Abstract: A method for sintering tube pre-forms in an furnace for obtaining ceramic tubes which are extremely straight is provided, in which, during sintering, the tube preforms are placed inside supporting tubes in ceramic material, the support tubes 1 containing the tube preforms being arranged parallel to each other forming stacks 7 of layers 3 supported by support plates 4 in a refractory material, the inside surface of the support tubes being out-of-true by less than 0.1 mm over a length of 90 mm.

Abstract: A fluid treatment module, particularly for treating ultra-pure fluids by separation or catalytic treatment having at least one treatment membrane in a porous sintered material comprises a rigid tube casing, a rigid compression plate at one or each end thereof having a coating compatible with the fluid(s) to be treated and at least one compensating plate able to slide on the coating, the dimensions and thickness of the compensating plate being set to ensure the module remains sealed over a complete temperature range at which the module is designed to operate.

Abstract: The present invention relates to a module for filtering, separating, purifying gases or liquids, or for catalytic conversion, comprising:- a substantially cylindrical housing (13),- at least one rigid element (4) of which at least one end (5) is substantially cylindrical and whose axis is parallel to that of the housing (13),- at least one elastically deformable metal part in the form of a ring (6), fixed firstly to the housing (13) and connected secondly to said end (5) of said element (4), characterized in that the joint between said ring (6) and said end (5) of said element (4) is a hoop fitting.

Abstract: The present invention relates to a module for filtering, separating, purifying gases or liquids, or for catalytic conversion, including:a substantially cylindrical housing (13),at least one rigid element (4) of which at least one end (5) is substantially cylindrical and whose axis is parallel to that of the housing (13),at least one elastically deformable metal part in the form of a ring (6), fixed firstly to the housing (13) and connected secondly to the end (5) of the element (4), characterized in that the joint between the ring (6) and the end (5) of the element (4) is a hoop fitting.

Abstract: Membrane apparatus for performing filtration, separation or a catalytic reaction, the apparatus including a macroporous block provided with parallel longitudinal through channels, the surface of each channel being covered with a respective membrane having finer pores than those of the block. According to the invention, the pores in both ends of said block are filled with a dense material (3) formed by a monometallic or polymetallic organic-inorganic polycondensate which has been subjected to heat treatment, this type of condensate being known under the name of ORMOSIL (organically modified silicate) or ORMOCER (organically modified ceramic).

Abstract: An organic-inorganic polycondensate characterized by the fact that it satisfies the following formula:C.sub.v H.sub.w O.sub.x Si.sub.y Me.sub.zwhere:v=4 to 48w=5 to 52x=5 to 48y=2 to 16z=1the ratio v/(y+z) being less than 7;C.sub.v H.sub.w being a carbon-containing chain carried by silicon; andMe being a metal or a mixture of metals chosen from groups IVA, VA, VIA, IIIB, and IVB of the periodic table of elements.

Abstract: A membrane for a filter device or a device for gas or liquid separation, the membrane being constituted by a porous structure made of at least one material selected from sintered ceramic, sintered metals, microporous carbon, microporous glass, and polymers, said structure including at least one microporous layer, wherein the entire outside surface and inside surface of the pores of said structure is covered by a thin and continuous film of a polyphosphazene, the thickness of said film lying in the range 0.01% to 10% of the mean diameter of the pores of said microporous layer.

Abstract: A membrane device comprising a macroporous block of sintered material with the pores at each end of the block being filled with a porous sintered material, wherein the porous sintered material comprises at least two types of grain: grains of a first type called "frame" grains having a diameter lying in the range about 1% to about 20% of the diameter of the pores in said block; and grains of a second type called "finishing"grains having a diameter lying in the range about 0.2% to about 20% of the diameter of the frame grains, with the finishing grains being received in the pores defined between the frame grains.

Abstract: A membrane for a filtration, gas or liquid separation or pervaporation apparatus comprising at least one porous layer of an inorganic material selected from sintered ceramic, sintered metal, sintered glass or carbon and a separating layer of organic material, the membrane being characterized in that said organic material is a polyphosphazene, in that the average diameter of the pores in said porous layer of inorganic material is between about 5 nm and 1 .mu.m, and in that said separating layer is continuous and only penetrates into said porous layer to a depth of less than five times the diameter of said pores in said porous inorganic layer, said layers being strongly bonded to each other.

Abstract: A method of assembling a rigid element in a module, the rigid element having a membrane for separation, filtration, or catalytic transformation purposes. The outside shape of the element is substantially cylindrical or prismatic. The element is made from a support of sintered substance, the ends thereof are sealed, and an active layer is deposited thereon. The module is intended to contain at least one rigid element within a shell which is substantially cylindrical about an axis parallel to said rigid element and closed by two end plates having openings to which the ends of the elements are fixed, together with intervening seals. Each of the ends is provided with an extra thickness which is bonded to the support. The extra thickness mass is machined in such a manner as to obtain a shoulder whose outside surface has a predetermined circularly-symmetrical shape about an axis close to that of the element.

