JPS62214112A - Method and apparatus for pressure equalization of hopper for furnace top charger - Google Patents

Abstract

PURPOSE:To decrease the amt. of the gaseous N2 to be used and to prevent damage of a stop valve by dust and heat by branching the blast furnace gas generated in a blast furnace in the mid-way of feeding said gas to a cleaner, mixing said gas with the gaseous N2, subjecting the gaseous mixture to dust collection, feeding the gaseous mixture to the inside of a hopper and executing secondary pressure equalization. CONSTITUTION:A branch pipe 11 is branched from the mid-way of a gas pipe 10 for taking the high-pressure gas out of the blast furnace 1 and is connected to the gas cleaner 3 via a flow rate regulating valve 12 interposed in the mid-way of the pipe 11 and an N2 mixer 14 for joining and mixing the gaseous N2 from a gas pipe 13 at the secondary side. After the raw materials are thrown into the pressure equalization and discharge hopper 2, the pressure equalization is executed by a primary pressure equalization device and thereafter, a valve 6 for the primary pressure equalization device is closed and the secondary pressure equalization is started. A gas shut-off valve 16 is opened to introduce the blast furnace gas through the pipe 10 for the above-mentioned purpose. The blast furnace gas and the gaseous N2 are mixed in a mixer 14. The flow rate of the blast furnace gas is decreased to lower the temp. of the gaseous mixture if the temp. of said gaseous mixture is higher than the specified temp. blowing is then executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pressure equalization method for a hopper for a furnace top charging device and an apparatus therefor.

[Conventional technology]

In order to charge raw materials into the furnace of a vertical furnace, after the raw materials are introduced into a hopper, the pressure inside the hopper is made equal to the pressure inside the furnace.

Conventionally, in a furnace top charging device, a pressure equalization hopper 2 is provided for charging raw materials into a high pressure tank 1, as shown in a system diagram in FIG.

This pressure equalization hopper 2 is provided with a primary pressure equalization device in which the blast furnace gas generated in the blast furnace 1 is semi-cleaned by a gas purifier 3 and a Bechley scrubber 4, and then guided to the top of the furnace through a semi-clean gas pipe 5. It is blown into the hopper 2 through the valve 6. - Next pressure equalization gas is passed through gas purifier 3. Since the raw material is blown into the hopper 2 through the Beshley 4, it is slightly lower than the furnace top pressure (it must be made equal to the furnace top pressure by secondary pressure equalization. Also, when discharging the raw material from the hopper 2, The internal pressure of the hopper 2 decreases by the volume of the discharged raw material, and therefore it is necessary to carry out secondary pressure equalization to prevent the raw material from being unsmoothly discharged.

Conventional secondary pressure equalization methods are either a method of injecting N gas while controlling the pressure (J) using an N2 gas flow rate adjustment valve 7 and a hopper internal pressure measuring device 8, or a method of directly injecting blast furnace gas using an on-off valve. has been adopted. In the figure, reference numeral 9 is a discharge pressure valve for lowering the pressure of the hopper 2 to atmospheric pressure.

(Problems to be Solved by the Invention) The above-mentioned conventional pressure equalization method has the disadvantage that when performing secondary pressure equalization using N2 gas, a large amount of N2 gas is used, and the N2 gas causes a decrease in the calorie content of the blast furnace gas. be.

Furthermore, when blast furnace gas is used, the on-off valve and the equipment attached to the hopper are easily damaged by heat due to poor sealing of the on-off valve due to dust and the high temperature of the blast furnace gas, and as a result, it is not used as regular equipment. It is only used in emergencies such as failure of the N2 gas secondary pressure equalization device.

