JPH0774344B2 - 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 an air-bed type coal gasifier for gasifying a fine powdery solid carbonaceous raw material such as coal, and more particularly, to a slag flow condition in a slag cooling section or a combustion condition of a heating burner The present invention relates to improvement of monitoring means for monitoring.

[0002]

2. Description of the Related Art Conventionally, various systems such as a fixed bed, a fluidized bed and a gas stream bed have been proposed as a device for gasifying a solid carbonaceous material such as coal. Among these methods, the airflow layer method is a method in which the raw material is made into fine powder and is supplied together with an oxidizing agent such as oxygen and air into a furnace at a temperature (about 1300 to 1600 ° C) higher than the melting point of the raw material ash to burn combustible components in the raw material. To gas, and to convert ash to slag, it has features such as high gasification efficiency compared to other methods, a wide range of applicable coal types, and excellent environmental compatibility. It is suitable for production of fuels and raw materials for combined power generation, fuel cells, etc., and is being developed in Japan and overseas.

FIG. 4 is an explanatory view of a conventional coal gasifier, which is a sectional view mainly showing the main body. The main body 2 of the coal gasifier 1 is composed of a gasification section 3, a heat recovery section 5 in the upper part thereof, and a slag cooling section 4 in the lower part. The gasification unit 3 is provided with a slag tap 6 on the lower hearth plate together with the coal burners 9 and 10, and the atmospheric pressure is several tens of atmospheres. On the upstream side of the coal burners 9 and 10, as shown in FIG. 5, the pulverized coal 45 in the supply hopper 44 at atmospheric pressure enters the lock hopper 49 through the valve 46, and the inert gas such as nitrogen from the pressurizing gas line is supplied. Is pressurized through the pressurizing gas valve 47 (48 is a valve). Next, the pulverized coal in the lock hopper 49 is transferred to the supply hopper 52 through the valve 50. The supply hopper 52 is pressurized by supplying a pressurizing gas, which is an inert gas such as nitrogen, from a pressurizing line through a valve 51. The pulverized coal is sent through valves 53, 54 and fixed amount feeders 55, 56, and ejector 6
In 1 and 62, together with the carrier gas such as nitrogen and carbon dioxide gas from the lines 57 and 58, the raw materials are supplied to the raw material supply lines 25 and 26 through the valves 59 and 60, and the oxidant is supplied to the oxidant supply lines 27 and 28 through the valves 63 and 64. , Are respectively supplied to the coal burners 9, 10.

In the slag cooling section 4, the molten slag 8 from the gasification section slag tap 6 is slag cooling water 7 below.
Since it falls inside and thermal stress is generated due to the temperature difference between the surface and the inside, it is granulated in the slag cooling water 7 to a size of about 2 to 5 mm.

In such a coal gasifier 1, various troubles will occur unless the molten slag 8 can be discharged stably. For example, if the slag tap 6 is clogged, the molten slag 8 accumulates in the hearth plate portion of the gasification section 3, and if the operation is continued, the molten slag 8 blocks the raw material and oxygen ejection port of the lower burner 10, so the operation of the device is stopped. I have no choice but to do it. In order to restart the operation, the main body 2 must be disassembled, the bottom of the main body 2 must be repaired, and the slag tap 6 must be replaced. In the worst case, the coal gasifier 1 cannot be restarted. Therefore, the air-bed type coal gasifier 1
Then, it is important to monitor the flow down state of the molten slag 8 in the slag tap 6. During operation of the coal gasifier 1, the slag tap 6 on the hearth plate is kept at a temperature above the melting point of the ash of the raw material, so the slag cooling section 4 is filled with combustible gas and has a high temperature. . Further, as the molten slag 8 flows down, some unburned chains also exist.

In the conventional method, the purge gas 12 'of the monitoring means A11 for monitoring the flow down state of the molten slag 8 is an inert gas such as nitrogen or a recycled gas produced by recycling the produced gas 22 produced by the coal gasifier 1. Was used as the sole flammable gas. In addition to the monitoring means A11,
Monitoring means B16 is provided to monitor the combustion state of the burner for heating the gasification section 3 and the burner for heating the slag tap 6 when the coal gasifier 1 is started up (hereinafter, monitoring means A11. And B16 are collectively referred to as "monitoring means"), and the monitoring means B is the same as the monitoring means A11.
As the purge gas 17 ', an independent gas such as an inert gas such as nitrogen or a combustible gas such as a recycle gas has also been used for the purge gas 17'.

