JP2968148B2 - Telescopic dust collection hood and dust collection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust collecting telescopic hood for collecting dust in a dust-containing gas generated in a metal melting furnace installed in a building, for example, and a dust collecting using the telescopic hood. About the method.

[0002]

2. Description of the Related Art In metal melting furnaces, waste incinerators, chemical reactors, and the like installed in a building and generating a large amount of dust-containing gas, dust collecting equipment is provided to prevent environmental pollution. . The dust collecting equipment includes a suction device for sucking the dust-containing gas from the dust-containing gas generating unit, and a dust collector for collecting dust in the dust-containing gas. The suction device includes a hood, a duct connecting the hood and the dust collector, a damper provided in the duct, and an exhaust fan attached to the duct near the dust collector. A bag filter, an electric dust collector, a cyclone, or the like is used as the dust collector.

In order to efficiently collect dust-containing gas without sucking extra outside air, it is necessary to bring the suction port (lower end) of the dust collecting hood as close as possible to the dust-containing gas generating section. However, if the distance is too close, the dust collecting hood may be burned out by radiant heat from inside the melting furnace, electrodes and the like. In addition, the amount of dust-containing gas and dust concentration generated by the melting furnace and the like depend on the operation conditions of these facilities (for example, furnace preheating, melting,
Flap, etc.). Therefore, it has been practiced to make the dust collecting hood extendable up and down, expand and contract the dust collecting hood according to the operation state, and efficiently collect dust-containing gas while preventing burning of the dust collecting hood (for example,
JP-A-58-219388, "Dust collection method in melting furnace").

[0004]

The conventional telescopic hood is
A heat-resistant cloth is stretched around a plurality of annular frames, a lifting wire is attached to each frame, and the wires are wound around pulleys. Therefore, the structure is complicated, and troubles such as disconnection of the wire at the time of elevating and lowering often occur.

[0005] Further, the dust-containing gas generator may move depending on the operation state. For example, in a steelmaking electric furnace, when melting is completed, the electric furnace is inclined forward, and molten steel is poured into a ladle from a tapping gutter projecting forward from the furnace body. For this purpose, the dust-containing gas generating part moves from the top of the furnace body to the tapping gutter and ladle, that is, forward. However, since the conventional telescopic hood simply expands and contracts up and down, it cannot follow the movement of the dust-containing gas generation unit, and cannot sufficiently collect the dust-containing gas. Therefore, the suction port of the dust collection hood is enlarged so that the dust-containing gas can be collected even when the dust-containing gas generating section moves. However, if the suction port is large, extra outside air must be sucked in, and the driving power of the exhaust fan increases, which is not preferable in terms of energy saving.

The present invention provides a dust collecting telescopic hood having a simple structure and a dust collecting method having a high dust collecting efficiency.

[0007]

SUMMARY OF THE INVENTION A dust collecting telescopic hood according to the present invention is vertically expandable and contractable so that a lower end thereof can be lowered to a position containing a dust-containing gas or directly above, and a suction device connected to a top portion. In a dust telescopic hood, a pair of opposing first screens, a pair of opposing second screens that are located between the opposing first screens and form a quadrangular cylindrical gas flow path with the first screen. And a first hoisting device and a second hoisting device for winding the first and second shutter curtains, respectively.

The curtain is made of a heat-resistant sheet such as aramid fiber. For example, an aramid fiber barrier can withstand up to 300 ° C. Both side edges of the second curtain are brought as close as possible to the first curtain surface so that the dust-containing gas does not leak out of the gap between them. A guide plate that sandwiches the curtain from both sides,
It may be provided near the upper side of the curtain. A rod-shaped weight may be attached along the lower edge of the shutter curtain to keep the shutter curtain vertical and prevent the rising curtain from fluttering.

