JPH0368415A - Production of element for gas sorbing machine - Google Patents

Abstract

PURPOSE:To form an element for a gas sorbing machine by impregnating a baked matrix made of inorganic fiber with water glass, heating and drying the baked matrix and thereafter immersing it in an aluminum sulfate aq. soln., producing and bonding silicate hydrogel thereto. CONSTITUTION:A honeycomb matrix having many small through-holes is molded by alternately laminating low-density flat paper and corrugated paper made of inorganic fiber such as ceramics fiber as a main component and thereafter baked. The baked matrix is impregnated with water glass, heated and dried. Thereafter this baked matrix is immersed in the aq. soln. of metallic sulfate such as aluminum sulfate. Silicate hydrogel is produced and boned to the spaces of fibers of paper and on the surfaces thereof. An element for a gas sorbing machine is obtained by washing and drying it. Then the metallic sulfate aq. soln. is cooled to crystallize and remove sodium sulfate. Production of the element for the gas sorbing machine is repeatedly performed by replenishing water glass and metallic sulfate.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention involves forming a block with a large number of small holes using a solid adsorbent that reversibly adsorbs moisture and other active gases.
The present invention relates to a method for continuously manufacturing an element for a gas sorption machine, in which a process gas and a regeneration gas are passed alternately through the passage hole to continuously obtain a gas, such as dry air, from which an active gas has been removed.

Conventional technology In Patent Application No. 86969 filed in 1985, the applicant of this patent proposed a paper made with low density paper made from inorganic fibers such as ceramic fibers with fpI layer, which has many small perforations for moisture exchange or total heat. Molding into the shape of a replacement element, impregnating the inorganic fiber paper with water glass before or after the molding process,
After molding, it is immersed in an aqueous solution of aluminum salt, magnesium salt, or calcium salt to produce a silicate hydrogel, which is then washed and dried with inorganic fiber paper as a matrix for moisture exchange or total heat exchange with silicate hydrogel as the main component. A method to obtain the device was proposed.

Problems to be Solved by the Invention and Means for Solving the Problems In the above-mentioned earlier application, as an example, water glass (sodium silicate) and aluminum sulfate were immersed in I and X, and water glass was immersed in the same aluminum sulfate solution. In case of continuous production by immersing the subsequent matrix one after another and simultaneously replenishing this mother liquor with aluminum sulfate one after another, there is a concern that an increase in the by-product sodium sulfate will affect the performance of the obtained dehumidifier element. I mentioned that there is no.

However, if the above-mentioned aluminum sulfate replenishment and silicate production reaction are repeated, the by-product sodium sulfate reaches saturation and crystallizes, and the solubility of aluminum sulfate decreases, making it impossible to perform the silicate production reaction satisfactorily. Therefore, the by-product sodium sulfate must be removed from the aluminum sulfate mother liquor from time to time.

Among the water-soluble aluminum salts, magnesium salts, and calcium salts that can react with water glass to form a silicate gel as exemplified in the previous application, '-1 Water-soluble aluminum salts and magnesium salts that can be obtained at reasonable prices are used. Looking at the reaction with water glass, that is, sodium silicate, Na*5iOs + Alt(SO4)s =
Alt(SiOs)s+ Na5SO4//
Al (lIxPo41 a = //
Na5PO4〃 Al(:ls
-4tt NaC1//Al
(NOx)s”/7 NBNOs/
/ MgS Oa = MgS i
Ox ◆Na5SO4〃MgC1*→//
Na1l // Mg (NOal * -tl
It becomes NaNOs. Magnesium phosphate is insoluble in water and cannot be used in the above reaction, and among the above, aluminum phosphate is rather expensive and undesirable, so it will not be discussed below.

6+ left! The by-products produced by the reaction between the metal salts of class I and water glass are sodium sulfate, common salt, and sodium nitrate, and the difference in solubility due to the temperature difference can be used to create a mixed aqueous solution of these by-products and the raw metal salt. The simplest method is to separate the by-product salt by crystallization.

