Prairie Dawg Practical
by Tim Holmberg, DEMI Equipment
Why do you suppose there was a need for a portable screening plant? What could possibly be the reason a producer would need to take his screen with him to the job, versus leaving it where it is anchored as a stationary unit? How can a portable screen be as effective as a stationary one? Will portable screens become more popular than stationary models, or has that already happened?
Portable screens have actually been around since the early 1900’s — and possibly before (depending on which definition of “portable screen” we are using). I can image ancient civilization figuring out how to classify or sort varying sizes of aggregates, since they first conceived concrete and other aggregate-based building projects — and most likely moved this sizing device between two connected chiseled wheels of stone. I can also imagine the most practical way to screen the aggregates would have been by hand-sifting motions and that this would have been the same time that the stationary counterpart was likely created — leaning against something stable, at a slant having material dropped onto the fixed inclined slant, allowing gravity to replace the manual sifting motion — which took a lot of energy to do. This would probably have been one of the first times the phrase “working smarter not harder” was delivered when asked how this came about.
Today, with all that we have at our fingertips, one can easily forget where the original concept of screening was invented. That’s ok; it is always to the consumer’s advantage to have competitive manufacturers trying to develop a better mousetrap on a yearly basis. Have we as manufacturers figured out all the benefits to building the perfect machine? No. Improvements are still being discovered regularly through productivity issues. Sometimes plant operators are best at discovering workarounds. Many homegrown temporary fixes have become igniters to solutions.
Oftentimes, what works in one location can be totally ineffective in another and therefore full design changes can’t always be 100 percent implemented throughout the product range. Screening is one of the most delicate processes within the industry due to specific gradation targets that are required in order to satisfy the next code or process recipe the material will be used for.
Today’s portable screens can be operated electrically or hydraulically, but either way is far superior in productivity and effectiveness than ever before. Portable screens have, in my opinion, become the screen of choice over the stationary model, since being designed portable; it has also been designed to be more universal.
By being more universal it may give up some production efficiencies as compared to a dedicated stationary unit, but not as bad as one might assume. Portable screen plants are designed as self-contained and fully functioning plants with onboard stacking conveyors and feeders so that all you need is a rubber tire loader and you can be in business as a gravel producer, topsoil provider and even recycler — all because these portable screening plants are being designed with the customers’ needs in mind, combining many features into one universal machine.
One machine hauled to a site becomes much more affordable, versus the many truck loads required to haul away, process and then haul back the site. This is the most important reason to take your portable screen to the job.
What keeps the portable screen from shaking away since it isn’t anchored to a foundation? Many times, the portable’s foundation is anchored to tracks, which having a significant footprint can easily be leveled within the parameters, offering excellent stabilization characteristics. Some of the larger portable screens — either tire mounted or track mounted — come with self-leveling hydraulic legs that assist in the perfect leveling of a machine. This also creates firm anchoring characteristics, as they are rigidly mounted to the equipment without slip moments such as with multiple wood blocks stacked upon one another.
Portable screens are not going away — rather the opposite. They are increasing in numbers as producers are diversifying their offerings, requiring newer technologically based tools to help them perform their work better and more efficiently.
As cities grow in size and larger equipment has less room to establish itself within these tightening boundaries, the need for all-in-one production plants becomes more relevant.
Do these machines come with unforeseen issues that will need fixing and redesigning? Yes. Should that discourage a producer from investing in the product? No. Proceed with confidence that the industry has come a long way since the first units were produced. If maintained correctly you will be pleased to see the production results, as well as maintaining the resale value, since the market is only continuing to grow.
If you enjoy these random aggregates and quarrying equipment-based subjects, tune back in for more topics to come. Send me a subject or topic you would like brought to light and any associated questions you would like to have discussed and I will gladly provide my best answer based upon my specific point of view and personal experience.
Questions or comments? Email Tim Holmberg at firstname.lastname@example.org or visit demiequipment.com .
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Tim Holmberg / 2915 Idea Ave. / Aberdeen, SD 57401