JPH0718268A - Gasifier - Google Patents

Abstract

PURPOSE:To remove unburnt residues deposited on the heat transfer surface of a heat recovery section efficiently at a low cost without changing the compsn. and calorific value of the produced gas by installing a slag supply means which removes the unburnt residues deposited on the heat transfer surface. CONSTITUTION:A molten slag 22 formed in a gasification chamber 12 is subjected to water granulation and separated with a separator 66. A part of the slag transported through a slag line 67 is fed into slag hoppers 71 and 81. Then, valves 73 and 83 are opened to transport the slag to slag lock hoppers 72 and 82 and to pressurize the hoppers 72 and 82. Valves 76 and 86 are then opened to jet the slag in the hoppers 72 and 82 or allow the slag to spontaneously fall onto the surface of a heat transfer section of a heat recovery chamber 30 or heat recovery boilers 42-45 in a heat recovery boiler section 40, thus removing unburnt residues deposited on the heat transfer surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gasification apparatus of gas stream type for gasifying a fine powdery solid carbonaceous raw material such as coal.
In particular, the present invention relates to a gasifier that efficiently removes unburned components adhering to the heat transfer surface of the heat recovery unit that recovers the heat of the generated gas generated in the gasification chamber.

[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 higher gasification efficiency than other methods, a wide range of applicable coal types, and excellent environmental compatibility. It is suitable for the production of fuels and raw materials such as fuel cells, and is being developed in Japan and overseas.

FIG. 4 is a system diagram for explaining a conventional gasifier. First, the structure of this gasifier will be described. The gasification device 1 includes a gas generation section 10, a heat recovery boiler section 40 and a collection section 100 located downstream of the gas generation section 10, and a slag separation section 60 located below the gas generation section 10.

The gas generator 10 comprises a gasification chamber 12 in a main body pressure vessel 11, and a heat recovery chamber 30 and a slag cooling unit 20 at the upper and lower parts of the gasification chamber 12, respectively. Gasification chamber 12
Are provided with burners 13, 13, and coal lines 14, 14 and oxidant lines 15, 15 are connected to each burner. A slag tap 21 is provided at the bottom of the gasification chamber 12.
Is provided. The heat recovery chamber 30 includes a heat transfer part 31, a space part 32, a refractory material 33, and the like, and the space part 32 is connected to a space part injection gas line 36. FIG. 5 shows a cross section of the heat transfer section 31 of the heat recovery chamber 30 in FIG.
A heat transfer section 31 is provided inside the main body pressure vessel 11, and the heat transfer section 31 is a structure assembled by welding a heat transfer tube 37 and a flat plate 38, and is a membrane used for a water wall of a general boiler. It is a structure called. Since this structure alone cannot withstand the internal pressure of several tens of atmosphere of the heat recovery chamber 30, the heat transfer section 31 is housed inside the main body pressure vessel 11. A space 32 is provided between the main body pressure vessel 11 and the heat transfer section 31. The slag cooling unit 20 has a space 25 located under the slag tap 21 and a water tank for enclosing the cooling water 23.
It is surrounded by. Further, headers 16 and 34 are provided in the lower side wall of the gasification chamber 12 and in the upper side wall of the heat recovery chamber 30.

The slag separating section 60 is located in the lower part of the main body pressure vessel 11, and is provided with a slag rack hopper 61 and a slag / water separator 66. Also, 63 and 64 represent water lines.

The heat recovery boiler section 40 is a boiler pressure vessel 4.
1, heat recovery boilers 42 to 45 are arranged in a plurality of stages, and water / steam lines 46 to 53 are connected to the respective heat recovery boilers 42 to 45.

The collector 100 is located downstream of the heat recovery boiler section 40, and is provided with a collector 101, a lock hopper 105, and a hopper 109.

As can be seen from the above description, the heat recovery section of the gasification apparatus 1 is located downstream of the gasification chamber 12 for gasifying the fine powdery solid carbonaceous raw material, and mainly heats by radiant heat transfer. And the heat recovery boilers 42 to 45 that mainly recover heat by convective heat transfer.