The above metal salt and by-product salt at 60° C. and 0° C. are reacted with water glass at 60° C., and then cooled to 0° C. to remove the by-product salt by crystallization. Looking at the solubility (wt%) in water of magnesium chloride
37.9 34.6 Salt
27.1 26.3 Aluminum nitrate
51.5 37.5 Magnesium nitrate
47.7 38.4 Sodium nitrate 55.
4 42.2. For example, in a mixed aqueous solution of aluminum chloride and salt, the solubility of aluminum chloride and salt in water hardly changes depending on the temperature, and in each combination of magnesium chloride and salt, aluminum nitrate and sodium nitrate, magnesium nitrate and sodium nitrate, Similarly, by cooling the above-mentioned four sets of mixed aqueous solutions, only one component thereof cannot be removed by crystallization in an almost pure form. On the other hand, in a mixed aqueous solution of aluminum sulfate and sodium sulfate, aluminum sulfate has a high solubility at both high and low temperatures, while sodium sulfate has a significantly low solubility at low temperatures and its solubility changes greatly due to temperature differences, so a concentrated mixed aqueous solution at a high temperature is When cooled, sodium sulfate containing almost no aluminum sulfate is precipitated, so that sodium sulfate can be separated and precipitated.

Water glass contains potassium silicate in addition to the above-mentioned sodium silicate, and the solubility of the by-product in water (wt%) when potassium silicate is reacted with aluminum salt and magnesium
) is 60℃ 0℃ Potassium sulfate 15.4 7.2 Potassium chloride 31.4 21.9 Potassium nitrate 52.2 11.7, and only potassium sulfate is separated by crystallization from aluminum sulfate and magnesium sulfate. However, potassium silicate is considerably more expensive than sodium silicate and is not preferred for mass production.

It can be said that it is suitable.

Another problem with the prior application is the safety of using the dehumidifier. The paper used as a raw material for manufacturing elements is inorganic fiber paper, but in this case, several percent of organic fibers such as wood bulbs and organic synthetic fibers are mixed in to facilitate paper making.

When dehumidifying with an element manufactured using this paper, high-temperature, low-humidity recycled air (temperature at the inlet of 120-180°C)
Since this high-temperature regeneration air passes through the element, there is a risk that the above-mentioned organic fibers will burn and damage the element. This baking process removes organic substances contained in the paper. Organic materials such as polyvinyl acetate and epoxy resin are used as adhesives when laminating papers to obtain a matrix.

If ethylene vinyl acetate copolymer or the like is used, this organic adhesive is also removed at the same time. This firing process further reduces the paper's apparent specific gravity, ie, its thickness, and increases its porosity, thereby further increasing the amount of metal silicate gel relative to the area of the paper, ie, its dehumidification capacity.

In addition, if water glass is used as the adhesive used for laminating paper, and instead of the organic adhesive after reaction, this water glass will react with the sulfate together with the water glass impregnated throughout the matrix, and the inorganic fiber paper will be absorbed into the matrix. The moisture absorption and other gas sorption performance of the device can be improved by about io~20% without fear of reducing the mutual adhesive strength.

As mentioned above, non-combustible inorganic fibers are used as the main component of the paper. Ceramic fibers are inorganic fibers.

Glass, 1RH1, carbon #! Any of the above-mentioned inorganic fibers may be used, or a mixture of 211 or more of the above inorganic fibers may be used. Other inorganic fibers include asbestos fibers, but asbestos fibers cannot be made into low-density paper, and if asbestos fibers are handled for a long time, they can lead to asbestos deposits, which can rarely cause lung cancer, and can cause cancer in the chest or chest. It cannot be used because it may cause special swelling in the peritoneum (primitive internal capsule layer).

The reaction of water glass impregnated into the matrix with sulfate produces gold fI! In producing the 4-silicate gel, prior to impregnation with the sulfate aqueous solution, the matrix is heated and the water glass is concentrated until it becomes a hydrous water glass with a water content of 3 to 30%, that is, a semi-solid state. Prevents loss of water glass and formed metal silicate gel due to elution or leakage into the sulfate aqueous solution.

