JPS6039412B2 - Manufacturing method and device for tubular filter member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a mineral tubular filter element, in particular a mineral tubular filter element comprising at least one metal oxide and/or at least one metal fluoride layer affixed to a ceramic or metal support. It concerns a filter having at least one thin layer.

According to known methods, this approximately tubular material is formed by shaping powdered mineral materials and subjecting them to heat treatment to ensure the mechanical strength of the assembly, based on conventional methods in the ceramic industry and in the powder metallurgy industry. Made by doing.

These materials may be alloyed with various metals such as steel, bronze, nickel, or oxides such as alumina, magnesia, citrate, or some such as fluorides, carbides, nitrides, and shelving materials. Can be made from refractory mixtures. When making tubes, these pulverulent materials are mixed with the organic material/dia and extruded under pressure through an annular nozzle.

After drying, these tubes are heat treated to remove the binder and to ensure the setting of the powder particles. This method is
1. For example, it is suitable for producing relatively thick tubes with a thickness of several millimeters.

However, in many applications, these porous supports or filters need to have maximum permeability so that maximum flow rates can be obtained and minimal pressure drop of the fluid flowing through them. There is.

Therefore, taking into account this necessary requirement, attempts have been made to manufacture these tubes with very thin walls, but while their engineering manufacture is difficult and time consuming, the tubes are It has only a small mechanical strength.

Accordingly, conventional high flow fillers have relatively large pore sizes and are made using lees powder. However, it is especially important to capture very fine particles, i.e.
It is often necessary for the member to have a very fine texture with a very small pore radius. This requirement is incompatible with the desired high transparency, which forms the essential feature of the filter element in question. In order to obtain a component that satisfies these requirements, it is necessary to form a multilayered material, i.e. a layer with a large permeability and a large pore radius in terms of thickness, and a layer with a small permeability with a very small pore radius. The current standard method is to make the materials. In the most commonly encountered cases, these components have a large permeable tubular support that provides mechanical strength to the assembly, over which is a very thin, usually mounted tube. A layer is applied, which imposes its own properties regarding flow rate and given pore size.

It is clear that this layer should be as thin as possible without significantly reducing the permeability of the assembly. The internal diameter of large permeable supports is often very small, so thin layers are applied by electrostatic or non-electrostatic jetting of suspended powder, as used in conventional coating techniques. is impossible.

Different coating methods have therefore been proposed, for example spraying dry powder into porous tubes pre-impregnated with a volatile liquid. Due to the difficulty of feeding the dry powder through the nozzle, this method tends to produce heterogeneous deposits of uneven thickness, which deposits are very fragile in nature. In practice, it is impossible to handle these areas without recovery after painting, and this very slow process cannot be used industrially. Another coating method comprises that a suspension of the powder to be deposited in a volatile liquid inert to the mineral powder is filtered through a porous support tube.

For equal suspension liquid concentrations, the layer thickness can be adjusted by measuring the furnace time or the furnace liquid volume.

Due to the vortex phenomenon during the furnace flow, it is not possible with this method to obtain the thin layers necessary to produce components with high flow rates. Additionally, this method involves the use of large, complex equipment and large amounts of suspended material. Other more complex methods, such as centrifugal attachment, may also be used.

A tube filled with powder suspension liquid is rotated about its marquee line, causing the powder to adhere to the inner wall of the support. It is also possible to paint by brushing a base made of powder and solvent. All these methods require relatively complex equipment, which cannot be easily used for the production of composite porous membranes on an industrial scale, and the desired properties, i.e. very limited thickness. adhesion layer and does not lead to the absence of defects within the layer.
In this area of filter production, the present invention provides significant improvements. It is an object of the present invention to have both high permeability and very small pores, and is composed of a rigid support of metal or ceramic and at least one thin porous mineral layer, each porous layer having is a method for producing a tubular filter member having pores smaller than the pores of the support; a liquid containing suspended mineral powder to constitute the porous layer and an inner wall and/or outer wall of the support; contacting the mineral powder, the liquid ensuring transfer of the mineral powder to the support and deposition of the powder, draining the liquid from the support, drying and compacting the support, An object of the present invention is to provide a manufacturing method characterized by heating.

The layer thus obtained is compressed onto the support using an elastic diaphragm, so as to compress the layer and give it a high mechanical strength and optionally reduce the size of the pores. Additionally, heat treatment may be applied to increase the mechanical strength of the layer. The suspension liquid of the mineral powder for the purpose of ensuring the adhesion to the porous support can be used as a temporary binder to ensure the adhesion of the particles of the mineral powder after removal of the liquid and It may contain a small proportion of one or more organic products which can act as agents to promote dispersion or anti-aggregation of the suspension or to modify the flow properties of the suspension. Therefore, the nature and concentration of the organic binder used, the pH of the suspension fluid, and the viscosity of the suspension fluid have a significant influence on the control of deposit thickness and deposits along the support.
The initial floating price is determined.

