Your's is the old story of the modern age. You should not attempt to design an ash conveying system if you are new to the business. Teus T, & Dr Mills have many spreadsheets which they would let you see, I guess. Even with the benefit of their vast knowledge base you would still make mistakes which would fill a forum. The best you can do is approach a reputable supplier and then check their work using TT's type spreadsheets. Its the way to learn. You ask based on what you have learnt. Then you get told, then you give it a whirl & then ask again. You can't design an ash conveyor overnight, just looking up on the plant layout & plonking values into a sample calculation sheet.

If you still insist on doing it yourself download the programs which have been posted on earlier pneumatic conveying threads over the past couple of years. And take a deep breath. ■

As John says; becoming an expert overnight is not really possible.

Apart from the theory and physics of pneumatic conveying, the technical set up of an installation is just as complex.

Start reading books, articles, forums, etc. Talk to the suppliers, based on offers, use your intelligence to sort out the information, learn from experience (including mistakes) and in time you will gain the necessary knowledge.

It took me since 1980 to build up and document a consistent theory and calculation program and I am still learning today.

The calculation method must be based on a logical set up of the theory, which is used and must be recognizable to the real installations.

Manufacturers tend to keep their theory and calculation methods hidden for the outer world for commercial reasons, which makes it rather difficult to start designing and building for yourself..

This forum is for exchanging general knowledge, ideas, experience and guidance.

The forum members are always there to help. Engineering is for the manufacturers.

success

teus ■

Go and see Dr V K Agarwal at the Indian Institute of Technology just a few miles north of Gurgoan, on your side of Delhi, on the ring road. He has a Pneumatic Conveying Laboratory there and has a lot of experience of conveying fly ash. You should have attended the short course that he ran at the IIT in January. He is in the ITMMEC Centre there. ■

I would recommend that you read some good books on pneumatic conveying you can search these forums and you will find many good books on this subject, some of them will also give you actual conveying data for various products which helps a lot. With your described experience I don’t see any reason you cannot become an expert, it might not happen overnight but you will get there in a week.

After having almost 10 years research and design experience in pneumatic conveying systems I have come to conclusion that this field is not as difficult as some people want us to believe. ■

Dear respondents,

Pneumatic conveying, in principle, is not difficult.

But as soon as you want to design and build a pneumatic conveying system, the lack of consistent calculation methods and appropriate field data become suddenly apparent.

The best proof of this complexity are the many questions in this forum and the given answers.

Building an installation without a proper design and calculation has a build in risk of failure.

Trying to use the basic principles for trouble shooting in a wrong design can hardly be considered a clever way of investing money or efforts.

My experience (more than 10 years, but not necessary fruitful) in grain- and powder unloading and conveying was only in many real installations, which were references for the mathematical model, I figured out.

But many other engineers went much deeper into the more scientific conveying characteristics of pneumatic conveying, using the higher mathematical approach and powerful computer programs. Saying that the world of pneumatic conveying is not as difficult as some want us to believe is not fair to them.

It is the combination of knowledge, experience, proper design calculations, application of various technologies and hard labor that makes a system work in an optimum and profitable way.

Again this forum proofs that professionals are needed to achieve the desired results in bulk handling installations (not only pneumatic conveying)

Do not give up ■

I have had a fair bit of experience with blowing various gypsum powders around the place. My recommendation is to talk to Clyde Materials Handling. They have an excellent and reliable product range, they have a test rig that they can trial your material on before committing to anything, if the application is new to them. Their real limitation at the moment (which they are aware of and are working hard on improving the situation) is their project management and the installation of the equipment. My experience has been painful here.

Once installed though, the system surpassed performance targets and has worked at 99%+ availability since (2005), and the duty is arduous (~8312hrs/yr). Their competitive advantage is the 'dome-valve' which really does keep maintenance requirements to a minimum. The largest application we have is conveying dry ground gypsum 800m at 60tph. They have examples of more than this though elsewhere.

We are actually going through a programme of replacing Portasilo dense phase conveying equipment that we were too quick to install without the proper investigation and trials. This kit might be good with less abrasive materials but with ours it increased maintenance requirements dramatically and design throughputs are only sustained for a week after their monthly planned maintenance routines.

I would agree with a couple of the previous posters in their recommendations of not trying to design it all yourself, unless you can't afford to farm out some of the risk. Talk to a decent supplier and they will provide much information on the back of a quotation, especially if presented with the opportunity of repeat work.

hope this helps. ■

Clyde Materials Handling and our sister company Clyde Bergemann Materials Handling have supplied hundreds of dense phase ash handling systems over the years.

To convey 60 tph of coal fly ash with a median particle size of 40-50 microns and low limestone compound content, over 1000m, typically the pipeline would be 200mm expanding to 250mm after approximately halfway, fed with a couple of 10m3 vessels filling and conveying alternately.

The power consumption would be approximately 235 kW.

Hope this helps. ■

Dear rellis,

I ran your calculation result through my computer and the results are:

horizontal length 980 m

vertical length 20m

5 bends

diameter pipe 200/250 mm

airflow 60 m3/min # 1 m3/sec

pressure 2.5 bar

Power 239 kw (oil free screw compressor)

Pipeline capacity 64.9 tons of fly ash/hr

blow tank 12m3

Fly ash content 10 m3

System capacity 56 tons/hr

residence time of flyash approx 79 seconds.

It would be interesting to know whether your intermediate results are also the same?

Attached the screen shots of the calculations

Attachments

flyashpressureconveying1000m (PDF)

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