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Tangential Flow Filtration Sys.

Tangential Flow Filtration (TFF for short) refers to the filtration form in which the liquid flow direction and the filtration direction are perpendicular.


Tangential flow filtration with different pore diameters




Disadvantages of dead-end filtration

Figure 1 schematic diagram of conventional liquid dead-end filtration and tangential flow filtration


The conventional liquid dead end filtration is the common filtration form adopted by most microporous filtration (MF, microfiltration), including the sterilization filtration. The flow direction of the liquid is consistent with the filtration direction. As the filtration goes on, the thickness of cake layer or gel layer formed on the surface of the membrane increases gradually and the flow rate decreases gradually. When the filtration medium is ultrafiltration membrane with small pore size or microfiltration membrane, or when the solid content in the feed liquid is very high, the flow rate will decrease rapidly when the dead-end filtration method is adopted. Therefore, the dead-end filtration is only suitable for the treatment of the liquid with small volume, large particles or low solid content.




Tangential flow ultrafiltration

Tangential flow ultrafiltration refers to the filtration form in which the liquid flow direction and the filtration direction are in a vertical direction, that is, the liquid flows along the direction parallel to the membrane and scour the membrane surface while filtering, so that the membrane surface will not form a gel layer and maintain a stable ultrafiltration rate.

Tangential flow ultrafiltration is widely used in research and development, pilot scale and industrial scale production. For larger-scale material and liquid filtration, the liquid flows on the surface of the filter medium that creates shear forces by adopting the tangential flow ultrafiltration mode, which reduces the accumulation of filter cake layer or gel layer and ensures stable filtration speed.


Figure 2 Hanbon Bio-TFF 4400 full-automatic UF/DF system




Tangential flow Filtration applications

Blood products:

detoxification, concentration and metal ion removal of albumin, globulin and other blood products.

Vaccine:

clarification of cell culture mediums, concentration and filtration of virus solutions, removal of heat source of buffer solutions.

Genetic engineered products: protein concentration, buffer replacement, bacterial collection.

Antibiotics:

fermentation liquor clarification, heat source removal of antibiotic bulk drugs, macromolecular impurities removal

Biochemical products:

protein concentrate, filtration, separation of large and small molecules.

Traditional Chinese medicine products:

traditional Chinese medicine injection can remove heat source, remove macromolecules, clarify material and liquid, and separate polysaccharide molecules.

Water for injection system:

heat source, bacteria removal of the water system and clarification.





Semi-automatic VS full-automatic ultrafiltration system

Figure 3 Millipore Cogent ® μ Scale ultrafiltration system


Semi-automatic ultrafiltration system is more suitable for daily small-scale to pilot-scale ultrafiltration experiments (concentration, clarification, cell collection, dialysis, etc.) and process optimization or pilot-scale production process. 


Figure 4 P&ID drawing of HANBON Bio-TFF4400 (Laboratory semi-automatic ultrafiltration system)


The full-automatic ultrafiltration system is suitable for pilot and industrial scale production.


Hanbon Sci &Tech Bio-TFF full-automatic ultrafiltration system has the following characteristics:

The system is equipped with a workstation that can edit methods to achieve CIP/SIP, automatic concentration, constant volume washing, automatic collection and advanced mode operation.

The system automatically detects the pressure of the inlet and outlet of the filter membrane and the filter out side, and calculates TMP automatically and records TMP Curve.

All parameters in the process of system operation are recorded in special files, and the map can be in real-time drawn for reference and audit tracking. The filter membrane outlet is equipped with precision valves, which can precisely control the opening of the outlet valve and realize the precise control of transmembrane pressure.

According to the process requirements, the system can be flexibly configured with flow meter, conductivity, pH meter, UV detector and other online detecting and monitoring devices to record the operation curve.




Ultrafiltration membrane materials

According to the different membrane components, the two types of ultrafiltration systems commonly used in the biopharmaceutical industry are membrane package type and hollow fiber type. Generally speaking, hollow fibers are more suitable for samples with larger/dirtier samples (such as solid-liquid separation, cell lysis buffer, etc.), while membrane packages are more suitable for cleaner samples (such as protein concentration, sample buffer replacement, or protein renaturation, etc.). In contrast, the flux of the embrane package sample with similar membrane pore size is larger than that of the hollow fiber. However, if the sample is dirtier, the membrane sample is easy to be blocked. However, because of their differences in materials, internal structures and the separation process, they have their own advantages in the separation of samples, so there is no better or worse.