JP3284032B2 - Method of suppressing carbon adhesion to brick surface in coke oven - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for suppressing the adhesion of carbon to bricks in a carbonization chamber when carbonizing coal in a coke oven for the purpose of producing coke for metallurgy.

[0002]

2. Description of the Related Art In the process of producing coke by heating coal in a coke oven, carbonized gas mainly composed of carbon compounds is generated from coal. This generated gas flows into the furnace top space in the upper part of the furnace, or flows into the gas path of the furnace lid, and is led to the gas purification step via the riser. The temperature of the furnace top space or the riser base varies depending on the operation rate or the furnace temperature. For example, since the temperature is 900 ° C. or higher, a thermal decomposition reaction of a hydrocarbon compound occurs, and carbon is attached to the brick surface. When the amount of carbon attached is small, it enters the joints of the bricks and works effectively in preventing raw gas leakage from the carbonization chamber to the combustion chamber.However, in general, the amount of carbon generated is large and dry distillation ends. It is common to extrude coke to introduce air from the outside during several tens of seconds until the next coal charging, and remove it by a combustion gasification reaction.

[0003] Alternatively, when carbon is extremely attached, such as at the base of a rising pipe or a vertical pipe, a method of burning and removing high-speed air using an air scarf- ing device mounted on an extrusion ram is widely used. Have been done.

[0004] The method of removing carbon by these methods is simple and effective, but since it is performed between operations, sufficient treatment is performed when the operation rate is high or when the temperature level of the furnace is high. Sometimes time cannot be secured. In addition, since a large amount of combustion gas is emitted to the atmosphere, it cannot be said that it is preferable in terms of environmental protection.

In order to solve these problems, the most effective means is to suppress the amount of carbon generated during carbonization, and many methods have been proposed. For example, as a method of forming a coating on a brick surface to reduce the amount of carbon attached, Japanese Patent Application Laid-Open No. 2-160896 and Japanese Patent Publication No. Sho 62-19
No. 477 and Japanese Patent Publication No. 63-13470. Further, as disclosed in Japanese Patent Publication No. Sho 59-10712, there is a method of preventing oxygen from adhering to carbon by injecting oxygen or oxygen from the back surface using gas permeability of refractory bricks. Alternatively, since the carbon deposition amount increases as the temperature increases, a method of suppressing the deposition by blowing a coke oven generated gas or compressed air into a furnace top space to reduce the carbon deposition speed (Japanese Patent Laid-Open No. Sho 61) -1884
No. 86, Japanese Unexamined Patent Application Publication No. 3-210389, Japanese Unexamined Patent Application Publication No.
-212486).

[0006]

The above-mentioned conventional method aims to reduce the amount of carbon attached by inhibiting the contact between the hydrocarbon which is the basis of carbon attachment and the brick surface, and to reduce the temperature. The purpose is to slow down the carbon production reaction.

[0007] However, the method of forming a coating on the surface of a brick can smoothly process the surface of the brick before the brick is incorporated into a coke oven, and can be expected to have an adhesion preventing effect. If it is to be applied to a heated brick surface, it is difficult to smooth the surface, and therefore, the amount of adhesion may increase due to an increase in the exposed surface area due to the surface roughness after the application.

Further, when injecting a coke oven gas, it is necessary to take out the generated gas once out of the coke oven with a gas suction pipe or the like and circulate the gas through a pipe. On the furnace, there are many restrictions such as installation so as not to hinder the movement of the loaded car. In addition, there is a concern that carbon and tar may be attached to the pipe wall in the suction pipe from the sucked coke oven gas.

[0009] It is an object of the present invention to solve the above problems and to develop a method for suppressing the attachment of carbon with low capital investment and low work load.

