TECHNOLOGY

 

 

 

 

 

 

 

LiqTech Ceramic Membranes

 
 

INTRODUCTION

On the basis of revolutionary silicon carbide (SiC) technology, LiqTech develops, manufactures and globally markets ceramic membranes for filtration of liquids. The membrane substrates as well as the coatings are made from 100% silicon carbide. This in turn gives our membranes some unique advantages compared to traditional ceramic and polymeric membranes.

 

MEMBRANE PROPERTIES

FEATURES AND BENEFITS

HIGHEST FLUX FOR ANY MEMBRANE MATERIAL

The high flux is reached through high membrane porosity (~45%) and a material with low resistance to transport of water and a low contact angle
- Reduce your foot print and system costs (less pipes, valves etc.)

CHEMICALLY INERT pH 0-14

- No limitations, fast cleaning, reduced down time during Cleaning in Place (CIP), filtration of acids and alkalis

THERMALLY RESISTANT UP TO 800 ˚C

- Steam cleaning, more efficient chemical cleaning, and high temperature applications

HYDROPHILIC MATERIAL (WATER LOVING)

- Unmatched performance in oil/water separation

ISO ELECTRIC POINT pH 2.4

- Unmatched performance in oil/water separation
- To some extent reduces fouling, easier to clean

EXTREMELY HARD AND DURABLE MATERIAL 2930 +/- 80 kg/mm3 (Vickers scale)

- Robust and long life time, less down time and maintenance, stable operation, cleaning with shock pulses, hard membrane surface not destroyed by sharp particles


SIC MEMBRANE TECHNOLOGY

The ceramic membrane carrier is based on the so-called honeycomb or monolith structure as shown below:

LiqTech Ceramic Membrane

Figure 1: Monolith structure


A number of parallel flow channels extend through the element in the porous support structure. The feed stream is introduced under pressure at one end of the element and flows through the channels during processing. The portion of the liquid passing through the membrane, the permeate, flows into the porous structure of the element. The combined volume of permeate from all flow channels flow toward the outer shell of the monolith support and is removed continuously.

The actual ceramic membranes are formed on the walls of the flow channels extending through the porous ceramic structure of the element by slip casting a specific coating of ceramic particles according to the desired pore size and distribution. The coating material, containing the silicon carbide, is dried and sintered. This process ensures a strong bond with the carrier material and provides the membrane with its unique ruggedness and durability. Several layers may be deposited on top of each other in order to reach the desired combination of membrane pore sizes and water flux.


Figure 2: SiC membrane layers on top of a SiC carrier


MEMBRANE CONFIGURATIONS

LiqTech produces an extensive range of sizes and configurations of SiC membranes. Below is an overview of our membrane products and filtration principles.

 

TUBULAR MEMBRANES

CROSS-FLOW AND DEAD END FILTRATION (INSIDE-OUT)

Our range of CoMem and CoMem Conduit elements are designed for cross flow filtration for filtration of liquids with high amounts of suspended solids, oil, algae, bacteria etc.

Cross flow filtration is a filtration method, where the feed flow is tangential to the surface of the membrane in order to sweep rejected particles and solutes away (se figure 3 below). The feed fluid is separated into two product streams, the permeate, which is depleted of the rejected particles, and the retentate (or waste/concentrate), which is enriched in those particles.

The great advantage of using cross flow filtration is the superior handling of liquids with high solids content, as the retained particles are being continuous removed from the membrane surface. In addition to the cleaning mechanism of cross flow filtration, the tubular membranes can be cleaned with the means of a traditional back wash, back pulse and/or periodic chemical cleaning.

LiqTech cross flow filtration

Figure 3: Cross flow filtration principle

 

Figure 4: CoMem elements

 

 

Figure 5: Typcial cross flow system


 

FLAT SHEET MEMBRANES (FSM)

SUBMERGED MODULES FOR VACUUM DRIVEN FILTRATION (OUTSIDE-IN)

Our range of FSM are offered as individual sheets or as ready to implement filtration modules which consists of multiple membranes built into a robust resin. The FSM are used in submerged vacuum driven filtration systems which are based on several stacks of modules built into filtration racks. The filtration mode is outside-in and cleaning is performed by a combination of airscouring, CEB (Chemical Enhanced Backwash) along with periodic chemical cleaning.

 

Figure 6: Flat sheet membrane principle

 

Figure 7: FSM sheets and modules

 

 

 

 

 

LIQTECH A/S  © 2017  -  RETTIGHEDER  -  DESIGN AND IDENTITY: HAUS COPENHAGEN