Shredding past, present and future; Two European companies under the spotlight
Guy Robinson
Within the waste industry the market for heavy-duty shredding equipment is more active than ever. M&J Industries A/S and Satrind S.p.A., well known brands in this sector, both celebrated significant anniversaries last year. And both have a growing range to meet global
by Guy Robinson
In 1857, a blacksmith named Søren Jochumsen and a merchant named Johan P. Møller founded the Danish company they called Møller & Jochumsen – M&J Industries A/S was 150 years old last year. Though many years younger, Satrind S.p.A. has a similar degree of experience in the waste shredding market and also celebrated an important anniversary in 2007. The company was 25 years old, having been established in 1982 by founders who had more than 10 years of prior experience in this field. This shared anniversary offers a welcome reason for rolling up our sleeves to explore the world of heavy-duty shredding, and raising a glass to M&J and Satrind.
M&J’s early days
In its infancy, during the second half of the 19th century, the core products at M&J were steam engines, steam boilers, forged and cast goods for mills and various other foundry products, such as iron windows, memorial crosses, kitchen ranges, stoves and furnaces, as well as household utensils and agricultural tools.
As time passed, the production of steam engines became the company’s key activity with this part of the business soon accounting for approximately 75% of sales. Soon after the turn of the century, competition in the market for steam engines heightened, not only from other steam engine producers, but also from manufacturers of kerosene engines and suction-gas plants. So, in parallel with the decline of steam engine sales, the company began to expand its interests – M&J sold its last steam engines in 1925.
Gradually a new focus emerged, namely the production of diesel engines. This continued for about three decades, with the last diesel engine produced in 1960. Thereafter the void in production was filled with various activities, ranging from the manufacture of a ‘diffusion trough’ for use in sugar extraction, to the manufacture of ‘environmental’ equipment such as water- and air-purification technology.
The company took its first major steps in the waste industry in 1979, when it started to produce decanter centrifuges for wastewater sludge treatment, sold under the brands NIRO and later also GEA/Westfalia. Since then its portfolio has diversified and several changes to management and company structure have taken place. M&J Industries entered the waste shredder market in 1988 and its focus on this sector has increased throughout the past two decades.
Following a different course?
One might think that a strong history in the manufacture of engines sets up a platform for activity in the waste-to-energy sector rather than heavy-duty shredding. Did M&J ever consider entering the waste to energy (WTE) market? I put this question to Claus Warming, Sales Manager at M&J.
‘Being a well-established factory with substantial local importance, M&J sought ways to broaden its industrial base in the late eighties, and chose to acquire a patent developed by a young Danish engineer to cope with the devastating effects of a terrible storm that completely destroyed most of the forests in parts of our small country. This patent covered a very efficient shredder working according to new principles − principles that M&J has since followed-up by further patents, remaining loyal to the original ideas. So, in those days, the idea of entering the WTE market was not on our minds; but it came later by becoming a supplier of shredders for a number of WTE installations around the world.’
As an aside, it is interesting to note the importance of patents to M&J. In one way they act as useful benchmarks to track the company’s evolution. In another way they are – as intended – tools for the company to protect its designs within the marketplace, which it has done on several occasions in recent years.
Taking over where Thor left off?
The fact that a terrible storm sparked the latest evolutionary stage of M&J is echoed in the company’s literature, which highlights the parallels between its equipment and the hammer-wielding Norse god of thunder, Thor. M&J’s Waste Reducer has ‘the same characteristics: crushingly strong and indestructible’.
The Waste Reducer is designed to handle many different types of waste, ranging from household waste and bulky items such as furniture, mattresses and refrigerators to industrial waste, wood waste and dead animals. As a result it can be applied to shred waste in a number of different contexts:
- preparing waste for combustion in incineration plants
- volume reduction at transfer stations
- volume reduction when landfilling
- on-site management of construction and demolition waste
- in slaughterhouses.
