Preventing Condensate Contamination in Evaporator Circuits in Sugar Industry

The sugar plant’s return condensate from the evaporator is typically pure and has very low conductivity, and is directly fed to the boiler feedwater.

Leakage in the evaporator circuit, where juices are heated, causes the juices to mix with the water, resulting in condensate contamination. This contamination increases condensate conductivity and decreases its pH.

Since this contaminated water is fed directly to the boiler, the high conductivity can lead to the scaling of boiler tubes.

The solution included:

• A plate-mounted system supplied along with a sample cooler and pressure regulating valve to decrease the condensate temperature and pressure.
• A dual-channel transmitter was supplied for monitoring pH/Cond (conductivity) reading.
• The system uses the transmitter to measure against limits and operate a high-limit relay. This relay operates a 3-way ON/OFF valve to divert the sample if the conductivity or pH goes beyond the desired limits.

Continuous Quality Monitoring: The system provides continuous, real-time monitoring of condensate quality, which ensures the immediate detection of contaminated condensate and diverts it from the boiler circuit, a process that was previously undetected without online pH or conductivity measurement.

Enhanced Process Control: The solution helped isolate contaminated condensate, leading to improved overall process control.

Reduced Contamination and Risk: By providing early detection and an automated online system, the plant significantly reduced contamination, which had previously occurred due to syrup mixing with the condensate during evaporator leakage.

Improved Efficiency and Purity: The automated system ensures consistent product purity and protects the brand’s reputation. It also requires minimal manual intervention, which reduces manpower effort and improves overall plant efficiency.