DrM Single-Use Pinch Valve

Pinch valves are often used in single-use applications for on/off flow control. As the valve does not get in contact with the process media it does not require replacement of any parts. Only the flexible tubing is being changed as a single use item. For non-pressure designs simple solenoid-driven pinch valves can be used, but when pressure needs to be applied, such as in filtration equipment the significantly tougher tubings together with the internal pressure pose a significant burden to the pinch valve and standard solenoids normally cannot do the job.

A newly developed design allows for on/off control of pressurized single-use tubings in a compact package. The electrically driven actuator is a microprocessor-controlled geared motor which opens and closes when an ON or OFF signal is received. The tubing firmly sits in a well-defined bed which guarantees uninterrupted operation for many cycles. The valve can easily be installed within a cabinet with only the actuated part being visible.

The combination of this component with our single use filtration system is a perfect fit.


FUNDABAC® SU – Multi-Batch Filtration System For The Flavor & Fragrance Industry

Meeting the Product Processing Goals of Flavor & Fragrance Manufacturers:

Flavor and fragrance manufacturers demand a high level of product quality and processing safety. Flavors and fragrances must be filtered to achieve desired standards of clarity, color and stability. Filtration needs range from clarification to final polishing.

The FUNDABAC® SU filter provides producers of flavors and fragrances with process flexibility and allows them to meet stringent product quality and processing safety requirements. The FUNDABAC® SU filter is not only capable of capturing solid particulate matter, including microbial contaminants, in flavor and fragrance products, but can also reduce haze, absorb essential oil, as well as remove insoluble waxes/ lipids, unwanted water and color.

Operational Principle:

DrM’s new single-use filter type, FUNDABAC® SU, consists of large surface area filter elements, packed into a fully contained plastic enclosure. The increased surface area boosts the filtration efficiency and results in a higher throughput. The filter bag is installed in a pressure vessel during filtration.

This unique system design allows for single batch or multi-batch product processing.
For multi-batch operation the solids can be flushed back from the filter elements and accumulated on the bottom of the bag. When desired, materials such as cellulose fibers, activated carbon, diatomaceous earth, bleaching earth or magnesium silicate adsorbent media can be injected into the plastic bag enclosure with the goal of coating the filter elements in order to reduce, adsorb or remove the non-particulate undesirables previously mentioned.


Key Advantages:

  • High product yield relative to filter media surface area
  • No cross-contamination
  • Virtually no liquid heel volume
  • Fully enclosed environment
  • No cleaning-in-place required
  • No operator contact with liquids or solids, therefore safe operation
  • Quick and easy disposable bag installation and replacement, minimal downtime
  • Lab and pilot size models for trials and scalability
  • Small footprint as a result of its compact design

DrM at Achema 2018

Once again the chemical processing World is in the midst of its preparation for the biggest show in its field: Achema 2018 in Frankfurt. Also at DrM activities are being intensified to get ready for the event in June.

However, this year the stakes are especially high: Some time back we started with a number of development projects which are coming to a closing end and we will use the show to introduce those to the broader industry. We are proud to have no less than 5 new patents and patent applications which we will show off in form of working products, models or animations. As a teaser to this important event we want to let you have a sneak peek into our presentations. But please take the opportunity to come and see us at our booth and get a life demonstration of these innovations. Because there’s nothing better than the real thing!

FUNDABAC® Overfill Protection Device 

Damage of filter internals due to overloading with solids can be a major headache for operators who run filtration systems at certain conditions.  Various designs, devices and instruments to prevent such incidences have been developed in the past but often not with satisfactory results. We now have chosen an entirely different route which we will present to you. The patented device can be installed both in new and existing filter systems and will help protect your equipment. 


The legendary vibratory mixer which has been on the market for the last few decades has its well established clientele in the pharma and biotech industry. It is a proven technology with thousands of units in operation. But now we are taking a big leap to an entirely new vibratory design. And it will be so silent you would not believe it is in operation.


