JP2594844B2 - Heat resistant needle felt filter material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a needle felt for a bag filter material for collecting dust generated at a high temperature in an incinerator, a boiler or the like, and particularly to a harmful gas such as dioxin. The present invention relates to a needle felt which is effective as a bag filter material in an incinerator or the like generated.

[0002]

2. Description of the Related Art Conventionally, as a filter material of this kind, since the operating temperature of a filter portion in an incinerator or the like is high, ethylene terephthalate (PTFE) fiber, aramid fiber, polyphenylene sulfide (PP)
S) Needle felt of high melting point fiber such as fiber and polyimide fiber has been used.

Recently, as disclosed in Japanese Patent Application Laid-Open No. 61-160466, 0.2 to 0.4 d
Needle felt (hereinafter referred to as "tephire") mixed with (3.4 to 4.7 .mu.) Fine glass fiber has been studied.

[0004]

However, in general, dust generated by combustion in an incinerator, a boiler, or the like becomes finer as the combustion temperature increases, and the collection efficiency decreases. In particular, in the needle felts of high melting point fibers as described above, the diameter of single fibers of these fibers was as large as 10 μm or more, and the collection efficiency for fine dust during high-temperature combustion was low.

[0005] In addition, although the trapping efficiency is improved, the above-mentioned tephire has a disadvantage that the removability of the trapped dust is poor.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a filter material having a high dust collection efficiency and excellent in the removability of the collected dust.

[0007]

[Means for Solving the Problems] The present invention provides a polyphenylene
Glass fiber of 1-20μ in thickness to lensulphide fiber
From 5 to 50% of the surface area of the dust collecting surface
In the range of 3/4, the polyphenylene sulfide
The fiber is partially melted and adhered to the glass fiber .

[0008]

The filter material of the present invention collects dust generated in an incinerator, a boiler, or the like, and its use atmosphere is usually around 180 ° C. Must be at least 180 ° C. or higher.

As the organic fiber having such a high melting point , the PPS fiber (glass transition point (Tg) 90 ° C.,
Melting point (mp) 285 ° C) and aramid fiber (Tg2
70 ° C, mp 415 ° C), polyimide fiber (Tg315
° C), polyester fiber (Tg80 ° C, mp260
° C), PTFE fiber (Tg130 ° C, mp327 ° C),
Polyetheretherketone fiber (Tg143 ° C, mp
345 ° C), 66 nylon fiber (Tg49 ° C, mp25
0 ° C.). In addition, a sea core or side-by-side type conjugate fiber having a melting point of 1
Only the melting point of so-called binder fibers at 80 ° C or higher
Can be used if

[0011]

However, in the present invention, the organic fiber
Is a part of which is melted and bonded to glass fiber.
Therefore, it must have low Tg and excellent melt adhesion
Is required, and it is difficult to bond by melting because it decomposes when melting.
Aramid fibers and polyimide fibers are unsuitable.
TFE fiber melts but has little adhesion
Is inappropriate.

In an incinerator or the like, various
Gas with high chemical resistance
Are required in the present invention.
PPS fibers are used to satisfy the above.

[0014]

As the glass fibers, those having a fiber diameter of 1 to 20 μm are used. If it is less than 1 μm, the strength is so small that the needle may be cut by the spines of the needle during needling. 20μ
If it exceeds 300, it will be easily damaged by needling due to the brittleness of the glass, and the dust collection efficiency will also be reduced. Therefore, it is appropriate to set it to 1 to 20 μ, more preferably 5 to 12 μ.

The amount of glass fiber to be mixed must be 5 to 50%. If it is less than 5%, the efficiency of collecting dust is insufficient, and if it exceeds 50%, sufficient entanglement of fibers in the needle felt cannot be obtained. Also, if there is too much glass fiber, P
Since the amount of the PS fiber is relatively small, the adhesiveness is reduced, and the removability of the dust is deteriorated.

Further, in the present invention, the PPS fiber is partially melted on the dust collecting surface of the filter material,
It must be bonded to glass fiber. PPS
The range in which the fibers are melted is a state where it is recognized that about 1/5 to 3/4, particularly preferably about 1/4 to 1/2, of the surface area of the dust collecting surface is melted by microscopic observation. It is. If the melting range is too large, the flexibility of the filter material tends to be impaired or clogging tends to be faster,
Conversely, if the melting range is too small, the dust collection efficiency will decrease.

As a means for fusing the PPS fiber and bonding it to the glass fiber, the dust can be melted by heating the dust collecting surface of the needle felt with a hot calender or a flame.

[0019]

In the present invention, when dust is collected by the filter material, in the initial stage, the gas passes through the highly permeable portion of the needle felt, and the dust is collected in that portion.

