Auxiliary and emergency feed pointsTroughed belt conveyors form the backbone of most bulk materials handling systems in terminals and process plant connecting the core machinery or processes, writes Barry Woodbine, AUMUND Group. Over time economics change driving modifications to the logistics chain often demanding new intake facilities to introduce new material sources not compatible with the original stockyard, or import systems concept.
In the cement industry this situation is particularly relevant with the introduction of co-products such as granulated blast furnace slag and flue gas de-sulphurized gypsum replacing clinker and natural gypsum in the final cement mix. In addition the source of cement clinker is now practically commoditized and certainly traded extensively internationally. Using imported clinker allows cement manufacturers to balance own production with perhaps more economical sources to maximize the utilization of on-site grinding capacity.
Often such situations may be temporarily driven by particular production or market considerations and as such budgets are always critical and in this situation the benefits offered by the Samson
TM surface feeder concept are very attractive. Surface feeders eliminate the deep pits and underground hoppers
associated with conventional truck intake solutions often allowing the feeder to be mounted at the same level as the existing ground conveyor equipment. Material may be discharged at a controlled rate from the feeder to the existing conveyor to suit the plant demands either to replace or augment the normal conveyor flow.
Two such solutions are illustrated herein; a long established installation at cement plant in Germany where clinker is imported by truck and discharged to an existing inclined conveyor using an intermediate feed point. In this application the side tipping Samson
TM solution allowed the new installation to be shoehorned into a very compact space between the conveyor gallery and an existing building. In this manner the established clinker conveying arrangement remained substantially unchanged and production losses during installation of the new equipment were minimized.
Clinker is extremely dusty material and generally requires a substantial dust plant to control pollution from conventional underground intake hoppers. With the wide apron belt design of the surface mounted Samson
TM the material free fall is minimized and therefore both particulate separation and displaced air velocity are minimized also thereby mitigating dust generation at source. When the truck is tipping only the first few tonnes fall free, and then only a metre or so, thereafter the bulk of the truck contents flow into the SamsonTM in a smooth stream with virtually no dust generation whatsoever.
Nevertheless dust control is often mandatory in such installations and in this case a local dust collector is mounted to the SamsonTM enclosure providing control of dust emissions both at the tipping point and also at the transfer point between the SamsonTM and the following conveyor. In this case the associated fan set is mounted at ground level and the cleaned air is ducted from the collector to the fan inlet.
A more recent application in South Africa at the AfriSam
plant of the Holcim Group based in Switzerland. AfriSam is South Africa’s second-largest cement producer and is a long- term customer of the Aumund Group going back to 1971 for the supply of chain elevators plus clinker transports. The most recent delivery to its Ulco plant involved a SamsonTM 800 Series surface which provides an intermediate feed point to an existing overland belt conveyor. In this case the SamsonTM is designed specifically for use with wheeled loaders operating from a clinker ground stockpile. Retrieving material from any ground stockpile it is likely the loader will pick up tramp material and particularly oversize lumps that have coagulated in storage. Large lumps are a problem for the transfer point and ongoing conveyor and for this reason the SamsonTM is supplied with a reject grill at the entry and any oversize material may be manually cleared from the grill surface periodically.
For AfriSam the SamsonTM provided a neat solution for the feeding of clinker with the minimum of civil works and practically no interruption of service excepting for a few hours lost during the modification of the belt conveyor to accommodate the new transfer loading point.
In this project a free standing dust collector is included positioned beside the transfer point and with de-dusting to the SamsonTM enclosure and to the extended feed boot of the overland belt conveyor. The collected dust is discharged from the filter bags to a hopper and released back to the conveyed material stream on the belt conveyor. Handling clinker by
wheeled loader is always likely to create excessive dust since the material free falls from the bucket to the feeder in an uncontrolled stream releasing dust particles that must be contained with the enclosure of the SamsonTM to mitigate any fugitive dust pollution. Clearly uncontrolled fugitive dust emissions will be windblown creating significant nuisance and local pollution.
Intermediate feed points are often used for blending trace elements onto a conveyor stream such as for example adding clay to a limestone belt to achieve the right raw meal mix in a modern cement plant. In addition the introduction of a new material flow to an existing conveyor has the potential to overload the system and suitable flow controls must be put in place to control both the additions rate and the blend ratio. The SamsonTM may deliver a variable output rate directly proportional volumetrically to the SamsonTM belt speed using a levelling blade to control the material bed depth. The mass output rate from the SamsonTM may be controlled by introducing a simple single idler belt weigher on the upstream and downstream sides of the new feed point to the associated belt conveyor. By computing the differential rate necessary to achieve the required blend ratio the SamsonTM belt speed may be automatically controlled using an Inverter variable speed device with feedback loop to continuous monitor the relative rates. Where only the ongoing conveyor handling rate must be monitored a single downstream weigher is all that is required avoiding over feeding.
In both of the examples discussed thus far we have applied the intermediate feed point to a low level section of the ongoing conveyor. However, in some applications, such as illustrated on p75 at Hong Kong Power, coal must be introduced to a high level transfer belt at a point between two transfer towers. For this purpose the StormajorTM by B&W provides an ideal answer. By incorporating a SamsonTM feeder section and radial stacking boom onto a single mobile chassis the StormajorTM offers the best of both worlds providing both an intermediate feed point to the existing conveyor installation and the opportunity to use the same equipment for other duties elsewhere in the plant. The StormajorTM is a truly mobile universal handling tool suitable for stockpiling or even rail or barge loading if the need arises.
