My first introduction to the productive work that can be accomplished with vibration was probably by my dad. Back in the day our family would on occasion sit down for some TV and popcorn. Sorry, no movies on demand, no DVDs or even VHS, I’m not sure how we made it through those dark days! This was pre-microwave popcorn and my mom would pop it the “old school” way, with a heavy pan and oil. I think you can still see this technique demonstrated at a museum or two. Traditionally the popcorn was served up in a large spun aluminum bowl. My dad had the rather annoying habit of shaking the bowl which would vibrate the un-popped kernels, “old maids,” down to the bottom of the bowl which created a rather loud noise as they hit the aluminum. More than once I asked him what the heck he was doing, he’d say he was “bringing the big popcorn to the top”. When I asked how that worked his pat response was – “physics”!! Read More…
“If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.”
― Nikola Tesla
As we are coming up on the anniversary of his death (January 7, 1943), this post will honor a man who came up with some of the most unique application of vibration for his time, Nikola Tesla. His creation of the “Earthquake Machine” and use of vibratory tables to relieve Samuel Clemens from constipation (It’s true. I read it on the internet.), will be hard to match innovations. However, on reflecting on 2013, I want to quickly highlight two of our customer’s applications of our vibrators that stood out as unique and noteworthy: Read More…
One of our lesser known products known to be made by The Cleveland Vibrator Company is our Pipe Bracket Assemblies. As you drive down our highway systems you will see many manufacturing companies with any number of pipes in several different sizes transporting many types of materials such as sand, coal, many types of powders, dust collectors etc. Our pipe bracket assemblies are designed to assist in the flow of materials through those pipes. The design allows for the assembly to be moved up and down the pipe depending on the location of a material flow problem. We currently manufacture pipe bracket assemblies Read More…
“Bend, but don’t break” is an old football saying that refers to a defense that “allows” the opposing team to move the ball down the field on offense, but ultimately prevents them from scoring touchdowns. While it’s not a perfect analogy, you could apply this statement to recommending externally mounted vibrators to aid in the flow of material down hoppers, bins, and chutes without damaging the mounting surface.
Our challenge is to recommend a vibrator that will flex (bend) the wall or surface where it’s mounted to aid in the flow of material but not break it. Some people do not use certain external vibrators as they’ve had the bad experience of cracking the mounting surface. It’s easy to blame that style of vibrator, or vibrators in general, and look for some other method to get their material to flow. Here, I will explain how vibrators should be utilized without damaging the mounting surface.
I recently finished a two-day safe grain handling course at the Asmark Institute in Bloomington, Illinois. This is part of our continuing efforts to learn more about grain, feed mill, and silo safety in our on-going efforts to assist in these areas. Cleveland Vibrator has manufactured and supplied vibrators to these industries for several decades but has never, until now, involved itself in the safety part of this industry beyond supplying vibrators as flow aides.
“What’s the amplitude of that industrial vibrator?” – I hear this question more often than one might think.
You’d think it’d be a simple question to answer. But, with industrial vibrators, it just doesn’t make sense and isn’t relevant to most applications. In my book, no vibrator has “an amplitude.” However, without a doubt, each vibrator model has unique performance characteristics that we can measure and record.
1200 VMSAC on pellet mill station bin
Once we understand the requirements for the application, like a vibrator on a bin or hopper to assist in material flow or mounted on a piece of equipment, the vibrator performance characteristics help our sales and engineering staff make the best recommendation for optimal performance. But you can’t say, “I need a vibrator with an amplitude of X,” and get several options.
What structure characteristics affect the amplitude of vibration?
When you start thinking about the amplitude of movement of anything with a vibrator attached to it, you’ve got to ask yourself several additional questions:
What’s the weight and wall thickness of the structure?
Is there isolation involved or is it rigidly fixed to a support?
Is the goal to move or compact material or just introduce “movement” in a section of the structure?
