Centrifugal Blower Design

To be brutally honest don't attempt this yourself. A blower needs the whole unit to be balanced and stress relived.

The danger is catastrophic failure, a 100HP fan failed while I was an apprentice. The rotor was found over a mile away. It went clean over the roof of the local church.

ha ha ha ha!!! Tony, i am going to get the impeller balanced ofcourse. We have been making centrifugal blower for some time now but have never designed one this big till now. I shall most certainly keep your advise in mind but if you can help me out with the calculation, i would be grateful. Atleast, i would like to know how big the impeller is that i was to design!! :-)

I do not get the point. You claim that you already "designed" centrifugal blowers. Then why do you ask how to design a bigger one ? Normally such fluid devices are "designed" using similitude laws and based on the experience of precedent designs, all of it based on a SOLID knowledge about how the theory of those blowers and the results match. I cannot accept that you claim to have "designed" such devices and do not know how to "calculate" them. May be you made drawings but this is not "design". Why do you not write the truth: you NEVER "designed" blowers you ONLY copied existing products and this is NOT "design". This is an illegal procedure. Be honest! Learn how to "DESIGN" not only to COPY! You are not a "designer" you are ONLY a "draughtsman". A true designer is able to make by himself ALL the computations for the device he has to develop and give indications for the draughtsman.

For one thing, it depends on how fast it rotates. For another, it also depends on the static pressure required. Leaving out these data suggests that you don't really know what you are doing. You also haven't said whether this will be based on forward-curved, radial, or backward-curved vane design, nor why. This question is not yet suitable for engineering discussion.

gsrarun: All design inputs you offered are not enough to follow design process, But Even if you offer all Fields I doubt anyone one will do it here on CR4, And I think you know ther reason for that, its whole long exercise and take time and money both,you can try out on CR4 and nothing wrong with that,But it will be without results.

As you said can someone help me? And answer is yes,But that for that you need to come up with some progress, question about doubts and certifications, so that people can help you on specific problem where it is really required.

You could get a similarity design at bigger scale. Or buy a copyright of other existing design. Designing fans blowers are specialized field. Get the experts to assure quality performance and assurance of the product. Liability is a great concern. Its ok, if the fans or blowers are to be installed in your own property, irregardless of failures, yourself wont sue you on court.

why a 40hp motor?????? go for a 20hp and then u can vary the speed by using the gears and the blade number may be of 6 in number

" 4405151 cfm) blower to be run by a 40 HP"

You'll need the help of this guy. Increasing Speed Gearboxes

Please send pictures of the 40 HP motor that will produce 4,405,151 CFM.

Sounds like a gazillion cfm to me lyn. Hehehe I wonder what this guy are up to. Could be building some sort of wind tunnel, for simulation of prototype aircrafts and space shuttles. Hahaha.

these are what you call blowers used to test Concords engines http://i741.photobucket.com/albums/xx53/MonkeyDan1980/Pyestock/IMG_5962_3_4_tonemapped.jpg

7500HP each

I havn't got a jar of glue what these centrifugal doo dars are but as you all are doing with me you are spouting a lot of hot air to put us down. This only drives us people onwards and upwards. This man can contact me and when our ideas gel the whole of mankind will be in awe of us. The only thing that concerns me with this type of air pressure is how many feet thick will the storage tank need to be ? Also your 40hp motor seems a little on the delicate side for such power.Don't worry though, I have the power.

Curiously you use same finish as M. Krspsky who always finished with " Power". If seems to be a contagious sickness. Why are you interested in the storage tank wall thickness you have only to supply the "power" ?

Hi Nick name ,it is obvious why I am interested in the storage vessel for the massive amount of energy that needs to be stored. I have recently got a quote for a 70,000 litre tank to store the pressure at just 400psi and the wall thickness for this cute little thing is 30mm or 1 1/4". This is only for the small prototype so why do you think I need to concern myself with such facts? I need to progress and have the most efficient use of this device that is possible. It is going to take an awful lot of high pressure air to replace these silly windmills that our governments are spending billions on,but one thing is for sure, the cost of them will be a thousand times cheaper.Not only this but while I am moving this air around I shall direct it through air scrubbers and clean it up prior to pumping it back out to join the rest of the filth that mankind is producing.You should be over joyed Nick Name that people like me exist,even though I am the man with the power. Love Joe.

I have my serious doubts on that wall thickness number. 70,000 liters is about the volume a a standard rail road tanker car.

