Patent DE-102011104521-A1 (DE)
Title: Device, useful for batch-wise heat treatment of workpieces e.g. light metal cast parts, comprises a heating chamber, a main chamber, an optional lock arranged between the heating and main chambers, and an air circulation unit
Inventor: BELTE MARKUS
IPC: C21D9/00
Filed: 2011-06-17
Abstract: The device comprises a heating chamber (3), a main chamber (5), an optional lock (15) arranged between the heating chamber and the main chamber, and an air circulation unit. The heating chamber and the main chamber comprise rollers (7', 7", 9) for transporting workpieces between the heating and main chambers. Heat radiators are arranged: at two sides of a transport path of the workpieces; between the rollers below the transport path in the direction of the transport path; and above the transport path. The heat radiator is adjustable with respect to its distance from the transport path. The device comprises a heating chamber (3), a main chamber (5), an optional lock (15) arranged between the heating chamber and the main chamber, and an air circulation unit. The heating chamber and the main chamber comprise rollers (7', 7", 9) for transporting workpieces between the heating and main chambers. Heat radiators are arranged: at two sides of a transport path of the workpieces; between the rollers below the transport path in the direction of the transport path; and above the transport path. The heat radiator is: adjustable with respect to its distance from the transport path; and selected such that a maximum heat output per surface element of each workpiece doubles in the heating chamber along the transport path and is 3 times larger than in the main chamber. The rollers in the heating chamber and the main chamber consist of a ceramic material with a bright surface having an albedo of 0.5 for the heat radiation. The device further comprises a station for transferring workpieces on the rollers of the transport path, where the rollers in the region of the transfer station are formed of a metal, a reading unit arranged along the transport path before the heating chamber, a coating unit, and a cleaning unit arranged along the transport path behind the main chamber. The reading unit is formed to read identifiers attached at the workpieces, to identify a control signal for the heat radiator based on the identifiers and to output the signal at the heating chamber and at the main chamber. The rollers arranged transverse to the transport path are mounted on a same axis, which has a drive at one end of its extension direction and is supported in the middle of its extension direction. The coating unit is arranged along the transport path before the heating chamber, and is formed to partially and completely coat the workpieces. The coating: comprises an average albedo of less than 0.1 in the wavelength range of the thermal radiation of the heat radiators; is a suspension of an absorber such as graphite and an adhesion promoter such as xylene-base; coats exposed surface regions of the workpiece; and converts radiation energy into heat in the coated surface regions. The cleaning unit is formed for liberating workpieces from the coating and for drying the workpieces after the cleaning by a channel connected with the main chamber to obtain waste heat from the main chamber. An independent claim is included for a method for batch-wise heat treatment of workpieces.