JP3183595B2 - Gas circulation method in molded coke production equipment - 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 circulating a gas circulating as a high-temperature heat medium in a facility for producing molded coke using a gas heat medium.

[0002]

2. Description of the Related Art Japanese Patent Publication No. Sho 56-47234 discloses an upright continuous dry distillation furnace for producing molded coke.

FIG. 1 shows a process flow chart in the continuous molding coke manufacturing and setting mold.

[0004] In the figure, molded coal A produced in a molded coal production facility 1 is introduced from the top of an upright continuous carbonization furnace 2 and cooled at a low temperature introduced through a tuyere 3 in an intermediate portion of the upright continuous carbonization furnace 2. The coke is sequentially heated and carbonized by the carbonization gas B and the high-temperature carbonization gas C introduced from the tuyere 4 at a position lower than the carbonization gas B, and the obtained coke descends to the cooling zone at the lower part of the upright continuous carbonization furnace 2, and Is cooled by the cold gas D introduced from the tuyere 5 and is cut out as molded coke E by the discharge device 6.

The gas generated during the carbonization of the formed coal A is mixed with the high-temperature and low-temperature carbonized gas to form a furnace top gas F,
After the dust is removed from the furnace top by a dust collector 9 through a gas cooler or a sensible heat recovery device 7 and a gas cooler 8, a part is sent to a recovery facility 10 as a recovered gas G.

Most of the other dust removal gases are circulated and blown into the upright continuous carbonization furnace 2 as the low-temperature carbonization gas B, the high-temperature carbonization gas C, and the cold gas D as the circulation gas H.

[0007] Except for the part of the circulating gas H that is introduced into the bottom of the carbonization furnace 2 as the cold gas D, it is partially heated by the low-temperature carbonization gas heater 11 and then ejected by the ejector 1.
After being mixed with the extraction gas K from the lower part of the furnace through the furnace 2, the mixture is introduced into the carbonization furnace 2 as a low-temperature carbonization gas B. Others are heated to a high temperature of about 1000 ° C. by the high-temperature carbonization gas heater 13 and then heated at a high temperature. The gas C is introduced into the dry distillation furnace 2.

At this time, cold gas D is introduced into the carbonization furnace through the cooling gas tuyere 5 at the lower part of the carbonization furnace, and the gas K after heat exchange with the formed coke is extracted from the extraction tuyere 14.
A small portion of the cold gas D that does not affect the flow of the upright continuous carbonization furnace is flowed upward.

[0009]

However, at this time, when the production rate of the molded coke is increased and the descending speed of the molded coal is increased, the convection time in the high-temperature carbonization zone is shortened, and the final carbonized temperature of the molded coal is reduced to a predetermined value. The temperature cannot be raised to the final carbonization temperature, and the quality of the obtained coke deteriorates. In addition, when trying to reach the final carbonization temperature of the molded coke, the amount of the introduced high-temperature carbonized gas must be increased, which is not preferable in terms of running costs.

[0010] The quality, especially the strength, of the molded coke is determined by the final carbonization temperature. Therefore, unless the predetermined final carbonization temperature is reached, the predetermined molded coke strength cannot be obtained.

An object of the present invention is to provide a gas circulation method for efficiently reaching a final carbonization temperature without increasing the flow rate of a heat medium in an upright continuous carbonization furnace for producing coke.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to provide only a specific flow rate of a high-temperature carbonized gas as a downward flow.
It can be achieved by flowing from the hot tuyere to between the extraction tuyere and extracting from the extraction tuyere.

That is, the low-temperature carbonized gas introduction tuyere is located substantially at the center, the high-temperature carbonized gas introduction tuyere is located below the low-temperature carbonized gas introduction tuyere, the cooling gas introduction tuyere is located below the low-temperature carbonized gas introduction tuyere. A gas circulation method for an upright continuous carbonization furnace for producing molded coke, which is provided with an extraction tuyere for extracting heat-exchanged gas between a carbonization gas introduction tuyere and a cold / hot carbonization gas introduction tuyere, It is characterized in that 5 to 20% by volume of the high-temperature carbonized gas introduced from the high-temperature carbonized gas introduction tuyere is used as a downward flow for carbonization of the molded coke and is extracted from the extraction tuyere.

The operating conditions of the dry distillation furnace are as follows:
2 by controlling the amount of gas extracted from the extraction tuyere.

[0015]

[Function] The ratio of the final carbonization temperature of the formed coal to the high-temperature carbonization gas temperature blown from the high-temperature carbonization gas tuyere can be a control factor of the high-temperature carbonization gas amount. It can be assumed that an amount sufficient to carbonize the coal has been introduced.

By making 5-20% of the amount of gas blown into the carbonization furnace as the high-temperature carbonization gas flow downward, the heat exchange rate increases, and the reduction of the high-temperature carbonization gas amount or the increase in the amount of molded coke is increased. It becomes possible.

