Wilden AODD Pumps for Ceramics Applications

Wilden Ceramics

• How do Wilden AODD diaphragm pumps handle ceramic slip or barbotine in ceramic processing?

  AODD pumps are ideal for handling ceramic slip or barbotine due to several key features:

  • Abrasion Resistance: They utilize abrasion-resistant thermoplastic elastomer diaphragms (such as Wil-Flex®, Saniflex™, Bunalast™ and polyurethane). The addition of Chem-Fuse™ Integral Piston Diaphragms (IPDs) further minimizes abrasion by eliminating the outer piston.

  • Shear Sensitivity: AODD pumps are shear sensitive. Unlike other pump technologies, they lack tight clearances or fast-moving elements that can cause excessive shear damage to the material.

  • Viscosity Handling: They can accommodate a wide range of viscosities, up to 25,150 cPs, and can handle changes in viscosity without being damaged.

  • Easy Maintenance: The clamped configuration of AODD pumps allows for simple disassembly, which facilitates easy cleaning and prevents the ceramic slip or barbotine from hardening inside the pump.

• What are the best abrasion-resistant AODD pump materials for ceramic slurries?

  Cast iron pumps are the most abrasion-resistant metal option for AODD pumps. Polypropylene and PVDF both offer good abrasion resistance for plastic pumps, with PVDF being more abrasion-resistant than polypropylene. For diaphragms, the thermoplastic elastomers Wil-Flex®, Bunalast™, Saniflex™ and polyurethane are abrasion resistant. The Chem-Fuse™ Integral Piston Diaphragm (IPD) design provides additional abrasion resistance by covering the outer piston in the diaphragm material, removing outer piston abrasion.

• Can Wilden AODD pumps transfer thick ceramic glazes without shearing?

  Wilden AODD pumps allow gentle transfer of shear-sensitive glazes without damaging the product. These pumps do not have tight clearances or fast-moving pumping elements, which reduces shear compared to other pump technologies. They can handle a wide range of viscosities up to 25,150 cPs and can accommodate changes in viscosity without damage, making them ideal for pumping thick glazes.

• How can I prevent diaphragm pump damage from settling solids in ceramic applications?

  To prevent diaphragm failures and other damage from settling solids, it is best practice to clear the pump of fluid that could solidify or contain solids that could settle after use. This is most commonly done by allowing the pump to run dry and clear out as much process fluid as possible before the pump sits for long periods. The pumps can also operate with water to flush the process fluid out after use. Wilden Brahma™ AODD Pumps utilize a unique top-inlet, bottom-discharge orientation and flap valves to allow passage of large solids and avoid damage from product entrapment or settling solids in intermittent-duty applications.

• Why does my AODD pump muffler freeze during ceramic plant operations?

  Muffler freezing, or "icing," in an air-operated double-diaphragm (AODD) pump occurs when compressed air rapidly expands upon exiting the pump. This expansion causes the air and the muffler to cool quickly, potentially leading to ice buildup that blocks airflow and stops the pump from cycling. This phenomenon is more frequent in humid environments due to the higher moisture content in the air.

  To prevent muffler icing, consider the following solutions:

  1. Modify the Air Line: Install an air line heater or an air line dehumidifier.

  2. Adjust Exhaust Piping: Add a section of piping between the pump exhaust and the muffler. This extends the distance the air has to expand before reaching the muffler.

  3. Maintain Spares: Keep a spare muffler readily available to quickly replace one that has frozen.