FRIESS FMF Magnetic Filter for Heating and Cooling Water Systems
Cooling-water circuits and solar thermal systems are often filled with a water-glycol mixture for frost protection. Propylene glycol also provides a degree of corrosion protection, but it slightly increases fluid viscosity and reduces the system’s ability to separate entrained air.
The Problem
At the very low flow velocities common in solar thermal systems, air bubbles can form and reduce—or completely block—circulation.
A seven-year-old solar thermal system therefore had to be flushed to remove air that had accumulated over time. Although its stainless-steel corrugated pipework and copper tubing gave little reason to expect iron particles or corrosion residues, the circuit was found to be significantly contaminated.
The Solution: A FRIESS Magnetic Filter
The circuit was flushed with a pump and a downstream FRIESS magnetic filter. After one hour, the flushing pump was disconnected and the system returned to service.
Despite a total circuit volume of only about 50 litres, the magnetic rods collected a large quantity of fine ferrous particles.
With magnetic filtration installed permanently in the cooling-water and solar circuits, ferrous particles are removed continuously. This prevents deposits, corrosion and pitting on sensitive stainless-steel components such as heat-exchanger plates and thin-walled corrugated hoses. The simple FMF design needs no consumables or filter aids, and annual cleaning during routine maintenance is normally sufficient.
Results at a Glance
- The magnetic rods retained a large quantity of fine ferrous particles
- Magnetic filtration continuously removes ferrous particles from cooling-water and solar circuits
- Sensitive stainless-steel components are protected against corrosion and pitting