JPS5912710B2 - Continuous production method of compression briquette coal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for continuously producing compression-molded coal having a bulk density of 1.0 wet tons/1ri' or more, which improves coke strength, expands the selection range of coking coal, and improves production. This paper proposes a method for producing compressed briquette coal for charging blocks into an indoor furnace, with the aim of improving performance, eliminating over-furnace work, and reducing dust pollution.

Traditionally, in Japan, the top-charging method has been widely adopted, in which each charge is dropped through a charging vehicle through a top charging hole.

Recently, attempts have been made to increase the bulk density of the top-charged coking coal by utilizing expansion during the coking process to compact the pulverized coal portion and improve its coking properties.

To this end, a molded coal partial charging method has been developed in which raw coal is preformed into briquettes using a molding machine, and 30% of the briquettes are mixed with charging coal to increase the bulk density by 10 factors.

This briquette coal partial charging method aims to improve the coke strength as mentioned above by increasing the bulk density of the charged coal, but the value is about 0.78 dry tons/d, and this value is about 0.78 dry tons/d. This is considerably lower than the bulk density of the invention (0.91 dry tons/m3 at 9% moisture).

As this type of conventional technology, for example, Japanese Patent Application Laid-Open No. 50-59
No. 404 proposes a molding device that uses a mold with a bottom plate and applies pressure with a press.

In this conventional apparatus, it is necessary to prepare a mold and a press device suitable for the size of the compression-molded coal.

As a result, the stroke of the hydraulic cylinder becomes long, the pressurized area is large, and the mold as a whole needs to be strong enough to withstand the pressure, resulting in the problem that the molding equipment becomes oversized and leads to increased costs.

Another drawback was that a separate step was required to take out the compacted coal molded by this conventional device from the mold, which increased the time required for the molding process.

In the present invention, compression molded coal to be charged into a block is compressed and molded by leaving compressed molded coal that has already been compression molded at the outlet of the mold, and then compression molding newly charged coking coal into this. The subsequent tracking briquettes obtained are combined to form briquettes with a bulk density of i, o wet tons/, 1 or more, and the process of sequentially extruding them is repeated to continuously produce endless compression briquettes. It's a method.

The details of the configuration will be explained below.

Normally, when powdered raw coal in a mold is pressurized, frictional force is generated on the wall of the mold.

This is the same when extruding compressed briquettes from a mold that has already been molded; during extrusion, pressure must be applied that exceeds the frictional resistance of the charcoal itself.

This invention utilizes the resistance force necessary to push the compressed coal out of the mold as a supporting force when compressing the coking coal to be charged next, and applies pressure that exceeds the resistance force. This method involves pushing the already compressed briquettes out of the mold.

In other words, by appropriately selecting the size and layer thickness of the compressed briquettes left in the mold, it is possible to obtain a frictional force that can withstand the pressure applied to compress the briquettes that will be produced subsequently. If raw coal is newly charged into the space between the previously produced compacted coal and compression molded by pushing the push plate, the bulk density of the subsequently produced tracked coal will be 1. By continuing to apply pressure as soon as the pressure reaches 0 wet tons/3 or more, it is possible to extrude the compressed briquette coal that was previously produced.

This invention achieves this by sequentially and intermittent repetition of such operations.
Endless compression molded coal can be produced continuously.

In block charging, where compressed molten coal is charged from the door side of the chamber furnace, the bulk density of the compressed molten coal must be 1.0 wet tons//, and if it is not 3 or more, it may break during charging and may not enter the furnace. Smooth charging is not possible.

In the worst case, the door will not be able to be attached and will collapse, or the compressed coal will ignite, causing operational trouble.

Therefore, the bulk density of the compression molded coal needs to be 1.0 wet tons/m3 or more, preferably 1.15 wet tons/m3.

Therefore, in the present invention, the pressure for compressing the charged coking coal with the press plate is adjusted so that the compressed coking coal becomes compacted coal with a bulk density of 1.0 wet tons/l, and The size is required to track and combine with the generated compressed briquette coal.

That is, when powdered raw coal is pressurized at a pressure of Pt/ci,
A pressure Pst/crIt is generated on the wall surface of the mold, and a frictional force μPSt/ff1 (μ: coefficient of friction) is generated.

Figure 2 shows the relationship between pressure P and frictional force μps at a minute layer thickness dH.

