JPH05245321A - Mist filter and mist collector - Google Patents

Abstract

PURPOSE:To provide a mist filter in which the collected liq. mist is not rescattered and having a low pressure drop and further to furnish a mist collector to which the mist filter is appropriately applied and which is easily attached or detached. CONSTITUTION:A gas current is passed through the cylindrical filter element 1 of a mist filter to separate the mist in the gas. The element is formed with the upstream layer 2, intermediate layer 3 and downstream layer 4 with respect to the gas current. The intermediate layer 3 is formed with a fine fiber, the upstream layer 2 is formed with a fiber thicker than that of the intermediate layer 3, and the downstream layer 4 is formed with the fiber thicker than that of the upstream layer 2. The element is freely detachably placed in a housing case consisting of a cylindrical gas-permeable body and a receiving plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mist filter used for separating and removing various mists such as acid mist, oil mist, plasticizer mist, water mist from gas, and mist collecting using the mist filter. Regarding the device.

[0002]

2. Description of the Related Art Heretofore, as this type of mist filter, a cylindrical filter element having an inner and outer two-layer structure of a fine glass fiber layer having a fiber diameter of about 1 μm and a glass fiber layer having a diameter larger than this is punched metal or the like. It is known that the air-permeable casing is housed and held in the air-permeable casing, and is detachably attached to a support plate provided in the mist collecting device.

[0003]

In the case of the above-mentioned conventional mist filter provided with a tubular filter element having a two-layer structure, a glass fiber layer having a large diameter is arranged on the upstream side of the gas flow and a fine glass fiber layer is arranged on the downstream side. When used as
There is a disadvantage that a large amount of mist liquid is contained in the fine glass fiber layer on the downstream side, and the mist liquid is re-scattered from the surface of the fine glass fiber layer due to the pressure of the gas flow. On the contrary, if the fine glass fiber layer is used on the upstream side of the gas flow and the large diameter glass fiber layer is arranged on the downstream side, all the mist is collected by the fine glass fiber layer on the upstream side. Therefore, there is an inconvenience that the content of the mist liquid increases and the pressure loss of the mist filter increases.

Further, since the filter element is housed and held in the breathable casing, the mist filter becomes a heavy object, and when the mist filter is attached to or detached from the support plate of the mist collecting device, the attachment,
It has the inconvenience that the removal work is inconvenient.

The present invention solves the above-mentioned conventional inconvenience, provides a mist filter which does not cause re-scattering of the collected mist liquid and has a large pressure loss, and is suitable for using the mist filter. It is an object of the present invention to provide a mist collecting device that can be easily attached and detached.

[0006]

In order to achieve the above object, the mist filter of the present invention is a mist filter which separates mist in gas by passing a gas flow through a cylindrical filter element. It has a three-layer structure consisting of an upstream layer, an intermediate layer, and a downstream layer for the gas flow,
The intermediate layer is formed as a fine fiber layer, the upstream layer is formed as a thicker fiber layer than the intermediate layer, and the downstream layer is formed as a thicker fiber layer than the upstream layer.

In this case, the upstream layer has a fiber diameter of 3 to 10 μm.
m, the intermediate layer preferably has a fiber diameter of 0.5 to 3 μm, and the downstream layer preferably has a fiber diameter of 10 to 50 μm. The reason why the fiber diameter in the above range is preferable is as follows. If the fiber diameter of the fibers of the upstream layer is less than 3 μm, the mist collection efficiency is too high, the pressure loss becomes high, clogging by dust is quick, the life becomes short, and if it exceeds 10 μm, the mist is sufficiently captured. This is because they cannot be collected and the load on the next layer increases. If the fiber diameter of the fibers in the intermediate layer exceeds 3 μm, the collection efficiency of fine mist cannot be sufficiently obtained, and if the glass fiber is less than 0.5 μm, the pressure loss becomes too high, and the production limit is further increased. Even if it is obtained, the cost will be extremely high. If the fiber diameter of the fibers in the downstream layer is less than 10 μm, capillary force is exerted to make it difficult for droplets of mist to drop and be removed to the lower part. If it exceeds 50 μm, the porosity is too large and the mist is liquified by the coalescing effect. This is because it cannot be made into drops.

