JPH0643160Y2 - Internal heat type rapid coal pyrolysis equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an internal heat type coal rapid pyrolysis for pyrolyzing coal powder in the process of pyrolyzing coal to obtain coal gas, tar and char (coke). The present invention relates to a thermal decomposition device.

(Prior Art) A coke oven has long been known as a process for thermally decomposing coal to produce coal gas, tar, and char. In addition, recently, a new method has been developed for the case where tar or coal gas is needed without the need for lump coke. For example, COED process ("Future coal chemical industry" Yoshida
(See page 282) and ORC process (Final report on DO
E contact No.EX-76-C-01-2244,1979), the former is a method of sequentially heating coal in a multi-stage (four-stage) fluidized bed to thermally decompose it, and high-temperature char is used as a heat source to generate oxygen. In the latter case, when pyrolyzing pulverized coal in a spouted bed, high temperature char (required 10 times the amount of coal) is recycled to the reactor as a heat source. . In these coal decomposition processes, the equipment is large, the operation is complicated, and there is a problem in the heat supply method.

In order to improve this, Japanese Patent Laid-Open No. 1-113491 discloses that a gas (hydrocarbon or hydrogen as a main component) produced from coal pyrolyzed in a reaction furnace is heated in a heat storage type heat exchange furnace, and this is again used in the reaction furnace. The method of circulating supply to is presented.

(Problems to be solved by the invention) Although a large amount of high-temperature char is used in the COED process and the ORC process for supplying heat during coal pyrolysis in the above-described conventional technology, this large amount of high-temperature char is handled. There is a problem in that it is conveyed as a whole, and it is also difficult to carry it out.
In the technique described in Japanese Patent No. 3491, there is a problem that soot (carbon) is generated due to decomposition of hydrocarbons during heat exchange of recycled gas, and a countermeasure against this is required.

The present invention solves the above-mentioned problem of directly supplying a heat source such as decomposition gas or char to a reaction chamber, and employs an indirect heating method to rapidly pyrolyze coal powder with a very simple facility. The purpose is to provide.

(Means for Solving the Problems) In order to achieve the above object, the gist of the present invention is: (1) Coal heat having a dispersion gas supply chamber in the upper part and a pyrolysis reaction chamber communicating with a coal supply pipe. In the decomposing device, a heat resistant heating pipe is provided in the pyrolysis reaction chamber, and an internal heat rapid coal pyrolysis device is provided.

(2) The heat-resistant heating tube disposed in the pyrolysis reaction chamber is made of ceramics or heat-resistant steel
It is an internal heat type rapid coal pyrolysis apparatus described.

FIG. 3 shows a reactor for thermally decomposing conventional coal in a produced gas circulation system. That is, the decomposition heating gas supply chamber 2 is provided above the thermal decomposition reaction chamber 1, and the pulverized coal inflow pipe 3 is provided.
Open to the reaction chamber 1. Reference numeral 4 is a partition wall provided with a heating gas jet port 5. Reference numeral 6 denotes a decomposition heating gas supply pipe through which a coal decomposition gas generated from the reaction chamber 1 is passed through a heat exchanger 7 to recover sensible heat and tar.
It is introduced into a char recovery system (not shown), and part of the gas is reheated (near 1000 ° C.) in a heat storage type exchange furnace (not shown) and introduced. The decomposition heating gas from the supply pipe 6 is ejected into the reaction chamber 1 from the ejection port 5 provided in the partition wall 4 of the supply chamber 2, and thermally decomposes the pulverized coal 7 supplied from the coal inflow pipe 3. The generated product gas is recycled as described above.

The present invention improves upon the conventional device shown in FIG. 3 as shown in FIGS. That is, FIG. 1 penetrates the ceiling 8 and the partition wall 4 of the coal powder thermal decomposition reactor,
A heating tube 9 extending to the reaction chamber 1 is provided. Heating tube 9
It has a double structure in which the gas flowing from the inner side 9-1 is discharged through the outer side 9-2 (or vice versa), depending on the size of the reactor 1. That is, the number of facilities is selected so as to be uniformly transmitted to the pulverized coal 7 flowing in from the inflow pipe 3. The heating tube 9 is made of ceramics or heat resistant steel. FIG. 2 shows a heating pipe 11 that horizontally penetrates the side wall 10 of the reaction chamber 1 from one side to the other side.
The construction material and the number of installation are the same as those in FIG. 1, but it is not necessary to have a double structure. Further, a method of turning or meandering in the reaction furnace may be adopted.

A circular jet port 5 for jetting a gas from the gas supply chamber 2 to the reaction chamber 1 is formed in a partition wall separating the gas supply chamber 2 and the reaction chamber 1. The jet port is as shown in FIG. It may be a slit-shaped continuous or discontinuous through hole. Further, it is preferable that the opening to the reaction chamber 1 is provided so as to be directed toward the center and be so inclined that the jet gas focus at the center is not far from the pulverized coal supply port.

Pulverized coal is supplied from the coal powder inflow pipe 3 into the reaction furnace 1 of the present invention and dispersed into the reaction furnace. Dispersion in the reaction furnace is made substantially uniform by the gas ejected from the gas ejection port 5. It is not necessary to use a special gas as the jet gas,
As long as it does not affect the decomposition reaction of pulverized coal, it can be freely selected and a relatively low temperature gas may be used. In addition, when inflowing pulverized coal, increasing the solid-gas ratio (kg-coal / kg-transport gas) reduces the amount of transport (inflow) gas entrained with coal,
This is preferable because the burden of heating is reduced.

