JPH08131736A - Dust collecting member consisting of porous screen - Google Patents

Abstract

PURPOSE: To efficiently remove oil from fluid through a porous screen while a rise in pressure loss is being prevented. CONSTITUTION: A first porous screen 1a and a second porous screen 1b are turned in opposite directions through 180 degrees, i.e., they are arranged inside out. A third porous screen 1c is turned in the direction opposite to the second porous screen 1b through 180 degrees in the same arrangement as the first porous screen 1a. By this arrangement, an oil-containing gas G passes through each opening 2a of the first porous screen 1a and changes into a downward flow G1 and then into an upward flow G2 on the second porous screen 1b. The gas again changes into a downward flow G3 on the third porous screen 1c. The oil contained in the oil-containing gas G such as oil mist and oil vapor is removed therefrom by the inertia resulting from the downward, upward and downward movement of the gas G and by the collision of the gas G against the walls of the porous screens.

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 effective for removing oil vapor.

[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. Exhausting such a gas containing oil mist or oil vapor (hereinafter referred to as "oil-containing gas") to the outside as it is is a cause of air pollution, and the oil adhering to the exhaust duct ignites and causes a fire. There is also a risk of causing. 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 type, for example, a device using a filter filled with an adsorbent such as activated carbon is provided as a device for removing oil vapor. Although this device has a relatively high oil vapor removal efficiency, it is not suitable for a gas in which oil mist coexists because the removal rate of oil mist is considerably low. Further, there is a problem that the removed oil tends to be retained, which causes clogging over time, the pressure loss greatly increases, and the risk of ignition due to the retained oil also increases.

On the other hand, the inertial collision method is mainly used to remove the oil mist. This method is particularly effective when the oil particles are large, but there is a problem that the collection efficiency decreases when the oil particles are fine. As an effective means for inertial collision, a certain angle (for example, 3
A mesh screen having a large number of openings having an inclination angle of 0 to 60 degrees is arranged, and a plurality of mesh screens are arranged so that the openings of the mesh screen are angularly displaced by 90 degrees in the plane direction. Another configuration has been proposed (Japanese Patent Application No. 58-27672).

According to the structure proposed above, the openings are separated from each other by 90 degrees.
Since the oil-containing gas passing through the openings of each screen forms a swirling flow, it is expected to effectively collect dust or oil by the inertial collision method. However, in order to exert such a trapping effect, it is necessary to stack about 10 mesh screens, in some cases about 20 mesh screens, and it becomes difficult to wash and remove the oil adhering to each mesh screen. .

Further, in the case of the filter type dust collecting, the dust collecting efficiency is not improved so much even if the passage speed of the fluid is increased.
The dust collection by the inertial collision method is inferior in efficiency in the low speed range as compared with the filter method, but the dust collection efficiency is significantly improved in response to the increase in the velocity of the passing fluid. Therefore, it is known that if the passage speed of the fluid is set to be high, it is possible to collect dust with higher efficiency as compared with the filter method. That is, in the dust collector using the inertial collision method, it is necessary to operate by increasing the passing fluid velocity in order to increase the dust collection efficiency. Will be enormous. For this reason, the running cost of the device is considerably increased as compared with the conventional device, such as increasing the capacity of the blower in order to maintain a high fluid passage speed, which is a problem.

[0007]

SUMMARY OF THE INVENTION The present invention is constructed in view of the above-mentioned problems, and has an inclination angle of a predetermined angle with respect to the flow direction of a fluid containing an object to be removed such as an oil-containing gas. A plurality of screens (hereinafter referred to as "perforated screens") having a plurality of openings each having a plurality of openings are arranged, and the adjacent perforated screens are inverted by 180 degrees so that the front and the back face each other, that is, they are turned inside out. The dust collecting member is configured so that

[0008]

The fluid flowing into the first perforated screen becomes, for example, a downward flow at an angle corresponding to the inclination angle of each opening, and in the next perforated screen in which the front and back are arranged in reverse, the downward flow is reversed and the openings are opened. Ascending flow along the inclination angle of. In this way, the fluid repeatedly descends and rises each time it passes through each porous screen, and most of the contained objects, such as oil mist, are collected by inertial collision, and the oil vapor also aggregates and collects in this process. Gathered.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an example of a porous screen used in the present invention, and FIG. 2 shows a first embodiment of a dust collecting member using this porous screen.

First, the structure of the perforated screen will be described with reference to FIG. The arrow 1 indicates the entire perforated screen, and this perforated screen 1 is, for example, SUS304 stainless steel,
It is formed of a metal material such as aluminum or nickel. However, being formed of a metal material is not an essential requirement for forming a porous screen, and other than these metal materials, it is possible to form, for example, plastics or ceramics. An example will be explained.