The upstream layer is composed of a fiber layer in which raw wool, which is obtained by spinning glass by a flame method, a centrifugal method or the like, is collected with a binder into a tubular shape and has a bulk density of 10 to 1
00 kg / m ³ , the average pore size is preferably 20 to 100 μm, and the thickness is preferably 10 to 20 mm.

Further, the intermediate layer is composed of a fiber layer in which wool obtained by spinning glass by a flame method and collecting cotton is formed into a felt, and has a bulk density of 10 to 200 kg / m ³ and an average pore diameter of 2 to 20 μm. The thickness is preferably about 3 to 10 mm. Moreover, the collection efficiency can be easily adjusted by adjusting the number of turns of the intermediate layer.

The downstream layer is composed of a fiber layer made of polypropylene non-woven fabric, polyester non-woven fabric, polypropylene mat, etc., and has a bulk density of 10 to 30 due to long fibers.
0 kg / m ³ , average pore size 70-500 μm, thickness 1
It is preferably about 10 mm. Further, particularly when the downstream layer is arranged as the outermost layer, the strength becomes extremely large, and the inner reinforcing air-permeable core is unnecessary.

Further, the mist collecting device of the present invention is a mist collecting device suitable for using the mist filter, which is hung on a support plate in a casing having a gas inlet and a gas outlet. A storage case composed of the tubular vent and the tray is arranged, and the mist filter of the present invention is detachably stored in the storage case.

If a shielding plate is provided in the vicinity of the gas outlet, the mist liquid will not leak to the outside through the gas outlet when the mist liquid overflows from the tray and drops on the drain receiving bottom plate. It is preferable that the mist liquid collected on the receiving bottom plate does not re-scatter and leak to the outside through the gas discharge port. If a drain receiving bottom plate with an inclination is provided at the bottom of the casing and a drain drain is provided at the bottom of the bottom plate, the mist liquid can be quickly and completely drained.

[0013]

According to the mist filter of the present invention, the intermediate layer composed of the fine fiber layer has an effect of efficiently removing the fine mist, and the upstream layer composed of the fiber layer having a diameter larger than that of the mist filter has a large mist without increasing the pressure loss. By reducing the burden on the intermediate layer by adding the action of removing the mist, and by further disregarding the collection efficiency in the downstream layer consisting of a fiber layer with a thicker fiber diameter, it has the function of forming mist droplets and removing the fall. , Prevents re-scattering of mist without increasing pressure loss.

Further, in the mist collecting device of the present invention, the mist filter can be easily attached and replaced by simply attaching and detaching the mist filter to and from the storage case.

[0015]

EXAMPLES Next, the mist filter and the mist collecting device of the present invention will be explained based on examples. FIG. 1 shows an embodiment F of the mist filter of the present invention, which is of a type in which a gas flow is passed from the inside to the outside of a cylindrical filter element, and 1 in the drawing shows a cylindrical filter element. The filter element 1 is formed in a three-layer structure of an upstream layer 2, a middle layer 3 and a downstream layer 4 against the gas flow from the inside, and the upstream layer 2 is made of a glass fiber layer having a fiber diameter of 3 to 10 μm. The intermediate layer 3 is a glass fiber layer having a fiber diameter of 0.5 to 3 μm, and the downstream layer 4 is a fiber diameter of 10 to 50 μm.
m polypropylene non-woven fiber layer.

FIG. 2 shows another embodiment F'of the mist filter of the present invention, which is of a type in which a gas flow is passed from the outside to the inside of the cylindrical filter element 1, and the gas is introduced from the outside. It is formed in a three-layer structure of an upstream layer 2, an intermediate layer 3 and a downstream layer 4 for the flow, and each of these fiber layers 2, 3 and 4 is configured in the same fiber layer as in the above embodiment. Incidentally, in the case of this embodiment, a reinforcing breathable core 5 made of plastic is provided inside in order to obtain strength.

