JPS6344917A - Ceramic filter - Google Patents

Abstract

PURPOSE:To prepare a ceramic filter of superb quality and performance for treating liquid and gas by distributing micropores of different diameters in the order of diameter sizes in the radius direction between inner and outer circumferences of a porous ceramic sintering tube. CONSTITUTION:Micropores of different pore diameters are distributed between inner and outer circumferences of a ceramic sintering tube in the order of diameter sizes, namely large-medium-small or small-medium-large. The diameters of these micropores are within a range of 0.001-1mum. Said ceramic sintering tube is manufactured by piling up pure SiO2 fine particles in the shape of a tube and sintering the same. By this process, the product contains a very small quantity of impurities, and has high quality, sufficient mechanical properties, acid resistance, and alkali resistance. Such oblique pore diameters can be prepared by varying the sintering temperature of inner and outer circumferential faces. The higher the sintering temperature, the smaller the pore diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field 1" The present invention relates to a ceramic filter suitable for use in liquid processing, gas processing, etc.

``Conventional Technology J'' Advanced water treatment, gas separation, etc. are highly dependent on precision and high-quality filters, and the technology that currently supports these filters is technology related to polymer membranes.

In the case of such polymer-membrane filters, general wastewater treatment,
Although it has achieved reasonable results in areas such as air purification, cutting-edge technology fields such as biochemistry require stricter specifications and actually require treatment with strong acid and strong alkaline water, so product Y -Membrane filters are difficult to deal with.

In order to deal with this, ceramic filters are being considered and attempts are being made to put them into practical use.

By the way, when producing a porous ceramic sintered tube as a ceramic filter, first, metal oxide powder, additives, and binder (organic substances, low melting point inorganic substances) are placed in a ball mill, and these are kneaded to create a slurry. To,
Pressure molded with a slurry die to create an unsintered tube.
Thereafter, the unsintered tube is sintered in an electric furnace to form a ceramic sintered tube.

1. Problems to be Solved by the Invention J In the case of the above-mentioned ceramic filter, that is, the porous ceramic sintered tube, there are the following problems.

One of these is due to the manufacturing method; since binders and the like are mixed in when making the slurry, a considerable amount of impurities remain in the filter, and these impurities have an adverse effect, for example, when producing high-purity water.

Another problem is that the diameter of each micropore in the filter is approximately constant, and therefore objects to be removed having different particle sizes cannot be effectively captured.

In view of the above two problems, the present invention aims to provide a ceramic filter having a porous ceramic sintered tube portion that is excellent in quality and performance.

Means for Solving Problem 1 The present invention provides a ceramic filter having a porous sintered ceramic tube portion having a large number of micropores, in which the sintered The desired purpose is achieved by having micropores having different diameters distributed in the order of diameter in the radial direction of the tube.

1 Effect 1 As mentioned above, the ceramic filter according to the present invention has the following features:
Between the inner and outer circumferential surfaces of the ceramic sintered tube, micropores with different diameters are distributed in order of diameter, such as large → medium to small or small → medium → large.

When processing fluid through such a ceramic sintered tube, from the outer peripheral surface of the ceramic sintered tube toward the inner peripheral surface,
Alternatively, the fluid is passed from the inner circumferential surface to the outer circumferential surface of the ceramic sintered tube, and at this time, various types of sparks contained in the fluid are removed. It is captured and removed step by step and efficiently.

The ceramic sintered tube described above is obtained by depositing pure Si02 fine particles in a tubular shape and sintering the same, so the content of impurities is extremely small and it can be a high-quality ceramic filter.

Of course, since such a filter is made of ceramics, it has sufficient mechanical properties, acid resistance, and alkali resistance.

1 Example 1 Hereinafter, examples of the ceramic filter according to the present invention will be described with reference to the drawings.

FIG. 1 shows an example of a ceramic filter according to the present invention, and this example ceramic filter is composed of a single porous ceramic sintered tube 1. As shown in FIG.

The ceramic sintered tube 1 is substantially made of 5i07, and the amount of metal impurities contained therein is very small, 100 pP or less.

Since the ceramic sintered tube l described above has a porous structure, it has a large number of interconnected micropores, but the pore diameters of these micropores are not constant, and those with a large pore diameter and those with a small pore diameter are Distributed within the canal wall of tubule l.

As a specific example, the diameter of the micropores on the inner peripheral surface of the sintered ceramic tube 1 is the smallest, and the diameter of the micropores gradually increases toward the outer peripheral surface of the sintered tube 1. There is.

