Anti-fouling Membrane Filtration System

FMX is a new anti-fouling membrane system based on the simple, yet innovative concept of using vortices to prevent fouling of the membrane for high density, high viscosity, and high solid applications. FMX has been used for wastewater treatment, separation and dewatering in manufacturing processes and recovery (reuse, recycle) applications in various industries, such as digestate & livestock waste, food & beverage, biotech, chemical, mining, and oil & energy.


What is FMX?

  • A revolutionary membrane filtration system that uses high-speed vortex generation to reduce fouling
  • Ideal solution for separation, concentration, recovery, de-watering, reuse, and/or treatment applications
  • Successful track record in challenging applications
  • A full range of models and membranes (MF, UF or NF) are available to satisfy our clients' demands


Limitations due to Membrane Fouling

Membrane filtration is becoming a popular choice for solid-liquid separation or wastewater treatment. However, industries have realized that membrane filtration technology also has its shortcomings. Fouling is one of the major concerns when membrane filtration technology is considered for wastewater treatment or a manufacturing process. Over time foulants form a boundary layer on the membrane surface, dramatically decreasing the permeate flow rate. This shortcoming often limits conventional membrane filtration systems to low-solid feed streams and requires complicated pre-treatments prior to the membrane filtration systems.

FMX Anti-Fouling Membrane Filtration System

FMX is the next generation membrane filtration system utilizing the Karman Vortex effectively to achieve fouling resistance. The rotating blades between the membrane surfaces of FMX generate and maintain turbulent flows on the membrane surfaces. As the boundary layers built by the foulants are disrupted on the membrane surface, the foulants are then carried away by the concentrate stream.


Conventional Membrane Filtration System

In conventional membrane filtration systems, such as spiral-wound, tubular, and plate-and-frame, the feed stream is pumped rapidly across the membrane surface to generate the cross-flow in order to remove the boundary layer built by foulants. However, this method is often ineffective because the shear force is the weakest near the membrane surface. As the membrane continues to foul, the permeate flow decreases and a water flush or chemical cleaning is required. Therefore, conventional membrane filtration systems require low-solid feed streams.




The membrane module is the core of FMX. It contains outer housings, membrane, vortex generators, and a center drive shaft. The vortex generators are placed between membrane trays and driven by the center drive shaft which is connected to the driving mechanism by a belt. Ten membrane trays and vortex generators form a membrane block. The total membrane surface area of a FMX machine is determined by how many membrane blocks are stacked together. Unlike other proprietary membrane systems on the market, FMX’s membrane module is serviceable and can be taken apart onsite if necessary to replace only the damaged membrane trays.


Driving Mechanism

The driving mechanism provides a rotating force to the vortex generators. Variable frequency drive is used to provide variable rotation speed to meet the feed stream characteristics and operation condition. A driving belt and pulleys are used to transfer rotation movement from the drive motor to the center drive shaft inside the membrane module.



The frame provides support for the membrane module and the driving mechanism. The frame feet has a built-in leveling function for uneven floors. There are four support beams connecting the top pressure plate on the membrane module to the frame.



The membrane module is constructed with flat sheet, vertically stacked membrane trays. The membrane trays are stationary, and are surrounded on each side by vortex generators.

The vortex generators are veined discs which spin at high RPM and to not come in contact with the membranes. High turbulence keeps solids in suspension and off the membrane surface.

The module is pressurized in order to push clean water through the membranes and into a clean water collection channel.



The standard class (FMX-S) was designed in close cooperation with Samsung Fine Chemical. As such, there were many design specifications with regards to the materials of construction, construction tolerances, and chemical tolerances. Full stainless construction and high temperature and pressure ratings combine to make the FMX-S ideal for chemical, petro-chemical, and other high value applications.

On the other hand, the economic class(FMX-E) was specifically designed to provide a cost effective alternative for other types of high solid, low value applications (i.e., biogas plant digester effluent treatment, food & beverage). Using fiberglass housing allows a lower cost, but there are pressure and temperature limitations. Thus, the FMX-E cannot be used for high pressure NF applications. The FMX-E results in a 40% cost savings compared to FMX-S




FMX-S Class

The FMX-S class is the standard model, designed in close cooperation with Samsung Fine Chemical, boasting many optimum specifications with regards to the materials of construction, tolerances, and chemical compatibility. Stainless steel construction and high temperature and pressure ratings combine to make the FMX-S Class ideal for chemical, petro-chemical, and other high value applications.

