A kaolin clay processing facility has discovered that the
Ronningen-Petter® patented DCF self-cleaning filter provides measurable advantages in the processing of slurries.

Improvements in the kaolin clay facility had created a problem for its process engineers — finding a filter to meet the facility’s newly doubled production rate.

Their solution was the Ronningen-Petter brand DCF-1600 multiplex self-cleaning filter.

Because the screen on the DCF filter is cleaned on demand and without interrupting production, a consistently high flow rate is maintained across the system.

SITUATION

Engineers made process changes in the kaolin facility and needed a filter that could protect the heat exchanger, keep up with the facility’s higher throughput, and handle the unique screening characteristics of kaolin slurry.

In addition, backwashing filters installed in other areas of the plant ran the risk of depositing water into the product and diluting the slurry.

RONNINGEN-PETTER SOLUTION

The facility’s engineers installed a Ronningen-Petter brand DCF-1600 four station multiplex self-cleaning filter system and have never looked back.

The DCF filter mechanically scrapes collected debris from the filtering screen with a disc that moves up and down the screen parallel to the liquid flow, then purges the solids from the filter.

This self-cleaning action is performed without halting production, and provides the highest quality filtering under continuous demand. Because the screen on the DCF filter is cleaned on demand and without interrupting production, a consistently high flow rate is maintained.

Higher Flow Rates — The high flow rates achieved with the installation of the Ronningen-Petter brand DCF filter enable the filtering system to keep up with the facility’s doubled production. And the high quality filtering provided by the DCF filter protects the newly installed equipment that is so critical to the maintenance of the improved production rates.

Does Not Introduce Water into Product — Ronningen-Petter brand DCF self-cleaning filters offer some clear advantages over the backwashing filters and vibrating gravity screens typically seen in the clay industry.

Backwashing filters that were already installed in other areas of the plant always ran the risk of depositing water into the product and diluting the slurry. In contrast, the DCF does not introduce any new fluids into the product, and the waste purged from the DCF filter is in a small, highly concentrated form.

RESULTS

Increased production rates: DCF filters outperformed and replaced several vibrating gravity screens by increasing throughput and reducing the filter floor space required by 70%

Labor savings: Operators don’t need to watch the filter, since the differential pressure across the filter media conveys its performance and can be monitored automatically.

Material savings: Saves the dollars spent on replacing vibrating gravity screens.

Superior flow rates: 30-200 gpm (113-756 l/min) at pressures to 150 psi (10.5 bar).

Lower maintenance: Saves costs and time.

CONCLUSION

Ronningen-Petter brand DCF self-cleaning filters, by their very nature, provide kaolin clay processors with higher flow rates and better quality filtering than backwashing filters and vibrating gravity screens typically used in the industry.

The DCF-1600 filter meets the challenges of variations in clay properties, particle size and flux rates to protect expensive processing equipment.

APPLICATION DETAILS

• Fluid: kaolin slurry
• Contaminant: rust silica
• Pressure: 80 psi (5.5 bar)
• Flow Rate: 200-250 gpm (755-945 l/min)
• Filtration Required: 50 micron (0.002 inch)

DCF MODELS

• DCF 400 flow up to 30 gpm (115 l/min).
• DCF 800 flow up to 60 gpm (230 l/min).
• DCF 1600 flow up to 200 gpm (755 l/min).

Higher Throughput, Lower Costs:

DCF filters outperform vibrating gravity screens typically used in slurry filtering by increasing throughput and reducing the filter floor space required by 70%.

The DCF requires minimal maintenance, compared to the motor repair, screen replacement and adjustments that are at minimum, an annual event with the gravity screen.

The enclosed screen on the DCF prevents slurry from drying on the filter surface and creating a debris source, which can be a common problem with gravity screens.

Operators do not need to watch a DCF filter, because the differential pressure across the filter media conveys its performance and can be monitored automatically.

In addition, one-story buildings are possible with the DCF filter, whereas the typical gravity filter is installed high on a second story over the tank, to facilitate gravity flow.

Handles Difficult Kaolin Clay Slurry:

Ronningen-Petter’s exclusive DCF filters are the ideal solution to the properties, particle size and particle shape that are unique to kaolin slurry.

Kaolin clay often has variations in regional mineral characteristics and within veins. When filtering the slurry, throughput rates and filter pressure drops through the filtering screen can vary, due to natural variations in the mineral’s original source.

Ronningen-Petter brand DCF filters provide the superior flow rates that are required to meet the challenge of these variations. The DCF-1600 is designed to provide flow from 30 to 200 gpm (113-756 l/min) at pressures to 150 psi (10.5 bar).

In addition, its self-cleaning feature prevents large pressure drops by regularly cleaning the filtering media before a significant build-up of debris occurs.

Ronningen-Petter brand DCF filtering media provide the highest quality filtering available, covering the range of particle sizes of kaolin slurry. Slotted wedge wire media offer particle retentions from 15 micron through 1125 micron, and feature a special slot opening design that helps prevent plugging while assuring total debris removal.

Ronningen-Petter also filters other white pigment slurries including: calcium carbonate (both ground and precipitated), titanium dioxide, aluminum trihydrate, precipitated gypsum, talc, and other kaolin products including delaminated, calcined and chemically structured clays.