JPS60161713A - Filter and its preparation - Google Patents

Abstract

PURPOSE:To obtain a filter having a large filtering area and reduced in pressure loss, by forming a specific honeycomb structure by laminating inorg. fiber paper and corrugated processed paper of said inor. fiber paper and sealing only one opening part of an individual cell. CONSTITUTION:Paper 1 comprising ceramic fibers bonded by a silicate gel and corrugated processed paper 2 formed by applying corrugating processing to said paper 1 are wound up to form a honeycomb structure which is, in turn, bonded by an inorg. adhesive. Only one end of each of tunnel shaped cells 4 formed by the fiber paper 1 and the corrugated processed paper 2 is sealed by a sealant 5 and the sealed ends of cells 4a formed by the corrugated processed paper 2 and the paper 1a inside said paper 2 are presented at the opening surface in the side opposite to the opening surface where the sealed ends of the cells 4b formed of the corrugated processed paper 2 and the paper 1b outside said paper 2 are present and sealed ends are reversed at every 1/2 layer. By this method, a filter having good heat resistance and heat shock resistance and showing no deformation is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a filter for use in filtering hot gases and a method for manufacturing the same.

Conventionally, filters for high-temperature gases have been made of heat-resistant fibers, such as those made of glass fibers intertwined in a felt shape, or filters made of paper mainly made of glass fibers, as well as those made of heat-resistant fibers, such as those made of fibers extruded into nitrous or nicom shapes. Products that utilize molded porous ceramics are used. However, since the heat-resistant limit temperature of glass fiber is not very high, products using Naganamu Glass AM can only be used to treat gases up to 30C (1'C).Also, even in terms of performance other than heat resistance, Glass M and M types have no filtration area per volume and have a low filtration capacity, and although paper processed into a special shape is considerably better in this respect, further improvements are desired. Many manufacturing methods require improvement.

On the other hand, ceramilas-based extrusion molded products have drawbacks such as poor thermal shock resistance even though they have a high heat-resistant limit temperature, high pressure loss, heavy weight, and brittleness. Furthermore, in terms of manufacturing, there are problems in that the process is complicated and takes a long time, and it is difficult to manufacture large products.

In view of the above-mentioned current situation, the present invention was completed as a result of repeated research by the present inventors with the aim of providing a better filter for high-temperature gases, and is the first invention related to filters. and a second invention relating to a method for manufacturing the filter.

The filter according to the first invention has a honeycomb structure in which inorganic fiber paper suitable as a gas filter medium and its full-gate processed product are alternately laminated with the corrugated directions aligned, and the cell openings of the individual cells are Only one of the openings at both ends is sealed, and the sealed end is partially sealed on the opposite side every 1/2 layer. Further, the method for manufacturing the filter of the first invention according to the second invention includes continuously supplying a long sheet of inorganic fiber paper or its precursor having suitability as a gas filter medium and sealing the edge of one side of the long sheet. At the same time, a corrugated workpiece of another similar sheet is supplied and bonded to the sheet surface to which the sealant has been applied, and the edge of the sheet and the corrugated workpiece are bonded with the applied sealant. Fill in the gaps, and then apply a sealant on the corrugated workpiece at the opposite edge to fill the valleys of the corrugated workpiece, and roll the sheet after the above treatment and the laminated sheet of the full-coated workpiece. It is characterized in that it is rolled up into a shape, subjected to a process for fixing the shape, and when an inorganic fiber paper nii precursor is used, a process for converting the precursor into inorganic fiber paper.

FIG. 1 is a perspective view showing an example of the filter of the first invention manufactured by the manufacturing method of the second invention. The basic structure of this filter is paper 1 made of ceramic fibers bonded by silicic acid gel and paper 2 made of a similar paper that has undergone full gate processing and rolled up to form a kind of honeycomb structure. The corrugated workpiece 2 is bonded to the corrugated workpiece 2 using an inorganic adhesive at the contact portion of the stepped top portion 3 of the corrugated structure. Moreover, only one end of the tunnel-shaped cell 4 formed of the paper 1 and the corrugated workpiece 2 is sealed with a sealant 5 in the following manner.

