From Manual to Automated: Whiskey Distillation with AutomationDirect PLCs

Welcome to AutomationDirect, your number one source for practical, high-value industrial automation solutions since 1994. Today, see how our Click Plus PLC and C-more HMI bring precise control to a real-world small-scale whiskey distillation project, delivering accurate temperature regulation, PID tuning, and effortless monitoring. Let's dive in!" Small whiskey distillers commonly use a double distillation process reflecting traditional practices. They make mash using grain, and once fermented, it goes through an initial stripping run using a pot still. A second, more selective distillation follows called a spirit run raising proof to a higher level for bottling or aging. Complications arise because ethanol content and, therefore, the boiling point varies during this process. So careful temperature control is crucial and requires some finesse. Our team wanted to apply big-industry techniques to this small-scale process application, using a cost-effective yet capable PLC and HMI, combined with RTD temperature sensors and control elements. To create an efficient and controllable separation process, we use a packed distillation column similar to industrial-grade equipment but on a smaller scale. A small dephlegmator, a shell-and-tube condenser, is located at the column top to create condensate for reflux, which falls back into the column for improved separation efficiency. This approach is highly effective, but requires careful cooling water flow control. Steam temperature at the dephlegmator exit defines the resulting ethanol content. For example, creating ethanol at 80% calls for steam around 83 °C. So, we make this value the set point and have the control system adjust cooling water flow accordingly. Previous attempts to control cooling water flow included a manual needle valve and, later, an Arduino-controlled pump. However, the best loop control results were achieved when we implemented PLC and HMI-based automation. For this operation, we chose a two-slot CPU from Automation Direct's Click Plus PLC family. A digital output card is in the first slot and a Node-RED controller in the second. Adding two four-channel RTD modules provides more than enough temperature inputs. This PLC offers considerable processing speed and native RTD interfacing as well as built-in PID control. It was also a simple matter to add a stepper motor controller for the parastoaltic pump and a C-more 10-in touchscreen HMI to display data and serve as an input device. This PLC and HMI combination is capable of measuring, displaying, and logging multiple temperature points using these values to modulate pump speed with a stepper motor via PID regulation. The PLC also includes automatic PID loop tuning, which is especially helpful for commissioning temperature control loops, which are notoriously difficult to dial in due to lag times. By simply adding an internet connection, easily accomplished with wired or wireless methods, cloud connectivity via Node Red allows data logging and monitoring from anywhere. This PLC HMI solution, based on easy-to-use off-the-shelf hardware and software, provides exceptional control versatility and access to process data, yielding multiple benefits. First, accurate temperature control yields high-quality product, and the many temperature measurement points are logged so we can analyze the data to document performance and investigate additional optimization options. Second, pump speed defines dephlegmator cooling water flow. When flow is combined with the inlet and outlet temperature differential, we can calculate the heat removal rate in watts, providing another useful operational metric. Third, clear visualization and effective control frees users to focus their efforts on improving the product. The HMI also enables addition of other enhanced functions such as accepting user inputs for indicating when quart jars are sequentially filled at the discharge through the run. This configuration allows the operator to control final ethanol percentage from start to finish. For a neutral spirit, running the column with a high reflex rate can easily deliver above 90%. Or lower to preserve the mash flavor profile. The key to achieving this is high-performance automation, able to adjust the reflux rate automatically when required throughout the run as available ethanol content decreases. It's all possible using basic off-the-shelf automation devices with simple programming learned through Automation Direct's tutorials and technical references. And THAT'S how AutomationDirect's Click Plus PLC, with native RTD support, built-in PID control, automatic tuning, and cloud connectivity via Node-RED, plus our reliable C-more HMI, turns complex processes like distillation into precise, repeatable results! Visit AutomationDirect.com to learn more, get free training, or shop these components. Like and subscribe for more automation tips and real-world demos, and hit the bell so you never miss an update! Automation Direct, THE number one value in Automation!