Design And Analysis Of Equipment For Septic Tank Disposal "In Situ"

As more and more resources are concentrated in the cities,more and more people are gathering in the cities,the load of septic tanks also increases.According to China’s regulations requirements,every six months each septic tank must be cleaned at least once.However,many septic tanks haven’t been cleaned since they were built.Only when they are blocked,professionals would be invited to dredge them.This results in the manure and sewage flow everywhere and has a negative impact on the environment.The reason is that the existing equipment is easy to be winded and blocked when dealing with the dirt with great viscosity and long fibers,and the humidity of the solid substances and the clarity of the liquids are difficult to meet the requirements of the specification.Furthermore,many septic tanks are distributed in the remote places of residential areas,the regulations require that dirt and sewage can be handled locally,meet the standards and discharged,it is really inconvenient to fix the processing equipment.Aiming to solve the above problems,this paper based on great number of literature researches,theoretical analysis,numerical calculation,etc.,a vehicle-mounted processing equipment was developed,which can separate liquid waste into solid and liquid in its place.The main research works are as follows:(1)Based on the characteristics of the existing solid-liquid separation equipment and the multiphase materials in septic tanks,an efficient centrifugal extrusion filter was designed and some operational parameters were obtained.(2)Based on the requirements of solid-liquid separation in septic tanks,the CFX software was used to establish and solve the fluid calculation model,and the flow pressure and velocity were obtained.The solid-liquid separation capability of the centrifugal extrusion filter was analyzed.(3)In order to meet the practical needs of the septic tanks in the remote areas,especially when those traditional suction-type sewer scavengers with single function can no longer fit in actual demands,a multifunctional mobile vehicle with solid-liquid separation equipment which can be processed in its location has been developed,the overall program and the design of the subsystems were completed,to verify whether the vehicle has met the design specifications and requirements through experiments.(4)In order to ensure the safety and reliability of the equipment structure,the finite element model of key components(vacuum tank and sieve)was established by using WORKBENCH software.The static analysis and modal analysis were completed.The vacuum tank sealing type and the thickness of cylinder were optimized,and better structure and structure parameters were obtained.