Abstract: Metal particles are melted by mixing them with molten metal contained in a bath. A shaft-supported, rotatable impeller is immersed into the molten metal and rotated so as to establish a vortex-like flow of molten metal. Metal particles are deposited onto the surface of the molten metal in the vicinity of the rotating impeller. The particles are submerged substantially immediately after being deposited onto the surface of the molten metal. The impeller includes a thin rectangular prism having sharp-edged corners and vanes that extend upwardly from the prism. The impeller also can be used to disperse gas into the molten metal by pumping the gas through a bore extending the length of the shaft and out of the impeller along the lower surface of the impeller. The gas is sheared into finely divided bubbles as it rises along the sides of the impeller.

Abstract: Metal particles are melted by mixing them with molten metal contained in a bath. A shaft-supported, rotatable impeller is immersed into the molten metal and rotated so as to establish a vortex-like flow of molten metal. Metal particles are deposited onto the surface of the molten metal in the vicinity of the rotating impeller. The particles are submerged substantially immediately after being deposited onto the surface of the molten metal. The impeller includes a thin rectangular prism having sharp-edged corners and vanes that extend upwardly from the prism. The impeller also can be used to disperse gas into the molten metal by pumping the gas through a bore extending the length of the shaft and out of the impeller along the lower surface of the impeller. The gas is sheared into finely divided bubbles as it rises along the sides of the impeller.

Abstract: A molten metal pump includes a filter that prevents ingestion of foreign material such as dross from molten metal within which the pump is immersed. The filter is a large structure that is secured to the base of the pump surrounding the pump's inlet. The filter forms a cavity adjacent the pump's inlet. The ratio of the surface area of the filter to the inlet area of the pump is very large due in part to a corrugated end wall included as part of the filter. The filter has a low porosity while maintaining a high flow rate for the pump.

Abstract: A molten metal pump includes an impeller disposed at the end of an elongate drive shaft. The drive shaft is disposed within an elongate, hollow post. The impeller and the end of the post are adapted to be immersed in molten metal. An inert gas is conveyed through the gap between the outer surface of the drive shaft and the inner surface of the post, which gas is discharged into the molten metal in the vicinity of the impeller. Because the drive shaft is insulated from the molten metal, it can be made of a durable material such as steel; because the post is stationary relative to the molten metal, the metal is stirred only by the impeller, and not by the drive shaft. The invention includes other features such as a quick disconnect capability and a radial adjustment capability.

Abstract: An impeller for a molten metal pump having a cup-shaped body comprised of a sidewall and a closed end portion that define a cavity. A plurality of shear vanes extend radially from the outer surface of the impeller, particularly from the end portion of the impeller. The impeller also has a plurality of openings extending laterally through its sidewall, wherein the openings have center lines disposed parallel to lines extending radially from the center of the cavity. The openings may be equidistantly spaced about the periphery of the sidewall. The impeller may also be comprised of a bearing member forming a portion of the sidewall.

Abstract: Metal particles are melted by mixing them with molten metal contained in a bath. A shaft-supported, rotatable impeller is immersed into the molten metal and rotated so as to establish a vortex-like flow of molten metal. Metal particles are deposited onto the surface of the molten metal in the vicinity of the rotating impeller. The particles are submerged substantially immediately after being deposited onto the surface of the molten metal. The impeller includes a thin rectangular prism having sharp-edged corners and vanes that extend upwardly from the prism. The impeller also can be used to disperse gas into the molten metal by pumping the gas through a bore extending the length of the shaft and out of the impeller along the lower surface of the impeller. The gas is sheared into finely divided bubbles as it rises along the sides of the impeller.

Abstract: A drive system for impeller shafts includes a coupling that has a universal joint that is lubricated under all operating conditions. A housing is connected to the universal joint, which housing includes a hollow end portion adapted to receive the non-threaded end of an impeller shaft. A threaded stud projects from the end of the shaft and into the housing where the stud is secured by means of a nut. The nut is readily accessible to the user so that the axial position of the shaft can be adjusted without difficulty. The nut is releasably held within the housing so that the shaft and stud, with nut attached, can be quickly disconnected from the coupling. The invention also includes a modified "square drive" configuration for the ends of the shaft that is extremely strong and enables the shaft to be connected to the impeller and the coupling very easily.

Abstract: A molten metal pump includes an impeller disposed at the end of an elongate drive shaft. The drive shaft is disposed within an elongate, hollow post. The impeller and the end of the post are adapted to be immersed in molten metal. An inert gas is conveyed through the gap between the outer surface of the drive shaft and the inner surface of the post, which gas is discharged into the molten metal in the vicinity of the impeller. Because the drive shaft is insulated from the molten metal, it can be made of a durable material such as steel; because the post is stationary relative to the molten metal, the metal is stirred only by the impeller, and not by the drive shaft. The invention includes other features such as a quick disconnect capability and a radial adjustment capability.

Abstract: A molten metal pump includes a filter that prevents ingestion of foreign material such as dross from molten metal within which the pump is immersed. The filter is a large structure that is secured to the base of the pump surrounding the pump's inlet. The filter forms a cavity adjacent the pump's inlet. The filter has a low porosity while maintaining a high flow rate for the pump. The filter is a semi-toroidal structure that is attachable to a pump base having an upper inlet. The filter surrounds the pump's inlet. The filter includes a central opening through which access can be had to the pump's impeller for purposes of inspection, repair, or replacement without disturbing the attachment between the filter and base.

