A feed hopper has a porous plate at the bottom; dry compressed air through it lifts the powder into a fluidized state so pumps can pull it at a steady rate. Too little air leaves dead spots and surging; too much blows powder out and starves the pumps. Reclaim and fresh powder are mixed here, and fines and moisture show up first as poor fluidization.
Feed hopper is ratholing in the corner, give it more fluidizing air and stir it up.
Also heard as
- hopper
- fluidizing hopper
Related terms
Boil
To bubble gently and evenly like simmering water, the way a properly fluidized hopper of powder should look.
Fines
The smallest particles in a powder, roughly under 10 microns, which fluidize, charge and recycle poorly.
Reclaim
Oversprayed powder collected from the booth and fed back into the system for reuse.
Spitting
Powder bursting out of the gun in clumps, leaving lumps and heavy spots on the part.