The Experimental Research Of Drying Characteristic Of Biosolid

In recent years, sewage sludge of Wastewater Treatment Plant, salvage of cartilage,dejecta of domestic animals and poultry, municipal incinerator, by-product of industry,(such as sawdust, bagasse,Rosaccea)are collectively referred to as biosolid,large amount of which are Municipal sludge and industrial sludge.Compost, landfill, incineration are general sewage sludge disposal methods, and drying is one indispensable important approach to deal with biosolid (municipal sludge and industrial sludge all belong to biosolid). In view of municipal sludge and sugar mill which are typical represents of biosolid, The dissertation studies drying characteristics.In order to research influence of different drying temperature on drying rate and effect of biosolid. Design and put up open type hot blast drying experimental facilities on which flux and temperature of hot blast can be regulated. Through on-line weigh we investigate drying characteristics of biosolid in heated-air drying.At first,biosolids are made into cylinder samples of similar shape. We research influence of different drying temperature(120℃,140℃,160℃)on drying characteristics in large space. Experimental results showed that the temperature of hot blast is higher, and the rate of temperature elevation and rate of drying is just faster. Results Compared with 140℃,no changes of Droughtindex were found in 160℃。Secondly, we investigate the influence of different additives (Rice, Rice husk powder, sugar cane)and mass of additive on drying effect and on shaping of sample.Experimental results showed that additive amount of biomass has a great effect on shaping of sample. When the mass of additive is low and the temperature of hot blast is similar,the sample can take shape.When the mass of additive is high the sample can't take shape and biosolid glues to the surface of additive. When the sample can take shape and the temperature of hot blast is similar, Drying time gradually decreased with the increase of additives when the temperature of hot blast is similar.When the sample can't take shape, the rate and effect of drying get better Compared with no additives in the same temperature of hot blastThe Closed Hot-air Circulating Dryer is used to heighten drying energy using efficiency and avoid explosion risk of biosolid because of too high temperature on a basis of open type hot blast drying experimental facilities. In this case,The drying process can be divided into two stages:air-drying, superheated steam drying.