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New Vibra Screw Press Release in BULK INSIDE
Vibra Screw Heavy Duty Screw Feeders are extremely versatile. One unit can precisely meter many different materials with little or no adjustment. When necessary, adjustments can be made quickly and easily. Screws and tubes can also be changed on some models for a wider range of feed rates.
All feeders are fabricated of high strength steel and contain only a few moving components. They are built to operate continuously with only a minimum of maintenance.
Unique Operation
Because maximum feed accuracy is dependent upon positive material flow from storage, we designed these Heavy-Duty Screw Feeders for use beneath bulk storage hoppers. Hoppers that pack or bridge should be equipped with a Vibra Screw Bin Activator to ensure consistent material flow to the feeder.
In operation, the feeder trough, screw and tube are subjected to continuous controlled vibration. This permits the material to move gently from the upper section of the trough to the feed screw without bridging, packing or flooding. Vibration further conditions the material to a constant bulk density and ensures that each flight or pitch of the screw is filled to its maximum in the filling area and completely emptied at the discharge end. The positive displacement of material is further ensured through the use of a rotating solid flight screw.
Rugged construction to operate 24 hours a day, Vibra Screw’s line of volumetric Heavy Duty Feeders will meter even the most difficult materials in an extremely reliable manner.
A patented controlled vibration principle ensures exceptional accuracy of ± 1%, minute-to-minute. A wide variety of products, from long fibers to micron-sized particles, and materials with bulk densities ranging from 2 to 200 lb/ft3 can be successfully handled with precision.
Available is screw sizes from 2” to 16” with feed rates from 2.3 to 9,800 ft3/hr.
As with all Vibra Screw equipment, the Heavy-Duty Screw Feeder is unconditionally guaranteed to perform in the service for which it is sold. With a staff of experienced and talented engineers, technicians and crafts people, Vibra Screw manufacturers high quality equipment to store, discharge, meter, convey, size and blend solid materials. The company’s comprehensive product range includes Bin Dischargers, Bulk Bag Unloaders and Fillers, Volumetric and Gravimetric continuous and batch feeders, Vibration Conveyors, Vibrating Screeners, Blenders, Process Controls and Turnkey systems.
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Every Vibra Screw product gets a serial number tag before shipping. Most importantly each piece of equipment gets another tag printed on the original equipment proposal sent to our customer. This tag is our PERFORMANCE GUARANTEE that covers the life of the equipment. No other industry source stands behind its products with the confidence and assurance of Vibra Screw, because no other company engineers and manufactures to our uncompromising standards.
What’s getting ready to ship.
Vibra Screw custom Loss-In-Weight Batching system consisting of a Bulk Bag Unloader and two batch feeders. The customer manufactures EV batteries and needed a way to accurately batch one of their main battery ingredients. Material comes in bulk bags, is transferred from the bags to the weigh feeders via pneumatic conveying system, and than into the LIW gravimetric batch feeders where the material is fed into “V” blenders with minor ingredients.
During a recent conversation with one of our Massachusetts customers who was looking to add several new Vibra Screw feeders to their production line, they also inquired about parts for an old Vibra Screw bin.
They sent photos of the bin and it turned out it was one of several Live Bins that were manufactured in Vibra Screws original Clifton, NJ building in 1958. The bins have been used for 63 years and we were able to provide necessary replacement parts (special vibration isolators). These bins are still using the old style gyrator (single shaft motor driving eccentric weights) without replacing parts. Built to Last, nice return on their investment.
This equipment is getting ready to ship after final testing and inspection. The customer is a custom seed coater and blender, and this is their third order from Vibra Screw in two years having purchased 8 large continuous Loss-In-Wight Feeders and two continuous blenders. This new order comprised of 3 Loss-In-Weight Feeders and two different size Vibra Blenders.
OMYA lnc., Florence, Vermont Major manufacturer of calcium carbonate used mainly in the plactics, paint, and paper industries as a filler, extender and coating.
The Verpol plant of OMYA Inc. is the, most modern plant of its kind in the world. It processes
both crushed and finely ground calcium carbonate through its completely computerized operation.
Bulk densities of the materials range from 25 to 70 Ibs. per cu. ft. To meet process and excess
storage requirements, the company has 27 bins ranging from 8 ft. to 26 ft. in diameter, of both concrete and steel construction. The bins are filled either pneumatically or by belt conveyor. Some of the bins are discharged through rotary valves to belt feeders or pan feeders, and some to bagging machines filling 50 lb. bags. Discharge rate varies from 4 tons per hour up to 40, depending on the stage of the process. However, calcium carbonate, especially the finely ground product, can be difficult to discharge from storage because it tends to bridge and clog.
