outlet, and finally discharges to the outside world.

The above-mentioned diffusion part is a diffuser without streamline guide vanes, and the nozzle part, the fan and the driving source are integrally arranged in the center of the diffusion part. Meanwhile, the area of the air outlet of the diffusion part is not smaller than the area of the air inlet. It is designed as a gradually increasing diffuser with an air outlet area larger than the air inlet area, and the ideal ratio of the air outlet area to the air inlet area is about 2.2 to 2.7; in addition, if viewed from the overall appearance of the diffuser , then it can be designed as a disk or a square disk, and the fan located in the center will blow the airflow to the peripheral position of the disk or square disk.

Therefore, the present invention is based on the design of the special diffuser. When the fan blows the airflow into the diffuser, it diffuses and decelerates evenly between the diffuser and the base. At this time, the air flow field will be affected by the diffuser The shape design will not produce separation and backflow, and then can achieve a good effect of converting dynamic pressure into static pressure, has ideal static pressure recovery and low total pressure loss, and solves the existing problem of high power consumption in clean rooms. The present invention The low-energy fan-filter unit has the advantages of simple manufacture, low cost, low noise, and good dust removal effect, and can be widely used in various clean rooms.

Description of drawings

Fig. 1A is the cross-sectional view of the preferred embodiment of the low energy consumption fan-filter unit of the present invention;

Fig. 1 B is the top view of the preferred embodiment of the low energy consumption fan-filter unit of the present invention;

Fig. 2 is the size schematic diagram of the experimental example of the preferred embodiment shown in Fig. 1A, 1B;

Fig. 3 is the graph of static pressure, dynamic pressure, total pressure and wind speed of the example shown in Fig. 2;

Fig. 4 is a curve diagram of the static pressure recovery value of the example shown in Fig. 2 under different AR values;

Fig. 5 is the sectional view of Embodiment 2 of the low energy consumption fan-filter unit of the present invention;

Fig. 6 is the efficiency comparison graph of embodiment 2 of the present invention shown in Fig. 5 and existing fan-filter unit;

Fig. 7 is the top view of Embodiment 3 of the low energy consumption fan-filter unit of the present invention;

Figure 8A is a sectional view of an existing fan-filter unit;

Figure 8B is a top view of an existing fan-filter unit; and

FIG. 9 is a graph showing changes in static pressure, dynamic pressure, total pressure and wind speed of the experimental example shown in FIGS. 8A and 8B .

Detailed ways

Example 1

The preferred embodiment of the low energy consumption fan-filter unit of the present invention is as shown in Figure 1A and Figure 1B, it is that the existing fan-filter unit is arranged in the center of a specially designed diffuser 30, so that it can easily Be located in the hole at the center of the diffuser 30, the diffuser 30 is a disk diffuser 30 as shown in the top view of Figure 1B, the overall low energy consumption fan-filter unit configuration includes, a semicircular arc-shaped inner wall The bell-shaped nozzle portion 10 of 10a, the fan 15 that is connected to the air outlet 12 of the nozzle portion 10, the motor frame 17 that carries the fan 15, the drive motor 16 that drives the fan 15 to rotate, and is arranged around the fan 15 The diffusing part 30, the diffusing part 30 defines an air inlet 31 and an air outlet 32 by the fan 15 and the motor frame 17, so that the air discharged from the fan 15 around enters the air inlet 31, In the diffuser 30 , it diffuses evenly and decelerates, and passes through the downstream ultra-high filter 41 (ULPA) from the air outlet 32 , and finally discharges to the outside.

The specific process is such that the diameter of the bell-shaped nozzle portion 10 decreases gradually from its inlet end 11, so as to concentrate the airflow and make the airflow be discharged from around the fan 15 under the guidance of the semicircular inner wall 10a, and enter The air inlet 31 of the diffuser 30 can be used to increase the overlapping and close contact between the fan 15 and the air inlet 31 of the diffuser 30 by the motor base 17, so that the airflow in the bell-shaped nozzle portion 10 can completely enter the fan 15. In the diffusion part 30, a partition plate 61 and an ultra-high filter screen 41 are arranged below the motor frame 17; at the same time, the diffusion part 30 is a diffuser without streamline guide vanes to reduce the noise during operation, and this In the embodiment, the diameter area of the diffuser 30 from its air inlet 31 is designed to increase gradually, that is, as shown in the sectional view of Figure 1A, the area of the air outlet 32 is greater than the area of the air inlet 31, so that the diffuser The top-view profile of 30 ( FIG. 1B ) is a diffuse disc with the outer edge higher than the inner edge.

Therefore, with the design of this diffuser 30, after the fan 15 operates to suck the outside air into the bell-shaped nozzle portion 10, the airflow of the air can be blown to the diffuser through the air inlet 31 by the fan 15. part 30, uniformly diffused between the diffuser part 30 and the motor frame 17, at this time, the air flow will be uniformly decelerated towards the air outlet 32 due to the gradually increasing diameter of the diffuser part 30, so as to achieve good dynamic pressure conversion efficiency, so that The recovery value of the static pressure of the airflow flowing out of the diffuser 30 is improved, that is, the loss of the overall total pressure is small (because no backflow occurs, so there is no eddy loss), thereby reducing the overall energy loss and achieving the low power consumption of the present invention Efficacy; In addition, the overall design of the present invention is only to integrate the fan-filter unit into a special diffuser 30, so it also has the advantages of simple manufacture and low cost, without changing the original mass production equipment, and will not A lot of noise is generated in the clean room, which is more in line with the energy consumption demand in the clean room.

