Precise regulation of pyrocarbon coating
US6274191A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 7, 1994 |
| Grant date | Aug 14, 2001 |
| Priority date | — |
| Expiry date | Mar 7, 2014 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J2208/00619
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Deposition of a pyrocarbon coating of precise thickness onto one or more substrates being levitated along with a bed of particles in a fluidized bed coating enclosure is accomplished by varying the amount of hydrocarbon supplied to the bed as a part of an upward levitating flow to compensate for changes which are detected in the size of the fluidized bed. Increases and decreases in the size of the bed are detected by monitoring either the differential pressure above and below the bed or the weight of the bed, and compensating changes are made to return the bed to its desired size by changing the flow rate of hydrocarbon. For example, when a growth in bed size is detected that is not attributable to an aberration in either particle supply or withdrawal, the amount of hydrocarbon being supplied to the bed is decreased so as to cause the size of the bed to gradually return to its desired value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.