The first winding device and the second winding device each include a winding shaft slightly longer than the width of the shutter curtain, and a motor for rotating and driving the winding shaft. An upper side portion of the blocking curtain is attached to the winding shaft along the shaft. The hoisting device is fixed to, for example, a beam near the ceiling of the building.

In the first dust collecting method of the present invention, the second pair of telescopic hoods is provided in accordance with the movement of the dust-containing gas generating section.
At least one of the curtains is translated along the first curtain.

In order to move the second curtain, for example, a hydraulic cylinder, an air cylinder or the like is used to push or pull the upper side of the second curtain in the moving direction. The winding amount of the second shutter curtain that moves in accordance with the moving amount of the second shutter curtain is adjusted so that the heights of the lower sides of the opposing second shutter curtains are aligned.

According to a second dust collecting method of the present invention, in accordance with the movement of the dust-containing gas generating portion, at least one of the pair of second shutter curtains of the telescopic hood has a gas flow path downward. Tilt to spread toward.

In order to incline the second shutter curtain, for example, the lower side of the second shutter curtain is pulled outward along the first shield curtain by a wire, or the wire whose lower side is drawn is loosened to tilt the second shutter curtain by its own weight. loosen. The winding amount of the inclined second curtain is adjusted according to the amount of inclination of the second curtain so that the lower sides of the opposing second curtains are aligned at the same height.

[0014]

According to the dust collecting telescopic hood of the present invention, since the telescopic hood is formed by the four shutter curtains, the structure is simple and the telescopic hood can be easily expanded and contracted.

Further, in the dust collecting method of the present invention, at least one of the pair of second blocking curtains of the telescopic hood is moved along the first blocking curtain in accordance with the movement of the dust-containing gas generating section. Or tilt. As a result, the suction port of the telescopic hood moves in accordance with the movement of the dust-containing gas generating section, so that it is not necessary to suck extra outside air, so that the dust-containing gas can be efficiently sucked and the power of the exhaust fan operation can be reduced. can do.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A dust collecting telescopic hood provided in a steelmaking electric furnace factory will be described as an embodiment.

FIG. 1 shows an example of a dust collecting facility of a steelmaking electric furnace factory provided with the telescopic dust collecting hood of the present invention.
FIG. 2 is a perspective view of the telescopic hood.

As shown in these drawings, in the building 1,
An electric furnace 5 for steelmaking is installed on the platform 3. An overhead crane 7 for charging raw materials, tapping steel, and the like is provided above the electric furnace 5.

An inverted funnel-shaped fixed hood 11 is attached to a base 9 on the roof 2 of the building 1 so as to protrude outside. A duct 13 is connected to the top of the fixed hood 11, and a damper (not shown) is provided near the entrance of the duct 13. The duct 13 is connected to a bag filter (neither is shown) via an exhaust fan.

Immediately below the fixed hood 11, a telescopic hood 21 is provided.
Is arranged. The telescopic hood 21 includes a pair of opposing first screens 23 and a pair of opposing second screens 25.
Consists of First and second screens 23 and 25
Is made of aramid fiber. The width of the first blocking curtain 23 is larger than the width of the second blocking curtain 25, and sandwiches the paired second blocking curtain 25. The paired second curtain 25
Is located between the opposing first screens 23 and the first screen 2
Together with 3, the gas flow path 27 has a rectangular cross section.

A guide plate 28 made of a steel plate extends downward from the gantry 9 as shown in FIG. Two guide plates 28 are paired so as to sandwich the curtains 23 and 25, and are provided for each of the curtains 23 and 25. Information board 2
The width of 8 is substantially equal to the width of the shutters 23, 25. Also,
A bar-shaped weight 29 is attached to the lower side of the first and second curtains 23 and 25 along the curtain width direction. The rod-shaped weight 29, together with the guide plate 28, holds the posture of the shielding curtains 23 and 25 forming the gas flow path 27, and prevents the shielding curtains 23 and 25 from fluttering by the rising dust-containing gas.

