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 and NF) are available to satisfy our clients' demands

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.

FMX maintains high flux and recovery rate under the most challenging conditions. Optimal Membrane Selection Program (OMSP) allows BKT to select the most suitable membrane based on the characteristics of feed and clients' demands. BKT does not manufacture membranes; instead, BKT adapts various types of membranes (MF, UF, and NF) to be used in FMX. 


How FMX Works


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 a 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.

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.

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.

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. This process prevents membrane fouling so that FMX can handle high TS contents, both total dissolved and suspended solid, over 1.5%, without frequent fouling issue.


Video: Conventional Membrane Fouling


Video: FMX Anti-fouling Mechanism





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.

FMX Vortex-Generating Membrane Filtration System FMX-S Series 3D Exploded View Animation

Standard & Economic Models


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 Full Scale Standard Model

FMX-S Full Scale Standard Model

FMX-E Ecomonic Model

FMX-E Ecomonic Model