Abstract: An oven is provided for baking a substrate having a printed circuit obtained by depositing on an insulating substrate, by silk screen printing, an insulating or resistive ink comprising an organic material which forms a temporary binder of this ink, which oven is provided with gas injection means for baking in the desired atmosphere, means for extracting the reducing gases and/or baking residues obtained by transformation of the organic materials under the effect of the temperature, and means for sweeping these reducing gases in the direction of the extraction means so as to accelerate removal thereof without creating any zone of stagnation or turbulent flow.

Abstract: An oven (20) includes an oven enclosure (24) having a conveyor (40) mounted therein for transporting food products through the oven. A plurality of ribbon burners (100) are mounted within the oven interior (32) adjacent the path of the conveyor to heat the interior of the oven. Heated gases generated by operation of the ribbon burners are received through inlet plenums (140) under operation of a circulation fan (146) and are discharged through discharge tubes (154) extending adjacent portions of the conveyor (40) remote from the locations of the ribbon burners (100). Exhaust gases are removed from the oven interior through discharge ports (180) by exhaust blower assemblies (184) which are operated to remove exhaust gases from the oven interior at a rate proportional to the flow rate of combustion air and gaseous fuel into the ribbon burners.

Abstract: A roller furnace having a passage (3) for the firing of ceramic or refractory products, such as tiles and the like, is provided with a passage (6) running parallel to, and arranged below the firing passage (3) for effecting a heat treatment on a product, possibly with hot gases removed from the firing passage (3).

Abstract: Drying and baking installation in which the products pass through the drying oven (S) and the baking oven (C) on the same carriages (1) by means of a single, continuous path, without intermediate handling; the products are stacked without contact with one another by means of superposed ceramic supports; the outlet from the drying oven is connected to the entrance to the baking oven by an air-tight enclosure, the system thus forming a continuous and tight enclosure and the pressure of the gases as the products enter the baking oven is at least equal to the pressure of the gases as the products leave the drying furnace.

Abstract: An oven (20) includes an oven enclosure (24) having a conveyor (40) mounted therein for transporting food products through the oven. A plurality of ribbon burners (100) are mounted within the oven interior (32) adjacent the path of the conveyor to heat the interior of the oven. Heated gases generated by operation of the ribbon burners are received through inlet plenums (140) under operation of a circulation fan (146) and are discharged through discharge tubes (154) extending adajcent portions of the conveyor (40) remote from the locations of the ribbon burners (100). Exhaust gases are removed from the oven interior through discharge ports (180) by exhaust blower assemblies (184) which are operated to remove exhaust gases from the oven interior at a rate proportional to the flow rate of combustion air and gaseous fuel into the ribbon burners.

Abstract: A multiple hearth furnace is constructed from a plurality of cylindrical heating chamber modules, connected in a vertical configuration. Each module contains a hollow hearth, which forms a floor in the chamber, the hearth having an open portion approximately centered in the chamber floor. A rotating central shaft is disposed vertically through open portions in the hearths and is provided with projections for distributing material to be heated across the hearths. Heating of the modules is accomplished by passing heated gases through the hollow hearths. Material to be heated is introduced into the uppermost module, is distributed across the hearth, and is discharged into successively lower modules, after which material exits the furnace. Gases which form during the heating can be removed separately from gases used to heat the furnace.

Abstract: A bakery oven, of the type employing a continuous spiral conveyor for carrying goods to be baked through an oven enclosure, employs an air distribution system to direct heated air from near the top wall of the oven enclosure to a plenum chamber, and from there through an air distribution network to at least certain ones of the tiers of the spiral conveyor. Preferably, heater elements are disposed beneath alternate ones of the tiers of the conveyor system within the oven enclosure, while the air distribution pipes are disposed beneath the remaining tiers. This arrangement serves to decrease fuel consumption for the burners, thereby increasing productivity, and further serves to decrease the stratification of heat layers within the oven enclosure, thereby providing uniform baking conditions throughout the oven enclosure.

Abstract: A furnace (10) has a preheater zone (12) into which exhaust gases from a combustion chamber (14) are recycled for preheating of articles passing through the furnace. The exhaust gases are supplied to the preheater zone (12) through jet pipes (18) which create a turbulent flow about the articles in the furnace (10). The exhaust gases are withdrawn by a fan (30) which is disposed in a duct (34) adjacent to the furnace entrance (13). To prevent the introduction of ambient air into the furnace (10), a pressure chamber (56), which is maintained at about atmospheric pressure, is provided within the preheater zone (12), with the chamber (56) pressurized by gases supplied by exhaust gases passing through a separate pipe (70) which has an adjustable valve (72) to adjust the pressure in the chamber (50). A sealing arrangement defined by the pressure chamber (56) and the articles passing through the furnace prevents the introduction of cool air through the preheater zone (12).

