A Guide to Configuring Portable Mixers Dos and Don’ts of Mixer Selection
Pumps may grab the headlines in industrial applications, but mixers are the leading technology for many critical mixing and blending tasks, provided they are configured and utilized properly.
Pumps are the acknowledged workhorses in industrial fluid-handling applications, capable of reliably, safely and consistently transferring thousands of gallons of varying commodities at a rate that helps plant operators satisfy the strict demands of challenging production schedules. However, there is another technology that, while not necessarily as highly regarded as the pump, plays a significant role in critical production and fluid-handling processes in industrial operations.
But like any other piece of industrial equipment, portable mixers only operate at their highest level of efficiency, effectiveness and reliability if they are properly configured for the specific mixing or blending task. With that in mind, there are a number of operational variables that must be taken into consideration when choosing and implementing a mixer.
Portable Mixer Categories
Portable mixers can be separated into many categories with the main ones outlined below.
- Style: The most common are lab and pail, drum and tote, and light- and heavy-duty mixers. Lab and pail mixers are very small and are most often used, as their name suggests, in labs for mixing in small vessels or industrial applications where a liquid product is provided in a pail. The most commonly used portable mixers in industrial operations are the drum and tote tank-mixer designs. Drum mixers are utilized with the 55-gallon-drums in which many industrial chemicals are shipped. Tote (IBC) sizes can vary anywhere from 220 gallons to more than 500 gallons. Drums and tote tanks generally have a lid or top opening that have a bung connection or a larger opening. The mixer will require that a small fixed or folding prop be attached to the end of the mixer shaft so that it can be properly inserted into the drum or tote opening. Most models of portable mixers are either gear-driven with speeds of 350 or 420 rpm, or direct-drive, with speeds of 1,750 rpm. Most can be fitted with variable-speed drives or air motors that can provide variable speed, if needed.
- Mounting: There are three main types of mounting configurations for non-drum or tote portable mixers. One is c-clamp, which normally has an adjustable angle of entry that is controlled by a ball-and-socket-design. The angle riser provides a fixed 10-degree angle of entry into the mixing vessel and the flange mount to attach to the flange on the tank. Drum and tote mixers can be threaded into the bung opening in a drum or tote, c-clamped above the vessel, attached to the drum lip or have special brackets designed to mount on the tote or bulk tank. These brackets can be unattached when the mixing process is completed.
- Props: There are three common models of portable mixer propellers that can be used: Square Pitch; 1.0 pitch or marine prop, which is one of the most effective pumping devices; and Super Pitch, which has a 1.5 pitch that allows it to deliver higher pumping rates at the same diameter as Square Pitch, though it does require more horsepower to operate. Specialty Hydrofoil blades, which offer a more directed flow pattern, can also be advantageous for the user.
- Shafts: The rule of thumb for portable mixers is to position the mixer propeller 1-2 propeller diameters from the bottom of the tank, which will determine shaft length. It is desirable to position the prop closer to the bottom of the tank (1 diameter) when mixing slurries or products with solids that have a tendency to settle out.