JPH11290633A - Wet dust collector - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent the adhesion and accumulation of dust clumps on the tower wall of a separation tower without requiring a complicated tower wall washing mechanism, and to reduce the amount of wastewater. To provide a wet dust collector that can A separation tower (1) for separating fine particles from a processing gas, a narrowing section (3) having a narrow flow path cross-section, and a means (4) for supplying a cleaning liquid for collecting the processing gas are provided in the middle of a pipe. And a wet-type dust collector in which the open end of the inlet pipe 2 is located inside the separation tower 1 in a fixed type with a predetermined interval below the open end. A swirling flow applying device 9 is provided so as to apply a swirling flow to the processing gas discharged from the opening end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet dust collector for separating and removing dust and mist in a gas by droplets, liquid films or the like generated from a cleaning liquid, and more particularly to a wet dust collector for exhaust gas from a blast furnace, a converter and the like. The present invention relates to a wet dust collector for collecting dust and mist.

[0002]

2. Description of the Related Art Conventionally, in order to collect dust and mist in exhaust gas from a blast furnace, a converter, etc., a wet type dust collector which cleans the exhaust gas by supplying a cleaning liquid such as water to the exhaust gas under pressure has been used. Have been.

FIG. 6 shows a schematic sectional view of such a conventional wet dust collector. 6, reference numeral 1 denotes a hopper-shaped separation tower, 2 denotes an inlet pipe for exhaust gas and a cleaning liquid inserted into the separation tower 1 and one end of which is open, and 3 denotes a throttle provided at a predetermined position in the inlet pipe 2. Reference numerals 4 and 4 denote spray nozzles disposed immediately above the throttle unit 3 and supplying a cleaning liquid for dust collection.

[0004] As shown in the figure, a separator 5 for collecting minute dust and mist in the exhaust gas is provided horizontally between the tower wall of the separation tower 1 and the opening of the introduction pipe 2.
The inside of the separation tower 1 is divided into two. On the tower wall below the separator 5, a plurality of cleaning spray nozzles 6 for supplying a cleaning liquid for cleaning the tower wall are arranged along the periphery of the tower wall, as described later. By flowing down along the wall, dust clumps are prevented from adhering to the inverted conical tower wall at the bottom of the separation tower 1. Reference numeral 7 denotes a cleaning pipe for introducing a cleaning liquid for discharging the collected dust, and reference numeral 8 denotes a dust collection drain pipe for discharging the dust collected together with the cleaning liquid.

In the wet type dust collector shown in FIG. 6, the exhaust gas introduced into the separation tower 1 through the introduction pipe 2 is mixed with the cleaning liquid for dust collection from the spray nozzle 4, and the cross-sectional area of the flow path in the throttle unit 3 is reduced. By reducing the size to a high-speed gas flow, the dust-collecting cleaning liquid is made into fine droplets, and dust and mist in exhaust gas are attached to the droplets to collect dust. The dust and mist trapped in the droplets of the cleaning liquid for dust settle down at the lower part of the separation tower 1 and are discharged to the outside through the dust collection drain pipe 8 together with the cleaning liquid supplied from the cleaning pipe 7.

The exhaust gas after dust and mist separation is:
After the separator 5 collects very fine dust, mist, and the like that have not been captured by the cleaning liquid for dust collection, the dust is exhausted to the outside.

[0007]

In the wet type dust collector of the type described above, the dust and mist trapped by the cleaning liquid for dust collection adhere to the inverted conical tower wall at the lower portion of the separation tower 1 and form a dust lump. Is easy to form. The dust clumps are enlarged with the increase of the operation time, and block the dust collecting drainage pipes 8. Also, various troubles such as a decrease in the separation efficiency of the separation tower 1 due to dusts separated from the dust clumps and the like are caused. Become.

Therefore, conventionally, as shown in FIG. 6, a plurality of cleaning spray nozzles arranged below the separation tower 1 supply a cleaning liquid for cleaning the tower wall, so that dust is applied to the tower wall of the separation tower. Prevents clumps from sticking.

