Plastic-jacketed filter underdrain block
US4923606A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 1988 |
| Grant date | May 8, 1990 |
| Priority date | — |
| Expiry date | Feb 26, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D24/4631
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A precast concrete, plastic-jacketed filter underdrain block for downflow or upflow filter units is disclosed. The plastic jacket additionally functions as a mold for the concrete. The plastic molds become an integral part of the finished filter underdrain block. Thus, relatively lightweight, inexpensive plastic molds can be fabricated and shipped to the filter construction site where they are filled with concrete, cured, and then placed in the filter unit to provide an underdrain system. The underdrain blocks may be equipped with handholds to facilitate the handling and placement of the blocks in the filter vessel. The blocks may also be provided with alternating vertical rigs on the outside vertical surfaces of the plastic jacket which create an interlocking system whereby when installed in the filter unit each block is interconnected to its adjacent side blocks thereby creating a uniform interconnected filter underdrain system which resists the uplifting and displacement of individual blocks during backwashing operations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.