[0010]

The present inventors have conducted various studies to solve the above-mentioned problems, and as a result, by spraying water on the top space of the coke oven, 1) the gas in the top space The temperature, the surface temperature of the furnace wall bricks in contact with the atmosphere gas in the furnace top space, and the surface temperature of the bricks in the carbonization room at the base of the riser pipe; Decrease in the concentration of hydrocarbons in the coke oven gas, which is the causative substance of carbon formation in the coke oven, and 3) reaction of the attached carbon with water sprayed on the furnace top space in the coking chamber (C + H ₂ O → CO + H ₂ ) By realizing gasification, it has been found that the amount of carbon adhering to the brick surface in the carbonization chamber can be reduced without causing damage to the brick in the coke oven or delaying the carbonization of coal near the furnace top, Based on the findings and have reached to complete the present invention.

[0011] The present invention provides a method of suppressing to generate carbon Supplementary kimono bricks carbide surfaces indoor when dry distillation of coal in coke ovens, furnace top space, and the temperature of the riser base 780-850 In the appropriate range to control to
A method for suppressing the adhesion of carbon to the brick surface in a coke oven characterized by spraying a quantity of water into the furnace top space during carbonization.
You .

[0012]

Embodiments of the present invention will be described below in detail.

It is generally well known that carbon adheres to brick surfaces in a carbonization chamber due to a thermal decomposition reaction of a carbonization product gas (coke oven gas) generated when carbonizing coal in a coke oven. The carbon deposition rate by this thermal decomposition was investigated using a test device shown in FIG.
In FIG. 7, 10 kg (anhydrous base) of coal blend 22 used for producing ordinary metallurgical coke is charged into a dry distillation vessel 18 kept at 1000 ° C. The carbonization gas generated by the heating of the coal is discharged outside through the inside of the attachment furnace 24. A brick piece 15 (material: silica stone, thickness: 6 mm, width: 20 mm, length: 40 mm) is suspended in the attachment furnace 24 by a metal wire 16, and the temperature of the brick piece 15 is controlled by an electric furnace 21. FIG. 8 shows the result of investigation on the relationship between the attachment speed of carbon attached to the surface of the brick piece 15 and the temperature in this manner.

In FIG. 8, the horizontal axis represents the temperature indicated by the thermometer 23, and the vertical axis represents the carbon attachment speed per unit time in terms of the weight per unit surface area of the brick piece 15. As shown in FIG. 8, the carbon attachment speed sharply increases as the temperature increases.

The temperature operating rate of furnace top space or above Noborikan base of the coke oven, or furnace temperature by different, (per coking chamber 1 Gate coke oven, the number of times to push the coke day) operation rate when high In the case, the amount of carbon attached to the brick surface of the carbonization chamber increases, but in such a case, when the atmosphere temperature of the furnace top space in the coke oven and the riser tube base is measured,
For example, it indicates a high temperature of 900 ° C. or more. Therefore, according to the results shown in FIG. 8, by keeping the atmosphere temperature of the furnace top space and the base of the riser at 850 ° C. or lower, preferably 830 ° C. or lower, the rate of adhering carbon to the brick surface can be significantly reduced. It is possible.

However, the temperature of the furnace top space cannot be lowered as much as possible, and there is a lower limit determined from the viewpoints of protection of bricks in the carbonization chamber, prevention of coal dry distillation delay, and ensuring coke extrudability. That is, a silica brick usually used as a furnace wall brick has a transformation point accompanied by a sudden expansion and contraction at 573 ° C., and the brick becomes brittle near this temperature. Therefore, it is not preferable to set the temperature below this temperature. Further, if the temperature is lowered more than necessary, the progress of carbonization of coal is delayed, and the coke strength is lowered. In addition, the coke burnout in the horizontal direction is insufficient, and the resistance when extruding coke at the end of carbonization increases. For this reason, the lower limit of the temperature is desirably 780 ° C, preferably 800 ° C.

Therefore, the temperature of the furnace top space and the riser base is preferably 780 ° C. to 850 ° C., more preferably 800 ° C. to 850 ° C.
Preferably, the temperature is 830 ° C.

Regarding the carbon attachment speed on the brick surface, besides the temperature, for example, a literature (Journal of Fuel Association, No. 48)
Vol., P. 732, 1969), the carbon deposition rate is influenced by the volatile content and moisture of the charged coal, and the higher the volatile content of the charged coal and the lower the moisture of the charged coal, the higher the carbon deposition rate. Is faster.

