JP2002088378A - Method for discharging treatment of slag in gasification of waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for carrying out discharging treatment of slag by which batch operations required to take out the slag produced in a high- temperature gasifying furnace to the outside of the system can be automated and safely and surely performed with a high efficiency in the method for gasifying organic wastes comprising primarily gasifying the organic wastes at a low-pressure gasifying furnace, secondarily gasifying the resultant gaseous material in a high-temperature gasifying furnace and recovering a useful gas and the slag. SOLUTION: This method for gasifying treatment of the wastes comprises a step of collecting the slag produced in a quenching chamber 6 under the high-temperature gasifying furnace in a downward slag lock hopper 11 against high-pressure water and a step of receiving the slag collected in the slag lock hopper 11 in a slag pot 25 and slowly discharging the slag together with water. A first series of operations to collect the slag in the slag lock hopper 11 and discharge the slag and a second series of operations to receive the slag in the slag pot 25 and discharge the slag are performed as a mutually independent series of operations, in interlocked manner and carried out in parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION Reflecting on the deterioration of the global environment due to the large consumption of fossil fuels, fuels other than fossil fuels,
That is, although the development of waste gasification technology is being promoted, the present invention relates to a slag discharge treatment method in waste gasification, and particularly to a high-temperature gasification furnace which gasifies in a low-temperature gasifier and accompanies the gas. Slag discharge processing for waste gasification by melting the ash introduced into the furnace at high temperature and cooling it in the quenching chamber below the high-temperature gasification furnace to reliably and efficiently extract the granulated slag outside the system About the method.

[0002]

[Prior art] Municipal waste, sewage sludge, waste plastic,
Organic waste typified by waste FRP, biomass waste, automobile waste, waste oil, etc. is gasified, and the useful components of the generated gas are converted to H ₂ (hydrogen) and CO (carbon monoxide) -based synthesis gas. A so-called chemical recycling method for recycling as a raw material for the chemical industry is proposed in, for example, JP-A-11-166185.

FIG. 3 is a flow chart showing a conventional example of a waste gasifier incorporating the above-mentioned chemical recycling. The prior art will be described with reference to FIG.

The organic waste a is supplied to a low-temperature gasification furnace 1 which is a fluidized-bed gasification furnace composed of a lower fluidized bed 3 and an upper freeboard section. Gas, tar, and char. On the other hand, among the metals contained in the waste, those having a melting point higher than the fluidized bed temperature are discharged from the bottom of the gasification furnace together with the fluidized medium as valuable metals in an unoxidized state.

The gas, tar, and unburned char that have come out of the top of the low-temperature gasification furnace 1 are supplied to the next-stage high-temperature gasification furnace 2 through the communication section. Here, secondary gasification is performed at a high temperature of 1200 to 1600 ° C. by blowing a primary gas, oxygen b as a gasifying agent, and, if necessary, steam c into the furnace.
A reaction chamber 4 lined with a refractory is formed in the upper half of the high temperature gasifier 2. Further, a quenching chamber 6 is provided below the high-temperature gasifier 2, and the reaction chamber 4 and the quenching chamber 6 communicate with each other through a throat section 5. Quenching chamber 6 at the lower part of the high temperature gasifier 2
Is supplied with water so that the water for gas quenching has an appropriate water level.

[0006] The secondary gas and the molten slag generated in the reaction chamber 4 pass through the throat section 5 and are blown into the water in the quenching chamber 6. The quenched gasified gas d is sent to a gas treatment process through a gas line from a gas outlet 8 provided above the water surface of the quenching chamber 6, and the molten slag is supplied by the water in the quenching chamber 6. Crushed into slag particles.

A slag lock hopper 11 is provided below the quenching chamber 6 below the high-temperature gasifier 2 and a slag sump 24 provided with an underwater conveyor 7 is provided below the slag lock hopper 11. The slag of the quenching chamber 6 is a quenching chamber. 6, was once collected by the slag lock hopper 11 together with the high-pressure hot water, and then dropped directly once at a time onto the lower slag sump 24, and the coarse slag e was recovered by the underwater conveyor 7.

[0008]

As described above, valuable metal is recovered from waste by the two-stage gasification method for waste,
Resource conversion can be achieved by converting to a synthesis gas mainly composed of H ₂ (hydrogen) or CO (carbon monoxide). However, the above-described slag discharge method has the following problems.

That is, in the conventional method, the slag and the high-pressure hot water from the high-temperature gasification furnace are simultaneously extracted to the lower slag-lock hopper at a time, so that the slag-lock hopper is exposed to a sudden high temperature, and Because hot water contains many corrosive components such as chlorine, the temperature of the slag discharge system repeatedly rises and falls every time slag is taken out of the system. There is a problem that the apparatus is easily caused, and the apparatus is expensive in terms of material due to corrosion.

For this reason, it is not preferable to store slag in the quenching chamber of the high-temperature gasifier and discharge the slag together with high-pressure hot water at one time. Instead, a method of gradually and continuously discharging only the slag from the cooling chamber is desired.

The underwater conveyor in the slag sump, in which slag is dropped from the slag lock hopper at one time,
Although it is in water, the pressure impact at the time of slag discharge is reduced, but there are many troubles and it is not preferable for maintenance and other means have been desired.

