SSI’s new shredder creates one-inch fractions for RDF
The SR900F high-speed, single-rotor shredder creates a one-inch fuel alternative to advance the waste-to-energy market
Industrial shredder manufacturer SSI Shredding Systems, Inc. has developed a new high-speed, single-rotor shredder designed to advance the waste-to-energy market. The product development team at SSI engineered the new shredder, the SR900F, to produce refined refuse-derived fuel (RDF), delivering one-inch-minus material with ample throughput and efficiency.
A need for finer fuels
The ability to size material at scale is the key to successfully producing fuels. Traditionally, SSI's RDF systems have relied on shear shredders to create two-inch-minus material. A PRI-MAX primary reducer coarsely breaks down material and feeds it into a Quad, or four-shaft shear shredder, which delivers the final particle size. This system processes heavily contaminated material while still providing a two-inch particle size in the finished fuel.
However, the growing demand for one-inch fuel meant an alternative was needed; thus, the SR900F concept was born.
"We knew the solution would be a Uni-Shear," recalled Dave Welters, mechanical engineer and project manager of the SR900F, "it's a knowledge base we have a lot of history and experience with."
Uni-Shear is SSI's line of single rotor shredders and grinders, which offer high throughput potential when processing clean materials. The SR900F takes that potential even further. With an increase of rotor speed, more than twice that of the original SR900G, the machine increases the number of cuts per minute, allowing for more aggressive shredding of light material.
Purpose-driven design
The team began by adapting the SR900G, a mid-speed single-rotor shredder originally designed for tough materials like tires and auto shredder residue. To refine the machine for lighter feedstock such as fuels, engineers traded some torque for higher rotor speed to improve throughput. In addition to increasing the rotor speed, the development team redesigned the cutter geometry and added a second anvil bed to enhance performance with light, high-volume material.
"We replaced our traditional diamond cutters with broader, flat cutters," said Paul Breithaupt, senior engineer at SSI. "That change increases the cutting surface while allowing for a tighter shear gap. It also helps channel material through the chamber and sweeps the screen more effectively."
The second set of anvils, stationary knives that sit opposite the rotor, doubles the number of cutting opportunities per revolution to further enhance the throughput capacity.
"After we showed the customer the maintenance features," shares Welters, "They were really excited by how easy it is to get in and service the cutters, the anvils, and pull the screens out."
