JPS6054085B2 - Arc furnace dust collector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an arc furnace dust collector, more specifically, an arc furnace and a steel receiving ladle are covered with an enclosure, and a ceiling suction line, a steel receiving ladle suction line, and a furnace body suction line are provided. , automatically selects the combination of suction lines and suction air volume to be operated according to furnace conditions,
The present invention relates to an energy-saving arc furnace dust collector that can be adjusted to increase operating efficiency and reduce equipment costs and running costs.

Conventional arc furnace dust collectors are divided into two types: one is a furnace body dust collector, which is designed to prevent the smoke and dust generated in the arc furnace from being released outside the furnace, and the other is a furnace body dust collector, which is designed to prevent smoke and dust that has unavoidably leaked from the furnace from being released outside the factory building. It consisted of a building dust collector.

However, in order to prevent smoke from emitting from the arc furnace, the furnace body dust collector is always operated with negative pressure inside the arc furnace.
Various basic units of alloys, bricks, etc. were reduced. In addition, the building dust collector is used to prevent smoke and dust leaking from the arc furnace from spreading.
Due to the increased volume, a large-capacity dust collector is required, which increases equipment costs.

Furthermore, since leaking smoke and dust cannot be quantitatively measured, a large-capacity dust collector must always be operated at a constant capacity, resulting in high running costs.

The present invention eliminates the above-mentioned drawbacks of the conventional dust collector, houses the arc furnace in an enclosure, and provides a ceiling suction line, a receiving ladle suction line, and a furnace body suction line, and improves the furnace condition of the arc furnace and the inside of the enclosure. An energy-saving arc furnace collection system that automatically operates the dust collector to increase operating efficiency, reduce running costs, and reduce equipment costs by controlling the suction air volume of each suction line according to the amount of smoke and dust. The purpose is to provide dust equipment.

That is, a ceiling suction line, a receiving ladle suction line, and a furnace body suction line each having a valve for switching and adjusting the suction air volume are installed in the enclosure housing the arc furnace and the receiving ladle, and a furnace condition detector is installed. and a device for controlling the valves of each suction line according to the furnace condition signal from the furnace condition detector, and a smoke dust concentration detector is provided in the enclosure, and the smoke dust concentration detected by the smoke dust concentration detector is provided. An air volume correction calculator is provided which calculates a suction air volume correction value for correcting the ceiling suction line suction air volume and the dust collection fan air volume set for each of the furnace condition signals from the signal, and sends the suction air volume correction signal to the control device. This invention relates to an arc furnace dust collector characterized by the following. Embodiments of the present invention will be described below with reference to the drawings.

The arc furnace 1 and the steel receiving ladle 2 are covered with an enclosure 3 to shut off the outside air, and a material charging door 4 is installed on the ceiling above the arc furnace 1 in the enclosure 3.
In addition, slag removal doors 5 are provided on the side surfaces of the arc furnace 1, and a ceiling suction line 10 is connected to the ceiling suction hood 6 with a conduit 9 having an air volume switching valve 7 and an air volume adjustment valve 8. A steel receiving ladle suction line 15 is provided above the inner arc furnace 1 and is formed by connecting a pipe 14 having an air volume switching valve 12 and an air volume adjusting valve 13 to a hood 11 for the steel receiving ladle.
Further, a furnace body suction line 21 is connected to the arc furnace 1 furnace body, and the furnace body suction line 21 is connected to the furnace body of the arc furnace 1, in which an air volume switching valve 17, an air volume control valve 18, a combustion tower 19, and a gas cooler 20 are sequentially provided on the downstream side of the pipe line 16.
, 14, and 16 on the downstream side to form a confluence pipe 22, and a dust remover 23 and a dust collection fan 25 driven by a dust collection fan motor 24 whose rotation speed is variable are provided on the downstream side of the confluence pipe 22. They are provided in sequence.