Abstract: The fiter membrane comprises a porous structure made of a material selected from sintered ceramics, sintered metals, microporous carbon, and microporous glass, and is characterized by the fact that its entire external surface, including the inside surface of the pores in the structure, is covered with a thin and continuous film of carbon or of an oxide. In a sintered aluminum membrane, the surfaces of pores are coated with a dense and continuous thin layer of zirconia which prevents the surfaces from being degraded in service. In the figure, curve 3 shows how the throughput of a membrane without a zirconia layer falls off over time, while curve 4 shows little change in the same membrane having such a layer.

Abstract: A module (1) for rigid cylinder membrane elements (2) for separation, filtration, or catalytic transformation, the elements (2) being received in a vessel which is generally cylindrical and parallel thereto, and closed by a first end plate (4) and a second end plate (5) to which the ends of the elements (2) are fixed by means of seals (6,7). The end plates are interconnected by at least one spacer constituted by at least three juxtaposed oblong parts (10, 20, 30) made of materials selected for reducing the expansion differences that would otherwise occur on a change in the temperature of the vessel and its membrane elements.

Abstract: The filter membrane comprises a porous structure made of a material selected from sintered ceramics, sintered metals, microporous carbon, and microporous glass, and is characterized by the fact that its entire external surface, including the inside surface of the pores in the structure, is covered with a thin and continuous film of carbon or of an oxide. In a sintered aluminum membrane, the surfaces of pores are coated with a dense and continuous thin layer of zirconia which prevents the surfaces from being degraded in service. In the figure, curve 3 shows how the throughput of a membrane without a zirconia layer falls off over time, while curve 4 shows little change in the same membrane having such a layer.

Abstract: A filter module comprises a plurality of parallel substantially tubular filter elements each of which comprises a ceramic support. Two apertured end plates are attached to a protective casing and each filter element is fixed via flexible seals into respective apertures in these end plates. The module is assemble by a method which begins with molding the blanks from an elastomer material that is resistant to organic solvents and to corrosive liquids and has a Shore A hardness between 30 and 95 and an elastic elongation per unit length in excess of 10%. Each blank can have any form of outside surface and has an internal cavity with a surface matched to the ideal external shape of a filter element, except that its dimensions are slightly smaller than the corresponding dimensions of the filter element. The resulting blanks are then fitted onto the ends of the filter elements.

Abstract: A porous material made from sintered inorganic particles. It has an open pososity of 30% to 40% by volume, a permeability to water at 20.degree. ranging from 0.6 to 60 m.sup.3 /h.m.sup.2.bar for a wall thickness of 2 cm as the average pore diameter varies from 2 to 20 microns and a crushing resistance, measured under conditions of isostatic compression, of 4.times.10.sup.8 to 5.times.10.sup.8 N/m.sup.2.

Abstract: A filter membrane for filtering liquid food stuffs or hot gases and including at least one filter layer. The membrane is constituted by a sintered inorganic material comprising grains which are fixedly connected to one another and the average roughness of the surface of said filter layer over a distance along said surface equal to at least five times the average grain size is less than one fifth of the average grain size in the region in question.

Abstract: An assembly of a tubular filter member (2) inside an envelope (5) surrounding the member includes a gasket (9) of elastomer or polymer material disposed at at least one of the ends of the filter member and of the envelope in between the outside surface of the filter member and the inside surface of the envelope.The outside surface of the filter member is provided over at least a portion of its surface area facing the gasket with roughnesses (11) or projections or hollows of sufficient size and number to prevent the filter element from sliding longitudinally relative to the gasket.Such an assembly is applicable to microfiltration, ultrafiltration and reverse osmosis.

Abstract: A method of making imprints on the walls of portions of a tube obtained by the continuous molding of a ceramics-based paste and the cutting up of the tube, wherein immediately after the tube portions have been molded and are still deformable, they are placed on means parallel with the axis of the tube portions for rotating them around their axes of revolution, means are applied to the rotary means for exerting a pressure on at least a portion of the tubes so that such portions are clamped between the rotary means and the pressure-exerting means, the pressure-exerting means or the rotary means are provided with at least one imprint-making tool, the or each tool having a main direction which does not coincide with the direction of the axes of revolution of the tube portions, and means are applied to create a second relative movement between the tube portion and the or each tool, so that there is substantially no sliding between the tube portion and the or each tool.

Abstract: This invention concerns a cellular, spherical bead of organic, macromolecular polymer material which when carbonized in the solid state retains its original beaded shape and has a high carbon content and methods for making such beads of polymer and carbon.