KR102600147B1 - Filter for high temperature and method for manufacturing of the same - Google Patents

Abstract

The present invention relates to a high temperature filter and a method of manufacturing the same.
One embodiment of the present invention provides a high-temperature filter containing slag fibers and a binder, wherein the binder is pulp, oxy-PAN fiber, or a combination thereof.

Description

High temperature filter and manufacturing method thereof {FILTER FOR HIGH TEMPERATURE AND METHOD FOR MANUFACTURING OF THE SAME}

One embodiment of the present invention relates to a high temperature filter and a method of manufacturing the same.

Recently, as the occurrence of fine dust related to the atmospheric environment has become a major issue, various policies are being reviewed to reduce pollution sources. Specifically, it has been reported that 30 to 50% of fine dust is generated from China, and 50 to 70% is generated domestically. In other words, since the level of fine dust generated in Korea is more than half of the total, there is a need to actively deal with it.

Fine dust can be emitted directly from factories, power plants, and automobile exhaust gases. Additionally, it may be released through condensation of air pollutants following a chemical reaction between nitrous oxide and sulfur dioxide. In particular, exhaust gases from thermal power plants are the biggest cause.

Dust in the air can be collected from exhaust gases generated from thermal power plants and large plants using dust collectors. These dust collectors use filters to capture dust. Specifically, ceramic filters with excellent heat resistance at high temperatures are being used to collect dust or gas above 500°C.

However, ceramic filters have weak impact resistance, so they have the problem of generating more than 10 times more load than typical fabric or non-woven bag filters. Accordingly, many inconveniences may arise in operation. In addition, ceramic filters have the disadvantage of being expensive because the production process is complicated and the manufacturing period is long.

Accordingly, the above problems can be solved by using fibers made from slag generated in the iron and steelmaking process as a filter.

To provide a high-temperature filter and its manufacturing method.

Specifically, one embodiment of the present invention seeks to provide a high-temperature filter using slag fibers and a method for manufacturing the same. Accordingly, fibrous inorganic materials can be used in high-temperature filters. In addition, a high-temperature filter can be provided using a binder that can be carbonized without being melted by heat even at high temperatures.

A high-temperature filter according to an embodiment of the present invention is a high-temperature filter containing slag fibers and a binder, and the binder may be pulp, oxy-PAN fiber, or a combination thereof.

Based on 100% by weight of the high-temperature filter, it may include 50 to 97% by weight of slag fiber and 3 to 50% by weight of binder.

The slag fibers may be randomly arranged.

The slag fibers may include coarse fibers with an average diameter in the range of 2 to 10 μm, and fine fibers with an average diameter of 2 μm or less.

The average shielding efficiency of the high-temperature filter may be 10 to 60% per 100 g/m ² basis weight.

The high temperature filter may be a high temperature filter applicable to an atmosphere of 800°C or higher.

According to one embodiment of the present invention, a high-temperature filter can be provided by combining slag fibers manufactured from slag and a binder. Specifically, by using a binder that does not melt even at 800°C or higher, a filter that can be applied even at high temperatures can be manufactured.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. The present embodiments are merely provided to ensure that the disclosure of the present invention is complete and to provide a general understanding of the technical field to which the present invention pertains. It is provided to fully inform those with knowledge of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Accordingly, in some embodiments, well-known techniques are not specifically described in order to avoid ambiguous interpretation of the invention. Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with meanings that can be commonly understood by those skilled in the art in the technical field to which the present invention pertains. When a part in the entire specification is said to “include” a certain element, this means that it may further include other elements rather than excluding other elements, unless specifically stated to the contrary. The singular also includes the plural, unless specifically stated in the phrase.

A high-temperature filter according to an embodiment of the present invention may include slag fibers and a binder. At this time, the binder may be pulp, oxy-PAN fiber, or a combination thereof.

Specifically, the unit cost can be reduced by using slag fiber as a filter material instead of glass fiber, which is a material for conventional HEPA (High Efficiency Particulate Air) filters. Additionally, by using slag fibers, a filter with excellent heat resistance and impact resistance can be provided. Accordingly, the service life of the filter can be extended.