Further, in order to reduce the thermal shock and pressure shock caused by the discharge of the slag, and to reduce the load on the apparatus, it takes time to discharge the slag, and the operating efficiency of the entire apparatus is sacrificed. is there.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to perform primary gasification using a low-temperature gasifier and secondary gasification using a high-temperature gasifier to obtain high-temperature gasification. When cooling the molten slag generated in the furnace and extracting the granulated slag out of the system, reduce the load on the equipment due to the thermal shock and pressure impact accompanying the discharge of the slag, and efficiently and reliably remove the slag It is an object of the present invention to provide a slag discharge treatment method in waste gasification for discharging.

[0014]

In order to achieve the above-mentioned object, the present invention provides a method for treating slag in waste gasification, which comprises the following steps: first, an organic waste in a low-temperature gasification furnace using a fluidized bed; Is supplied to the primary gasification, the gaseous matter obtained in the low-temperature gasification furnace is introduced into a high-temperature gasification furnace, and secondary gasification is performed under a high temperature. A slag discharge treatment method for gasification of waste,
The slag in the quenching chamber was set down at the lower end of the slag discharge pipe by lowering the slag in the slag discharge pipe against pressurized water rising in the slag discharge pipe connected to the lower part of the quenching chamber provided at the lower part of the high temperature gasification furnace. Collecting the slag collected in the slag lock hopper into a slag pot communicated below the slag lock hopper, and collecting the slag received in the slag lock hopper below the slag lock hopper. A step of gradually discharging the slag received in the slag pot and a step of gradually discharging the slag in the quenching chamber to a slag rock hopper. A second series of operations including a step of discharging the slag to the slag vibration filter are performed in parallel with each other.

Second, the first series of operations includes a step of depressurizing the slag lock hopper, a step of purging a depressurization line connected to the slag lock hopper, and a step of discharging the slag lock hopper from the slag lock hopper to the slag pot. Slag dumping process,
The slag lock hopper includes a pressurizing step, a slag collecting step in the slag lock hopper, and a slag collecting step.The second series of operations includes a slag discharging step from the slag pot to the slag vibration filter, The process comprises a water supply step to the slag pot, a slag reception standby step in the slag pot, and a slag reception step in the slag pot, and the slag reception standby in the slag pot in the second series of operations. During the process, after starting the depressurizing step of the slag lock hopper of the first series of operations, and after the slag dumping step from the slag lock hopper to the slag pot of the first series of operations is completed And starting a slag discharging step from the slag pot to the slag vibration filter.

Third, the first series of operations is automatically controlled as a first sequence, the second series of operations is automatically controlled as a second sequence, and the two sequences are operated in conjunction with each other. It is something to do.

[0017]

DETAILED DESCRIPTION OF THE INVENTION Organic waste is supplied to a low-temperature gasifier using a fluidized bed according to the present invention to be primary gasified, and the gaseous substance obtained in the low-temperature gasifier is subjected to high-temperature gasification. In the slag discharge treatment method in waste gasification that recovers useful gas and slag by introducing into a furnace and secondary gasification at high temperature, the waste gasification method connects to the lower part of the quenching chamber provided at the lower part of the high temperature gasification furnace. The slag in the quenching chamber is lowered in the slag discharge pipe against the pressurized water rising in the slag discharge pipe and collected in a slag lock hopper installed at the lower end of the slag discharge pipe. The water does not fall down the slag discharge pipe, and only the slag is gradually discharged from the quenching chamber of the high-temperature gasification furnace, so that the thermal shock and the pressure shock to the slag lock hopper are reduced, and the slag can be reliably recovered.

Further, in the slag discharge treatment method for waste gasification according to the present invention, a slag pot and a slag vibration filter, which did not exist conventionally, are provided in order between the slag lock hopper and the slag sump installed therebelow. The slag collected in the slag lock hopper is temporarily received in the slag pot, and the slag received in the slag pot is gradually discharged to the slag vibration filter below the slag pot, thereby reducing the pressure impact on the slag vibration filter, Coarse-grain slag can be collected before the slag sump, and there is no need to use a troublesome underwater conveyor, and reliable slag discharge is possible.

Further, a first series of steps including a step of collecting slag in the quench chamber against a slag lock hopper below against pressurized water rising in a slag discharge pipe connected to a lower portion of the quench chamber of the high temperature gasifier. The operation and the second series of operations including the step of discharging the slag received in the slag pot to the slag vibration filter below the slag pot are linked and performed in parallel, so that the slag from the quenching chamber to the slag lock hopper is operated. The time for discharging slag and the time for discharging cooling slag from the slag pot to the slag vibration filter can be used effectively, and the collection of slag from the quenching chamber to the slag lock hopper is almost continuous with a slight interruption. Slag accumulates in the quenching chamber and does not block the quenching chamber discharge port, enabling steady and stable slag discharge. It made. Further, the above-mentioned effect of reducing the thermal shock and the pressure shock to the device and enabling the reliable slag discharge processing can be sufficiently exhibited, and the efficient slag discharge processing can be performed.

Hereinafter, a specific embodiment of a slag discharge treatment method in waste gasification according to the present invention will be described in detail with reference to the drawings.

The structure of the gasification treatment apparatus is the same as that of the conventional gasification treatment apparatus shown in FIG. 3, so that it is omitted here, and the slag discharge system below the high-temperature gasification furnace will be described in detail below. I do. FIG. 1 is a flow chart of a slag discharge system of a gasification treatment apparatus according to one embodiment of a slag discharge treatment method in waste gasification of the present invention.

