JPH03186311A - Filter for removing dust - Google Patents

Abstract

PURPOSE:To absorb the difference in thermal expansion by filling a clearance between a connection member and a cylindrical wall with inorganic fibers having elasticity in a compressed state and attaching a cylindrical member to a part of the inorganic fibers. CONSTITUTION:A cylindrical space between the inner periphery of a cylindrical wall 12 and a cylindrical part 9 of a connection member 10 is filled with inorganic fibers 13 having elasticity in a layered and compressed state. Cylindrical members 14, 15 composed of inorganic material having inelasticity are placed at the upper and lower ends of the inorganic fibers 13 respectively. In this manner, the difference in thermal expansion produced between a filter element and a casing can be surely absorbed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a dust removal filter device in which a dust removal filter such as a ceramic filter for high temperature gas is attached to a can body.

(Prior art) As methods for removing solids from gas, wet processing methods using scrubbers, etc., and dry processing methods using electrostatic precipitators, bag filters, etc. have been known for a long time. The transition to dry processing methods is progressing from the viewpoint of processing and sensible heat recovery. Especially when collecting dust from high-temperature gases, electric precipitators do not have sufficient collection efficiency or heat resistance, and bag filters only have a heat resistance of about 250°C.
Dust removal filter devices using ceramic filter elements made of SiC or the like are becoming popular.

Such a ceramic filter element is fixed inside the can body and constitutes a dust removal filter device, but due to the high operating temperature, thermal expansion occurs between the filter element and the metal can body. The difference reaches several tens of minus.

For this reason, conventionally a thin metal bellows was attached between the end of the ceramic filter element and the mounting plate on the can body side, and the expansion and contraction of the bellows was used to absorb this difference in thermal expansion and prevent gas leaks. Structured dust removal filter devices have been used.

However, dust removal filter devices with this structure use thin-walled metal for the bellows, so they are susceptible to high-temperature oxidation and dust corrosion, and lack long-term reliability. The temperature is also 8 (10) °C
There were problems such as poor reliability of welded parts.

(Problems to be Solved by the Invention) The present invention solves the conventional problems as described above, and can absorb the large thermal expansion difference that inevitably occurs between the can body and the filter element without any problem. , and the installation of a filter element with excellent dust sealing properties, heat resistance, corrosion resistance, etc. has been completed in order to provide a dust removal filter device with a structure.

(Means for solving the problem) The above problem is solved by attaching a connecting member having a cylindrical portion to the upper end of the filter element, passing this connecting member through the hole wall on the can side, and connecting the connecting member and the hole wall. The problem is solved by a dust removal filter device that is filled with compressed layers of elastic inorganic fibers, and a cylindrical member made of an inelastic, heat-resistant inorganic material is attached to a part of the inorganic fibers. can do.

The present invention will be explained in more detail below with reference to illustrated embodiments.

(Example) In Fig. 1, (1) is a can body with the bottom of the dust collector body;
(2) is an upper partition wall provided inside the can body (1);
) is a support plate, and a ceramic filter element (4) is attached between the upper partition wall (2) and the support plate (3). Also, (5) is the can body (1
), the dust-containing gas inlet (6) is formed on the side wall of the can body (1
) is the clean gas outlet formed at the upper end, and (7) is the backwash gas inlet.

As shown in Figure 2, the filter element (4)
A flange-shaped metal fitting (8) is connected to the upper end of the
Further, a connecting member (10) having a cylindrical portion (9) is attached above the metal fitting (8). This connection member OI
The cylindrical portion (9) is inserted into a circular through hole (11) formed in the upper partition wall (2) of the can body (1). Further, a hole wall Q21 is provided around the through hole Ql), and an elastic layer is formed in the cylindrical space between the zero-force inner peripheral surface of the hole wall and the cylindrical portion (9) of the connecting member OI. Inorganic fiber G
E is packed in layers in a compressed state.

