JPH11217574A - Ignition method and apparatus for gasifier - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To enable ignition of a gasifier with a simple device,
Reduce ignition time and reduce fuel required for ignition. SOLUTION: An ignition burner is provided on an upper part of a slag pot at a lower part of the gasification furnace so that a combustion frame of the ignition burner reaches an outlet of the gasification burner. Is provided with a pipe for supplying gaseous fuel and a valve for switching between them. Ignition is
First, the ignition burner is ignited by an igniter, and then the gas fuel of the gasification burner is ignited by the ignition burner. After the gasification furnace temperature rises, the fuel of the gasification burner is sequentially switched from gas fuel to solid fuel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for igniting a spouted bed gasifier for gasifying fine powder of a solid fuel such as coal using an oxidizing agent.

[0002]

2. Description of the Related Art A method of converting coal or the like into pulverized coal and gasifying it in a spouted bed gasifier is excellent in that high thermal efficiency and gasification efficiency can be obtained. A method of igniting fine solids such as coal in a gasifier is to install a preheat burner in a preheat furnace provided at the lower part of the gasifier, and first guide the combustion exhaust gas of the preheat burner to the gasifier through a slag tap. A general method is to preheat a gasification furnace and start gasification after the temperature reaches the ignition temperature of solids or higher. However, in this method, the preheating furnace,
Not only is a preheating burner necessary, but the amount of heat taken by the cooling water of the slag pot below the preheating furnace is large, and preheating is performed with the combustion exhaust gas, so the heat utilization efficiency is low, so it takes time to preheat, depending on the burner capacity. There is a problem that a preheating time of 12 hours or more is required, and as a result, a large amount of fuel is required.

Japanese Patent Application Laid-Open No. 8-295890 proposes a method in which a preheating burner is installed in a gasification furnace to ignite fine powder of solid fuel in order to shorten the preheating time and reduce the amount of preheating fuel. However, in this method, since the ignition burner and the preheating burner are installed in the furnace of the gasification furnace, they are exposed to the furnace at 1400 to 1600 ° C. during gasification, so that the ignition burner and the preheating burner are prevented from becoming high temperature. There is a need to. As a prevention method, there are a method of cooling the burner with water cooling and a method of passing an inert gas such as nitrogen gas through the burner.However, the increase of heat loss due to cooling water and the inert gas entering the furnace are not considered. It is not preferable in that gas calories decrease. Furthermore, the gasifier has a self-lining structure, and the furnace wall is generally composed of a water tube and cooled by the heat of evaporation of water to recover heat.However, the burner part has a complicated furnace shell structure. Preferably, the number of burners is small.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems and to ignite a gasification burner with a simple facility and a small amount of fuel consumption in a spouted bed gasification furnace. A method and an apparatus (gasification furnace) are proposed.

[0005]

Means for Solving the Problems In order to solve the above problems, the present inventor has proposed that the gasification burner is a system in which fine powder of solid fuel such as coal is transported in a gas stream and supplied to the gasification burner. It was noted that if gas fuel was supplied instead of solid fuel, it could be used as a gas burner such as LPG. That is, solid fuels such as coal have a relatively low ignition temperature, but it is difficult to stably burn them at the beginning of combustion. On the other hand, gas fuels such as LPG have a high ignition temperature, but once ignited, combustion is stable. Thus, at least one gasification burner is first burned with gaseous fuel to form stable combustion and raise the gasification furnace temperature. Thereafter, if the other gasification burners are switched one by one to solid fuel, ignition can be performed in the gas combustion flame, and combustion can be continued. By the way, an ignition burner can be installed in the gasification furnace to ignite the gasification burner. However, since the gasification furnace temperature becomes 1400 to 1600 ° C during the gasification operation, a spark is generated at the time of ignition. The installation in the gasifier is not preferable because the igniter to be damaged is damaged. The slag pot at the lower part of the gasifier is shielded from the gasifier by the slag tap, so the furnace temperature will be 800 ° C or less, the igniter will not be damaged, and the ignition burner frame will be connected to the gasifier burner through the slag tap. The ignition burner was installed in the slag pot because it could reach the gasifier.

