Particle size classifier

US6220446A · kind A · utility

Assignee

• PQ Corporation · US

Inventors

• Reinhard Witt · Endingen am Kaiserstuhl, DE
• Robert Morgan Holland · Wichita, US

Key dates

• Filing date: Mar 25, 1999
• Grant date: Apr 24, 2001
• Expiry date: Mar 25, 2019

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B07B1/24
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A particle size classifier in which feed material composed of product and overs moves downwardly through a separator unit by the action of negative pressures created by a first air blower associated with the collection of product and a second air blower associated with the collection of overs. As the feed material moves downwardly, the product and the overs are separated with the product passing from within a screen unit to outside the screen unit and the screen unit preventing passage of the overs. Blowback air, applied to the screen unit from the outside cleans the cylindrical screen unit to permit continued passage of product through the screen unit.