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In some applications a bulk powder, granular material and liquids may be combined to produced a thick slurry.  One example is the production of concrete, either in a batch plant, precast operation, block plant or other type of facility.  Depending on the angle of your discharge, the thickness of the slurry mix and the mixture ratios themselves, there may be a problem getting the mixture to flow readily. 

One example where this problem can occur is with the discharge of concrete mix from mix trucks.  Here's a quick look at one of my concrete trucks, it's a collectible die-cast of course.  The problem associated with bulk material flow, even concrete, is two things, the cohesive strength of the material and the friction between the material and the material of the vessel the material needs to flow down.  Check out the bulk solid material flow experts for more resources and information on flow properties.

The solution in most cases is using an industrial vibrator.  This is for very good reason.  For example, using our concrete truck illustration let's look at an installation of a turbine vibrator on the discharge chute.  In this case (shown in photo at top) the vibrator is quietly introducing several hundred pounds of force into the material through the wall of the chute to promote and maintain the concrete flow.  In this case the Turbine vibrator replaced a piston type vibrator because of the noise associated with piston vibrators.  The Turbine type is very quiet, well within OSHA guidelines.

Need help with a material flow problem?  Give me a call at 800-262-2106 or 815-224-1200.

Joe Lewis

I participated recently in an interview with a major magazine that is writing a feature article about Gundlach's storied history as the first crusher manufacturer to figure out how to size coal at the mine in three dimensions. It reminded me of how much real growth comes from resourceful designers and engineers who create the capital equipment, that make the products, that grows an economy, that leads to real wealth. Here are just two brief examples from two companies I'm most familiar with.

In 1948 the U.S. had recently come out of the two great dislocations of the 20th century--the Great Depression and WWII. There was a booming market for coal sized to fit automated coal stokers, but most mines couldn't supply the properly sized coal. Gundlach responded to that need with the first two-stage roll crusher that could size coal at the mine to fit in all three dimensions, delivering valuable stoker coal precisely sized at ¾ in. x ¾ in. x ¾ in.

Jump forward to the late 60s and early 70s, and it's a plastics boom. Anyone who has seen 1967's hit movie "The Graduate," remembers this prophetic cocktail party scene: 

Mr. McGuire (played by Walter Brooke): I want to say one word to you. Just one word.
Benjamin (Dustin Hoffman): Yes, sir.
Mr. McGuire: Are you listening?
Benjamin: Yes, I am.
Mr. McGuire: Plastics.

Benjamin (the recent graduate) greets this revelation with a puzzled look, but those who figured out how to meet the needs for the capital equipment that make plastic production possible forged businesses that remain leaders in the world today.

Take for example the world's first digitally controlled weigh belt feeder, introduced by K-Tron in 1972. Plastic compounders needed a feeder that could deliver material continuously and accurately to their extruders. The new extruders of the era demanded accuracy that previous feeders simply couldn't deliver.

As the demands grew for greater process speed, more flexibility and ever more accurate feed ratios, the innovations continued. In 1976, K-Tron introduced the first loss-in-weight feeders with digital weighing. In 1989 they introduced the first modular feeders that let processors quickly reconfigure their K-Tron feeders for different materials. These ground-breaking modular feeders also featured the first Smart Force Transducer weighing technology, which delivered even greater feed accuracy.

The innovation at K-Tron goes on to this day with a wide array of gravimetric feeders, many of them fine tuned to feed minor and micro-ingredients, meter at high rates, or provide precise multi-stream ratio control.

Whether it's growth in productivity for existing markets or growth in capacity for new markets, you'll find capital equipment makers making it possible. Economies go up and down. But thanks in part to the innovations of our equipment makers, and the vision of the buyers of that equipment, the long term trend continues upward. That's how real wealth is created.

We need to tell the stories of these creators of the small yet vital single pieces of equipment, the suppliers and designers of massive complete systems, and the manufacturers who invest in this productive capacity so they can finish the job of producing something of value for the world. We need to tell and re-tell these stories so that others can understand. If you have a story to share, send it to me here at the powderandbulk.com blog.

Don Dunnington
Moderator