Evaporative-cooling apparatus and method for the control of web or web-production machine component surface temperatures

摘要

Disclosed is an apparatus for providing a shower of fog onto a web or a machine component in contact with a web. The fog, which has a temperature lower than the temperature of the surface of the web or the machine component to be cooled, is applied to the surface and is caused to evaporate by the difference in the temperatures. A supply of dry air is supplied to transport the evaporated fog from the region adjacent the surface to be cooled. Fog may be generated through the use of an air-atomizing nozzle which propels water and compressed air through a small orifice under pressure to create an atomized mist or fog. In one embodiment, the fog may also be supplied in controlled specified quantities locally as required to provide for a controllable fog application rate across the full apparatus width. The fog is thus generated at a single source and then supplied to a common cross-machine plenum with the flow of fog to each local region being regulated by a locally adjustable outlet of the apparatus through which the fog and dry air flow.