JPH07188676A - Gasifier - Google Patents

Abstract

PURPOSE:To discharge slag falling from a pressurized cooling water from the system stably without fail by installing a gas holding tank in a slag rock hopper formed for the purpose of discharging the accumulated slag from a quenching section. CONSTITUTION:This gasifier is one of an air stream bed type consisting of a gasifying section 10 for gasifying a pulverized solid carbonaceous material to convert the combustibles into the formed gases and to convert the ash into a molten slag, a quenching section 20 situated below the gasifying section 10 and having a cooling water pool 21 for quenching the molten slag formed in the gasifying section 10, and a slag rock hopper 30 for discharging the accumulated slag from the quenching section 20, wherein a gas holding tank 31 is formed in the slag hopper 30. The gas holding tank 31 formed in the slag rock hopper enables the bridge formed in the quenching section 20 and an extension tube 35 to be broken when the accumulated slag is transferred from the cooling water pool 21 to the slag rock hopper 30 and thereby enables the slag to be led stably from the quenching section 20 to the slag rock hopper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas-flow type gasifier which takes out combustible components of finely divided solid carbonaceous raw material as produced gas and discharges ash as molten slag, and particularly discharges molten slag stably. The present invention relates to a gasifier that does this.

[0002]

2. Description of the Related Art Conventionally, various apparatuses such as a fixed bed, a fluidized bed, and a gas stream bed have been proposed as an apparatus for gasifying a fine powdery solid carbonaceous raw material such as coal. In these devices, the airflow layer is a finely powdered solid carbonaceous raw material made into fine powder, together with an oxidizing agent such as oxygen and air, at a temperature above the melting point of the raw ash (about 1300 to 1600).
(° C), the combustible components in the finely divided solid carbonaceous raw material are converted into product gas, and the ash components are converted into molten slag, and the molten slag is discharged from the lower part of this gasifier to the outside of the system.
Therefore, the gas stream bed gasifier has features such as higher gasification efficiency than other devices and excellent environmental compatibility due to a wide range of applicable coal types. Therefore, the gas-flow type gasifier is suitable for the production of fuels such as combined power generation and fuel cells, and raw materials such as synthesis gas, and is being developed in Japan and overseas.

Conventionally, as a gas stream type gasifier capable of obtaining high gasification efficiency, for example, one shown in FIG. 4 is known. The gasification device 1 includes a gasification unit 10,
Quenching section 20 and slag lock hopper 3 provided below it
When the molten slag 6 generated in the pressure type gasification unit 10 is rapidly cooled and the slag 7 is discharged, the quenching unit 2 is used.
0 and the slag lock hopper 30 are provided with a pressure equalizing line 50, and the slag lock hopper 30 is constantly filled with pressurized gas, and the gas is cooled by the pressure equalizing line 50 when the slag is moved from the quenching unit 20. In FIG. 4, reference numeral 51 is a slag crusher, 52 is a rotary valve, 53 is a safety valve, 54 is a pressure regulator, and 55 is Gas supply lines for high-pressure air or steam are shown respectively.

On the other hand, as shown in FIG. 5, in the slag discharge device 60 for cooling and solidifying and discharging the molten slag 6 generated in the gasification section 10 of the gasifier 1 for generating the generated gas, the gasifier A slag discharge port 62 that opens and closes is formed in the lower part of the main body 2, and a cooling water pool 21 that collects the molten slag 6 and cools and solidifies the molten slag 6 is formed above the slag discharge port 62, and in the cooling water pool 21. A slag discharge device 60 provided with a stirring flow generation means 61 for generating a stirring flow
Is known (Japanese Utility Model Publication No. 1-161241).
In FIG. 5, reference numeral 35 indicates a slag discharge water system.

Further, as another gasification device, Japanese Patent Application Laid-Open No. Sho 5
9-176391, JP-A-60-92391, JP-A-61-98840, JP-A-62-162244,
There are publications such as Japanese Utility Model Laid-Open No. 3-70256 and Japanese Utility Model Laid-Open No. 3-123537.

