The art of pelleting often is an admiring reference to skilled pellet press operators who can produce pellets of consistently high quality for a wide range of feed products. The technical complexity of this achievement has been an ongoing challenge to suppliers of feed plant automation software and equipment. However, pelleting is becoming a 'science' through automatic online measurement of key variables and rapid electronic feedback in process control systems to optimise pellet durability, measured as pellet durability index or PDI and pelleting system efficiency.
The proportion of automated online PDI systems worldwide is growing as feed manufacturers seek consistent, predictable results in pelleting, even as more least-cost co-products enter their feed formulas. How important is the development of this technology to your own pelleting and feed manufacturing operation? If you would like to participate in an exclusive Plant Managers Panel on Online Pellet Quality Control, please respond to FEED INTERNATIONAL's editor by e-mail email@example.com, subject line 'Online PDI' with your questions on this new technology.
Cold mash moisture content, steam quality, conditioner retention time, mash particle size, and of course the ingredients themselves, all play a part in pellet durability. Fortunately, knowledge and measurement of the many variables are moving pellet quality control from art towards science. A recent article in FI July 2005 described many of the parameters involved in pelleting. In a recent letter to FI, Malcolm Munday, managing director of UK-based TekPro, notes that authors Mssrs Milandinovic and Svihus make very clear the importance to profitability of achieving greater accuracy and control over the pelleting process.
"Unfortunately," Mr Munday writes, "they did not cover the very practical need for accurate determination of pellet durability index, for without this information, full efficiency cannot be achieved."
He goes on to note that TekPro manufactures and markets worldwide the proven New Holmen pellet durability tester, "which can be fully integrated into the mill, taking and testing samples and automatically adjusting the pellet press settings to deliver optimum quality and maximum efficiency."
Mr Munday makes the point: "With many mills now running 24/7 (24 hours per day, 7 days per week), it is vital to automate quality assurance if quality is to be maintained effectively."
Other suppliers also provide technology to control parts of the puzzle of pellet quality.
See FI's January 2006 Buyers Guide' entries related to pellet mills or presses, conditioners, coolers, and other equipment.
See also pellet-related technology from the suppliers listed below.
Feed processing equipment: More than 40 years of experience
For more than 40 years, General Dies has produced:
- Dies, rolls, roll shells, and other spare parts for any pellet mill;
- Hammers, screens, rotors for hammer mills;
- Dies, screws and other spare parts for extruders;
- Pellet mills, coolers, crumblers, sieves, hammer mills, mixers, conveyors, etc.;
- Turnkey installations, refurbishing, and extension of existing plants and maintenance servicing; and
- Technical consultancy.
Mixers, coaters, and vacuum coaters
"In the Forberg mixerbatch mixing or continuous mixing designsyou will achieve a homogeneous powder mixing in few seconds with no regard to size, shape, or density of the products," says Forberg International, originator and developer of the twin-shaft paddle mixer for feed industry applications.
The Forberg mixer is also used for coating of powders and pellets. A new rotating vacuum coater (RVC) is available for coating of aquafeed, petfood, and animal feed. Capacities are available in the range of 6-8000 litres.
Worldwide: Pelleting and hammer milling spares
Jacobs Corporation is the leading manufacturer of pellet mill and hammer mill replacement parts worldwide, the company states.
Jacobs pellet mill dies are drilled on state-of-the-art computerised gundrills, ensuring smooth holes for easy die start-up, the company adds. The pellet mill division also manufactures long-wearing XTR roll shells, assembly parts, and offers a roll reconditioning service.
Jacobs says its hammer mill parts division features the industry-leading STC+2 hammer for severe wear applications, XTR rods, and screens to fit most makes and models of mills.
Bulk materials handling
Guttridge Services Ltd describes itself as a leading UK manufacturer of bulk materials handling machinery: "Our range of competitively-priced conveyors, elevators, and ancillary machines is designed to suit the needs of a wide range of industry sectorsfrom animal feed, petfoods, cereals, and minerals, to foods, chemicals, and pharmaceuticals.
"If you need to move powders, granules, flakes or pellets, then talk to uswe have many different solutions to offer."