JP7522486B2 - Flue gas reformer and flue gas treatment device equipped with same - Google Patents

Description

The present invention relates to a flue gas reformer for efficiently treating flue gas containing large amounts of oil mist emitted from restaurant kitchens, yakiniku restaurants, yakitori restaurants, etc., and a flue gas treatment device equipped with the same.

Generally, the smoke generated in restaurant kitchens and yakiniku and yakitori shops contains a lot of oil (oil mist), so the exhaust duct through which it flows requires a filter or oil separator to separate and remove the oil. Conventionally, filters for separating oil from exhaust smoke have often been made of metal using a metal mesh, as well as nonwoven fabric filters such as those shown in Patent Document 1 below.

On the other hand, oil separators other than filters include, for example, a baffle type, an inverted baffle type as shown in the following Patent Document 2, and a type equipped with a spiral passage composed of spiral blades. Furthermore, the following Patent Documents 3 and 4 propose placing one or more windmill-shaped devices with multiple blades around a rotating shaft inside the exhaust duct, and rotating these to capture and centrifuge the oil mist in the flue gas flowing through the exhaust duct.

JP 2000-24433 A Japanese Unexamined Patent Publication No. 60-34713 JP 2002-239323 A JP 2012-120947 A

However, with conventional filter methods, if the oil separated from the filter accumulates, the filter becomes clogged, which requires frequent cleaning and replacement, which is a hassle. On the other hand, with oil separators that use baffles or centrifugal separation, the oil separated from the flue gas adheres thickly to the baffles, the surface of the wind turbine, and the inside of the exhaust duct, which means that these areas must be disassembled and extensive cleaning work must be carried out periodically.

Therefore, the present invention was devised to solve these problems, and its main objective is to provide a new flue gas reformer and flue gas treatment device equipped with the same that can efficiently treat flue gas containing a large amount of oil and significantly reduce the frequency of exhaust duct cleaning work, etc.

To solve the above problems, the first invention is a flue gas reformer that includes a cylindrical casing through which flue gas flows and a windmill-shaped rotating member positioned across the casing, the rotating member being made up of a motor, a hub attached to the rotating shaft of the motor, and multiple rods extending radially from the hub.

With this configuration, when exhaust smoke containing oil mist (oil mist) generated inside the store or kitchen is flowed from the exhaust duct into the casing, the rotating member inside the casing is rotated at high speed, causing the multiple rods to collide violently with the oil mist in the exhaust smoke, breaking it down even further and changing the particle size from mist to gas. As a result, the oil mist does not adhere to the inner walls of the casing or the surface of the rotating member, but is instead flowed downstream together with the exhaust gas and released into the atmosphere, so it does not adhere to the inner walls of the exhaust duct, and the frequency of cleaning work, etc. can be significantly reduced.

The second invention is the flue gas reformer of the first invention, characterized in that the rotating member has a first group of rods located at the axial front end of the hub and a second group of rods located at the axial rear end of the hub. With this configuration, more oil mist in the flue gas collides with each rod, accelerating the reforming of the mist into a gaseous state.

The third invention is a flue gas reformer according to the first or second invention, characterized in that a spiral groove is formed on the surface of each of the rods. With this configuration, unevenness is formed on the rod surface, so that the Karman vortex that occurs on the rear side of the rod in the rotation direction, i.e., air resistance, is reduced, allowing the rod to rotate at high speed even with a small driving force. This increases the impact force and contact area between the rod and the oil mist, accelerating the reforming into a gaseous state. In addition, the noise of the rotating parts caused by air resistance can also be suppressed.

The fourth invention is an exhaust gas treatment device characterized in that an exhaust gas duct is provided with an exhaust gas reformer according to any one of claims 1 to 3, an electric dust collector, a blower, and a deodorizer, in that order from the upstream side in the flow direction of the exhaust gas. With this configuration, even exhaust gas containing a large amount of oil mist from restaurants with fryers, yakiniku restaurants, yakitori restaurants, etc. can be effectively treated because not only can the amount of oil adhering to the exhaust gas duct be greatly reduced, but also the soot and odorous components contained in the exhaust gas can be removed.

According to the present invention, the oil mist in the exhaust gas containing oil mist (oil mist) is broken down into small particles and reformed into a gaseous form, so that the oil mist does not adhere to the inner walls of the casing or the surfaces of the rotating parts, but is instead carried downstream together with the exhaust gas and released into the atmosphere. This prevents oil from adhering to the inner walls of the exhaust duct, and significantly reduces the frequency of cleaning work for the exhaust duct.

