Subsequent thermal insulation of a 250-m³ storage tank with Energocell® foam glass granules

September 2018

The 250-m³ storage tanks of an Eastern Hungarian food manufacturing plant needed retrofitting with thermal insulation. The industrial tank of 26-m² area and 250-m³ capacity (~10-m clear height) imposes a 13-t/m² load on the new bottom plate. Due to the high loads only highly resistant - non-shrinking - thermal insulation could be used, that needed to be heat resistant as well to withstand the welding of the bottom metal plates. The Energocell® foam glass granules fully satisfied the listed criteria.
The building of the new bottom plate started with a collar made of metal plates and fitted with ribs for support. Then the foam glass was placed and compacted to a 18-19 cm thick layer. The foam glass granules were shoveled into the tank through a side opening.

Compaction along the collar was executed with hand-operated compaction tools, because of the space limitations and to protect the collar; but on the larger continuous surfaces electrical vibratory plates were used (because of the enclosed space). The applied compaction rate was 1:1.3, and the final 18-19 cm thick layer resulted from a 23-25-cm layer of loosely spread material. Granules of 10-60 mm fraction size, and fine granules of 4-8 mm were placed and compacted on this layer, to include them between the larger granules, and to level the surface - preparing it for the very high 13-tonne/m² load and the metal plating.

The 18-19-cm compacted Energocell® foam glass granule layer was then covered with 5 mm thick metal plates that were joined by continuous weld at their faying surfaces (on the photo only the temporary joins are visible).