A new twin drive wire rope hoist is used in conjunction with the necessary condition monitoring systems type SMC 22, SCC 32 and SRC 22. The twin drive concept meets and exceeds all requirements for hoists stipulated by DIN EN 14492-2 Appendix B.
If a fault should occur (for example, gear breakage) the load can be lowered using the two manual release brakes. “Retrieving the load” is, thus, no longer necessary.
The crane, type ZL-A 350/100-9.020 E, is equipped with a 35t winch type SHWF 8200-20 4/2-1 L2 as main hoist and an SH6050-16 2/1 L2 wire rope auxiliary hoist. The latter is needed to be able to reach components just under the crane runway.
The electrics are mounted on a gallery next to the furnaces, which noticeably reduces the dimensions of the crane and protects the controls from radiant heat.
An energy chain is used for the crane and crab power supply. As required by the customer’s specifications, frequency inverters are used on all motion axes so that the loads can be moved precisely.
Using radio remote controls, the crane operator can control the system from all positions in the casting plant. Set points can be freely programmed for the field-proven four-step joysticks. Stahl devised a solution for the short approach dimensions, for example, the cross travel approach dimension of 570mm and, most importantly, the requirement for the safety-critical electronics, safety category 3.
Other features included access restriction, obstacle avoidance control, additional protective barriers and hinged railings with electric interlock.
A 400t mobile crane was required to remove the roof of the building and erect the crane system. Building supports were reinforced and the whole of the original crane runway replaced.
As the modification involved shutting down a section of the plant, only six days were available for completing erection. Teams from Stahl’s Kaltenkirchen and Berlin branch offices worked two shifts.
Stahl had previously supplied wire rope and chain hoists and cranes to Norddeutsche Affinerie AG.
The NA Group produces approximately 1 million tonnes of copper cathodes and over 1.2 million tonnes of copper products per year. The NA Group employs around 4,700 people at 12 plants in seven European countries.
