JP2968162B2 - Measuring method of gas pressure in coal bed of 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 measuring a gas pressure in a coal bed in a coke oven.

[0002]

2. Description of the Related Art In the process of producing coke from coal in a carbonization chamber of a coke oven, the coal expansion pressure acting on the furnace wall of the coke oven due to the expansion of the coal damages the furnace wall of the coke oven and makes it impossible to operate. Expansion pressure management is an important issue in furnace body management, as the coke oven may be forced to shut down.

In recent years, attention has not been paid to inflation pressure in Japan. However, in the future, the aging of the furnace body will progress and the strength of the furnace body will decrease, and the introduction of coal pretreatment technologies such as the humidifying coal method and the preheating coal method will increase the coal charge density in the coking chamber, and Is increasing, so attention to the inflation pressure is needed.

It is known that the cause of the expansion pressure is the gas pressure in the coal bed in the softened and molten state. In a small test coke oven, the gas pressure in the softened molten layer can be easily and accurately measured, and the test coke oven is capable of directly measuring the expansion pressure acting on the oven wall with one wall movable. Many researchers found that there is a correlation between the maximum inflation pressure when the coal layers softened and melted in the center of the coking chamber and the gas pressure peak value in the coal layer in the softened and molten state at the same time. (Eg, CC Russe)
ll et al. , Proceedings Bla
st Furnace, Coke Oven and
Raw Materials, AIME, 12 (195
3), p. 197).

However, an actual coke oven has a height of several meters,
The length is as long as several tens of meters, and the variation in the state of coal filling in the furnace height direction and the furnace length direction is extremely large. For example, when viewed in the furnace height direction, since the charging density immediately below the coal charging inlet is higher than that between the coal charging inlets, it is considered that the expansion pressure is also high. As described above, it is presumed that there is a distribution of the expansion pressure in the furnace height and the furnace length direction in the actual furnace.

[0006] Since the expansion pressure is a force applied to the furnace wall and cannot be directly measured in an actual coke oven, gas pressure measurement in a softened molten coal layer which is a cause of the expansion pressure has been attempted in an actual furnace.
Conventional gas pressure measurement methods in actual furnaces include:
It is measured by inserting a metal tube having an inner diameter of several mm with a slit at the tip into the furnace from the coal loading inlet or the furnace lid. For example, Latshaw et al. (GM Lat.
Shaw et al. , Ironnaking Co
nancence Proceedings, AIM
E, 43 (1984), p. 373) is a real furnace (U.S.A.).
S. Steel, Clairton, B Batter
In y), the probe is inserted horizontally from the furnace lid and vertically from the charging port to measure the gas pressure. The probe inserted from the furnace lid has an inner diameter of 9.525 mm and a length of 3 m.
And 3.175mm diameter with 6m steel pipe
Are formed at upper and lower sides at intervals of 25.4 mm from the probe tip. On the other hand, the probe to be inserted from the inlet is a steel pipe with an inner diameter of 25.4 mm, length of 1.5, 2.7 and 3.9 m, and holes of 3.175 mm in diameter at right and left 75.4 mm apart from the probe tip. (Probes are inserted so that the holes are lined up in the furnace length direction). However, in such a method, firstly, the probe insertion position cannot be fixed clearly, secondly, coal is clogged in the probe in the process of inserting the probe into the furnace, and thirdly, the size of the probe Is too large compared to the thickness of the softened molten layer to be measured, the reproducibility is poor, and reliable data is not available, so the expansion pressure distribution of the actual coke oven cannot be accurately grasped. It is the current situation.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a method for accurately measuring the gas pressure in a softened molten coal layer in an actual coke oven.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a method for measuring the gas pressure in a coal bed of a coke oven, comprising the steps of: And pulling out the metal pipe while leaving the probe at the position, and then measuring the gas pressure in the coal seam with the probe, wherein the probe has an outer diameter of 2 mm or less, And inner diameter 1mm
A coal bed of a coke oven characterized in that a tip is taken out of a metal pipe and the end is oriented in a direction opposite to the direction of insertion into the coal bed. This is a method for measuring the internal gas pressure.