This may be due to the characteristics of the slag fiber depending on the content of FeO and MgO in its composition. FeO and MgO are rarely contained in glass fibers, but are contained on average at about 20 to 30% in slag fibers. This composition may be slightly different depending on the type of slag. Steelmaking slag may contain 20 to 30% FeO, and blast furnace slag may contain almost no FeO and around 10% MgO.

The binder may be pulp, oxy-PAN fiber, or a combination thereof.

Specifically, the application temperature range of the filter can be improved by using the above binder. More specifically, since the binder is carbonized rather than melted at high temperatures, a filter containing it can be applied even at high temperatures.

Specifically, since typical polymers have a melting point or softening point, they have fluidity at high temperatures and then undergo gradual crystallization and decomposition processes. If it melts during this process, it will not be able to maintain its shape and will flow out. However, if the molecular weight is maximized in advance through cross-linking through an oxidation reaction, etc., it can be structurally solidified without going through the melting point. Therefore, it can be easily applied to high temperature filters.

Accordingly, pulp and oxy-PAN fibers, which are binders used in a high-temperature filter, which is an embodiment of the present invention, are characterized in that liquefaction does not occur due to heat treatment.

Based on 100% by weight of the high-temperature filter, it may include 50 to 97% by weight of slag fiber and 3 to 50% by weight of binder.

When the weight of the slag fiber is within the above range, shielding efficiency and pressure differential characteristics may be the best. When the weight of the binder is within the above range, filter application at high temperatures may be easy. Specifically, the smaller the binder content, the better, but in order to maintain the shape of the filter, it must be contained within the above range.

The slag fibers may be randomly arranged.

Specifically, the slag fibers may be arranged without directionality along the length and breadth of the high-temperature filter. More specifically, the slag fibers may be in the form of randomly arranged non-woven fabric.

When in the form of non-woven fabric, it can be said to be effective in the inertial effect, gravity effect, diffusion effect, and blocking effect as a filter particle collection mechanism.

The slag fiber may be a fiber manufactured by collecting blast furnace or converter slag.

Specifically, when using blast furnace slag, based on 100% by weight of the total slag fibers, CaO: 40 to 45% by weight, SiO ₂ : 35 to 40% by weight, Al ₂ O ₃ : 15 to 20% by weight, the balance MgO and others. May contain unavoidable impurities.

On the other hand, when using converter slag, based on 100% by weight of the total slag fibers, CaO: 40 to 45% by weight, SiO ₂ : 10 to 15% by weight, Al ₂ O ₃ : 3 to 7% by weight, FeO and/or Fe ₂ O ₃ : 20 to 25% by weight, the balance may include MgO and other unavoidable impurities. However, it is not limited to this.

The slag fibers may include coarse fibers with an average diameter in the range of 2 to 10 μm, and fine fibers with an average diameter of 2 μm or less.

When using a mixture of coarse fibers with a relatively large diameter and fine fibers with a relatively small diameter, the shielding efficiency of the filter can be increased.

Specifically, when a mixture of coarse fibers and fine fibers is used, the differential pressure characteristics may be better than when only coarse fibers are used. Accordingly, filter efficiency is improved and fine particle removal can be facilitated.

Accordingly, the average shielding efficiency of the high-temperature filter according to one embodiment of the present invention may be 10 to 60% per 100 g/m ² basis weight. This is an excellent value compared to the average shielding efficiency of conventional ceramic filters.

Additionally, the high-temperature filter according to one embodiment of the present invention may be applicable to an atmosphere of 800°C or higher. This is due to the binder described above. Specifically, this is due to the binder's characteristic of carbonizing rather than melting even at high temperatures.

Hereinafter, it will be described in detail through examples. However, the following examples only illustrate the present invention, and the content of the present invention is not limited by the following examples.

Example

First, slag, a by-product generated from a blast furnace or converter, was collected.

The collected slag was melted and then spun to produce slag fibers.

A filter was manufactured by a wet method using the slag fibers prepared above. The composition of the fiber and binder used at this time is as disclosed in Table 1 below.

