JP5772740B2 - Dust collector - Google Patents

Description

  The present invention relates to a dust collector used in a coke dry digestion facility (CDQ: Coke Dry Quenching) or the like.

  The coke dry digestion equipment is a technique for charging red hot coke discharged from a coke oven into the chamber from the top, blowing a cooling gas from the bottom of the chamber, and cooling the red hot coke by heat exchange with the cooling gas. In such a coke dry digestion facility, the cooling gas blown from the bottom of the chamber rises while cooling the coke that gradually descends in the chamber, and is discharged from the top of the chamber. The discharged cooling gas (exhaust gas) is heated by heat exchange with coke, and the temperature reaches, for example, 800 ° C. or higher.

  Therefore, it is common to send exhaust gas to a boiler, recover heat, and blow it into the chamber again as cooling gas. By circulating the gas and recovering heat, the sensible heat of red hot coke can be used effectively. However, since the exhaust gas collected from the chamber contains a lot of dust due to coke, if it is sent to the boiler as it is, the equipment of the boiler will be worn out due to the dust. Therefore, as described in Patent Documents 1 and 2 below, a dust collecting device for removing dust from the exhaust gas is installed.

  The hopper-type dust collection device described in Patent Document 1 is provided with a collision plate that blocks the flow of exhaust gas flowing through the flue, and collects the dust that collides with the collision plate by a hopper formed below. is there. Furthermore, in the technique described in Patent Document 1, the dust collection rate is improved by forming the side plate on the downstream side of the hopper portion vertically or by expanding the width of the flue at the collision plate mounting portion. It has been tried. On the other hand, in the technique described in Patent Document 2, the dust collection rate is improved by using a hot cyclone as the dust collection device.

JP-A-7-268344 JP-A-7-268341

  However, in the technique described in Patent Document 2, although the dust collection rate is improved, the hot cyclone has a relatively short device life, and therefore the replacement cost of the dust collection device itself is increased. Therefore, in terms of cost, a hopper type dust collecting device as described in Patent Document 1 is advantageous. However, even if an improvement as described in Patent Document 1 is added, a part of the dust collected in the hopper part is scattered again and returned to the exhaust gas flow, and as a result, the dust collection rate is sufficient. I could not say.

  Therefore, the present inventors have investigated the cause of the re-scattering of dust in the hopper type dust collector using numerical fluid analysis. As a result, as described later, it was found that dust re-scattered due to the occurrence of drift of exhaust gas in the flue.

  The present invention has been made on the basis of such knowledge, and an object of the present invention is to prevent dust re-scattering by suppressing the drift of exhaust gas in a hopper type dust collecting device. It is an object of the present invention to provide a new and improved dust collection device capable of improving the collection rate.

In order to solve the above problems, according to one aspect of the present invention, dust in exhaust gas flowing through a flue via an annular channel is formed in the flue under a collision plate that blocks the flow of the exhaust gas and the collision plate. A dust collecting device for collecting using a hopper portion, wherein a dust plate is provided in a flue to divide and guide the flow of exhaust gas in the left-right direction. Is provided.

  By arranging the flow straightening plate in the flue, the drift of the exhaust gas in the left-right direction at the dust collecting unit including the collision plate and the hopper is prevented. Therefore, dust re-scattering is suppressed, and as a result, the dust collection rate is improved.

  In the above dust collecting apparatus, the rectifying plate may be installed, for example, between the entrance of the flue and the hopper, or may be installed in the hopper. In any case, by preventing the drift of the exhaust gas, it is possible to suppress dust re-scattering and improve the dust collection rate.

  As described above, according to the present invention, in the hopper type dust collecting device, it is possible to prevent the dust from re-scattering by suppressing the drift of the exhaust gas, and to improve the dust collecting rate.

It is a figure showing the whole coke dry digestion equipment composition concerning a 1st embodiment of the present invention. 1 is a partial perspective view of a coke dry digestion facility according to a first embodiment of the present invention. It is AA sectional drawing of FIG. It is sectional drawing similar to FIG. 3A in the comparative example in which a baffle plate is not provided. It is a fragmentary perspective view of the coke dry-digestion equipment which concerns on the 2nd Embodiment of this invention. It is a graph which shows the result of the simulation concerning the example of the present invention.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
First, a first embodiment of the present invention will be described with reference to FIGS. 1, 2, 3A, and 3B. In the present embodiment, in the coke dry digestion facility, a rectifying plate is disposed between the inlet of the flue and the hopper.

  FIG. 1 is a diagram showing an overall configuration of a coke dry digestion facility according to a first embodiment of the present invention. The coke dry digestion equipment 1 is provided with a chamber 2. The red hot coke is charged from the top of the chamber 2 and gradually descends from the pre-chamber 2a to the cooling chamber 2b. On the other hand, cooling gas is blown from the bottom of the chamber 2. The injected cooling gas cools the coke while rising in the cooling chamber 2b.

