As pure PTFE and expansive graphite are hopeful as the material of non-asbestos seatgaskets, the comparison with the performance of asbestos seat gaskets are carried out for one of non-asbestos seat gaskets. They have the same size in dia. and the thickness of 1.0, 1.5, 2.0 and 3.0 mm respectively. The items of the test are the maintenance “m” factors and yield “y” stresses. The test pressure with the nitrogen gas are 2.06 MPa and 0.014 MPa respecively. The “m” factors of 1.0, 1.5 and 2.0 mm thickness of PTFE and graphite seats have the constant figures of about 10 and 25 respectively without depending on thickness. The “y” stresses of them also have about 12 MPa and 3 MPa respectively. But the figures of both gaskets of 3.0 mm in thickness have different ones so that they may be depended on thickness, if it would be over 2.0 mm. And it was confirmed that the “y” stresses of asbestos seats by gas fluid are remarkably exchanged with thickness. Though the performance of graphite seatgasket is a little inferior in “m” factor and the “y” stresses of PTFE of 3.0 mm in thick is little high, PTFE and graphite seat gaskets can replace asbestos one with the select of temperature, corrosive fluid and so on in cosequence of the result.
Double rubber mount system of main engine was adopted to the research vessel of Fisheries Agency in order to achieve high performance as vibration isolator. In this paper, design method of doublerubber mount system, it's effect of vibration isolation and the measurement result of underwater noise level radiated from the vessel are described.
Blending pyrolitic oil (or Waste Plastic Disposal, called WPD for short) produced from household and industrial plastic wastes with natural bitumen, which is 70% (v) of orimulsion, reduces the viscosity of the natural bitumen. The experimental results indicated that, the WPD mixing ratio of 20% (v) reduces the natural bitumen's viscosity from more than 500 cSt to 20 cSt at 50°C. The blended oil has been applied to a small size high-speed single-acting 4 stroke diesel engine (14 kW, 2200rpm) without preheating the oil. The engine test with non-preheated blended natural bitumen has proved the possibility of WPD-blended natural bitumen as a fuel for diesel engines. In order to improve the engine performance and exhaust characteristics, the far-infrared fuel filters have been tested. The engine test result has shown the effect of the far-infrared fuel filter in the aspect of enhancing the engine performance stability and reducing NOx and N2O emission.
In order to establish the measuring method of particulate emission from marine diesel engines during voyage, following two experiments were carried out. (1) Trial to measure the particulate emission from a 2342 GT experimental ship equipped with a 2795 kW 2-cycle marine diesel engine and a controllable pitch propeller. (2) Trial to clarify the effect of measuring procedure of particulate emission using a high-speed marine diesel engine on the test bench. For both the ship and the test engine, same partial-flow dilution tunnel was applied. Results obtained from the examinations are as follows. (1) According to the measured emission data from the experimental ship, the higher the engine load was, the more particulate emission (g/kWh) was emitted both with propeller and generator characteristics. (2) It was also confirmed that measuring the output horsepower accurately on board was as important as measuring the accurate particulate emission because the data should be evaluated as g/kWh same as the data on the test bench. (3) As a result of the examination on the measuring procedure using the high - speed marine diesel engine, the effect of filter loading, dilution ratio, shape of sampling probe, length of sampling line were clarified.
The exhaust gas of marine diesel engine contains a lot of NOx, SOx and PM, that is, it contributes to global warming and air pollution, and the IMO has regulated the NOx emissions for the vessels built after January 1st, 2000. KHI has the experience of research about DeNOx methods, for example, timing retard, EGR, fuel-water emulsion, natural gas and methanol ignited with pilot fuel oil, and SCR with NH3 or HC. This paper introduces the test results of DeNOx system for marine diesel engine by SCR with liquid hydrocarbon extracted from marine diesel oil, which has the advantage in cost, treatment and supply compared with troublesome NH3 system.