Abstract: The invention relates to a combustion method which is performed in a furnace that is equipped with energy recovery means and burners, whereby the heat from the combustion fumes is recovered by energy recovery means and said recovered heat is used in order to heat the air. According to the invention, at least part of the burners performs the combustion of an oxygen-rich comburent and a fuel and at least part of the air heated by the energy recovery means is used to heat the oxygen-rich comburent and/or fuel for the burners.

Abstract: An oven includes a cooking chamber, a gas-fired heat exchanger external of the cooking chamber and a flow path for circulating air from the cooking chamber past the heat exchanger to pick-up heat and then back to the cooking chamber under operation of a blower. A first combustion path gas flow path runs from the heat exchanger to an exhaust system for delivering combustion path gases away from the oven, and a second combustion path gas flow path runs from the heat exchanger to the cooking chamber for delivering combustion path gases into the cooking chamber. A control arrangement is configured to selectively control the flow of combustion path gases along at least one of the first combustion gas flow path or the second combustion gas flow path.

Abstract: The heat recovery system includes an oven having a treatment air with a treatment air temperature and a treatment air dew point temperature to treat a product or product in process. A zone outlet exhaust waste treatment air following the treatment of the product. A preheating zone includes a preheating inlet for the introduction of preheating air having a preheating air temperature and a preheating air dew point temperature to preheat the product. A transfer duct extends between the zone outlet of the oven and the preheating zone to transfer a portion of waste treatment air from the oven to the preheating zone to create the preheating air to preheat additional product. The preheating air preheats the product in the preheating zone to a product temperature that is at least equal to the treatment air dew point temperature to eliminate surface condensation on the product during treatment in the oven.

Abstract: An apparatus for uniform reactive thermal treatment of thin-film materials includes a chamber enclosing a tube shaped space filled with a work gas and heaters disposed outside the chamber. The apparatus further includes a loading configuration for subjecting a plurality of planar substrates to the work gas in the tube shaped space. Baffles are disposed above and below the loading configuration.

Abstract: A process and device for drying the coating of containers made of thermoplastic material. The process involves feeding said containers through a furnace divided into two areas: in the first, most of the solvent of the coating is removed by heating the paint with infrared lamps, while the temperature of the containers is controlled through an airflow; in the second, the remaining solvent is removed using said airflow coming from the first area of the furnace.

Abstract: A drier for objects, particularly for vehicle bodies, comprises, in a per se known manner, a housing in which is formed a drying chamber which accommodates the objects. In the said drying chamber, the objects are subjected to an IR radiation generated by at least one catalytic radiator. The drier can be used as a device for purifying air which contains pollutants, in that the intake air supplied to the drying chamber is routed exclusively via the catalytically active layer of the catalytic radiator, so that the organic impurities contained in the intake air can be catalytically oxidized there in a controlled manner. In this case, the catalytic radiator must be of heat-resistant design, such that it does not require air cooling. Both unpurified air, originating from another location, and the air containing organic impurities which is produced in the drier itself can be purified in the drier.

Abstract: In a combustion installation for burning a fuel, which installation includes a hearth operating as a circulating fluidized bed, and in which installation at least a fraction of the flow of solid particles resulting from the combustion of the fuel in the hearth is returned to the hearth via a heat exchanger operating as a fluidized bed, the method of decreasing nitrogen oxide emissions consisting in the heat exchanger being fed with a fluidization gas which is considerably poorer in oxygen than air.

Abstract: Disclosed is a paint drying furnace for baking and drying paint films on painted objects following a painting process. The furnace of the invention has an interior combustion type heating device arranged on fresh air passages upstream of points of connection to furnace interior circulating gas passages for heating passing fresh air. The combustion type heating device is a direct heating type, combustion type heating device for burning a fuel directly in an atmosphere of passing fresh air to be heated.

