1600KW FAN VARIABLE SPEED DRIVE

[SRC99]

I am working on a cooling fan for cement kiln, the motor is 1600KW with speed variable in 50-100% range. VFD is not considered because of the cost. A squirrel cage motor and fluid coupling drive is preferred at this moment. Is there any better solution for this application? Thanks a lot.

 

[DougMSOE]

The question to ask is how smooth does the speed need to be changed?
You might want to consider a motor that can be configured into a multiple speed motor by changing the number of poles. In this case for example start the motor as a 14 pole. When it is up to that speed switch to 10 pole, etc. Would this be of interest? However in the above approach magnetic flux air gap harmonics will play into the design of the motor. There are some pole combinations that will work with the rotor/stator slot ratios and some that WILL NOT WORK!
If more control of the RPM is required maybe a wound rotor induction motor (WRIM) would be of consideration as this is the ultimate in the simple soft start approach if done correctly.

 

[gsimson]

What are all your needs ?
- Variable speed ?
- Energy saving ?
- Smooth start for the power system ?
- Reliability ?
- Simple maintenance - No skilled technicians ?
- Upgradation of technology over a period ?
- Power factor improvement ?
The decision can be based on the above factors.

 

[jraef]

Add to gsimon's list:
-Do you already have a motor or is the motor part of the design criterea? (just to be sure)
-What is the capacity of your power system? Limited? Small transformer? On-site generator? No problem?

 

[jbartos]

Suggestion: Visit

http://www.magnadrive.com

for a variation of VFD via a special motor-load coupling that will probably be the better solution, if the cost permits.

 

[macmil]

jb, unfortunately MagnaDrive adjustable speed drives are only available up to 1500 HP at 1800 rpm (at this time). If the rating was ok, it would be an excellent option.
by the way SRC99, is this a cooling fan, or an i.d. fan ?

 

[jbartos]

Comment on the previous posting: There is a small margin between 1500kW and 1600kW. Magnadrive might be contacted regarding this small margin.

 

[SRC99]

Thank you for all your posts.

Let me clarify my question: I do need to find a better solution (motor + drive) for the new cooling fan meeting the following three requirements: start up the fan smoothly, realize the speed of the fan variable in 50-100% range with accuracy around 2% of the full speed; minimize equipment cost and operation cost. No other factor is important.

Dougmose, WRIM and resistor starter is my second option too; can the resistor handle the high temperature when the motor is running continuously in lower speed?

Jbartos, VFD can achieve the best speed control for the whole range, if the cost is acceptable. Can you give me some budget price for the VFD system including motor, transformer and VFD? (Note: the motor stator voltage is 10KV)

Magna drive seems to be a good solution, compared to VFD, how much cheaper is it?

By the way, in your opinion, what’s major issue if the fluid coupling with variable speed control is used for this application?

 

[jbartos]

Comment on the previous posting marked ///\\
Jbartos, VFD can achieve the best speed control for the whole range, if the cost is acceptable. Can you give me some budget price for the VFD system including motor, transformer and VFD? (Note: the motor stator voltage is 10KV)
///Visit

http://www.thomasregister.com

and type Drives: Motor under Product or Service, which will return 172 companies to approach to
It is better to negotiate the price by yourself since this technology products vary widely from the manufacturer-to-manufacturer.\\Magna drive seems to be a good solution, compared to VFD, how much cheaper is it?
///Visit

http://www.magnadrive.com

for generic information about the MagnaDrive savings.
Please, notice that there are many factors in technical comparisons of products. The comparisons impact the price. The MagnaDrive price will probably vary from the Client-to-Client. They claim the MagnaDrive solution has noticeable advantages over the VFD solutions.\\

 

[cbarn24050]

Hi, a voltage controller works for fan loads, probably not down to 50% but your unlikely to really need that.