JPH08117531A - Unit combination filter element - Google Patents

Abstract

PURPOSE: To obtain a unit combination filter element capable of largely taking a filtering area by combining two plate-shaped sheets obtained by heating felt composed of a highly heat-resistant polyimide fiber having a specific structure so as to provide an interval therebetween to form a filter element and parallelly arranging a plurality of the formed filter elements. CONSTITUTION: Felt composed of a highly heat-resistant polyimide fiber composed of a repeating unit represented by general formula 1 [wherein (n) is an integer larger than 1, (x) is a tetravalent aromatic group and R is a divalent aromatic group] is heated to form an air permeable plate-shaped sheet. Two sheets are provided and fixed on both surfaces of frames 9 under tension so as to provide a space between the sheets to form one filter element unit 2. A plurality of the filter element units 2 are parallelly combined to obtain a unit combination filter element 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter element for separating powder from gas containing powder such as dust, and more particularly to a heat resistant filter element for separating powder from high temperature gas.

[0002]

2. Description of the Related Art Conventionally, in various plants in the fields of steel and ceramics, for separating powder from gas containing generated powder, or for collecting dust and other powder in incinerator exhaust gas. In the filter element,
For example, there is known a filter element formed from a synthetic fiber nonwoven fabric or needle felt disclosed in Japanese Patent Laid-Open No. 5-277321 into a plate shape having a corrugated cross section. The synthetic fiber is a non-woven fabric or needle felt, and as the synthetic fiber used to form a filter element from them, polyimide fiber, aramid fiber, polyphenylene sulfide fiber, polyester fiber, polypropylene fiber, etc. are known. Filter elements made of polyimide fibers, aramid fibers and polyphenylene sulfide fibers are known for producing heat resistant filter elements.

The structure of a powder separator for separating solid-gas from a large amount of gas by using a plurality of filter elements will be described with reference to FIG. A gas containing powder such as dust is introduced into the powder separation device 1 through the gas supply port 16 and filtered and separated through the filter element 13 airtightly attached to the can body 3 in the dust-containing gas chamber 14 of the device 1. The purified air or gas is discharged from the clean gas chamber 15 to the outside of the system through the gas discharge port 11, and the powder accumulated on the gas supply side surface of the filter element is stored in the powder discharge hopper 17 and the discharge port 18 is provided.
It is structured to be taken out from.

The powder separating device 1 has a filter element 2
The method of mounting is that the gas supply chamber 14 of the apparatus 1 is provided with the can body 3 for mounting the filter element 13, and the top plate 4 of the can body 3 separates the powder separating apparatus 1 into the dust-containing gas chamber 14 and the clean gas chamber 15. A plurality of filter elements 13 are normally airtightly fixed to the top plate 4 of the partition by a fixing member 10. An opening is provided in the top plate 4 of the can body 3 in accordance with the exhaust port 11 of the purified gas from the filter element 13. There are various shapes of filter elements provided in the powder separation device. For example, it is a cylindrical filter element or a flat box type filter element. In addition, there are cases where the outer shape of the filter element is cylindrical or flat box type, and the surface is smooth or corrugated, but in many cases in order to increase the filtration area. In the above-mentioned JP-A-5-277
As disclosed in Japanese Patent No. 321, 321, a corrugated or rectangular cross section is used.

The powder deposited on the dust-containing gas chamber side surface of the filter element is cleaned by blowing clean compressed air from the clean gas chamber side of the filter element and back-washing it off, or high-pressure air on the dust-containing gas chamber side surface. To clean the surface of the filter element on the dust-containing gas chamber side. In the flat box type filter element having the corrugated or square unevenness, the width is thick because the filtering surface is corrugated or square unevenness. Further, in the flat box type filter element, as shown in FIG. 3, the filtering section 5 of the flat box type filter element 13 is fixed to the element mounting member 10 connected to the “separated gas discharge port 11 shown in FIG. 4”, Further, a gas supply pipe for backwashing for backwashing the filtering section 5 by sending clean compressed air from the purified gas side of the flat box type filter element 13 inside the flat box type filter element mounting member 10. 8, the flat box type filter element 13 is provided.
Has a wide width, and the powder accumulated on the dust-containing gas chamber side surface of the filtering part 5 of the flat box type filter element 13 needs to be dropped by backwashing. Due to the circumstances, it is inevitable that the flat box type filter element 13 has a large interval. Therefore, the number of flat box type filter elements 13 that can be stored in the can body 3 is limited. (In FIG. 4, there are four units.)

[0006]

It is an object of the present invention to utilize a conventionally used can body in which a greater number of filter elements can be installed than in the can body, and thus for example conventional filtration. It is an object of the present invention to provide a unit-combined filter element that has a larger filtration area as a result than the case of using the flat box type filter element having a corrugated or square-shaped cross section in its part. Furthermore, the unit-combined filter element of the present invention is a unit that has high efficiency of processing such as filtering of dust-containing gas, backwashing of the filter element, and dropping / elimination of accumulated powder, and the manufacturing cost of the filter element is low. To provide a combined filter element.

