Hyun Dong Lee

Defects Diagnosis Technology of Water Supply Pipe's Network Using Pipe Endoscope Camera of High Resolution/High Pressure Resistance Performance

The size of pipe network accident caused by aging of water distribution system, rapid urbanization, abnormal climate or a disaster such as an earthquake is gradually becoming larger. Accordingly, it is required to improve the technology to maintain the water distribution system so that the related technologies can be scientifically and systematically applied. The paradigm of Korean water supply service is changing from supply era to maintenance era, and it is required to apply equipment and method to effectively check, diagnose and test the internal condition of the pipe without stopping water supply. If photographing and diagnosis of the burial environment around the water service pipeline and inside the pipe can be carried out without stopping water supply effectively utilizing the surrounding facilities such as straight piping and air valve to the maximum, decrepit pipe (defective pipe) improvement projects can be effectively carried out by making adequate decisions. Also, a systematic and more efficient water supply service maintenance system can be established by building a database of surrounding pipeline directly investigated and selecting priority of direct/indirect evaluation. This study has raised accuracy of a diagnosis by applying a camera capable of securing high resolution without generation of distortion in case of photographing the inside of a pipe, and suggested an application method of the pipe endoscope camera using an inspection hole inside a pipe.

Establishment of Waternode Stations for Water Quality Monitoring by IP-USN

Waternode station is a floating composite water quality monitoring device. The waternode station houses the multiple water quality measurement devices, control panel for wireless communication and solar cells for applying electric power. The floating devices are classified into general model with vertical dropping system and river model without vertical dropping system. The water quality measurement device measures pH, water temperature, conductivity, dissolved oxygen, turbidity and nitrate. And it measures all parameters simultaneously. The control panel is used for IP-USN system. USN (Ubiquitous Sensor Network) is a network system by water quality measurement devices. IP-USN is a USN system that identifies particular sensor connected to the internet. The data information is transferred by wireless modem based on TFB (Triple Frequency Band). Field application results showed that the waternode station is a reliable and cost-effective water quality monitoring solutions.

Evaluating Durability and Burying Characteristic of PVC Pipe

Currently, there are cast iron pipe, protective coating steel pipe, PE pipe, GRP (Glass-Fiber Reinforced Pipe), PVC pipe etc in use in Korea. Since there is rather very low recognition of synthetic resins pipe among those in case of Korea, the kind of pipes for use is very few compared with the actual performance. Once analyzing foreign data, synthetic resin pipes are widely used in even drainpipe and items for piping such as connecting parts are diverse and accessories of piping for general use are being laid underground. It is necessary to mine pipes with selection of various kinds of pipes considering surrounding environment and local circumstances in Korea. This study evaluated the features of soil pressure using load-strain feature and simulated scale down box test through 3-point deflection test for the evaluation of basic features by vertical load such as breakage of PVC pipe and leakage in mining environment in which live loads and cavity exist.

Remodeling Techniques of Water Storage Tanks and Residual Chlorine Remaining Devices

We developed the remodeling techniques of water storage tanks and the residual chlorine remaining devices. Eco-TIR((Total Internal Remodeling) is remodeling technique that cover the inside wall of concrete tank with SMC(Sheet Mold Compound) Block. Eco-SL(Stainless steel Lining) and Eco-GS(Glass sheet) is similar to Eco-TIR(Total Internal Remodeling) but stainless steel or glass tile is substituted for SMC block as a cover material. We tested the residual chlorine remaining devices and the results are as follows. First, it was estimated that mixing efficiency is increased if inflow energy to the water tank is used in the results of variation of residual chlorine concentration. Secondly, result showed that the removal percent of residual chlorine concentration was up to 90% by using ACF filter and feed water of high residual chlorine concentration can be controlled to 0.2mg/L〜0.4mg/L by using ACF and by-pass of inflow to the water tank. Also, in the water tank inlet pipe of 3-ways out using inflow energy is more effective in mixing than conventional inlet pipe. It is expected to enhance the safety of service water and management efficiency by applying mentioned techniques properly.