JPH05262539A - Apparatus for producing porous pipe having selectively plasma-treated surface and porous pipe produced by the same apparatus - Google Patents

Abstract

PURPOSE:To provide the subject porous pipe involving a hydrophilic or hydrophobic part on a desired surface selected from the outer wall, the pore wall and the inner wall. CONSTITUTION:A porous pipe 11 is set in a vacuum tank 23 and the vacuum tank 23 is evacuated by vacuum pumps 25 and 27. An oleophilic gas or a hydrophilic gas is supplied from a gas-supplier 43 to the inside of the porous pipe 11. If applying the pressure difference between the inside and the outside of the porous pipe 11 in this state and applying a voltage to an electrode 45 so as to generate plasma, a surface to which the most suitable pressure for generation of plasma is applied is plasma-treated. Thereby, the desired surface among all the surfaces of the porous pipe 11 can be plasma-treated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for selectively plasma-treating a surface of a porous pipe by changing the distribution of atmospheric pressure in a vacuum vessel to perform plasma treatment of the porous pipe, and a method therefor. The present invention relates to an invention of a manufactured porous pipe.

[0002]

2. Description of the Related Art As a powerful mixing device for mixing a plurality of types of fluids to obtain a mixture of them, a mixing device using a porous pipe made of a porous member (porous material) is known. .. The structure of a general mixing device using a porous pipe is as shown in FIG. 6, and the porous pipe 1 is placed inside an impermeable casing 13.
1 is installed, and a press-fitting chamber 13a is formed between the porous pipe 11 and the casing 13.

In the above mixing device, oil is press-fitted into the press-fitting chamber 13a from the outside.
The inside of the porous pipe 11 serves as a mixing chamber, and water is introduced into the mixing chamber by a pump 15.
The raw material water is stored in the tank 17, the water in the tank 17 is guided to the mixing chamber 13b by the pump 15, and the water that has passed through the mixing chamber 13b is returned to the tank 17 again.

In such a mixing device, the press-fitting chamber 1
The oil press-fitted into 3a penetrates the porous pipe 11 and is supplied to the mixing chamber 13b. Here, the porous pipe 11
Since the porous material has a fine hole with a diameter of several microns, as shown in FIG. 7, the oil that has permeated the porous pipe 11 is supplied as fine particles to the water in the mixing chamber 13b. become. Since a predetermined flow is formed by the pump 15 in the mixing chamber 13b,
The oil that has penetrated the porous pipe will be immediately dispersed in the water. In this way, the oil becomes dispersoid,
A mixture with water as the dispersion medium will be formed.

[0005]

By the way, in the mixing apparatus using such a porous pipe 11, the characteristics (for example, particle size) of the fine particles formed in the mixture are different from those of the permeated fluid fine particles. Since it also depends on the ease of peeling from the inner wall of the porous material, most of the porous pipes 11 are surface-treated in order to obtain a mixture having desired properties.

However, the surface of the porous pipe is not only the outer wall and the inner wall, but also the surface of the fine holes (hereinafter referred to as the hole wall) is the surface of the porous pipe. It is an important factor to decide. Therefore, when performing the surface treatment of the porous pipe, it is necessary to perform all the surface treatments of the outer wall, the inner wall and the hole wall of the porous pipe. Further, when performing the surface treatment, it is necessary that not only the surface treatment be performed, but also that a hydrophilic or hydrophobic portion can be freely formed on the surface of the porous pipe.

However, the outer and inner walls of the porous pipe
It was difficult to obtain a porous pipe having desired characteristics by performing surface treatment by freely controlling the distribution of the hydrophilic portion or the hydrophobic portion over the entire surface of the pore wall.

The present invention has been made in view of the above problems, and an object thereof is to provide a porous pipe manufacturing apparatus capable of easily obtaining a porous pipe having a hydrophobic portion or a hydrophilic portion in a desired portion. To do.

[0009]

In order to solve the above problems, in the present invention, the pressure in the vicinity of the inner wall / hole wall / outer wall of a porous pipe in a vacuum container into which a small amount of gas is introduced is adjusted. Then, plasma is generated in the vacuum vessel with the pressure being adjusted, whereby plasma is selectively generated on each of the inner wall surface, the hole wall surface, and the outer wall surface of the porous pipe. It is characterized in that a porous pipe is formed by plasma treatment.

