JP2021116965A - Oil content collection device - Google Patents

Abstract

To provide an oil content collection device capable of more efficiently collecting an oil content from an exhaust gas.SOLUTION: A rotary plate 8 is arranged inside an exhaust flow passage Ps so as to cross the same, openings 81 to 83 are formed at the plate face of the rotary plate 8, the plate thickness T of the opening side face 8a on the upstream side in the rotary direction of the openings 81 to 83 is set to prescribed dimensions higher than the dimensions decided from the circumferential velocity Vc of the rotary plate 8, the flow velocity Vg of an exhaust gas passing through the openings 81 to 83 and the width W of the openings 81 to 83, and an oil content comprised in the exhaust gas flow passing through the openings 81 to 83 is caught by the opening side face 8a and is thereafter derived in the outer circumferential direction of the rotary plate 8.SELECTED DRAWING: Figure 4

Description

The present invention relates to an oil collecting device, and in particular, collects oil in exhaust gas with a rotating perforated plate.

For example, Patent Document 1 discloses a device in which a rotating perforated disk is provided as an oil collecting device at a position upstream of a fan in an exhaust duct. An example of the disk of the oil collecting device shown here is made of stainless steel with a plate thickness of 0.5 mm, and even if the plate thickness is changed between 0.5 mm and 1.0 mm, the oil collecting rate remains high. Since it does not change, most of the oil is collected on the surface of the filter, and the holes formed on the plate surface can have various shapes such as a circle, an ellipse, and an oval.

JP 2013-139946

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By the way, in the above-mentioned conventional oil collecting device, the oil is collected and separated by the plate surface of the perforated disk, but the inventor's knowledge is that the oil is collected when the exhaust gas flows through the hole in the plate surface. It is more efficient to attach it to the inner peripheral surface of the hole and collect it.

Therefore, an object of the present invention is to provide an oil collecting device capable of collecting oil more efficiently from the exhaust gas based on the above findings.

In order to achieve the above object, in the first invention, a rotating plate (8) is arranged in the exhaust flow path (Ps) so as to cross the exhaust flow path (Ps), and an opening (81 to 8) is provided in the plate surface of the rotating plate (8). 83) is formed, and the length (T) of the opening side surface (8a) on the upstream side in the rotation direction of the opening (81 to 83) in the exhaust flow direction is set to the peripheral speed (Vc) of the rotating plate (8). ), The exhaust flow velocity (Vg) passing through the openings (81 to 83) and the length (W) of the openings (81 to 83) in the circumferential direction of the rotating plate are set to a predetermined dimension equal to or larger than the dimension determined. After the oil contained in the exhaust flow passing through the openings (81 to 83) is captured by the opening side surface (8a), it is led out toward the outer periphery of the rotating plate (8).

In the first invention, the length of the side surface of the opening on the upstream side in the rotation direction in the exhaust flow direction is determined from the peripheral speed of the rotating plate, the exhaust flow velocity passing through the opening, and the length of the opening in the circumferential direction of the rotating plate. Since the dimension is set to a predetermined dimension equal to or larger than the determined dimension, all the oil passing through the opening reaches the side surface of the opening on the upstream side in the rotational direction, adheres to the side surface of the opening, and is collected. The collected oil is led out toward the outer periphery of the rotating plate by centrifugal force.

In the second invention, a vertical wall (84) is provided on the opening edge (8a) on the upstream side of the opening (81 to 83) in the rotation direction so as to increase the length of the opening side surface (8a) in the exhaust flow direction. ..

According to the second invention, the length of the side surface of the opening on the upstream side in the rotation direction in the exhaust flow direction can be set to a predetermined dimension equal to or larger than the above-determined dimension while making the entire rotating plate thin and lightweight.

In the third invention, the tip of the vertical wall (84) is further bent to the downstream side in the rotation direction of the rotating plate (8), oil is captured by the bending corner portion (85), and the oil is led out toward the outer periphery of the rotating plate. To do so.

According to the third aspect of the present invention, the oil adhering to and collected on the side surface of the opening on the upstream side in the rotation direction is captured by the bent corner portion without being mixed again in the exhaust flow, and in the captured state, toward the outer periphery of the rotating plate. You will be guided reliably.

In the fourth invention, the opening is an elongated hole opening (81 to 83) having a constant length in the circumferential direction of the rotating plate and extending in the radial direction of the rotating plate (8).

According to the fourth invention, it is possible to secure a sufficient length of the opening side surface on the upstream side in the rotation direction for collecting oil.

In the fifth invention, the opening is an opening (86) extending in the radial direction of the rotating plate (8) while gradually expanding the length in the circumferential direction of the rotating plate.

