Technische BeschreibungThe conveyor technology specialist SEH Engineering installs conveyor systems in foundries that can withstand the rough production conditions. Now the company has developed a planning technology that uses 3-D scanners to visualize and fit conveyor systems in foundry halls. In this way, existing machines, factory aisles and building constructions are taken into account and thus errors in the design of the conveyor systems are avoided.
By Holger Schmidt, Ostrhauderfehn
Foundries in Germany manufacture high-quality components and parts of more than 5 million tonnes of metal per year. Among these metallic materials are iron, steel, aluminium, copper, zinc and magnesium, which, after being processed, not only fulfil important functions in road vehicle construction, but are also used in mechanical engineering, electrical engineering, aerospace and medical technology. However, before they can be used there, cast components undergo various multi-stage processes. Especially in mold and model making, casting of the molten metal and subsequent machining, manufacturers often face the challenge of moving heavy parts in the production plant. The use of conveyor technology helps significantly in production, but must meet all specific requirements and conditions in order to be both reliable and efficient.
Not every conveyor system can be used
External conditions in foundries determine the choice and use of conveying systems significantly. The systems not only have to transport the goods, but also withstand extreme external influences such as extreme heat, dirt and steam. Technically innovative solutions such as modern electric monorail systems rarely succeed under these conditions. The weight of the elements to be conveyed also determines the choice of conveyor technology. Castings from a few kilograms up to several tons have to be handled and transported daily.
Flexible process despite high loads
In harsh environments such as foundries, cardan chain or especially drop forged rivetless chain conveyors are used due to their high temperature resistance. Highly stable steel and cast iron components ensure the required sturdiness of these systems. However, thanks to their conveyor system elements, such as permanently lubricated rollers, the operating costs are low. Both Power-and-Free cardan and drop forged rivetless chain conveyors offer individual possibilities in line layout, as they can be adapted flexibly and thus efficiently to the respective conditions and circumstances according to the modular principle. The free rail carries the load, which is transported by the trolley train with the continuous chain. The trolley train is engaged or disengaged as required at stopping points or in areas of the buffering system. The resulting possibility of multiple buffer and storage points as well as machining stations along the production line proves to be particularly advantageous. Thus, individual castings can be removed from the production chain if the curing times vary in length without impeding ongoing operations or even stopping them. In order to place them back in the right place in the predefined sequence at a later point in time, additional routings, so-called bypasses, allow the conveyed material to be subsequently inserted at the original position.
New possibilities for the conventional drop forged rivetless chain
Due to their load capacity, drop forged rivetless chain systems in particular are among the conventional conveyor systems in foundry operations. However, the standard plug-in chain conveyor is oversized for die-cast aluminium with smaller unit weights of less than 500 kilograms. The solution here is a hybrid system form, which combines the robust drop forged rivetless chain with the cost-effective elements of the power-and-free technology of the cardan system. Above all, due to its high compatibility with other systems, the cardanic system can be integrated perfectly into the drop forged rivetless chain system technology. In order to guarantee both the functionality and the efficiency of the system combination, components of the cardanic conveyor system such as curves, switches, stoppers, drive and inclined conveying lines had to be newly developed and designed for operation with the drop forged rivetless chain. For particularly low-maintenance and long-lasting operation of the system, system engineers integrated, for example, an automatic lubrication station for chain and trolley trains. As this hybrid system form has proven itself in the harsh foundry environment, it is now one of the standard systems in conveyor technology.
Efficient management of changes in the production environment
Even in an industry rich in tradition such as foundries, production environments change when process technologies are expanded, storage conditions are changed or conveyor systems are renewed. When modernising, companies should use space and time as efficiently as possible, because wasted space costs money and prevents optimum capacity utilisation. It is not always necessary to buy a completely new system, as components can often be improved and reused. However, the integration of new conveyor systems requires careful planning and flexibility in component production, especially when combining system elements from different manufacturers.
Recycling instead of decommissioning – with safety
If companies refurbish and reuse old equipment, the cost savings are massive compared to purchasing new equipment. Here it is possible to combine an existing design principle with a new chain system. However, cooperation with a supplier who manufactures and can adapt the parts themselves has proven to be useful. The so-called re-use project follows the following procedure: Careful dismantling of the system is followed by reconditioning of the individual components, replacement of all wear parts and the installation of rail elements. If necessary, conveyor technology specialists often make quick adjustments and produce specific components to prepare the system in the best possible way, because standard parts cannot be optimally integrated everywhere. This also includes the renewal of control, drive and safety technology to meet all current safety standards. In this context, the safety of the plant itself is particularly important if the work processes are to run smoothly in the production environment of a foundry, which is by itself already dangerous. Each production facility has individual challenges that need to be overcome. Fully functional test facilities are therefore built as required in order to reliably clarify the technical integration of the system. All newly developed and to be integrated technologies and conveyors are thus checked in detail in advance so that the functionality of the conveyor system is ensured during and after the construction at the customer’s site.
Precise planning with Predictive Engineering
Detailed planning and implementation of a conveyor system requires precise knowledge of the environment. If planning is too narrow or wrong, this prevents a smooth material flow in the operative implementation. In order to avoid errors and problems right from the start of the project, SEH Engineering GmbH, which specializes in conveyor technology, has developed the so-called Predictive Engineering. This planning technology captures the entire shop floor in its current state using 3-D scanners – with all possible interfering contours. This includes precise information about already installed systems, machine paths or building technology designs, which must be taken into account in the planning. But planning alone is not everything. For this reason, Predictive Engineering provides a combination of computer-aided design with on-site comparison via augmented reality and virtual reality. Design ideas can be visualized in real format even before the beginning of planning so that contractors can see the planned system on a monitor, walk around the room and find out all the requirements for the production line. Besides identifying potential pitfalls during the planning phase, continuous monitoring also helps in the engineering phase to detect and regulate deviations at an early stage. Clash detection (collision control) helps to ensure that conveyor technology and steel construction do not collide with existing equipment at any point. Precise planning thus ensures cost-effective installation as well as efficient and optimal use of the available space in the production facility.
Author: Holger Schmidt, Managing Director of the SEH site in Ostrhauderfehn