A first hoisting device 31 and a second hoisting device 32 are provided on the gantry 9 of the roof 2. Second
The hoisting device 32 is disposed immediately above the first hoisting device 31 so as not to interfere with the first hoisting device 31. First
The hoisting device 31 and the second hoisting device 32
A winding shaft 35 slightly longer than the widths of the winding shafts 3 and 25, and a first rotation driving device 36 and a second rotation driving device 37 for driving the rotation of the winding shaft 34 are provided. First rotation drive 3
A speed reducer 40 is connected to each of the first motor 38 and the second motor 39 of the second rotary driving device 37. The output shaft of the speed reducer 40 is connected to the gear box 41. The gear box 41 accommodates a transmission mechanism such as a bevel gear and a bearing (both not shown). Transmission shaft 44
Is supported by the gear box 41 and the intermediate gear box 42. The winding shaft 34 is supported by the intermediate gear box 42 and the bearing stand 43. Each hoisting device 31, 3
In 2, the winding shaft 34 is parallel, and the transmission shaft 44 of the first winding device 31 and the transmission shaft 44 of the second winding device 32 intersect at right angles. The upper side portions of the shielding curtains 23 and 25 are attached to the body 35 of the winding shaft 34 along the axis. First motor 38 and second motor 39
Are synchronously driven to rotate. Therefore, the first and second curtains 23 and 25 move up and down while maintaining the same height.

In the dust-collecting telescopic hood constructed as described above, the first closing screen 23 depends on the operation state of the electric furnace 5.
Then, the second curtain 25 is moved up and down. For example, when charging a material into the electric furnace 5, the overhead crane 7 comes above the electric furnace 5, so that the first and second curtains 23 and 25 are provided.
Is wound up above the overhead crane 7. Also,
At the time of preheating and melting, the first curtain 23 and the second
The curtain 25 is lowered to just above the electric furnace 5. At this time, since a narrow range just above the electric furnace 5 is sucked, the dust-containing gas can be sucked efficiently.

FIGS. 4 and 5 show another embodiment of the present invention. The same reference numerals are given to the same devices and members as those in the above embodiment, and the description thereof will be omitted.

In this embodiment, the second curtains 25a, 25
b can be moved in the horizontal direction along the first curtain 23. A pair of hydraulic cylinders 51 facing each other are mounted directly below the gantry 9. At the tip of the piston rod 52,
The drive rod 53 is fixed horizontally. The drive rod 53 is in contact with the second hanging curtains 25a and 25b which hang vertically. By driving the hydraulic cylinder 51, the piston rod 52
Is advanced, the second curtains 25a and 25b advance. Conversely, when the piston rod 52 is retracted, the second curtains 25a and 25b that have been pushed forward are retracted by their own weight.

FIG. 4 shows a state during melting, in which one of the second curtains 25a is retracted and the other second curtain 25b is advanced. At this time, the centers of the curtains 25a and 25b are located almost directly above the electric furnace 5.

FIG. 5 shows a state during tapping. The dust-containing gas generating portions are a tapping gutter 6 and a ladle 8 of the electric furnace 5, and are moved forward from the center of the electric furnace 5. And one of the second
The shutter 25a is moving forward, and the other second shutter 25b is moving backward. At this time, the centers of the curtains 25a, 25b are located almost directly above the tapping gutter 6 of the electric furnace 5.

It is to be noted that the amount of suction air from a blower (not shown) is adjusted according to the operation state of the electric furnace 5.

FIG. 6 shows still another embodiment of the present invention, which shows an example of a dust collecting facility provided with a dust collecting telescopic hood.
Note that the same reference numerals are given to the same devices and members as those in the above-described embodiment, and description thereof will be omitted.

Two third hoisting devices 55 are installed on the pedestal 9 of the roof 2 corresponding to each of the opposing second blocking curtains 25. Each of the third hoisting devices 55 winds a suspending wire 56, and the leading end of the suspending wire 56 is attached to the rod-shaped weight 29 at the lower end of the second curtain 25.