The FMX-S Class membrane system is available in varying sizes ranging from 16 m2 (180 ft2) to 95 m2 (1021 ft2) for the FMX-S20 and FMX-S100, respectively.


FMX-E Class

For lower temperature and pressure applications, the FMX-E class (economic model) was specifically designed to provide a cost effective alternative for other types of high solid applications (i.e., biogas plant digester effluent treatment, food & beverage, etc.). Using a fiberglass housing and basic mechanisms allows for lower cost, but at the expense of pressure and temperature limitations. FMX-E Class is suitable for MF and UF applications only, resulting in a 40% cost savings compared to the standard FMX-S model on a comparable capacity basis.


FMX-P Class

The FMX-P Class is a pilot scale membrane filtration system with all the benefits of the FMX-B class, but with a larger membrane surface area to develop a more accurate design basis.

Benefits of the FMX-P Class:

  • Finalize design factors for reliable full-scale FMX system installation
  • Confirm long term operability and optimum cleaning procedures
  • Can be used as a standalone system for low flow applications
  • May also be used as an emergency drinking water filtration system
  • Complete turn-key system including pumps, control, valves, tanks, etc

FMX-B Class

The FMX-B Class is a bench-top model ideal for R&D and testing the feasibility of membrane separation for unconventional applications. This model is also ideal for quick membrane selection and analyzing budgetary design factors. The FMX-B Class consists of one membrane sheet with a vortex generating blade above it.

The FMX-B Class is beneficial in a number of ways:

  • Enables feasibility studies for various applications
  • Confirming enhanced performance of commercial membrane with FMX vortex generator
  • Quickly verify maximum membrane performance
  • Save time and expense when determining the optimum membrane for the given application
  • Preliminary calculation of FMX design factors for industrialization
  • Easy membrane module assembly and disassembly


Environmental Wastewater Biogas Plant Digester Effluent Treatment
Pretreatment for reverse osmosis
MF backwash
COD/BOD reduction
Processing Colloidal suspensions
Precious metal recovery
Recovery Methyl Cellulose Recovery
Industrial wastewater treatment
Pulp & Paper Paper Coating Effluent Recovery / Concentration
& Pharmaceuticals
Biotechnology Algal Biomass harvesting for Biogas Production
Pharmaceuticals Culture Fluid Recovery & Concentration
Food & Beverage Recovery Beer Tank Yeast Recovery
Concentration Juice Concentration
Processing Vinegar Clarification
Fish processing water bacteria removal
Bakery wastewater
Oil & Energy Processing Waste oil recycling

Pilot Testing

BKT can provide a variety of in-house and on-site pilot testing options to verify FMX feasibility and performance. This flexibility allows us to accommodate each client’s specific needs in regards to testing.

In-House Pilot Testing

At our facility in Anaheim California, in-house testing can be conducted using the FMX-B laboratory scale filtration system and/or the larger FMX-P pilot testing unit. The FMX-B is ideally suited for membrane selection, while the FMX-P is suited for the collection of full-scale design parameters, such as flux, and determining the best membrane cleaning procedure.

A typical in-house pilot test begins with a membrane selection test, during which 3-5 membranes are tested using the FMX-B system. This enables the comparison of various membranes for parameters such as rejection and flux. Testing a variety of membranes enables us to provide the optimum membrane for each application, providing each client with a customized solution.

Once the optimal membrane has been selected, testing continues on the FMX-P pilot system. The FMX-P system has a larger membrane surface area then the FMX-B, providing more accurate design parameters and optimum membrane cleaning procedures. Key targets for FMX-P testing are typically to obtain a stable operating flux and to achieve the best water recovery rate for each application.

On-Site Pilot Testing

BKT offers a variety of options for on-site testing. The smaller FMX-P10 and P20 systems are suited for on-site applications with lower flow rates, or areas with pilot equipment size constraints. Also available are full-scale FMX-E and FMX-S20 units for on-site pilot testing. These units are trailer mounted with all internal plumbing connections, allowing for quick and easy on-site installation.

All of the on-site piloting systems provide full-scale design data and can confirm both membrane performance/longevity over multiple batches and membrane cleaning procedures. Testing time can vary from two weeks to a few months depending on the clients' needs. Typical on-site tests are conducted to mimic a full scale installation, providing the best results for full scale design and installation.