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US 4,381,898 AGranted
Device for the controlled feeding of powder material
AssigneeEutectic Corporation
InventorsAnthony J. Rotolico, Eduardo Romero, John E. Lyons
Life of this patent
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AssigneeEutectic Corporation
InventorsAnthony J. Rotolico, Eduardo Romero, John E. Lyons
Estimating the term…
The invention contemplates a powder-feeding system for gas-propelled delivery of a powder to be controllably supplied, as to a flame-spraying gas torch or to a transferred-arc plasma torch. A fluidizing chamber receives (a) fluidizing-gas flow from below a porous screen, and (b) a restricted gravitational flow of powder at a relatively small central discharge location above the porous screen. A gas conduit extends transversely through the chamber between the powder-discharge location and the porous screen; it has a carrier-gas supply connection at one end and a gas-propelled powder-delivery connection at its other end. The conduit also has an upwardly extending opening virtually beneath and facing the powder-discharge location, but a shed interposed between this opening and the powder-discharge location sufficiently overlaps the opening to assure that no powder will pass through the opening and into the conduit unless it has been gas-fluidized. The powder-discharge flow is blocked to gas flow when powder is being delivered by the carrier-gas flow, but the powder delivery is terminated promptly upon gas-venting the fluidizing chamber, via the powder-discharge flow or otherwise.
A powder-feeding system for gas-propelled delivery of a powder to be supplied in loose particulate form, wherein the powder has a characteristic angle of repose, said system comprising:
The powder-feeding system of clam 18, and carrier-gas back-pressure indicating means operatively connected to said carrier-gas connection between said valve means and said upwardly directed opening.
Powder-feeding means for gas-propelled delivery of a powder to be supplied in loose particulate form, comprising a fluidizing-chamber body having an internal fluidizing-chamber cavity having an upper region of substantially larger sectional area than its lower region and having a convergent region between said upper and lower regions, powder-supply means including a restricted vertical tubular powder-inlet passage projecting downward from the upper end of said body and through said upper region for downward discharge of powder into said convergent region, a fluidizing gas-supply connection including a gas-permeable porous screen positioned in said lower region to effectively define the bottom of said chamber so that flow of fluidizing gas supplied to said body beneath said screen will be distributed over the area of said screen, and a gas conduit extending transversely of the convergent region of said chamber cavity, said conduit having a carrier-gas supply connection at one end and a gas-propelled powder-delivery connection at its other end, said gas conduit in the region of said vertical passage having an upwardly directed opening to said chamber for conduct of gas-fluidized powder from said chamber and into said conduit, and a shed interposed between and in vertically spaced relation from both said passage and said opening, said shed being of such substantially greater overlapping area than said opening in relation to its spacing from said opening that no gravity flow of powder into said chamber can pass into said opening in the absence of a fluidizing gas flow via said fluidizing gas-supply connection.
Dependencies are inferred from the claim text.