Moving from R&D to Full-Scale Production with Consistent Results
A successful pilot batch is an important milestone. The next challenge is producing the same result consistently at commercial volumes.
Scaling a mixing process involves more than increasing the size of the tank and multiplying ingredient quantities. As batch volume increases, tank geometry, mixing energy, impeller performance, heat transfer, ingredient addition, and process timing all change. A process that works well in a 50-gallon pilot vessel needs to be carefully evaluated before moving into a 500, 2,000, or 5,000-gallon production tank.
The goal of scale-up is to understand which process conditions created the successful pilot batch and then design commercial equipment that can reproduce those conditions reliably.
Start with What Made the Pilot Process Successful
Before designing production equipment, document the pilot process in detail.
Understanding the recipe is important, but understanding how the recipe becomes the finished product is equally valuable. Mixing speed, ingredient addition sequence, temperature, shear, processing time, and other operating conditions can influence the result.
Useful information to document includes:
- Batch volume and working volume
- Product viscosity throughout the process
- Mixer speed and impeller configuration
- Ingredient addition order and timing
- Heating and cooling requirements
- Mixing and hold times
- Critical product quality characteristics
This information creates a baseline for determining what needs to remain consistent as production increases.
Tank Geometry Changes the Mixing Environment
Moving from a pilot tank to a larger vessel changes the physical environment in which mixing occurs.
Diameter, sidewall height, working volume, and liquid depth all influence circulation. Increasing tank capacity without considering these relationships can change how material moves through the vessel.
A larger tank may require a larger impeller, multiple impellers, or a different agitation strategy to maintain the circulation achieved during pilot production. The tank’s aspect ratio can also affect solids suspension, top-to-bottom turnover, and the ability to maintain uniform product conditions.
Our guide to mixing tank sizing provides additional information about how working volume, diameter, and sidewall height affect mixing performance.
Mixing Energy Needs to Scale with the Process
Mixer RPM alone is not an effective way to scale a process.
A small impeller operating at a particular speed in a pilot vessel does not create the same mixing conditions when that RPM is applied to a much larger impeller. Impeller diameter, tip speed, power, torque, flow pattern, and the volume of product being moved all contribute to mixing performance.
The right scale-up approach depends on what the mixer needs to accomplish. That may include:
- Maintaining solids in suspension
- Blending two or more liquids
- Incorporating powders
- Creating or maintaining an emulsion
- Moving high-viscosity materials
- Achieving a specific level of shear
Understanding the objective allows engineers to select a mixer and impeller configuration that reproduces the important characteristics of the pilot process at a larger scale.
Our impeller and agitator guide explains how different impeller designs influence flow, shear, and product movement.
Heat Transfer Becomes More Important at Scale
Heating and cooling behavior changes as tanks become larger.
A small pilot batch can often reach its target temperature quickly because there is relatively little product to heat or cool. At commercial scale, considerably more energy must move through the vessel while maintaining acceptable batch times and temperature uniformity.
Tank geometry, jacket surface area, thermal media, agitation, and product viscosity all influence heat transfer.
During scale-up, manufacturers should define:
- Target heating and cooling times
- Maximum and minimum process temperatures
- Required temperature uniformity
- Available steam, glycol, hot water, or other utilities
- How viscosity changes with temperature
Agitation is particularly important because the mixer moves product across the vessel’s heat-transfer surfaces. Thermal design and mixer design should therefore be evaluated together.
Ingredient Addition Can Change at Commercial Scale
The way ingredients enter the process can become more important as batch size increases.
Adding a bag of powder to a small pilot vessel may take seconds. Adding hundreds of pounds of the same ingredient to a production vessel creates a different mixing challenge. The rate of addition can affect hydration, dispersion, agglomeration, and overall batch time.
Liquid additions can present similar challenges. Flow rate, location of the inlet, timing, and interaction with the mixer can all affect the final product.
Scale-up should therefore consider both the amount of each ingredient and how that ingredient reaches the active mixing zone.
Controls Help Make Scale-Up Repeatable
Commercial production introduces more opportunities for process variation.
Integrated controls can help manufacturers maintain the conditions established during development by controlling mixer speed, temperatures, pumps, valves, ingredient additions, and batch sequences.
Instead of relying entirely on individual operator decisions, a control system can establish repeatable operating parameters and provide useful process data.
Important variables may include:
- Mixer speed and operating time
- Temperature and heating or cooling sequences
- Ingredient addition timing
- Transfer sequences
- Batch and hold times
This becomes increasingly valuable as production expands across multiple shifts, operators, tanks, or facilities.
Think Beyond the Mixing Tank
Commercial scale-up should consider the entire production process.
Raw materials need to reach the mixing vessel efficiently. Finished batches need to move into storage or downstream production. Cleaning needs to occur within the available production schedule. Pumps, piping, valves, controls, and utilities all need enough capacity to support the larger process.
A well-designed liquid process system coordinates these functions so increasing mixing capacity does not simply create a bottleneck somewhere else in the facility.
Planning these requirements early also makes future expansion easier.
Build Commercial Production Around the Proven Process
The most valuable outcome of pilot production is knowledge. It provides real information about how ingredients behave, what process conditions matter, and what is required to produce the desired result.
Successful scale-up uses that knowledge to engineer commercial equipment around the process.
If you are preparing to move a product from R&D or pilot production into commercial manufacturing, contact Mixing Tanks USA for a quote on your next mixing and storage tank project. Our team can work with your process requirements to develop equipment designed for repeatable production at the scale your business needs.
About Mixing Tanks USA
Mixing Tanks USA is an American manufacturer of stainless steel mixing and storage tanks and liquid process systems serving the food and beverage, life science, and industrial and chemical industries.
Our equipment is manufactured in Portland, Oregon, with a focus on precision engineering, quality fabrication, dependable performance, and long-term customer support. We design standard and custom equipment around the products, processes, facilities, and production goals of the manufacturers we serve.