Intermediate feed points
can perform other functions in any utility, process plant or terminal providing in an emergency a means of introducing material to the existing stockyard belts in the event the normal intake machinery, reclaimer or ship unloader for example, is temporarily unavailable. Typically in an electricity utility coal-fired power plant, if a bucketwheel reclaimer is down for repair or maintenance, this can be a major outage, often requiring as much as six months’ downtime. During this time period, alternative solutions or coal recovery must be found. In several applications the SamsonTM and StormajorTM have fulfilled this duty handling limestone in cement plant, coal in power plant and iron ore in steel works.
In conclusion there are many circumstances where material must be introduced to an existing troughed belt conveyor network either through changing trading patterns or to accommodate an emergency in the stockyard and in all of these situation the flexibility of surface mounted and mobile plant is a major benefit offering fast track and minimum impact solutions.
Driving global commodity flow: Guttridge looks forward to new conveying challenges
Despite recent economic difficulties, a report from Standard Chartered1 issued in 2010 suggests that the world is currently in the grip of a ‘super-cycle’, a prolonged period of historically high economic growth, in this case being driven by the industrialization of emerging economies. Estimates that the global economy will grow year on year by, on
average, 3.5%, well beyond the next decade, point to opportunities for those in bulk materials with the global flow of commodities continuing to rise.
“We’re certainly living in exciting and challenging times,” says Paul Gott, sales and marketing director at Guttridge Ltd, a major UK-based manufacturer and supplier of bulk materials handling systems. “For Guttridge, 2012 marks 50 years in business, a half-century in which we’ve delivered conveyors for a vast array of materials and have amassed substantial expertise across many different industries and applications. We will be celebrating this year but our driving focus is applying our knowledge and
experience to developing solutions that support our customers in meeting the demands of 21st century handling and processing.”
Guttridge industrial range: chain conveyor drive end section for a power station contract
DELIVERING SOLUTIONS,WHATEVER THE APPLICATIONAt its large modern plant in the UK, Guttridge designs, manufactures and tests materials handling machinery for applications that span the dry materials sectors and beyond. Solutions specifically tailored to customer requirements are developed using the latest 3-D software and manufactured in a state-of-the-art machining, painting and assembly facility. The product range includes:
- bucket elevators; y screw conveyors;
- chain conveyors; y belt conveyors;
- load and discharge hoppers; and
- vertical blenders and live bins.
The company’s range also includes the spouting and fittings, slide valves, diverters and other ancillary equipment needed to Guttridge high capacity two-way diverter valves.
engineer a robust, integrated solution. For any conveying application it is essential to
select the best equipment for the job and here experience really does count. Guttridge makes
equipment for feeds, cereals, and pet foods, chemicals and minerals, foods and pharmaceuticals. Such diversity informs the company’s extensive knowledge base and practical know-how. All of these are put to the best possible use when tackling new challenges. ”Conveying requirements continue to evolve,”
reflects Gott, “both in terms of scale and the range of materials handled. For example, the food industry has well-established processes but continues to develop new products that may be delicate or difficult to handle, or both. On a larger scale we now see more from the biomass and wastewater treatment sectors, involving some tough-to-handle or more abrasive solids. Storage facilities at docks, and at a national level, are tending to increase in scale, a change that drives demand for larger-capacity equipment.” A recent project with Heygates, the UK’s largest independent flour miller, illustrates this trend. Here the brief was to increase
grain handling capacity by around 700%, with the aim of improving efficiency and minimizing queuing times for grain delivery. Grain can be abrasive, so build quality and materials of construction played an important role in equipment selection.The installed solution, which comprises intake screws, bucket elevators and chain
conveyors, works reliably with little downtime. Grain leakage has been eliminated, as have the lorry queues.
DELIVERING RELIABLY,TO AGREED TIMESCALESEngineering a solution that performs reliably and efficiently is critical, but reliability in meeting agreed delivery deadlines is equally vital. Conveying equipment is often installed as part of a much larger project so the implications of any delay can be significant. Well-run companies deliver to time and customers are increasingly judging performance on this basis.
“Our workshop, and the skills of those who operate it, are crucial to our business and our ability to meet customer requirements,” continues Gott. “To position us for future growth we’ve recently carried out a comprehensive review. We measure the ability of the workshop to deliver using the parameter ‘On time, in full [OTIF]’ – which speaks for itself! With OTIF figures running in excess of 97% customers can be confident of getting the solution they need, when they need it.”
LOOKING AHEADAs economies emerge and participate more fully in global economic activity, the demand for commodities rises, bringing with it requirements for associated conveying and storage solutions. The scale of growth in China, India, parts of the Middle East and South America will centre activity in these regions but for conveyor suppliers the goals remain the same.
“Whether you are conveying coffee or grain, cement or bauxite, what you need is reliable cost-effective solutions,” concludes Gott.“Knowing how to handle an array of materials, and having a reliable partner with the ability to design and manufacture systems that really work is absolutely essential.”
4B Australia moves to new premises
After only one year in operation, bucket elevator and conveyor component supplier 4B Australia has already outgrown the premises that it started up in, and has relocated to a new modern 450m3 office/warehouse complex located at Acacia Ridge in Brisbane. The new premise enables 4B Australia to now support the supply of all of the 4B products in Australia.
Managing director Paul Dennis explains how the move underlines the company’s strategy of maintaining high stock levels to be able to respond quickly to local customer demand.
“Our product inventory in Australia now consists of the full range of sizes in the CC-S HDPE elevator buckets range, the pressed steel and the industrial Atlas AA Nylon elevator bucket ranges also. We stock both FRASOR and food grade elevator belts in a variety of tensile strengths, as well as many different style/size elevator bolts in both metric and imperial sizes.