That is, FIG. 2 (partial enlarged view of the cell opening surface l side in FIG. 1) and FIG. 3 (cell opening surface ■ in FIG. 1)
As is clear from the side partial enlarged view), the sealed end of the cell 4a (hereinafter referred to as A-layer cell) formed by the full-gate workpiece 2 and the paper 1a on the inside (center side) is cordate. The sealed end of the cell 4b (hereinafter referred to as B-layer cell) formed by the workpiece 2 and the paper outside the workpiece 2 is located on the open side opposite to the open side. Since the two types of cells in the same layer in the laminated structure have different sealed ends, the sealed ends are reversed every 1/2 layer.

-1. Due to the structure described above, when the gas to be filtered is pumped from the opening side I of this filter, the gas is first sealed on the opening side L as shown in Figure 4. The dust enters the 8-layer cell 4b, which has not been processed, and then passes through the cell's partition wall 6 (made of paper 1 or full-gate processed material 2) and moves to the adjacent A-layer cell 4a. It is collected and filtered. The filtered gas that has entered the A-layer cell 4a is discharged from the unsealed opening side (2).

The filter of the present invention does not need to be made of a rolled laminate as in the above example, but as shown in FIG.
An alternate laminate of inorganic fiber paper 7 and its corrugated product 8 cut at an appropriate high temperature may be subjected to the same cell sealing treatment as in the example.

The thickness and filtration characteristics of the inorganic fiber paper of the filter of the present invention, the area and length of the openings of the cells, and the area and shape of the openings of the filter as a whole can be arbitrarily selected depending on the application and usage conditions. be able to.

Next, the manufacturing method of the second invention, which is the most advantageous manufacturing method of the filter of the invention, will be explained.

As the inorganic fiber paper used as the starting material, various ceramic F
The one made of IJL navy blue is the best in terms of heat resistance, thermal shock resistance, acid resistance, etc., followed by the one made of IJL navy blue, but these inorganic fiber papers, especially the ceramic fiber paper Since the fiber M1 is generally rigid, the required full-gate processing and subsequent winding may be difficult to perform in the laminating process.

Therefore, in that case, Kuroiso W, which is easy to process
A paper obtained by mixing an appropriate amount of organic WL fiber and an organic binder with an L-fiber paper precursor, such as Kuroiso F&A, is prepared, and this is used at least as a raw material for corrugated paper to form a laminate. manufactured and then fired at an appropriate stage to remove the organic fibers and organic binder.

To explain in more detail the manufacturing method using an inorganic fiber paper precursor, first, paper is made from a mixture of ceramic fibers and organic fibers by a conventional method. Ceramic fibers include highly heat-resistant inorganic fibers such as silica fibers, alumina fibers, aluminosilicate fibers, and zirconia fibers, such as 7
Ain 7 Renx and Chias KK products), Su 7 Rashir (
The organic WL fibers include fibers that are hydrophilic, have good dispersibility in water, and are not thermoplastic, such as rayon fibers, cellulose WLs such as wood pulp, i1. is optimal, but various synthetic fibers such as vinylon fiber, polyethylene fiber, acrylic i-fiber, and polyester fiber can also be used. It is preferable that the fineness is 3 denier or less, the fiber length is about 3 to [1)+nm, from the viewpoint of the dispersibility of the fibers in water and the paper strength. Blending an appropriate amount of organic fibers not only improves processability using a full-gate processing machine as mentioned above, but also enables the dispersion of rigid and non-self-adhesive ceramic fibers due to the synergistic effect with the organic binder during the papermaking process. This has the effect of enhancing paper forming properties and improving the shape retention of the molded product after processing.

The aqueous dispersion of the fibrous raw material for papermaking contains an organic binder. Organic binders are effective in increasing the dispersibility of fibers during the papermaking process, and in increasing the shape stability of paper by adhering wL fibers to each other and fixing the paper structure after paper is formed. .

Examples of preferred binders include acrylic T64 resin, vinyl acetate resin, ethylene/vinyl acetate resin, polyvinyl alcohol resin, CMC, starch, and the like.

