To:JLSeagull
The whole point of solid DESIGN is to make sure procedural difficulties do not become uncontrollable. Sure, a design done by a licenced PE might get into trouble, but less likely. When a PE affixes his signature, he will only do so unless he is satisfied the design is trustworthy...
Editor: 30 June 2010
Letters, PE magazine (via email to pemagazine@nspe.org)
Sir or madam:
The following letter was published in the Pasadena [CA] Star-News in the 25 June 2010 edition.
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Re: The Gulf Oil Spill
As a thoroughly schooled, experienced...
It seems to work by causing the coalescing of each phase. None-the-less there will be a certain amount of uncoalesced material - - a mix of oil and water droplets stabilized by the solid particles. That's why, when Unocal filtered their sludge, the filtrate separated without a hitch. There...
The stream I have been referring to is the DAF (dissolved air flotation) overflow at the Wilmington (California) refinery. Typically it consists of 5% crude, but on a good day can be 50%, and on a bad day 1% --- the balance is water. I would not attempt to do this on the entire refinery feed...
Evaporation is one, single stage. Fractionation is multiple stages. The Swenson evaporator test was at about 300 degF. This was not optimum. A recycle of blended light and heavy organics is used to control the fluidity of the material in the evaporator. The Swenson test did not contemplate...
Just envision the evaporator as follows.
The entering stream consisists of water, salt and crude petroleum. Two streams leave the evaporator. The light (overhead) stream is water with some light organic low molecular weight material (say pentane on up through C18). The heavy (bottoms) stream...
What is the ratio of organic to water? I roughly guess that the cost would be acceptable at ratios 1 to 100 and upward. At 50 to 100, it's a no-brainer.
True. Failures can be tied to causes. My point is that FRP failures can be catostrophic. Failures of metal tanks are always presaged by small leaks. Often these leaks are easily repaired with tantalum plugs.
I maintain my original position: Do not store large amounts of hazardous materials...
I would not store more than 100 gallons in an FRP tank.
I know of a tank for storing 36% HCl of 10,000 gallons or so that failed suddenly, without warning. All 10,000 gallons were lost at once. This is the problem with FRP: it can fail in a catastophic fashion -- not warning, then suddenly...
The report sponsored by the California Department of Health Services is described as follows:
***** Start Here:
DEWATERING OF REFINERY SLUDGES
USING A FORCED CIRCULATION EVAPORATOR
DRAFT REPORT
DOHS CONTRACT NO. 89-T0120
DECEMBER 1990
California Department of Health Services
Alternative...
At the Wilmington (CA) refinery, Unocal obtained instant separation of phases by filtering though a filter precoated with diatomaceous earth. (This was around 1990, when Unocal still owned the Wilmington refinery.) The filtration removed the many micron-sized solids that kept the emulsion from...
A experienced designer told me when I was still learning the ropes: "Two heads are thicker than one."
What he was saying was that the back and forth discussion between two people produces more ideas than two individuals engaged in their own private thoughts. Add more people, get more synergy...
I do not have direct experience, but many years of observing physical, thermal effects on many materials, I offer the following.
Kiln dried sawdust will give a "mild" drying effect.
Cement kiln dust will give a "large" drying effect.
Many tables show cellulose vs. equilibrium data. Books...
