Board drying process and drier

US5659975A · kind A · utility

Assignee

• Babcock-BSH GmbH · DE

Inventors

• Friedrich Bahner · Lengede, DE
• Manfred Braun · Bad Hersfeld, DE
• Karl Lang · Berlin, DE
• Gerhard Lehn · Bad Hersfeld, DE
• Karl Paul Maurer · North Branch, US
• Manfred Schmidt · Krefeld, DE
• Josef Steinkuhl · Bad Hersfeld, DE

Key dates

• Filing date: Jan 25, 1996
• Grant date: Aug 26, 1997
• Expiry date: Jan 25, 2016

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P70/10
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

In order to dry boards, the boards are guided on racks through a drier and brought into contact with drying air in two stages. In a stage A with a higher drying power, the drying air is supplied at a higher temperature and with an at least average humidity, and in the other stage B, it is supplied at an average temperature and with a low humidity. The waste heat of the outgoing air from stage A is used for preheating the drying air. This process should reduce the consumption of primary energy. For that purpose, a process is known that consists of also using the outgoing air condensation heat. This has the inconvenience, however, of requiring substantially more secondary energy, as important air mass flows are required to transfer heat because of the low condensation temperature. Primary energy should be reduced by using condensation heat without substantially increasing secondary energy requirements. According to the invention, the outgoing air from stage A is supplied to stage B through a heat exchanger arranged in the rack of the drier. The drying air of stage B is supplied in counter-current through the drier with a low humidity and temperature, so that the boards are dried in s…