JPH06254329A - Ceramic filter - Google Patents

Abstract

PURPOSE:To prevent the damage due to thermal shock of a filter. CONSTITUTION:In a ceramic filter, a gas introducing chamber 3 connected to a gas introducing pipe 6 for high temperature gas to be treated contg. dust contg. an unburned portion is installed in the upper part of a vessel 1 and also a dust chamber 5 is installed below it, and a pass for making them communicate with each other is formed of ceramics to be a filter 9, and the gas to be treated from the gas introducing chamber 3 is passed through the filter 9 to remove dust from the gas. The gas introducing pipe 6 is provided with a venturi 8. The venturi 8 is connected to a suction pipe 14 evacuated by gas passing through the venturi 8 and also a suction port 15 of the suction pipe 14 is arranged in the dust chamber 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is installed in a coal gasification system, a coal-fired pressurized fluidized bed boiler combined cycle power generation system, or the like, and removes dust-containing high-temperature gas containing unburned components from the pressurized fluidized bed boiler or the like. The present invention relates to a ceramic filter for treating dust.

[0002]

2. Description of the Related Art Dust-containing high-temperature high-pressure gas containing unburned matter,
For example, it has been attempted to use a ceramic filter as a device for dedusting a dust-containing gas to be treated at about 900 ° C from a pressurized fluidized bed boiler.

As the ceramic filter, for example, a tubular porous ceramic filter is erected in a pressure vessel, and the gas to be treated introduced above the filter is lowered inside the filter, and at the same time, the gas to be treated is filtered. Through which the dust in the gas is collected by the filter. When the filter is regenerated, a high-pressure backwash gas (inert gas such as nitrogen) from the backwash nozzle of the backwash device.
Is injected from the direction opposite to the gas to be treated so as to pass through the filter, and this backwashing removes the dust collected and accumulated on the filter from the filter for regeneration. The removed dust is discharged from the discharge port at the bottom of the container.

[0004]

In the ceramic filter described above, the gas to be processed descends in the filter, and the gas to be processed gradually passes through the filter and is dedusted while it descends. The velocity component of the gas in the filter becomes smaller as it goes downward, and the velocity component of the gas in the lower part of the filter may become zero. When the velocity component becomes zero in this way, dust stays in the filter, and in the worst case, dust stays suspended like a cloud. When the concentration of the unburned component in the staying portion increases, the unburned component is likely to burn due to the high temperature gas, and the unburned component may be reburned as the atmospheric temperature rises. as a result,
Thermal shock may be applied to the filter, causing a temperature difference between the inner and outer surfaces of the filter and applying stress, which may damage the filter.

Therefore, the present invention has been made in consideration of such circumstances, and an object thereof is to provide a ceramic filter capable of preventing the filter from being damaged by thermal shock. To do.

[0006]

In order to achieve the above-mentioned object, the present invention provides a gas introduction chamber, to which a gas introduction pipe for a high temperature gas to be treated containing dust containing unburned matter is connected, in the upper part of a container. Along with the provision of a dust chamber underneath it, a passage that connects them is made of ceramic to form a filter,
In the ceramic filter for dedusting the gas by passing the gas to be treated from the gas introduction chamber through the filter,
A venturi is provided in the gas introduction pipe, a suction pipe sucked by gas passing through the venturi is connected to the venturi, and a suction port of the suction pipe is arranged in the dust chamber.

[0007]

[Function] By providing a venturi on the gas introduction pipe and arranging the suction port of the suction pipe sucked by the venturi in the dust chamber, the high temperature gas to be treated containing dust is introduced from the gas introduction pipe through the venturi to the gas introduction chamber. Is introduced into the suction chamber, part of the gas in the dust chamber is sucked into the suction pipe through the suction port,
Returned to the gas introduction chamber. By sucking a part of the gas in the dust chamber in this way, a downward flow is generated in the filter, so that dust is not suspended and retained in the filter. Therefore, re-combustion of unburned components is prevented, and damage to the filter due to thermal shock is prevented.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a pressure vessel, and this pressure vessel 1 has a vertical shape and is formed in a cylindrical shape with its upper part closed.

Tube plates 2 are provided above and below the pressure vessel 1, and the upper portion of the vessel 1 is in the gas introducing chamber 3.
The central part is partitioned into the dust collecting chamber 4, and the lower part is partitioned into the dust chamber 5. The upper side surface of the pressure vessel 1 contains dust-containing high temperature and high pressure gas containing unburned matter, for example, high temperature and high pressure (860 to 870 ° C., 4 to 16 Kgf / cm ² ) unburned matter from a pressurized fluidized bed boiler. A gas introduction pipe 6 for the gas to be treated is connected to the axis of the container 1 substantially at right angles. The tip of the introduction pipe 6 extends into the gas introduction chamber 3 from the center thereof (the axial center of the container), and the throat portion 7 is formed in the pipe 6 at the axial portion of the container 1 by the high temperature and abrasion resistant material. Is formed, and the tip of the introduction pipe 6 is formed as a venturi 8.

In the dust collecting chamber 4, a tubular porous ceramic filter 9 is disposed in the axial direction thereof, and the upper and lower ends of the filter 9 are attached to the tube sheets 2 and 2, respectively. Plays a role of a passage that connects the gas introduction chamber 3 and the dust chamber 5. As a result, the gas introduction chamber 3
The dust-containing treated gas introduced into the filter descends in the filter 9,
While descending there, the gas gradually passes through the filter 9 and the dust in the gas is collected by the filter 9 to perform the dedusting process of the gas.