Our electronics range has now also grown to include the highly successful range of level indicators, and we now stock almost all of the electronics that 4B offer globally to support the growing requirement for products that meet the high standards of IECex certification. Since re-locating we can now also offer our customers from stock, the 4B range of forged chain products for drag conveyors with a variety of flight options.”
4B Australia is the latest subsidiary of the 4B Braime Group, leading supplier of bucket elevator and conveyor components and electronic monitoring equipment.
4B Braime has been a pioneer of the material handling industry, introducing the first seamless steel elevator bucket back in 1909 and since then leading the field in elevator bucket and bolt design and manufacture. 4B supplies the highest quality forged chain and elevator belting and 4B Braime’s electronic division specializes in level controls, electric sensors and safety control systems that prevent costly downtime and reduce the risks of explosions in hazardous areas.
“As a worldwide manufacturer of materials handling components, 4B has always delivered, technology, innovation, quality and value”, says Dennis. “And now with the new 4B Australia premises we can also offer a greater availability of inventory which supports our customers’ requirements for the highest standards of service.”
DSI Snakes continue to grow in Spain
In 2003, Dos Santos International — in co-operation with PHB Weserhu¨tte — commissioned a DSI Snake Sandwich High Angle Conveyor for the Aceralia Steel Mill in Gijon,Asturias Spain. The conveyor system provides a high angle conveyor path to the existing pulverizing plant and then continues on to a new pulverizing plant. The DSI Snake replaced a problematic vertical pocket belt system that served the old pulverizing plant. The Snake elevates raw coal at a 75° angle to the discharge, at which point the material is completely discharged and scraped clean using standard belt scrapers. This installation has been in successful operation for seven years and counting.
The success at Aceralia did not go unnoticed. Since then, two new DSI Snakes have been ordered for operation in Spain for Repsol Refineries. The first has been ordered by Duro Felguera for the Muskiz refinery near Bilbao in northeastern Spain. The second was ordered by TAIM for operation in the Cartagena Refinery on the Mediterranean Sea in southern Spain.
The new DSI Snake at the Muskiz Refinery elevates coke and delivers the hot product to a truck loading bin. Designed to operate in an enclosed, potentially explosive environment,
this Snake is subject to, and compliant with, the latest and strictest ATEX standards. The start up for the Snake at Muskiz was completed in September 2011.
A second DSI Snake at the Cartagena refinery is of ‘C-shaped’ profile. The refinery expansion consists of two complete storage facilities. The first one is for petroleum coke storage and the second is for sulphur storage. The DSI Snake is part of the sulphur storage facility. Its function is to transport the solid particles generated during the solidification process at the plant and temporarily store them in piles to be taken to the port facilities. Start up for the DSI ‘C’ Snake was completed in October 2011. The two DSI Snakes for Spain are part of a growing list of
installations for Dos Santos International which includes a variety of applications throughout the world. DSI offers many unique systems from stationary units in all sizes, to a fully mobile high-angle shiploader designed to accommodate wharves with limited space. The versatility of the DSI Snake is demonstrated with each application, but the full potential of the system will only become realized as more units are installed for the wide range of industries that have yet to implement this well-established technology.
Flexco adds Bob Lord and Chris Poe to support growing product lines
Bob Lord and Chris Poe recently joined the Flexco team in product management roles. Lord will be focusing on the Flexco global transfer chute programme and operating out of the Bolingbrook, Ill. facility, while Chris Poe will be supporting the CoreTechTM roller line for Flexco.
In his role as product manager, Lord will be responsible for the overall marketing strategy and activities associated with the transfer chute program, including the most powerful controlled-flow technology on the market:Tasman Warajay TechnologyTM.
“I’m looking forward to growing the transfer chute business into a global product offering for various bulk material types,” Lord said.“I am already impressed by the real culture of teamwork and collaboration at Flexco and feel that this atmosphere will support our objectives.”
Lord brings with him years of experience in product management, product development, and engineering.
“Bob’s strong technical background and marketing skills will be instrumental in assisting in the growth targets set forth for the global chute program,” said Chip Winiarski, director of heavy duty marketing at Flexco.“His hands-on approach and enthusiasm is a welcome addition to Flexco.”
Poe will take on the responsibility of the CoreTech global marketing program in his role as product manager. He will facilitate the ongoing business planning for the programme, working closely with operations in Lemont and City Deep, South Africa, as well as subsidiaries and selling regions around the world, to ensure that Flexco has strategies in place to achieve its long-term objectives.
“Flexco is clearly committed to long-term growth and innovation, and I am looking forward to participating in this world-class professional culture while integrating into the CoreTech team,” Poe said.
Poe brings over 15 years of experience in marketing to this position, including valuable experience
introducing new products to market, establishing value propositions for new technologies, and supporting industrial
sales networks. “Chris will be a key addition to the team, bringing
a strong industrial product management background to the program,” Mike Stein, vice president of marketing at Flexco, said.
Flexco provides the world’s belt conveyors with efficient, safe products, services, and solutions for mechanical splicing, belt cleaning, belt tracking, spillage, and slippage. The company is based in Downers Grove, Illinois and operates subsidiaries in Australia, Chile, China, England, Germany, India, Mexico, Singapore, and South Africa. Flexco markets
its broad line of products through a worldwide network of distributors, under the Flexco®, Mineline®, CoreTechTM, and Tasman Warajay TechnologyTM brand names.
Cracking up: the effects of ozone on rubber conveyor belts
Conveyor belts are a very significant purchase for any company that uses them. As a consequence, users of conveyor belts usually go to great lengths to make sure that full and proper consideration is given to a wide range of technical factors such as pulley diameters, tensile strength and other characteristics such as resistance to abrasion.