[0006] The means of the present invention are as follows.

(1) First, the ignition burner is ignited, and then the combustion flame of the ignition burner supplies gaseous fuel to at least one gasification burner positioned in front of the gasification burner in the blowing direction of the gasification burner. After igniting and then supplying gaseous fuel to another gasification burner that is capable of sequentially switching fuel and igniting, after the furnace temperature of the gasification furnace rises, the fuel of the gasification burner is supplied to the burner 1. A method for igniting a gasifier, characterized by switching to solid fuel one by one.

(2) In a gasification furnace having a slag pot provided at a lower portion of the gasification furnace and a plurality of gasification burners for gasifying fine powder of solid fuel such as coal, at least one gasification furnace is provided.
A fuel pipe for supplying fine powder of solid fuel and a gas pipe for supplying gas fuel such as LPG are switchably connected to the gasification burner, and an ignition burner is provided on the upper wall of the slag pot. An ignition device characterized in that the ignition direction is arranged such that the blowing direction of the combustion frame is provided to a tip end of a gasification burner which enables the fuel to be switched through a slag tap provided at a lower portion of the gasification furnace. Equipped gasifier.

An ignition burner installed in the lower part of the gasification furnace is ignited by an igniter, and this combustion frame passes through a slag tap to ignite one of the gasification burners using gas fuel. Next, the ignited gasification burner's combustion flame also ignites the other gasification burners with gaseous fuel and raises the temperature of the gasification furnace. After that, one gasification burner
A gasification furnace ignition method and apparatus (gasification furnace) for shifting to gasification with solid fuel in a gasification furnace by switching to solid fuel one by one.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an entire apparatus of a gasification furnace according to the present invention, which comprises a gasification furnace 1, a gasification burner 2, an ignition burner 3, a slag tap 4, and a slag pot 5. The fuel supply pipe of the gasification burner 2 has a valve 6
Switching between the solid fuel and the gas fuel is possible through a and 6b.

In the gasification furnace 1, two or more gasification burners 2 are arranged on the side wall on the circumference, and a gasification agent for fine powder such as coal is gasified with an oxidizing agent. The gasified gas is discharged from the throat 7 at the upper part of the gasification furnace, and the slag component is melted in the gasification furnace 1 and falls from the slag tap 4 to the slag pot 5. The gasifying agent is char that pyrolyzed coal in addition to coal,
Pyrolysis char of garbage incinerator, waste plastic, etc. can be used. As the oxidizing agent, oxygen or oxygen-enriched air can be used in addition to air.

Next, a method and an apparatus for igniting the gasification burner 2 will be described. The ignition burner 3 is a gas or kerosene burner, and includes an igniter 8 for generating a spark and an ignition transformer 9. The ignition burner 3 is arranged above the water surface of the slag pot 5 so that the combustion frame passes upward through the slag tap 4 to reach the outlet of the gasification burner 2. The ignition burner 3 is preferably of a type in which the shape of the combustion flame is small.

After the ignition burner is ignited, one of the gasification burners is supplied with a gaseous fuel and an oxidant to the gasification burner facing the frame of the ignition burner to ignite one of the gasification burners. Thereafter, the gaseous fuel and the oxidizing agent are supplied to the other gasification burners to ignite. Combustion of each burner is stable,
When the temperature of the gasification furnace rises, the valves 6a and 6b are switched to sequentially switch to the solid fuel. However, since the other burners are burning, ignition of the solid fuel is possible. As a gas fuel, a gas such as natural gas or COG can be used in addition to LPG. Although the supply of gaseous fuel to the gasification burner can be performed by a single burner, it is preferable that all burners can be burned with gaseous fuel because ignition stability and preheating time can be shortened.

[0015]

EXAMPLE A gasifier as shown in FIG. 1 was used to ignite a gasification burner using pulverized coal. The gasification furnace had a diameter of 1600 mm and a height of 2200 mm, and four gasification burners were used. The gasification burners were arranged to swirl inside the gasification furnace, and LPG was used as the gas fuel.

