How to set HF Transformer NWL

The chances of someone from <...Nothelfer Winding Laboratories...> responding to the original post are remote-to-negligible!

The <...We...> needs to telephone <...Nothelfer Winding Laboratories...> directly and obtain advice "straight from the horse's mouth", and not wait around on CR4 on the off-chance that someone, somewhere, might be tempted enough to respond.

I have already contacted them & got some help. We had some improvements. We still have smokes coming out of our stack on bagasse. The NWL guy works in an office & usually does not have field experience. Other persons working in a power plant who have encountered similar problems with HF transformer on bagasse may help.

So is that the end of the matter (rhetorical question - NNTR)?

Get back onto the supplier and seek further help until the issue is rectified. Become their pest! If necessary, obtain a site visit from someone there that can help!

You are only chipping at the smallest piece of the iceberg...

https://www.thermalenergysystems.com/issct10.pdf

Check the condition of the bags.Check the differential pressure across the bags.They may be clogged by fine particulates.Perform a thorough examination of the bag material.Holes in the fabric can allow unfiltered gas to escape.This would normally show up as a decrease in differential pressure,but if the bag media is clogged,the differential in pressure may not be noticeable.Check the condition/adjustment of the forced draft and induced draft fans and check the chemical composition of the stack gases.You may be running with insufficient air.

The excessive smoke is not caused by the NWL,it may simply be overloaded.A well designed,properly sized and installed static precipitator can replace bag house filters and require less maintenance and cost.A bag house requires about six times the energy to pull the gases through the filter media.

Some applications and areas do not allow only Electrostatic participators,so check with the local authorities.

When you call Nothelfer Winding Laboratories again, be a "squeaky wheel",pester them,nag them until you finally get results.

Our ESP is not a bag filter. It consists of metal electrodes. It has 3 fields which are energised by transformers. Operating voltage is around 50 kV 500 mA. We have 2 sets of turbo-alternators, boilers & ESPs. ESP 1 is working quite well on both coal & bagasse. ESP 2 is working well on coal but there is lot of smoke on bagasse.

In June we did our annual maintenance. We repaired some holes in the ESP casing, replace the roof, repare holes in the economizer hopper just before the ESP. We replaced the transformer on field 1 with an HF Transformer NWL. This has a higher kVA and is the latest technology and is supposed to collect more ash.

The problem is that the company who did maintenance on our ESP, installed the HF transformer. They purchased it from another company not directly from NWL. We managed to get a contact from NWL on the website who helped us. We got some improvement. But still we have smoke from our stake. So NWL has not obligation towards us.

We have fine tuned the rapping times of the collecting & discharge plates. May be there is still some improvement to do here.

I will like to know if I can increase my kV & mA on the HF transformer on manual mode. Now on bagasse, it is 48 kV and 676 mA .

When there is collecting plate rapping on field 1, there is a peak in opacity. I need to solve this issue.

The rapping times are as follows:

It would seem that the airflow must be adjusted between coal and bagasse, either increased or decreased...

Your flue gas velocity may be too high to charge the particulate in time, which is likely much finer and perhaps more conductive than the original design. Your burner settings and design could be different enough between the 2 boilers to require a different design, or burner operation is not as it was before, secondary air mixing, combustion zone temperatures. The intensity of rapping may be dislodging the particulate rather than allowing it to slip down, especially if lighter and/or finer.