Far beyond driven - drives and control systems

THE CONDITION-MONITORING-SYSTEM CONTROLS SHIFTING FORCES AND DIRECTLY INTERVENES IF ANY PROBLEMS OCCUR.

Machine stoppages can’t always be fully avoided — even with most extensive precautionary measures. When energy supply systems are open, parts or tools can fall into the chain and block the motion. The possible consequence: damages that require partial or complete replacement of the chain and the guided cables.

In these cases, to keep damages to a minimum, igus offers the appropriated ‘Push Pull Force Detection System’ (PPDS) for such applications. igus could significantly reduce the space requirement due to the use of state-of-the-art electronic components: previous and partly clumsy switchboxes for evaluation units of shrink about two-thirds in size and price. With it the ‘brain of the energy chain’ now becomes cost- effective standard equipment.

RELIABLE PREVENTION OF DAMAGES

It has been ten years since igus introduced the first PPDS. Its function: the PPDS monitors occurring shifting forces at energy chains. If something blocks the motion, shifting forces increase. From a firmly defined threshold value, PPDS sends a signal to the system control to stop all motors. This avoids severe damages at the energy chains and the cables. The field of application of the PPDS family starts at travels of 10 metres and reaches up to plants with travels of 500 metres and more.

COMPACT MONITORING OF THE STATE FOR ALL SIZES

To monitor ways between 10 and 100 metres, the especially cheap PPDS basic has been part of the igus programme since 2012. It registers shifting forces via two small sensors that are located between the connecting element of the energy chain and the towing arm. The evaluation unit PPDS.EU.01 displays the forces, records occurring exceeding of the limit values and in case of emergency — sends the signal to the machine control.A complete system inclusively sensors, evaluation unit and connection cable is available from stock for less than €1,000.

For travels of 100 metres and more, the floating moving ends are used to compensate lateral tolerances during the floating end drive. For this purpose igus provides the PPDS advanced with a special sensor variant. This allows reliable monitoring of shifting forces also in this case. In the heavy-duty area with its very long travels and high additional loads, igus offers the PPDS pro. It is particularly designed for the application, controls shifting forces on the basis of position dependent limit values. Previously an evaluation for the systems advanced and pro, clumsy switchboxes were used, whereas today thanks to smart electronics, a compact unit of the protection class IP65 — smaller than a DIN A4 sheet — overtakes this task.

igus GmbH is a world-leading manufacturer in the field of energy chain systems and polymer plain bearings. The family-run company is based in Cologne, represented in 29 countries and contracts 2,200 employees worldwide. In 2012 igus generated a turnover of €399 million. igus operates the largest test laboratories and fabrics in its branch to offer customers innovative and tailor-made products and solutions within the shortest time.

Nimble giant

This sludge processing plant was planned, constructed and commissioned over a period of only 30 months. Its key components are an arched bridge as well as two mobile, high- performance pumps that transfer the sludge by means of extremely stable and thick hoses. The largest plastic energy chain in the world today is used to reliably guide the heavy hoses.

Despite the enormous filling weights, this chain guarantees the anticipated long service life of the entire plant. From the very first day, the plant construction company and system supplier successfully collaborated during the design of this large- scale project. This early collaboration is now bearing fruit.

The Port of Antwerp is the largest port in Belgium. More than 187mt (million tonnes) of freight was cleared during 2011 alone. With these figures it can be counted among the largest ports in Europe and the world. “In the interests of smooth loading and unloading operations, the shipping lanes must always remain open, thus permitting the gigantic container ships to clear their loads as quickly as possible,” emphasizes Joury van Gijseghem from the specialized company, DEME. The Belgian company specializes in, among other things, the maintenance and dredging of shipping channels, land reclamation, and offshore oil and gas services.

Because the available space to deposit dredged sediments has continued to shrink over time, alternatives needed to be found. The Port Authority and Flemish authorities have now decided to invest in a state of the art mechanical sludge dewatering plant that conforms to the latest ecological standards. After the shipping channels have been dredged, the roughly-sorted sediments are pumped through a pressurized pipeline to the plant at a distance of 4km, where they are mechanically dewatered, processed in an environmentally-friendly manner and then stored. Nearly 500,000 tonnes per year are processed this way. The ambitious project was christened under the name ‘AMORAS’ (Antwerp Mechanical Dewatering, Recycling and Application of Sludge). A consortium of companies, ‘SeReAnt’, of which DEME is a member, is responsible for the construction and entire operation of the plant.

