Overview of paper sludge
Sludge dewatering is a treating method used to remove water from the native, concentrated or digested sludge and turn it into semi-solid or solid mud. After dehydration, the moisture content of sludge can be reduced to 55 to 80%, depending on the nature of sludge and sediment and the performance of dewatering equipment. Further dewatering of sludge called sludge drying, the moisture rate of drying sludge is less than 10%. Dewatering methods are mainly natural drying method, mechanical dewatering and granulation method. Natural drying method and mechanical dehydration method is suitable for sewage sludge. Granulation method is applicable to the coagulation and sedimentation of sludge.
Paper mill sludge dewatering method
Usually the sludge is first to be preprocessed, to improve the dewatering performance and then dewatering. Currently the most common preprocessing method is adding inorganic salt or polymer coagulant. In addition, there are washing method and heat treatment method. Centrifugal method commonly used in horizontal decanter centrifuge (referred to as the decanter centrifuge), it consists of an inner drum and an outter drum. One end of the drum is cylinder shape and the other end is conical shape. Speed up to 3000 rpm or higher and the two drums have a certain speed difference. The decanter centrifuge operates continuously and control automatically, with good sanitary conditions and small footprint, but has a high requirement on the sludge pretreatment. Mechanical dewatering method is mainly used in primary sedimentation tank sludge and sludge digestion. The moisture content of dewatered sludge relates to the sludge properties and dehydration method.
Typical process flow of paper mill sludge dewatering
Paper mill sludge dewatering process of typical sludge treatment, including four treatment or disposal periods. The first stage is sludge concentration, the main purpose is to make the volume of sludge preliminarily reduced in order to reduce the volume or capacity of subsequent structures to be processed; second stage is sludge digestion, decompose the organic matters in the sludge; the third stage is sludge dewatering, to further reduce the volume of sludge; fourth stage is sludge disposal, using some ways to digest the sludge.
Horizontal decanter centrifuge selection
Choose centrifuge models correctly is very important for the customers. Usually what we based is the quantity of material to be processed per day, and then make modifications on our exisitng design of centrifuges according to different materials and customer requirements so as to maximum meeting customer requirements.