JP2502445Y2 - Wet dust collector with water drop entrainment prevention means - Google Patents

Description

[Detailed description of the device]

[0001]

[Industrial application] The present invention is a water drop entrainment configured so that the water drops after cleaning do not flow into a conduit tube as much as possible when collecting dust in a gas containing dust discharged from a blast furnace or a converter. The present invention relates to a wet dust collector equipped with a prevention means.

[0002]

2. Description of the Related Art The construction of this type of wet dust collector is known, for example, in a furnace top gas purification plant for a high pressure blast furnace described in Japanese Patent Publication No. 52-50002. That is, in this purification plant, as shown in FIG. 5, the untreated gas conduit 32 connected to the furnace top of the high-pressure blast furnace 31, the rough separator 33, and the top of the rough separator 33 and the untreated gas conduit 32A. The first chamber 4 of the pre-cleaning chamber having the connected cleaning water injection nozzle 7, the second chamber 5 defined by the conical bottom plates 2 and 3, and the conduction connecting the first chamber 4 and the second chamber 5 with each other. Pipe and differential pressure cleaning unit 10A, gas branch conduit 34 leading out from the second chamber 5,
It is mainly composed of a water drop separator (mist separator) 18 having spiral blades connected to it, a clean gas discharge passage 35, and the like. In the differential pressure cleaning unit 10A, a spiral nozzle 14 for injecting cleaning water to the upstream side and a conical inner body 15 that can be adjusted up and down are arranged downstream of this. The slime water accumulated on the bottom plate 2 that works for collecting slime water is discharged by the discharge pipe 8. Reference numeral 36 is a turbine that drives the generator 37 by utilizing the pressure of the top gas. This conventional example is a top gas purification facility in a high-pressure blast furnace,
This type of purification facility is also provided for exhaust gas from the converter (see, for example, Japanese Patent Publication No. 53-33926).

FIG. 6 is an enlarged sectional view showing a portion of a wet type dust collector having substantially the same structure as the conventional example.
The structure, operation, etc. of such a wet dust collector will be described in detail with reference to FIG. 6. The dust collector 1 is divided into a first chamber and a second chamber by conical or inclined bottom plates 2 and 3 provided in two upper and lower stages. Has been done. Dust collection tower 1 for dust-containing gas discharged from blast furnace or converter
It is introduced from the top introduction port 6 and the cleaning water is sprayed from the spray nozzle 7 in the first chamber (preliminary cleaning chamber) 4 to roughly collect dust. Then, a gas flow is introduced into the conduit tube 10 from the conduit tube inlet portion 11 that opens upward, and another spray nozzle 1
The inner body 1 in the shape of a truncated cone, which is washed after
5 is passed through the annular gap passage 16 of the ring slit element (RSE) and is injected into the second chamber 5 as a high-speed flow, and in this process, the final dust is collected. In this case, most of the water droplets that have captured dust in the gas when passing through the spray water film in the first chamber 4 ride on the gas flow and flow through the conduit 1.
It flows into the second chamber 5 via 0. The structure of this type of conduit tube 10 is disclosed in Japanese Patent Publication No. 60-4723. As shown by an imaginary line in the figure, the mist separator 18 installed outside in the above-mentioned conventional example may be installed downstream of the ring slit element (RSE) in order to save space.

[0004]

The above-mentioned prior art has the following inconveniences.

Since the conduit pipe inlet 11 is open upward, the dirty water that has been coarsely collected directly enters the portion (second chamber) 5 where the final dust should be collected through the conduit pipe 10. However, the large amount of invasion adversely affects the dust collection efficiency.

Usually, a system is used in which the collected wastewater in the second chamber 5 is pumped to the first chamber 4 through the discharge pipe 9 and the water is reused. The amount of water that circulates increases, and the pump capacity and its operating costs become excessive.

When the amount of water droplets penetrating from the conduit tube 10 increases, it is necessary to install a mist separator 18 or the like installed in the ring slit element (RSE) having a large capacity. However, since the mist separator that can be installed is naturally limited in the water drop separation performance, it may be necessary to install another mist separator on the outside, and in this case, the meaning of installing the mist separator is lost.

Also, the drainage piping system from the second chamber 5 must have a large capacity.

