JPS5895193A - Method for heat recovery from crude gas produced in coke oven - Google Patents

Abstract

PURPOSE:To improve a heat exchanging efficiency of a jet flow layer cooler by a method wherein the crude gas produced in a coke oven is temporarily gathered in a gas collecting tube and then the apparent heat of the gas is collected only by a heat exchanger with the jet flow layer cooler. CONSTITUTION:The crude gas produced in a coke oven is gathered temporarily in a gas collecting tube and then the apparent heat of the gas is collected only by the heat exchanger with the jet flow layer cooler 7. In the cooler 7, the gas flows in through a gas inlet part 19 of an outer cylinder 18 and ascends within an inner cylinder 21, and flows out through a particle rush-out preventing plate 22 and out of a gas outlet part 20. On the other hand, heat medium particles 28 ascend within the inner cylinder 21 together with the ascending gas, collide the plate 22 and drop down between the inner and outer cylinders 21 and 18, thus recirculating within the inner cylinder 21. By the flow of the gas and circulation of the particles 28, the heat of the gas is transferred from the particles 28 to the heat exchanging water within a tube 25. In a gas-requid separator 23, the steam is separated and the heat is recovered. The substance contained in the gas such as tar is condensed on the surface of the particles 28 and carbonized while the particles 28 descend. The tar drops off from the particles 28 if they collide with each other. Thus, the tar is prevented from attaching to the wall of the tube.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for recovering sensible heat from coke oven crude gas generated in a coke oven carbonization chamber, and in particular to a method for preventing the occurrence of coking and stabilizing a heat exchange device for a long period of time. The present invention relates to a heat recovery method for the above gas, which can be operated at

Conventionally, the crude gas generated in a coke oven at a temperature of 600 to 800°C generated in a coke oven carbonization chamber is reduced to 85°C by fluffing with ammonium water.
After being cooled to around 0.9°C, the gas is sucked and pumped into the gas purification process, and the sensible heat of this gas is not effectively utilized.

In order to utilize the sensible heat of this gas, when the gas is directly led to a heat exchanger for heat exchange, the following eight problems occur with a normal heat exchanger, making it impossible to operate stably for a long period of time. .

In other words, the crude gas generated from the coke oven contains pensols,
Contains a large amount of high-boiling substances such as tar, moisture, and other soluble impurities, and in an environment of 450℃ or higher, pensols and tar decompose at high temperatures and carbon is deposited on the heat transfer tube, and if the temperature is lower than 450℃. In this environment, high boiling point substances such as tar condense on the heat exchanger tubes. As a result, the waste tube and the heat exchanger are blocked, so-called coking occurs, pressure loss increases, and heat exchange efficiency decreases, making it impossible to operate the device stably for a long period of time.

Therefore, the inventors of the present invention have conducted studies to prevent the occurrence of coking and to recover and effectively utilize the sensible heat of the crude gas generated in the coke oven, which has not been used in the past, through long-term stable operation of the heat exchange equipment. First, we established the technology for thermal circulation 1 [7] using a spouted bed turf and a wet wall cooler, and filed a patent application in 1986-111.
No. 196 was filed, but subsequent research led to the discovery that heat can be effectively recovered using a spouted bed cooler alone, leading to the present invention.

That is, the present invention provides a coke oven produced crude gas which is characterized in that after the coke oven produced crude gas is once collected in a collection pipe, the sensible heat of the gas is recovered by a spouted bed cooler using only a heat exchanger. This invention relates to a gas heat recovery method.

Hereinafter, the method of the present invention will be explained in detail with reference to the accompanying drawings.

FIG. 1 is a diagram 70- showing an embodiment of the method of the present invention.

In FIG. 1, two gas pipes 3.4 are provided in the riser pipe 2 connected to the carbonization chamber of the coke oven 1, and the gas pipes 5KVi
Trace valve 5, air collection pipe 6, spouted bed cooler 7, ammonium water cooler 8,
A flow rate control device 9 and a gas blower 10 are sequentially provided in the furnace, and the pipe line 6
Connect the end of the dry main 12 to the dry main 12. The other gas pipe line 4 includes a water seal valve 11, a dry main 12, a pressure f control device @13, a primary cooler 14, a pressure control device 15,
A gas blower 16 is provided in sequence, and the end of the pipe line 4 is connected to a gas purification device (not shown).

The above-mentioned spouted bed cooler 7 is of m configuration as shown in FIG. 2. That is, a gas inlet 19 is provided at the lower end of the outer cylinder 18, a gas outlet 2° is provided at the upper end, and a cylinder 21 is provided inside.
A particle splash prevention plate 22 is provided above the inner cylinder 21.
will be established. (External) Heat medium particles 28 are filled between the cylinder 18 and the inner cylinder 21, and a heat exchange water pipe 25 is provided in the bed filled with particles 28. The pipe line 25 is connected to a steam separator 25 provided outside the outer cylinder 18 and a pump 2.
4 to form a circulation path, and water for heat exchange is circulated by the pump 24.

Further, a pipe line 27 is connected to the steam-water separator 23, and a pump 26 is provided in the pipe line 27, and an amount of water corresponding to the amount of steam is supplied to the gas-liquid separator 23 via the pump 26 and the pipe line 27. Supply-
and keep the liquid level in the steam/water separator 23 constant.