FIG. 3 shows an embodiment of the mist collecting apparatus according to the present invention. In the figure, 10 indicates a casing having a gas inlet 11 and a gas outlet 12. The casing 1
The upper part of 0 is a lid 10a, and the lid 10a is provided with the gas inlet 11 and a rectifying diffusion plate 13 made of punching metal arranged in the vicinity thereof. A pre-filter 15 is placed on the pre-filter receiver 14 downstream thereof, and is fixed by a pre-filter retainer 16.
A support plate 17 is arranged downstream of the prefilter 15, and a storage case 18 is attached to the support plate 17. The storage case 18 is composed of a cylindrical ventilation wall 18a made of punching metal and a tray 18b, and the mist filter F is detachably stored in the storage case 18. Reference numeral 19 in the drawing denotes a main filter stop ring, which can be fixed to the support plate 17 by a bolt 20.

An inclined drain receiving bottom plate 21 is provided at the bottom of the casing 10, and a drain drain 22 is provided at the bottom of the bottom plate 21. Gas outlet 1
A shield plate 23 is provided in front of 2, and a duct 25 having a blower 24 is connected to the gas outlet 12.

Thus, by driving the blower 24, the gas containing mist flows from the gas inlet 11 to the gas outlet 12, and first, the gas rectified and diffused by the rectifying diffusion plate 13 is prefiltered by the prefilter 15. Coarse dust and the like are removed, and the mist filter F flows downstream. In the mist filter F, coarse mist is removed in the upstream layer 2,
Next, the residual fine mist is removed in the intermediate layer 3. Then, the mist droplets and sedimentation are reliably performed by the downstream layer 4 to prevent re-scattering, the mist liquid 27 is collected in the internal space 26 of the mist filter F, overflows from the cylindrical ventilation wall 18a, and the drain receiving bottom plate is formed. It is dripped on 21 and collects. When a predetermined amount of mist liquid 27 accumulates on the drain receiving bottom plate 21,
The drain 22 removes the mist liquid 27.

Since the shielding plate 23 is provided in front of the gas discharge port 12, even if the mist liquid 27 on the downstream layer 4 of the mist filter F or the drain receiving bottom plate 21 is re-scattered, it is duct 25. It can be prevented from leaking to the outside through the. When the mist filter F reaches the end of its life, the mist filter F can be easily replaced by removing the stop ring 19.

Specific examples will be described below together with comparative examples. Example 1 In the structure of the mist filter F of the above-described example, the upstream layer 2 was formed by using a glass fiber having a fiber diameter of 6 μm and a fiber length of 5 to 30 mm as a binder, a bulk density of 50 kg / m ³ , an average pore diameter of 43 μm, and a thickness. A bulk density of 10 k obtained by forming a 20 mm tubular glass wool molded product, and collecting glass fibers having a fiber diameter of 1 μm and a fiber length of 10 to 20 mm as an intermediate layer 3 on the outer periphery thereof.
Wound once with felt-like glass wool with g / m ³ , average pore size 8 μm and thickness 7 mm, thickness 4 mm, bulk density 18
It is compressed to kg / m ^{3 and} has a bulk density of 104 kg / m ³ consisting of polypropylene long fibers having a fiber diameter of 25 to 35 μm as the downstream layer 4 on the outer periphery thereof, an average pore diameter of 84 μm and a thickness of 1.2 mm.
This was wound twice and coated with a non-woven fabric of 2.4 mm to obtain a mist filter having a total thickness of 27.4 mm.

Example 2 The upstream layer 2 had a thickness of 18.0 mm and the intermediate layer had a thickness of 4.0 mm.
And the downstream layer 4 has a bulk density of 44 kg / m ³ made of polyester long fibers having a fiber diameter of 25 μm and an average pore diameter of 130 μm.
A mist filter was prepared in the same manner as in Example 1 except that a non-woven fabric having a thickness of 8 mm and a thickness of 8 mm was used.