The present invention has been made in view of the above-mentioned problems of the prior art, and is provided with a water droplet entrainment preventing means at the entrance of the conducting tube to reduce the amount of water droplets penetrating through the conducting tube and improve the dust collecting efficiency. With the goal.

[0010]

In order to achieve the above object, the water droplet entrainment prevention means in the wet dust collector according to the present invention has a gas flow path directly above the inlet of the conduit in the downward flow from the gas inlet. A cap-shaped body that covers the inlet part while maintaining the gap is formed, and a cylindrical body with an open lower end that is loosely fitted concentrically with the conduction pipe is connected below the cap-shaped body. It may be configured by bending the inlet part at the upper part of the pipe downward from the horizontal direction into a substantially U-shape and providing an opening at the lower end thereof. Further, an outer tube is provided which covers the inlet of the conducting tube and is loosely fitted in the conducting tube in a concentric manner to form an annular passage between the outer tube and the conducting tube. An inner cylinder is concentrically provided, the upper part of the inner cylinder is opened to the first chamber as an annular inlet, and the lower part is opened to an annular passage, and the inner cylinder is horizontally crossed to communicate between the annular passage and the conducting pipe. A plurality of communication conduits may be provided to configure the water droplet entrainment prevention means.

[0011]

In the above structure, the gas flow after the coarse dust is collected in the first chamber is turned into a steep angle by the function of the water droplet entrainment preventing means immediately before the entrance of the conducting pipe to flow into the conducting pipe.
The amount of water droplets (roughly dusted dirty water) flowing into the conduit decreases due to the accompanying water droplets being removed or the water droplets being collected. As a result, the dust collection efficiency in the second chamber for finishing dust collection becomes good, and the mist separator provided in the downstream can have a small capacity, and the capacity of the pump and the like and the operating cost can be kept small.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In the figure, the same components as those of the conventional example are designated by the same reference numerals.

FIG. 1 is a schematic sectional view of a wet dust collector according to the first embodiment.

The inside of the dust collecting tower 1 is divided into a first chamber 4 which is an upper pre-cleaning chamber and a second chamber 5 which is a lower part by bottom plates 2 and 3 provided in upper and lower stages. An inlet 6 for dust-containing gas discharged from a blast furnace, a converter or the like is provided at the top of the dust collecting tower 1.
Is provided so as to face the first chamber 4, which is a preliminary cleaning chamber.
A plurality of stages of spray nozzles 7 are installed immediately downstream of the introduction port 6, from which cleaning water is sprayed to lower the gas temperature, and when dust-containing gas passes through this spray water film, It is designed to capture dust and collect roughly.

At the lowest parts of the bottom plates 2 and 3 provided at the middle and lower positions of the dust collecting tower 1, discharge pipes 8 and 9 for discharging the cleaning waste water accumulated therein are respectively introduced. On the other hand, a conducting pipe 10 is provided so as to penetrate through the bottom plate 2 provided at the middle position, and the first chamber 4 and the second chamber 5 communicate with each other through the conducting pipe 10. That is, the upper half of the conducting pipe 10 on the first chamber 4 side has a cylindrical shape, and the upper end inlet portion 11 thereof opens to the first chamber 4 side and the lower half of the conducting pipe 10 on the second chamber 5 side. The part is formed in a venturi shape, and the lower end is open to the second chamber 5 side.

Immediately above the inlet portion 11 of the conduit tube 10 is provided a water drop entrainment preventing means 12 formed in a cap shape so as to cover the inlet portion 11 while maintaining a gap serving as a gas flow path. The water drop entrainment prevention means 12 may be formed by connecting a cylindrical body 13 which is loosely fitted in the conducting tube 10 below the cap-shaped body as shown by an imaginary line. The gas flow path in this case is formed between the cylindrical body 13 and the conducting tube 10. By the water droplet entrainment prevention means 12, the gas flow flowing into the conduit pipe inlet portion 11 is reversed to a steep angle in the direction of a solid line or an imaginary line arrow (a sudden change) immediately before flowing into the conduit pipe 10.
Then, the water drops entrained at this time are blown off to reduce the amount of water drops flowing into the conduit 10.

