The Meaning of Screening

Screening-product manufacturers have a variety of innovative products and equipment solutions to offer soil and mulch producers.

By Mark S. Kuhar

       Soil and mulch producers live and die by their ability to create a consistent and viable product. So it is important when considering screening media to identify which features are best for your operating efficiency.
     Also important is the flexibility to adjust equipment for specific applications. The ability to switch to a different product specification while on the job can be critical. And a focus on productivity is always a key performance criteria.
     Manufacturers are always seeking ways to improve screening products which, since the very first screens were used, were designed to do one specific job: separate and size a variety of types of materials.
     There are a number of screening products designed to bring high performance and operational efficiency to materials producers. Key products include:
* Portable plants: A stand-alone shredding or grinding machine that separates and sizes product in one operation, typically utilizing a radial stacker.
* Star screens: A screen with an easy size adjustment, typically used with high-moisture materials.
* Shaker screens: A vibrating screening unit used to separate material and minimize blinding and clogging of screen media.
* Trommels: A cylindrical screening unit that uses the power of rotation to separate material.

Some of the most important things to consider when purchasing screening equipment include: 1. Will you be screening mostly wet or dry material and what type of material will you be screening (wood, compost or soil)? 2. What particle size(s) are you looking to produce? 3. What size area (footprint) do you have available for your screening system? 4. Does the manufacturer offer a warranty period and/or maintenance support for their equipment? 5. Is the equipment easy to operate and does it allow for ease of changing out screen sizes, and 6. Does the manufacturer offer replacement parts and onsite service?

While there are well over a dozen screening equipment manufacturers in North America, the following is a short list of some of the top manufacturers who provide screening equipment for use in topsoil, mulch and compost applications. Please note that these companies are listed in alphabetical order, and that the content of each company profile is based solely on the information gathered from each company.

Allu Group
www.allu.net
800-939-ALLU (2558)
201-288-2236
     The ALLU Group, Inc., offers more than 50 models of screener and screener crushers for materials processing. The portable devices are designed to be used with wheel loaders, backhoes and excavators; because they work with those machine’s existing hydraulics system, they do not need any extra hydraulics.
     “This isn’t static. It’s mobile,” notes Dale Mickle, national sales manager in the U.S. for ALLU. “It can be used on-site, off-site, at a remote location. Any place you take your wheel loader or your backhoe or your excavator you can take the ALLU along just like any other attachment.”
     ALLU, founded more than 30 years ago in Finland and with U.S. sales headquarters in Teterboro, N.J., touts the product’s ability to “replace expensive and hard-to-move screening plants.”
     “The beauty of it is you can use it as a screener or use it as a crusher screener and its portability, changeability and the fact it will fit any base machine,” Mickle says.

The ALLU can screen, crush, aerate, mix, separate, and load quickly and efficiently materials like soil, mulch and green waste. Screening sizes start from 5/8” minus and also having a capacity of half yard to six yards depending on the model. With the ALLU Screener Crusher, the amount of screening surplus is smaller than in a typical screening plant. The Screener Crusher can process a variety of materials, including topsoil, excavated soil, contaminated soil, clay, peat, bark, compost, biowaste, construction waste, milled asphalt and glass.

Amadas Industries
www.amadas.com
757-539-0231
     Suffolk, Va.-based Amadas Industries has been industrial equipment, and engineered recycling systems for composting, yard waste and construction debris, since 1963. Current product lines include trommels, peanut combines, peanut diggers, Reel Rain irrigators, cotton stalk puller/choppers, edible bean combines and other equipment for both the horticultural and recycling industries.
     The company’s self-contained portable trommel features multi-product capability, overhead return conveyors and maximum throughput efficiency, according to the company.

Amadas manufactured a custom trommel system that is one of the largest on the east coast. The trommel is 60 feet long with a diameter of 96 in. It was constructed in three sections and transported to the operation site. Amadas field technicians installed all components, performed the final test, and trained the site personnel. This system has the ability to process 40-50 tons-per-hour when processing residential yard-waste material.

Amadas developed their screening equipment, for use in organics processing, by simply adapting their existing technology used in the harvesting and processing of peanuts.

According to the company, their peanut classifying system was made larger and heavier so that it could handle heavier material such as wood waste. Today the company specializes in building custom stationary trommels to handle the specific needs of each customer.

DoppstadtUS
www.doppstadtus.com
440-937-3411

     Doppstadt trommels are manufactured for maximum versatility, providing numerous innovative features that precisely control the machine’s various functions. This allows operators to realize significant production with a minimum amount of wear, fuel and labor. One of the key benefits, according to the company, is the punch plate steel drum, which provides a large active screening area, thus increasing output. And with the ability to swap screening drums in less than 15 minutes, material processors can switch applications and end products with ease.
     For customers that process organic material, extremely wet conditions can have a negative impact on productivity. To maintain high throughput in these conditions, the Doppstadt SM 720 and 720K trommels can quickly convert into a star screen with the drum insert option. Simply remove the existing drum, replace with the star screen insert, and resume operation.
     Equally as effective as a dedicated standalone star screen, the star screen insert allows customers to extend the flexibility of their existing SM 720 trommel throughout any season and conditions. Wet, clumpy organic material with moisture content as high as 60% or more can continue to be processed.
     The Doppstadt star screen works on a revised principle utilizing a softer urethane star design for extended life. The star shape on the shaft is oblong, rather than conventionally round, which aids dramatically in shaft cleaning. Alternate shaft speeds on the deck, are extremely effective in the stratification of material feed, leading to a cleaner oversize product and increased production rates.

“This is a great option for customers to maintain full function of their trommel all year,” added Hugh Fagan, DoppstadtUS sales director. “It eliminates the need for many operations to invest in a second machine for only partial use in certain conditions.” Doppstadt will be releasing a star screen insert compatible with the SM 617 and SM 726 trommels later this year.

ORBIT SCREENS, Inc.
www.orbitscreens.com
563-922-9230
     Utilizing a tilted rotating screen, Orbit Screens Inc., of Delhi, Iowa, describes its line of screens as using “Mother Nature’s principles of material flow to effect an easy, quick and natural particle size separation.”
     Orbit Screens was started in 2000 by veteran businessman and equipment developer Brad Schnittjer, whose involvement in the composting industry spans some 30 years. That background convinced him of the need for a better way to screen material for mulch-type materials.
     “I came up with what I consider a better mousetrap,” he says of Orbit Screens.
     Called “orbital action,” the Orbit Screens he developed utilize what he says is “mother nature’s way of separating particle sizes.”
     The tilted and rotating screens are designed so that when material rolls over itself, it automatically separates by particle size, with larger items coming to the surface and small particles going to the bottom.
     “We captured that in the pocket of the screen as it turns. The shape of the screen and the centrifugal force and the rolling action of material separates it,” Schnittjer says.
     Orbit Screens are available in two different sizes, a Series 50 with a 5-foot diameter screen, and the larger Series 60 with its 6-foot diameter screen. The equipment can process one ton of material on an ounce of fuel, Schnittjer says.
     Schnittjer says a key selling point of Orbit Screens is the simplicity of the screening process and how that equates to higher value per dollar invested. The machines are designed to be trouble free and easy to service.
     “We think it’s probably the most general purpose screening plant that there is,” he says.

REMU USA Inc
www.remu.fi
888-600-0018
     Remu Ltd, a supplier of innovative screening and excavation systems in Europe, has expanded its sales network to the United States and Canada, operating through its subsidiary Remu USA Inc.
     The high-capacity Remu Combi is a non-clogging screening plant, first developed to screen mainly topsoil and compost. Because of its durable structure, it is now used more and more to separate difficult materials such as yard waste, compost, clay and other sticky materials. The structure of Combi is very compact but it can reach the capacity of 300 m³/h (400 y³/h).
     The non-clogging screening element is built to last. The blades in the screening element of the Combi are made from steel, not rubber. This enables screening in all the weather conditions.
     When ordering the screening plant, the customer can decide the blade spacing for the particle size desired. Minimum blade spacing is 20 mm (3/4-in.) and it produces grain sizes of 0-15 mm (5/8-in. minus). The largest grain size that can be produced is 0-100 mm (4-in. minus).
     The capacity and quality of the screening can be adjusted by changing the hydraulic screening element’s angle from five to 20 degrees.
     The product also features an electronic “watch dog” that prevents clogging by starting automatic backward rotation. The backward rotating of blades cleans the screen efficiently and there is no need to stop the process for manual cleaning.
     The ready-to-use Combi screening plant can be used skid-mounted as standard, available with wheels for temporary worksite use; with two axles for work site transportation; and crawler track mounted, with optional wireless remote control.

Screen USA, Inc.
www.screenusa.net
770-433-2440
     With its line of trommels, shakers and shredding equipment, Screen USA, Inc. focuses on the screening of high-moisture compost and organic materials with its Tornado Star Screeners, available in small, medium and large sizes, according to Rick Cohen, president.
     “Shaker Screens, trommel screens, and starscreens are commonly used to screen soils and compost,” he says. “The key is to know which application requires which screening technology. Screen USA dealers are thoroughly trained to apply the best screening technology for each customer's needs. “Screen USA’s Trom406 Series of trommel screens are designed specifically for small producers utilizing a one yard or smaller loader bucket. This highly portable screening plant can be pulled down the road behind a 3/4 ton pick-up truck and can be ready to screen in only three minutes. The optional pulverizer/shredder allows producers of clumpy soil and compost to break up the material before it enters into the 4-ft. diameter by 6-ft. long screen.

According to the company, the pulverizer/shredder is a key component of this screener and allows the machine to outperform larger, more expensive plants. “Another advantage of the Screen USA Trom406 is that the actual screen area is 6-ft. long,” Cohen says.

