Combustion product condensing water heater
USRE33082E · kind E · reissue
Assignee
Inventors
Key dates
| Filing date | Sep 13, 1985 |
| Grant date | Oct 10, 1989 |
| Priority date | — |
| Expiry date | Sep 13, 2005 |
Classification
- Technology area (CPC —)General
Abstract
In a water heating system, vapor in the products of combustion gases is condensed in a secondary heat exchanger positioned in a housing with the primary heat exchanger and combustion chamber. The two heat exchangers are coaxial coils with the secondary coil positioned below the primary. Gases flow radially through the primary coil and then axially through the secondary coil at an increased velocity. The gases are then used to pre-heat a gas/air mixture in a third heat exchanger within the secondary heat exchanger. The pre-heated gas/air mixture is burned in a burner within the primary heat exchanger and the gas products are drawn through the exchangers by a blower. A water storage tank is designed to enhance stratification of hot water over cooler water. The cooler water is used to condense vapor in the secondary heat exchanger.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.