Drying sewage sludge using a drying device having a double-walled drum mixer, comprises conveying the dehydrated sewage sludge into the drum mixer after pre-drying, and continuously intermixing the dehydrated sewage sludge with the hot air

摘要

The method for drying sewage sludge (2) using a drying device having a double-walled drum mixer (1), comprises conveying the dehydrated sewage sludge into the double-walled drum mixer after pre-drying, continuously intermixing the dehydrated sewage sludge with the hot air (3), discharging the water from the sewage sludge in the form of water vapor, guiding the water vapor with dust using a ventilator (5) through a filter and moisturizing as circular flow, and evacuating the dried sludge through spiral sheet into allocated containers by simply changing the rotating direction. The method for drying sewage sludge (2) using a drying device having a double-walled drum mixer (1), comprises conveying the dehydrated sewage sludge into the double-walled drum mixer after pre-drying, continuously intermixing the dehydrated sewage sludge with the hot air (3), discharging the water from the sewage sludge in the form of water vapor, guiding the water vapor with dust using a ventilator (5) through a filter and moisturizing as circular flow, and evacuating the dried sludge through spiral sheet into allocated containers by simply changing the rotating direction. The drum mixer is double-walled, so that the air flows through between the double walls. A gap sieve is present in an inner part of the double-walled drum mixer. The gap sieve enables the flow of the hot air and/or circulating air (4) through the dehydrated sewage sludge. The specialty in the sieve is the arrangement of the rods, which prevent an outward blockage by its shape distribution of the gap. The hot air doubles the contact surface with the circulating air through the gap sieve. The hot air or circulating air flows through the double-walled drum mixer, which has a black steel surface and/or solar collector. The hot air is additionally warmed by the sun radiations and the external coating of the double-walled drum mixer is warmed by the flow of the hot air between the double-walls of the drum mixer. The solar energy is used in the double-walled drum mixer for the dehydrated sewage sludge.