A quenching chamber 6 is provided below the high-temperature gasifier 2, and a reaction chamber (not shown) and the quenching chamber 6 are connected to a throat section 5.
In communication. Water is supplied to the quenching chamber 6 at the lower part of the high temperature gasification furnace 2 so that the water for gas quenching has an appropriate water level. The molten slag generated in the high temperature gasifier 2
The slag particles are granulated by the water in the quenching chamber 6 and discharged from below the quenching chamber 6 by the discharge treatment method of the present invention.

In the slag discharge system of the gasification treatment apparatus to which the slag discharge treatment method of the present invention is applied, a slag pot 25 and a slag vibration filter 23 which have not existed between the slag lock hopper 11 and the slag sump 24 are conventionally provided. Is provided. That is, a quenching chamber 6 is formed below the high-temperature gasifier 2, and a slag lock hopper 11, a slag pot 25, a slag vibration filter 23, and a slag sump 24 are provided below the quenching chamber 6.
Are installed in order. The quenching chamber 6 and the slag lock hopper 11 are connected by a slag discharge pipe 10 having a slag inlet valve 13, and the slag lock hopper 11 and the slag pot 25 are connected via a slag outlet valve 14. Further, below the slag pot 25, a slag discharge valve 21 capable of adjusting the opening degree of the valve is connected, and the slag in the slag pot 25 gradually falls to the lower slag vibration filter 23. In addition, the slag discharge pipe 10 is supplied with high-pressure circulating water GW1 for forming an ascending flow in the slag discharge pipe 10 as pressurized water through a pressurizing valve 18, and is supplied between the slag lock hopper 11 and the slag pot 25. Nitrogen is allowed to flow through the piping to prevent air from entering the system.

Further, a water supply drum 12 to which the low-pressure circulating water GW2 is supplied is connected to the slag lock hopper 11 via a flash valve 15, and after the slag is collected, the pressure inside the slag lock hopper 11 is changed to the atmospheric pressure. The depressurization line 19 is connected to the slag lock hopper 11
6 is connected to the vent gas abatement tower. The low-pressure circulating water GW2 is supplied to the depressurizing line 19 through the purge valve 17 to clean the depressurizing line 19. Further, low-pressure circulating water GW2 is supplied to the slag pot 25 via the makeup water supply valve 22 in order to reduce the impact of slag reception.

Next, the slag discharge processing method of the present invention will be described with reference to FIG. The slag discharge treatment method of the present invention comprises the steps of: supplying an organic waste to a low-temperature gasification furnace using a fluidized bed to primary gasify; and converting the gaseous substance obtained in the low-temperature gasification furnace to a high-temperature gasification furnace. A slag discharge treatment method in waste gasification for recovering useful gas and slag by introducing the gas into a secondary gas at a high temperature and introducing the secondary gas at a high temperature, comprising a quenching chamber provided at a lower part of the high temperature gasifier 2 A slag lock hopper 11 installed at the lower end of the slag discharge pipe 10 by lowering the slag in the quenching chamber 6 in the slag discharge pipe 10 against the pressurized water rising in the slag discharge pipe 10 connected to the lower part of the slag discharge pipe 10.
To be collected. The slag cooled and crushed by water in the quenching chamber 6 is passed through a slag discharge pipe 10 to a slag lock hopper 11.
In order to prevent the high pressure hot water in the quenching chamber 6 from entering the slag lock hopper 11, the slag is supplied in advance from the water supply drum 12 to the slag lock hopper 11. The pressurized water of the low-temperature high-pressure circulating water GW1 rising at a low speed flows through the discharge pipe 10. The pressurized water of the high-pressure circulating water GW1 has a flow rate as low as not impeding the gravity drop of the slag particles, for example, 0.01 m
At a rate of 0.1 m / sec to 0.1 m / sec while flowing countercurrently with the slag, and enters the quenching chamber 6. Further, since the pressurized water of the low-temperature high-pressure circulating water GW1 flows into the slag discharge pipe 10, hot water does not enter the slag lock hopper 11. Thereby, the slag continuously descends from the quenching chamber 6 to the slag lock hopper 11 while being cooled.

Next, the slag collected in the slag lock hopper 11 in this manner is transferred to the lower slag pot 25.
Accept. When extracting the slag in the slag lock hopper 11 into the slag pot 25, the supply of the high-pressure circulating water GW1 is stopped, the communication with the high-temperature gasification furnace 2 is cut off, the pressure in the slag lock hopper 11 is reduced, and the pressure reduction line 19 is disconnected. After washing, the slag outlet valve 14 is opened to communicate the slag lock hopper 11 with the slag pot 25, and the slag is dropped into the slag pot 25 together with the water while washing the inside of the slag lock hopper 11 with the low-pressure circulating water GW2. A predetermined amount of low-pressure circulating water GW2 is supplied to the slag pot 25 in advance before the slag is discharged, in order to reduce the impact of slag discharge to the slag pot 25.

