DE3920562C1 - Plate membrane used in micro- and ultra-filtration - obtd. by forming polymer membrane layer on rigid and porous plate through phase inversion process - Google Patents

Abstract

A plate membrane for use in micro- and ultra-filtration is made by producing a polymer membrane layer on a rigid and porous plate through a phase inversion process. The plate is passed at an angle of under 90 deg. and with a distance of 20-1000 microns from the solution pouring device into the precipitating bath. The plate is a porous sinter product or a mat of glass-, carbon- or metal fibres. The pref. polymer material is PES,PVF or polyamide. ADVANTAGE - This eliminates the difficulty of handling flexible plate membrances.

Description

The invention relates to polymer inorganic composites membranes for use in micro and ultrafiltration and a Process for their production.

To date, the following synthetic membrane types are from the various materials known:

- Wood fiber membranes
- capillary membranes
- tubular membranes
- flat membranes.

These are used in membrane separation processes puts. In addition to tubular membranes, these membrane types are common mean characterized by great flexibility.  

It is known that especially when mounting Plattenmo It is very difficult to handle flexible flat membranes is. It depends on the rolling properties of the membranes grasslands. That is why the flexible membranes are often placed on plates glued.

The present invention solves the problem in a simple manner. According to the invention this is achieved in that the membrane formation ( 2 ) takes place directly on a porous and rigid plate ( 1 ) which at the same time ensures uniform permeate removal. Here, the rigid carrier plate ( 1 ) can be a porous sintered metal, sintered glass or sintered ceramic, but also fibrous fabrics and nonwovens, in particular made of glass, carbon or metal fibers. In these materials, polymeric resins are used before for reinforcement, which can be made porous and rigid with pyrolysis processes.

Other advantages of the rigid insert are the good ones Conditions for double-sided membrane polymer coatings. The radial continuation of the permeate in the direction of the larger one Radii, due to an even and congestion-free per can be ensured.  

The membrane formation takes place after the so-called phase inverter process. For this purpose, a polymer should be known per se Be solved in one or more solvents. If necessary, non-solvents or salts can be added will.

The resulting homogeneous pouring solution is spread over a large area applied the rigid and porous plate, the Beschich thickness is 20 to 1000 µm.

The viscosity of the casting solution should be adjusted so that only partially pour the casting solution into the plate cross-section does not penetrate.

The casting solution is applied to the porous and rigid plate ( 1 ) with the aid of the application device ( 3 ), a fixed distance of 20 to 1000 μm being set between the application device and the porous plate. The plate coated in this way is then introduced into the precipitation bath at an angle between the plate surface and the surface of the precipitation liquid of less than or equal to 90 ° ( FIG. I).

Alternatively, the casting solution is applied to the porous and rigid plate ( 1 ) on both sides, so that the plate is guided vertically with a fixed distance between 20 and 1000 microns to the standing polymer application device down into the precipitation bath ( 4 ) ( Fig. II ).

The immersion time in the precipitation bath can be between 1 and 120 min be.

The unwanted rolling up of the membrane in the course of Drying is prevented with plate membranes.

In this case, the polymer cannot run through it permeate obtained in the direction of the free cross-sectional zone of the outer edge of the membrane plate.

Claims (4)

1. plate membranes, characterized by a polymer membrane layer ( 2 ) with a porous and rigid plate ( 1 ) mechanically insoluble, depending on the selection, the thickness of the plate ( 1 ) between 50 microns and 5000 microns, the pore size of the rigid plate ( 1 ) of between 5 microns and 500 microns, the porosity of the rigid plate (1) between 0.1 and 0.9 and the strength of the bonded polymeric membrane layer (2) is between 20 and 1000 microns, obtainable by the polymer membrane layer (2) is generated on the porous and rigid plate ( 1 ) by means of a phase inversion process, in that the plate ( 1 ) is at an angle of less than or equal to 90 ° to the horizontal, advantageously in an inclined position with a fixed distance between 20 and 1000 μm to the standing application device of the casting solution ( 3 ) is led down into the precipitation bath ( 4 ). 2. plate membranes according to claim 1, characterized by two-sided coating of a porous and rigid plate ( 1 ) with a polymer membrane layer ( 2 ), wherein depending on the selection, the thickness of the plate ( 1 ) between 50 microns and 5000 microns, the pore size of the rigid plate ( 1) microns between 5 and 500 micrometers, the porosity of the rigid plate (1) between 0.1 and 0.9 and the strength of the bonded polymeric membrane layer (2) are between 20 and 1000 microns, obtainable in that the polymer layer (2 ) is produced on both sides of the porous and rigid plate ( 1 ) by means of a phase inversion process, in that the plate ( 1 ) coated on both sides with casting solution is guided vertically downward into the precipitation bath ( 4 ). 3. plate membrane according to claim 1 and 2, characterized by a polymer membrane layer ( 2 ) with a porous and rigid plate ( 1 ) mechanically non-detachably, the material of the porous and rigid plate ( 1 ) has a chemically and pyrolytically reinforced symmetrical or asymmetrical structure and consists of glass or carbon or ceramic or metal fiber, or fleece, or sinter. 4. Plate membrane according to one of claims 1 to 3, characterized characterized in that the polymer material Polyether sulfone, polyvinylidene fluoride or polyamide consists.