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Thayer Scale Keeps Corn Syrup Plant "On-Track"

By Tom Picone
May 19, 2005, 21:43

Keokuk, IA -- Roquette America is a French-owned producer of corn syrup. Originally it was the Hubinger Co., the plant was bought by Roquette in the late 1990’s. Roquette America buys locally grown corn and produces huge quantities of corn syrup used in everything from soft drinks to salad dressing. Most of the product is shipped by rail to destinations across the United States and Canada.

To keep track of inventory as well as controlling the process, Roquette uses a precision Thayer Model 6RF-6AR-24 Conveyor Belt Scale. This scale was installed in August of 1993 and has had little factory maintenance throughout its twelve-year life span. On one such visit, the customer was left with a guide composed by the service engineer instructing him on how to properly conduct a material test. It is unknown if Roquette had ever conducted material tests on their own; but at one point, a diverter plate was fabricated and a downspout attached at the head of the belt to facilitate the cause.

During a recent service visit, the Thayer belt scale was inspected and cleaned of excess dust and tramp material. This scale comes with a Thayer LC-137 LVDT load cell that uses a dashpot for added vibration dampening. The dashpot was inspected and a small amount of the proper viscosity silicone fluid was added.

Using the existing logistics, a true test of the scale’s accuracy was performed by filling a dump truck and weighing it on the onsite truck scale. The following are the results of the two tests we performed.

Test #1:
Truck tare weight: 21,420 lbs
Truck gross weight: 40,280 lbs
Net weight: 18,860 lbs (gross-tare)
THAYER totalizer (9.43 tons or 18,860 lbs)

The Thayer belt scale was found to be without error on this test.

Test #2:
Truck tare weight: 21,420 lbs
Truck gross weight: 41,640 lbs
Net weight: 20,220 lbs (gross-tare)
THAYER totalizer (10.10 tons or 20,200 lbs)

A difference of 20 lbs, calculates out to 0.098%.
Note, the truck scale used reads out in 20 lb graduations.

This type of scale is a netweigher and, thus, must be mechanically zeroed. The mechanical zero was checked and found to be right on. The next step was to verify that the instrumentation was reading the correct belt speed by checking the instrument against a certified tachometer. No adjustments were necessary. At this point an initial calibration was performed; the totalizer was reset and repeatability was verified by successive calibrations. The scale repeated in the range of five hundredths of one per cent (0.05%). Also noted was that the scale had had no electronic adjustment in it whatsoever (K-Factor = 1.00000).

About Thayer Scales

Founded in 1949, Thayer Scale is a pioneering developer of continuous weighing and feeding equipment for the dry solids conveying and processing industries. Our Conveyor Belt Scales and Weigh Feeders of both the Weigh Belt and Loss-in-Weight types, cover an extremely wide range of applications covering virtually all industries that involve dry solids conveying and processing.

From Loss-In-Weight Feeders that feed vitamins into cereals at rates below 1 pound per hour to 6-Idler Conveyor Scales weighing coal at rates up to 10,000 tons per hour, there are more than 100 proven product variations available to suit most application requirements.