[0006]

Generally, the gasifier is a pressurizing device of 20 to 30 atm, and a quenching section having a cooling water pool is provided below the gasification section. The quenching section has a gasification section. The molten slag flowing down from the slag tap is water granulated into several mm due to thermal stress. A pipe and a valve are connected between the quenching section and a slag lock hopper that repeatedly pressurizes and pressurizes the slag, and the size of the valve is generally about 200 mm. Therefore, the lower part of the quenching section has a conical shape, and short pipes equal to the inner diameter of the valve are installed above and below the valve.

The gasifier according to the prior art described above is mainly related to the bridge (bridge) of the slag in the conical portion of the quenching section, but according to the experiments by the present inventors, Bridges (bridges) occur in the conically squeezed part, and this is the part that receives the maximum weight of the accumulated slag. It was also found that the short pipe portion having the smallest diameter was also clogged, and if the short pipe was vibrated by other equipment, the slag was extremely compacted. If the slag is blocked by this short pipe, even if the conical portion is agitated, there is no effect in eliminating the blockage by slag compaction of the short pipe. Furthermore, the slag falls from the quenching section to the slag hopper, and the cooling water in the slag lock hopper rises to the upper part according to the amount of the falling slag, so the cooling water suppresses the falling speed of the falling slag, and this phenomenon It also causes blockage. Further, the gasifier according to the prior art shown in FIG. 5 can prevent the slag from bridging into the conical portion of the quenching portion or the short pipe, but in such a case, a very large amount is required. Cooling water must be supplied, and a large diameter supply pipe and supply pump are required, which is impractical. Further, when the slag is not discharged from the quenching section and is accumulated and the slag is above the cooling water level, the molten slag is not cooled in the quenching section and becomes a large lump. As a result, the gasification part may be damaged or may not be restarted.

The object of the present invention is to ensure a stable and reliable system without the molten slag falling from the gasification section under pressure clogging the lower part of the cooling water pool of the quenching section or the short pipe below it and clogging it. An object of the present invention is to provide an air flow layer type gasifier which discharges to the outside.

[0009]

In order to achieve the above object, the first invention is to gasify a fine powder solid carbonaceous raw material,
A gasification section that converts the combustible content of finely divided solid carbonaceous material into generated gas and ash content into molten slag, and a cooling water pool located below this gasification section that rapidly cools the molten slag generated in the gasification section In an airflow layer type gasification apparatus provided with a quenching section and a slag lock hopper for discharging slag accumulated in the quenching section, the slag lock hopper is provided with a gas reservoir tank.

A second aspect of the present invention is the gasifier according to the first aspect of the present invention, in which the water rising pipe for connecting the slag lock hopper and the cooling water pool of the quenching section and the pipe line of the water rising pipe are opened and closed. It is equipped with a valve.

According to a third aspect of the present invention, in the second aspect of the present invention, the gas reservoir tank is provided on the slag lock hopper side of the valve that opens and closes the conduit of the water rising pipe.

[0012]

According to the above construction, since the slag lock hopper is provided with the gas reservoir tank, when the slag accumulated in the cooling water pool provided in the lower part of the gasification section is moved to the slag lock hopper, the cooling water pool If you open the valve that opens and closes the connection pipe provided in the lower part and change the gas pressure of the gas reservoir tank provided in the slag lock hopper from atmospheric pressure to the pressure of the gasification section,
The gas in the gas reservoir tank is compressed, and the slag in the cooling water pool and the cooling water corresponding to the compressed volume rapidly drop to the lower part, and bridge the slag generated in the cooling water pool and the short pipe ( Destroy the bridge). Therefore, the slag is stably guided from the quenching section to the slag lock hopper.

