Issues:
• Process unstable when entering deep vacuum
o Enter vacuum in a more controlled manner, fine-tune level control PID’s, place bigger balance tank.
• The times we lost the level in the dearator, the process remained in the “production” step. Automation should switch to product circulation when this happened.
o Modify step in PLC program
• When the balance tank ran dry, the product went into circulation (as intended), but the supply feed was stopped. This caused the system to run dry.
o Modify step in PLC program
• The target temperature of 28oC was not met.
o Lower speed of circulation pump
• The viscosity of the product was low.
o Ensure deep vacuum in order to stabilize homogenization temperature; Measure visco at higher frequencies, increase homogenization pressure at higher frequency.
• Low level of the buffer tank was not properly detected by the automation can only detect when 2 tanks are empty (usually the two buffer tanks are used in series).
o Place a low level switch in the discharge line to overrule the old level switches, which cannot be used efficiently by the new automation.
• Unusual high current for CP001.
o Talk with TetraPak on their design choice. Pump performs poor when running on SCM