JPS5828317B2 - Coke liquid quenching method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Considering the background of the invention, hot metallurgical coke exiting a slotted coke oven is usually immediately quenched by spraying with a large amount of water.

The hot coke emerging from the furnace is conveyed in quench cars to a spray quenching location where the car and its contents are submerged until quenched by spraying water over the entire surface of the coke.

This process often results in over-quenching of the coke, leaving as much as 20% of water in the cooled porous coke.

It is particularly required that the coke have a moisture level within the range of 2 to 4.

If the coke has a moisture content of less than 2 ml, the coke tends to turn into powder during handling, and if the coke has a moisture content of about 4 φ or more, an excess of water must be transported, resulting in very high transportation costs.

However, the most important drawback of the existing quenching methods is that
Since the water content in coke is unstable and the amount of carbon cannot be calculated accurately, the average water content is increased, and as a result, blast furnace operations can only be done in a sloppy manner by using coke.

It is therefore an object of the present invention to propose a quench coke process in which the moisture content is reduced to an acceptable level below that obtained by conventional quench processes and to obtain even more constant moisture content at lower levels. .

A further object of the invention is to propose a method that reduces the time required to rapidly cool coke loaded in a vehicle.

Another object of the invention is to reduce the amount of water required to quench the coke load and thus reduce the amount of water discharged to the atmosphere.

The foregoing objects and others, which will become apparent from the accompanying drawings and the following description, demonstrate that, in accordance with the present invention, a rapid liquid of hot coke (usually We propose a water) quenching method and the vapor and liquid permeate through the surrounding bed in all directions, so that the quenching liquid penetrates before complete vaporization and quickly quenches the coke at regular intervals. This is accomplished by flowing a quenching liquid through the coke bed.

The top 5 of the surface area of the coke bed with respect to the inclined quenching surface
It is known in practice that it is advantageous to run a substantially uniform quench liquid stream.

The liquid stream penetrates the coke bed and diffuses downward through the hot coke until the liquid stream contacts the unquenched coke and permeates downward through the hot coke bed while quenching. It flows down a sloped rapidly cooling surface.

The method of the present invention is in stark contrast to the speculative and often categorical requirement of uniform spraying over a coke bed that has been proposed heretofore.

Contrary to previous lessons, short quench times can yield constant low moisture coke, but this can be achieved by applying a quench liquid stream to less than the total surface area instead of spraying.

Since the liquid stream does not spread significantly before it reaches the coke surface, a depth of 2.44 m (8 feet) permeating the bed can be reached before complete vaporization.

In previous approaches, the quench fluid was sprayed across the coke bed and vaporization was often so intense that the droplets of the quench fluid reached the quench bath without contacting the coke.

In the liquid flow quenching method of the present invention, the quenching liquid penetrates considerably deep into the bed, resulting in more effective quenching as shown by the fact that the shorter the quenching time, the less residual water content in the quenched coke. .

Referring to Figures 1 and 2, the average depth is approximately 91.5
A car 1 loaded with hot coke 2 in 6rrL (3 feet) is connected to a quenching liquid container (not shown) by a main connection 7 and connected by a header 6 about 38m downward.
(1-% in) under a quench hood with a number of pipes 5.

As shown in FIG. 2, as soon as the car 1 is in position under the hood 4, for about 1 minute, all of the quenching liquid 8 is transferred to the top of the coke bed 2 (which is placed on an incline 9). poured into.

Coke 2 is completely quenched and hot spots (
After about 1 minute, the car 1 is moved to the wharf, and the coke containing a homogeneous moisture content of about 3 kg by weight passes through the gate 10. It passes through and is discharged.

Referring to FIG. 8, liquid poured into the upper side of the inclined bed of coke 2 flows through the bed in the direction of the arrow until it penetrates the bottom surface 9 and contacts the hot coke.

There, it penetrates in the direction of the arrow and often escapes from the surface of the bed and hits the side of the car 1.

A portion of the quenching liquid flows down the sloped bottom surface 9 and exits from below the gate 10.

Another example is shown in FIGS. 4 and 5.

