Vertical vs. horizontal pile cloth disc filter
The filtration principle, the pile cloth media, the achievable effluent quality and the vacuum backwash are identical in both configurations. What differs is how the discs are arranged in space — and therefore which building or basin they will fit into. This is a geometry decision, not a process decision.
The options at a glance
Vertical disc filter (RF-VCF)
The discs are mounted vertically on a horizontal shaft, side by side. Filter area grows by adding discs along the shaft.
Strengths
- Smallest plan area per m² of filter area — the standard tertiary configuration
- Scales simply by adding discs to the same shaft
- Well suited to deep rectangular tanks and existing clarifier structures
- Compact for containerised and skid-mounted installations
Limitations
- Needs sufficient water depth and headroom above the tank for disc removal
- A tall installation in a low building can be a constraint
Best suited for
Restricted plan area, deep tanks, retrofits into existing basins, container solutions.
Horizontal disc filter (RF-HCF)
The discs are mounted horizontally, stacked in a shallow arrangement. Filter area grows across the plan area rather than in height.
Strengths
- Very low overall height — fits into buildings with limited headroom
- Suits shallow existing channels and basins
- Good top access to the cloth segments for inspection
- Low centre of gravity, simple foundation requirements
Limitations
- Larger plan area for the same filter area
- Less convenient where land is the constraint rather than headroom
Best suited for
Low buildings, shallow channels and basins, plants where headroom rather than plan area is the limiting dimension.
Criteria compared
| Criterion | Vertical disc filter (RF-VCF) | Horizontal disc filter (RF-HCF) |
|---|---|---|
| Filter area per disc | Up to 5 m² | Up to 5 m² |
| Hydraulic capacity per disc | Up to 50 m³/h | Up to 50 m³/h |
| Achievable effluent quality | Identical | Identical |
| Plan area required | Small | Larger |
| Overall height | Higher | Low |
| Required water depth | Greater | Shallow |
| Retrofit into deep clarifier | Ideal | Possible |
| Retrofit into shallow channel | Difficult | Ideal |
| Access for cloth replacement | From above, disc by disc | From above, good access |
| Containerised installation | Preferred | Possible |
Decision guide
Land is tight but the tank is deep.
Vertical (RF-VCF).
The building has limited headroom.
Horizontal (RF-HCF).
You are retrofitting into an existing secondary clarifier.
Vertical in almost all cases.
You are placing the filter into an existing shallow channel.
Horizontal.
The unit goes into a container or on a skid.
Vertical — the more compact arrangement per m² of filter area.
Our conclusion
Choose by the dimension that constrains you. Vertical disc filters are the default because plan area is usually the scarce resource. Horizontal disc filters exist for the case where height is the scarce resource — and in that case they are the only sensible option.
Frequently asked questions
Is the effluent quality different between the two?
No. Both use the same pile cloth media, the same outside-in flow and the same vacuum backwash. Achievable TSS and phosphorus values are identical; the choice is driven by geometry.
Can I mix both configurations on one site?
Yes, and it happens where different parts of a plant have different structural constraints. Spare parts, filter cloths and control philosophy remain the same, which keeps stockholding simple.
Which is easier to maintain?
Both are maintained from above and cloth segments are replaced individually. The horizontal arrangement gives slightly more comfortable access; the vertical arrangement requires less walking around the unit.
Data basis
Based on the RF-VCF and RF-HCF series data: up to 5 m² filter area and up to 50 m³/h hydraulic capacity per disc, modular configuration.
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