JPH0238171Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is used in a fluidized bed boiler that supplies coal into a fluidized combustion chamber in which sand flows and burns it, heating water in a heat transfer tube to generate steam. This invention relates to a device for adjusting the height at which a desulfurizing agent for desulfurizing exhaust gas after combustion is drawn out of the machine.

[Conventional technology]

In recent years, fluidized bed boilers have been developed as boilers with high combustion efficiency and low waste gas pollution. This type of fluidized bed boiler is equipped with three chambers, a storage chamber, a combustion chamber, and a desulfurization chamber, which are separated from the bottom in order from the bottom of the boiler body. The sand stored in the combustion chamber is fluidized by blowing air, and the coal supplied to the combustion chamber is combusted while flowing together with the sand,
Steam is generated when water passing through the heat transfer tube of the combustion chamber is heated by the combustion gas.
Further, the combustion gas is desulfurized and exhausted in the desulfurization chamber, and unburned gas is captured and burned in the desulfurization chamber.

[Problem that the invention attempts to solve]

However, in conventional fluidized bed boilers, the extraction height of the desulfurizing agent in the desulfurization chamber is the same regardless of whether the sulfur content of the combustion gas is high or low, and the blower power is always maintained to match the maximum sulfur content. Because of this, not only is power often wasted, but also there is a problem that optimal desulfurization conditions cannot be obtained when considering pressure balance during operation.

[Means for solving problems]

In order to solve these problems, in the present invention, the desulfurizing agent extraction tube is supported in an inclined manner on the ground metal on the outer wall of the boiler body, with the inlet facing the upper layer of the desulfurizing agent, and this extraction tube is connected to the inlet. It was formed so that it could move forward and backward at will so that it could move diagonally up and down.

[Effect]

With this configuration, the desulfurization agent stacked in the desulfurization chamber overflows and is discharged from the extraction tube when the layer height becomes higher than the inlet of the extraction tube. By moving the extraction cylinder forward and backward, the inlet port moves obliquely up and down, and the height at which the desulfurizing agent is extracted is adjusted.

[Example] Figures 1 and 2 show an example of the desulfurizing agent extraction height adjusting device according to the present invention. FIG. 3 is a longitudinal cross-sectional view of the agent extraction height adjusting device.
In the figure, the main body 1 of the fluidized bed boiler is formed into a rectangular box shape surrounded on four sides by water-cooled walls 2 in which a plurality of water-cooled pipes (not shown) are buried. An air chamber 7, a storage chamber 8, a combustion chamber 9, and a desulfurization chamber 10 are separated from each other in order from the bottom by partition plates 4, 5, and 6 containing water-cooled pipes 3. Air pipes 11 and 12 connected to an unillustrated blower are inserted into the air chamber 7 and the storage chamber 8, respectively, and air is blown into the combustion chamber 9. A pneumatic coal supply pipe 13 connected to the hopper via a dryer and a crusher is inserted to supply coal. moreover,
A pneumatic limestone transport pipe 14 connected to a coal stone supply hopper (not shown) via a crusher is inserted into the desulfurization chamber 10, so that a predetermined amount of limestone 15 is always kept in the desulfurization chamber 10. It is supplied to be stored. 16 is a heat transfer pipe installed in a curved manner so as to reciprocate in a staggered manner within the combustion chamber 9, and an air supply pipe 17 connected to one end thereof is connected to a circulation pump, and is connected to the other end. The supplied supply pipe 18 is connected to steam-using equipment. In addition, in this embodiment, the air supply pipe 17 and the supply pipe 1
A bypass is provided midway to connect with 8, and serves as a transmission tube for a separately provided waste heat utilization boiler. A plurality of distributors 19 are provided on each of the partition plates 4, 5, and 6, and distribute the blown air uniformly and blow it up sequentially into the upper chambers.

Sand 20 as a fluid medium having a diameter of about 1.6 mm is stored in the storage chamber 8.
Also, the same sand 20 is stored in the combustion chamber 9 below the supplied coal. Reference numerals 21 and 22 indicate an upcomer and a downcomer for the sand 20, which are provided in communication with the storage chamber 8 and the combustion chamber 9, respectively.The sand 20 is transferred to both chambers 8, 9 manually or by level detection using a sensor. The combustion chamber 9
It is constructed so that the amount of sand 20 inside is kept constant at all times. On the other hand, an exhaust port 23 for discharging combustion gas is provided at the upper end of the desulfurization chamber 10, and is connected to the chimney via the exhaust heat utilization boiler via a duct.

Further, the desulfurization chamber 10 is provided with a desulfurization agent extraction device 24 equipped with a extraction height adjustment device. That is, an outer cylinder 27 connected to an ash storage tank (not shown) via a pipe body 26 is fixed to a bracket 25 fixed to the outer surface of the water-cooled wall 2 in an inclined manner. A bearing 28 fixed to the outer surface of the outer cylinder 2 has an extraction cylinder 29 that is slidably fitted into the outer cylinder 27 and inclined concentrically with the outer cylinder 27.
is supported via a gasket 30 so as to be freely movable diagonally up and down. Reference numeral 31 denotes a packing holder that prevents the packing 30 from coming off. The extraction tube 29 penetrates the water-cooled wall 2 and is inserted into the layer of limestone 15, and the limestone 15 that has been altered by desulfurization and collected in the upper layer overflows into the extraction tube 29.
The ash is configured to be discharged into the ash storage tank via the outer cylinder 27 and the pipe body 26. Furthermore, both cylinders 2
7 and 29, flanges 32 and 33 are welded to face each other, and the flanges 32 and 33 are connected by a telescopic bellows 34, and a plurality of bolts 35 and nuts are connected. 36, and by loosening the nut 36, the extraction cylinder 29 is connected to the fixed outer cylinder 27.
By advancing and retracting the extraction cylinder 29
The inlet 29a, which is the upper open end of the inlet 29a, is configured to move diagonally up and down to adjust the height at which the limestone 15 is extracted.