Each of the doors 4 and 5 is attached to the material charging door 4 and the slag removal door 5 mounting part.
Limit switches 26 and 27 are respectively provided to detect the open/closed state of the steel receiving ladle 2, and a limit switch 28 is provided on the steel receiving ladle 2 placement part to detect that the steel receiving ladle 2 is in the steel receiving position. ．． The furnace condition detection signal that detects the furnace condition of the arc furnace is sent to the furnace washing detector 29.
The furnace condition detector 29 outputs the furnace condition signal to the suction line selector 30 and the suction air volume setting device 31.

Each of the suction lines 10, 1 from the suction line selector 30
The suction line 1 sends a command signal to each air volume switching valve 7, 12, 17 of 5, 21 and operates according to the input furnace condition signal.
0, 15, 21 can be selected, and each suction line 10, 15, 2 can be selected from the suction air volume setting device 31.
A set air volume signal is output to the air volume control valves 8, 13, 18 of No. 1 and the dust collection fan motor 24, and each suction line 10, 15
, 21 so that the suction air volume becomes the set air volume.
, 13, and 18, and the rotational speed of the dust collection fan motor 24 is adjusted so that the suction air volume in the confluence pipe 22 becomes the total set air volume.

Furthermore, a television camera, a light sensor,
A detector 32 such as a temperature sensor or a gas analyzer is provided to measure the concentration of smoke, and a detection signal from the detector 32 is sent to a smoke monitor 33. The air volume correction value signal is input to the correction calculator 34, and the air volume correction value signal calculated by the suction air volume correction calculator 34 is input to the suction air volume setter 31. The setting air volume signal output to the motor 24 can be corrected.

The arc furnace dust collector of the present invention automatically operates each suction line 10, 15, 21 according to the furnace condition of the arc furnace 1 to remove smoke and dust generated from the arc furnace 1 and steel receiving ladle 2 in the enclosure 3. Collect dust by doing this.

The furnace condition of the arc furnace 1 is determined by the limit switches 26 and 2 installed on the material charging door 4 parts, the slag removal door 5 parts, the steel receiving ladle 2 mounting part, etc.
7, 28 and the operation signals of the arc furnace 1, etc., and are automatically detected and classified. Assuming that there are five furnace condition classifications as an example, the detection methods are as follows.

The material charging period is when the opening command (electrical signal) of the material charging door 4 is issued and the limit switch 26 of the material charging door 4 is detected to be open, and the melting period is when electricity is applied to the electrodes of the arc furnace 1. During the refining period, when the limit switch 27 of the slag removal door 5 is detected to be open, and when the oxygen gas injection start signal (electrical The tapping period is determined by the activation of the limit switch 28 that detects that the receiving ladle 2 is in the receiving position, and by the time when the furnace body tilting start command (electrical signal) is issued. The furnace repair period is when the limit switch 28 detects that the steel receiving ladle 2 has escaped from the steel receiving position.

The furnace condition detection signals, arc furnace 1 operation signals, etc. detected by each limit switch 26, 27, 28 in this way are sent to the furnace condition detector 29, where the predetermined furnace condition category is detected, and the furnace condition is detected. A furnace condition signal is sent from the device 29 to a suction line selector 30 and a suction air volume setting device 31.

The suction line selector 30 is set in advance with the furnace condition and the combination circuit of the suction lines 10, 15, and 21 to be operated, and automatically selects the suction line to be operated based on the furnace condition signal input from the furnace condition detector 29. select each applicable suction line 1
The air volume switching valves 7, 12, and 17 of 0, 15, and 21 are opened and closed.

Similarly, the suction air volume setting device 31 is set in advance with a combination circuit for the furnace condition and the set air volume of each suction line 10, 15, 21 to be operated. The set air volume of each suction line 10, 15, 21 to be operated and the total set air volume (the total set air volume of each suction line 10, 15, 21).

) for each applicable suction line 10, 15.
, 21 and the dust collection fan motor 24. With this, each air volume control valve 8,
The opening degrees of the valves 13 and 18 are adjusted so that the suction air volume becomes the set air volume, and the rotation speed of the dust collection fan motor 24 is adjusted so that the suction air volume becomes the total set air volume. Here, a signal detected by a detector 32 such as a television camera is converted into a smoke concentration signal by a smoke monitor 33, and then sent to a suction air volume correction calculator 3.
4 is input.