FIFTEEN YEARS OF OPERATIONAL RELIABILITY

The planning and construction of the sludge processing plant took approximately 30 months and concluded at the end of 2010. Once finished it became operational for a period of no less than 15 years. “And these 15 years are set in stone”, claims Joury van Gijseghem. As project manager, he is responsible for the planning and operation of the exterior plant. “All key components were designed for this minimum operational period.” But the requirements profile goes a step further. The dewatering plant is in continual use nearly 365 days per year. Operational reliability is paramount. Unnecessary maintenance and downtime must be avoided.

A central component of the sludge processing plant is an imposing arched bridge with a span of nearly 180m in the exterior grounds. Two mobile, independently operated high- performance pumps are mounted on the rotating bridge. These pumps travel a distance of nearly 140m at a maximum speed of 15m/min by means of an energy chain. The excavator pumps vacuum roughly 600m3 of sediment or sludge every hour from the sediment basin below and convey the sludge through enormous hoses, with a diameter of 300mm, for further processing. The basins are partitioned into four sections. Each has a capacity of roughly 120,000m3.

An extremely robust polymer chain from igus GmbH, Cologne, is used to reliably guide the hoses across the entire distance. The maintenance-free E4.350 model can be opened from both sides and is from the E4.1 series, which has proven itself in countless applications. It has demonstrated its versatility in composting and water treatment plants, machine tools and construction equipment, crane technology and wood processing, among others.

TESTED UNDER REAL-LIFE CONDITIONS

The tests show that the energy chain has no difficulty guiding even voluminous and heavy loads. A special design using glide rollers was developed to perfectly guide the hose within the energy chain and to minimize the resulting mechanical abrasion. These rollers, made from the tribologically optimized bearing material iglidur J, are integrated into the opening crossbars. Light, corrosion-free and insensitive to dirt, they ensure that the energy supply system can glide without problem around-the- clock. This significantly reduces the friction caused by the hose in the chain, thereby ensuring stability. “For this and comparable cases, where we wish to supply our customers with ideally adapted solutions, our expertise in developing special plastic materials continues to pay dividends, in that we have the required know-how under our own roof. The variety of special plastic materials from the energy chain and bearing field, in combination with our in-house test laboratory, gives us the ability to conduct on-the-spot tests under realistic conditions, resulting in the best solution for the customer,” states a confident Frank Schlögel.

“We were also convinced by the fact that the entire energy chain system is very compact,” reminisces Joury van Gijseghem. "This was genuinely important to us, for instance, because we had to deploy drive cables in addition to the hoses, and could not provide an unlimited amount of space.” Moreover, in comparison to a steel chain, the plastic chain is much lighter. This not only provides savings on the required drive rating on the travelling pump systems, but also in the weight of the overall rotating bridge system. The rollers integrated into the load bearing surface of the chain links additionally reduce the displacement forces by up to 75%. “For example, we can use smaller motors. On the one hand, these are less expensive, and on the other, the weight load on the bridge is further reduced. This in turn improves economic feasibility.”

A specially-designed guide trough made of hot-dipped galvanized steel and floating moving ends are deployed in addition to the energy supply. These are needed to compensate for potential lateral displacement tolerances. The energy chain, which is filled with hoses and cables, is now always reliably guided over the entire length under any weather conditions. Despite operational difficulties and environmental conditions, no failures have been recorded to the present day.

INCREASED OPERATIONAL RELIABILITY BY MEANS OF AUTOMATIC MONITORING It was decided to integrate the PPDS (Push Pull Force Detection System) monitoring system in order to increase the operational reliability of the bridge design. The diagnostic tool, which in particular has proven to work over long distances, continuously measures the push/pull forces on the energy chain and compares these with a calculated target value. Should malfunctions occur, the plant is automatically stopped as a preventative measure to avoid damage. “At any time, we can also consult the data stored on our data server retroactively,” the project manager confirms. “We are therefore always on the safe side, and, if needed, have enough advance notice to schedule maintenance and service work.”

COMPELLING PROJECT EXPERTISE

The decision in favour of the relatively light-weight, plastic energy supply system was made quickly. From the very first day, both companies confidently co-operated on the engineering process.

