JPH1081886A - Char conveying equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide char conveying equipment which can feed finer char particles into an oven without stagnation while separating the char discharged from a coal gasifier and collected by a cyclone into finer and coarser particles by subjecting it to an air stream without resort to mechanical means. SOLUTION: This equipment has a swirling air stream container 57 which is provided at the center on the top thereof with a char inlet pipe 71 for introducing char 25 from a cyclone and in which a swirling stream around the gravitational axis is formed by a conveying gas 27, a char discharge pipe 41 drooping from the peripheral part at the bottom of the container 57, a char conveying duct 31 branching horizontally from the pipe 41 at its lower end and extending to a coal gasifier, and a coarse particle separation pipe 72 drooping from the bottom port of the pipe 41. The char 25 is continuously sucked into the center of the swirling stream in the container 57 and allowed to flow out through the pipe 41 by the conveying gas 27, and char particles coarser than a certain size corresponding to the speed of the gas flowing down in the pipe 72 are allowed to fall, while finer char particles 25' are continuously conveyed through the duct 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for separating chars recovered from a coal gasifier into fine particles and agglomerates (or coarse particles), and transferring the fine char to a coal gasifier. A char transfer device that returns a fine-grained char continuously into a furnace in a high-pressure atmosphere while removing lumps (or coarse particles) by a gas separation method without using any mechanical means. It relates to a transport device.

[0002]

2. Description of the Related Art Conventionally, as a means for quantitatively returning a char containing unburned carbon to a pressurized state, the char is discharged from a hopper by a mechanical means such as a rotary feeder or a screw feeder, dropped freely, and then conveyed. In many cases, a method in which gas is forcibly supplied into the furnace is adopted. In addition, as a method of removing foreign matter, lump and the like mixed in the char and stably transporting the char, a classifier (sieve) is installed in a hopper into which the char flows, and after removing the lump and the like with the classifier. ,
In general, fine char is supplied to a carrier, and supplied into the furnace by air flow using a carrier gas. FIG. 14 shows a typical example. Both a coal supply system from the coal crusher 1 to the eductor 6 via the plurality of hoppers and a char circulation system from the cyclone 20 to the char eductor 6 'via another plurality of hoppers are lock hopper systems, The powder solid transporter adopts a transport method using a combination of mechanical means and a transport gas (combination of feeder and eductor). In the coal supply system, from a crusher 1 that crushes coal into pulverized coal,
Atmospheric pressure hopper 2, which opens and closes sequentially, Atmospheric pressure-
The pulverized coal 3 is supplied to the coal supply hopper 5 through the pressurized hopper 4, and the pulverized coal 3 in the coal supply hopper 5 is taken out by the mechanical feeder 7 and is converted from the eductor 6 into an inert gas (N ₂ or CO ₂ ). Then, it is conveyed toward the coal gasifier 15.

Next, a char circulation system provided downstream of the coal gasifier 15 will be described in detail. As shown in FIG. 14, a cyclone 20, a cyclone hopper 21, a char recovery hopper 22, a char supply hopper 2
3, a classifier 36 for removing lump contained in the char introduced into the char supply hopper 23, and each hopper 21
And the hoppers 21 to 23 which connect the particles
Two switching valves 34 and 35 provided therebetween, a mechanical char feeder 26 for extracting and supplying the char in the char supply hopper 23, a char transport eductor 6 ′, and a weight of the char recovery hopper 22 and the char supply hopper 23. Load cells 24 and 24 'for measurement are provided. The cyclone 20, the cyclone hopper 21, the char recovery hopper 22, and the char supply hopper 23 are connected in this order, and the cyclone 20 is supplied with the product gas generated in the coal gasification furnace 15 and the char associated therewith.

[0004] After being separated into generated gas and char (or dust) 25 by the cyclone 20, the recovered char 25 first enters the char recovery hopper 22, and the recovered amount is determined by a load cell 24 ′ installed in the char recovery hopper 22. Figure out. When the char 25 is filled in the hopper 22, the switching valve 34 on the inlet side of the hopper 22 is closed, and the pressure of the char recovery hopper 22 is made equal to or slightly higher than the pressure of the char supply hopper 23 on the downstream side. Is opened to transfer to the char supply hopper 23.
At this time, the classifier 36 installed in the char supply hopper 23
To separate the lump 63 contained in the char 25 and collect it in the coarse particle collector 33. After filling the hopper 23,
After closing the valve 35 on the inlet side of the hopper 23 to make the pressure of the recovery hopper 22 on the upstream side the same as the pressure on the coal gasifier 15 side, the valve 34 on the inlet side of the recovery hopper 22 is opened to start a steady operation. Repeat this operation. Char supply hopper 2
A high-temperature char 25 is quantitatively discharged from the furnace 3 into the furnace 15 by using a char feeder 26, dropped freely, and then supplied to an eductor 6 ', and a carrier gas (inert gas or generating furnace gas) 27 And supplied into the coal gasification furnace 15 via the char burner 28. This is a dry solid transfer method using a lock hopper method, in which a plurality of hoppers in series are sequentially opened and closed with a pressure difference to transfer a char.