FUNDABAC® SU Single Use Filter Technology

The biotech industry is jumping more and more onto Single Use technology. It promises a number of advantages to the traditional stainless steel equipment. But existing single use filtration technology seems to rely on old principles. At DrM we were hard at work to come up with an entirely new device which will significantly reduce operating cost. We have done it the typical DrM fashion and developed an entirely new process around a novel single use filter design to come up with a compact and cost efficient equipment. And it is not only for biotech. Also chemical companies have shown interest for cases where operators need to be protected from hazardous substances.


FUNDAMIX® SU - Full AssemblyFUNDAMIX® SU Single Use Mixing Technology

Vibratory devices are very well suited for single use equipment as rotating parts often create sealing issues. Lacklustre mixing devices for single use equipment on the market hardly have any punch. The FUNDAMIX® with its extremely effective high frequency mixing plate can create amazing mixing results at low shear forces. The complete system is patented and will be presented in conjunction with the FUNDABAC® SU.


Single Use Valve

This innovative valve was developed due to the need to find a single use ON/OFF valve which can operate at higher pressures required for filtration. Most of the items on the market can only pinch tubes at atmospheric pressure or require an expensive replacement head for every change. This single use pinch valve can securely operate at 4 bar pressure and does not require any replacement parts apart from the single use tubing.


So, if you make it to the Achema this year, take the opportunity to visit us at our booth: Hall 5.0 / Stand B16. We will have enough people present not to keep you waiting.

Introducing Patented FUNDABAC® Overfill Protection Device (OPD)

Filtration involves separation of two phases while one phase passes through a media and the other is retained. The retained phase accumulates in the filter and if not removed at certain intervals, it can lead to all sorts of complications, such as difficulties during removal, blocking or even disastrous damage of the filtering device. There were a number of attempts to control or monitor the loading of filters but results have been mediocre. This has to do with the fact that it is difficult to measure phase differences such as solid/liquid-phases inside the filtering device.




DrM now developed and patented a new device which does not attempt to monitor the phase but rather the forces acting on the filtering device. When overfilling occurs the filtering elements are displaced and such displacement is detected and a signal indicates that filtration shall be terminated.

The design incorporates distance sensors which are mounted above certain sections of the filtering device. Displacements of a few mm are enough to activate a signal.




Single-Use Filtration and Mixing Innovations

After intense developments we are proud to announce the launch of our new Single-Use (SU) filtration and mixing solutions.

Our aim was the development of a disposable filter and a mixing solution for industries dealing with sterility and hazardous products. The simplicity of an SU equipment is well appreciated in the industry, but due to a number of shortcomings there are still many organisations who have major concerns with this technology. We at DrM, with our roots in the processing industry put all of our knowledge and expertise together to bring a fresh look into this by focussing on the process aspects and as a result developed something uniquely new:


Single-Use Filter FUNDABAC® SU

Single-Use Filter FUNDABAC® SU

The value proposition of our FUNDABAC® Single-Use filter is its ability to reach high throughputs and increased solids capacity while maintaining high filtrate quality. This is achieved with its multi-cycle operation: Instead of running the filtration in one single cycle until the SU bag needs to be disposed, the filtered solids can be discharged from the filtering elements. They settle in the bottom where they accumulate while the regenerated filter elements can filter a second, third or any number of multiple cycles until the complete bag is filled with solids.

A high filtration flux is maintained by small cake thicknesses (traditional designs rely on thick cakes to increase solids holding capacity but sacrifice heavily of flux). With the ability to add filter aid, the flows can be increased further, however, this is not a requirement and is usually decided during testing. After the batch is processed the heel volume of the bag is simply squeezed and compacted to a minimum. This is achieved by the unique design of the filter equipment which allows air pressurisation of the cavity between the SU bag and its housing.

With this patented approach we brought the concept of Single-Use filtration to a whole new level. It challenges once-through designs and sets new standards in this emerging industry.

