Filter medium retains solids
Cloth or ceramic behavior affects initial capture, resistance, filtrate and release.
A continuous cycle around each disc
How a Vacuum Disc Filter Works
Learn each vacuum disc filter stage: cake formation, dewatering, drying, discharge and cloth cleaning, plus the main operating variables that affect results.
Continuous rotationOperation
Pressure differenceDriving force
Form to dischargeCycle stages
Measured dutyKey proof
Operating principleSurface Vacuum path Rotation
Pressure Difference Draws Liquid Through the Medium
Each sector connects through an internal flow path to timed vacuum and blowback zones. Solids retained at the medium form cake while filtrate passes into the sector and onward to the filtrate system.
Sector carries filtrate and air
Sector, neck, center shaft, valve, receiver and piping create the connected flow path.
Zones create a repeating cycle
Disc speed and valve timing divide immersion, drying and discharge time.
One revolution1 2 3 4 5
Follow the Sector Through Five Stages
Zone names and details vary by model, but the functional sequence remains recognizable.
Immersion
The sector enters slurry and vacuum begins drawing liquid through the medium.
Cake formation
Retained solids build a cake while filtrate moves into the sector.
Dewatering
The sector exits slurry and continued vacuum removes additional liquid.
Discharge
Blowback and/or mechanical assistance releases cake at the set zone.
Media cleaning
Washing or another cleaning step restores usable permeability.
Operating variables
What Changes Capacity, Moisture and Release
Variables interact: changing disc speed changes formation and drying time; changing feed solids changes cake buildup and can alter release.
Feed solids and levelControl cake pickup and immersion consistency.
Particle and mineral behaviorDetermine cake structure, permeability and retention.
Vacuum and leakageProvide driving force; excessive air ingress consumes capacity.
Disc speed and zonesAllocate time to formation, drying and discharge.
Media conditionBlinding, damage or poor fit changes resistance and filtrate.
Discharge and washingSupport cake release and recovery of usable permeability.
Beyond the filterVacuum Filtrate Controls
The Vacuum and Filtrate System Matters
A filter body cannot sustain pressure difference without correctly selected, sealed and controlled auxiliaries.
Pump and air-handling path
Size for vapor, air ingress and process conditions, not a vacuum number alone.
Receiver and liquid removal
Separate gas and liquid and prevent receiver flooding or unstable transfer.
Interlocks and operating modes
Coordinate feed, rotation, vacuum, discharge, wash and downstream availability.
Safety before inspection or maintenance
Stop the equipment and isolate all hazardous energy that can cause rotation, vacuum, pressure, stored mechanical movement, electrical energization or chemical exposure. Follow the site lockout and permit procedure; inspection and maintenance must be performed only by authorized personnel.
Continue the project path
Turn the Principle into a Selection
Use testing and sizing to apply the cycle to a real slurry.
Practical answers
Frequently Asked Questions
These answers support project preparation; the final recommendation depends on the actual duty.
Why is representative slurry data required?
Mineral names do not define filterability. Particle-size distribution, mineralogy, clay, reagents, solids and temperature can change cake formation, permeability and release. Use filterability testing when results matter commercially.
What should be sent for a preliminary review?
Provide dry-solids throughput, feed solids, particle-size data, target cake moisture, operating schedule, elevation and available utilities through the quote request.
Can BOYUN promise cake moisture from the mineral name alone?
No. A defensible target must be tied to representative feed data, test conditions, equipment scope and an agreed operating basis.
Define the Next Engineering Step
Share the feed, throughput, operating target and site constraints. BOYUN will identify missing information and recommend testing, sizing or the appropriate equipment scope.