JPS61197690A - Coal gasifying equipment - Google Patents

Abstract

PURPOSE:To prevent adherence of molten ash in coal to a nozzle and avoid clinker troubles, by employing a metallic double tube as gasifying agent blowing nozzle for a fluidized bed coal gasifying oven and circulating a coolant in the space between inner and outer pipes of the double tube. CONSTITUTION:Raw material dust coal 10 is fed into a reaction chamber 2 of a fluidized bed coal gasifying oven 1 by means of a screw feeder 5 and a gasifying agent consisting of a mixt. of O2 or air with water vapor is fed through a gasifying agent blowing nozzle 6 which is made of metal such as stainless steel in a double-tube structure and is cooled with a coolant (e.g. water) circulated in the space between inner and outer pipes, to effect gasification reaction. Produced gas 12 is fed from the oven top to a next process and a part of it is blown into a combustion chamber 3 from a burner 8 for reaction with a mixt. of O2 or air with water vapor 13 fed through a gasifying agent blowing nozzle 7. The gas is led into the reaction chamber 2 through a throat 4 to fluidize the dust coal 10. Cooling of the gasifying agent blowing nozzle in the double-tube structure prevents adherence of molten ash to the tip of the nozzle 6.

Description

[Detailed description of the invention] [Field of practical use] The present invention relates to improvements in coal gasifiers.

[Conventional technology]

Recently, as the progress of coal gasification has been declining, various gasification devices have been developed.

One example is equipment that uses a furnace. When gasifying using a fluidized bed furnace, it is known that if the temperature of the fluidized bed is raised to perform a high-temperature reaction, the gasification reaction rate will increase and the gasification rate will also increase. Acid points are where problems occur due to the ash content inside. In other words, when the gasification reaction temperature rises and the ash approaches the 1 melting point, the ash melts and adheres to the dispersion plate and walls in the fluidized fluidized furnace, causing so-called tarinka trouble.For this reason, ordinary fluidized fluidized furnaces It is considered difficult to raise the gasification temperature above i,00°C.

By the way, a commonly used fluidized bed furnace has a perforated dispersion plate installed at the bottom of the furnace, and a gasifying agent such as air, oxygen, or steam is sent from below to fluidize the coal on the dispersion plate and perform a gasification reaction. It's tight. However, in this method, stagnation of coal particles occurs between the pores of the dispersion plate, which contacts the gasifying agent and is locally heated, causing the ash in the coal particles to melt and close the pores. Linker problems are likely to occur.

To avoid this, change the gasification temperature! ' to about 50% higher than the melting point of ash
If the temperature is lowered by 0°C and the chestnut operation is carried out at around 950°C, problems arise in that the gasification efficiency decreases and the generation of tar, phenol, etc. increases.

To solve this problem, a fluidized bed furnace that does not use a dispersion plate was developed and is currently in use. Figure 2 is a cross-sectional view of this fluidized fluidized furnace, where (1) is the fluidized fluidized furnace, (2) is the reaction chamber, (3) is the combustion chamber, and (4) is the reaction chamber (2) and combustion chamber (3). The connecting throat part, (5) is the charcoal supplying screw R1 Euphida, (6), (7) i gasifying agent injection nozzle, (8)
i burner, (9) is char, shout is powdered coal, α]) is gasifying agent, CI2 is generated gas, αJ is gasifying agent, Q4 is combustion gas, (to) is lumpy ash, αQ is ash circulation It is a lineage.

As shown in the figure, the fluidized fluidized furnace (1) has a reaction chamber (2) in the upper part of the furnace.
It consists of a lower combustion type (3), and a throat part (4) that connects the two. The charcoal scream of the raw material is Suku I
It is charged into the reaction chamber (2) from the I-Euphita (5) and reacts with the mixture of oxygen or air and water vapor fed through the nozzle (6) formed of a heat-resistant material such as alumina at the bottom of the reaction chamber. A gasification reaction is carried out in the chamber (2), and the produced gas □□□ is led to the next process from the top of the furnace. A part of this produced gas is returned to the combustion mold (3) and sent to the burner (8). ) into the combustion chamber (3) and reacts with the acid or the mixture of air and water vapor supplied from the gasifier injection nozzle (7) and burns, and the combustion gas α→ is blown into the combustion chamber (3). Department (
4) is discharged into the reaction chamber (2) in step (a) to fluidize the powdered coal αO and completely form a fluidized bed. The combustion temperature of the combustion chamber (3) is 12
It is around 00℃.