Since the weight of coking coal is small compared to the pressure, if ignored, the frictional force μps can be understood as a function of pressure P1 layer thickness of coking coal H1 pressurized area F and mold circumference U as shown in equation (1). be done.

ttPs2f (P t Ht F , U ) ””
...'' (1) Once the target furnace for charging the blocks is determined, the circumferential length U and pressurizing area F of the mold are determined from the furnace dimensions.

The compression-molded coal at the layer thickness H has a frictional force μps against the upper pressure, and in short, this frictional force μPs
The supporting force of the residual compacted coal within the mold is determined by:

Therefore, as mentioned above, when the pressure P and layer thickness H are given, the frictional force μPs can be found, and as a result, from equation (1), it is possible to determine the amount, that is, the size, of the pre-produced compacted coal that should remain. can.

According to experience, the pressure of the press plate required to obtain compacted coal with a bulk density of 1.0 wet tons/m3 in a mold of 350 mm x 1,000 mm is about 50 kg/ffl.

Then, the pre-compressed pre-molded coal having a bulk density of 10 wet tons/d or more is left in the outlet part of the whole mold, and the raw coal is newly added between the press plate in the mold and the pre-compressed pre-prepared coal. When the coal is charged and pressurized during the process, the previously formed compacted coal remaining in the mold functions as a supporting force when compressing the newly charged coking coal. The newly charged coking coal is compressed to the maximum due to the frictional resistance immediately before and after extrusion.

In this way, by appropriately selecting the layer thickness of the previously produced compressed compacted coal to be retained and the amount of the newly charged coking coal, that is, the layer thickness, the bulk density is 1.0 wet tons/77+''. The pressure required to mold briquette coal (50 kg/cyr
t ), the pressure (100 kg/i 2 ) necessary to obtain compacted coal having a bulk density of preferably 1.15 wet tons/d can be applied to the press plate.

If the pressurization is continued at a pressure P that exceeds the balance with the frictional force μps, the compressed briquette coal generated in the mold can be pushed out of the mold, and these intermittent sequential operations can be used endlessly. Compression briquettes can be produced.

By configuring the mold as described above, it is sufficient to make the mold correspond to the minimum size of the charging block, so it can be made into a size that is economical and easy to handle. However, in the case of horizontal molding, since the pressurized area is the smallest, the molding equipment can be made the most compact and exhibit excellent economic efficiency.

However, in the case of the present invention, there is no restriction on the type of compression molded coal production apparatus, and it may be of a vertical type, horizontal type, or inclined type.

FIG. 3 of the drawings shows an example of a manufacturing method using a horizontal device.

Stage A shows a stage in which the previously produced compressed briquette coal is left on the outlet side 1a of the mold 1, and raw coal is charged into the space behind it.

The figure shown above shows the stage in which the charged coking coal is compressed by the advance of the pusher plate, and the new compressed briquette coal (tracking briquette coal) produced by the next pressurization is tracked and combined with the previously produced compressed briquette coal. .

Furthermore, the diagram shown in C shows a stage in which a pressure exceeding the frictional resistance of the compressed molten coal and the tracked molten coal is applied to push the press plate forward to force the compressed molten coal out of the mold.

By the operation at this stage, the compressed briquette coal is pushed out of the mold, and the newly generated tracking briquette coal moves to the exit side of the mold.

By repeating these steps, an endless amount of compacted coal can be produced, and the compacted coal is cut into pieces of length suitable for the chamber furnace to be charged into blocks.

In the present invention, there are no restrictions on the driving mechanism for molding, and hydraulics, water pressure, links, racks, cranks, screws, etc. can be employed.

In addition, there are no restrictions on the type or particle size of coking coal (coal used as a raw material), and raw materials used in coke production, such as petroleum-based or coal-based binders, petroleum coke, coke breeze, and char, are blended. Good too.

The moisture content should be at least 8.5%; if it is less than that, add water or add sticky materials such as lignin liquid, resin, petroleum-based or coal-based caking agent with a lower softening point, etc. It is molded by doing this.

Next, embodiments of the invention will be described.

Using a mold 1 (cross-sectional dimensions: 350 mm x 1,000 mm, length: 3,000 mm), at its exit part there is provided an extraction pedestal 5 (storage case cross-sectional dimensions: 380 mm x 1,050 mm) that moves in synchronization with the speed of the press plate. , length 2,000m
Compression briquettes were produced using a press with a compression capacity of 1,000 m).

The raw coal was blended indoor furnace coal having a moisture content of 10%, a particle size of -3 mm, and a yield of 82%, and was charged into the mold 1 through a hopper 2 and a gate damper 3.