Abstract: Apparatus for injecting gas into molten metal includes a porous ceramic body having a first surface through which gas can be introduced into the body, and a second surface through which gas can flow from the body. A refractory member is attached to the body and surrounds at least the first surface, while leaving the second surface exposed. The refractory member is impervious to gas, while having a coefficient of thermal expansion approximating that of the body. Preferably, a refractory sealant securely attaches the refractory member to the body. By use of the present invention, the refractory member and the body remain tightly connected to each other at all times. Accordingly, gas leaks are prevented and all gas flowing into the body is discharged through the second surface, as desired.

Abstract: A detectable tape including a ductile metal foil layer which is enclosed in a sheath of thermoplastic coating which provides a sealed edge along the length of the tape. The thermoplastic coating sheath protects the foil from corrosion when the detectable tape is placed underground above a nonmetallic body such as plastic pipe. The sealed edge detectable tape can also include a reinforcement layer which provides additional tensile strength.

Abstract: A method of melting metal particles includes the steps of swirling molten metal in a vortex within a crucible, adding metal particles onto the surface of the metal, and submerging the metal particles substantially immediately after the particles have been added onto the surface. Apparatus for carrying out the method includes a mixer having a vertically oriented sleeve secured to the bottom of the crucible, the sleeve supporting a plurality of blades on its outer surface and having a plurality of openings adjacent its bottom. The blades force the metal particles beneath the surface of the metal and create turbulence which ensures rapid melting of the particles. The blades as well as the openings adjacent the bottom of the sleeve break up any agglomerated metal particles. Discharge piping is connected to the bottom of the crucible. A vortex breaker is disposed in the piping to control the vortex in the crucible.

Abstract: A reinforced metallic and polymer tape which has a light reflecting metallic layer and can have a color coating. The reinforcing material is usually a nonwoven clear resin through which the color is clearly visible. The combination of the metallic layer and reinforcing layer produces a high tensile strength, tear resistant tape. The combination also produces a tape that does not have the tendency to curl.

Abstract: A molten metal transfer device for withdrawing a selected quantity of molten metal from a bath includes structure defining a chamber disposed within the bath, the chamber including a first opening through which molten metal can flow from the bath into the chamber and a second opening through which molten metal can flow outwardly from the chamber. A cup-like bucket is disposed within the chamber for vertical reciprocating movement, the bucket having a generally vertically oriented slot included as part of its sidewall. The device includes a displacement mechanism for urging the bucket laterally toward engagement with the surface of the chamber. The device also includes mechanisms for easily removing buckets and chambers and replacing them with new buckets and chambers.

Abstract: Propylene is polymerized with an improved titanium chloride catalyst. The improved titanium chloride catalyst is prepared by treating TiCl.sub.4 with an aluminum alkyl and treating the resulting titanium chloride catalyst with carbon dioxide and a Lewis base, such as di(n-butyl) ether in a hydrocarbon medium at an elevated temperature.

Abstract: Titanium chloride catalysts having improved activity to polymerize propylene are prepared by treating TiCl.sub.4 with an aluminum alkyl and treating the resulting titanium chloride catalysts with carbon dioxide and a Lewis base such as di(n-butyl) ether at an elevated temperature.

Abstract: An improved process is provided for incorporating additives into thermoplastic polymers. The desired additive(s) are dispersed in a continuous solid phase which is a mixture of a wax and a normally liquid hydrocarbon to form a Bingham fluid composition. These Bingham fluid compositions, while solid at ambient temperature and pressure, will flow under an applied pressure and can be pumped to feed the additive to a molten polymer. When this mixture is passed through a mixing apparatus such as an extruder, the additive is uniformly dispersed throughout the polymer. The process is particularly well suited to incorporate additives into a molten ethylene polymer either as, or immediately after, the molten ethylene polymer is discharged from the reaction zone in which the polymer is prepared.

Abstract: A process is provided for the continuous high-pressure mass polymerization of ethylene in which novel means are employed to continuously introduce the free radical generating polymerization initiator into the polymerization zone. The process is carried out by pumping into the polymerization a Bingham fluid which has a free-radical generating polymerization initiator uniformly dispersed throughout a solid continuous phase, which is a mixture of a wax and a liquid hydrocarbon.

Abstract: An improved process is provided for incorporating finely-divided inorganic additives such as diatomaceous earth into thermoplastic polymers. The desired additive(s) are dispersed in a normally liquid hydrocarbon to form a Bingham fluid composition. These Bingham fluid compositions, while solid at ambient temperature and pressure, will flow under an applied pressure and can be pumped to feed the additive to a molten polymer. When this mixture is passed through a mixing apparatus such as an extruder, the additive is uniformly dispersed throughout the polymer. The process is particularly well suited to incorporate such additives into a molten ethylene polymer either as, or immediately after, the molten ethylene polymer is discharged from the reaction zone in which the polymer is prepared.

Abstract: A process is provided for preparing a copolymer of ethylene and acrylic or methacrylic acid. Typically, a copolymer of ethylene and methyl acrylate is dissolved in a diarylalkane such as 1,1-dixylylethane. A transesterification catalyst and either isopropanol or tertiary butanol is added to the polymer solution which then is heated to reflux to convert the polymerized methyl acrylate moiety to the isopropyl or tertiary butyl acrylate moiety. Following completion of the transesterification reaction, any excess isopropanol or tertiary butanol is removed from the reaction system by distillation. The polymer solution then is heated to a temperature of the order of 320.degree. C to thermally crack the isopropyl or tertiary butyl acrylate and form the corresponding ethylene-acrylic acid copolymer. The ethylene-acrylic acid copolymer is insoluble in the diarylalkane and can be recovered by filtration.