JP2726382B2 - Design method of suction device for local ventilation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for designing a suction device for local ventilation, and more particularly to a method for designing a local ventilation system for general household or business use, which is detachably attached to a range hood ventilation fan installed in a kitchen. The present invention relates to a method for designing a suction device for local ventilation including a filter to be mounted.

[0002]

2. Description of the Related Art A hood and a fan are used as a means for discharging oil-containing smoke or steam generated from a range cooker installed in a kitchen or the like, which is used for local ventilation for general household or business use. There is a range hood ventilation fan that integrates As shown in FIG. 12, the range hood ventilation fan is generally disposed above a range cooker 1 installed in a kitchen or the like, and has a structure in which a filter 4 is detachably attached to an opening 3 of the hood 2. It is. Food 2 described above
The filter 4 attached to the filter 4 collects the contaminated air such as smoke and steam generated by the heating cooking in the range cooker 1 by the rotation of the fan 5, and the soot contained in the contaminated air. A contaminant medium such as oil or oil mist (small oil particles) is collected to prevent dirt from attaching to the hood 2, the fan 5, and the duct.

More specifically, the filter 4 has a zigzag bent flow through which contaminated air passes by forming a single filter or a single filter in which a metal lath plate having a mesh-shaped opening is held by a rectangular support frame. There is a structure in which a road is formed [Japanese Unexamined Patent Publication No. 3-47509, Japanese Utility Model Application Laid-Open No. 3-94916.
No.). In this type of filter, contaminated air generated by heating cooking in a microwave cooker is collected by the rotation of the fan to smoke, and when the contaminated air passes through the opening of the metal lath plate, the opening is zigzag. The contaminated medium contained in the contaminated air is adhered and collected on the surface of the metal lath plate while passing through the bent flow path because of being formed in the bent flow path.

[0004]

Generally, the filter 4
Because of the need for excellent smoke collection and collection functions, it is necessary to ensure appropriate smoke collection efficiency for contaminated air and collection efficiency for contaminated media. If proper smoke collection efficiency cannot be obtained, it will be difficult to reliably collect contaminated air, and the kitchen will be filled with contaminated air, and proper collection efficiency will not be obtained. Otherwise, it will be difficult to reliably collect the contaminated medium, and the hood 2, the fan 5, and the duct will be contaminated.

Here, even if the number of revolutions of the fan 5 is increased in order to improve the smoke collection efficiency of the filter 4, the noise generated from the fan 5 is increased, resulting in noise and a large amount of clean air in the room. It has been found that it is difficult to improve the efficiency of smoke collection simply because it results in the emission of smoke. For example, in the above-described filter 4 having a metal lath structure,
In order to improve the collection efficiency, it is necessary to consider the filter aperture ratio and the degree of bending of the bent channel. However, if the filter aperture ratio is reduced and the degree of bending is increased, the collection efficiency is increased, but the clogged metal lath plate is quickly clogged by the collected contaminated medium, and is likely to change with time. Therefore, in addition to the above-described filter aperture ratio and degree of bending, the rate of change with time must be taken into consideration.

As described above, generally, in order to set the smoke collection and collection efficiency in the filter 4 to appropriate values, it is necessary to consider the filter opening ratio, the degree of bending of the bent flow path, and the rate of change with time. Moreover, at present, it is unclear how the filter 4 is designed, while the grounds for determining these conditions remain unclear.

Accordingly, the present invention has been proposed in view of the above-mentioned problems, and has as its object the basis for considering various conditions for properly setting smoke collection and collection efficiency. It is an object of the present invention to provide a method of designing a suction device for local ventilation which clarifies the above.

