Chongqing Fengyu Oil Purifier Factory

Li Guangmo (5 patents owner)

Keywords: Storage tanks and pipelines should fulfil waterproof, drainage and moistureproof; Dry air generator can ensure the fast processing.

When the power departments used the DZL-150A double-stages oil purifier to deal with the transformer oil for the Daya Bay Nuclear Power Plant and others in Harbin, after treated over 10 times for oil, the breakdown voltage has been kept about 45kv and the moisture kept over 10ppm. Therefore, our technical personnel went to the site and changed the filter element. There was a little impurity in the filter element. The effect for breakdown voltage of impurity was eliminated. The key was moisture. There has been appeared a little vapor from vacuum pump exhaust. It indicated the moisture was not got rid of from the oil. The reason was the structure of oil tank. Handling oil tank as follow:

We put suction head and small plastic pipe into the # 1 pot from manhole. With siphon absorbed the bottom oil, we found bead in it. It proved there was water in the bottom. Therefore, the deposit of water could not be got rid of one time, when the oil was flowing. The treated oil all along existed moisture in order to the breakdown voltage could not be raised within 40kv to 45kv. Finally removed the # 1 pot, we had been found seeper in the bottom and absorbed moisture with cotton yarn. The oil was filtrated again, the breakdown voltage reached above 60kv. Where did the deposit of water come from? There were the following reasons that based on the analysis by our technology that dealt with the oil at the site.

1) When the storage and transport of old and new oil, once it was rain and humid weather, the water was unavoidable to enter. Once moisture entered into the flat barrel, whatever oil purifiers could not get rid of the moisture in one day. The oil would release micro-moisture long and slowly.

2) Although the drain tap was wrapped with plastic sheeting, by the sun and the rain, plastic sheeting has been cracking. It was entirely possible for the mositure to enter from the vent-pipe in the rainy and snowy weather.

3) The oil pot must breathe a time every day. After outside a biggish moisture enters the oil pot and meets cold oil, it will be freezed bead and sinked in the bottom of pot.

4) The water may be entered because the top is flat and welding line easily bring rust and perforation, or the screws of manhole flange are not full installed above is flattened, or the flange gasket was destoried or lost springiness.

5) The hose of jerrican is too thick or the pipeline of oil purifier is too thin, which all easily bring the seeper circs. In this connection, we suggest you use the standard oil tank. Figure # 2 is characterized by:

①Underside is taper can not cause dead area of moisture accumulation. Any external moisture will be removed from the bottom.

②The top has also a certain taper avoids seeper, rust, perforation, waterleakage and airleakage.

③Setting a respirator with oil seal and alterable silicagel, has avoided outside humidity to enter. The respirator can rapid handle, if you want the breakdown valtage is more than 70kv and the water content is less than 10ppm. Checking the oil locality to see whether it’s normal or the silicagel becomes red, when the oil was filterated. If the silicagel doesn’t work, we should take it out and bake it at 120℃ until it becomes blue, or use a new and blue silicagel.

④The hose at the bottom of oil tank should keep identical with that of oil purifier, which can avoid the underside thick pipeline that engenders seeper phenomenon. On designed and formed underside thick pipeline, we should connect with lesser oil filtration pipe.

⑤When the fresh oil is entered the oil tank, it should be hold still one day. Then the water should be removed from the bottom drainvalve.

⑥According to the national standards " the guidelines of the vacuum oil purifier". Before oil is entered to the vacuum oil purifier, the impurity and moisture should be removed by the plate pressure oil purifier. So as to the breakdown voltage can reach at least 25kv and the water content is less than 50ppm. Avoiding the water and impurity enter the oil purifier. And avoiding the filter element and vacuum tank are polluted.

⑦Using dry air generator to connect it with the oil filltration system, shown as following graph. Under especially the hot and humid conditions, it is not easy to ensure the outside moisture to enter the oil tank, filling in dry air immediately will greatly shorten processing time for the oil treatment project.

⑧ Simply using the plate pressure oil purifier and dry-air machine can also improve the breakdown voltage and reduce the water content of the oil. But for the being treated oil with strict requirements for gas contents, we should adopt the vacuum oil purifier.

Postscript: The double stages vacuum oil purifier deal with the transformer oil at site, as a result of the above factors and climatic conditions, such as in dry winter, the moisture in the air is 6ppm/l. In the summer or indoor the moisture can be achieved above 60ppm/l. The difference of the disposal effect is great. The processing time in the humid climate is generally 10 times than that in dry air. If using the dry air generator and the water content of gas is below 0.13ppm/l. it will greatly reduce the water content of the air in oil tank. And it will quite isolate the influence of outside humid air. Under any climatic conditions, it can guarantee enhancing the efficiency of oil filtration. Forenamed situations are the practice of handling oil at site, supply reference for needing rapid processing time of oil treatment.