While many users may first think of the biotech industry as the main target for such an equipment, its applications may well go beyond this traditional market. Besides typical downstream processes we had a number of very specific inquiries for toxic batches where containment of the product is of highest importance.

FUNDAMIX® SU Vibratory Mixer

Single-Use Mixer, FUNDAMIX® SU

Single-Use Mixer, FUNDAMIX® SU

The FUNDAMIX® Vibromixer has originally found its role in the biotech industry as its non-rotating agitation allows for a simple and secure sealing system in sterile applications. For the last 50 years it has provided high mixing efficiencies at low shear forces and very little energy input. It is a very mature product which now has been rejuvenated by redesigning the mixing plate for Single-Use operation.

The required changes were minimal as the FUNDAMIX® is ideally suited for Single-Use applications. However, we came up with some great designs to make the assembly of the bag in the housing as easy as possible. The drive unit itself did not require any changes but our patent includes a special docking mechanism to connect the mixing shaft to the Single-Use mixing plate.

Compared to existing Single-Use agitators the mixing intensity is significantly improved while at the same time keeping tip speeds well below what traditional agitators produce. As the amplitude is just a few Millimetre, the mixing plate can be mounted only a few Centimetre above the bottom of the Single-Use bag. This reduces liquid heel considerably and hence increases yield.

With the launch of these new products we believe to have two equipment which enrich the Single-Use industry and provide new opportunities for operators to look at their process design in a different light. The know-how of our process and development engineers can further help you enhance process design when it comes to integration of the equipment, so feel free to contact us.

Behind the development of these products was a whole team of engineers, who put a lot of effort into the design and as a responsible for Single-Use Technologies at DrM, I would like to express my gratitude:
Andy Fleischmann – Production manager and responsible for the development of the FUNDABAC® SU
Kevin Wetter – R&D Manager and responsible for the development of FUNDAMIX® SU

With kind regards,

Benjamin Dietiker
Benjamin Dietiker
Responsible SU Tech
DrM, Dr. Mueller AG

Flexible woven metal filter media with 3D-structure

Woven Filter Media

For liquid filtration at high temperatures the material of choice is often sintered metal powder (PM) type filter. Tubular elements are available in a range of alloys and with pore sizes below 1 micron. The operational life of the media can easily extend over years, and its low maintenance is a strong argument for adoption. At least, in theory…

In practice it is often another story. While there are cases where PM works as promised, there are instances where the results disappoint. To understand the reasons for this, we need to take a closer look at the design of such a sintered PM element:

The element wall is built of narrow sized stainless steel powder, which is sintered at high temperatures to form a rigid, but porous structure. Since the pore size is determined by the size of the sintered particles, the finer the particles, the smaller the resulting pore size.

In solid/liquid separation, typically a fraction of those particles finer than the pore size of the filtering media pass through, the largest particles are held back in the filter cake on top of the media and some get stuck within the PM structure. It is this last solids fraction, which normally cause trouble, because the rigid porous layer prevents any movement and back-flushing does not always remove those particles. Over time trapped solids accumulate and begin clogging the porous metal. Ultimately, the PM elements need to be either chemically treated to dissolve the entrapped solids, heated to a high temperature to burn off the impurities, or they have to be replaced altogether.

As an alternative to traditional sintered PM elements, and specifically to address operational deficiencies, DrM has recently developed a new type of filter media built on a 3D-woven structure made of stainless steel microfiber. This media has a significantly higher open area for flow than PM, but is still capable of retaining particles down to the 1 micron range. Another key feature is that the woven structure flexes outward during back-flushing. This expansion movement releases trapped particles, thus preventing solids build up and eventual clogging. In addition, the media is rated for temperatures well above 300ºC and both slurry and dry cake discharge is possible.

In short, the woven stainless steel microfiber elements significantly extend the application range of our filtration products without sacrificing any of the process options the well-established FUNDABAC filter provides.