Note that the heat medium particles 28 have heat resistance and wear resistance.
High quality, low density alumina pole etc. are used.

Hereinafter, in the flow configured as shown in E, the coke oven generated crude gas enters the spouted bed cooler 7 via the shutoff valve 5 and the air collection pipe 6. In the spouted bed cooler 7, the gas enters from the gas inlet 19 of the outer cylinder 18, rises in the inner cylinder 21, passes through the particle splash prevention plate 22, and flows out from the gas outlet 2o. On the other hand, the heat transfer medium particles 28 rise within the inner cylinder 21 as the gas rises, then hit the particle splash prevention plate 22 and fall between the inner cylinder 21 and the outer cylinder 18, and the space between them is manipulated. Inner cylinder 21 again
circulate within. Due to the above-mentioned gas flow and circulation of the particles 28, the heat of the gas (600 to 800°C) is transferred from the particles 28 to the heat exchange water in the pipe 25, and steam is separated in the steam-water separator 2 filter. Heat is recovered. Heat exchange water is circulated through a pipe 25 by a pump 24, and make-up water corresponding to the amount of steam is supplied to the steam-water separator 23 from a pipe 27 by a pump 26.

As mentioned above, heat is recovered in the spouted bed cooler 7 and
The coke oven gas, which has reached a temperature of about 00°C, is led to an ammonium water cooler 8, where the ammonium water injected from a pipe 81 reaches a temperature of about 70°C.
After dropping by ~80°C VcfM, the dry main 1 passes through a blower 10 for pressure compensation incorporating a flow rate controller 9.
2, after 7 minutes, pipe 4, primary cooler 14,
The gas is sent to the gas purification process via the blower 16.

In addition, the water seal valve 11Fi and the cutoff valve 5 are opened together, and the pressure control device 13 provided in the gas pipe line 4 is used to control the gas pipe line 3.
It is preferable to control the pressure so that a predetermined amount of gas flows into the chamber, thereby enabling stable pressure control and gas suction.

FIG. 6 is a flowchart showing another embodiment of the method of the present invention. In FIG. 6, the same reference numerals as in FIG. 1.2 indicate products with the same functions as in FIG. 1.2.

The flow shown in FIG.
A pressure control device 17, a spouted bed cooler 7, an ammonium water cooler 8, a primary cooler 14, a pressure control device 15, and a gas blower 16 are provided, and the other gas pipe 4 is equipped with a water seal valve 11, a dry main 12, and an output control bag [ 13, and the end of the gas pipe line 4 is connected between the ammonium water cooler 8 and the primary cooler 140.

In Fig. 6, even if gas is not passed to the i-line main 12 side, the i-line main 12 is always flushed with ammonium water to prevent a drop in temperature, and if the operation is to be stopped due to a breakdown, inspection, etc., the switch can be switched immediately. It is preferable to make it possible. (The reason for preventing the temperature drop in the dry main 12 is that the dry main is fixed to the coke oven body, and there is a risk of distortion occurring due to thermal expansion when subjected to temperature changes. (This is because the flow shown in Fig. 1 is the same as the gas pipe line 4 and the equipment installed in the pipe line 4 as is the conventional equipment.)
The method of the present invention is suitable for applying to an existing coke oven, and the flow shown in FIG. 3 omits the gas blower 10 in the flow of FIG. It is suitable when applied.

The effects of the method of the present invention explained above are summarized as follows.

(1) Since heat is recovered from high-temperature coke oven gas in the spouted bed cooler 7, tar, pinch, etc. in the gas condense on the surface of the heat carrier particles 28, and carbonize while the particles 28 descend. Furthermore, the particles 2B are prevented from peeling off due to collisions with each other and adhering to the heat exchange water pipe 25, thereby increasing the heat exchange efficiency of the spouted bed cooler 7 (in the spouted bed cooler 7, the particles 2B are separated from each other and attached to the heat exchange water pipe 25). It has been confirmed through experiments that it is possible to recover high-pressure steam as described above.) Furthermore, the heating medium particles 28 are self-regenerating, and extraction and regeneration are not necessary.

i21 No need to handle large amounts of condensed tar.

(3) Equipment to prevent tar solidification when coke oven gas introduction is interrupted for decoking gas piping or boiler inspection, etc.
For a certain amount of time, there is no need for equipment to remove the tar that increases during heat recovery operation, and the ancillary equipment can be simplified.

(4) It is easy and safe to drive. When using a wet wall cooler, it is necessary to switch the line to pass hot air through the bypass line of the wet wall cooler during preheating operation at startup or decoking operation, but in the case of the present invention, preheating, decoking The operation time is the same as that during normal heat recovery, and steam recovery can also be performed during decoking.

[Brief explanation of drawings]

1 and 3 are flows showing one embodiment of the method of the present invention, and FIG. 2 is a diagram showing the configuration of a spouted bed cooler used in the method of the present invention. Sub-agents 1) Meifuku agent Ryo Hagiwara -

Claims (1)

[Claims] 1. A method for recovering heat from coke oven crude gas, which comprises collecting the coke oven crude gas in a gas collection pipe and then recovering the sensible heat of the gas using only a spouted bed turf heat exchanger.