The Alfa Laval Membrane-UF system is a cross-flow ultrafiltration plant which is designed for automatically controlled product concentration in continuous mode. The system provides cost-effective standardized solutions for specific concentration requirements and is designed with a minimal hold-up volume and a stringent focus on hygiene throughout
The Alfa Laval Membrane-UF system (AL-mem UF) is normally used as a concentration and purification stage within other processes, reducing the volume of a liquid by removing water and other low-molecular substances.
The AL-mem UF system can be used for cost-effective concentration of proteins, gums and other feeds prior to further evaporation. Units of this type are widely used for installations processing blood plasma, gelatine, egg, pectin extract, carrageenan and chitosane. Also for the production of natural colours and for the recovery of protein from waste streams these units are the ideal choice.
The actual process temperature is related to the particular feed product being treated. Typical temperatures lie in the range of 5 to 90°C (41 to 194°F).
The Alfa Laval Membrane-UF system is supplied as a frame-mounted plant with pre-assembled components and prefabricated piping. It is ready for operation as soon as it is installed and connected to external supply systems.
The system offers easy, reliable operation along with straightforward maintenance thanks to its pre-assembled and frame-mounted setup. This helps keep downtime to a minimum.
The piping, pumps, strainers, valves and fittings as well as the control panel are all manufactured by Alfa Laval. This provides significant advantages in terms of effective service and reduced spare parts inventory.
All piping and equipment in contact with the product or cleaning liquids are of sanitary-level design, as are also the spiral membranes. Steel parts are made of AISI 316L stainless steel.
The AL-mem UF system is controlled and monitored via a PLC operator panel which includes a motor control centre equipped with frequency drivers on pumps to keep down energy consumption.
Product concentration and purification are conducted in continuous mode which is automatically controlled. Cleaning is based on operator controlled and monitored CIP procedures.
- Frame-mounted modules with pre-assembled components and prefabricated piping
- Main components and control panel are manufactured by Alfa Laval
- All piping and equipment in contact with the product or cleaning liquids are of sanitary-level design. AISI 316L stainless steel parts
- PLC operator panel for system control and monitoring of data
- Automatically controlled product concentration in continuous mode
- Operator controlled Cleaning-In-Place procedures
How does the ultrafiltration process work?
During the ultrafiltration (UF) process, spiral membranes reduce the volume of a liquid by removing water and other low-molecular substances. The product is introduced into the feed tank system by the level control valve and pumped to a number of membrane filtration stages connected in series (loops). Each ultrafiltration loop consists of a number of housings containing Alfa Laval spiral membranes. The membranes allow salts and water to pass into the permeate stream (rejecting proteins, gums, etc). The concentration of the feed product increases as it passes through the sequence of loops.
The actual ultrafiltration process temperature is related to the feed product being treated. Typical temperatures lie in the range of 5° to 90°C (41° to 194°F).
Pump and cooling system
Each loop has a recirculation pump system to provide the membranes with the appropriate cross-flow to minimize fouling, taking into account the overall capacity of the system. The unit also contains a cooling system to remove heat generated by the pumps. The frequency drivers on pumps keep energy consumption low.
The permeate collected from the loops during the ultrafiltration process enters the permeate tank system where it is discharged upstream or downstream for recycling or disposal via a drain system.
Flow rate control
The retentate flow rate output is normally controlled by a flow ratio system (VCF value) or by an optional refractometer/density in-line instrument to obtain the desired product concentration or volume reduction.
The ALMEM-UF system is fully automatic. The easy-to-use MemProC® control system ensures safe and reliable operation and features separate modes where you can select different production, cleaning, sanitization and water recirculation operations, complete with all the necessary sub-sequences.
Product displacement and CIP
Once a cycle has been completed in the ultrafiltration process, the product is displaced by water to ensure maximum product recovery. The displacement sequence is followed by a water flushing stem to remove any product residue on the membrane surface. Finally, a CIP sequence cleans the membranes and the loops.