September 22, 2008 | General

Nuts & Bolts: Windrow Turners

BioCycle September 2008, Vol. 49, No. 9, p. 32
Demand for windrow turners has been growing in the agricultural sector as farms look to replace synthetic fertilizer with compost produced from their own residuals. The international marketplace has been strong as well.
Rhodes Yepsen

FOR Marvin Urbanczyk, who introduced the SCARAB windrow turner to the compost market in 1972, composting is just as straight forward today as it was more than 35 years ago. “Basically you put your organic material in a windrow that is 14 to 20 feet wide and 6 to 8 feet tall, bring it to 60 percent moisture, and turn it twice a week until you arrive at a product you can sell. The USEPA tells you what has to be done in terms of pathogens, vectors and metals, but it doesn’t give you a definition of when compost is done. That is defined by what the markets want.”
Over the years, residential and commercial development has encroached upon existing composting facilities’ borders, leading some to enclose operations. In other cases, the climate alters the approach. “If it rains too much, then go under a roof,” says Urbanczyk. When asked about air quality regulations in California that may negatively impact outdoor windrow composting operations, he emphasized that being vigilant about pile moisture content is a top Best Management Practice.
“Starting at 60 percent means that when you squeeze the material, the water almost drips out. Turning a pile when it is too dry can create dust. We recommend using a hose reel to add water, versus adding it with a turner attachment.”
The City of Wichita Falls, Texas started composting in 1993 with a grinder and a front-end loader. It purchased a Wildcat turner before dedicating a 30-acre section of the landfill to composting yard trimmings, food waste and animal mortalities. The facility currently processes 22,000 tons/year. The city purchased a larger windrow turner to speed up the composting process, with a more frequent and thorough turning schedule. “We sold more compost last year than ever before,” says Larry Wilkinson, Landfill Supervisor with the City of Wichita Falls. “Because of the increased demand, we purchased a 20-foot wide SCARAB, which enabled regular turning, good temperatures and a finished product in less time.”
Wilkinson recommends that potential customers ask for an on-site demonstration of the turner they want to buy. “Everybody’s composting operation is different, with various types of composting pads, materials being processed, etc.,” he says. “The only way to get a real idea of how the machine will handle at your site is with a demo with your feedstocks.”
Other considerations when shopping for a turner include portability. Foster Brothers Farm/Vermont Natural Ag Products purchased a Komptech Topturn X53 last year. It previously had a SCAT turner, which was purchased used and eventually wore out. Primary considerations when looking to purchase a new turner included quality of construction, operator comfort, performance and its portability from site to site. “Maneuverability actually became the deciding factor, because we wanted to have the option of taking the turner to other sites for custom blending,” says Jim Foster. “With a pivoting cabin, it can be switched from transport position to working position, without the need for other equipment or lengthy disassembly. Within 30 seconds we’re ready to operate.”
There has been a learning curve with the new turner, such as with placement of the windrows. “With the old SCAT turner, we had to go down both sides of each windrow, which was extra work and meant a lot of extra room was needed for spacing,” recalls Foster. “Now we can put our windrows toe to toe, and maximize our space and time. We’re running it on B20 biodiesel, as we do with all of our off-road equipment.”
This issue’s Nuts & Bolts article updates product details provided in BioCycle’s “What’s New – Windrow Turners” article in October 2007. We also asked manufacturers about composting trends, overseas markets and whether their equipment can run on biodiesel blends. Table 1 summarizes equipment data supplied by windrow turner manufacturers. As the table indicates, one characteristic that distinguishes turners from each other is the mechanical action of the turning unit. They can be categorized as auger-type, elevating face, rotating drum with a housing that covers the windrow, straddle-type and trapezoidal (a more detailed explanation is available in last year’s article).

ALLU is introducing an updated version of the AS38H, its straddle-type track-driven turner. “The update will include cost saving features on fuel and efficiency,” says Xylene Afable, marketing manager for ALLU. “Work is also in progress on one additional turner and four additional ALLU SM processing attachments for food waste, animal mortalities, aerating compost, etc.” The company has seen trends developing in the composting industry, such as the preparation of special mixes for feeds, and processing manure as a cost saving substitution for fertilizer. The market for compositing biosolids in Europe has also been booming, says Afable. ALLU equipment can operate on biodiesel, but customers must specify this preference at the time of purchase, so that engines can be set accordingly.

BACKHUS now offers Condition Monitoring on its turners, an interactive display that shows parameters such as hydraulic oil, engine and rotor speed, cooling water, or fuel consumption. By monitoring these parameters the operator is able to assess the status of the turning machine at all times. In terms of trends, Martin Meyer, Marketing and Communication Manager for BACKHUS, says that the “ever increasing cost of synthetic nitrogen is forcing farmers to take a look at how they can convert their on-farm waste materials into nitrogen based fertilizer products.” He also notes that Europe is moving towards in-vessel systems near populated areas, because of the ability for effective odor management. BACKHUS turners can be operated on biodiesel.

Brown Bear has been finishing Tier III emissions upgrades on its machines. Its aerators can be either attached to a loader or to its own tool carrier tractors. As fertilizer prices have gone up, and more farmers are utilizing compost for fertilizer, Brown Bear units have been popular with dairy and poultry operations. “We have been active overseas, with units as far away as southern Africa, used for biosolids composting,” says Stan Brown, President of Brown Bear. “Both CAT and Cummins have told us their engines, used in Brown Bear equipment, will run on B20 biodiesel.”