According to the fifth invention, the opening area of the rotating plate can be increased to reduce the pressure loss of the exhaust, and the entire side surface of the opening on the upstream side in the rotation direction of the opening can be effectively used for collecting oil.

In the sixth invention, the oil content that penetrates outward in the radial direction of the rotary plate (8) from the opening side surface (8a) on the upstream side in the rotational direction of the opening (86) and opens on the outer peripheral surface of the rotary plate (8). A lead-out hole (861) is provided.

According to the sixth invention, the oil adhering to and collected on the side surface of the opening is smoothly discharged in the outer peripheral direction through the oil lead-out hole by centrifugal force.

In the seventh invention, the opening is a notched opening (87) that opens outward in the radial direction of the rotating plate.

According to the seventh invention, the oil adhering to and collected on the side surface of the opening is quickly led out to the outside of the rotating plate along the side surface of the opening by centrifugal force.

In the eighth invention, an oil component lead-out groove (871) extending outward in the radial direction of the rotary plate is formed on the opening side surface (8a) on the upstream side in the rotation direction of the notch opening (87).

According to the eighth invention, the oil component adhering to and collected on the side surface of the opening is more smoothly led out to the outside of the rotating plate.

The reference numerals in parentheses indicate the correspondence with the specific means described in the embodiments described later for reference.

As described above, according to the oil content collecting device of the present invention, oil content can be collected more efficiently from the exhaust gas.

It is a system diagram of the arc furnace exhaust system provided with the oil collecting device in the 1st Embodiment of this invention. It is a vertical sectional view of an oil collector. It is an overall plan view of a rotating plate. It is sectional drawing of the main part of the rotating plate along the line IV-IV of FIG. It is sectional drawing of the main part of the rotating plate in 2nd Embodiment of this invention. It is sectional drawing of the main part of the rotating plate in 3rd Embodiment of this invention. It is an overall plan view of the rotating plate in 4th Embodiment of this invention. It is a main part plan view of the rotating plate in 5th Embodiment of this invention. FIG. 8 is a side view of the main part of the arrow A in FIG. It is a main part plan view of the rotating plate in 6th Embodiment of this invention. It is a side view of the main part of the arrow B of FIG.

The embodiments described below are merely examples, and various design improvements made by those skilled in the art within the scope of the present invention are also included in the scope of the present invention.

(First Embodiment)
FIG. 1 shows an example of an exhaust system of an arc furnace provided with the oil collecting device of the present invention. In the figure, the high-temperature exhaust gas discharged from the arc furnace 1 flows into the scrap preheating device 3 via the combustion column 2, where the scrap additionally charged into the arc furnace 1 is preheated. At this time, the oil adhering to the scrap evaporates and mixes into the exhaust gas.

Exhaust gas containing oil goes to the cooling tower 4, but when such exhaust gas flows into the bag filter 5 at the rear stage of the cooling tower 4, clogging often occurs. Therefore, the oil collecting device 6 of the present invention is provided on the inlet side (or the outlet side as shown by the chain line) of the cooling tower 4. A blower 7 is provided at the final stage of the exhaust system, and the exhaust gas is sucked into the blower 7 and discharged to the outside air.

FIG. 2 shows a cross-sectional view of the oil collecting device 6. The oil collecting device 6 is provided with a cylindrical housing 61, and inlet openings 611 and outlet openings 612 are provided on both end surfaces thereof, and exhaust gas from the scrap preheating device 3 (FIG. 1) is encapsulated through the inlet openings 611. It flows into the body 61, circulates therethrough (arrow in the figure), and flows out from the outlet opening 612 toward the cooling tower 4.

A holding plate 71 is provided in the housing 61 so as to cross the exhaust flow path Ps, and the drive motor 72 is supported on the central portion of the holding plate 71. The holding plate 71 is provided with an opening 711 having a sufficiently large size at an appropriate position so that exhaust gas can flow substantially without resistance.

A rotating plate 8 is attached to the tip of the drive shaft 721 that penetrates the holding plate 71 and projects from the drive motor 72. The rotating plate 8 is arranged so as to cross the exhaust flow path Ps in parallel with the holding plate 71, and the outer periphery of the rotating plate 8 is so close to the peripheral wall of the housing 61 that exhaust cannot substantially pass through. A large number of elongated hole openings 81 to 83 extending in the radial direction are formed on the plate surface of the rotating plate 8 which is rotated at a constant speed by the drive motor 72 (arrow in FIG. 3). The elongated hole openings 81 to 83 are appropriately arranged on the plate surface of the rotating plate 8 with short ones among the long ones so that each part of the plate surface has an aperture ratio of substantially the same. The length (that is, width) W (mm) of the elongated hole openings 81 to 83 in the circumferential direction of the rotating plate is the same.

