JPS61207492A - Coal gasifying apparatus - Google Patents

Abstract

PURPOSE:To provide the titled apparatus capable of gasifying coal at a sufficiently high temperature of the inside of a combustor with high gasification efficiency and high adaptability to coal, by igniting, carbonizing and mixing a fuel such as a finely divided coal and conducting an endothermic gasifying reaction of the carbon particle. CONSTITUTION:A part of a finely divided coal 10, a circulating char 16 and O2 or air 11 which is a pressurized gasifying agent are fed to a combustor 1 of a gasifying oven which is accommodated in an autoclave 6, surrounded with water-cooled wall 4 and lined on the inside wall surface with a heat-resistant and refractory material 5 in a relatively small thickness and ignited at 1,400-1,800 deg.C under a pressure of about 40kg/cm<2>G. The high temperature gas and fuel are fed to a diffuser 2 while the remaining coal 12 is also fed to conduct the carbonization. The carbonization products are homogeneously mixed and the flow thereof is uniformalized. The endothermic gasifying reaction of the carbon particles is conducted in a reductor 3. The gas is cooled down to about 400 deg.C with a heat exchanger 7 provided at the output of the gasifying oven to recover heat. The char is collected with a cyclone and fed to the combustor 1 as a circulating char while the molten slag which has flowed down is discharged to the outside of the system as water-cooled slag 15 from an ash hopper 9.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a coal gasification device.

(Conventional technology) A conventional coal gasifier (single-stage spouted bed type) is shown in Figure 3.

In Fig. 3, 100 to 15 Qv
A refractory heat insulating material 22 with a thickness of m or more is provided, and a gasifier 23 is provided in the upper part and a cooler 24 is provided in the lower part. Gasifier 23
A supply means 25 for supplying coal, oil, air, or oxygen is disposed in the upper part of the cooler part 24, a radiant cooler 26 is disposed in the cooler part 24, and a gas outlet 27 is disposed in the lower part.
is provided. Further, an ash hopper 28 is formed in the lower part of the cooler section 24.

When starting up the apparatus, oil and air or oxygen are supplied from the supply means 25 into the gasifier 23 and burned to perform warming. When the temperature inside the gasifier 23 reaches a predetermined temperature, for example 1400 degrees Celsius, oil is gradually switched to coal. When switching to coal, the amount of air or oxygen supplied is reduced, causing incomplete combustion of the coal and producing combustible gases such as Co, H, and gas. The combustible gas enters the cooler section 24 from the gasifier 23, where it is cooled to about 1000 to 1100 degrees Celsius by the radiant cooler 26. Celsius 1
The gas cooled to about 000 to 1100 degrees exits from the gas outlet 27 and is sent to the heat exchanger. Gasifier 23
The slag generated in the ash hopper 2 passes through the cooler section 24
8 and is discharged from the outlet at the bottom of the ash hopper 28.

In such a conventional single-stage spouted bed two-coal gasifier, the entire furnace must be maintained at a high temperature to ensure melting and outflow of ash. This results in the following drawbacks.

■ Gasification efficiency is poor because the furnace as a whole increases the amount of air or oxygen input to keep the temperature high.

Since it is difficult to obtain gas with a high calorific value, gasification using oxygen is essential.

■ Heat dissipation is low because thick heat-resistant/refractory materials (generally 100 to 150- or more) are used to prevent heat from being transferred to the pressure vessel, and the heat-resistant/refractory materials reach the same temperature as the inside of the furnace, so their lifespan is short. . For this reason, the temperature of the furnace cannot be raised too high, so it is not compatible with coal, which has a high melting point. In other words, it depends on the compatibility with the coal type.

■ In order to control the gas temperature at the inlet of the heat exchanger to below the softening temperature of the ash, cooling by water quenching or heat dissipation to the water side by a radiant boiler is essential, and the disadvantage is that the gasification efficiency decreases accordingly. have.

