6. APPLICATION IN OTHER FIELDS
6.1 Reliability of Hydraulic Machines
A construction machine company in Japan adopted the kidney system. As the result, their products are much improved in reliability [3]. Table 4 shows that machine troubles reduced to 0.26% from 8.99% by using the kidney system.
Table 5 shows a comparison between fresh oil and oil being used. As is shown, the oil in use even became cleaner than the fresh oil and the oil grade was improved to NAS6 from NAS8 in the machines equipped with the kidney system. This is why the machines equipped with the kidney system are improved in reliability.
6.2 LO Recycle from Waste Water
Kidney system was adopted to recycle LO mixed in waste water from some compressors of a fertilizer plant. In the fertilizer plant air is compressed and cooled. Water vapor in air is condensed to water in the cooling process and some LO is mixed into the condensed water.
A large amount of waste water mixed with LO was generated every day and this had been a hard environmental problem for the fertilizer company. The authours have developed a system that enabled it to separate and recycle the LO mixed in waste water [5]. The system has been working well for about ten years.
The recycling process is as follows. (1) The waste water is evaporated by using excess steam which is available for no cost in the plant. The waste water includes about 99% water and about 1% LO in in the seansons of high moisture such as in summer. (2) After evaporating the water, the contaminated LO is cleaned by the kidney system.
Fig. 12 shows (a) fresh oil, (b) waste water mixed with 1% LO which looks milky and (c) the recycled LO. The recycled oil became even cleaner than fresh oil from NAS 9 to NAS 8 in this case. As the result, LO consumption decreased to about 1/10 using the recycled oil.
6.3 Model Plant without Any Waste Water and Waste Oil
The concept of the kidney system was applied to build a model plant without any waste water and waste oil in Thailand. Also in Thailand, waste water from the industrial problem. Therefore, it was planned to build a model plant with a closed system of water flow and LO system without any waste water and any waste oil.
Fig. 12 Recycled oil from waste water
