Abstract: A gas condenser apparatus and method is described employing two heat exchanger stages for condensing water vapor and other contaminates, such as organic solvents, out of hot air or other treated gas by means of a cooling gas which is provided by feeding back the treated gas through the cooling passages of such heat exchanger stages after removal of the water and solvents. The heat exchangers are of the counterflow type so that the treated gas and the cooling gas flow in opposite directions therethrough. Preferably, water vapor is removed from the treated gas by condensing it in the first stage and the solvents are removed by condensing them in the second stage thereby separating the condensed water and solvents. Auxiliary cooling coils are provided at the input of the first stage and at the output of the second stage for further cooling of the treated gas.

Abstract: A closed loop oxygen reduced gas recirculation system for an industrial dryer includes high volume primary and low volume secondary gas recirculation paths with a condenser apparatus in the secondary path for removing water and solvent. A natural gas burner produces both oxygen reduced gas for the system and the required energy for the dryer. An optional condenser apparatus removes water vapor from the oxygen reduced gas output of the burner prior to its reaching the dryer. The condenser apparatus may include a first heat exchanger and a pair of parallel alternately operating downstream output heat exchangers, such as refrigeration coils. The first heat exchanger condenses most of the water vapor from the dryer gas and vaporized solvent is condensed in one of the output heat exchangers while the other is being defrosted.

Abstract: An apparatus for condensing water vapor and vaporized solvent from process exhaust gas, such as from an industrial solvent drying oven process is described. The apparatus includes two parallel condenser assemblies which are alternately shifted between condensing and defrost modes. One of the assemblies is shifted into the condensing mode while the other is in the defrost mode and the other is shifted into the condensing mode while the one is in the defrost mode. When in the condensing mode, water vapor is condensed from the process exhaust gas in a water condenser such as a counterflow heat exchanger and solvent vapor is condensed therefrom by a solvent condenser such as a refrigeration coil positioned within a cold zone of the assembly. When in the defrost mode, a recirculating defrost loop is provided through which gas is circulated and heated for defrost purposes. Following defrosting, the defrosted condenser assembly is pre-cooled prior to shifting from the defrost mode back to the condensing mode.

Abstract: A counterflow heat exchanger is described with two sets of heat exchanger passages separated by heat exchanger plates disposed in substantial parallelism within the exchanger and supported so that the passages extend substantially vertically. The heat exchanger may be employed as an air-to-air or as an air-to-water heat exchanger and can be used to remove moisture or pollutants from hot exhaust air by condensation within the exchanger passages. When employed as an air-to-water heat exchanger, the water is sprayed onto the surfaces of the upper ends of one set of passages so that it flows down their length, while air is transmitted into the lower end of the other set of passages and caused to flow upward.

Abstract: A heat exchanger with metallic or otherwise conductive exchanger plates disposed in substantial parallelism within the exchanger. In making the exchanger, the exchanger plates are arranged in substantial parallelism and edges joined together with clips which tie the plates together as a unit bundle. A layer comprising a mixture of hardenable resin and reinforcing material is prepared, and the unit bundle of plates is placed with a set of adjacent edges of the plates in said layer. When the resin hardens, the layer forms a rigid slab extending along said set of edges. The process may be repeated on the opposite set of adjacent edges in the bundle of exchanger plates. The hardened resin masses which bind the edges of the plates together form part of an enclosing housing which is prepared about the exchanger plates to complete the exchanger.

Abstract: A heat exchanger with a set of channels through which grease laden air travels. Relatively cool air passes through the heat exchanger in a second set of channels. Washing means including liquid tubes within the first set of channels is provided for washing collected grease from the surfaces defining the first set of channels. A cooking facility including a hood for collecting grease laden air connected to a heat exchanger. Relatively cool air from an outside source passes through the heat exchanger to promote the collection of grease in the exchanges from the grease laden air received from the hood. The air from the outside source is raised in temperature on passing through the exchanger. Such heated air may be used as a source of heat for heating a building enclosure.