Water heater

US5464006A · kind A · utility

Assignee

• Max-Planck-Gesellschaft zur Föderung der Wissenschaften e.V. · US

Inventors

• Konstantin Ledjeff · Schwalbach, DE
• Alexander Schuler · Konstanz, DE
• Jurgen Gieshoff · Bad Orb, DE

Key dates

• Filing date: Jun 30, 1994
• Grant date: Nov 7, 1995
• Expiry date: Jun 30, 2014

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F24H1/0045
• WIPO field: Thermal processes and apparatus
• WIPO sector: Mechanical engineering

Abstract

A water heater has a gas inlet (8) for a mixture of gas and air and an in for a fluid (2) to be heated. The gas-air mixture passes through a combustion chamber (11,18) which is at least partly surrounded by at least one fluid chamber (4,7) filled with the fluid (2). The exhaust gas leaving the combustion chamber(s) (11,18) passes through an exhaust gas heat exchanger together with the fluid (2). Here there are two combustion stages, the first (16) being a catalytic gap burner (11) and the second being a monolithic burner (18,19). Owing to the two-stage arrangement, about 80% of the combustion gas is burned in the combustion stage (16) while the remainder is consumed even at the low partial pressures in the second combustion stage (20) virtually without any residue, and especially without emission of NO.sub.x.