After the slag is discharged from the slag lock hopper 11 to the slag pot 25, the slag outlet valve 14 is closed to cut off the communication between the slag lock hopper 11 and the slag pot 25, and the water supply drum 12 to the slag lock hopper 11
The slag lock hopper 11 is pressurized by supplying the low-pressure circulating water GW2 and the pressurized water of the high-pressure circulating water GW1, and the slag collection from the quenching chamber 6 is started again. As a result, slag collection from the quenching chamber 6 can be performed almost continuously with only a slight interruption, and slag can be reliably collected.

Next, the slag received in the slag pot 25 is mixed with the slag pot 25 and the slag lock hopper 11.
After the slag outlet valve 14 is closed, the slag discharge valve 21 below the slag pot 25 is gradually opened to gradually discharge the slag to the slag vibration filter 23. This slag pot 2
By gradually discharging the slag from 5 to the slag vibration filter 23, the impact on the slag vibration filter 23 can be suppressed. The coarse slag is collected on the sieve of the slag vibration filter 23, and the slag under the sieve (slurry water containing fine slag) falls to the slag sump 24.

After the slag in the slag pot 25 is discharged to the slag vibration filter 23, the slag discharge valve 21 below the slag pot 25 is closed, the low-pressure circulating water GW2 is supplied to the slag pot 25, and the water level in the slag pot 25 is adjusted. Recover,
The inside of the slag pot 25 is always sealed with water.
Thus, the next slag is to be discharged from the slag lock hopper 11.

The discharge pipe between the slag lock hopper 11 and the slag pot 25 is always supplied with nitrogen gas (N ₂ ). This is to prevent the inside of the slag lock hopper 11 from becoming a negative pressure due to the opening and closing of the plurality of valves, and to prevent the invasion of air, thereby preventing the corrosion of the device due to dissolved oxygen.

In the present invention, the quenching chamber 6 described above is used.
A first series of operations including a step of collecting slag in the slag lock hopper 11 and a second series of operations including a step of discharging the slag received in the slag pot 25 to the lower slag vibration filter 23 Are linked and performed in parallel. As a result, the slag discharging time from the quenching chamber 6 to the slag lock hopper 11 and the slag discharging time from the slag pot 25 to the slag vibration filter 23 can be effectively used, and can be made longer. The slag can be collected almost continuously into the slag lock hopper 11 with only slight interruption. Thereby, the slag accumulates in the quenching chamber 6 and the discharge port of the quenching chamber 6 is not blocked, so that the slag can be constantly and stably discharged. At the same time, a slag pot 25
The discharge of the slag from the slag to the slag vibration filter 23 can also be gradually performed over time.

As described above, according to the slag discharge processing method of the present invention as described above, slag collection from the quenching chamber 6 to the slag lock hopper 11 is performed almost continuously with a slight interruption. The slag accumulates in the quenching chamber 6 and the discharge port of the quenching chamber 6 is not blocked, and a steady and stable slag discharge is possible, and the slag is gradually discharged while cooling only the slag. It is possible to discharge slag reliably with less thermal shock and pressure shock. Further, since the high-pressure hot water does not enter the slag lock hopper 11, the toxic gas in the high-pressure hot water does not flash out when the slag lock hopper 11 is depressurized. Further, regarding the discharge of the slag from the slag pot 25 to the slag vibration filter 23, the time for collecting the slag from the quenching chamber 6 to the slag lock hopper 11 is effectively used,
It is possible to gradually discharge the slag to the slag vibration filter 23 over time.
3 can reduce the thermal shock and the pressure shock, and there is no need to use an underwater conveyor having many troubles as in the related art.

In the first series of operations of the present invention, the quenching is performed against pressurized water rising in a slag discharge pipe 10 connected to a lower part of a quenching chamber 6 provided in a lower part of the high temperature gasifier 2. The method includes a step of lowering the slag in the chamber 6 through the slag discharge pipe 10 and collecting the slag in a slag lock hopper 11 installed at the lower end of the slag discharge pipe 10. The first series of operations and the second series of operations may be performed as long as the method includes a step of gradually discharging the slag received in the slag pot 25 below the slag pot 25. In the following manner, more reliable and efficient slag discharge processing becomes possible.

A first series of operations including a step of collecting slag from the quenching chamber 6 to the slag lock hopper 11 and the slag received in the slag pot 25 are subjected to a slag vibration filter 2 below.
FIG. 1 shows a second series of operations including the step of discharging to FIG.
This will be described with reference to FIG. FIG. 2 is a time chart showing the operation of the slag discharge processing method according to one embodiment of the present invention.

The first series of operations including the step of collecting slag from the quenching chamber 6 to the slag lock hopper 11 includes a step of depressurizing the slag lock hopper 11 and a depressurizing line 19 connected to the slag lock hopper 11. , A step of dumping slag from the slag lock hopper 11 to the slag pot 25, a step of pressurizing the slag lock hopper 11, and a step of collecting slag in the slag lock hopper 11.

The specific operation of each step is as follows. (1) Depressurizing step (S11): This step is performed in a state where all of the slag inlet valve 13, the slag outlet valve 14, the flush valve 15, the depressurizing valve 16, the depressurizing line purge valve 17, and the pressurizing valve 18 are closed. A series of fixed sequence operations including opening the depressurizing valve 16 allows the slag lock hopper 1
This is a step of depressurizing 1 and reducing the pressure until it completely becomes equal to the atmospheric pressure.

