Procedure and equipment for the production of solid fuel from wastewater sludge

Procedure for the production of solid fuel from wastewater sludge, during which the wastewater sludge containing 2-8% dry material is first subjected to mechanical water removal, during which the absorption water is removed and we produce wastewater sludge with a dry material content of at least 25-30%, the significant proportion of the remaining capillary water, favourably at least half of it, is removed by an accelerated evaporation process, drying, characterised by that we pre-dry the wastewater sludge containing at least 25-30% dry material using the heat of the flue gas of the burning equipment operated by us to a dry material content of 50-55%, we extract the steam created and gases released during pre-drying, filtering them if necessary and utilise them by returning them to the burning equipment, we pelletize the wastewater sludge containing 50-55% dry material at a high pressure of, favourably, 800-900 bar, then we perform final drying of the pellet product created in this way to a dry material content of at least 80-85% by making further use of the heat of the flue gas of the burning equipment operated by us, we use a part of the solid pellet final product, favourably at least 30-50% of it as fuel in the burning equipment operated by us.