Abstract: A combination infrared/convection dryer or oven for drying travelling webs. A shutter assembly is provided between the infrared radiation source and the moving web in order to selectively expose the web to infrared radiation. Drying efficiency is optimized by adding heated impinged air at high velocity on the machine direction ends and between the infrared elements. The air being discharged on the web is heated as it is pulled across the elements to a centralized return air duct. The return air is pulled into the inlet of a close coupled supply fan which then discharges the air to the nozzles. A portion of the air is also exhausted to atmosphere to maintain the oven enclosure in a negative pressure state, thus drawing fresh make-up air into the oven housing through the web inlet and outlet slots. Flotation nozzles can be used where contactless support of the running web is desired. Enhanced drying of the web and/or a coating on the web at high speed is achieved without a concomitant increase in dryer length.

Abstract: Air flotation dryer for floatingly drying travelling webs. The dryer includes a housing having a web inlet and a web outlet spaced from the web inlet, and a plurality of elongated air nozzles arranged transversely to the direction of movement of the web and preferably located on opposite sides of the web, the nozzles being secured directly to, supported by and in air-receiving communication with longitudinally extending supply air ducts. An air supply fan is in communication with the supply air ducts to supply air to the nozzles. Heat is provided to the apparatus with a draw-through style burner, which fires into the dryer enclosure and the proper amount of air flow to be heated by the burner (e.g.

Abstract: A regenerative thermal oxidizer in which contaminated air is first passed through a hot heat-exchange bed and into a communicating high temperature oxidation (combustion) chamber, and then through a relatively cool second heat exchange bed. The apparatus includes a number of internally insulated, ceramic filled heat recovery columns topped by an internally insulated combustion chamber. From the combustion chamber, the air flows vertically downward through another column containing heat exchange media, thereby storing heat in the media for use in a subsequent inlet cycle when the flow control valves reverse. Temperature is sensed within the bed of heat exchange media in order to monitor the temperature profile and control a bypass of hot combustion gases should the temperature exceed a predetermined level.

Abstract: Regenerative thermal oxidizer in which a gas such as contaminated air is first passed through a hot heat-exchange bed and into a communicating high temperature oxidation (combustion) chamber, and then through a relatively cool second heat exchange bed. The apparatus includes a number of internally insulated, ceramic filled heat recovery columns topped by an internally insulated combustion chamber. Process air is fed into the oxidizer through an inlet manifold containing a number of hydraulically or pneumatically operated flow control valves (such as poppet valves). The air is then directed into the heat exchange media which contains "stored" heat from the previous recovery cycle. The process air is heated to near oxidation temperatures. Oxidation is completed as the flow passes through the combustion chamber, where one or more burners are located. The gas is maintained at the operating temperature for an amount of time sufficient for completing destruction of the VOC's.

Abstract: Control system and method for monitoring and controlling the stoichiometry of a secondary air burner in a thermal oxidizer. The burner control system secures a certain stoichiometry independent of possible simultaneous changes of the gas mixture flow rate and/or of the combustible impurity concentration in the process gas. The firing rate of the burner is adjusted by a controller. Additionally, the flow of the burner fuel and of the process gas mixture are measured and transformed into separate signals. Both signals are sent to an evaluation apparatus that compares the signals and generates a third signal based upon that comparison. This third signal is in communication with a device that changes the gas mixture flow resistance, and thus the desired amount of gas mixture will be diverted for the combustion of the fuel.

Abstract: An exemplary skid-resistant roofing underlayment provides a pressure-sensitive membrane attached to a carrier support sheet having at least two different plastic films, the carrier sheet being corrugated with ridges in the machine direction to provide skid resistance when the underlayment is installed on a sloped roof. Especially preferred are corrugated, cross-laminated composites having a polypropylene or high density polyethylene layer co-extruded with a linear low density polyethylene layer. An exemplary method for making the roofing underlayment involves corrugating at least two different plastic film layers to provide a carrier support sheet for a waterproofing membrane adhesive layer.

