KR101323689B1 - Mothod for controlling roll-gap by the compacting machine of hot compacted iron - Google Patents

Abstract

The present invention relates to a roll gap control method of a hardened reduced iron forming apparatus for quickly correcting a roll gap when a roll down occurs in a roll to perform stable operation, and a roll gap control method of a hardened reduced iron forming apparatus according to an embodiment of the present invention. A method of controlling roll gap in a compacted reduced iron forming apparatus in which a reduced powder (DRI) in the form of silver is passed between a pair of rolls to be formed into a hot compacted iron (HCI). Obtaining feedback of the rotational torque of the roll in real time to obtain a rotational torque real-time value; Detecting a torque down using the rotational torque real-time value; And adjusting the roll gap such that the gap between the pair of rolls is narrowed upon detecting the torque down.

Description

Method for controlling roll gap of hardened reduced iron forming apparatus {Mothod for controlling roll-gap by the compacting machine of hot compacted iron}

The present invention relates to a roll gap control method of a hardened reduced iron forming apparatus for quickly correcting a roll gap when a roll down occurs in a roll to perform a stable operation.

In general, the blast furnace method that has been the mainstream of the molten iron production equipment to date is limited in the characteristics of the raw material to use a raw material having a certain level of strength and particle size to ensure the breathability in the furnace due to the blast furnace and process characteristics.

As a carbon source used as a fuel and a reducing agent in such a blast furnace method, coke processed with specific raw coal is used, and as a molten iron source, sintered or pellets which have undergone aggregation processes such as sintering and pelletizing, which are pretreatment processes ( depends mainly on pellets).

Accordingly, the current blast furnace method must be accompanied by raw material pretreatment facilities such as coke manufacturing facilities, raw material coal, sintering facilities for the compaction of ores, and pelletizing facilities. The competitiveness of the current blast furnace method is rapidly being eroded by the enormous investment costs of environmental pollution prevention facilities to overcome global regulations on environmental pollutants generated from facilities.

In order to cope with the above situation, in the art, general coal is directly used as a fuel and a reducing agent, and as a molten iron source, a new steelmaking process is manufactured using molten iron ore, which occupies 80% or more of the world's ore production. Spurs on

Accordingly, recently, a FINEX facility, which is a fluidized bed reduction process that can use iron ore and coal, has been developed and used.

FIG. 1 is a view schematically showing a general Finex equipment, and FIG. 2 is a view schematically showing an HCI manufacturing apparatus among Finex equipment.

As shown in FIG. 1, the Finex plant includes a plurality of fluidized-bed reduction reactor 10, an HCI forming apparatus 100, a Korex reduction furnace 50, and a melt gasification furnace 20. In addition, the reducing gas supplied to the reduction furnace 10 is the gas generated and discharged from the melting furnace 20 is supplied to the reduction furnace 10 through the reduction gas supply pipe 30. In this case, a fine dust collector 60 may be installed to prevent the fine powder contained in the reducing gas discharged from the molten gasifier 20 from scattering. In addition, a dust collector 70, a compressor 80, and a PSA 40 provided in the exhaust gas pipe 90 are included as necessary.

In particular, the HCI molding apparatus 100 is a main apparatus for producing hot compacted iron (HCI), which is a raw material of the Finex molten iron, and has a high temperature powder of DRI (Direct Reduction Iron) of 600 ° C or higher, which is reduced in the fluidized bed reduction furnace 10. ) Is a device for molding.

As shown in FIG. 2, the HCI molding apparatus 100 forms a feed tank (Force Feeder Bin) 121 for supplying and feeding the DRI, and forms a powdered DRI supplied from the feed tank 121. It consists of a molding machine 120, the primary crusher 130a and the secondary crusher 130b for crushing the HCI formed in the molding machine 120 to an appropriate particle size.

The forming machine 120 is provided with a pair of tire rolls 123a and 123b rotated in opposite directions and a motor (not shown) for providing rotational force to the tire rolls 123a and 123b. One roll (fixed roll; 123a) of the pair of rolls is fixed to the forming machine 120, and the other roll (flow roll; 123b) is slid according to the amount of DRI descending from the feed tank 121 (flow). The gap between the rolls may change, and the flow roll 123b is operated by a hydraulic cylinder (not shown). Thus, during normal operation of the forming machine 120, the rotational torque of the rolls 123a and 123b is 360 to 400 kNm, and the pressure of the hydraulic cylinder is operated between 240 and 260 bar.

However, during the operation of the molding machine 120, the torque of the roll 123a, 123b is lowered to 100 kNm or less than the normal operating value, causing a torque down phenomenon in which the return is delayed for 4 seconds or more. If a torque down phenomenon occurs, there is a problem in that the yield is reduced because the equipment must be stopped for recovery, the operator must manually intervene, and the operating speed of the molding machine 120 must be sequentially increased for normal operation. Because there was a problem that the efficiency of the work is lowered.