Here, the pressure detecting probe has a tube diameter sufficiently smaller than the thickness of the softened molten layer to be measured. The probe may be used alone or may be accompanied by a detecting end of a temperature measuring means. The bent probe is put out of the pipe at the end of the open metal pipe, or the probe is turned back at the end of the metal pipe. Preferably, immediately after charging, insert the probe into an arbitrary position in the actual coke oven using the furnace lid as a guide from the furnace lid with a hole made of a probe with a metal pipe, and then pull out the metal pipe.
By determining the probe position and preventing coal clogging during the probe insertion process, the gas pressure in the softened molten coal layer equal to the expansion pressure acting on the coke oven furnace wall, or the gas pressure distribution in each part in the furnace, is accurately determined. It is to be measured.

[0010]

The present inventor has proposed a gas pressure measuring method (for example, GM Latshaw e) in a conventional coke oven.
t al. , Ironnaking Conferen
ce Proceedings, AIM, 43 (19
84), p. As a result of repeated studies on the reason why accurate data could not be obtained in 373), the following points were found to be the causes.

First, the probe insertion position is not fixed for each experiment. Since the expansion pressure shows the maximum value when the softened molten layer meets at the center of the carbonization chamber,
Normally, gas pressure measurement is performed when the softened and molten layers meet at the center of the furnace width of the coking chamber. However, in an actual coke oven, there are several meters from the coal charging inlet or the furnace lid to the measurement point, and it is necessary to insert a few meters probe into the furnace. For this reason, it is extremely difficult to accurately position the gas pressure detecting end position at the center of the furnace in the furnace width direction, which is the measurement point, and it is usually shifted to the left or right. In addition, a method of fixing the probe using a fixing jig in the carbonization chamber in an empty kiln state in advance is also conceivable, but the fixing jig becomes a resistance when charging coal, causing a change in the bulk density of the coal, and a steady state during the steady state. Gas pressure cannot be obtained. If the gas pressure deviates slightly from the center of the coking chamber, the gas pressure value will differ greatly, and the gas pressure during steady state cannot be measured due to the change in coal bulk density. In addition, a method is required that can measure the gas pressure at the steady bulk coal density. Second, coal is clogged in the probe during the process of inserting the probe into the furnace. Since the slit at the tip of the probe is as narrow as about 1 mm, little attention has been paid to this point in the past. However, the inventor has confirmed that coal enters the probe in the process of being inserted into the furnace.
If the coal that has entered when the softened molten layer has reached the probe tip position is simultaneously softened and melted, the gas pressure in the softened molten layer apparently becomes higher than the actual value. Also, if the coal inside the probe softens and solidifies before the softened molten layer reaches the probe tip position, the probe will be blocked by the solidified coke, so when the softened molten layer reaches the probe position, the gas pressure will actually Is detected lower than the value of. Therefore, it is necessary to make the probe structure such that coal does not enter.

Third, the conventionally used probe is too large. Conventionally, the probe was required to have a certain thickness in order to be inserted into the coal seam, but as a result, a probe having the same thickness as that of the softened molten layer was used. This caused a remarkably large disturbance. In order to solve this problem, it is necessary to use a probe as small as possible.

Based on this finding, the inventor has devised the following specific method.

In the present invention, a probe having a pipe diameter sufficiently smaller than the thickness of the softened molten layer to be measured is used as the gas pressure probe. Softened molten layer thickness is 2-3mm near the wall
Therefore, the inner diameter of the probe must be 1 mm or less, which is smaller than the thickness of the softened molten layer, and the outer diameter must be at most 2 mm or less so as not to affect the process of forming the softened molten layer. If necessary, the detection end of the temperature measuring means having a diameter of 1 mm or less is fixed to the probe with a wire. The thickness of the detection end of the temperature measuring means is limited by the thickness of the softened molten layer and must be 1 mm or less.

The specific procedure will be described below with reference to FIGS.

