ENEL POWER PLANT
Decommissioning Thermoelectric Group

The industrial decommissioning site is opened in March 2021.

The work is being carried out at the same site where Armofer has just successfully completed similar work on two other Thermoelectric Power Units sister to the present one. The complete decommissioning of the plant, as requested by the Client, commits a dedicated team for several months of work. The preliminary phase, after the inspection and preparation of detailed and executive plans, involves securing the areas to begin with the scoibentation of the plants. The work then involves dismantling operations of above-ground carpentry plants, up to very high elevations (about 80 m). Controlled dismantling is then carried out with the help of dedicated crane trucks and lifting equipment.

When above-ground structures have been taken to heights around 35-40 m, the "big machines" intervene, mechanical excavators the UHD setup for top-down demolition. For this site Armofer brings to the field the flagship of the red fleet, Liebherr 974, 120-ton class the ultra high demolition setup whose boom is operational at pivot heights up to 42 meters.

The deconstruction of structures by controlled dismantling

The controlled dismantling of the above-ground structures of the plants proceeds gradually according to a precise order and operational procedure developed by the technicians. It must take into account the configuration and weights of the structures; the capacity of the individual cranes that assist; and the environmental conditions at altitude (wind in particular) that may affect the handling of such loads. The executive study of the slinging of the individual structures is in fact particularly important for the safe movement in the ground area dedicated to secondary cutting. The cutting of steelwork structures takes place at height and can be done hot or cold with the aid of hydraulic shears. For each dismantling of large components, Armofer prepares, in consultation with the safety managers, a detailed demolition plan with identification of the slinging points, weights, placement of operating cranes and lifting equipment.

Beforehand, the structure was secured so that the personnel could operate from the structure itself, but if this is not possible or not safe, the personnel will be taken to heights inside personnel baskets secured to a dedicated crane.

As we see from the gallery below, the stripping of the ashlars includes 'throws' of several tonnes and has been repeated dozens of times! 

Lowering boilers with jacks

The demolition of the imposing boilers takes place using a top-down technique from the ground up to a height of 25-30 m. Then, after having demolished the top part on the roof, the abseiling system with hydraulic jacks is mounted on the roof, which, appropriately arranged and sized, will assist the lowering of the artefact by distributing the stresses. Or rather, the abseiling, since the enormous artefact is previously sectioned in several points in order to manage operations with reduced weights. When the artefact is placed on the ground, it is hydraulically demolished for portions of 10-15 m from the ground; then the cycle begins again until the complete lowering and demolition of the boiler. Only then is the steel castle that contained it demolished, with the structures being dismantled at height and the various pieces lowered by crane.