[0017]

FIG. 2 is a view showing an embodiment of the present invention, in which the hot tuyere 4 of the high-temperature carbonized gas C and the tuyere of the cold gas D in the upright continuous carbonization furnace 2 shown in FIG. The gas flow K of 14 parts and the falling situation of the coal briquette E are shown.

In FIG. 1, the ejector 12 shown in FIG.
, The high-temperature carbonized gas C introduced from the high-temperature tuyere 4 is branched into an upward flow C ₁ and a downward flow C ₂ , and rises from below from the extraction tuyere 14 located below. It is extracted together with the temperature-raised gas K that has undergone heat exchange with the cold gas D. Under these conditions, the position of the hot tuyere 4 is changed to the first measurement point by changing the ratio of the downward flow to the amount of the high-temperature carbonized gas C introduced from the hot tuyere 4, and the hot tuyere 4 and the extraction tuyere. The temperature of the coal at each of the measurement points was measured with the intermediate position between the points 14 and 14 being the second measurement point and the point of the extraction tuyere 14 being the third measurement point.

The temperature of the coal at each measurement point is expressed as a ratio to the high-temperature carbonization gas temperature. If this ratio is 90% or more, it can be said that the heat exchange rate in this carbonization furnace is in an operating condition close to an ideal state.

FIG. 3 shows the relationship between the ratio of the downward flow in the introduced high-temperature carbonized gas flow at each measurement point and the ratio between the temperature of the coal and the high-temperature carbonized gas temperature.

As is apparent from the figure, the heat exchange efficiency can be increased by extracting 5 to 20% by volume of the high-temperature carbonization gas in a downward flow, and the final carbonization temperature reaches a predetermined temperature. Becomes possible.

That is, the flow rate ratio to the extraction tuyere is 5% by volume.
In the following, the residence time in the high-temperature dry distillation zone is short, and the coal is not sufficiently heated. The flow rate to the extraction tuyere is 20
If the volume percentage is not less than the volume%, the amount of gas flowing into the high-temperature carbonization zone is small, and the gas enters the seal zone without being sufficiently heated. As a result, the temperature of the coal is not sufficiently increased. Assuming that the flow rate to the extraction tuyere is 5% to 20%, the temperature can be appropriately increased in the high-temperature carbonization zone, and then can be increased to a predetermined temperature in the seal zone. Further, according to the present invention, it is possible to achieve a reduction in the amount of high-temperature carbonized gas in a region around 10% by volume where the graph shows a peak. Further, the final carbonization temperature can be estimated from the strength of the molded coke discharged from the discharging device.

[0023]

According to the present invention, the following effects can be obtained.

(1) The heat exchange efficiency can be increased, and it is possible to reach a predetermined final carbonization temperature even if the descending speed of the coal is increased to increase the production amount.

(2) It is possible to reduce high-temperature carbonized gas.

[Brief description of the drawings]

FIG. 1 shows an example of an upright continuous carbonization furnace to which the present invention is directed.

FIG. 2 is an explanatory diagram of each tuyere portion for explaining the present invention.

FIG. 3 shows the ratio of the downward flow in the introduced high-temperature carbonized gas stream,
The relation between the temperature of the coal and the ratio of the high-temperature carbonized gas temperature is shown.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 molded coal production equipment 2 upright continuous carbonization furnace 3 low temperature carbonization gas tuyere 4 high temperature carbonization gas tuyere 5 cold gas tuyere 6 discharge device 7 sensible heat recovery device or gas cooler 8 gas cooler 9 dust collector 10 recovery equipment 11 Heater 12 Ejector 13 High-temperature carbonized gas heater 14 Extraction tuyere

Continuation of the front page (56) References JP-A-56-57880 (JP, A) JP-A-2-124996 (JP, A) JP-B-56-47234 (JP, B2) (58) Fields investigated (Int) .Cl. ⁷ , DB name) C10B 53/08 WPI (DIALOG)

Claims (1)

(57) [Claims] 1. A low-temperature carbonized gas introduction tuyere is provided substantially at the center, a high-temperature carbonized gas introduction tuyere is located below the low-temperature carbonized gas introduction tuyere, a cooling gas introduction tuyere is located below the low-temperature carbonized gas introduction tuyere. A gas circulation method of an upright continuous carbonization furnace for producing molded coke provided with an extraction tuyere for extracting heat-exchanged gas between a carbonization gas introduction tuyere and a cold and hot carbonization gas introduction tuyere, A gas circulation method in a molded coke manufacturing facility in which 5 to 20% by volume of the high-temperature carbonized gas introduced from the high-temperature carbonized gas introduction tuyere is used as a downward flow for carbonization of the molded coke and is extracted from the extraction tuyere.