A suitable blending ratio of the above papermaking raw materials is 80 to 96% by weight of ceramic fiber, 2 to 10% by weight of Ariiso fiber (preferably 3 to 6% by weight), and 2 to 10% by weight of organic binder. (preferably 3 to 6% by weight). The more organic matter there is, the easier it is to make paper and the shaping process before firing (described below), but the air permeability of the final product increases and it tends to lack strength.
The total amount is preferably within 15% by weight. however,
Other heat-resistant inorganic powders such as mica and kaolin can also be mixed into the papermaking raw material.

The raw material for papermaking is made into a slurry with a concentration of about 0.1 to 0.3% by a conventional method, and then processed into a slurry with a thickness of preferably about 0.15 to 0.5011 II 11.
A relatively bulky paper with density (', ), 2-0, 4 H/c+a3 (all values for dry material) is formed and dried. The resulting mixed paper (if inorganic fiber paper is used as the starting material) is divided into two parts, and one half is subjected to so-called corrugation processing using, for example, a full-gate processing machine for manufacturing corrugated board. The waveform, wave height, and wave interval are arbitrary. Full-gate processed paper and unprocessed flat paper are integrated as described above while being coated with a sealant, and then rolled up. It is efficient to use a device like the one shown in . The paper 9 for corrugating is fed between the two rolls 10 and 11 and is corrugated there. processed paper 9
At the top of the corrugation, while this paper is on the corrugated roll 11,
The inorganic binder is applied from the left side in FIG. 6 using a coating device (not shown). On the other hand, similar paper 12 is sent to the corrugated roll 11 and press roll 13, but on the way,
A paste sealant 14 is applied to one side edge. Since the gap between the corrugated roll 11 and the press roll 13 is approximately equal to the thickness of the full-date processed paper 9 and the flat paper 12, the material that comes out from between the two rolls is so-called Papers 9 and 12 overlap each other in a single-sided corrugated board shape, and a sealant 14 is filled in the gap between the two at one end. [Adding full date to this polymeric sheet] On the second paper 9, apply the sealant 15 at the edge opposite to the edge to which the sealant has been applied so that the valleys of the full date are filled and the top surface is flat. Make it adhere. Note that 16 and 17 are rollers for flatly depositing the sealant at a predetermined height, and 18 is a scraping plate for removing the sealant that does not protrude to the sides. After the above processing is completed, winding is performed using a winding device (not shown) while applying a binder to all or part of the top of the step as necessary.

The sealant and binder used in the above steps include:
Considering the usage conditions of the product, use an inorganic binder with sufficient heat resistance, thermal shock resistance, chemical resistance, etc. It is acceptable to use the same binder as the sealant and the binder (for adhesion), but it is desirable to use a sealant that exhibits less volume shrinkage during curing and has good filling action. Specific examples of inorganic binders that can be used for sealing and/or adhesion include:

■ Refined bentonite or products to which titanium oxide, silica powder, alumina sol, etc. are added.

■ Made of silica powder and alumina powder.

■ Alumina powder made from kaolin with Froeglsilk or ceramic fiber added.

■ Composed of zirconia fibers and froidal silicon.

(Both use water as a diluent.)■ A mixture of kaolin and mica with addition of floidal silicate or ceraminoku fiber.

Commercially available products include FF adhesives such as Chias KK products) and Sumiceram (Sumitomo Chemical Industries KK products).

The resulting rolled laminate is heated to cure the sealant and binder. After that, a binder treatment is applied to bond the delicate pieces together to stabilize the shape and adjust the pore size. Binders used in this treatment include floidal silica or ethyl silica, mica or (and)
Those to which kaolinite is added are preferred, and any one of these is uniformly impregnated, and then the impregnated silicon compound is converted into a silicic acid gel and subjected to a hardening process. When impregnated with Frogl silica, 150 to 170°
If it is dried with step C, the curing in step 1 is completed. When impregnated with ethyl silicate, the ethyl silicate is hydrolyzed within the tissue of the paper to form a silicic acid gel. For this purpose, methods such as impregnating with ethyl silicate stock solution or solution and then exposing to high temperature steam, or adding hydrochloric acid or the like as a catalyst to the ethyl silicate solution to be impregnated, and leaving the impregnation for several hours are adopted. The method using ethyl silicate is more preferable than the method using colloidal silicate in that it is easier to obtain a uniform treatment effect. This process is
Although it depends on the use of the product, it is desirable to fix 70 to 300 g of SiO2 per 100 g of paper, preferably about 180 to 240 g.