In the example, the inorganic fiber (13) has a fiber diameter of 2.
．． Alumina-silica ceramic fibers with a diameter of 8μ and a true fiber specific gravity of 2.6 are formed into a layered body with a bulk density of 128 gird.
The material used is compressed to 40Kg/rrf.

Cylindrical members 04) and 05) made of inelastic inorganic material are attached above and below this inorganic fiber 0. These cylindrical members 04) and 05) have the role of maintaining the layered body of inorganic fibers in a compressed state, and also have the role of guiding the cylindrical part (9) so that it does not swing from side to side. be. With this structure, the connecting member OI of the filter element (4) maintains its dust sealing property under a sliding load of about 50 to 150 kg from the inner circumferential surface of the hole wall QZ. 0
It allows the filter element (4) to expand and contract due to the difference in thermal expansion without impairing dust sealing properties at high temperatures up to .degree.

This sliding load is greatly influenced by the compressed state of the inorganic fiber (13). Figure 3 shows the relationship between the compression residual ratio (dimension after compression/dimension before compression) on the horizontal axis and the sliding load on the vertical axis. It can be seen that the sliding load increases rapidly as the value decreases.

It can also be seen that even if the compression residual ratio is the same, the sliding load increases after being subjected to a heat cycle compared to when it is in a fresh state. This is because the inorganic fiber 09 is hardened by the heat cycle.

The nozzle shown as (10) in Fig. 2 is a backwashing nozzle that jets compressed air in pulses from the upper end of the filter element (4).
4) is for dropping dust attached to the outer surface.

(Function) The dust removal filter device of the present invention configured as described above has the following features:
Like the conventional filter, it is used for filtering dust-containing gas, etc. However, in the present invention, elastic non-receiving fiber (
13) is packed in a compressed state in a layered manner, even if a large thermal expansion difference occurs between the upper end of the filter element (4) and the metal can body (1) during high-temperature use, the connection member 0
The cylindrical portion (9) of ff) can move freely against the hole wall 021 while being dust-sealed by the inorganic fibers. For this reason, the above-mentioned difference in thermal expansion is absorbed without any problem, and dust leakage is also reliably prevented.

In addition, in the present invention, the cylindrical member (2), 05) is made of an inelastic inorganic material in a part of the inorganic fiber θ.
Since it is attached, the upper end of the filter element (4) is reliably supported without swinging from side to side against the hole wall 02+ on the side of the can body, and excessive leaping of the inorganic fibers can be prevented. Furthermore, filter element (4)
This also prevents bending stress from acting on the structure. Furthermore, if this cylindrical member is made of metal, the connection member QO
) is likely to be welded to the cylindrical part (9), so a heat-resistant inorganic material is preferable.

(Effects of the Invention) As explained above, the dust removal filter device of the present invention can eliminate the large thermal expansion difference that inevitably occurs between the ceramic filter element and the metal can without fear of dust leakage. In addition to ensuring absorption, the upper end of the filter element can be supported without swinging from side to side. Further, in the present invention, unlike the conventional thin-walled metal bellows is not used, sufficient corrosion resistance can be exhibited even against corrosive gases, etc., and reliability can be significantly improved. As described above, the present invention is particularly suitable for use under high-temperature conditions, and as a dust removal filter device that eliminates conventional problems, it will greatly contribute to the development of industry.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view showing an embodiment of the present invention, Fig. 2 is an enlarged sectional view of the main part, and Fig. 3 shows the relationship between the compression residual ratio of inorganic fibers and the sliding load of the connecting member. This is a graph showing. (4): Filter element, (9): Cylindrical part, O(
D. Connection member, 021 = hole wall on can body side, 0: inorganic fiber, (14), (151 = cylindrical member.

Claims (1)

[Claims] A connecting member (10) having a cylindrical portion (9) is attached to the upper end of the filter element (4), and this connecting member (10)
is passed through the hole wall (12) on the can body side, and an elastic inorganic fiber (13) is filled in a compressed state between the connecting member (10) and the hole wall (12), and the inorganic fiber (13) ), cylindrical members (14) and (15) made of an inelastic inorganic material are attached to a part of the filter.