System for introduction of concentrated liquid chemical foamant into a water stream for fighting fires
US5494112A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1993 |
| Grant date | Feb 27, 1996 |
| Priority date | — |
| Expiry date | Oct 29, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/2531
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A fire fighting system introduces a liquid chemical foam concentrate into a water stream. The system may incorporate either or both of a hydraulic motor driven pump under control of a microprocessor-based hydraulic valve driver and an electric motor driven pump under control of a DC motor drive circuit. The DC motor drive circuit is adapted to be connected in electrical communication with the hydraulic valve driver and with a display/controller also incorporating a microprocessor. When operating in the dual mode, when the quantity of chemical foamant that must be added to the water stream to maintain a desired percentage mixture exceeds the capacity of the electric motor driven foam pump, control is transferred, via the hydraulic valve driver, to allow a hydraulic motor to drive a separate foam pump. In this fashion, the electric motor driven foam pump can cover a first range of flow rates from a very low rate to an intermediate rate and the hydraulic system then taking over to extend the range from the intermediate flow rate to a relatively high flow rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.