That is, in the porous pipe manufacturing apparatus according to the present invention, a vacuum container accommodating the porous pipe whose one end is closed, an exhaust means for discharging gas from the vacuum container and the porous pipe, It has a gas introducing means for guiding a gas into the porous pipe from the other end of the porous pipe, a pressure adjusting means for adjusting the pressure inside and outside the porous pipe, and a plasma generating means for bringing the gas in the vacuum container into a plasma state. Then, by adjusting the pressure near the inner wall / hole wall / outer wall of the porous pipe, the plasma generation location is adjusted, and the inner wall / hole wall / outer wall surface of the porous pipe is selectively treated with plasma. Is characterized by. It should be noted that this plasma processing characteristic of the present invention is defined as selective plasma processing.

When exhausting the inside of the vacuum container, the gas is directly discharged from the vacuum container as described above, while the gas is indirectly discharged from the porous pipe through the porous wall. On the contrary, the gas may be directly discharged from the porous pipe and indirectly discharged from the vacuum container. That is, a vacuum container accommodating a porous pipe whose one end is closed, an exhaust means for exhausting gas from the porous pipe and the vacuum container, a gas introducing means for introducing gas to the outside of the porous pipe, and the porous pipe. It has a pressure adjusting means for adjusting the pressure inside and outside, and a plasma generating means for making the gas in the vacuum container into a plasma state, and the inner wall of the porous pipe
It is characterized in that the plasma generation location is adjusted by adjusting the pressure in the vicinity of the hole wall / outer wall, and selective plasma treatment of the surface of the porous pipe is performed.

Further, in the above-described manufacturing apparatus, the porous pipe or the plasma generating means includes a moving means for moving the porous pipe in the vertical direction, and the porous pipe and the plasma generating means are moved in the vertical direction relatively to each other. It is characterized in that the entire surface of is uniformly and selectively plasma-treated.

[0013]

In the porous pipe manufacturing apparatus and method of the present invention having the above-described structure, the plasma generation location is adjusted by adjusting the pressure near the inner wall, hole wall, and outer wall of the porous pipe, As a result, the surfaces of the inner wall, the hole wall and the outer wall of the porous pipe are selectively plasma-treated. In this way, it becomes possible to selectively perform plasma treatment on the inner wall, hole wall, and outer wall of the porous pipe, so that a porous pipe or the like in which only the inner wall (or hole wall, outer wall) is subjected to plasma treatment can be used. First, it becomes possible to manufacture a porous pipe which has been subjected to a desired plasma treatment from the inner wall to the outer wall.

Here, since the wall surface of the porous pipe after the treatment can be made hydrophilic or hydrophobic (lipophilic) by changing the type of gas used in the plasma treatment, it becomes hydrophilic. The inner and outer parts are the hydrophobic and hydrophobic parts
It is possible to create a porous pipe having a desired distribution over the outer wall. Further, by performing the selective plasma treatment while moving the porous pipe and the plasma generating means relatively in the vertical direction, it becomes possible to uniformly and selectively perform the selective plasma treatment on the entire surface of the porous pipe.

The porous pipe in which the hydrophilic portion and the hydrophobic portion have a desired distribution from the inner wall to the outer wall enables the dispersoid to be favorably dispersed in the dispersion medium. That is, when the hydrophilic dispersoid is dispersed in the hydrophobic dispersoid, the dispersoid becomes easier to disperse when the wall surface on which the dispersion occurs is hydrophobic. On the contrary, when the dispersoid is hydrophobic, the more dispersoid is dispersed in the dispersoid, the more hydrophilic the wall surface on which the dispersoid occurs.

By changing the distribution state of the hydrophilic portion and the hydrophobic portion from the inner wall to the outer wall,
The easiness of dispersion of the dispersoid in the dispersion medium, the characteristics of the resulting mixture, that is, the size of the particle size of the dispersoid, the way of aligning the particle size of the dispersoid, and the like are adjusted.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the construction of a porous pipe manufacturing apparatus according to a preferred embodiment of the present invention.

Porous pipe manufacturing apparatus 2 according to this embodiment
1, a porous pipe 11 is installed in a vacuum container 23, and the vacuum container 23 is evacuated by vacuum pumps 25 and 27. The upper portion of the porous pipe 11 is fixed by the upper fixing portion 29, and the lower portion is fixed by the lower fixing portion 31. An adjustment plug 33 that closes the end of the porous pipe 11 is installed in the lower fixing portion 31. A valve is installed in the adjusting plug 33, and the open / close state of the valve of the adjusting plug 33 is controlled by the controller 49 connected thereto.

A movable rotary shaft 34 is installed on the upper fixed portion 29, and the movable rotary shaft 34 is connected to a drive unit 35. A vertical drive unit 35a (not shown) and a rotary drive unit 35b (not shown) are provided in the drive unit 35, and the vertical pipe drive unit 35a drives the porous pipe 11 in the vertical direction. Move and rotate drive machine 35b
Is driven to rotate the porous pipe 11.