If this dry technique is employed for pressurization, the following problems occur. (1) In the method in which the char is discharged from the rehopper 23 by a mechanical means (a rotary feeder or the like) 26, the char is connected to the outlet of the hopper depending on the kind of the raw material, the particle diameter of the recovered char, the packing density, and the like to form a bridge, Often it is not emitted at the time of discharge. Therefore, as a preventive measure such as formation of a bridge, it is necessary to provide vibration to the vibrator, aeration for blowing air or gas, or to install a mechanical stirrer in the supply hopper, and it is necessary to add extra equipment.

(2) Since the pressure of the apparatus itself is high, gas leakage from the seal portion of the feeder occurs, and supply of char and the like is stopped. In particular, since the temperature of the char 25 scattered from the furnace 15 is as high as 700 ° C. to 900 ° C. in the char circulating system, the char circulating system is heated and maintained by a heater or the like so that the char does not condense. For this reason, it is difficult to supply the char as much as the temperature rises, and the sealing member is loosened due to the influence of heat or the like, and the occurrence of gas leakage is high.

(3) Since the lock hopper system is used, a minimum of three hoppers are required for collecting and supplying the char, and the operation procedure (from transfer from the recovery hopper to the supply hopper to the inside of the coal gasification furnace) Supply, etc.) becomes complicated, the operation takes time, and the number of devices attached to each hopper increases, resulting in high cost.

(4) The biggest problem of the char transfer system is how to stably transfer char and the like. As described above, the char itself is at a high temperature, and if a change in temperature occurs, granules due to condensation or lumps (particle diameter: 10 mm or more) due to scattering in the furnace are mixed into the char, and the lumps and the like become eductor 6 '. It accumulates and blocks at the outlet and inside the transfer pipe 32, and makes it difficult to transfer the char.

[0009] If the raw materials cannot be supplied stably according to the above (1) to (4), this may cause adverse effects on gasification efficiency and stable operation. Therefore, without using the mechanical means described above, even when supplying to a high-temperature raw material and a high-pressure container,
There is a demand for a transporter that can preferably transport while removing lump and the like continuously. Further, simplification of the char circulating system is desired according to (3).

Conventionally, as a means for stably transferring a powdered solid without using mechanical means such as a hopper and a rotary feeder, the following methods are representative. (A) Eductor type supply device. A method of extruding and transferring a powder solid by injecting a gas fluid at a high speed from a nozzle (Japanese Patent Application Laid-Open Nos. 51-24189 and 55-177)
No. 29). (B) A pressure feeder. A system in which compressed air is continuously fed to a riser at a large mixing ratio by using compressed air (Japanese Patent Laid-Open No. 46-24854). (C) A method for transporting a powdered solid by a high-speed swirling flow in a pipe (Japanese Patent Application Laid-Open No. Sho 60-31437). (D) For the purpose of simplifying the char supply system and reducing the equipment cost and operation cost, the cyclone connected to the upper part of the gasification furnace by a pipeline and the lower end of a straight pipe suspended from this cyclone are connected. A method in which a char collected by a cyclone is sucked by the injector and supplied to a gasification furnace through a transfer pipe (Japanese Patent Laid-Open No. 5-239474).

However, there has not been a transporter provided with a means for removing lump (or coarse particles) or the like by airflow separation in the char transporter itself.

[0012]

As a method for stably supplying a raw material by a dry supply method, in the above-mentioned method (a), when there is a pressure fluctuation at the inlet side and the outlet side of the eductor, the pressure in the pipe is reduced. There is a drawback that a pool phenomenon occurs and a continuous flow cannot be obtained. In addition, since the gas flow velocity may cause blockage due to deposition near the outlet, the structure of the gas outlet in the eductor is problematic.

When transporting a high-temperature char,
It is important to always discharge the char from the hopper side stably so as not to condense the char. However, it is conceivable that the discharge from the hopper stops due to the free fall due to the pressure fluctuation in the eductor. For this reason, it is common practice to make the pressure on the supply hopper side higher than the furnace side pressure or to combine with a mechanical means such as a rotary feeder to minimize the influence on the pressure fluctuation and to discharge the gas stably. It is a target. However, even in this method, in order to avoid a bridge or the like at the outlet of the hopper as described in the problem (1), it is often impossible to discharge unless measures such as a vibrator and aeration are taken.

In the continuous pressure feeding method (b), when the hopper side pressure and the gasification furnace side pressure upstream thereof fluctuate, the supply amount becomes unstable. In addition, since the supply amount is controlled by the pressure difference, the supply amount changes a lot even when the pressure fluctuates a little, so it is effective when the supply amount is largely changed, but it is difficult to adjust the fine adjustment. There is.

The method (c) using a high-speed swirling flow is suitable for conveying particles having a large particle size. However, particles having a particle size of 40 μm or less are conveyed only at the central portion and accumulate on the inner wall side of the pipe. There are drawbacks. In addition, since a swirling flow is formed in the transfer pipe, the transfer pipe has a double structure in which a gas blowout port is provided, so that the structure of the transfer pipe is complicated.