(2) Depressurizing line purging step (S12):
In this step, following the depressurizing step (S11), the slag inlet valve 13, the slag outlet valve 14, the flush valve 15, the depressurizing line purge valve 17, and the pressurizing valve 18
This is a step in which the pressure release line purge of the slag lock hopper 11 is performed by opening the pressure release line purge valve 17 from the state where the pressure is closed and the pressure release valve 16 is open. The purpose of purging the depressurization line 19 is to remove slag from the slag lock hopper 11 with the low-pressure circulating water GW2 since slag may be accumulated in the depressurization line 19. The depressurizing step and the depressurizing line purging step are completed within a short time within 2 to 3 minutes after the end of slag collection, and immediately after that, the next slag dumping step is started.

(3) Slag dumping step (S13): In this step, following the depressurizing line purging step (S12), the slag inlet valve 13, the slag outlet valve 1
4. When the flush valve 15 and the pressurizing valve 18 are closed and the depressurizing valve 16 and the depressurizing line purge valve 17 are opened, the depressurizing valve 16 and the depressurizing line purge valve 1
7, the flush valve 15, the slag outlet valve 14, and the depressurization line purge valve 17 are sequentially opened to discharge the slag. After the slag is discharged, the slag outlet valve 14, the depressurization line purge valve 17, and the flush valve 15 are discharged.
This is a step of discharging the slag collected in the slag lock hopper 11 by a series of fixed order operations including closing the slag.

(4) Pressurizing step (S14): This step
Slag inlet valve 13, slag outlet valve 14,
Flash valve 15, depressurizing valve 16, depressurizing line purge valve 1
7 and the pressure valve 18 are all closed,
Is a step of pressing the slag lock hopper 11 by a series of fixed sequence operations including pressing the slag lock hopper 11 to a predetermined pressure and then closing the slag lock hopper 11. The slag lock hopper 11 is pressurized by making the pressure in the portion above the slag inlet valve 13 and the pressure in the portion below the slag inlet valve 13 in the slag discharge pipe 10 substantially the same. This is to prevent a shock when the inlet valve 13 is opened. Pressurization is performed by a pump (not shown) provided near the pressurizing valve 18.
This is performed by pressurizing the inside of the slag lock hopper 11 with the discharge pressure. When the pressure below the slag inlet valve 13 becomes slightly higher than the pressure above the slag inlet valve 13, pressurization is temporarily stopped.

(5) Slag collecting step (S15): In this step, the slag inlet valve 13, slag outlet valve 14, flush valve 15, depressurizing valve 16, depressurizing line purge valve 17 and pressurizing valve 18 are all closed. From the state, the slag inlet valve 13 is opened, the pressurizing valve 18 is opened, supply of pressurized water of the high-pressure circulating water GW1 is started, and slag is collected for a predetermined time (for example, 25 minutes). This is a step of collecting slag from the quenching chamber 6 to the slag lock hopper 11 by confirming that the slag is present, and performing a series of fixed sequence operations including closing the pressurizing valve 18 and the slag inlet valve 13. In this slag collecting method, the slag of the quenching chamber 6 is connected to a slag discharge pipe 1 connected to a lower portion of the quenching chamber 6.
Because the slag in the cooling chamber 6 is collected in the lower slag lock hopper 11 against the pressurized water rising in the inside 0, and the slag collection is performed continuously over time. Then, only the slag is gradually discharged without the high-pressure hot water descending from the quenching chamber 6, so that the thermal shock and the pressure shock to the slag lock hopper 11 are reduced, and the slag can be reliably collected. Further, since the high-pressure hot water does not enter the slag lock hopper 11, the toxic gas in the high-pressure hot water does not flash out when the slag lock hopper 11 is depressurized.

The above is the configuration example of the first series of operations. On the other hand, the second series of operations including the step of discharging the slag received in the slag pot 25 to the lower slag vibration filter 23 is a slag The process includes a slag discharge process from the pot 25 to the slag vibration filter 23, a water supply process to the slag pot 25, a slag reception standby process in the slag pot 25, and a slag reception process in the slag pot 25.

The specific operation of each step is as follows. (6) Slag discharging step (S21): This step includes a makeup water supply valve 22 provided in a flow path for introducing the low-pressure circulating water GW2 into the slag pot 25, and slag collected in the slag pot 25. To the lower slag vibration filter 2
Slag discharge valve 21 provided in the pipe for discharging to 3
After the slag discharge valve 21 is gradually opened from the closed state and the slag is discharged for a predetermined time, the slag collected in the slag pot 25 is subjected to a series of fixed sequence operations including closing the slag discharge valve 21. This is the process of dropping it up. By gradually discharging the slag, thermal shock and pressure shock to the slag vibration filter 23 can be reduced,
There is no need to use a troublesome underwater conveyor as in the past.

(7) Water supply step (S22):
After a predetermined time has passed with the slag discharge valve 21 and the makeup water supply valve 22 closed, the makeup water supply valve 2
2 is a step of supplying the low-pressure circulating water GW2 into the slag pot 25 by a series of fixed sequence operations including closing the makeup water supply valve 22 when a predetermined amount of water is supplied to the slag pot 25.

(8) Stand-by step (S23): This step comprises:
In this step, the slag discharge valve 21 and the make-up water supply valve 22 are closed, and the process waits until conditions for slag reception are satisfied.

