Pressure filter vessels are a key component in the water treatment process, designed to filter out contaminants from raw water. The stages of the filtration process in a pressure filter vessel are outlined below: 

1. The raw, unfiltered water enters the filter vessel through the upper inlet connection. To ensure the water is evenly distributed across the filter bed, it passes through multiple diffusers located at the top of the vessel. These diffusers help spread the water uniformly over the entire surface area of the filtering media below, preventing uneven flow and ensuring consistent filtration.
2. Once the water passes through the diffusers, it flows downward through the filtering media, which can consist of various materials such as sand, activated carbon, or other specialised media. The filtering media acts as a barrier that traps contaminants (such as suspended solids, dirt, bacteria, or other particles) in its numerous small channels. The effectiveness of the filtering media depends on the type and size of the media used.
3. After the water has passed through the filtering media and the contaminants have been captured, the clean, filtered water reaches the lateral collector arms or nozzle plate. These are located at the bottom of the filter bed and are responsible for collecting the filtered water. The collector arms help maintain an even distribution of water across the surface area of the filtering media, ensuring consistent filtration.
4. The clean water is then directed to the outlet. This water is now free from suspended particles and other contaminants.

Filtering Process 

1: Multiple Diffuser 

2: Filtering Media                                     

3: Lateral Collector Arms 

4: Unfiltered Water

5: Filtered Water

It is important to monitor the following to ensure effective operation of the filtration process.

• Input water quality
• Output water quality
• Inlet and outlet differential pressure
• Filtration run time

In summary, the process in a pressure filter vessel efficiently removes contaminants from raw water by dispersing it through a filter bed, where it is purified before being collected and sent out as clean, filtered water.