Debris filter

Application

 

Condenser debris filter plays an important role to prevent macro-fouling in open circuit cooling system. It catches foreign matters in cooling water and keeps condenser clean in power plants. Despite the use of pre-screening at cooling water intake, debris filter is necessary to remove things like marine life, shell, plastics, leaves, grasses, seaweed, etc. Or else, the debris will obstruct the water flow in condenser tubes and affect operation and performance of condenser. Further, overall thermal efficiency of the power plant is influenced. Debris filter provides protection to downstream condenser and taprogge cleaning system.

 

Structure

 

Debris filter consists of filter element, cylindrical shell, worm gear, rotor, discharge valve, upstream scoop, differential pressure transmitter, control cabinet, etc.

 

Filter element consists of framework and mesh. It is reinforced by rib plates to get enough rigidity and strength. Reinforcing ribs separate filter element into several radial compartments. Stainless steel mesh with holes Φ5-10mm is welded to framework. Cylindrical shell is made of superior steel plate. When seawater is used as cooling medium, the shell must be equipped with protective anode or use material above 1Gr18Ni9Ti.

 

 

Working principle

 

During operation, when debris fouls on the surface of filter element, pressure will rise here. Differential pressure before and after filter element is detected by a transmitter. When the signal is bigger than setting value, a cleaning cycle is started. Discharge valve is opened. Upstream scoop, which is connected with discharge valve and line, will cover on the face of each compartment to create reverse pressure. Backwash water will clean the debris and send them to discharge pipe. When differential pressure is low to setting value, discharge valve is closed, cleaning is stopped.

 

 

Features

 

• Low percentage of circulating water is used for backwash during cleaning.
• Low pressure loss, excellent cleaning performance.
• Self flushing based on differential pressure, timer actuation or manual.
• DCS connection for remote control.
• Labyrinth seal & hydraulic seal for bearing.
• Perfect matching between scoop and compartment to enhance backwash performance.

 

Reference

 

1. Indian Vedanta Aluminium, 2*600MW.
2. Sri Lanka Puttalam Power Plant, 1*300MW, seawater.
3. Indonesia Banten-Labuan Power Plant, 2*600MW, seawater.
4. Vietnam Mao Khe Power Plant, 2*300MW.
5. Indonesia Perusahaan Listrik Negara, 2*300MW, 2*600MW, seawater.