■ Furthermore, if fireproof insulation is installed directly on the inside of the pressure vessel and there is no water-cooled wall, the thickness of the fireproof material will be large, and it will take a long time to warm up at startup, and there will be restrictions when the load fluctuates. It has the following drawback.

(Problems to be solved by the invention) The present invention aims to solve the drawbacks of conventional coal gasifiers. 1) Realization of a high-efficiency gasifier (compatible with thermal power generation); This improves gasification efficiency.

(2) Expansion of compatibility with coal types: Adoption of a water-cooled wall structure and thin heat-resistant/refractory lining construction to increase the furnace temperature while minimizing heat loss, even for coal types with high ash melting temperatures. Make available.

(3) Achieving a highly reliable gasifier; shutting off high-temperature gas with a water-cooled wall; (4) Achieving a gasifier with high operability; reducing warming time by using thin refractory and heat-resistant materials.

The purpose of this project is to provide a coal gasification device that enables this.

(Means for Solving the Problems) The present invention has the following features: (1) A two-stage spouted bed system is used to efficiently perform gasification mainly by utilizing the endothermic characteristics during the gasification reaction, and to quench water at the furnace outlet. (2) The thin refractory lining keeps the inside of the furnace at high temperatures (14
This is a coal gasification device that maintains the coal gasification temperature (00 to 1800°C) and expands the compatibility with coal types, and has the following technical configuration.

(1) A combustor section that combusts fuel to form a high-temperature atmosphere; it is located above the combustor section and communicates with the combustor section, and carbonizes and thermally decomposes the fuel, and the high-temperature gas and fuel from the combustor section and a reductor section located above the diffuser section and communicating with the diffuser section to perform an endothermic gasification reaction to gasify carbon particles from the diffuser section. (2) A combustor section that burns fuel to form a high-temperature atmosphere; a combustor section that is located above the combustor section and communicates with the combustor section, and carbonizes and thermally decomposes the fuel; A diffuser section that mixes the high temperature gas and fuel from the combustor section, and a diffuser section that is located above the diffuser section and communicates with the diffuser section, performs an endothermic gasification reaction to remove carbon particles from the diffuser section. A coal gasifier characterized in that it has a gasifier consisting of a reductor section for gasification, and the gasifier is formed from a water-cooled wall and a relatively thin heat-resistant and heat-resistant material lined inside the water-cooled wall. .

(3) A combustor section that combusts fuel to form a high-temperature atmosphere, which is located at the top of the combustor section and communicates with the combustor section, carbonizes and thermally decomposes the fuel, and also communicates with the high-temperature gas from the combustor section. A gasification system consisting of a diffuser section that mixes fuel with fuel, and a reductor section that is located above the diffuser section and communicates with the diffuser section and performs an endothermic gasification reaction to gasify carbon particles from the diffuser section. 1. A coal gasification apparatus comprising a furnace, the gasification furnace housed in a pressure vessel, and pressurized gas injected between the gasification furnace and the pressure vessel.

FIG. 1 shows the structure of an embodiment of a coal gasification apparatus according to the present invention, and FIG. 2 shows a gasification principle diagram of the apparatus of the present invention to help understand the operation and effect of the apparatus of the present invention.

(Configuration) In Figure 1, the gasifier is normally approximately 40 to 9/as”G
It consists of three parts: a combustor 1, a diffuser 2, and a reductor 3. It is surrounded by a water-cooled wall 4, and a relatively thin (approximately 50 m or less) heat-resistant and refractory material 5 is installed inside the furnace. It is stretched.

Part of the coal 10, circulating char 16 and air or 0.11 are charged into the combustor 1, and a high temperature state (1400
~1800°C) to provide the necessary heat for gasification in the upper part while melting and draining the ash. (Second
(see figure), the gasifying agent (air or 03) is pressurized by a compressor (not shown) and is supplied into the furnace.

