Selecting the Correct Mixer - Sponsored Whitepaper

In any manufacturing operation there is typically more than one way to reach your goal. This is also true when blending dry Points to Consider in bulk solids. Horizontal and vertical batch mixers and continuous mixers of various designs are available for a wide Selecting Equipment variety of applications; most mixer designs are viable in many applications.

Points that must be considered in selecting mixing equipment include: deciding between batch and continuous mixers, determining the best mixer size and agitator type, feeding and discharging methodology, accessories, and other process considerations.

Batch or continuous? The first thing to determine is whether you need a batch mixer or a continuous mixer. Your decision should take into account the different manner in which these mixers receive and discharge their contents. A batch mixer requires an operator to manually load and discharge the mixing vessel. A continuous mixer, as the name implies, must be fed continuously and the final product must be removed continuously. Hence a continuous mixer typically requires a volumetric or loss-in weight feeder for each ingredient. While feeders add cost and complexity to the mixing process, this added cost is sometimes less expensive than the batch mixer alternative.

To better appreciate differences between these types of mixers, consider mixing 10 tons of ingredients per hour at a bulk density of 45 lb/ft3. A fully manual operation using a horizontal batch mixer may only process one batch per hour, depending how quickly it’s loaded and unloaded. For this example, let’s assume that the batch size is 444 ft3 and that the mixer is filled 100 percent.

A ribbon batch mixer large enough to handle a batch this size requires a 100-horsepower motor and would have a footprint at least 7 feet wide and 10 feet long. By comparison, a continuous mixer capable of handling the same 444 ft3 could be much smaller: slightly longer than 6 feet, and requiring a 7.5-horsepower motor.