Method of and apparatus for the surface cleaning of workpieces

Claim 1

A process for the surface treatment of a workpiece to effect degreasing, derusting or descaling thereof, which comprises: (a) disposing the workpiece in a fluidized bed of particles of an abrasive selected from the group which consists of corundum or quartz sand; (b) fluidizing the bed from below by air; and (c) while fluidizing the bed and independently thereof, directing against said surface fine gas streams of air at high pressure from nozzles in annular array spaced from the surface of the workpiece and surrounding same whereby the streams upon emergence from said nozzles entrain particles of the bed against said surface.

Claim 5

An apparatus for the surface cleaning of a workpiece comprising: (a) a closed fluidizing vessel having a bottom chamber and a perforated wall above said bottom chamber and fluidized bed chamber; (b) a blower communicating with said bottom chamber for feeding a fluidizing gas thereto for fluidize a bed of abrasive particles in said fluidizing chamber; (c) means for positioning a workpiece in the fluidized bed in said fluidizing chamber; (d) means for feeding abrasive particles to said fluidizing chamber; (e) a plurality of nozzles in an array surrounding and trained upon said workpiece while being spaced therefrom within said fluidized bed; (f) a source of high-pressure gas connected to said nozzles; (g) an exhaust conduit leading from said vessel for carrying away gas and entrained particles; (h) means connecting said exhaust conduit to a first cyclone for removing coarse particles from the gas traversing said exhaust conduit; (i) means for recycling particles from said first cyclone to said fluidizing chamber; (k) a second cyclone connected to said first cyclone for recovering fine particles from the gas traversing said exhaust conduit; and (l) a supply bin containing fresh abrasive and connected by a lock chamber to said fluidizing vessel.

Claim 6

An apparatus for the surface cleaning of a workpiece comprising: (a) a closed fluidizing vessel having a bottom chamber and a perforated wall above said bottom chamber and fluidized bed chamber; (b) a blower communicating with said bottom chamber for feeding a fluidizing gas thereto for fluidize a bed of abrasive particles in said fluidizing chamber; (c) means for positioning a workpiece in the fluidized bed in said fluidizing chamber; (d) means for feeding abrasive particles to said fluidizing chamber; (e) a plurality of nozzles in an array surrounding and trained upon said workpiece while being spaced therefrom within said fluidized bed; (f) a source of high-pressure gas connected to said nozzles; (g) an exhaust conduit leading from said vessel for carrying away gas and entrained particles; (h) means connecting said exhaust conduit to a first cyclone for removing coarse particles from the gas traversing said exhaust conduit; (i) means for recycling particles from said first cyclone to said fluidizing chamber; (k) a second cyclone connected to said first cyclone for recovering fine particles from the gas traversing said exhaust conduit; and (l) a supply bin containing fresh abrasive and connected by a lock chamber to said fluidizing vessel.