Another spray nozzle 14 is provided in the conducting tube 10, and a truncated cone-shaped inner body 15 is provided in the divergent portion of the venturi-shaped conducting tube 10.
A ring-shaped slit (annular gap passage) 16 is formed between the conduit tube 10 and the conduit tube 10. The portion where the interior body 15 is present is called a ring slit element (RSE). Interior body 1
The shaft 5 can be moved up and down by a shaft 16 so that the size (passage cross-sectional area) of the ring-shaped slit 16 can be adjusted to maintain and adjust the gas flow velocity flowing out from it at high speed. Further, the mist separator 18 may be installed on the downstream side of the RSE as shown by an imaginary line to omit the external mist separator to save space.

In the above structure, the dust-containing exhaust gas sent from the blast furnace or the converter is provided with the inlet 6 at the top of the dust collecting tower 1.
Then, the water sprayed from the spray nozzle 7 roughly collects dust. Then, the water droplets that have taken in the dust at this time are prevented from directly flowing into the conducting tube 10 by the water droplet entrainment preventing means 12 formed in a shade, where the gas flow suddenly changes and enters the conducting tube. It will come in. Most of the water droplets accompanied by this sudden change in the gas flow were thrown off, and the conduit 10
Water droplets are prevented from entering. The gas flow that has flowed into the conduit tube 10 passes through the lower annular slit 16 together with the spray water from the spray nozzle 14 in the conduit tube 10, where it becomes a high-speed gas stream and is finished and dust-collected, then the second chamber 5 Then, the gas reverses upward and flows, and is discharged from the discharge port 17, while the water droplets in the gas flow are separated downward and collected on the bottom plate 3 and discharged from the discharge pipe 9. The system in which the water discharged from the discharge pipe 9 is circulated to the spray nozzle 7 of the first chamber 4 and reused is also adopted in many cases. The capacity of the system and circulation pump can be reduced.

FIG. 2 shows a second embodiment. In this example, the inlet portion 11 of the conduit 10 is bent horizontally to form the water droplet entrainment prevention means 12, and the gas flow is bent horizontally as shown by the arrow of the solid line to flow into the conduit 10, or further imagined. The water droplet entrainment prevention means 12A is configured so that the inlet portion 11 is opened downward as shown by a line, and the gas flow is reversed so that the gas flows from the lower side toward the upper side. In this way, the gas flow is suddenly changed immediately before entering the conducting pipe 10 to separate and release the entrained water droplets to reduce the amount of water droplets entering the conducting pipe 10. The rest of the configuration is the same as that of the first embodiment, and the same components are assigned the same reference numerals and explanations thereof are omitted.

FIG. 3 shows a third embodiment. As shown in FIG. 3 (a), a means 12 for preventing water droplets from being entrained in the gas flow immediately above the inlet 11 of the conduit.
The mist collection mechanism that is one of the above is installed.
This mist collecting mechanism is a sectional view taken along the line AA of (a).
As shown in (b), the channel steels 12a and the like are vertically arranged in two staggered rows in a zigzag arrangement. Gas is grooved steel 12a
When passing through the gaps between them while deflecting as indicated by arrows, the water droplets in the gas flow are separated and collected in the grooved steel 12a, and then fall along the inclination and are collected on the bottom plate 2. As a result, the amount of water droplets in the gas stream entering the conduit 10 is greatly reduced.

FIG. 4 shows a fourth embodiment. In this example, the water droplet entrainment prevention means 12 is configured as follows. That is,
An outer cylinder 19 which is loosely fitted to the conduction pipe 10 so as to cover the inlet of the conduction pipe 10 is provided, an annular passage 19a is formed between the outer cylinder 19 and the conduction pipe 10, and the lower portion of the outer cylinder 19 has a funnel shape. One water collecting channel 19b is formed by being squeezed, and the end outlet is opened on the upper surface of the bottom plate 2. On the other hand, the inner cylinder 20 is loosely fitted along the conducting pipe 10, and the upper part of the inner cylinder 20 is opened to the first chamber 4 as an annular inlet 20a. A mist separator 21 is attached to the lower part of the inner cylinder 20. Mist separator 2
Reference numeral 1 has a conventionally well-known structure in which swirl vanes are provided, and centrifuges water droplets contained in a gas flow. Further, several communication conduits 22 are provided radially across the inner cylinder 20 in the horizontal direction so as to communicate between the annular passage 19a and the conduit 10.

