Drying system for intaglio printed web - has closed loop control of solvent recovery from drying air

摘要

Drying system for rotary intaglio press has a hood through which drying air is passed. The volume of air fed into the hood is regulated by a first closed loop which has feedback from a sensor (1) measuring the moisture content of the web leaving the dryer. A part of the outflowing air is abstracted (17) for recovery of the ink solvent. - A second control loop regulates the minimum volume of the abstracted air in proportion to the total mass flow. A third loop acts on the solvent recovery plant to keep the amount of solvent vapour in the abstracted air to a minimum.