Fitted with four load hooks, the Demag LDC-Q quadro chain hoist allows different load handling attachments to be lifted and transported at the same time. The available LDC-Q sizes enable loads weighing up to 3.2 t to be handled safely and efficiently.

The Demag LDC-Q quadro chain hoist, a series hoist unit from Demag’s DC range that has a successful track record all over the world, can be used for a wide variety of handling requirements in production and logistics applications. Equipped with four load hooks, LDC-Q units can handle and transport customer-specific load handling attachments or flat components and feed materials to the relevant workstations.

Demag LDC-Q quadro chain hoist design with four load hooksDemag LDC-Q quadro chain hoist design with four load hooks

 The basis for this broad range of applications is the technology offered by the LDC-D double chain hoist and some dedicated characteristics. For example, these include a design that combines two double chain hoists which have only one drive, which is a special technical feature. This means that only one chain hoist motor transfers power to the other three chain lead-offs of the Demag LDC-Q quadro unit via corresponding connections. Mechanically synchronised hook lead-offs provide for uniform and precise load handling. This arrangement enables loads with an asymmetrical weight distribution up to a ratio of 70:30 to be picked up without any problems.

 ProHub integrated variable speed control, which is a feature unique to Demag chain hoists, also permits rated speeds of up to 90 percent higher in the partial load range.Operators can utilise sizes DC 10 and DC 25 for handling loads weighing up to 3.2 t. The Demag LDC-Q quadro chain hoist offers benefits for safe and efficient lifting. Operation of the control unit with low voltage (24 V contactor control) as well as smooth starting and braking for low load sway are also significant factors. Further safety-related functions satisfy at least Performance Level c and Category 2 to EN ISO 13849-1.

 Besides safety, service is also of major importance. The generously dimensioned slipping clutch and gearbox, which is maintenance-free for up to 10 years, as well as fast and simple maintenance of individual components thanks to its modular design, help to make the Demag LDC-Q quadro chain hoist easy to service. These are all important aspects that minimise downtimes and extend the unit’s service life for improved productivity.

 For control of the Demag LDC-Q quadro chain hoist, operators also benefit from DSC/DSE control pendants with their low-fatigue actuation force for improved ergonomics. To meet specific ergonomics needs, operators can choose between radio controls or cable-connected control pendants that can be integrated into stationary control units.

 And ultimately, 2D and 3D geometry models in the Demag Designer tool give owners the opportunity to view a potential solution and its precise arrangement in their existing building and machinery infrastructure already at the pre-planning stage.

Published inMachinery
Thursday, 28 January 2016 10:17

Makeover for two overhead travelling cranes

With a comprehensive modernisation package, Demag Service has given two identical double-girder travelling cranes a makeover at the Albbruck-Dogern (RADAG) hydrolectric power station. Following extensive work on the drive and control systems, both of the overhead travelling cranes, which are now more than 80 years old, meet state-of-the-art requirements and ensure high availability to support the replacement of machine parts.

Modernisation concept with demanding requirements

The two double-girder overhead travelling cranes were each equipped with a 150 t hoist unit and a cantilever crab to be able to perform repair work on the turbines and to replace machine parts. Besides the modernisation of the drive systems for three motion axes, the customer also wanted the entire electric equipment on the cranes to be replaced and a crane control system with safety functions to be installed. The availability of one crane installation had to be ensured throughout the entire conversion phase.

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In order to lift the components, which weigh more than a ton, to the working level, Demag Service first installed a I-beam girder with a chain hoist below the building’s roof structure. This additional lifting device was the key for the logistics challenges at this construction site.

Carolin Paulus, Vice President Service and globally responsible for Demag Service, explains: “The demanding challenges of this project already became obvious during the planning phase. Besides a strong technical solution, the customer also needed an experienced team that not only covers the various disciplines required for crane and hoist applications, but also delivers performance and ensures reliable installation and smooth logistics on site.”

Lifting solution for 150 tons

The first requirement involved the replacement of the drive units on both of the 150 t hoist units, which had an additional intermediate gearbox. On the basis of a fresh survey, Demag Service designed a shaft with which the output of the new hoist motor is transferred to the gearbox. The integration of a safe dual-channel load sensor system in the steel superstructure of the existing crabs ensured that further requirements were met for the new lifting solution.

Improved flexibility with additional hoist units

Due to the limited capacities of the crab, the Demag modernisation experts developed a stand-alone tender solution which is mechanically coupled with the main crab for a second hoist unit. Thanks to its faster lifting speeds and smaller bottom block, the customer uses this 10 t hoist as a co-axial unit for flexible maintenance and repair work.

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Previously, an additional hoist unit had travelled along the outer edge of the crane girder on a cantilever crab. This arrangement offers the advantage of also reaching the edges of the workshop with the crane hook. The installation of a new cantilever crab of compact design with a Demag 6.3 t rope hoist met the need for a versatile lifting device.