In the method (d), an injector is installed at the lower end of the cyclone, and the char is sucked by a high-speed jet and supplied to the gasification furnace. The structure of the injector itself (the positions of the ejection gas nozzle and the outlet of the transfer pipe and the dimensions such as the pipe diameter are important) is complicated. In addition, since the gas is discharged while moving in the straight pipe suspended in the cyclone, the char scatters after the cyclone depending on the amount of discharge, and the char supplied to the gasification furnace is reduced, reducing the gasification efficiency. I do. In addition, when a lump (or coarse particles) is contained in the char, the lump accumulates and blocks in the injector, and stable transport cannot be performed. In the case of load fluctuation, the char generation amount in the gasifier fluctuates and the char release amount fluctuates accordingly.Therefore, depending on the conditions, the char level in the straight pipe decreases, and the pressure on the cyclone side downstream of the furnace increases. There is a danger that the gas in the gasification furnace will flow back to the char transfer line returning the char to the furnace.

What can be said of the methods described in (a) to (d) is that, when foreign matter and lumps are mixed in the raw material, a means for removing the foreign matter and lump is not provided, and these foreign matters are not provided. If it exists, there is a drawback that it accumulates on a supply line or the like, closes, and cannot be stably transported.

An object of the present invention is to provide the above hopper, sieve,
Without using mechanical means such as a rotary feeder, the char discharged and recovered from the coal gasifier is gas-flow-conveyed and continuously separated into fine particles and aggregates (or coarse particles), and the fine-grain char is separated. To provide a char transfer device capable of supplying the coal to a coal gasifier.

[0019]

Means for Solving the Problems To achieve the above object, a first char transporter of the present invention introduces a char separated and recovered by a cyclone contained in a gas generated in a coal gasifier. An apparatus for separating fine particles and coarse particles of char and returning the fine particles to a coal gasifier, wherein a char inlet pipe disposed downstream of the cyclone and the char inlet pipe are provided at the center of the upper end; A cylindrical swirling airflow container that internally generates a swirling flow about the axis in the direction of gravity by a transfer gas that transfers the gas, and a char whose diameter falls down from the bottom of the swirling airflow container to a tapered shape. A discharge pipe, a char transfer pipe branched laterally at the tapered portion of the char discharge pipe and extending to the coal gasifier, a coarse separation pipe hanging down from an outlet at a lower end of the char discharge pipe, and discharging from the coarse separation pipe. Hopper for storing coarse particles Characterized by comprising and.

The swirling airflow container preferably has a plurality of nozzles attached tangentially to the inner peripheral wall of the container, and the nozzles blow out a char carrier gas to form a swirling airflow. The swirling airflow container is a cylindrical container horizontally provided on the upper plate and the bottom plate of the container, or the upper plate is inclined upward in the outer diameter direction and the bottom plate is inclined downward in the outer diameter direction. A modified container may be used. In this modified container, since the volume increases in the outer peripheral direction, the char riding on the swirling flow easily moves to the outer periphery.

FIG. 10 is a diagram showing a pressure distribution in the cylindrical swirling airflow container when a swirling airflow is formed by the carrier gas in the container. The pressure at the center of the vessel (also the center of the swirling flow) is low, and the pressure distribution near the inner peripheral wall is high. The swirling airflow container utilizes the fact that a negative pressure is generated at the central portion of the swirling flow and the pressure at the peripheral portion of the swirling flow increases, and the char inflow pipe is provided in a region corresponding to the central portion where the negative pressure is generated. The structure has a structure in which the char in the cyclone is forcibly sucked, and a char discharge pipe is provided in a region corresponding to the peripheral portion of the high-pressure swirling flow, so that the carrier gas carrying the char flows out.

FIG. 11 shows the flow rate of the carrier gas forming the swirling airflow in the swirling airflow container and the amount of the char discharged from the container.
FIG. 4 is a diagram showing a relationship between (weight) and a pressure of an inner peripheral wall portion of the container. As the flow rate (F) of the carrier gas increases, the outflow amount of the char increases, and the pressure on the inner peripheral wall of the container increases. Thus, by increasing or decreasing the flow rate of the transport gas,
It is possible to control the amount of char supplied to the coal gasifier. This result is a condition when the furnace-side pressure is fixed at P = 4 atg. When the furnace-side pressure changes, the char supply amount inevitably also changes.

Therefore, in order to supply the char stably, a pressure difference monitoring device for monitoring the difference between the furnace side pressure and the pressure in the swirling airflow vessel is installed, and the char is controlled by using the pressure difference as a guide. Can be supplied stably. Confirmation of the amount of char transfer at regular time is performed by monitoring the pressure inside the swirling airflow container, the differential pressure between the cyclone and the swirling airflow container, and the differential pressure between the swirling airflow container and the char transfer pipe to grasp the supply state. .
In order to maintain these differential pressures at predetermined values, the flow rate of the carrier gas supplied to the swirling airflow container is adjusted. By controlling the flow rate of the transfer gas, it is possible to perform a precise control for stably transferring the char.

Further, the char transfer device may be provided with an auxiliary pipe through which an inert gas flows in the course of the coarse particle separation tube in order to adjust the flow rate of the carrier gas in the coarse particle separation tube. By changing the flow rate of the carrier gas in the coarse particle separation tube, coarse particles having different sizes can be separated and removed. In other words, fine particles having a certain size or less can be returned to the coal gasifier. The relationship between the flow rate of the carrier gas and the size of the coarse char to be separated will be described later in the embodiments.