Further, since the water rising pipe for connecting the slag lock hopper and the cooling water pool and the valve for opening and closing this pipe are provided, the slag descending to the slag lock hopper by opening this valve. Depending on the amount of cooling water and the amount of cooling water, the water of the slag lock hopper is guided to the cooling water pool through the water rising pipe, so the action of bridge (bridge) collapse of the slag accumulated in the rapid cooling part is more reliable. Become.

Further, since the gas reservoir tank is provided on the slag lock hopper side of the valve for opening and closing the pipe of the water rising pipe, when the slag is moved from the quenching section to the slag lock hopper side, in addition to the above action, Every time the water rises from the slag lock hopper to the quenching section, the inside of the gas reservoir tank is not washed and the gas reservoir tank itself is not clogged.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to the drawings. FIG. 1 is a partially omitted system diagram of a gasifier according to the present invention, FIG. 2 is an enlarged sectional view of an essential part mainly showing the quenching section and slag lock hopper in FIG. 1, and FIG. 3 is another quenching corresponding to FIG. It is a principal part expanded sectional view which mainly shows a part and a slag lock hopper.

FIG. 1 shows a partially omitted system diagram of a gasifier 1 according to the present invention. The gasification device 1 is connected to a gasification section 10 for gasifying a fine powder solid carbonaceous material, a quenching section 20 located below the gasification section 10 for quenching the molten slag 6, and a pipe for connecting to the quenching section 20. A slag lock hopper 30 for discharging the slag accumulated in the quenching section and a heat recovery section 45 for recovering heat from the generated gas generated in the gasification section 10 are provided.

The gasification section 10 includes burners 11, 11 connected to a raw material supply line 3 for supplying a fine powdery solid carbonaceous raw material and an oxidant supply line 4 for supplying an oxidant, and the gasification section 1.
It has a slag tap 12 which is located at the bottom of 0 and discharges the molten slag 6. The quenching unit 20 includes a cooling water pool 21 for quenching the molten slag 6, an upper space 26 located above the cooling water pool 21, a cooling water supply line 22 for supplying cooling water and a cooling water for discharging cooling water. It has a discharge line 23. Further, the level of the cooling water is controlled by the valve 24. The slag lock hopper 30 is a gas reservoir tank 31.
, A water supply line 36, and a water discharge line 37 for overblowing, and valves 34a and 34c are provided above and below. The heat recovery unit 45 has a generated gas discharge line 46.
And a boiler water discharge line 16. 14 is a refractory material.

The quenching section 20 and the slag lock hopper 30 are composed of a short pipe 35 and a valve 34a for opening and closing the pipe line of the short pipe 35.
Connected through. Furthermore, slag lock hopper 3
0 and the cooling water pool 21 are connected to each other through a water rising pipe 32 and a valve 33 provided in the water rising pipe 32. The lower part of the slag lock hopper 30 is provided with a valve 34c for discharging the slag 7, and an ejector 38 and a slag transport line 40 which are operated by high pressure water in a high pressure water line 39 downstream thereof. The slag transportation line 40
Although not shown, the solid-liquid separation device, the slag tank, and the wastewater treatment facility are reached.

The gasification apparatus 1 of the present invention having the above structure
Works as follows. In the gasification section 10, the fine powder solid carbonaceous raw material such as coal is fed from the raw material supply lines 3 and 3,
The oxidizer such as air is supplied to the burners 11 and 11 from the oxidizer supply lines 4 and 4, respectively, and the combustible components in the raw material are produced gas rich in hydrogen and carbon monoxide, and the ash content in the raw material is supplied to the molten slag 6. To be converted. That is, the molten slag 6 is generated in the gasification section 10 kept at a high temperature of about 1300 to 1600 ° C., which is higher than the melting temperature of the raw material ash, and drops from the slag tap 12 into the cooling water pool 21 of the quenching section 20. To do. Since the molten slag 6 has a temperature difference of several hundreds of degrees between the surface and the inside, it is water granulated to about 3 mm or less due to thermal stress and temporarily stored in the cooling water of the cooling water pool 21.

