Weighbelt Feeder Calibration

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Defining Calibration

 To correlate the readings of an instrument with those of a standard in order to check the instrument's accuracy. 


With regards to a belt feeder, or a weighbelt batcher, this means that you can trust the massflow reading that the controller is displaying. Without calibrating and verifying this process variable, there is no way to know if it's accurate. Gravimetric feeders are expensive. You need to know how to quantify their performance.  Leming Process Services LLC can calibrate any controller type, KCM, SCM, KSM, K10s. 

K-Sampler Certification

Coperion K-Tron ®  has developed their own program to automatically test, calibrate, and certify their load cells. 

With a belt feeder, K-Sampler will need a secondary scale. This scale weighs and records the product coming from another feeder. The feeder being tested is started in normal operation while its output is diverted directly to the K-Sampler Scale. The program runs for a period of time and can analyze the consistency of the samples to verify performance of the feeder. 

Download Sample report

Weighbridge Alignment

The alignment of the weighbridge in your belt feeder is extremely critical. Whether it is a W300, W600, SWB300, SWB600, SWB1000, or SWB1200, the alignment is equally critical. The first step when servicing a weigh feeder is to confirm proper alignment and adjust if necessary. There is no reason to do anything else first. The weigh bars are checked for wear, the stops are checked for proper adjustment, and the other critical components of the belt feeder are properly inspected corrected if necessary. 

Catch Samples

Physically catching material from the weighbelt is the only true way to verify accuracy. There should always be space at the feeder outlet to allow room for a catch container. Unfortunately, the higher rates of a belt feeder make it very difficult to sample.  It is ideal to allow the belt feeder to run into a large container that can hold a few minutes of material at the desired rate. Then the container is weighed on a scale. That value is compared to the expected mass amount. 

 The best practice is to use a K-Sampler to handle the testing of catch samples.  This removed any human error related to timing and catching the material. 

Span Adjustment

 The span is one of the most important parameters on a Coperion K-Tron Belt Feeder. At 1.000 by default, it offers a way to calibrate the scale. For example, if the sample weighed 200 lbs on a secondary scale, and the controller totalizer only showed 195 lbs, you would adjust the span so the totalizer showed 200 lbs. 


The span does not correct for mechanical problems such as incorrect weighbridge alignment, improper belt tension, or inconsistent belt loading. 

Best Practices

To have the best performance from your Coperion K-Tron Feeders you should do the following: 


  1. Have an annual calibration/PM by Leming Process Services LLC.
  2. Use the factory silicone bellows at the feeder inlets and outlets to minimize feeder vibration from the environment. 
  3. Always use Coperion K-Tron Belts.
  4. Keep product and dust from building up inside the machine and inside the belt. 
  5. Keep product/Belt load centered on the belt and away from the side skirts.
  6. Educate operators and maintenance in proper operation and handling of the feeders. Tare the belt feeder after each cleaning. Static and dynamic tares! 

Downloads

KSampler-Continuous-sample (pdf)

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