JPH0794667B2 - Slag tap heating method for coal gasifier - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slag tap provided in the hearth of a jet bed type furnace in a coal gasification furnace, and more particularly to a method for preventing cooling and solidification of molten slag in the slag tap.

[0002]

2. Description of the Related Art Conventionally, in a coal gasification furnace, as a method for preventing cooling and solidification (clogging) when discharging molten slag which is coal residue from a slag tap, as shown in FIG. By using the combination of the gas tap 5 provided at the lower part of the side wall 10 and the slag tap 4 provided near the lower part of the side wall 10, the pressure difference (distribution) generated in the gasification section 2 is used to circulate the high-temperature generated gas 19 from the slag tap 4 to the gas tap 5. There is known a method of preventing cooling and solidification of the molten slag 18 in the slag tap 4, that is, a self-circulating heating method.

[0003]

However, in the above-mentioned conventional self-circulation heating method, the molten slag is cooled and solidified (fixed) in the slag tap due to the decrease in the circulation amount of the produced gas due to the fluctuation of the furnace pressure and the like. By this cooling and solidification, the gas flow path of the slag tap was narrowed, and the reduction of the gas amount further promoted the cooling and solidification of the molten slag. In such a case, the attached heating burner 14 is activated to melt and remove the adhered molten slag. However, in such a conventional technique, since the gas flow of the heating burner 14 of the slag tap faces the circulation of the generated gas flow, this self-circulation is hindered and the mutual effects are canceled out, so that the sufficient effect cannot be exerted. There was a problem. Further, since the heating by the heating burner widely heats the hearth, it is not always necessary to heat the slag tap itself so that it is difficult to control or manage the temperature of the slag tap, and an excessive amount of heating heat is required, resulting in poor thermal efficiency.

It is an object of the present invention to provide a method for heating a slag tap of a coal gasification furnace, which solves the problems of the conventional self-circulation heating method and achieves a stable downflow of molten slag in the slag tap.

[0005]

In order to achieve the above object, the first invention of the present application is a gasification section for gasifying coal, and coal generated in the gasification section provided in the hearth of the gasification section. A slag tap that discharges the molten slag that is a residue, and a quench part that is adjacent to the bottom of the gasification part and that quenches the molten slag discharged from the slag tap are provided, and the gas is between the gasification part and the quench part. In the slag tap heating method of the coal gasification furnace for heating the slag tap by circulating the generated gas generated in the gasification section,
The slag tap is heated by injecting an oxidant-containing gas containing an oxidant from the inner peripheral surface of the slag tap to burn the oxidant-containing gas and a part of the generated gas.

The second invention of the present application is the same as the first invention of the present application.
The method of ejecting the oxidizing agent-containing gas is to eject the oxidizing agent-containing gas obliquely downward.

[0007]

With the above structure, in the present invention, the oxidant-containing gas containing the oxidant is ejected from the inner peripheral surface of the slag tap, so that a part of the generated gas contains the oxidant containing the oxidant ejected from the inner peripheral surface of the slag tap. While reacting with the gas to heat the slag tap itself, the circulation of the produced gas due to the pressure distribution of the gasification section that has been conventionally operating is such that the slag tap passes from the slag tap to the quench space and then from the quench space to the gas tap again. It flows to the chemical department. Therefore, unlike the conventional case, the circulation amount of the produced gas is not reduced due to the fluctuation of the furnace pressure and the like, so that the temperature drop of the slag tap is prevented and the cooling and solidification of the molten slag is prevented. Moreover, the temperature of the slag tap instantly rises due to the combustion of a part of the circulation-produced gas and the jetted oxidant-containing gas, and the temperature control characteristic is good. Further, since the heating heats the slag tap itself, the heating efficiency is good, and the heating burner, which has been conventionally required, becomes unnecessary.

Further, according to the present invention, since the oxidant-containing gas is jetted obliquely downward from the inner peripheral surface of the slag tap, it becomes the same direction as the circulating gas flow, and the self-circulation of the circulating gas flow due to the ejector effect. Promotes action.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a diagram for explaining an embodiment of a slag tap heating method for a coal gasification furnace according to the present invention, a partially omitted sectional view centering on the hearth, and FIG. 2 is a main part centering on the slag tap in FIG. It is an expanded sectional view.

Referring to FIG. 1, a coal gasifier 1 of the present invention is shown.
Is equipped with a gasification section 2 and a quench section 12 below the gasification section 2 with a hearth 3 interposed therebetween. The gasification section 2 is
A hearth 3 is provided on the side wall 10 made of a refractory material and a lower part thereof, and at least one slag tap 4 and at least one gas tap 5 are provided on the hearth 3. A heat transfer tube 9 is provided around the side wall 10 of the gasification section 2. The quench portion 12 is filled with quench water 15 below it, and the starter burner 13 is disposed in the upper space portion 16 of the quencher portion 12 so that the tip thereof is obliquely upward. Used to raise.

