[AT] More on Air Lines

[Greg Hass]

This information may not be practical for anyone on the list, but I would 
just like to show that there is vast array of solutions to the various 
problems that we may run into.

Our area has long been known for growing white edible beans.  The quality 
of the beans being completely dependent on the weather, bad weather can 
cause many off-color beans to be harvested.  To sort the beans, they use 
machines that around here are commonly called "the eyes".    Although I 
know little of the more modern ones used in the last 15 years, the ones 
used before that were approximately 2' x 2' x 5' high.  Each machine had a 
small belt that would drop one single file row of beans down a one-ft. 
square opening.  On one side was an electric eye, and when it saw a "bad 
bean", an electric coil would open a little needle valve and a puff of air 
would blow that bean out of the stream and onto the "reject" conveyor.  The 
way the eye worked was that for each grade, 3 of the side panels would be 
changed to matched the color of bean that was being processed, according to 
grade.  The electric eye would then pick up any bean that did not match the 
backdrop color.  Because the beans were processed single file, each machine 
was able to process only 400 lbs. per hour.  Therefore, there were 
approximately 40 machines in one room.  The air was supplied by two 10-HP 
compressors.

The problem that they ran into was that water from the air lines would get 
into the electric coils that opened the needle valves and burn them 
out.  According to people that worked there it was quite a problem.  The 
answer was a machine about the size of an 8-cu.ft. chest freezer.  I am not 
sure of the inner workings of it, however it had a refrigeration compressor 
on it and cooled the compressed air as it went through, similar to a 
dehumidifier.  Beside it were a couple of 5-gal. pails.  They said they 
took out about 5-gal. of water per shift.  However, in the 4 years they had 
had the machine, they had not burned out a single coil on the electric eyes.

The reason I said at the beginning that this may not be practical is that, 
if I remember right....(CRS is in play here)... the price was $5000 for the 
air dryer.  Still, an interesting solution to a nagging problem.

Greg Hass