A distribution pipe 37 is installed inside the rotary shaft 34. With this distribution pipe 37, the porous pipe 1 is provided.
The exhaust from the inside of 1 and the supply of the gas into the inside of the porous pipe 11 can be performed. Further, the vacuum container 23 is provided with an exhaust hole 39 and an introduction hole 41 so that the vacuum pumps 25 and 27 can exhaust the inside of the vacuum container 23 from the exhaust hole 39. A gas of a predetermined type is supplied from the hole 41 by a gas supply device 43.

Further, an electrode 45 is installed in the vacuum container 23, and a plasma is formed in the vacuum container 23 by a radio wave supplied from a radio wave generating and supplying device 47 connected to the electrode 45. ing.

Here, a three-way cock 51 is installed in this apparatus. When the three-way cock 51 is in a state as shown in FIG. 1, gas is supplied into the porous pipe 11 and at the same time. Evacuation is performed from the inside of the vacuum container 23, which causes the porous pipe 11 to pass through the porous wall.
Gas is exhausted from the inside to the outside. On the other hand, three-way cock 5
1 is placed in a state such as 51b, the vacuum container 2
The gas is supplied to the inside of the porous pipe 11, and the gas is exhausted from the inside of the porous pipe 11, so that the gas in the vacuum container 23 is exhausted from the inside of the porous pipe 11 through the porous wall.

By the way, if the gas supplied from the gas supply unit 43 is a mixed gas of a hydrophilic gas such as hydrophilic gas or air, such as O ₂ and H ₂ O and NH ₃ is porous after the plasma treatment The surface of the pipe 11 has hydrophilicity. On the other hand, when a lipophilic gas such as CH ₄ or C ₂ F ₆ or a mixed gas thereof is introduced into the vacuum container 23 for plasma treatment, the surface of the porous pipe 11 has hydrophobicity. ..

However, in this case, in order to perform the plasma processing properly, the atmospheric pressure when the discharge is performed needs to be 1 to 10 Pascal. According to the experiment
At this time, the discharge output is 100 to 200 W, the discharge voltage is 1000 to 1600 V, and the discharge frequency is 13.5.
It was 6 MHz and the discharge time was 1 to 5 minutes. However, in any case, it is known that good plasma treatment cannot be performed unless the discharge pressure is between 1 and 10 Pascal. Hereinafter, this range will be referred to as an optimum pressure range.

The characteristic feature of the porous pipe manufacturing apparatus according to the present embodiment is that the output of the vacuum pumps 25 and 27 and the amount of gas supplied from the gas supply device 43 are controlled so that the porous pipe 11 has a predetermined size. Keeping the surface in the optimum pressure range. When plasma is formed in the vacuum container 23, the surface of the porous pipe 11 in this optimum pressure range is effectively plasma-processed. Therefore, by controlling the formation location of the optimum pressure range, That is, it becomes possible to control the location of the surface treatment of the porous pipe 11. In the present application, this is defined as selective plasma treatment of the porous pipe 11.

Further, in the porous pipe manufacturing apparatus according to the present embodiment, the evacuation from the vacuum container 23 and the supply of the gas into the vacuum container 23 are appropriately controlled to make the gradient of pressure inside and outside the porous pipe 11. By forming, it is possible to easily control the formation position of the optimum pressure range. That is, the porous pipe manufacturing apparatus of the present application is characterized in that the selective plasma treatment of the porous pipe 11 can be easily performed. In addition,
By controlling the open / closed state of the valve of the adjusting plug 33 by the controller 49, fine adjustment of the pressure gradient formed inside and outside the porous pipe 11 is performed.

The graph shown in FIG. 2 (a) shows the pressures on the inner wall side, the inside wall and the outer wall side of the porous pipe 11 when the gas is supplied into the porous pipe 11 and the gas is exhausted from the vacuum container 23. It is a graph which showed change. In this case, since the exhaust is performed from the outer wall side and the gas is supplied from the inner wall side, the pressure on the inner wall side becomes higher than that on the outer wall side. Since many fine holes exist in the wall of the porous pipe, gas flows out from the inside of the porous pipe 11 (FIG. 3A), and the pressure gradually decreases from the inner wall side to the outer wall side. A pressure gradient is formed in the wall of the porous pipe 11.

Here, 1 to 10 surrounded by a chain line
Although the optimum pressure range is between Pascals, when plasma is formed in the vacuum container 23, the plasma treatment is performed on the wall surface within the optimum pressure range.

