Hot-galvanising company, Helling & Neuhaus, in conjunction with Terex Material Handling and with input from the industrial employers’ mutual insurance association, has developed a solution which allows operators to work beneath suspended loads. The lift and lower sections of the two Helling & Neuhaus conveyor lines have each been equipped with two Demag double chain hoists, which are connected by means of a tandem control system. According to the manufacturer, this concept, which satisfies the requirements of BGV D8 Plus hoists, is an innovative solution, which provides maximum safety for a wide range of industrial applications.
In many production facilities, including galvanising plants, it is necessary for operators to work beneath suspended loads, which are held by chain hoists. Applications such as these are subject to special safety requirements, which are laid down in the BGV D8 safety regulations.
Safe and reliable solution for D8 Plus hoists to meet risk assessment requirements
Helling & Neuhaus GmbH, part of the Seppeler Group, operates two parallel production circuits at its plant in Gütersloh, Germany. The lifting motions at each of the pick-up and deposit stations were previously provided by chain hoists fitted with a catch. This arrangement had met the customer’s requirements, but safety issues dictated the development of an alternative solution.
Michael Rother, Engineering Director, stated: “Together with Terex Material Handling and the industrial employers’ mutual insurance association, we first carried out a risk assessment and analysis. On the basis of the results, a concept was developed to satisfy the requirements of the BGV 8 Plus regulations, allowing operators to work beneath the trolleys.”
The solution employed by the galvanising specialist utilises Demag LDC-D size 10 double chain hoists, which are paired to each other by a tandem control system. Developed for transporting long materials and spreader operation, the LDC-D has two mechanically synchronised chain lead-offs, which are rigidly connected to each other by a common frame. The LDC-D unit drives a separate lifting block that has its own chain drive via a connecting shaft.
To accommodate load-dependent lifting speeds of up to 24 m/min, the LDC-D units are designed for high handling rates. In addition, they provide for longer chain service life as there are no additional chain return sprockets.
High safety and reliability for lifting and lowering
The four attachment and removal stations employed at Helling & Neuhaus comprise six metre-long I-beam sections, which are integrated into the conveyor track. They are held by two stationary LDC-D double chain hoists, which have a hook centre distance of 800 mm. When a spreader trolley reaches one of the stations, the spreader is first locked in position and then the rail section is lowered to allow the parts to be attached for the galvanising process.
Two chain lead-offs also double the level of safety. Synchronised operation of the hoists is also monitored by the tandem control system. This arrangement ensures that the four hooks are always level with each other during lifting and lowering motions. Even if one of the chains were to break, the load bar would remain in a stable position. The lifting and lowering stations operate with several secondary safety features, including a double brake system, to ensure optimum safety and reliability for workers.