Mercury vapor discharge lamp having means for reducing mercury leaching
US5994838A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 6, 1998 |
| Grant date | Nov 30, 1999 |
| Priority date | — |
| Expiry date | Mar 6, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/82
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a mercury vapor discharge lamp having an envelope of light-transmitting vitreous material and containing an inert gas and a quantity of elemental mercury at least partially convertible to soluble mercury, and first and second electrodes disposed within the envelope for establishing an arc discharge therebetween, an improvement comprising an effective amount of a nonmetallic copper-containing compound disposed in the lamp which, when the lamp is pulverized to granules and subjected to a suitable aqueous acid solution, dissolves in the aqueous acid solution, resulting in a concentration of extracted mercury less than 0.2 mg per liter of solution; and a method for reducing the amount of mercury extracted from a mercury vapor discharge lamp when the lamp is pulverized to granules and subjected to a suitable aqueous acid solution, such that the resulting concentration of extracted mercury is less than 0.2 mg per liter of solution, the method comprising the step of placing in the lamp in manufacture thereof an effective amount of a nonmetallic copper-containing compound soluble in the aqueous acid solution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.