Abstract: This invention relates to a pipe handling apparatus for oil drilling operations, which is designed so as to handle simply without errors the pipes used for oil drilling operations, and which is provided with a pipe transfer unit for transferring a pipe mechanically between a pipe storage space and the oil well center, a pipe lift unit capable of lowering a pipe, which has been carried to the oil well center by the pipe transfer unit, thereinto and withdrawing a pipe from the oil well center, and a pipe transfer unit for transferring a pipe, which has been withdrawn from the oil well center by the pipe lift unit, to a pipe rack unit automatically so as to store the pipe therein.

Abstract: With a metal pipe comprising a double-pipe section connected with a single-pipe section, the double-pipe section in which dead water remains has a lesser degree of heat transfer effect so that it cannot be heated to a steady state. According to the present invention, firstly the single-pipe section starts to be heated and after a predetermined time the double-pipe section starts to be heated. After a predetermined time, the heating of the double-pipe section is stopped and then after a predetermined time the heating of the single-pipe section is stopped, whereby improvement of stresses in the inner wall surface of the pipe can be attained.

Abstract: In a roll of the type in which a sleeve is fitted over a roll core, the sleeve is expanded radially outwardly so that the roll profile is varied optimumly depending upon a complex profile or cross section of a strip to be rolled.

Abstract: A device for locking a platform of an offshore structure wherein each of legs vertically rest on the sea floor and is provided with a rack. The platform in adapted to move upward or downward along the legs and is provided with chocks which engage with the racks, respectively, of the legs. The teeth of the chock has a whole depth deeper than that of the teeth of the rack so that when the chock engages with the rack, the deddendums of the chock is caused to deflect themselves respectively about the deddendums, which are made into engagement with the rack, so as to follow the displacement of the platform in the direction of gravity.

Abstract: A welding machine is used to heat the outer surface of a butt welded joint of pipe sections such that the weld heat input condition q/t.sup.2 (where q: heat input and t: the thickness of the wall of a pipe) is higher than approximately 0.01 and the relative heat transfer coefficient ht/.lambda. (where h: the heat transfer coefficient between a coolant and the inner surface of a pipe and .lambda.: the thermal conductivity of a pipe) is higher than approximately 2, whereby the residual stresses at the inner surface of the weld can be relieved by utilizing the temperature difference between the outer and inner surfaces of the pipe.

Abstract: The outer surface of a butt-welded joint is build-up welded such that a ratio h/t is higher than approximate 0.2 and a ratio L/.sqroot.Rt is higher than approximate 1, where h denotes height of a build-up welded portion; t, wall thickness of a pipe; L, width of the build-up welded portion; and R, radius of the pipe. As a result, the residual stresses in the build-up welded portion counterbalances the residual stresses in the welded joint, whereby the residual stresses at the inner surface of the welded joint can be relieved.

Abstract: Disclosed is a method for causing bubbles in a fluid to coalesce into a coherent mass by use of a vessel having a cylindrical space therein wherein the fluid is caused to flow into the vessel at such a velocity that a vortex is generated to flow from one end of the space to the other while establishing a state in which the pressure on the center axis of the cylinder rises from one end toward the other, then reaches a maximal value and thereafter drops, and this coalescing of the bubbles is effected at the field near the axis of the vortex and between a position close to the inflow position and the position of the highest pressure. The method greatly facilitates deaeration.

Abstract: In a rolling mill of the type in which horizontal pushing forces are exerted to a work roll exerted with a rolling force so as to bend the work roll, thereby controlling the flatness of a strip being rolled, a method and apparatus for controlling rolling correction in the rolling mill for eliminating variations in rolling load due to the horizontal pushing forces.

Abstract: Disclosed is a grinding machine for use with a rolling mill capable of carrying out the continuous grinding operation of the cylindrical or rolling surface of a work roll without removing the work roll from the rolling mill while the continuous rolling operation is being carried out, whereby labor saving can be attained and the downtime of the rolling mill can be remarkably reduced.

Abstract: According to the present invention, white cement clinker particles are not burned in a rotary kiln and the burned clinker particles are not immersed in the water to be cooled. White cement clinker raw materials are burned in a fluidized bed burning furnace with a fluid bed or a spouted bed and the clinker particles thus burned are reduced with a reducing gas. The clinker particles thus reduced are first cooled with the water which is sprayed over the clinker particles and then further cooled with the air. The white cement clinker raw material particles fed into the fluidized bed burning furnace are burned into clinker particles while forming a fluidized bed and then the clinker particles thus burned drop through a jet injection pipe into a reduction chamber disposed below the burning furnace and are reduced. The clinker particles thus reduced are rapidly cooled to 600.degree.-700.degree. C.

Abstract: When the winding operation is started, the leading edge portion of the sheet is sucked and held by one of a pair of horizontally disposed rollers and the extension of the leading edge portion of the sheet beyond the one roller is controlled by rotation of said one roller. An adhesive with a suitable viscosity is sprayed against a core from the position below the core. The core and said one roller are rotated so that the sheet is clamped between the one roller and the portion of the core which is applied with the adhesive and consequently is bonded to the core. Thereafter the pair of rollers are rotated at a low speed so that the slack of the sheet is eliminated. Next the sheet is wound around the core at a high speed. After the winding operation, an adhesive with a suitable viscosity is sprayed against a roll of paper from below so that the sheet is bonded by the weight of the roll of paper itself. Thereafter the sheet is cut off and the roll of paper is pushed out.

Abstract: A device for disassembling and reassembling a main steam isolation valve which is extended at an angle from a main steam pipe extended from a nuclear reactor. The disassembly and reassembly of the isolation valve which requires a high degree of accuracy can be accomplished quickly in a simple manner without the need of skilled workers. Thus, the time required for disassembling and reassembling the isolation valve can be shortened.

Abstract: Disclosed is a method and apparatus for controlling lateral unstable movement and camber of a strip being rolled in which the lateral displacement and the camber magnitude of the strip being rolled are directly detected. The lateral unstable movement is controlled by changing the right and left roll gaps of the horizontal rolling mill while the camber of the strip is corrected by changing the path line through the vertical rolling mill. As a result, the lateral unstable movement of the strip can be prevented so that the rolling operation can be carried out in a stable manner. In addition, the quality of the rolled strip can be improved and the yield can be increased.

Abstract: Pressure is exerted on the interior of casting rolls with a negative crown so that the rolls may maintain a true cylindrical surface without any crown when the continuous casting operation is initiated. When the cylindrical surface of the rolls is heated by molten metal as the continuous casting operation continues, the interior pressure of the rolls is decreased, whereby the rolls may maintain a true cylindrical surface without any crown.

Abstract: Disclosed is a method for preventing hydrogen-induced disbonding of austenitic stainless steel cladding, which is made on a low alloy steel, in a reactor vessel which has been used in a high-temperature and high-pressure hydrogen atmosphere. The clad steel is cooled from its operating temperature to a temperature which is not lower than 100.degree. C. Then, the clad steel is maintained at a temperature between said temperature which is not lower than 100.degree. C. and a postweld heat treatment so as to effect hydrogen degassing treatment. Thereafter, the clad steel is further cooled.

Abstract: A method for controlling the temperature of water to be fed into a water cooling tower in which when the driving power required to drive motors to be controlled is in excess of the power which can be derived from a frequency converter, some of the motors are driven by a constant-frequency power supply while the remaining motors are driven by the frequency converter. Therefore, the temperature of water to be fed into the water cooling tower can be continuously controlled without increasing the capacity of the frequency converter.

Abstract: A tank for storing a liquid is provided with a circulation passage for circulating the liquid by a suction pump. A pressure at the suction port of the suction pump is maintained at a negative pressure lower than a pressure at which gases dissolved in the liquid and the liquid is circulated, whereby the gases having been dissolved in the liquid are separated and the bubbles entrained by the liquid grow in size. These gases and bubbles are collected, agglomerated and discharged in the line connected to the discharge port of the suction pump.

Abstract: Disclosed is a rolling mill in which an intermediate roll is interposed between a work roll and a backup roll and is offset by a suitable distance in the direction of the rolling line. A horizontal bending force is exerted to the intermediate roll so that the flatness of the rolled product can be controlled with a higher degree of accuracy.

Abstract: A rolling mill is disclosed in which, in order to improve the quality of rolled products, a work roll with a small diameter is used and is offset by a predetermined distance from the reduction line and the horizontal bending force is exerted to the small-diameter work roll through a horizontal intermediate roll from a sectionalized roll so that flatness of a workpiece being rolled is controlled. The small-diameter work roll, the horizontal intermediate roll and the sectionalized roll are so arranged that their axes are maintained in coplanar relationship with each other. Therefore the axes of these rolls can be automatically aligned with a high degree of precision.

Abstract: Moving molds are disposed in one array around the periphery of a casting wheel. A series of consecutive moving molds are closed during a predetermined angle range of the periphery of the casting wheel to define a continuous mold cavity between the closed moving molds and the casting wheel. A molten metal is poured into the thus defined continuous molding cavity at an upstream end thereof and is solidified while the casting wheel is rotated in unison with the moving molds. Then, moving molds are opened just before they arrive a cast outlet, and the cast is taken out.