However, in the related art, only a follow-up to the torque down phenomenon has been proposed, and there is no method for preventing the torque down phenomenon.

In particular, conventionally, the torque down phenomenon has been recognized by detecting a sudden drop in the hydraulic pressure provided to the roll, and the measure is to provide hydraulic pressure to the hydraulic cylinder for adjusting the roll gap to narrow the roll gap, and when the hydraulic pressure reaches the maximum pressure, the flow rate It was a simple 0n-off concept of flow control to stop supply. Therefore, in the related art, the reaction rate for correcting the roll gap was considerably slow.

The present invention provides a roll gap control method of a hardened reduced iron forming apparatus capable of returning the rotational torque of a roll normally by quickly correcting the roll gap when a roll down occurs when HCI is formed.

In the roll gap control method of the compacted reduced iron forming apparatus according to the embodiment of the present invention, a powdered reduced powder (Direct Reduction Iron (DRI)) is passed through a pair of rolls to be formed into hot compacted iron (HCI). A method of controlling a roll gap in a compacted reduced iron forming apparatus, the method comprising: obtaining feedback of a rotation torque of a roll in real time during HCI molding to obtain a rotation torque real time value; Detecting a torque down using the rotational torque real-time value; And adjusting the roll gap such that the gap between the pair of rolls is narrowed upon detecting the torque down.

The method further includes setting an appropriate rotational torque value of the roll to a roll gap indication value before forming the HCI, and adjusting the roll gap includes a difference between the roll gap indication value and the roll gap indication value using the roll gap real-time value fed back in real time. Compensating the roll gap operation value calculated in real time.

Adjusting the roll gap is characterized in that carried out by adjusting the hydraulic pressure provided to the hydraulic cylinder for adjusting the gap between the rolls.

When the roll gap is corrected in real time, the maximum value of the roll gap correction speed by the hydraulic cylinder is 4 mm / sec.

The detecting of the torque down may include detecting a change in the hydraulic pressure provided to the hydraulic cylinder.

According to an embodiment of the present invention, in the hardened reduced iron forming apparatus, when the torque down problem of the roll occurs, the torque of the roll can be quickly returned normally by compensating the roll gap, which is a main factor for determining the torque of the roll, in real time. Accordingly, the hardened reduced iron forming apparatus can be continuously operated, thereby increasing the productivity of the HCI.

1 is a view schematically showing a general Finex equipment,
Figure 2 is a schematic view showing the HCI manufacturing apparatus of the Finex facility,
3 is a view schematically showing an HCI manufacturing apparatus of the Finex facility according to the present invention,
4 is a view for explaining factors affecting the roll rotation torque,
5 is a graph showing the change of the main factors when the torque down occurs,
6 is a flow chart showing a roll gap control method of the compacted reduced iron forming apparatus according to an embodiment of the present invention,
7 is a result of comparing the roll gap correction speed when the torque down occurs during the HCI molding according to the present invention and HCI molding according to the conventional general method.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know. Wherein like reference numerals refer to like elements throughout.

Figure 3 is a schematic view of the HCI manufacturing apparatus of the Finex facility according to the present invention.

First, the roll gap control method of the compacted reduced iron forming apparatus according to the embodiment of the present invention is a method carried out in the equipment applied to the Finex facility, which is a fluidized bed reduction process that can use the iron ore and ordinary coal using a fluidized bed The overall description of the Finex equipment has been described above with reference to FIGS. 1 and 2, and thus, detailed descriptions thereof will be omitted.

HCI molding apparatus 100 according to the present invention is a feed tank (Force Feeder Bin; 121) for supplying while feeding (Reed Iron (DRI, "DRI").) A pair of rolls 123a and 123b and a pair of rolls 123a and 123b which are installed to face a lower portion of the 121 to form a DRI supplied in a powder state from the supply tank 121 and to rotate the pair of rolls 123a and 123b. A rotation drive unit 200; A movement driving part 300 for moving any one of the pair of rolls 123a and 123b to adjust a gap between the rolls 123a and 123b; Control unit 400 for controlling at least one of the rotation driver 200 and the movement driver 300 according to the operation value calculated by calculating the difference between the roll gap real-time value and the roll gap proper value fed back in real time from the movement driver 300 ).

The supply tank 121 is a means for providing between the pair of rolls (123a, 123b) while adjusting the supply amount of the DRI by a screw feeder in a state in which the DRI is stored.

