What to Know About Membrane Systems

Membrane systems are used to concentrate dilute feed streams, to separate the constituents in the feed stream, and to separate and concentrate at the same time.

Membrane Systems: Common Abbreviations Explained

RO (reverse osmosis): Process by which primarily water passes through a tight, semi-permeable membrane in such a way that dissolved solids are retained in the concentrate.
NF (nanofiltration): A slightly more open membrane than RO, NF allows for selective filtering, passing water and monovalent ions while retaining divalent ions and larger molecules (such as sugar).
UF (ultrafiltration): Type of membrane filtration where pore size is defined by the molecular weight cut-off of the membrane used. Can be used to produce potable water and is used in the dairy industry to make MPC and WPC by holding pack protein molecules while passing the milk sugar and minerals.
MF (microfiltration): Often the pre-treatment step prior to ultrafiltration. Used in water, dairy and beverage processing. Generally removes all undissolved solids, so often used for clarification, removal of fats, and removal of bacterial contaminants.

The most common membrane system configuration consists of spiral elements arranged into different diameters such as 8″ by 38″ long. This is most common because it deploys the most membrane area in the smallest space.

Membrane Systems for Wastewater Recovery

A variety of membrane materials and configurations are used in wastewater treatment such as ceramic and polymeric membranes in tubular, spiral, hollow fiber and flat sheet configurations.

Read Caloris case studies on membrane filtration for wastewater treatment here (RO condensate polisher) and here (rinse water RO).

CALORIS MEMBRANE systems can be used in a variety of water treatment processes:

  • Concentration of liquid streams
  • Polishing of evaporator condensate and RO permeate for reuse
  • Reclamation of high-strength caustic and acid solutions to extend chemical life and minimize total dissolved solids discharge\
  • Separation of components (proteins, minerals, sugars) in a feed stream
  • Purification of supply water for boiler to increase operating efficiency in cleaning, sanitation and utility (boiler, cooling tower) applications

Skidded Systems for Immediate Installation

CALORIS MEMBRANE filtration units arrive at your facility pre-assembled and ready to plug into your process system. Upon arrival of the unit, Caloris staff will oversee installation and configuration. Our engineers will work with your production team to commission the unit and train employees.

CALORIS MEMBRANE systems can be configured to accommodate many of the complex processing needs of different product streams. Contact our sales and technical specialists at 410-822-6900 or email problem.solved@caloris.com to discuss your specific needs and to place an order. You can also schedule an on-site test with our pilot RO unit.


About Caloris

Caloris transforms process systems design for the better with unexpected, future-focused solutions that solve real operational problems. We engineer efficient, dependable and productive solutions that also improve environmental sustainability where practical. Designed with the end user in mind to drive plant productivity. Caloris offers evaporation, membrane filtration and spray drying process systems for food and dairy industries, as well as for water reuse and wastewater treatment applications. Both Caloris’ custom and pre-engineered packaged systems are designed to meet our customers’ specific concentration/purification needs utilizing the most cost effective and energy efficient technologies available. Whether concentrating dairy, food or juice products at a high-volume production facility, or processing industrial wastewaters to reduce transportation and treatment costs and recover re-usable water, Caloris provides a range of options and technologies.