JPS6068030A - Dust removing apparatus - Google Patents

Abstract

PURPOSE:To moderate difference of elongation or shrinkage due to difference of coefft. of thermal expansion between a ceramic porous pipe and a vessel body by supporting each tube plate by a means not influenced by temp. etc. and providing a margin for expansion so as not to impair the vessel body. CONSTITUTION:A horizontal member 7 is fixed to a tube plate 3, and the horizontal member is extended to the outside of a vessel body 1 where it is fixed to a vertical member 8. Further, each peripheral part of the vessel body 1 between tuble plates 3, 3 adjacent to each other is cut to provide a clearance, and the clearance is used to serve as margin for expansion 9. Simultaneously, the clearance for the margin 9 for expansion is connected by a semicylindrical annular expansion ring 10 such as Adamson joint. The expansion ring 10 covers the expansion margin 9 on the vessel body 1 and prevents flowing out of gas to the outside of the vessel body 1. Even if the expansion margin 9 is reduced by the elevation of temp. of the vessel body 1, further bending of the expansion ring 10 permits the expansion of the vessel body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dust removal device suitable for processing high-temperature dust-containing gas.

BACKGROUND ART Various devices have been put into practical use as devices for removing dust from dust-containing gas. However, it has been difficult to remove dust from high-temperature dust-containing gas with high dust removal efficiency without lowering the temperature. For example, bag filters require the dust-containing gas temperature to be below 250℃, and electrostatic precipitators cannot be used unless the dust-containing gas temperature is approximately 550℃ or below, and although cyclones can still be applied to relatively high-temperature dust-containing gases, Only dust with large particle size can be removed, and the dust removal efficiency is only about 90%.

On the other hand, obtaining clean gas by filtering dust-containing gas through a porous ceramic tube is well known and has been put to practical use. It is also well known that ceramic porous tubes have excellent heat and corrosion resistance. Therefore, as an industrial-scale device that uses ceramic porous tubes to continuously remove dust from large amounts of high-temperature dust-containing gas discharged from industrial equipment such as electric furnaces and converters, we have installed ceramic porous tubes installed vertically. proposed a dust removal device that includes a tube plate that supports the end of a limb canal via a sealing material, and a can body that houses the limb tube and the tube plate and is provided with a dust-containing gas inlet and a clean gas outlet. Ru.

In such dust removal devices using porous ceramic tubes, steel or other metal materials are often used for the can body due to strength requirements, and therefore the coefficient of thermal expansion is large. Quality tubes generally have a small coefficient of thermal expansion. Therefore, when a dust removal device is applied to a high-temperature dust-containing gas, a difference in thermal expansion occurs, which causes the vertical position of the tube sheet that supports the porous tube to change to a predetermined position of the porous tube. This may cause problems such as displacement from the supporting position, failure to achieve the desired seal, damage to the porous tube or fall-off, and cracking or damage to various parts of the device.

An object of the present invention is to alleviate the expansion/contraction difference due to the difference in coefficient of thermal expansion between the porous ceramic tube and the can body in a decapitation device using a porous ceramic tube that can be applied to high-temperature dust-containing gas. An object of the present invention is to provide a dust removal device that can eliminate the inconveniences caused by the above problems. Other objects of the invention will become apparent from the description below.

The present invention provides an electrically installed ceramic porous tube, a tube sheet that supports the end of the limb tube through a sealing material, and a tube sheet that accommodates the limb tube and the tube sheet and is provided with a dust-containing gas inlet and a clean gas outlet. In a dust removal device comprising a can body, members fixed to the tube sheet and extending outside the can body are fixed to each other outside the can body, and an expansion allowance is provided in the can body between the tube sheets. This is a dust removal device characterized by:

EMBODIMENT OF THE INVENTION Hereinafter, the dust removal apparatus of this invention will be explained in detail based on the drawing of an Example.

As shown in FIGS. 1 and 2, the dust removal device is constructed by housing a plurality of ceramic porous tubes 2 in a can body 1. As shown in FIGS. In the illustrated example, the can body 1 is cylindrical, but
The shape is not limited to this, and may be, for example, in the shape of a rectangular tube. Further, the porous tube 2 is also cylindrical and easy to manufacture, but is not limited to this, and may have a rectangular tube shape, for example. The porous tube 2 is manufactured by molding and sintering ceramic powder.