[0007]

The above objects are accomplished by the unit combination filter element of the present invention. That is, 1) In a powder separating apparatus from gas using a filter element, a breathable material obtained by heating a felt or a nonwoven fabric made of highly heat-resistant polyimide fiber having a repeating unit represented by the following general formula (1). Two flat sheets are stretched and fixed on both sides of the frame to form one unit of filter element with a space between the two sheets, and the plural filter elements are combined in parallel. According to the above, a unit-combined filter element characterized by forming a dust-containing gas chamber and a clean gas chamber.

[0008]

Embedded image

2) A large-sized unit-combined filter element, characterized in that the unit-combined filter elements described in 1) above are connected to form a collective type.

The above-mentioned high heat resistance polyimide fiber can be formed into fibers of various thicknesses. These fibers are
For example, it can be formed into a non-woven fabric or needle felt by the method described in Austrian patent application A495 / 88. Regarding the non-woven fabric or needle felt preformed from the polyimide fiber of the present invention, 280
In the temperature range of up to 420 ° C, when the temperature is kept at an appropriate temperature for a predetermined time according to the thickness of the spun fiber, the parts where the constituent fibers are in contact with each other are fused, and the fiber segment between the fusion points is The strain is relieved, and a fairly homogeneous sheet-like molded article which is breathable while shrinking as a whole is obtained.

Conventionally, as described above, in many cases, in order to increase the filtration area of the filter element, a molding die is used when the needle felt or the non-woven fabric is formed into the homogeneous sheet shape having the air permeability. Make a corrugated section or corrugated section on the sheet (filtering part of the filter element). One of the features of the present invention is that when a needle felt or a non-woven fabric is formed into a uniform sheet shape that maintains air permeability, the sheet (filter part of the filter element) does not have unevenness, and a smooth surface filter sheet is obtained. It is in molding.

Molding of the filter element of the present invention comprises:
For example, as shown in FIG. 1, when two needle felts (or non-woven fabrics) are fixed to a U-shaped frame 7 and heated to a predetermined temperature, the portions where the constituent fibers are in contact with each other are fused, The voids inside the molded product gradually shrink and shrink,
It is formed into a homogeneous sheet-like plate (filtration part 5) supported by the frame 7 and maintaining air permeability. At this time, a supporting rod (not shown) is replenished in advance to one side of the U-shaped frame 7 which is not formed, and the replenished supporting rod is removed after the molding. It is desirable to form it as a frame. The method for forming the filter element is one specific example of the present invention, and it is formed in advance from a needle felt (or a non-woven fabric) into a homogeneous sheet-like plate that retains air permeability, and the formed plate is a U-shaped frame 7 The filter element 2 may be manufactured by a method in which the filter element 2 is evenly adhered to, and adhered and fixed.

Further, in the present invention, as shown in FIG. 2, by attaching frame rods 9 to the front and rear of the filter element 2, and adjoining filter elements 2 in parallel via the frame rod 9, On the side of the U-shaped frame 7 (inside the filter element), the dust-containing gas chamber A (see FIG.
And a clean gas chamber B (which communicates with the clean gas chamber 15 of the can body 3 shown in FIG. 5) between adjacent filter elements. A pair of adjacent filter elements is a unit-combined filter element of the present invention having a unit of several pairs or dozens of pairs.

FIG. 5 shows a state in which the unit-combined filter element thus assembled is incorporated into the powder separating apparatus 1 as shown in FIG. Further, since the unit-combined filter element of the present invention has a compact structure, as shown in FIG. 6, the structure of the powder discharge hopper 17 in the dust-containing gas chamber is multi-staged and multi-staged. A large-sized powder separation device is provided by installing the can bodies 3 in a multi-stage and multi-stage corresponding to the hopper 17 in the upper part of the container and housing the unit combination filter element of the present invention in the can bodies 3. It is possible to install a filter element 2 in which a large-sized unit is combined in a multi-unit and multi-stage type. Here, the can body 3 for accommodating the flat box filter element 13 shown in FIG. 4, the can body 3 for accommodating the unit combination filter element 2 of the present invention shown in FIG. 5 and the can body 3 shown in FIG. The can bodies 3 housed in the large-sized powder separating apparatus 1 in which the can bodies 3 are housed in multiples and in multiple stages according to the present invention have a slightly different structure, but the essential structure is the same. Therefore, the flat box type filter element 13 can be obtained by slightly modifying the can body 3.
Alternatively, the unit-combined filter element 2 of the present invention can be housed in the can body 3, and the can body 3 can be housed in the powder separating apparatus 1 for powder separation.

[0015]

As described above, in the case of a filter element (for example, the combination filter element 2 of the present invention shown in FIG. 2) having a flat plate surface without corrugated or square irregularities in the filtering portion In the dust-containing gas chamber 14, in the direction of supplying a gas containing dust (dust-containing gas) and when removing the powder collected on the outer wall of the filter part 5 of the filter element 2, The direction of falling from the outer wall and falling is the same. Therefore, when the filter element 2 is backwashed by sending a clean gas from the clean gas chamber 15 side, the powder does not drift between the outer walls of the filter part 5 of the filter element 2, and the collected powder lumps are Since it easily falls off from the outer wall (filtration part 5) and falls, the filtration efficiency is good. For this reason, in the filter element 2 of the present invention, the distance between the adjacent filter elements (the distance between the dust-containing gas chambers A) can be reduced. Further, since the thickness of the filter element itself (distance between the clean gas chambers B) may be the same as the distance between the adjacent filter elements 2, the thickness of the filter element itself may be thin. Therefore, in the unit combination filter element of the present invention, a large number of filter elements of the present invention can be installed at regular intervals.

