Inorganic membranes are made of inorganic materials like Al2O3, TiO2,SiC,316L..Noramally there are three types of inorganic membranes:  Al2O3 Ceramic membrane, SiC membrane  and 316L stainless steel membrane.  Compared with polymeric membranes, inorganic membrane has very unique specification:
* Acid & Alkali stability
* Oxidation stability
* Thermo stability
* Sovent stability
* Abrasive
* High flux 
The market of  inorganic membrane is seeing very fast increasing in recent years. 

Stainless steel membranes feature excellent alkali resistance, while their manufacturing cost is much higher than that of other membrane types.SiC membranes offer greater porosity and higher pure water flux.Both SiC and Al₂O₃ membranes are well suited for solid–liquid separation in the process industry.Compared with SiC membranes, Al₂O₃ membranes come at a lower cost, making them more cost-effective for budget-sensitive projects.

Ceramic membrane system can be designed into different operation modes.  Normally we can make a  Batch design for small capacity , and make a Continuous design for a high capacity. For batch operation, retentate will flow back to Feed tank, while permeation will flow out into permeation tank. For continuous operation, most retentate will not flow back to Feed tank, it will flow out continuously together with permeate. 

CRM Ceramic membrane is made of pure Al2O3 under very high temperature. The specification is very stable in most of chemicals like strong acid, alkali, oxidation. During normal application in process industry, ceramic membrane can keep a very long life time comparing with polymeric membranes. 

The worklife of ceramic membranes is effected by following factors:
● Membrane quality
● Specification of feed fluid
● Pretreatment design
● Membrane process design
● Daily careful operation
...
TANGENT provides reliable grade ceramic membranes and professional integrated design packages for membrane systems, enabling long-term stable operation with consistent performance over many years.

Ceramic membrane element and housing must be thoroughly cleaned before storage,otherwise bacteria will grow fast on membrane.
●  CRM membranes can be stored either in dry or wet condition.
●  Membranes can be kept inside the module for long-term storage.
●  Remove all contaminants (including proteins, organics and metal substances) from the membrane and support layer by using cleaning agents containing enzymes, acids, alkalis or oxidants.
●  Shut down the permeate side valve first, circulate for 30 to 60 minutes, and then open the permeate side valve.
● Pure water or deionized water is recommended for cleaning and rinsing.
●  Test the water flux. If the water flux is well restored after cleaning, the cleaning procedure is considered successful. Before reusing ,a CIP cleaning with NaOH 1% with 2000ppm NaClO is highly recommended. 

 

Ceramic membrane normally runs under a CROSSFLOW mode, the feed liquid flows a fast velosity 3-6m/s across inside membrane layer. Here is calculation of cross flowrate for a membrane housing:
For example, we use a housing CRH61-30 which is loaded with 61pcs CRM3019-1200mm membrane. 
The inside diamter of membrane is 4.0mm
If we apply 4.5m/s crossflow velosity 
So the cross flowrate for a single membrane is Qmembrane=3.14*0.002*0.002*19*3600*4.5=3.87m3/h
So the cross flowrate for a housing is Qhousing=61*3.87=236m3/h