The ignition burner ignited 40,000 kcal / H with air using an igniter. Ignition burner ignition 3
One minute later, among the gasification burners, the burner facing the combustion frame of the ignition burner was ignited by LPG, and then the remaining three gasification burners were ignited by LPG. Oxygen gas was used as the oxidizing agent for the gasification burners, and the combustion amount of each burner was about 600,000 kcal / H. Five minutes after the start of combustion with LPG, the fuel was switched from LPG to pulverized coal one gasification burner at a time when the temperature in the gasifier furnace reached 500 ° C., and the switching to pulverized coal combustion was completed. As a result, the switching of the gasification burner to pulverized coal was completed in about 10 minutes after the ignition of the ignition burner. The oxidizing agent for the ignition burner is desirably oxygen because it has a higher combustion temperature, but it is air because the igniter is melted at a high temperature. On the other hand, the oxidizing agent for the gasification burner uses oxygen even in pulverized coal combustion, and because oxyfuel combustion has a higher oxygen concentration and can increase the combustion capacity, and has a higher combustion temperature, it uses oxygen combustion. However, air combustion is also possible.

A comparative example will be described. Under the condition of preheating by installing a preheating burner of 1,000,000 kcal / H under the slag tap, it took 18 hours for the gasification furnace temperature to reach 700 ° C. and ignite the gasification burner.
This is because the cooling water loss of the slag pot below the preheating furnace is large. In this method using a gasification burner for ignition, combustion takes place in a gasification furnace, so that pulverized coal can be ignited from an LPG combustion flame even at a gasification furnace temperature of 500 ° C.

As a result, not only can the time required for ignition be greatly reduced, and the fuel used for preheating can be reduced, but also a large-capacity preheating burner is not required, and a small-capacity ignition burner is required. And the equipment can be simplified. Further, since the ignition burner and the preheating burner are not installed in the gasification furnace, there is no loss of cooling water of the burner and no damage to the burner. In the present embodiment, the case of pulverized coal combustion was described, but char obtained by pyrolyzing coal,
It is also applicable to pyrolysis char of garbage incinerators and ignition of gasification of waste plastics.

[0019]

According to the present invention, the gasification burner can be ignited by a small-capacity ignition burner, and further, the ignition time can be shortened and the fuel required for preheating the gasification furnace can be greatly reduced. Become.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a coal gasifier of the present invention.

[Description of Signs] 1 gasifier 2 gasification burner 3 ignition burner 4 slag tap 5 slag pot 6a fuel switching valve 6b fuel switching valve 7 throat 8 igniter 9 ignition transformer

 ──────────────────────────────────────────────────続 き Continued on the front page (71) Applicant 000002118 Sumitomo Metal Industries Co., Ltd. 4-5-33, Kitahama, Chuo-ku, Osaka-shi, Osaka (71) Applicant 000004123 Nippon Kokan Co., Ltd. 1-1-1, Marunouchi, Chiyoda-ku, Tokyo No. 2 (72) Inventor Yoshimasa Ikeda 20-1 Shintomi, Futtsu City Nippon Steel Corporation Technology Development Division

Claims (2)

[Claims] An ignition burner is first ignited, and then the combustion flame of the ignition burner supplies gaseous fuel to at least one gasification burner positioned in front of the gasification burner in the blowing direction. After igniting and supplying gaseous fuel to other gasification burners capable of sequentially switching fuel and igniting, after the temperature of the gasification furnace rises, one gasification burner fuel is burned. A method for igniting a gasification furnace, wherein the method is switched to solid fuel. 2. A gasification furnace having a slag pot provided at a lower portion of a gasification furnace and a plurality of gasification burners for gasifying fine powder of a solid fuel such as coal, wherein at least one gasification is performed. A fuel pipe for supplying fine powder of solid fuel and a gas pipe for supplying gas fuel such as LPG are switchably connected to the burner, and an ignition burner is provided on the upper wall of the slag pot. A gasification furnace equipped with an ignition device, characterized in that the blowing direction is arranged to pass through a slag tap provided at a lower part of the gasification furnace and toward a tip end of the gasification burner capable of switching the fuel.