Desirable ceramic materials include mullite, cordierite, silicon carbide, and silicon nitride, which have poor thermal shock resistance. Although it is generally desirable for the length of the porous tube 2 to be long, it is set to approximately 0.5 to 2 m in consideration of improved yield during molding and sintering, prevention of deformation, and strength during use.

A plurality of porous tubes 2 (three in the example) are connected in series to form a long tube, and a plurality of rows of the long tubes (21 in the example)
rows) are arranged in parallel in the can body 1. This group of long tubes is supported by the tube plate 3 via the sealing material 4 at both its upper and lower ends and at the connection portion, that is, at the end of each porous tube 2 . The tube plate 3 has its peripheral edge firmly attached to the can body 1, and the perforated tube 2
The required number of holes are drilled into which the holes are to be inserted.

Parts A and B, which are the parts where the porous tube 2 is supported by the tube plate 3, are shown enlarged in FIGS. 3 and 4, respectively.

FIG. 5 shows the connection part of the porous tube 2. A cooling passage 6 is provided inside the tube sheet 3, which is provided with a heat insulating material layer 5 on both sides to prevent heat loss and protect the tube sheet. Cooling air is circulated through a cooling air outlet (not shown) to thermally protect the tube sheet 3 and sealing material 4. The size of the hole in the tube sheet 3 is large enough to allow the porous tube 2 to be inserted loosely, and the porous tube 2 and the tube sheet 3 are
A sealing material 4 is inserted between the two, and the porous tube 2 is supported by the tube sheet 3, and the connecting portion of the porous tube 2 is sealed, and the upper and lower sides of the tube sheet 3 are also sealed. . The sealing material 4 does not need to block the passage of gas, and may be any material that substantially blocks the passage of dust. In addition, it is important to have heat resistance against high-temperature gases, so ceramic fiber ropes, carbon fiber blunt Harakin ropes, and metal fiber ropes such as stainless steel are used. The method of supporting the upper end of the long pipe is almost the same.

4, which shows the lower end of the long tube, is almost the same except that an annular rib 11 supporting the lower end of the long tube is formed on the inner circumferential surface of the hole in the tube plate 3.

A part of the can body 1 above the top tube sheet 3 is equipped with a dust-containing gas port 12, and a part of the can body 1 below the bottom tube sheet 3 forms a hopper 13, and a hopper 15 A dust discharge port 14 is installed at the bottom, and a sludge-containing gas extraction port 15 is provided at the side of the hopper 13 as required. Although not shown, a clean gas outlet is provided in the can body 1 between the uppermost tube sheet 3 and the lowermost tube sheet 3.

If a communicating hole is provided in the intermediate tube sheet, there should be at least one clean gas outlet zone, and if each tube sheet is not provided with a communicating hole, there should be at least one clean gas outlet zone between the adjacent tube sheets. Each body 1 is provided with a clean gas outlet. A heat insulating material layer 5 is also formed on the inner surface of the can body 1 as required to prevent heat loss.

When high-temperature dust-containing gas is introduced into this dust removing device from the dust-containing gas port 12, the dust-containing gas enters each long pipe, is filtered by the porous pipe 2 having air permeability that constitutes the long pipe, and The clean gas passes through the wall of the porous tube 2 and is discharged to the clean gas outlet. On the other hand, the dust separated from the dust-containing gas coagulates with each other and descends mainly along the inner wall of the porous tube 2 due to its weight and due to the kinetic energy of the dust-containing gas.
Collects in hopper 15. Note that the dust outlet 14 is normally closed and is opened intermittently to discharge dust. Further, if necessary, a part of the supply gas may be extracted from the dust-containing gas extraction port 15 in order to impart downward kinetic energy to the separated dust, particularly the dust at the lower part of the long pipe.