[0007]

However, in the conventional coal gasifier 1, the purge gas 12 ', 17' is used.
When injected into the slag cooling unit 4, the gas in the atmosphere is cooled in a portion mixed with the gas in the atmosphere, so that the combustion intermediate products such as C radicals and C2 radicals of the combustible gas in the atmosphere are cooled. Soot is generated and adheres to the vicinity 31 and 32 of the purge gas ejection port of the monitoring means, and although not shown, a window for monitoring the monitoring means or a detection window of the monitoring equipment A14, B19 (hereinafter, for monitoring the monitoring means Window or the detection windows of the monitoring devices A14 and B19 are collectively referred to as "monitoring window").
There was a problem that the field of view of the observation window was narrowed, or the observation window became unclear because it adhered to the observation window. In particular, purge gas 1
When nitrogen gas is used as 2'and 17 ', unburned tires are digested into black particles in the vicinity of the purge gas ejection port 31 and 32 of the monitoring means, and the field of view of the monitoring window is further narrowed. Becomes unclear. On the other hand, if a large amount of purge gas is injected so as not to narrow the field of view of the monitoring window, the lower part of the gasification section 3, especially the slag tap 6, is cooled, and the fuel supply amount of the heating burner 15 for heating the slag tap 6 is increased to prevent it. Then, there is a problem that the combustion products increase and the calorific value of the generated gas 22 of the coal gasifier 1 decreases.

An object of the present invention is to prevent the field of view of the monitoring window of the monitoring means for monitoring the slag flow-down condition or the monitoring means for monitoring the combustion condition of the heating burner from being narrowed in the slag cooling section of the coal gasifier. Is clear,
By increasing combustion gas by burning more fuel than necessary,
It is an object of the present invention to provide a coal gasifier which does not reduce the calorific value of generated gas.

[0009]

In order to achieve the above object, the first invention of the present application has a gasification section and a slag cooling section located in a lower portion adjacent to the gasification section, and the slag cooling section is a slag. In a gas stream coal gasifier having a monitoring means for monitoring a flow-down situation and a monitoring means for monitoring a combustion situation of a heating burner, the slag cooling section is provided with a means for supplying a gas containing an oxidant. Is.

The second invention of the present application is the same as the first invention of the present application,
The means for supplying a gas containing an oxidant is a purge gas supply means for supplying a purge gas containing oxygen gas in the monitoring means, and the oxygen gas concentration of the purge gas is 2 to 2.
That is 10%.

The third invention of the present application is the same as the second invention of the present application.
That is, the combustible gas supply means is provided upstream of the purge gas supply means.

In a fourth invention of the present application, in the second invention or the third invention of the present application, the purge gas supply means is means for supplying a purge gas mainly containing nitrogen gas, and the combustible gas supply means is generated in the coal gasifier. That is, it is a means for supplying a recycled gas obtained by recycling the generated gas.

[0013]

According to the present invention, there is provided a gasification section and a slag cooling section located adjacent to and below the gasification section. The slag cooling section monitors the slag flow-down condition and the combustion condition of the heating burner. In the coal gasifier of the air flow layer system having and, since the slag cooling unit is provided with a means for supplying a gas containing an oxidant, the combustible gas and unburned chaff filling the slag cooling unit are By mixing with the gas containing the oxidant from the means for supplying the gas containing the oxidant, the combustible gas or the unburned chain reacts with the oxidant, so that soot or black particles are not generated. Therefore, the field of view of the monitoring window of the monitoring means is not narrowed or the monitoring window is not obscured.

The monitoring means is a purge gas supply means for supplying a purge gas containing oxygen gas, and since the oxygen gas concentration of the purge gas is 2 to 10%, a combustible gas or an unburned fuel is present near the purge gas ejection port. And the oxygen gas of the purge gas undergo a combustion reaction, and the same action as described above is achieved. Moreover, since the combustion reaction is not radical, the temperature of the monitoring device does not rise so much that it is protected and does not malfunction. Further, since the slag cooling unit is not excessively cooled, the burner for heating the slag tap does not supply an extra fuel, the combustion products are small, and the calorific value of the gas produced by the coal gasifier does not decrease.

