Induction Billet Heater Coil

please look at this book and find the information you needed... http://books.google.com/books?id=FRmqNkwTvGAC&pg=PA470&lpg=PA470&dq=induction+billet+heating+coil&source=bl&ots=0UeuxuE6V9&sig=gIGBiypVvxzVaSg4-Q0ooiXKGUc&hl=en&sa=X&oi=book_result&resnum=1&ct=result#PPA484,M1

hi keshi123

Need more information about your inductor failure to find out the cause of failure and to think of probable cause of failure.

What is the frequency used for heating .Is it mains frequency ( 50/60 Hz) or higher frequency ?

What is the voltage at the inductor and source of supply?.

What was the life given by the original Inductors supplied by the manufacturer?

Is the failure noticed after replacement of original coils supplied by the manufacturer?

Is the coils properly mounted in the box and do not vibrate ?

Is the air gap between coil and billet uniform or is there any variation ?

What is the pressure of water in the heater coil?

Is the water properly treated to avoid scaling?

How often the descaling or cleaning of inductor coil is carried out?

Does the water leaks from the surface of inductor and fall on billets?

Is the movement of billet uniform with out jerks and stops in between.

Is the spark occurs at same place in all failures or is it at different locations.

Please make proper check and give the replies.

Probably if all the above points are optimised the failure may get stopped.

Dear Sir,

Thank you very much for your reply. I would like answer all your question, so that we conclude some outcomes.

1.Frequency used on this heaters 1khz to 3 khz.its main frequency is 50hz.

2. voltage at inductor terminals is 600 to 1000v.at the source is 430 to 580v.

3.No data

4.No data

5. Properly mounted and free from vibration.

6. Air gap between the coil is uniform

7. water pressure for coil cooling is 4Kg/cmsq

8.We are using treated water only.

9.Every shift end cleaning done by forced air.

10.Movement of billet is free from jerks.no stoppages in between.

11.Spark may occur any place inside the coil.

awaiting for your reply.

Hi keshi123

From the information provided it appears that your billet size is not for a single standard size but you are having products of different sizes and you may be changing the frequency and power to suit your product.It is only my assumption as you have not provided the details of power of the source and actual voltage frequency of specific operation at which the inductor is getting damaged. you have to select the correct combination of such settings to suit your job and inductor .

The normal cause of such inductor failure is due to wrong settings ,faulty design of inductor,faulty manufacture or poor quality copper tubes used for making inductor.

The other cause is use of higher voltage and power than recommended by the inductor manufacturer which can cause exes vibration of coil beyond the design parameters of the inductor coil . The inductor design is highly technical job and needs best quality material and high tech design. If the inductors are sealed in ceramic insulation in the box, the quality of binding clay will play an important role for the life of inductor. Get a new set of inductors designed by professional manufacture who will guarantee against failure.

Ensure that the water used de mineralised water pressure and water flow switches are connected in the circuit to ensure proper cooling of the inductor which provider long life of inductors.

Please read the link below for more information .

http://www.springerlink.com/content/qgq75733m81p7121/

You say you have no data on the original coils? How do you know that the coils you are making are up to the required specifications?

Air gap spacing of coils could be to small, you have a variable frequency available to allow for different set ups so maybe a redesign should be considered.