In simple terms its Waste Reducer consists of a heavy-duty box whose bottom forms a cutting table into which are embedded one or two rotating knife shafts. As one might expect, the knives cut waste into smaller pieces before pushing it through the holes in the cutting table.
M&J knives
Manufactured by M&J in Denmark, the company’s knives are constructed of ‘Hardox 500’ – abrasion-resistant refined steel. They are welded to the main shafts and designed to shred in both directions. (In this context, rather than wielding one big hammer, Thor wields a number of double-edged hammers – which sounds a good deal more threatening!) The edges of the knives are ‘hardfaced’ to maximize their lifespan – a cladding process is used to strengthen areas of the blades that are particularly prone to wear.
The company’s cutting tables are not normally tilted, though M&J has supplied one shredder with the option of hydraulically tilting the cutting table in order to empty it. When quizzed on this point, Lars Laursen, Area Sales Manager for M&J, commented ‘This is not the norm; but we are very flexible, adapting to customer desires.’
Processing capacities
The Waste Reducer is available in eight different versions: four models are static – the 1000S, 2000S, 4000S and 6000S – and four models are mobile – 1000M, 2000M, 4000M and 6000M (see Table 1). While the 4000 model remains the company’s ‘bread and butter’ in terms of primary shredder sales revenue, the company is expanding its offerings in the field of pre-shredding and secondary shredding. The newest member of the family is the 1000 model, also included in Table 1, which is designed as a pre-shredder and has a processing capacity of up to 25 tonnes per hour. I asked Lars why the M&J 1000 model has twin shafts. The answer, he tells me, is that twin shaft technology helps to optimize the shredding capability. In addition, it proves efficient when handling a wide range of different types of material, and it assists with redistribution of material within the hopper.
With exchangeable wear parts (specifically, the shafts and the so-called counter-knives in the cutting-zone), M&J’s 1000 is designed for clients who need a universal shredder without a very large throughput.
If pre-shredding offers front-end shredding capacity, then secondary shredding offers a back-end option for final treatment (see box for more). And in this regard, the company offers a special version of its M&J 4000 machine as a secondary shredder. Called the M&J 4000-12F, this machine produces approximately 30 tonnes per hour of output, 95% of which is smaller in particulate size that 80 mm (when fed from an M&J 4000-8). The digits added at the end of the model name describe the number of rotating cutting blades included in that particular model.
M&J’s markets
Currently M&J exports about 80% of its production to countries such as Germany, Italy, Spain, France, the UK, Belgium and China. In addition the company is expanding its interests in central and eastern Europe and the USA. In central Europe, the company has established distributors in Poland, Hungary, Slovakia and the Czech Republic (among others). And, turning to eastern Europe ‘the markets are growing at different rates’ Lars tells me, ‘but we are looking at these markets too.’
Heading across the Atlantic, some years ago M&J established a collaborative venture with an American manufacturer of shredders, SSI out of Portland, Oregon. M&J supplies the cutting table and SSI completes the picture with its own power-packs, chassis, conveyors and so on. This collaboration ensures that the final products are appropriate for the US market, though little can be done to counter trends in exchange rates, which have hampered M&J’s recent growth in the USA.
Made in Italy
Adopting a similar global outlook is Satrind S.p.A., an Italian producer of shredders and crushers, based in Arluno, near Milan. The company currently exports about 70% of its production and during its 25 years of activity it has sold over 4000 shredders worldwide through its sales and distribution network in over 40 countries.
Designed to operate in both primary shredding and secondary shredding stages, its shredder models have from one to four shafts and an installed power ranging from 10 horsepower (HP) to 400HP. Key waste streams handled include municipal solid waste (MSW), waste electrical and electronic equipment, tyres, refrigerators, drums, industrial waste and hazardous waste (among others).
During recent years Satrind has expanded its offering to include crushers that reduce the size of more voluminous wastes. It employs the term ‘crusher’ for these machines, which are put to work at the outset of the processing chain, as distinct from ‘shredder’. Not all companies active in this sector employ this distinction. Its crushers are not designed to guarantee a uniform controlled shred size, but instead prepare the material for subsequent shredding.
