JPS5942045B2 - Venting feeder for feeding pulverized coal to the blast furnace hearth - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to iron metallurgy, and more particularly to an aeration feeder for feeding pulverized coal to a blast furnace hearth.
There is also a note regarding on feeder.

BACKGROUND OF THE INVENTION In prior art feeders, the surfaces of the devices for dispensing batches of pulverized coal to the blast furnace lining are subject to severe wear, thereby causing the batches of pulverized coal to be delivered to the blast furnace. accuracy is reduced.

Venting supplies known in the art (Yaroshevsky
S, L, et al, Pri menenie
Pyleugolnog.

topliva dlya vyplavki chu
guna, Kiev, 1974, str, 1.1
9-120) comprises a ventilation compartment with a gas distribution screen disposed across the compartment and a discharge pipe having a bell-shaped opening at its end disposed within this compartment.

A closing rod suitable for axial movement is arranged concentrically with the bell-shaped opening of the discharge tube, and this rod periodically interacts with the inner surface of the bell with its closed end.

Fluidization (flotation) of the pulverized coal takes place in the ventilation compartment of the feeder and the pulverized coal is fed into the discharge pipe through the bell-shaped opening.

Batch treatment of the pulverized coal discharged from the feeder along the discharge pipe and interruption of the pulverized flow are carried out by varying the distance between the inner surface of the bell-shaped mouth and the closed end of the rod,
The closed end moves axially until it approaches the bell-shaped mouth of the tube, closing the entrance of fuel into the tube.

The inner surface of the bell-shaped mouth and the closed end of the rod in the flow of pulverized coal are subject to severe wear, resulting in disturbances in the batch processing accuracy of the pulverized coal fed to the blast furnace tuyeres. is clear.

Another ventilation supply known in the art (USSR Inventor's Certificate No. 512241) comprises a ventilation compartment equipped with a gas distribution screen and an exhaust pipe, which has a discharge door on its side. and a closing and adjusting device rigidly connected to a hollow rod suitable for axial movement.

A hollow rod is arranged concentrically with the discharge pipe so that the nozzle-shaped closing and adjusting device is inserted into the discharge pipe in a telescoping manner,
By moving the hollow rod in the axial direction, the closing/adjusting device partially or completely opens the discharge door provided in the discharge pipe.
This results in a batch of pulverized coal (
(dose amount).

The feeder operates as follows.

Air is supplied to the vent compartment, which fluidizes the pulverized coal as it passes through the gas distribution screen.

Under a pressure in the ventilation compartment depending on the resistance at the inlet of the discharge pipe and the required capacity of the feeder, pulverized coal is fed into the discharge pipe through the side discharge door.

The capacity of the feeder is regulated by moving the rod into the aforementioned discharge door of the conveying pipe, and the closure and adjustment device of the aforementioned rod changes the inlet cross-section of the discharge door, so that a certain amount of pulverized coal is supplied to the blast furnace lining by a feeder.

However, in this feeder, the closed surfaces are also rapidly worn under the action of the pulverized coal, with the result that the accuracy of the batch process is disturbed.

In particular, the gap between the rod closing/adjusting tool and the discharge pipe increases.
Through this gap, an unlimited portion of the aerated mixture is returned into the ventilation compartment.

Moreover, the increase in the cross-sectional area of the discharge door caused by the wear of the side walls defining the discharge door also results in uncertain batch handling of the pulverized coal fed into the discharge pipe and from there to the blast furnace lining. .

DISCLOSURE OF THE INVENTION A needed closure and adjustment device in a vent feeder for feeding pulverized coal to a blast furnace improves the flow of pulverized coal fed to a blast furnace by reducing wear on surfaces in contact with the pulverized coal. This provides high accuracy in batch processing.

The present invention provides a vent feeder for feeding pulverized coal to a blast furnace, which comprises a vent compartment and a gas distribution screen (e.g. perforated plate or glass fiber layer) disposed across the vent compartment. , an exhaust pipe, the exhaust pipe having a discharge door on the side surface of its end, the end of which is located in the ventilation compartment, and a hollow rod inserted telescopically into the exhaust pipe; The closure and adjustment device is in the form of a rotary bushing having calibrated apertures which alternately communicate with a discharge door provided in the discharge pipe.