[0008]

As a technical means for achieving the above-mentioned object, the present invention provides a method in which a plurality of columnar members having a V-shaped cross section are arranged in parallel at a constant pitch along the width direction thereof. Two types of fence-shaped filters held by a rectangular support frame are alternately stacked in a plurality of stages along the thickness direction, and a columnar member of the other filter has a step between adjacent columnar members of one filter. A method of designing a suction device comprising a filter having a zigzag bent flow path through which contaminated air passes and is disposed, wherein a suction-side dynamic pressure generated in the filter due to a pressure difference between the inside and outside of the hood is introduced, and a fan is provided. The suction side movement calculated from the air volume of the filter and the flow path area of the filter.
The flow speed due to the pressure is determined to be equal to or higher than the rising speed of the contaminated air, and based on the suction side dynamic pressure and the smoke collection and collection efficiency,
The arrangement pitch of the columnar members arranged in the width direction of the filter alone,
The arrangement pitch of the columnar members arranged in the thickness direction and the V-shaped angle of the columnar members are set.

The present invention also provides a filter having a metal lath plate having a mesh-shaped opening portion held by a rectangular support frame in a single layer or a plurality of layers to form a zigzag bent flow path through which contaminated air passes. a the method of designing the suction device consisting of filter, introducing suction side dynamic pressure generated in the filter by the pressure difference of the hood and out, the suction-side dynamic pressure calculated from the flow rate and the flow area of the filter fan the flow rate <br/> determined to be equal to or greater than the increase rate of the contaminated air by its absorption
Based on the intake side dynamic pressure , smoke collection and collection efficiency,
The filter opening ratio and the degree of bending of the bending flow path are set.

[0010]

In the method of designing a suction device for local ventilation according to the present invention, the suction-side dynamic pressure generated in the filter due to the pressure difference between the inside and outside of the hood is introduced into any of the above-described structures or the filter having the metal lath structure, and The flow rate based on the suction-side dynamic pressure calculated from the air volume and the flow path area of the filter is determined to be equal to or higher than the rising speed of the contaminated air. Thus, the filter is generated based on the flow path area of the filter.
Focusing on the suction side dynamic pressure, by an appropriate suction side dynamic pressure, contamination of the clean air flowing from the speed difference between the flow at low speed is suppressed to a minimum, it is possible to enhance the smoke collecting and trapping efficiency Become.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for designing a suction device for local ventilation according to the present invention will be described with reference to FIGS. Hereinafter, a case where the method of the present invention is applied to a kitchen range hood ventilation fan as a local ventilation suction device will be described in detail below.

As shown in FIGS. 1 (a) and 1 (b) and FIGS. 2 (a) and 2 (b), a plurality of columnar members 12a having a V-shaped cross section are provided.
Two types of fence-shaped filters 14a and 14b, which are arranged in parallel at constant pitches Pa and Pb along the width direction thereof and held by a rectangular support frame 13, are prepared. 1 (a) and 2
(A) Columnar member 1 of one filter unit 14a shown in FIG.
The arrangement pitch Pa of 2a is the same as the arrangement pitch Pb of the columnar members 12b in the other filter unit 14b shown in FIGS. 1B and 2B, and one filter unit 14a
The other columnar member 12b is located at an intermediate position between one columnar member 12a by shifting the columnar member 12a of the other filter unit by a half pitch from the columnar member 12b of the other filter unit 14b.

As shown in a developed view of FIG. 3, the columnar members 12a and 12b constituting each of the filter units 14a and 14b have projecting pieces 16 integrally formed at both ends of a long flat plate member 15, and the flat plates It is formed by bending the shaped member 15 in a V-shape along the center and bending the protruding piece 16 inward. On the other hand, on the inner surface of the opposing side of the rectangular support frame 13 where the columnar members 12a and 12b are aligned, a stopper 17 having an inverted C shape for regulating the position of the columnar members 12a and 12b is formed (see FIG. 2). Then, the projecting pieces 16 of the columnar members 12a, 12b are fixed by welding or the like in a state where the positions thereof are regulated by the stoppers 17 of the rectangular support frame 13, thereby producing the filter units 14a, 14b.

