Pipeline Separators

Pipeline Magnetic Separators

Pipeline separators capture metal contamination in processes where liquid and paste-consistency products are conveyed in closed pipelines. Their fundamental difference from free fall separators is that the product moves by pump pressure rather than by gravity; that requires the magnet housing to be designed to withstand the line pressure and to stay sealed.

The magnet bars sit inside a smooth, polished 316 stainless steel tube housing. The polished surface matters not only for hygiene but also for reducing flow resistance: a rough surface starts a build-up in a viscous product and narrows the line over time.

Where is it used

Sauces, chocolate, oils, jams, coating mixtures, pharmaceutical suspensions and chemical slurries are the most common applications. What they have in common is that they are viscous and that cleaning is wanted without opening the line.

What CIP compatibility means

CIP (cleaning in place) is the ability to wash the line by circulating a cleaning solution without dismantling it. It is standard in food and pharmaceutical plants because it shortens the production stoppage. A separator being CIP compatible means that the housing is designed to leave no dead zones and that the sealing elements withstand the cleaning chemicals.

What to watch for when choosing

• Line diameter and flow rate — the separator must not narrow the line, and the pressure loss has to be taken into account
• Working pressure and temperature — these determine the choice of housing and gasket
• Product viscosity — with thick products the bar spacing is kept wide, otherwise the flow blocks
• Cleaning method — CIP or manual dismantling; the two call for different housing designs
• Magnet strength — neodymium for fine iron dust, while ferrite may be sufficient for coarse pieces

Outside liquid lines, free fall separators are used for bulk material streams and conveyor belt separators for streams on a belt. Where metal contamination enters the production line from is covered in detail in the metal separation guide.

Commissioning and maintenance

After installation the pressure loss of the line should be measured and it should be verified that the pump copes with this added resistance. The cleaning interval is established in the first weeks by daily checks. On lines with CIP, the resistance of the gaskets to the cleaning chemicals is an item to be reviewed at the annual maintenance.

Mounting position

The separator should be placed in the section of the line where the product flows most homogeneously. Positioning it too close to the pump outlet lowers the capture rate because of turbulence; immediately after a bend is similarly unsuitable. Determining the position from the line diagram before installation removes the need to relocate it later.