Automated continuous mixing delivers real-time process assessment and consistency round the clock.
Continuous mixers allow for all parameters to be constantly monitored and saved digitally, including ingredient stream rates, dough temperature, mixing energy input, throughput, mixer shaft speed, coolant temperatures, starts and stops, ingredient refill status, ingredient totalizers, dough totalizers, and many others. Exact Mixing’s continuous mixing systems, for example, are fully automated, meaning that the operators need only respond to alarms in case readings show parameters deviate from preset values, which doesn’t happen very often. The collected data is saved and used to generate graphs to compare actual values against set points. Information quantifying the dough production is also available, with details about its current progress, the amount completed per shift, or sorted by any other criteria that are useful to production.
”We now offer five distinct continuous mixing models for different applications and customer requirements. The HDX Mixer is just one example of technology expansion.“
Jim Warren, Vice President, Exact Mixing
“The analysis of the data can then be configured in any way that the end-user sees fit. In the control system, all parameters are constantly monitored, and statistical analyses of parameters are available. The available information is only limited by the imagination of the person seeking the data,” Jim Warren, Vice President, Exact Mixing, explains.
Systems ready for the unexpected
The ingredients’ temperature commonly varies during the mixing process. Differences can be cyclical if the flour is stored in a silo outside or can occur between days and seasons. When dough is produced with continuous systems, other parameters are not likely to vary in the absence of external influences. With continuous mixing, products and processes are fully repeatable from shift to shift and day to day because the metering and mixing processes are fully automated. If there are variations identified, they are generally corrected automatically, before the operator has time to react.
But, “If one parameter continues to create alarms, the system needs to be inspected to determine the cause of the upset. For example, temperature variations can be automatically compensated for with our dough temperature measuring instrument when used in conjunction with our water blending valve,” Warren explains. The water temperature is automatically adjusted to match a set point for the dough temperature. However, in case of a failure with the hot water supply in the plant, the mixing water temperature cannot be reached. “In this situation, the operator would have to be involved because the source of the hot water is outside of the mixing control system scope,” he recommends.
© RBS
“Technology is constantly improving”
Fully automated ingredient metering into the mixer is part of the Exact Mixing scope, as accurate metering is critical to the success of continuous mixing. For this reason, developments for this technology have advanced at the same pace with R&D of upgrades to mixing technology.
“Accuracy is ensured using the latest metering technology including loss-in-weight dry metering technology and mass flow liquid metering technology,” Exact Mixing’s VP explains. The measurements recorded are continuously compared with the setpoint data to adjust the process if necessary, or issue warnings if automated corrections are not possible, to protect consistent dough quality. Ingredient delivery technology is a continuous improvement priority for Exact Mixing. The company has recently developed systems that accurately meter ingredients such as solid shortenings, nut-butters, diced cheese, and dried fruit.
The mixing specialist is also constantly bringing improvements to its continuous mixing technology. “For example, we now offer five distinct continuous mixing models for different applications and customer requirements. The HDX Mixer is just one example of technology expansion.” It was developed 10 years ago to allow for the mixing of highly developed doughs such as bread and buns. “More recent technology breakthroughs include the high-speed developer and Hydrobond Technology instant hydration units,” Warren details. All advancements can be fitted onto existing systems. “The core of our continuous mixing has been stable and built around automation. The systems and technologies that are newly developed are meant to augment this base, not replace it,” Warren elaborates. New features are commonly brought online to existing equipment; program upgrades can be made locally, in most cases, and remotely on newer systems with connectivity features.
In addition to these advancements, automation features can step up as requested, with many options available to choose from, such as the automated control of the ingredient and water temperature, automated dough re-work, automated control of the dough hopper level downstream – to name a few. Fully-automated control packages Exact Mixing provides include (but are not limited to):
+ Recipe setup, storage, and control
+ Recipes can run for a fixed amount of time, or production can be set for a fixed amount of resulting product
+ Fully graphical presentation for controls, for easy management
+ All parameters are recorded as well as all alarms, input changes, and operator interventions. Other types of data can also be added for monitoring and analysis.
+ System parameter changes are indicated by color changes on the operator interface
+ A general operations screen for an overview of the process, as well as detailed screens for subsystems
Overall, continuous mixing is designed for maximum process efficiency. Such steps are established to do just that, to ensure all parameters are measured and recorded, and that the resulting data is immediately useful. “The goal is to have the operators focus less on ‘making dough’ and focus more on making the best dough. For this to happen, we must give the operator the best, real-time information possible,” Warren underlines.
The article is part of an extended feature, which was originally published in [BBI 2 – 2022]. Read the full article in the magazine:
