Question: are all electronic ballast equal? I guess not but maybe someone here can tell me what's going on with my setup.
In my work I shoot high frame rate digital video up to 1000 frames per second. At this framerate flickering can ruin my work. Ordinary fluorescents with magnetic ballasts...
Is anyone familiar with the use of a standing sonic wave to pulverize the solid content of a liquid stream?
I remember reading years ago about sonic cavity design that, coupled with a sonic transducer, could create thousands of pounds of sonic pressure.
Ring any bells?
I have a recurring failure problem with the packing on a high pressure pump. The fluid is pretreated with iron salts in an upstream process. The fluid is then screened to 1 millimeter but I suspect that some fines are getting through and ruining my seal.
The pumping cylinder is made of...
Modbus TCP is modbus running over ethernet. The support of the specific features will depent on who's Modbus TCP driver you use.
Try Software Toolbox's TopServer or Wonderware's Modbus ethernet
IRSTUFF writes…
“A computer safety system can only behave, if it's working correctly, as the designer intended and for whatever conditions the designer foresaw. Any deviation from the designer's ground rules could be a potential disaster if the safeties cannot be overridden.”
This must...
Here's another note on lime slurries from another website:
Viscosity of slurry
The viscosity of hydroxide slurry can vary greatly from lime to lime as well as different process conditions. Certain changes in the hydration conditions or impurities in the lime will increase the viscosity of the...
I’m sorry, I guess I got ahead of things. I thought you had your problem solved.
I thought it was obvious from your data that the operational problems were the result of high viscosity. It still seems like that’s your problem. How do you get high viscosity? How about too much lime in the...
Dimtec,
Good to see you've solved your mystery.
Small changes in density create large changes in viscosity and the changes in viscosity explain all of your operational problems.
More sensitivity on your density monitoring and increasing your pumping capacity sounds like a winning combo...
Seroney
Here's something else that you might find useful. It's an excerpt from another foreum.
...........................
(Posted on AD listserver in response to a question about measuring digester
performance - CH4, CO2, H2S, pH and what is useful in day to day operation.)
If you...
Two main bacteria groups are involved. The first turn waste into acids. The second group turns the acids into methane. The first group work much faster than the second group (10x) and lower the ph. The second group is very sensitive to ph change and will die off if the ph get too low.
The...
Why don't you just put a pressure transducer on the pump discharge and just use the VFD to control feed pressure?
That should smooth out all your controls.
Thanks for all the feedback.
While I’m usually focused on the control side of things, I’m also building the MCC for this project. As I said I’m scaling up from a single 150 hp pump to 6 - 250 hp pumps. The pumps are belt driven three cylinder reciprocating compressors. Normally these pumps...
When the pump is started the discharge pressure is zero. No VFD. After the pump is up to speed the discharge pressure is slowly ramped up by means of closing a downstream valve. This is done independently for each pump.
The installation is new and the electric service will be new. I'll be...