Next, the operation will be described. Gasification chamber 12
In the coal line 14
From this, oxidants such as oxygen, air and water vapor are introduced from the oxidant line 15 through the burners 13 and 13 into the gasification chamber 12 which is maintained at a temperature equal to or higher than the melting point of the ash of the solid raw material. The combustible content is a gas rich in hydrogen (H ₂ ) and carbon monoxide (CO), and the ash content of the solid raw material is a molten slag.
Converted to 2. The molten slag 22 is the slag tap 21.
2 to 5 in the cooling water 23 because it falls into the cooling water 23 below and thermal stress is generated due to the temperature difference between the surface and the inside.
It is water granulated to a size of about mm. In the heat recovery chamber 30, the generated gas generated by gasification is the gasification chamber 12
Heat is exchanged in the heat recovery chamber 30 which is located above the heat recovery chamber 30 and mainly recovers heat by radiant heat transfer. Main body pressure vessel 11 and heat transfer section 3
The space 32 between the first and the _second gas is a purified gas obtained by removing nitrogen (N ₂ ), carbon dioxide (CO ₂ ) or corrosive hydrogen sulfide (H ₂ S) from the space injection gas line 36. Is injected so that the pressure in the space 32 is slightly higher than the pressure in the heat recovery chamber 30 to prevent inflow of high-temperature product gas containing hydrogen sulfide (H ₂ S) or steam. .

In the heat recovery boiler section 40, the produced gas that has passed through the produced gas line 2 is heat-exchanged in the heat recovery boiler section 40 which mainly recovers heat by convective heat transfer. In the heat recovery boiler section 40, heat recovery boilers 42 to 45 are installed in multiple stages, and heat is efficiently recovered.

The collection unit 100 receives the product gas from the heat recovery boiler unit 40 from the product gas line 96, the purified gas is contained in the product gas line 111, and the unburned tire is contained in the collector 10.
1. Collected by the lock hopper 105 and the hopper 109,
It is taken out from the chain line 110. 102, 106
Is a valve.

The slag separating portion 60 divides the water granulated slag from the gas generating portion 10 into slag and water. The slag is stored in the slag rack hopper 61 through the valve 62 and then through the valve 65. The water separator 66 separates slag into a slag line 67 and water into a water line 68. 63 and 64 represent water lines.

[0013]

Originally, gasification is a partial combustion, and therefore unburned cheers scatter from the gasification chamber 12 together with the produced gas. A part of this unburned component adheres to the inner wall surface of the heat recovery chamber heat transfer section 31 or the surfaces of the heat recovery boilers 42 to 45 of the heat recovery boiler section 40 and reduces the heat recovery amount. When the heat recovery amount decreases, the sensible heat of the product gas passing through the product gas line 96 or the product gas line 111 increases, so that energy recovery deteriorates. Further, the temperature of the gas passing through the product gas line 96 rises, which adversely affects downstream equipment.

Even in a normal pressure boiler that completely burns pulverized solid carbonaceous fuel such as coal to generate steam, unburned components and ash components of the fuel are scattered together with the combustion gas, and the radiant heat transfer section or convective heat transfer is performed. Adhere to the part. In such a case, a method of injecting steam to the heat transfer section to remove it is adopted. However, even if this method is applied to the present gasification apparatus, the effect of removing deposits is reduced because the gasification chamber has a high pressure of several tens of atmospheres. Furthermore, when water vapor is injected into the produced gas, the water vapor (H ₂ O) partial pressure increases, so that the water vapor becomes carbon monoxide (C 2
The gas composition changes because the transfer reaction of hydrogen (H ₂ ) and carbon dioxide (CO ₂ ) by reacting with O) progresses. Furthermore,
If steam is added, even the calorific value of the produced gas per unit volume is changed. There is a plan to circulate the generated gas of the refined gas in order to keep the calorific value of the generated gas unchanged, but it is necessary to further increase the pressure by several tens of atmospheric pressure from the downstream refined gas step, which significantly increases the operating cost. Will increase.

