JPS5823388Y2 - pelletizing equipment - Google Patents

Description

[Detailed description of the invention] This invention uses a polling drum to produce fine powder magnetically separated concentrate-20.
This relates to a pelletizing device for producing raw material pellets for blast furnaces and reduced iron as oxidized pellets by granulating 0 to 80% of 325 mesh within a 100% of 0 mesh to a predetermined particle size and firing.

The granulation process using a conventional beretizing device is shown in Figure 1.
As shown in Figure 2, a predetermined amount of water is supplied from the concentrate hopper by the rotation of the rotary feeder (■), passes through the belt conveyor (■), enters the inclined polling drum (■), and the appropriate amount of water is pumped through the valve (■) and the compressor (■). While being added as a spray with air, it is formed into a ball shape by rotation and sieved by a rotating sieve (■), and the fine particles pass through belt conveyors (■, ■, [phase], and ■) and then enter the drum again to reach a predetermined particle size. It is operated cyclically until

The wet pellets that have passed through the rotary sieve are transferred to an inclined conveyor (■), where large pellets are removed by a shielding plate (not shown), and crushed by a crushing roller (
(not shown) and circulated on a circulation conveyor.

The wet pellets that have passed through a shielding plate with a predetermined gap pass through a conveyor (3), enter a rotary sizing drum (2) having a rotary sieve 11, are sized, and are fed into a sintering furnace (0).

The bottom of the rotary sieve ◎ enters the polling drum (■) via the conveyor (■), [phase], and ■.

However, there are limits to artificial granulation control using this method, and the amount of granulation of wet pellets of a predetermined particle size is not constant, which causes fluctuations in the furnace top stock line, especially in a vertical burning furnace, and when the stock line rises. The water vapor of the pellets, which have a moisture content of 9.5 to 10%, comes in contact with the pellets at room temperature at the top, cools down, and turns into water again due to the excess moisture, creating a compaction flow of the wet pellets, and when descending, the pellets, which are red-hot on the surface, are exposed to water from above. When the pellets at room temperature touch, the moisture contained therein instantaneously turns into steam, and the resulting thermal shock causes the wet pellets to rupture, causing poor air permeability in the furnace and making it difficult to sinter with uniform heating in the sintering furnace.

This invention improves the above-mentioned drawbacks by automatically adjusting the amount of concentrate supplied and the amount of water added to keep the granulation amount of wet pellets constant and maintain the level at the top of the sintering furnace. This device makes it possible to produce fired pellets of uniform quality with little loss under the sieve and high yield.

Next, FIG. 3 shows an embodiment of the device of the present invention.

To adjust the amount of added water, measure the moisture content of the supplied concentrate using a neutron moisture meter for measuring concentrate moisture, add this measurement result to the setter that has set the target water addition amount, and calculate the difference using an integrator. Add to.

On the other hand, an electric belt scale installed on the belt (2) measures the amount of supplied concentrate transported on the belt (2), and the result is added to the totalizer @.

The integrator @ integrates the above-mentioned inputs, and this integrated amount is amplified by the amplifier [F], and is carried out by a series of automatic moisture addition devices that control the opening and closing of the solenoid valve (①) via the control motor 0.

Through this operation, the moisture content of the wet pellets could be adjusted to ±0.25%.

Further, regarding the adjustment of the amount of concentrate supplied, empirically, a constant granulation amount can be obtained by supplying a predetermined amount of concentrate while keeping the circulation amount flowing through the belt conveyor shown in FIG. 1 (2) constant.

Therefore, the target circulation amount of the electric belt scale shown in FIG. 3 23 is set on the circulation conveyor using the setting device 24,
The voltage is changed by the amplifier and 26 phase shifters, and this goes into the thyristor controller 27, which controls the strong and weak rotation of the table feeder drive DC motor 28.It is equipped with an automatic feed concentrate amount adjustment device. The rotation of the table feeder stops when the set circulation amount is exceeded, and rotates when the circulation amount decreases, so that it is possible to adjust whether the amount of concentrate added is increasing or decreasing by changing its weight.

As a result, the operating rate of 28 drive DC motors was approximately 70%.
It was confirmed that constant granulation could be achieved by adjusting the amount of concentrate supplied so as to keep the circulation amount approximately 25 times the target production amount of wet pellets.

As mentioned above, this device prevents the formation of a compaction flow of wet pellets in the vertical kiln furnace and prevents the bursting of wet pellets.
In addition, the loss under the sieve was halved from 7% to 3.5%, the yield was improved, and fired pellets of uniform quality could be produced.

[Brief explanation of drawings]

FIG. 1 is a plan view of a conventional beretizing device, FIG. 2 is a side view of FIG. 1, and FIG. 3 is an explanatory view showing an embodiment of the present invention. 1: Concentrate hopper, 2: Table feeder, 3, 6° 7.8, 9, 10, 13: Belt conveyor, 4: Polling drum, 5: Rotating sieve, 12: Sizing drum, 11
: Rotating sieve, 15: Neutron moisture meter, 16: Belt scale, 17: AC motor, 18: Setting device, 19: Amplifier, 20: Control motor, 21: Solenoid valve, 22
: Air compression valve, 23: Belt scale, 24: Setting device, 25: Amplifier, 26: Phase shifter, 27: Thyristor, 28: DC motor, 29: Added water adjustment valve.

Claims (1)

[Scope of utility model registration request] A drum-shaped pellet granulation device consisting of a drum-shaped granulation section, a classification device provided at the outlet of this granulation section, and a return path for returning unqualified products sorted by this classification device to the granulation section, A moisture automatic system that adds water to the raw material in the drum-type pellet granulator to maintain a constant moisture content in accordance with the moisture content of concentrate newly supplied to the granulation unit and the amount of concentrate supplied. An automatic feed concentrate amount adjustment device that detects the return amount of raw materials in the addition device and the return tread section and controls the newly supplied amount of concentrate in a direction that decreases or increases, respectively, in response to an increase or decrease in the return amount. A pelletizing device is characterized in that it is equipped with the following and suppresses fluctuations in the production amount of qualified products discharged from the classification device.