Selecting this media makes sense for applications with high temperatures (above 200ºC) and where the feed solids have a tendency to clog. Target markets are in chemical syntheses where catalysts need to be removed at high temperatures, and in refineries for the removal of FCC catalyst fines from heavy cycle gas oil.



Ever since the introduction of the FUNDABAC® Filter various kinds of clamps have been applied to securely fix the filter flexible media to the FUNDABAC® filter element. The clamps come in various forms, such as plastic wedge rings, one way clamps in stainless steel and re-usable screw clamps in stainless steel, titanium and zirconium. Clearly, as with the materials of construction for the rest of the filtration system, the choice of clamping materials is dependent upon the properties of the materials being handled in the filter and the process conditions.

FUNDABAC® Clamp-Less Candle

For applications like chlor-alkali, viscose and other processes where we employ our polypropylene (PP), polyvinylidenfluoride (PVDF) or polyphenylenesulfide (PPS) filter internals we have previously used polymeric PP, PVDF or PPS wedge rings or titanium or zirconium wire clamps. DrM are proud to announce the launch of a new design of clamp-less candles, which will be offered in PP, PVDF and PPS.
With the introduction of the clamp-less design for our plastic filter elements, separate clamps become obsolete. Here, the filter media is fixed with a special screw mechanism that is part of the filter element.

This offers a number of advantages over the previous design:

• Smooth design: No cake deposit on the clamp
• Metal free
• No difference in thermal expansion
• No corrosion attack
• Suitable for metallic and plastic registers
• Suitable for a wide range of filter media
• Filter elements can be supplied with the filter media already assembled

The clamp-less candle is now being offered as a standard part from DrM Filter Technology Pvt. Ltd., but the previous design with separate filter media clamps is also still available upon request.

Ganesh Aghav, DrM

Tianqi Lithium

Kuala Lumpur, Malaysia. DrM, Dr Mueller AG has signed a contract for the supply of specialised filtration equipment for Tianqi Lithium Australia’s newest lithium hydroxide processing plant, which will be located in Kwinana, Western Australia.
Tianqi Lithium, which controls a majority stake in the Greenbushes mine, the world’s premier producer of lithium concentrate from spodumene, is building a downstream processing plant for lithium hydroxide in Kwinana, 40 km south of Perth. The plant will convert around 161,000 Te per year of spodumene concentrate into 24,000 Te of lithium hydroxide, for use in the growing global market for lithium ion batteries.


DrM has won a contract for supplying equipment that will support critical functions in the overall process. DrM’s CONTIBAC® candle filters will be used as main process filters on three key extraction stages and a number of DrM CONTIBAC® SM filters will be deployed in key areas as guard filters.
Whilst the commercial aspects of the project were handled from DrM’s SEA Sales and After-Sales Service Centre in Malaysia, the units will be manufactured at DrM’s Asian production plant located in Shanghai and be supplied as complete modular skid mounted filtration units. DrM has already supplied a number of process filters to Tianqi’s lithium processing plants in P R China and Tianqi now operate a range of DrM CONTIBAC® candle filters (slurry discharge) and FUNDABAC® candle filters (dry cake discharge) units
for lithium processing.
This latest contract has been awarded due to DrM supplying “the best available technology” and the long-term experience with the economy of operation, reliability and efficiency of the DrM systems.

Scope: 5 x CONTIBAC® candle Process units, 6 CONTIBAC® SM Guard units
Customer: Tianqi Lithium, Australia
EPC: MSP, Perth

Shaken, not stirred

It is probably the oldest procedural field: mixing of fluids and the appurtenant term of stirring. The experience that has been gathered throughout the years, the implemented research, and the broad know-how in the field have been growing for decades. Therefore it is hardly astonishing how much the knowledge and the literature about this technical process have grown. Every one of us thinks of a stirring process as a rotatory movement that agitates a liquid in motion – after all, that is how we all do it in the mornings with our cup of coffee. Many of us, regardless whether we are a mechanical engineer or a process technician, will at some point in their lives rack their brains about the mixing process. However, very few think about abandoning the rotary movement. So when performing a mixing process without the so familiar rotary movement, how is it called: mixing or stirring?

