JPH10337428A - Ceramic filter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic filter device having a long service life without being damaged sealing property even with vibrations in a backwashing operation, in a filter device using a tube type ceramic filter. SOLUTION: This device is constituted to remove impurities at high temp. and high pressure gas. In this case, the tube type ceramic filter 1 is formed the lowest part at an inverse conical shape, and also is received with a hole formed at the inverse conical shape matched to the inverse conical shape at a lower tube plate 5 side via a seal material 8 in a sealing state by dead load to be supported.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic filter device using a tube type ceramic filter, which is suitable for supplying clean gas to a gas turbine.

[0002]

2. Description of the Related Art In a fluidized bed boiler, combustion gas generated in a boiler is sent to a gas turbine for re-combustion. Before sending the gas to the gas turbine, it is necessary to remove ash in the combustion gas using a cyclone or a filter. Tube type ceramic filters are used.

In a ceramic filter device using a tube-type ceramic filter, a plurality of tube-type ceramic filters 1 are housed in a rigid pack 2 as shown in FIG.
As shown in FIGS. 4 to 6, the upper tube sheet 3, the intermediate tube sheet 4, and the lower tube sheet 5 hold and seal.

The combustion gas 6 containing ash enters from the upper part of the filter 1, and the clean gas filtered by the tubular ceramic filter 1 is sent to the gas turbine via the clean gas duct 7.

[0005] The rigid pack 2 is made of metal and cannot be integrally formed due to a difference in thermal expansion coefficient from that of the tube type ceramic filter 1. Therefore, the tube-type ceramic filter 1 is self-supporting via the sealing material 8.

[0006]

As the tube type ceramic filter 1 in a ceramic filter device used in a fluidized-bed boiler is used, ash adheres to the filter surface and the pressure loss increases as the filter is used. For this reason, as shown in FIG. 3, a backwashing operation is performed in which backwashing air 10 is periodically supplied from the inner tube 9 for backwashing to the tubular ceramic filter 1 in a direction opposite to that in the normal operation to remove adhered ash. There is a need. At the time of backwashing, since a backwash pressure is instantaneously applied, dynamic pressure, vibration force and the like by the backwash air act on the tubular ceramic filter 1.

The tube type ceramic filter 1 needs to have a large surface area in order to exhibit a filter effect.
Inevitably the longer the better. Therefore, the long tube-type ceramic filter 1 has a structure that easily swings when subjected to a backwash pressure. The tube type ceramic filter 1 is self-supporting by its own weight in the rigid pack 2.

The lowermost and uppermost portions of the tubular ceramic filter 1 in contact with the rigid pack 2 prevent the leakage of the combustion gas by the sealing material 8. In particular, when the tube-type ceramic filter 1 vibrates in the backwashing operation, the seal member receiving its own weight rubs and wears, and the sealability of the lower tube sheet 5 cannot be secured. Therefore, unclean combustion gas flows into the gas turbine. May cause damage.

The combustion gas has a temperature of about 850 ° C. and the rigid pack expands thermally. Even if it does not move with the steady rest 11 at the time of a cold body, if a combustion gas is ventilated, it will thermally expand and a gap will be formed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a filter device using a tube-type ceramic filter, which has a long life without deteriorating the sealing performance even by the vibration in the backwashing operation.

[0011]

According to the present invention, there is provided a ceramic filter device which is configured to remove impurities of a high-temperature and high-pressure gas by using a tube-type ceramic filter. Is formed in an inverted cone shape, and is received in a sealed state by its own weight in a hole on the lower receiving side formed in the inverted cone shape corresponding to the inverted cone shape.

In the ceramic filter device according to the present invention, the tubular ceramic filter is preferably penetrated through the rigid pack, and the conical portion of the tubular ceramic filter has a sufficient length. .

[0013] In the ceramic filter device of the present invention configured as described above, the tube-shaped ceramic filter has its lowermost inverted-cone-shaped portion fitted by its own weight into a similar inverted-cone-shaped hole formed on the lower receiving side. The seal material can prolong the life of frictional wear because the tube movement is minimized.