The remaining coal 12 is charged into the diffuser 2, where it is carbonized, mixed uniformly with gas, and the flow is averaged (see Figure 2). The pulverized coal is pressurized by a lock hopper system (not shown) and transported into the furnace.

In the reductor 5, the carbon particles are gasified and the gas is cooled (see FIG. 2), and the generated char is collected by a collector (not shown) and is reinjected into the combustor 1 as circulating char. (See FIG. 2) An ash hopper 9 is provided at the bottom of the ash hopper 1, and the molten slag flowing down is water-cooled here and discharged to the outside as water-cooled slag 15. (See Figure 2) Cooling water is supplied to the water cooling wall 4 from the inlet header 8.
The water is kept cool.

A heat exchanger 7 is installed at the outlet of the reductor 3 to cool the gas to a predetermined temperature (approximately 400° C.) and to perform effective heat recovery.

The entire gasification furnace is housed in a pressure vessel 6, and an inert gas 14 is injected into the space between the inside of the furnace and the pressure vessel by the action of a valve controlled by a differential pressure detector 13 to control the differential pressure. It is now possible to do so.

(Functions/Effects) (1) High gasification efficiency can be obtained because the furnace outlet gas temperature can be controlled to an appropriate value (below the softening point of ash) mainly by utilizing the endothermic properties during the fuel gasification reaction. .

That is, there is an advantage that there is no heat loss due to water quench or love-ant cooler methods.

[2] The effect of (1) above and the effect of the thin refractory/insulating material lined with the water-cooled wall (even if the internal temperature of the refractory/insulating material becomes high, the refractory/insulating material is relatively thin, so It is possible to easily radiate heat to the water-cooled wall and raise the temperature inside the furnace without damaging the fireproof and heat-insulating materials. It can be used and has excellent compatibility with coal types.

(3) By providing a diffuser, it is possible to uniformly mix high temperature gas and fuel, stabilize the gas flow, and obtain high gasification efficiency.

(4) Starting characteristics are improved by eliminating thick heat-resistant and heat-insulating materials.

(5) By injecting pressurized inert gas between the gasifier and the pressure vessel, the water-cooled wall can be protected from deformation due to the internal pressure of the gasifier, and high reliability can be maintained.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the structure of one embodiment of the coal gasification apparatus of the present invention, Fig. 2 is a diagram of the gasification principle of the present invention to help understand the operation and effect of the coal gasification apparatus of the present invention, and Fig. 3 The figure is a diagram for explaining a conventional coal gasifier. Sub-agents 1) Meifuku agent Ryo Hagiwara -

Claims (3)

[Claims] (1) A combustor section that combusts fuel to form a high-temperature atmosphere; it is located above the combustor section and communicates with the combustor section, and carbonizes and thermally decomposes the fuel, and the high-temperature gas and fuel from the combustor section and a reductor section located above the diffuser section and communicating with the diffuser section to perform an endothermic gasification reaction to gasify carbon particles from the diffuser section. A coal gasifier characterized by having: (2) A combustor section that combusts fuel to form a high-temperature atmosphere; it is located above the combustor section and communicates with the combustor section, and carbonizes and thermally decomposes the fuel, and the high-temperature gas and fuel from the combustor section and a reductor section located above the diffuser section and communicating with the diffuser section to perform an endothermic gasification reaction to gasify carbon particles from the diffuser section. 1. A coal gasifier characterized in that the gasifier is formed from a water-cooled wall and a relatively thin heat-resistant/refractory material lined inside the water-cooled wall. (3) A combustor section that burns fuel to form a high-temperature atmosphere; it is located above the combustor section and communicates with the combustor section, and carbonizes and thermally decomposes the fuel, and the high-temperature gas and fuel from the combustor section and a reductor section located above the diffuser section and communicating with the diffuser section to perform an endothermic gasification reaction to gasify carbon particles from the diffuser section. 1. A coal gasification apparatus comprising: a gasification furnace housed in a pressure vessel, and pressurized gas injected between the gasification furnace and the pressure vessel.