The above-described rectangular support frame 13 is manufactured by forming members constituting each side into a rectangular shape, and connecting the four corners thereof with rivets or the like to integrate them. , The filter unit 14a, 1
4b is provided with a through hole 19 for inserting a screw 18 for connecting and integrating each filter unit 14a, 14b when the filter 4b is laminated (see FIG. 1).

As shown in FIGS. 4 and 5, one filter unit 14a and the other filter unit 14b are alternately arranged in a plurality of stages along the thickness direction (for example, six stages in the drawings).
And each filter unit 14a, 14
The filter 11 is manufactured by inserting screws 18 into the through holes 19 communicating with the four corners of b to connect and integrate the respective filter units 14a and 14b. As a result, the columnar member 12a of one filter unit 14a and the columnar member 12b of the other filter unit 14b are arranged with a step corresponding to the filter unit between the columnar members 12a and 12b adjacent to each other. A zigzag bent flow path 20 through which contaminated air passes is formed in the filter 11 by the positional relationship between the columnar members 12a and 12b.

In the above embodiment, one filter unit 14
Although a description has been given of an arrangement in which one-stage columnar members 12a and 12b are arranged on a and 14b, the present invention is not limited to this. For example, a two-stage columnar member having the above-described arrangement pattern as shown in FIG. The members 12a and 12b may be formed by a single filter 14 'held by one rectangular support frame 13'. In this way, only one type of filter 14 constituting the filter 11 is required, and the number of layers can be reduced to half (three levels in the figure) of the above-described embodiment.

As shown in FIG. 7, the filter 11 having the above structure is detachable from the opening 3 of the hood 2 of the range hood ventilation fan arranged above the range cooker 1 installed in a kitchen or the like as shown in FIG. Attached to. The filter 11 mounted on the hood 2 collects the contaminated air such as smoke and steam generated by heating cooking in the range cooker 1 by the rotation of the fan 5 and collects each filter unit 14a, 1
While passing through the zigzag bent flow path 20 formed by the columnar members 12a and 12b of FIG. 4b, the contaminated medium such as soot and oil mist (small oil particles) contained in the contaminated air is removed from the columnar members 12a and 12b. Aggregate and collect on the outer surface of 12b.

In the filter 11, the columnar members 12a, 12a
b, the contaminated medium drops on the outer surface of the filter unit 14a because the columnar member 12b of the other filter unit 14b is located immediately below the columnar member 12a of the other filter unit 14a. There is no drip inside and it is stored, and it does not fall down to the range cooker 1 so that the range cooker 1 is not soiled. Although the lowermost columnar members 12a and 12b are not shown, the columnar members 12a and 12b are arranged with a slight inclination in the longitudinal direction.
If a tray is attached to the lower end, the columnar member 1
The contaminated medium agglomerated on the outer surfaces of 2a and 12b moves down the slope and can be collected by the receiving tray. Since the columnar members 12a and 12b having a V-shaped cross section are arranged in a plurality of stages in the above-described arrangement pattern, no clogging occurs due to a contaminated medium when compared with a conventional metal lath structure. Less likely to change over time.

Here, the present inventor has determined that the pressure difference between the inside and outside of the hood is different.
The suction-side dynamic pressure generated in the filter 11 by the
It was noted that this is an important factor in designing No. 1. This
The dynamic pressure on the suction side of the
It is generated based on the nozzle effect due to the filter opening.
It is.

That is, the range hood ventilation fan is composed of a discharge device as a fan and a suction device as a filter, and the harmony between the discharge function of the discharge device and the suction function of the suction device is the basis of local ventilation. . Therefore, a suction device that is suitable for the discharge capacity of the discharge device is required.

As shown in FIG. 7, the inside of the hood 2 is in a negative pressure state due to the discharge of the contaminated air due to the rotation of the fan 5, and the same amount of the contaminated air as the discharge amount of the contaminated air enters the hood 2 through the filter 11. At this time, a pressure difference occurs between the inside and outside of the hood 2, and based on this, the filter 1
1 generates a suction-side dynamic pressure . The suction side dynamic pressure, and air volume of the fan 5, generated from the flow passage area of the filter 11 bent flow path 20 is formed. On the other hand, a contaminated medium such as an oil mist passes through the curved flow path 20 due to contact or collision with contaminated air due to a difference in inertia with the contaminated air.
Aggregated and collected on the outer surface of 2b.