Furthermore, in the above-mentioned char transfer device, the pressure in the inner periphery of the swirling airflow vessel is higher than the pressure in the coal gasifier,
In addition, it is preferable to perform control for adjusting the flow rate of the carrier gas supplied to the swirling airflow container so that the difference between the two pressures becomes constant.
By this control, it is possible to stably supply the fine-grained char from the swirling airflow container to the coal gasifier.

In the above-mentioned char transfer device, it is preferable to provide a shut-off valve in the char inlet pipe. By closing this shutoff valve, it is possible to prevent a backflow generated from the gasification furnace through the char transfer pipe downstream of the char circulation system. When the coal gasifier is started up or is unsteady, the pressure on the furnace side may be higher than the pressure in the swirling airflow vessel, and a backflow from the gasifier side is conceivable. This shutoff valve is effective and can improve the reliability of the char transfer device.

In order to achieve the above object, the second char transport device of the present invention uses a cyclone-shaped swirl airflow container instead of the cylindrical swirl airflow container of the first char transport device. It was what was. In this case, a char transfer pipe branched laterally from the lower end of the swirling airflow container and extending to the coal gasifier is provided, and a coarse separation pipe is provided at the lower end of the container so as to hang down.

In order to adjust the flow rate of the carrier gas in the coarse-grain separation tube, the second char conveyance device is provided with an auxiliary tube for introducing an inert gas into the course of the coarse-grain separation tube.
The point of adjusting the flow rate of the carrier gas supplied to the swirling airflow container such that the pressure of the inner peripheral portion of the upper portion of the swirling airflow container is higher than the pressure in the coal gasifier, and the difference between the two pressures is constant.
The point that a shutoff valve is provided in the char inflow pipe is the same as that of the first char transport device.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
This will be described more specifically with reference to FIG. FIG. 1 is a schematic diagram of a coal gasification system using the char transfer device of the present invention. This coal gasification system consists of a coal supply system, a combustion furnace, and a char circulation system.

In the coal supply system, the pulverized coal 3 generated by the pulverizer 1 is supplied to a coal normal pressure hopper 2 and a coal normal pressure-pressure hopper 4.
Is stored in the raw material supply hopper 5 and sent into the eductor 6 by the feeder 7. The pulverized coal 3 is an inert gas (nitrogen gas or carbon dioxide (CO ₂ )) flowing into the eductor 6.
8 and distributed through a pulverized coal transportation line 9 to a distributor 10
After being conveyed to the reactor and branched into several tubes, the raw materials are supplied into the reaction section 16 of the gasification furnace 15 by the raw material burners 11. On the other hand, the oxidant (oxygen, air or steam) 14 supplied to the gasification reaction section 16 together with the pulverized coal 3, after adjusting the flow rate by the oxidant flow rate control valve 13, flows through the oxidant flow line 12, Through the burner 11, a contact reaction with the pulverized coal 3 is made at the tip of the burner 11. This coal supply system has the same configuration as that already described with reference to FIG.

A gasification reaction section 16 of a coal gasifier 15 constituting a combustion furnace divides the pulverized coal 3 into an upper part and a lower part by a distributor 10. 14 is reduced. On the other hand, in the lower zone 29, the supply amount of the oxidizing agent 14 is increased in order to melt the ash in the pulverized coal 3 and turn it into molten ash (or slag), and the temperature of the lower zone 29 is raised to 1600 ° C. or higher. A combustion reaction of C + O ₂ → CO ₂ is caused. Further, the slag 17 generated in the lower zone 29 is allowed to freely fall into the slag collection hopper 18 filled with water, and is rapidly cooled and solidified.
Discharge to the outside. On the other hand, since the generated gas generated in the gasification reaction section 16 contains char containing unburned carbon, the cyclone 20 (char circulation system) for collecting char, dust and the like installed in the gasification furnace outlet line 19 is used. Where the product gas and char are separated, and the char is recovered in cyclone 20.

The char circulating system includes a cyclone 20 for separating and collecting the char contained in the produced gas, a cyclone hopper 21 for accommodating the collected char, and a cyclone 21.
The char transfer device 39 with a coarse-grain separation function, which sucks the char 25 (see FIG. 3) from the air and separates the fine-grain char into the air flow while separating the fine-grain and coarse-grained air, and separates the char 25 with this char-conveying device 39 A char transfer pipe 31 for transferring the obtained fine-grained char to the furnace 15, a char burner 28 for burning the conveyed fine-grained char and supplying it to the gasification furnace 15, and a char separated by the char transfer device 39. It comprises a coarse particle collecting device 33 that collects 25 coarse particles and a coarse particle collecting hopper 43 that stores the collected coarse particles of the char 25.

The control system for controlling the char circulation system includes the gasification furnace 15, the char transfer device 39 and the char transfer pipe 3.
A data processing device 54 for calculating the appropriate value of the differential pressure based on each pressure in 1; an air amount for transfer to the char transfer device 39 according to the numerical value obtained by this device 54; A control device 55 for operating pressure and the like;
And a pressure difference monitoring device 46 for monitoring the pressure difference between the pressure on the side and the pressure in the char transfer device 39.

FIG. 2 is a diagram showing another coal gasification system having the same effect as that shown in FIG. This other coal gasification system is configured so that the cyclone hopper 21 is removed from the system shown in FIG. 1 and the char 25 flows directly from the cyclone 20 into the char transfer device 39. Other configurations are the same as those of the system shown in FIG.