Here, the length (plate thickness T) of the rotating plate 8 in the exhaust flow direction is determined as follows.
Assuming that the exhaust flow rate: Q (m3 / h), the rotating plate diameter: D (m), the rotating plate opening ratio: A, and the rotating plate rotation speed: N (rpm),
The exhaust flow velocity Vg is given by the following equation (1).
Vg (m / s) = (Q / 3600) / ((D / 2) ** 2, π, A) ... (1)
Here, ** means a power, and the peripheral speed Vc of the rotating plate 8 at the position L from the center of rotation is given by the following equation (2).
Vc (m / s) = 2 ・ π ・ L ・ N / 60 ... (2)
Therefore, in FIG. 4 showing a cross section of the elongated hole opening 81 in the width direction, the rotating plate 8 is reached before the oil (oil droplet) Op at the rotational downstream position of the elongated hole opening 81 reaches the rotational upstream position in the width direction. Let X be the distance to move in the plate thickness direction of, and the distance X is given by the following equation (3).
X (mm) = Vg ・ W / Vc ... (3)
If the plate thickness T of the rotating plate 8 is set to X (mm) or more, all the oil that passes through the elongated hole opening 81 reaches the opening side surface 8a on the upstream side in the rotational direction, adheres to the opening side surface 8a, and is collected. The collected oil is guided by centrifugal force along the plate surface of the rotating plate 8 toward the outer circumference of the rotating plate (on the front side of the paper surface). Therefore, if an oil storage groove or the like is provided on the inner peripheral wall of the housing below the outer peripheral edge of the rotating plate 8, the oil that reaches the outer peripheral end of the rotating plate 8 falls into the oil storage groove and is recovered.

For example, when the exhaust flow rate Q: 400 m3 / h, the rotating plate diameter D: 0.3 m, the rotating plate opening ratio A: 0.6, the width of the elongated hole opening W: 5 mm, and the rotating plate rotation speed N: 1500 rpm, the rotation occurs. The moving distance Xi of the oil content in the plate thickness direction at the innermost peripheral position of the plate (0.05 m from the center of rotation) is calculated to be 1.669 mm from the above equations (1) to (3). Further, the moving distance Xo of the oil content in the plate thickness direction at the outermost peripheral position of the rotating plate (0.145 m from the center of rotation) at this time is calculated to be 0.576 mm. Therefore, if the plate thickness T of the rotating plate 8 is set to about 2 mm, all the oil contained in the exhaust gas flowing through the elongated hole openings 81 to 83 reaches the opening side surface 8a on the upstream side in the rotation direction and adheres to the opening side surface 8a. Be collected.

(Second Embodiment)
In the first embodiment, the thickness of the entire rotating plate 8 is set to a required thickness, but the total plate thickness is made thinner than the required thickness, and the elongated hole openings 81 to 83 are shown at the opening edge on the upstream side in the rotation direction. As shown in 4, a standing wall 84 having a required height may be provided. According to this, the entire rotating plate 8 is made thin and lightweight, and the actual plate thickness of the opening side surface 8a on the upstream side in the rotating direction is increased. The moving distance of the oil content in the plate thickness direction can be X or more.

(Third Embodiment)
As shown in FIG. 6, when the upper end of the vertical wall 84 (see FIG. 5) in the second embodiment is further bent in the rotational downstream direction, the oil content adhering to and collected on the opening side surface 8a on the upstream side in the rotational direction is released. It is captured by the bent corner portion 85 without being mixed in the exhaust flow again, and is reliably guided in the outer peripheral direction (front side of the paper surface) of the rotating plate 8 in the captured state.

(Fourth Embodiment)
As shown in FIG. 7, a plurality of openings 86 having the same shape are formed on the plate surface of the rotating plate 8 at intervals in the circumferential direction. The opening width W of the formed opening 86 is gradually widened from the inner peripheral side to the outer peripheral side. According to this, the opening area of the rotating plate can be increased to reduce the pressure loss of the exhaust gas. Further, the moving distance X of the oil content in the plate thickness direction (see the above equations (2) and (3)) can be made substantially constant from the inner peripheral side to the outer peripheral side, and the entire surface of the opening side surface 8a on the upstream side in the rotational direction of each opening 86 can be made substantially constant. Can be effectively used for collecting oil.