In the apparatus illustrated in FIG.
From there it flows down to the top of the inclined coke bed and flows through the coke to the bottom surface 9 and percolates to the upper side similar to the diagram of FIG.

As discussed below, it is possible, but not necessary, to provide multiple spray nozzles 13 to spray the quench liquid onto the coke bed shown in FIG.

As shown in FIG. 5, when the hot coke car 1 is moved under the quench hood 4 along the track 3 in the direction of the arrow, the quench liquid passes through a single large diameter pipe 12 to the upper side of the coke bed. It is discharged.

Other schemes, such as a number of different types of piping arrangements similar to the one described in Figure 4, are possible for flowing the quench liquid rapidly into the coke bed to permeate through the coke bed and into the top. be.

Sometimes it is desirable to use a shape in which the pipe 5 exits the header 6 from the top, as shown in FIG.

Such a shape avoids the possibility of clogging by coke breeze or other particles that tend to get stuck in the pipe, while at the same time ensuring uniformity of flow from the pipe.

However, as shown in Fig. 7, if the straight length 1 of the pipe 5 extending from the header 6 is at least 3 times, preferably 8 times the diameter d, a flow that is satisfactory for permeation into the coke bed can be obtained. Dew.

Although the invention is generally applicable to the quenching of relatively porous thermal materials where short quenching times are required to achieve low residual moisture content, the invention is particularly applicable to quenching relatively porous thermal materials from slotted coke ovens. Used for rapid cooling of hot coke.

When the hot coke falls from the slot coke oven to the quench truck, it does not fall evenly.

Instead, the temperature is about 993~11496C (1800~
2100'F), density approximately 0.43-0.537r/i(
27-331b s/ft”) coke is
Fall into the mobile quench truck in irregular piles as schematically illustrated in the figure.

The method of the invention allows liquid to permeate the bed and flow in a diffused liquid stream, preferably to the sloping bottom, so that a uniform straight coke bed surface is quickly reached and cooled.

As the liquid and accompanying vapor permeate to the top of the bed,
This results in uniform, effective and rapid quenching of the entire coke bed.

Where liquid escapes into the valley between two mounds of coke, it splashes against the sides of the mounds and quenches the coke.

Where the liquid rises directly below the coke mound, the liquid continues to rapidly cool the coke surface.

It is a feature of the present invention that in contrast to the sprays employed heretofore, a liquid stream is used which is essentially capable of penetrating the coke bed.

Furthermore, the discharge device, such as the pipe, should have minimal diffusion of the quench liquid before it hits the coke bed.

In other words, the system should be such that there is essentially no dispersion of the quench liquid into droplets as it falls from the discharge device onto the coke bed surface.

Of course, falling of otherwise uncontained liquid into the gas will tend to disperse into droplets due to the surface tension of the liquid.

However, if the fall length is not too long, there will not be much dispersion of the liquid flow before it hits the coke bed.

In practice, the distance from the discharge point to the bed surface is proportional to the width-to-length ratio of the pipe and the velocity of the liquid flow, preferably about 1.
Maximum 3.66m (12f) below 83m (6feet)
eet), optimal is 1.83-2.44771 (6-8
It is known that it should be ``feet''.

The length/width ratio is such that the pressure at the header is 0.28 kg/
For a liquid stream exiting a pipe at crA (4 psi), the distance is 6 to 8 feet.
t ) is a preferred value.

It is unclear how deep a hot coke bed can be effectively penetrated by the liquid flow quenching method of the present invention, but generally for ease of handling and most effective control of residual moisture, The maximum length is 2.44 m.

Average depth approximately 0.304-1.83 m (1-6 fe
et) is desirable.

The average depth of coke is 0.304~0.912m (
1~3 feet), (maximum depth 1.22m (4fe
et ), it is desirable to adjust to

The time required for quenching the coke car is very important in a trench coke oven because excessive quench time will interfere with the coke car movement schedule.

In addition, the hot gas filling the pores leaves voids that easily absorb liquid when cooling, so the density is 0.43 to 0.53.
Pr/CTL (27-331 bs/ft')
Since the coke absorbs liquid rapidly, the amount of residual moisture is related to the amount of time that the quench liquid is in contact with the hot coke.

