MATERIALS HANDLING
“T e discharge valve is off set at a 15° angle, so it reduces the residue left in the mixer from an average of 2-3% to just 1%. With agitation style rotation, the powders create a slope inside the mixer that increases the total discharge,” explains Paul.
BOMB BAY DOORS Bomb bay door designs can further reduce product loss and residue on horizontal mixers. Since bomb bay doors can extend the full length of the bottom of the mixer, there is essentially nowhere for product or residue to remain after gravity-fed discharge when the doors open. Additionally, the design signifi cantly shortens the discharge time, which reduces the batch time and increases production.
VERTICAL MIXERS Although most mixers are horizontal in design, a vertical mixer can dramatically reduce product loss. With vertical mixers, there is 100% discharge of product, leaving no residue in the equipment as all product discharges through a single shaft, fed by gravity. Vertical mixers also provide more surface
area for heat transfer, so can be more effi cient when heating or cooling product. In addition, vertical mixers require less fl oor space than horizontal units and off er more fl exible minimum batch sizes.
SEEK FLEXIBILITY IN AGITATION STYLE According to Paul, industrial processors are increasingly seeking more fl exibility in their mixing capabilities for multiple reasons. Often, they must mix ingredients of diverse densities or viscosities and mixer systems are generally not interchangeable. T e requirements may also change due to customer or market demands. In any case, processors increasingly do not want to be committed to any single mixing style on the production line. Contract processors, by defi nition, also value fl exibility of agitation style due to the variability of production needs on each new project. In response, leading mixer OEMs
are developing mixers that simplify changing agitation styles without having to reconfi gure the production fl oor. “Processors can have multiple styles of agitation and switch them according to their mixing requirements,” says Paul. PerMix even manufactures a “four-in- one” machine that can be easily converted
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from a fl uidised zone mixer to a plough, paddle or ribbon mixer when needed. In addition to converting the agitation style, the mixer is segmented into two parts to allow for multiple confi gurations. “When you switch
from a paddle on a plough mixer, you need to also switch from a U-shaped trough design to tubular. You can do this by removing the two sides. When you switch from a plough mixer to a panel mixer, the round top is changed,” he explains. T e OEM originally developed the design for its test lab to enable a single machine to perform the work of its four most popular mixer types. After strong customer response, the company now off ers the
four-in-one design to various industries.
FIND WAYS TO REDUCE CAPITAL AND OPERATING COSTS Paying less for an industrial mixer is always preferred. Unfortunately, the component manufacturers and middlemen involved in fabricating, selling, integrating, and maintaining most industrial mixers can substantially increase the purchase price. As a solution, some vertically organised
mixer OEMs such as PerMix can reduce the overall cost by a factor of 3 or even 4x by manufacturing all components in-house, in the USA. Larger mixer manufacturers can also leverage their purchasing power with distributors to receive substantial discounts based on their volume, which is then refl ected in the fi nal price. Simplifi ed design features can also reduce
costs. While a conventional mixer with hydraulic pistons can cost from US$30,000 to US$60,000 depending on its size, a comparable cantilever designed mixer can cost less than US$10,000. Paul also cautions processors to watch out for manufacturers that tack on extra fees after the initial quote. Another aspect of aff ordability is
lowering the long-term cost of maintenance
Industrial processors are
increasingly seeking mixers with a host of advanced design features
and production downtime, which can rapidly escalate if replacement parts are unavailable or must be ordered (with the long lead times that can often entail). For large, multinational operations, this can become an issue if the necessary replacement parts vary in design or manufacture from region to region due to diff erent local sources. Ideally, the OEM would instead
provide consistent and standardised components to any location worldwide. “Off ering the same equipment design and replacement parts reduces service and training time, and ensures a more consistent mixing performance,” says Paul. “Our multinational clients order the same components on every mixer, saving money on spare parts and training.” Although the specifi c types of mixers and options vary by industry and application, selecting state-of-the-art designs that allow greater diversity of mixer style, along with effi ciency on the production line, is becoming a best-in-class practice among processors.
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