Abstract: Preforms are thermally treated in a continuous-run oven equipped with infrared lamps. The portions of the oven exposed to infrared radiation are cooled by an air flow, whose temperature is kept constant by mixing air at ambient temperature with hot air. The latter is obtained by recycling at least part of the cooling air flow, which becomes heated as it carries away excess heat. A recycling mechanism in the form of a plenum box 13 equipped with a pivotable shutter 16 for adjusting the proportions of recycled hot air and ambient temperature air makes it possible to keep the temperature of the cooling air constant.

Abstract: An apparatus having an incineration chamber and at least one burner for oxidizing fumes is provided. First and second regenerators are in fluid communication with the incineration chamber, as is a bypass which introduces unburnt fumes to the incineration chamber without passing them through either of the regenerators. While the fumes are in the bypass, a purging device, including a purge fan and accompanying conduits and valves, introduces a purge gas to either one of the regenerators to force unburnt fumes therefrom. The purged fumes and the purge gas are mixed with the incoming fumes from the bypass in an annular plenum downstream of the purged regenerator before they are introduced to the incineration chamber for oxidation. The flow of incoming fumes to the system may be continuous, even during purging, and the purge fan may also be continuously operated.

Abstract: An improved heat transfer arrangement for use in a unique multi-function, industrial heat treat furnace which employs a sealed, closed end, heat exchanger shell member containing the work. The heat transfer arrangement includes a totally contained, internal recirculation system which develops an especially configured annular jet stream that produces highly efficient, convective heat transfer with the shell member. After heat transfer between the entrained gases in the jet stream with the shell member has occurred, the jet flow is reversed at one end of the shell and impinged against the workpiece, the spent stream being reformed into the annular jet at the opposite end of the shell member.

Abstract: A system and method for conditioning and recycling inert gases which are used in a plasma furnace. The method comprises the steps of receiving the gas that is output from the plasma furnace and cooling the gas to a desired temperature. Substantially all the dust is removed from the gas and then the gas is compressed to the desired pressure using an oil-flooded screw compressor. Any oil which is introduced by the compressor is removed from the gas and an alarm is provided to signal a high oil level. Substantially all water vapor in the gas is removed and the gas is filtered to remove any remaining dust and small particulates. The amounts of water vapor and oxygen in the gas are monitored. The gas is then recycled to the plasma furnace.

Abstract: Radioactive organic wastes, such as granular or powdered ion exchange resins and organic filter aids, are treated by oxidation decomposition using hydrogen peroxide in the presence of iron ions in an aqueous medium under refluxing an effluent which is condensed from evaporated components during the oxidation. Condensed water containing a very small amount of organic matter is obtained.

Abstract: A conveyor is driven in a helical endless fashion within a horizontally annular baking chamber while carrying products to be baked. The air within the chamber is heated by means of burners disposed beneath the conveyor and in non-parallel relationship thereto. Heated air is drawn through an air permeable cover across the top of the chamber and into an upper air space thereabove. The air is circulated from that upper air space to a lower air space located beneath the chamber. The air is then circulated into the chamber through an air permeable floor disposed across the bottom of the chamber. The permeability of the cover and floor varies in order to assure a uniform passage of heated air therethrough.

Abstract: A continuous combustion furnace in which the charges to be heat processed is passed through the tunnel in the kiln having three temperature zones comprising a preheating zone, a firing zone subsequent to the preheating zone and a cooling zone subsequent to the firing zone, wherein turbulant flows of atmosphere are induced in each of the temperature zones so that the charges are preheated, fired and thereafter cooled uniformly.

Abstract: A fume incineration system for an industrial process site such as a paint-drying oven (10) producing a combustible effluent. A first duct system (34, 38, 42) conveys effluent to the incinerator (14). A second duct system (44, 48) conveys incinerated effluent back to the site. A third duct system (52, 56) conveys part of the incinerated effluent to an atmospheric vent (57). Control dampers (50, 74) in the duct systems operate sequentially to handle temperature changes, and control damper (84) controls system air flow balance. All ducts and thermal devices except the incinerator are located in an insulated housing (12). A thermal incinerator (14) having an internal preheater comprising an annular tube bundle is disclosed.