At this time, the wet method used a conventional method of manufacturing a filter. Specifically, after the slag fibers and binder were dispersed in water, the water was removed using equipment equipped with a screen mesh. Afterwards, the filter was prepared by drying at 120°C for 5 minutes.

Comparative example

In addition, filters containing slag fibers and polyvinyl alcohol (PVA) as a binder were prepared in Comparative Examples 1 to 3. Filters based on organic/inorganic fibers were prepared in Comparative Examples 4 and 5. At this time, the inorganic fiber is a mineral fiber purchased from KCC.

This is also disclosed in Table 1 below.

Experiment example

Using the filters manufactured in Examples and Comparative Examples, shielding efficiency and differential pressure were compared. The shielding efficiency and differential pressure measurement methods are as follows.

<Shielding efficiency and foreclosure Measurement method>

The equipment used is an automated filter tester, and the equipment model is TSI 8130. Specifications related to shielding efficiency and differential pressure measurement were implemented in accordance with Modified BS EN 143.

The fine particles subject to shielding were NaCl particles (average particle diameter 0.26㎛) and were tested at two flow rates of 5L/min and 32L/min, and achieved a shielding efficiency of 99.97%, which is the HEPA grade standard, and a differential pressure of 1 inch H2O (=25.4mmH2O). Compare and evaluate.

division Fiber composition
(wt.%) basis weight
(g/ ^m2 ) 32L/min Shielding efficiency (%) Differential pressure (mmH ₂ O) 1 time Episode 2 3rd time average 1 time Episode 2 3rd time average Example 1 Slag fiber/pulp
= 90/10 100 16.8 17.2 16.2 16.7 1.0 1.1 1.1 1.1 Example 2 Slag fiber/pulp
= 80/20 100 21.8 22.4 21.5 21.9 1.8 1.8 1.8 1.8 Example 3 Slag fiber/pulp
= 50/50 100 35.0 36.2 37.4 36.2 6.6 6.6 6.7 6.6 Example 4 Slag fiber/pulp
= 50/50 200 53.5 54.2 54.5 54.1 12.1 12.2 12.2 12.2 Comparative Example 1 Slag fiber/
polyvinyl alcohol
(PVA) fiber
=97/3 100 7.4 7.3 7.2 7.3 0.4 0.4 0.3 0.4 Comparative Example 2 150 8.9 8.2 8.6 8.6 1.3 1.3 1.3 1.3 Comparative Example 3 200 10.6 12.2 11.5 11.5 1.4 1.4 1.4 1.4 Comparative Example 4 Inorganic fiber/PVA
= 90/10 100 5.4 7.2 6.7 6.4 0.3 0.3 0.3 0.3

In addition, Examples 1 to 4, in which filters were manufactured by combining slag fibers and pulp, are Comparative Example 1, in which filters were manufactured by combining slag fibers and polyvinyl alcohol (PVA) fibers. It can be seen that the turn efficiency is better than that of 3.

In addition, it can be seen that Examples 1 to 4 have superior pressure differential results compared to Comparative Examples 1 to 4.

As a result, it was confirmed that the shielding efficiency of Comparative Example 4, which was manufactured by combining inorganic fibers and polyvinyl alcohol (PVA) fibers, was the poorest.

Therefore, it can be seen that when the filter is manufactured including slag fiber and pulp as in an embodiment of the present invention, the shielding efficiency and pressure differential are the best.

Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features. You will be able to understand it.

Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. .

Claims (6)

A high-temperature filter containing slag fibers and binder,
The binder is pulp, oxy-PAN fiber, or a combination thereof,
The average shielding efficiency of the high-temperature filter is 10 to 60% per 100 g/m ² basis weight,
The slag fibers are,
Coarse fibers with an average diameter ranging from 2 to 10 μm; and
A high-temperature filter containing fine fibers with an average diameter of 2㎛ or less.
In paragraph 1:
A high-temperature filter comprising 50 to 97% by weight of slag fiber and 3 to 50% by weight of binder, based on 100% by weight of the high-temperature filter.
In paragraph 2,
A high-temperature filter in which the slag fibers are randomly arranged.
delete delete In paragraph 1:
The high-temperature filter is a high-temperature filter applicable to an atmosphere above 800°C.