Cumulative ventilation air drying potential as an indication of dry mass content in wastewater sludge in a thin-layer solar drying facility

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Controlling low-temperature drying facilities which utilise nonprepared air is quite difficult, due to very large variability of ventilation air parameters - both in daily and seasonal cycles. The paper defines the concept of cumulative drying potential of ventilation air and presents experimental evidence that there is a relation between this parameter and condition of the dried matter (sewage sludge). Knowledge on current dry mass content in the dried matter (sewage sludge) provides new possibilities for controlling such systems. Experimental data analysed in the paper was collected in early 2012 during operation of a test solar drying facility in a sewage treatment plant in Błonie near Warsaw, Poland.

[1] Brodowicz K.: The Theory of Heat and Mass Exchangers. PWN, Warsaw 1982 (in Polish).

[2] Cebeci T., Bradshaw P.: Physical and Computational Aspects of Convective Heat Transfer. Springer Verland, New York 1984.

[3] Katsiris N., Koszeli-Katsiris A.: Bound water content of biological sludges in relation to filtration and dewatering. Water Res. 21(1987), 1319-1327.

[4] Palipane K., Driscoll R.: Moisture sorption characteristics of - Stell macadamia nuts. J. Food Eng. 18(1992), 63-76.

[5] Vaxelaire J.: Moisture sorption characteristics of waste activated sludge. J. Chem. Techn. Biotechn. 76(2001), 377-382.

[6] Korczak-Niedzielska M., Gromiec M.: Drying of sewage sludge. In: Proc. Scientific-Technical Conference ‘Problems of sludge in wastewater treatment plants’.Czestochowa 1998 (in Polish).

[7] Krawczyk P.: Research of the Thermal-hydraulic Processes in Sewage Sludge Solar Dryer. PhD thesis, Division of Power Machines and Devices, Institute of Heat Engineering, WarsawUniversity of Technology, Warsaw 2008 (in Polish).

[8] Kneule F.: Drying. Arkady, Warsaw 1970 (in Polish).

[9] Strumiłło Cz.: Fundamentals of Theory and Techniques of Drying. WNT, Warsaw 1983 (in Polish).

[10] Weiss, A.: Algorithms for the calculation of moist air properties on hans calculator.Trans. ASAE 20(1977), 1133-1136.

[11] Stull R.: Wet-Bulb Temperature from Relative Humidity and Air Temperature.American Meteorological Society 2011 DOI: 10.1175/JAMC-D-11-0143.1

[12] Krawczyk P., Badyda K.: Investigation of thermo-flow processes in a solar thinlayer wastewater sludge drying facility. Ambient conditions impact on drying rates.Polish J. Env. Stud. 21(2012), 5A , 246-250.

[13] Krawczyk P., Badyda K.: Modelling of heat and flow processes in thin layer solar sludge dryer. Impact of using mixing baffles on the basic parameters of the dryer.Polish J. Env. Stud. 20(2011), 4A, 185-189.

Archives of Thermodynamics

The Journal of Committee on Thermodynamics and Combustion of Polish Academy of Sciences

Journal Information

CiteScore 2016: 0.54

SCImago Journal Rank (SJR) 2016: 0.319
Source Normalized Impact per Paper (SNIP) 2016: 0.598


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