JPS622004B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention automatically controls the production and supply status of oxygen gas according to the operating status of furnace equipment such as blast furnaces and converters in steel plants, thereby reducing losses such as atmospheric release. This invention relates to an oxygen gas production and supply device improved to improve oxygen gas production efficiency.

In steelworks, pig iron and steel production are carried out using blast furnaces, converters, etc., which are installed in clusters, and the furnace equipment such as blast furnaces, converters, etc. Supplying oxygen gas. Oxygen gas production and supply equipment is installed to supply oxygen gas to this furnace equipment, and this production and supply equipment monitors the operating status of the furnace and supplies the required amount of oxygen gas according to the operating status. so that it is manufactured and supplied,
It is operated and operated by experienced hands.

For example, in the case of converters that are usually equipped with multiple units, hot metal is brought into each converter, blown into the furnace, and then transported out as a product. In each converter, oxygen gas is supplied a predetermined time before the hot metal is introduced, and the supply of oxygen gas is controlled to continue until the blowing is completed. Therefore, the supply control of oxygen gas used in the converter is performed intermittently according to the work in each converter, such as loading hot metal and blowing, and the operating status of each furnace is controlled. It is impossible to monitor the oxygen gas production and supply equipment with sufficient care and operate it properly based on human experience alone. However, there are many inconveniences such as release.

In other words, the intermittent oxygen gas supply control described above makes the operating state of the oxygen gas production and supply equipment unstable, and the oxygen gas supply to each converter becomes unstable, causing the furnace operating state to become unstable. This destabilizes the oxygen gas, sometimes resulting in an excess or deficiency state, and other times leading to a state in which excess oxygen gas is supplied than necessary. For this reason, it is usually set up to produce and supply more oxygen gas than necessary in order to adequately respond to the operating conditions of the furnace, and in particular to prevent failures due to lack of oxygen gas. Therefore, 5 to 10% of the required supply amount of oxygen gas is released into the atmosphere, resulting in a loss.

The intermittent oxygen gas supply control described above is difficult to keep the oxygen gas supply pressure constant, and is extremely undesirable in order to maintain the oxygen gas production and supply equipment system in a stable state. For this reason, an accumulator for storing oxygen gas at a predetermined pressure is usually provided between the oxygen gas supply equipment and each furnace, as a means for alleviating pressure fluctuations that accompany fluctuations in the amount of oxygen gas supplied. However, even when using this accumulator, artificial control based on empirical rules,
It is not possible to sufficiently cope with intermittent operation in which each of a plurality of furnaces is operated independently.

Oxygen gas production and supply equipment usually consists of an air separation device that separates and extracts oxygen from the air in the atmosphere, but this air separation device separates oxygen gas, nitrogen gas, etc. I try to separate them. Therefore, it takes a considerable amount of time to stabilize the desired amount of oxygen gas production due to fluctuations in operation, and there is a large time delay in following up on fluctuations in operation. It is. For this reason, it is difficult to properly respond to and control the intermittent fluctuations in the oxygen gas supply amount that corresponds to the operating status of the converter, and the amount of oxygen gas produced becomes unstable, resulting in efficient operation. making control more difficult.

This invention has been made in view of the above points, and is based on the standards set based on production planning information and predictions, etc., in relation to the oxygen gas demand of the furnace equipment, the oxygen gas production mode, etc. By controlling the operation based on the system, it is possible to stably supply oxygen gas that is suitable for the operating mode of the furnace equipment, and to set the oxygen gas production state that is suitable for the consumption amount, so that it can be operated automatically and with high efficiency. The present invention aims to provide an oxygen gas production and supply device for use in steelworks systems.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing an oxygen gas production and supply system, in which a plurality of air separation devices 11a, 11b... are set up, and these air separation devices 11a, 11b... are each operated according to an operation command. It will be operated. These air separation devices 11a, 11b
..., the air from the outside taken in through the raw air intake control valves 12a, 12b, respectively, is supplied to air compressors 13a, 13b, respectively.
It is supplied via the control valves 12a, 12
The amount of air taken into the separation devices 11a, 11b, etc., depending on the opening degree of b..., that is, this separation device 1
The amount of oxygen gas produced in 1a, 11b, . . . is controlled.

