JP3342083B2 - Spouted bed 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 a spouted bed gasifier for producing coal gas by jet combustion of pulverized coal.

[0002]

2. Description of the Related Art FIG. 4 is a longitudinal sectional side view showing an example of a conventional spouted bed coal gasifier which is a premise of the present invention, and FIG.
FIG. 6 is a view showing a situation where ash adheres and accumulates on the inner surface of the reducer. In these figures, (01)
Is a combustor, (02) is a reducer diffuser,
(03) is a reducer, (04) is a water pipe, (05) is a slag tap, (06) is a pressure wall, (07) is a pulverized coal burner for a combustor, (08) is a recycler burner,
(09) is a pulverized coal transport pipe for a combustor, (10) is a recycler transport pipe, (11) is a combustion air air pipe,
(12) pulverized coal for combustors, (13) recycle char, (14) combustion air, (15) pulverized coal burner for reducer, (16) pulverized coal transport pipe for reducer,
(17) pulverized coal for a reducer, (18) crude coal gas, (19) refractory material, (20) slag hopper, (2)
1) is a water tube fin, (22) is a molten slag, (23)
Indicates the deposited ash.

[0003] Nitrogen from coal not shown milled equipment pulverized coal which is conveyed by an inert gas or air (hereinafter, N ₂ hereinafter) or the like, a combustor for pulverized coal (1
2) and the pulverized coal for reductor (17) are sent to the pulverized coal burner for combustor (07) and the pulverized coal burner for reductor (15), respectively.

[0004] The pulverized coal (12) for combustor sent to the pulverized coal burner (07) for combustor is the burner (0).
7) It is blown into the combustor (01).
Combustion is performed together with the combustion air (14) that is pumped through the combustion air supply pipe (11). Chars (flammable solids remaining after the volatile components in the pulverized coal have been completely burned) contained in the generated crude coal gas (18) and collected by a dust removing device (not shown) also include: It is blown into the combustor (01) from the recycle chamber burner (08) and is provided for combustion. Usually, the transport of the recycle char (13) is performed by using clean (dust-removed and desulfurized) coal gas. Combustor (0
In the combustion in 1), it is ideally desirable to perform partial combustion with a low air ratio, but in order to easily melt and discharge the ash generated by pulverized coal combustion), the combustion is performed at an air ratio close to the ideal air amount and the temperature is increased. Generate gas.

[0005] The pulverized coal (17) for the reducer is blown from the pulverized coal burner (15) to the high temperature crude coal gas (18) generated in the combustor (01) from the pulverized coal burner (15) in the reducer diffuser section (02). The reducer diffuser section (02) is composed of crude coal gas (18) sent from the combustor (01) and pulverized coal for the reducer (17).
Is provided for the purpose of uniform mixing and dry distillation of the pulverized coal (17) for the same reducer. The blowing amount of the pulverized coal for the reducer (17) is set so that the air ratio of the crude coal gas (18) at the outlet of the reducer diffuser section (02) is in an appropriate range for gasification.

[0006] The crude coal gas (18) leaving the diffuser section (02) is sent to the reducer (03). In the reducer (03), a gasification reaction of the char generated by dry distillation of the pulverized coal for the reducer (17) mixed in the crude coal gas (18) is performed. This is, for example, the following reaction.

[0007] By such a gasification reaction of the char in the C + CO ₂ → 2 CO C + H ₂ O → CO + H ₂ CO + H ₂ O → ← CO ₂ + H ₂ reducer (03), the crude coal gas (18) undergoes a gasification reaction. It becomes a combustible gas containing the finished char.

The crude coal gas (18), which has been subjected to the char gasification reaction in the reducer (03), has a high temperature of 1000 to 1100 ° C. at the outlet of the reducer (03) and is sent to a gas cooler (not shown). After being adjusted to a predetermined gas temperature, the gas is similarly sent to a dust removal facility and a desulfurization facility (not shown) to produce clean refined coal gas.