(9) Slag receiving step (S24): This step is performed by the slag discharge valve 21 and the makeup water supply valve 2.
In this step, the slag is received from the slag lock hopper 11 into the slag pot 25 while the slag 2 is closed. In addition, in order to prevent the inside of the slag lock hopper 11 from becoming a negative pressure and invading air when performing the mass transfer from the slag lock hopper 11 to the slag pot 25 by opening and closing the valve, as shown in FIG. Slag pot 2
Nitrogen gas is always flowing through the pipe between the five. This prevents a negative pressure from being generated due to the movement of water, thereby preventing intrusion of air and preventing the apparatus from being corroded by dissolved oxygen.

As one embodiment of the slag discharge processing method of the present invention, the slag lock hopper 11 of the first series of operations is depressurized in the slag receiving standby step of the slag pot 25 of the second series of operations. Starting the process, and
After the process of receiving the slag collected by the slag lock hopper 11 in the series of operations in the lower slag pot 25 is completed, the slag vibration filter 23 is removed from the slag pot 25.
By starting the discharge of the slag, the slag transfer and the slag discharge processing operation between the first series of operations and the second series of operations can be rationally linked with each other, and The slag discharge processing can be made more efficient and reliable.

The slag discharge treatment method of the present invention is characterized in that:
Can be automatically controlled in a first sequence, the second series of operations can be automatically controlled in a second sequence, and the two sequences can be operated in conjunction with each other.
At this time, efficient automation can be achieved by using the flag to link the two independent sequences.
For example, if the slag pot 25 in the second series of operations is in the slag receiving standby step, a value indicating the slag pot 25 is set in the flag, the flag is detected in the first sequence, and the slag pot 25 It should be possible to start preparing to do a slug dump to the slag. Conversely, when the slag dump from the slag lock hopper 11 to the slag pot 25 in the first series of operations is completed, a value indicating that fact is put in a flag, and the slag pot 25 in the second series of operations is set. Slag discharge to the slag vibration filter 23 therebelow can be started.

In this manner, the two sequences are linked well, and slag discharge processing in waste gasification with little waste can be performed. Further, when the discharge process is automated by using two independent sequence control methods as described above, for example, the slag pot 25 related to the second sequence and the valves, pipes, instruments, and the like connected thereto can be used. In the event that a failure occurs, the second sequence can be temporarily stopped and the failure can be eliminated. During that time, it is not necessary to stop the first sequence and slag can be collected continuously, Has the effect that stable operation can be performed. It should be noted that two different flags may be used as the above-mentioned flags, or that one flag may be used. Further, it is also possible to perform the processing in one sequence without using a flag. In this case, if any problem occurs in a part of the discharge system of the apparatus, the entire sequence must be stopped.

[0049]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the slag discharge processing method of the present invention is performed by sequence control will be described below with reference to FIGS.

In the present embodiment, a first series of operations including a step of collecting slag in the quenching chamber 6 into the slag lock hopper 11 is defined as a first sequence SEQ1, and a slag pot 25 is used.
A second series of operations including a step of discharging the slag received in the slag vibration filter 23 to the second sequence SE
Q2 is controlled by two independent sequences, and the linkage of the two sequences is controlled by two flags (flag A and flag B).
Perform using. The flag A indicates whether slag can be received in the slag pot 25, and the flag B indicates whether slag discharge (slag dump) from the slag lock hopper 11 has been completed. Flags A and B in FIG.
Black line indicates flag value = 1, white line indicates flag value = 2
, And the dotted lines of the flags A and B indicate the flag value = 0.
The thick line in the column of each valve in FIG. 2 indicates the open state of the valve, and the length of the thick line indicates the valve open time.

The features of the sequence control of this embodiment are as follows. 1) A series of operations from collecting the slag to the slag lock hopper 11 from the quenching chamber 6 and transferring the slag to the slag pot 25 are performed in the first sequence SEQ1. 2) This first sequence SEQ1 includes five steps, ie, depressurization (S11), depressurization line purge (S12), slag dump (S13), pressurization (S14), and slag collection (S1).
It is composed of step 5). 3) Continuous operation is possible by linking the slag pot 25 with the second sequence SEQ2. 4) A series of operations for dropping the slag received in the slag pot 25 to the slag vibration filter 23 and discharging the siege (slurry water containing fine slag) to the slag sump 24 are performed in the second sequence SEQ2. 5) The second sequence SEQ2 has four steps, namely, slag discharge (S21), water supply (S22), standby (S23),
It consists of a slag receiving (S24) process. 6) In the slag discharge operation, the opening degree of the slag discharge valve 21 is gradually performed in a maximum of five stages. 7) First sequence SEQ1 of slag lock hopper 11
Continuous operation is possible by linking with.

Since the first sequence SEQ1 and the second sequence SEQ2 can be started from either of them, a case where the operation is started from the second sequence SEQ2 will be described as an example.

The starting conditions of the second sequence SEQ2 are as follows: the slag outlet valve 14 is closed, the slag discharge valve 21 is closed,
Makeup water supply valve 22 is closed. Also, low-pressure nitrogen is supplied to the slag pot 25 and the slag sump 24 to purge the inside of the system with nitrogen. In this state, the sequence is started from the opening degree “1” of the slag discharge valve 21 in the slag discharge step of the slag pot 25 (see step S21).

