Bar Screen

JX Filtration June 19, 2024 Wedge Wire Screen

Bar Spacing
(1) The bar spacing of the screen before the pump should be determined according to the pump's requirements.

(2) The bar spacing of the screen before the wastewater treatment system should meet the following requirements: maximum spacing is 40mm, with manual cleaning ranging from 25-40mm and mechanical cleaning ranging from 16-25mm. Wastewater treatment plants can also set up coarse and fine screens, with coarse screen bar spacing ranging from 50-100mm.
(3) Large wastewater treatment plants can set up three screens: coarse, medium, and fine.
(4) If the bar spacing of the screen before the pump is not greater than 25mm, no additional screen is needed before the wastewater treatment system.

Screenings
(1) The amount of screenings is related to various factors. In the absence of local operational data, the following information can be used:
* Bar spacing 16-25mm: 0.10-0.05m³/10³m³ (screenings/wastewater).
* Bar spacing 30-50mm: 0.03-0.01m³/10³m³ (screenings/wastewater).
(2) The moisture content of screenings is generally 80%, with a bulk density of about 960kg/m³.
(3) For large screens at large wastewater treatment plants or pump stations (daily screenings volume greater than 0.2m³), mechanical cleaning is generally used.

Other Parameters
(1) The flow velocity through the screen is generally 0.6-1.0m/s.
(2) The flow velocity in the channel before the screen is generally 0.4-0.9m/s.
(3) The inclination angle of the screen is generally 45°-75°. A smaller angle is less labor-intensive but requires more space.
(4) The power unit of the mechanical screen should generally be installed indoors or other protective measures should be taken.
(5) The structure housing the screen device must consider having good ventilation facilities.
(6) Lifting equipment should be installed in medium and large screen rooms for equipment maintenance and daily removal of screenings.