In addition, in the gasification combustion in the reaction chamber (2),
When the gasification temperature is raised to near the melting point of the ash in the burner (9), the ash is coagulated and granulated to become lumpy ash, and the combustion gas α in the throat part (4) is generated near the center of the furnace. It is blown upward by the explosion, descends at the periphery, and circulates within the reaction chamber (2) as shown by the arrow (G).

As a result, the granulation progresses roughly, and the lumpy ash QB, which has increased in both particle size and density, is produced at the throat part (4) where the gravity acting on it is larger than the buoyancy caused by the combustion gas α4 (
Then, it falls into the combustion chamber (2) fF3 and is discharged outside the furnace. By appropriately controlling the flow rate of the combustion gas Q-1, the lumpy ash Q5 can be efficiently dropped and discharged out of the furnace.

[Problems that the original party is trying to solve]

This type of fluidized bed reactor does not use a dispersion plate, which not only reduces the number of problems caused by the flow rate, but also allows the temperature and flow inside the reaction chamber to be controlled independently, making the operation easier than with conventional methods. This has the advantage of being much easier to do. However, even in this fluidized bed furnace, when the gasification temperature is raised to 1200°C, which is 50°C lower than the melting point of ash in the coal, the ash fuses to the tip of the gasifier injection nozzle (6).
The blowing of the gasifying agent αη into the furnace may be inhibited.

This is the drawback of this fluidized furnace.

The present invention aims to provide a gasifying agent injection nozzle that does not cause the above-mentioned ash melt layer in a fluidized bed furnace of this type.

[Means for solving problems]

In a fluidized bed furnace used for gasifying coal, the gasifying agent injection nozzle has a double tube structure of gold ms, and a refrigerant T-ring is placed between the inner surface U and the outer cylinder a.

[Effect]

By appropriately selecting the material and thickness of the double pipe, the flow rate of the refrigerant, etc., the gasifying agent injection nozzle can be cooled.
The surface temperature can be maintained below the viscosity temperature of coal ash (temperature of the metal surface at which the slag droplets adhere to the metal surface when bath-melted slag droplets are dropped onto the metal surface). As a result, troubles such as ash being fused to the gasifying agent injection nozzle and clogging the gasifying agent injection port can be prevented.

[Embodiments of the invention]

FIG. 1 is a sectional view of a fluidized bed furnace showing an embodiment of the present invention. (1) - Port Q are the same parts as the conventional device.

The handle is a gasifying agent injection nozzle according to the present invention, (20a)
(20b) is its outer tube, and (20b) is its inner tube.

In the figure, the gasifying agent blowing nozzle (7) is
Inner diameter 27 molded from vx-174 (SUS 304)
．． 6-a.

It consists of an outer rill '# (20a) with an outer diameter of 34111111 and an inner rtJ tube ('20b) made of the same material and molded with an inner diameter of 16.1 ml and an outer diameter of 21.7 m.
Between the inner and outer cylinders there is a water outlet υk, 0.3 L/m as a refrigerant.
In, it passes at a rate of . Therefore, even if the gasification temperature rises during operation of the fluidized bed furnace, the gasification agent injection nozzle (7)
The surface temperature of the coal is about 680° C. at its lowest point, which is kept below the sticking temperature of the coal ash, so that the ash in the coal is prevented from adhering to the surface.

[@Ming effect]

The present invention provides a fluidized bed furnace used for gasifying coal, in which the gasifying agent injection nozzle provided in the reaction chamber has a double pipe structure made of stainless steel A, and cooling water is passed between the inside and outside mf. Since the gasification agent injection nozzle was cooled, even if the gasification temperature in the reaction chamber of the fluidized bed furnace was increased to a certain extent, the fear that the natural substances in the coking coal would fuse to the gasification agent injection nozzle was eliminated. .

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a fluidized bed furnace used for coal gasification, showing an embodiment of the present invention, and Figure 2 is a cross-sectional view of a conventional fluidized bed furnace.
This is the cause. In the figure, (1) is the fluidized fluidized furnace, (2) is its reaction chamber, αη is the gasifying agent, and the wire is the gasifying agent injection nozzle. (2L] a) tt
l is the outward tube, (20b) is the cylindrical tube, and υ is the cooling water. Agent Patent Attorney Sanro Kimura Figure 1 6: 1f') -4t4pl -Do12=No Nu, 1shi1
7 kj tan = q

Claims (1)

[Claims] In a fluidized bed furnace for gasifying coal, the gasifying agent injection nozzle provided in the reaction chamber is formed of a double metal pipe, and the refrigerant is circulated between the inner and outer pipes. A coal gasification device characterized by being configured as follows.