DrM Fundamix Vibromixer pahrmaceutical industry

DrM Fundamix Vibromixer pahrmaceutical industry

A Lively Technology

The solution is called the vibratory mixing technology and has been represented in various fields of application as a vibromixer for several years. As the name already implies, the mixing process is not executed by means of a rotary mixing element but by means of vibration. However, the vessel is not rocked in this case. Also this technology uses a mixing element, which is designed significantly differently and uses high-frequency up-and-down movements.

This device that was developed and enhanced already 30 years ago by D.Eng. Hans Müller is marketed by the company named FUNDAMIX® . What distinguishes this vibratory mixing technology, what are its advantages and fields of application? Before we can take a look at the decision making features, it makes sense to explain the operating principle of the device first: The drive motor, that was designed and manufactured by the manufacturer of the device, uses a sinusoidal alternating current power supply (Europe 50 Hz, America 60 Hz…) to create an oscillatory motion in the form of an amplitude. A coil with an electromagnetic core creates a magnet field (the static part). The rising voltage in the positive sinusoidal part causes the dynamic component to be pulled in by means of magnetic force. During this process, the integrated spring system stores energy and triggers the resetting motion of the system in the falling portion of the sine wave. In the identical process of the negative sinusoidal part of the wave, the motion is repeated identically, however in the opposite direction. That way, the device transforms the directly supplied mains frequency into a double stroke of the mixing element – 100 Hz in Europe and 120 Hz in America. As opposed to an AC motor the mixing intensity in this system is adapted through the changes in the voltage and not the frequency.

Reduced Residual Volume

The mixing element is attached to the already mentioned dynamic part of the motor, which follows the Bernoulli’s Principle by means of its geometrical features. Therefore the amplitude generated by the drive is transferred to the mixing element comprised of a shaft with an attached mixing disc. The up-and-down stroke (oscillation) of the disc pushes the liquid through conical holes similar to a nozzle. The generated vertical flow thus causes the mixing of the content of the entire vessel. The tapered from of the conical holes allows for an upward (type A) or downward (type B) flow. For this purpose, the entire mixing disc is turned upside down. The layout of the discs (there is a possibility of several discs generating various flow directions) and thus the orientation of the cones is determined by the process to be used. Discs directing the flow downwards (type B) are used for processes with sedimenting solids or strongly frothing media, whereas the type A discs are suitable for emptying vessels. The latter can be placed so closely to the bottom of the vessel that even in a larger process vessel, also the smallest of amounts of the medium in the vessel will be mixed. This is also the reason why the technology has found its place, e.g. in the filling of insulin vials since the pharmaceutical company has to make sure that the expensive insulin is moving until the very end of the process. Any volume that is not mixed has to be disposed of, which means a loss of money. The optimal mixing throughout all levels of the vessel without any baffles (since there is no rotation, there are no whirls) not only has a positive impact on the mixing process, but also saves investment costs in the construction of the vessel or the design of the cleaning system. The mixing elements are made of AISI316L stainless steel in accordance with the general strict requirements in the pharmaceutical industry. By request, more affordable versions are also available: The available materials reach from stainless steel to titanium, Hastelloy, and plastic.

