JP3503083B2 - Dust collection member with pressure drop gradient - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust collecting member that can be used to remove dust or carbon in a gas stream, and particularly to a gas stream containing fine oil particles (oil mist) or oil vapor. And a dust collecting member configured to remove oil vapor efficiently.

[0002]

2. Description of the Related Art For example, in a kitchen of a hotel or a restaurant, a large amount of oil is formed into fine particles (mist) or vapor during the cooking process. Discharging such oil mist or oil vapor, or gas containing steam in some cases (hereinafter referred to as "oil-containing gas") to the outside as it is is one of the causes of air pollution, and oil adhering to the exhaust duct. There is also a risk of fire causing a fire. For this reason, it is necessary to remove the oil content contained in the oil-containing gas before it is discharged to the outside, and various devices have been proposed and are currently used for removing the oil content.

[0003]

Among the conventional oil removing devices of this kind, for removing oil vapor, for example, a filter filled with an adsorbent such as activated carbon is used to filter the oil content of the oil-containing gas. Adsorption and removal, or an inertial collision method that removes oil content by suddenly changing the flow path of oil-containing gas with baffle plates or perforated plates or by colliding this oil-containing gas with the wall surface Has been done. These methods, for example, can increase the collection efficiency in the filtration method, but the removal efficiency of the collected oil is low, so that a rapid increase in pressure loss occurs due to the clogging of the filter, and in the inertial collision method, Although the efficiency of removing the collected oil is high, in order to efficiently remove the oil itself from the oil-containing gas, the flow velocity of the oil-containing gas must be increased, and the operating cost of the device is high due to the large capacity of the air blower. There are advantages and disadvantages to each.

In any case, the technical purpose of any of the above-mentioned methods is to improve the efficiency of collecting the oil component from the oil-containing gas flowing into the device, that is, the oil component from the oil-containing gas after flowing into the device. The important point is to improve the collection efficiency of the oil, and in some cases to remove the collected oil from the filter. Little was done.

FIG. 7 shows a suction state of an oil-containing gas in an oil collecting device (commonly called a "grease filter") provided with a conventional dust collecting member. Reference numeral 20 denotes an oil collecting device, and a plurality of dust collecting members 21 are installed in the depth direction of the drawing in a state of being slightly inclined downward, for example. The oil-containing gas is sucked into the device by an induction type blower (IDF / not shown) installed in the device or in a duct connected to this device, and the dust collecting member 21 is inertial when it is a member of a filtration system. Despite being a collision type member, the oil content contained when passing through these dust collecting members 21 is collected,
Moreover, the collected oil is discharged to the outside through the oil sump 22.

Conventionally, it is natural that the distribution of the pressure loss in the front portion (suction surface) of the dust collecting member 21 attached to the above apparatus is uniform regardless of the filtering method and the inertial collision method. No. 21 had no particular technical doubt in absorbing gas evenly over the entire suction surface.

On the other hand, in most cases, in a kitchen or the like, an oil-containing gas is generated from a specific portion, as represented by a cooking utensil 23 such as a frying pan. The oil collecting device is installed on the ceiling surface of the kitchen or a portion close to the ceiling surface, and sucks the rising oil-containing gas. in this case,
As a matter of course, the rising concentration of the oil-containing gas G is higher in the portion near the cooking utensil 23 that is the generation source, and as the temperature rises, the concentration of the oil-containing gas G is reduced by being diffused into the air in the room. Here, since the conventional dust collecting member absorbs the gas evenly on the suction surface as described above, the cooking utensil 23
Nearly the same amount of suction is performed by the lower part of the dust collecting member and the upper part diffused in the air A in the room. That is, the dust collecting member 21
Since a large amount of room air A that does not need to be sucked is also sucked in the upper part of the above, it is necessary to suck a large amount of gas in order to suck almost all of the oil-containing gas G that has diffused into the room. At the same time as the cost is increased, the oil collection efficiency is also reduced because the oil content is removed from the oil-containing gas having the reduced concentration.

[0008] Since the dust collecting member 21 through which the gas having a higher concentration of gas passes is sequentially clogged and the pressure loss of the portion increases, the center of gas suction in the dust collecting member 21 with the passage of time. Moves to the upper part where the oil-containing gas concentration is low. As a result, the relative suction amount of the indoor air A that does not need to be sucked is further increased, and the wind speed must be further increased in order to eliminate the oil-containing gas and increase the efficiency of collecting the oil component in the oil-containing gas. Fall into a vicious circle.

[0009]

SUMMARY OF THE INVENTION The present invention is constructed in view of the above-mentioned problems, and is one of the gas suction surfaces of a dust collecting member arranged in a dust collecting apparatus such as an oil collecting apparatus. The gas suction surface of the dust collecting member is configured to have a gradient of pressure loss so that the pressure loss of the portion close to the generation source of the gas to be dust-collected such as the contained gas is lower than the other portions. It is a characteristic dust collecting member.