Fig. 2 is an example of the above-mentioned embodiment, its size is marked in the figure, and the ratio AR of the area of the air outlet 32 of the diffuser 30 to the area of the air inlet 31 is designed to be 2.2, the actual intake and exhaust experiments The result is then shown in the graph of Figure 3, the horizontal axis in the figure is the distance between the measuring point in the diffuser 30 and its air inlet, and the unit is meter (m), and the vertical axis then represents the air pressure and wind speed of the airflow at each position respectively , it can be seen from the curve in the figure that the wind speed (Speed) of the airflow is uniformly decreased towards the direction of the air outlet 32, if compared with the measurement results of the existing fan-filter unit 50 in Fig. 9, it can be found that by the present invention The diffusion part 30 design, its static pressure (Ps) recovery effect is better than the existing products, and the loss of the overall total pressure (Pt) is also much smaller than the existing unit, the total pressure loss of the existing unit is as high as 80Pa due to the backflow of the airflow As mentioned above, the airflow total pressure loss of the present invention is only about 30 Pa, which shows that the dynamic pressure (Pv) conversion is very ideal, and the overall electrical efficiency is also greatly improved and the effect of reducing energy consumption is achieved.

The present invention further discloses the preferred range of the ratio AR of the area of the air outlet 32 of the diffuser 30 to the area of the air inlet 31. The result is shown in FIG. 4, and this graph is also the result obtained from the experimental example shown in FIG. 2. It can be seen that the relationship between different AR values and the static pressure (Ps) recovery value of the air outlet 32, from the curve in the figure, it can be known that when the AR value increases to 3.2, the static pressure recovery function of the diffuser 30 is greatly reduced. The air flow between the diffuser 30 and the motor frame 17 begins to separate, so it can be inferred that the ideal ratio AR of the area of the air outlet 32 of the diffuser 30 to the area of the air inlet 31 is about 2.2 to 2.7.

Example 2

In addition, in addition to the diffuser 30 disclosed in the above-mentioned embodiment, the low energy consumption fan-filter unit of the present invention can also adopt a diffuser 35 with the same height as the air inlet 31 and the air outlet 32, as shown in Figure 5 of the present invention The sectional view of embodiment 2, it is to use a disc diffuser 35 with the same height as the inner and outer edges, and it is also a diffuser with no streamline guide vane, which can equally play the role of making the air flow uniformly diffuse and decelerate, and reduce backflow; Concrete effect also can be shown in the graph of Fig. 6, and it is that the height of the air inlet 31 of this diffuser 35 and the air outlet 32 are all designed as 73 centimeters, as can be known if with existing fan-filter unit (blank mark) Compared, when the air outlet wind speed is 0.4m/sec, the power consumption (icon square mark curve) of the low power consumption fan-filter unit of the present invention (marked in black) will be reduced from 289W to 229W, and its full piezoelectric Efficiency (icon triangle mark curve) will rise from 17.7% to 21.6%, and its electrical efficiency is higher than that of existing products from the data.

The diffusion parts 30 and 35 shown in the above-mentioned embodiments are all in the shape of a disk when viewed from the top view, so that the nozzle part 10, the fan 15 and the driving motor 16 are located in the center of the circle center, and this shape is not a limitation of the present invention , the diffusion part of the present invention can also be the top view as shown in Figure 7, adopts a square plate 40, and this nozzle part 10, fan 15 and driving motor 16 are arranged in its center, can bring into play the effect of the present invention equally, and Compared with the design of the circular disk, the square disk design has the advantage of being easier to manufacture, and because the space around its periphery is larger than that of the circular disk, it will also have a better airflow static pressure recovery effect.

Therefore, the design of the special diffuser disclosed by the present invention enables the low-energy fan-filter unit to exert high electrical efficiency and low total pressure loss. At the same time, the present invention has the advantages of easy manufacture and low cost, and can Mass produced and widely used in clean rooms.

Claims (9)

1. a low power consuming blower fan-filter bank is characterized in that, this blower fan-filter bank comprises:

Spray nozzle part has an arc inner wall, and comprises an inlet end and an outlet side;

Fan connects the outlet side of putting at this spray nozzle part;

Support is in order to carry this fan;

Drive source drives this fan and rotates, and makes surrounding air enter this spray nozzle part from this inlet end, and borrows the arc inner wall of this spray nozzle part, discharges around this fan through this outlet side;

Diffusion part, has a hole, highly be same as the fan outlet height, be arranged on this fan around, make this fan be installed with in this hole, and borrow this support and fan and define air inlet and gas outlet, make the air of discharging around this fan enter this air inlet and evenly spread and slow down, and then this gas outlet drains into the external world certainly, wherein, this diffusion part is the cumulative diffusion part of a gas outlet area greater than the air inlet area, and this gas outlet area to the ratio of air inlet area between 2.2 to 2.7.

2. low power consuming blower fan-filter bank as claimed in claim 1 is characterized in that, this spray nozzle part, fan and drive source are the central authorities that one is configured in this diffusion part.

3. low power consuming blower fan-filter bank as claimed in claim 1 is characterized in that, this diffusion part is a no streamline guide vane diffuser.

4. low power consuming blower fan-filter bank as claimed in claim 1 is characterized in that, this diffusion part is the contour diffusion part that a gas outlet height equals the air inlet height.

5. low power consuming blower fan-filter bank as claimed in claim 1 is characterized in that, the external form of this diffusion part is to be a disk.

6. low power consuming blower fan-filter bank as claimed in claim 1 is characterized in that, the external form of this diffusion part is to be a square plate.

7. low power consuming blower fan-filter bank as claimed in claim 1 is characterized in that, this spray nozzle part is a bell shaped nozzle.

8. low power consuming blower fan-filter bank as claimed in claim 1 is characterized in that, this spray nozzle part is decrescence from the bore of its inlet end.

9. low power consuming blower fan-filter bank as claimed in claim 1 is characterized in that, this drive source is a motor.

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