Upstream of the purge gas supply means of the monitoring means,
Since the combustible gas supply means is provided, the combustible gas is well mixed with the purge gas, and directly combusts and reacts in the vicinity of the purge gas ejection port to perform the same operation as described above, and to the extent equivalent to the supply amount of the combustible gas. The amount of purge gas can be reduced.

The purge gas supply means is a means for supplying a purge gas mainly composed of nitrogen gas, and the combustible gas supply means is a means for supplying a recycle gas obtained by recycling the produced gas produced in the coal gasification apparatus. In addition to the same effect as above, it is not necessary to prepare a special gas as the purge gas and the combustible gas.

[0017]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is an explanatory view of a coal gasifier according to the present invention, which is a sectional view centering on a main body. The main body 2 of the coal gasifier 1 comprises a gasification section 3, a heat recovery section 5 adjacent to the upper part of the gasification section 3, and a slag cooling section 4 adjacent to the lower part. The gasification section 3 is provided with coal burners 9, 10. On the inner wall of the heat recovery unit 5, headers 20, 21 connected to the boiler feed waters 41, 42 and a heat transfer tube 43 are provided. The slag cooling section 4 is provided with a monitoring means A11 for monitoring the flow down state of the molten slag 8, and further, a burner for heating and heating the gasification section 3 at the time of starting the coal gasification apparatus 1 and a slag tap 6 for the hearth plate. A burner for heating the burner is provided.
It is shown as 5. Further, monitoring means B16 for monitoring the combustion state of the heating burner 15 is provided.

FIG. 2 is an enlarged cross-sectional view of the main part in FIG. As shown in FIG. 2, the monitoring means A11 has an image fiber which is the monitoring equipment A14 and a window for monitoring not shown, and the monitoring means B16 has a monitoring equipment B19.
There is a flame detector and a window for monitoring (not shown).
Both monitoring means are provided with purge gas supply means A12 and B17, and purge gas lines 29 and 30 and oxygen gas lines 33 and 34 connected to these are provided, respectively. That is, in this embodiment, the means for supplying the gas containing the oxidant is formed by the purge gas lines 29, 30 and the oxygen gas lines 33, 34. The heating burner 15 is connected to a fuel line 40 for methane gas, light oil, etc., and an oxygen-containing gas line 35 for supplying air, oxygen, etc.

In the gasification section 3, coal burners 9, 10
Are connected to raw material supply lines 25 and 26 for supplying a fine powdery carbonaceous solid raw material typified by coal and oxidant supply lines 27 and 28 for supplying an oxidizer such as oxygen, air, and steam, respectively. The oxidizer is introduced from coal burners 9, 10. The line system and equipment used on the upstream side of the raw material supply lines 25, 26 and the oxidant supply lines 27, 28 connected to the coal burners 9, 10 are those shown in FIG. 5 described in the conventional coal gasifier. Since it is the same as, the description will be omitted. Since the gasification section 3 is maintained at a temperature equal to or higher than the melting point of the ash of the fine powdery carbonaceous solid raw material, the combustible content of the solid raw material is a produced gas rich in hydrogen (H ₂ ) and carbon monoxide (CO). At 22, the ash content of the solid raw material changes to the molten slag 8. The generated gas 22 flows into the heat recovery section 5 above the gasification section 3. The molten slag 8 drops from the slag tap 6 located on the bottom hearth plate of the gasification section 3 to the slag cooling section 4 below.

In the heat recovery section 5, the produced gas 22 generated in the gasification section 3 is cooled mainly by radiant heat transfer and reaches a dust remover 24 such as a cyclone through a produced gas line 23 (FIG. 1).