However, in the above-mentioned method, a washing spray nozzle is disposed inside the separation tower and a supply system of a washing liquid for washing the wall of the tower is required, so that the wet dust collector is inevitably complicated and expensive. In addition, in order to check the operation status of the cleaning spray nozzle and the effect of cleaning the tower wall,
Periodic inspection and maintenance are required.

Further, since a cleaning liquid for cleaning the tower wall is required in addition to the cleaning liquid for collecting dust, the amount of wastewater is increased, and a large-scale wastewater treatment is required.

An object of the present invention is to solve the above-mentioned problems in the prior art. That is, an object of the present invention is to prevent the adhesion and accumulation of dust clumps on the tower wall of the separation tower without requiring a complicated tower wall washing mechanism, and to further reduce the amount of wastewater. It is to provide a wet dust collector.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a separation tower for separating fine particles from a processing gas, a narrowed section having a narrow flow path cross-sectional area, and a cleaning liquid for collecting the processing gas. Means and an inlet pipe for the processing gas provided in the middle of the pipeline, wherein the open end of the inlet pipe is located inside the separation tower, in the wet dust collector, below the open end, a predetermined This is achieved by providing a fixed type swirling flow applying device with an interval provided so as to apply a swirling flow to the processing gas discharged from the opening end.

[0013] The fixed type swirling flow applying device is provided with a plurality of outwardly extending spiral passages extending from a central portion to an outer peripheral direction, or a screw-shaped spiral wound around a fixed shaft at least half a turn or more. It can be of a type having blades.

[0014]

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

FIG. 1 is a schematic sectional view showing an example of an embodiment of a wet dust collector according to the present invention. Here, the same members as those in FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted.

In the embodiment shown in FIG. 1, a swirl flow is applied below the opening of the introduction pipe 2 to the processing gas to be introduced into the separation tower 1 from the introduction pipe 2 and subjected to the separation operation. Is provided.

As shown in FIG. 2 (a), the swirling flow applying device 9 is provided with a plurality of spiral passages 9a having a shape extending outward from a central portion to an outer peripheral direction.
As shown in (b), there is a type having a screw-shaped blade 9c wound around the fixed shaft 9b by a half turn. The blade 9c may be wound around the fixed shaft 9b by a half turn or more as necessary. The structure of the swirling flow applying device 9 is not particularly limited as long as it can convert the flow of the processing gas into the swirling flow, other than the above-described type, but the processing gas can be efficiently converted. In terms of being capable of converting into a swirling flow, a swirling flow applying device having a spiral processing gas flow path as shown in FIG. 2 is preferable. In addition, the material of the swirling flow applying device 9 is not particularly limited as long as it has corrosion resistance to a processing gas or a cleaning liquid and can be used for a long period of time. It is preferable to make it.

When dust and mist are collected using the wet dust collector of FIG. 1, the cleaning gas for dust collection from the spray nozzle 4 is added to the processing gas introduced into the separation tower 1 through the introduction pipe 2. The mixed gas of the processing gas and the cleaning liquid is made into a high-speed gas flow by mixing and reducing the cross-sectional area of the flow path in the throttle unit 3. The high-speed gas flow collides with the swirling flow applying device 9 from the opening end of the introduction pipe 2 and flows along a spiral flow path formed in the spiral flow applying device 9 itself as shown in FIG. , Its traveling direction changes. Finally, the high-speed gas flow introduced directly downward from the opening of the introduction pipe 2 is converted into a high-speed spiral flow and injected toward the column wall of the separation tower 1. Therefore, even if the dust and mist trapped by the dust-collecting cleaning liquid supplied from the spray nozzle 4 approach the inverted conical tower wall at the lower part of the separation tower 1, the high-speed swirling gas flow existing around the tower wall Does not adhere to the tower wall due to the cleaning action. In addition, since the swirling flow is generated by the action of the high-speed swirling gas flow also in the washing liquid supplied from the washing pipe 7 and stored in the lowermost part of the separation tower 1, the vicinity of the dust collection drain pipe 8 is generated by the washing action of the swirling washing liquid. No dust clumps adhere to the surface.

FIG. 3 is a schematic sectional view showing another embodiment of the throttle unit 3 for converting a mixed gas of a processing gas and a cleaning liquid for dust collection into a high-speed gas flow. In the embodiment shown in FIG. 3, a supply pipe of the cleaning liquid for dust collection is disposed inside an annular throttle unit 3 that projects into the pipeline from the inner peripheral surface of the introduction pipe 2 at a predetermined position. The cleaning liquid for dust collection is sprayed from a plurality of nozzles 3a drilled on the side wall opening toward the center of the tube 3. The supply pressure and flow rate of the cleaning liquid for dust collection can be adjusted by a control mechanism (not shown).

FIG. 4 shows still another embodiment of the aperture section 3. As shown in FIG. In the embodiment shown in FIG. 4, a damper 10 is provided on a throat portion of a venturi-shaped introduction pipe 2 with a rotating shaft 10 a.
Is mounted so as to be rotatable around the
Is rotated by a predetermined angle, so that the flow path area of the introduction pipe 2 can be adjusted. Also, the damper 10 of the introduction pipe 2
A supply pipe for the cleaning liquid for dust collection is provided at a location corresponding to the above, and a nozzle 3a is open in an annular shape on the inner peripheral surface of the introduction pipe 2 facing the damper 10. Accordingly, the cleaning liquid for dust collection supplied from the supply pipe is injected into the introduction pipe 2 from the nozzle 3a. The point that the supply pressure and the flow rate of the cleaning liquid for dust collection can be adjusted by a control valve (not shown) is the same as in the embodiment of FIG.

FIG. 5 shows another embodiment of the wet dust collector according to the present invention. Here, the same members as those in FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted. FIG.
(A) is a wet dust collector of the type provided with the throttle unit shown in FIG. 3, FIG. 5 (b) is a wet dust collector of the type provided with the throttle unit shown in FIG. 4, and FIG. 5 (c) is FIG. 2) is a sectional view taken along line AA. The illustration of the supply pipe for the cleaning liquid for dust collection is omitted.

In the wet dust collector shown in FIG. 5, a preliminary separation tower 11 is provided above the separation tower 1 and
The embodiment differs from the embodiment shown in FIG. 1 in that the and the separation tower 1 are connected in series.

In a wet dust collector of the type shown in FIG. 5A, a first spray nozzle 4a, a first throttle portion 3a and a first swirling flow applying device 9-1 are provided in a preliminary separation tower 11. ing. At the lower part of the preliminary separation tower 11, an upper end of an introduction pipe 2 for conveying the processing gas to the separation tower 1 protrudes, is supplied from the first spray nozzle 4a, and captures dust and mist in the processing gas. The collected cleaning liquid for dust collection is stored in a space between the tower wall of the preliminary separation tower 11 and the upper end of the introduction pipe 2, and is disposed on the first side wall of the preliminary separation tower 11.
Is discharged to the outside through the dust collection drain pipe 8a.

On the other hand, in the wet type dust collector of the type shown in FIG. 5B, the connection of the pipe for introducing the processing gas to the preliminary separation tower 11 with the preliminary separation tower 11 is a Venturi-type first throttle section 3a. The damper 10 is rotatably disposed inside the pipe. In addition, in the lower part of the preliminary separation tower 11,
The upper end of the introduction pipe 2 for transporting the processing gas to the separation tower 1 protrudes, and is supplied from the first spray nozzle 4a to supply dust and mist in the processing gas, as in the type of FIG. The cleaning liquid for dust collection having adsorbed thereon is discharged to the outside via the first dust collection drainage pipe 8a disposed on the tower wall of the preliminary separation tower 11.

In the separation tower 1 shown in FIGS. 5 (a) and 5 (b), a second swirling flow applying device 9-2 is provided inside the separation pipe 1 as in the embodiment shown in FIG. The separator 5 is fixed below and divides the space inside the separation tower into two.