[Means for solving problems]

In order to solve the above-mentioned problems of the prior art, the present invention has a hopper for charging the top of a vertical blast furnace, and provides a pressure equalization method for equalizing the pressure in the hopper with the pressure inside the blast furnace. It is characterized by branching the generated blast furnace gas on the way to the gas purifier and mixing it with N2 gas, lowering the temperature of the blast furnace gas, collecting dust, and then feeding it into the hopper for secondary pressure equalization. The first method is to equalize the pressure of the hopper for the top charging device.
As an invention and an apparatus used to carry out the above method,
In a vertical blast furnace having a hopper for charging at the top of the furnace,
A blast furnace gas flow rate adjustment valve is installed from the blast furnace gas pipe side to a branch pipe that branches from the blast furnace gas pipe of the blast furnace and is connected to Horapa, and N2 gas is mixed in order to lower the temperature of the blast furnace gas.
A gas mixer, a gas purifier to remove dust from the gas, and a gas cutoff valve are installed in sequence, and the blast furnace gas pipe is equipped with a gas temperature measuring device, and the blast furnace gas is controlled by the temperature measured by this temperature measuring device. Connect the blast furnace gas flow rate adjustment valve to control the temperature of the N2
An equalizer for a hopper for a furnace top charging device, characterized in that the gas pipe is equipped with an N2 gas flow rate adjustment valve □ that controls the mixing ratio in the N2 gas mixer based on the value detected by a hopper internal pressure detector that detects the hopper internal pressure. The second invention is a pressure device.

[For production]

With the above configuration, the N2 gas and blast furnace gas are mixed to lower the temperature of the blast furnace gas, and after being purified by the gas purifier, it is blown into the hopper by the gas cutoff valve, so the amount of N2 gas used is small. Corner 1: Energy saving can be achieved.

〔Example〕

Embodiments of the present invention will be described below with reference to the attached FIG. 1, using the same reference numerals for parts common to FIG.

In FIG. 1, reference numeral 1 indicates a blast furnace, and 2 indicates a pressure equalization hopper.

A branch pipe 11 is branched in the middle of a blast furnace gas pipe 10 that takes out high-pressure gas from the blast furnace 1, and this branch pipe 11 has a blast furnace gas flow rate adjustment valve 12 in the middle, and an N2 gas pipe 13 on the secondary side of this adjustment valve 12. A N2 gas mixer 14 for merging and mixing the N2 gases from the gas cleaner 3 is connected to the gas purifier 3. It is desirable to use a valve without a gas sealing function, such as a damper type valve, so that the sealing surface of the valve is not damaged by the dust contained in the blast furnace gas (rough gas) and the temperature of the blast furnace gas.

A discharge valve 15 is provided at the bottom of the gas purifier 3,
Dust is returned to the blast furnace gas pipe 10 through this discharge valve 15. Further, the upper part of the gas purifier 3 and the pressure equalization hopper 2 are communicated by a pipe 17 via a gas cutoff valve 16 that starts and stops secondary pressure equalization.

Is there an N2 gas flow in the N2 gas pipe 13? A regulating valve 18 is installed, and the opening degree of this N2 gas flow regulating valve 18 is controlled according to the value measured by the hopper internal pressure measuring device 8, so that the internal pressure of the hopper 2 is equalized. The flow rate of N2 gas is controlled to be reduced as the blade approaches.

In Fig. 1, the reference numeral 6 is the same as in Fig. 2, 9 is the valve for the pressure equalization device, 9 is the valve for the exhaust pressure device, and 19 is the temperature measuring device for the mixed gas of blast furnace gas and N2 gas. The opening degree of the blast furnace gas flow rate regulating valve 12 is controlled based on the temperature value measured by the device 19.

Next, the operation of the above embodiment will be explained.

After the raw materials are introduced into the pressure equalization hopper 2, the pressure is equalized by the primary pressure equalization device, and after the pressure is equalized, the valve 6 for the primary pressure equalization device is closed, and secondary pressure equalization is started. To do this, first, the gas cutoff valve 16 is opened, blast furnace gas is introduced through the blast furnace gas pipe 10, and secondary pressure equalization is performed.