The ones they use for transporting anhydrous ammonia and propane are rated for over 400 PSI and they are only about 3/8 inch thick at the most and they are over built to handle the stresses of being constantly on the move.

Sounds to me like your tank design adviser cant do basic math either.

He might be closer than you think. 48" diameter 250 psi ammonia receivers of SA516-70 are often 1/2" thick (maybe 3/8" if 100% radiographed). Thickness is proportional to diameter x pressure (with slight miscellaneous factors).

But his tank will be rather expensive, and if it is compressed air, there won't be all that much energy in it. But then the world-savers seem never to know how to do basic arithmetic. Notice that they seldom if ever give formulas or calculations. Or maybe the decimal point is 2, 3, or even 4 places off.

You are right, ,at 400 psi (2.758 N/mm²) and a volume of 70 m^3 the wall thickness is 5.8 mm for spherical reservoir and 13.2 for a cylinder l=3d. I considered a stress level of 280 N/mm². It is only a indicative dimension since I did not take into consideration any other coefficients as normal in gas pressure recipients. The energy contained is very low. Pneumatic accumulators for wind systems have been developed and are in test in Germany (I think) but if energy has to be stored the only way is high pressure up to 20.0...25.0 MPa in several bottles connected in parallel. Due to the low cycling the transformation can be considered as isotherm so that the losses are not so big. The idea is to use the compressor as well as motor.

"This man can contact me and when our ideas gel the whole of mankind will be in awe of us."

Don't forget my fee for putting you two geniuses together.

Thank you Lyn for introducing me to this site. The difference between us two alleged nutters is the fact that I have already proved mine as a working model. If the law of levers remains the same then I have truly got a force that none of you engineers are capable of taming. The UK Government have not even answered my Email to them,telling them of this new force. They too must think I am a loon. It looks as though I may have to involve the Chinees,if I am to progress with my project. I will wait for a few more comments from CR4 engineers. One never knows who is out there. Love Joe.

More "power" to ya, Joe.

I can't imagine why your e-mail hasn't been answered by the British. No sense of humor, I'll wager.

Oh, by the way, Joe, don't quit your day job, if you have one.

How about that patent number. I'll tell you what, if you send me your patent number, I'll send you one of my patent numbers in exchange.

Hi Lyn, I have got a good sense of humour but I don't like Naysayers that are having a go ,when they do not know the facts. I admit I should have backed up what I am claiming with the facts of the patent app. I have told you that I do not have the full grant of patent yet and do not wish to talk too much. I am going out in half an hour but I promise I will give you the application number in the morning,can't look for it now. I will be back on line at 10am UK time tomorrow. Believe me Lyn, I have the power. Love Joe.

I'd be interested to know who is supporting you in this odyssey.

So far, myself excluded, these "naysayers" are a rather intelligent group. Let me make that VERY intelligent. I'm sure we'd all be delighted to be proven wrong. Bring on the proof.

I'm checking outta this discussion now, I've had enough.

Power.

4,000,000 cfm at 1.00 inch_H2O (which is a mild pressure) would require something like 1200 hp (~900 kw). [Quickie calc only] So 40 hp is a total joke. Also, the inner cylindrical area would be on the order of 1000-2000 ft². Good luck....

Hi again Lyn, After lying awake most of the night I have concluded that I do not wish to give my patent application number out until I have fully secured the intellectual property rights. This type of innovation only occurs once in each new century and it would be silly of me to allow all you mech heads to get your brains on this technology.I thank you for discussing the air tank pressure etc, but the company are experts on building tanks of this size and I can only go by what they are saying I need.70,000 litre tanks are approx 30feet long and 12feet in Dia.As I said this is only to run a small prototype. The completed wind farm would have perhaps one hundred of these tanks placed underground,with the same number of safety valves.Sorry that I have broken my promise Lyn but I can't wait until the day that I can shout my invention to the world.Our UK patent offices are inundated with renewable energy applications and it is taking up to five months to grant them.I will explain that I have only invented the method of multiplying the strength of the wind unto infinity. That is all. I am only asking you engineers to convert this force into usable energy./ power. Love Joe.

The conversion given by OP 124740 Cubic Mtr/hr (approx 4405151 cfm) is wrong. It should be only 73419 cfm. It has misled all CR4 gurus, who also didn't bother to check. A 40 hp motor assuming 70% overall efficiency can blow this capacity, but the pressure rise will be only about 60 mmwc.

So, comparing the OP with joe.fordham is wrong.