JPS5912952B2 - Control method for cast bed dust collector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of controlling a cast bed dust collector in a blast furnace.

As blast furnaces become larger and more efficient, the amount of iron tapped per unit has increased to 60
00 to 10,000) has reached 71 days, but since there is a limit to the tapping speed (5 to 10) from one taphole (77 minutes) and the tap time, the taphole must be changed every few tens of minutes. Therefore, the operation is carried out under conditions of continuous tapping, and as a result, a large amount of dust is generated.

Therefore, from the perspective of preventing air pollution and improving the working environment,
Recently, in addition to local dust collection, equipment for building dust collection has become available.

Therefore, in order to effectively utilize the air volume of both dust collectors, it is necessary to adjust the opening of the dust collector's hood damper according to the operating conditions of the blast furnace. However, from the standpoint of labor and energy saving, it is desirable to automate the dust collection pattern, such as the effective opening of the dust collection damper and the adjustment of the blower speed, according to the operational status of the blast furnace.

The present invention grasps the scheduled opening time of the blast furnace, the level of molten material in the furnace, and the state of molten material discharge, selects a predetermined dust collection pattern, adjusts the opening of the hood damper of each dust collection port, and controls the blower. By stopping the operation or adjusting the speed, the casthouse dust collector is automated, labor-saving, and energy-saving, depending on the amount of dust depending on the status of the casthouse work, and ensures reliable dust collection. The purpose is to provide equipment.

The present invention will be explained below with reference to embodiments shown in the figures.

Fig. 1 shows the structure of a local dust collector, and Fig. 2 shows the structure of a building dust collector, and both are used in combination for processing.

In the local dust collector shown in Fig. 1, for example, there are three tapholes TH in the blast furnace from AI to No.3, and each taphole has a
Taphole, gutter, skimmer, hot metal sluice,
Equipped with suction ports 81 to 87, dust collection dampers 51 to 57, and main dampers 5 to 7 provided corresponding to each of the hot metal tilting trough, slag slag pouring trough, and slag tilting trough to collect dust from each suction port. It is discharged to the outside via a filter 1, a suction damper 2, a blower 3, and an exhaust tower 4.

In the building dust collector shown in Figure 2, each taphole (AI
The dust sucked from the suction eyes 801 to 803 provided corresponding to the main damper 5 to
7. The dust is discharged to the outside via the dust collection devices 1 to 4.

FIG. 3 is an explanatory diagram of the tapping schedule and the required air volume for dust collection.

In normal tapping mode, individual tapping is performed in which only one tap hole is opened and tapped, but the amount of tapped iron is large (in continuous tap mode, two tap holes are opened as shown in the figure). is lapped and tapped.

By the way, the amount of dust generated in the tapping process varies depending on the time of opening the hole, during tapping, and from the time of slag tapping to blockage. For example, when the hole is opened to start tapping, black smoke and dust are generated. The total air volume is nearly twice that during tapping, as it wraps violently when the holes are opened and closed.

When collecting dust, it is desirable to adjust the air volume to the optimum level according to changes in the tapping process. For example, when tapping starts and when the tap is blocked, a lot of dust is generated, so the opening degree of the dust collection damper for local dust collection should be adjusted. At other times, reduce the opening of the damper for local dust collection, and reduce the opening of the dust damper for building dust collection to suppress the air volume. This improves the dust collection effect, reduces the total air volume, and saves power.

In this way, in order to suppress the total air volume, suction is focused on areas with a lot of dust, depending on the situation of each taphole, and places with relatively little dust or where the influence of pollution is less are insufficient. However, the amount of suction is reduced from normal to effectively distribute the overall air volume.

Therefore, the opening degree of the dust collection damper of each suction port should be adjusted according to the tapping process such as opening, tapping, slag tapping, and blockage for each taphole. The opening degree of each dust collection damper is determined by the combination of processes.

FIG. 4 represents a block diagram of one embodiment of the present invention.

20 is a tap schedule setting section, which sets a predetermined tap time schedule and the actual output at each blockage based on the equipment status consisting of a time setting panel and digital control device and the expected tap time of each tap hole. It consists of a part that calculates the pig ironing time and corrects the time schedule for the start of next time's tapping in relation to the time Δt of the difference between the forecast and actual results, and a part that issues an output signal when the time to start tapping is reached. .

This output signal is reset when tapping is started.

Reference numeral 21 denotes an in-furnace molten material level calculation unit, which is composed of a digital control device. Find the level of things.

In addition, at the top of the furnace, the expected amount of pig iron production and the expected amount of slag produced, which are calculated from the pre-prepared mix calculation of the raw materials charged, are carried out according to the rate of decline of the raw material level in the furnace, and the amount of iron that has been tapped is It may be determined by subtracting quantities.

The in-furnace molten level calculation unit outputs a signal indicating that the hole can be opened when the calculated in-furnace molten level reaches a certain value or more.

Reference numeral 22 denotes a tapping preparation completion signal generation mechanism for the taphole, which generates a signal indicating that preparations for opening the hole in front of the furnace, such as preparation of the hole opening mechanism and maintenance of the gutter, have been completed.

26 is a molten material weighing calculation unit, which calculates the weight of the pig iron mixer car 240 (for example, the output signal of the load cell when the weight of the molten material flowing in through the gutter 23 is measured by the load cell 25), or the hot water level in the pig iron mixer car. A calculation unit that measures the rate of change over time and determines the mid-tapping period when the amount of slag coming out is low and the amount of tapped iron increases, the mid-tapping period when the amount of tapped iron decreases, and the blockage period. It is.