In the filter 11 for collecting the contaminated air generated and raised by the cooking in the microwave cooker 1 by the rotation of the fan 5, the generated amount, the viscosity and the rising speed of the contaminated air increase in proportion to the amount of heat. In order to release the viscosity of the contaminated air and capture the contaminated air with high smoke collection efficiency, the suction speed must be higher than the rising speed of the contaminated air.
Requires lateral dynamic pressure . The rising speed of the contaminated air
It has a maximum value at a certain height from the cooker, and the height is
Determined by the heating power (high, medium and low heat)
It is. Therefore, based on the heating power in the range cooker,
The rise speed of the contaminated air may be measured at the height. For example,
Assuming that the rising speed of the contaminated air is 0.4-0.8 m / s,
The flow velocity due to the dynamic pressure on the suction side of the filter 11 is 0.4 to
0.8 m or more is required. That is, when the air flow rate of a fan having a two-stage speed difference of high speed and low speed is 300 m ³ per hour, the surface area of the filter as the suction device is 700
m ^2, the flow channel area and 100 cm ^2, the capture flow rate per second of about 0.833m next to contaminated air, at a high speed per hour 600
In the case of the discharge amount of m ^3, the speed is about 1.66 m / sec.

As described above, the flow velocity is higher than the rising velocity of the polluted air.
With the suction side dynamic pressure, the contaminated air that rises while being guided by the hood is captured and sucked by the filter surface area without any increase, and the mixing of clean air flowing at a low speed due to the flow speed difference is minimized. The contaminated air can be trapped with high smoke collection efficiency, and the contaminated air does not fill the kitchen. Is exhausted by the rotational force of the fan 5 to achieve complete ventilation without waste.

Therefore, in the filter 11 in which the columnar members 12a and 12b having a V-shaped cross section are combined in a predetermined arrangement relationship over a plurality of stages as in the above-described embodiment, it is important to improve the smoke collection and collection efficiency. The main elements are the columnar members 12a, 1 arranged in the width direction of the filters 14a, 14b.
2b and the columnar members 12 arranged in the thickness direction thereof.
The arrangement pitch of a and 12b and the angle of the V-shape of the columnar members 12a and 12b are set by the following design method.

That is, the flow velocity based on the suction-side dynamic pressure generated by the pressure difference between the inside and outside of the hood 2 is calculated from the air volume of the fan 5 and the flow area of the filter 11 in which the bent flow path 20 is formed.
I do. The flow rate due to the suction side dynamic pressure is (fan air volume)
/ (Filter flow area), for example, fan
Wind amount of hourly 300m ^3, the flow channel area of 100cm ² Der
Then, the flow velocity due to the suction side dynamic pressure at that time is about 0.833
m / s.

Here, the suction side of about 0.833 m / s
The flow speed due to the dynamic pressure depends on the shape of the hood in the filter 11.
Effect by nozzle and nozzle effect by filter opening
As a result, it becomes about 10 times larger, and the filter 11
The passing core velocity is about 8.33 m / s. This sucking
The core flow rate due to the inlet side dynamic pressure
And collection efficiency.

Based on the suction-side dynamic pressure , smoke collection efficiency and collection efficiency thus obtained, the filter units 14a, 14b
An array pitch of the columnar members 12a and 12b arranged in the width direction (hereinafter referred to as a horizontal arrangement pitch), an arrangement pitch of the columnar members 12a and 12b arranged in the thickness direction thereof (hereinafter referred to as a vertical arrangement pitch), and a columnar member. An angle (hereinafter, referred to as a V angle) forming a V-shape of 12a and 12b is set.

