Study On The Molding Conditions And Fuel Characteristics Of Municipal Sludge Mixed Straw Pressed Fuel

Biological treatment of urban sewage will produce a large amount of sludge with high water content.The increasing sludge has caused a sharp increase in energy consumption and disposal costs.Nowadays,sludge disposal tends to be used as resources.This article discusses the resource utilization of sludge after electro-osmotic dehydration treatment.The electro-osmotic sludge is mixed with biomass straw to make fuel particles,which are dried and used for incineration to generate electricity,in order to realize the resource utilization of sludge and biomass.At the same time,it can relieve the pressure of environmental energy to a certain extent.Taking electro-osmosis dehydrated sludge and corn stalks as objects,the influence of molding pressure,raw material ratio and raw material particle size on the physical properties of fuel particle density,bulk density,relaxation density,shatter resistance,water permeability,and calorific value were studied.And analyze the related mechanism.The density of fuel particles is mainly affected by the forming pressure,and the impermeability is mainly determined by the proportion of sludge in the raw material.The order of the overall improvement effect on the physical properties of the fuel is molding pressure>raw material ratio>raw material particle size.Considering the optimal cost and physical properties of the fuel,the best molding conditions are:the raw material particle size is 60 mesh,the molding pressure is 10 MPa,and the mass ratio of electro-osmotic dehydrated sludge to corn straw is 7:1.The calorific value of fuel particles and the ratio of raw materials can be predicted with the curve y=13672.9+59424.3e^-x/0.934.Through the thermal drying experiment of raw sludge,electro-osmotic dehydrated sludge and electro-osmotic sludge-corn stover fuel particles at different temperatures,the key step of drying this sludge resource utilization is studied.The results show that:（1）In the range of 25%-70%moisture content,the drying speed of electro-osmotic sludge is significantly higher than that of the original sludge,and can reach twice the drying speed of the original sludge.When the moisture content is lower than 25%,the drying rate of electroosmotic sludge is close to that of the original sludge.（2）The drying time of fuel particles mainly depends on the rate of the first deceleration stage.The higher the starting temperature,the greater the drying rate of the fuel particles in the first deceleration stage and the shorter the drying time.