[0016]

EXAMPLE An example of the above-described polyimide fiber molding of the present invention and a method for producing the same will be described below with reference to FIG. However, the present invention is not limited to the examples below.

Example 1 Prepared from a polyimide obtained by condensing benzophenone-3,3 ', 4,4'-tetracarboxylic dianhydride and 4,4'-methylene-bis- (tolylene isocyanate). Using a polyimide fiber having a draw ratio of 1: 5 and a thickness of 30 μm, a basis weight 475 preformed by a needle punch method.
g / m ² , felt 2mm thick, width 1,600m
A test piece having a length of m and a length of 1,150 mm was cut out. The chemical structural formula of the polyimide constituting the above polyimide fiber is shown below.

[0018]

Embedded image

As shown in FIG. 1, the width is 1.5 m and the height is 1.
The above-mentioned needle felt was pasted on both sides of a 0 m U-shaped frame 7, and the needle felt attached to the U-shaped frame 7 was sandwiched between a pair of upper and lower metal molds at 340 ° C, 1.0 kgf.
The unit type filter element 2 shown in FIG. 1 was obtained by pressing and heating for 30 minutes under the condition of / cm ² . As shown in FIG. 2, the unit type filter element 2 shown in FIG. 1 is sandwiched between the unit type filter element 2 and the unit type filter element 2 and the frame type rod 9 are adhered to each other to form a pair of adjacent unit type filter elements. Formed,
Fourteen such pairs were bonded in series to form a laminated element (unit combination filter element of the present invention), which was placed in the can body 3 of the powder separating apparatus as described above.

[0020]

EFFECT OF THE INVENTION The combined filter element of the present invention is formed into a needle felt or a non-woven fabric made of an aromatic polyimide fiber which is flame-retardant and excellent in heat resistance, and the two are fixed to a frame and heated. Or, by fixing two sheets of flattened sheets by heating to a frame, a filter element unit having a simple structure with a smooth filtering part surface is manufactured, and the unit type filter element is attached to a frame rod. To produce the compact unit combination filter element. The unit combination filter element 2 of the present invention is the same as the conventional flat box type filter element 13 shown in FIG. 4 and having a corrugated or square unevenness on the surface of the filter section (installed in a can body of the same size). When the filtration area of the filtration part is calculated (as a condition), four can be installed in the can body in the case of the conventional flat box type filter element in the can body, whereas fourteen combination filter elements of the present invention can be installed in the can body. When corrugated or square irregularities are added to the surface of the filtration part, the effective filtration area ratio is 1.25
If it is twice, the effective filtration area per unit is: Conventional type: (1 × 1.5 × 2) × 2.5 = 7.5 (m ² ) Invention: (1 × 1.5 × 2) = 3.0 Conventional type per one can body: 7.5 x 4 = 30 Invention: 3. O × 14 = 42 Therefore, the powder separation device according to the present invention has a filtration capacity 1.4 times that of the conventional type, and the device can be downsized accordingly. Moreover, the combined filter element of the present invention is compact and simple in structure, and thus can be manufactured at a lower cost than conventional filter elements.

[Brief description of drawings]

FIG. 1 is a perspective view of a combined filter element of the present invention.

FIG. 2 is a perspective view of the combined filter element of the present invention.

FIG. 3 is a side sectional view of a flat box type filter element.

FIG. 4 is a side view showing a configuration of a conventional powder separation device.

FIG. 5 is a perspective view of a partial cross section showing the configuration of the powder separation device of the present invention.

FIG. 6 is a schematic diagram showing the structure of a multi-stage, multi-stage powder separation device of the present invention.

[Explanation of symbols] 1 unit filter element 2 combination filter element 3 can body 4 top plate 5 filtration section 6 clean gas discharge pipe 7 frame 8 backwashing gas supply pipe 9 frame rod 10 mounting member 11 separated gas discharge port 13 flat Box type filter element 14 Dust-containing gas chamber 15 Clean gas chamber 16 Gas supply port 17 Powder discharge hopper 18 Outlet A Dust-containing gas chamber B Clean gas chamber

Claims (2)

[Claims] 1. A gas separating apparatus using a filter element for separating air from gas, which is obtained by heating a felt or a non-woven fabric made of a highly heat-resistant polyimide fiber having a repeating unit represented by the following general formula (1). Two flat sheet sheets of the above are stretched and fixed on both sides of the frame to form a unit of filter element having a space between the two sheets, and the plurality of filter elements are combined in parallel. Thus, a unit-combined filter element, which forms a dust-containing gas chamber and a clean gas chamber. Embedded image 2. A unit-combined filter element having a large size, wherein the unit-combined filter element according to claim 1 is connected to form a collective type.