Example 3 The intermediate layer in Example 1 was wound twice and compressed to a thickness of 7.0 mm and a bulk density of 20 kg / m ³ to give a total thickness of 3
A mist filter was prepared in the same manner as in Example 1 except that the thickness was 0 mm.

Example 4 The intermediate layer in Example 1 was wound three times and compressed to a thickness of 7.6 mm and a bulk density of 28 kg / m ³ to give a total thickness of 3
A mist filter was prepared in the same manner as in Example 1 except that the thickness was 0 mm.

Comparative Example A mist filter having a two-layer structure having a total thickness of 24 mm in the mist filter of Example 1 was provided as a comparative example without providing a downstream layer.

The mist filters of the above-mentioned respective examples and comparative examples were attached to the mist collecting device of the above-mentioned examples, and the collection efficiency at 0.3 μm particles and the re-scattering of mist were tested.
The results are shown in Table 1.

[0027]

[Table 1]

As is clear from Table 1, the mist filter of the comparative example showed re-dispersion of mist, but the mist filter of this example did not show re-dispersion of mist at all. Further, in the case of this example, it is apparent that the collection efficiency can be easily adjusted only by changing the number of windings of the intermediate layer.

[0029]

As described above, according to the mist filter of the present invention, it is possible to provide a mist filter which does not cause re-scattering of the collected mist liquid and has a large pressure loss and a long life. Further, according to the mist collecting device of the present invention, the mist filter can be easily replaced, and a mist collecting device suitable for using the mist filter can be obtained.

[Brief description of drawings]

FIG. 1 is a front sectional view of an embodiment of the mist filter of the present invention.

FIG. 2 is a front sectional view of another embodiment of the mist filter of the present invention.

FIG. 3 is a front sectional view of an embodiment of the mist collecting device of the present invention.

[Explanation of symbols]

 1 Filter Element 2 Upstream Layer 3 Intermediate Layer 4 Downstream Layer 5 Reinforcing Breathable Core 10 Casing 10a Lid Part 11 Gas Inlet Port 12 Gas Discharge Port 13 Rectifying Diffusion Plate 14 Prefilter Receptor 15 Prefilter 16 Prefilter Hold 17 Support Plate 18 Storage case 18a Cylindrical ventilation wall 18b Receiving tray 19 Stop ring 20 Bolt 21 Drain receiving bottom plate 22 Drain removal 23 Shielding plate 24 Blower 25 Duct 26 Internal space 27 Mist liquid

Claims (5)

[Claims] 1. A mist filter for separating a mist in a gas by passing a gas flow through a tubular filter element, wherein the filter element has a three-layer structure of an upstream layer, an intermediate layer and a downstream layer for the gas flow. A mist filter, wherein the intermediate layer is formed into a fine fiber layer, the upstream layer is formed into a fiber layer thicker than the intermediate layer, and the downstream layer is formed into a fiber layer thicker than the upstream layer. 2. The upstream layer has a fiber diameter of 3 to 10 μm, the intermediate layer has a fiber diameter of 0.5 to 3 μm, and the downstream layer has a fiber diameter of 1 μm.
The mist filter according to claim 1, wherein the mist filter is made of fibers having a fiber diameter of 0 to 50 µm. 3. The mist filter according to claim 1, wherein the upstream layer and the intermediate layer are made of a glass fiber layer, and the downstream layer is made of a nonwoven fabric of thermoplastic resin fibers. 4. A storage case comprising a tubular vent and a tray suspended from a support plate is disposed in a casing having a gas inlet and a gas outlet, and the storage case is provided with the storage case. A mist collecting device, wherein the mist filter described in 1 above is detachably accommodated. 5. A shielding plate is provided in the vicinity of the gas discharge port, an inclined drain receiving bottom plate is provided at the bottom of the casing, and a drain drain is provided at the bottom of the bottom plate. The mist collecting device described in 1.