In this embodiment, the inclination of the second curtain 25, that is, the extension hood 2 depends on the winding amount of the suspending wire 56.
The position of one suction port can be adjusted. For example, when the rewinding amount of the hanging wire 56 is appropriately adjusted when the second shutter curtain 25 is lowered, the interval between the opposing second shutter curtains 25 is maintained while maintaining the interval indicated by the dashed line.
Can be lowered to just above the electric furnace 5. At this time,
The second shutter 25 is in the vertical position, and the width of the suction port in the longitudinal direction (the left-right direction in the drawing) is minimized. When the suspension wire 56 is wound up while rewinding the second curtain 25 from this state, the second curtain 25 is inclined so that the suction port is opened. The broken line in FIG. 6 shows such a state.

[0032]

According to the dust collecting telescopic hood of the present invention, since the telescopic hood is formed by the four shutter curtains, the structure of the hood itself and the hood telescopic mechanism are simplified.

Further, in the dust collecting method of the present invention, at least one of the pair of second dust curtains of the dust collecting telescopic hood is moved along the first dust curtain in accordance with the movement of the dust-containing gas generating section. The hood suction port can be moved or tilted. Accordingly, it is not necessary to suck extra outside air, so that the dust-containing gas can be efficiently sucked, and the power for operating the exhaust fan can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a dust collecting facility provided with a dust collecting telescopic hood of the present invention.

FIG. 2 is a perspective view of the telescopic hood shown in FIG.

FIG. 3 is a side view of a guide plate for guiding a blocking curtain.

FIG. 4 is a longitudinal sectional view showing another example of the dust collecting equipment provided with a telescopic dust collecting hood, in which an electric furnace is in a melting step.

FIG. 5 is a drawing of the electric furnace in FIG. 4 in a tapping process.

FIG. 6 is a longitudinal sectional view showing still another example of a dust collecting facility including a telescopic dust collecting hood.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 building 2 building ceiling 5 electric furnace 7 overhead crane 9 gantry 11 fixed hood 13 duct 21 telescopic hood 23 first shutter curtain 25 second shutter curtain 28 guide plate 29 rod-shaped weight 31 first hoisting device 32 second hoisting device 34 winding Shaft 36 First rotation drive device 37 Second rotation drive device 38 First motor 39 Second motor 41 Gear box 42 Intermediate gear box 43 Bearing stand 51 Hydraulic cylinder 52 Piston rod 53 Drive rod 55 Third hoisting device 56 Suspension wire

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Toshiki Fujimori 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Corporation Technology Development Division (56) References JP-A-58-219390 (JP, A) ( 58) Field surveyed (Int.Cl. ⁶ , DB name) B01D 46/42 B01D 46/02 B03C 3/34 F27D 17/00 105

Claims (3)

(57) [Claims] 1. A dust collecting telescopic hood in which a lower end can be lowered to the position of a dust-containing gas generating portion or immediately above the dust generating gas generating portion and a suction device is connected to a top portion thereof, and a pair of opposing first shutoffs is provided. The curtain is between the opposing first curtains and the first
A pair of opposing second shutters forming a quadrangular cylindrical gas flow path together with the shutters, and a first hoisting device and a second hoisting device that wind the first and second shutters, respectively. A telescopic hood for dust collection, characterized in that: 2. The dust collecting method according to claim 1, wherein at least one of the pair of second shutters of the telescopic hood is first shut off in accordance with the movement of the dust-containing gas generating unit. A dust collection method characterized by parallel movement along a curtain. 3. The dust collecting method using an extendable hood according to claim 1, wherein at least one of the pair of second shutters of the extendable hood is connected to a gas flow path according to the movement of the dust-containing gas generating section. A dust collection method characterized by inclining so that the water spreads downward.