As another specific example, the diameter of the micropores on the outer peripheral surface of the sintered ceramic tube l is the smallest, and the diameter of the micropores gradually increases toward the inner peripheral surface of the sintered tube l. Attached.

Each micropore of the ceramic sintered tube 1 has a diameter of 0.
．． It is within the range of 001 to 17zmφ.

Fig. 2 shows another embodiment of the ceramic filter according to the present invention, and the ceramic filter of this embodiment has a plurality of porous ceramic sintered tubes l having different diameters (from Niki to L) stacked together. A double tube structure 41 is used, but each micropore extending from the inner circumferential surface of the inner tube to the outer circumferential surface of the outer tube changes in diameter as described above, such as dog→medium→small or small→medium→large. They are distributed in order.

Next, 1: A method of manufacturing the arranged porous ceramic sintered tube 1 will be explained with reference to FIGS. 3 and 4.

FIG. 3 shows the first step in the preparation of a porous soot layer by the method A.1.

In this process, 50% of the liquid raw material is added to the bubbling tank 11.
iC1a is stored, and after blowing an inert gas (for example, Ar) into the bubbling tank 11 to evaporate each raw material listed in L, the gas phase raw material 5iCIa is supported by a carrier gas (Ar). and is supplied to the burner 12 having a multi-tube structure.

The burner 12, which has a multi-tube structure, has a plurality of mutually concentric flow paths, and each flow path of the burner 12 contains hydrogen (H2), oxygen (02), and seals in addition to the gas phase raw material described above. Gas (Ar) is supplied, and 5i02 fine particles are generated by a flame hydrolysis reaction of each gas via the burner 12.

The 5i02 fine particles generated in this way are injected and deposited from the burner 12 onto the outer periphery of the deposition member 13. At this time, since the burner 12 reciprocates along the longitudinal direction of the deposition member 13, the outer periphery of the deposition member 13 is A porous soot layer 14 having a predetermined length and thickness is formed.

Since the deposition member 13 needs to be heated with electricity in the next step II, a material capable of this is used, and as a specific example, a carbon rod is used in FIG. 3.

FIG. 4 shows the sintering process of the porous soot layer 14 using the electric furnace 15.

In this step, a porous soot layer 14 is formed inside the electric furnace 15, that is, inside the furnace core tube 17 having the electric heater 16 on the outer periphery.
is inserted and lowered in a rotating state, and the porous soot layer 1 is
4 are sintered through the electric heater 1G and the deposition member 13, which are heated with electricity, respectively. During such sintering, the heating temperature by the electric heater 6 is low and the heating temperature by the deposition member 13 is high. These temperatures are set relatively.

- Generally, when the porous soot layer 14 is sintered to obtain the porous ceramic sintered tube 1, the average pore diameter of the micropores is determined by the temperature during sintering, and the higher the sintering temperature, the smaller the micropores are. The smaller the pore size and the lower the sintering temperature, the larger the micropore size.

Therefore, when the porous soot layer 14 is sintered by setting the sintering temperature as described above, since the heating temperature by the deposition member 13 is high and the heating temperature by the electric heater 6 is low, the porous soot The temperature distribution in the radial direction of the layer 14 has a gradient of high temperature on the inner peripheral surface and low temperature on the outer peripheral surface, and the porous soot layer 14, that is, the ceramic sintered tube 1, is sintered at the sintering temperature of this distribution. The diameter of the micropores on the inner peripheral surface side is the smallest, and the diameter of the micropores gradually becomes larger toward the outer peripheral surface side.

Thereafter, the porous ceramic sintered tube 1 is separated from the deposition member 13, and thus a ceramic filter having a porous structure is obtained.

Specific Example When manufacturing a ceramic filter according to the steps shown in FIGS. 3 and 4, step L in FIG. 3 is carried out under the conditions shown in Table 1,
The process shown in FIG. 4 was carried out under the conditions shown in Table 2.

Table 1 The fourth passage is the outermost passage of the burner. ) Porous ceramics (Si
02) The sintered tube has an outer diameter of 10.5 mmφ and an inner diameter of 8+wmφ.
, and the pore diameters of the micropores distributed in the radial direction were different as follows.

In other words, small micropores of 0.01 gtaφ are distributed on the inner circumference of a ceramic sintered tube sintered at a relatively high temperature. On the outer periphery, large micropores of 0.07 mm + 11φ were distributed, and the pore diameter of each micropore was changing stepwise among these.

Incidentally, the relative relationship between the diameter of the micropores and the sintering temperature is shown in FIG.

