Natural drying system by solar radiation of sludge from WTP and WWTP
SOILAR T
CATEGORY SLUDGE
TYPOLOGY SOLAR DRYER
WHEN IT IS USED
SERECO eco-sustainable system for the natural drying of previously dehydrated sludge from WTP and WWTP “SOILAR T” type transforms a big environmental and ecological problem both in terms of environmental protection and in a business. This system, without the need for external heat, is able to reduce the volume and weight of the dehydrated sludge by about four times. The use of this system is perfect when it is necessary to avoid han dling sludge in favour of a product that is grainy, dry, free from unpleasant odours and above all easy to handle, to store and reusable as organic fertilizer.
HOW IT IS MADE
The SOILAR T system consists of one or more parallel drying corridors on a flat concrete slab bounded on all sides by a low wall with the sole exception of the sections where the entrance and exit gates are present; from a steel and greenhouse of the same dimensions in plan of the perimeter wall and of height calculated specifically according to the environmental conditions of the installation site; from a sludge handling system, implemented by SERECO on pilot plants, SOILARR model that travels on rails with the possibility of movement in six directions; by a sludge ventilation system with variable flow rate fans mounted in strategic points inside the greenhouse and suitable for optimizing the degree of sludge drying; from a system of continuous extraction of the humid air from inside the greenhouse that allows main taining the right level of humidity set inside; from an internal and an external weather station; from a PLC and from the dedicated SOILAR software, suitable fo managing the entire automatic drying system.
HOW IT WORKS
The sludge loading into the system can take place in a discontinuous way, by wheelbarrow, trailer or tipping truck, mechanical shovel or similar, or automatically by feeding screws suitable for the distribution of sludge at the entrance of the greenhouse. The sludge is taken up by the SOILARR machine and slowly distributed over the entire surface of the greenhouse, at the same time it is aerated, turned over and transported slowly towards the exit side. The SOILARR moving machine is able to make a complete cycle even in a few minutes in the smallest greenhouses and in a maximum of two hours in the larger ones. Normally from a minimum of two to a maximum of six complete daily cycles are performed according to the climatic conditions. The internal ventilation system is always in operation, if there is sludge to be dried in the greenhouse, but the number of fans in operation and their flow rate is always adjusted according to the climatic conditions. Instead, the air extraction system starts and regulates itself according to the internal and external climatic conditions. Even the dried sludge can be drained either manually or automatically. Being dry and odor-free material there are no particular precautions so the same can be stored in pile on the inner side of the greenhouse exit and then be loaded on trucks and removed if necessary for its reuse. Alternatively, the dry sludge can be continuously extracted by means of belt and/or screw conveyors for removal or store in suitable storage silos for specific needs.
