Abstract:
In a device for atomizing and granulating liquid oxidic slags such as, e.g., converter slags, blast furnace slags or waste incineration slags, including a slag tundish having an outlet opening into which a height-adjustable lance for a propellant jet opens and to which a cooling chamber is connected, the outlet opening is surrounded by an immersion tube arranged concentrically therewith while forming an annular gap. A guide body capable of being adjusted in the axial direction of the lance is arranged in the region of the nozzle mouth of the propellant jet lance, which guide body deflects the propellant jet in the radial direction. (FIG. 2)
Abstract:
Methods for controlling the superheat of the stream of molten metal from an electroslag refining apparatus is taught. The methods include the introduction of unrefined metal into an electroslag refining process apparatus in which the unrefined metal is first melted at the upper surface of the refining slag. The molten metal is refined as it passes through the molten slag. The refined metal is collected in a cold hearth apparatus having a skull of refined metal formed on the surface of the cold hearth for protecting the cold hearth from the leaching action of the refined molten metal. A cold finger bottom pour spout or exit orifice is formed at the bottom of the cold hearth to permit dispensing of molten refined metal from the cold hearth. The super heat of the molten metal flowing through the exit orifice of the cold finger apparatus is controlled, preferably utilizing a processor, such as a computer, by coordinating the rate of induction heat supplied to the metal within the cold finger apparatus and the rate of heat removal from the metal within the cold finger apparatus through the cold finger apparatus itself thereby providing metal having a specific superheat exiting the exit orifice.
Abstract:
A method of electroslag refining of metal is taught. The method includes the introduction of unrefined metal into an electroslag refining process in which the unrefined metal is first melted at the upper surface of the refining slag. The molten metal is refined as it passes through the molten slag. The refined metal is collected in a cold hearth apparatus having a skull of refined metal formed on the surface of the cold hearth for protecting the cold hearth from the leaching action of the refined molten metal. A cold finger bottom pour spout is formed at the bottom of the cold hearth to permit dispensing of molten refined metal from the cold hearth. The flow rate of molten metal through the cold finger apparatus is controlled by coordinating, among other parameters: the rate of melting of the unrefined metal; the hydrostatic head of molten metal and slag above the bottom pour cold finger orifice; the rate of induction heat supplied to the metal within the cold finger apparatus; the rate of heat removal from the metal within the cold finger apparatus through the cold finger apparatus itself and through adjacent gas cooling means; and by applying electromagnetic force to selectively speed up, slow down and/or interrupt the flow of metal through the cold finger apparatus via an electromagnetic orifice, preferably utilizing a processor, such as a computer.
Abstract:
A method of electroslag refining of metal is taught. The method starts with the introduction of unrefined metal into an electroslag refining process in which the unrefined metal is first melted at the upper surface of the refining slag. The molten metal in the form if droplets is refined as it passes through the molten slag. The refined metal droplets are collected in a cold hearth apparatus having a skull of refined metal formed on the surface of the cold hearth and protecting the cold hearth from the leaching action of the refined molten metal. A cold finger bottom pour spout is formed at the bottom of the cold hearth to permit dispensing of molten refined metal from the cold hearth. The rate of flow of molten metal through the cold finger apparatus is controlled by controlling the rate of melting of the unrefined metal; by controlling the hydrostatic head of molten metal and salt above the bottom pour cold finger orifice; by controlling the rate of induction heat supplied to the metal within the cold finger apparatus; by controlling the rate of heat removal from the metal within the cold finger apparatus through the cold finger apparatus itself and through adjacent gas cooling means; and by applying force to slow down and/or interrupt the flow of metal through the cold finger apparatus.
Abstract:
A nozzle assembly design and a method for making the nozzle assembly, as well as a method for controlling a continuous skull nozzle process employing the nozzle assembly are provided wherein the cooling heat transfer coefficient at the nozzle is increased to maintain a steady-state solidified layer of a noncontaminating liner material, the cooling heat transfer coefficient being increased by reducing the contact resistance between a nozzle outer wall member and an inner liner made of the noncontaminating material, the reduction in contact resistance being achieved by shrink-fitting the nozzle outer wall member around the inner liner to increase the contact pressure between those members.
Abstract:
Titanium is induction melted to produce a molten mass thereof and a water-cooled crucible having a nonoxidizing atmosphere and a bottom opening. The current to the coil used for induction melting is adjusted to produce a levitation effect on the molten mass in the crucible to prevent the molten mass from flowing out of the bottom opening. The molten mass is also maintained out-of-contact with the crucible by providing a solidified layer of titanium between the molten mass and the crucible. After production of the molten mass of titanium, the current to the induction coil is reduced to reduce the levitation effect and allow the molten mass to flow out of the bottom opening of the crucible as a free-falling stream of molten titanium. This stream is struck with an inert gas jet to atomize molten titanium to form spherical particles. Spherical particles are cooled to solidify them and are then collected. The free-falling stream from the crucible may be directed to a tundish from which the molten mass flows through a nozzle for atomization. The titanium may be melted to form the molten mass outside the crucible with a molten mass then being introduced to the crucible.
Abstract:
A molten metal spray-depositing apparatus employs an ejection nozzle for receiving a molten metal stream and having a configuration for confining and imparting mechanically an angular momentum thereto which produces stream break-up into a metal particle spray when the stream becomes unconfined upon exiting the nozzle. There are stationary and rotating versions of the ejection nozzle. The stationary ejection nozzle has a flow channel with internal angular elements, such as spiral grooves, which engage the moving molten metal stream to impart angular momentum thereto as it passes through the channel. The rotating ejection nozzle may have internal elements within the flow channel, such as notches or serrations, which engage the moving molten stream and cause it to rotate with the nozzle as it passes through the channel. The two nozzles can also be combined to impart the angular momentum and accomplish melt stream break-up.
Abstract:
A molten metal gas-atomizing spray-depositing apparatus employs an asymmetrical gas-atomizing device for generating one-sided shear forces for breaking-up and atomizing a stream of molten metal into metal particles in a divergent spray pattern of higher mass density at an upstream leading peripheral portion of the spray pattern, relative to the direction of movement of a substrate, than either of a center region or downstream trailing peripheral region of the pattern.
Abstract:
System and method for producing metal or alloy powder are described comprising an electromagnetic levitating coil having an outlet for supporting a molten source of the metal or alloy and controllably discharging a molten stream thereof, an electromagnetic confining coil disposed at the outlet of the levitating coil and surrounding the molten stream for controlling the diameter of the molten stream, and either an atomization die and associated pressurized fluid source for disintergrating the confined molten stream into molten droplets for subsequent cooling to powder, or a controllable electromagnetic coil surrounding the confined molten stream for generating a downwardly and radially outwardly directed electromagnetic force interacting with the molten stream to form the droplets.