FMX: 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.



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



FMX Models


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.

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


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fmx spec material.jpg

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.

B Class

The FMX-B Class is a bench-top model comprised of a single membrane module constructed from one membrane sheet under a vortex-generating blade. The small scale of the FMX-B class facilitates efficient membrane selection and analysis of budgetary design factors.

Our FMX-B class is also 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 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


Customization Procedure


From Our Lab to Your Site

Pilot tests measure the performance of FMX technology for our potential clients’ process objectives. We develop and customize test procedure based on information provided by the clients via Process Engineering Survey (PES) and Test Sample Description.

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.

To optimize the dynamic membrane filtration process, in-house testing attempts to isolate and assess several variables, including optimal membrane selection, temperature, operating pressure, concentration factor and/or % recovery rate, fouling Incidence, and CIP, etc.

Once the in-house pilot test has been conducted to identify the main process variables and verify the technical feasibility and economic justification of the FMX system for the specific application, the next step is to confirm the application of FMX membrane system at greater length and depth during on-site pilot test studies.  This pilot test will employ an FMX pilot unit, pilot size system, equipped with the previously determined optimal membrane.


Step 1

Process Engineering Survey (PES)

Process Engineering Survey is the very first step in sharing your project information with us. You will need to provide us with basic project information like your water quality and your goal by filling out our survey form.

Step 2

In-house Test (IhT)

At BKT, we understand that each sample has unique characteristics and each individual client’s goals will vary. For this reason, we prefer a hands-on approach in processing your sample to determine the optimal choice of membrane for your application. 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. Testing a variety of membranes enables us to provide the optimum membrane for each application, providing each client with a customized solution. Just send us a minimum of 5 gallons of your sample to be processed with FMX technology for analysis. 

  • Definition of project goals

  • Analysis of client’s sample

  • Selection of optimum membrane


Step 3

On-site Test (OST)

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To facilitate maximum accuracy of our design, we then emulate a full-scale processing of your sample on our larger pilot units. BKT offers a variety of options for on-site testing with full-scale FMX-E5 or FMX-S20 units. These units are trailer mounted with all internal plumbing connections, allowing for quick and easy on-site installation. However, in the events of logistical difficulties or shortage of samples, our labs can accommodate an In-House Test (IHT) with FMX- P. 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. Typical on-site tests are conducted to mimic a full scale installation, providing the best results for full scale design and installation. Both IHT and OST allow us to help you determine the best real-time operation strategy, but OST provides more accurate design factors. 

  • Verification of flow rates which can be achieved using FMX technology

  • Confirm long term operation and reliability

  • Formulate optimum cleaning procedures and other operating variables

Step 4


By installing a full-scale industrial unit, you can consolidate several processes into one single step using the FMX Membrane filtration System. FMX technology can help you achieve higher concentration goals, retrieve formerly wasted materials for additional revenue, conserve resources by using less, among other benefits.

  • Consultation on ideal treatment process per BKT’s wide range of experience

  • Ideal model selection considering PRE and POST treatment with overall project objectives

  • Quantitative analysis of economic benefits and financing options

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