The smoke concentration signal is integrated over a set sampling time to determine the rate of change in concentration over time, and when the rate of change exceeds the set value, the air volume correction value (increase or decrease) is sent as the air volume correction value signal. The set air volume signal is outputted from the suction air volume correction calculator 34 to the suction air volume setter 31, and outputted from the suction air volume setter 31 to the air volume control valve 8 of the ceiling suction line 10 and the dust collection fan motor 24. is corrected. As a result, the opening degree of the air volume control valve 8 is adjusted so that the suction air volume is corrected, and the motor rotation speed of the dust collection fan motor 24 is adjusted so that the suction air volume becomes the corrected total set air volume. . Note that the arc furnace dust collector of the present invention is not limited to the above-mentioned embodiments, and a temperature monitor consisting of a thermocouple and a measuring resistor is installed at the dust remover inlet to measure the temperature of the suction gas, and its signal is sucked. This includes correcting the air flow by inputting it into the airflow correction calculator, connecting the furnace body suction line to the furnace lid instead of connecting it to the furnace body of the arc furnace, and using a pressure switch or photoelectric switch instead of a limit switch. Of course, various changes can be made without departing from the gist of the invention.

As described above, according to the arc furnace dust collector of the present invention,
I The arc furnace and steel receiving ladle are housed in a sealed enclosure, and a ceiling suction line, steel receiving ladle suction line, and furnace body suction line are installed to collect dust, so the smoke and dust generated from the arc furnace, etc. is enclosed. Since the dust is confined within the body, it is only necessary to collect a small volume of gas within the enclosure, and equipment costs can be significantly reduced by requiring small-capacity dust collection equipment such as a dust collection fan.

■ Ceiling suction line, receiving ladle suction line, and furnace body suction line.For example, use the ceiling suction line during the material charging stage, the furnace body suction line during the melting and refining stages, and the receiving pan suction line during the tapping stage. By using each type in appropriate combinations, and controlling the suction air volume by quantitatively measuring the smoke dust generated using smoke monitors, etc., the dust collector can be operated at the minimum necessary capacity, increasing efficiency. I can drive well. Therefore, the running cost of the dust collector can be reduced. ■ As a result of efficient dust collection, the arc furnace can be operated with positive internal pressure.
It is possible to prevent the reduction in various basic units (energy such as electric power, electrodes, alloys, bricks, etc.) that was caused by conventional operation with the internal pressure of the furnace being negative, and it is possible to significantly improve various basic units.

etc., exhibits various excellent effects.

[Brief explanation of the drawing]

The figure is an explanatory diagram of the arc furnace dust collector of the present invention. In the figure, 1 is an arc furnace, 2 is a steel receiving pot, 3 is an enclosure, 6 is a ceiling suction hood, 7, 12, 17 are air volume switching valves, 8, 1
3 and 18 are air volume control valves, 10 is a ceiling suction line, 11 is a hood for the steel receiving ladle, 15 is a steel receiving ladle suction line, 21 is a furnace body suction line, 24 is a motor for a dust collection fan, and 25 is a dust collection fan , 29 is a furnace condition detector, 30 is a suction line selector, 3
1 is a suction air volume setting device, 32 is a detector, 33 is a smoke monitor,
34 indicates a suction air volume correction calculator.

Claims (1)

[Claims] 1. A ceiling suction line, a receiving ladle suction line, and a furnace body suction line each having a valve for switching and adjusting the suction air volume are installed in the enclosure that houses the arc furnace and the receiving ladle, and a furnace condition detector is installed. and a device for controlling the valves of each suction line according to the furnace condition signal from the furnace condition detector, and a smoke dust concentration detector is provided in the enclosure, and the smoke dust concentration detected by the smoke dust concentration detector is provided. An air volume correction calculator is provided which calculates a suction air volume correction value for correcting the ceiling suction line air volume and dust collection fan air volume set for each of the furnace condition signals from the signal, and sends the suction air volume correction signal to the control device. An arc furnace dust collector featuring: