Summary

Foam collecting at the top of a filtered juice-filled tank was causing the tank to overflow, wasting product and causing safety hazards. Engineer Ober Yela uses the UniStream PLC + HMI’s embedded, autotuned PID and a 3rd-party laser level sensor capable of reading foam level, while programming both the control program and HMI with UniLogic free automation software—problem solved!

The Company

With over 40 years of operation, Azucarera del Norte (Azunosa) is one of Honduras’s leading sugar producers and a regional pioneer in automation-driven clean energy generation. Located in the Sula Valley near San Pedro Sula, the mill integrates advanced process control systems to maximize efficiency, reliability, and sustainability across its sugar production and power generation units. Azunosa produces 36 million kWh of renewable energy annually, supports more than 13,000 people through direct and indirect employment, and partners with over 450 local suppliers, contributing to both industrial innovation and community development.

The Challenge

To produce sugar from sugarcane, the harvested stalks are first washed, shredded, and crushed to extract the juice. Next, the juice is then clarified, concentrated by boiling, and then crystallized. These crystals are spun in a centrifuge to separate them from the liquid molasses, producing raw sugar.

Engineer Ober Yela, head of projects at Central de Mangueras in Honduras needed to solve a recurring issue in this process: the filtered juice tank frequently overflowed due to foam buildup. at the top of the tank. Foam spills were relatively frequent, leading to product waste, cleanliness issues, and operational safety.

The existing level measurement technology could read the liquid level—but not the foam level.

The Solution

Engineer Yela, an experienced user of Unitronics automation products, selected a UniStream PLC + HMI controller to meet this application's challenge.

He used the UniStream’s embedded, autotuned PID functionality and a 3rd-party laser level sensor capable of reading foam level. After selecting, installing, and commissioning the laser sensor, he fine-tuned the PID loop to obtain tight control of the pump to tank level.

The HMI trend graph on the UniStream panel clearly illustrates precise control, thanks to the modulation of the pump frequency that transfers the juice to the next process. The two curves—which appear almost as one because the variation between the process value and the setpoint are very similar— show a horizontal line (a mixture of green and red).

Benefits / Results

Engineer Yela’s elegant use of the PID feature that is embedded in UniStream PLCs enabled him to maintain consistent tank level. Eliminating foam-related overflows preserves raw product, boosts production efficiency, and improves safety while reducing cleanups; in short, problem solved—no more spills!

UniLogic automation software, the all-in-one programming environment for UniStream controllers, allowed Mr Yela to configure the PID, control the pump of the tank system, and to design HMI screens that enable close tracking of tank level.

Via UniStram’s embedded HMI panel, operators both can view and control the application.

Engineer Yela reports: “Over the years, I have built many projects using Unitronics’ automation products. Their all-in-one products enable me to give my clients excellent results”.