Therefore, as shown in the graph α of FIG.
If the atmospheric pressure on the inner wall side is kept within the optimum pressure range, plasma treatment will be performed on the inner wall surface, and plasma treatment will not be performed on other parts. On the other hand, as shown in the graph β, if the atmospheric pressure on the inner wall side is made larger than 10 Pascal and the atmospheric pressure on the outer wall side is made smaller than 1 Pascal, and control is performed so that the inside of the wall is within the optimum pressure range, Plasma treatment will be performed on the hole wall surface. Further, by controlling the atmospheric pressure on the outer wall side to fall within the optimum pressure range as shown by the graph γ, it becomes possible to perform plasma treatment on the outer wall surface.

When the pressure is controlled as shown by the graph δ, the inside wall and the outer wall are kept within the optimum pressure range, the plasma treatment is not applied only to the inner wall surface, and the plasma treatment is applied to the hole wall surface and the outer wall surface. Will be done. Similarly, by appropriately adjusting the pressure difference between the inner wall and the outer wall, for example, it is possible to obtain a porous pipe in which the plasma treatment is performed over the entire inner wall with about half the hole wall surface. In this way, by appropriately adjusting the pressure difference between the inner wall and the outer wall, it becomes possible to manufacture the porous pipe in which the plasma treatment is performed at a desired position. The fine adjustment at this time is performed by controlling the opening / closing of the valve of the adjusting plug 33.

Here, FIG. 2B is a graph showing the pressure change (pressure gradient in the wall) of the highly viscous gas and the low viscous gas. In this graph, graph A represents a change in a gas having a low viscosity, and a steep change occurs in the wall. On the other hand, the graph B shows a pressure change of the gas having a relatively large viscosity, and shows a gentler pressure change than the graph A in the wall.

FIG. 2 (c) is a diagram showing a pressure change when gas is supplied into the vacuum container 23 by exhausting gas from the inside of the porous pipe 11. In this case,
As shown in (b), gas is allowed to flow from the outside of the porous pipe 11 to the inside of the porous pipe 11, and the pressure is gradually changed in the wall through the fine holes. Here, as shown in the graph α of FIG. 2A, if the outer wall portion is controlled to be within the optimum pressure range, the outer wall portion 57 shown in FIG. 3B is subjected to the plasma treatment. Become. Further, as shown by β in FIG. 2A, if the control is performed so that the pressure is within the optimum pressure range in the wall, the surface of the hole wall 58 is subjected to the plasma treatment. Further, as shown by γ in FIG. 2A, if the inner wall portion is controlled so as to be within the optimum pressure range, the surface of the inner wall 59 is subjected to the plasma treatment. Even in this case, by appropriately adjusting the pressure difference between the inner wall and the outer wall, the position of the surface to be subjected to the plasma treatment can be appropriately adjusted. Here, the manufacturing apparatus operates in a method as shown in FIG.

First, when the porous pipe is installed in S101, the vacuum container 23 or the porous pipe 11 is evacuated (S102). In this state, hydrophilic gas or lipophilic gas is supplied (S1
03), the pressure difference between the inside and outside of the porous pipe 11 is adjusted (S104), and then the voltage is applied to the electrode 45 to perform the plasma treatment (S105). Here, the adjustment of the atmospheric pressure in S104 is a characteristic step in this embodiment, and the surface of the porous pipe 11 to be plasma-treated can be adjusted by the adjusting method at this time. As described above, the controller 49 controls the opening and closing of the valve installed in the adjusting plug 33 to finely adjust the pressure difference between the inside and outside of the porous pipe 11.

The electrodes 45 installed in the vacuum container 23 may be wound in parallel as shown in FIG. 1, but in addition to this, for example, as shown in FIG. 5, they are spirally wound. Even if it does so, good results can be obtained.

The vertical drive unit 35 in the drive unit 35
By driving a and moving the porous pipe 11 in the vertical direction, uniform selective plasma processing is performed. Therefore, when the optimum pressure range forming portion is adjusted so as to form a hydrophobic portion on the entire inner wall portion and half of the hole wall portion, the porous pipe 11 is moved in the vertical direction at the same time so that the porous pipe 11 The hydrophobic portion is formed evenly over the entire inner wall portion and half of the hole wall portion. By moving the porous pipe 11 in the vertical direction in this way, uniform selective plasma treatment is performed, but by rotating the porous pipe 11 at the same time,
It becomes possible to perform the selective plasma treatment more uniformly. In order to perform the uniform selective plasma processing as described above, the electrode 45 for generating plasma may be moved in the vertical direction instead of moving the porous pipe 11 in the vertical direction by the vertical drive unit 35a. Good.
That is, if the porous pipe 11 and the electrode 45 are moved relative to each other in the vertical direction, it is possible to perform a uniform selective plasma treatment on the porous pipe 11.

