Investment mold slurry curtain apparatus

An investment mold slurry coating manifold apparatus, comprising:

• a slurry manifold having a slurry chamber configured to receive a flow of a slurry fluid;
• an inlet conduit disposed on the slurry manifold, the inlet conduit having an inlet opening into the slurry chamber, the inlet conduit configured to provide the flow of the slurry into the slurry chamber;
• and
• an outlet, the outlet configured to dispense a curtain of the slurry.

An investment mold making apparatus, comprising:

• a conveyor, the conveyor configured to convey an investment mold pattern assembly between a plurality of stations, the mold pattern assembly comprising a longitudinal axis, an axially-extending central sprue, at least one gate extending radially outwardly from the central sprue to at least one pattern, the mold pattern assembly comprising a fugitive (removable) material, the axially-extending sprue disposed on a mandrel, the mandrel and mold pattern assembly rotatably disposed substantially horizontally on the conveyor;
• a slurry coating station, the slurry coating station comprising a slurry curtain comprising an aqueous slurry, the conveyor configured to position and rotate the mold pattern assembly under the slurry curtain to provide a wet slurry coating layer;
• a stucco coating station, the stucco coating station comprising a plurality of dispersed dry stucco particles comprising a refractory material, the conveyor configured to position and rotate the mold pattern assembly within the dispersed dry stucco particles to dispose a layer of dry stucco particles on the wet slurry coating layer;
• and
• a drying station, the conveyor configured to convey the mold pattern assembly from the slurry coating station or the stucco coating station to the drying station and position and rotate the mold pattern assembly within the drying station, the drying station configured to dry the slurry coating layer and provide a dried slurry coating layer.

A method of making a refractory shell mold, comprising:

• providing an investment mold pattern assembly, the investment mold pattern assembly comprising a longitudinal axis, an axially-extending central sprue, at least one gate extending radially outwardly from the central sprue to at least one pattern, the investment mold pattern assembly comprising a removable material, the axially-extending sprue disposed on an axially extending rotatable mandrel, the rotatable mandrel and central sprue disposed substantially horizontally;
• rotating the mandrel and investment mold pattern assembly under a first slurry curtain of a first slurry comprising a liquid, a binder and first refractory particles to provide a wet coating layer of first refractory particles on an outer surface of the investment mold pattern assembly and provide a wet slurry coated investment mold pattern assembly;
• and
• removing the wet slurry coated investment mold pattern assembly from the slurry curtain.

A method of making a refractory shell mold, comprising:

• (a) providing an investment mold pattern assembly, the investment mold pattern assembly comprising a longitudinal axis, an axially-extending central sprue, at least one gate extending radially outwardly from the central sprue to at least one pattern, the investment mold pattern assembly comprising a removable material, the axially-extending sprue disposed on an axially extending rotatable mandrel, the rotatable mandrel and central sprue disposed substantially horizontally;
• (b) rotating the mandrel and investment mold pattern assembly under a slurry curtain of a slurry comprising a liquid, a binder and refractory particles to provide a wet coating layer of refractory particles on an outer surface of the investment mold pattern assembly and provide a wet slurry coated investment mold pattern assembly;
• (c) optionally applying a layer of dry refractory stucco particles to the wet coating layer of the refractory particles to provide a wet stucco coated investment mold pattern assembly;
• (d) drying the wet stucco coated investment mold pattern assembly to remove the liquid and provide a dried stucco coated investment mold pattern assembly comprising a dried layer comprising refractory stucco particles and refractory particles;
• and
• (e) repeating (b) through (d) a plurality of repetitions to provide a refractory shell mold comprising a plurality of dried layers of refractory stucco particles and refractory particles.