The relationship between the channel area, the suction-side dynamic pressure , the smoke collection efficiency, and the collection efficiency will be described below based on specific examples in which the horizontal arrangement pitch, the vertical arrangement pitch, and the V-angle of the columnar members 12a and 12b are different.

For example, FIGS. 8A and 8B show two examples in which the horizontal pitch is changed. FIG. 8A shows the case where the horizontal pitch is 30 mm, the vertical pitch is 10 mm, and the V angle is 75 °. FIG. In this case, the pitch is 40 mm, the vertical pitch is 10 mm, and the V angle is 75 °. Comparing these two examples,
In (a), since the flow path area is small, the suction side dynamic pressure is large,
On the other hand, the smoke collection and collection efficiency are high, whereas in (b), the flow area is large, so that the suction side dynamic pressure is small and the smoke collection and collection efficiency is low.

FIGS. 9A and 9B show two examples in which the vertical pitch is changed. FIG. 9A shows the case where the horizontal pitch is 40 mm, the vertical pitch is 10 mm, and the V angle is 90 °. FIG. 9B shows the horizontal pitch. 40 mm, vertical pitch 20 mm, V-angle 9
This is the case of 0 °. Comparing these two examples, in (a), the flow path area is small, so that the suction side dynamic pressure is large, and smoke collection and collection efficiency are high, whereas in (b), the flow path area is large, so that the suction side The dynamic pressure is small, and the smoke collection and collection efficiency are low. In FIG. 9B, reference numeral 21 denotes a rectangular frame-shaped spacer inserted between the filters 14a and 14b to change the vertical pitch.

FIG. 10 shows an example in which the horizontal pitch and the V-angle are changed, and the horizontal pitch is 20 mm, the vertical pitch is 10 mm, and the V-angle is 55 °. The V angle is for controlling the frictional resistance coefficient of the flow path based on the total pressure of the fan, but also affects the collection efficiency and the flow path area. In this case, although the horizontal arrangement pitch is smaller than in the above-described example, the V angle is small, the flow path area is large, the suction-side dynamic pressure is small, and therefore, the frictional resistance coefficient is small. However, smoke collection and collection efficiency are reduced.

Based on the above relationship, by experimentally setting the horizontal pitch, vertical pitch and V-angle of the columnar members 12a and 12b to various values, the frictional resistance coefficient as an optimal suction device can be improved. Smoke collection and collection efficiency, suction side
Dynamic pressure is obtained. Incidentally, as shown in FIG.
It is also possible to form the folded portion 22 along both side edges of the a and 12b.

The design method of the filter 11 is not limited to the one composed of a plurality of filter units 14a and 14b combining the columnar members 12a and 12b having a V-shaped cross section as described above, but also to a conventional metal lath structure, that is, a mesh. It is also applicable to a filter in which a zigzag bent flow path through which contaminated air passes is formed by forming a single unit or multiple layers of a filter holding a metal lath plate having a rectangular opening in a rectangular support frame, in which case From the air volume of the fan and the flow path area of the filter in which the bent flow path is formed, the flow velocity based on the suction side dynamic pressure generated by the pressure difference between the inside and outside of the hood is calculated. like this
Based on the suction-side dynamic pressure , smoke collection and collection efficiency, and the rate of change over time, the filter opening ratio and the degree of bending of the bent flow path are set.

The filter 11 includes a plurality of columnar members 12.
filter unit 14 in which a and 12b are arranged at a constant pitch
a, 14b is laminated in a plurality of stages, so that the filters 18a, 14b can be easily disassembled by removing the screws 18 for connecting and integrating the filters 14a, 14b during regular cleaning or replacement. Can be
It is possible to clean or replace each filter unit 14a, 14b individually, and it is very easy to clean each filter unit 14a, 14b because the columnar members 12a, 12b are only arranged at a constant pitch. A good cleaning effect can be obtained.

In the above-described embodiment, the case where the present invention is applied to a range hood ventilation fan installed in a kitchen has been described. However, the present invention can be used for other purposes such as dust removal.

