How it works
A disk-stack centrifuge spins a stack of more than a hundred closely spaced conical disks. The feed suspension enters at the outer radius and flows inward through the thin channels between the disks. Rotation imposes a strong centrifugal field, so every particle denser than the liquid is driven outward and downward onto the underside of a disk, then slides to the outer radius where the sediment collects and is discharged. The clarified liquid continues inward and leaves at the center.
The short inter-disk distance is the trick: a particle only has to settle across a thin channel before it reaches a disk surface, so even fine particles are captured at modest residence time. Capture therefore depends on both particle size and the density difference between solid and liquid — a larger particle or a denser solid settles faster and is caught more completely. Higher rotational speed, more disks, and lower throughput all sharpen the separation; high feed concentration hinders settling because particles get in each other’s way.
The model
Dyssol Pro computes the clarification at the population level: for every particle size class and every solid compound it determines the fraction settled out to the sediment, splitting the suspension into a sediment with defined residual liquid content and a clarified liquid — at every time point of the dynamic flowsheet.
The capture calculation follows the settling physics of the machine: a particle in the centrifugal field between the disks settles the faster, the larger it is and the more its density exceeds that of the liquid, while the geometry of the disk stack sets how far it must travel before it is caught. Rotational speed, the disk radii and cone angle, the channel spacing, and the throughput drawn from the connected stream all enter the grade efficiency — so a faster bowl, a tighter stack, or a lower feed rate sharpens the predicted separation exactly as it does on the machine.
Liquid viscosity and the density of every solid compound come from the materials database, so mixed feeds separate by size and density simultaneously, and hindered settling can be switched in when the suspension is concentrated enough for particles to obstruct each other. Dyssol Pro covers centrifugal clarification duties from beverage polishing to cell harvest and fine-chemical recovery, inside the connected solid–liquid flowsheet.
Equipment this model can represent
Any centrifugal clarification duty for low-to-moderate-solids suspensions of fine particles.
Clarifiers (solid-retaining)
Low solids load; periodic manual cleaning of the retained sediment.
Self-cleaning separators
The bowl opens periodically to eject accumulated solids automatically.
Nozzle separators
Continuous solids discharge through peripheral nozzles for higher solids loads.
Purifiers / concentrators
Liquid–liquid–solid duty, e.g. separating two liquid phases plus solids.
Typical engineering studies
What teams investigate with the disk-separator models.
Clarification prediction
Predict clarification efficiency and sediment/permeate splits for a given machine and feed.
Geometry & speed studies
Study capture versus rotational speed, disk spacing, channel count, and throughput.
Concentration effects
Account for hindered settling on dense feeds at higher solids concentration.
Calibration & scale-up
Calibrate the model’s adjustment factors to measured performance, then scale up.
Multi-density separation
Resolve multi-density solid mixtures, since separation is computed per compound density.
Technical FAQ
How does a disk stack separator work?
Closely spaced rotating conical disks create a centrifugal field thousands of times gravity; solids denser than the liquid settle the short distance onto a disk underside, slide outward, and collect as sediment while the clarified liquid leaves at the center. Dyssol Pro reproduces this with a grade efficiency resolved by particle size and density, computed from the machine geometry and speed.
What is the difference between a disk separator and a decanter centrifuge?
A disk stack clarifies dilute-to-moderate suspensions of fine particles to high clarity; a decanter handles high solids loads and delivers a drier, conveyable cake at a coarser cut. Dyssol Pro provides both units, so clarification and dewatering can be compared for the same feed in one flowsheet.
How can I improve fine particle removal in a disk separator?
Fine capture improves with higher bowl speed, tighter disk spacing and more disks (a shorter settling distance), and lower throughput — and with anything that raises the density difference or lowers the liquid viscosity. In Dyssol Pro speed, disk geometry, and feed rate are inputs to the grade efficiency, so you see which lever moves the fine end of the curve most.
Why is my disk separator losing product in the reject stream?
Product reports to the sediment when the separation is set sharper than the product’s size and density require — typically too much speed or too little flow for the duty. Dyssol Pro’s size- and density-resolved efficiency shows exactly which classes go where, so speed and throughput can be retuned to recover the product.
How does flow rate affect disk separator efficiency?
Higher flow shortens the residence time in the channels, so fine capture falls — every disk stack has a throughput above which clarity degrades visibly. Dyssol Pro takes the volume flow from the connected stream, so efficiency versus throughput is read directly from the flowsheet.
How do I choose between nozzle discharge and self-cleaning disk separators?
