Abstract: The present disclosure relates to an apparatus for measuring the thickness of a paint coating on a substrate.

Abstract: An automatic air-fuel ratio control apparatus for use in a combustion system of a type in which combustion air is preheated, which is so arranged that a push rod depresses one end portion of a rocking lever in accordance with temperature of preheated combustion air and consequently the other end portion of the rocking lever depresses a valve member to correct pressure of working fluid for controlling a flow of fuel so as to obtain best air-fuel ratio, and further that a bearing member for pivotally supporting the rocking lever can be diagonally shifted to change the air-fuel ratio.

Abstract: A continuous heat-treating furnace comprises, a housing structure having an entrance and an exit defined at its opposite ends, respectively, and also having defined therein a preheating zone adjacent the entrance, a cooling zone adjacent the exit and a high temperature zone intermediate between the preheating and cooling zones, a recirculating duct fluid-connecting a portion of the housing structure in register with the preheating zone to another portion of the housing structure in register with the cooling zone, and a blower for forcibly drawing gas inside the preheating zone and directing it into the cooling zone through the recirculating duct.

Abstract: An improved ceiling beam construction for a heating furnace in which ceiling beams having closed cross sections are adopted for utilizing the interior of the beams as ducts for passing gases through them so as to reduce spaces required for installing separate gas ducts, with a consequent decrease in the number of duct supporting fittings or fixtures.

Abstract: An apparatus is disclosed for cooling the skid pipes of a continuous slab reheating furnace by the circulation of pressurized hot water, not cold water or steam, through the skid pipes where the hot water is heated to even higher temperatures. The heated hot water is relatively cooled by passage through a heat exchanger, after which the relatively cooler hot water is recirculated to the skid pipes. Means are provided for keeping the hot water under a pressure sufficient to maintain the hot water in a liquid state and prevent its evaporation into steam, as the hot water circulates through the apparatus, especially the skid pipes of the furnace.

Abstract: A scale-covered, hot-rolled steel work is heated under a reducing atmosphere and is then allowed to slowly cool while placed under the reducing atmosphere. Thereafter the work is maintained at a predetermined temperature under an oxidizing atmosphere to cause the scale to be re-oxidized. The work with the re-oxidizing scale is then allowed to stand to cool quickly, imparting fine cracks to the scales. The scales can readily be removed from the work during the subsequent pickling step.