Abstract: A furnace is described as having a heat treatment chamber which is provided with banks of radiant heaters to heat a load that is placed within the chamber for heat treatment. The radiant heating of the load is improved by the addition of convection heating which is carried out by a plurality of nozzles that are designed to direct jets or streams of heated gas against the load positioned in the chamber.

Abstract: To dry wet fabrics, a hot drying gas is introduced into a drying chamber containing the fabrics. The drying chamber is maintained at a sufficiently high pressure greater than atmospheric pressure so that a portion of the gas in the drying chamber can be discharged directly to the atmosphere. The remainder of the gas in the drying chamber is withdrawn, and at least a portion of the withdrawn gas is used to produce the hot drying gas introduced into the drying chamber. This is effected by increasing the pressure of the withdrawn gas, heating the withdrawn gas, and combining it with a dilution gas. The amount of the dilution gas which is combined with the withdrawn gas comprises from about 5 to about 20% by volume of the hot drying gas introduced into the drying chamber. Before the withdrawn gas is heated, preferably it is filtered by a lint screen for removal of lint and other contaminants. Novel lint screens capable of self-cleaning during a cooling mode of operation are described.

Abstract: A high efficiency system and method for supplying heat energy to a combustible effluent producing primary process, such as to a paint drying oven, in which the output of an incinerator-heater is controlled in order to be matched to the heat energy requirements of the process. At the same time, the incinerator burner temperature is sufficiently high to incinerate the combustible effluent developed by the primary process. Effluent laden air is circulated from the process site through a preheat heat exchanger into which is transferred a portion of the heat of the incinerated air prior to entry into the incinerator chamber. The incinerated air is recirculated to the process site in order to provide the heat energy requirements of the drying oven or other process. A proportion of the incinerated air is vented to an exhaust stack via an air-to-air heat exchanger which preheats incoming fresh air circulated to the process site to make up the vented flow of incinerated air.

Abstract: A system of drying ovens is disclosed with associated means for heat reclamation and air pollution control. The ovens are primarily for drying or baking paint or other coatings on pipes or the like where the emissions are primarily hydrocarbons.In this system of ovens, hydrocarbon fumes are concentrated at the ends of the oven. Solvent laden fumes are, therefore, collected where the concentration is the highest. The exhaust from the oven is located at the central portion and leads to a combustion/incineration chamber where it is exhausted to atmosphere after incineration and a major part of the heat is recovered and recirculated to the oven. In a sequence of ovens, the exhaust from one oven is circulated to the next at a high linear velocity, but low volume (at 25% LEL) and heated to a high temperature (1400.degree. F.) by in-line incineration of the fumes.

Abstract: A continuous flow heating oven of the industrial type used for the heating of ingots, sheet material and the like, which may be of light metal or light metal alloy, includes a burner fired with a liquid or gaseous fuel disposed within a heating chamber. The material to be heated is placed within the oven with the convection air currents generated from the burners directed thereon, with the hot combustion gases produced by the flames. In addition, the exhaust gases are compressed and directed back onto the object to be heated interspersing with the convection air currents originally generated to increase the efficiency of heating the material.

Abstract: A method of curing a solvent based coating on a strip comprising passing the strip through oven zones, circulating hot gases in the zones to vaporize solvents and entrain them in such gases and cure the coatings, the solvents being released in high volume one zone, and in low volume in another zone, incinerating some of the gases in the zones to oxidize solvent vapors and returning them to the zones, extracting some solvent-rich gases without incineration from the high release zone and distributing them to other zones, incinerating the solvent-rich gases as they are introduced into the other zones to oxidize solvent vapors and discharge high temperature combustion gases in the zones supplying some heat for the zones and reducing solvent vapors, extracting some of the gases from some zones and introducing them into the high solvent release zone to partially replace the gases transferred, the balance being made up by upstream migration of zone gases within said oven, and exhausting some gases to atmosphere.