In the operation of the second sequence SEQ2, the slag discharge valve 21 is advanced with the opening degree "1 to 5".
Further, each time the “opening degree 5” of the slag discharge valve 21 ends, one batch is added to a batch counter (not shown), and “batch number” is displayed.

After the slag is discharged from the slag pot 25, the slag discharge valve 21 is closed. At this time, the flag B is set to "1". After a predetermined time (e.g., 5 minutes) after this closing, the makeup water supply valve 22 is opened and water is supplied into the slag pot 25, and the water level in the slag pot 25 is recovered. afterwards,
After the water level reaches the predetermined height, makeup water supply valve 22 is closed (see step S22). At this time, the flag A is set to "1". As a result, the slag pot 25 enters a slag receiving standby state (see step S23). In the waiting state of the slag pot 25, as shown in FIG. 2, the slag dump operation of the first sequence SEQ1 is waited. That is, the first sequence SEQ1 goes to see the flags A and B. If both the flags are "1", the slag collecting operation of the slag lock hopper 11 is ended and the depressurization is started, and the slag pot 25 is started. In the standby state, the slag is received from the slag lock hopper 11 into the slag pot 25 (see step S24).

On the other hand, as preparation before the start of the first sequence SEQ1, the slag lock hopper 11 is purged with nitrogen.
After the nitrogen purge, the slag lock hopper 11 is filled with water using the liquid filling in the quenching chamber 6. Further, low pressure nitrogen is supplied to the water supply drum 12 to purge the inside of the water supply drum 12 with nitrogen. Next, water supply to the water supply drum 12 is started, and it is confirmed that water is supplied to the water supply drum 12.

The starting condition of the first sequence SEQ1 is that the slag inlet valve 13 of the slag lock hopper 11
Closed, slug outlet valve 14 closed, flush valve 1
5 is closed, the depressurizing valve 16 is closed, the depressurizing line purge valve 17 is closed, and the pressurizing valve 18 is closed.

First, the depressurizing valve 16 is opened to start the first sequence SEQ1 from the depressurizing step of the slag lock hopper 11 (see step S11). Thereafter, the pressure release line purge valve 17 is opened to purge the pressure release line (see step S12). Next, the depressurizing valve 16 and the depressurizing line purge valve 17 are closed, the flash valve 15, the slag outlet valve 14, and the depressurizing line purge valve 17 are opened, and the slag lock hopper 11 performs slag dumping (see step S13). The flag A is set to "2" when the slag outlet valve 14 is opened, and the flag B is set to "2" when the slag outlet valve 14 is closed after dumping the slag. As a result, when both the operating flags A and B are set to “2”, in the second sequence SEQ2, the process shifts from the process of receiving slag to the slag pot 25 to the process of discharging slag from the slag pot 25 to the slag vibration filter 23. (Step S24,
See S21).

In the first sequence SEQ1, after the slag dumping step of the slag lock hopper 11, all the open state of the sequence valves of the first sequence SEQ1 are closed, the pressurizing valve 18 is opened, and the slag lock hopper 11 is operated. (See step S14). In this pressurized state, the slag inlet valve 13 is opened, and slag is collected by the slag lock hopper 11 (see step S15). Even when the sequence SEQ1 is restarted, the operation is always performed from the depressurizing step of the slag lock hopper 11. The automatic stop operation of this sequence SEQ1 is such that the slag inlet valve 13 is closed, the slag outlet valve 14 is closed, and the flash valve 15
Is closed, the depressurizing valve 16 is closed, the depressurizing line purge valve 17 is closed,
The pressure valve 18 is closed.

In the automatic stop operation of the second sequence SEQ2, the slag discharge valve 21 is closed and the water supply valve 22 is closed.
Even when the sequence SEQ2 is restarted, the slag is always discharged from the slag pot 25 to the slag vibration filter 23 from the "opening degree 1" of the slag discharge valve 21.

In the method of this embodiment, a series of batch operations is divided into two independent systems, and each system is operated by two independent sequences SEQ1 and SEQ2. They wait on each other and operate in parallel. For this reason, in the batch operation formed in a series, slag collection cannot be performed and wasteful time increases until operations other than slag collection are completed. However, in the sequence control method of the present embodiment, two sequences are not performed. It is possible to make effective use of time and perform an automatic operation utilizing the effects of the present invention as it is.

Further, the sequence control method of this embodiment has an advantage that even if a trouble occurs in one sequence, it is not necessary to stop the other sequence. For example, when a malfunction occurs in a valve, a pipe, an instrument, or the like connected to the slag pot 25, the second sequence can be temporarily stopped to eliminate the malfunction, and the first sequence does not stop during that time. Slag collection can be continued, and stable operation can be performed against fluctuation factors.