Drive concept with frequency inverter

The installation of a railing on the inside of the crane bridge as additional protection against falling provides for improved safety. All work on the walkways had to utilise bolted connections, since the riveted steelwork precluded any welding due to the expected deformation caused by the higher temperatures.

The previous complicated power supply line via a cable drum with a power infeed point in the centre of the workshop was replaced by a narrow conductor line system installed beneath the crane runway. The crabs are now supplied via trailing cable lines that are suspended from KBK 25 profile sections.

Makeover with state-of-the-art control system

The integration of many electronic components has enabled both overhead travelling cranes to bridge a technological gap of more eight decades and their control systems are now on par with those of current process cranes. To this end, a Siemens S7 failsafe PLC was installed which communicates via Profibus and Profinet.

The hoist unit and supporting structure are protected against overloads by the electronic load detector. The load spectrum recorder records all loads on the hoist units during operation.

Thanks to the new control system, synchronised operation of both cranes is ensured in tandem mode for the main lifting and cross-travel motions. In addition, run-on of the cross-travel drives has been synchronised. This enables the cranes to safely lift and transport the turbines and other large-volume parts of the installation, for example. To do this, both cranes communicate over a reliable Profinet connection via an optical data transfer system.

The inverter systems integrated into the installation also features power recovery, with which any superfluous energy can be utilised.

The cranes can be controlled at a convenient distance from the load via a radio control system that was also included in the modernisation package. The crane operator can also receive important status information and messages via the display on the radio transmitter.

Following the modernisation work, the crane still has some open gear components, which have to be reliably maintained. In the past, this had to be done regularly by hand. Today, the task is performed by a central lubrication system, which pumps the required lubricants to the various points where they are needed at specified intervals.

Hydroelectric power station for eco-friendly power generation

The Rheinkraftwerk Albbruck-Dogern hydroelectric power station (RADAG) was built between 1930 and 1933 on the border between Germany and Switzerland. As a running-water power station, it utilises the course of the Rhine to generate eco-friendly regenerative energy. Three Kaplan turbines that each have a capacity of 350 m³/s operate in the machine shop of the Rheinraftwerk Albbruck-Dogern hydroelectric power station (RADAG), which entered service in 1933. Together with a weir power plant at the same location, the operating company Schluchseewerk AG generates an average of 650 million Kilowatt hours of electricity for 180,000 households every year without emitting any CO2.

Published inProduction

Vince Maynard see's first hand the latest innovation from Terex Material Handling & Port Solutions

Terex Material Handling has launched a new generation of cranes which sets a new standard in the industry with its Demag V-type crane. Thanks to its V-type design, which uses less material and helps to save resources, the V-type girder weighs on average 17 per cent less than comparable box-section profile girders. The reduced crane deadweight produces less wheel pressure, minimises the forces transmitted to the existing building structure and increases the maximum load capacity. Consequently, the new Demag V-type crane gives architects greater freedom for planning new factory buildings and is also suitable for companies that want to employ it in existing assembly and production bays.

  • 17 per cent less deadweight than cranes with box-section girders
  • Oscillation characteristics cut by up to 30 per cent
  • More than 500,000 changes of load double the service life

The design (patent pending), which features diaphragm joints, also cuts oscillation of the crane girder by up to 30 per cent. The reduced oscillation characteristics cause lower loads to be transmitted to the crane and its components, as well as to the entire building, and double the service life of the crane to more than 500,000 changes of load. In addition, the improved oscillation characteristics enable heavy and sensitive loads, such as glass panels, fluids or aluminium shell sections for aircraft, to be positioned more precisely and quickly.

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“The new V-type girder is the result of our continuous development in the crane engineering sector”, explains Andreas Hambrock, Head of the Universal Cranes Business Line at Terex Material Handling. “The new crane is an ideal supplement to our existing range of rolled and box-section girders. Thanks to its special design, sensitive loads can also be transported safely and precisely indoors and in outdoor applications. We are now able to cater to our customers‘ needs even better and can offer them solutions to meet their specific load handling requirements, boost their productivity and, at the same time, improve their operating safety.”

The new Demag V-type girder is initially available as a single-girder crane on the German market. It can be employed for various crane types, such as overhead travelling cranes, suspension cranes, portal cranes or wall-mounted travelling cranes.

Demag V-type crane: versatile, fast, long service life

Oscillation is a natural phenomenon that occurs in cranes. Lifting and travel motions result in forces that can cause a crane to resonate. That not only subjects the crane to loads. If the crane oscillates too much, it becomes difficult for the crane operator to handle loads precisely.

Terex Material Handling has developed a crane that is specially designed for transporting sensitive loads with its Demag V-type crane.