Abstract: A strip curing oven apparatus for treating a workpiece carrying a coating containing a vaporizable solvent which is oxidizable to provide at least part of the heat requirement of said oven apparatus and which oven apparatus comprises an oven having a plurality of oven zones, such workpiece being movable through said oven zones in sequence, radiant header means disposed within one said oven zone so as to radiate heat toward a workpiece moving through that oven zone, incinerator means for incinerating oven gases to oxidize solvent vapors contained therein and to discharge such gases, after incineration, at an elevated temperature and with a reduced solvent vapor content, into said radiant header means, first gas-transferring means for transferring oven gases containing untreated solvent vapors from at least one of said oven zones to said incinerator means, oven gas circulation means located in said oven zone containing said radiant header means for circulating oven gases for passage between said radiant header

Abstract: A method and apparatus for recirculation of atmosphere in a vacuum furnace which comprises a recirculation loop in which there is a low pressure line from the furnace chamber leading to a recirculation pump which pumps the recycled gas at a higher pressure to a high pressure line back into the furnace chamber. A means to analyze the furnace atmosphere is in communication with the high pressure line and signals its measurements of the atmosphere analysis to a valve on an enriching line. The enriching line passes enriched gas into either the high pressure line or the furnace chamber as the valve opens or closes. A means is provided to withdraw the gas from the furnace chamber in order to maintain the desired furnace chamber pressure as enriching gas is added.

Abstract: An improved atmosphere circulation system involving the use of aspirators for inducing turbulence of pressurized atmosphere within a vessel promotes temperature uniformity within the vessel and, for a given degree of temperature uniformity, reduces energy consumption.

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.

Abstract: Device for removing carbonizable residues includes a closed furnace heatable to low-level carbonization temperature, the furnace having an outlet for carbonization gases formed therein, means for burning off carbonization gases from carbonizable residues and utilizing the heat of combustion therefrom for heating the furnace, the means comprising a burner and a combustion chamber connected to the burner and forming part of a hot gas circulatory system, the hot gas circulatory system also including a container wherein the furnace is disposed so as to be heatable by hot gas circulating through the hot gas circulatory system, a carbonization gas return line connecting the furnace and the combustion chamber for returning to the combustion chamber carbonization gases formed in the furnace, and an inert gas line communicating with the interior of the furnace for supplying inert gas thereto.

Abstract: A means and method for processing cement raw material containing fuel of high volatile content in a reinforced grate preheater kiln system by collecting the unburned volatiles of the high volatile fuel from the pellet bed and utilizing the collected volatiles as a fuel source elsewhere in the system.

Abstract: Leaf tobacco or the like in a substantially airtight enclosure is cured and dried by circulating through the enclosure air that is controllably heated by a forced air fuel burner located in an elongated vertically oriented duct outside the enclosure. The outlet end of the duct is communicated with the enclosure at the bottom thereof, and its upper inlet end is controllably communicable with the enclosure at the top thereof and with the ambient atmosphere. The air intake port of the fuel burner receives only air flowing through the duct. Air circulation is effected by an electric motor driven fan near the inlet of the duct, and a restriction in the duct produces a pressure drop across the burner that prevents back-drafts through it.

Abstract: An apparatus and method of textile drying and finishing wherein a portion of the discharge air from the dryer containing moisture is recirculated directly into the combustion zone of a burner wherein it is blended with fresh air then returned to the dryer.

Abstract: Burners of an oven are operated to satisfy heat loads changeable between a high load and substantially smaller loads. At least under the smaller loads the burners are cyclically controlled in a cycle of time periods T-1 and T-2. During the periods T-1 the burners are steadily regulated to maintain a uniform temperature in the oven. For periods T-2 the burners are periodically controlled to admit one of two selected magnitudes of fuel flow to the oven. At least under the smallest loads the latter magnitudes are periodically controlled to be zero or close to zero.