[0010]

[Function] Since the amount of suction of the oil-containing gas of the dust collecting member in the portion having a high concentration close to the source of the oil-containing gas is larger than that in other portions, most of the oil-containing gas is sucked before being diffused into the air The oil is efficiently removed from the sucked and sucked oil-containing gas.

[0011]

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. Reference numeral 1 is a first filter into which the oil-containing gas G first flows, and the configuration shown in the drawing shows a filter. Further, this filtration type filter may have any structure such as a metal porous body called metal foam or a non-woven fabric. This first
Since the filter 1 of FIG. 1 shows a portion where the concentration of the oil-containing gas G to be filtered is high, that is, a position close to the generation source, in the illustrated case, the generation source is below the first filter 1, The lower part of the filter height H is configured to reduce the pressure loss (static pressure) of the passing fluid. Hereinafter, such a change in the pressure loss distribution on the gas suction surface of the filter in a specific direction will be referred to as a “pressure loss gradient”. That is, in the illustrated configuration, the pressure loss gradient is set so that the pressure loss is reduced in the lower portion of the filter where the concentration of the oil-containing gas G is higher in the first filter 1.

Various methods are conceivable for realizing the above pressure drop gradient. First, in the case where the filter 1 is a filtration filter, when the aperture ratio of the entire filter is set to be the same, the method of decreasing the passage cross-section of the fluid toward the lower part of the filter, that is, the thickness of the filter is decreased. A method, a method of increasing the aperture ratio toward the lower side when the filters are formed with the same thickness, a method of using both of them, and the like can be considered.

In the case of an inertial collision type filter, the opening ratio is changed, or the width of the baffle through which the oil-containing gas passes is changed to obtain a pressure loss gradient similar to that of the filtration filter. It is possible to set.

Next, reference numeral 2 is a second filter arranged behind the first filter 1. In the structure of this embodiment, the second filter 2 has a pressure loss gradient over the entire gas inflow surface of the filter. That is, the first filter 1 and the second filter 2 are integrated so that the dust collecting member 3 is formed.

FIG. 2 shows the suction state of the oil-containing gas G in the oil collecting device to which the dust collecting member 3 having the above structure is attached. The dust collecting member 3 of the present embodiment is attached to both sides of the oil collecting device 20 (the device itself can use the conventional device of FIG. 7 as it is). Incidentally, there is an apparatus in which the oil collecting device 20 is attached to the wall surface and the dust collecting member 3 is attached only to one surface of the device, but the dust collecting member 3 is also attached to such a one-sided device. It is possible from the beginning. In the illustrated oil collecting device 20, the oil-containing gas G rising from the cooking utensil 23 as the generation source of the oil-containing gas G enters the room at the lower part of the dust collecting member 3 near the generation source and with little pressure loss. Most of it is sucked into the device 20 in a high concentration before being diffused. Note that the amount of oil adhered to the lower part of the dust collecting member where the amount of oil-containing gas G that has passed is relatively large with the passage of time, but since the pressure loss is set to a low level in advance, the conventional type dust collector with zero pressure loss gradient is used. The increase in pressure loss in the lower part of the filter as compared with the dust member is suppressed low.

The oil which has not been removed by the first filter 1 is removed by the second filter 2 in the back. In this case, the passage amount of the oil-containing gas G is reduced in the second filter 2 having a zero pressure loss gradient. A large amount of oil-containing gas G that flows into the second filter due to a gradual increase in pressure loss under the filter
Will tend to flow in from above the second filter as shown in the figure over time. As a result,
When viewed over time, the entire second filter 2 can be used for removing oil without excess or deficiency.

FIG. 3 shows a second embodiment. In this embodiment, the pressure loss gradient is set so that the pressure loss decreases in the lower part of the filter where the concentration of the oil-containing gas G is higher in the first filter 1 as in the first embodiment. On the contrary, the pressure loss gradient of the second filter 4 arranged behind the filter is set so that the pressure loss is lower in the upper part of the filter. Further, behind the second filter 4, there is arranged a third filter 5 having a zero pressure loss gradient similar to the second filter 2 in the first embodiment. 4A, 4B, and 4C show changes in pressure loss (pressure loss gradient) in the height H direction in the filters 1, 4, and 5, respectively. Further, (1), (4), and (5) in each diagram correspond to the signs of these filters.

In this embodiment, the oil-containing gas G which has mainly passed through the lower portion of the filter in the first filter 1 is inverted in the second filter 4 and passes through the upper portion of the filter, whereby the filter of each filter is filtered. Further utilization of the surface and whether the first and second filters are filtration filters or inertial / collision filters, the first filter 1 to the second filter 4
The flow path of the oil-containing gas G is changed in the course of, and the oil content can be removed by the inertia by changing the flow path.