The oxygen gas produced by the air separation devices 11a, 11b, . . . is collectively compressed to a predetermined pressure by a compressor 14, and is led to an accumulator 15 and stored therein. This accumulator 15 is provided with a pressure gauge 16,
Detecting the oxygen gas pressure inside the accumulator 15,
The amount of stored gas is now monitored.

The oxygen gas stored in the accumulator 15 is supplied to the blast furnaces 17a, 17b, which are the demand side, and the converter 1.
8a, 18b..., and the oxygen supply pipes for each furnace are provided with control valves 19a, 19a, 19b, 19b, 19b, 19b, 19b, 19b, 19b, 19b, 19b, 19a, 18b, .
9b..., and 20a, 20b... are provided. Then, the hot metal 21 produced in the blast furnaces 17a, 17b... is transported to the converter furnaces 18a, 18b... by carrier cars 23a, 23b... on the rails 22a, 22b..., and the operating state of each converter 18a, 18b... Accordingly, the steel is charged into the converters 18a, 18b, and blows into steel.

In this case, for example, the rails 22a, 22b... are provided with detection switches 24a, 24b..., and the transport vehicle 23
a, 23b... are obtained and sent to the converter 1.
8a, 18b...Used as a signal before charging and blowing of hot metal 21 respectively. in particular,
By the detection signals of the switches 24a, 24b...
The control valves 20a, 20b, . 20
b... is closed, the supply of oxygen gas is stopped, and the detection switch 24 corresponds to the injection of the next hot metal 21.
It is assumed that signals from a, 24b, . . . are expected.

Here, the injection control of the hot metal 21 into the plurality of converters 18a, 18b... is performed in accordance with the operation schedule and status of each of the converters 18a, 18b... In addition, in order to eliminate the intensive supply of oxygen gas, the timing of charging the hot metal 21 to each converter 18a, 18b... will be different. For example, if there are two converters, The inputs of 21 are performed alternately.

Here, in the blast furnaces 17a, 17b, etc., the supply of oxygen gas is normally uniform, and the supply control is not particularly important.
Control of supply of oxygen gas to a, 18b, . . . will be explained.

FIG. 2 shows the mode of signals related to the operation of the converter.
B, etc., the blowing preparation signal A corresponding to each converter is obtained, and the blowing time B is set after a predetermined time, for example, 5 minutes, from this signal. This blowing time B is, for example, 20
minutes, and the blowing end signal C is generated at the time when the preparation time and the blowing time B are added to the blowing preparation signal A. And this operation is the interval D,
For example, it is repeated at intervals of about 40 minutes.

In addition, in the case of the accumulator 15, as shown in Fig. 3, the internal pressure is usually set between PMID and PLOW, and when it exceeds PMAX, it releases acid.
When it drops below PMIN, it is backed up with other prepared liquid acids. Then, when PHIG is exceeded, for example, a liquid acid device is operated to liquefy excess oxygen gas and store it elsewhere before acid is released.

Here, the PMID and PLOW values that determine the normal pressure setting rate in the accumulator 15 are determined by the predicted operating state of the oxygen gas supply load of the converter, etc. It is determined based on specifications, etc.

That is, a monthly plan for required oxygen gas is created in accordance with monthly production specifications, and a daily plan is read based on this monthly plan. Then, this daily plan is read, for example, in units of one minute to calculate the scheduled oxygen gas supply amount at that time, and the operating status of the converter at that time is also detected to calculate the predicted oxygen gas consumption amount. As a means of obtaining this predicted oxygen gas consumption, for example, every hour, the number of times of converter blowing in the past four hours is measured, and compared with the past measured values and the daily plan, It predicts the number of times the converter will be blown, and a predicted oxygen gas consumption value will be obtained in accordance with this predicted number of times that the Converter will be blown.

Then, in accordance with this predicted oxygen gas consumption per unit time, for example, the normal set pressure range of the accumulator 15 is raised or lowered to correspond to future oxygen gas consumption.