The pair of rolls 123a and 123b are provided in a tire type, and one of the pair of rolls 123a and 123b (fixed roll; 123a) is installed to fix a position and the other roll (flow roll) 123b is installed by the moving driver 300 to adjust a gap with the fixing roll 123a. In addition, the pair of rolls 123a and 123b are rotated in directions opposite to each other in conjunction with the rotational force provided by the rotation driver 200. The DRI supplied between the pair of rolls 123a and 123b receives a compressive force between the pair of rolls 123a and 123b and is referred to as Hot Compacted Iron (HCI) hereinafter having a predetermined particle size. Molded into).

The rotation driving unit 200 is a means for controlling the rotation torque while rotating the pair of rolls (123a, 123b), for example, a motor is used. At this time, the pair of rolls (123a, 123b) is preferably rotated by the same rotation torque is connected to rotate in the opposite direction by one motor.

The moving drive unit 300 is a means for moving one of the pair of rolls 123a and 123b, that is, the flow roll 123b back and forth in the fixed roll 123a direction, for example, a hydraulic cylinder is used. Thus, the pressure and the roll gap provided to the rolls 123a and 123b can be adjusted by adjusting the hydraulic pressure provided to the hydraulic cylinder.

Meanwhile, the present embodiment feeds back real-time values such as rotation torques, roll gaps, and roll pressures of the rolls 123a and 123b controlled by the rotation driver 200 and the movement driver 300 to provide the rotation driver 200. And a controller 400 for controlling the operation of the movement driver 300.

At this time, the real-time rotation torque value of the roll (123a, 123b) is calculated by receiving the feedback of the operating amount of the motor, the real-time roll gap and roll pressure of the roll (123a, 123b) is provided to the moving distance of the hydraulic cylinder and the hydraulic cylinder It is calculated by receiving the change in hydraulic pressure.

The controller 400 may determine a difference between a real time rotation torque real time value, a roll gap real time value, and a roll pressure real time value fed back from the rotation driver 200 and the movement driver 300, and an appropriate value of a preset rotation torque, roll gap, and roll pressure. At least one of the rotation driving unit 200 and the moving driving unit 300 is controlled to compensate for the difference by calculating.

The method of shaping | molding HCI using the hardened reduced iron (HCI) shaping | molding apparatus comprised as mentioned above is demonstrated.

First, the relationship between the main factors to be considered in order to properly maintain the rotational torque of the roll in HCI molding will be described.

FIG. 4 is a diagram illustrating factors influencing roll rotation torque, and FIG. 5 is a graph showing changes in main factors when a torque down occurs.

As shown in FIG. 4, the main factors for maintaining the rotational torque T of the roll include the inflow velocity and amount of the DRI spectral amount, the roll pressure P and the roll gap G due to the hydraulic force provided to the hydraulic cylinder. There is). At this time, the inflow rate and the amount of the DRI spectroscopy can be easily controlled by the operation control of the supply tank 121, and since the inflow rate and amount of the DRI spectroscopy is controlled by controlling the operation of the supply tank 121 in the past In this embodiment, the inflow rate and amount of the DRI spectroscopy are preferably excluded from the main factors under the assumption that they are controlled.

4 and 5, when the rotational torque T of the roll decreases, the roll pressure P decreases and the roll gap G decreases simultaneously. This shows the correlation between the rotational torque T and the roll pressure P and the roll gap G.

However, as can be seen in FIG. 5, it can be seen that the change rate of the roll gap G is considerably slower when a torque down phenomenon occurs, and the roll pressure P also does not react sensitively to the change in the rotational torque T of the roll. have. This is because the conventional system is designed without considering non-ideal conditions such as a torque down phenomenon, and thus the roll gap (G) control and roll pressure (P) maintenance control system are insufficient in construction, and thus the rotational torque (T) variation of the roll is changed. We do not believe this will be promptly compensated. In other words, in order to control the optimum conditions for forming the HCI, it is important to maintain the rotational torque T of the roll appropriately, and to maintain the rotational torque T of the roll properly, the roll gap G and the roll pressure P Appropriate adjustments can be made to improve.

Accordingly, the present invention adopts a method of controlling the roll gap G and the roll pressure P in real time as a method of properly maintaining the rotational torque T of the roll to prevent the torque down phenomenon, and in particular, the rotational torque of the roll A method of correcting the roll gap G in real time is provided by providing hydraulic pressure to a hydraulic cylinder that adjusts the gap between the rolls 123a and 123b when a decrease in torque down occurs.

6 is a flowchart showing a roll gap control method of the compacted reduced iron forming apparatus according to an embodiment of the present invention.

