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Consulting

I. Consulting Support, Pre-Sale

Equipment selection

Centrifuges are difficult to specify, because so much is nearly unknowable to the average engineer. Quality resides in the mechanical design, the bearings, the hard surfacing, and the process efficiency. For the most part, all manufacturers have access to the same components, so profit goes to he who builds the cheapest. And the technical data the vendors release? It's typically is sales fluff.


I can take you through the centrifuge specifications, and tell you what they really mean, and where the loop holes are that will allow the manufacturer to walk away from the job, and leave you with little recourse. A little of my time up front will save you and your client a pot of money later on.

II. Let me tell you two stories:

We're Going to Sue the Bastards!

One municipal client was thoroughly dissatisfied with the performance of their new centrifuges. The performance was no where near what was specified, and as a result the operating costs were way out of line. The authority's lawyer hired me look over the specifications and the start up testing reports to see if they had a case to sue the equipment manufacturer. The centrifuge performance did look particularly bad, considering the sludge they had, and better optimization might well have improved the performance. Unfortunately, the specification was flawed. It specified a sludge that the plant could never produce. The centrifuge manufacturer evidently saw that specification for the sludge was wrong, and was able to cut the startup short, announcing in effect "what you see is what you get" because the sludge would never meet the specification, thereby relieving the manufacturer of their liability. My evaluation was; the centrifuge manufacturer had a loop hole big enough to drive a truck through, and if anyone was liable, it was the engineer.

Why is this brand a maintenance hog?

One client, during a training class, asked me to tabulate the differences between the two brands of centrifuges, one they had operated for twenty years, and new ones made by a different manufacturer. One very big difference quickly apparent was that the new centrifuges recommended main and conveyor bearing changes every year. The existing centrifuges had bearings that lasted 5-10 years or more.
"But the specification says the B10 life of those bearings is 100,000 hours!" said the boss. Well, yes it does, but the B10 bearing life calculation:

1 Assumes a vibration level, a load, and a speed
2 Assumes no contamination
3 Assumes no lubrication failure

In short, it doesn't predict bearing life in the real world, unless the vibration level and speed used in the calculation are about the same as experienced over the life of the bearings.

We have experts who can tell you the questions to ask, and can also check the calculations the manufacturers submit.

When you write a specification, it's hard to know what, exactly, you are going to get. Municipalities have to give deference to low price. Different manufacturers deliberately interpret the specification to suit their convenience. Then too, they cry proprietary if you don't use their language, which guts the specification. In the end, did they deliver a centrifuge that in fact meets the specification? Mostly they do, but often some have been known to take the job on low price, and argue later, if caught, oh we made a mistake. No one can guarantee you won't be bamboozled (to use a charming phrase), but having an expert on your side reduces the likelihood that it will happen

III. Post Sale Support

The job is in trouble, the contractor and vendors are finger pointing, and blaming others, and all seem to have a point. I have been in this position many times, and generally was able to work it out to everybody's satisfaction. It's not uncommon for the technicians the manufacturer sent out to genuinely ignorant of the base cause of the problem. It's not so uncommon for the equipment to be improperly set up, and sometimes the problem is in the design. It helps to have an expert on your side, to cut through the acrimony, and find the problem, and show the way forward.

 


Phone: 215-348-7879
Mobile: 267-252-3283
E-Mail: Peter@TheCentrifugeGuy.com