Two shaft shredders, usually employed in a primary shredding stage, produce a shred size smaller than that achieved via crushing. And three shaft shredders with an integrated screen refine the particulate size of output material. Such ‘size-selection’ screens enable the operator to obtain a shred size from 20mm to 150mm.
Moving toward modularity and tougher performance
Over time, Satrind has tended to develop stronger and heavier machines, responding to demands for ever-increasing performance. And it has sought to develop machine modularity, meaning that – for example – the R series models (which represent its latest shredder range) have interchangeable components. This enables Satrind to maintain lower stock levels than would otherwise be possible, at the same time as speeding up delivery of spare parts. The company indicates that it can supply larger shredding solutions in less than 45 days.
This ethos of flexibility also impacts upon the operation and maintenance of the machines. Satrind has designed its latest models to enable the operator to remove components as/when required, including the size selection screen (see photo). This allows the operator to inspect and change worn or damaged sections safely and quickly. On top of this, the screens and other spare parts have been reinforced to reduce further the risk of damage and extend operational life.
Satrind’s blades
Mentioning operational life brings us neatly on to the company’s blades. Satrind adopts a different approach from M&J. The shredder and cutter blades on all Satrind’s shafts are fitted mechanically and not welded. Each single blade may be removed from the shafts and replaced, in the event of breakage or wear, without having to replace the full shaft.
Made of wear-resistant steel, its shredder blades originate from billets which are hot forged into a mould of predefined shape. This process allows the designers to obtain a radial distribution of the steel fibres, thus reducing the possibility of tiny cracks during the tempering process. This means that the blades can be ground down several times before being replaced on the shaft.
Satrind’s crusher blades are made of Hardox and their cutting action is engineered to occur on both sides of the blade as well as cutting against the counter-blades that are bolted on to the underside of the shredding chamber. Furthermore, the counter-blades can be adjusted independently from each other, thus allowing the operator to close the gaps caused by regular wear, which is never uniformly distributed along the shafts of the machine. Bruno Meneghini, Sales and Marketing Manager for Satrind, comments: ‘Any operator will confirm that wear is always heavier and concentrated in the middle of the shredding area and diminishes gradually toward the extremities of the chamber.’ With this in mind, Satrind’s system allows users to close all the wear gaps along the shafts regardless of the position or dimension of the wear.
Looking to the future
Looking to the future, Satrind is seeking to work with partners that are experts in their field of application. By co-operating with specialized companies and by integrating its know-how and consolidated experience, Satrind is confident that it can offer innovative technical solutions for complete systems that satisfy very specific requirements. In addition, the company is seeking to provide customized solutions for different types of application. For example, one of the latest solutions that Satrind has developed is a waste plant for handling hazardous waste, whereby the shredder is fed with drums and similar containers under nitrogen blanketing.
Like Satrind, M&J also envisages a busy time ahead; and it, too, is looking at develop more specialized waste handling solutions. In M&J’s case, one area of current research is adapting the company’s knife design to specific types of material, thereby optimizing existing equipment and expanding the existing product palette.
Satrind is looking to increase its business by at least 20% each year for the next five years. This is indicative of the enthusiasm in this market, coupled with an increasing demand for recycled and recovered materials.
Guy Robinson is Editor of Waste Management World
e-mail: wmw@pennwell.com
What makes a secondary shredder different?
Secondary shredders output material at a grain size of less than 80 mm; some machines even generate particulate material smaller than 30 mm in size. They are designed for cutting, rather than both cutting and breaking, which occurs during pre-shredding and, to a certain extent, in primary shredding. This means that secondary shredders undertake ‘finer’ work than pre-shredders and thus are more vulnerable to impurities in the waste stream. Generally speaking, they are used towards the end of a waste treatment process, enabling production of the desired output.
Add RSS Feed