In the above structure, the gas flow having undergone the coarse dust collection by the spray nozzle 7 flows from the inner cylinder inlet 20a and is separated into water droplets by the lower mist separator 21 and then reverses and rises in the annular passage 19a. Then, it flows into the conduit 10 through the communication conduit 22. The water droplets separated by the mist separator 21 and blown off by the sudden change of the gas flow are collected from the lower water collecting passage 19b on the bottom plate 2 while water-sealing the gas, and other cleaning waste water is collected. Along with this, it is discharged from the discharge pipe 8. Therefore, the amount of coarsely collected water droplets entering the conduit tube 10 is extremely small.

[0023]

According to the present invention described above, the following effects can be obtained.

The gas flow flowing into the inlet of the conduit is
By the water drop entrainment prevention means being bent at a steep angle just before the entrance, the water drops entrained will be wiped off,
It is possible to greatly reduce the inflow amount of water droplets (water that has undergone coarse dust collection) into the conduit tube. As a result, the dust collection efficiency in the second chamber can be improved, and the capacity of the discharge pipe, the pump, etc. can be reduced. In addition, a mist separator with a small capacity can be installed on the downstream side of the RSE, and space can be saved.

By installing a mist collecting mechanism, which is one of the means for preventing water droplet entrainment, at the inlet of the conduit, it is possible to reliably separate and collect the water droplets in the gas flow and to inject the gas into the conduit. Since the amount of water droplets can be drastically reduced, the effect of finishing dust collection in the second chamber can be further enhanced and the overall dust collection efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a wet dust collector according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view of a wet dust collector according to the second embodiment.

FIG. 3A is a schematic sectional view of a wet type dust collector according to the third embodiment, and FIG. 3B is a sectional view taken along the line AA of FIG.

FIG. 4 is a schematic cross-sectional view of a wet dust collector according to the fourth embodiment.

FIG. 5 is an overall view of a blast furnace gas purification plant according to a conventional technique.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Dust collection tower (of wet type dust collector) 4 ... 1st chamber (preliminary washing chamber) 5 ... 2nd chamber 10 ... Conducting pipe 11 ... (Conducting pipe) inlet part 12 ... Water droplet entrainment prevention means 18 ... Mist separator

Claims (3)

(57) [Scope of utility model registration request] 1. A water drop entrainment prevention means is provided in a conducting pipe which connects a first chamber, which is a pre-cleaning chamber having a gas inlet at an upper portion formed in a dust collecting tower, and a second chamber for finishing dust collection. In a wet dust collector that is provided to collect dust in a dust-containing gas discharged from a blast furnace or a converter, the water droplet entrainment prevention means is provided directly above the inlet of the conduit to hold a gap serving as a gas flow path. Provide a shade to cover the entrance,
A wet dust collector having a water drop entrainment prevention means, characterized in that a cylindrical body having an open lower end concentrically fitted in a conduit tube is continuously provided below the cap-like body. 2. A water drop entrainment preventing means is provided in a conducting pipe that connects a first chamber, which is a pre-cleaning chamber having a gas inlet at an upper portion formed in the dust collecting tower, and a second chamber for finishing dust collection. In a wet dust collector that is provided to collect dust in a dust-containing gas discharged from a blast furnace or a converter, etc., the above-mentioned water droplet entrainment prevention means is formed by bending the upper inlet part of the conduit from a horizontal shape downward into a substantially U-shape. A wet dust collector having a water droplet entrainment prevention means characterized in that an opening is provided at the lower end thereof. 3. A water drop entrainment prevention means is provided in a conducting pipe that connects a first chamber, which is a pre-cleaning chamber having a gas inlet at an upper portion formed in the dust collecting tower, with a second chamber for finishing dust collection. In a wet type dust collector that is provided to collect dust in a dust-containing gas discharged from a blast furnace or a converter, the above-mentioned water droplet entrainment prevention means covers the inlet of the conduit pipe and is fitted concentrically with the conduit pipe. A tube is provided to form an annular passage between the outer tube and the conducting tube, and an inner tube is provided concentrically with the conducting tube inside the outer tube, and the upper part of the inner tube serves as the annular inlet in the first chamber. A water droplet entrainment prevention, characterized in that a plurality of communication conduits, which are opened and a lower part is opened in an annular passage, and which traverses the inner cylinder in the horizontal direction to communicate between the annular passage and the conducting pipe, are provided. Wet dust collector with means.