1 is a perspective view showing an embodiment of a flue gas reformer 100 according to the present invention. 1 is a front view showing an embodiment of a flue gas reformer 100 according to the present invention. 3 is a cross-sectional view taken along line AA in FIG. 2. FIG. 4 is a partial enlarged view showing a portion S in FIG. 3 . FIG. 4 is an exploded view of part S in FIG. FIG. 2 is a conceptual diagram showing the modification of oil mist. 1 is an explanatory diagram showing an embodiment of a flue gas treatment device 200 according to the present invention.

Embodiments of the present invention will now be described with reference to the accompanying drawings. Figures 1 to 6 show one embodiment of a flue gas reformer 100 according to the present invention, and Figure 7 shows one embodiment of a flue gas treatment device 200 incorporating the flue gas reformer 100. First, as shown in Figure 7, the flue gas reformer 100 constitutes part of the flue gas treatment device 200 installed in an exhaust duct D extending from the interior of the store or the kitchen.

That is, the flue gas treatment device 200 is configured by connecting the flue gas reformer 100 according to the present invention, the electric dust collector 300, the blower 400, and the deodorizer 500 in this order from the upstream side in the flow direction of the flue gas (room smoke). The structure and operation of the flue gas reformer 100 will be described in detail later, but it mainly reforms the oil mist contained in the flue gas and sends it to the electric dust collector 300. The electric dust collector 300 applies an electric charge to fine particles of various dust particles such as soot contained in the flue gas, and collects them by attracting them to the dust collecting electrode.

The blower 400 sucks smoke generated inside the store or kitchen into the exhaust duct D together with the indoor air and releases it outside, and is composed of, for example, a motor-driven sirocco fan. The deodorizer 500 adsorbs or decomposes the odorous components in the exhaust smoke to eliminate odors, and is composed of, for example, multiple layers of deodorizing filters made of porous plates carrying activated carbon or air catalysts.

Therefore, according to this exhaust smoke treatment device 200, as shown in FIG. 7, indoor smoke generated in a store or kitchen is sucked into the exhaust duct D together with indoor air by the suction force of the blower 400, and then passes through the exhaust smoke reformer 100 to reform the oil mist contained therein, and then passes through the electric dust collector 300 to remove various dust particles such as soot, and purify the exhaust gas into colorless and transparent exhaust gas. The exhaust gas leaving the electric dust collector 300 then passes through the chamber 410 and the blower 400 in order, and is sent to the deodorizer 500, where the odorous components are removed or decomposed, and the colorless and odorless gas is released into the atmosphere.

As shown in Figures 1 to 3, this flue gas reformer 100 is composed of a cylindrical casing 110 and a windmill-shaped rotating member 120 positioned so as to traverse the inside of this casing 110. This casing 110 is open at both ends, one of which is a flue gas inlet 111 that communicates with the exhaust duct D, and the other is a flue gas outlet 112 that communicates with the electric dust collector 300. An annular flange 113 is provided on the periphery of this flue gas inlet 111, and as shown in Figure 3, the exhaust duct D is connected to the inlet of the electric dust collector 300 so as to sandwich this flange 113, so that it traverses the inside of this exhaust duct D.

The rotating member 120 is composed of a motor 121, a hub 123 attached to the rotating shaft 122 of the motor 121, and a number of rods R extending radially from the hub 123. The rotating member 120 further has a first rod group R1 attached to the axial front end (smoke exhaust outlet 112 side) of the hub 123, and a second rod group R2 attached to the axial rear end (smoke exhaust inlet 111 side) of the hub 123, as shown in FIG. 4.

Each rod R that makes up the rod groups R1 and R2 is made of a high-strength, highly corrosion-resistant metal bar (round bar) such as stainless steel, with a diameter of, for example, 1 to 1.5 mm and a length of 100 to 200 mm. Approximately 100 rods in each rod group R1 are attached radially to the hub 123 at roughly the same angle, for a total of approximately 200 rods. As shown in the figure, each rod R has a spiral groove g formed on its surface.

Figure 5 is an enlarged cross-sectional view of the hub 123 when disassembled. The hub 123 is composed of a disk-shaped hub body 12a to which the rotating shaft 122 of the motor 121 is connected, and a pair of fixing plates 12b, 12b attached to both sides of the hub body 12a with bolts B. The rods R are attached and fixed radially around the hub body 12a by fitting the roots of the rods R into a plurality of mounting grooves 12c formed along the edges of both sides of the hub body 12a and then attaching the fixing plates 12b, 12b. The roots of the rods R are bent in an L-shape, and the tips of the rods R are inserted and fitted into the holes of the mounting grooves 12c to prevent them from falling out of the hub body 12a even when pulling or centrifugal forces are applied.