To summarize the gist of the present invention as described above, ceramic fiber, glass #Im, carbon 1RHI or the above fiber 2
A honeycomb matrix with many small pores is formed by alternately laminating low-density plane paper and corrugated paper mainly composed of inorganic fibers selected from a mixture of more than 1,000 species. →The density of the paper is further lowered by firing to remove organic matter contained in the paper and adhesive, and the fired tux is immersed to form and bond silicate hydrogel to the fiber gaps and surface of the paper through reaction with water glass. After washing and drying, a gas sorption element having a framework of paper inorganic fibers and silicate aerogel as a main component was obtained, and the sulfate aqueous solution was cooled to produce a reaction by-product, which was dissolved in the sulfate aqueous solution. crystallizing out the sodium sulfate present, replenishing the water glass aqueous solution after impregnation with water glass, replenishing the sulfate aqueous solution after the reaction,
After the reaction, the production of gas sorption device elements is repeated.

Embodiments will be described in detail below with reference to the drawings.

Embodiment FIG. 1 shows an example of an apparatus used in the molding process, which is the first step of the present invention. 2 is in contact with the pressure roller 3, and the surface speeds of both are approximately the same. 4.5
1 is an adhesive applicator having adhesive containers 4a, 5a and an adhesive applicator roller 4b, respectively.

5b, an adhesive 6.6 whose main component is polyvinyl acetate or water glass is put into the adhesive containers 4a, 5a, and a part of the adhesive application rollers 4b, 5b is immersed in the adhesive container 4a, 5a. It is provided close to the forming gear 2.

Ceramics 1i 70-90%, wood pulp 5-20%
, 5-10% binder, thickness 0.1-0.5m
m, a very porous paper with a density of less than 0.5 g/cm' (less than 100 g/m' for a paper thickness of 0.2 mm) 7
. After applying the adhesive 6 to the crest of the corrugated paper 7a, the adhesive 6 is passed between the forming gear 2 and the pressure roller 3 together with the other paper 8 to bond them together, resulting in a single-corrugated molded article 9. corrugated paper 7a
After applying adhesive 6 to the crest of the wave by the adhesive application roller 5b of the adhesive application device 5, the adhesive 6 is rolled up to form a cylindrical honeycomb matrix with a large number of small holes penetrating between both end faces as shown in FIG. Get 11.

The obtained honeycomb matrix 11 is put into a furnace and heated to 200~
The paper is baked in air at 500°C to remove organic matter contained in the paper and adhesive, further lowering the density of the paper.
It is immersed in a ~35% aqueous solution and dried at 80-100°C for about 1 hour, and the immersion/drying process is repeated once again. In this way, a honeycomb body is formed in which 2 to 2.5 times the weight of the matrix is adhered and infiltrated with Japanese water glass, and then immersed and shaken in a 20 to 30% aqueous solution of aluminum sulfate or magnesium sulfate to form a honeycomb body of aluminum silicate or magnesium silicate. Drogel is generated, pulled up from the liquid, washed with water to remove the by-product sodium sulfate and excess sulfate aqueous solution, and the silicate hydrogel that is not fixed to the matrix, and heated and dried to form the erogel mainly made of aluminum silicate or magnesium silicate. A gas sorption borrowing element is obtained.

Water glass and sulfate are appropriately added to the water glass aqueous solution and sulfate aqueous solution, and the post-reaction operation is repeated. The sulfate aqueous solution is maintained at 60 to 70°C, and the matrix after the water glass treatment is immersed in it. This operation is repeated, and when an amount of sodium sulfate has accumulated to the extent that it becomes the sulfate aqueous solution, the aqueous solution is Cool to around ℃, precipitate sodium sulfate, and remove by filtration. As shown in Figure 3, the solubility of aluminum sulfate and magnesium sulfate in water is significantly different from the solubility of sodium sulfate in water at low temperatures.
Furthermore, the solubility of Meikai, which is a double salt of aluminum sulfate and sodium sulfate, in water is almost the same as that of aluminum sulfate, and sodium sulfate can be crystallized as crystals containing almost no aluminum sulfate or magnesium sulfate.

In the above embodiment, an example was described in which the matrix 11 was molded and then fired in air at 200 to 500°C, but the inorganic fiber paper 7.8 was first fired and then impregnated with water glass, so that the water glass became slightly sticky. After it dries to the extent that it leaves paper 8
The matrix may be formed by patterning the paper into a corrugated shape and stacking papers 7 and 8.

Further, according to the above matrix, the gas sorption borrowing element can be used not only in a cylindrical or rotary type as shown in FIG. 2, but also in a parallel flow type as shown in FIG. 4, or a cross flow type as shown in FIG. .

