Abstract: Apparatus for adding materials, especially powdered or granular materials, to a flowing stream, e.g. of molten metal, comprises a nozzle for compressed gas, blowing the additive into the stream, and a detector that detects the stream and switches the flow of additive on and off according to whether the stream is present or absent. The detector is preferably of a non-contact type, sensing radiation from the stream, preferably visible light. The rate of flow of additive can be adjustable. There can be a fail-safe optical detector arrangement monitoring the flow of additive and signalling an alarm if the flow fails or if the nozzle is blocked. The timings of the start and end of the flow in relation to the detection of the metal stream are independently adjustable to ensure that the additive and metal coincide.

Abstract: A ferrous melt, e.g. of steel, is refined beneath a slag layer by blowing from above with an oxygen-containing gas through a lance and by bubbling an inert gas through the melt from the bottom. According to the invention, the consistency of the slag layer and/or its level is continuously detected on the one hand and the rate of decarburation of the bath is detected on the other hand and in response to these measurements the volume rate of flow of the bubbling gas is controlled on the one hand to maintain a predetermined spacing of the slag layer from the head of the lance and, on the other hand, a fluid consistency of the slag.

Abstract: An apparatus and method is provided for heat treating a tubular type heat exchanger. A heat fluid is passed through the tube bundle in order to heat the exchanger from within.

Abstract: An apparatus for casting metals wherein the molten metal is contained and formed into a desired shape by the application of an electromagnetic field. A control system is utilized to minimize variations in the gap between the molten metal and an inductor which applies the magnetic field. The gap or an electrical parameter related thereto is sensed and used to control the current to the inductor.

Abstract: A method for controlling furnace temperatures of a multi-zone heating furnace having a feedback control system for detecting and inputting a furnace temperature and a furnace temperature setting device or a combustion control computer of the type for determining an optimum furnace temperature for each slab and outputting it as a set point to said feedback control system, the method comprising the steps of determining, under predetermined limit conditions which are required for the operations of the furnace, a furnace temperature pattern or a slab temperature rise curve which may minimize the overall flow rate of fuel, heating the furnace along the furnace temperature pattern or the slab temperature rise curve which is determined, reducing, in response to the instruction for suspending the discharge of slabs from the furnace, the flow rate of fuel to be supplied to the furnace to a predetermined level, and heating the furnace along a new slab temperature rise curve which is obtained by shifting the steady stat

Abstract: In a method of treating a coil spring to improve its performance and reliability when operating at elevated temperatures, the spring is first stressed by applying a load of preselected magnitude and then, while the load is maintained, the spring is heated until it relaxes or collapses to a predetermined extent at which stage the heating is automatically discontinued and the applied load is afterwards removed. Apparatus for carrying out the method in relation to compression springs includes a spring supporting base, an overhead operating head with a vertically movable ram or plunger for applying the predetermined load, means for passing an electric heating current through each spring while beneath the operating head, and limit switch means which responds to the position of the ram or plunger and terminates the supply of heating current when the loaded spring has reached the required predetermined value of relaxation or collapse.

Abstract: Apparatus and method for monitoring selected samples in situ in an iron ore converter the stages of reduction of the ore into iron sponge pellets having a desired iron content. The apparatus comprises a series of induction coils encircling the converter. The coils are coupled to an R F Circuit which is coupled to a meter which indicates the inductance values correlated with the iron content of the measured sample and its temperature thus providing indicia of the stage of conversion of the ore.

Abstract: One form of the invention discloses an apparatus and a method for positioning the snorkel of a vacuum degassing apparatus beneath the interface of the molten metal and slag in a ladle utilizing means for determining the interface, which means comprises an electrode adapted for positioning within the ladle in electrical contact with the material, indicating means for indicating a first range of voltages produced at said electrode by an electrochemical reaction between the molten metal and the electrode as well as a second range of voltages produced at the electrode by an electrochemical rection between the slag and the electrode, with means for supporting the electrode independently of the ladle and adapted to enable the electrode to be raised or lowered within, and relative to, the ladle, wherein the electrode is moved to a position within the ladle and relative movement is subsequently produced between the electrode and the ladle whereby the position of the interface will be determined by noting a change in

Abstract: A dead band and a feed forward control are part of a closed loop system for converting the batch flow of sinter into an accumulating hopper into a steady flow of sinter out of this hopper.

Abstract: In a method and apparatus for continuously measuring the annealing level on wires or strips, a wire or strip is passed, in a continuous feed, over a pulley of small diameter, at a tension less than that corresponding to the elastic limit of the material of which the wire or strip is made, so as to produce permanent elongation of 0.1 to 1%, this elongation being taken as a measurement of the annealing level, and utilized to control the annealing level.

Abstract: In a method of and apparatus for closing a tap hole of a metallurgical vessel for separating metal and slag compressed gas is introduced into the tap hole after the metal has been poured off, the gas being introduced in a direction contrary to the pouring-off direction of the metal. The gas is introduced in such a manner that air is sucked inwardly along the mouth of the tap hole to aid in the burning-off of deposits around such mouth.

Abstract: In a method and apparatus for continuously measuring the annealing level on wires or strips, a wire or strip is passed, in a continuous feed, over a pulley of small diameter, at a tension less than that corresponding to the elastic limit of the material of which the wire or strip is made, so as to produce permanent elongation of 0.1 to 1%, this elongation being taken as a measurement of the annealing level, and utilized to control the annealing level.