Simple Sealing Principle

An additional benefit is the simple sealing principle: Since there is no rotary motion, the sealing is considerably simplified and only encompasses a membrane. The membranes available in various materials as well as the FDA and USP Class VI certification, providing sealing during the stroke reaching from 0 to 3 mm from the vessel, allows for a simple sealing without any mechanical seals, e.g. expensive and complex face seals. During the movements of the mixers and the seal, there are no abrasive strokes therefore the mixing process is suitable for various sterile applications. Mechanical seals, including their wear and tear, frequently cause problems with product contamination. Membrane seals are as standard suitable for pressures of -1/5 bar, however can also be provided in higher classes by request. The temperature classes reach to approx. 150 °C, which are also covered by the standard CIP and SIP cleaning processes. This solution also massively reduces maintenance costs: A replacement membrane, which shall usually be replaced once annually, only costs a couple of euros.

Maintenance Cost Reduction

When it comes to maintenance costs, the owner can benefit from additional features, such as the low-wear drive motor. It lacks any mechanical guide elements such as roller bearings or guides, which are subject to wear and tear. During the regular inspection of the drive motor, the user has to thus replace the springs, springs seats, and smaller wearing parts. At DrM however, vibration motors that have been in use daily for over twenty years, are simply re-installed into the device after an inspection. At the same time, low energy costs positively impact the operating costs of the system. Compared to a rotary mixer, a vibromixer only consumes a third of the energy. This can be traced back to the variant of the mixing technology: The features of flow mixing in this case will provide benefits in the form of product-friendly, low shearing energy mixing in the low viscosity area (up to approx. 500 mPas). Due to the high share of vertically oriented flows no slanting and fast rotating mixing blades that could e.g. damage cell cultures are necessary. The flow allows for a high product circulation resulting in a highly homogeneous product within the entire process vessel. This homogeneity can only be achieved by means of high rotation speeds in the traditional mixing systems (such as with magnetic mixers attached to the bottom).

Certified Safety

All the production stages of the technology, from the laboratory stage all way to the full-scale production system, are also Atex certified. The current certification covers Zone 1 for gas from the Temperature class T4 on. Continuous development shall also make it possible to offer an Atex Zone 0 version in the future. Additionally, all systems are EMC tested, provide IP protection, and the company is ISO9001 certified.


® BeatBrogli,  Former Manager of Business Unit FUNDAMIX DrM, Dr. Mueller AG

Carlo Castaldi, Head of FUNDAMIX Business Unit DrM, Dr. Mueller AG

DrM Filter Testing Pilot Plants & Scale Up

In many chemical processes, the filtration step is considered a bottleneck. Therefore a properly designed filter that factors in its sizing is critical for successful plant operation.

In addition to DrM’s extensive filtration experience and know-how in hundreds of different processes which DrM has acquired as a result of its 3000 filter references, DrM is capable of supplying a wide array of pilot filters ranging from lab scale (0.012 m2 filtration area) to industrial production scale (50.7m2 filtration area).

Screenshot 2016-09-19 10.11.24Many conclusions can be drawn as a result of observing the following 8 pilot testing aspects:

1. An accurate flux rate per m2, essential in order to properly size an industrial filter, can be determined

2. The best performing filter cloth can be selected as a result of observing  filtrate quality

3. The determination of filter cake thickness

and dehydration potential, as well as filter cake discharge behavior (the latter, in the case of the FUNDABAC® filter)

4. The performance of filter cake washing, if required for the process

5. The determination of optimal filter cake formation

Screenshot 2016-09-19 10.11.33

6. Solids concentration or Total Suspended Solids (TSS), in the case of  CONTIBAC® slurry discharge

7. Determination of an optimal cloth cleaning procedure to ensure original flow rate repeatability, batch after batch to ensure a much longer cloth life time

8. Cake discharge procedure as a result of cake discharge observation

DrM has recently developed a new test software in which the most important parameters for filtration unit design are highlighted. The parameters include:

– Required flow rate to correctly size a filter

– Cake thickness and dryness to obtain an accurate estimate of waste associated costs or alternatively the design of post treatment driers

– Optimum total cycle time considering both filtration and down times (filter filling, draining, drying, washing and cake discharge)

Test report for news

Once key parameters are known, industrial filter sizing for optimal operation can be determined accordingly.