The porous pipe 11 can be made of various porous materials such as ceramics and metals, and among them, porous silica glass is most suitable. Among these, those produced from the abundant volcanic ejecta (shirasu) shirasu glass in southern Kyushu are suitable. First, lime and boric acid are added to this porous silica glass, which is melted at 1300 ° C. to synthesize a basic glass as a matrix of the porous glass. Then, this is used as a raw material and molded into a pipe adapted to the final purpose of use, and then heat treated at about 600 to 700 ° C. to change the composition of the glass to release CaO and B ₂ O _{3 as} raw materials, that is, Generate a split layer. Since this layer is easily dissolved in an acid, if the heat-treated product is treated with an acid, this can be eluted to obtain a porous glass having innumerable fine cells. The porous silica glass thus obtained is very suitable as a raw material for forming the porous pipe according to the present invention because its pores and the like can be easily controlled in processing. The porous pipe 11 formed in this way is hydrophilic because it is vitreous, and becomes more hydrophilic by plasma treatment with a hydrophilic gas, and desired by plasma treatment with a lipophilic gas. It becomes possible to form a hydrophobic portion on the surface of the.

[0038]

As described above, according to the present invention,
It is possible to easily obtain a porous pipe having a hydrophilic portion and a hydrophobic portion of desired sizes uniformly on desired surfaces of the outer wall, the hole wall, and the inner wall.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a porous pipe manufacturing apparatus according to an embodiment.

FIG. 2 is a graph for explaining the relationship between optimum pressure and pressure control.

FIG. 3 is a diagram illustrating a porous pipe and a gas flow direction.

FIG. 4 is a flowchart showing a method for manufacturing a porous pipe according to the present invention.

FIG. 5 is a diagram showing another configuration of electrodes of the porous pipe manufacturing apparatus according to the present embodiment.

FIG. 6 is a diagram showing a configuration of a conventional mixing device using a porous pipe.

FIG. 7 is a diagram for explaining the operation of the mixing device using the porous pipe.

[Explanation of symbols]

 11 Porous Pipe 21 Manufacturing Device for Porous Pipe 23 Vacuum Container 25, 27 Vacuum Pump 33 Adjusting Plug 34 Rotating Shaft 35 Driving Device 37 Distribution Pipe 39 Exhaust Hole 41 Introducing Hole 43 Gas Supply Device 45 Electrode 47 Radio Wave Generation Supply Device 49 Controller 51 Three-way Cock 57 Outer wall 58 Hole wall 59 Inner wall

Claims (4)

[Claims] 1. A vacuum container accommodating a porous pipe whose one end is closed, an exhaust means for discharging gas from the vacuum container and from the porous pipe, and a gas from the other end of the porous pipe into the porous pipe. A gas introducing means for guiding the gas, a pressure adjusting means for adjusting the pressure inside and outside the porous pipe, and a plasma generating means for bringing the gas in the vacuum container into a plasma state, and an inner wall / hole wall / An apparatus for producing a porous pipe, characterized in that a plasma generation location is adjusted by adjusting a pressure in the vicinity of the outer wall, and the inner wall, the hole wall and the outer wall of the porous pipe are selectively subjected to plasma treatment. 2. A vacuum container for accommodating a porous pipe whose one end is closed, exhaust means for exhausting gas from the porous pipe and from the vacuum container, and gas introducing means for introducing gas to the outside of the porous pipe. Pressure adjusting means for adjusting the pressure inside and outside the porous pipe, and plasma generating means for bringing the gas in the vacuum container into a plasma state, and adjusting the pressure near the inner wall, hole wall, and outer wall of the porous pipe. The porous pipe manufacturing apparatus is characterized in that the plasma generation location is adjusted by this, and the inner wall surface, the hole wall surface, and the outer wall surface of the porous pipe are selectively subjected to plasma treatment. 3. The manufacturing apparatus according to claim 1, further comprising moving means for moving the porous pipe or the plasma generating means in a vertical direction, while relatively moving the porous pipe and the plasma generating means in a vertical direction. An apparatus for producing a porous pipe, wherein uniform selective plasma treatment is performed over the entire surface of the porous pipe. 4. A porous pipe manufactured by the porous pipe manufacturing apparatus according to claim 1, claim 2, or claim 3.