When the temperature of the mixed gas of blast furnace gas and N2 gas taken in through the blast furnace gas pipe 10 is higher than the specified temperature, the flow rate is reduced by the blast furnace gas flow rate adjustment valve 12 to lower the mixing ratio with N2 gas. , lower the gas temperature and perform the blowing. In this case, after the dust is collected by the gas purifier 3, it is passed through the gas cutoff valve 16 to protect the gas cutoff valve 16. In addition, when the temperature of the mixed gas is low, the blast furnace gas flow rate and the N2 gas flow rate are set in advance, and only the blast furnace gas flow rate is adjusted according to the gas temperature. Either the flow rate of N2 gas may be increased or decreased to compensate for the excess or deficiency of N2 gas.

Since N2 gas has a higher pressure than the furnace internal pressure, in order to prevent the internal pressure of the hopper 2 from becoming higher than the furnace internal pressure, the internal pressure of the hopper 2 is measured with the hopper internal pressure detector 8, and when pressure equalization is near completion, the N2 gas is released. Reduce the flow rate. The dust trapped in the gas purifier 3 is discharged into the furnace through the discharge valve 15 at times other than during the secondary pressure equalization operation.

〔Effect of the invention〕

As explained above, according to this invention, -Next 7
- During the secondary pressure equalization after pressure equalization, the blast furnace gas is lowered in temperature by a mixed gas of blast furnace gas and N2 gas, and after being purified by a gas purifier, it is blown into the hopper, so the amount of N2 gas used is reduced compared to the conventional method. It requires significantly less energy than the previous model, and can greatly contribute to energy saving.

Further, according to the pressure equalizing device according to the present invention, the temperature of the secondary pressure equalizing gas passing through the gas cutoff valve is lower than the specified value, so damage to the valve due to heat is prevented, and the temperature of the secondary pressure equalization gas passing through the gas cutoff valve is prevented. Since the dust in the next pressure-equalizing gas is collected by the gas purifier, there is no damage caused by dust encroachment, and the collected dust can be returned to the furnace, eliminating the need for dust treatment. It has various effects such as making it possible to equalize the pressure by regular use of blast furnace gas.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional technique. DESCRIPTION OF SYMBOLS 1... Blast furnace, 2... Pressure equalization hopper, 3... Gas purifier, 6... Valve for secondary pressure equalization device, 9... Discharge valve, 1
0... Blast furnace gas pipe, 11... Branch pipe, 12... Blast furnace gas flow rate adjustment valve, 13... N2 gas pipe, 14...
N2 gas mixer, 15...Discharge valve, 16...Gas cutoff valve, 18...N2 gas flow rate adjustment valve, 19...Temperature measuring device.

Claims (2)

[Claims] (1) A vertical blast furnace has a top charging hopper, and in a pressure equalization method that equalizes the pressure inside this hopper with the pressure inside the blast furnace, the blast furnace gas generated in the blast furnace is sent to the gas cleaning device. Pressure equalization of a hopper for a furnace top charging device characterized by branching in the middle and mixing with N_2 gas to lower the temperature of the blast furnace gas and collecting dust before feeding it into the hopper and performing secondary pressure equalization. Method. (2) In a vertical blast furnace having a top charging hopper, a blast furnace gas flow rate adjustment valve is installed from the blast furnace gas pipe side to a branch pipe that branches from the blast furnace gas pipe of the blast furnace and is connected to the hopper; A N_2 gas mixer that mixes N_2 gas to lower the temperature of blast furnace gas, a gas purifier that removes dust from the gas, and a gas shutoff valve are installed in sequence, and the blast furnace gas pipe is equipped with a gas temperature measurement device. and a blast furnace gas flow rate adjustment valve that controls the temperature of the blast furnace gas based on the temperature value measured by this temperature measuring device, and the N_2 gas pipe is connected to the N_2 gas mixing valve according to the value detected by the hopper internal pressure detector that detects the hopper internal pressure. A pressure equalization device for a hopper for a furnace top charging device, which is equipped with an N_2 gas flow rate adjustment valve to control the mixing ratio in the furnace.