Similar to the gasification section 3, the slag cooling section 4 is filled with a combustible gas, and some unburned cher is present. Therefore, by providing the means for supplying the gas containing the oxidant in the slag cooling section 4, the combustible gas and the unburned chaff inside the slag cooling section 4 are the oxidizers of the gas containing the oxidant. Burning reaction with
Since the temperature is higher than about 300 ° C, soot is not generated from the combustible gas, and the cheers do not become black particles. Therefore, the field of view of the surveillance window is not narrowed and the surveillance window is not obscured.

Since the means for supplying the gas containing the oxidant is the purge gas supplying means A12 and B17 for supplying the purge gas containing the oxygen gas in the monitoring means, the oxygen gas in the purge gas injected into the slag cooling section 4 is ,
It does not generate soot because it reacts with the combustion intermediate products such as C radicals and C2 radicals of the flammable gas in the atmosphere, and it adheres to the purge gas ejection port vicinity 31, 32 to narrow the field of view of the monitoring window, Alternatively, it cannot be said that it adheres to the monitoring window and obscures the monitoring window. Also, when nitrogen gas containing oxygen gas is used as the purge gas, unburned tires are digested into black particles in the vicinity 31 and 32 of the purge gas ejection port of the monitoring means, and the field of view of the monitoring window is further narrowed. It does not become obscured or obscure the observation window. Further, since it is not necessary to inject a large amount of purge gas so as not to narrow the field of view of the monitoring window, the lower part of the gasification section 3, particularly the slag tap 6, is not cooled, and the fuel supply amount of the heating burner 15 for heating the slag tap 6 is reduced. There is no need to increase it, so the amount of combustion products does not increase. Therefore, there is no problem that the calorific value of the generated gas 22 of the coal gasifier 1 is reduced.

According to experiments by the inventors, soot could not be observed in the monitoring window when the oxygen gas concentration in the purge gas was about 2% or more. On the other hand, if it exceeds 10%, the flammable gas in the atmosphere and the oxygen gas in the purge gas react violently, and the temperatures of the monitoring devices A14 and B19 rise. It is estimated that this is because relatively slow combustion occurs when the oxygen gas concentration in the purge gas is in the range of 2 to 10%. Therefore, the oxygen gas concentration in the purge gas is preferably in the range of 2-10%.

FIG. 3 is an explanatory view of another coal gasifier according to the present invention, and is an enlarged sectional view of a main part corresponding to FIG. In this embodiment, a combustible gas supply means A13 or B18 is provided upstream of the purge gas supply means A12 or B17 of the monitoring means in the embodiment shown in FIG. By providing the combustible gas supply means A13 or B18 on the upstream side of the purge gas supply means A12 or B17, the combustible gas and the purge gas containing oxygen gas come into contact with each other on the downstream side and burn, so that the monitoring device A14 is used. The image fiber, the flame detector that is the monitoring device B19, the window for monitoring, and the like are protected from high temperatures, and the monitoring devices A14 and B19 do not malfunction. When an image fiber is used as the monitoring device B19, the image fiber itself does not have heat resistance, so the image fiber itself needs to be cooled with a low-temperature gas. Similarly, the window for monitoring the monitoring means has a pressure resistance. Although heat resistant glass is used, it is preferable that the temperature is as low as possible. Therefore, the combustible gas supply means A13 or B18 is provided on the upstream side of the purge gas supply means A12 or B17 as described above.
Also, the purge gas used in the monitoring means A11, B16,
Recycled gas is at room temperature. As in the case of FIG. 2, the upstream line systems of the raw material supply lines 25 and 26 and the oxidant supply lines 27 and 28 connected to the coal burners 9 and 10 are explanatory diagrams of a conventional coal gasifier. The description is omitted because it is the same as the system diagram of FIG. Also in the embodiment of FIG. 3, the raw material supply lines 25 and 26 and the oxidant supply line 2 connected to the coal burners 9 and 10 are also used.
The upstream line systems and equipments used in Nos. 7 and 28 are the same as those shown in FIG. 5 described in the conventional coal gasifier, and therefore description thereof is omitted.

In each of the above-mentioned embodiments, the means for supplying the gas containing the oxidant is provided in the purge gas supplying means 12, 17, but the structure is not limited to this. A means for supplying a gas containing an oxidant to the vicinity of the lower portion of the slag tap 6 in the slag cooling section 4 is a purge gas supply means 12, 17
It may be provided separately from.