Therefore, if the temperature of the surface of the brick to which carbon is attached and the volatile matter of the charged coal are reduced by some method, and the moisture of the charged coal is increased, the amount of carbon attached to the brick in the coke oven is reduced. Things are possible.

Filling a coke oven with water is generally prohibited because a sudden change in the temperature of the brick causes destruction due to expansion and contraction and delay in carbonization of coal charged near the top of the oven. I have. However, when spraying into the furnace top space and riser tube (base and vertical tube) of the operating coke oven, the furnace top space and riser tube are instantaneously vaporized due to high temperature, There is no drip or contact with the brick wall or coke surface as it is, causing damage to the brick or delay in carbonization.

As the nozzle for watering, a commercially available nozzle can be used, and it is not particularly limited, but a nozzle which becomes mist at ordinary tap water pressure ( ^{2 to 3} kg / cm ² ) is desirable. The upper limit of the watering rate is determined by the protection of the furnace wall brick and the progress of carbonization of coal at the furnace top.

The use of steam instead of water makes it possible to sprinkle water into the furnace without using a nozzle, using an ordinary pipe or the like. However, considering the unit steam consumption, it is advantageous to use water as it is. is there. Injecting water vapor can be expected to have the effect of diluting the carbonization product gas and the effect of removing carbon attached to the brick surface in the coke oven by the reaction of aqueous C + H ₂ O = CO + H ₂ , but does not deprive heat of evaporation. Therefore, the effect on the temperature drop is small.

The following is an example in which a brick piece is put into a coke oven using the present invention, and the amount of water applied to the brick surface, the amount of water spray, and the effect of the water spray method are examined.

FIG. 1 shows an outline of a coke oven in which the present embodiment is performed.
Shown in

As a method of quantifying the amount of adhesion to the brick surface during carbonization, it is desirable to actually measure the amount of adhesion to the furnace wall of the coking chamber. However, in practice, measurement in a high-temperature atmosphere is a work load. Is very high. Therefore, as shown in FIG. 1, the first inlet 9, the third inlet 8, the fifth inlet 7, the furnace top space 5 in the coking chamber, and the riser pipe base 2 Brick pieces (20 × 20 × 40mm) in 11
Was inserted together with the thermometer 6, and the amount of the attached matter attached to the brick piece 10 immediately after charging the coal until the coke was extruded was determined from the weight difference before and after the attachment.

FIG. 2 schematically shows a method of spraying water on the furnace top space 5. A water pipe 12 is laid in the furnace top space 5, a branch pipe is provided from the first inlet 9, the third inlet 8, and the fifth inlet 7 to the furnace top space 5, and water is sprayed at the tip thereof. A watering nozzle 13 was attached so that the water could be sprayed. If the sprinkled water directly hits the furnace wall or ceiling bricks, the bricks may be damaged due to a sudden change in volume. Was placed 20 ° downward with respect to the horizontal, and arranged in the furnace width direction along the center line of the coke oven in the furnace width direction. The water spray direction may be on the riser side or on the opposite side of the riser.However, in order to avoid clogging of the nozzle tip due to carryover powder and high molecular weight components in the carbonized gas, the gas flow in the furnace top space should be in the downstream direction. It is preferable to sprinkle water toward the rising pipe side.

[0027]

【Example】

Example-1 The operation rate of the coke oven at the time of performing the test in the example was 121%, and the amount of coal charged was 23 tons (dry amount). The properties of the charged coal 4 are as follows: volatile matter 26.4%, moisture 5.6.
% And the particle size is 78% when the particle size is 3 mm or less. During the execution of this example, the operation of the coke oven and the properties of the charged coal were kept as constant as possible. This condition is the same in other embodiments.

