JP3282273B2 - Ceramic filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field 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, etc., and removes dust-containing high-temperature gas containing unburned components from a pressurized fluidized-bed boiler or the like. The present invention relates to a ceramic filter for dust treatment.

[0002]

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

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

[0004]

By the way, in the above-mentioned ceramic filter, the gas to be treated descends inside the filter, and while descending there, the gas to be treated gradually passes through the filter and is subjected to dust removal processing. The velocity component of the gas in the filter may decrease as it goes down, 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, the dust floats and stays like a cloud. When the concentration of the unburned portion in the staying portion increases, the unburned portion is easily burned by the high-temperature gas, and the unburned portion may be reburned with an increase in the ambient temperature. as a result,
When a thermal shock is applied to the filter, a temperature difference occurs between the inner and outer surfaces of the filter, stress is applied, and the filter may be damaged.

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

[0006]

According to the present invention, there is provided a gas introduction chamber to which a gas introduction pipe for a dust-containing high-temperature gas to be treated containing unburned components is connected at an upper portion in a container, and a gas discharge chamber at a central portion. tube
The dust collection chamber to which the
The gas introduction chamber and the gas
Tubular ceramic filter that communicates with the strike chamber
And filter the gas to be treated from the gas introduction chamber.
Pass the dust through the dust collection chamber and guide the dust to the dust chamber.
In a ceramic filter that performs dust removal of gas by
Dust-containing high-temperature gas is introduced into the gas introduction pipe facing the gas introduction chamber.
A venturi for injecting the gas to be treated is provided;
When the suction tube is formed sufficiently smaller than the above filter diameter
In both cases, the suction tube is inserted through the approximate axis of the filter, and
Are arranged so that the suction port at the lower end faces the dust chamber .

[0007]

According to the above construction, the gas inlet pipe is provided with a venturi, and the suction pipe sucked by the venturi is formed into a tubular shape.
Make the filter sufficiently smaller than the diameter of the ceramic filter.
The suction tube is inserted through the approximate axis of the filter and the suction
By disposing the inlet in the dust chamber, when the dust-containing high-temperature gas to be treated is introduced from the gas introduction pipe into the gas introduction chamber via the venturi, part of the gas in the dust chamber is transferred from the suction port to the suction pipe. It is sucked and returned to the gas introduction chamber. By sucking a part of the gas in the dust chamber in this way,
Since a downward flow is generated in the filter, dust does not stay in the filter in a floating state. Therefore, reburning of the unburned portion is prevented, and breakage of the filter due to thermal shock is prevented. Also, the suction tube is sufficiently smaller than the filter diameter.
By forming and passing through the approximate axis of the filter,
Without sucking dust that falls from the
Also, the filtration area of the filter is not reduced.

[0008]

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 is formed in a vertical shape and a cylindrical shape whose upper part is closed.

A tube plate 2 is disposed above and below the pressure vessel 1, respectively.
The central part is formed in the dust collecting chamber 4 and the lower part is formed in the dust chamber 5. The upper side surface of the pressure vessel 1 includes a dust-containing high-temperature and high-pressure gas containing unburned components, for example, a high-temperature and high-pressure (860 to 870 ° C., 4 to 16 kgf / cm ² ) unburned component from a pressurized fluidized-bed boiler. A gas introduction pipe 6 for the gas to be treated is connected substantially at right angles to the axis of the container 1. The leading end of the introduction pipe 6 extends from the center (the axis of the vessel) into the gas introduction chamber 3, and the throat section 7 made of a high-temperature and wear-resistant material is inserted into the pipe 6 at the axis of the vessel 1. Is formed, and the tip of the introduction tube 6 is formed as the venturi 8.

In the dust collecting chamber 4, a tubular porous ceramic filter 9 is disposed in the axial direction thereof, and upper and lower ends of the filter 9 are attached to the tube plates 2 and 2, respectively. Serves as a passage communicating the gas introduction chamber 3 and the dust chamber 5. Thereby, the gas introduction chamber 3
The dust-containing gas introduced into the filter descends in the filter 9,
While descending there, the gas gradually passes through the filter 9, dust in the gas is collected by the filter 9, and the dust removal processing of the gas is performed.

The filter 9 is formed of three stages of filters, upper, middle and lower. A tube sheet 2 similar to the above-mentioned tube sheet 2 is arranged at the joint of these filters, and the dust collecting chamber 4 has upper, lower, middle and lower three-stage filters. The two gas chambers 4a, 4b, and 4c into which the dust-removed gas flows are formed. Gas exhaust pipes 10a, 10b, 10c are connected to these 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. Further, a backwashing device (not shown) for removing dust collected and accumulated on the filter 9 is provided, and the backwashing is performed by a high-pressure backwashing gas (an inert gas such as nitrogen) from the backwashing device. The dust collected and deposited on the filter 9 is removed from the filter 9 and
Fall inside.