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V-type design for efficient material flow
Whether for logistics contractors, aircraft manufacturers or steel producers – all sectors of in- dustry now face strong international competition. To maintain their position in today’s market, they need optimum efficiency throughout their material flow processes. “That already begins with fast and precise load handling”, explains Andreas Hambrock, Head of the Universal Cranes Business Line at Terex Material Handling. “We want to give our customers the best possible support with our cranes.” For this reason, the development of the Demag V-type crane focussed on factors such as handling rates, a high lifting-capacity-to-deadweight ratio, high load capacity and stability. Cost effectiveness and the certainty of a reliable investment also played an important role. “The goal of our engineers was to design a high-performance crane that operates with a high level of precision for a lower weight and longer service life.”

The result is a new design. “The crane girder is designed according to bionic engineering principles based on nature”, explains Andreas Hambrock. In a similar way to bone structure, material is only employed where it is necessary. Parts that are subjected to high loads are provided with additional stiffeners. “Diaphragm joints provide for optimum dissipation of force and, at the same time, an even distribution of pressure and tensile forces. That makes the Demag V-type crane extremely resilient to loads.” The result is a crane girder that weighs up to 17 per cent less, has up to 30 per cent less oscillation and offers double the service life. Terex Material Handling has patents pending for the new technologies incorporated in the Demag V-type crane.

Lower deadweight, higher load capacity
Thanks to its V-type design, Terex Material Handling has cut the deadweight of the Demag V-type girder by an average of 17 per cent with reference to a comparable box-section girder. This enables companies to utilise any reserves offered by their building structures and – de- pending on the load classification of the relevant rope hoists – to increase the lifting capacity of their installations even further. In this way, they are able to transport greater loads and no longer have to operate in the upper load capacity range. The lower deadweight also means that V-type cranes exert lower wheel pressures and transmit lower loads to the existing build- ing structure. Cranes can be integrated into existing workshops, assembly and production bays, often without the need for costly building refurbishment or changes to the building superstruc- ture. In addition, the eco-friendly use of materials also helps to protect the environment.

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Lower oscillation and improved precision
The optimised deadweight-to-lifting ratio and improved dissipation of force enable the crane to steady the load more quickly. Crane owners benefit from higher performance and improved handling rates, since crane operators can position valuable and sensitive loads, such as glass panels, fluids and aluminium shell sections for aircraft, more gently and precisely.
And this can already be accomplished without the need for electronic control systems. The

Demag V-type crane as standard already offers more performance.
A further benefit: thanks to its reduced oscillation characteristics, the entire crane installation, including its components, the crane runway and its supports as well as the building and its foundations are subjected to lower loads. This is reflected by reduced wear, for example. In addition, the crane also boosts cost-effectiveness, since heavier loads can be moved in exist- ing building without the need for companies to modify the building structure. Furthermore: the Demag V-type crane can manage some 500,000 changes of load and, therefore, can achieve double the service life with reference to a comparable crane that has a box-section girder. That provides greater certainty of a reliable investment.

One crane to meet all requirements worldwide
Thanks to its new design, the V-type crane is also suitable for outdoor operation, since its surface area that is exposed to the wind is up to 55 per cent smaller in comparison with crane that has a box-section girder. For indoor operation, the girder allows 30 per cent more light to pass in comparison with conventional box-section girders, which provides for a brighter and more attractive working environment. The improved light situation also allows companies to save costs for indoor lighting. Besides allowing more light to pass through, the improved view also benefits safety at the workplace: users have an improved field of view and can see what is happening on the other side of the crane.

Compared to enclosed box-section girders, this benefit also pays off for service technicians, who can view the workshop through the crane girder. Since the design of the V-type crane affords a view of all weld seams, inspections and maintenance work can be carried out more easily.

In principle, most of the drive motor output is needed simply to move the crane. A further benefit of the new Demag V-type crane: the lower crane deadweight may enable motors with a reduced rating to be employed for improved energy efficiency. That saves operating costs and is kinder to the environment.

Emphasis was also placed on eco-friendly manufacturing processes for production of the crane. For example: the crane is blast-cleaned with dry ice before it is painted. The actual paints are water-soluble, thus avoiding the use of solvents that are harmful to the environment.

At the product launch, the Demag V-type crane will initially be available in single-girder design in the form of overhead travelling, suspension, portal and wall-mounted travelling cranes.

The overhead travelling and suspension cranes are available with spans of up to 30 metres and cover load capacities up to 12.5 tonnes. The Demag V-type crane is initially available in five different model variants for an optimum match with individual building contours. Depending on the situation – such as a bevelled or sloping inclined roof or installed pipes and conduits – the shape of the crane girder end will vary accordingly. Thanks to the new variable design, the V-type crane can be adapted with millimetre accuracy to the height of existing or planned buildings and modified in line with specific needs. Experienced Demag sales engineers can configure the best possible girder design for the given application based on customer wishes with a completely new Designer Tool in advance. Example for the height: depending on how much space is available between the crane runway and the lower edge of the building, the corresponding X and U dimensions are entered into the Crane Designer system to determine the optimum height of the crane.

 

Published inProcessing