When experiencing ozone concentration instability in a bottled purified water filling line, which equipment and parameters should the operations team inspect first?

In the production of purified water for PET bottles, maintaining precise ozone levels during the finished water storage and sterilization phase is critical. Ozone concentration instability can lead to inadequate sterilization or residual odor in the final product before the washing, filling, and capping stages. When operations teams detect fluctuations in ozone levels, a systematic inspection of the generation, mixing, and control equipment is required.

Priority Equipment & Parameter Inspection Checklist

To diagnose ozone concentration instability, focus on the following core subsystems:

• Ozone Generator Unit: Check the cooling water temperature and flow rate; excessive heat reduces ozone yield. Inspect the air preparation system to ensure the intake air dew point is sufficiently low. Verify that the input power voltage is stable, as voltage drops directly impact discharge efficiency.
• Gas-Liquid Mixing System: Inspect the Venturi injector or mixing pump for blockages, wear, or cavitation. Check the water pressure and flow rate entering the mixer, as a drop in water pressure will reduce the suction volume of ozone gas, altering the gas-to-liquid ratio.
• Monitoring and PLC Control System: Verify the calibration of the inline ozone concentration sensor. A fouled sensor probe can send false low-reading signals to the PLC, causing the system to overcompensate. Check the PLC feedback loops and ensure the proportional valves are responding correctly to setpoint changes.
• Storage and Contact Tanks: Inspect the finished water storage and sterilization tanks for proper sealing and exhaust valve function. Excessive off-gassing or pressure drops in the tank can cause dissolved ozone to escape prematurely.

Service Conditions and Safety Preparations

Before conducting physical inspections on the ozone generator or mixing pipelines, the operations team must isolate the power supply and ensure adequate ventilation in the equipment room, as ozone is a toxic and highly reactive gas. Routine checks like sensor calibration and pressure gauge readings can be performed during normal operation, but internal component inspections require a scheduled line shutdown.

Service Boundaries and Limitations

While on-site teams can handle parameter verification, sensor cleaning, and filter replacements, internal faults such as degraded dielectric tubes in the ozone generator, severe cavitation in the mixing pump, or complex PLC logic errors require specialized intervention. Attempting to repair high-voltage discharge components without proper training poses severe safety risks and may void the equipment warranty.

Next Steps

If the basic parameter checks do not resolve the instability, compile the PLC alarm logs, historical concentration trends, and current operating pressures. Contact Chuxin Mingwei’s after-sales support team with this data. Our technical engineers will provide remote diagnostics or dispatch a specialist to inspect the water treatment and sterilization equipment, ensuring your purified water production line returns to optimal stability.