Next, the details of the char transfer device 39 having the coarse particle separation function will be described. FIG. 3 is a cross-sectional view of a char transfer device with a coarse particle separation function of the present invention, and FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. The char transfer device 39 includes a cylindrical container (referred to as a swirling airflow container) 57 that forms a swirling airflow therein, a char inflow pipe 71 provided at the center of the upper surface of the container 57,
A heat-resistant shut-off valve 37 provided in the char inflow pipe 71, a plurality of nozzles 27 ′ attached tangentially to the inner peripheral wall of the cylindrical swirl container 57, and an outer peripheral portion at the bottom of the swirl container 57. Char discharge pipe 4 with drooping tip
1, a char transfer pipe 31 branched laterally from a lower portion of the char discharge pipe 41, a coarse-grain separation pipe 72 connected to the lower side of the char discharge pipe 41, and a middle part of the coarse-grain separation pipe 72b. And a gas pipe 44 ′ for micro-adjustment which feeds the gas 44. Here, four nozzles 27 'are provided. In addition, an inert gas or a generator gas is used as the carrier gas 27.

Next, the operation of the swirling airflow container 57 will be described. The carrier gas 27 is supplied at high speed from the nozzle 27 ′ into the cylindrical swirling airflow container 57, and a strong swirling airflow is formed in the container 57. Due to this swirling airflow, the pressure near the central axis in the container 57 decreases and the pressure near the inner peripheral wall increases. The char 25 is forcibly sucked from the cyclone hopper 21 as shown in FIG. 1 or from the cyclone 20 through the char inlet pipe 71 as shown in FIG. It swirls strongly on the swirling flow 56 of the working gas 27, and then flows downward through the char discharge pipe 41 at the bottom of the swirling chamber 57. As described above, since the char 25 is forcibly sucked, there is no adverse effect such as formation of a char bridge at the outlet of the hopper 23 described with reference to FIG. It is discharged from the part to the low pressure part at the outlet of the char discharge pipe 41. Char discharge pipe 4
The flow rate of the char flowing through the pipe 1 is reduced at the tapered portion where the diameter of the pipe is reduced.
As a result, the flow of the air flow is stopped, so that the fine particles tend to stay in the tapered portion. Since the char transfer pipe is provided there, fine-grained char flows into the char transfer pipe.

A lump (or foreign matter) 63 is mixed in the discharged char 25, and if the lump 63 is not continuously removed, the lump 63 accumulates in the char transfer pipe 31 and is blocked. Need to be continuously removed. Therefore, a cylindrical coarse-grained separation pipe 72 that hangs down following the outlet of the discharge pipe 41.
, And a gas pipe 44 ′ for minute amount adjustment is provided in the middle of the coarse particle separation pipe 72. A gas of the same type as the carrier gas is horizontally supplied from the micro-adjustment gas pipe 44 ′ as needed to supply a small amount of gas, and the speed of the gas flow flowing down the coarse particle separation pipe 72 is adjusted. By setting, coarse particles having a certain diameter or more can be dropped into the coarse particle separation tube 72. The carrier gas that has flowed into the coarse particle separation tube 72 returns to the coarse particle separation tube 72 after dropping the coarse particle char and flows into the furnace 15 via the char conveyance tube 31. Here, the speed of the gas flow at which coarse particles having a diameter equal to or more than a certain diameter flowing down in the coarse particle separation tube 72 can be dropped is referred to as “terminal speed”.

FIG. 12 shows the relationship between the particle diameter of the char and the terminal velocity. The terminal speed increases as the particle diameter to be separated and removed increases. It can be seen that the terminal speed should be set to 1.0 m / s in order to remove the lump 63 of 1.0 mm or more. Therefore, if the pressure of the gasification furnace, the inner diameter of the char transfer pipe 31 and the flow velocity in the char transfer pipe 31 are determined, the inner diameter of the coarse particle separation pipe 72 is determined. When the char particle size supplied to the gasification furnace side is set to 1.0 mm or less, the coarse particle separation tube 72
The internal gas flow rate may be set to 1.0 m / s, and the
Particles of m or more fall in the coarse particle separation tube 72. Whether the classification of the char particles is good or not is determined based on the differential pressure level by the differential pressure gauge 64 between the char transfer pipe 31 and the coarse particle recovery device 33. FIG. 13 shows the experimental results. The particle size distribution of the char 25 in the cyclone hopper 21 on the upstream side of the char transfer device 39 and the particle size of the char extracted from the coarse particle collecting device 41 on the downstream side of the char transfer device 39 are shown. The results are shown in comparison with the diameter distribution. 1.0 m in the char extracted from the coarse particle collector 41
100% of particles of m or more are collected and in the char in the cyclone hopper 21 (containing 10% of particles of 1.2 mm or more)
All lump is collected. On the other hand, particles having a diameter of 1.0 mm or less are conveyed by a gas stream and flow into the char transfer pipe 31 branched laterally at the outlet of the discharge pipe 41 as coarse-grain removing char 25 ′. It can be continuously supplied to a furnace with high pressure stably.

