It’s like flossing your teeth or not procrastinating on submitting your expense report – it’s good to make a habit out of getting it done early and often. 

The same concept applies to calibrating the volumetric feeders on your activated carbon injection (ACI) silos or bulk bag unloaders (BBUs). 

It’s one of those things that everyone SHOULD do, but they usually don’t or don’t do it often enough. At the moment, you may not notice anything wrong. Let it go long enough and the issues start to show up.  But if you ignore it or put it off long enough, not calibrating your volumetric feeders could cause more damage than you might think. 

Whether you’re just starting up your feeders for the first time or changing up what you’re feeding through the system, it will need to be calibrated for both efficiency and safety. Knowing your feeder’s throughput capability is one way to determine if you’re spending more time or resources than necessary on your operation. Proper calibration can also prevent headaches for your accountant as they attempt to forecast operational costs over the coming months and years.

The throughput rate is also the first step to determining if you are losing any material through cracks or openings in your system. Loose material can be a deflagration issue – which can immediately put you out of compliance and risk the safety of your employees.

How To Calibrate your Volumetric Feeder:

• Set the system in Maintenance Mode (or whatever your setting might be called, where you can operate equipment individually) at the maximum feeder rate (60 hz) 
• Use a trash bag or collection bucket below the feeder discharge to collect the material (this may require removing some of the piping between the feeder discharge and the eductor). Make sure to calculate the TARE value for the collection device you choose!
• Run the feeder and collect the material to calculate the maximum feeder capacity. 
• Start the feeder and a timer/ stopwatch.
• Once the material is fed through, stop the screw feeder and the timer
• Weigh the product collected
• Calculate the feed rate delivered through the system in pounds per hour (X lbs caught * 60 / Y minutes run ) 
• For example: feeding for 5 minutes results in 10 lbs collected: 10*60/5 = 120 lbs/hr
• Assuming  0 lbs/hr at 0 Hz and X lbs/hr at 60 Hz (from the calculation above), you can create a curve that will show the expected feed rates at all frequencies. 

We help plants calibrate their volumetric feeders as a part of our preventative maintenance program and show you how simple it is to calibrate your system. 

If it’s been a while, or you think you need a hand, give us a call.