This calculation section 26 receives as input an analog signal of the weight of the pig iron mixer car or the level of hot water inside the pig iron mixer car, and is processed by a digital control device having a function of determining each period.

Reference numeral 31 denotes a signal processing unit that detects the flow shape of molten material 29 such as hot metal and slag from the tap hole 28 of the blast furnace wall 27 from the side of the flow direction using a visible light or infrared camera 30.
The shape of the outflow is imaged, the video signal obtained from the camera 30 is processed to capture the shape, and this shape is compared with the model shape of each tapping process set in advance to understand each tapping process. Simply put, the tapping process is grasped by capturing the distance from the taphole to the gutter and the area of the image of the molten material 29, which is similar to the molten material weighing calculation section 26. Has a function,
It has the advantage of being able to quickly detect changes in conditions and quickly identifying abnormalities such as iron tapping.

In addition, in reality, the melt weighing calculation section 26 and the signal processing section 31
You may select and install one of these to simplify the equipment.

32 is a signal selection section, 101 to 107 are AND elements (the circle marked at the input terminal indicates the function of inverting the phase of the input signal), 108 to 110 are OR elements, 11L11
2 is a flip-flop (S is its set terminal, R is its reset terminal), and is a logic section (elements 102 to 110) that determines which signal of the state signals of the tapping process outputted from each section is adopted. It consists of a part that holds a tap start signal and a blockage start signal.

The switch 113 is configured to select the output of the molten material weighing calculation section 26 which has a fast detection speed during tapping and when the block is closed, and selects the output of the signal processing section 31 which has a small noise during tapping.
The holding circuit (flip-flops 111 and 112) for the tap and blockage start signals is reset, for example, when the dust concentration is automatically and continuously measured and the value falls below a certain value, or when the operation of the working machine is completed. It can be reset using a detection signal and a timer, or it can be reset manually.

33 is a dust collection pattern discrimination unit which receives process status signals for each tap hole, such as a tap start signal, tapping, slag tapping, and blockage start signals, and determines an appropriate combination of these signals. Outputs a signal that selects the dust collection damper opening command value and suction damper 2 opening command value, the blower rotation speed command value, or the blower motor operation command pattern that provides the optimal attraction for dust collection. do.

Specifically, a selection signal is outputted to one of the dust collection patterns stored in the dust collection pattern storage section 34 by inputting a signal of the tapping process state for each taphole. , whose structure is made of, for example, a diode matrix AND circuit.

Reference numeral 34 denotes a dust collection pattern storage unit that stores the opening command for each dust collection damper and the air volume of the blower or the opening degree of the suction damper 2 corresponding to the air volume in order to perform optimal induction according to the process status of each tap hole. A command value, a specified rotation speed value of the blower 3, etc. are stored as a dust collection button.

If there are multiple blowers, a command to select the number of blowers is also stored as part of the dust collection pattern.

The dust collection button storage unit 34, which manually receives the pattern selection signal from the dust collection pattern determination unit 33, sends an output signal corresponding to the stored content of the selected pattern to the dust collection damper and suction damper drive unit 35, or to the blower drive. device 36.

As described above, the present invention stores in advance a dust collection pattern consisting of a combination of the opening degree of the dust collection damper, the opening degree of the suction damper, the speed of the blower, the number of operating blowers, etc. By changing the selection of the dust collection pattern according to the situation, the dust collection damper and suction damper drive device 35, blower drive device 36, etc. are controlled, making it possible to automate dust collection in the casthouse. The invention has saved labor in casthouse work, made it possible to collect dust properly, and also made it possible to save energy by effectively using the air volume induced by the dust collection blower.

[Brief explanation of drawings]

1 to 3 are explanatory diagrams of a dust collecting mechanism and its control, and FIG. 4 is a block diagram of an embodiment of the present invention. 1 is a filter, 2, 5, 6, 7. 51 to 57 are tampers,
3 is a blower, 20 is a tapping schedule setting section, 21 is a molten material level calculation section in the furnace, 22 is a tapping preparation completion signal generation mechanism, 23 is a gutter, 24 is an iron mixing car, 25 is a load cell, 26
2 is a melt weighing calculation unit, 27 is a blast furnace wall, 28 is a tap port, 2
9 is a melt, 30 is a camera, 31 is a signal processing section, 32 is a signal selection section, 33 is a dust collection pattern discrimination section, 34 is a dust collection pattern storage section, 35 is a drive device for a dust collection damper and a suction damper; 36 is a blower, drive device, 81 to 87
is a suction port, 101 to 107 are AND elements, 108 to 11
0 is an OR element, 111 and 112 are flip-flops, and 113 is a selection switch.

Claims (1)

[Claims] 1. In a blast furnace cast bed dust collection device that is equipped with a blower and a dust collection filter and collects dust via a dust collection damper, the scheduled tap time signal from the tap schedule setting section and the output of the in-furnace molten material level calculation section are used. Based on the ready-for-pigment signal and the ready-for-tapping signal, a taping start signal for that taphole is given to the dust collection pattern discriminator, and the molten material weighing calculation section or the signal processing section for the taping shape using the camera outputs the tapping signal. An output signal indicating the process status is applied to the dust collection pattern discrimination section, the dust collection pattern at that time is selected, and the opening degree of the dust collection damper is automatically operated according to the output signal to perform dust collection. A method for controlling a cast bed dust collector, characterized in that: