Heating powder feeder

[landemarre]

Hello

I'd like to know if there is an interest to have heating powder feeder in thermal spraying (except for Vaccum Plasma Spraying). Does someone use this material for APS or HVOF, with witch type of powder?


Thanks

Olivier

[pabloarriola]

Hi,

We use heating powder feeder for plasma spraying an abradable material, Al Si Polyester, to improve "flowability" of the powder.
Any other application any one?

Pablo

Hello

I'd like to know if there is an interest to have heating powder feeder in thermal spraying (except for Vaccum Plasma Spraying). Does someone use this material for APS or HVOF, with witch type of powder?


Thanks

Olivier

[Gordon]

Hi Olivier and Pablo

I assume you mean heating the powder prior to placing in the powder feeder.

I'm not sure whether warming the powder (in pristine condition) really significantly effects flow ability, but it can certainly help with reducing any tendency for it to pick up moisture, which can seriously effect powder feeding properties.

I know a few companies that use ovens near their work stations to store powder ~40-60 *C and claim to benefit from this practice.

Careful storage in a nice constant warm and dry environment, with thorough tumbling before use are important factors in avoiding potential problems.

I remember a batch of chromium oxide based powder, which would not feed properly. This was spread out on baking trays and placed in an oven overnight. Next day, perfectly baked solid biscuits Moral of the story, don't let your powder get damp in the first place, warming/drying a damp powder may actually make things worse.

[landemarre]

hello Pablo

I think heating polyester should not be good for electric loads, but because heating powder feeder are conductor altogether, it help for the flowability of the powder, no?

Olivier

Hi,

We use heating powder feeder for plasma spraying an abradable material, Al Si Polyester, to improve "flowability" of the powder.
Any other application any one?

Pablo

---

Hello Gordon

I have see some factory using chromium oxide based powder, and they use heating powder feeder, this is probably a solution to not have too much humidity in powder feeder and not clean it when powder is not used, but probably it is better to have a gate on the tube of powder between powder feeder and injector no?

Olivier

Hi Olivier and Pablo

I assume you mean heating the powder prior to placing in the powder feeder.

I'm not sure whether warming the powder (in pristine condition) really significantly effects flow ability, but it can certainly help with reducing any tendency for it to pick up moisture, which can seriously effect powder feeding properties.

I know a few companies that use ovens near their work stations to store powder ~40-60 *C and claim to benefit from this practice.

Careful storage in a nice constant warm and dry environment, with thorough tumbling before use are important factors in avoiding potential problems.

I remember a batch of chromium oxide based powder, which would not feed properly. This was spread out on baking trays and placed in an oven overnight. Next day, perfectly baked solid biscuits Moral of the story, don't let your powder get damp in the first place, warming/drying a damp powder may actually make things worse.

[Steph]

I use a Praxair 1264 hopper with heat blankets rapped around the canister...
Like Gordon said it just keeps the powder nice and dry!

Take guard not to let the powder sit too long in the hoppers on the pretext that it is dry and warm, in the case of the Al Si Polyester the powder needs agitation to have a homogenous blend.