Effect of the Invention Figure 6 shows the reaction of silicate erogel obtained by reacting aluminum sulfate and magnesium sulfate with hydrohydrate glass by heating it to 60 to 70°C and commercially available silica bagel at room temperature (2
The graph shows the equilibrium moisture absorption amount (% by weight) at 5°C. Equilibrium moisture absorption of various Erogels at relative humidity of 75% is: 37.6% using aluminum sulfate, 37.6% using commercially available silica gel, 31% using magnesium sulfate.
It was 23.5%.

Figure 7 shows that ceramic fiber paper is impregnated with water glass in the same manner as described in the example, and then impregnated with a 19-21% aqueous solution of aluminum sulfate and magnesium sulfate at 60-70°C to form a gas sorbent gel into a ceramic material. The equilibrium adsorption amount of water vapor per rn' of ceramic paper at 25° C. when fixed on paper is shown.

Figure 8 shows the use of polyvinyl acetate (PVAc) as an adhesive for paper lamination using a 19-21% aqueous solution of aluminum sulfate and magnesium sulfate at 60-70°C according to the example.
and the equilibrium moisture absorption amount at 25° C. of a gas sorption element manufactured using water glass (WG).

According to the example, after each immersion, sodium sulfate was removed from the aqueous solution of aluminum sulfate, and water glass and aluminum sulfate were replenished.
The equilibrium moisture absorption amount at 5° C. and 75% relative humidity is shown in FIG.

FIG. 10 shows a dehumidifier assembled with the gas sorption element 11 shown in FIG. It is separated into a zone 14 and a regeneration zone 15, and the element 11 is rotated by a geared motor 16 and a drive belt 17, and high-humidity treatment air 18 is sent to the treatment zone 14, and high-temperature and low-humidity regeneration air 19 is sent to the regeneration zone 15. , the treated air 18 is dehumidified to obtain dry air 20. 21 in the figure
is a pulley, 22 is a tension pulley, 23 is a rubber seal, and 24 is a regenerated air heater.

According to the example, the diameter of the corrugated paper 7a is 320 mm, the thickness is 200 mm, the wavelength is 3 mm, and the wave height is 2 m as shown in FIG.
Water glass (WG) was used as the adhesive for ma, and water glass aluminum sulfate (A
I) The gas sorption-like element obtained by the treatment and the moisture exchange element of the previous application manufactured under the same conditions were molded to the same size using the same ceramic fiber paper, and 8% of the matrix E1m was used as a moisture absorbent. The dehumidifier shown in Fig. 10 was assembled using a conventional dehumidifier element impregnated with lithium chloride, and the treated air 18 and regenerated air 19 were fed at a speed of 2 m/sec in front of the element at a constant time. The ratio of the amount of regenerated air to the amount of processed air is 1:3, and the number of rotations of the element is 1.
8r, p, h, the temperature at the inlet of the processing air is 20°C.
, the relationship between the absolute humidity [g/kg] at the inlet and outlet of the processing air when the temperature at the inlet of the regeneration air is 140°C and the absolute humidity at the inlet of the regeneration air is the same as the absolute humidity at the inlet of the processing air. It is shown in FIG.

As is clear from the above data, the gas sorption device obtained according to the present invention not only has significantly superior dehumidification performance compared to the conventional dehumidifier device impregnated with lithium chloride, but also has the ability to It can be seen that the performance is improved even compared to the dehumidifier element of the present invention, and the performance is particularly improved when water glass is used as the lamination adhesive.

