JPH01296081A - Control of operational condition of cupola - Google Patents

Abstract

PURPOSE:To facilitate control operations proximate to an objective operational condition, by a method wherein measuring data for controlling temperatures in respective parts of a cupola, the flow rate of ventilating air, the compositions of molten metal or generating gas and the like are detect to obtain respective controlling objective data of the objective operational condition together with an output including a graph indicating mutual relative relation of the controlling measuring data. CONSTITUTION:Detecting signals from detectors 25-36, 38, 39, a throw-in counter 37 and analyzers 40-43 are converted by a signal converter 50 and is transmitted to a computer device 51. An indicating means 53 indicates the temperatures, flow rate of air, pressures, operating numbers and the like in a real time to indicate the present condition of the cupola 1. When the specification of the cupola, the objective molten metal composition, the nature of coke and the like are inputted by employing a key inputting means 52 previously, a processing means 55 indicates graphs and the like with respect to various measuring data indicating the present condition of the cupola based on the accumulated data and inputted data. Based on the above-described indications, manual or automatic controlling operations may be effected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for controlling the operating conditions of a cupola, which is a type of cast iron melting furnace.

In operating a conventional cupola, metal and coke are used as charges, combustion air is supplied, and combustion auxiliary materials (pulverized coal) are supplied as necessary.

In producing cast iron with a target composition, the combustion conditions in the cupola, the composition of the charged coke and ingots, and the ingots also include ferroalloys, waste pig iron, return pig iron, scrap steel, and pig iron. It is necessary to appropriately control the formulation of

Regarding cupolas, until recent years, such control of operating conditions has relied on the intuition and experience of skilled operating engineers, and this trend remains strong even today.

Problems to be Solved by the Invention In recent years, there has been a shortage of skilled engineers due to the aging of skilled engineers. With such an operation control method that relies on experience and intuition, unless the engineer has sufficient experience, the control of the operating state is uncertain and the operation efficiency cannot be improved, resulting in poor quality of the cast iron produced. The problem was that it also became unstable.

The purpose of the present invention is to solve the above-mentioned technical problems and to enable efficient control of the operating state toward the target operating state without relying on the experience and intuition of skilled engineers when operating a cupola. An object of the present invention is to provide a method for controlling the operating state of a cupola.

Means for Solving the Problems The present invention detects various types of control measurement data such as the temperature of each part of the cupola, the air flow rate, the composition of molten metal and generated gas, and the weight of each of a plurality of types of charges. an output including a chart showing the correlation between the plurality of types of control measurement data in the operation of the cupola, based on the control target data of the type in the target operation state of the cupola and the control measurement data; This is a cupola operating state control method characterized in that a control operation is performed to bring the current operating state closer to the target operating state based on the output.

According to the present invention, when operating a cupola, various types of control measurement data such as the temperature of each part of the cupola, the flow rate of air flow, the composition of molten metal and generated gas, and the weight of each of a plurality of types of charges are collected. To detect. On the other hand, based on each of the types of control target data and the control measurement data in a predetermined target operation state of the cupola, the correlation between the plurality of types of control measurement data in the operation of the cupola of the relevant type is determined. You will get an output containing a diagram showing the . This output may be output as a printed output, for example, or may be output using a visual display means, or may be output in a manner equivalent to the output without outputting such output in a visually appealing format. A control operation may be performed to bring the current operating state closer to the target operating state based on the data processing results obtained.

When the output is performed as a chart, printed output, output by a video display means, etc., the operator may visually check the chart and manually perform the control operation.

Embodiment FIG. 1 is a system diagram showing the configuration necessary for operating a cupola 1 according to an embodiment of the present invention. The configuration of this embodiment will be explained with reference to FIG.

Coke, metal, and the like are alternately charged into the cupola 1 through its charging port 2, and are deposited in layers inside the cupola. In order to burn the charge to the cupola 1, combustion air is supplied into the cupola 1 from the tuyere (not shown) of the cupola 1 via the wind box 3. Molten metal 5 is tapped from the tap 4.

Ferroalloy, coke, waste pig iron, returned pig iron, steel scrap, pig iron, and the like are used as charges for the cupola 1. These are stored in hoppers 6 to 11 for each type, and individually dropped onto a conveyor belt 18 by feeders 12 to 17. The dropped charge is loaded into a packet 19 by the conveyor belt 18, this packet 19 is conveyed to the charging port of the cupola 1, and the contents are charged into the cupola 1.

Here, the above-mentioned charges are conveyed so that when they are introduced into the cupola 1, metal and coke are deposited alternately in layers.

The combustion air supplied to the cupola 1 is passed through a dehumidifier 21
Air is blown from the air blower 22 through the air.