Table 1 shows the manufacturing conditions and product quality.

The initial conditions shown in Case 1 in the table are (with a receiving plate provided on the exit side of the mold), and the raw coal is 600 ml as shown in Table 1! 9!
is charged into the mold, the push plate 4 is set, and the pressure is 350 tons.
Pressure was applied at a surface pressure of 100 kg/crit.

As a result, compression molded coal with a bulk density of 1.15 and a length of 1,490 mm was obtained.

In case 2, the receiving plate installed at the outlet of the mold was removed and 200 kg of coking coal was newly charged and pressurized, resulting in a pressure of 335 tons, which is converted to surface pressure of 96 kg.
/ffl.

Subsequently, pressure was applied to push the compacted charcoal out of the mold.

The compressed molten coal was received by an extraction cradle that could be synchronized with the speed of the pushing plate and extruded to a length of 480 mm.

During this time, the pressure gradually decreased and was 260 tons when extrusion was stopped.

In case 3, 200 kg of raw coal was newly charged and pressurized to extrude compression molded coal, but the conditions in case 2 could be reproduced.

Case 4 was further charged with 250 kg of raw coal and pressurized.

In this case, it was possible to pressurize at a pressure of 370 tons, which is higher than in case 1, and a surface pressure of 106 kg/d.

In both cases, the bulk density is 1.0 wet tons/m3
The above compression molded coal was obtained.

As explained above, according to the present invention, as is clear from the relationship between the bulk density of the charge and the abrasion strength (TI) of the coke obtained from the charge shown in FIG. Compared to the partial charging method, it is possible to obtain blast furnace coke having a wear strength (TI) superior to that of the partial charging method.

In addition, the conventional top-charging method requires the use of high-quality coking coal, but considering the depletion of that resource, it is becoming increasingly difficult to utilize non-slightly coking coal, which is said to account for 80% of recoverable reserves. In this regard, according to the present invention, excellent coke strength can be obtained even when such non-slightly caking coal is used, so it is possible to blend a large amount of the non-slightly caking coal, and it is possible to You can expand the selection range.

Furthermore, in the case where the bulk density of compacted coal is 1.15 wet tons/, 1 (1.04 dry tons/m3 at moisture 9).

Compared to the bulk density of the top charge method, which is 0.70 dry tons/liter, the bulk density increases by approximately 48%, so productivity is improved even considering the extension of carbonization time, and coke production can be increased.
Since dust generation during charging, which occurs with top charges, can be reduced, dust pollution can be prevented.

In particular, according to the present invention, the size of the mold can be reduced to the necessary minimum size, so the stroke required for pressurization is shortened.
Moreover, since there is no need to take out the extruded compression-molded coal from the mold, the process can be simplified, the molding equipment is economical and efficient, and the installation area of the molding equipment is smaller, making the layout easier. The effects can be expected.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between the bulk density of the charge and the abrasion strength TI of the 00 coke obtained therefrom;
Figure 2 is a schematic diagram showing the relationship between pressure and frictional force, and Figure 3 is a cross-sectional view showing the compression molding process. Fig. 3 shows a state in which the tracked briquette coal produced by the above steps is combined, and C shows a state in which the compressed briquette coal is pushed out and the tracked briquette replaces it and moves to the exit side of the mold. A...Top charge normal charging method, B...
・・Top charge briquette coal partial charging method, C・・・・・・
Block charging, P... Pressing plate pressure (TA), P
s...Pressure on mold wall surface (T/d), μ...
...Friction coefficient, dH...Layer thickness, F...
・Pressure area (i), U... Mold director ((m),
1... Mold, 2... Hopper, 3...
...Gate damper, 4...Press plate, 5...
...cradle.

Claims (1)

[Claims] 1. A method for obtaining compression molded coal by charging raw coal into a mold and pressurizing it with a press plate, the raw material being charged into a mold whose end in the direction of pressure is open. , when pushing the press plate forward to mold the compressed molten coal in the mold, and pushing it further and extruding it from the opening outlet in the pressing direction, the previously generated compressed molten coal is transferred to the mold outlet section. A process in which raw material is newly charged between the compressed briquette coal and the press plate, compressed by applying pressure to the press plate, and the tracked briquette coal to be generated subsequently is combined with the pre-compressed briquette coal. A compression molded coal characterized in that an endless compression molded coal is obtained by repeating a sequential operation consisting of a step of applying pressure to the combined compression molded coal on a press plate and pushing the already compressed molded coal out of the mold. continuous manufacturing method.