Settlement tanks DN
Use
Settlement tanks are vertical squared sedimentation units intended for waste water treatment plants up to 5000 EI. They are installed behind the activation stage and they serve for the separation of biological sludge in WWTPs and then for its thickening and sedimentation.
Supplies
Settlement tanks are manufactured in 7 sizes, made of concrete and steel or of plastic as units built in the activation reservoirs. The arrangement of the inlet, discharge and sludge pipes may be variable. It is also possible to select the method of sludge pumping for each type of tank (by a air lif pump or sludge pipe).
Unit description
Settlement tank consists of a reservoir with inlet and discharge ducts, a footbridge and a building-in. Concrete reservoir is not part of supply. Steel tank consists of a steel casing made of the separate shipping parts with reinforcement and corrosion-resistant coating. The casing is not self-supporting, however, it provides for water-tightness and replaces a mould for concreting-in. Plastic tank is only used as a building-in into another tank made of concrete or plastic, filled with water. The footbridge is made of steel with galvanized grids and railing, and it also serves for fastening the whole building-in. The building-in contains the following: inlet and discharge pipes, collecting trough, circular baille, air lift pumps (event. sludge pipe) for the withdrawal of excess and return sludge, air lift pump for the withdrawal of floating sludge, sludge pipe and air pipe including blower nozzles to ensure the movement of floating sludge, valves for adjusting the air lift pump output.
Technical parameters
Settlement tank made of concrete and steel
| Dimensions | Size | |||||||
|---|---|---|---|---|---|---|---|---|
| Des. | Unit | 300 | 360 | 420 | 480 | 540 | 600 | |
| tank width | A | mm | 3000 | 3600 | 4200 | 4800 | 5400 | 6000 |
| overall tank height | C | mm | 3900 | 4200 | 4800 | 5100 | 5700 | 6000 |
| tank area | P | m2 | 9 | 12,96 | 17,64 | 23,04 | 29,16 | 36 |
| sedimentation area volume (up to the level) | U | m3 | 18,67 | 25,27 | 37,48 | 46,08 | 63,42 | 73,8 |
| sludge area volume | V | m3 | 1,06 | 1,87 | 3,02 | 4,54 | 6,49 | 8,94 |
| steel tank weight | - | kg | 2150 | 2600 | 3350 | 3900 | 4800 | 5400 |
| minimum air pressure | kPa | 36 | 39 | 45 | 48 | 54 | 57 | |
| sludge pipe outside diameter | ø d | mm | 160 | 160 | 160 | 160 | 160 | 160 |
| orient. max. air consumption | m3/h | 12 | 15 | 20 | 25 | 30 | 40 | |
Inserted plastic settlement tanks in the activation zone
| Dimensions | Size | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Des. | Unit | 260 | 300 | 360 | 420 | 480 | 540 | 600 | |
| internal tank width | Ap | mm | 2400 | 2800 | 3400 | 4000 | 4600 | 5200 | 5800 |
| minimum concrete tank width | mm | 2800 | 3200 | 3800 | 4400 | 5000 | 5600 | 6200 | |
| overall tank height - type |
Cp | mm | 3000 | 3900 | 4200 | 4800 | 5100 | 5700 | 6000 |
| overall tank height - minimum |
MIN.Cp | mm | 2200 | 2500 | 3100 | 3500 | 4000 | 4600 | 5100 |
| tank area | Pp | m2 | 5,76 | 7,84 | 11,56 | 16 | 21,16 | 27,04 | 33,64 |
| minimum overall volume | MIN.Vc | m3 | 6,00 | 8,75 | 15,99 | 23,03 | 33,87 | 50,37 | 68,05 |
| maximum plastic tank weight | - | kg | 640 | 885 | 1090 | 1340 | 1600 | 1900 | 2020 |
| minimum air pressure | kPa | 19 | 22 | 29 | 32 | 37 | 43 | 49 | |
| sludge pipe outside diameter | ø d | mm | 160 | 160 | 160 | 160 | 160 | 160 | 160 |
| orient. max. air consumption | m3/hod | 7,5 | 10 | 15 | 20 | 25 | 30 | 40 | |