ISSUE using SG100 plasma torch w/ 9MP feeder

[HBX]

Hi everyone,

We just bought a new SG-100 plasma torch with 24" extension and 45° nozzle, in order to replace our 11MB.
This SG-100 actually has an internal powder injection, which leads to a slight increase of the pressure inside the powder feeder.
We used to feed the powder with a 9MP feeder, which works perfectly with conventionnal external powder injection. However, the pressure rise from the internal injection seems to completely block the powder flow.. nothing is getting out of the torch while it's working.

Is it a common issue with this type of torch ?
Does anybody have a solution to this problem ?
All ideas are welcome


Thank you.

[djewell]

Powder feed rate in the 9MP is determined by a pressure differential. It sounds like you have a high back pressure from your gun, so there is no pressure differential in the feeder, so it is not going to pick up any powder. You need a mechanical type feeder like a V4 from UniqueCoat Technologies.

[HBX]

I actually make it work with a 6MP mechancial feeder.
However, the feed rate isn't accurate at all
Of course it is better than nothing, but I still believe there is a way to setup the 9MP up to feed through this torch.
For instance this type of fluidized feeder are use with HVOF torchs, which have a tremendous back pressure compare to this SG100 plasma torch.

[djewell]

Metco makes a special version of the 9MP feeder for use with HVOF guns - because of the back pressure.

[HBX]

Thanks for your feedback.
The 9MP feeder designed for HVOF is called 9MP-HP, as High Pressure
Still, the back pressure isn't the same order of magnetude than that generated by plasma torch.
Moreover I have been told by colleagues in the field that this torch works with 4MP feeder, which is very similar with 9MP (same fluidized bed w/o back pressure compensation).

So I would like to know if anybody else are using SG100-type internal injection plasma torch with a basic 9MP-type feeder ?
If yes, is there any tweak to perform.. ?

[loriolo]

Hi HBX
You must change the powder feeder to the twin version, because fluidized bed powder feeders are not so good for thermal spray applications, as well as the powder rate is determined by a pressure differential, you could not change carrier gas pressure in order to have more parameters choise and possibility to change in pressure without changing the powder rate