The pulverized coal 7 dispersed in the reaction chamber 1 is (50 mesh [300 μ
There is no problem if m] or less is 80% or more, but fluctuations can be seen in the produced amount at about 1 mm, so it is better not to make it too rough. ) It is indirectly heated to 700 to 900 ℃ by the heating pipe 11 and pyrolyzed.

The heating pipe 11 is a self-generated pyrolysis gas generated in the reactor, LP
G, LNG, blast furnace gas, or converter gas is used alone or as a fuel, air is mixed, and burned gas is supplied to heat the atmosphere to a temperature slightly higher than the ambient temperature. At this time, the reaction chamber 1 may be operated at a high pressure, and it is necessary to make the pressure inside the heating pipe 11 equal to that of the reaction chamber 1 so that gas leakage does not occur. Further, when the pressure fluctuation in the reaction chamber becomes high, there is a pressure distribution along with the flow of the combustion gas in the longitudinal direction of the heating tube itself, so that a gas leak may occur even if the pressure equalization is maintained between the two. is there.

In this case, a leak from the heating pipe to the reaction chamber is allowed to some extent, but in the opposite case, flammable coal gas enters the heating pipe and affects the air-fuel ratio, and at the same time as gas leak, coal It is not preferable for two reasons that fine powder is mixed.

For this reason, it is preferable that the pressure on the heating tube side be slightly higher than the pressure in the reaction chamber during the operation so that the maximum difference is 0.05 kg / cm ² . For such pressure adjustment, it is advisable to provide an internal pressure detecting means in the reaction chamber and the heating tube.

(Example) In the apparatus shown in FIG. 1, a coal flow of 100 kg / HR (coal analysis values are shown in Table 1) was carried in a pipe 3 with nitrogen gas and blown into the furnace 1. The amount of nitrogen gas at this time was about 2 kg / HR. To improve the dispersion of the coal flow in the furnace, 40 Nm ³ / HR of coal pyrolysis gas generated in this furnace was blown from the nozzle 5 at an angle of 45 ° to the coal flow.

The coal flow is rapidly heated by the heating pipes 11 (three) while being lowered in the furnace 1 having a diameter of 50 cm, and undergoes thermal decomposition.
The heating tube 11 is a radiant tube having an outer diameter of about 10 cm and a furnace length of 2 m, which is manufactured from a ceramic containing silicon carbide as a main component. The inner tube shown in 9-1 is replaced with air and coal decomposition gas (5500 Kcal). / Nm ³ ) of the combustion gas passes through, makes a U-turn at the tip (burner not shown), and is discharged from the outer diameter 9-2. There is a recuperator (not shown) behind the outer pipe 9-2, and heat exchange is performed between the combustion exhaust gas and the combustion air.

The combustion amount was 4.55 Nm ³ / HR (2500 Kcal / HR) with three heating tubes, and this heat amount was about half of the heat amount for raising coal from normal temperature to 900 ° C.

It was measured by another experiment that the surface temperature of the heating tube 11 reached about 1400 ° C. However, the temperature of the char gas flowing down is 880 just above the heat exchanger on the exit side of the furnace.
℃ was detected. Almost no adhesion of coal char was observed on the surface of the heating pipe 11, but this is due to the high surface temperature. On the contrary, the inner wall of the furnace 1 showed some growth of char because the temperature was slightly low, but the growth stopped after a certain period of time.

The heating tube 11 and the burner metal part are a ceramic-metal joint, and the possibility of leakage cannot be eliminated. Therefore, the combustion air pressure and combustible gas pressure were controlled so that the pressure inside the tube was always higher than the furnace pressure by 200 mmAg.

As a result, some leakage of combustion gas into the furnace from the joint occurred, but gas leakage from the inside of the furnace to the heating pipe 11 could be prevented.

Tables 2 and 3 show the conversion rates of the produced gas, char and tar and the gas components as a result of this thermal decomposition.

(Effect of the Invention) As described above, according to the present invention, the reaction product can be obtained by decomposing coal with simple equipment, and the operation is stopped due to the trouble caused by soot generation in the conventional circulation system. It is possible to operate efficiently.

[Brief description of drawings]

1 and 2 are views showing an embodiment in which a part of the device of the present invention is shown in section, and FIG. 3 is a view showing a conventional device. 1: Pyrolysis chamber, 2: Heating gas supply chamber, 3: Pulverized coal inflow pipe, 4: Partition wall,
6: Heating gas outlet, 7: Pulverized coal, 8: Ceiling, 9: Heating tube, 10: Side wall

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Takafumi Kawamura Inventor Takafumi Kawamura Kitakyushu City 1-1-1 Edami, Hachimanto-ku, Nippon Steel Co., Ltd. 3rd Technical Research Laboratories, Nippon Steel Co., Ltd. 1-1-1 Edamitsu, Yawatahigashi-ku, Kitakyushu, Japan

Claims (2)

[Scope of utility model registration request] 1. A coal pyrolysis apparatus having a dispersion gas supply chamber in the upper part and a pyrolysis reaction chamber communicating with a coal supply pipe, wherein a heat resistant heating pipe is provided in the pyrolysis reaction chamber. The feature is an internal heat type rapid coal pyrolysis system. 2. The rapid thermal decomposition apparatus for internal combustion coal according to claim 1, wherein the heat-resistant heating pipe arranged in the pyrolysis reaction chamber is made of ceramics or heat-resistant steel.