Process Perfomance Issues?
Posted by: Bob Dowd
I recently visited a wet limestone FGD system because the customer called complaining that there were solids building up in the bottom of their limestone slurry storage tank. I arrived at the site and went to look at the agitator (not a Philly) to try to get a handle on the problem. The agitator drive was running smoothly, quiet and cool. There was no apparent mechanical problem on the top side of the system.
I talked some more with the FGD operations and they were happy with the mill product tank operation and the level of limestone solids supspension that was being achieved.
I then checked the drawings of the agitator from the OEM and did some quick calculation on the amount of torque per gallon being applied. I used 90 percent of the motor horsepower as an estimate of the power draw at the impeller. That all looked reasonable for off bottom suspension agitation requirements. Next, I started to ask questions to see if the agitator (about 15 years old) had ever been modified from the original design due to a failure and no time to get exact replacement parts. No one knew, so I had to schedule another trip to the plant when I could see the impeller and confirm its location in the tank.
Anyone have similar issues with process performance? More later.
About the author: Mr. Dowd has been with PMSL for 30 years. He has a BS in Business Management. He holds several patents for agitation and process development.
Tags: performance, process, suspension agitation