Abstract: Raw gas burner that maximizes fuel efficiency of the burner, minimizes residence time, and reduces or eliminates flame contact with the process air or gas in order to minimize NOx formation. Process air flow such as from the cold side of a heat exchanger associated with thermal oxidizer apparatus is directed into and around the burner. The amount of process air flowing into the burner is regulated based upon the pressure drop created by the burner assembly. The pressure drop is, in turn, regulated by one or more of an external damper assembly, an internal damper assembly, and movement of the burner relative to the apparatus in which it is mounted. To ensure thorough mixing of the fuel and process air, process air entering the burner is caused to spin by the use of a swirl generator. The fuel/process air mixture proceeds into the combustion section of the burner, where the swirling flow is caused to recirculate to ensure complete combustion of the fuel in the combustion chamber.

Abstract: Apparatus and process for the non-contact drying of a web of material. The apparatus includes air flotation nozzles for floating the web, and direct air impingement nozzles for enhanced drying of the web. A plurality of air flotation nozzles or air bars are mounted in one or more sections of a dryer enclosure in air-receiving communication with headers, preferably both above and below the web for the contactless convection drying of the web. In conjunction with these air flotation nozzles, one or more sections of the dryer also includes direct impingement nozzles such as hole-array bars or slot bars. The drying surface of the web is thus heated by both air issuing from the air flotation nozzles and from the direct impingement nozzles. As a result, the dryer has a high rate of drying in a small, enclosed space while maintaining a comfortable working environment.

Abstract: Drying apparatus including pressure control of air supply feeding an air bar and subsequently impinging upon a web, so as to avoid or compensate for web shift without disturbing the cushion pressure and flotation techniques necessary for adequate web flotation and drying, as well as a method of regulating the pressure of supply air to such air bars. A damper or valve is positioned in the header system between first and second ducts feeding each air bar. Proper adjustment of the damper regulates the pressure of supply air in each duct, and compensates for web shift or minimizes or prevents web shift from occurring.

Abstract: A regenerative thermal oxidizer in which contaminated air is first passed through a hot heat-exchange bed and into a communicating high temperature oxidation (combustion) chamber, and then through a relatively cool second heat exchange bed. The apparatus includes a number of internally insulated, ceramic filled heat recovery columns topped by an internally insulated combustion chamber. Process air is directed into heat exchange media in one of said columns via an annular distribution system, which allows for the uniform flow of gas in the apparatus, and greatly reduces the flushing volume. Oxidation is completed as the flow passes through the combustion chamber, where one or more burners are located. From the combustion chamber, the air flows vertically downward through another column containing heat exchange media, thereby storing heat in the media for use in a subsequent inlet cycle when the flow control valves reverse.

Abstract: Process and apparatus for burning combustible constituents in process gas in a main combustion enclosure, preferably a thermal post-combustion device, whereby the main combustion enclosure is separated from a combustion chamber, into which oxygenic gas and gaseous fuel are fed, mixed and burnt. The fuel for the apparatus is fed through a lance which opens into a mixing chamber supplied with oxygenic gas, which is either itself the combustion chamber or merges with it, and the outer surface of the combustion chamber is exposed at least partially to the process gas. The fuel is burned completely or nearly completely in the burner combustion chamber and the mixture of burned fuel and gas leaving the combustion chamber oxidizes the combustible constitutes in the process gas flowing outside of the combustion chamber by yielding flameless heat energy to them.

Abstract: Process and apparatus for burning combustible constituents in process gas in a main combustion enclosure, preferably a thermal post-combustion device, whereby the main combustion enclosure is separated from a combustion chamber, into which oxygenic gas and gaseous fuel are fed, mixed and burnt. The fuel for the apparatus is fed through a lance which opens into a mixing chamber supplied with oxygenic gas, which is either itself the combustion chamber or merges with it, and the outer surface of the combustion chamber is exposed at least partially to the process gas. The fuel is burned completely or nearly completely in the burner combustion chamber and the mixture of burned fuel and gas leaving the combustion chamber oxidizes the combustible constitutes in the process gas flowing outside of the combustion chamber by yielding flameless heat energy to them.

Abstract: Raw gas burner that maximizes fuel efficiency of the burner, minimizes residence time, and reduces or eliminates flame contact with the process air or gas in order to minimize NOx formation. Process air flow such as from the cold side of a heat exchanger associated with thermal oxidizer apparatus is directed into and around the burner. The amount of process air flowing into the burner is regulated based upon the pressure drop created by the burner assembly. The pressure drop is, in turn, regulated by one or more of an external damper assembly, an internal damper assembly, and movement of the burner relative to the apparatus in which it is mounted. To ensure thorough mixing of the fuel and process air, process air entering the burner is caused to spin by the use of a swirl generator. The fuel/process air mixture proceeds into the combustion section of the burner, where the swirling flow is caused to recirculate to ensure complete combustion of the fuel in the combustion chamber.

