• Journal of the Korea Safety Management & Science
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• v.13 no.2
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• pp.275-282
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• 2011

A core device of foam system is the in-line eductor and it is the device to mix the foam liquid into liquid solution proper to the use density and the mixture ratio must be kept regularly regardless of changing fluid condition of the front and rear end of the in-line eductor. However, if the flux of the pressurized water changes, the mixture ratio is not kept regularly, and so it becomes a cause which a performance of fire-extinguishing deteriorates in discharging foam liquid. I devise a method to improve it that the metering orifice type in-line eductor is improved into the metering venturi type in-line eductor, the fluctuation of the mixture ratio to the flux change of the pressurized water is minimized and the performance of fire-extinguishing is kept regularly. As this method is simple in its structure and can be designed at a low cost, it helps for maintenance as well. In the future, it seems to need the research for the metering nozzle type in-line eductor in the future.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1998.10a
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• pp.180-192
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• 1998

One of the conventional gas burners has nowadays been used for ladle preheating. As a ladle is one of the open-type furnaces, however, it causes to consume much fuel because of high temperature of exhaust gas from the ladle and the exhaust gas passing through ladle cover makes it worsen a working environment nearby. Therefore, the objective of this study is to develop the recuperative burner system applying for an existing teeming ladle , which is integrated with burner, recuperator and eductor as one of the new type combustion equipments and has many advantages of simple installation, compactness and easy control, especially a great deal of energy saving through the waste heat recovery from exhaust gas. The contents of the study is to design, manufacture of recuperative burner system and to perform its tests experimentally after applying to the teeming ladle in the capacity of 100 ton. Its heat release rate is 1,700,000 kcal/h with COG(Cokes Oven Gas) as fuel gas. The test items are the temperature distribution inside the ladle and the preheated air temperature change depending upon the exhaust gas. Nox, exhaust gas analysis and noise.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.740-746
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• 2017

Infrared signatures emitted from hot exhaust gases generated by the internal combustion engine and generator of naval ships and from the metal surfaces of the funnel have become the targets of infrared homing missiles, which is the main cause of a reduced survivability of naval ships. The infrared signatures from the exhaust gas and the metal surface of a funnel can be reduced by installing an infrared signature suppression (IRSS) system on a ship. The IRSS system consists of three parts: an eductor that generates turbulent flow of the exhaust gas, a mixing tube that mixes the exhaust gas with ambient air, and a diffuser that forms an air film using the pressure difference between the inside and outside air. As a basic study to develop an IRSS system using domestic technology, this study analyzed the model test conditions of an IRSS system developed by an overseas engineering company and installed on a domestic naval ship, and a numerical heat-flow analysis was conducted based on the results of the aforementioned analysis. Numerical heat-flow analysis was performed using a commercial numerical-analysis application, and various turbulence models were considered. As a result, the temperature and velocity of the exhaust gas at the educator inlet and diffuser outlet and that of the metal surface of the diffuser were measured, and found to agree well with the measurement results of the model test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.793-798
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• 2017

In modern naval ships, an infrared signature suppression (IRSS) system is used to reduce the metal surface temperature of the heated exhaust pipe and high-temperature exhaust gases generated from the propulsion system. Generally, the IRSS systems used in Korean naval ships consist of an eductor, mixing tube, and diffuser. The diffuser reduces the temperature of the metal surface by creating an air film due to a pressure difference between the internal gas and the external air. In this study, design variables were selected by analyzing the shapes of a diffuser designed by an advanced overseas engineering company. The characteristics of the design variables that affect the performance of the IRSS were investigated through the Taguchi experimental method. A heat flow analysis technique for IRSS systems established in previous studies was used analyze the performance of the diffuser. The performance evaluation was based on the area-averaged value of the metal surface temperature and exhaust gas temperature at the outlet of the diffuser, which are directly related to the intensity of the infrared signature. The results show that the temperature of the exhaust gas was significantly affected by changes in the diameter of the diffuser outlet, and the temperature of the diffuser's metal surface was significantly affected by changes in the number of diffuser rings.