The lower base of the rigid pack supporting the tube-type ceramic filter is made of metal, and thermally expands when combustion gas enters, so that the diameter of the hole of the lower base becomes large. When the diameter of the hole increases, the conical portion at the lowermost portion of the tube-shaped ceramic filter slips under its own weight until it reaches the diameter of the hole of the lower receiving table, so that no gap is always formed. When cold, the lower cradle shrinks, but the shrinking force pushes the tubular ceramic filter upward.

The angle at which the tubular ceramic filter is pushed upward by the contraction force is optimally 60 to 70 degrees. The lower part of the tube-type ceramic filter is penetrated through the lower part of the rigid pack, and the portion of the lower part of the rigid pack that contacts the tube-type ceramic filter is formed into a conical shape having the same angle as that of the lowermost part of the tube-type ceramic filter.

With the above structure, the lower portion has a stronger binding force than the conventional product, and the backwash pressure acts on the tube-type ceramic filter, so that the lower portion of the tube-type ceramic filter does not move as much as the sealing material is worn out. The sealing effect is maintained and a clean gas can always be supplied.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a ceramic filter device according to the present invention will be specifically described based on one embodiment shown in FIG. In FIG. 1, the ceramic filter 1 is cylindrical, and the combustion gas 6 discharged from the boiler is fed into the inner peripheral side, and only the clean gas is discharged to the outer peripheral side of the ceramic filter 1 to drive a turbine or the like. Used for Further, impurities such as ash are captured on the inner peripheral side of the ceramic filter 1.

As described earlier with reference to FIGS. 2 and 3,
Although a plurality of ceramic filters 1 are inserted into the upper tube sheet 3 and the lower tube sheet 5, only one filter is shown in FIG. Further, the tube sheet is fixed to a casing (not shown).

The inner diameter of the tube type ceramic filter 1 is the same as the conventional one, but the outer diameter portion in contact with the lower tube sheet 5 is formed in an inverted conical shape so as to have an angle to increase. The hole of the lower tube sheet 5 is also provided with an inverted conical angle so as to match the angle. The ceramic filter 1 is dimensioned to penetrate the lower tube sheet 5. The sealing material 8 is sized to surround the periphery of the hole in the lower tube sheet 5.

With the above arrangement, even if the tube-type ceramic filter 1 vibrates due to the application of the backwashing pressure, the lower tube sheet portion does not largely swing. If it does not fluctuate greatly, the life and effect of the sealing material 8 increase, reliability is improved, and cost is reduced. Further, the combustion gas 6 has a high temperature, and the lower tube sheet 5 thermally expands. When thermally expanded, the space between the lower tube sheet and the ceramic filter becomes narrower, and a sealing effect is increasingly obtained.

[0021]

As described above, in the ceramic filter device according to the present invention, the lowermost portion of the tube-type ceramic filter is formed in an inverted conical shape, and the tube-shaped ceramic filter is formed in an inverted conical shape corresponding to the inverted conical shape. Tube-type ceramic filter supported by the inverted conical hole of the lower tube sheet even if backwash pressure is applied during backwashing of the ceramic filter because it is received in the lower receiving side hole in a sealed state by its own weight. Has almost no vibration and little damage to the sealing material, the sealing effect lasts for a long time, and the reliability is improved and the cost is reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a tube-type ceramic filter in a ceramic filter device according to one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state of the ceramic filter device during normal operation.

FIG. 3 is an explanatory diagram showing a state during a backwash operation in the ceramic filter device.

FIG. 4 is a sectional view showing an upper tube sheet part in a conventional ceramic filter device.

FIG. 5 is a cross-sectional view showing an intermediate tube plate part in a conventional ceramic filter device.

FIG. 6 is a sectional view showing a lower tube sheet part in a conventional ceramic filter device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tube-type ceramic filter 2 Rigid pack 3 Upper tube sheet 4 Intermediate tube sheet 5 Lower tube sheet 6 Combustion gas 7 Clean gas duct 8 Sealing material 9 Backwash inner cylinder 10 Backwash air 11 Steady-stop

Claims (1)

[Claims] 1. A ceramic filter device configured to remove impurities of a high-temperature, high-pressure gas using a tube-type ceramic filter, wherein the lower portion of the tube-type ceramic filter has an inverted conical shape, and A ceramic filter device, which is received in a sealed state by its own weight in a hole on the lower receiving side formed in an inverted conical shape corresponding to (1).