Next, the valve 34d of the water supply line 36 and the valve 34b of the water discharge line 37 are opened to supply high pressure water, and when the slag lock hopper 30 is filled with high pressure cooling water, the valve 3
4b and 34d are closed to stop the supply of cooling water, and the valve 34a
Open and open the pressure of the slag lock hopper 30 to the gasification section 10.
To the same pressure as. Of course, at this time, the valves 33 and 34c are closed. The pressure of the gas, eg, air, in the gas reservoir tank 31 provided in the slag lock hopper 30 is rapidly compressed from normal pressure to 30 kg / cm ² g, and the liquid height in the gas reservoir tank 31 changes from h ₀ to h _1. . Therefore, the cooling water pool 21
As for the slag 7 accumulated in the conical portion 25 of the slag 7, the amount of the slag 7 corresponding to the gas compression volume V ₁ of the gas storage tank 31 rapidly moves to the slag lock hopper 30 side, and the water in the slag lock hopper 30 Is guided to the cooling water pool 21 through the water rising pipe 32 according to the amount of slag that has flowed down, and after a certain period of time, the valve 34a is closed again. At this time, the valve 33 for opening and closing the water rising pipe 32 is opened after the valve 34a below the cooling water pool 21 is opened. In this way, by shifting the opening / closing timing of the valve 34a and the valve 33,
It is possible to cause the slag 7 of the cooling water pool cone portion 25 under pressure to flow down to the slag lock hopper 30 side stably and reliably. When the valve 34c at the bottom of the slag lock hopper 30 is opened, the slag lock hopper 30 is depressurized to normal pressure. Thereafter, as shown in FIG. 1, the ejector 38 is operated by the high-pressure water line 39 to discharge the mixture of slag and water in the slag lock hopper 30 to the outside of the system via the slag transport line 40.

FIG. 3 is an enlarged cross-sectional view of essential parts mainly showing another quenching section and a slag lock hopper corresponding to FIG.
The gasifier 1 shown in FIG. 3 has a slag lock hopper 3 of a valve 33 for opening and closing a water rising pipe 32 connecting the slag lock hopper 30 shown in FIG. 2 and the cooling water pool 21.
A gas reservoir tank 31 is provided on the 0 side. Since other configurations are the same as those in FIGS.
The same reference numerals are given to the same functional parts, and the description thereof will be omitted.

The gasifier 1 of FIG. 3 operates as follows. First, the action of the molten slag 6 in the gasification section being accumulated as slag in the quenching section cooling water pool 21 is as shown in FIG.
The explanation is omitted because it is similar to the explanation of 2. next,
Valve 34d of water supply line 36, valve 3 of water discharge line 37
4b is opened and high-pressure water is supplied to the slag lock hopper 30.
When is filled with high-pressure cooling water, the valves 34b and 34d are closed to stop the supply of cooling water, and the valve 34a is opened to make the pressure of the slag lock hopper 30 the same as that of the gasification section 10.
At this time, the valves 33 and 34c are closed.

Slag lock hopper 30 and cooling water pool 2
The pressure of the gas, eg, air, in the gas reservoir tank 31 provided on the slag lock hopper 30 side of the valve 33 for opening and closing the water rising pipe 32 connecting to 1 rapidly changes from normal pressure to 30 kg / cm.
Compressed to ² g, the liquid level in the gas reservoir tank 31 increases from h ₀ to h ₁
Becomes Therefore, as for the slag 7 accumulated in the conical portion 25 of the cooling water pool 21, the amount of slag 7 corresponding to the compressed gas volume V ₁ of the gas reservoir tank 31 moves from the cooling water pool 21 side to the slag lock hopper 30 side. Move abruptly. Next, when the valve 33 is opened, the water in the slag lock hopper 30 is guided to the cooling water pool 21 through the water rising pipe 32 in accordance with the amount of slag that has flowed down, and after a certain period of time, the valve 34a
Is closed again. At this time, the valve 33 of the water rising pipe 32
Is opened after the valve 34a below the cooling water pool 21 is opened. At the same time, the water in the slag lock hopper 30
According to the amount of slag that has flowed down, when it is guided to the cooling water pool 21 via the water rising pipe 32, the inside of the gas reservoir tank 31 is washed by the rising water, and slag and other foreign substances enter the gas reservoir tank. It never gets stuck. Thus, valve 3
By shifting the opening / closing timing of 4a and the valve 33, the slag 7 of the cooling water pool cone portion 25 under pressure can be made to flow down to the slag lock hopper 30 in a stable and reliable manner.
Next, when the valve 34c at the lower part of the slag lock hopper 30 is opened, the slag lock hopper 30 is depressurized to normal pressure. After that, the ejector 38 is operated by the high-pressure water line 39 similar to that shown in FIG. 1, and the mixture of slag and water in the slag lock hopper 30 is discharged to the outside of the system through the slag transport line 40.