The flue gas reformer 100 of the present invention, which has such a configuration, performs its function by rotating the rotating member 120 inside the casing 110 at high speed by the motor 121 when indoor smoke containing oily mist (oil mist) generated inside a store or kitchen is flowed from the exhaust duct D into the casing 110 as shown in Figure 5. In other words, when the rotating member 120 is rotated at high speed, the multiple rods R collide violently with the oil mist in the flue gas, which breaks it down further as shown in Figure 6, and the particle size is reformed from mist to gas.

The particle size of oil mist generated inside stores and kitchens varies depending on the source, but most are generally around 0.1 to 10 μm. Of these, particles with a diameter of 4 μm or more are particularly susceptible to the effects of inertia and gravity, and are known to separate from the exhaust gas flow and collide with and adhere to the inner walls of exhaust ducts. Oil separators that use the conventional baffle or inverted baffle method make use of this phenomenon.

In consideration of such a phenomenon, the flue gas reformer 100 of the present invention is designed to break down the oil mist into particles of 0.1 μm or less by rotating a windmill-shaped rotating member 120 having many rods R at high speed in the flue gas containing oil mist, as shown in FIG. 6. This reduces the particle size of the mist-like oil, which has a large particle size, to a gaseous state, making it easier to flow along with the flow of the exhaust gas, and significantly reduces the amount of oil that adheres to the inner walls of the exhaust duct D, etc. Then, the gaseous oil that flows downstream of this flue gas reformer 100 is released into the atmosphere together with the exhaust gas, with almost no adhesion to the electric dust collector 300, blower 400, deodorizer 500, etc.

As a result, the amount of oil adhering to the exhaust duct D is significantly reduced, allowing for a significant reduction in the frequency of cleaning work. Note that there is no particular restriction on the type of windmill-shaped rotating member 120, and it will vary depending on the amount of oil mist generated, but as a result of numerous demonstration experiments, good reforming results were obtained in the range of approximately 1000 to 2000 rpm for smoke generated at yakiniku and yakitori restaurants.

In addition, by forming a spiral groove g on the surface of each rod R, unevenness is formed over the entire surface of the rod R. As a result, a special air flow is generated on the rear side of the rotation (movement) direction of the rod R, i.e., the generation of a Karman vortex, which reduces air resistance, allowing the rod R to rotate at high speed even with a small driving force. This increases the collision force and contact area between the rod R and the oil mist, which breaks the oil mist down more finely and promotes its reformation into a gaseous state. Furthermore, the reduced air resistance also reduces the noise (wind noise) of the rotating member 120.

In this embodiment, the first rod group R1 and the second rod group R2 are provided at the front and rear axial ends of the hub 123 of the rotating member, respectively, to crush the oil mist in multiple stages, two times in the front and rear of the gas flow direction. However, if the number of rod groups is further increased to crush the oil mist three or more times, a more significant reforming effect can be obtained. In addition, the rods R of the first rod group R1 and the second rod group R2 can be offset in the flue gas flow direction to achieve more efficient reforming.

Reference Signs List 100: Exhaust gas reformer 110: Casing 111: Exhaust gas inlet 112: Exhaust gas outlet 120: Rotating member 123: Hub 12a: Hub body 12b: Fixing plate 12c: Mounting groove 200: Exhaust gas treatment device 300: Electric dust collector 400: Blower 500: Deodorizer D: Exhaust duct R: Rod R1: First rod group R2: Second rod group g: Groove

Claims (4)

The flue gas exhaust fan has a cylindrical casing through which flue gas flows, and a windmill-shaped rotating member disposed so as to traverse the casing.
The rotating member of this flue gas reformer is characterized in that it comprises a motor, a hub attached to the rotating shaft of the motor, and a plurality of round rods extending radially from the hub to collide with the oil mist in the flue gas flowing inside the casing and reduce its particle diameter . The flue gas reformer according to claim 1,
The flue gas reformer according to claim 1, wherein the rotating member has a first group of rods located at an axial front end of the hub and a second group of rods located at an axial rear end of the hub. The flue gas reformer according to claim 1 or 2,
A flue gas reformer characterized in that a spiral groove is formed on the surface of each of said rods. An exhaust gas treatment device characterized in that an exhaust gas duct is provided with an exhaust gas reformer according to any one of claims 1 to 3, an electric dust collector, a blower, and a deodorizer, in that order from the upstream side in the flow direction of the exhaust gas.

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