Of course, these are all well recognized as being everyday considerations when selecting the most suitable and cost-effective belts. What is less well recognized (and publicized) is the extremely harmful long-term effects of ozone on rubber conveyor belts.
FROM PROTECTOR TO AGGRESSORAt high altitude, ozone acts as a protective shield by absorbing harmful ultraviolet rays. At low altitude, ozone becomes a pollutant. Research has shown that exposure to ozone can have several consequences such as a surface cracking and a decrease in the tensile strength of the rubber. It is becoming increasingly common to see belts being replaced prematurely because of surface cracking even though the covers are not completely worn.
Ozone also occurs in cities and industrialized areas, when it is formed by the photolysis of nitrogen dioxide from automobile exhaust and industrial discharges. The actual level of ozone exposure at ground level can vary depending on geographical and climatic conditions such as higher altitudes and coastal areas, which is of particular relevance to
seaport based organizations. Belts that do not operate under
shelter are especially prone to surface cracking, which can have very serious consequences in terms of the performance of the belt and its working life. There are also significant environmental and health and safety consequences because fine particles penetrate the cracks, which are then discharged (shaken out) on the return (underside) run of the belt. It is becoming increasingly common to see belts being replaced prematurely because of surface cracking even though the covers are not completely worn.
HIDDEN EFFECTSAt first glance, fine cracks in the surface rubber may not seem to be a major problem but over a period of time the rubber becomes increasingly brittle. Transversal cracks deepen under the repeated stress of passing over the pulleys and drums and, if the conveyor has a relatively short transition distance, longitudinal cracks can also begin to appear. Again, surface cracking may not initially seem to be a cause of concern but there are often hidden long-term effects.
One of those hidden effects is that moisture seeps into the cracks and penetrates the actual carcass of the belt. In multi-ply
belts, the fibres of the weft strands of the plies expand as they absorb the moisture, which in turn causes sections of the carcass to contract (shorten) as the weft strands pull on the warp strands of the ply. This can often result in tracking problems that are difficult to pinpoint and which no amount of steering idler adjustment can compensate for.
EN/ISO 1431 TESTINGAlthough largely ignored by much of the industry on cost grounds, the growing importance of ozone resistance has led Netherlands-based Dunlop Conveyor Belting to take advantage of new technology to measure the effects of ozone. Mandatory testing to EN/ISO 1431 international standards using an ozone testing cabinet was introduced for all Dunlop belting products as well as applying comparison tests to samples of belts made by its competitors.
Samples are placed under tension (20% elongation) inside the cabinet and exposed to highly concentrated levels of
ozone for up to 96 hours. Dunlop says that, as a general rule and based on its experience, failure to exceed more than eight hours under test without cracking will almost certainly mean that (under normal working conditions) the belt will start to deteriorate. Dunlop’s director of production and product development, Dr. Michiel Eijpe, believes that EN/ISO 1431 ozone resistance testing has proved to be a wise investment. “Tests have already shown that all Dunlop (belt) covers achieve extremely high standards of resistance although some performed better than others. As a result, we have revised the compound recipes on a small number of belts to ensure that every Dunlop belt
reaches the highest possible level of resistance to ozone. In effect, we have found another very important quality advantage that helps to further extend the operational life of our belts.”
Beumer supplies curved pipe conveyor to Sweden
The Swedish high-tech minerals group LKAB, based in Northern Sweden, has commissioned BEUMER to provide a curved pipe conveyor for the transport of olivine in summer and quartzite in winter, each at 800tph (tonnes per hour). This material is used for the production of high-quality iron ore pellets. The system will be installed at the company- owned transshipment port in Narvik (Norway). It will automate the storage of material and the filling of railway wagons, which is currently done manually. These wagons transport the material to the main plants in Kiruna and Malmberget.
The complete system comprises the feeding area with vibrating feeders, the pipe conveyor with a centre distance of 341.2 metres, the steel structure and a reversible troughed belt conveyor feeding the customer’s silos. The pipe diameter of the pipe conveyor is 300 millimetres, and its conveying
Pipe conveyors transport bulk materials through rough terrain and can handle extreme differences in height. (photo: BEUMER Group GmbH & Co. KG)
speed is 3.1 metres per second. The decisive factor for the contract award to BEUMER
was an almost identical system that has been operating very successfully at another mining company for more than ten years. This reference, as well as the good work of the project team during the quotation phase, convinced LKAB. The complete system will be supplied, installed and commissioned by BEUMER.
The BEUMER Group is an international manufacturer of intralogistics for conveying, loading, palletizing, packaging, sortation and distribution technology. Together with Crisplant a/s and Enexco Teknologies India Limited, the BEUMER Group employs about 3,000 people and achieves an annual turnover of about €450 million. With its subsidiaries and sales agencies, the BEUMER Group is present in many industries the world over.
Tenova TAKRAF’s ash removal system for Bulgaria’s new power plant
In Bulgaria’s energy supply, lignite from the Maritza basin plays a major role. Three large power plants Maritza East 1, 2 and 3 provide about 40% of Bulgaria’s total energy production. Since 2006, under the new ownership of AES Maritza East 1 has been replaced, consisting now of two 300MW units. Energy production from lignite generates considerable quantities of fly ash and gypsum that is either disposed off or reused. AES decided to dump the entire residue in a former opencast site in 9km distance of the power plant.
