JP2814826B2 - Smelting furnace ore supply equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for converting raw ore, silica sand, lime and the like (hereinafter, referred to as ore) into compressed air (hereinafter, referred to as compressed air) using a lance in a smelting furnace. The present invention relates to a smelting furnace ore feeder that blows into a molten metal of a smelting furnace.

[0002]

2. Description of the Related Art A conventional smelting furnace ore feeder is shown in FIG. 4 (see Japanese Patent Publication No. Sho 61-54096).

[0003] The ore is fed into a service tank 6 by a screw conveyor 5 and is fed into a lift tank 9 through a feed source valve 7 and a feed valve 8. The compressed air (for example, 7 kilograms / square centimeter) A for transporting the ore is guided into the lift tank 9 through the pressure reducing valve 10, the pressure regulating valves 11 and 12, and also passes through the pressure reducing valve 13 and the booster valve 14. It is led to the junction with the ore from the lift tank 9. By these compressed air for transportation A,
The ore in the lift tank 9 passes through the transport valve 15 and the lance 3
Is pumped into the inner tube 3a. On the other hand, compressed air G for reaction
Is fed into the lance header 3c through the control valve 16. In the figure, reference numeral 17 denotes a level switch for detecting the upper surface in the service tank 6, reference numeral 18 denotes a pressure reducing valve for reducing the pressure in the lift tank 9, and reference numeral 19 denotes a load cell for weighing the ore M put into the lift tank 9. is there.

In such a conventional smelting furnace feeder,
The operation is performed with the degree of opening of the pressure reducing valves 11 and 12, the pressure reducing valve 13, and the booster valve 14 being constant, and a predetermined amount of compressed air and ore is supplied from the lance 3 into the molten metal in the smelting furnace 1.

[0005]

However, in the conventional smelting furnace feeder, the pressure reducing valve 1
1, 12, the pressure reducing valve 13 and the booster valve 14 are operated at a constant opening, so that the pressure in the lift tank 9 becomes
A phenomenon occurs in which the ore M decreases as the ore M is conveyed or increases due to fluid resistance in the supply path of the ore M, and the amount of ore supplied per unit time from the lance 3 into the molten metal fluctuates. There is. As a result, the reaching distance of the lance 3 fluctuates, and if the reaching distance becomes larger than the bath depth from the surface of the molten metal in the smelting furnace to the hearth, the compressed air and ore collide with the hearth and the furnace If the erosion of the floor is promoted, but the blowing distance is significantly smaller than the bath depth from the surface of the smelting furnace to the hearth, mixing of compressed air, ore and molten metal in the smelting furnace is incomplete. And the smelting efficiency decreases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and can suppress fluctuations in the blowing reach by a lance, thereby reducing the smelting furnace furnace efficiency without lowering the smelting efficiency. An object of the present invention is to provide a smelting furnace ore supply device capable of preventing floor erosion.

[0007]

According to the present invention, there is provided a smelting furnace ore supplying apparatus, wherein a lance inserted into the smelting furnace, a lift tank storing ore, and an ore communicating the lift tank with the lance are provided. A supply path, and a compressed air supply path for sending compressed air to the lift tank, wherein the ore is blown into the molten metal of the smelting furnace through the lance together with the compressed air, The air supply path is provided with a pressure setting device for setting the pressure of air supplied to the lift tank, and the ore supply path and the compressed air supply path are connected by a connection path, and the connection path is connected to the connection path. A flow setting device for setting a flow rate of the compressed air flowing through the passage;
The flow rate setting device and the pressure setting device calculate a lance blowing reaching distance from the supply amount of ore per unit time and a flow rate of the compressed air, and the lance blowing reaching distance is calculated from the level of the molten metal in the smelting furnace to the furnace. A control device for issuing a control signal is connected to the pressure setting device and the flow setting device so as to be substantially equal to a bath depth to a floor.

[0008]

According to the smelting furnace ore feeding apparatus of the present invention, compressed air is guided from the compressed air supply path into the lift tank, and the ore is guided together with the compressed air to the lance through the ore supply path. Into the melt. Here, the control device calculates the lance blowing reach from the supply amount of ore per unit time and the flow rate of the compressed air. A control signal is issued from the control device to the pressure setter and the flow setter so that the calculated lance blowing reach is substantially equal to the bath depth from the surface of the smelting furnace to the hearth, and the compressed air The pressure of the air supplied from the supply path to the lift tank and the flow rate of the compressed air in the connection path communicating with the ore supply path are adjusted. By this adjustment, the blowing reach becomes appropriate with respect to the bath depth, so that erosion of the hearth of the smelting furnace can be suppressed, while the smelting efficiency can be kept high.

[0009]

An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a service tank 21 is provided below the flow conveyor 20 in the figure, and the service tank 21 and the flow conveyor 20 are connected via a receiving valve 22. The service tank 21 has a limit switch 23 for detecting the amount of ore input,
24, 25 are provided, and the limit switch 23,
24 is for detecting the upper limit of the ore, and the limit switch 25 is for detecting the lower limit of the ore. The service tank 21 is provided with a vibrator driven by a motor 26.

A lift tank 27 is provided below the service tank 21 in the figure. The lift tank 27 and the service tank 21 are connected in series via a charging valve 28 and a charging valve 29. The lift tank 27 and the service tank 21 are connected via a large exhaust valve 30 and a small exhaust valve 31.

The lift tank 27 is connected to compressed air supply paths 32, 33, and 34 connected to a compressor (not shown). The compressed air supply passage 32 is connected to the lift tank 27
The compressed air supply path 32 is provided with an upper pressurizing valve 35. The compressed air supply passage 33 communicates with the lower portion of the lift tank 27 and
3, a pressure setter 36 and a fluidizing valve 37 are provided in series. The compressed air supply path 34 communicates with the compressed air supply path 33 and communicates with the lower part of the lift tank 27, and the compressed air supply path 34 is provided with a lower pressurizing valve 38.

The lift tank 27 is connected to a lance 40 via an ore supply path 39. The ore supply path 39 is provided with a transport valve 41, and a downstream side of the transport valve 41 is connected to a compressor (not shown) via a connection path 42. Branching from the middle of the connecting road 42 to branch road 4
3 is provided, and the branch path 43 communicates with the lift tank 27. The branch passage 43 is provided with a primary booster valve 44. A secondary booster valve 45 and a flow rate setting device 46 are connected in series to the connection path 42. In the figure, reference numeral 48 denotes an aeration valve.

The pressure setting device 36 and the flow setting device 46 are connected to a control device 47. An electric signal indicating the ore supply amount and an electric signal indicating the flow rate of the compressed air are input to the control device 47. Based on these electric signals, the lance blowing reach distance is calculated. A control signal is issued to the pressure setting device 36 and the flow rate setting device 46 so that the lance blowing reach distance is substantially equal to the bath depth from the molten metal surface in the smelting furnace to the hearth. The flow rate setting value is changed.

Next, the operation of this embodiment will be described.

One cycle includes a charging step, a pressurizing step, a transporting step, and an exhausting step.

First, the ore is charged from the service tank 21 into the lift tank 27 by opening the large exhaust valve 30, the charging valve 29, the charging source valve 28, and the aeration valve 48 (charging step). When the timer is counted up, or when the load cell provided in the lift tank 27 measures a fixed amount, the large exhaust valve 30, the input valve 29, the input valve 2
8. Close the aeration valve 48 to stop ore charging.

Next, the upper pressurizing valve 35 and the lower pressurizing valve 38 are opened to increase the pressure in the lift tank 27 (pressurizing step). When the pressure in the lift tank 27 reaches the pressure set by the pressure setting device 36, the upper pressurizing valve 35 and the lower pressurizing valve 38 are closed to stop pressurizing.

Next, the secondary booster valve 45 and the transport valve 4
1. The ore in the lift tank 27 is transported together with the compressed air toward the lance 40 by opening the fluidization valve 37 and the primary booster valve 44 (transportation step). When the weight of the ore in the lift tank 27 is reduced to a predetermined value or less by the load cell provided in the lift tank 27, the secondary booster valve 45, the transport valve 41, and the fluidizing valve 3
7. Close the primary booster valve 44 to stop ore transportation.

Next, the secondary booster valve 45 and the transport valve 4
1. When a predetermined time has elapsed after closing the fluidizing valve 37 and the primary booster valve 44, the large exhaust valve 30 and the small exhaust valve 31 are opened to exhaust the air in the lift tank 27. (Exhaust process). Then, when the timer counts up, the large exhaust valve 30 and the small exhaust valve 31 are closed to stop the exhaust.