(Fifth Embodiment)
As shown in FIG. 8, the opening 86 of the rotary plate 8 shown in the fourth embodiment penetrates the rotary plate 8 radially outward from the opening side surface 8a on the upstream side in the rotational direction and opens to the outer peripheral surface thereof ( FIG. 9) An oil lead-out hole 861 is provided. According to this, the oil adhering to and collected on the side surface 8a of the opening is smoothly discharged in the outer peripheral direction through the oil lead-out hole 861 by centrifugal force. Of course, such an oil component lead-out hole may be provided in each elongated hole opening (see FIG. 2) shown in the first embodiment.

(Sixth Embodiment)
In the present embodiment, as shown in FIG. 10, each opening 86 (see FIG. 7) in the fourth embodiment is opened outward to form a notch opening 87, and the notch opening 87 is on the upstream side in the rotation direction. An oil component lead-out groove 871 extending outward in the radial direction is formed on the side surface 8a of the opening as shown in FIG. As a result, the oil adhering to and collected on the side surface 8a of the opening is smoothly discharged in the outer peripheral direction through the oil lead-out groove 871 by centrifugal force.

As shown in FIGS. 11 (1) to 11 (3), the cross-sectional shape of the oil content lead-out groove 871 may be a hook-shaped cross section capable of capturing more oil content Op from the semicircular cross section. Further, each elongated hole opening 81 to 83 shown in the first embodiment is opened outward to form a notch opening, and an oil content lead-out groove similar to the above is formed on the opening side surface on the upstream side in the rotation direction of these notch openings. You may do so. Further, the structure shown in the first embodiment and the fourth embodiment may be provided with the oil content outlet groove 871 and the oil component outlet 861 (see FIG. 8) so as to communicate with the oil component outlet groove 871 without forming a notch opening. good.

(Other embodiments)
The shapes of the elongated hole opening and the notch opening are not limited to those shown in the above embodiment.
The oil collecting device of the present invention is not limited to the exhaust system of an industrial furnace, and can be used by incorporating it into a ventilation device for a kitchen or the like.
The surface of the rotating plate may be surface-treated to promote peeling of oil. Further, by providing a heater on the rotating plate and maintaining the surface temperature thereof high, the viscosity of the oil component adhering to the rotating plate may be kept low so that the heater can be quickly separated from the surface of the rotating plate. In this way, cleaning of dirt due to oil adhesion on the rotating plate can be reduced.

8 ... Rotating plate, 8a ... Open side surface, 81, 82, 83 ... Long hole opening (opening), 84 ... Standing wall, 85 ... Bending corner, 86 ... Opening, 861 ... Oil outlet, 87 ... Notch opening, 871 ... Oil lead-out groove, T ... Plate thickness (length in the exhaust flow direction), Vc ... Peripheral speed, Vg ... Exhaust flow velocity, W ... Width (length in the direction of the rotating plate), Ps ... Exhaust flow path.

Claims (8)

A rotating plate is arranged in the exhaust flow path so as to cross the rotating plate, an opening is formed on the plate surface of the rotating plate, and the length of the side surface of the opening on the upstream side in the rotation direction in the exhaust flow direction is determined. The oil content contained in the exhaust flow passing through the opening is set to a predetermined dimension equal to or larger than the dimension determined by the peripheral speed of the rotating plate, the exhaust flow velocity passing through the opening, and the length of the opening in the circumferential direction of the rotating plate. Is captured by the opening side surface, and then led out toward the outer peripheral direction of the rotating plate. The oil collecting device according to claim 1, wherein a vertical wall is provided on the opening edge on the upstream side in the rotation direction of the opening so as to increase the length of the side surface of the opening in the exhaust flow direction. The oil collecting device according to claim 2, wherein the tip of the standing wall is further bent to the downstream side in the rotation direction of the rotating plate, and the oil content is captured at the bending corner portion and led out to the outer peripheral direction of the rotating plate. The oil collecting device according to any one of claims 1 to 3, wherein the opening is an elongated hole opening extending in the radial direction of the rotating plate with a constant length in the circumferential direction of the rotating plate. The oil collecting device according to any one of claims 1 to 3, wherein the opening is an opening extending in the radial direction of the rotating plate while the length in the circumferential direction of the rotating plate gradually expands. The oil collecting device according to claim 1 to 5, wherein an oil content lead-out hole is provided which penetrates outward in the radial direction of the rotating plate from the opening side surface on the rotation upstream side of the opening and opens on the outer peripheral surface of the rotating plate. The oil collecting device according to claim 1 to 5, wherein the opening is a notched opening that opens outward in the radial direction of the rotating plate. The oil collecting device according to any one of claims 1 to 7, wherein an oil lead-out groove extending outward in the radial direction of the rotating plate is formed on the side surface of the opening on the rotation upstream side of the opening.

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