Of the charging ports shown in FIG. 1, water is sprayed using only the watering nozzle 13 of the fifth charging port 7 closest to the rising pipe, and the base of the rising pipe is formed immediately after charging coal to immediately before coke extrusion. FIG. 3 shows the results of examining the effect of the amount of water spray on the amount and temperature of the attachments attached to the surface of the brick piece 10 inserted in 11. Here, the relative attachment amount on the left side of the vertical axis indicates the ratio of the attachment amount when watering is performed to the attachment amount when the watering amount is zero, and the smaller the value is, the more effective the watering effect on attachment suppression is. Means high. The temperature on the right side of the vertical axis is a temperature measured by the thermometer 6 inserted at the same position as the brick piece 10, and is an average value of values recorded every 5 minutes in a period from immediately after coal insertion to immediately before coke extrusion. It is.

From FIG. 3, it can be seen that the amount of adhering to the surface of the brick piece and the temperature decrease as the amount of water sprinkling increases.
, The amount of carbon adhering to the surface of the brick piece could be significantly reduced.

When the amount of water sprayed is 1.6 liters / minute or more, the relative amount of attachment increases and the temperature rises. Before the temperature rises, water drops are dropped on the surface of the charge (coke) on the furnace top in a high-temperature state, and the fine powder is wound up with rapid vaporization, which flows into the riser 2 together with the dry distillation generated gas as carryover powder. This is because it was attached to the brick piece surface. That is, it means that there is an appropriate range for the watering amount, and watering exceeding the value is not preferable.

Example 2 In the same manner as in Example 1, when water is sprayed only from the watering nozzle 13 at the No. 5 inlet 7 closest to the riser 2, the amount of carbonized gas generated immediately after charging coal is increased. The effect of the amount of water spray on the temperature of the riser base 11 up to 2 hours after insertion was investigated. FIG. 4 shows the results. Here, the temperature drop amount on the left side of the vertical axis indicates the temperature drop amount from the temperature of the riser base 11 immediately after charging the coal shown on the right side of the vertical axis. It shows that the effect on the temperature drop when spraying is large. In addition, the temperature decrease amount shown here is an average value of the values recorded every 5 minutes during the investigation period, as in Example 1. The temperature is the temperature of the riser base before measurement.

FIG. 4 shows that the amount of decrease in temperature increased with the increase in the amount of water sprayed, and the tendency of the decrease in the amount of carbon attached to the surface of the brick piece installed at the base of the riser tube was the same as in Example 1.

Example 3 As in the case of Example 1, when water was sprayed only from the watering nozzle 13 at the fifth inlet 7 closest to the riser 2, the riser was used immediately after charging the coal to immediately before coke extrusion. The effect of the duration of watering (watering started immediately after charging coal) on the amount of attachments on the surface of the brick piece inserted into the base 11 and the temperature of the riser base 11 was investigated.

FIG. 5 shows the results. Here, the relative deposition amount on the left side of the vertical axis is the same definition as in the case of the first embodiment, and the temperature on the right side of the vertical axis is inserted into the riser pipe base 11 in a period from immediately after charging coal to immediately before extruding coke. The temperature of the thermometer 6
The average of the values recorded every minute. The watering duration on the horizontal axis represents the ratio of the watering time started immediately after charging coal to the time required from coal charging to coke extrusion in percentage, and the value on the horizontal axis is 0%. Watering time means zero, and 100% means that watering was performed over the entire carbonization period. The amount of water sprayed in this embodiment is 1.6 liter / minute.

FIG. 5 shows that the longer the watering time, the lower the relative attachment amount and the temperature. This is because attachment to the brick surface in the carbonization chamber has occurred over the entire carbonization period. From this, the furnace top space temperature was set to 780
In order to control the temperature to 850 ° C., in this embodiment, watering is preferably performed for at least 80% or more of the total carbonization period, and particularly preferably watering for the entire carbonization period.

Example 4 The extent of the effect of the present invention when water was sprayed into the furnace top space from the spray (sprinkling) point was investigated. That is, when water is sprayed only from the watering nozzle 13 at the No. 1 charging inlet 9 shown in FIG.
The amount of the attachment attached to the surface of the brick piece 10 inserted in each of the Nos. 5 and 5 and the base of the riser tube was examined. FIG. 6 shows the results. Here, the relative attachment amount on the vertical axis indicates the ratio between the attachment amount when the watering amount is zero and the attachment amount when the watering is performed at the insertion location of each brick piece, as in the case of the first embodiment.
The horizontal axis indicates the name of the place where the brick piece is installed.