[0027]

According to the first invention of the present application, since the slag cooling section is provided with the means for supplying the gas containing the oxidant, soot and black particles are not generated in the slag cooling section, and the monitoring means It does not narrow the field of view of the surveillance window or obscure the surveillance window.

According to the second aspect of the present invention, the purge gas supplying means for supplying the purge gas containing the oxygen gas in the monitoring means has an oxygen gas concentration of 2 to 10.
%, Soot and black particles are not generated in the vicinity of the purge gas ejection port of the monitoring means, and the field of view of the monitoring window of the monitoring means is not narrowed or the monitoring window is not obscured. Moreover, since the combustion reaction is not radical, the temperature of the monitoring device does not rise so much and it is protected, and the monitoring device does not malfunction. Further, since the slag cooling unit is not excessively cooled, the burner for heating the slag tap is not supplied with additional fuel, the combustion products are small, and the calorific value of the produced gas of the coal gasifier is not reduced.

According to the third invention of the present application, since the combustible gas supply means is provided upstream of the purge gas supply means,
Since the combustible gas is well mixed with the purge gas and directly combusts in the vicinity of the purge gas ejection port, the purge gas amount corresponding to the supply amount of the combustible gas can be reduced in addition to the effect of the second invention of the present application. In addition, the monitoring device or the window for monitoring is protected from being heated to a high temperature, and the monitoring device does not malfunction.

According to the fourth invention of the present application, the purge gas supply means is means for supplying the purge gas mainly composed of nitrogen gas, and the combustible gas supply means supplies the recycled gas obtained by recycling the generated gas generated in the coal gasifier. In addition to the effect of the second invention or the third invention of the present application, it is not necessary to prepare a special gas as the purge gas and the combustible gas.

[Brief description of drawings]

FIG. 1 is an explanatory view of a coal gasifier according to the present invention, which is a cross-sectional view centering on a main body.

FIG. 2 is an enlarged cross-sectional view of a main part in FIG.

FIG. 3 is an explanatory view of another coal gasifier according to the present invention,
It is a principal part expanded sectional view corresponded to FIG.

FIG. 4 is an explanatory view of a conventional coal gasifier, which is a sectional view centering on a main body.

5 is an explanatory diagram of a conventional coal gasifier, and is a system diagram on the upstream side of a raw material supply line and an oxidant supply line to a coal burner in FIG. 4.

[Explanation of Codes] 1 coal gasifier 3 gasifier 4 slag cooler 6 slag tap 8 molten slag 11 monitoring means A 12 purge gas supply means A 13 combustible gas supply means A 14 monitoring equipment A 15 heating burner 16 monitoring means B 17 Purge Gas Supply Means B 18 Combustible Gas Supply Means B 19 Monitoring Equipment B 22 Generated Gas 29, 30 Purge Gas Lines 33, 34 Oxygen Gas Lines 36, 37 Combustible Gas Lines 38, 39 Recycled Gas

Front Page Continuation (72) Inventor Shuntaro Koyama 7-1-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Yoshihiro Koizumi 3-1, Nakasode, Sodegaura-shi, Chiba Coal-utilizing hydrogen Manufacturing Research Union Driving Research Institute

Claims (4)

[Claims] 1. A gasification section and a slag cooling section located below the gasification section, and the slag cooling section monitors the combustion status of a heating burner and a monitoring means for monitoring the slag flow-down status. A coal gasification apparatus of an air flow bed type having a monitoring means, wherein the slag cooling unit includes means for supplying a gas containing an oxidant. 2. The means for supplying a gas containing an oxidant according to claim 1, wherein the means for supplying a purge gas containing an oxygen gas in the monitoring means is a purge gas supply means, and the oxygen gas concentration of the purge gas is 2 to 10. % Coal gasifier. 3. The coal gasifier according to claim 2, wherein a combustible gas supply means is provided upstream of the purge gas supply means. 4. The purge gas supply means according to claim 2 or 3, wherein the purge gas mainly comprises nitrogen gas, and the combustible gas supply means recycles a produced gas produced in the coal gasifier. A coal gasifier characterized by being a means for supplying.