• The KSFM Journal of Fluid Machinery
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• v.4 no.4 s.13
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• pp.22-27
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• 2001

The pump/motor selection program for optimized selection of regional water supply facilities was developed based on a flowchart compiled from basic operational data, total head requirement, initial pump/motor specification selection etc. This program was developed in Visual Basic. The program accepts, as in the flowchart, operational requirements of pumps and other system requirements, and calculates specific speed based on flow rate, total head and rotational speed. Then the calculated specific speed is used to select pump types and speed prior to determining likelihood of cavitation occurring at the calculated NPSH. Power requirement is then calculated for safe operation of pump to assist final pump selection. Test results of the program match very closely to the design values of Paldang intake pump station(3rd stage) proving that the program can be used as an effective and practical aid for designing new regional water supply systems.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.171-176
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• 2001

The Pump/Motor Selection Program for optimized selection of regional water supply facilities was developed based on a flowchart compiled from basic operational data, total head requirement, initial pump/motor specification selection etc.. This program was developed in Visual Basic. The program accepts, as in the flowchart, operational requirements of pumps and other system requirements and calculates specific speed based on flow rate, total head and na Then the calculated specific speed is used to select pump types and rpm Prior to determining likelihood of cavitation occurring at the calculated NPSH. Power requirement is then calculated for safe operation of pump to assist final pump selection. Test results of the program matches very closely to the design values of Paldang intake pump station(3rd stage) proving that the program can be used as an effective and practical aid for designing new regional water supply systems.

• Proceedings of the Korea Water Resources Association Conference
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• 2002.05a
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• pp.287-292
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• 2002

• 수도
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• v.23 no.1_2 s.76_77
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• pp.82-94
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• 1996

• The KSFM Journal of Fluid Machinery
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• v.5 no.3 s.16
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• pp.33-39
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• 2002

The head-capacity corves for pumps developed by the pump manufacturer are based on tests of a single pump operating in a semi-infinite pool with no nearby walls or floors and with no stray currents. Hence, flow into the pump suction is symmetrical with no vortices or swirling. Pump station designers rely on these curves to define the operating conditions for the pump selected. However, various constraints such as size, cost, and limitations on storage time require walls, floors, and pump intakes to be close proximity to each other. From this background, the authors are carrying out a systematic study on the flow characteristics of intakes within a sump found in pump stations. Model pump intake basin is designed and PIV is adopted as a measuring tool to capture the instantaneous flow patterns. Special attention is paid to investigate the flow patterns near the free surface, side-wall, and back-wall due to different clearances from back-wall to vortical intake pipe. Moreover, the locations and patterns of the various types of vortices that were found in the examinations are discussed.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.563-569
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• 2001

The head-capacity curves for pumps developed by the pump manufacturer are based on tests of a single pump operating in a semi-infinite pool with no nearby walls or floors and no stray currents, Hence, flow into the pump suction is symmetrical with no vortices or swirling. Pump station designers rely on these curves to define the operating conditions for the pump selected. But various constraints such as size, cost, and limitations on storage time require walls, floors, and pump intakes to be close proximity to each other. From this background, the authors are carrying out a systematic study on the flow characteristics of intakes within a sump found in pump stations. Model pump intake basin is designed and PIV is adopted as a measuring tool to capture the instantaneous flow patterns. Special attention is paid to investigate the flow patterns near the free surface, side-wall and back-wall due to different clearances from back-wall to vertical in take pipe. Moreover, the locations and vorticities of the various types of vortices that were found in the examinations are discussed.

• The KSFM Journal of Fluid Machinery
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• v.20 no.1
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• pp.74-80
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• 2017

Pump sump system or pumping stations are built to draw water from a source such as river and used for irrigation, thermal power plants etc. If pump sump is improperly shaped or sized, air entraining vortices or submerged vortices may develop. This may greatly affect pump operation if vortices grow to an appreciable extent. Moreover, the noise and vibration of the pump can be increased by the remaining of vortices in the pump flow passage. Therefore, the vortices in the pump flow passage have to be reduced for a good performance of pump sump station. In this study, the effect of pump intake leaning angle and flow rate on the pump sump internal flow has been investigated. There are three cases with different leaning angle. Moreover, a pipe type with elbow also has been studied. The flow rate with three classes of air entraining vortices has been examined and investigated by decreasing the water level. The result shows that the air entraining vortices easily occurs at the pump intake with large leaning angle. Moreover, the elbow type of the pump intake easily occurs air entraining vortices at the high flow rate (or velocity) in comparison to other pump intake type.

• Journal of the Korean Society of Safety
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• v.26 no.1
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• pp.1-7
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• 2011

When the pumps stopped in the operation by the power failure, the hydraulic transients take place in the sudden change of a velocity of pipe line. Each and every water hammer problem shows the critical stage to be greatly affected the facts of safety and reliability in case of power failure. The field tests of the water hammer executed at Cheong-Yang booster pump station having an air chamber. The effects were studied by both the practical experiments and the CFD(Computational Fluid Dynamics : Surge 2008). The result states that the system with water hammering protection equipment was much safer when power failure happens. The following data by a computational fluid dynamic analysis are to be shown below, securing the system stability and integrity. (1) With water hammering protection equipment. (1) Change of pressure : Up to $15.5\;kg/cm^2$ in contrary to estimating $16.88\;kg/cm^2$. (2) Change rate of water level : 52~33% in contrary to estimating 55~27%. (3) Note that the operational pressure of pump runs approx. 145 m, lowering 155 m of the regularity head of pump. (4) Note that the cycle of water hammering delays from 80 second to 100 second, together with easing the function of air value at the pneumatic lines. (2) Change of pressure without water hammering protection equipment : Approximate $22.86\;kg/cm^2$. The comprehensive result says that the computational fluid dynamics analysis would match well with the practical field-test. It was able to predict Max. or Min. water hammering time in a piping system. This study aims effectively to alleviate water hammering in a pipe line to be installed with air chamber at the pumping station and results in making the stability of pump system in the end.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1309-1312
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• 2005

A multi-chemical supply system is developed and applied to a wet station, which uses the multi-chemical process in one bath. To control the concentration of two chemicals, control logic of a supply pump is programmed using the programable logic controller (PLC). By using the multi-chemical supply system, wet station with single bath is applied to cleaning process using multi chemicals such as buffed oxide etchant (BOE) and standard clean 1 (SC-1). The concentration of each chemical is measured in the bath to verify the multi-chemical supply system. The control range in the each chemical concentration is measured to 1.33weight% in NH4OH and 0.23weight% in H2O2. The multi-chemical supply system can be movable and usable as an independent module of fixed wet station. By simply midifying the PLC, a multi-chemical supply system can be developed for a wet station.

• Journal of Korean Society on Water Environment
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• v.23 no.4
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• pp.543-550
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• 2007

In this study, combined sewer overflows (CSOs) from five independent rainfall events in rural city area were collected and investigated. First flush effect in sewage pumping station located near the WWTP was retarded 30 to 60 minutes from booster pumping station. The ratios between SS, COD and TP concentrations prior to rainfall and peak concentrations during the period of rainfall were highly increased but nitrogen was relatively constant, which indicates that it is not associated with particles washed off from the surface of watershed. Mass balance results show that 30% of CSO was generated from booster pump station and 66.5% of CSO was from the whole runoff area. In the area of newly constructed sewer system, CSO problem was related with pump and sewer capacities, but in other old sewer system equipped area, it was due to the collection efficiency. Finally, Log-Log pollutant rating equations were suggested.