Thus, when using a suspension liquid with a so-called Newtonian flow, the upper part of the support of the liquid colander is stripped off, but its base is filled, leading to a marked heterogeneity of deposits. By choosing the composition of the suspension liquid, especially the organic matter/indider, to have an "initial flow" or even "maximal shearing force", the deposits can be completely homogeneous. According to the invention, the filter element fills the support with a suspension liquid, leaves the suspension liquid in contact for a given period of time, and drains the suspension liquid;
It can be manufactured by a simple method, which comprises leaving the parts coated in this way to drain and dry.

The filter is then heat treated to remove organic binders or volatile chemicals and to strengthen the deposited mineral film. It is also an object of the present invention to provide a sealed container having a supply closure for suspended mineral powder, a pipe for pressurizing and evacuating the inside of the container, and a tube for pressurizing and exhausting the inside of the container, an apparatus for carrying out the method according to the invention, comprising a tubular member and a support tube capable of supporting a device for controlling the height level of a suspended liquid by means of a transparent tube inserted into the member; It is to provide.

According to one embodiment of the device, the tubular section is provided with a gasket, by means of which the upper part is connected to a tube, which, due to its transparency, is suitable for checking the suspension liquid bell. It is equipped with a phototube plugging device which allows the suspension liquid level to reach the transparent part and ensures that the painting is stopped. The lower end of each tubular member is connected to a support tube submerged in suspension liquid located in a closed tank to which a pressure greater than atmospheric pressure is applied.

This above-atmospheric pressure causes the suspension liquid to rise within the support,
Allow the painting to take place. For preferred embodiments of the invention,
This will be explained below with reference to the accompanying drawings.

Tubular filter member 1 having gaskets 2, 3 at both ends thereof
is connected to the glass tube 4 through its upper part and to a metal support tube 5 integral with the tank 6 through its lower part.

This tank has a T-tube 7, each branch of which is equipped with a valve 8, 9, respectively, to allow the introduction of compressed gas and the return to atmospheric pressure. The support tube 5 is submerged close to its base in a tank filled with suspension liquid 10, which tank is filled through a sealed opening 11. The level of the suspension liquid is checked by means of a phototube 12, its receiver 13 and a control device 14. This coating operation is performed by installing the filter member 1 between the pipes 4 and 5, closing the atmospheric pressure return valve 9, and closing the pressurized gas supply valve 8. This pressure on the suspension liquid 10 causes the suspension liquid to rise into the support tube. When the level of the suspended liquid reaches the detection limit of the phototubes 12 and 13, the phototubes close the valve 8 and the atmospheric pressure return valve 9 via the control device 4. The suspension liquid descends into the tank 6 again. After draining, the support can be removed from the apparatus and the coating operation can proceed with a new support. Instead of applying pressure to the suspension liquid, it is possible to generate a vacuum by means of the tube 4, so that the suspension liquid rises in the same state in the support, and this modification does not fall within the scope of the invention. It is clear.

[Brief explanation of the drawing]

The drawing shows a longitudinal sectional view of a device according to an embodiment of the invention. DESCRIPTION OF SYMBOLS 1... Filter member, 4... Glass tube, 5... Support tube, 6... Container, 7... T-shaped tube, 10... Suspension liquid,
DESCRIPTION OF SYMBOLS 11... Effect part, 12... Phototube, 13... Light receiver, 14... Control device.

Claims (1)

Claims: 1. A metal or ceramic rigid support with both high permeability and very small pores, and at least one thin porous mineral layer, each porous layer having is a method for producing a tubular filter member having pores smaller than the pores of the support; a liquid containing suspended mineral powder to constitute the porous layer and an inner wall and/or outer wall of the support; in contact with the mineral powder, the liquid ensuring transfer of the mineral powder to the support and deposition of the powder, draining the liquid from the support, drying and compacting the support, A manufacturing method characterized by heating. 2. Flow of the mineral powder suspension liquid such that it ensures good mechanical stability of the thin layer after drying and good adhesion of the thin layer to the support. 2. A method according to claim 1, comprising a small amount of organic binder which serves to modify the properties. 3. The manufacturing method according to claim 1, wherein the porous mineral layer has at least one metal oxide layer. 4. The manufacturing method according to claim 1, wherein the porous mineral layer has at least one metal fluoride layer. 5 having both high permeability and very small pores, consisting of a rigid support of metal or ceramic and at least one thin porous mineral layer, the porous layer being more closely spaced than the pores of the support. An apparatus for manufacturing a tubular filter member having small pores, wherein a liquid containing suspended mineral powder to constitute the porous layer and an inner wall of the support and/or
or in contact with the outer wall, the liquid ensuring the transfer of the mineral powder to the support and the adhesion of the powder, draining the liquid from the support, drying the support and compacting it. an apparatus comprising: a closed container having a feed opening for a mineral powder suspension; pressurizing the interior of the container;
a tube for evacuating and immersed up to the base of the vessel;
An apparatus for manufacturing a shaped filter member, comprising a tubular member and a holding tube capable of supporting a device for controlling the height of a suspended liquid using a transparent tube placed on the tubular member. . 6. The device of claim 5, wherein the assembly for detecting the suspension liquid bell comprises an electrical detection device and a control device for controlling pressurization and evacuation of the interior of the container. 7. The apparatus of claim 5, wherein the suspension fluid level detection assembly includes a photocell, a light receiver, and a control device for controlling pressurization and evacuation of the interior of the container.