The most problematic in the conventional spouted bed gasifier described above is the treatment of coal ash generated by pulverized coal combustion in the combustor (01). The pulverized coal combustion in the combustor (01) causes the combustor (0)
Since the internal gas temperature of 1) and the reducer diffuser section (02) is increased to several hundred degrees Celsius (Celsius), the generated coal ash becomes molten slag (22), and the combustor (01) composed of the refractory material (19). ) And flows down along the wall surface of the reducer diffuser portion (02). Combustor (0
1) A slag tap (05) is provided on the bottom,
Combustor (01) and reducer diffuser (02)
The molten slag (22) flowing down the wall of the slag enters the slag hopper (20) from the slag tap (05),
It is finely granulated in the water stored in the slag hopper (20).

However, the coal ash generated in the combustor (01) is not entirely recovered as molten slag (22) in the combustor (01) and the reducer diffuser section (02), but is partially recovered as coarse coal. The gas is mixed into the gas (18) and is carried over to the further upper reducer (03). Since the inner wall of the reducer (03) is constituted by the water pipe (04), the wall surface temperature is much lower than the melting point of coal ash. Therefore, in this reducer (03), when the continuous operation time is short, slugging does not occur even at a place where the gas temperature is equal to or higher than the melting point of the coal ash, and only a small amount of powdery coal ash adheres to the inner wall of the reducer (03). is there. When the continuous operation time is short as described above, the adhesion of the coal ash to the inner wall of the reducer (03) is extremely small, but when the continuous operation is performed for a long time exceeding a certain time (depending on the type of coal), the reducer ( 03) The amount of coal ash adhering to the inner wall increases. Investigations after shutting down the gasifier revealed that this was comparable to the thickness of the deposited ash in the reducer diffuser section (02).

This phenomenon is caused by the fact that the amount of coal ash adhering to the surface of the water pipe (04) forming the inner wall of the reducer (03) increases with a lapse of operation time, albeit little by little, and at the same time, the surface temperature also rises and becomes constant. It is presumed that when the thickness reaches the thickness, the surface of the attached ash begins to melt and eventually the ash is deposited. According to the investigation of the ash deposition after the gasification furnace was stopped, the ash deposition near the inner wall of the reducer (03) was
Due to the bridges between the ash particles rather than the welding, the deposited ash (23) could easily fall off with a little force, and the deposition of the deposited ash (23) was only near its surface From the above, it was estimated as described above.

As described above, in the conventional spouted bed coal gasifier, the deposited ash (22) attached to the inner wall of the reducer (03) grows as the operation time elapses, and finally comes off and falls due to vibration or thermal shock. Slag tap (0
5) Alternatively, there was a possibility that the reactor diffuser portion (02) was closed, making it impossible to operate the furnace.

[0013]

In the conventional spouted bed coal gasifier, as the operating time becomes longer, the deposited ash (22) grows on the inner wall surface of the reducer (03). Is deposited by bridges between ash particles on the adhesion surface, and furthermore, the surface side is welded and turned into slag, so when the growth becomes large, it easily peels off due to slight vibration or thermal shock, etc. It may fall off as a lump. Then, there is a possibility that the slag tap (05) or the reducer diffuser part (02) may be closed to make the operation of the furnace impossible.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention provides a gas which blows pulverized coal together with a carrier gas into a combustor having a slag tap at the bottom to generate a high-temperature flammable gas. In the gasification furnace, a plurality of slugging preventing gas chambers are provided around a water pipe group wall forming an outer wall of a reducer disposed above the combustor, and the slugging preventing gas chambers each having a ventilation valve are provided in each of the slugging preventing gas chambers. A jet, wherein an air supply pipe is connected, and a water pipe fin which forms the water pipe group wall together with the water pipe is provided with a gas jet hole for preventing slugging which communicates between the gas chamber for preventing slugging and the inside of the reducer. Floor coal gasifier; and, in addition to the above requirements, a plurality of annular falling-off preventing partitions vertically along the inner circumference of the outer wall of the above-mentioned reducer. It proposes a entrained flow coal gasifier, characterized in that provided.