The filter 9 is composed of upper, middle, and lower three-stage filters, a tube plate 2 similar to the above-mentioned tube plate 2 is arranged at the joint of these filters, and the dust collecting chamber 4 has an upper middle lower 3 It is divided into gas chambers 4a, 4b, 4c into which the dust-removed gas flows. Gas exhaust pipes 10a, 10b, 10c are connected to the gas chambers 4a, 4b, 4c, and the exhaust pipes 10a, 10b, 10c are connected to a gas conduit 11 for guiding the gas to another system. In addition, a backwashing device (not shown) for removing dust collected and accumulated on the filter 9 is provided, and by backwashing with a high-pressure backwashing gas (inert gas such as nitrogen) from this backwashing device. The dust collected and accumulated in the filter 9 is removed from the filter 9
Fall inside.

The lower portion of the pressure vessel 1 which defines and forms the dust chamber 5 is formed in a hopper shape so that the falling dust is collected, and the collected dust is discharged from the discharge port 12. A pipe support member 13 that supports a pipe is attached to the center of the dust chamber 5.
Further, one end of a suction pipe 14 having a smaller diameter than the filter 9 and arranged at the axial center of the filter 9 is supported, and a suction port 15 which is an opening thereof is directed downward. The other end of the suction pipe 14 is connected to the throat portion 7 of the venturi 8 at the tip of the introduction pipe 6 so that the suction pipe 14 is sucked by the gas flowing through the gas introduction pipe 6, and the gas flowing through the introduction pipe 6 causes dust to be generated. A part of the gas in the chamber 5 is sucked into the suction pipe 14, and a downward flow of gas is generated in the filter 9.

Next, the operation of this embodiment will be described.

The dust-containing gas to be treated is introduced from the gas introduction pipe 6 into the gas introduction chamber 3 and descends in the filter 9. The gas to be treated gradually passes through the filter 9 while descending there,
The dust in the gas is collected by the filter 9 and the gas is dedusted. The gas that has been subjected to the dedusting process is stored in the gas chambers 4a, 4
The gas flows into the gas conduit 11 via b, 4c and the exhaust pipes 10a, 10b, 10c and is guided to another system.

When the dust-containing gas to be treated is introduced from the gas introduction pipe 6 into the gas introduction chamber 3, it passes through the venturi 8 at the tip of the introduction pipe 6, so that the suction pipe 14 connected to the venturi 8 is sucked and the suction pipe is sucked. A part of the gas in the dust chamber 5 is sucked through the suction port 15 of 14. The suction gas rises in the suction pipe 14 arranged in the filter 9, and is returned from the tip of the introduction pipe 6 to the gas introduction chamber 3 and circulates. In this way, by sucking and circulating some of the gas in the dust chamber 5,
Since the gas in the lower part of the filter 9 is sucked into the dust chamber 5, a downward flow of gas is generated in the filter 9, so that the dust easily descends in the filter 9 and is easily guided to the dust chamber 5. Large dust easily falls into the dust chamber 5 under its own weight.

Therefore, since dust is not suspended and accumulated like a cloud in the lower part of the filter 9, recombustion of unburned components in the filter 9 is prevented and damage of the filter 9 due to thermal shock is prevented. Will be.

Further, since the suction pipe 14 has a smaller diameter than the filter 9 and is arranged at the axial center of the filter 9, the filtering area of the filter 9 (the area of the portion for dedusting the gas) is not reduced. That is, when a plurality of filters 9 are provided in the pressure vessel 1, by using one of them as the suction pipe 14, the entire filtration area is reduced.

Further, by disposing the suction pipe 14 at the axial center of the filter 9, the inside of the filter 9 which is a passage connecting the gas introducing chamber 3 and the dust chamber 5 having a hole can be effectively used, and the penetrating portion is There is no need to worry about seals or the like when provided. In addition, the sucked gas is once taken out of the container 1,
Without being sent to the gas introduction chamber 3 by a blower or the like, the inside of the suction pipe 14 arranged in the container 1 is lifted to raise the gas introduction chamber 3
Since it is returned to, the gas can be circulated without loss of heat dissipation.

In this embodiment, the ceramic filter for dedusting gas with one ceramic filter has been described. However, the present invention can be applied to a ceramic filter having a plurality of filters. The suction pipe may be arranged, or the suction pipe may be arranged only in an arbitrary filter so that a downflow is generated in all the filters. When a part of the gas in the dust chamber is sucked by the plurality of suction pipes and the gas is unbalanced, the suction port of the suction pipe is arranged, for example, in the center of the dust chamber.

[0021]

In summary, according to the present invention, a venturi is provided in the gas introduction pipe, and the suction port of the suction pipe sucked by the venturi is arranged in the dust chamber, so that damage to the filter due to thermal shock can be prevented. Exerts an excellent effect.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention.

[Explanation of symbols]

 1 Pressure Vessel 3 Gas Introducing Chamber 5 Dust Chamber 6 Gas Introducing Pipe 8 Venturi 9 Filter 14 Suction Pipe 15 Suction Port

Claims (1)

[Claims] 1. A gas introduction chamber to which a gas introduction pipe of a dust-containing high-temperature processed gas containing unburned matter is connected is provided in an upper part of a container, and a dust chamber is provided in a lower part of the gas introduction chamber to connect these passages. Is made of ceramic as a filter,
In the ceramic filter for dedusting the gas by passing the gas to be treated from the gas introduction chamber through the filter,
A venturi is provided in the gas introduction pipe, and the venturi is
A ceramic filter, characterized in that a suction pipe sucked by a gas passing through a venturi is connected and a suction port of the suction pipe is arranged in the dust chamber.