You can find them in the Australian mine, on the high sea or in skiing areas – chains of Thiele from Iserlohn between Ruhr and Sauerland. The treasure trove of experience of the family-owned company, which was founded in 1935 on the current location, reaches from filigree snow chains up to huge anchor rode that fixes oil platforms. It is not any longer just about the mere combination of chain links. Together with research institutes the company develops intelligent chains that are equipped with strain gauge strips and a small chip as well as complete conveying systems for the mining.
Despite the gigantic measures of the chain links, highest precision is required in this field too. Smallest tilting of the drag chain conveyors, which are moved through a pair of chains, could result considerable abrasion which could lead in attrition or even a stoppage of the plant. For this reason quality control is very important for Thiele and all processes are permanently monitored and optimized regularly.
STEP7 solutions are preferred
Andreas Kemper, responsible for the electrical engineering at Thiele, ensures that the down times of the machines, which are in non-stop operation on the 40,000 m² of production area, are reduced to a minimum. “If somewhere a fault appears each of the 10 employees of the electrical workshop has to be able to repair, so the production can continue without interruption”, he says. After all the company with the long-standing tradition has full order books and works in the three-shift operation – so maintenance and reparations have to be done as fast as possible. For this reason Thiele decided to rely on consistently STEP7 programmable solutions that are familiar to all. As a supplier VIPA was selected by Andreas Kemper for more than 10 years. Primarily because of the compact design of the VIPA 200V series with which he was able to modernize old S5 controllers without the need of rebuilding the complete control cubicle. Further advantages are the easy installation via connectors and the possibility to change the hardware at first, so that the old S5 program is still in operation and only later to convert to an identical S7 CPU. “So I am able to replace the old defective hardware and still keep the system in operation”, he says. “So I can arrange the rest without ruffle and excitement”.
One supplier for all applications
Today components form VIPA can be found everywhere in the factory – besides the industrial applications, also the access control at the entrance as well as the pump stations for water cooling are realized with products of VIPA: “Thus I am able to optimize my stock holding, as I require only few components as spare parts and every employee is able to handle installation and programming”, says Andreas Kemper, explaining why he exclusively relies on a single manufacturer.
A further important factor is that all VIPA SPEED7 CPUs have Ethernet interfaces as a standard for years. “And here we are requiring this for the machine data logging”, says the electrical engineering technician. Thus, all production data at Thiele, such as cycle times or quantities, are logged, which are later used for the calculation of the task wages.
If the machines stop, the employee responsible has to enter the reason – so, for example, is could be possible that modification is required or material is missing. Thus, the reasons for the down times can be analyzed and so material flow and production processes can constantly be improved. Andreas Kemper has also realized a load management, so that the peak load, which has been agreed with the power company and currently stands at 9 MW can be met. “All consumption values are monitored and according to defined priorities single plant parts are cut back or shut down”, says Andreas Kemper.
The high speed of the VIPA SPEED7 CPUs is particularly important for the application at Thiele: thus, there is a huge hammer in the drop forge where the guidance elements for the drag chain conveyor are forged. The giant air hammer, whose agitations are already perceivable meters, was delivered 25 years ago with a Klöckner-Möller Suco control. There was a 19-inch rack using special switching time cards, through which the valve timing of the air hammer was controlled. The problem was only: after that long time there were no replacement cards available and in case of failure the complete control had to be repaired at the factory of Klöckner-Möller. It was therefore obvious to modernize the control and to set on the STEP7 standard which is already applied at Thiele.
“So the synchronization control was a real challenge”, says Andreas Kemper. The reason was the air cushioning of the gigantic hammer. Here a compressor creates with 300 kW an air cushion on which the hammer swings up and down very lightly. The impact force of the hammer, which can be selected via foot pedals, is regulated by the switch-on times of the valves. To ensure the smooth function of this regulation, two synchronization switches determines if the hammer is moving up or down and give the hammer to fall freely only in the downward swing. All these single steps have to be proceeded within 20 ms – at smaller hammer even within 5 ms. “So we need a CPU that is able to guarantee extremely short reaction times”, say Andreas Kemper. And even here VIPA products met the high requirements. “The hammer has been working trouble-free for one year with the new VIPA 315 SB/DPM”, says the electrical engineering technician. “We were able to reduce the down times of the machines from 30% to less than 5% compared to the old solution. This results in a noticeable higher profit”.