Back to results
US 4,590,683 AGranted
Method of and apparatus for drying wound fiber or yarn
AssigneeMTM Obermaier GmbH & Co. KG
InventorBerthold Magin
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeMTM Obermaier GmbH & Co. KG
InventorBerthold Magin
Estimating the term…
Fiber or yarn wrapped on spools is dried in a pair of vessels in an alternating gas flow arrangement. Each vessel is located in a separate circulation loop. The two circulation loops have a common circulation leg. Each of the circulation loops is connected to an evacuation device via an evacuation duct. The evacuation duct contains valves for selective connection of the evacuation duct to one or the other circulation loops. The common circulation leg contains a blower, a heater, a connection for introducing moisture into the gas used in the circulation loops, a cooler and a moisture separator. Valve controlled bypasses are connected to each of the circulation loops and to the common circulation leg so that a selected flow of heating gas can be provided in one of the loops when it is being evacuated. High frequency heaters are arranged in each of the vessels for supplying additional heat to the fiber or yarn. While heating gas flows in one circulation loop, the other circulation loop is connected to the evacuation device for completing the drying operation. The circulation loops alternate between flowing heating gas and evacuating the vessel in the loop.
Method of drying fiber or yarn wound on spools in a vessel comprising the steps of alternately heating, using an approximately moisture-saturated gas, and vacuum drying the fiber or yarn on the spools in the vessel whereby first the contents of the vessel are heated and subsequently, after terminating the heating step, the contents are then vacuum dried, wherein the improvement comprises the steps of during the heating step adjusting the moisture content of the heating gas in correspondence with the moisture content of the fiber or yarn being heated, and during the vacuum drying step, after drying the outer layer of the fiber or yarn on the spool, for a limited time intermittently introducing a flow of the moisture-saturated heating gas into the vessel while continuing the vacuum drying step for effecting an intermediate pressure in the vessel relative to the vacuum drying pressure whereby due to the introduction of the flow of the heating gas while continuing vacuum drying moisture located inwardly of the surface layer of the fiber or yarn on the spool is moved to the outer surface layer for facilitating the vacuum drying step until the drying step is completed.
Apparatus for drying fiber or yarn wound on spools comprising a circulation loop, a circulation leg in said loop, a vessel located in said circulation loop spaced from said circulation leg, an evacuation duct connected to said circulation loop at a location spaced from said circulation leg, an evacuating device connected to said evacuation duct for establishing a vacuum within said vessel, a condenser located in said evacuation duct between said evacuation device and the location of the connection of said evacuation duct to said circulation loop, valve means in said evacuation duct for controlling communication between said evacuation duct and said circulation loop, valves in said circulation loop with said valves selectively admitting or blocking flow through said circulation loops from said circulation leg, a blower located in said circulation leg for circulating gas selectively through said circulation loop, a heater located in said circulation leg for heating the gas, means for introducing moisture into the gas flow in said circulation leg, a cooling device located in said circulation leg for cooling the gas flowing therethrough, means in said circulation leg for separating moisture from the gas flowing therethrough, a bypass connected to said circulation loop and said circulation leg around one of said valves, to provide flow communication between said circulation leg and said circulation loop when the one of said valves blocks flow from said circulation leg into said circulation loop, and a control valve in said bypass for controlling flow therethrough.
Dependencies are inferred from the claim text.