For high moisture compost, Screen USA recommends a portable starscreener. Starscreeners are designed specifically for high-moisture organics. “Our Screen USA Tornado Star Screeners have a unique continuous-cleaning system that keeps the screen clean,” Cohen says. “This allows for optimal production. Another big advantage of starscreens is that the operator can change particle size by simply turning a dial. It can take up to a full day to change a screen on a trommel screen.”

Universal Equipment Manufacturing Inc.

www.universalequipmentmfg.com

614-586-1780
     Launched about three years ago, Universal Equipment Manufacturing prides itself on being an American company that produces its 720 Hornett trommel solely from American parts. Owner Jim Weber and vice president Bob Holmes have a combined 50 years experience in the soil and mulch industry.
     The Hornett trommel was developed after Weber, who also owns Ohio Mulch, became frustrated with purchasing expensive parts from overseas. He initially started building trommels for his business, and then quickly discovered a ready market for the product. Universal Equipment, headquartered in Columbus, Ohio, is a subsidiary of Ohio Mulch.
     Holmes says one of the biggest selling point of the 720 Hornett trommel is availability of parts.
     “The equipment here is made by Americans with American parts,” Holmes says. “You can go down the street in any city in this country and buy every single part for our machine right off the shelf. All the parts are U.S. parts that are readily available anywhere in this country.”
     The 720 Hornett trommel, with its 99hp Cummins turbo-diesel engine, features a variety of engineering components for successful operation in handling products such as mulch, top soil, gravel, recyclables, organic wastes and yard wastes. An adjustable drum speed accommodates those various materials. Other features include easy-to-install interchangeable solid punch-plate drums that can be replaced in 15 minutes and an extra large hopper capacity (9.0 yd³) to increase production efficiency. The Hornett has a screen diameter of 7 feet and a 20-foot screen length.

West Salem Machinery Co
www.westsalem.com
800-722-3530
     West Salem Machinery’s (WSM) line of heavy duty screening and size-reduction machinery is ideally suited for converting bark and wood waste into premium quality soil and landscape products, according to the company. From individual grinding and screening machines to complete bark and mulch processing systems — WSM's products and systems are proven industry performers for creating high-value fiber and mulch products.
     WSM Disc Screens are designed for high volume, rough classification of many materials including bark, wood chips, and compost material. The company reports that size and configuration are customized for each customer’s needs. WSM Disc Screens include low speed, smooth operation which eliminated the need for special support structures.

WSM vibrating screens provide high capacity, precise classification of a wide range of products and are available with optional metal detection. Additional, optional ball deck assemblies provide additional agitation when processing wetter material.

      WSM Trommel Screens are used to screen compost materials for use as landscaping and soil amendment products. WSM Trommel Screens are available in 4-, 6-, 8- and 10-ft. drum diameters and lengths from 15 to 60 ft. Production capacities are available up to 500 cubic yards per hour.  The company notes its trommel screens are built for severe-duty applications and are designed to provide years of trouble free separation.
     WSM oscillating screens provide efficient and effective classification of a variety of wood and bark materials. The company’s heavy duty design includes numerous features for improved operation. Production capacities are available up to 80 units per hour. All WSM oscillating screens are available with a full range of options and are designed to meet customer requirements, according to the company.

Wildcat Manufacturing Co.
www.wildcatmfg.com
605-925-4512‎
     Wildcat Manufacturing Co., part of the Vermeer group of companies, builds its equipment for maximum screening efficiency. Wildcat trommel screens were designed by actual operators, the company says. The large feed hopper sits low to the ground, so it’s easy to feed material into the screening drum. A large throat opening between the hopper and drum helps minimize material bridging, according to the company.
     Additional features include:
     * Removable side panels expose the full length of the drum screen, providing for easy maintenance and cleaning.
     * Put the finished product where you need it – loading directly into a truck or stockpiling using the optional radial stacking conveyor that swings a full 200 degrees.
     * Avoid jams because both the drum and feed conveyor are reversible.
     According to the company’s Tim O’Hara, there are two major advantages to a Wildcat trommel. “The first is our tensioned screen panels,” O’Hara says. “Tensioning the screen panel adds strength to the panel allowing the customer to install a smaller diameter wire for certain applications. This increases open screening area and thereby increased production. Smaller diameter has the added ability to process wetter material due to the smaller diameter wire. The second advantage of Wildcat trommels is the Vermeer dealer network, which offers parts and service worldwide.”
     Setting up a screening plant to meet the needs of the customer is critical to the success of an operation, according to O’Hara. “The most important aspect of our relationship with our customers is continued communication, adapting the unit as their needs change.”
     Along with standard options such as radial and extended conveyors Wildcat offers hopper grids, electric units, magnets, specialized conveyor belting and of course a wide variety of screen panel selections, including stainless steel.

Mark S. Kuhar is a Medina, Ohio-based freelance writer.