JPS58164991A - Recovering method for heat of crude gas in cokefurnace - Google Patents

Abstract

PURPOSE:To prevent the generation of coking and to make it possible to operate a heat exchanger in a stabilized condition for a prolonged period of time by a method wherein crude gases generated in the cokefurnace are once collected in a collecting pipe and the sensible heat of the crude gases are collected only by a heat exchanger through a tar cooler. CONSTITUTION:The crude gases generated in the cokefurnace enter the tar cooler 7 through an interrupting valve 5 and a gas collecting pipe 6, enter a gas-liquid contact chamber 21 from a gas inlet port 19 and then flow out from a gas outlet port 20 from a flowdown pipe passage 25 through a gas-liquid separating chamber 22. On the other hand, a circulating oil flows down in the flowdown passage 25 as it forms itself a film, pools in the gas-liquid separating chamber 22 and is returned to the gas-liquid contact chamber 21. The heat of the coarse gases generated in the cokefurnace due to the circulation of the gases and the circulating oil moves to heat exchanging water flowing through a heat exchange water chamber 31 to thereby forms a film and the vapor of the water is separated by a gas-water separator 30 so as to recover heat. Further, the temperature of the gases at the gas flowout port 20 is detected by a temperature sensor 39 and the overflowing position of heat exchange water is adjusted by a control valve 36 so that the surface area of heat transfer of the flowdown passage 25 is increased or decreased to thereby control the temperature of the gases constant.

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 particularly for preventing the occurrence of coking and stably operating a heat exchange device for a long period of time. The present invention relates to a method for recovering heat from gas.

Conventionally, the crude gas generated in a coke oven at a temperature of 600 to 800℃ is reduced to 85℃ by flushing with ammonium water.
After being cooled to around 10°C, the gas is pumped to the gas purification process, and the sensible heat of this gas is not used effectively.

When one gas is directly led to a heat exchanger for heat exchange in order to utilize the sensible heat of this gas, the following problems arise in a normal heat exchanger, and it is not possible 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, pensoles 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, gas pipes and heat exchangers are blocked, so-called coking occurs, pressure loss increases, and heat exchange efficiency decreases, making it impossible to operate the equipment stably for a long period of time.

Therefore, the inventors of the present invention have conducted research to prevent the occurrence of coking and to recover and effectively utilize the sensible heat of the crude gas generated in coke ovens, which had not been used in the past, through long-term stable operation of the heat exchange equipment. , established a technology for heat recovery using a spouted bed tarp and a wet wall cooler, and filed a patent application as Japanese Patent Application No. 114196/1989, but subsequent research revealed that heat recovery could be effectively achieved using a tar cooler alone. This is what led to the present invention.

That is, the present invention relates to a heat recovery method for coke oven generated crude gas, which is characterized in that the coke oven generated crude gas is once collected in an air collecting pipe and then the sensible heat of the gas is recovered using only a heat exchanger using a tar cooler. It is.

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

FIG. 1 is a flowchart showing an example of an embodiment of the method of the present invention.

In FIG. 1, two gas lines 3.4 are provided in the riser pipe 2 connected to the carbonization chamber of the coke oven 1, and the gas line 6 is provided with a shutoff valve 51. , a dream trachea 6, a tar cooler rough, a cheap water cooler 8, a flow control device #9, and a gas blower 10 are installed in this order, and the end of the channel 6 is connected to a dry main 12.
Connect TIrc. The other gas pipe 4 has a water seal valve 1.
1. A dry main 12, a pressure side (II device 13, a primary cooler 4, a pressure control (3) device 15, and a gas blower 16 are installed in this order, and the end of the pipe line 4 is connected to a gas purification device (not shown).

The tar cooler 7 described above has a configuration as shown in FIG. 2. That is, a gas-liquid contact chamber 21 having a gas inlet 19 and a gas-liquid separation chamber 22 having a gas outlet 20 are provided inside the outer cylinder 1B.
In between, a downstream pipe 25 for circulating oil for heat exchange such as self-by-product tar or medium oil with high solubility is provided by tube plates 23 and 24, and the space between the tube plates 23 and 24 is used as a water chamber 31 for heat exchange. . Outer cylinder 18
A circulation pump 26 and a pipe line 27 are provided outside of the gas-liquid separation chamber 22 to return oil to the gas-liquid contact chamber 21, and a pump 31. is provided to circulate water for heat exchange. ? , conduit 56.34.
35, a steam/water separator 60 is provided, and a replenishment pump 3 for replenishing heat exchange water to the steam/water separator 30)
7. Provide a pipe filter 8. Note that a temperature sensor 59 for controlling the gas temperature at the gas outlet 20 and a mechanism for controlling the liquid level in the gas-liquid separation chamber 22 are provided with a bell meter 29 and a pipe branching from the above-mentioned pipe line 27. A control valve 2B is provided in the passage 40.

In the flow configured as above, the crude gas generated in the coke oven passes through the shutoff valve 5 and the air collection pipe 6 to the tar cooler 7.
to go into. In the tar cooler 7, the above gas flows through the gas inlet 1.
The gas enters the gas-liquid contact chamber 21 from 9, passes through the downstream pipe 25, passes through the gas-liquid separation chamber 22, and exits from the gas outlet 20. On the other hand, the circulating oil flows down from the gas-liquid contact chamber 21 through the downstream pipe 25 while forming a liquid film, accumulates in the gas-liquid separation chamber 22, and is returned to the gas-liquid contact chamber 21 by the action of the pump 260. Due to the above-mentioned gas flow and circulation of the circulating oil, the heat of the crude gas generated in the coke oven is transferred from the liquid film of the circulating oil to the heat exchange water flowing through the heat exchange water chamber 61, and the steam is separated in the steam separator 50. heat is recovered.