After forming the silicic acid gel, in an oxidizing atmosphere, approximately 1
By firing under 1'C, organic substances such as organic fibers and organic binders are burned off.

In the manner described above, a filter having the same shape as that shown in FIG. 1 is obtained, the main component being paper made of ceramic fibers bonded by silicic acid gel.

Considering the pressure loss and collection efficiency of the product as well as the difficulty of manufacturing, the inorganic fiber paper, which is the main constituent material of the filter of the present invention, has a porosity of about 10 by selecting the raw materials and processing conditions.
35% and an average pore diameter of about 0.3 to 31i, thereby achieving a collection efficiency of 40 to 99%.

The filter of the present invention as described above has many advantages over conventional gas filters.

(Virtually all the constituent phases of the filter are filtration membranes, and because they are arranged in a unique shape, the filtration area per unit volume is extremely large, making it possible to achieve high space utilization.

(b) For the same reason and because paper is the filter medium, pressure loss is small.

(c) It has good heat resistance and thermal shock resistance, and in particular, those using ceramic fiber paper can withstand use up to about 11) l) l) 'C, and have good acid resistance and chemical resistance.

(d) Even if paper is used as a filter medium, it is hard as a whole like a ceramic molded body, and there is no risk of partially deforming or shaking during use, resulting in unstable performance.

(E) Since it is light and consists of one 70-ink, replacement and maintenance and inspection work is easy, and there is no risk of re-scattering of the collected dust.

(f) When used for filtering organic or carbonaceous dust, it can be recycled by firing as it is.

According to the manufacturing method of the second invention, this high-performance filter can be easily manufactured with extremely high productivity.

[Brief explanation of drawings]

Figure 11: A perspective view showing an example of a filter according to the present invention. FIG. 2: A partially enlarged view of the cell opening surface l side in FIG. 1. Figure 3: Portion on the cell opening surface Il side in Figure 1, Oguchi. FIG. 4: An explanatory diagram of seven gas leaks when using the filter of FIG. 1. 5l: A perspective view showing another example of the filter according to the present invention. 6th N: An explanatory diagram of an example of lamination-1- in the manufacturing method of the present invention. No. 7l: Fig. 6 (plan view). 1: Ceramink fiber paper 2: Full gate processed product 4: Cell 5. ]4,15: Sealing 11-Shaving 7: Inorganic fiber paper 8
Nicol gate processed product 9.12: Inorganic fiber paper precursor 1
n, ++: Dan Il Roll Agent Patent Attorney Itai - Accent Diagram 6

Claims (5)

[Claims] (1) Cell openings in a honeycomb structure in which inorganic fiber paper and its full-gate products, which are suitable as gas filtering media, are laminated alternately with the direction of the full gates aligned, and the openings at both ends of individual cells. A filter that is partially sealed so that only one side of the sealed end is sealed and the sealed end is on the opposite side every 1/2 layer. (2) The filter according to claim 1, wherein the inorganic fiber paper is made of ceramic fibers bonded by silicic acid gel. (3) The filter according to claim 1, wherein the honeycomb structure is formed by stacking inorganic fiber paper suitable as a gas filter medium and a full-gate processed product thereof, wound up into a roll, and fixed. (4) A long sheet of inorganic fiber paper or its precursor, which is suitable as a gas filtering medium, is continuously supplied and a sealant is attached to the edge of one side of the sheet, and the sheet surface is coated with the sealant. A corrugated workpiece of another similar sheet is supplied and bonded, and the space between the sheet edge and the corrugated workpiece is filled with the applied sealant, and then sealed on the corrugated workpiece at the opposite edge. When a fixing agent is attached to fill the valleys of the corrugated product, the sheet after the above treatment and the laminated sheet of the corrugated product are rolled up into a roll, and a shape fixing treatment and an inorganic fiber paper precursor are used. A method for producing a filter, which comprises performing a process of converting the precursor into inorganic fiber paper. (5) The manufacturing method according to claim 4, wherein the inorganic fiber paper precursor is a paper product comprising inorganic m, m, organic fibers, and an organic binder.