[0036]

According to the design method of the present invention, by determining the suction side dynamic pressure required for the suction device for local ventilation, the mixing of clean air flowing at a low speed due to the flow speed difference is minimized. Without discharging indoor clean air, it is possible to easily improve the smoke collection and collection efficiency in the local ventilation suction device, and to provide a high-performance local ventilation suction device without waste, As a part of energy saving, it is possible to realize the standardization of the appropriate exhaust air volume, the suction side dynamic pressure and the collection efficiency based on the calorific value of the range cooker.

[Brief description of the drawings]

FIG. 1A is a plan view showing one filter alone constituting a ventilation filter of the present invention, and FIG. 1B is a plan view showing the other filter alone.

2 (a) is a partial cross-sectional view showing one filter alone in FIG. 1 (a), and FIG. 2 (b) is a partial cross-sectional view showing the other filter alone in FIG. 1 (b).

FIG. 3 is an expanded view of one columnar member.

FIG. 4 is a side view showing a state in which a single filter is stacked.

FIG. 5 is a cross-sectional view showing a state in which a single filter is stacked.

FIG. 6 is a partial cross-sectional view showing a modification of the filter alone.

FIG. 7 is a schematic configuration diagram showing a range hood ventilation fan using the ventilation filter of the present invention.

FIG. 8A is a partial cross-sectional view showing a specific example in which a single filter is laminated, and FIG. 8B is a partial cross-sectional view showing a state in which the horizontal arrangement pitch of the columnar members in FIG.

9A is a partial cross-sectional view showing another specific example in which a single filter is stacked, and FIG. 9B is a partial cross-sectional view showing a state in which the vertical arrangement pitch of the columnar members in FIG.

FIG. 10 is a partial cross-sectional view showing a state in which the V angle and the horizontal pitch of the columnar members are changed.

FIG. 11 is a partial cross-sectional view showing an example in which folded portions are formed on both side edges of a columnar member.

FIG. 12 is a schematic configuration diagram of a range hood ventilation fan.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Ventilation filter for kitchen 12a, 12b Column-shaped member 13 Rectangular support frame 14a, 14b Filter only 20 Bent flow path

Claims (2)

(57) [Claims] 1. A plurality of columnar members having a V-shaped cross section are arranged in parallel at a constant pitch along a width direction of the columnar members, and two types of single fence filters held by a rectangular support frame are alternately arranged along the thickness direction. From a filter that has a zigzag bent flow path through which contaminated air passes by arranging a columnar member of the other filter unit with a step between adjacent columnar members of one filter unit. A suction side movement generated in a filter due to a pressure difference between the inside and outside of the hood.
Introducing pressure, from the air volume and the flow passage area of the filter fan
The calculated flow velocity based on the suction side dynamic pressure is determined to be equal to or higher than the rising speed of the contaminated air, and based on the suction side dynamic pressure and smoke collection and collection efficiency, the columnar members arranged in the width direction of the filter unit are used. A method for designing a suction device for local ventilation, wherein an arrangement pitch, an arrangement pitch of columnar members arranged in the thickness direction thereof, and an angle of the columnar members forming a V-shape are set. 2. A filter having a zigzag bent flow path through which contaminated air passes by forming a single filter or a single filter in which a metal lath plate having a mesh-shaped opening is held by a rectangular support frame in a single layer or a plurality of layers. A design method of a suction device, wherein suction side motion generated in a filter due to a pressure difference between the inside and outside of the hood.
Introducing pressure, from the air volume and the flow passage area of the filter fan
The calculated flow velocity based on the suction side dynamic pressure is determined to be equal to or higher than the rising speed of the contaminated air, and based on the suction side dynamic pressure and the smoke collection and collection efficiency, the rate of change with time, the filter opening ratio and the bending flow rate are determined. A method for designing a suction device for local ventilation, wherein a degree of curvature of a road is set.