Further, the gas temperature at the gas outlet 20 is detected by a temperature sensor 59, and the overflow position of the heat exchange water (i.e., the pipe line 6
The heat transfer area of the downstream pipe 25 is increased or decreased by adjusting the control valve 3 (5) or the pipe 35), thereby maintaining the gas temperature at the gas outlet 20 at a constant (200 to 300°C). do. Gas-liquid separation chamber 2
The level of circulating oil in 2 is detected by a level meter 29,
When the level rises, the control valve 28 is opened, the circulating oil is extracted to the outside through a pipe 40 branching from the circulation pipe 27 of the circulation m, and the level is adjusted.

As mentioned above, the heat is recovered in the tar cooler 7 and the
The coke oven gas, which has reached a temperature of about 00°C, is led to an ammonium water cooler 8, where it is heated to a temperature of about 70°C by ammonium water injected from a pipe 8.
After the temperature drops to 80°C, it passes through a blower 10 for pressure compensation incorporating a flow rate control device 9, enters the dry main 12, and then passes through a pipe 4, a primary cooler 14, and a blower 16, and then enters the gas purification process. Sent.

Further, it is preferable that the water seal valve 11 is opened together with the cutoff valve 5 and the pressure is controlled using a pressure control device 13 provided in the gas pipe line 4 so that a predetermined amount of gas flows into the gas pipe line 6. This allows for stable pressure control and gas suction.

FIG. 3 is a flowchart showing another embodiment of the method of the present invention. In FIG. 3, 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 tar cooler 7, an ammonium water cooler 8, a primary cooler 4, a main control device 15, and a gas blower 16 are provided, and the other gas pipe 4 is provided with a water seal valve 11, a dry main 12, and a pressure control device 13. , the end of the gas pipe line 4 is connected between the ammonium water cooler 8 and the primary cooler 4 described above.

In FIG. 5, even if gas is not passed to the drain main 12 side, the drain main 12 is constantly filled with water to prevent the temperature from dropping.
:'i It is preferable to be able to switch immediately even when the operation is stopped due to failure, inspection, etc. (Note that the temperature drop in the dry main 12 is prevented because the dry main is fixed to the main body of the coke oven (7), and there is a risk of distortion due to thermal expansion when the temperature changes. (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.)
It is suitable for applying the method of the present invention to an existing coke oven, and the flow shown in Fig. 3 omits the cass blower 1° in the flow of Fig. 1, making it suitable for applying the method of the present invention to a newly installed coke oven. It is suitable for cases where

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

(1) Tar cooler odor: tar in °C1 gas,
Even if pinches etc. condense, they can be washed and dissolved with a large amount of circulating oil, preventing caulking, improving the heat transfer performance of the machine, and reducing mortar pressure loss.

(2) In a tar cooler, the self-byproduct tar circulating in the tar cooler has high thermal stability (the decomposition temperature of tar is 3
00~400℃ mark above), 60kg/crr? A(8) medium pressure steam can be recovered.

(3) Since tar coolers can recover heat while preventing coking, they can operate stably and continuously for long periods of time.

(4) Compared to the previously applied patent application (Japanese Patent Application No. 55-111196) mentioned above, (1) the overall pressure loss can be reduced to less than 10%, and the electricity cost of the gas blower can be saved; (11) the cooling of the tar cooler can be improved. The capacity is high and the entire device can be made compact.

(5) In a tar cooler, the outlet gas temperature and the circulating oil (tar) fiI degree are approximately equal in life, so the gas cooling temperature is determined by the properties of the circulating oil (tar) (according to experiments, Below ℃, the viscosity of tar increases rapidly, and above 600℃, thermal transformation of tar begins.
The tar temperature that can be stably handled is 200 to 300°C. Therefore, the tar cooler outlet gas temperature ((gas cooling temperature)) may be adjusted to 200 to 300°C. ) (9)

[Brief explanation of the drawing]

1 and 3 are flowcharts showing one embodiment of the method of the present invention, and FIG. 2 is a diagram showing the configuration of a tar cooler used in the method of the present invention. Sub-agents 1) Post-Morning agent Ryo Hagiwara - (10) Procedural amendment (formality) Commissioner of the Japan Patent Office Kazuo Wakasugi 1. Indication of case 1982 Patent Application No. 1917! i2 No. 2-51 Ming'>lJj+: Method for recovering heat from coke oven crude gas 3, relationship with the case of the person making the amendment Patent applicant fl, Address: 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Name (620) Mitsubishi Heavy Industries, Ltd. (Name: B1 (and 1 other person) "'7j Nee VIJIX 7., = Engineering, 16 Dainitsu Toranomon Chiyoda Building Telephone (5o4) Number 1894 Name Patent attorney (7179) IB
Akira (and 1 other person) (1) 1 Drawing subject to amendment Content drawing of surface a amendment (Fig. 3) t-Submit as shown in the attached sheet. )

Claims (1)

[Claims] A method for recovering heat from coke oven crude gas, which comprises collecting the coke oven crude gas in an air collecting pipe and then recovering the sensible heat of the gas using only a heat exchanger using a tar cooler.