JPH0313290B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for measuring the weight of raw material in a top charging device of a vertical furnace such as a blast furnace.

[Prior Art] In recent years, a bellless center feed type charging device has been developed as a top charging device for a blast furnace. An example is shown in FIG.

This charging device has an upper hopper (raw material input hopper) 2 and a lower hopper (raw material storage hopper) 3 arranged in series above the reactor body 1 along the core extension line, and is charged from a belt conveyor (not shown). The raw material to be heated is moved downward approximately along the center line of the furnace and fed into the furnace body 1, and the structure is roughly as follows.

Upper hopper 2 is the tower (fixed part) at the top of the blast furnace.
A raw material cutting gate 4 is provided at the lower end discharge port of the hopper 2. The lower hopper 3 underneath is supported by a tower 6 via a weighing device 5 so that it can be moved up and down according to its own weight by the amount required for weighing. A raw material flow rate adjustment gate 7 is provided to adjust the flow rate of raw material discharged into the furnace body 1. The two hoppers 2 and 3 are both used to temporarily store raw materials, but the lower hopper 3 in particular is a pressure equalizing hopper to prevent the gas in the furnace from dissipating into the atmosphere. An upper seal valve 8 and a lower seal valve 9 are provided on the upper and lower sides, respectively.

The raw material flow rate adjustment gate 7 and the lower seal valve 9
The gate unit 10 and the seal valve unit 1
Each is included in 1. The upper end of the casing 12 of the gate unit 10 is connected to the lower hopper 3, and the lower end is connected to the seal valve unit 11 via a telescopic tube 13. Also, the lower end of the seal valve unit 11 is connected to the furnace body side unit 14. The structure is such that the furnace gas will not leak out from each connection. 15
is a chute for distributing the raw material that has passed through the gate unit 10 into the furnace body, and is designed to be rotated and tilted by a drive mechanism 16 within the furnace body side unit 14.

Furthermore, the weight of the raw material present in the lower hopper 3 is measured by the weighing device 5, and for this reason, a gate unit 10 and a seal valve unit 11 are provided at the connection between the lower hopper 3 and the upper hopper 2. A retractable dustproof cover 17 is interposed which performs the same function as the retractable pipe 13 interposed therebetween,
The structure is such that the free vertical displacement of the lower hopper 3 is not hindered. Note that the lower hopper 3 is provided with a pressurized gas injection means 18 for pressure equalization.

In the charging apparatus having the above configuration, raw materials are charged into the furnace body 1 as follows.

First, raw materials are introduced into the upper hopper 2 from a belt conveyor (not shown). This raw material is stored until the lower hopper 3 is ready to receive the raw material by closing the raw material cutting gate 4.
It is stored in the upper hopper 2.

Then, when the lower hopper 3 is ready, the raw material cutting gate 4 is opened to charge the raw material into the lower hopper 3. At this time, the raw material flow rate adjustment gate 7 is closed, and the lower seal valve 9 is closed to prevent the gas from dissipating in the furnace.
The upper seal valve 8 is opened to maintain the inside of the lower hopper 3 at atmospheric pressure. Then, the load on the lower hopper 3 is measured by the weighing device 5, and the weight of the raw material inside is calculated.

Next, when charging raw materials into the furnace body 1, first, the upper seal valve 8 is closed while the lower seal valve 9 is closed. Then, gas is injected into the lower hopper 3 by the pressurized gas injection means 18,
The gas pressure in the lower hopper 3 is made equal to the pressure in the furnace body 1. In other words, the pressure is equalized.

After that, open the raw material flow rate adjustment gate 7,
Raw materials are evenly distributed and introduced into the furnace body 1 at a predetermined flow rate.

After the raw material in the lower hopper 3 has been discharged,
The lower seal valve 9 and raw material flow rate adjustment gate 7 are closed.

Then, the gas pressure in the lower hopper 3 is released to make the pressure in the lower hopper 3 equal to atmospheric pressure. Thereafter, by repeating the above procedure, raw materials are sequentially introduced.

Conventionally, the weight of the raw material in the above process has been determined as follows. That is, the weight of the lower hopper 3 and the objects that are vertically displaced therewith are applied to the weighing device 5 from the beginning. Therefore, the weighing device 5 is set from the beginning with the value at that time being zero, and the weight of the raw material is determined.

[Problems to be Solved by the Invention] By the way, the weight of the lower hopper 3 fluctuates as the operation progresses because raw materials adhere to it and the liner wears. In this regard, in the conventional weighing method described above, since the tare reference value at the time of weighing is fixed from the beginning, there is a problem that the measurement accuracy is poor.