The probe and the detection end of the temperature measuring means are inserted into a metal pipe 1 having a length corresponding to the measurement position and having a diameter of about 20 A, and the probe 2 is placed 20 mm outside the pipe at the tip of the pipe.
Fold back about. After extruding the coke in the coke oven carbonization chamber, the furnace lid 3 having a hole having a diameter of about 40 mm is attached to the gas pressure measurement position in the furnace height direction, and coal is charged. The probe 2 and the detecting end of the temperature measuring means are inserted together with the metal pipe 1 into a predetermined position in the coke oven furnace, and the probe 2 and the detecting end of the temperature measuring means are left in the predetermined position. Out of the furnace. The probe 2 and the detecting end of the temperature measuring means, which are outside the furnace lid 3, are connected to the pressure transducer 4 and the temperature recorder 5, respectively, to record changes in gas pressure and temperature with time.

In an actual coke oven, since the expansion pressure acting on the coke oven wall is equal to the gas pressure in the softening and melting layer, the temperature at the gas pressure measurement position is in the softening and melting temperature range of the coal to be measured (normally 400 ° C.). (500 ° C.) is defined as the expansion pressure. After the coal carbonization, the probe and the detection end of the temperature measuring means are cut, and coke extrusion is performed in the same manner as usual.

According to the method of the present invention, the probe insertion position can be accurately positioned at any position in the coke oven carbonization chamber, a steady coal bulk density can be secured, and coal clogging during the probe insertion process can be avoided. , Since the probe does not affect the formation process of the softened molten coal layer,
It is possible to accurately measure the gas pressure in the softened molten coal layer in an actual coke oven.

[0019]

EXAMPLES Volatile content 26.8%, ash content 9.0%, maximum flow rate 470DDPM, softening and melting temperature range 414 ° C to 489 ° C
In a coke oven having a furnace width of 430 mm, a furnace height of 6500 mm and a charged coal amount of 30 ton, a furnace temperature of 1100 ° C.
From the furnace bottom immediately below the inlet by the method of the present invention.
At a height of 0 mm, the changes over time in the gas pressure and temperature in the coal seam were measured. At this time, the probe for gas pressure detection has an outer diameter of 2 mm and an inner diameter of 1 mm, and the metal pipe has a diameter of 20 mm.
A was used. The temperature detection end is 1 mm in diameter.
A sheath thermocouple was used.

The gas pressure in the softened molten layer (414 ° C. to 489 ° C.)
Table 1 shows the measurement results of the maximum value of the gas pressure at ℃.
From Table 1, it can be seen that the reproducibility of the measured values is very good and the variation is very small.

[0021]

[Table 1]

[0022]

According to the present invention, in an actual coke oven,
It has become possible to accurately measure the gas pressure in the softened molten coal layer, which is the cause of the expansion pressure.

This makes it possible to evaluate the influence of the expansion pressure on the furnace body, thereby preventing damage to the furnace body due to the expansion pressure, and further extending the life of the coke oven, and has a great economic effect.

[Brief description of the drawings]

FIG. 1 is a diagram showing a state in which a gas pressure detecting probe according to the present invention is inserted into a metal pipe.

FIG. 2 is a view exemplifying a method of measuring a gas pressure in a softened molten coal layer in the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Metal pipe 2 ... Probe for gas pressure detection 3 ... Furnace lid 4 ... Pressure transducer 5 ... Temperature recorder

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-272992 (JP, A) JP-A-4-1322791 (JP, A) JP-A-55-87929 (JP, A) JP-A-55-87929 165986 (JP, A) JP-A-6-264068 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C10B 57/00 C10B 29/04 C10B 41/00

Claims (1)

(57) [Claims] In the method for measuring gas pressure in a coal bed of a coke oven, a metal pipe into which a pressure detecting probe is inserted is inserted from a hole provided in a furnace lid to an arbitrary position of the coal bed in the furnace, and the probe A method of measuring the gas pressure in the coal seam with the probe after extracting the metal pipe while leaving the metal pipe at the position, wherein the probe has an outer diameter of 2 mm.
mm or less, and 1 mm or less in inside diameter, the tip is taken out of a metal pipe, and the direction of the end is configured so as to be opposite to the direction of insertion into the coal bed, characterized by using For measuring gas pressure in a coal bed of a coke oven.