Performance and screening quality where conventional vibration screening machines fail 

FLIP FLOW SCREENING MACHINES HEIN LEHMANN

Screening of difficult to screen, fine and sticky materials under any conditions.

Specific high-frequency screening machines fitted with membrane polyurethane screens with self-cleaning effect.

PRINCIPLES OF SCREENING:

• The screen surface uses the principle of high acceleration of the screened material (trampoline-based movement) in combination with the self-cleaning effect of the screens.
• The movement of the material on the screen is not enabled by the eccentric shaft or the vibrator, but it is based on a combination of the movement of the screen “sheets” (membranes) and the inclination of the screening machine.

BASIC DESCRIPTION:

• High screening ability under almost any conditions (increased humidity, mud, clay, dustiness)
• Long lifetime of the screen surfaces (screens are made of elastic polyurethane, the lifetime of which is several times higher than for wear-resistant steel screens)
• Self-cleaning screens. A specific feature of the LIWELL screening machines is their ability to overstrain the screen surfaces. At this extreme point, the mesh on the screen is enlarged up to 10 mm for a small moment. At this point, the material that would normally get stuck in the screen mesh falls down, leaving the screen area clean and available for further screening.
• High sharpness of screening. The high screen efficiency of the screening machine guarantees the sharpness of screening as well as screening of the material that would be very difficult to achieve (under any conditions) on a conventional vibration screening machine.
• Due to the specific screening method and the large acceleration of the material to be sorted, all screens are fitted with a cover as standard, ensuring that the material does not fly out of the screening machine.

EXAMPLES OF THEIR USE IN PRACTICE: 

Crushed aggregates (quarries)

• Material: dolomite, andesite, melaphyre, basalt and others.

• Screening range: 0,9-10 mm (most often fractions 0-2 in Slovakia)

• Humidity: 2-15%

• Capacity: 20-300 t / h

Gravel (gravel pits)

• Material: mined and crushed gravel, sand and others

• Screening range: 1-15 mm (in the Slovak Republic 0-2 or plaster mixtures)

• Humidity: up to 10%

• Capacity: 20-300 t / h

Slag

• Material: blast furnace slag and others

• Screening range: 2-20 mm

• Humidity: up to 20%

• Capacity: 20-300 t / h

Compost

• Material: natural or waste compost and others

• Screening range: 4-20 mm

• Humidity: 30-50 mm

• Capacity: 5-30 t / h