Figure 5 shows the data when each sample (porous soot) obtained in the process in Figure 3 is sintered in the process in Figure 4.
The samples were sintered under the conditions shown in Table 3.

At this time, the deposition member was not electrically heated, and the sintering temperature in the furnace tube was set only by the electric heater 1B of the electric furnace.

Table 3 In order to confirm the effectiveness of the porous ceramic sintered tube manufactured under the conditions of 1.2 above, when dirty water was passed from the outside to the inside of the sintered tube, particles were found in the outer layer. It is possible to remove clay inorganic substances with a diameter of about 1 g and mφ, and in the middle layer it is possible to remove bacteria with a size of up to about 0.1 gmφ, and in the inner layer it is possible to remove 0.1 gmφ.
．． It was possible to remove colloidal substances of 0.01 gmφ or more.

These results show that the porous ceramic sintered tube is extremely effective as a water treatment filter.

Of course, the above filter can be applied to a dust collection filter for capturing and removing fine dust in exhaust gas, and other various filters.

When manufacturing the ceramic filter according to the present invention, in the step shown in FIG.
3 was used to create a porous soot layer by depositing Si02 fine particles on the outer circumferential surface of the porous soot layer.On the contrary, the inner material method deposited Si07 fine particles on the inner circumferential surface of the deposition member 13 made of a carbon pipe. Even if a porous soot layer is prepared by and sintered in the same process as shown in Fig. 4,
A porous ceramic sintered tube, that is, a ceramic filter is obtained.

In the porous ceramic sintered tube obtained by this method, the temperature distribution in the radial direction at the stage of the porous soot layer has a gradient such that the inner peripheral surface is high temperature and the outer peripheral surface is low temperature. The diameter of the micropores is the smallest, and the diameter of the micropores gradually increases toward the inner peripheral surface.

When depositing a porous soot layer using either the external method or the internal method described above, the surface temperature of the deposited layer may be changed, or the sintering temperature may be changed each time a soot layer of a predetermined thickness is formed. Each soot layer may be sintered without changing the soot layer, and the pore diameter of each micropore extending in the radial direction of the porous sintered ceramic tube can also be changed by these means.

In addition, Si02 fine particles for forming the porous soot layer can also be obtained by a sol-gel method using an organometallic compound.

1. Effects of the Invention J As explained above, the ceramic filter according to the present invention has a sintered ceramic tube between the inner and outer circumferential surfaces.

In other words, micropores with different pore diameters are distributed in the radial direction of the sintered chain tube in the order of their pore diameters.
Satisfies both quality and performance as a filter for liquid processing and gas processing.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a smaller embodiment of a ceramic filter according to unexploited oil 1, FIG. 2 is a smaller perspective view of another embodiment of the same, and FIGS. 3 and 4 are ceramic filters according to the present invention. FIG. 5 is an explanatory diagram schematically showing the manufacturing process of the filter, and FIG. 5 is an explanatory diagram showing the relationship between the 4i average pore diameter of micropores in a porous ceramic sintered tube and its sintering temperature. 1... Porous Ceramic Sintered Pipe Agent Patent Attorney Yoshio Saito Figure 1 Figure 12 Figure 5 - Juice! 1. ! Agriculture&(' Figure 3 Figure 5IN4

Claims (6)

[Claims] (1) In a ceramic filter made of a porous sintered ceramic tube having a large number of micropores, between the inner and outer peripheral surfaces of the porous sintered ceramic tube, there are micropores with different diameters extending in the radial direction of the sintered tube. A ceramic filter characterized in that pores are distributed in order of pore diameter. (2) A patent claim in which the diameter of the micropores on the inner peripheral surface of the porous ceramic sintered tube is the smallest, and the diameter of the micropores gradually increases toward the outer peripheral surface of the sintered tube. Ceramic filter according to scope 1. (3) A patent claim in which the diameter of the micropores on the outer peripheral surface of the porous ceramic sintered tube is the smallest, and the diameter of the micropores gradually increases toward the inner peripheral surface of the sintered tube. Ceramic filter according to scope 1. (4) The ceramic filter according to any one of claims 1 to 3, wherein each micropore of the porous ceramic sintered tube has a diameter within a range of 0.001 to 1 μmφ. (5) The porous ceramic sintered tube is substantially SiO_2
The content of metal impurities in the sintered tube is 100pp.
The ceramic filter according to any one of claims 1 to 4, wherein the ceramic filter has a diameter of less than m. (6) The ceramic filter according to any one of claims 1 to 5, wherein the porous ceramic sintered tube has a double tube structure.