[0063]

As described above, the slag in the quench chamber is removed from the slag discharge pipe against the pressurized water rising in the slag discharge pipe connected to the lower part of the quench chamber provided at the lower part of the high temperature gasifier. Lowering the slag and collecting the slag collected in the slag lock hopper into a slag pot communicated below the slag lock hopper; and Gradually discharging the slag received in the pot to a slag vibration filter installed below the slag pot, and further comprising a step of collecting the slag in the quenching chamber by the slag lock hopper. And a second series of operations including a step of discharging slag received in the slag pot to the slag vibration filter. By doing so in parallel, it becomes possible to collect slag from the quenching chamber to the slag lock hopper almost continuously with only a slight interruption, and slag accumulates in the quenching chamber. Steady and stable slag discharge is possible without blocking the discharge port of the quenching chamber, it is possible to gradually discharge slag while cooling only slag, little thermal shock and pressure shock, reliable Slag discharge becomes possible. Further, since the high-pressure hot water does not enter the slag lock hopper, no toxic gas in the high-pressure hot water flashes out when the slag lock hopper is depressurized. Further, regarding the discharge of the slag from the slag pot to the slag vibration filter, the time for collecting the slag from the quenching chamber to the slag lock hopper is effectively used to discharge the slag to the slag vibration filter. It is possible to do it gradually,
Thermal shock and pressure shock to the slag vibration filter can be reduced, and there is no need to use a troublesome underwater conveyor as in the related art.

The first series of operations includes a depressurizing step of the slag lock hopper, a purging step of a depressurizing line connected to the slag lock hopper, and a slag dumping step from the slag lock hopper to the slag pot. The slag lock hopper pressurizing step and the slag lock hopper collecting slag step. The second series of operations includes discharging slag from the slag pot to the slag vibration filter. A water supply step to the slag pot, a slag reception standby step of the slag pot, and a slag reception step of the slag pot. The slag reception standby step of the slag pot of the second series of operations. In the step, the depressurizing step of the slag lock hopper of the first series of operations is started, and the first series of operations is performed. After the receiving step of the slag collected in the slag lock hopper into the lower slag pot is completed, the slag is discharged from the slag pot to the slag vibration filter, so that the first series of operations and the first Delivery and operation of slag between the second series of operations and operations can be rationally linked, and the entire slag discharge process can be performed more efficiently and reliably.

Further, the first series of operations is controlled in a first sequence, the second series of operations is controlled in a second sequence, and the two sequences are operated in conjunction with each other, whereby: The two sequences work well together to automate the slag discharge process in waste gasification with little waste, and furthermore, the slag pot related to the second sequence and the valves, pipes, instruments, etc. connected to it When a temporary inconvenience occurs, the second sequence can be temporarily stopped to solve the problem. During that time, the first sequence does not need to be stopped, and stable operation can be performed even with respect to fluctuation factors. This has the effect.

[Brief description of the drawings]

FIG. 1 is a flow chart of a slag discharge system of a gasification treatment apparatus according to one embodiment of a slag discharge treatment method in waste gasification of the present invention.

FIG. 2 is a time chart showing the operation of the slag discharge processing method according to one embodiment of the present invention.

FIG. 3 is a flowchart of a waste gasification treatment apparatus showing a conventional slag discharge method.

[Explanation of symbols]

 1: low-temperature gasifier 2: high-temperature gasifier 3: fluidized bed 4: reaction chamber 5: throat section 6: quenching chamber 7: underwater conveyor 8: gas outlet 10: slag discharge pipe 11: slag lock hopper 12: water supply Drum 13: Slag inlet valve 14: Slag outlet valve 15: Flush valve 16: Depressurization valve 17: Depressurization line purge valve 18: Pressurization valve 21: Slag discharge valve 22: Makeup water supply valve 23: Slag vibration filter 24: Slag sump 25: Slag pot a: Organic waste b: Oxygen c: Steam d: Gasification gas e: Coarse slag

Claims (3)

[Claims] An organic waste is supplied to a low-temperature gasifier using a fluidized bed to primary gasify, and a gaseous substance obtained in the low-temperature gasifier is introduced into a high-temperature gasifier. A slag discharge treatment method in waste gasification for collecting useful gas and slag by secondary gasification at a high temperature, comprising a slag connected to a lower portion of a quenching chamber provided at a lower portion of the high temperature gasifier. A step of lowering the slag in the quenching chamber against the pressurized water rising in the discharge pipe and lowering the slag in the slag discharge pipe and collecting the slag in a slag lock hopper installed at the lower end of the slag discharge pipe; and collecting the slag in the slag lock hopper. Receiving the slag in a slag pot communicated below the slag lock hopper, and gradually discharging the slag received in the slag pot to a slag vibration filter installed below the slag pot. And a step of discharging the slag received in the slag pot to the slag vibration filter, including a first series of operations including a step of collecting slag in the quenching chamber into the slag lock hopper. A slag discharge treatment method in waste gasification, wherein a second series of operations are linked and performed in parallel. 2. The first series of operations includes a depressurizing step of the slag lock hopper, a purging step of a depressurizing line connected to the slag lock hopper, and a slag dumping step from the slag lock hopper to the slag pot. , The pressurizing step of the slag lock hopper, each step of slag collection step in the slag lock hopper, the second series of operations, a slag discharge step from the slag pot to the slag vibration filter, The slag pot comprises a water supply step to the slag pot, a slag reception standby step in the slag pot, and a slag reception step in the slag pot, and the slag reception in the slag pot in the second series of operations. During a standby step, a step of depressurizing the slag lock hopper of the first series of operations is started, and before the first series of operations. The slag discharge process from the slag pot to the slag vibration filter is started after the slag dump process from the slag lock hopper to the slag pot is completed. Processing method. 3. Automatically controlling the first series of operations as a first sequence, automatically controlling the second series of operations as a second sequence, and operating the two sequences in conjunction with each other. The slag discharge treatment method in waste gasification according to claim 2, characterized in that: