8 Feathers Distillery explains how Kason Corporation treats their waste stream to eliminate sewage surcharges, decrease solid waste disposal fees, and provides a “free” food source for local livestock to nearby farmers in an article published across the globe in Filtration + Separation, Industrial Water World, Brewer & Distiller International, and other publications.
The Stillage Challenge
8 Feathers Distillery produces a wide variety of spirits using locally-sourced grains and water from a nearby artisanal well. The distillery could not lauter because their hammer mill grinding process produces fine grains that clogged the filter media. In searching for solutions, filter presses, screw presses and chemical flocculation were investigated and ruled out. When comparing rotary sieves and centrifugal sifters, Kason’s CENTRI-SIFTER was found to be the most cost-effective choice for its capacity to dewater spent grains quickly, as well as its small footprint, minimal maintenance requirements and simple cleaning options.
Testing Screening & Sifting Options
8 Feathers provided a 10-gallon (38-litre) sample of stillage for testing which was conducted on both circular vibratory and centrifugal sifters. In the footprint desired, the CENTRI-SIFTER accomplished the desired dewatering target of 50 GPM (189 l/min) with capacity to spare.
8 Feathers Distillery was further encouraged by the test when the sifter processed a sample of 1,500-gallons (5,678-litres) and pushed 40 GPM (151 l/min) without performance degradation. With those results, 8 Feathers purchased a Kason model MO-SS CENTRI-SIFTER with a 140-mesh (105 micron) heavy-duty reinforced stainless steel screen. This configuration provided effective screening and separating with minimal risk of screen blinding.
Processing over 3,000 pounds of grain a week while distilling, 8 Feathers produced more than 7,500 pounds of stillage waste as a byproduct. To avoid increased sewage charges, this waste must also be free of solids and within an acceptable pH range before being discharged into the municipal waste system.
Installing the Centrifugal Sifter
The CENTRI-SIFTER was Installed 8.5 feet (2.6 meters) above the plant floor, directly over the vat that receives the water. The unit measures 21 inches (533 millimeters) wide, 33 inches (832 millimeters) tall and 75 inches (1899 millimeters) long, including its 3 hp (2.2 kW) motor.
With the centrifugal sifter in place, 8 Feathers was able to sustainably and economically dispose of its grain slurry waste by separating the grain from water.
The CENTRI-SIFTER's aggressive screening action removed liquid from the spent grain fast, minimizing both sewer surcharges and waste transportation costs. It also made the grain suitable to be donated to local farmers as livestock feed. 
The Separation Process
- The liquid/grain mixture is fed into the centrifugal sifter
- The liquid is acidic and therefore must have a pH level closer to water
- The watery/grain mixture passes into the horizontal screen cylinder
- The auger and rotating paddles propel the mixture against the screen, which accelerates the passage of liquid through the screen
- The liquid then passes through a vat and is treated with ash to reduce the pH level before flowing into the public water system
- Grain solids unable to pass through the screen are funneled into a tote
The centrifugal sifter’s end cover plate can be easily hinged open, allowing tool-free removal of the screen cylinder and paddle assembly from the cantilevered shaft for cleaning. The operators simply backwash the sifter with water, cleaning the pipes and the screens at the same time. This cleaning process only took 8 Feathers two or three minutes.
To learn more about Kason's centrifugal sifters and how they can help distillers lower operational costs, download our Buyer's Guide Today!
