Bar Screen - Definition
A Bar Screen is a pretreatment piece of equipment used in wastewater treatment plants to retain coarse debris present in wastewater.
Definition of a Bar Screen
An automatic Bar Screen is a machine designed to retain bulky materials and all kinds of debris contained in wastewater. It is a wastewater pretreatment device that forms part of the liquid/solid separation process.
Wastewater pretreatment
Pretreatment consists of removing certain materials from wastewater, such as solid matter, fats, oils, or sand. It is a crucial step, because if pretreatment is not properly carried out, the entire wastewater treatment process is affected.
The first stage of pretreatment is the so-called screening stage. Wastewater, laden with solid materials, passes through a screen, where the solids are trapped. Screening consists of manually or automatically removing these materials from the screen and collecting them in a container, such as a bin or a waste hopper.
Manual screening consists of placing a screen across the effluent, with a person manually collecting the waste using, for example, a simple rake or a manually lifted screening basket operated by a cable. This is an archaic process that quickly reaches its limits as soon as flow rates or the amount of debris increase. It is also an operation that can be hazardous for the person carrying it out.
Problems encountered
- Clogged lifting pumps
- Clogged manual basket
- Saturated fine screens
- Clogged aeration manifolds
- Rags on the grease remover
The solution: the automatic Bar Screen
A device known as an automatic Bar Screen is installed across the effluent. Waste is still retained by a screen, but this screen is automatically cleaned by the Bar Screen, which collects the solid materials and discharges them directly into a waste bin or into a screw conveyor/compactor. This ensures optimal screening under all conditions, at both low and high flow rates, and eliminates the need for personnel to carry out this operation.
FB Procédés offers a complete range of automatic Bar Screens that fully meet all the efficiency and quality criteria required for optimal pretreatment and screening:
- Effective protection of pumps
- Reduces the load on treatment processes at the plant
- Takes up no more space than a manual basket
- Not all debris is retained, unlike manual baskets
- Little or no modification of existing structures required
- Debris lifted out of the pumping station and discharged directly into a bin
- Can be adapted to all types of installations
- Direct installation inside the pumping station, surface-mounted against the vertical wall
- Bar Screen maintenance carried out exclusively outside the pumping station