Since the porous tube 2 is supported by the tube plate 3 via the sealing material 4, vibrations are alleviated and there is little possibility that the porous tube 2 will be damaged. Further, the difference in thermal expansion between the tube plate 3 and the porous tube 2 in the horizontal direction is absorbed by the sealing material 4. However, the vertical position of the tube plate 3 must be at both the upper and lower ends of the long tube and at the connecting portion. In other words, if the vertical position of the tube sheet deviates from this position, the porous tube 2 will come into direct contact with the tube sheet 6 or its heat insulating material layer 5, damaging the porous tube or preventing dust from being sealed. This may cause inconveniences such as failure or the sealing material falling off. Particularly when processing high-temperature dust-containing gas, the can body 1 that supports the tube sheet 3 or its heat insulating material layer 5 generally has a large coefficient of thermal expansion, while the porous tube 2 is made of ceramic, particularly with excellent thermal shock resistance. Since it is made of ceramic, its coefficient of thermal expansion is small, and the difference in thermal expansion becomes large at high temperatures, which may lead to the above-mentioned problems.

Therefore, in the dust removal device of the present invention, the tube plates 3 are held together by means that are not affected by temperature, etc., and the distance between them is kept constant, and the expansion is prevented from damaging the can body 1. 9 is provided. That is, a horizontal member 7 is fixedly attached to the tube sheet 5, and this horizontal member 7 extends outside the can body 1, preferably to a position where the can body 1 is not substantially affected by the heat. In this position, the horizontal member 7 is fixed to the vertical member 8. Although it is desirable that the interval between each horizontal member 7 be equal to the interval between each tube sheet 3, it is not necessarily limited to this. In this way, since the members that are firmly attached to the tube sheet 3 and extend outside the can body 1 are fixed to each other outside the can body 1, these members are made of metal or other material with a relatively large coefficient of thermal expansion. □Even if it is made of a thin material, the temperature is much lower than that inside the can body 1, and therefore the amount of vertical thermal expansion is substantially equal to that of the porous tube 2, and each tube sheet 3 will no longer be at risk of shifting from its predetermined position.

In addition, in the illustrated embodiment, as shown in detail in FIG. The gap is set to an expansion margin 9, and the gap between the expansion margins 9 is connected with an expansion ring 10 such as an annular semicylindrical Adamson joint. The expandable ring 10 covers the expansion allowance 9 provided in the can body 1 and expands the can body 1.
Even if the temperature of the can body 1 rises and the expansion margin 9 is narrowed, the expansion ring 1
0 bends further to follow this. Note that the shape and structure of the expansion margin 9 are not limited to those described above, and various forms can be adopted, and the expansion ring 10 may be replaced with other suitable joints.

In the above explanation, we have explained the case where a long pipe with porous pipes connected to it is used, but the same applies to the case where a single stage porous pipe without a connecting part is used, and the present invention It is included in

Since the dust removal apparatus of the present invention is constructed and operates as described above, it can be effectively used as an apparatus for removing dust from high-temperature dust-containing gas on an industrial scale and obtaining high-temperature clean gas. In particular, since a porous ceramic tube is used for the decapitation member, high-temperature gas can be processed as is, and thermal energy can be recovered with high efficiency. In addition, in the device of the present invention, even if the can body is made of a metal material such as steel, the influence of the difference in thermal expansion coefficient between the metal material and the ceramic porous tube is alleviated, and failures due to temperature changes, especially in the ceramic porous tube, are alleviated. Accidents such as damage to porous pipes are prevented. Furthermore, since it has been subjected to anti-vibration treatment, there is less risk of accidents due to earthquakes, equipment vibrations, etc. Therefore, the device of the present invention has great industrial utility value.

[Brief explanation of drawings]

1 and 2 are longitudinal sectional views and transverse sectional views of essential parts of an embodiment of the dust removal device of the present invention, and FIGS. 3, 4, and 5 are section A in FIG. 1, respectively. It is an enlarged view of part B and part 0. DESCRIPTION OF SYMBOLS 1... Can body, 2... Porous tube, 5... Tube sheet, 4...
...Sealing material, 5...Insulating material layer, 7...Horizontal member,
8... Vertical member, 9... Expand. Kaya 2 Same Kaya 6 rivers

Claims (1)

[Claims] (1) An erected ceramic porous tube, a tube plate that supports the end of the limb canal via a sealing material, and a tube plate that accommodates the limb tube and the tube plate and is provided with a dust-containing gas inlet and a clean gas outlet. In a dust removal device comprising a can body, members fixed to the tube sheet and extending outside the can body are fixed to each other outside the can body, and an expansion allowance is provided in the can body between the tube sheets. A dust removal device characterized by being installed.