  The cooling gas heated by heat exchange with the coke is discharged to the annular channel 3 through a gas discharge port (not shown) provided in the upper part of the cooling chamber 2b. The annular channel 3 is a channel provided around the chamber 2 and has an annular horizontal cross section. The discharged cooling gas (exhaust gas) further flows into the flue 4 communicating with the annular channel 3. A hopper-type dust collector 5 is provided in the middle of the flue 4 to remove dust in the exhaust gas. In the present embodiment, a rectifying plate is provided in the flue 4 in order to prevent the drift of the exhaust gas in the dust collection unit 5. The details of the current plate will be described later together with the internal structure of the flue 4.

  The exhaust gas that has undergone primary dust removal in the dust collection unit 5 continues to flow through the flue 4 and is sent to the boiler 6. At this time, if a large amount of dust remains in the exhaust gas, the wear of equipment such as the piping inside the boiler 6 becomes serious, so it is important to effectively remove the dust in the exhaust gas by the dust collecting unit 5. . The exhaust gas heat-recovered by the boiler 6 is subjected to secondary dust removal and then blown again from the bottom of the chamber 2 by the blower 7 as cooling gas.

  FIG. 2 is a partial perspective view of the coke dry digestion facility according to the first embodiment of the present invention. In the figure, an annular channel 3, a flue 4, a dust collector 5, and a boiler 6 are shown. As described above, the cooling gas (exhaust gas) discharged from the cooling chamber 2 b to the annular channel 3 flows through the flue 4 and is sent to the boiler 6. At this time, the dust in the exhaust gas is removed by the dust collector 5 provided in the middle of the flue 4. 2, 3 </ b> A, and 3 </ b> B, illustration of the chamber 2 and piping inside the boiler 6 is omitted.

  The dust collecting unit 5 is provided with a collision plate 8 and a hopper unit 9. The collision plate 8 is disposed so as to be orthogonal to the flow of the exhaust gas flowing in the flue 4 in a substantially horizontal direction. The exhaust gas flowing through the flue 4 is blocked by the collision plate 8 and changes the flow direction downward. At this time, the dust in the exhaust gas falls by inertial collision with the collision plate 8.

  The fallen dust is collected by a hopper portion 9 formed below the collision plate 8. Here, the hopper portion 9 is a portion where the bottom surface of the flue 4 protrudes downward to form a funnel-shaped hopper. On the other hand, the exhaust gas bypasses the lower end of the collision plate 8 and further flows through the flue 4 to reach the boiler 6. An arc-shaped notch as shown in the figure may be formed in the lower part of the collision plate 8 so that the exhaust gas can easily bypass.

  Furthermore, in this embodiment, the flow path 10 which divides | segments the flow of waste gas into the left-right direction and guides it in the flue 4 is provided. The rectifying plate 10 is installed between the inlet of the flue 4 and the hopper portion 9 formed in the flue 4 in parallel with the flow of the exhaust gas.

  Note that the “left-right direction” in the present specification means the left-right direction when the traveling direction of the exhaust gas flow, that is, the direction connecting the annular channel 3 and the boiler 6 is the front-rear direction. In FIG. 2, the front-rear direction is illustrated as the x-axis direction, the left-right direction is the y-axis direction, and the up-down direction is illustrated as the z-axis direction. In this description, the mouth of the flue 4 on the annular channel 3 side is the inlet, and the mouth of the boiler 6 side is the outlet.

  The arrangement of the rectifying plate 10 is not limited to the illustrated example, and various variations are possible. For example, in terms of length, the rectifying plate 10 may reach the inlet of the flue 4 or may be installed at a distance from the inlet as shown. Further, as shown in the figure, the rectifying plate 10 may be installed so as not to cover the inclined portion reaching the hopper portion 9 of the flue 4, or may be installed so that at least a part thereof covers the inclined portion. .

  On the other hand, regarding the height, it is desirable that the rectifying plate 10 is installed such that there is a gap between the upper end and the ceiling surface of the flue 4 in consideration of thermal expansion due to the influence of high-temperature exhaust gas. In order to improve the rectifying action, the gap may be filled with glass wool or elastic joint material. Further, the number of rectifying plates 10 is not necessarily limited to one, and may be two or more.

  In the present embodiment, due to the action of the rectifying plate 10, dust re-scattering due to the occurrence of a lateral drift of the exhaust gas flow in the dust collector 5 is suppressed, and as a result, the dust collection in the dust collector 5. The rate is improved. This point is further described below with reference to FIGS. 3A and 3B.

  3A is a cross-sectional view taken along the line AA in FIG. FIG. 3B is a cross-sectional view similar to FIG. 3A in a comparative example in which a current plate is not provided. As shown in FIG. 3B, Karman vortices are generated in the exhaust gas flowing through the flue 4 when the current plate is not provided. Therefore, the flow rate of the exhaust gas in the flue 4 becomes non-uniform in the left-right direction, and as a result, in the dust collecting unit 5, a drift occurs in which the exhaust gas flow is biased to the left or right side. Due to this uneven flow, a part of the dust collected by the hopper unit 9 rescatters and returns to the exhaust gas flow.