In other words, hot coke absorbs liquid when it is quenched.

However, short quench times of 45 seconds to 1 minute are common in the distribution of the quenched liquid obtained when practicing the present invention, and 45 seconds to 1 minute compared to 1.5 to 3 minutes for conventional spray methods.
5 minutes is easily obtained.

The spacing between the quenching streams is important for coke with a large surface area; for example, a hot coke truck has a
00ft2).

Such a large area requires liquid flow to penetrate the bed at least every 5 feet along the length of the coke car.

In other words, the interval between downward liquid flows is 1.52 m (5 feet
t) or more.

However, when a longitudinal liquid stream is poured from the apparatus as shown in Figure 4 or from a single pipe as in Figure 5, sufficient quenching liquid reaches the bottom slope and forms a flatly distributed bed. Postpone the onset of osmosis at the bottom.

However, where the pipe is placed more than % above the surface,
Pipes should not be separated by more than 1.52 m (5 feet) and preferably no more than 1.22 m (4 feet) apart.

In the present invention, it is essential for the quenching liquid to fall onto the coke bed in a liquid flow.

As mentioned above, this is opposed to previous techniques that emphasize watering the coke bed with relatively small droplets.

However, this does not mean that a combination of a liquid stream flowing through the coke bed and a spray applied to the coke is not within the scope of the invention.

- In accordance with the specific example, in particular as shown in Figure 4, the upper %
The liquid flow to the surface is used for infiltration, while a relatively small amount of atomized liquid by a conventional atomizer 13 is used in the lower percent of the bed to meet the upwardly penetrating quench liquid.

As a practical matter, there is no need to spray the bottom % of the bed as sufficient quenching can be obtained in about 1 minute using only a liquid stream.

However, this method is useful in cases where the upper coke surface is particularly uneven.

Although the pressure of the liquid flow varies over a wide range, it is generally
Pressures above about 0.56 kg/ff1 (8 psi) are disadvantageous here.

At or below this pressure, sufficient quenching liquid can pass through the coke; high pressures disturb the coke bed too much;
This results in the coke being crushed and thrown away from the car.

Perforated headers are unsatisfactory for application with the method of the invention.

Perforations without length in the pipe that direct the liquid flow result in a spray of quench liquid spreading over the coke bed.

The quenching liquid is almost always water, although this amount is somewhat less than that currently required by conventional processes, but this means that the residual water content in the coke obtained by the process of the invention is 2.
Consistently lower values of ~4% are less important.

The total amount of water added to normal coke is approximately 1.136 to 3,02
81/1on (300~800gal/ton)
It is.

In order to deeply penetrate the bed of a conventional hot coke truck, which has a maximum bed depth of 2.44 m (8 feet),
The ratio of flow rate to "direct contact area" is important.

As used herein and in the claims, "direct contact area" means an area that is directly under the flow of liquid.

The liquid flow is about 8,150 to 24,450 to the direct contact area.
13/mm1n, (200~6009a13/
ft 2 /min,).

According to one embodiment of the invention, all or most of the quench liquid is directed to the upper side, preferably the upper percent, of the quench car with a bottom slope.

This unconventional and previously unapproved technique avoids excessive water accumulation and flooding of the coke near the gate and reduces over-quenching within the vicinity.

By providing the upper percent of the coke bed with dual liquid streams or a single longitudinal liquid stream, it is possible to achieve satisfactory quenching without the application of any other quenching liquid.

Laboratory studies using a small amount of coke have shown that when using a spray nozzle, a very small amount of water does not flow into the coke below the top layer until the top layer is almost saturated.

It was also found that the upper layer of coke contained 30 to 50% water even though the bottom layer was still in a white-hot state.

However, in the liquid flow type of the present invention, although the volume of water that falls into the upper layer of coke is large, the amount of water absorbed is time-dependent, so the upper layer absorbs only a small amount of the water used. Excess water quickly flows down to the bottom layer.

The test consisted of a high-volatility 75% Pittsburg seam and a low-volatility 25% Pocahontas seam for a total of 13.51y.
(30lb) of coal at 1,0938C (2000'F)
The test was carried out by holding in two pressure test furnaces to make coke and placing the coke.