[0024]

According to the first aspect of the present invention, since the slag lock hopper is provided with the gas reservoir tank, the slag accumulated in the cooling water pool is moved to the slag lock hopper to generate in the quenching section and the short pipe. The bridge (bridge) of the existing slag is destroyed, and the slag is stably guided from the quenching section to the slag lock hopper.

According to the second aspect of the present invention, in the first aspect of the present invention, the slag lock hopper is provided with the water rising pipe for connecting the slag lock hopper and the cooling water pool and the valve for opening and closing the pipe. The water in the slag lock hopper is guided to the cooling water pool through the water rising pipe in accordance with the amount of slag and the amount of cooling water that have descended, and the effect of the first aspect of the present invention becomes more certain.

According to the third aspect of the present invention, in the second aspect of the present invention, the gas reservoir tank is provided on the slag lock hopper side of the valve that opens and closes the conduit of the water rising pipe, so that the slag lock hopper is cooled to the quenching section. Every time the water rises, the inside of the gas reservoir tank is cleaned and the gas reservoir tank is not clogged, and in addition to the effect of the second invention, stable discharge of slag can be achieved.

[Brief description of drawings]

FIG. 1 is a partially omitted system diagram of a gasifier according to the present invention.

FIG. 2 is an enlarged sectional view of a main part mainly showing a quenching section and a slag lock hopper in FIG.

FIG. 3 is an enlarged cross-sectional view of a main part mainly showing another quenching section and a slag lock hopper corresponding to FIG.

FIG. 4 is a system diagram of a gasifier according to a conventional technique.

FIG. 5 is a cross-sectional view of an essential part of another gasifier according to the related art.

[Explanation of symbols]

 1 Gasifier 6 Molten slag 7 Slag 10 Gasification part 20 Quenching part 21 Cooling water pool 30 Slag lock hopper 31 Gas storage tank 32 Water rising pipe 33 Valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Susumu Yoshioka 3-36 Takaracho, Kure-shi, Hiroshima Babcock Hitachi Ltd. Kure Laboratory (72) Eiji Kida 6-9 Takaracho, Kure-shi, Hiroshima Babcock Hitachi Ltd. Kure Factory

Claims (3)

[Claims] 1. A gasification section for gasifying a finely divided solid carbonaceous raw material to convert combustible components of the finely divided solid carbonaceous raw material into product gas and ash into molten slag, and a gasification section located below the gasification section. In an airflow layer gasifier provided with a quenching section having a cooling water pool for quenching the molten slag, and a slag lock hopper for discharging the slag accumulated in the quenching section,
The gasifier, wherein the slag lock hopper includes a gas reservoir tank. 2. The gasifier according to claim 1,
A gasification apparatus comprising: a water rising pipe that connects the slag lock hopper and the cooling water pool; and a valve that opens and closes a pipe line of the water rising pipe. 3. The gasifier according to claim 2, wherein the gas reservoir tank is provided on the slag lock hopper side of a valve that opens and closes a conduit of the water rising pipe.