Hitachi RCUE40AG2 Service Manual page 161

Maintenance
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Step 4:
Wastewater treatment
Acid-proof pump operation is stopped.
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Wastewater is put to the tank for wastewater collection.
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Water is put in the tank for cleaning and the tank is washed with pump.
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Water used before is also put to the tank for wastewater collection.
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While confi rming with pH test paper, neutralization agent is added gradually to
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neutralise the tank.
Neutralised wastewater should be treated by industrial waste disposal contractor.
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In case that wastewater is diluted by much abundant of water and drained to public
sewer, consult with a cleaning agent company in advance.
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Step 5:
Neutrization treatment
Water is put in the tank for cleaning.
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Acid-proof pump is operated while air is pulled out.
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While confi rming with pH test paper, neutralization agent is added gradually so that pH
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value be 7~9.
After pump is operated for prescribed time, neutrization treatment is fi nished.
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After fi nishing neutrization treatment, neutrization liquid is drained to public sewer.
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Circulation pump is operated and circulation system is washed suffi ciently until dirty
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liquid is totally out.
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Step 6: Re-start operation
Water pipe is installed as before the cleaning.
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After cleaning, water treatment is performed to prevent the corrosion occurred at
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operation start.
pag. 159
SMGB0003 rev.0 - 11/2006
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