FIG. 4 shows the configuration of the daily operation command device corresponding to one converter. Discrimination device 26 is controlled. for example,
Assuming that the device part shown in the figure corresponds to the converter 18a, when the blowing preparation signal A is issued by the switch 24a, the time B from this point until the blowing ends is
(See FIG. 2), the converter discrimination device 26 generates an output signal indicating that blowing is present, and at other times, it generates an output signal indicating that blowing is not performed. and,
When the converter discriminating device 26 outputs a determination of "no" blowing, it controls the weight loss command device 27 to generate a weight loss command signal.

In addition, the converter discrimination device 26 indicates that blowing is “present”.
When the determination signal is generated, a command is given to the determination device 28 of the air separation device, which determines the content of the command for increasing, sustaining, or decreasing the amount of air to the air separation device at that time, and obtains the determination output signal. If a dose increase command or a sustain command is in progress, the increase command device 29 and sustain command device 30 are controlled to issue an increase command or a sustain command, and if a decrease command is in progress, a sustain command is issued. The device 31 is controlled to generate a sustain command.

In other words, "with" blowing in the corresponding converter
Alternatively, one of the command signals of increasing, sustaining, or decreasing can be obtained depending on the state of "no" blowing and the contents of the current operation command of the air separation device. Then, such operation is repeatedly performed according to the sampling time set by the sampling circuit 32,
A command signal for increase, decrease, or continuation is obtained each time.

As mentioned above, such a driving command device is
It is installed corresponding to each converter to be installed, and command signals for increase, decrease, and continuation corresponding to each of the multiple converters can be obtained in accordance with the sampling time, and each converter The signal corresponding to the command is a new comprehensive command signal corresponding to the combination of the command contents. For example, if there are two converters and there are two sets of operation command devices corresponding to the converters, this new command signal will be set as follows according to the command content from each command device. be done.

(a) Increase command + increase command → new increase command (b) increase command + sustain command → new increase command (c) increase command + decrease command → new sustain command (d) sustain command + sustain command → new sustain command (e ) Continuation command + weight loss command → new weight loss command (f) Weight loss command + weight loss command → new weight loss command In this way, when a new weight increase, sustain or weight loss command is obtained, these commands are A to C in Figure 5, respectively. As shown in FIG. 2, the pressure in the accumulator 15 is processed as an actual command to the air separation device.

First, when a new increase command is received as shown in Fig. A, it is determined whether the pressure in the accumulator 15 is higher than PMAX, and if the acid release state is higher than PMAX, an actual command for decrease is issued. Furthermore, when the pressure is lower than PMAX, it is determined whether the pressure is higher than the upper limit PMID of the set pressure, and if the pressure is higher, a continuous actual command is issued, and if it is lower than PMID, an actual increase command is issued.

In the case of a new sustaining command as shown in figure B, when the pressure of the accumulator 15 exceeds PMAX, a reduction actual command is issued, when it is lower than PMAX and higher than PMIN, an actual sustaining command is issued, and when it is lower than PMIN, an actual increase command is issued. .

Furthermore, as shown in diagram C, when the pressure of the accumulator 15 is higher than the lower limit of the set pressure PLOW with a new weight loss command, the actual weight loss command is set to PMIN lower than PLOW.
When it is higher than PMIN, a continuation actual command is issued, and when it is lower than PMIN, an increase actual command is issued.

As described above, actual commands for increase, sustain, and decrease can be obtained by integrating the set pressure range of the accumulator corresponding to the operation prediction in the monthly plan, daily plan, and sampling timing, as well as the operating status of the converter. Based on this actual command, the amount of air input to the air separation devices 11a, 11b, . . . is controlled by the control valves 12a, 12b, . . ., thereby controlling the amount of oxygen gas produced.

In this case, if there are a plurality of air separation devices 11a, 11b, etc., the control system would become complicated if the amount of oxygen gas produced by all of the air separation devices was variably adjusted. For this reason, for example, if an air separation device is composed of three units, two of them can be set using predicted values obtained every hour or can be manually controlled, and the remaining one can be controlled as described above. It is effective to control based on actual commands.