  On the other hand, as shown in FIG. 3A, when the rectifying plate 10 is provided, the rectifying plate 10 divides the flow of the exhaust gas in the left-right direction and guides the generation of Karman vortices in the exhaust gas flowing through the flue 4. It is suppressed. Therefore, the flow rate of the exhaust gas in the flue 4 becomes substantially uniform in the left-right direction. Therefore, it is possible to prevent the dust collected by the hopper 9 from re-scattering.

  The occurrence of drift in the flue 4 as described above has not been found in the steady analysis by the conventional half model. The present inventors pay attention to the fact that such conventional analysis does not match the actual behavior of dust in the exhaust gas in the coke dry digestion facility 1, and as a result of conducting a transient analysis by a full model, the drift due to Karman vortex Found outbreak of. In the present embodiment, the Karman vortex is generated when the exhaust gas passes through the annular channel 3 before flowing into the flue 4.

  In 1st Embodiment of this invention demonstrated above, the dust collection rate in a dust collection part improves by arrange | positioning a baffle plate between the entrance of a flue and a hopper part. As a result, dust that reaches the boiler together with the exhaust gas is reduced, and wear of the boiler equipment can be prevented.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, a baffle plate is installed in the hopper part of a flue. In addition, about the whole structure of a coke dry-digestion equipment, since it can be set as the structure similar to said 1st Embodiment, detailed description is abbreviate | omitted.

  FIG. 4 is a partial perspective view of a coke dry digestion facility according to a second embodiment of the present invention. In the figure, the annular channel 3, the flue 4, the dust collection part 5, and the boiler 6 are shown similarly to said FIG.

  Also in the present embodiment, the flue 4 is provided with the rectifying plate 11 that divides and guides the flow of the exhaust gas in the left-right direction. The rectifying plate 11 is installed in the lower part of the hopper portion 9 formed in the flue 4 in parallel with the flow of the exhaust gas. The rectifying plate 10 in the first embodiment described above suppresses the generation of the left and right Karman vortices in the portion of the flue 4 in front of the dust collecting part 5, thereby causing dust due to drift in the dust collecting part 5 The rectifying plate 11 in the present embodiment prevents the re-scattering of the dust by directly suppressing the occurrence of the lateral drift in the dust collecting unit 5.

  In addition, since the collision board 8 is installed above the hopper part 9, the baffle plate 11 and the collision board 8 oppose in the state orthogonal to each other. In consideration of thermal expansion due to the effect of high-temperature exhaust gas, it is desirable to provide a gap between the upper end of the rectifying plate 11 and the lower end of the opposing collision plate 8. As shown in the figure, the rectifying plate 11 may be a large one having a relatively small gap with the lower end of the collision plate 8 or a small one having a large gap with the collision plate 8. May be.

  In the second embodiment of the present invention described above, the dust collection rate is improved by arranging the current plate in the hopper portion of the flue provided as the dust collection portion. As a result, dust that reaches the boiler together with the exhaust gas is reduced, and wear of the boiler equipment can be prevented.

  Next, examples of the present invention will be described. In the following example, numerical fluid analysis is performed between an example in which two types of rectifying plates according to each of the first embodiment and the second embodiment are installed and a comparative example in which no rectifying plate is installed. The simulated dust collection rates were compared.

As analysis conditions, the cross section of the flue was about 6 m wide, about 4 m high, and the circulating cooling gas flow rate was 28.5 × 10 ⁴ Nm ³ / h. The dust to be analyzed is dust having a diameter of 500 μm, which has a great influence on the wear of the boiler equipment and whose dust collection rate is greatly affected by the drift. Furthermore, the wall surface restitution coefficient e in the flue was simulated for two types: 0.2 and 0.5. The wall surface restitution coefficient varies depending on the adhesion of dust to the wall surface.

  FIG. 5 is a graph showing the results of the above simulation. In the “comparative example”, the current plate is not provided. In “Example 1”, as described in the first embodiment, a current plate is provided between the inlet of the flue and the hopper. In “Example 2”, as described in the second embodiment, a current plate is provided in the hopper portion of the flue.

  As shown in the graph, in the comparative example, the dust collection rate, which was in the latter half of the 30% range, is improved to about 50% in both Example 1 and Example 2. This result can be said that the installation of the current plate in the embodiment of the present invention is effective in improving the dust collection rate. As described above, the dust having a diameter of 500 μm that is the object of this simulation is a dust that has a great influence on the wear of the boiler equipment. Therefore, an improvement in the collection rate of dust with this diameter has a great effect in preventing wear of the boiler equipment.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Coke dry-digestion equipment 2 Chamber 3 Annular channel 4 Flue 5 Dust collection part 6 Boiler 7 Blower 8 Collision board 9 Hopper part 10,11 Current plate

Claims (3)

A dust collector that collects dust in exhaust gas flowing through a flue through an annular channel using a collision plate that blocks the flow of the exhaust gas and a hopper formed in the flue below the collision plate. There,
A dust collecting device, characterized in that a rectifying plate is provided in the flue to divide and guide the flow of the exhaust gas in the horizontal direction of the flow.   The dust collector according to claim 1, wherein the current plate is installed between an inlet of the flue and the hopper portion. The dust collecting device according to claim 1, wherein the current plate is installed in the hopper portion.

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