Enhanced operational reliability by filtration

By Janne Rantanen, Product group manager / Regional manager

Water purification includes a wide variety of possibilities to achieve the desired result. Filtration is a very popular and simple method of water purification.

The purpose of filtration

Filtration is used to remove e.g. solids from water and other heat transfer liquids. The filtration need is influenced by water quality and the set water standards. Water quality varies depending on the origin of water e.g. surface water, well water or municipal water. The quality of municipal water may be sufficient for household use but not for industrial applications.

Water filters are used in many industrial applications such as cooling, aqua heat recovery and ventilation systems. Without filtration deposits and other impurities circulate in the system causing corrosion and increased energy consumption. They may also block the system and disturb the operation of regulating units.

Criteria for filter selection

Choosing the right kind of a filter for each purpose depends on the following criteria:

• System (type): heating, cooling, heat recovery, district heating, sealing water, cooling tower etc.
• Volume of water (if a closed system)
• Origin of water: municipal water, untreated water, river or lake water, mechanically processed water, chemically purified water, district heating water, water-glycol solution etc.
• Worst contaminator: deposits, iron sediment, dirt, humus, sand, dust, turf etc.
• Flow rate of water/liquid: m3/h or l/s
• Connection: main flow or by-pass
• Diameter of connection
• Maximum water/liquid temperature
• Maximum water pressure
• Desired filtering degree
• Total solids (if known)