Reference numeral 2 is an opening, and the perforated screen 1 is formed by arranging a large number of openings 2. For example, as a forming method thereof, a large number of cuts (slits) are formed in a metal plate in advance, and the cut part is opened by pulling the metal plate in a predetermined direction, that is, a formation called expanded metal. The method etc. are used. Each opening 2 is opened obliquely with respect to the flow direction of the oil-containing gas G at a predetermined angle α. It is effective that the angle α is such an angle that the oil content contained when the oil-containing gas G flows into the opening is separated by inertia and the flow does not become a turbulent flow and maintains a substantially laminar flow. From such a point, as a result of the test conducted by the inventors, it was concluded that the value of α is preferably 25 to 70 degrees.

FIG. 2 shows an example of the construction of a dust collecting member using three perforated screens 1 shown in FIG. 1a is the porous screen 1 shown in FIG. 1 arranged in the same state as that of FIG. 1, that is, each aperture 2 is arranged obliquely upward at an angle α, and 1b is the porous screen 180
Shown is the one that is inverted, that is, turned over. Therefore, since the opening 2 of the perforated screen 1b is directed downward at an angle α, the opening angle with respect to the oil-containing gas G at the opening of the perforated screen 1b will be indicated by −α hereinafter.
1c is arranged at a position where the perforated screen 1b is further inverted by 180 degrees, that is, returned to the position of the first perforated screen 1a. Therefore, the opening angle is α, which is the same as that of the perforated screen 1a. In the following description, the aperture 2 of the porous screen 1a is 2a, the aperture 2 of 1b is 2b, and the aperture 2 of 1c is 2c. Although three porous screens 1 are arranged in the configuration shown in the figure, it is possible to arrange four or more perforated screens. However, in comparison with the collection efficiency and the pressure loss, the number is larger than that in the three-panel configuration shown in the figure. Also, it is preferable to have about 5 sheets.

FIG. 3 shows the entire dust collecting member composed of three porous screens shown in FIG.
The a to 1c are configured as an integral dust collecting member 4 by the frame 3, and the dust collecting member is detachably arranged in an oil-containing gas flow path (not shown) to collect the oil component. In addition, it is possible to dispose of the dust collecting member as a matter of course, but it is better to replace it regularly, collect the removed dust collecting member, and send it to the washing step to recycle it for reuse for environmental hygiene or Economically desirable.

Next, the operating state of the above configuration will be described mainly with reference to FIG. The oil-containing gas G is sucked by an induction type blower (IDF / not shown) arranged on the downstream side of the dust collecting member 4 and heads toward the first porous screen 1a. In this case, the oil-containing gas G in the first porous screen 1a
The IDF is operated so that the inflow speed of is about 0.5 to 2.0 m / sec. Since the openings 2a of the oil-containing gas G reaching the first perforated screen 1a are obliquely opened at a predetermined angle α, a downward flow G1 is generated while colliding with the opening wall surface and adhering the contained oil mist to the opening wall surface. To form. The contained oil vapor is also partially condensed by this collision and adheres together with the mist, and the adhered oil flows down along the perforated screen due to its own weight and is collected in an oil reservoir (not shown).

On the other hand, the oil-containing gas G discharged from the first perforated screen 1a then flows again into the opening 2b of the second perforated screen 1b which is opened by -α, and the downflow G1 is turned around to rise up G2. Becomes During this reversal, most of the oil mist that was not collected in the first porous screen 1b is distributed and removed by inertia (indicated by the broken arrow in the figure). Further, the oil-containing gas G that has turned into the upward flow G2 has its oil mist removed by the same inertial collision method as in the first porous screen 1a, and the oil vapor is condensed and removed on the opening wall surface.

Upflow G exiting the second perforated screen 1b
2 again becomes a descending flow G3 in the third porous screen 1c, and most of the remaining oil content is removed by the same action as the first porous screen 1a. As described above, in the above-mentioned configuration, the oil-containing gas G is added to each porous screen 1
Since a to 1c are sequentially reversed 180 degrees and arranged,
Ascending and descending are repeated, during which oil collection by collision, aggregation of oil vapor, and oil removal by inertia during fluid inversion are repeated. In this way, the oil-containing gas G drastically changes the flow path between the adjacent porous screens, so that the oil removal efficiency in one porous screen is high. Therefore, the number of perforated screens to be arranged is, for example, three as shown in the figure, and the number can be greatly reduced to 1/3 to 1/10 as compared with the number of conventional constitutions, and the oil can be removed efficiently. Therefore, the pressure loss of the entire device can be significantly reduced.

FIG. 4 shows a second embodiment of the present invention, in which the shape of the wall surface of the opening is improved so as to more efficiently remove the collected oil from the porous screen.

First, in the configuration (A), the groove 5 is formed along a wall surface height direction, that is, a flow direction of the oil-containing gas G in a part of the wall surface forming the opening 2 (a central portion in the illustrated structure). There is. Due to the formation of the groove 5, the oil content colliding and adhering to the wall surface of the opening 2 is assisted by the flow of the oil-containing gas G and collects on the groove 5 side. run down.

The structure of FIG. 2B shows a structure in which a plurality of grooves 5 are formed. In this configuration, the oil component that has collided and adhered to the wall surface of the opening 2 flows into each groove 5 and travels through these grooves 5 to descend.