Nozzle machines suit continuous, higher solids loads; self-cleaning bowls suit intermittent, lower loads where clarity matters most — the deciding numbers are the sediment rate and how wet it may be. Dyssol Pro quantifies exactly that duty: the sediment mass flow and its liquid content for your feed.
What causes fouling in a disk stack centrifuge?
Fouling comes from adhesive solids, precipitating species, or heat-sensitive product coating the disks; it narrows the channels until clarity and capacity fall, and the remedy is feed conditioning plus cleaning cycles. Dyssol Pro helps by modeling the upstream steps that set the fouling propensity and the solids load actually arriving at the machine.
How can I reduce maintenance frequency for a disk separator?
The maintenance interval is driven by fouling rate and mechanical wear, so the process lever is running at the mildest operating point that still meets clarity — the lowest speed and load, and the cleanest feed. Dyssol Pro finds that operating point by mapping the required clarity against speed and throughput.
How does particle density difference affect disk separator performance?
Settling velocity scales with the density difference between solid and liquid, so a small difference needs disproportionately more centrifugal effort — which is why cell debris is harder to clarify than mineral fines. Dyssol Pro takes each compound’s density from the materials database, so mixed-density solids separate by size and density automatically.
How can I simulate liquid-solid separation in a disk separator?
This is the unit’s purpose: the machine geometry, rotational speed, and feed properties define a size- and density-resolved settling efficiency that splits the suspension into sediment and clarified liquid. In Dyssol Pro you place the unit in the flowsheet and it returns the split and both stream compositions dynamically.
How do I optimize discharge frequency in a disk separator?
The bowl should discharge just before accumulated sediment reaches the disk stack and disturbs clarity — so the frequency follows from the solids arrival rate and the sludge-space volume. Dyssol Pro predicts that solids arrival rate and the sediment’s liquid content, which is precisely the basis for setting the interval.
Why is my disk separator producing unstable separation results?
Instability usually traces to fluctuating feed flow or solids concentration, and at higher concentrations hindered settling amplifies the swings. In Dyssol Pro you impose the measured feed transients, with the hindered-settling correction active, and see whether the process alone explains the variation.
How does viscosity affect disk stack separator performance?
Settling velocity is inversely proportional to liquid viscosity, so a viscous broth or a cold feed can cut capture dramatically — preheating the feed is often the cheapest capacity upgrade. Dyssol Pro takes viscosity from the materials database at the operating condition, so its effect appears directly in the predicted efficiency.
What causes solids buildup inside a disk separator?
Build-up means solids arrive faster than the discharge removes them — a mismatch of feed load, discharge capacity, and timing. Dyssol Pro predicts the sediment mass flow from the feed and the separation, which is the number the discharge system has to keep up with.
How can I reduce product loss during sludge discharge?
Losses scale with how much liquid — and the product dissolved or suspended in it — leaves with each ejection, so partial-discharge settings and correct timing matter most. Dyssol Pro tracks the sediment’s liquid content and mass flow, so the entrained product per discharge can be minimized on the process side.
How do I choose the right disk spacing for separation?
Narrower channels shorten the settling distance and capture finer particles, but reduce hydraulic capacity and clog sooner — fine clarification runs tight stacks, fibrous or fouling feeds need wider ones. In Dyssol Pro the channel spacing and count are model inputs, so spacing is traded against efficiency and throughput before touching the machine.
How can I improve phase separation in a disk separator?
Phase separation improves with more centrifugal effort (speed), more settling area (disks), longer residence (lower flow), and a feed conditioned toward larger effective particle size — flocculation helps where shear allows it to survive. Dyssol Pro ranks these levers by their effect on the sediment/permeate split for your actual feed.
What is the effect of temperature on disk separator efficiency?
Temperature acts mainly through liquid viscosity — warmer, thinner feed settles solids markedly faster — with a smaller effect through the density difference. In Dyssol Pro you run the unit at the corresponding liquid properties and read the efficiency gain of preheating directly.
How do I troubleshoot vibration in a disk stack separator?
Vibration in a disk stack points to bowl imbalance — uneven sediment deposits, damaged disks, or worn bearings — and is diagnosed mechanically, starting with cleaning and inspection. Simulation contributes prevention: Dyssol Pro predicts the solids load and discharge duty, so the bowl is not run into the loading that creates uneven deposits.
How can I model centrifugal clarification of fine suspensions?
Centrifugal clarification is described by a grade efficiency over particle size and density, derived from settling in the rotating channels — with a hindered-settling correction when the suspension is concentrated. That is exactly the Dyssol Pro disk-separator unit, returning clarified-liquid quality and sediment load inside the connected flowsheet.