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PD Blower "Free" Oil Analysis - There Is Usually A Good Reason For It

  
  
  
  

Oil analysis and vibration analysis make a great tag team when it comes to assessing rotating equipment condition.  Even if oil analysis trending is carried out by itself it still can be a powerful tools assessing whether or not there may be trouble coming down the pike – rolling element bearings, gears and other key components leave key evidence of them failing behind in the lubricant.  Depending on your plant size and usage of lubricant, quite a few lubricant suppliers also offer free oil analysis.  While that seems great at the first glance, there are quite a few wrinkles that can lead straight to catastrophes that the analysis was supposed to help prevent.  I will review a few issues and elaborate on what an analysis report should cover in the course of this blog. 

For one, the report is only as good as the one who reads it can understand and interpret it.  Most reports that I have come across in my career have a line with CYA-ish terminology in them, e.g. “Action: Resample next service interval to further monitor”.  How are you supposed to make any heads or tails of it on your own?  The advice tends to be too broad to be useful.  Two more big issues can arise if you do not know what all the different tests that are out there and which one you should apply for which machine.  The greatest print out will not do you any good if it is the wrong test or you really do not know what the readings mean. One of the most often overlooked issue id the task of sampling the oil.  Location, time and sampling cleanliness have a huge impact on analysis accuracy.   Is the sample taken from a sump or a centralized pressurized lube oil system?  Is the sample bottle and sampling port clean?  Are you taking the sample with the machine down and not having operated in quite some time allowing for sediment to settle in the sump?  Are you taking it from a running machine up or down stream of the filter (if any), oil pump, sump?

Aerzen Oil Change

Then there is the lubricant.  Only when you know what you put into the machine in the first place (and you let the analysis crew know what it is) will the report be meaningful.  Finally, there is the issue with knowing what kinds of parts reside on the inside of the machine you got the report for.  Your analysis accuracy goes way down, if you do not know what kind of bearings, cage materials, how many bearings there are, what kind of gears may be contained in the machine, etc.  What other parts are in the machine?  Are there lip seals, labyrinth seals, or other parts that may come in contact with one another?  All of these components leave traces of themselves behind that can be invaluable in the condition monitoring process. 

I bet that most people who offered the free oil analysis to you did not tell you about all these potential issues.  There is a method to this madness.  First identify how critical the machine is for the operation of your plant.  For those machines do yourself and management a favor and get either the manufacturer or an oil analysis lab, e.g. Stavely involved.  Most reputable OEM’s offer a good condition monitoring program.  For machines that you feel like you can make use of the free oil analysis, make sure that the following criteria and information is included in the report:

  • Oil make, quality and quantity
  • Viscosity @40C is Cst and @100C in Cst
  • Viscosity index or VI change
  • Spectrochemical analysis in ppm
  • Wear element concentration (particle couont) as per ISO 4406
  • Water concentration in %
  • Additives listing
  • TAN index (for some applications the TBN index)
  • Oxidation index

Next best thing is to contact the equipment manufacturer and obtain their expert opinion where, when and how the sampling should take place.  While you are at it please ask them too what their best lubricant and test recommendation is.  Ask them for a list of bearings, gears and any other wear and tear items within the machine.  Please call our product support group, if you need any Aerzen blower, compressor, hybrid or vacuum booster information. 

In the Internet age nothing beats free advice – I love it myself and make use of it as much as possible.  Think twice before starting to rely on free oil analysis for critical machines though.  

Please drop me a note in case you have comments, suggestions or questions.    

describe the imageAerzen USA
Ralf Weiser
Technical Manager
rweiser@aerzenusa.com

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Experts fix what needs fixing

  
  
This is directed to anyone who owns and operates any plant in any given industry.  I am in awe.  This is the year 2009 where saving money is more important than ever and yet unplanned emergency repairs costs due to run-to-failure as well as the dated run time based maintenance drain your manpower and cash reserves more than ever.  Do not get me wrong, there are pre-existing conditions that you sometimes cannot prevent, or your organization has done it for so long that the cultural change will take years for you to change. 

