Modular Combined Sludge Drying Machine And Energy Saving Drying System Design

The sludge production in China is huge and its water content is high.According to statistics,in the first half of 2018,the output of urban sludge?water content 80%?is about 18 million tons.Drying treatment is the premise of sludge disposal.Drying is a stage of high energy consumption.China's national economy is in a period of rapid development,and the energy problems it faces will become more prominent.Therefore,energy must be used reasonably and effectively to continuously improve energy efficiency.This paper first proposes a modular design method.The core idea of modular design is to decompose the system into several modules according to functions.Different products can be obtained through different combinations of modules.According to the customer's requirements and product features,the modular drying design was adopted,and the basic drying unit of the sludge dryer was designed.Based on this,a series of products were expanded to obtain different series of products.Secondly,according to the design parameters,the specific structural design and mechanical calculation of the main working parts of the drying unit were carried out.Through the extrusion molding analysis of the transfer,it is found that when the friction angle between the sludge and the transfer is greater than the contact angle between the sludge and the transfer,the sludge will be squeezed out of the gap;At the same time,the transverse pressure of sludge on a single Turner is calculated to be₁P=4.47KN,which provides a reference for the selection and design of auxiliary equipment.Finally,the energy-saving drying system was designed by using pinch technology,mechanical steam recompression technology and direct-indirect combined drying technology.Then the theoretical analysis and calculation of the conservation of heat in the system are carried out according to the first law of thermodynamics.The results show that when processing 500kg/h of wet sludge,the saturated steam quality of0.5Mpa is 437.13kg/h;When using a steam compressor with a compression ratio of2.4,the secondary steam generated in the drying process is recovered,and the sludge is continuously dried as a new heat source,and only the raw steam quality is supplemented to 105.1 kg/h,and the technical performance of the system is calculated using this method.The coefficient COP=4.167,the energy saving effect is remarkable.In order to solve the problem of high energy consumption in the process of sludge drying,this paper provides a combined dryer based on modular design idea and a low energy consumption drying system for sludge drying technology,which has important theoretical significance and market application value for sludge disposal.