Batch mixing is a staple in many manufacturing processes across the world. From food and beverage manufacturers or pharmaceutical operations or industrial chemical production to oil and gas refining, almost all manufacturing processes use some type of batch mixing. Despite the commonality of batch mixing, there are many intricacies that determine what types of equipment should be selected for any given process. Things such as powders addition, product viscosity, batch composition, and automation can all play into equipment selection. In this blog, we will explain the process of batch mixing, and address three key factors that influence batch mixing equipment selection.
What is Batch Mixing and Why Does it Matter?
Batch mixing, or batch blending, is exactly what it sounds like – the combination of two or more ingredients in one exercise. It could be as simple as making the batter for a batch of cookies, or as complex as mixing the ingredients for the newest fuel additive. Batch mixing is the conventional way of manufacturing a product, whereas continuous, or inline, blending is a more progressive niche alternative.
Although batch mixing is considered to be the conventional method of mixing products, there are several factors that determine how the system should be designed and what types of equipment should be used. It’s important to understand what to look for when designing a system. Doing so will that each batch turns out as planned, and the batch mixing system continues to run as designed for a long time.
How to Select Batch Mixing Equipment
When selecting batch mixing equipment many factors can inform the types of equipment you should choose. Below are three key components that you should consider when deciding which batch mixing equipment selected for a system.
1. Number and Types of Ingredients
The number of ingredients, and the composition of those ingredients, can greatly influence the types of equipment that are chosen for a batch mixing system. Additions such as powders, highly viscous liquids, or hazardous materials can all influence the types of equipment selected.
Powders can require screw augers, supersack handling equipment, specialized raw material storage, and/or additional rotary valves. Viscous materials, either resulting from powders addition or materials that are simply viscous on their own, will affect the types of equipment selected. Viscosity will determine the types of pumps used and pipe size to start. Viscosity also can determine whether you’ll need a ribbon blender, a high shear mixer, or another industrial mixer to be integrated. Hazardous materials will determine the electrical area classification needed for the control panel and the instruments used on the system, as well as potentially changing the design of the tank or the materials of construction used. The number of ingredients used in the batch will largely determine the size or quantity of the tanks, mixers, pumps, and other instruments used.
When selecting batch mixing equipment, the level of automation desired will determine what types of equipment are selected. If possible, opting for a highly automated system will increase batch consistency, as it eliminates the human error. But not every situation warrants a completely automated system. Ultimately, there is no blanket right or wrong answer for how automated a batch mixing system should be. Moreover, each system should be properly designed and automated for its individual needs.
Things that will be affected by the choice of automated vs. manual components are usually raw material additions, batch start/stop, and final product handling. In more automated situations, all or most ingredients will be added via automatic pumps and flow meters; batches will start once the ingredients are appropriately added; and once the batch is finished the product will be sent to further processes automatically. Batch mixing systems that have less automation usually have multiple manual ingredient additions; an operator must start the batch and monitor it throughout; and the final product could be manually transferred to further processing or packaging.
Again, the amount of automation used will affect the equipment chosen, and it could improve the quality of the batches. But with that said, not every system needs thousands of dollars’ worth of instrumentation and controls. Contact a design/build firm like EPIC to design a batch mixing system that is properly automated.
3. Washouts and Changeovers
What happens after a batch runs its course? Is the system going to make another unique batch? Is it going to run a different SKU? Or is it going to sit idle for some period? Either way, the equipment that is integrated into the system will be affected by the washout and changeover schedule. The system can be designed with two tanks, so while one is in washout the other is producing. A Clean-in-Place (CIP) system also might be a necessary addition to the batch mixing system, if washouts are a must-have.
Depending on batch compositions, it might make more sense to use a continuous mixing system or a Late Product Differentiation (LPD) skid instead of a batch mixing system. For any questions related to properly designing a system for washout or changeover contact a design/build firm with experience in batch mixing systems.
Remember batch mixing is as simple as it sounds but will require thorough engineering to work through the quirks. Things such as the number of ingredients, the composition of those ingredients, the level of automation desired, and washouts/changeovers are just a few big factors that influence the type of equipment selected.