FIG. 2 shows the relationship between the transported weight and time in one cycle. The ore is transported only during the time A in the time B of one cycle, and the ore is not transported during the time other than the time A. Here, A / B is called the feed rate,
In a normal operation state, it is 40% to 60%.
When the weight of ore transported during one cycle is W, the value obtained by dividing the W by the above-mentioned ore supply rate is referred to as an instantaneous ore supply amount. The instantaneous ore supply is a numerical value proportional to the ore supply per unit time of ore blown into the smelting furnace from the lance, and substitutes the ore supply per unit time.

In this embodiment, the above-mentioned supply rate and instantaneous supply quantity are calculated by measuring the time B of one cycle and the time A required for transporting the ore in one cycle. The instantaneous supply amount is input to the control device 47 as the supply amount per unit time. further,
The control device 47 has a connection passage 42 communicating with the ore supply passage 39.
The flow rate of the compressed air in the inside is input, and the blowable distance of the ore blown with the compressed air from the lance 40 is calculated based on the instantaneous supply amount and the flow rate. Further, the control device 47 compares the calculated blowing reach distance with the bath depth from the surface of the molten metal in the smelting furnace to the hearth, and finds that the blow reach distance in the lift tank 27 becomes substantially equal to the bath depth. The pressure and the flow rate of the connection path 42 are set. Then, the set values are transmitted to the pressure setting device 36 and the flow setting device 46 to change the set values of the pressure and the flow. As a result, the blowing reach is adjusted to an appropriate value reflecting the ore supply state in the immediately preceding cycle, so that damage to the hearth can be prevented and smelting efficiency can be increased. Further, since the hearth can be used for a long time, continuous smelting becomes easy. Further, since a large number of lances can be provided, it is possible to cope with a large furnace.

FIG. 3 shows changes in the pressure in the lift tank 27 and the weight of the ore in the lift tank 27 during the cycle. The pressure in the lift tank 27 increases linearly in the pressurizing step, is kept substantially constant in the transporting step, and gradually decreases in the exhausting step. On the other hand, the weight of the ore in the lift tank 27 gradually decreases as the ore is supplied to the lance 40 in the transportation process.

[0024]

As described above, according to the present invention,
A lance inserted into the smelting furnace, a lift tank for storing ore, an ore supply path communicating the lift tank with the lance, and a compressed air supply path for sending compressed air to the lift tank; In a smelting furnace ore feeding device that blows ore into a molten metal of a smelting furnace through a lance together with compressed air, a pressure setter that sets a pressure of air supplied to the lift tank is provided in the compressed air supply path. The ore supply path and the compressed air supply path are connected by a connection path, and the connection path is provided with a flow rate setting device that sets a flow rate of the compressed air flowing through the connection path. And the pressure setter calculates the lance blowing reach from the supply amount of ore per unit time and the flow rate of compressed air, and the lance blowing reach is from the molten metal surface in the smelting furnace to the hearth. Since a control device for issuing a control signal is connected to the pressure setting device and the flow setting device so as to be substantially equal to the bath depth, it is possible to suppress a variation in the reach distance of the lance by the lance. Erosion of the hearth of the smelting furnace can be prevented without lowering the smelting efficiency of the smelting furnace.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 2 is a view showing a change state of a transport weight in one embodiment of the present invention.

FIG. 3 is a diagram showing a change state of a tank weight and a tank pressure in one embodiment of the present invention.

FIG. 4 is an overall configuration diagram showing a conventional smelting furnace ore supply device.

[Explanation of symbols]

 27 Lift tank 39 Ore supply path 32, 33, 34 Compressed air supply path 36 Pressure setting device 40 Lance 42 Connecting path 46 Flow rate setting device 47 Control device

Claims (1)

(57) [Claims] 1. A lance inserted into a smelting furnace, a lift tank for storing ore, an ore supply path communicating the lift tank with the lance, and a compressed air supply path for sending compressed air to the lift tank. In the smelting furnace ore feeding device that blows the ore into the molten metal of the smelting furnace through the lance together with the compressed air, the pressure of the air supplied to the lift tank is set in the compressed air supply path. The ore supply path and the compressed air supply path are connected by a connection path, and the connection path is provided with a flow setter that sets the flow rate of the compressed air flowing through the connection path. The flow rate setting device and the pressure setting device calculate a lance blowing reaching distance from the supply amount of ore per unit time and a flow rate of the compressed air, and the lance blowing reaching distance is a level of the molten metal in the smelting furnace. A control device for generating a control signal is connected to the pressure setting device and the flow setting device so as to be substantially equal to a bath depth from the furnace to the hearth.