OT Bark Bin Level Measurement

[bwheat]

Have a couple of dead nuclear source level detectors measuring the level in a bark bin for a boiler. These have been in service for at least 20 years and I am told the company that made these are not in busines anymore. I would like to replace these units with something other than a nuclear source due to LOTS of paper work involved. Has anybody used radar, sonar, vision systems, etc. to measure level. Have to have continous level measurment. Bark pile level is used to control the speed of the bark screws.

 

[Thomas]

other stuff

I have seen polarized microwave transmitter/reciever pair used for level detection in a rubber hopper.

 

[Lancie1]

bwheat,

For a wood-fired boiler that burns sawdust and shreded chips, I have used two different types of bin level detectors. One type, the "Bindicator", has a paddle wheel driven by a small synchronous motor. When material blocks the paddle, it trips a mechanical limit switch and indicates a level. However this type does not give a continuous level measurement, so I use two in each bin, a low and high level and anytime the bin level is between the two switches, I know I am OK. Other type used is a capacitance level probe, which will give continuous analog signal, but is more expensive, not as reliable, and not as simple to calibrate as the paddle wheel switch.

 

[danw]

If the bark bin is a feeder bin, not subject to combustion temperatures, then ultrasonics will probably work. I've used Siemens (formerly Milltronics) ultrasonics on paper waste applications where the pile forms a fairly high angle of repose. But ultrasonics only go to about 200°F normally, sometimes 300°F with a high temp version.

If the bark bin see combustion temps, radar might work, depending on where it's installed. I found a spot to put an LR400 in at 350°F and it worked well for 22'(7m) shots.

Dan

 

[jimbo3123]

I used a laser level that was specifically designed for wood chips on a job recently.
It was a Riegl LD90.
Their website isn't working for me right now, but it was riegl.com


good luck.

-Jim