Now that we have a Pugmaster, is there some type of periodic
maintenance we need to be doing on any of this equipment?
The
instrumentation selected is almost maintenance free. The belt
scale calibration will shift as the empty belt weight changes.
This is due to wear of the belt and moisture changes in the belt. The
change is very gradual. All that is required is to re-zero the belt
scale two or three times a year. (Run the belt empty and go through
the zero calibration on the Ramsey Integrator) This takes about 15
minutes. If you ever change the length of the belt or change belt
speed you will need to do a full calibration.
The same is true
of the moisture transmitter. As the lenses becomes dirty the
calibration will shift. This also is very gradual. You have a
filtered air purge on the lens. We have found the light source
in the instrument will last about five (5) years. About every two years the
transmitter should be taken down and the lens cleaned and checked for
damage. We also recommend calibration at this time as well.
In the Pugmaster
Classic The Yokogawa
Instruments in the main panel are very robust and should never require calibration.
I have never found one out of calibration in the past 13 years.
The display on the Main Controller the YS170 will dim after 3 or 4 years
depending on ambient temperatures. It will have to be replaced.
In the new
Pugmaster Plus we have gone to a PLC based platform. The PLC does
all the work and we use a PC and touch screen as a window into the PLC.
We are finding the PLC is very robust. Our objective is five (5) years
out of the PC. The additional power for historical trending and visual
feedback to the operator is in our opinion well worth the price of a PC
every five years.
The control
valves will be your biggest source of trouble. You need to carry spare
valves. The Asco valves will last 2 to 3 years. (Least expensive
items in the system) Water control valve about the same. We
recommend spare valves.
You also need a
spare load cell for the Ramsey belt scale. They usually are damaged by
mechanical stress ( someone walking on the belt) or blown electrically,
(someone welding on the conveyor).
The Pugmaster
will continue to work quite well while with the gradual shifts in
calibration of the moisture transmitter and belt scale. The operator
just selects a slightly different column moisture setpoint. After two
years he may be running the column .5% higher or lower than normal.
The change is so gradual he never knows it. He is changing the
setpoint any way because of the other variables in the clay. (density,
temperature, plasticity). The weak link will always be the
moisture transmitter. I expect about 5-10 years will be the life
there. Still not bad. What we have found is that after about two
years we need to come back for about 3 to 4 days and go through the same
routine we did on start up. Run a new
calibration curve on the moisture transmitter and clean it up. Check mechanical
alignment and calibration of the belt scale. But most
important is to go through the operator training program again. You
will have had so little trouble with the system that everyone forgets what
it does and how to calibrate/troubleshoot the system. You will
also have new people that need to be introduced to the Pugmaster.
When you do have
trouble, we hope most of your problems can be solved on the phone with the
guys you have sent to us for training.
I notice that a
lot of your class attendees come from energy companies. What
would be the use of the pugmaster in these companies?
I can thank
my friends at J. C. Steele & Sons for that.
It was
part of an "Alternative Energy Program" set up by Jimmy Carter
during the oil embargo. If you can recycle a waste product into
useable fuel you can get huge tax credits. A company in Utah
"Covol" developed a process to convert "Coal Fines"
into fuel for the power industry. The "Raw Material" was
the "Tailing Ponds" at the Coal Processing Plants. They
cover many acres and can be 100 feet deep. Drain the ponds, scoop
out the "Fines" with a front end loader, Add a binder
and conditioner in a Steele 90 pug mill and extruder. The
results - Coal Nuggets worth $ 20.00 /ton tax credit Plus whatever you
can charge the power company. Rick Steele sold equipment for
12 of the 24 plants that were constructed in 1998. Pugmasters were included
in the Steele proposal to control moisture content of the nuggets and
perform ratio control of the additives. That is were the Pugmaster
"Grew Up". All the hard lessons learned there were
transferred to the Brick Industry.
And
to think that I always thought that the brick industry was what got
ole Ernie in the Pugmaster business. Interesting story!
Well, you are
not wrong. The Brick Industry is the only reason the
Pugmaster is around. It all started at Pine Hall Brick in
Madison, North Carolina. Vernon Moore asked me to take a look at
the water controls on his Pugmill. I asked "What is a
Pugmill?" That was in 1990. Four years of trial and
error resulted in the first "Working" Pugmaster Installation
at their Plant 4 Line 41 in October of 1994. It was not
immediately accepted in the Brick Industry. A few were installed
over the next four years. It was in 1998 when the Coal Industry
stepped up to the plate and provided the capital that got us over
the hump. The Brick Industry got us started. The Coal
Industry forced the development of training and installation procedures.
It pays to be ready when opportunity comes calling. It would not
have happened without the support of Vendors, Customers, and fellow
Employees who believed in me and the application. I have had a lot
of help and my share of good luck. I was also fortunate enough to
meet some key men in the Brick Industry who knew their process well
enough to recognize a solution to a problem when they saw it.
Thanks for all your help.
Ernie Wright