Primary reduction equipment, or slow-speed high-torque shredders, are used to process a variety of materials across of wide array of industries involved in reclamation and destruction. Instead of shredding material in a conventional manner, primary-reduction equipment breaks material into smaller pieces using impaction. Already popular outside the United States in countries where landfill space comes at a high cost, the domestic trend is following suit, as landfill space becomes increasingly more expensive stateside.

Greg Wright is sales director at Granutech Saturn Systems. The firm has been in business over 40 years, sells products worldwide and “offers several lines of shredders that provide solutions for challenging applications.”

He went on to describe, “Saturn, our most versatile line, offers low speed, high torque, 2 and 4 shaft rotary shear shredders (11-50 rpm). The Roto-Grind model is a ram-fed, single rotor grinder (80-115 rpm), and our Grizzly product is a massive, gravity-fed, single-rotor grinder (321 rpm),” Wright reported.

He said that choosing the shredder most appropriate for a given job involves several factors, including the material to be shredded, the amount of contamination in that material, the production rate required and the final product size.

“Oftentimes, multiple machines or stages will be integrated together to achieve the required result. For example, a company might use our two or four shaft shredder, followed by our Grizzly shredder to achieve maximum cleanliness, or a smaller product size. Our focus is typically on the larger side of processing equipment, with most of what we build being greater than 150 hp. We also build a lot of hydraulic-driven equipment for the advantages it has over electric-drive in tough applications. These advantages include instant and multiple reversals of the shafts, no need for an external gearbox or clutch, and the ability to clip amperage spikes with no need to constantly re-start electric motors,” said Wright.

He added, “When more than just shredding is required, we’re also able to integrate ancillary equipment such as our conveyors, eddy current or density separators, metal detectors, cross belt magnets and air/dust collection systems.”

Wright claimed that as people everywhere attempt to reduce the amount of waste generated and find new uses for what was once considered waste, the need for finer processing continues to grow. Waste-to-energy, biomass reduction, and refuse derived fuel applications are becoming more prevalent, and many of these applications require a small final shred size. “Our Grizzly shredder is very successful in these applications because it produces a very small and consistent product size – the ideal end product for fuel usage,” Wright said.

Hammel shredders do it differently. “Our shredders operate under a ‘ripping and tearing’ principle instead of ‘cutting and shearing.’” This is how Ralf Semler, regional manager, at Hammel New York differentiates Hammel shredders from those made by other manufacturers.

“This difference makes our machines extremely tolerant to any kind of material contamination, which can quickly dull or damage a sharp cutting edge type of shredder. Because we are not concerned with maintaining sharp edges and tight tolerances in the shredding mill, our maintenance and operating costs are among the lowest in the industry,” said Semler.

Hammel’s main product line offers slow-speed, high-torque primary shredders, offered in several models: VB450, VB750, VB850 and the VB950 – the “Red Giant.” When processing solid waste, the throughput capacity of these machines range from 10 tons per hour up to 200 tons per hour.

Hammel products are manufactured in Bad Salzungen, Germany where approximately 250 shredders are produced annually. “Hammel invented the first synchronized dual-shaft, slow-speed, high-torque shredder for processing dirty stumps 30 years ago. Since then, our products have evolved to handle applications such as processing MSW, C&D, green waste, industrial waste, counterfeit or confiscated goods, tires with or without rims and scrap metal items such as white goods, appliances, aluminum, steel – even entire cars,” Semler said.

He said Hammel’s product line focuses mainly on machines that offer superior volume reduction, ferrous metal reclamation or preparation (sizing) of material for further processing. The company also designs and builds entire turnkey recycling plants and special equipment according to customer specifications.

According to Semler, “Our newest products include the MMS 150DK Mobile Metal Screen and the MWA 1000E Mobile Eddy Current Separator. When used along with our VB950 primary shredder, we can provide a mobile plant that is designed to process scrap metal, appliances, white goods, etc. Ferrous, nonferrous and fluff elements are reduced to a six inch or less size, and all three items are then divided into separate streams for final output. Our mobile primary shredders are self-contained and require no set-up other than hydraulically unfolding the discharge conveyor.

“Most of our shredders are remote controlled and track-mounted but we also offer semi-stationary and stationary machines.” Semler believes that domestic market demand for the type of shredder design offered by Hammel will continue to grow. “Domestic interest in minimizing landfill usage is increasing and volume reduction equipment is the simple, straight-forward solution whether it is used on a transfer station to recover ferrous metals and reduce trucked-off material volume or right at the working face of the landfill, to increase compaction, recover ferrous metals, and prolong the lifespan of each cell,” Semler predicted.

In the opinion of Jason Bradley, Republic Machine’s Modular Split-a-Part, Eagle and Pipe Single and Multiple-Shaft Shredder cutting systems incorporate the best of the firm’s patented engineering innovations.

Bradley, vice president of sales, explained the innovations further, “The modular construction of our shredders facilitate the best accessibility, easiest cleanout and most efficient maintenance in the industry today. Our Modular Split-a-Part machine features cutter knife rotation and the bed knife reduces readjustment time by half compared to a typical non-split machine. Our patented Zoidal Cutting product is a non-wrapping precision cutting system designed to maximize production in a single pass and is utilized in all film and fiber applications.

“The large Zoidal product is the gold standard for carpet shredding and the system’s patented design provides throughput from 2,500 to 8,000 pounds per hour ‘sustainable.’ The product offers lowered operating costs to less than a penny per pound when processing more than a million pounds of carpet in a live production setting. Our patented Monorail Self-Guiding Ram assembly eliminates the need to replace any guide rails and is part of our Eagle Series Single Shaft Shredder family.

“Perhaps most important of Republic’s latest innovations in single-shaft shredders is our Insta-torque Detection System. This system provides the most reliable drive train in the industry today, and the ultimate protection to the gearbox in the event of metal contamination,” Bradley said. Belt drive and right angle drive lash-ups are also available. The Insta-torque system is included in all Falcon, Eagle and Modular Split-a-Part single-shaft shredders made by Republic and he believes the system represents the added value customers demand and deserve.

In describing the company’s newest product, Bradley announced, “Republic’s newly designed and re-engineered pipe shredder solves the problem of pre-cutting pipe. It is the only North American-made pipe shredder on the market that can grind 20-foot and longer pipes. It is also the first North American-made pipe shredder sold at an attainable price point. The machine’s modular design includes a flexible size bed that begins at 20 feet and can be extended to 60 feet long. The shredder is intended to serve well in any difficult-to-process, single-shaft shredder applications.”

Bradley said innovations at Republic are driven by customer needs that arise within the variety of markets they serve, and he expects Republic Machine will continue as a leader in single-shaft size reduction in North America.