[0015]

According to the present invention, aeration at regular intervals slugging preventing gas consisting of inert gas sequentially any to multiple slagging prevention gas chamber such as N ₂ or water vapor,
Injects into the reducer from the gas outlet for slugging prevention. In this case, the opening / closing time of each ventilation valve is adjusted so that the slugging prevention gas is not simultaneously injected from the plurality of slugging prevention gas chambers. By sequentially injecting the slugging preventing gas from the slugging preventing gas chamber in this manner, the ash can be prevented from being injected and deposited, and the deposited ash can be removed without closing the slag tap.

In the case where a plurality of drop-preventing partition plates are provided, only a part of the deposited ash in the drop-preventing partition plate falls off. Can be prevented from being blocked.

[0017]

1 is a longitudinal sectional side view showing one embodiment of the present invention.
FIG. 2 is an enlarged view of the lower part of the reducer in FIG. 1, and FIG. 3 is a horizontal sectional view taken along the line III-III of FIG. In these figures, the same parts as those of the related art described with reference to FIGS. 4 to 6 are denoted by the same reference numerals to avoid redundancy, and detailed description is omitted. As reference numerals newly used in FIGS. 1 to 3, (101) is a partition, (102) is a gas feeding pipe for slugging prevention, (103) is a ventilation valve, (104) is a gas ejection port for slugging prevention, (104) Numeral 105) indicates a gas for preventing slugging, (106) indicates a partition plate for preventing falling off, and (107) indicates a gas chamber for preventing slugging.

In this embodiment, a partition wall (101) is provided between the water pipe (04) group wall and the pressure wall (06) constituting the outer wall of the reducer (03), and the water pipe (04) group wall and the partition wall (101) are provided. By applying vertical and horizontal partitions to the annular space formed by),
A plurality of slugging preventing gas chambers (107) are provided around the wall of the water pipe (04). Each slugging prevention gas chamber (10
At 7), a gas feed pipe (102) for preventing slugging is connected through a pressure wall (06). A ventilation valve (103) is mounted on each slugging prevention gas air pipe (102) near the slugging prevention gas chamber (107).
The wall between the slugging prevention gas chamber (107) and the reducer (03) is provided with a plurality of water pipes (0) arranged in parallel with each other.
4) and a water tube fin (21) for connecting the water tubes (04) to each other. This water pipe fin (21) has a plurality of gas ejection holes (104) for preventing slugging.
Is perforated. In addition, individual gas chambers to prevent slugging
A plurality of (five in the illustrated example) annular drop-off preventing partition plates are vertically arranged along the inner periphery of the outer wall of the reducer (03) inside (107).
(106) is provided.

A slugging prevention gas (105) sent from a blowing facility (not shown) through a slugging prevention gas air pipe (102) is a vent valve in a fully closed state.
Stop by (103). Slugging prevention gas (10
As 5), an inert gas such as N ₂ is used so that the properties of the coal gas do not significantly change in the reducer (03). After the operation of the gasification furnace is started, some of the ventilation valves (103) are opened, the slugging prevention gas (105) is sent into the slugging prevention gas chamber (107), and the slugging prevention gas ejection holes (104) are opened. ) Into the reducer (03).

First, the ventilation valve (103) connected to one determined slugging prevention gas chamber (107) is opened, and the slugging prevention gas (105) is injected from the slugging prevention gas ejection hole (104). . After injection for a certain time, the relevant vent valve
(103) is fully closed. Next, the vent valve (103) connected to the other slugging prevention gas chamber (107) is opened, and the same operation is performed. When the injection from all the slugging prevention gas chambers (107) is completed in this manner, the flow returns to the first slugging prevention gas chamber (107) again to inject the slugging prevention gas (105).

The injection amount of the slugging prevention gas (105),
That is, the opening time of the vent valve (103) and one vent valve (1
The time until the next vent valve (103) is opened after fully closing 03) is determined by the progress of ash deposition on the inner wall of the reducer (03), the ash content of the coal used and the ash melting point. The slagging prevention gas (105) is injected to prevent ash from adhering and accumulating. However, even if the ash is adhering and accumulating on the inner wall of the reducer (03), the ash can be removed.

