Regeneratable filter for combustible particles, particularly soot filter

US5571298A · kind A · utility

Inventor

• Alfred Buck · Nagold, DE

Key dates

• Filing date: Aug 9, 1995
• Grant date: Nov 5, 1996
• Expiry date: Aug 9, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S55/30
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

To prevent damage to an electrical resistance heater (13-16) which, when energized by electrical energy, for example in the order of 100 A at 12-24 V, a heat reservoir substance is included in the filter, positioned in heat transfer relation to the electrical resistance heater (13-16) and located, with respect to the flow direction of the gas stream through the filter, upstream of the filter material (15). Preferably, the electrical resistance heater is a perforated, tubular sheet-metal structure, axial ends of which are electrically connectable by connecting bolts (21, 25) to an electrical energy supply. The heat reservoir substance (14) is either wrapped at the outside over the tubular resistance heater (13-16), applied as a layer (14a) at the inside of the tubular resistance heater, or filled into the hollow interior thereof in form of a wire wool (14b). This substantially increases the heat transfer or heat exchange surface between the resistance heater and gases flowing therethrough, thus decreasing required electrical heating energy and protecting the resistance heater (13-16) against overheating upon variations in gas flow when the heater is energized. A typical heater tempe…