FIG. 6 shows another embodiment in which the liquid acid system described in FIG. 3 is added, and the same components as those in FIG. 1 are given the same reference numerals and the explanation thereof will be omitted.

That is, a valve 34 controlled by the pressure gauge 16 of the accumulator 15 is provided, and when the pressure inside the accumulator 15 exceeds PHIG, this valve 34 is opened.
The produced oxygen gas from the compressor 14 is bypassed and taken out, and is supplied to the liquefaction device 35 to become liquefied oxygen. Then, this liquefied oxygen is stored in the storage tank 36.

The liquid acid in the storage tank 36 is taken out by a pump 37, vaporized by an evaporator 38, and then supplied to the compressor 14 through a valve 39 together with oxygen gas from the air separation devices 11a, 11b... Then, when the pressure in the accumulator 15 becomes lower than PMIN, the pump 37 is driven, the valve 39 is opened, and the oxygen gas is backed up into the accumulator 15 using liquid acid to maintain the pressure in the accumulator 15 at a normal value. Oxygen gas is smoothly supplied to the converter side.

Here, the liquefaction of oxygen gas is not only carried out to treat surplus gas in the accumulator 15 or to back it up in times of shortage, but can also be used as it is to produce liquefied oxygen for sale. In this case, it is sufficient to manufacture oxygen gas by adding it to the daily plan for oxygen gas consumed in converters, etc., based on the monthly specifications for liquefied oxygen. According to the state of gas consumption, liquefied oxygen is produced using the surplus gas at that time, and the operating efficiency of the device is significantly improved.

As described above, according to the present invention, it is possible to automatically control the production of oxygen gas according to the consumption amount in the furnace equipment of the steelworks, and to operate the oxygen gas production equipment very efficiently. I can do it. In the conventional case, 5 to 10
% of the oxygen gas release rate was the limit, but according to this invention, the amount of oxygen gas released can be reduced to 1% or less of the amount of oxygen gas generated, and the oxygen gas can be automatically released. Through follow-up operation, it is possible to supply with the minimum unit consumption, and the number of operating personnel can be greatly reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram illustrating the overall configuration of an oxygen gas production and supply apparatus according to an embodiment of the present invention, FIG. 2 is a diagram illustrating the operating state of a converter, which is the demand side of oxygen gas, and FIG. 3 4 is a diagram illustrating the pressure relationship of the accumulator in the above supply device, FIG. 4 is a diagram illustrating the operation command control unit for oxygen gas production in the above embodiment, and FIG. 5 is a diagram illustrating the actual production command unit based on the above operation command. The explanatory diagram, FIG. 6, is a diagram showing another embodiment of the present invention. 11a, 11b...Air separation device, 12a, 12
b...Control valve, 13a, 13b..., 14...Compressor, 15...Accumulator, 16...Pressure gauge, 17
a, 17b...blast furnace, 18a, 18b...converter, 19
a, 19b..., 20a, 20b... control valve, 21
...Hot metal, 24a, 24b...Switch, 34, 39
...Valve, 35...Liquefaction device, 36...Storage tank, 37...Pump, 38...Evaporator.

Claims (1)

[Claims] 1. In a steelworks system comprising an air separation device that separates and extracts oxygen gas, an accumulator that compresses and stores oxygen gas generated from this device, and a furnace device that supplies and consumes oxygen gas from this accumulator, the above-mentioned furnace means for determining the presence or absence of conditions that require oxygen gas related to the input of raw materials into the device, means for detecting the command state for increasing, sustaining, or decreasing the amount of air separation device at that time based on the oxygen gas required conditions; means for generating a new command for sustaining or increasing the amount in response to the detected command state; means for generating a new command for reducing the amount when oxygen gas is not required in the furnace; and means for generating a new command for increasing, sustaining or reducing the amount In response to the new command, the system is equipped with a means for issuing an actual command to the air separation device that detects the internal pressure of the accumulator to increase, maintain, or reduce the amount of generated oxygen gas, and according to the set production plan information. An oxygen gas production and supply device characterized in that the amount of oxygen gas generated is set as a standard and the operation of the air separation device is controlled in accordance with the actual command.