Ideally, anyone in charge of maintaining equipment - especially the ones of you who responsible for the budgeting - should sit on a rock and ponder how your organization can implement what I call Precision Maintenance philosophy.  No rocket science or big costs involved here.  It just describes the process of setting up trending your assets precisely.  The precise part is divided into three similarly important yet mind boggling simple steps:  Plan - Do - Review. 

In the planning phase is the toughest part.  You prioritize which items are the most important to trend.  Do not be shy to start monitoring machines that seem to have low capital cost.  You will be surprised how much low cost machinery really cost you when you review the total costs of ownership (i.e. energy, failure history, etc.) .  Reliable trending is best done with vibration analysis, oil analysis, Infra Red imaging, power consumption, load, pressure and many more.  There is awesome instrumentation out there that does not cost much to buy is easy to install and integrate into your plant operating system.  If real time monitoring cannot be done, you will need trained manpower that will walk scheduled routes and record the data for you.  If necessary, pull in your OEM (Original Equipment Manufacturers) to help establish alarm and shut down values for any of the parameters that you are recording. 

The Doing part comes easiest to most of us.  With an increasing trend of troublesome data the machines that seem in need of attention have to be pulled, evaluated and eventually repaired.  Make sure to record any abnormalities in the tear down and inspection reports and compare them with the machinery trends.  Ask yourself if the failure symptoms are linked to the trend information, for instance defective bearings and an increase of vibration.

The most forgotten part is the review phase of any of your activities.  Immediately upon repairing or even installing a new machine you need to take a set of data - did you really address the root cause of a problem or merely a symptom of it?  If it is the former, you can go about your daily business.  If it is the latter, your job is not done yet.  Now is the time to tenaciously finding the reason what is causing the abnormal values. 

With Precision Maintenance you can easily save tenths of thousands of Dollars every year.  Make sure you make good use of that knowledge in the ROI (Return Of Investment) calculation - the more instrumentation you can afford the better.  For blowers and compressors there are many standardized platforms we could help you with.  As always, I am looking for your feedback. 

Aerzen USA - Technical Director - Ralf Weiser

Ralf Weiser - Technical Manager
Aerzen USA
rweiser@aerzenusa.com

Listen to Ralf Weiser's Podcast on Expert Level Maintenance

Do you believe in everything you see and hear about Turbo Blowers?

  
  

Do you believe in everything you see and hear about Turbo Blowers?

That is a loaded question.  Especially here in North America we tend to be drawn to the "New" and the "Better" like a moth to a light unlike any other society that I know. In the last couple of years there has been an increasing amount of incredible power saving claims by single shaft turbo blower and compressor companies in comparison to positive displacement machines such as our own GM and VM Generation 5 Delta Blower and Delta Screw series.  When you look behind any claim, is there not usually the typical "it depends" clause that must be considered?  Typically this takes time and effort and thus it is no surprise that only few people give this further consideration. 

We felt like we should put the different technologies and compare it in a realistic context and compared the different primary air moving technologies.  You can down load the white paper from our web site and learn about the pro's and con's of the different machine types.  You will be positively surprised about the depth and volume of information that the author Pierre Noack compiled for you.  I truly believe in one thing:  Nothing is either universally bad or good - with very rare exceptions and those usually involve two legged ones. 

 

Ralf Weiser
rweiser@aerzenusa.com

What not to forget when you correct rotating equipment problems

  
  

What not to forget when you correct rotating equipment problems...

You've just finished repairing a machine for the umpteenth time and you are exhausted because it could not be done in a single shift.  A couple of months later you find yourself doing this again.  Does this sound familiar to you?  Do not be afraid to admit it, this is a rampant problem at many different companies and settings. 

It was not until about a decade ago when I finally realized the step we usually forget about in this process:  Immediate and continuous review if anything we labored implementing really addressed a root cause or a mere symptom.  It sounds so easy and yet is so often either not done at all or not done in frequency and depth. 

There is a really basic principle I recommend for the root cause failure finding and subsequent remedying process.  First start to ask why the problem exists.  For every item you ask again why that particular issue could have caused the problem.  You do this for a total of five times.  By that time I can all but guarantee that you have found the real issue.  Devise a corrective action implementation plan and carry it out. 

