Colorants manufacturer, Color Corporation of America in Louisville, Kentucky, needed a solution for its open bag filter used to remove undispersed pigments and contaminants from its products.

A Ronningen-Petter brand Mechanically-Cleaned (self-cleaning) DCF filter was installed to provide a closed system specifically designed to address the special challenges of filtering viscous liquids.

SITUATION:

Fed by gravity through a bag filter at the base of a blending vessel (let-down tank), colorant was deposited into an accumulating vessel. From there, a pump transferred the product to the designated filling line.

Both the bag and accumulating vessel were open to the atmosphere--and although the release of Volatile Organic Compounds (VOCs) from the bag and vessel were well below local, state and federal regulations--Color Corporation’s process engineers sought a goal of zero emissions.

The bag filters also had trouble handling increases in product solids or viscosity. These situations resulted in faster blinding of the filter bag and an increase in differential pressure across the bag.

Increased differential pressure sometimes led to burst bags — resulting in product contamination, system shutdown, lost productivity and increased labor costs.

Ronningen-Petter SOLUTION:

Color Corporation’s process engineer, Shawn O’Donnell looked at available alternatives to the bag filter system, and consultations with Ronningen-Petter led to the installation of a closed system Ronningen-Petter brand Mechanically- Cleaned DCF-800 filter.

The DCF filter and a pump are mounted on a mobile cart. The suction of the pump is connected to the base of the let-down tank. The discharge of the pump, including a pulsation dampener, is directed to the filter inlet.

The outlet of the filter is connected to a filling machine, and the entire colorant filling process is closed to the atmosphere. The filling machine controls the mobile pump and filter unit.

To begin a fill, the operator pushes a button to open the compressed air supply to an air-operated double diaphragm pump, which sends the colorant through the DCF-800 self-cleaning filter and filling machine head.

When the system recognizes a container is full, it automatically stops the air supply to the mobile unit. The DCF filter performs its self-cleaning cycle when instructed by the filling machine.

RESULTS:

Installation of the Ronningen-Petter brand DCF-800 Mechanically-Cleaned filter has eliminated the release of VOC’s in the filling process by completely enclosing the filtering of colorant before sending it to the designated filling line.

The patented DCF filter is uniquely able to handle the feed variables of the viscous colorants, and maintain a low differential pressure across the filter, thereby producing higher flow rates in the system.

Color Corporation is no longer faced with shutting down a fill line to change loaded filter bags, or the problems of filter bags bursting or blowing off their retainer.

The DCF filter provides uninterrupted filtering and a better quality colorant product.

CONCLUSION:

The Ronningen-Petter brand DCF Mechanically- Cleaned filter has eliminated an open bag filter and accumulating vessel before the fill line, and the problems associated with the open bag filter system.

With the help of the completely enclosed DCF filter, Color Corporation is gaining on its process engineer’s goal of zero VOC emissions.