ANFD / Agitated Nutsche Filter Dryer Part 1

ANFD / Agitated Nutsche Filter Dryer Part 1

Today’s blog post is about an ANFD, i.e. Agitated Nutsche Filter Dryer. Many of our customers are surprised to know that in addition to our legacy businesses such as pressure reactors, flow chemistry, and pilot plants, we at Amar also have several other pieces of process equipment that we specialize in. One such product is an ANFD.

An Agitated Nutsche Filter Dryer (ANFD) is a multifunctional piece of equipment used in the pharmaceutical, chemical, and fine chemical industries for solid-liquid separation processes, such as filtering and drying of slurries. It combines the operations of filtration, washing, reslurry, and drying in a single unit, under vacuum or pressure conditions, enhancing product quality and operational efficiency. ANFDs are particularly valued for their ability to process high-value or sensitive products with stringent purity requirements, offering a combination of operational safety, efficiency, and quality control in a single unit.

ANFDs are very versatile for washing operations as both displacement and slurry washing can be performed in the same equipment. The term Rosenmund filter is sometimes used and refers to the traditional manufacturer of this type of batch filter (https://www.dedietrich.com/en/about-us/our-brands/rosenmund). Many of our customers prefer ANFds in completely closed systems designs that allow the handling of hazardous materials.

At Amar, we have a technology collaboration with the firm HLE Glascoat on our ANFD technology. We have the ability to design custom ANFDs for your specific needs and also have a wide range of off-the-shelf models.

To judge the versatility of Nutsche filters we refer our blog readers to the following Table from the Coulson & Richardson set of books on Chemical Engineering (Vol 6; Chapter 10) which provides an excellent table to help users with filter selection.  For a wide variety of slurry types, a Nutsche is a good candidate. In our opinion, every process development lab needs an ANFD as a very versatile part of the toolkit of the R&D chemist or engineer. As an aside, such gems of information as the Table below are often hidden deep inside reference books and one of the goals of our blog series at Amar is to expose our readers to such valuable information. Often one paragraph in a good reference can save days or weeks of wasted effort in the lab or worse tens of thousands of dollars spent (wasted!) on the wrong equipment selection!

ANFDs have various other applications in the process industries. For example (extract from the CRC Handbook of Membrane Separations by Pabby & Sastre):  “Heterogeneous catalysts made of transition metals on various supports such as carbon are used in many reactions. At the completion of the reaction, the catalyst needs to be removed from the product mixture and recycled. The recovery of the catalysts can be conducted by centrifugal discharge or by using ANFDs. ANFDs retain large masses of solids and have the capability of washing and drying them. The filtrate is usually filtered through a solvent-compatible cartridge to remove any fines that may still be in the liquid.”

Stand by for Part 2 of this blog series on ANFDs for more useful information!

Meanwhile, talk to us at Amar for your next requirements for ANFDs [email protected]