| With the continuous development of China’s economy and the continuous advancement of urbanization,the ensuing problems of urban environmental pollution and energy consumption have attracted increasing attention.Large amounts of domestic sewage and industrial waste water from factories have caused the sludge production in sewage treatment plants to increase day by day.Although the sludge contains a lot of harmful substances,it also contains trace elements such as N、P、K needed for plant growth,so it can be used in agricultural production and construction materials.No matter what kind of harmless treatment of sludge,it needs to go through the sludge transport link.Therefore,choosing an efficient transportation method is of great significance for the final treatment of sludge.Sludge is a non-Newtonian fluid,and its transport characteristics are closely related to rheological characteristics.Sludge rheological characteristics are related to water content,temperature,and pretreatment.In order to study the rheological and transport characteristics of sludge,several experiments were designed in this paper,namely,sludge samples with water content of 48.32%、54.23%、63.71%、70.33%、79.82% and 81.77% were prepared and used.The water bath heating method uniformly heats the sludge,obtains sludge samples at different temperatures,and measures the rheological characteristics by a rotary viscometer to study the effect of moisture content and temperature on the rheological characteristics of the sludge;based on Teflon(PTFE))Anti-sticking of the material.In order to study the effect of different surface materials on sludge transport,the sludge transport experiment was carried out on the sludge with a water content of 48.32%、54.23%、66.33%and 81.77% through a 304 stainless steel plate and a Teflon plate.According to the experimental results:(1)As the moisture content of the sludge continues to increase,the viscosity of the sludge continues to decrease.When the moisture content is low,the effect on the sludge rheological parameters is significantly higher than that when the moisture content is high.When the water content is 48.32%～63.71%,the sludge viscosity is too large,which is not suitable for long-distance pipeline transportation.When the water content is 70.33%～81.77%,the rheological parameters are low,the pumpability is good,and it is suitable for remote Distance pipeline.(2)With the gradual increase of temperature,the viscosity of sludge is showing a trend of continuous decrease.The sensitivity of sludge with low water content to temperature is higher than that of sludge with high water content,and the trend of viscosity change is greater.(3)When the sludge moves on the flat plate,the Teflon coating can play a significant role in reducing resistance and viscosity during transportation,and the sludge viscosity reduction effect is more obvious at low water content.According to the results of the experiment,it is understood that the water content is 81.77%,and the pumpability is good.Through analysis and demonstration,the hydraulic double-cylinder piston pump is used to transport the sludge in this project,and the sludge pump is carried out according to the actual equipment layout and transportation distance.Selection and design of related components,and according to the research results of rheological characteristics and transport characteristics experiments,several methods of sludge pump pipeline resistance reduction are proposed. |
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