With vibrating equipment, it is relatively easy to calculate the expected “amplitude” of the finished unit while we’re still in the design phase. Using solid modeling, we have a good sense of the weight of the unit. Put this together with the performance parameters of the vibrator and we can accurately predict the expected amplitude of the finished unit. Take the weight of the unit, frequency of the vibrator, and its known force, toss in a conversion factor, and you can kick out a decent estimated amplitude of the completed assembly. This helps us predict the performance and capacity of the equipment, be it a feeder, screener, or compaction table.
What factors does the amplitude of vibration depend on?
When asked, “Hey, what’s the amplitude of the 1200 VMSAC Pneumatic Vibrator?” you can’t fire back, “Oh, it’s 0.157 of an inch”. Unfortunately, it just doesn’t work that way. Amplitude is not an independent parameter of the vibrator. Amplitude depends on two factors:
The structure to which the vibrator is mounted
The freedom of movement of that structure
What hopper characteristics are important for industrial vibrator installation?
Frequently, the customer is trying to improve bulk material flow in a storage container. Typically, the amplitude of the vibrator doesn’t solve bulk material flow problems. Over the company’s history, The Cleveland Vibrator Company has developed sizing charts and guidelines for hopper applications; this involves the characteristics of the hopper, including the following:
Hopper wall thickness
Volume of the hopper
Sometimes material type, if it is difficult to move or sticky
I can’t recall anyone in sales or engineering telling a customer they need a specific vibration amplitude. There are times when the nature of the material will lead us to recommend a “larger stroke or amplitude.” With rotary electric vibrators, this translates to a lower frequency vibrator, resulting in larger vibration amplitude. Given the same force output, a slower frequency vibrator will produce a larger amplitude or stroke when compared to a higher frequency vibrator on the same structure.
Turbomite Turbine Vibrator
As a side note, this relation leads to one of our primary design considerations for our Turbomite Pneumatic Turbine Vibrator line. You will notice we produce forces similar to our competitors at much lower frequencies.
The application of industrial vibrators is rarely an exact science – here’s how we can help!
There are many years of experience here at The Cleveland Vibrator Company. Folks have seen and heard about hundreds, if not thousands, of applications over the years. But what keeps things interesting is the challenge of a new application where you need to explore your options.
We can reach back into the knowledge base and make a good recommendation more often than not. If that doesn’t seem to be the best route, we can generate a computer solid model and run an FEA analysis. This may give us a better prediction of the amplitude of a vibrator-structure assembly. But let’s not use that approach to apply a VM-25 Air Piston Vibrator on a thin-walled hopper section. It’s probably more cost-effective to simply buy one and try one! On the other hand, you could always ask about our 30 day trial period.
There are two basic designs available when selecting a vibrating (linear) feeder: electromagnetic and electromechanical. Air powered vibrating feeders are basically an alternate to the electromechanical feeders as they have the same simple brute force design concept – the vibratory drive is directly attached to the tray. Our challenge is to obtain as much information about the application to make recommendations Read More… Share this blog post:
We were recently asked by one of our foundry customers to quote our 1200 SI Air Knockers to replace hammers used by his employees to beat on the side of casting forms in order to free the casting from the mold. Because of the current process, they currently have two employees on workman’s compensation with carpal tunnel problems related to using hammers to loosen the castings. With the SI series developed to replace such manual processes, we can mount the vibrator on the mold and control the number of hits per minute plus control the force of the impact that the piston strikes the mold with our timer and five port spool valve set up. This simple solution can not only save the health of the employees, but also thousands of dollars in lost time and claims. If you have a manual process requiring employees to use hammers to dislodge material from molds, bins, hoppers or chutes, contact us to see if we can help. Share this blog post:
As further follow-on to my previous post, I wanted to look at a specific subset of Grain Entrapment and Engulfment cases. As I mentioned, I don’t think industrial vibrators and/or timed knockers are the silver bullet for preventing all cases. However, I do think they can be effective for Read More… Share this blog post:
Recently a customer inquired about purchasing a new lab test sieve shaker. His current laboratory sieve was an old, noisy, clunker of a test sieve shaker (I don’t think I need to name names…..). He was complaining of too many fines in the product – ground glass powder. While the customer seemed to think his lab shaker was operating properly, he was concerned the test results were not accurate. However, the end-user of his product was also complaining Read More…
