Our company cleared a large-capacity sugar silo in a professional manner and, above all, in compliance with occupational health and safety regulations. The technical clearance was a major challenge for all those involved. In order to implement this requirement in terms of safety and rescue, our expert assessor prepared practical rescue documentation and safety assessments in advance. The quantities of material in the silo were previously mined by another company without observing appropriate safety and rescue guidelines.
The life-weary “climbers” climbed around on these mountains in “freestyle” and danced against death with pickaxes and spades. The plant operator then pulled the ripcord and commissioned us to carry out and remove approx. 8000 tons of partially caked and pressure-compacted sugar.
As our company specializes exclusively in work in silo and tank facilities, we immediately knew how to quickly eliminate this problem. An emission-free excavator was brought into the silo plant and the mountain of material was deliberately and consistently removed safely. The piles of material were gradually brought down without endangering the employees present. The activity of excavating requires a great deal of skill in handling this technology, as there were only slight signs that the material could start to slide and possibly spill over the excavator.
For this reason, a 3D processing plan was designed in advance, which clearly defined the slipping behavior and the processing areas. This procedure led to a breakthrough success after just a few hours, in which large quantities of material were removed and could be fed to the material removal screw. The risk assessment of such a measure is burdened with considerable unknown factors, but this burden can be reduced with some redundancies and proven scenario experience.
The basic prerequisite for risk reduction is the specialized company used and its employees and managers. In confined spaces, i.e. work in confined spaces, no work should be started unless the rescue has also been theoretically documented and sampled.
The manual removal behavior of cured sugar of different grain sizes is proportioned differently in a large-capacity silo system than in a silo cell or significantly smaller system. The reason for this is, on the one hand, the large capacity and, on the other hand, the lack of pressure impact load when the loose material has already been removed from the large capacity silo system.
In essence, the effect is as follows: The applied volume pressure per cm² is more or less constant in a filled large-capacity silo system, as material is constantly being removed and added. In storage systems, material is discharged until empty and the large-capacity silo system is refilled when empty.
If piles of bulk material or material bridges form, these are inherently “semi-stable” constructs if the pressure is a constant factor. If this support pressure is missing, these structures become unstable in a large-capacity silo system. However, the instability is so low that the material spans or material mountains do not collapse.
However, if manual activities by rope access technicians come into play, the situation is different. The effect of mechanical and pneumatic influences brings the instability to a critical level and the mountain threatens to slide or partially detach. If there are negligent rope access technicians in this area, they will be buried like an avalanche. So let’s hold on tight.
From the outside, semi-stable constructions appear stable and quite capable of being stepped on. However, if you take a closer look at the static pressure influences, you come to the conclusion that these piles of bulk material, mountains and cornices are not as stable as they appear. We basically speak of semi-stable and not capable of being stepped on.
The rope access technician and his team must explicitly apply the corresponding scenario for this purpose. In the sinking and burying scenario, multiple rescue and securing mechanisms are required, which definitely save and preserve lives.
The working procedure we use saves manpower and money and is also much safer and more manpower-friendly.
The excavator used can be completely dismantled and reassembled. All parts were disinfected in advance and sampled by QS.
A win-win situation for our customers 😉