As shown in FIG. 6, the relative attachment amount is 1 at the sprinkling point.
Although the number of brick pieces at the numbered entrance is the smallest, as the distance from the location toward the riser tube base decreases, the margin of decrease in the relative attachment amount decreases, and the effect of water sprinkling on carbon attachment decreases.

From the above, it is most effective that the spraying of water to the top space of the coke oven by the method of the present invention is carried out in the vicinity of the place where carbon attachment is to be suppressed.

Immediately after charging coal and before watering, the furnace top space measured by the thermometer 6 inserted from the first, third, and fifth charging inlets, and the thermometer 6 inserted into the riser base, and The temperatures at the tube base were 900 ° C., 923 ° C., 931 ° C., respectively.
And 942 ° C. Average temperature at the location when watering was performed under the above conditions (average value of values recorded every 5 minutes for the temperature of thermometer 6 inserted at the location during the period from immediately after charging coal to immediately before coke extrusion) ) Is 79
0 ° C, 856 ° C, 886 ° C, and 936 ° C.

In this embodiment, at the riser tube base 11,
Despite the temperature drop of only 9 ° C., the relative deposition amount is small, but the water sprayed into the furnace top space by watering becomes steam and becomes a source of attached carbon. This is because the concentration of the carbonization product gas was diluted, and the removal effect by the reaction of C + H ₂ O = CO + H ₂ was developed.

The amount of water sprayed in this embodiment is 1.6.
Water was sprayed from the charging of coal to immediately before coke extrusion under these conditions.

[0042]

According to the present invention, in a coke oven, the amount of carbon adhering to the brick surface in the coke oven can be suppressed by spraying water into the coke oven top space when carbonizing the coal. , Its economic and technical effects are extremely high.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing installation positions of brick pieces and a thermometer in a carbonization chamber in an embodiment of the present invention.

FIG. 2 is a schematic view showing an installation position of a watering nozzle in a carbonization chamber in the embodiment of the present invention.

FIG. 3 is a view showing a relationship between a watering amount and a relative attachment amount of a riser tube base in the embodiment of the present invention.

FIG. 4 is a diagram showing the relationship between the amount of water spray and the amount of temperature decrease at the base of the riser in the embodiment of the present invention.

FIG. 5 is a view showing a relationship between a watering time and a relative attachment amount of a riser tube base in the embodiment of the present invention.

FIG. 6 is a view showing relative attachment amounts at different places in the carbonization chamber in the embodiment of the present invention.

FIG. 7 is a view schematically showing a test apparatus for examining a relationship between a carbon attachment speed to a brick piece surface and a temperature.

FIG. 8 is a diagram showing the relationship between the speed of attaching carbon to the surface of a brick piece and the temperature.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Dry main 2 ... Rise pipe 3 ... Furnace lid 4,22 ... Coal or coke 5 ... Furnace top space 6,23 ... Thermometer 7 ... 5th entrance 8 ... 3rd entrance 9 ... 1st entrance 10, 15 ... brick piece 11 ... riser tube base 12 ... water pipe 13 ... watering nozzle 14 ... supply water 16 ... Metal wires 17, 20, 2
DESCRIPTION OF SYMBOLS 1 ... Electric furnace 18 ... Dry distillation furnace 19 ... Dry distillation product gas 24 ... Attachment furnace

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C10B 43/14 C10B 43/08

Claims (1)

(57) [Claims] 1. A method of inhibiting the carbon Supplementary kimono bricks carbide surfaces indoor side is generated when the dry distillation of coal in coke ovens, furnace top space, and the temperature of the riser base 7
Water in the proper range to control to 80-850 ° C
A method for suppressing the adhesion of carbon to the brick surface in a coke oven, wherein the carbon is sprayed into the furnace top space during carbonization .