As the dust adheres to the portion having high air permeability and the air permeability gradually decreases, the gas gradually passes through the portion having low air permeability, where the dust is collected and adhered. .

These processes are the same for the conventional filter material. In conventional filter media, all parts of the needle felt have more or less air permeability, so that dust eventually adheres to all parts, and the dust adheres to each other and grows. A phenomenon occurs, and the air permeability decreases rapidly, and the dust removability decreases.

However, in the filter material of the present invention,
Since the PPS fiber is melted and adhered to the glass fiber on the dust collecting surface, the portion has almost no air permeability. Therefore, dust does not adhere to the melted portion, and the collected dust becomes uneven, so that bridging hardly occurs.

Therefore, air permeability is ensured through the thin portion of the dust, and the removability is improved without the dust being densely packed.

[0024]

According to the present invention, therefore, the dust collecting efficiency is high, the collecting function is exhibited for a long time, and the removability of the collected dust is good.

In general, glass fibers have a smooth surface and are slippery. In a filter using the glass fibers, high-temperature gas passes through the openings, resulting in a decrease in collection efficiency and dust entering the inside of the felt. As a result, the removability of dust decreases. However, in the present invention, since the glass fiber is bonded and fixed with the PPS fiber , there is no aperture, dust is collected on the surface of the felt, the collection efficiency does not decrease, and the releasability is good. .

Further, since the PPS fiber is melted and adhered to the glass fiber on the dust collecting surface of the filter material, there is no fluff and bridging does not easily occur.

Further, since the surface of the glass fiber has a small wetting property, the moisture contained in the dust does not condense,
The condensed water does not hinder the dust removability.

[0028]

【Example】

Example 1 50% by weight of PPS fiber (manufactured by Teijin Limited, 2d × 51 mm) and glass fiber (manufactured by Unitika UM Glass Co., Ltd., 6% by weight)
(× 50 mm) and 50% by weight, and through a needling step, a needle felt having a basis weight of 614 g / m ² was prepared.

Next, the needle felt is heated on a dust collecting surface by using a burner using a gas flame to melt organic fibers of about 1/3 of the surface area of the felt and adhere to glass fibers. A filter material was created.

Example 2 A filter material was prepared in the same manner as in Example 1 except that the weight ratio of PPS fiber to glass fiber was 70/30.

Example 3 A filter material was prepared in the same manner as in Example 1 except that the weight ratio of PPS fiber to glass fiber was 85/15.

Comparative Example 1 A needle felt was prepared using only the PPS fiber, and the dust collecting surface was heated in the same manner as in Example 1 to produce a PP.
The S fibers were melt bonded to each other to prepare a filter material.

Comparative Example 2 A commercially available tefire was used as it was as a filter material.

Comparative Example 3 The needle felt prepared in Example 2 was directly used as a filter material without heating.

Comparative Example 4 A filter material was prepared in the same manner as in Example 1 except that the weight ratio of PPS fiber to glass fiber was 97/3.

Test conditions Dust: slaked lime (JIS super-special grade) Concentration: 10 g / m ³ Speed: 3.0 m / min Collection efficiency: measured at ΔP = 150 mmAq (by gravimetric method) H. C: Dust holding amount until ΔP = 150 mmAq Removal amount: 5 m / min × 3 after ΔP = 150 mmAq
The removal rate was measured by a headwind of 0 seconds (gravimetric method). Table 1 shows the physical properties and test results of the filter materials of the examples and comparative examples.

[0037]

[Table 1]

As can be seen from Table 1, the filter material of the present invention has a high collection efficiency, a high wiping rate and good dust releasability.

In particular, comparing Example 2 with Comparative Example 3,
Example 2 in which the PPS fiber was melt-bonded to the glass fiber on the dust collecting surface in spite of the fact that the material constituting the needle felt was the same, compared to Comparative Example 3 in which the melt bonding treatment was not performed. It can be understood that the drop rate is improved in each step, and that the melt bonding treatment in the present invention is extremely effective. Comparative Example 1 uses only PPS fiber.
Which has been subjected to a fusion bonding process, but according to the present invention.
DHC is smaller, clogging is faster, and it is paid off
Filter rate is low.
The effect of the present invention does not occur if only the surface is melt-bonded.
It is.

When the filter material of Example 2 was used as a bag filter for a garbage incinerator at a maximum temperature of 200 ° C., it could be used stably for a long period of one year or more.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location D04H 1/42 D04H 1/42 Q

Claims (1)

(57) [Claims] (1) The polyphenylene sulfide fiber has a thickness of
5 ~ 50% glass fiber of 1 ~ 20μ mixed, dust
In the range of 1/5 to 3/4 of the surface area of the collecting surface,
The polyphenylene sulfide fiber partially melts and
Heat resistant knee characterized by being bonded to lath fiber
Dorfeld filter material