For more than eight years HUBER has gathered experience in the field of solar sewage sludge drying, the eco-friendly way of drying sewage sludge within a greenhouse. The customer’s requirements have always been our primary goal. These are low maintenance and operating requirements, odour and dust elimination as well as the provision of optimal conditions for the introduction of additional heat.

The HUBER SRT system is able to perfectly meet all these requirements. The degree of automation of SRT systems is freely selectable and adapted feed and discharge assemblies are available. Our both national and international sales success combined with the great feedback from customers and consultants proves that we have been able to set a milestone in sludge drying with our SRT dryer. As the technically mature technology additionally is offered at a favourable price, we expect sales to increase significantly.

A new system size, available for two years, has now been extended to all greenhouse widths: Machines for 12 m, 10 m or smaller plants of 7 m width are available. The sludge turning assembly consists of a rotating double shovel that draws itself through the greenhouse along chains. While the shovel rotates and at the same time travels forwards, the sludge is aerated, turned around, granulated and transported. When the sludge turner arrives at the end of the hall, each individual sludge granulate grain has been aerated. As the complete sludge bed is restacked, the aerobic condition of the sludge is reliably maintained and the preconditions for drying are optimal. Furthermore, the sludge is continuously backmixed. The double shovel is also used to move sludge from one place to another. Sludge feed and removal can take place on the same gable side of the drying hall.

Backmixing of dry granulate into a sludge feed with 20 % dry residue increases the dry residue to 40 % directly after feeding. At this dry residue level, any odour-intensive biological activities are stopped. In addition, sludge with 40 % DR is more open-pored, easier to dry, less pasty and therefore easier to process mechanically so that the long life of the applied technology is guaranteed. Backmixing of dry sludge provides another benefit: The area in which dust is produced due the very dry granulate being moved mechanically is limited to the last metres of the thermo-shell.

A variety of reference installations are available for visits to experience live the quality of HUBER SRT systems. One of the latest projects is WWTP Penzing-Weil near Munich International Trade Fairs. Our sales staff will be glad to show our plants to operators, engineers and everyone else interested.