The coke was extruded when the center of the coke reached 982°C (1800°F).

This produced about 9.1 kg (20 A?b) of coke, which is about 45.7 cm (20 A?b) of Example 1-10 shown in Table 10.
A coke column of approximately 91.5 cr IL (36 in) high was placed in an expanded metal cage for scraping.
) The coke coming out of the furnace using a basket with a height of 18.1
It was placed in a basket until it weighed 40 kg (40 zb).

The basket is 2.03 X 25.4 CrrL (8X10in)
Has a cross section.

The water was sprayed through a spray nozzle and 2 according to the invention as shown in the table.
2 coming out of the steel drum can of 081 (55j!all)
, 5 x 15.2c/n or 3.8 x 15.2
cm (I x 6 in or 1·% x 6 in) jet type pipe into the hot coke basket.

A quick-acting valve is provided in each pipe to regulate liquid flow.

Once the coke basket is in place, a valve opens and water flows into the hot coke basket.

The amount of water used was determined by measuring the difference in the height of the water in the end of the drum before and after the test.

The coke was rapidly cooled by pouring a measured amount of water over the coke, which was then sprayed with water for 2 minutes.

The 45.7 cm (18 in) column was divided into two halves, an upper part and a lower part, and the moisture content of each part was determined.

The 91.5 cIrL (36 inch) column was divided into four parts and the water content of each part was determined.

In some cases, the coke basket moved back and forth down the jet stream.

In other cases, the jet stream was applied intermittently.

The test is for jet numbers 1 and 2 coming from the bottom of the drum can.
and 4 pipes.

These test results are summarized in Table 1.

For typical large commercial scale quenching, 15.2 length x 3
．． 66m width, (50 feet length x 12 feet width) quenching car, angle of inclination from the extrusion side of the car to the gate side 30
', and about 45 nia cIrL (15fe
etc.) and loaded with coke to an average depth of 55.7 rrt.
A coke truck with a horizontal area of 3.8 crfL (1%
in) Pipe, longitudinal direction (1.065 cm (3,5
feet) is extruded under a quenching tower with four vertical rows.

Water is added at a rate of 1,324 A (350 gaA) per unit direct contact area four times per minute.

Total 18.9001! (5,0009all) of water was added.

The coke truck can be completely quenched in one minute and easily dumped onto the coke wharf within two minutes without any evidence of incandescence.

Although the invention has been described in considerable detail herein, such detail is for illustrative purposes only, and many changes may depart from the spirit and scope of the invention other than as set forth in the claims. It is understood that this can be done from these excellent techniques without having to do anything.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of a liquid flow quenching station according to the present invention, showing a hot coke car under a large number of quenching liquids; FIG. 2 is a vertical sectional view taken along the line ■-■ in FIG. 1; Figure 3 shows
FIG. 4 is a vertical sectional view of a coke quenching station and another type of apparatus for the liquid flow quenching method of the present invention, and FIG. Figure 6 is a vertical cross-sectional view showing single stream quenching by moving a hot coke car under one discharge, and Figure 7 is an enlarged cross-sectional end view of the header and flow tube designed for multiple stream quenching. 8 is an enlarged cross-sectional end view of a single liquid flow header and pipe showing the relationship between pipe diameter and length, and FIG. 8 is a schematic perspective view showing quench liquid flow through a coke bed.

Claims (1)

[Claims] 1(a) Distributing hot coke on a tilted bed of a coke fire extinguishing truck to form a hot coke tilted bed; (b)
A relatively concentrated quenching liquid is caused to flow through the hot coke inclined bed at a plurality of locations with relatively large intervals on a predetermined surface area of the hot coke inclined bed, excluding the lower surface area, so that the quenching liquid is completely absorbed. coke, characterized in that the liquid reaches an inclined bed of the coke car before evaporation, and the entire hot coke bed is quenched as the liquid and its vapor permeate through the surrounding hot coke bed. liquid quenching method. 2. The predetermined surface portion is a surface portion of 1/2 of the soil portion of the tilted hot coke bed, and the lower surface portion is the surface portion of the lower 1/2 of the tilted hot coke bed. A liquid quenching method for coke according to claim 1.