The operation of the fluidized bed boiler configured as above will be explained. After supplying coal to the upper layer of sand 21 stored in the combustion chamber 9 and sending air to the air chamber 7 and storage chamber 8, when the coal preheated with a burner etc. is ignited, the combustion air is supplied. Then, the coal burns, and this combustion is promoted by the sand 21 and the coal flowing with the air blown up from the distributor 19, resulting in efficient combustion. This combustion heats the water in the transfer tube 16 to generate steam, which is supplied to steam-using equipment. On the other hand, the combustion gas enters the desulfurization chamber 10 via the distributor 19, the sulfur content is removed, the gas becomes harmless, and it is discharged from the exhaust port 23, while unburned carbon is captured and combusted in the desulfurization chamber 10. do. Discharge port 23
When the combustion gas discharged from the chamber passes through a separately provided boiler, it heats up the steam heading from the supply pipe 18 to the vapor deposition equipment, and then is discharged from the chimney.

In addition, among the limestone 15 in the desulfurization chamber 10, the limestone 15 that has changed in quality due to desulfurization and has gathered in an upper layer so as to be higher than the inlet 29a overflows from the inlet 29a, and the extraction cylinder 29, the outer cylinder 27, and the pipe The ash is discharged through the body 26 to an ash storage tank or the like. When the sulfur content in coal is low,
When you want to obtain the optimal desulfurization conditions by considering the pressure balance during operation, etc., for example, when you want to lower the overflow height, tighten the nut 35 while the boiler is operating, and the extractor tube 29 will close to the flange 33 with a bellows. While compressing the outer cylinder 27
The height of the inlet 29a decreases, and the overflow height decreases. After adjusting in this way, the bed height of the limestone 15 will always be lower than the illustrated position. In addition, when it is desired to increase the extraction height, by loosening the nut 36, the extraction cylinder 29 moves to come out from the outer cylinder 27 by the elastic force of the bellows 34, and the inlet port 29a
position becomes higher. In addition, by providing the gasket 30, the combustion gas inside the main body 1 will not leak to the outside of the main body 1.

FIG. 3 is a longitudinal cross-sectional view showing another embodiment of the present invention corresponding to FIG. 2, and the same reference numerals as in FIG. 2 have the same configuration, so the explanation thereof will be omitted. . In the extraction device 24A shown in this embodiment, an inclined inner cylinder 37 flanged to the tube body 26 is fixedly supported on the water cooling wall 2 side via a bracket 25, and an outer cylinder is attached to the bearing 28. 38
is slidably supported via a gasket 30. The inner cylinder 37 and the outer cylinder 38 are slidably fitted together via a gasket 40 held down by a gasket holder 39, and eccentricity is restricted by a spacer 41. rib 4
Movement in the axial direction is restricted by fixing No. 2. With this configuration, when the split rib 42 is loosened and the outer cylinder 38 is moved back and forth on the inner cylinder 37, the height of the inlet 38a is adjusted. Note that by providing the gaskets 30 and 40, combustion gas does not leak out of the main body 1.

[Effect of idea]

As is clear from the above explanation, according to the present invention, in the desulfurization agent extraction height adjustment device for a fluidized bed boiler, the desulfurization agent extraction tube is placed in the ground on the outer wall side of the boiler body with the inlet facing the upper layer of the desulfurization agent. By supporting the metal in an inclined state and forming this extraction tube so that it can move forward and backward so that the inlet can move diagonally up and down, when the layer height of the desulfurizing agent is higher than the inlet, it will overflow and be discharged to the outside of the main body. At the same time, by loosening the fixing member of the extraction cylinder and moving the extraction cylinder diagonally forward and backward, the overflow position of the desulfurizing agent layer changes vertically, so the optimal desulfurization conditions for pressure balance etc. can always be obtained. In addition to improving the properties of the boiler, it can also be easily used in cases where the sulfur content is low and a desulfurizing agent with a high bed height is not required, and the amount of air blown is not wasted, resulting in savings in air blowing power. be able to.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the desulfurizing agent extraction height adjusting device in a fluidized bed boiler according to the present invention, FIG. 1 is a longitudinal cross-sectional view of the fluidized bed boiler in which this is implemented, and FIG. 2 is a FIG. 3 is a longitudinal sectional view of the desulfurizing agent extraction height adjusting device, and FIG. 3 is a longitudinal sectional view corresponding to FIG. 2 of another embodiment of the present invention. 1...Main body, 2...Water cooling wall, 15...Limestone,
24, 24A...Extraction device, 27...Outer cylinder,
28... Bearing, 29... Extracting tube, 29a, 3
8a... Inlet, 30... Packing, 31... Packing holder, 35... Bolt, 36... Nut,
37...Inner cylinder, 38...Outer cylinder, 42...Split rib.

Claims (1)

[Scope of utility model registration request] A cylindrical desulfurizing agent extraction tube is supported in an inclined manner on the ground metal on the outer wall side of the boiler body, with the inlet facing the upper layer of the desulfurizing agent, and
A desulfurizing agent extracting height adjusting device in a fluidized bed boiler, characterized in that the desulfurizing agent extracting cylinder is formed so as to be adjustable in advance and retreat so that the inlet port moves in accordance with the layer height of the desulfurizing agent.