The injection of the slugging prevention gas (105) is
Only from the two slugging prevention gas chambers (107),
The reason why the gas is not simultaneously discharged from a plurality of gas chambers (107) is that a large amount of deposited ash (22) falls off at a time, and the slag tap (05) or the reducer diffuser (0) is used.
This is to ensure that 2) is not blocked.
A plurality of falling-off preventing partitions (106) are provided vertically along the inner peripheral wall of the reducer (03) corresponding to the individual slugging-preventing gas chambers (107) because the slugging-preventing gas (105) is used. At the time of injection, only the deposited ash (22) in the drop-prevention partition (106) located in the slugging-preventing gas chamber (107) is made to fall off, and a wide range of deposited ash (22) is removed at one time. This is to prevent the slug tap (05) or the like from falling off and closing the slug tap (05).

In FIGS. 1 and 2, the partition (1
01) is applied to the lower half of the reducer (03), and it seems that the gas chamber (107) for preventing slugging is provided only in the lower half of the reducer (03). Needless to say, it is good.

As described above, it is possible to prevent ash from adhering and accumulating in the reducer (03).

[0025]

According to the present invention, it is possible to prevent ash from adhering and accumulating on the inner wall of the reducer of the spouted bed coal gasifier, and to prevent the ash already adhering and accumulating without blocking a narrow portion such as a slag tap. Can be removed.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing a gasification furnace according to one embodiment of the present invention.

FIG. 2 is an enlarged view showing a lower part of a reducer in FIG. 1;

FIG. 3 is a horizontal sectional view taken along the line III-III of FIG. 2;

FIG. 4 is a vertical sectional side view showing an example of a conventional spouted bed coal gasifier.

FIG. 5 is a horizontal sectional view taken along line VV of FIG. 4;

FIG. 6 is a view showing a situation where ash adheres and accumulates on the inner surface of the reducer.

[Explanation of symbols]

 (01) Combustor (02) Reductor diffuser section (03) Reductor (04) Water pipe (05) Slag tap (06) Pressure wall (07) Pulverized coal burner for combustor (08) Recycler burner (09) Pulverized coal for combustor Transport pipe (10) Recycle char transport pipe (11) Combustion air pneumatic pipe (12) Combustor pulverized coal (13) Recycle char (14) Combustion air (15) Reductor pulverized coal burner (16) Reductor pulverized coal Conveying pipe (17) Pulverized coal for reducer (18) Crude coal gas (19) Refractory material (20) Slag hopper (21) Fin for water pipe (22) Molten slag (23) Adhered ash (101) Partition wall (102) Slugging prevention Gas supply pipe (103) Vent valve (104) Slagging prevention gas outlet (105) Slagging prevention gas (106) Successful prevention partition plate (107) Slugging prevent gas chamber

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-267398 (JP, A) JP-A-2-45594 (JP, A) JP-A-59-59789 (JP, A) JP-A 61-267 238887 (JP, A) JP-A-2-83027 (JP, A) JP-A-6-228578 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C10J 3/46 C10J 3 / 54

Claims (2)

(57) [Claims] 1. A gasification furnace which blows pulverized coal together with a carrier gas into a combustor having a slag tap at a bottom to generate a high-temperature combustible gas, and constitutes an outer wall of a reducer disposed above the combustor. A plurality of gas chambers for preventing slugging are provided around the water pipe group wall, and the gas pipes for preventing slugging with ventilation valves are respectively connected to the gas chambers for preventing slugging, and the water pipe forming the water pipe group wall together with the water pipe. A spouted bed coal gasifier comprising a fin formed with a gas outlet for preventing slugging which communicates between the gas chamber for preventing slugging and the inside of the reducer. 2. The spouted bed coal gasifier according to claim 1, wherein a plurality of annular drop-off preventing partitions are provided vertically along the inner periphery of the outer wall of the reducer.