 Structure or construction for mounting a pressure detector |
| The main object of the present invention is to solve the above-mentioned problem encountered when ... |
|
| Process for applying a composite insulative coating to a substrate |
| What is claimed is: 1. A process for applying an adherent electrically insulative moisture-... |
|
| Shielded energy transmitting surgical instrument and methods therefor |
| Accordingly, it is a primary object of the present invention to overcome the above mentioned ... |
|
| Separator for an alkaline cell and a method of producing the separator |
| What is claimed is: 1. A method of producing a separator for an alkaline cell, comprising the steps ... |
|
| Coatings for cutting implements |
| We claim: 1. A method of treating an edged cutting implement which comprises depositing a coating ... |
|
| Press-cushion sheet |
| We claim: 1. A press-cushion sheet comprising a multiple-ply woven fabric having three- to six-ply ... |
|
| Membrane separation of hydrocarbons |
| OF THE INVENTION As was previously discussed, the present invention relates to a process for the ... |
|
| Chromatographic separation method and associated apparatus |
| The present invention has met the above-described need by providing means for effectively ... |
|
| Photomask blank and photomask |
| It is an object of this invention to overcome the problems encountered with respect to known hard ... |
|
|
Composite ceramic micropermeable membrane, process and apparatus for producing such membrane
| Details |
Inventors: Van 'T Veen, Willem H.; Engel, Albertus J. G.; Bonekamp, Benedictus C.; Veringa, Hubertus J.; Terpstra, Rinse A.;
Assignee: Hoogovens Groep BV (NL)
Primary Examiner: Spear; Frank
Assistant Examiner:
Attorney, Agent or Firm: Stevens, Davis, Miller & Mosher
A microporous ceramic membrane comprising a porous support and a microporous layer firmly bound to each other, with a sharp geometric transition between the support and the microporous layer, the microporous layer being free of pin-holes. The microporous membrane has a predetermined average pore diameter and it is suitable for microfiltration. The membrane can comprise further microporous layers making it suitable for ultrafiltration and hyperfiltration. The membrane can be prepared by suspension coating of a support, whereby the support and/or the suspension are pretreated in order to lower temporarily the affinity between the support and the suspension. |
|
DETAILED DESCRIPTION The invention has the following features: the microporous layer is firmly bound to the geometric outer surface of the porous support, making the membrane structurally stable and suitable for multiple regeneration by applying high back flush pressures, if necessary; the microstructural transition between the porous support and the microporous layer is very sharp, the packing of the particles being such that the support material and the microporous layer material do not interfere with each other's permeabilities; the microporous layer is thin and has a smooth outer surface, resulting in a high and uniform permeability; the microporous layer has a predetermined average pore diameter, depending on the intended use, and it has a narrow pore diameter distribution; in particular, the diameter distribution is sharply confined with respect to larger pore diameters than the average, for example, 99% of the pore volume consists of pores with a diameter of less than 1:15 times the average diameter, and 99.
9% of the pore volume consists of pores with a diameter of less than 1.
2 times the average diameter; the microporous layer is free of pin-holes and other structural irregularities which would seriously impair the separation performances of the membrane; the inner face of the microporous layer closely follows the surface of the porous support in such a way that pores in the support having an even greater diameter than the thickness of the microporous layer are spanned by the microporous layer; the membrane has a high permeability.
The thickness of the microporous layer can be chosen according to the intended use of the membrane.
It is typically between 10 and 100/.
mu.
m and preferably between 15 and 30 .
mu.
m.
The average pore size of the microporous layer can have any value in the microfiltration range i.
e.
about 20 nm to 1 .
mu.
m.
It is preferably between 100 and 500 nm; The microporous layer consists preferably of at least one metal oxide such as aluminium oxide, titanium oxide, zirconium oxide, yttrium oxide, silicon oxide etc
|
|
Semiconductor manufacture 