In the old power plant the ash was stored on an ash pond and later transported by rail to the dumping area. For the new power plant the disposal handling has been re-evaluated completely. As Bulgaria is a member of the EU, current EU regulations and standards must be considered in addition to the applicable Bulgarian legislation. The transport route is passing a village and half of the hauling distance is exposed to public areas. So, railway and truck transport was not considered as a transport option right from the beginning of the planning phase. Due to the complicated routing along the former railway line a tube conveyor system was chosen.
Based on the budget, the power plant operator decided on a 4.5km-long tube conveyor with truck loading station at the end of the conveyor and truck transport over the remaining 4.3km distance. This alternative requires the lower initial investment. An option for a later extension facilitated by a second 4.3km- long tube conveyor was taken into account. The system is flexible as the fleet of trucks is already available for the final transport distance. However, the transport by 24t trucks requires sophisticated logistics and is very sensitive to bad weather conditions.
According to the specifications the material to be transported consists of 48% fly ash, 45% gypsum and 7% bottom ash. Moisture content and density of the material can vary. Besides the mixture of the three substances a separate transport of each material is required as an option too.
The waste transport system starts at the outlets of the bottom ash silo, where the wet, slag containing bottom ash is fed onto a chain conveyor. This conveyor transfers the material onto the belt conveyor BC-1B, a normal troughed belt width of 1,400mm and 35° trough angle. Conveyor BC-1B traverses the entire silo unit underneath. The moistened fly ash is fed from three silo outlets and gypsum from two silo outlets on top of the bottom ash that is already located on the belt. The amount of material on the belt is recorded continuously by a belt scale placed at the end of the conveyor BC-1B. On the downstream conveyor BC-1C at first tramp iron is removed by a self-cleaning magnetic separator and a metal detector. Since the density of the material being conveyed can vary and the tube conveyor must be driven at full power with a filling degree up to 80%, volumetric and mass flow rate control on the upstream conveyor is required.
The ash-gypsum mixture is further transported by tube conveyor TC-3A. The 4,535m-long tube conveyor connects the power station with the truck loading point, and has got numerous vertical curves and eight horizontal curves. The
minimum curve radius is 350m. The tube (inside) diameter is 400mm. The associated belt width is 1,500mm, and the conveyor speed of 4.8m/s results in a cross-section utilization of 72%. The first 800 metres of the conveyor route runs on bridges crossing two railway lines. The tail station of the tube conveyors is located inside a transfer tower. For environmental protection, the closing area of the conveyor belt is located in a closed conveyor bridge. The tube is shaped in this area by means of adjustable three idler stations. The trough angle of the side rollers can be adjusted by the whole pattern of the support frame in the range of 0° to 90°.
The first two bridges are enclosed completely. All other elevated sections are designed as integrated conveyor bridges where the return strand runs inside the bridge structure. Facilitating better access for maintenance and repair the belt is supported by removable modules on the ground. For noise reduction, structure-borne sound-insulated idlers are used in the conveyor system complying with the permitted noise levels in village areas. Close to the properties in villages the conveyor is equipped with sound insolating plastic sheeting in order to keep the sound level caused by the tube conveyor below 50dB (A).
At the truck loading station TL-2 the tube conveyor discharges onto a movable shuttle conveyor, which feeds the truck loading conveyors TC-5A and B. There, in a frequency of 60 seconds 24t trucks need to be loaded. The loading points are equipped with telescopic chutes featuring ring nozzles at their outlet in order to prevent dust generation during the loading process. An operator who has a direct view to one loading point controls the loading process.
Since the beginning of 2011 the residue transport system has been in operation. All expectations in regards to environmental protection, operational safety and reliability have been met. Despite a wide variety of chemical and physical properties of the material mixture transported the system shows stable operation in a temperature ranging between +35 and –20°C.
De Regt Conveyorsystems: focusing on service, quality and flexibility
De Regt Conveyorsystems is a family business, which was established in 1988. It has 22 employees, and is headquartered in Biervliet,The Netherlands.
The company specializes in the development, manufacture, assembly and maintenance of conveyor systems. Keywords that sum up De Regt Conveyorsystems are service, quality and flexibility.
De Regt Conveyorsystems has great expertise in the manufacture of mobile and fixed belt conveyors, roller conveyors (gravity and driven), chain conveyors, bucket elevators, screw conveyors, bunker and supporting structures.
The majority of the company’s conveyors are used to handle bulk products, including fertilizers, rice, maize, feed-pellets, grains, sand and gravel, coals, waste and recycling products etc.
De Regt’s engineering department uses HiCad (a three-dimensional package) for the design and development of its conveyor systems. It is a solid and growing company, something which is illustrated in the growing list of customers, which include major companies such as Cargill,Verbrugge Terminals, Solvic Lillo, Group Galloo, Ovet BV, Schelde Logistics NV, Inashco,Van Heyghen Recycling, Argex Kruibeke, Euroports Belgium, Oosterlee S.E.A.M. ,Ghent Transport & Storage, Zoutman, Osse Overslag Centrale and Wagenborg Bulk Terminal bv.
De Regt Conveyorsystems sells its products not only in the Netherlands, but also to customers in Belgium, France and sometimes Germany and Italy. Almost all of its customers are involved in the dry bulk handling market. Others include waste and recycling companies and concrete manufacturers.
One of the major issues for De Regt Conveyorsystems is dust control, and ensuring that all Atex regulations and zones are observed (to eliminate the risk of dust explosions). Every conveyor made by De Regt Conveyorsystems is developed in such a way that all such regulations are adhered to, and the company strives daily to improve its systems as much as possible.
Every day, De Regt’s sales team reaches out to potential new customers to expand its business network. Recent successfully completed projects are:
Six linked mobile conveyors De Regt Conveyorsystems made six mobile linked conveyors with hydraulic height adjustment.