[Means for Solving the Problems] The present invention provides a raw material weight measuring method in which a raw material storage hopper is provided at the top of the furnace body, and the weight of the raw material stored in the hopper is determined by measuring the weight of this hopper. , The process of charging raw materials into the hopper, storing and discharging the raw materials is one cycle, and the weight data of the measuring device immediately before inputting the raw materials into the hopper is used as the tare reference value.
This tare reference value is updated for each cycle, and the weight of the raw material during the cycle is calculated based on this reference value.

[Example] Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2.

The measuring device 5 is capable of constantly outputting measurement data, and once all the raw materials in the lower hopper 3 have been discharged to the furnace body 1, the measured value becomes a constant value. The value at this time indicates the tare (the weight of everything that is displaced together with the lower hopper 3) when the next raw material is charged.

If this output value is W ₁ , W ₁ is input to the reference value updating device 19 that updates and sets the reference value every cycle, and is stored here throughout the cycle. In this state, the raw material is put into the lower hopper 3. Then, the weighing device 5 outputs a weight value including the tare, and the value W ₂ is input to the calculation device 20. This arithmetic device 20 is simultaneously inputted with the signal W ₁ from the storage device 19,
Here, the calculation W ₂ −W ₁ is performed, and the weight W of the raw material is calculated as a result.

Therefore, the weight of raw materials can always be measured accurately in each cycle, and is almost completely unaffected by changes in the tare weight as the operation progresses, that is, changes in container weight due to adhesion of raw materials or abrasion of the liner. Therefore, highly accurate measurement becomes possible. Therefore, the raw material flow rate adjustment gate 7 can be appropriately managed, which helps stabilize the furnace condition.

In addition, in the charging apparatus shown in FIG. 1, when the pressure in the lower hopper 3 is equalized, a lifting force is applied due to the pressure increase. For this reason, there is an inconvenience that slight fluctuations occur in the weight measurement data before and after the pressure equalization process. In this respect, the device shown in FIG. 3 has the advantage of not causing such fluctuations. Of course, the present invention can also be applied to the charging device shown in FIG.

In this charging device, a raw material flow rate adjustment gate 7 and a lower seal valve 9 are provided below the lower hopper 3.
A gate unit 21 incorporating the gate unit 21 is connected thereto, and a telescopic tube 13 is further connected to the lower side of the gate unit 21, and the gate unit 21 is connected to the furnace side unit 14 via the telescopic tube 13. That is, in this charging device, the vertical positions of the lower seal valve 9 and the telescopic tube 13 are reversed from those described above.

As a result, the internal pressure of the furnace body 1 is reduced by the lower seal valve 9
When it is closed, it is applied to the seal valve 9, but since this seal valve 9 is located above the telescopic pipe 13 and moves up and down together with the lower hopper 3, the lifting force due to the internal pressure acts on the lower hopper 3. . In this case, it is completely irrelevant whether the pressure inside the lower hopper 3 is equalized or not. Further, when the lower seal valve 9 is open, the furnace internal pressure is applied to the upper seal valve 8, and the resulting lifting force acts on the lower hopper 3. That is, the lower hopper 3 always
It is affected by the lifting force caused by the pressure inside the furnace, and the weight measurement data always includes the lifting force, and there is no change in the load before or after the pressure equalization process.

When the present invention is applied to this charging device, the same effects as described above can be obtained.

[Effects of the Invention] The method for measuring the weight of raw materials of the present invention consists of the steps of charging raw materials into a raw material storage hopper, storing and discharging the raw materials as one cycle, and measuring the weight of the measuring device immediately before loading the raw materials into the hopper. The data is used as a tare reference value, and this tare reference value is updated every cycle, and the weight of the raw material in the cycle is calculated based on this reference value, so the raw material weight is always accurate for each cycle. can be measured. Therefore, it is virtually unaffected by changes in the tare weight as operations progress, that is, changes in container weight due to adhesion of raw materials or abrasion of the liner, enabling highly accurate weighing and optimizing raw material input. The reactor conditions can be stabilized by promoting the reactor.

[Brief explanation of the drawing]

Figure 1 is a side sectional view showing an example of a furnace top charging device;
FIG. 2 is a block diagram of a metering mechanism for explaining the method of the present invention, and FIG. 3 is a side sectional view showing another example of a furnace top charging device. DESCRIPTION OF SYMBOLS 1...Furnace body, 3...Lower hopper (raw material storage hopper), 5...Measuring device, 19...Reference value updating device, 20...Calculating device.

Claims (1)

[Claims] 1 In a raw material weight measurement method in which a raw material storage hopper is provided at the top of the furnace body and the weight of the raw material stored in the hopper is determined by measuring the weight of this hopper, the raw material is charged into the hopper and the raw material is stored. The post-discharging process is considered as one cycle, and the weight data measured by the measuring device immediately before feeding the raw material into the hopper is used as the tare reference value.This tare reference value is updated every cycle, and based on this reference value during the cycle. A method for measuring the weight of raw material in a furnace top charging device, characterized in that the weight of the raw material is calculated.