The combustion air from this blower 22 is transferred to a heat exchanger 23.
The temperature is increased by heating. Exhaust gas from the cupola 1 is supplied to this heat exchanger 23 via a duct 24, and serves as a heat source.

In the configuration related to such a cupola 1, a large number of measuring instruments for measuring various data are provided. Measuring instruments for detecting temperature include a tapping temperature detector 25 for detecting the temperature of the produced molten metal 5, and a furnace wall temperature detector 26.
, a furnace top gas temperature detector 27, a blast temperature detector 28, and an outlet exhaust gas temperature detector 29 of the heat exchanger 23. In addition, as a configuration for measuring weight, the hoppers 6 to 11
Alternatively, in connection with the feeders 12-17, heavy I detectors 30-35 are respectively provided for each charge. Regarding such charges, a throwing personnel level detector 36, a charging counter 37, etc. are provided.

On the other hand, regarding the supply path of the combustion air, a blowing flow rate detector 38 and a wind box pressure detector 39 for detecting the wind box pressure are provided.

As a component analyzer, a first analyzer 40 that detects the composition of carbon oxide in the top gas and a second analyzer 41 that detects the composition of carbon dioxide are arranged. Further, a molten metal composition analyzer 42 is arranged to detect the composition of various components of the molten metal 5 to be tapped.

Further, in order to control the combustion state of the cupola 1, an oxygen-enriched air adjustment section 43 that adjusts the supply amount of oxygen-enriched air and a pulverized coal l adjustment section 44 that adjusts the supply amount of pulverized coal (breath) are provided.

A combustion air conduit 45 directed toward a heat exchanger 23 is connected to the air blower 22 , and a conduit 46 directed toward the wind box 3 is connected to the heat exchanger 23 . A bypass pipe line 47 is provided between the pipe lines 45 and 46 before and after the heat exchanger 23. Flow control valves 48 and 49 are provided in the pipe line 45 and the bypass pipe line 47, respectively, to adjust the amount of air flowing therethrough.

Each of the detectors 25 to 36, 38, 39, input counter 3
Detection signals from 7 and analyzers 40 to 43 are converted into, for example, digital signals by a signal converter 50 and sent to a computer device 51.

The computer device 51 performs data processing and includes key input means 52 such as various keyboards, display means 53 such as a CRT (cathode ray tube), printing means 54 such as various printers, and various microprocessors. It is configured to include processing means 55.

The output signal from the computer device 51 is output to a control device 56 that controls the operation of various components related to the cupola 1, and the control device 56 controls the amount of operation of the feeders 12 to 17 in order to achieve the target composition of molten metal. Each of them is controlled individually, and the operating speed of the conveyor belt 17 and the packet 19 is also controlled. Control of such operating speed is an important element for temperature management within the cupola 1. In addition, in order to control the combustion state in the cupola 1, a flow control valve 48°49
, and the flow rate and temperature of combustion air supplied to the wind box 3. At the same time, the oxygen-enriched air adjustment section 43 and the pulverized coal adjustment section 44 are also controlled to control the combustion state within the cupola 1.

In the above-described configuration, the display means 53 displays a display as shown in FIG. 2, for example. In this display example, the temperature, flow rate, pressure and number of operations of each part of the cupola 1 are displayed in real time. . In this way, the operator can know the current status of the cupola 1 simply by looking at the display means 53.

The display means 53 also displays, as shown in FIG. 3, the composition of carbon dioxide and carbon monoxide in the furnace top gas, the amount of air blown, the tapping temperature, the raw material input timing, and the like over time. By observing such a display, the operator can easily grasp the fluctuation state of the operating status.

Further, the display means 53 displays a thermal calculation diagram as shown in FIG. This makes it possible to utilize heat effectively.

The operating procedure for the configuration shown in FIG. 1 will be described below. The operator uses the key manual means 52 to input in advance the specifications of the cupola 1 to be used, the target molten metal composition and its temperature, the components of each charge, coke properties, and the like. In the computer device 51, the processing means 55 is equipped with various storage devices, and such input data is stored. on the other hand,
The storage device stores data such as the specifications of various types of cupolas, the temperature distribution inside the furnace, the air flow rate, and the required amount of various raw materials to achieve the target temperature and composition of molten metal for each specification. . Based on this accumulated data and the input data, the processing means 55 displays charts such as line charts to be described later regarding various measurement data indicating the current state of the cupola 1.