These mobile linked conveyors are for the transportation of grains, fertilizers and feeds with a capacity of 500tph (tonnes per hour). All six conveyors have a length of 20,000mm and a width of 1,000mm.
Stainless steel conveyors
For the transportation of salt with a feed capacity of 900tph, de Regt Conveyor systems made a total of three conveyors . One conveyor has a length of 7,000mm, one conveyor has a length of 85,000mm and the third conveyor has a total length of 155,000mm. All conveyors have a width of 1,200mm and made out of stainless steel.
Recycling sorting line
A sorting line that holds a various of conveyor belts and a sorting cabin. One 17° inclination conveyor belt with a length of 12,000mm and a width of 1,400mm. The conveyor runs at a speed of 1m/s. Two conveyors with a inclination of 17° a total length of 22,500mm and a width of 1,000mm.
Mobile bunker with a swivel and sliding conveyor belt
Mobile bunker with a swivel and sliding conveyor for the transportation of coal, ore and
feeds with a capacity of 900tph (left). One mobile bunker, measuring 9,500mm × 3,500mm and with a content of 20m3.
Attached to the mobile bunker is a swivel and sliding conveyor mounted with a hydro motor.
De Regt Conveyorsystems’ most recent ongoing project is the construction of a mobile telescopic conveyor belt. This conveyor will have a capacity feed of 600tph and will carry fertilizers. The telescopic conveyor has a maximum length of 30,000mm, minimum of 19,000mm, width of 1,200mm and holds a chute of stainless steel.
Air-supported conveyors cut downtime and maintenance
Martin
® Air-Supported Conveyors are industry- proven to move bulk material with less maintenance, reduced cleanup and fewer operating headaches than conventional belt conveyors. The design uses a film of pressurized air released from a troughed pan to carry the belt and cargo. Air support for the belt eliminates the maintenance time and costs of installing, lubricating, maintaining and replacing idlers on the conveyor’s carrying side. The environmentally-friendly system is fully- enclosed to contain airborne dust and prevent wind erosion, with finely controlled tracking to reduce spillage and cut cleanup costs.
“Air-supported conveyors eliminate the carrying-side idlers used on conventional designs,” explained Martin Engineering’s European sales and marketing manager,Werner Baxmann. “By removing a source of friction and the need for periodic maintenance, air-supported designs can offer significant advantages, including energy, environmental and safety benefits,” he said. “With fewer friction points, there is also less wear on the belt’s bottom surface.”
Martin Air-Supported Conveyors are best suited for light to medium-duty applications where lump size is limited to 8 inches (200mm) or less, the cargo is loaded in the centre of the belt and loading zone impact and air entrainment levels are minimized. They can be used in new construction or retrofit conveyor upgrades, with system engineering and installation available from Martin Engineering.
The concept of the air-supported design is fairly simple, with the load zone and carrying sections contained in a plenum, which is pressurized by a centrifugal fan. The carrying surface of the plenum is typically shaped to roughly the same profile as a conventional belt conveyor, with a ~35o trough. Holes in the top of the plenum create an air film between the plenum and belt, which supports the moving load.
The size and distance between the holes are critical factors in designing an air-supported conveyor, with the holes centered under the belt to match the air pressure with the weight distribution of belt and cargo. By starting with the weight of the belt and the load, system designers can estimate the pressure needed to deliver about 1mm of lift, which requires minimal air volume in most applications.
The thin film of air can properly support loads and deliver high speed operation, while generating virtually no mechanical friction. The system needs no compressor, and is able to power up to 600 feet (183 metres) of conveyor, supported by a single low-power fan. Extremely low friction inherent to the design can reduce overall drive power requirements vs. conventional conveyors by as much as 30% on a horizontal run.
The return run does not require air support, and many systems incorporate conventional idlers on the return side.
By using standard take-up drives, chutes and support structures, the air-supported design allows conversions of, or connections to, existing standard belt conveyors.
The design is well suited to conveyors with a steep incline, where conventional designs can disturb the load sufficiently that it dislodges lumps and causes them to roll back down the belt. Limiting load disturbance minimizes this tendency and helps eliminate some of the dust
that can be caused by material interaction during transport. With its stable path, an air-supported conveyor can operate at a steeper incline than roller conveyors, which can reduce the overall length and installed cost in some applications.
Tracking accuracy is another advantage of the air- supported system. On conventional conveyors, belt tracking is typically accomplished by ‘knocking’ the idlers. Over time the repositioning of the idlers can be problematic, sometimes to the point of causing belt damage as the original path is altered. The use of air supported conveyors eliminates the need for idler adjustment to correct belt tracking issues. The benefits include extended belt life, reduced maintenance cost and improved safety by reducing employee exposure to moving components.
Best suited for light to moderate load weights, air- supported conveyors can now be found in many solids handling facilities that require excellent control of dust and spillage. That number is likely to increase, as plant owners and operators seek ways to step up fugitive material control to protect workers, reduce maintenance costs and facilitate good community relations.
While not appropriate for all applications, air-supported conveyors can offer significant improvements over conventional roller conveyors in certain applications. According to Baxmann, the key is to provide stable belt loading conditions to reduce impact and centre the load. “When installed in combination with engineered flow loading chutes, bulk material handlers can reap the benefits of clean, energy-efficient conveying, with lower maintenance requirements than roller conveyors,” he concluded.
Martin Air-Supported Conveyors can be used with engineered transfer chutes and accumulation-resistant support structures as part of the company’s New Architecture for Modern Conveying. The new architecture “re-thinks” many of a conveyor system’s design details, in particular as they relate to fugitive material control.
