For chrome/vegetable tanning drums the same size drum have shelves 80cm high and alternating shoe pegs. Smaller retanning drums of 4m x 3.5m have shelves which are 75cm high.
Vallero claim that an electrical energy saving of up to 65% can be made and a water saving of 40%. They also claim a 20% saving in chemical usage and 40% increased loading capacity.
Vortex drums are less noisy and improve opening of the hides during processing due to the compressing and sponging mechanical action. Processing can be carried out at low drum speeds which means that hides may have lower cuts and scratches and the final leather quality is higher. During processing the ‘dragon’ shelves move the hides continuously while traditional drums with pegs pick the hides up sporadically and they may not receive the same mechanical action and penetration from hide to hide within the same batch. This is eliminated when using the Vortex system where hides are compressed and squeezed in the liquors and get a better contact with the float.
Vortex from Vallero
Vallero International have introduced a revolutionary inner drum system called Vortex which they have patented. The internal system is composed of three high ‘dragon’ shelves and it can be used for all drum processes and installed in any vessel whether made from wood, plastic or stainless steel. The shelves are directed to the drum centre allowing rotation in both directions and the top profile is wave shaped and not linear. The height of the shelves depends on the operation and drum size. In soaking and liming drums of 4.2 x 4.5m the shelves are 1m high.