511J is a graph showing the change over time in the tapping temperature of the molten metal 5, and FIG. 6 is a graph showing the relationship between the air flow rate and the carbon ratio in a line diagram on a coordinate plane whose coordinate axes are the tapping temperature and the melting rate. It is. The carbon ratio here refers to the ratio of carbon retained in combustion in the coke supplied to the cupola 1. The display means 53 displays such a chart or the like. Based on this graph, the outlet hot water temperature starts to decrease rapidly from time t1, which is about 7 minutes after the predetermined time. The operating conditions of the cupola 1 before this drop starts are shown in FIG. In other words, the air flow rate is approximately 77 (Nm'
/m"・min) and carbon ratio of 11.3%, a dissolution rate of 6.8 (t/m"・h) and a tapping temperature of approximately 1480° C. were achieved. Such 4N operating conditions are indicated all at once by displaying a circle at point P1 in the display diagram of FIG.

However, under the operating condition indicated by point P1, a furnace condition is shown in which the tapping temperature has decreased. The reduced state at this time is indicated by point P2 in FIG.

In the present invention, under such a situation, the operator may, for example, refer to a chart like the one shown in FIG. , or the computer device 51 may automatically perform such a manual operation without performing such a manual operation.
, a tolerance range of 62° C. is set below, and when the fluctuation in the tapping temperature exceeds this tolerance range, the return control operation is started. Similar tolerance ranges are controlled for other control data as well.

FIG. 7 shows an example of the chart display corresponding to FIG. 6 after the operating conditions such as air flow rate have been changed. Point P2 is also attached to the position corresponding to point P2 in FIG. The position representing the condition is indicated by point P3, that is, by changing the air flow rate and the carbon ratio, it was possible to restore the tapping temperature without changing the dissolution rate.

In the present invention, other types of variables may be used as variables in such diagram display examples, and the combination of variables to be displayed depends on the type of cupola, the operating conditions at each point, and the occurrence of the occurrence. It can be selected as appropriate depending on the type of abnormal situation.

The above-described operation regarding the cupola 1 may be performed in a fully automatic manner using the computer device 51, or in a manual manner in which the operator manually performs the return operation etc. while observing graphical display examples such as those shown in FIGS. 5 to 7. It may be an operating method, or it may be performed manually or automatically only for variables predetermined by the operator.

In addition, although the above example shows an example in which the tapping temperature is controlled to the target temperature, other important controlled elements such as dissolution rate, molten metal composition, and molten metal suction rate can also be controlled in this manner. It can be performed.

Effects of the Invention As described above, according to the present invention, a plurality of types of control target data are determined in advance, and based on the control target data and the same type of control measurement data, the type of cupola being used is determined. It is now possible to obtain output including a chart showing the correlation between the control measurement data in the operation of the system. Based on this output, control operations that bring the current operating state closer to the target operating state are reliably performed. Such control operations may be performed fully automatically or at least partially manually; however, as described in the prior art section, this This eliminates the need to rely on the experience and intuition of skilled engineers for such control operations, thereby significantly improving operational efficiency.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a configuration according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of displaying the current furnace status, and FIG. 3 is a diagram showing an example of displaying a graph showing changes in furnace status over time. , Fig. 4 is a diagram showing an example of displaying a heat calculation diagram, Fig. 5 is a diagram showing an example of displaying a graph of time change in outlet temperature, and Figs. It is a figure which shows the example of a display of the line diagram which shows the correlation of control data. DESCRIPTION OF SYMBOLS 1... Cupola, 5... Molten metal, 25... Tapping temperature detector, 26... Furnace wall temperature detector, 27... Furnace top gas temperature detector, 28... Air blowing temperature Detector, 29...
・Outlet exhaust gas temperature detector, 30...pig iron weight detector,
31... Steel scrap weight detector, 32... Return pig iron weight I detector, 33... Waste pig iron weight detector, 34... Coke weight detector, 35... Ferroalloy weight detector, 36... Official material level detector, 37... Input counter, 38...
・Air flow rate detector, 39...Wind box pressure detector, 40・
... first analyzer, 41 ... second analyzer, 42 ... molten metal composition analyzer, 43 ... oxygen enriched air adjustment section, 44.
... Powdered coal amount adjustment section, 51 ... Computer device, 53
...Display device, 54...Printing device, 55...Processing device Agent Patent attorney Number of strokes Keiichi $2 Zushu Essence of death 1; Yoru Saito 26. Fu-zm**
32.62"/. Figure 4 'X Figure 5 Removal File? (ke) Figure 6 C Figure 7

Claims (1)

[Scope of Claims] Various types of measurement data for control such as the temperature of each part of the cupola, the air flow rate, the composition of molten metal and generated gas, and the weights of multiple types of charges are detected, and the target operation of the cupola is determined in advance. Based on the above-mentioned type of control target data in the state and the control measurement data, an output including a chart showing the mutual correlation between the plurality of types of control measurement data in the operation of the cupola of the relevant type is obtained, and A method for controlling the operating state of a cupola, characterized in that a control operation is performed to bring the current operating state closer to the target operating state based on the output.