Founded in 1944, Martin Engineering a major force in making bulk materials handling cleaner, safer and more productive. The firm is headquartered in Neponset, IL, with global reach from operations in Brazil, China, France, Germany, Indonesia, Mexico, South Africa,Turkey, India and the UK.
Rulmeca celebrates 50 years
In 2012 Rulmeca, a major manufacturer of rollers for belt conveyors, is celebrating 50 years of activity.
Since it was founded in 1962 in Alme`, Bergamo in Italy, the company has undergone changes and has developed alongside the market. Its product offering has also developed, so that it has remained a relevant Italian entity, as well as the headquarters of the 22 Rulmeca companies worldwide, specializing in the production and sales of rollers, motorized pulleys and components for belt conveyors in bulk handling applications.
Behind the high quality of Rulmeca products there is a brand full of history, innovation, international evolution and research.
Rulmeca is a company that has produced rollers since 1962 thanks to the will and to the entrepreneurial spirit of the founder Antonio Ghisalberti.
During its early years, the company’s focus was on the development and manufacture of rollers for medium- and heavy-duty belt conveyors for quarries and mining applications.
The experience and expertise acquired over many years has allowed the company to grow constantly and to widen its product range.
At the beginning of the 1970s, thanks to its co-operation with Interroll, Rulmeca was able to increase its product range, adding all the components for the industry’s conveyors, for assembly lines and unit handling. Later, it added motorized pulleys and all the equipment for flow storage.
In the 1980s Rulmeca started to explore the international market with the first acquisition of competing foreign companies. Recently Rulmeca has kept its focus on the international market. Today, the Rulmeca Group comprises 22 manufacturing and/or sales companies with 1,100 employees and a turnover of €150 million , now managed by the Rulmeca Holding S.p.A.
Acquiring the most important quality certifications, both for the company and for its production processes, shows how much care Rulmeca puts into all aspects of its activities. Rulmeca has a large customer portfolio, covering a wide range of applications. this is partly due to its collaborative attitude, not only as a supplier but also as a partner. It constantly updates its production processes, and focuses particularly on the development of environmentally friendly products (recent examples include the eco-friendly thermoplastic roller TOP and the new Interroll ‘energy-saving’ EC310 RollerDrives).
Last but not least Rulmeca has always been very sensitive to the local area and community, offering donations and sponsorship especially in the field of art restorations and for the support to sports activities dedicated to children and the disabled.
Soft braking conveyor solution: 15 kilometres downhill!
LONG-DISTANCE DOWNHILL CONVEYORSConveyors are the most efficient equipment in industrial mines and metallurgical plants. But conveyors, like other heavy equipment, pose several hazards to employees. It is difficult to ensure the safety of the equipment, in particular with the long- distance downhill conveyor, where the operation is mostly unmanned due to its distance, terrain and profile.
Generally, long-distance conveyors move material uphill or uphill followed by downhill and along the surface of the earth. The challenge in designing the conveyors when different section combinations are loaded/empty causes natural instability.
With increase in tonnages and high negative lift conveyors with several hundred metres of drop, it is imperative to develop an intelligent soft braking system to address the starting and stopping requirements under various load conditions.
DAMANJODI MINE IN ORISSA STATE, INDIAThe Damanjodi Mine is situated in the Koraput district of State Orissa at the east coast of India. The conveyor was designed and installed in the early 1980s with a single distance of 14.7km and a deepest single downfall of 530 metres. This conveyor plays a vital role as life line to the alumina plant ore supply which was also built and commissioned in the early 1980s.
The challenge Supplied by Cable Belt UK and in operation for more than 25 years, the Damanjodi Downhill Conveyor is Asia’s longest downhill conveyor.
Initially, the conveyor belt was supplied with 2 x 1,050kW sync motors with dynamic resistor bank to generate braking in regenerative mode and with a battery backup — grid resistor bank for breaking during power failure.
Only a hydro pneumatic parking brake was provided, which was used only during stop and maintenance condition.
This article describes the critical design criteria on one of the largest regenerative conveyors overcoming disadvantages in mechanical braking systems and control technologies of the past.
Long distance special belt conveyor demands gradual application and release of brakes. The gradual application of brakes reduces the forces in the main belt member as well as longitudinal vibration along the conveyor. As the conveyor is a high inertia machine, the situation is more demanding when high inertial mass is resting on elastic tension belt members. Therefore, hydraulic operated soft braking disc brakes are more suitable and effective used for long distance, downhill, high speed and regenerative conveyors.
These disc brakes are capable of creating braking torque to full value gradually depending on need, which is adjustable through programming with multiple deceleration braking ramps. It also provides an option of rollback control for the uni- direction conveyor and, most importantly for uphill/downhill regenerative conveyors, the opening of braking can also be controlled in a gradual programmable way. The latter is done by continuously monitoring the conveyor’s speed by means of encoder and controlling the braking ramp action.
THE NEW BRAKING SOLUTIONDuring the operational period, it has often been necessary to stop the conveyor while it is running, which can be difficult. This challenge was overcome in 2008 after a review of site conditions and existing equipment. As a result of that review, the old sync motor control was replaced, and a new Svendborg Brakes disc brake solution was installed, with its intelligent programmable soft braking module for service and emergency braking needs.
It was a great challenge to carry out the contract to satisfy all the requirements, considering the condition of the existing equipment, and to provide a solution that could fulfil the full torque requirement of 2,500kW at 21rpm, with a braking torque requirement of 1,700KNm during service, emergency and power failure situations. During the refurbishment project the following major changes were considered:
- removal of existing synchronized motor and replacement with VFD grade induction motor and regenerative drive panel;
- introduction of failsafe disc brake solution with soft braking system;
- introduction of PLC-based control and SCADA.