Now comes the most important part:  Make absolutely sure that you carry out tests such as - but not limited to vibration analysis, oil analysis, infrared thermography, current draw, and so many others.  It would of course be best if you had baseline and perhaps even a history of data to compare with.  If the problem you started out with presents itself in the new review data you can at least preemptively start with corrective action again - without having to go through yet another repeat disaster.  This process also works in other plant and process settings, but that is for another Blog session.  Do you have any questions or comments?  Please feel free to drop me an email. 

 

Ralf Weiser - Technical Manager
rweiser@aerzenusa.com

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Hello Mechanical World please meet Mrs. Electronics!

  
  
  
  

Hello Mechanical World please meet Mrs. Electronics! 

Positive displacement blowers and compressors have been around for well over 100 year.  Predominately process and maintenance folks have viewed them as mere mechanical devices that did not represent any worth in protecting and managing them electronically.  How dramatically different our world looks like today!  In a time where machinery is expected to fend for itself it makes great sense to monitor and manage your blowers and compressors and treat them as the assets they represent to your company.  The problem is how to best do it when you either buy new machines or systems.  Or how do you retrofit old blowers and compressors with systems that will later nicely integrate into your plant operating system? 

The system integration has always been one big obstacle in the integration process - next to cost of course.  Aerzen USA has generated a new approach to this challenge in form of our iAir Pneumatic Control Blower and Compressor control system that is offered as an augmentation to the already well known AS and ASG control platforms.  Here we have a controller

that is easy to use as it features a touch screen interface with all the pertinent information on a single screen shot.  If you want more information, simple touch the area of your interest and more details will show of on the display.  It can handle blower as well as single stage oil free compressor applications. In its basic version it can be connected to your plant system via Ethernet TCP, Modbus, Profibus or simply SCADA I/O's. 

Using instrumentation solves a whole variety of issues.  The most important one is that it protects against overloading or abuse of the blower or compressor.  Basic operating parameters are monitored and if necessary provide an alarm or shut down signal.  Another big ticket item especially in the construction phase of a new installation is that hard wiring cost can be greatly reduced by using a two-wire communication protocol that can connect at least up to 12 machines and still provide all the information as if you stood in front of the controller itself.  That is really powerful information for operators and plant managers alike.  Would you not want your machine telling you automatically that it needs attention?  How about uptime management that you would be able to do with it?  Please drop me an email if you are interested to learn more about how we can put money back onto your bottom line. 

Ralf Weiser - rweiser@aerzenusa.com

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Right-sizing Aeration Blowers in Waste Water Treatment Plants

  
  
  
  

Right-sizing Aeration Blowers in Waste Water Treatment Plants

As the main consumer of electricity in a wastewater treatment plant, the aeration system greatly influences the overall cost of operation, that in the longterm by far exceed the initial investment cost. Several blower technologies can be chosen from and it therefore behooves the engineer to accurately evaluate the characteristics of the aeration blowers and carefully interpret some of the claims made by various manufacturers. The most energy efficient solution must be based on actual conditions that, in reality, will vary over an extended period of time.

The economical operation of a wastewater treatment plant depends largely on the design and the interplay of the aeration and process controls. Moreover, the human factor and the management objectives are at the heart of the plant's reality and should also be taken into consideration. Selection and thoughtful integration of all the subsystems is of paramount importance.

Taking a pragmatic approach, Aerzen USA developed a whitepaper on the subject. This paper presents ways to minimizing the energy usage: right-sizing, aeration control, defining the operating range and matching the blower technology to the application, and comparing operating data over time.

The paper presents four types of blowers: two dynamic and two positive displacement machines. Since each technology has its place, a comparison is made specifically based on the treatment of wastewater. Taken into account are the daily and seasonal swings in oxygen demand, fouling and aging of diffusers, air flow control and turndown capabilities, total blower efficiency and energy consumption over time, mode of operation, blower accessories, and plant set-up. The paper recommends engineers to exercise due professional diligence and to select the most suitable aeration blower technology based on a relevant comparison.

To learn more about selecting to correct aeration blower for your application download the new whitepaper "Aeration blowers in the wastewater industry in North America"

Video:Tom McCurdy explains Right-sizing Aeration Blowers in Waste Water Treatment Plants

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