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At present, many domestic areas due to gravity pipe network is expensive or topographical constraints can not be laid. This paper aims to develop a new type of vacuum sewer system. It uses a small diameter, ladder laying pipeline burial depth is greatly reduced, and can be appropriate climbing, flexible, adapted to local conditions, saving investment. Learn from foreign experience and summarize the research results of the research group on the basis of improved design methods from the user to the terminal, including valve wells, pipe network, the design of the vacuum station. Client sewage households tube connected to the valve pit valve well the upper and lower levels, lower sewage full capacity installed in the upper vacuum interface valve open, the system pressure the pressure difference between the inside and outside of the sewage into the vacuum pipe; vacuum tube network based on terrain the laying of the ground when the distance set-raising section, along the uphill slope set to enhance segment, no downhill enhance the segment; vacuum station is the power source of the entire system, including vacuum pumps, sewage pumps, sewage tank, storage tank, wherein the selection of a vacuum pump is very important, the need to ensure that the working time of 1.5 to 3 minutes, so that the pressure within the pipe network system restored to 0.03 Mpa or less, in order to meet the power requirements of the vacuum suction. Using the above method, the engineering design for an area of ??about 4 square kilometers, serving a population of nearly 600 people in the Lake District. In order to ensure that all users connected into the vacuum tube network, the design of the service area is divided into three, with three main pipe were collected. According to the flow of the actual collection of the pipe sections, respectively 110mm and 160mm diameter pipeline. 110mm pipeline upgrade once every 50 meters, 160mm pipeline upgrade once every 70 to 80 meters. The maximum total design flow 3.03L / s, and the The vacuum station working pressure range of 0.03 MPa to 0.05 MPa, determined by calculating the displacement of the vacuum pump 110L / s, sewage pump displacement to 3.03L / s, the volume of sewage tank as 1636.2L. Construction investment cost of about $ 2.2 million, while the construction of the traditional construction of the drainage system cost about $ 290 million. This article using the Visual Basic language developed a computer program to draw the pipe network laying plans by the user according to the actual terrain and design requirements, then the pressure loss of the pipe network flow calculations and pipe network calculations, and to judge whether the pressure value exceeds the design requirements, the final calculation vacuum vacuum pump station, sewage pump, storage tank, sewage tank parameters. The article also discussed theoretically vacuum sewer system at different flow patterns (single-phase flow, mixed flow, split-phase flow) under the conditions of pipeline pressure loss calculation method. The design of a vacuum conveyor test device, homogeneous flow, split-phase flow model of the pressure loss is calculated coefficient test test, and have come to some interesting conclusions: With the reduction of the gas, liquid two-phase flow rate have appeared in the vacuum pipe annular flow, wavy flow, slug flow in three flow-type, pipe friction resistance loss with the increase of the transport water rise gradually decreases with increasing pipe diameter. To make both the theoretical basis and experimental verification of vacuum pipe pressure loss formula made an initial attempt.
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