What is Filter Unit?
Kyowa's Filter Unit is a product which protects rivers, seashores, bridges and mono piles from scour damage. For Filter Unit is made of mesh net and rocks, it prevents flood and bridge scour without destroying environment. Filter Unit perfectly fits in the environment because living things such as small fish and plants can live in the interspace inside Filter Unit.
Recently, Filter Unit is applied to the protection of marine cable and pipeline in environment-friendly way.
Kyowa's Filter Unit is a product which protects rivers, seashores, bridges and mono piles from scour damage. For Filter Unit is made of mesh net and rocks, it prevents flood and bridge scour without destroying environment. Filter Unit perfectly fits in the environment because living things such as small fish and plants can live in the interspace inside Filter Unit.
Recently, Filter Unit is applied to the protection of marine cable and pipeline in environment-friendly way.
Filter Unit is used for...
1. Scour protection of foundation of wind turbine
2. Cable and pipeline protection and counter measures of pipeline floating.
3. Adjustment of unevenness of the seabed for cable and pipeline.
4. Creation of cable and pipeline crossing.
Feature Of Filter Unit
Flexibilty
Close adherence installation to uneven seabed is possible without leveling.
Seabed is uneven.
Filter Unit fits even with uneven seabed without gaps.
As Filter Unit fits each other well, it is possible to add more Filter Units without further arrangements.
Filter Unit is installed.
Filter Unit will follow the fluctuation of ground even if it is scoured from outside the structure and sinks.
It is very easy to carry out remedial work.
High Productivity
[Example] Maintenance work for rock dumping method.
Rocks are covering marine cable.
A part of dumped rocks are washed away by flow of water.
Repair work at damaged part of rock dumped area by Filter Unit.
It is possible to install multiple Filter Units at one time with lifting frame.
Image of installation of three Filter Units at one time.
Scour Protection and Suction Prevention Effect
Filled stones which creates multiple layers and high covering effect, Filter Unit protects seabed from scouring and sucking.
High Durability
As Filter Unit is made of synthetic fiber, it is strong against corrosion that it has a long durability. At the same time, it has durability against ultraviolet rays equivalent to 30 years exposure under the sun.
Weather test of net (acceleration test of ultraviolet rays irradiation for 7500 hours equivalent to 30 years' exposure under the sun.)
Consideration For Environmental Issues
Filter Unit has a porous structure that it will become a habitat of aquatic creatures.
At the same time, stable ground created by Filter Unit becomes a base of growth* for seaweeds etc.
* The growth of seaweeds depends on environmental condition of the sea.
Product Specifications
| Type | Mesh size | Unit weight, Filter Unit empty |
Dimensions in meters, Filter Unit installed | Applicable velocity | The stuffing material. Particle diameter |
||||
|---|---|---|---|---|---|---|---|---|---|
| Height(m) | Diameter(m) | Surface(m2) | Vol(m3) | Unit | Grouped | ||||
| Eco-Green 2t | 25 mm | 6 kg | 0.4 | 1.9 | 2.8 | 1.25 | 3.1 m/s | 4.6 m/s | 50 mm |
| Eco-Green 4t | 25 mm | 13 kg | 0.6 | 2.4 | 4.5 | 2.5 | 3.4 m/s | 5.2 m/s | 50 mm |
| S Type 8t | 50 mm | 48 kg | 0.7 | 3.0 | 7.0 | 5.0 | 3.9 m/s | 5.8 m/s | 75 mm |
There is a risk of damage if Filter Unit is used at following places.
- Wave breaking points where waves hit constantly. (Places where stuffed stones move and rub the net from inside and net breaks.)
- In case a lot of rolling stones exist at the seabed, Filter Unit may be hit by stones and partially broken at stormy weather.
- Above applicable velocity of flow is a theoretical value when Filter Unit is installed in seawater.
We recommend filling stones of diameter 50mm for 2t & 4t types and
75mm for 8t type. However, it is possible to use maximum diameter 200mm for all types.
*Specific gravity of filling stones should be 2.6-2.65.