An object of the present invention is to provide a gas stream type gasifier capable of efficiently and inexpensively removing unburned matter adhering to the surface of a heat transfer section, while hardly changing the composition or calorific value of generated gas. That is.

[0016]

In order to achieve the above object, the first invention of the present application resides in a gasification chamber for gasifying a finely powdered solid carbonaceous raw material and a gasification chamber located downstream of the gasification chamber. In a gasifier equipped with a heat recovery unit for recovering heat,
The heat recovery section is provided with a slag supply means for removing unburned components adhering to the surface of the heat transfer section.

The second invention of the present application is the same as the first invention of the present application.
The heat recovery section provided with the slag supply means is at least one of the heat recovery chamber and the heat recovery boiler section.

The third invention of the present application is the same as the second invention of the present application.
The slag supply means of the heat recovery boiler section is a means for supplying slag in multiple stages.

The fourth invention of the present application is a gasification system comprising a gasification chamber for gasifying a finely powdered solid carbonaceous raw material and a heat recovery unit located downstream of the gasification chamber for recovering the heat of the produced gas. The apparatus is provided with a vibration applying means for applying vibration to the heat transfer section of the heat recovery section.

The fifth invention of the present application is the same as the fourth invention of the present application.
The vibration applying means is provided with a vibration generator that uses the pressure of the inert gas or the product gas generated by the gasifier as a drive source.

[0021]

According to the present invention, the heat recovery section is provided with the slag supply means, and the heat recovery section provided with the slag supply means is at least one of the heat recovery chamber and the heat recovery boiler section. On the other hand, the granulated slag that is generated and recovered by gasification in the gasification chamber and has a large specific weight and a large momentum of slag, the heat transfer chamber surface of at least one of the heat recovery chamber and the heat recovery boiler part to which unburned components adhere By supplying to the heat transfer surface, the unburned components adhering to the heat transfer surface are easily scraped off and the composition of the produced gas or the calorific value does not change. The slag supply means of the heat recovery boiler section is a means for supplying slag in multiple stages, so that the unburned fuel adhered to the heat transfer surface from the uppermost heat recovery boiler of the heat recovery boiler section toward the lowermost heat recovery boiler. The part can be removed and the removal work can be done reliably. Further, by providing the heat transfer part of the heat recovery part with vibration applying means for applying vibration, the surface of the heat transfer part of the heat recovery part vibrates, and the unburned components adhering thereto are easily removed. The vibration applying means is provided with a vibration generator driven by the pressure of the inert gas or the generated gas generated by the gasifier, so that even if an explosive gas is used in the space where the vibration applying means is provided. It is possible to safely drive the vibration generator to remove the unburned components adhering to the heat transfer surface.

[0022]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a system diagram of a first embodiment of a gasification apparatus according to the present invention, in which heat recovery chamber 30 and heat recovery boiler section 40 are provided with slag supply means 70 and 80. The same parts as those shown in FIGS. 4 and 5 for explaining the conventional gasifier are designated by the same reference numerals and the description thereof will be omitted. The slag supply means 70, 80 are the slag hoppers 7.
1, 81, sluggable hoppers 72, 82, pressurizing lines 74, 84, and depressurizing lines 75, 85. Further, at the bottom of the heat recovery boiler section 40, a slag recovery section 90
Is provided, and a slag recovery device 91 and a recovery hopper 92 are provided. The downstream side of the produced gas line 96 is the same as the downstream system of the produced gas line 96 shown in FIG. 4 for explaining the conventional gasifier, and therefore the description thereof is omitted.

