IEDCO In-Line Vacuum Screener

Inline scalping during pneumatic transfer

Process role: The screener adds a size-control step to the conveying route before powder reaches downstream equipment or packaging.

IEDCO describes sanitary construction and a range of mesh sizes for food, chemical and pharmaceutical powder processes.

What the screen can and cannot do

A scalping screen can retain lumps, foreign material or oversize particles larger than its opening.

It doesn’t automatically disperse strong agglomerates, classify a broad particle-size distribution with high precision or detect contaminants smaller than the aperture.

Aperture: State the required separation as an aperture and an acceptance test, not just “remove lumps.” Select the opening from the largest acceptable product particle and the smallest reject that must be retained. Nominal mesh count alone is incomplete because wire diameter changes the clear opening and open area.

An inline screener is useful when the reject load is small and the mesh stays open. If the product routinely arrives as hard lumps, a delumper or a different upstream control may be the more honest solution.

Pressure drop, blinding and usable capacity

The mesh adds resistance to the gas-and-solids path. Blinding increases that resistance and can reduce conveying rate or destabilize pickup.

Open area, wire diameter, solids loading, particle shape, moisture and electrostatic behavior all affect performance.

Capacity depends on how much screen area remains available under solids loading. A fine screen can pass clean powder in a bench test yet blind rapidly when moisture, fat, static charge or soft agglomerates appear in production.

Inspection and process protection

The housing needs safe access for screen removal without releasing residual vacuum or dropping retained contamination into good product. Screen identity, orientation and condition should be checked after installation. Where a torn screen creates a critical hazard, use a documented integrity check and a traceable mesh record.

Monitor vacuum or pressure on both sides when the process risk justifies it. A rising differential can indicate blinding, but a damaged screen may reduce resistance and still pass unwanted material.

Before committing to a configuration, also confirm:

• Expected oversize load and the method of removing rejects.
• Permitted good-product loss at the selected aperture.
• Contact materials, surface finish and cleaning validation.
• Failure detection when the screen is damaged or incorrectly installed.

Acceptance trials should measure clean pressure loss, maximum sustainable solids rate, reject capture, good-product loss and the cleaning interval with representative powder.