Waste shredding - An important precursor for efficient sorting

With the demand for faster and more efficient recycling technologies showing no signs of abating, the market for faster, more efficient shredding equipment is of course on the up. Here, we take a look at the latest developments in today’s market. by Claudine Capel To the man on the street the term shredding most likely brings to mind the transformation of business documents, bank and credit card statements into a bird’s nest of paper a practice we now rely on worldwide to prevent fraudsters accessing our personal financial data and sensitive information. But to waste industry professionals the term brings to mind a whole spectrum of equipment and, nowadays, a world of new technology. It means big business, as shredding of waste is common practice across almost all areas of the waste industry. Far from focusing simply on paper, shredding is a disposal technique for everything from agricultural to household waste and electrical to industrial waste. Put simply, shredding is breaking down waste into smaller parts. Companies that have put their efforts into developing new shredding techniques are finding they have chosen well. The overall trend in today’s market tends to be ‘shred first and sort later’. Shredding of waste material as a precursor to sorting is useful for two reasons. It reduces the size of the waste, allowing for greater ease of transportation, but perhaps more importantly at a time when recycling as much material as effectively as possible is paramount it allows for more effective sorting afterwards. And logically, effective sorting equals greater opportunity for recycling. The particular shredding process used will be dictated by the material that needs shredding, and there is a multitude of options that are undergoing constant refinements and updates. Furthermore, there is some grey area in the overlap between shredding and crushing, thus broadening the scope for size reduction in waste handling. Types of shredder include, for example, the cross-flow shredder, which uses a system of beating the waste until it breaks down into smaller parts; the single-shaft shredder, which employs the more traditional blade system to cut waste particles down, and the two-, three- and four-shaft shredders, which employ various methods of forcing materials between and against blades. Companies such as AU+T, Erdwich and M&J have long been big players in this industry and continue to go from strength to strength. Today’s market is also seeing promising things from MeWa and Lindner, whose innovations are starting to change the way we look at shredding. Here we dip our toes into the sea of shredding technology, offering an overview of some of the options available and an insight into the direction that the market is taking. Shred first, separate later Anlagenbau Umwelt + Technik Chemnitz GmbH (AU+T) is a German company that does everything from consultation to erection of waste processing plants, and all the processes necessary along the way, including sorting, recycling and, of course, shredding. AU+T offers two types of ‘cross flow’ shredder for companies that need to liberate composite material and recover raw material. AU+T’s first machine, which was made in 1996, is simply called the ‘cross flow shredder’ the company followed this with its Diabolo machine in 2007. The Diabolo machine by AU+T Click here to enlarge image A ‘cross flow’ shredder doesn’t shred material in what might be regarded as the traditional way using blades, but crushes it using a rotating chain. The machines can be used for WEEE, such as refrigerators and other electrical equipment, but also for vehicle parts, plastic and metal packaging, glassplastic composites (such as car glass or safety glass), RDF, toner cartridges and waste wood, all the way down to much smaller waste such as food and drinks cans. Both machines can cope with large-scale waste and no significant dismantling is needed before they begin their crushing. Certain parts such as screens, LCD-units and glass panes must be removed manually, but then the waste can be fed straight into the machines before they break it down using flexible beating elements. AU+T’s cross flow shredder Click here to enlarge image A conventional cross flow shredder tends to process between one and eight tonnes an hour whereas the Diabolo is designed to treat up to 10 tonnes an hour. Another essential difference between the two is that the conventional cross flow shredder simply crushes the waste to the smallest grain size the specific material can be physically broken down into, whereas the Diabolo can get particles down to a specified size using its two-stage process of pre-crushing and then milling. The breakdown of material occurs, for the most part, due to the force of the impact between the input materials as they are smashed together. This means the cross flow shredders are efficient long-term as the wear and tear on their own internal parts is reduced. The flexible rotating chain system used to break material down in AU+T’s machines is patented by the company and has proved very effective. The fact that the Diabolo machine can produce specific grain sizes means it is a popular choice in a marketplace which follows the shred first, separate later trend. The machine eliminates the need for further post-shredder processing such as hammer milling, granulation and drum sieving. The second chamber of the Diabolo machine has conically-arranged hammer disks with flexible beating elements that grind the pre-crushed material to the desired size. MeWa expands the cross flow shredder market Twenty-five-year-old German company MeWa was set up by Heimo Wabnig and specializes in recycling equipment. MeWa also has a cross flow shredder, the QZ, which employs the same shredding-by-attrition principle as AU+T’s technology. Flexible beating elements spin waste material together and it is broken down through the impact of the parts hitting each other. This machine comes into its own when dealing with refuse scrap, which is a mixed fraction of iron, steel and waste. The QZ is claimed to be able to separate refuse scrap with 100% accuracy meaning the iron and the smaller amount of non-ferrous fraction can then be sold on. The QZ machine at the company’s Esslingen site deals with 15,000 tonnes per year. MeWa’s QZ machine Click here to enlarge image MeWa’s latest development is an efficient and compact machine they call the Smash Boom Bang or the SB2. This machine has an important role to play in today’s shredding market, when one considers the need to shred then sort, as its specialty is breaking materials down into smaller parts without actually damaging the individual elements. Despite its ability to deal with four to 20 tonnes per hour and its rather destructive name, it is in fact capable of being extremely delicate. The Smash Boom Bang (SB2) machine from MeWa Click here to enlarge image Consumer electronics, household appliances, computers, printers and scanners, as well as waste that requires more sensitive handling due to the harmful liquids contained within, such as condensers, batteries and ink cartridges, can all be dealt with swiftly and delicately by the Smash Boom Bang. The machine’s technology consists of a horizontal, rotating drum with ‘actuators’ on the inside of it. The actuators lift the waste material up and then drop it from a specific height before it hits a throwing mechanism which launches it back up into the air again. When the waste hits the side of the rotating drum it is broken up by the force of this impact. This cycle is repeated several times and the waste is broken up efficiently and carefully. The throwing mechanism of MeWa’s Smash Boom Bang Click here to enlarge image The beauty of the Smash Boom Bang is that the dismantled parts come out intact and ready to be sold on. Any leftover material that needs further reduction can then be fed into a shredder such as the QZ. Another impressive feature is the sound-insulated casing which allows the machine to operate remarkably quietly for something whose name certainly suggests otherwise. Energy efficiency While every customer on the lookout for a shredder is interested in efficiency, one thing that will also attract a potential buyer is energy efficiency. With the large environmental challenges facing the world today, waste industry professionals are increasingly aware of the need to make sure their businesses are as kind to the environment as possible. The operation of large-scale equipment such as shredding machines naturally uses a large amount of power, and machines which can run effectively on a lesser amount have an advantage over their competitors. Not only will buyers be able to rest assured that they are reducing their carbon footprint, but they also know that a more energy efficient machine is also cheaper to run and therefore more attractive as a long-term investment. The inner workings of AU+T’s Diabolo machine: the pre-crushing chamber for beating Click here to enlarge image Austrian-based company Lindner prides itself on being able to reduce not only waste but also costs and problems for its customers. Its shredding technology comprises single and twin shaft shredders, and the company also plans and constructs specialized turnkey recycling plants. and the conically-arranged hammer disks for milling Click here to enlarge image Two of Lindner’s flagship technologies at the moment are its Jupiter and Power Komet machines, which work particularly well when used in tandem. The two machines are both single-shaft shredders which use the more traditional blade systems to shred waste material down to a smaller size. Each of them has patented design features which help them do their jobs efficiently. Both have an easy-to-access maintenance door, which also serves as a flap to collect foreign objects, and the Power Komet has a new design of screen unit and scrapers, which at the time of going to press were patent pending. The Jupiter is a primary shredder breaking down waste with large parts and the Power Komet is the secondary shredder which granulates the waste both do different jobs, but maintain the high company standards of being energy efficient. Lindner’s Power Komet Click here to enlarge image The Power Komet features belt pulleys with a high rotary speed. These build up the centrifugal force which enables the machine to use less energy. Other machines on the market that have a lower centrifugal force use more electricity to generate the power they need. Lindner now hopes to apply this technology to its other machines and to be able to provide shredding systems and plants with high energy efficiency. Aesthetics are important Another energy-efficient system in the shredding world has been developed by Austrian company Untha which unveiled its TR series machine in grand style in the manner of a Trojan horse at this year’s IFAT 2008 trade show in Munich. The system is a secondary shredding system which is used for the shredding of fine materials. Once it has done its job the by-products can be converted into alternative fuels (RDF) which are much in demand in today’s marketplace. Untha’s TR Series machine revealed at the IFAT 2008 show in Munich Click here to enlarge image Untha has invested much time and effort into getting the design just right, and the TR series is a good example of what a shredding machine should be high quality, reliable and compact. Untha’s manager for application engineering, Christian Lanner, says ‘Clients these days have a wide choice of shredder suppliers. They can see the products at exhibitions, on advertisements or on-line and will not always contact the manufacturers first. This means first impressions are very important, and good design is a basic component to persuade.’ The Untha machine is just one example of the increasing trend towards top-notch design in the shredding, and indeed the overall waste, markets. As the demand for waste disposal equipment increases, the competition to make the best machines possible heats up and buyers find themselves almost spoilt for choice. In order to stay ahead of the game companies such as Untha have raised the bar when it comes to almost every aspect of their machinery and one area where there has always been much room for improvement among shredders is aesthetics. Thus, the TR series is a neat but impressive-looking piece of kit that any expert would be proud to have in their waste disposal plant. Christian Lanner says of the TR series, ‘The design should not only be aesthetic but functional. The function of the suction hoods is to prevent people having to reach inside the machine, to reduce the noise of the machine and to protect the inner component from dust and dirt.’ So, aesthetics are not the reason for an increased trend towards design, merely a happy by-product of a trend that was there anyway. Ostensibly, the main aim of redesigning and reworking shredding machines is to increase energy efficiency, and Untha has realized an energy-saving potential estimated at up to 6000 kWh per year. The first point to mention in relation to Untha’s energy efficiency is its quick-change cutter system reducing the amount of time the machine needs to be switched off. The drive system also saves energy that would otherwise be lost as the TR series uses a high pin count, air-cooled asynchronic motor which allows it to consume less energy. A professional finish Another company that has recognized the increased importance of design in today’s marketplace is Finland’s Tana. Its ‘new generation’ Tana Shark 220D shredder has new and improved features, including the exterior design and styling. While this has obviously had the benefit of making the machine look better, functionality has been the key focus of these improvements. The main difference in the machine is that it now has 20% more shredding power than the previous model. The Tana Shark 220D Click here to enlarge image The control system has been improved to allow the user a greater choice of shredding programmes, and there is an option to add on a remote management system which would allow a connection to the machine via the internet from wherever the user may happen to be in the world. This system is a real selling point for Tana as it saves time for customers and allows problems to be fixed swiftly and efficiently, thus reducing the machine’s downtime. Making shredders mobile The majority of companies that employ a shredding machine will be transporting the waste to their site and doing all their recycling there. But, there is also a significant need for shredders that can be transported to a site and used on a temporary basis. ARTech Recyclingtechnik GmbH has one such machine the Mobile Rotary Shear. The machine can arrive at a site on a 6-wheel semi-trailer and is a stand-alone fully functioning unit with conveyor belt. It can shred eight tonnes of waste per hour including tyres and other car parts, white goods and domestic household waste. The final grain size of the output is approximately 60 mm wide and 300 mm long. The machine has a crane which has several functions and the energy is supplied by a diesel aggregate generator. The ARTech Mobile Rotary Shear this self-contained shredding unit can handle eight tonnes of waste every hour Click here to enlarge image One of the limitations of mobile shredding technology is that the option to use two machines such as a primary and then a secondary shredder is not viable. But the need to shred waste at remote or temporary locations will always exist and this type of technology will grow more and more sophisticated in its versatility as a result. Established shredding experts such as M&J from Denmark have a range of both mobile and staionary machines for every customer’s needs. Changes in the shredder market So what lies ahead in the field of shredding technology? Recycling is booming so there are set to be many opportunities for companies that can provide cost-effective, energy-efficient shredding solutions. One good example of this is Czech company Luter. Established for just 15 years the company is relatively young, but has been putting all its efforts into developing within the recycling market. General Manager Luca De Pieri gave Waste Management World an insight into the company’s plans. ‘One scheme under way is a brand new factory for machine production. The 4000 m2 factory will include a 1000 m2 area in which potential customers can see the machines in action.’ Future highlights of the display area are four new machines Luter will be trialling from September to October 2008 and then putting on the market in early 2009. One new unit is for cathode ray tube (CRT) recycling treatment and will feature completely new cutting systems, while another shredder will focus on tyres. The company operates in middle and eastern Europe, but is hoping to spread its wings into the German market soon. M&J’s 1000m mobile shredder Click here to enlarge image M&J has had great success with its ‘slow-turning’ shredding technology and plans to continue to produce this type of machine as well as employing its popular patented ‘cutting table’ technology. But while the technology has remained consistent things have changed in a corporate sense. 2007 saw a change in ownership and top management for the company at the same time it was celebrating its 150th anniversary. The owners at the time sold most of their shares and the company now has a capital fund as a majority shareholder. A new managing director, Kim Buchwald, was brought in from Johnson Controls Europe, which has been good for the company on an international level. M&J’s shredding technology at work in Holland Click here to enlarge image Claus Warming, vice president of sales and marketing, says: ‘A lot has changed in the past year. We have gone through a process of establishing a strategic action plan for the company. It’s a plan to continue the positive development we have already benefited from, but we have structured our organization differently. In many ways we are becoming much sharper and more focused.’ M&J’s new strategic plan includes looking into different markets worldwide, particularly South America. The company hopes to take its shredding technology over there but realizes that the application of such technology will require a different approach from that employed in Europe. M&J’s 2000m machine Click here to enlarge image One potential area of divergence in the sector exists when it comes to breadth of offering, with some companies providing turnkey solutions and others focusing on key parts in the chain. Weima is another well known brand in this field and the signs are that it lies within the latter camp, consolidating its position in the waste shredding sector rather than supplying all links in the chain. It will be interesting to observe how both strategies evolve over time, and how this active marketplace integrates with other aspects of waste handling. Claudine Capel is Associate Editor of Waste Management World e-mail: wmw@pennwell.com