Therefore, when it is desired to remove a lump having a certain particle size or more, the gas flow rate in the coarse particle introduction pipe 72 may be set based on the terminal speed. The char circulation system keeps the temperature around 250 ° C. so that the char does not condense.

Next, another char transfer device will be described. The char transfer device 39 with the coarse particle separation function shown in FIGS. 6 and 7 and the char transfer device 39 with the coarse particle separation function shown in FIGS. 8 and 9 have the same effects as those in FIG.

FIG. 6 shows a char transfer device 3 with a coarse particle separation function.
9 shows a swirling airflow container 57 'in a cyclone system. FIG. 7 is a view taken in the direction of arrows VII-VII in FIG. This swirling airflow container 57 'is a conical shape having a cylindrical upper portion and a lower portion tapering downward, and is provided with a char transfer pipe 31 branching laterally from the lower portion, and at a lower outlet of the swirling airflow container 57'. The coarse-grain separation tube 72 is provided in a hanging manner. The char inlet pipe 71 is located at the upper center of the swirling airflow container 57 '.
A plurality of nozzles 27 ′ for injecting the carrier gas 27 are provided tangentially to the peripheral wall of the container 57 so as to form a swirling flow in the swirling airflow container 57 ′.
, The carrier gas 27 is ejected at a high speed. The char 25 is sucked from the char inflow pipe 71 by the carrier gas 27, and the mixed phase flow of the carrier gas 27 and the char 25 moves downward and is supplied to the coarse particle separation pipe 72 installed below the swirling airflow vessel 57 ′. . By appropriately setting the gas velocity in the coarse particle separation tube 72 to the terminal speed, the lump 63 having a certain size or more in the char 25 is dropped and removed into the coarse particle separation tube,
Then, the fine particles in the char 25 are supplied from the char transfer pipe 31 into the gasification furnace 15.

FIG. 8 shows a char transfer device 39 with a coarse separation tube.
Of the swirling airflow container 57 ″ of FIG. 8 is a substantially cylindrical container having a cylindrical shape that expands outward as the height increases in the outer diameter direction. FIG. 9 is a view taken in the direction of arrows IX-IX in FIG. .
In this char transfer device 39, the char inflow pipe 71 is located at the upper central portion of the swirl container 57 ". The carrier gas nozzle 27 'is configured to form a swirl flow in the swirl container 57". A plurality of tubes are installed tangentially to the peripheral wall, and the carrier gas 27 is ejected at high speed from the carrier gas ejection holes 73. When the char 25 is sucked from the char inflow pipe 71 by the swirling flow of the carrier gas 27, the char 25 Is formed along the flow of the swirling flow 56 of the swirling chamber 57, and at the same time, the cross-sectional area of the swirling airflow container 57 "is expanded from the center to the peripheral wall side, so that the char 25 is forcibly moved to the peripheral wall side, The char 25 flows out of the discharge pipe 41 provided on the periphery of the bottom of the 57 ".
It is supplied to the lower coarse particle separation tube 72, and the lumps 63 in the char 25 are removed by the gas velocity in the tube 72, and the remaining fine particle char 25 is supplied into the gasification furnace 15 from the char transfer tube 31. .

Next, a method of operating the char transfer device 39 having a coarse particle separation function of the present invention will be described with reference to FIG. When the gasification furnace 15 is started up, a swirling airflow vessel 57,
A predetermined amount of carrier gas (inert gas and generating furnace gas) 27 is circulated to the gasification furnace 15 through the char discharge pipe 41 and the char transfer pipe 31 to confirm that the char transfer pipe 31 is not closed. This is a differential pressure gauge 49 for detecting a difference between the pressure in the peripheral portion in the swirling airflow container 57 and the pressure in the char transfer pipe 31.
Check at the differential pressure level. When the pulverized coal 3 as the raw material is supplied from the coal supply system, the char 25 containing unburned carbon is generated together with the generated gas in the gasifier 15, and the char 25 is collected by the cyclone 20. This char 2
5 is forcibly sucked from the cyclone 20 into the swirling airflow vessel 57 by the swirling flow of the carrier gas (inert gas and generating furnace gas), and is discharged through the char discharge pipe 41. While removing the lump (or coarse particles) 63 in the char 25 by the
Is supplied through the char transfer pipe 31 into the reaction section 16 of the gasification furnace having a high pressure. At this time, the peripheral pressure in the swirling airflow vessel 57 is monitored by the vessel-side pressure detector 47 and slightly higher than the outlet pressure of the gasification furnace 15 detected by the furnace-side pressure detector 45. Further, when the pressure on the furnace 15 side becomes equal to the pressure on the peripheral part in the swirling airflow vessel 57 for some reason, a signal 51 for transmitting the equality is transmitted to the data processing device 54, and the data processing device 54 Is transmitted to the shut-off valve driving unit 38 via the control device 55 to operate the shut-off valve 37 provided in the char inflow pipe 71 in the closing direction so as to maintain the pressure difference in the swirling airflow container 57. The pressure in the section is increased to prevent the generated gas from flowing backward through the char transfer pipe 31 from the gasification furnace 15 side. The differential pressure gauge 4 installed between the cyclone hopper 21 and the swirling airflow vessel 57
8 and the differential pressure level of the differential pressure gauge 49 installed between the swirling airflow container 57 and the char transfer pipe 31 is monitored to check whether the supply is stable.

