Mercury vapor discharge lamp containing means for reducing mercury leaching
US5229687A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 1991 |
| Grant date | Jul 20, 1993 |
| Priority date | — |
| Expiry date | Oct 9, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/82
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A mercury vapor discharge lamp having an envelope of light-transmitting vitreous material containing an inert starting gas and a quantity of elemental mercury at least partially convertible to soluble mercury. Enclosed within the lamp is an amount of chemical agent suitable for electrochemically reducing a substantial portion of the soluble mercury to elemental mercury when the lamp is pulverized as a result of disposal. Preferably, the chemical agent is an element (i.e., copper or iron) which has an electrode potential for oxidation reactions higher than mercury. In a preferred embodiment, the chemical agent is sealed within an enclosure (e.g., glass) which is rupturable upon pulverization of the lamp. The sealed enclosure is disposed within the envelope or external to the envelope, such as within a cavity defined by a lamp base member. In another embodiment, the chemical agent is mixed with the basing cement used to secure the lamp bases to the envelope.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.