FIG. 5 and FIG. 6 show a third embodiment,
The structure is based on the structure of the second embodiment. In the figure, reference numeral 1A is the first in the second embodiment.
The pressure loss gradient is set so that the pressure loss in the lower part of the filter is lower than that in the second embodiment. There is. 6A shows this state. In the diagram, (1) shows the pressure drop gradient of the first filter 1 of the second embodiment, and (1A) shows the first pressure drop in the present embodiment.
3 shows a pressure loss gradient of the filter 1A of FIG. Similarly, the second filter 4A located behind is also the second filter 4A as shown in FIG.
The pressure loss gradient is the same as that of the second filter 4 of the second embodiment, but the pressure loss is lower than that of the second filter of the second embodiment as a whole. However, compared to the pressure loss difference ΔP1 between the first filters 1 and 1A, the pressure loss difference ΔP2 between the second filters is set to be smaller than ΔP1.

Reference numeral 5A designates a third filter located behind the second filter 4A, which is set to a pressure loss gradient of zero like the third filter 5 in the second embodiment.
The pressure loss is set to be smaller than the pressure loss of the third filter 5 by ΔP3 [see FIG. 6 (C)]. However, the ΔP3 is set to be smaller than the ΔP2. Reference numeral 6 denotes a fourth filter arranged behind the third filter 5A, which is also set to zero pressure loss gradient.

In this embodiment, the pressure loss gradients are set upside down in the vertical direction of the first and second filters, and the pressure loss of each filter changes in the passage direction of the oil-containing gas G. By doing so, it becomes possible to more efficiently perform the suction of the oil-containing gas G and the removal of the oil component in the oil-containing gas G.

Although the structure of the present invention has been described by taking the case of removing the oil component from the oil-containing gas G as an example, it can be applied to other fluids as a matter of course.

[0024]

As described above in detail, the present invention diffuses the fluid in the vicinity of the source of the fluid on the fluid suction surface of the dust collecting member arranged in the dust collecting apparatus such as the oil collecting apparatus. Since the pressure loss of the portion close to the non-treated portion is lower than that of other fluid suction surfaces, the fluid to be treated can be effectively sucked by the dust collector before diffusing. Therefore, it is possible to economically and effectively collect oil and collect dust without increasing the suction speed of the fluid.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a dust collecting member showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the oil collecting device showing a suction state of the oil-containing gas in the oil collecting device provided with the dust collecting member according to the present invention.

FIG. 3 is a schematic sectional view of a dust collecting member showing a second embodiment of the present invention.

4 (A), (B) and (C) are diagrams showing the pressure loss gradient in the height direction of each filter shown in FIG.

FIG. 5 is a schematic cross-sectional view of a dust collecting member showing a third embodiment of the present invention.

6 (A), (B), (C), and (D) are diagrams showing pressure loss gradients in the height direction of the filters shown in FIG.

FIG. 7 is a cross-sectional view of an oil collecting device showing a suction state of an oil-containing gas in the oil collecting device provided with a conventional dust collecting member.

[Explanation of symbols]

1,1A First filter 2, 4, 4A Second filter 3 Dust collector 5, 5A Third filter 6 Fourth filter 20 Oil collector A indoor air G oil-containing gas

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-245321 (JP, A) JP-A-3-284317 (JP, A) Actual opening 4-1344 (JP, U) Actual opening Sho-59- 132020 (JP, U) Actual development 60-74720 (JP, U) Actual development 62-179318 (JP, U) Actual development 54-155682 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F24C 15/20 B01D 46/10 F24F 7/06

Claims (4)

(57) [Claims] 1. Dust, oil particles, water droplets, oil vapor, etc.
The gas to be processed including the object to be removed passes through the filter.
The filter to remove the gas in the process gas.
If the object to be removed is collected and removed,
Filter the gas passes is provided in one or more, processed gas inflow surface of the first filter this out at least the processing target gas is initially flows, the concentration sources such as the processed gas to be processed gas is high A dust collecting member provided with a pressure loss gradient, characterized in that a pressure loss gradient is provided so that the pressure loss of the passing gas decreases as it goes to the side. 2. The dust collecting member provided with a pressure drop gradient according to claim 1, wherein the pressure drop gradient is formed by the cross-sectional area of gas passing through the filter. 3. The dust collecting member provided with the pressure loss gradient according to claim 1, wherein the pressure loss gradient is formed depending on the opening area of the filter. 4. A second filter is arranged behind the first filter, and a gas inflow surface of the second filter is provided with a pressure loss gradient opposite to that of the first filter. The dust collecting member provided with the pressure loss gradient according to any one of claims 1 to 3.