Séparation with organic membranes - Technifiltration Filtration industrielle

TECHNI FILTRATION SPRL

Le Spécialiste en Filtration Industrielle

Séparation with organic membranes

Membrane filtration is a filtration method for separating water from soluble substances, such as oils, organics materials (soaps), suspended solids and metals (ionic or particulate).

It can be used both for eliminating the waste water pollutants and to produce process water, as well any separation of molecules in a liquid medium.

Operating principle of a dead-flow filtration (left) and a cross-flow (right). The organic membranes that we propose work always in "cross flow".

Schematic diagram of a system of membran filtration

Ultra Micro Nano filtration and reverse osmosis in relation to the sizes of the various elements to filter

RO and NF membranes are coated with a nonporous film , while those in MF and UF have only one porous dense film

Porous dense and nonporous film

Spiral membranes such as those above are usually used for reverse osmosis and nanofiltration

Settings and terminology RO membranes

Settings and terminology RO membranes

The permeability increases but the relative retention of salts decreases with the temperature

The flux and retention of salts relative increase differently depending on the supply pressure

Retention relative salts and the permeability decreased with the concentration of salts

Beyond a certain concentration rating of concentrate , salt retention and permeability collapse

In a spiral membrane , the liquid to be filtered flows along the membrane ( cross-flow ) through the ' feed channel spacer ' to be then collected by the ' permeate collection material' and finally be sent to the central tube

The membranes can beings nested in series in a common housing via simple waterproof sockets in the central pipe

For ultra and micro filtration long hollow fibers are used. Pictured above, the fibers are assembled on a cassette submerged in the liquid to be filtered. A suction pump circulates the liquid.

Pictured above, the principle is the same except that it is a supply pump that puts the liquid under pressure in the carters

Separation ceramic membranes

Filtration ceramic membranes is generally used as an alternative to filtration organic membranes in the following cases :

- Viscous liquid filtration
- High temperature Filtration
- Liquid filtration incompatible with organic membranes

Operating principle of a "dead flow filtration" (lef) and a cross-flow filtration (right). The tubular ceramic membranes we offer work always in "Cross-Flow"

Schematic diagram of a membrane filtration system

Above cross flow principle applied to the tubular ceramic membranes, the liquid is always supplied from the inside outwards.

Tubular membranes have silicone endcaps to ensure watertight connections with the housings in which they are located.

The surface area of the tubular membrane may substantially change depending on the number of channels

Filtration grade of such membranes sweep the entire spectrum of microfiltration (1,4 µm) to the nanofiltration (1kD) via ultrafiltration

The layers above the membrane represent the media of the membrane, the layers underneath are the media support.

Some membranes are Isoflux patented technology. The thickness of the layer thins gradually in fonction of the length of the tubular membrane to keep a constant flow.