When dust and mist are collected by using the wet dust collector shown in FIG.
The cleaning gas for dust collection from the first spray nozzle 4a is mixed with the processing gas introduced into the nozzle, and the cross-sectional area of the flow path is reduced in the first throttle portion 3a to mix the processing gas and the cleaning liquid for dust collection. The gas is a high-speed gas stream. The high-speed gas flow collides with the swirling flow applying device 9-1, flows along a spiral flow path formed in the swirling flow applying device 9-1 itself, and changes its traveling direction. The dust and mist in the processing gas are captured by the flowing dust-collecting cleaning liquid, and are collected together with the dust-collecting cleaning liquid by the first dust collecting pipe 8a.
Is released to the outside through

The processing gas from which most of the dust and mist has been removed in the pre-separation tower 11 is passed through the introduction pipe 2 to the separation tower 1.
And mixed with the cleaning liquid for dust collection from the second spray nozzle 4b. Then, dust and mist in the processing gas are further removed inside the separation tower 1 by the same separation operation as in the case of FIG. The second spray nozzle 4b
The cleaning liquid for dust collection introduced into the introduction pipe 2 by the above is finally converted into a high-speed spiral flow by the second swirling flow applying device 9-2 and separated as shown in FIG. It is injected toward the tower wall of the tower 1.

Accordingly, dust captured by the dust-collecting cleaning liquid supplied from the second spray nozzle 4b,
Even if the mist approaches the inverted conical tower wall at the lower part of the separation tower 1, the mist does not adhere to the tower wall due to the cleaning action of the high-speed swirling gas flow existing around the tower wall. Since the spiral flow of the cleaning liquid for dust collection is also generated inside the preliminary separation tower 11 by the first swirling flow applying device 9-1, dust clumps may adhere to the tower wall of the preliminary separation tower 11 as well. There is no. And by continuously performing the operation of separating dust and mist from the processing gas by the separation tower, high removal efficiency can be achieved.

[0029]

The present invention has the following effects.

(1) adhesion of dust lumps to the tower wall of the separation tower,
Deposition can be effectively prevented.

(2) No complicated tower wall washing mechanism is required.

(3) The amount of wastewater required for removing dust and mist from the processing gas can be reduced.

(4) There is no need to install a manhole or the like in the separation tower and perform regular inspection and maintenance. (5) The dust and the like can be separated with high efficiency by continuously performing the operation of separating the dust and the mist as needed.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of an embodiment of a wet dust collector of the present invention.

FIG. 2 is a schematic perspective view showing a specific example of a swirling flow applying device 9.

FIG. 3 is a schematic cross-sectional view showing another embodiment of the throttle unit 3.

FIG. 4 is a schematic sectional view showing still another embodiment of the throttle unit 3.

FIG. 5 is a schematic sectional view showing another example of the embodiment of the wet dust collector of the present invention.

FIG. 6 is a schematic sectional view of a conventional wet dust collector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Separation tower 2 Inlet pipe 3 Throttle part 4 Spray nozzle 5 Separator 6 Cleaning spray nozzle 7 Cleaning pipe 8 Dust collection pipe 9 Swirl flow giving device 10 Damper

Continued on the front page (72) Inventor Tadayuki Uesuma 46-59 Nakahara Ohara, Tobata-ku, Kitakyushu Nippon Steel Plant Design Co., Ltd. (72) Inventor Tatsuhisa Iwata 46-59 Nakahara, Oaza Nakahara, Tobata-ku, Kitakyushu Design Inc.

Claims (3)

[Claims] 1. A separation tower for separating fine particles from a processing gas, a narrowed section having a narrow flow path cross-sectional area, and a unit for supplying a cleaning liquid for collecting the processing gas are provided in the middle of the pipe. A wet gas precipitator, wherein an open end of the inlet pipe is located inside the separation tower, wherein a fixed swirl flow is provided at a predetermined interval below the open end. A wet dust collector, comprising: an apparatus for applying a swirling flow to the processing gas discharged from the opening end. 2. The wet dust collector according to claim 1, wherein the fixed swirl flow applying device includes a plurality of outwardly extending spiral passages extending from a central portion to an outer peripheral direction. 3. The wet dust collector according to claim 1, wherein the fixed swirling flow applying device includes a screw-shaped blade wound at least half a turn around a fixed shaft.