Effects of the Invention Since the present invention is constructed as described above, water glass has a high affinity with inorganic fibers and not only wets the surface of the inorganic fiber paper well, but also penetrates well into the fiber gaps inside the 8I fiber paper, and this water glass Since the glass is heated and dried to produce a hydrogel-like or semi-solid form with a water content of 5 to 45%, this hydrogel or the aerogel obtained from it is strongly bonded to the paper fiber gaps and surface, and As in the case of the above application, there is no risk of the device falling off during use or storage. In addition, since the water content of the above hydrogel is extremely small, about 40 to 50%, the gel is strong even before drying and has a strong binding force to the inorganic fiber paper, so there is a risk that the hydrogel will fall off from the paper when washed with water after the reaction. That's not it. Furthermore, this hydrogel loses its water content f1140 to 50% by drying.
Since the Erogel leaves minute pores corresponding to the degree of drying, there is almost no shrinkage during drying, and an Erogel with a high degree of cracking or fineness can be obtained. 4 The present invention further provides that the matrix is
Since all organic components contained in the paper and adhesive are removed by firing with air at a temperature of 00 to 500 degrees Celsius, the resulting element consists only of inorganic materials that cannot be combustible, and can be dehumidified using high-temperature recycled air. There is no risk of accidents due to ignition and combustion during operation, and since the inorganic fiber paper used is of low density, the proportion of the gas sorbent, that is, silicate aerogel, in the entire element is extremely large, and therefore the gas absorption relative to the weight of the element is small. The gas sorption capacity is also very high, and when water glass is used as an adhesive in matrix molding, the gas sorption capacity is even higher.

In addition, since the gas sorption device obtained by the present invention uses an adsorbent made of silicate aerogel as a gas sorption agent, unlike conventional absorbent hygroscopic agents with deliquescent properties such as lithium chloride, it is difficult to absorb excess moisture. If dust adheres to the device during use, it can be removed by washing with water without the risk of carryover.

By proceeding with this double decomposition reaction at a high temperature of 60 to 70°C and cooling it to a low temperature of about 10°C or less after the reaction is completed, the by-product sodium sulfate can be produced.
It has the effect that raw materials can be used effectively, and it can be manufactured at a low cost without requiring any special skill.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show examples of the present invention, FIG. 1 is a cross-sectional explanatory diagram showing the first step of the present invention, and FIG. 2 shows the matrix obtained by the process of FIG. 1 or the present invention. A perspective view showing an example of a gas sorption-like element obtained by using aluminum sulfate,
Magnesium sulfate. Graphs showing the solubility curve of sodium sulfate, FIGS. 4 and 5 are perspective explanatory views showing other examples of gas sorption elements obtained by the present invention, and FIGS.
FIG. 1 is a graph showing the dehumidifying performance of the element for a gas collector obtained according to the present invention, and FIG. In the figure, 1 and 2 are forming gears, 3 is a pressure roller, 4.5 is an adhesive coating device, 7 and 8 are low-density Al II fiber-free paper, 18 is processing air, 19 is recycled air, and 20 is a dryer-9゜Calculation Z Account 3ro

Claims (1)

[Scope of Claims] 1. A large number of low-density plane papers and corrugated papers, each consisting mainly of inorganic fibers selected from ceramic fibers, glass fibers, carbon fibers, or a mixture of two or more of the above-mentioned fibers, are alternately laminated. A honeycomb matrix with small pores is formed, the matrix is fired to remove organic matter contained in the paper and adhesive, and the density of the paper is further lowered, the fired matrix is impregnated with water glass, and then heated and dried. The matrix is immersed in an aqueous solution of a metal sulfate such as aluminum sulfate or magnesium sulfate, and the silicate hydrogel is formed between the paper fibers and into the spaces between the paper fibers by reaction with the water glass. The material is bonded to the surface, washed and dried to obtain an element for a gas sorption device whose main component is silicate erogel, with the inorganic fibers in the paper as the framework.
The metal sulfate aqueous solution is cooled to crystallize and remove the sodium sulfate produced as a reaction by-product and dissolved in the metal sulfate aqueous solution, water glass is replenished to the water glass aqueous solution after impregnation, and the metal after the reaction is removed. A method for producing an element for a gas sorption machine, which comprises repeating the above-described production of the element for a gas sorption machine by replenishing the metal sulfate to an aqueous sulfate solution. 2. The method for producing an element for a gas sorption machine according to claim 1, wherein the paper is impregnated with water glass before or after the lamination step. 3. The method for producing an element for a gas sorption machine as claimed in claim 1, wherein flat paper and corrugated paper are impregnated with water glass and fired in air at 200 to 500°C before or after the sides of the paper. 4. A patent claim in which water glass is used as an adhesive for forming and laminating a single wave molded body, and a silicate aerogel having adsorption activity while maintaining adhesive strength is produced by the reaction between the water glass and a metal sulfate. A method for producing an element for a gas sorption machine according to scope 1.