Many other diesel engines equipped with the kidney system show the same and good results. LO consumption has reduced to about 1/5 〜 1/10 of the conventional LO system in most engines.
Table.1 shows an analysis of LO sludge. LO sludge is composed of FO, LO, combustion products, deteriorated FO, LO and solid impurities. The deterioroted FO and LO are soluble in toluene and can be separated from sludge. Table 1 shows that the sum of the deterioroted FO and LO amounts to only 5.9〜6.9Wt% of the total sludge. On the other hand, sludge generation rate(αs) is 1.35〜6.9g/kw/1000h in Table 1. In our experience, αs is below 13.5g/kw/1000h in ordinary engine condition. Let it be that α s is between 1.35〜13.5g /kw /1000h and that the maximum ratio of the oxdized LO in sludge is 10%. Then, generation rate of LO deteriorotion is 0.135〜1.35g/kw/1000h. In general, LO capacity of marine diesel engines is about 1.35L/kW. This means that only 0.01〜0.1% of LO content is deteriorated every 1000 hour in ordinary engine running condition.
Table 1 and Fig.3 verify the fundamemtal assumption of the authors' theory.
Table 1 Deteriorated LO in sludge
3.2 Performance Comparison
(1) LO Cleanliness A comparison test was carried out in three ships of the same type equipped with the engines of the same type. No cleaning system, the conventional and the kidney system were compared. As is shown in Fig.4, n-P insoluble was kept below 0.1% in the kidney system during 10,000 hour running. In other two systems, however, n-P insoluble increased rapidly and LO was renewed with fresh oil in 4000〜6000 running hours.
Table.2 is the result of the other comparison test. The test was conducted on two engines. One of them was equipped with the conventional system and the other with the kidney system. The two engines started running at the same time and a measurement of number of eontaminant particles was made after 5000 hour running. As shown in Table 2, number of contaminant particles in the kidney system is 1/7〜1/4 of that in the conventional system.
Fig. 4 Comparison test
Table 2 Comparison test of filtration
(LO dilution ratio 1/100)
Dia ; Particle diameter
Kid ; Kidney system
Con ; Conventioal system
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