Next, the operation of collecting coarse particles will be described. Below the coarse particle separation tube 72, a coarse particle recovery unit 33 and a coarse particle recovery hopper 43 are sequentially installed.
A valve 40 is provided between the coarse particle collecting device 33 and the coarse particle collecting device 33, and a valve 42 is provided between the coarse particle collecting device 33 and the coarse particle collecting hopper 43. Further, a load cell 60 for measuring the weight is installed in the coarse particle collecting device 33, and a gas release valve 59 is provided above the coarse particle collecting device 33.

During steady operation, the valve 40 below the coarse particle separation pipe 72 is open, and the valve 42 below the coarse particle collector 33 is closed. When the measured value of the load cell 60 of the coarse particle collecting device 33 exceeds a certain set value, the load cell 6
From 0, a signal 67 is transmitted to the data processor 54 to notify that the coarse particle collector 33 is full.

In response to this, the data processing device 54 controls the valve 4 on the inlet side of the coarse particle collecting device 33 via the control device 55.
After transmitting 65 to 0 and closing this valve 40, it transmits 62 to the degassing valve 59 of the coarse particle recovery device 33 and operates this valve 59 to bring the pressure in the coarse particle recovery device 33 to normal pressure. . Next, the valve 42 on the outlet side of the coarse particle collecting device 33 is opened by the signal 61 from the control device 55, the lump 63 is dropped freely from the coarse particle collecting device 33, and collected in the coarse particle collecting hopper 43.

When the filling into the coarse particle collecting hopper 43 is completed, the coarse particle collecting device 3 is removed from the load cell 60 of the coarse particle collecting device 33.
If the inside of 3 is empty, it is transmitted 67 to the data processing device 54. In response to this, the data processing device 54 transmits a signal 61 via the control device 55 to close the valve 42 on the outlet side of the coarse particle collecting device 33, and further operates the pressure adjusting gas control valve 58 according to the signal 66, The tensioning gas is supplied into the coarse particle recovery device 33, and the pressure in the recovery device 33 is set to be the same as the pressure of the upstream transport device 39. After that, the valve 40 on the entrance side of the coarse particle collector 33 is opened by the signal 65, and the normal operation starts. The collection state of the lump 63 into the coarse particle collecting device 33 is determined by transmitting a signal 68 indicating the differential pressure level of the differential pressure gauge 64 between the char transfer pipe 31 and the coarse particle collecting device 33 to the data processing device 54 at all times. Monitor and confirm.

At the time of stop, the char 25 is supplied into the gasification furnace 15, and the differential pressure indicating level of the differential pressure gauge 48 between the cyclone hopper 21 and the char transporter 31 and the differential pressure gauge 49 between the char transporter 31 and the discharge pipe 41 are indicated. Circulates back to gas-only levels. The transfer gas 27 flows to the end for lowering the temperature in the furnace 15 and for replacing the gas.

If the pressure 45 on the gasification furnace 15 side changes, the variation in the supply amount becomes large and the supply itself becomes unstable. Therefore, the pressure 45 at the outlet of the gasification furnace 15 and the pressure around the periphery of the char transfer device 39 'are always constant. It is important to keep the pressure difference from the pressure 47 constant. Therefore, a pressure difference monitoring device 46 for monitoring the pressure difference between the pressure detected by the pressure detector 45 on the furnace 15 side and the pressure detected by the pressure detector 47 on the periphery of the conveyor 39.
When the pressure on the furnace 15 fluctuates, the monitoring device 46 sends 51 to the data processing device 54 to operate the carrier gas control valve 56 (see FIG. 1) to adjust the flow rate of the carrier gas 27. Thus, the pressure in the swirling airflow container 57 is adjusted, and the char 25 is supplied stably.

Although the embodiment applied to the spouted bed gasifier has been described above, the present invention is not limited to this and can be applied to any type of furnace.

[0051]

According to the present invention, a char carrier is provided with a swirling airflow vessel below a cyclone for collecting char contained in gas generated in a coal gasifier, and a carrier gas is provided in the vessel. To form a swirl flow, and to force the char from the cyclone into the low-pressure region at the center of the swirl flow, and to discharge the char from the high-pressure region around the swirl flow by carrying it on the carrier airflow. The char can be flowed into the container without stagnation in the char inflow pipe, the char can be sent out stably and continuously without clogging due to the accumulation of the char discharge pipe. A coarse-grained separation pipe is provided downstream of the swirling airflow vessel, and only the lump char is dropped at an appropriate gas flow rate in the coarse-grained separation pipe to continuously remove the lump char. It can be stably transported to the gasification furnace.

As described above, in the char transfer device of the present invention, the transfer of char and the removal of coarse particles are performed by airflow treatment without using mechanical means, so that the char is easily attached to a pipe or the like at a high temperature. Can be processed stably.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a coal gasification system provided with a char carrier of the present invention.

FIG. 2 is a schematic view of another coal gasification system provided with the char transfer device of the present invention.

FIG. 3 is a structural diagram of a char transfer device according to an embodiment of the present invention.

FIG. 4 is a sectional view taken along the line IV-IV of FIG. 3;

FIG. 5 is a diagram for explaining an operation method of the char transfer device of the present invention.