Abstract: A bakery oven, of the type employing a continuous spiral conveyor for carrying the goods to be baked through the oven enclosure, employs an air distribution system to direct heated air from near the top wall of the oven enclosure to a plenum chamber, and from there through a pipe distribution network to at least certain ones of the tiers of the spiral conveyor. Preferably, heater elements are disposed beneath alternate ones of the tiers of the conveyor system within the oven enclosure, while the air distribution pipes are disposed parallel to and beneath the remaining tiers. This arrangement serves to decrease fuel consumption for the burners, thereby increasing productivity, and further serves to decrease the stratification of heat layers within the oven enclosure, thereby providing uniform baking conditions throughout the oven enclosure.

Abstract: The process treats a continuous stream of containers of solid material effecting melting or heating of the material within the package. The dwell time within the process is minimized while at the same time the maximum temperature achieved by any of the material is held within an allowable maximum.

Abstract: A device for thermally treating scrap employs a charging facility for conveying scrap to a furnace chamber. The charging facility is fitted with a waste gas flue and a loading port and has a pre-loading space in which the scrap is pre-heated. The device is easily operated and can be run with relatively little loss of energy by having the pre-loading space of the charging facility releasably connected to the furnace chamber and/or waste gas flue such that the pre-loading space is fed with waste heat from the furnace chamber. Preferably the pre-loading space is part of a waste gas or waste heat circuit. The pre-loading space is also provided with an extendable unit which can be pushed into the mouth or loading port of the furnace for feeding the scrap to the furnace.

Abstract: A heat-treating apparatus for practicing a method in which when red-hot iron pipes produced by a centrifugal casting machine are cooled, the pipes are slowly cooled over the temperature range of 800.degree. to 700.degree. C. to ferritize the pipes without separately annealing the pipes. A heat-treating furnace disposed close to one end of the rotary mold of the casting machine has furnace chambers each provided with pairs of rotatable rollers for supporting the pipe in rotation to prevent the deformation of the pipe. Each of the chambers has heating burners or a cooling heat exchanger for adjusting the temperature and cooling speed of the pipe placed in the chamber. According to a preferred embodiment, the furnace chambers are separated by openable partition members of circular-arc section, and each of the chambers has turnable levers for transferring the pipe to another chamber adjacent thereto.

Abstract: A kiln includes a hollow elongated housing which has an inlet and an outlet spaced from each other defining between them the interior of the housing designed to receive through the inlet the items to be treated. The housing includes a number of sections operative for treating the items as they gradually pass through the sections towards the outlet with different respective treating regimes. The sections downstream of the housing are interconnected with the section upstream of the housing so as to recover the heated gas from the downstream sections and supply the same into the upstream section in predetermined quantities and at a predetermined temperature.

Abstract: A heated soaking furnace, a chamber for preheating cold steel pieces in communication with said soaking furnace, means for transferring a portion of the heat from the furnace to the chamber, means for moving the steel pieces through the chamber to preheat the steel pieces and means for conveying the steel pieces from the outlet of the chamber to the inlet of the furnace.

Abstract: A sintering plant in which sinter exhaust gases and cooling gases are collected in separate gas collecting systems. A cooling gas gas-collecting main is located beneath the lower strand of a sintering belt and is connected to opposite sides of each of the wind boxes underlying the cooling section of the sintering strand by at least two cooling gas connecting pipes, and at least one sinter exhaust gas gas-collecting main is disposed adjacent to said cooling gas gas-collecting main and connected to each of the wind boxes underlying the sintering section. Both the cooling gas gas-collecting main and the sinter exhaust gas gas-collecting main are exhausted through a plurality of gas evacuating fans and flue connecting pipes to a flue.

Abstract: After replacement of the walls of one chamber of a coking battery this one chamber is heated up by withdrawing relatively hot air from another still-hot chamber of the coking battery and injecting it into the cold chamber. This is done by means of a conduit extending between the two chambers and provided with an internal nozzle that conducts the hot gas from the hot chamber to the cool chamber by jet-pump action. This hot gas is mixed with relatively cool air so as slowly to heat the cool chamber up.

Abstract: A system for heating a furnace having a heating chamber defined by furnace walls is provided with a plurality of individual burner assemblies mounted on a furnace wall to direct heating gas streams into the heating chamber, each of the burner assemblies including a diffusion chamber, a burner arranged to direct products of combustion through the diffusion chamber into a furnace heating chamber and means for directing the flow of diffusion gases into the diffusion chamber to admix with the burner products of combustion so that the gas stream entering the furnace heating chamber has a greater mass velocity than the burner products of combustion, there being provided a diffusion gas supply means connected to the heating chamber of the furnace for delivering hot gases from the furnace heating chamber to the diffusion chambers of each of the burner assemblies.