Abstract: Heat is indirectly transferred between a process fluid and ambient air in apparatus that includes an evaporative heat transfer cell operative in a wet mode or a dry mode, a dry heat transfer cell and a fan. The air may bypass the dry heat transfer cell to flow through a first air passage or may flow through a second air passage through the dry heat transfer cell and in either event, then through the evaporative heat transfer cell. The air may partially flow through and partially bypass the dry heat transfer cell, and then through the evaporative heat transfer cell. The evaporative heat transfer cell optionally may include a direct contact evaporative heat exchanger.

Abstract: A hybrid heat exchange apparatus for indirectly transferring heat between a process fluid and ambient air includes an evaporative heat transfer cell operative in a wet mode or a dry mode, a dry heat transfer cell and a fan. The air may bypass the dry heat transfer cell to flow through a first air passage or may flow through a second air passage through the dry heat transfer cell and in either event, then through the evaporative heat transfer cell. The air may partially flow through and partially bypass the dry heat transfer cell, and then through the evaporative heat transfer cell. The evaporative heat transfer cell optionally may include a direct contact evaporative heat exchanger. Manually or automatically controlling air flow based on ambient conditions provides efficient and economical control of the hybrid heat exchange apparatus, while avoiding problems in freezing conditions.

Abstract: A louver assembly is disclosed for use in a heat exchanger associated with a liquid basin. The louver assembly is made of a plurality of generally vertically oriented, non-corrugated sheets attached to adjacent corrugated sheets of material. Spaces between the corrugations and the non-corrugated sheets form air passageways extending downwardly through the louver assembly from an inlet face to an outlet face of the louver assembly. The corrugated and non-corrugated sheets have a V-shape in a top plan view defined by two acute angles X and Y on one surface of the sheets with respect to a transverse reference plane, resulting in a vertex angle Z on an opposite surface of the sheets of about 120° to about 140°. The V-shape of the sheets provides each of the corrugations and air passageways with a single inlet portion and a single outlet portion.

Abstract: A non-destructive method for testing sealed packages for leakage, particularly packages having a gas-permeable portion and a non-gas-permeable portion, by applying a temporary barrier over the gas-permeable portion, wherein the temporary barrier has an aperture, and connecting the aperture to a pressure monitor, and recording the pressure drop in the sealed package, via the aperture, for a predetermined time.