Abstract: Apparatus and process for the non-contact drying of a web of material. The apparatus includes air flotation nozzles for floating the web, and direct air impingement nozzles for enhanced drying of the web. A plurality of air flotation nozzles or air bars are mounted in one or more sections of a dryer enclosure in air-receiving communication with headers, preferably both above and below the web for the contactless convection drying of the web. In conjunction with these air flotation nozzles, one or more sections of the dryer also includes direct impingement nozzles such as hole-array bars or slot bars. The drying surface of the web is thus heated by both air issuing from the air flotation nozzles and from the direct impingement nozzles. As a result, the dryer has a high rate of drying in a small, enclosed space while maintaining a comfortable working environment.

Abstract: Flotation drying apparatus for the staged (indirect) heating of solvent laden air recirculating within a drying enclosure, and a method of optimally controlling and directing solvent laden recirculation air such that condensation and sapping of solvent and various solvent-based by-products may be effectively reduced or eliminated. In addition to the reduction of condensate, a greater and more uniform mixing of the atmosphere within the drying enclosure is achieved, thereby enhancing safety and the drying process as pockets of high concentration solvent vapors are reduced. Air from outside the dryer enclosure is heated within the dryer enclosure, and is mixed with solvent-laden air. The mixed air is recirculated to the first drying zone of the dryer.

Abstract: Method and apparatus for eliminating the danger of inadvertent failure of a weight-bearing retraction system, such as a dryer hood retraction system. A load lifted using a fluid cylinder can be easily locked in place against gravity by using a double rod ended cylinder, where the rod end not exerting the force is permitted to move through a clearance hole while the load is being lifted, and is then blocked to prevent the return motion until the load is to be released.

Abstract: Flotation drying apparatus for the staged (indirect) heating of solvent laden air recirculating within a drying enclosure, and a method of optimally controlling and directing solvent laden recirculation air such that condensation and sapping of solvent and various solvent-based by-products may be effectively reduced or eliminated. In addition to the reduction of condensate, a greater and more uniform mixing of the atmosphere within the drying enclosure is achieved, thereby enhancing safety and the drying process as pockets of high concentration solvent vapors are reduced. Air from outside the dryer enclosure is heated within the dryer enclosure, and is mixed with solvent-laden air. The mixed air is recirculated to the first drying zone of the dryer.

Abstract: A method of drying [apparatus for ] a strip of material or web, which may advantageously be performed by providing a drying apparatus including a conditioning zone immediately following but fully integrated with the [dryer] drying zone, to lower the bulk temperature of web. The web of material can be introduced to conditioned air which is substantially free of contaminants being evolved from the coating on the web. The temperature of the conditioned air is low enough to absorb heat from the web, effectively lowering the solvent evaporation rate, and can be controlled such that it is greater than the dew point of the contaminants being evolved from the web, thereby mitigating condensation that normally forms and visible vapors that form outside of the dryer enclosure. Pressure control is provided in the conditioning zone so that solvent vapors will not escape and so that ambient make-up air can be regulated as required.

Abstract: Telescoping slot nozzles for use with a rail assembly are disclosed. Each nozzle includes a fixed portion and at least one telescoping portion slidably guided in the fixed portion. Metal-to-metal contact in the nozzle is avoided, thereby allowing the nozzles to operate at high temperatures. The configuration of the nozzle discharge opening can be easily modified to form an air knife, depending upon the particular application. Each nozzle is independent of the others, thereby facilitating retrofitting existing ovens and maintenance of individual nozzles.

Abstract: Sprayable fireproofing compositions for structural members such as steel columns are provided, as well as a method of applying multiple coatings thereof. The compositions comprise a Portland cement-based material, stucco, a high density aggregate and an accelerator. The compositions eliminate the long setting times typical of Portland cement-based materials, and improve the hangability thereof. The product is produced by dry blending a mixture of Portland cement, a high density aggreagte, stucco (calcium sulfate hemi-hydrate) and optionally, a stucco set retarder and shredded polystyrene aggregate. Upon the addition of water, sprayable slurries are formed which can be pumped to the point of application. An accelerator is added in close proximity to the point of injection. The slurries adhere to the structural member in the slurried state and after setting to provide excellent fire and heat protection.