For one, this relates to the complex design process of the bridge structure. A host of design drawings for the respective project status were readily made available. The extensive laboratory tests, conducted in advance, also provided compelling evidence. According to Joury van Gijseghem,“the sustained support during this large-scale project ultimately led to success.” “Our combined efforts from the first to the last day made this project possible.”

The plant construction company also relied on the available assembly expertise. The energy supply system specialist configured and installed the entire system on site and on time, while utilizing its own employees and assistance from the construction site. The system has been operating without a problem from day one. “At no time have we regretted the decision to use the plastic energy supply system,” Joury van Gijseghem emphatically concludes.“We also benefitted greatly from bringing the system supplier into the project from the very beginning. From the very start all the way through system acceptance, our excellent collaboration contributed greatly to the smooth execution of the project”.

DBIS (Software and Automation) Ltd has recently delivered its KPI dashboard tool to a number of clients.

DBIS delivers terminal management software to bulk operators and currently has 24 operational systems on four continents.

In 2012 DBIS hosted a User Group Meeting where their clients from around the world gathered to discuss new developments and topical issues from the industry. The outcomes of the meeting were used to create the product roadmap for DBIS and one key item was a KPI Dashboard, which could be accessed via the web and provide operational data to key stakeholders in real time.

The objective was to utilize data mined from the automation systems to ensure that the dashboards presented the user with a true account of events in the timeliest manner. Interfaces to PLC and SCADA systems would be required to make this possible and therefore only an organization with expertise in both automation and IT systems would have the capability to deliver the required systems.

The German company SIBRE (Siegerland Bremsen GmbH) is a system supplier with representatives throughout the world and operates production branches in China and sales and service branches in India, Spain, Italy and the USA. The current portfolio is characterized by a wide breadth and depth of standardized industrial brakes and components for drive technology.

The drum coupling ABC-V is optimally in line with the distribution channels and the one-stop-supplier-strategy of SIBRE. The drum coupling is completely designed and made in the German headquarter. The design of the SIBRE drum coupling is performed on the basis of the steel iron guidelines (Stahl-Eisen-Betriebsblatt) SEB 666 212. Due to compatible fitting sizes,ABC-V couplings are interchangeable with various series of barrel couplings on the market.

Launched in 2010, the ABC-V is specifically designed for the transfer of medium and high torques in crane hoists, conveyors, stackers, ship unloaders, container cranes as well as in heavy, rough smelting works. Torques of up to 1,025kNm and radial loads of up to 550kN can be transferred with a maximum coupling diameter of 1,025mm, which provides a high overload safety.

High quality coated forged steel guarantees durability, wear resistance and high material strength. Together with the arched barrel rollers (hardened roller bearing steel) the hub can oscillate relative to the housing. This allows for a compensation of angular displacement up to ±1° and an axial shifting from ±4mm up to ±10mm.The increased capacity of the ABC-V results from an optimized geometry of torque-transmitting components. Quenched and tempered hub- and gear teeth provide a high wear resistance.

GENERAL ASSEMBLY

The drum coupling largely consists of an axially fitted hub part and housing part. Barrel pockets are equally arranged in the intersection of hub and housing. The torque transmission of the hub part onto the housing part occurs with positive locking. Hardened barrel rollers are fit into the barrel pockets, which are formed from the two circular gearings, as power transmission elements. The sealing of the coupling is achieved through double-sided covers with lip seals. This prevents escape of lubricant from the coupling and the intrusion of dirt into the coupling. The semicircular gearing of the hub over the outer diameter is crowned.

CONSTRUCTIONAL ADVANTAGES

Together with the arched drum roll it is possible for the hub to oscillate relative to the housing part, therefore angular displacement and axial shifting are also possible as above- mentioned. Due to the convex and concave fit of the barrel roller to the coupling hub and the coupling’s exterior housing, the forces are spread across a large contact surface which leads to favourable compressive forces.

The coupling housing comes with a flange for bolting the coupling e.g. to the rope drum. The transmission of momentum between the coupling and the rope drum occurs partially by friction and partially by interlocking form fit of the oppositely lying camming surfaces of the housing. Grade 10.9 high-tension bolts are to be used as connection bolts. The coupling is built with visual wear and position display. Thanks to a wear cam on the housing part and wear grooves on the hub part, the wear on the coupling gearing can be easily checked from the side of the coupling. The wear cam further serves for checking the axial location of the coupling housing to the coupling hub.