Abstract: An apparatus for galvanizing which comprises a plating tank, a dross removing tank, a means to transfer the molten metal bath from the plating tank to the dross removing tank, and an opening located on the plating tank to recycle the molten metal bath from the dross removing tank to the plating tank.

Abstract: The method for hot dip galvanizing comprises the steps of: dividing a plating vessel holding a molten metal into a plating tank and a dross removing tank; conducting hot dip galvanizing to a steel strip by immersing thereof in the molten metal bath; then transferring the molten metal bath from the plating tank to the dross removing tank; removing a dross from the molten metal bath in the dross removing tank; and recycling the molten metal bath from the dross removing tank to the plating tank through an opening located on the plating tank. The apparatus for galvanizing comprises a plating tank, a dross removing tank, a means to transfer the molten metal bath from the plating tank to the dross removing tank, and an opening located on the plating tank to recycle the molten metal bath from the dross removing tank to the plating tank.

Abstract: The method for hot dip galvanizing comprises the steps of: dividing a plating vessel holding a molten metal into a plating tank and a dross removing tank; conducting hot dip galvanizing to a steel strip by immersing thereof in the molten metal bath; then transferring the molten metal bath from the plating tank to the dross removing tank; removing a dross from the molten metal bath in the dross removing tank; and recycling the molten metal bath from the dross removing tank to the plating tank through an opening located on the plating tank. The apparatus for galvanizing comprises a plating tank, a dross removing tank, a means to transfer the molten metal bath from the plating tank to the dross removing tank, and an opening located on the plating tank to recycle the molten metal bath from the dross removing tank to the plating tank.

Abstract: An apparatus for continuously cooling a heated metal plate lying horizontally, which comprises: an upper cooling water ejecting means, arranged above the metal plate in parallel to the width direction thereof, for ejecting cooling water onto the upper surface of the metal plate; a water tank, arranged below the metal plate, for receiving cooling water; and a lower cooling water ejecting means having a lower cooling water ejecting bore, arranged in the water tank in parallel to the width direction of the metal plate. The lower cooling water ejecting means ejects, in the form of a jet stream, cooling water from the lower cooling water ejecting bore together with cooling water received in the water tank, onto the lower surface of the metal plate. The above-mentioned jet stream is surrounded by a jet stream guide duct arranged between the lower cooling water ejecting means and the lower surface of the metal plate.

Abstract: A method for recovering and utilizing heat of coke-oven gas, which comprises: through heat exchange with a high-temperature coke-oven gas generated from a coke oven battery and containing vaporized coal tar, vaporized low boiling point substances and dust, drying and preheating a blended raw material coal fine to be charged into coking ovens of said coke oven battery, and, on the other hand, causing most of said coal tar contained in said coke-oven gas to condense and deposit onto the particle surfaces of said coal fine during the process of said heat exchange, thereby recovering and utilizing sensible heat and condensation heat of said coke-oven gas and substances contained therein, and at the same time, eliminating most of the contained coal tar from said coke-oven gas.

Abstract: In continuous induction heat treatment of an elongated metal member, additional local induction heating is applied to an end portion or portions of the metal member, thereby to obtain uniform induction heating temperature distribution over the whole length of the metal member. The additional local heating or preheating the end portion of the metal member is performed by the use of a preliminary induction heating coil which is maintained in predetermined relative relationship with the metal member for a predetermined period of time.

Abstract: In rapidly cooling a large diameter metal pipe for quenching purposes, the essential requirements for ensuring uniform cooling of the pipe, namely, the jet velocity and the dip angle and transverse angle of jets of the cooling water directed against the surface of the pipe from a large number of spray nozzles contained in each of a first and second ring header encircling the pipe, and the distance between the circumferential line defined on the pipe by connecting the points of impingement onto the pipe surface of the water jets sprayed in the direction of the second header from the spray nozzles of the first header and the similar circumferential line defined on the pipe by connecting the points of impingement onto the pipe surface of the water jets sprayed in the direction of the first header from the spray nozzles of the rear second header, are specified with numerical values.

Abstract: A steel ingot having a still-liquid portion therein is charged into a soaking pit; then, said ingot is heated by injecting a fuel from a combustion unit of said soaking pit into said soaking pit with a constant and minimum fuel flow rate capable of holding a pit temperature higher by from 10 to 100.degree. C than the cold point temperature of said ingot at the completion of solidification of said still-liquid portion in said ingot, until said still-liquid portion in said ingot is completely solidified; and then, upon the completion of said solidification, the surface portions of said ingot are further heated up to above a prescribed temperature permitting rolling thereof by injecting a fuel from said combustion unit into said soaking pit with a constant fuel flow rate of at least 60% of the maximum fuel flow rate of said combustion unit, thereby reducing the fuel consumption in said soaking pit.

Abstract: A cooling method and apparatus wherein in the process of continuously hardening a metal pipe by heating the metal pipe as it passes through a heating unit and then cooling the inner surface of the metal pipe, an annular cooling nozzle having a large number of nozzle openings is placed in the metal pipe, and the spray direction of jets of cooling medium from the nozzle openings is selected so as to maintain a dip angle of between 30.degree. and 70.degree. and a transversal angle of between 30.degree. and 90.degree. and either cooling water or a mixture of cooling water and compressed air is sprayed with a jet velocity of greater than 5 meters per second onto a large number of points on the circumference of the inner wall of the metal pipe.

Abstract: A method of quenching a large-diameter thin-walled metal pipe includes the steps of moving the metal pipe through a heating zone and passing the pipe through a cooling zone following passage of the pipe through the heating zone. The cooling zone includes a plurality of nozzles for spraying a cooling liquid onto the pipe from the nozzles, so as to quench the pipe. The process steps further include detecting the amount of strain on the outer periphery of the quenched pipe at the rear end of the cooling zone, as seen in the direction of movement of the pipe, so as to obtain a deviation of a detected value from a preset value, and adjusting the amount of cooling liquid sprayed onto the pipe from the nozzles in accordance with the amount of deviation from the preset value, so that the adjusted cooling water spray controls the deviation of pipe emerging from the cooling zone, for example, reduces the eccentricity of a circular pipe.

Abstract: When a concavity-shape part is formed in the center of skid material and cooling mechanism is arranging in the concavity-shaped hole, a steel material, e.g. slab, bloom or the like, can be cooled without any of deformation of said material.

Abstract: In an evaporative cooling method by natural circulation of cooling water by the use of an evaporative cooling device comprising a cooling pipe fitted to an object to be cooled and a steam separator drum arranged above said cooling pipe, said cooling pipe and said steam separator drum being connected together by a downcomer and a riser, the cooling water in said cooling pipe is kept in complete liquid state and part of cooling water is evaporated only in said riser and said steam separator drum by setting parameters to satisfy the following formula:Q/V.sup.. .rho..sup.. c<.DELTA.T.sub.eq (P.sub.o, Ph.sub.3)WhereQ : Thermal load acting on said cooling pipeV : Amount of circulated cooling water in said cooling pipe.rho. : Lensity of cooling waterc : Specific heat of cooling waterP.sub.o : Pressure of said steam separator drumPh.sub.3 : Pressure of cooling water in the uppermost part of said cooling pipe.DELTA.T.sub.eq (P.sub.o, Ph.sub.3) : Boiling equilibrium temperature difference between P.sub.o and Ph.sub.

Abstract: Heated steel material which is to be cooled is multi-sectioned in the longitudinal direction of said material into n zones. Spaced apart zones of the n zones are individually cooled, and then the material is finally cooled as a whole.

Abstract: A method of preventing occurrence of pulsation in a circulating liquid for evaporative cooling which, in the case of passing the circulating liquid received within a steam separator through a cooling stave of a blast furnace and feeding said circulating liquid back into the separator through an inlet thereof thereby to perform the evaporative cooling operation for said blast furnace, comprises the step of raising, where the fraction dryness of the circulating liquid fed back into the separator is not greater than a prescribed value, the surface level of the circulating liquid within the separator up to a position higher than said inlet, and the step of lowering, where said fraction dryness of said circulating liquid exceeds said prescribed value, said surface level up to a position lower than said inlet.

Abstract: In heating a material radiant at high temperatures, such as a steel product, in a heating furnace, the said material is charged into the heating furnace to heat. A discrimination mark is previously drawn on the surface of material to be discriminated on a portion readily watched from outside the furnace. A heat resisting paint sensitive to near ultraviolet rays is used to make the mark. The said material radiant-heated in the heating furnace is discriminated from outside the furnace as being radiant by applying near ultraviolet rays of a high pressure mercury lamp thereto from outside the furnace to provide a sharp contrast between the said material surface and the said discrimination mark for the discrimination of the said mark from outside the furnace.

Abstract: A system for measuring and controlling the concentration of an emulsion, wherein a measuring pipe included in an emulsion feed line is fitted with an emulsion concentration-detecting device; the ultrasonic wave transmitter of the concentration-detecting device sends forth ultrasonic waves into an emulsion running through a circulation line so as to be caught by an ultrasonic wave receiver; the concentration-detecting device generates an output signal corresponding to the velocity with which ultrasonic waves are propagated from the ultrasonic wave transmitter to the ultrasonic wave receiver, utilizing the fact that the velocity of said propagation is substantially proportional to the concentration of an emulsion flowing through the circulation line, and also delivers an output signal corresponding to temperature variation from a detection terminal through a transducer to a circuit for correcting the measured concentration of the emulsion according to temperature variation in view of the fact that the propagati