The slag hoppers 71 and 81 are provided in the gasification chamber 12
The molten slag 22 generated in (1) is water granulated, and the generated slag is separated by the slag / water separator 66, and a part of the slag transferred by the slag line 67 is filled. Valve 73,
83 is opened, the slag is moved to the slug lock hoppers 72, 82, the valves 73, 83 are closed, and the slug lock hoppers 72, 82 are pressurized. As a pressurizing method, gas may be supplied from the pressurizing lines 74 and 84, or the valves 76 and 86 may be opened. When the pressurization is completed, the valves 76 and 86 are opened to open the slug lock hopper 72,
The slag in the heat recovery chamber 30 or the heat recovery boiler unit 4
Zero heat recovery boilers 42 to 45 are naturally dropped or jetted onto the heat transfer surface. The slag collides with the surface of the heat transfer section, and the unburned components attached to the surface of the heat transfer section can be removed. The slag that naturally falls or is sprayed onto the surface of the heat transfer section of the heat recovery chamber 30 falls into the gasification chamber 12 installed below, is melted again, and is discharged from the gasification chamber 12. Slug Hot Spa 7
For the slag replenishment of Nos. 1 and 81, it is sufficient to provide a slag conveying means from the slag line 67 to the slag hoppers 71 and 81. On the other hand, the slag spontaneously dropped or injected into the heat recovery boiler 42 of the heat recovery boiler section 40 not located in the vicinity of the upper part of the gas generation section 10 is removed in all directions after removing the unburned components adhering to the surface of the heat transfer section. The unburned components that scatter and adhere to the heat transfer surfaces of the other heat recovery boilers 43 to 45 are sequentially removed, and reach the lower part of the heat transfer surface of the heat recovery boiler 45. This heat recovery boiler 42
For the slag supplied to the heat transfer part of ~ 45, it is necessary to separate the unburned component and the slag, but at this time, it may be conveyed from the slag line 97 to the slag / water separator 66,
It may be conveyed to the normal pressure slag hopper 71 located near the upper part of the heat recovery chamber 30 and returned to the gasification chamber 12 again. When returning to the slag hopper 71 under normal pressure, there is an advantage that some unburned matter collected together with the slag can be returned to the gasification chamber 12.

As described above, according to the present invention, the unburned components can be removed only by supplying the slag generated in the gasification chamber 12 from the slag rack hoppers 72 and 82, so that the composition and calorific value of the produced gas are changed. The predetermined heat can be recovered in the heat recovery chamber 30 and the heat recovery boiler section 40 without performing the above operation. Therefore, it is possible to inexpensively remove the unburned matter adhering to the surface of the heat transfer section without adversely affecting the equipment subsequent to the heat recovery section. Further, the gasification efficiency can be improved by removing the unburned matter adhering to the surface of the heat transfer section and returning it to the gasification chamber 12.

The first embodiment relates to the gasifier 1 in which the heat recovery section is provided with the slag supply means 70 or 80 in at least one of the heat recovery chamber 30 and the heat recovery boiler section 40. However, the present invention is not limited to this, and the present invention can be applied to a gasification apparatus of an air flow layer type for gasifying a fine powdery solid carbonaceous raw material such as coal and the heat recovery section thereof. .

FIG. 2 is a second embodiment of the gasifier according to the present invention, and is a main part system diagram in a state in which means for supplying slag to the heat recovery boiler section 40 in multiple stages is provided. Similar to the first embodiment, the same parts as those shown in FIGS. 4 and 5 for explaining the conventional gasifier are designated by the same reference numerals and the description thereof will be omitted. In the second embodiment, the slag hopper 8 is provided in the heat recovery boiler section 40 that recovers heat from the generated gas by convective heat transfer that is not arranged above the gas generation section 10.
1, slack hopper 82 and slack hopper 8
2 is provided with a pressure line 84 and a pressure reduction line 85, and
The heat recovery boilers 40 to 45 of the heat recovery boiler section 40 are provided with means for supplying slag in multiple stages. The heat recovery boiler section 40 has a plurality of heat recovery boilers 42 to 45, and water / steam lines 46 to 53 are provided in each heat recovery boiler. At the top of the heat recovery boiler section 40 is the gas generating section 10.
Is connected to the generated gas line 2 from, and the same one as the slag recovery section 90 shown in FIG.
The same parts are designated by the same reference numerals, and the description thereof will be omitted. The downstream side of the generated gas line 96 is the same as the downstream system of the generated gas line 96 shown in FIG. 4 for explaining the conventional gasifier, and therefore, illustration and description thereof are omitted.