CBT Wear Parts, Inc. is an aftermarket parts supplier to the composting industry. It manufactures long life replacement flails and other parts for most of the windrow turners on the market including SCARAB, Resource Recovery’s KW, Wildcat and Double T.

Farmer Automatic, at the January 2009 International Poultry Expo in Atlanta, Georgia, will unveil a new machine with increased hydraulic power, a single handle joy stick control and track drives. This will bring its product line up to three CompostCat windrow turners, along with its Compost-A-Matic in-vessel equipment. “The high cost of commercial fertilizer is opening many doors,” says David Leavell of Farmer Automatic. “Due to the compact size of our machine, it is great for smaller municipalities looking for an extremely cost-effective solution to their smaller composting requirements.” Farmer Automatic is active overseas, mostly in poultry waste operations, but is also in the planning process with a mine land waste remediation project.

Frontier has seen sales increase for both its self-propelled and tow-behind turner models, and has noticed the connection between rising fertilizer costs and interest in managing farm residuals. While biosolids composting has been a strong area of growth for Frontier, contaminated soil remediation has not taken off as much as anticipated. “We recently sold a turner to the Greater Moncton Sewerage Authority in New Brunswick for the purpose of premixing material ahead of its GORE system,” says Brad Glaze of Frontier. “We’ve seen more opportunities emerging in the biofuel market, but not as much with anaerobic digestion.” Frontier has equipment across Canada, Mexico, South America and Asia.

HCL Machine Works has been evaluating ways to increase the speed of its tow-behind turners without sacrificing thorough mixing and aeration of the pile. “The speed element is something that we are looking at for possible inclusion in future models if it can be accomplished while still maintaining our composting standards,” says Casey Campbell of HCL. “In an attempt to move towards that goal, we have already increased our drum RPMs.” HCL has been active in overseas sales, particularly with cities in developing countries. “They are using international funds to purchase our equipment to help alleviate the worldwide problem of waste storage, and to address the need for increased nutrients in their soils,” explains Campbell.

Komptech recently introduced a Lateral Displacement option to its largest turner, the X67. “It can turn up to 5,900 yards of material laterally, making it optimal for site space utilization,” says Todd Dunderdale, Director of Sales for Komptech USA. He notes that Komptech is seeing more composting operations incorporate food waste, which requires more focus on turning and contaminant removal. “Another trend is smaller farmers looking to compost with PTO driven turners, when in the past they just had the product hauled away,” notes Dunderdale. “This could be due to the trend in organic farming, or the increased costs of fuel and disposal.” Komptech turners use Caterpillar’s ACERT engines, which can run on biodiesel.

Midwest Bio-Systems enhanced the tines on all of its pull-behind and self-propelled turners in 2008. “We call it the ‘clean sweep,’ because it leaves less material on the ground, increasing the aerobic capacity of the windrow and reducing the material that is wasted,” says Edwin Blosser of Midwest Bio-Systems. The company has seen growing interest in using compost for increased crop yields, in part due to global food shortages. “We also see growth in bioremediation, and have actually developed a special drum and a specialized drive train to work with the heavier soils involved,” continues Blosser. In the past year, Midwest Bio-Systems has exported equipment worldwide with a surge in Latin America. “In our case, most of this activity is related to food production rather than waste processing,” he adds.

Resource Recovery Systems has seen a marked increase in dairies and cattle feed yards using its self-propelled windrow turners. Internationally, it is involved primarily in biosolids projects and those handling the organic fraction of MSW. “We’re currently serving as a consultant for a project in Egypt that anticipates composting one million tons of sludge per year, mixed with 300,000 tons of rice straw,” says Les Kuhlman of Resource Recovery Systems. “We see opportunities for composting in the emerging biofuels and anaerobic digestion markets, both domestically and internationally. However, solving the waste problems now can be achieved by composting, while developing facilities for energy production are planned, proven and brought online.”

SCARAB builds each self-propelled turner to the customer’s specification. “There is no cookie cutter machine from SCARAB, because customers call and have a particular set of ideas for what they want to do,” says Marvin Urbanczyk of SCARAB. This includes matching up the frame, drum design, engine, drive system and other components to the customer’s needs. Both hydraulic and belt driven machines are available. “With higher fuel costs, we’re seeing a growing interest in belt-driven machines, which are 20 percent more fuel efficient than the hydraulic, because they are more efficient at delivering power to the drum,” says Urbanczyk. Recently, Denise (Urbanczyk) Winter joined the family business. She introduced the Total Cost package, which guides customers in getting the machine that best fits their needs and operational goals.

Vermeer will soon release its CT1010TX, a large elevating face self-propelled windrow turner that is on tracks. It will have a 10-foot by 10-foot face, instead of the 6 by 10-foot face on the smaller CT670 turner. The elevated face turner is able to stack material, in addition to forming windrows, which can allow almost three times more material to be composted at a given site, notes Jeff Bradley of Vermeer. “Municipalities that are bringing in more and more materials, such as biosolids or food waste, but that have limited space, are moving away from windrows and looking at stacking,” explains Bradley. The CT1010TX was unveiled at the company’s media days in August and will be introduced into the market in October.

Wildcat now offers a PT Tech clutch on its tow-behind and self-propelled windrow turners. “With the value of the U.S. dollar declining, there is an excellent value to an American made turner, which has led to increased interest overseas,” says Tim O’Hara, Sales and Service Manager for Wildcat. O’Hara adds that Wildcat turners can operate on biodiesel with no effect on the warranty.

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