Posted On January 16, 2025
A bleached paper and board mill in North Carolina, USA, needed to provide consistent green liquor temperature to two causticizing lines in the recovery process. The mill operates two causticizing and lime kiln lines and heats green liquor to each line. Precise temperature control of the green liquor to the slaker is crucial to a smooth operation.
HEATER 1
- Fluid: Green Liquor
- Flow Rates: 600-1000 GPM [136-227 m³/hr]
- Inlet Temperature: 165°F [74°C]
- Discharge Temperature: 180-185°F [82-85°C]
- Steam Supply Pressure: 150 PSIG [10.3 barg]
HEATER 2
- Fluid: Green Liquor
- Flow Rates: 1200-2400 GPM [273-545 m³/hr]
- Inlet Temperature: 160°F [71°C]
- Discharge Temperature: 185°F [85°C]
- Steam Supply Pressure: 150 PSIG [10.3 barg]
SOLUTION
Hydro-Thermal has supplied a K414AN and K415AN Hydroheaters for the two differing production rates of the causticizing lines. The first orders were 23 years ago and have been operating a Hydroheater for green liquor since. The mill is pleased with the consistent performance of the heaters and has developed a preventative maintenance plan to rebuild the heaters annually to ensure uninterrupted operation – per the mill “we probably over do it (with preventative maintenance) but it’s a critical operation so we can’t take a chance”. The mill purchased an upgraded model in the K515AN in 2009 to replace the K415AN and is continuing with the same performance.
GOAL
• Precise temperature control
• Smooth operation
ACCOMPLISHMENTS
• Precise temperature control
• Uninterrupted operation
• Eliminated downtime due to maintenance
“We probably over do it (with preventative maintenance) but it’s a critical operation so we can’t take a chance.” – Mill Maintenance Mgr.
Are you wondering what applications are ideal for direct steam injection? Visit our industries page to learn more about industries and applications.