As shown in the drawings, the roll gap control method of the compacted reduced iron forming apparatus according to the embodiment of the present invention includes the steps of setting the appropriate rotational torque value of the roll to the roll gap indication value before HCI molding; Obtaining feedback of the rotational torque of the roll in real time during HCI molding to obtain a rotational torque real-time value; Detecting a torque down using the rotational torque real-time value; And adjusting the roll gap such that the gap between the pair of rolls is narrowed upon detecting the torque down.

In other words, before setting the HCI, the appropriate value of the roll gap G is set to the roll gap indication value, and then the HCI molding is started.

The real time rotation torque value and roll gap real time value are calculated | required in real time during the shaping | molding of HCI. The torque down phenomenon is detected using the rotation torque real-time value among the rotation torque real-time value and the roll gap real-time value thus obtained. At this time, the detection of the torque down phenomenon can be known by detecting a change in which the rotational torque of the roll is sharply lowered. The torque down phenomenon is to detect a case where the rotational torque of the rolls 123a and 123b is lowered to 100 kNm or less than the normal operating value and the return is delayed for 4 seconds or more during the operation of the molding machine 120. In addition, the torque down phenomenon may be confirmed by detecting a change in which the hydraulic pressure provided to the hydraulic cylinder is sharply lowered.

When a torque down phenomenon occurs, it is quickly detected, and then a roll gap calculation value is calculated by calculating a difference between the roll gap real time value and the roll gap real time value using the roll gap real time value fed back in real time.

If the roll gap calculated value is calculated in this way, the amount of hydraulic pressure supplied to the hydraulic cylinder is increased in real time to narrow the roll gap G. In this case, it is preferable to compensate for the roll gap calculated by calculating a difference between the roll gap real time value and the roll gap real time value using the roll gap real time value fed back in real time.

Further, when correcting the roll gap G in real time, it is preferable that the maximum value of the roll gap G correction speed by the hydraulic cylinder does not exceed 4 mm / sec. The reason for this is that when the roll gap G is corrected faster than the suggested speed, a deviation of the roll gap G may occur rapidly, and hunting of the roll pressure P may occur, which may cause an HCI particle size deviation.

Next, when a torque down occurs, the method according to the present invention is compared with the conventional method.

7 is a result of comparing the roll gap correction speed when the torque down occurs during the HCI molding according to the present invention and HCI molding according to the conventional general method.

As can be seen in Figure 7, when the torque down occurs when forming the HCI according to the conventional general method to provide a hydraulic pressure to the hydraulic cylinder for adjusting the roll gap simply to narrow the roll gap, when the hydraulic pressure reaches the maximum pressure to stop the flow supply It was. Accordingly, the conventional roll gap correction speed was up to 0.16 mm / sec.

On the other hand, when a torque down occurs when forming the HCI according to the present invention, it is possible to quickly control the hydraulic pressure provided to the hydraulic cylinder according to the calculated roll gap correction value, thereby improving the roll gap correction speed up to 4 mm / sec.

Accordingly, by forming the HCI according to the present invention, it is possible to improve the roll gap correction speed when a torque down occurs, thereby quickly returning the torque of the roll to normal.

Although the present invention has been described with reference to the accompanying drawings and the preferred embodiments described above, the present invention is not limited thereto but is limited by the following claims. Accordingly, those skilled in the art will appreciate that various modifications and changes may be made thereto without departing from the spirit of the following claims.

121: supply tank 123a: fixed roll
123b: flow roll 200: rotary drive unit
300: moving drive unit 400: control unit

Claims (5)

A method for controlling a roll gap in a compacted reduced iron forming apparatus in which a powdered direct reduction iron (DRI) is passed between a pair of rolls to be formed into a hot compacted iron (HCI),
Obtaining feedback of the rotational torque of the roll in real time during the HCI molding to obtain the rotational torque real-time value;
Detecting a torque down from a change in which the rotational torque of the roll is sharply lowered using the rotational torque real-time value;
Adjusting a roll gap to narrow the gap between the pair of rolls upon detecting the torque down;
Adjusting the roll gap is carried out by adjusting the hydraulic pressure provided to the hydraulic cylinder for adjusting the gap between the rolls,
And the maximum value of the roll gap correction speed by the hydraulic cylinder when correcting the roll gap in real time is 4 mm / sec.
The method according to claim 1,
Setting the appropriate rotational torque value of the roll to the roll gap indication value before HCI molding,
The adjusting of the roll gap is a roll gap control method of the hardened reduced iron forming apparatus, which compensates in real time a roll gap calculation value obtained by calculating a difference between a roll gap indication value and a roll gap real time value using a roll gap real time value fed back in real time.
delete delete The method according to claim 1,
The detecting of the torque down may include detecting the change of the hydraulic pressure provided to the hydraulic cylinder.

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