FIG. 2 mainly shows the slag tap 4 in FIG. Slag tap 4 as shown
Is provided with an oxidant-containing gas supply pipe 6, and the oxidant-containing gas supply pipe 6 is provided with an introduction pipe 6a and a supply ring 6b positioned so as to surround the vicinity of the outer periphery of the slag tap 4.
Further, from the supply ring 6b, a plurality of nozzles 7a, 7b, 7
c are provided so as to be opened obliquely downward over the entire circumference of the inner peripheral surface 4a of the slag tap 4. Introductory pipe 6a
A flow rate adjusting valve 8 is provided on the other hand, while a temperature sensor 8a is provided near the inner peripheral surface 4a of the slag tap 4, and the signal thereof is transmitted to the flow rate adjusting valve 8 by a signal transmission circuit 8b.

The present embodiment having the above structure operates as follows. In FIG. 1, the molten slag 18, which is the coal residue generated in the gasification section 2, flows down the surface of the side wall 10 and collects in the hearth 3. Then, the molten slag 18 flows down from the slag tap 4 opening in the hearth 3 and falls into the quench water 15 located below the quench section 12. When dropped into the quench water 15, the molten slag 18 is crushed by thermal shock.

On the other hand, as shown in FIG. 2, a part of the generated gas 19 generated in the gasification section 2 forms a high temperature circulating gas flow 21 due to the pressure distribution generated in the gasification section 2, and the slag tap 4 is formed. Heating the molten slag 18 in the slag tap 4
Prevent solidification by cooling. During operation, due to changes in internal pressure,
When the amount of self-circulating gas decreases and the temperature of the slag tap 4 decreases, the temperature sensor 8a detects this temperature change, and the nozzle 7 opened on the inner peripheral surface 4a of the slag tap 4
From a, 7b, 7c ..., Air or a mixed gas of oxygen and nitrogen (including the case of only oxygen) which is the oxidant-containing gas 20 corresponding to the temperature change amount is ejected. Since the circulating gas flow 21 of the produced gas containing CO and H ₂ as main components circulates between the slag taps 4 or between the slag taps 4 and the gas taps 5,
A part of this circulating gas flow 21 is ignited to cause local combustion in the slag tap 4, so that a temperature rise of the slag tap 4 can be obtained. In addition, the energy ejected from the air or a mixed gas of oxygen and nitrogen has an effector effect, promotes the circulation of high-temperature gas, and has a synergistic effect of self-circulation and local combustion, which instantaneously covers the temperature drop. Good temperature control characteristics. Further, since the slag tap 4 burns locally, the fuel consumption is about one tenth of that of the conventional slag tap heating burner, and the heating efficiency is good.

On the other hand, conventionally, one heating burner was required for each slag tap, but when the furnace diameter becomes large,
Although there is a problem that the number of slag taps and the number of burners need to be increased accordingly, the present invention enables simple equipment such as addition of a supply nozzle for an oxidant-containing gas.

The ejected oxidant-containing gas and the hot gas combusted with this gas are in the same direction (downward) as the self-circulating gas flow and do not impede the flow, but rather promote self-circulating heating due to the effector effect. To do.

When the oxidant-containing gas is supplied in cascade with the temperature of the slag tap, the slag tap 4 is not clogged due to cooling and solidification, and stable discharge operation of the molten slag under the slag tap flow can be continued.

[0017]

As described above, according to the present invention, since the conventional self-circulation heating is added with the local combustion heating, the circulating gas amount of the generated gas due to the fluctuation of the conventional furnace pressure is obtained. It is easy to control the temperature due to the synergistic effect of self-circulation heating and combustion heating, which complements the drawbacks such as the decrease of Further, the heating according to the present invention is a local heating of the slag tap itself, so that the heating efficiency is good. Further, the conventional heating burner for each slag tap is not required and the apparatus can be simplified.

Since the oxidant-containing gas is jetted obliquely downward, in addition to the above effects, self-circulation heating up to now is promoted.

[Brief description of drawings]

FIG. 1 is a view for explaining an embodiment of a slag tap heating method for a coal gasification furnace according to the present invention, and is a partially omitted sectional view centering on a hearth.

FIG. 2 is an enlarged cross-sectional view of a main part centered on the slag tap in FIG.

FIG. 3 is a partially omitted sectional view for explaining a slag tap heating method for a coal gasification furnace according to a conventional technique.

[Explanation of symbols]

 1 Coal Gasifier 2 Gasifier 3 Hearth 4 Slag Tap 4a Inner Surface 12 Quench 18 Molten Slag 19 Product Gas 20 Oxidant-Containing Gas

Claims (2)

[Claims] 1. A gasification section for gasifying coal, a slag tap provided on a hearth of the gasification section for discharging molten slag which is a coal residue generated in the gasification section, and a lower part of the gasification section. And a quench unit that quenches the molten slag discharged from the slag tap adjacent to the slag tap, and heats the slag tap by circulating the product gas generated in the gasification unit between the gasification unit and the quench unit. In a slag tap heating method of a coal gasification furnace, an oxidant-containing gas containing an oxidant is ejected from the inner peripheral surface of the slag tap to burn the oxidant-containing gas and a part of the generated gas, and heat the slag tap. A slag tap heating method for a coal gasification furnace, comprising: 2. The slag tap heating method for a coal gasification furnace according to claim 1, wherein the method of ejecting the oxidant-containing gas comprises ejecting the oxidant-containing gas obliquely downward.