In the first embodiment, the slag for removing unburned components was supplied from above the heat transfer section of the heat recovery boiler 42, but in the second embodiment, the effect of removing deposits is further increased. Is a good one. After removing unburned components adhering to the lower heat recovery boiler heat transfer unit, for example, the heat transfer unit of the heat recovery boiler 45, unburned components attached to the upper heat recovery boiler heat transfer unit, for example, the heat transfer unit of the heat recovery boiler 42. If is removed, the unburned components will adhere again to the surface of the heat transfer section from which the unburned components have been removed previously.
For efficient removal, it is preferable to gradually supply the slag for removing unburned components from the surface of the upper heat transfer section, that is, the surface of the heat transfer section of the heat recovery boiler 42 to the lower surface of the heat transfer section. Compared to the first embodiment, this embodiment requires a larger amount of gas for supplying slag, but removes unburned components adhering to the surface of the heat transfer section due to the momentum of slag particles having a large specific gravity. Is large compared to the conventional structure using only gas,
Has little effect on the gas composition etc.

FIG. 3 shows a third embodiment of the gasifier according to the present invention, which is a main pressure vessel 1 of the heat transfer section 31 of the heat recovery chamber 30.
It is a principal part system diagram in the state provided with the vibration provision means 120 at the 1 side. Similar to the first and second embodiments, the same parts as those shown in FIGS. 4 and 5 for explaining the conventional gasifier are as follows.
The same numbers are assigned and the description thereof is omitted. Also, the second
Similar to the embodiment described above, the downstream side of the produced gas line 96 is the same as the downstream system of the produced gas line 96 shown in FIG. 4 for explaining the conventional gasifier, and therefore, illustration and description thereof are omitted.

In the third embodiment, the heat transfer section 3 of the heat recovery chamber 30 is used.
1, which is provided with a vibration applying means 120 on the main body pressure vessel 11 side, and a vibration generator 121 and an inert gas line 122 for supplying an inert gas for driving the vibration generator 121 or a generated gas line 123 for supplying a generated gas. It is connected to the. The vibration generator 121 is specifically a knocker or a vibrator. The gasification chamber 1 is provided in the space 32 outside the heat transfer section 31.
The inert gas or the generated gas is supplied from the space injection gas line 36 so as to maintain the pressure slightly higher than the pressure of 2. Therefore, a vibration generator, which uses these gases as driving power, is installed in the vibration generator 121 such as a knocker or a vibrator, and the heat transfer section 31 is vibrated.
This vibration removes the unburned matter adhering to the surface of the heat transfer section. As a result, the amount of heat absorbed by the heat transfer section 31 is not reduced. A device that uses electricity to drive the vibration generator 121 may be installed, but the space 3
A gas containing several tens of percent of hydrogen flows in No. 2, and even if an explosion-proof structure is adopted, it is not a preferable facility in terms of safety. Therefore,
When an electric vibration generator is installed, the purified gasified gas cannot be used as the pressure maintaining gas in the space 32.

This embodiment shows an apparatus for removing unburned matter adhering to the surface of the heat transfer section of the heat recovery chamber 30 for recovering heat by utilizing radiant heat transfer, but the present invention is not limited to this. The present invention can be applied to any heat recovery unit in a gasification apparatus that includes a gasification chamber for gasifying a fine powdery solid carbonaceous raw material and a heat recovery unit located downstream of the gasification chamber for recovering heat of the produced gas. The amount of produced gas, the gas composition, and the calorific value of the gas are not changed at all, and there is no adverse effect on the subsequent equipment of the gasifier.

[0031]

According to the first aspect of the present invention, since the heat recovery part is provided with the slag supply means for removing the unburned components adhering to the surface of the heat transfer part, the composition of the produced gas or the calorific value is almost changed. It is possible to efficiently and inexpensively remove the unburned matter attached to the surface of the heat transfer section.

According to the second invention of the present application, in the first invention of the present application, the heat recovery section provided with the slag supply means is at least one of the heat recovery chamber and the heat recovery boiler section.
In addition to the effects of the invention, it is possible to remove unburned matter adhering to the surface of the heat transfer section by simply adding a simple slag supply facility, and to remove the unburned matter adhering to the surface of the heat transfer section into the gasification chamber. The gasification efficiency can be improved by returning to
It does not adversely affect the equipment subsequent to the heat recovery section.

