Over the years it has been interested dealing with major aerospace engineers as well as current and former NASA engineers. Most folks believe that these engineers walk around with pocket protectors, slide rules and stumble around like in “Revenge of the Nerds.” The reality is that they are indeed brilliant and very good at the job they perform. And then there is B&D Technologies— what we bring to this table is the ability to
take one of their ideas (that was likely have been jotted down on a napkin) and marvelously transform the idea into reality. We recently created an air velocity measurement senor and alarm
annunciator array for a very high-tech aerospace company (you likely know the name, we just can’t voice it).

Challenge

The customer needed to determine if the air supply to a fume hood reduced or stopped air flow. The challenge presented itself simply—no one creates a pre-configured solution. We needed to determine the range and how they wanted to display and create alarm events.

The calculation is not very tricky for SCFM…EG:

  • The sensor is 4m/sec.
  • 1 m/s x 1 ft/0.3048 m x 60 s/1 min = 197 ft/min
  • Duct size 14″ x 15″ x 1 ft²/144 in² = 1.46 ft²
  • 1.46 ft² x 197 ft/min = 288 ft³/min
  • So 14” x 15” duct would give us 1152 SCFM for the range.

The challenge with the calculation is that they did not always know where the sensor was going, and may vary as the coordination of several systems change.

We decided to scrap the calculation and go for an exact sensor measurement of CFM, measuring just air velocity because it has a correlation without requiring the calibration on duct size. It gives us the representation of data without having to know where the unit has to go.

Design

We used a Dwyer air velocity sensor, ABB AC500 eCoPLC, IMO Text Panel, and a Banner stack light. The Text Panel allows for the user to input a low signal and a low-low signal to set the alarm thresholds. The state of the stack lights are green for good, yellow for low and red/audible alarm for low-low.

https://www.bannerengineering.com/us/en/products/lighting-and-indicators/tower-lights.html#gs.c6hcORI

http://technical.imopc.com/itext_datasheet.pdf

http://new.abb.com/plc/programmable-logic-controllers-plcs/ac500

Opinion

Low cost does not always mean simple. As a distributor, our main purpose is to sell and support hardware. Specifically, higher technology products like drives and PLCs. The key is always when to work with one of our strategic integration partners. It would have been easy for us to push the design to someone like R&L Engineering or Infinity Controls, but it was logistically easier for us to do it ourselves. If and when it is necessary to bring the data into a larger SCADA system, then an integrator partner makes total sense.

Final Words

I always find it interesting when we have a decades-long customer (the company is 70 years old!) that we have worked with on the power transmission side, and they suddenly realize that we can also automate their processes with the help of our in-house team and external partners.

Every PT Company says they can do this if you ask or go to their website. That is more of the exception than the rule, and I always advise customers to ask for example projects and references. We have tons.

CTolbert DOE