The lower part of the pressure vessel 1 which defines the dust chamber 5 is formed in a hopper shape so that falling dust is collected, and the collected dust is discharged from a discharge port 12. A pipe support member 13 for supporting the pipe is attached to the center of the dust chamber 5.
In addition, one end of a suction tube 14 having a diameter sufficiently smaller than that of the filter 9 and disposed substantially at the axis of the filter 9 is supported, and a suction port 15 as an opening thereof faces downward. Suction tube 14
The other end of the Venturi 8 at the tip of the introduction pipe 6 is drawn so that the suction pipe 14 is sucked by the gas flowing through the gas introduction pipe 6.
A part of the gas in the dust chamber 5 is sucked into the suction pipe 14 by the gas flowing through the introduction pipe 6 and a downward flow of the gas is generated in the filter.

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.
Dust in the gas is collected by the filter 9 to perform a dust removal process on the gas. The dust-treated gas is supplied to the gas chambers 4a and 4a.
b, 4c and the exhaust pipes 10a, 10b, 10c, flow into the gas conduit 11, and are led to another system.

When the dust-containing gas to be treated is introduced into the gas introduction chamber 3 from the gas introduction pipe 6, 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 A part of the gas in the dust chamber 5 is sucked from the suction port 15 of 14. The suction gas rises in the suction pipe 14 arranged in the filter 9 and circulates from the tip of the introduction pipe 6 back to the gas introduction chamber 3. As described above, a part of the gas in the dust chamber 5 is sucked and circulated,
Since the gas in the lower portion 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 guided to the dust chamber 5. Large dust easily falls into the dust chamber 5 by its own weight.

Accordingly, dust does not stay in the lower portion of the filter 9 like a cloud, so that reburning of unburned components in the filter 9 is prevented, and damage of the filter 9 due to thermal shock is prevented. Will be.

[0018] The suction tube 14 is diameter than the filter 9 is ten
Since the filter 9 is disposed approximately on the axis of the filter 9, the filtration area of the filter 9 (the area of the portion for removing the dust from the gas)
Never reduce. That is, if the filter 9 is provided with a plurality of the pressure vessel, the use of one its Te and suction tube <br/>, although filtration area of the whole is reduced, the filter 9
The filtration area is reduced by arranging the suction tube 14 on the approximate axis of the
Because there is nothing to do .

Further, by arranging the suction pipe 14 at the axis of the filter 9, the inside of the filter 9, which is a passage connecting the gas introduction chamber 3 and the dust chamber 5, which are perforated, can be effectively used. There is no need to worry about seals when provided. Further, 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 raised and the gas introduction chamber 3 is raised.
The gas can be circulated without loss of heat radiation.

Although the present embodiment has been described with respect to a ceramic filter in which gas is removed by a single ceramic filter, the present invention can also be applied to a ceramic filter having a plurality of filters. A suction tube may be arranged, or a suction tube may be arranged only in an arbitrary filter so that a downflow occurs in all filters. When a part of the gas in the dust chamber is sucked by the plurality of suction pipes, when the gas drifts, the suction port of the suction pipe is arranged, for example, at the center of the dust chamber.

[0021]

In summary, according to the present invention, the gas inlet tube is provided with a venturi, and the suction tube sucked by the venturi is sufficiently larger than the diameter of the tubular ceramic filter.
It is formed small and its suction tube is inserted through the approximate axis of the filter.
By arranging the suction port at the lower end in the dust chamber,
Dust-containing high-temperature gas to be treated
When introduced into the gas introduction chamber via the
Is sucked into the suction tube from the suction port and
Will be returned. Thus, a part of the gas in the dust chamber is sucked.
As a result, a downward flow occurs in the filter,
Dust does not stay in the filter.
You. Accordingly, prevents re-combustion of unburned is, Ru prevents damage due to thermal shock of the filter. The suction tube is filled
Formed sufficiently smaller than the diameter of the filter
Sucks dust that falls from the filter to the hopper
Without reducing the filtration area of the filter
There is no.

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure vessel 3 Gas introduction chamber 5 Dust chamber 6 Gas introduction pipe 8 Venturi 9 Filter 14 Suction pipe 15 Suction port

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-47226 (JP, A) JP-A-6-114226 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01D 46/24 B01D 39/20

Claims (1)

(57) [Claims] 1. A gas introduction chamber to which a gas introduction pipe for a dust-containing high-temperature gas to be treated containing unburned components is connected at an upper part in a container.
In the center, the dust collection chamber to which the gas exhaust pipe is connected,
Dust chambers for discharging dust are formed in each section
And a tubular for communicating the gas introduction chamber and the dust chamber.
A ceramic filter is installed in the gas introduction chamber.
When these gases are passed through the filter and into the dust collection chamber,
In a ceramic filter that conducts dust to both the dust chamber and the gas to remove dust ,
Vent that injects high-temperature gas containing dust into the
A tuuri is provided, and the suction tube of the venturi is
It is formed to be sufficiently smaller than the diameter and the suction tube is filtered.
Through the shaft, and the suction port at the lower end of the
A ceramic filter, which is disposed so as to face a room .