This project was engineered, supplied and implemented in
February 2009 and has been operating successfully ever since.
SOBO (Soft Braking Option)
A specified braking time is achieved, almost independently of the applied load. The braking torque during soft braking will not reach the maximum level for instance during a sudden braking situation.
The overshoot and oscillations at the end of the braking sequence are minimized or eliminated.
To ensure a very fast response in case of emergency braking, one of the directional valves is drained directly to the tank, bypassing any throttle and accumulator that may slow down the system.
SOFT BRAKING SYSTEM ADVANTAGESBelt stretch is drastically reduced during emergency, worst case and normal stopping. This was concluded by observing the take up counter weight lifting by less than 2m as against general lift of 8–10m.
Each stop of the conveyor is in full control of operation to achieve the same stop time of belt leading to uninterrupted sequence operation of material feed.
The belt is ensured of uniform loading or no empty patch along the conveyor due to free run of conveyor for more than 20 minutes, compared to earlier non- controlled braking and during power failure.
The new brake control avoided manual unloading of material in the uphill position before starting, which was created due to uncontrolled run out of conveyor without controlled braking.
Full control and easy maintenance of the conveyor is possible with the SOBO braking solution.
Making the best choices in the design of bulk conveyor equipment
Some individuals try to limit the selection criteria to power consumption and initial cost only, but there are a number of other important criteria that must be considered when designing and selecting the proper conveying equipment as:
- mode of operation;
- capacity requirement;
- conveying distance;
- material characteristics;
- flexibility;
- environmental consideration; and
- process requirements.
The table (right) indicates conveyor choices on the basis of some common functions.
Experience may even vary from plant to plant. Often, a plant will use only specific types of conveyors, that particular selection based on past successes or failures, or a desire to standardize equipment. This practice is acceptable and even recommended, as long as the individual making the selection remembers that each type of conveyor has its proper application.
One of the most widely used mechanical conveyors today is the conventional troughed belt conveyor, especially because belt conveyors are the most useful due to the wide range of possibilities with dry and sticky material handling.
The troughed belt conveyor is not a complicated piece of equipment that is difficult to use: advances in belting, bearings, idlers, and pulleys have made the belt conveyor an economic, reliable method of conveying materials.
The belt conveyor can be used for conveying goods of different nature and in large quantities.
This feature of makes it suitable for use in different industries like cement, the chemical industry, the power industry and more. The cement industry relies heavily on belt conveyors handling
crushed rock from the quarry to the raw milling facilities. In
terms of capacity and distance, the only system capable of matching the belt conveyor is a fleet of trucks!
Bedeschi has implemented various systems. All the critical equipment is manufactured by Bedeschi in its production facilities under strict quality control.
A few material handling systems implemented by Bedeschi recently are as discussed below.
Scorpio Logistics — ‘Mara’ Project
Sometimes there is a requirement for large buffer storage, especially when the barging distance is large or cargo sourcing is varied. This was exactly the situation faced by Scorpio Logistics, when it decided to implement a system with large floating storage and a high loading rate. For this purpose, it was decided to convert the Panamax-size vessel Mara into a transshipper to be used for coal loading operations in Kalimantan, Indonesia.
The floating terminal Mara has storage of about 70,000 tonnes and is equipped with four cranes, two with extension arms and two without. The Bedeschi-supplied cargo handling system comprises two large hoppers each serving two cranes. The specially designed hoppers are capable of receiving coal from two cranes simultaneously. Basically, they are two hoppers each of 50m3 combined into one. The hoppers are equipped with variable-speed belt extractors leading to longitudinal conveyors systems moving in the opposite directions. The two conveyors converge onto a hopper to transfer the coal onto a transverse conveyor, which transports the coal across the beam of the transshipper onto the port side. On the port side, two large shiploaders are installed with swivelling and luffing capabilities. They have also been fitted with retractable delivery booms, to enable delivery of coal into all the parts of the OGVs’ (ocean-going vessels) holds. The system has the capability of loading coal at a daily rate exceeding 60,000 tonnes per day. The advantage of having a large floating storage is that the loading operations can take place even when there are no barges alongside. Several belt conveyors have been installed with widths from 1,600mm up to 2,000mm and capacities ranging from 1,500tph up to 4,000tph coal.
The system is operating in Kalimantan and is loading at rates exceeding 75,000 tonnes per day. It also has the capability of blending two grades of coal and delivers a homogeneous grade.
The annual capacity of the system is in excess of 15 million tonnes, which has helped the user Glencore to significantly increase its competitiveness.
Aitbaha (Morocco) new Italcementi plant
In the summer of 2008, Ciments du Maroc (Italcementi Group) awarded Bedeschi the contract for the complete handling and storage section of the new greenfield plant in the Ait Baha Agadir region, south of Morocco.
The project includes the design, manufacturing, supply and erection of:
y four receiving stations for the different raw materials; y four longitudinal storages unit for limestone, clay additives and
petcoke; y approximately 4km of several belt conveyors with a capacity
from 500tph (tonnes per hour) up to 1,500tph; and y several bag filters to dedust transfer points and receiving
station
The commissioning of the plant is in progress and will be completed shortly. To date, the moment belt conveyors, stackers and reclaimers are completely assembled.
The main conveyor from quarry to the plant has a length of approximately 1,600m and a capacity of up to 1,000ph. The design was elaborated considering different ground levels and site restrictions as well as strict design criteria given by the client and by the Socotec, the local Company approving all the detailed design.The conveyor is transferring limestone from the quarry up to the storage inside the plant.