According to the third invention of the present application, in the second invention of the present application, since the slag supply means of the heat recovery boiler section is means for supplying slag in multiple stages, in addition to the effects of the first invention and the second invention of the present application. The unburned matter does not adhere again to the surface of the heat transfer portion where the unburned matter has been removed previously. According to the fourth invention of the present application, since the heat transfer section of the heat recovery section is provided with the vibration applying means for applying vibration, the composition of the generated gas or the calorific value is almost changed by simply adding simple equipment. The unburned components adhering to the surface of the heat transfer section can be efficiently and inexpensively removed without adversely affecting the equipment subsequent to the heat recovery section.

According to the fifth invention of the present application, in the fourth invention of the present application, the vibration applying means is provided with a vibration generator driven by the pressure of the inert gas or the product gas generated by the gasifier. In addition to the effect of the fourth invention of the present application, even if the ambient atmosphere of the vibration generator is an explosive gas such as hydrogen, there is no danger of explosion and it operates safely.

[Brief description of drawings]

FIG. 1 is a system diagram of a first embodiment of a gasifier according to the present invention in a state where a heat recovery chamber and a heat recovery boiler section are provided with slag supply means.

FIG. 2 is a main part system diagram of a second embodiment of the gasifier according to the present invention, which is provided with a means for supplying slag in multiple stages to a heat recovery boiler section.

FIG. 3 is a system diagram of an essential part of a third embodiment of the gasifier according to the present invention in a state where a heat recovery chamber is provided with vibration applying means.

FIG. 4 is a system diagram illustrating a conventional gasifier.

FIG. 5 is a cross-sectional view of the heat recovery chamber heat transfer section in FIG.

[Explanation of symbols]

 1 Gasifier 2, 96, 111 Product gas line 10 Gas generation part 12 Gasification chamber 20 Slag cooling part 22 Molten slag 23 Cooling water 30 Heat recovery chamber 31 Heat transfer part 32 Space part 36 Space injection gas line 37 Heat transfer tube 40 heat recovery boiler section 42, 43, 44, 45 heat recovery boiler 60 slag separation section 61 slag hopper 55 slag / water separator 67 slag line 68 water line 70, 80 slag supply means 71, 81 slag hopper 72, 82 slag Lock hopper 90 Slag recovery unit 91 Slag recovery unit 92 Recovery hopper 97 Slag line 100 Collection unit 105 Lock hopper 109 Hopper 110 Cheer 120 Vibration imparting means 121 Vibration generator

Front page continued (72) Inventor Shinji Tanaka 7-1 Omika-cho, Hitachi City, Ibaraki Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Shuichi Matsuoka 3-1 Nakasode, Sodegaura City, Chiba Coal utilization Hydrogen Manufacturing Technology Research Association Driving Research Institute

Claims (5)

[Claims] 1. A gasification apparatus comprising a gasification chamber for gasifying a pulverized solid carbonaceous raw material and a heat recovery unit located downstream of the gasification chamber for recovering the heat of the produced gas. The gasification device, wherein the recovery part is provided with a slag supply means for removing unburned components adhering to the surface of the heat transfer part. 2. The gasifier according to claim 1, wherein the heat recovery section provided with the slag supply means is at least one of a heat recovery chamber and a heat recovery boiler section. 3. The gasifier according to claim 2, wherein the slag supply means of the heat recovery boiler section is a means for supplying slag in multiple stages. 4. A gasification apparatus comprising a gasification chamber for gasifying a pulverized solid carbonaceous raw material and a heat recovery unit located downstream of the gasification chamber for recovering the heat of the produced gas, A gasification apparatus comprising a vibration applying means for applying vibration to the heat transfer section of the recovery section. 5. The gasifier according to claim 4, wherein the vibration applying means includes a vibration generator that uses a pressure of an inert gas or a generated gas generated by the gasifier as a drive source.