Such a structure of the feeder for feeding pulverized coal allows the pulverized coal to pass through the discharge door into the discharge pipe and directly contact the contact surface of the bush and the contact light of the pipe through the opening provided in the bush. The accuracy of batch processing can be improved by supplying

Preferably, the evacuation tube is provided with an additional evacuation door diametrically opposite to the aforementioned evacuation door, and the bushing is preferably arranged with paired and symmetrically calibrated apertures.

The application of two diametrically opposed discharge doors in the discharge pipe and the provision of a calibrated opening in the bushing as described above makes it possible to create countercurrent flows of pulverized coal inside the bushing of the feeder. This considerably reduces wear on the bushing walls and reduces the possibility of feeder damage.

The structure described above also makes it possible to increase the pressure gradient between the ventilation compartment and the conveying pipeline, which allows for a more flexible and more precise adjustment of the feeder capacity depending on this pressure gradient.

A wear-resistant insert with a flow passage is placed into the calibrated aperture, the total area of each pair of diametrically opposed passages being between 0.05 and 0.20 of the cross-sectional area of the discharge tube. That's good.

Such a construction reduces wear on the walls defining the calibrated apertures and provides the necessary improvement in batch accuracy without additional energy consumption only at the above percentage of the total area of the flow path. It is possible.

It is not preferable to reduce the total area of the flow paths to 0.05 or less of the cross-sectional area of the discharge pipe.

This is because it is necessary to increase the power of the injection means for a predetermined consumption of pulverized coal, thus leading to an increased energy consumption for exposing the pulverized coal to air.

If the total area of the flow channels provided in the insert exceeds 0.20 of the cross-sectional area of the discharge pipe, the batch accuracy is particularly high due to the reduction in the pressure gradient between the ventilation compartment and the discharge pipe. I can't.

[Brief explanation of the drawing]

