Benefits of using Twin Wire Electric Arc 400 Process over weld overlay are:
- Less Downtime.
- Higher Deposit Rate – No heat affected zone.
- Absence of thermal stress and distortion to the base metal.
- No annual maintenance – minimal inspection time.
- No pre-heat required. Base metal seldom above 150 degrees F. As a result thermal distortion is virtually non-existent.
- Under normal operating conditions, coating wear rates of one to four mils per year can be expected, depending on cooking environment. Compare that to 15-25 mils per year experienced with carbon steel.
Some examples of coated continuous digesters:
- Carter Holt Harvey in New Zealand, 125 vertical feet arc sprayed. Annual inspection of coating put on in 1999, verified very little or no wear after 4 years.
- International Paper Co., Franklin, V.A. coating was put on in 2000. 1800 Square feet coated, 34 vertical feet, K-1 Digester, very little wear, if any has been recorded.