Temperature control is one of the few production parameters in beverage manufacturing where there is genuinely no acceptable margin for error. For a brewing customer expanding their site, the reliability of the refrigeration system cooling their large beer tanks was not a convenience feature, it was a direct determinant of product quality, since beer temperature falling out of specification at any point in the process represents a serious quality failure with no straightforward way to correct it after the fact.
The challenge
As part of the customer’s ongoing site expansion, Bevtech was approached to implement an automated control system to manage two glycol refrigeration units responsible for delivering cooling to the site’s large beer tanks. The system needed to continuously monitor temperature and pressure across both units, calling the units and their associated pumps into operation precisely as required to maintain cooling within specification. Given that any lapse in this cooling function would risk the beer temperature moving out of specification, the control system needed to be both highly reliable and precisely tuned, with no tolerance for the kind of erratic or delayed response that a poorly configured control loop can produce.
The engineering approach
Bevtech’s control system engineers designed and implemented the solution around a Siemens 1500 series PLC, selected for its processing capability and reliability in continuous duty industrial applications, paired with a Siemens touchscreen HMI giving operators clear visibility and control over the refrigeration system’s status and parameters. ABB variable speed drives were integrated to provide precise, modulated control over the refrigeration units and pumps, rather than the cruder on or off control that a simpler system would rely on, allowing the system to respond proportionally to actual cooling demand rather than cycling abruptly between fully on and fully off states.
At the core of the control strategy, PID, proportional integral derivative, control loops were configured to continuously balance temperature and pressure feedback against the cooling demand of the beer tanks, smoothing out the response to avoid the kind of overshoot and oscillation that a poorly tuned control loop can introduce. This precision matters considerably in a refrigeration application where the consequence of overshoot is not just minor inefficiency, but a genuine risk to product quality if temperature swings outside the required range, even briefly.
Why this approach was chosen
The combination of Siemens PLC and HMI with ABB variable speed drives reflected a deliberate choice to prioritise both reliability and operator transparency. The HMI gives site staff immediate visibility into system status and any developing issues, supporting faster response if a fault does occur, while the modulated, PID controlled approach to the refrigeration units themselves reduces mechanical wear compared to abrupt on or off cycling, supporting longer term reliability of the refrigeration equipment alongside more stable temperature control.
The outcome
The completed system gave the customer continuous, automated management of their glycol refrigeration capacity across both units, with the precision control needed to keep beer tank temperatures reliably within specification throughout the site’s expanded production capacity. By removing manual intervention from the routine cooling control function and replacing it with a properly tuned automated system, the customer gained both the reliability needed to protect product quality and the operational visibility, via the HMI, to monitor and respond quickly should any parameter begin to drift.
The broader lesson for beverage manufacturers
This project illustrates a pattern that applies broadly across temperature and pressure critical processes in beverage manufacturing, that the value of a well engineered control system is not simply automation for its own sake, but the precision and reliability that proper PID tuning and quality components like variable speed drives bring to a process where the cost of getting it wrong is measured in product quality, not just convenience. For manufacturers running refrigeration, temperature control, or similarly critical processes on ageing or manually managed systems, this kind of project demonstrates what a properly engineered automated solution can deliver.
Engineering support for critical process control
Bevtech Engineering and Automation specialises in control system design for the food and beverage manufacturing sector, with direct experience delivering precision refrigeration, temperature, and pressure control projects using both Siemens and Allen Bradley platforms. To discuss a similar control system project for your facility, contact Bevtech on +61 400 881 321 or admin@bevtech.com.au, or visit 25 Silvio St, Richlands QLD.