5 and 6 show a third embodiment. In the figure, reference numeral 6 is a gutter for flowing the oil collected in the perforated screen, between the first perforated screen 1a and the second perforated screen 1b, and between the second perforated screen 1b and the third perforated screen 1c. And also behind the third perforated screen 1c in some cases. Further, this gutter 6 is provided with these perforated screens 1a, 1
It also serves as a spacer interposed between b and 1c. In order to collect the oil efficiently, it is necessary to have a space of about 1 to 3 mm between the perforated screens, but the gutter 6 can also function as a spacer for holding this space. It is convenient.

6 (A) and 6 (B) show the arrangement state of the gutter 6 in the dust collecting member 4, and FIG. 6 (A) shows the gutter 6 so as to descend obliquely toward one side edge of the dust collecting member 4. FIG. 6B shows a configuration in which the gutter 6 is disposed so as to descend obliquely from the central portion of the dust collecting member 4 toward both side edges. In both configurations, the gutter 6 is configured to descend toward one or both side edges, so that the collected oil flows down along the gutter 6. Further, an oil collecting path (header) 7 arranged along the side edge of the dust collecting member 4 is provided at the end of the gutter 6 on the descending side, and an oil sump 8 is provided at the lower end of the collecting path 7. It is provided. It is of course possible to open the lower end of the oil collecting passage 7 so that the collected oil collects in a common oil reservoir provided in an oil-containing gas flow path (not shown).

In the above construction, the oil component flowing down along the wall surface of each opening 2a of the first perforated screen 1a and the oil component separated when the descending air flow G1 is changed to the ascending air flow G2 are the first gutter 6 Gather in. Since these gutters 6 are obliquely arranged as shown in FIG. 6, they flow down along the gutter 6 and are separated and removed from the dust collecting member. In addition, in the part arrange | positioned between the 2nd perforated screen 1b and the 3rd perforated screen 1c which change to the descending flow G3 from the ascending flow G2, it is mainly 2nd.
The oil blown up along the wall surface of the opening 2b will be collected and removed. Further, the gutter 6 arranged behind the third porous screen 1c further removes the oil component separated from the downflow G3.

The structure of the present invention has been described above by taking the case where the fluid to be treated is an oil-containing gas as an example. However, the present dust collecting member is not effective only for an oil-containing gas containing oil. It is easily presumed by those skilled in the art that it is widely effective for fluids containing various dusts regardless of solid or liquid.

[0025]

According to the present invention, a plurality of adjacent perforated screens are arranged so that the front and back sides thereof face each other.
The fluids passing through each of the perforated screens flow in a vertically undulating manner when passing through each of the perforated screens because they are arranged so as to be inverted by 0 degrees, that is, arranged so as to be turned inside out. Therefore, the efficiency of inertial / collision dust collection is high, and therefore the efficiency of collecting an object in one perforated screen is high, so the number of installed perforated screens is a fraction of that of conventional devices. Therefore, the pressure loss of the entire dust collecting member can be set low while maintaining high dust collecting efficiency, and a blower having a smaller capacity than the conventional one is sufficient and the operating cost of the device can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective partial view of a perforated screen used in an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of the dust collecting member according to the first embodiment of the present invention, in which each perforated screen corresponds to the cross-sectional view taken along the line AA in FIG.

FIG. 3 is a cross-sectional view in which a part of a dust collecting member is omitted.

4A and 4B respectively show configuration examples of the cross-sectional shape of the opening wall surface taken along the line BB in FIG. 3, where FIG. 4A shows a configuration having one groove, and FIG.
Indicates a structure in which a plurality of grooves are formed.

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

FIG. 6A and FIG. 6B are schematic front views of the dust collecting member showing the arrangement of the gutters in the dust collecting member.

[Explanation of symbols]

 1 Perforated Screen 1a First Perforated Screen 1b Second Perforated Screen 1c Third Perforated Screen 2 Opening 2a First Perforated Screen Opening 2b Second Perforated Screen Opening 2c Third Perforated Screen Opening 3 Frame Body 4 Dust collection member (consisting of perforated screen) 5 Groove 6 Gutter

Claims (3)

[Claims] 1. A dust collecting member having a plurality of perforated screens having a large number of openings, wherein each opening of the perforated screen is formed obliquely at a predetermined angle with respect to a fluid flow direction, In addition, the adjacent porous screens are arranged so that the opposite surfaces thereof are turned upside down by 180 degrees so that the fluid passing through the porous screens is configured to repeatedly descend and rise. Dust collecting member. 2. A dust collecting member comprising a perforated screen according to claim 1, wherein one or more grooves are formed along the fluid flow direction on the wall surfaces of the apertures that respectively define the openings of the perforated screen. 3. A gutter is provided between the perforated screens, and the gutter is arranged such that at least one end thereof descends toward a side edge of the perforated screen. A dust collecting member comprising the perforated screen described in the above.