27 Vibra Screw Bin Activators of 3 different diameters (4 ft., 6 ft., and -12 ft.), carbon steel construction, most of which have an epoxy coated interior.
To assure reliable flow of material in its computerized operation, where such reliability is critical, the company decided to install Vibra Screw Bin Activators under all its storage bins. This was possible because the Bin Activators work equally well on both concrete and steel bins. Flexibly mounted to the bottom of the bin, the Bin Activator, but not the bin, is subjected to controlled vibration. An integral baffle located just above the discharge outlet directs vibrations high up into the bin, keeping the material free flowing. An important factor in the handling of calcium carbonate, this action rids the material of entrained air, conditioning it to a uniform bulk density, which helps speed conveying and bagging operations.
OMYA Inc. relies on its Bin Activators to help it produce an uninterrupted flow of high quality product In the words of a company official, “It would be difficult to operate the plant without our Bin Activators.”
We were recently contact by a long time customer who is in the process of replacing five storage silos at their plant. These silos were erected in 1981 and they included (5) 10 ft diameter Vibra Screw Bin Activators.
The bins are in pretty bad shape due to 39 years of exposure to the elements. Our customer, thinking that if the bins were in tough shape, that the Bin Activators would also be on the same condition. So they were planning to replace everything is the system.
We visited the site and checked the metal thickness of each Bin Activator body and collection cone for wear using Ultrasonic Wall Thickness Gauge. No wear was found to exist after all these years. The customer has not replaced any parts of the Bin Activators in 39 years. Not going to replace the Bin Activators and we have a happy customer.
Built to Survive
The Merrill–Crowe Process is a separation technique for removing gold and silver from the solution obtained by the cyanide leaching of precious metal ores. This process is currently used at the 10 largest gold producing mines in the free world. As part of the process, zinc dust is added in small amounts but due to the variation in gold to silver ore ratio the amount of zinc need fluctuates and needs to be precisely fed to maintain steady state process.
Zinc dust has a bulk density at 220 lbs/ft3, with a particle size of 2-9 micron. The feed rates are low between 8 to 35 kg/hr. The material will settle out, de-aerate and become a non-free flowing powder. Over the years Vibra Screw has developed a Loss-In-Weight feeding system which incorporates its vibrated Versi Feeder which uses controlled vibration to assure consistent flow of material from the hopper through the feed screw and into process. The Live Bottom Bin above the feeder stores a shift worth of material and discharges the material to the feeder when the control system requires. Vibra Screw has been providing feeders for over 40 years to gold extraction processes.
Vibra Screw has been designing batch and continuous gravimetric control systems for decades. We were quick to adopt useful technology by incorporating digital and graphics displays, as well as an ever-growing number of I/O interfaces into our products. As expected, customer response to these improvements was overwhelmingly favorable.
However, all gravimetric control systems, no matter how fancy the user interface, measure weight using a transducer called a load cell. (See Figure 1) The load cell converts mechanical weight into an electrical signal. The most common type of load cell employs a strain gauge transducer (See Figure 2) in a Wheatstone bridge and can be found in devices ranging from deli scales to systems designed to process solid rocket fuel.
While computer technology has enabled high tech gravimetric control systems to evolve significantly over the last 40 years, a load cell is still the basic workhorse at their core. And, though it may be hard to believe, the strain gauge load cell technology got its start in the late 1800’s. In 1843 Sir Charles Wheatstone perfected and popularized his Wheatstone bridge. (See Figure 3) A resistance change in the bridge produces a proportional change in voltage across the bridge. Then almost 100 years later, in 1930’s, Edward E. Simmons and Arthur C. Ruge invented a device that could measure strain in an object.
It wasn’t long before the strain gauge and Wheatstone bridge technologies were combined and the “load cell” was born. This transducer changes mechanical energy into a proportional electrical signal. Even with the invention of the transistor following World War II, the load cell still found it’s primary application in laboratory test instrumentation. The small signal created by the load cell wasn’t ready for commercial/process gravimetric control systems. Lever scale and balance remained the preferred method of measuring weight.
Finally, in the computer age of the late 20th century, electronic technology had advanced enough to accurately measure small signal changes and the load cell started to replace the balance and mechanical lever scales used in processing industry. Even in today’s cutting edge technology, over 170 years later, the strain gauge load cell continues to be the preferred transducer used for process weighing and gravimetric control and the one used by Vibra Screw.
