Tunnel kiln adapted for firing frost-resistant bricks in a reducing atmosphere
US4773851A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 16, 1987 |
| Grant date | Sep 27, 1988 |
| Priority date | — |
| Expiry date | Jul 16, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P40/60
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
Cermic materials (i.e. architectural face-bricks) are fired in a tunnel kiln of the type having a firing zone and a downstream cooling zone. The cooling zone is segregated into indirect and direct cooling zones via a sealed gate structure therebetween. The heated gases in the indirect cooling zone are thus preliminarily cooled by suitable means (for example, a heat exchanger) and the cooled gases are returned via a closed-loop path to the indirect cooling zone. The fired ceramic materials in the direct cooling zone are finally cooled by the direct introduction of an oxygen-rich gas (i.e. ambient air). In such a manner, a reducing atmosphere may be maintained in the firing zone and in the indirect cooling zone while final cooling of the bricks occurs in the direct cooling zone. Thus, the oxygen-rich atmosphere of the direct cooling zone is prevented from entering the indirect cooling zone via the sealed gate structure thereby permitting frost-resistant bricks to be fired and cooled on a continual basis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.