FIG. 6 is a structural view of a char transfer device according to another embodiment of the present invention.

FIG. 7 is a sectional view taken along the line VII-VII of FIG. 6;

FIG. 8 is a structural view of a char transfer device according to still another embodiment of the present invention.

FIG. 9 is a sectional view taken along line IX-IX of FIG. 8;

FIG. 10 is a diagram showing a pressure distribution in a carrier constituting the char carrier of the present invention.

FIG. 11 is a diagram showing the influence of a carrier pressure and a carrier gas flow rate on a char discharge amount.

FIG. 12 is a diagram illustrating a relationship between a particle diameter and a terminal velocity.

FIG. 13 is a diagram comparing the particle size distribution in the cyclone hopper and the coarse particle collector.

FIG. 14 is a diagram illustrating a coal gasification system including a conventional char transporter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pulverizer 2 Coal atmospheric pressure hopper 3 Pulverized coal 4 Coal atmospheric pressure-pressure hopper 5 Coal supply hopper 6 Eductor 7 Pulverized coal feeder 8 Inert gas (nitrogen gas, carbon dioxide) 9 Pulverized coal transportation line 10 Distributor 11 Raw material Burner 12 Oxidant supply line 13 Oxidant flow control valve 14 Oxidant 15 Gasifier 16 Gasification reactor 17 Molten ash (or slag) 18 Slag recovery hopper 19 Gasifier outlet line 20 Cyclone 21 Cyclone hopper 25 Char 25 ′ Coarse particle removal char 27 ′ Nozzle 27 Carrier gas (inert gas or generating furnace gas) 28 Char burner 31 Char carrier pipe 37 Heat-resistant shut-off valve 38 Shut-off valve drive unit 39 Char carrier device 40 Valve 41 Char discharge pipe 42 Valve 43 Coarse particle recovery hopper 44 Micro-adjustment gas 45 Gasifier side pressure detector 46 Pressure Differential monitoring device 47 Pressure detector on swirling air flow container side 48 Differential pressure gauge between cyclone and swirling air flow container 49 Differential pressure gauge between swirling air flow container and char transfer pipe 50, 51, 52, 53 Signal 54 Data processing device 55 Control device 56 Rotation Flow 57 Swirling airflow container 58 Gas pressure regulating valve 59 Gas release valve 60 Load cell 61 Signal 62 Signal 63 Lump (or coarse particle) 64 Differential pressure gauge 65, 66, 67, 68 between char transfer pipe and coarse particle collector , 69, 70 Signal 71 Char Inflow Pipe 72 Coarse Grain Separation Pipe 72 'Coarse Grain 73 Gas Outlet for Transport

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Atsushi Morihara 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Inside Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Yoshio Naganuma 7-1, Omikamachi, Hitachi City, Ibaraki Prefecture No. 1 Hitachi, Ltd. Hitachi Research Laboratory (72) Inventor Sadao Takahashi 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Inside Hitachi Research Laboratory Hitachi Research Laboratory (72) Inventor Eiji Kida Takaracho, Kure City, Hiroshima Prefecture 6-9 Babcock Hitachi Kure Factory

Claims (5)

[Claims] 1. A char transfer device for introducing a char discharged from a coal gasifier and recovered by a cyclone and returning the char to the coal gasifier, wherein a char inlet pipe disposed below the cyclone and an upper end of the char inlet pipe. A cylindrical swirling airflow container that is provided at the center and forms a swirling flow around the axis in the direction of gravity inside by the transfer gas for transferring the char, and a pipe diameter that hangs down from a peripheral portion of the bottom of the swirling airflow container and is downward. A char discharge pipe that contracts in a tapered shape, a char transfer pipe that branches laterally at a taper portion of the char discharge pipe and extends to a coal gasifier,
A char transfer device comprising: a coarse particle separation tube hanging down from an outlet of a lower end of the char discharge tube; and a coarse particle collector for collecting coarse particles discharged from the coarse particle separation tube. 2. The char transfer device according to claim 1, further comprising an auxiliary pipe through which an inert gas flows in the course of the coarse particle separation tube in order to adjust a flow rate of the carrier gas in the coarse particle separation tube. . 3. The flow rate of the carrier gas supplied to the swirling airflow container so that the pressure in the inner peripheral portion of the swirling airflow container is higher than the pressure in the coal gasifier. Char transfer device. 4. A char transfer device for introducing a char discharged from a coal gasifier and recovered by a cyclone and returning the char to the coal gasifier, wherein a char inlet pipe disposed below the cyclone and an upper end of the char inlet pipe are provided. A cyclone-shaped swirling airflow container which is provided at a central portion, has a cylindrical upper portion and a lower portion tapered downward, and forms a swirling flow around the axis in the direction of gravity by the char carrier gas at the upper portion; and a lower end portion of the swirling airflow container A char transfer pipe that branches laterally and extends to the coal gasifier,
A coarse-grained separation tube hanging from a lower end of the swirling airflow container,
And a coarse particle collecting device for collecting coarse particles discharged from the coarse particle separation tube. 5. The char transfer device according to claim 8, wherein an auxiliary pipe through which an inert gas flows is provided in the course of the coarse particle separation tube in order to adjust the flow rate of the carrier gas in the coarse particle separation tube.