Limestone contactors in steel tanks
The DrinTec™ design of upflow limestone contactors of constant height simplifies the reload operation by means of feeding the granulated limestone continuously, under water and directly on to the limestone bed by a limestone feeding system, thus maintaining a constant bed height all the time.
It‘s a very effective system that operates continuously for many years without needing to perform a backwash.
DrinTec™limestone Contactors of constant height in vertical tanks feature limestone feeding system, internal perimeter spillways, underdrain system for water and air and built-in calcite silo. Each unit is made according to project specific needs.
The designs generally include a turbid water recovery and recirculation system to ensure a plant with an autonomy of more than 30 days and zero discharge during operation. This procedure has the advantage that the quality of the outlet water is always constant. Consequently, the operation and maintenance costs are reduced considerably over the traditional designs.
The limestone contactors are usually placed in parallel. Because they have the same height they offer the same counter-pressure. This facilitates the hydraulic design of the inlet manifold and provides an uniform and constant water distribution to the different tanks.
The limestone contactors operate by gravity with a low pressure drop, so they can operate directly with the outlet pressure of the reverse osmosis racks.
The turbidity is controlled using dust free material and maintaining a constant flow rate, i.e. avoiding sudden changes in flowrate. If the current flow is going to be increased, flow is initially diverted and incorporated gradually thereafter to the contactor.
There is very little need to purge the limestone contactors, as they operate upflow and do not tend to clog. However, at least once a year a 5 minutes sponging is recommended to reduce the risk of formation of preferential pathways.
Internal parts and the DrinTec™ process are protected by various patents.
Brochures
Advantages of DrinTec™ limestone contactor process:
- Equipment shipped in standard ocean container
- Modular installation
- Very high efficiency
- Flexible automation: fully, partial, none
- Constant performance and water quality
- Low maintenance cost
- Minimum or no energy consumption
- No moving parts
- More than 30 days autonomy
- No need for qualified workforce to operate
- No need for frequent backwash: At start up and then once a year
Technical specifications:
| Flow range per tank | Up to 9400 m³/day. |
| Filtration media | Granulated calcite (CaCO3) |
| Contact time | 10-30 minutes |
| Height | 6 m |
| Diameter | 5 m |
| Maximum inlet pressure | 1 bar |
| Outlet pressure | Atmospheric |
| Outlet turbidity | <1 NTU** |
| Autonomy of internal silo | >30 days |
| Flow direction | Upflow |
| Internal parts delivered by DrinTec™ | – Underdrain floor in HDPE – Modular spillways – Limestone feeding system |
| Manufacturing country | Spain |