The invention will be explained by way of example with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view of the entire aeration feeder for supplying pulverized coal to a blast furnace according to the present invention, and FIG. 2 is an enlarged longitudinal sectional view of part 1 in FIG. Figures 3, 4 and 5 show the outlet tube with outlet door and the bushing with a calibrated aperture in the operating position, and Figures 3, 4 and 5 show the closure and adjustment bushing in the operating position; FIG. 3 is a cross-sectional view of an example embodiment with a discharge pipe; BEST MODE FOR CARRYING OUT THE INVENTION A vent feeder for feeding pulverized coal to a blast furnace comprises a vent compartment 1 (first
3), the receiver comprises a container 3 and a branch pipe 4 for supplying ventilation air. A discharge pipe 5 with a side discharge door 6 is inserted into the ventilation compartment 1 . Inside the discharge tube 5 a closing and adjusting device is arranged, which is a rotatable bush 7 connected to a hollow rod 8, the other end of which exits from inside the tube 5 through a backing gland 9. . The end of the hollow rod 8 is closed, to which the nozzle 10 is attached. This bundle rotates the hollow rod 8 and the bush 7. Hollow rod 8 has an opening 11 to allow air to flow inside the bush 7.
installed on the side wall. The bushing 7 has a plurality of calibrated apertures 12 which form a side door 6 in the discharge pipe 5.
, which ensures the supply of material at a predetermined flow rate. Such a construction of the vent feeder makes it possible to increase batch accuracy since the pulverized coal is fed directly through the bush into the discharge pipe. The contact surfaces between the bush and the tube do not wear, which prevents uncontrolled leakage of gas therebetween. As shown in FIG. 4, the discharge pipe 5 of the feeder is provided with an additional side discharge door 13 arranged diametrically opposite the first door, and a calibrated aperture 12 in the bush 7.
are provided in pairs and symmetrically. Such a construction makes it possible to feed the pulverized coal in a countercurrent flow into the bush, which considerably reduces wear on the bush and increases the pressure gradient between the ventilation compartment and the discharge pipe, thus increasing the pressure gradient between the ventilation compartment and the discharge tube. This allows for more flexibility (and more precise adjustment) of the batches of pulverized coal fed to the plant. A wear-resistant insert 14 (e.g., a metal-ceramic insert) is disposed within the 70 caliber aperture 12. The insert 14 is provided with a flow passage 15 that connects a pair of diametrically opposed The total area of the flow passages 15 is 0.05 to 0.2 of the cross-sectional area of the discharge pipe 5. As mentioned above, the total area of the flow passages 15 is reduced to 0.05 or less of the cross-sectional area of the discharge pipe. is unfavorable, since at a predetermined consumption of pulverized coal it is necessary to increase the power of the injection means, thus leading to an increased energy consumption for the pulverized coal. If the total area of the flow paths exceeds 0.20 of the cross-sectional area of the discharge pipe, the batch accuracy may not be practical due to the reduction of the pressure gradient between the ventilation compartment and the discharge pipe. The feeder operates as follows: Venting gas, e.g. 5 to 15% of the flow rate of the carrier gas of the pulverized coal.The pulverized coal placed above the gas distribution screen 2 in the ventilation compartment 1 becomes suspended and one of the apertures 12 measured 70 caliber in the bush. This coal is fed from within the ventilation compartment 1 into the interior of the discharge pipe when the coal is aligned with the discharge door 6 of the discharge pipe 5. While feeding the carrier gas through the aperture 11 of the hollow rod 8, the coal is pulverized. The discharge of coal from the feeder to the blast furnace lining is started. The pulverized coal is conveyed from the pulverized coal discharge compartment through a pneumatic conveying pipeline onto the gas distribution screen in the ventilation compartment; It is periodically loaded from the storage compartment via the lock compartment.
7-500652)). In the embodiment of the feeder shown in FIG. 4, in which the tube 5 is provided with an additional discharge door 13, the pulverized coal enters the bush 7 in the form of a countercurrent flow and reaches zero on the bush inner surface. It is discharged into the discharge pipe 5 at a similar speed, thereby reducing wear on the bushing. Due to this fact a higher pressure gradient will be achieved between the compartment 1 and the discharge pipe 5. This pressure gradient is, for example, 2 X 10"Pa, I
considerably higher than the intensity of pressure pulsations of ~2X 104 Pa. Therefore, the system (feeder-pipeline-tuyere)
The influence of the aforementioned pulsations on the total hydraulic resistance is small. In this way, high accuracy in the batch (batch amount) of pulverized coal to be supplied to the blast furnace bed is achieved. INDUSTRIAL APPLICATION The present invention will be found most useful in blast furnace melting, which utilizes injection of pulverized coal into the blast furnace hearth.

Claims (1)

Claims: 1. A ventilation compartment with a gas distribution screen located across the ventilation compartment and an exhaust door located on the side of the central part of the exhaust pipe located within the ventilation compartment. for supplying pulverized coal to a blast furnace, comprising: a discharge pipe having a diameter of 10 mm, and a closing and adjusting device inserted telescopically into said discharge pipe, comprising a hollow rod and periodically closing said discharge door; In the ventilation feeder, the closing and adjusting device is made in the form of a rotatable bushing with a calibrated aperture 12, said aperture being provided in the outlet pipe 5 and alternating with a letter outlet door 6. An aeration supply device characterized by communicating with. 2 the discharge pipe 5 at a position diametrically opposite the discharge door 6;
2. Ventilation feeder according to claim 1, characterized in that an additional discharge door (13) is provided in the vent, and the calibrated apertures (12) are arranged symmetrically in pairs. 3 A wear-resistant insert 14 having a passageway 15 is disposed within said diameter-calibrated aperture 12 , the total area of each pair of diametrically opposite passageways being equal to or greater than the cross-section of said discharge tube 5 . The ventilation supply device according to claim 2, characterized in that the area is 0.05 to 0.20.