This what size filter press do i explains what to check before you buy, so you can compare options with confidence.
Short answer: To size a filter press, calculate the dry solids you must remove per day, convert that into wet cake volume, divide by the number of cycles you can run per day, and match the result to a chamber volume. Most industrial jobs land between 100 L and 5,000 L of total chamber volume.
Filter press capacity is sold in chamber volume (litres), not in slurry flow rate. That is the single point most first-time buyers get wrong. A press rated 630 L does not process 630 L of slurry per hour; it holds 630 L of filter cake per cycle. Two plants feeding the same 40 m³/day of slurry can need presses that differ by 4x, purely because one slurry is 1% solids and the other is 5%.
Everything below is the arithmetic a supplier runs before quoting you. Doing it yourself takes ten minutes and stops you from buying a machine that is 40% too small.
What Size Filter Press Do I: How do you calculate the filter press size you need?
Use four steps. You need three inputs: daily slurry volume, solids concentration by weight, and expected cake dryness.
- Dry solids per day (kg) = slurry volume (m³/day) × slurry density (kg/m³) × solids % by weight.
- Wet cake mass (kg) = dry solids ÷ cake dry-solids fraction.
- Wet cake volume (m³) = wet cake mass ÷ cake bulk density (typically 1,100–1,600 kg/m³).
- Chamber volume per cycle (L) = wet cake volume ÷ cycles per day, × 1,000. Add 20–30% margin.
Worked example: 40 m³/day of 3% wastewater sludge
- Dry solids: 40 × 1,020 × 0.03 ≈ 1,200 kg/day
- Cake at 35% dry solids: 1,200 ÷ 0.35 ≈ 3,430 kg/day wet cake
- At 1,300 kg/m³ bulk density: 3,430 ÷ 1,300 ≈ 2.64 m³/day
- Running 16 h/day with a 2 h cycle = 8 cycles/day → 2.64 ÷ 8 = 330 L per cycle
- Add 25% margin → 410 L chamber volume → about 20 chambers of 1000 × 1000 mm plates
If your cake only reaches 28% dry solids instead of 35%, the same plant needs roughly 515 L — 25% more machine. This is why cake dryness must be confirmed by a lab or pilot test, not assumed. A membrane filter press squeezes the cake after filling and typically lifts dry solids by 5–10 percentage points over a standard recessed chamber, which can let you buy a smaller frame.
What plate size should I choose?
Plate size sets the cake volume per chamber and the footprint. Larger plates mean fewer chambers, faster plate shifting, and lower cost per litre — but a higher minimum order size. The table below gives typical values at 30 mm cake thickness; confirm exact figures against the manufacturer's general-arrangement drawing.
| Plate size (mm) | Filtration area per chamber | Cake volume per chamber | Typical chamber count | Typical total chamber volume |
|---|---|---|---|---|
| 630 × 630 | ~0.5 m² | ~7 L | 20–60 | 140–420 L |
| 800 × 800 | ~0.9 m² | ~13 L | 30–80 | 390–1,040 L |
| 1000 × 1000 | ~1.4 m² | ~21 L | 40–100 | 840–2,100 L |
| 1250 × 1250 | ~2.2 m² | ~33 L | 50–120 | 1,650–3,960 L |
| 1500 × 1500 | ~3.2 m² | ~48 L | 60–150 | 2,880–7,200 L |
| 2000 × 2000 | ~5.8 m² | ~87 L | 80–150 | 6,960–13,050 L |
As a rule of thumb: under 500 L, use 630–800 mm plates. Between 500 and 2,000 L, 1000–1250 mm is usually the lowest cost per litre. Above 3,000 L, 1500–2000 mm plates are standard, and a plate shifter stops becoming optional. See our chamber filter press range for the sizes we build most often.
How many cycles per day can a filter press run?
A standard chamber filter press completes a cycle in 1.5 to 4 hours; a membrane press with air squeeze typically runs 45 to 120 minutes. A cycle is fill, filter, (squeeze), air blow, open, discharge, close.
The number that matters is cycles per operating day, not per 24 hours. A plant staffed one shift (8 h) at a 2 h cycle gets 4 cycles — half the capacity of the 16 h example above, so it needs double the chamber volume. Manual plate opening also adds 15–40 minutes per cycle on a 60-plate machine, which is why a fully automatic filter press often pays for itself on labour alone above 40 plates.
Slurry filterability drives filtration time more than anything else. Fine, compressible material such as clay or biological sludge filters slowly; coarse mineral concentrate filters quickly. Never accept a cycle-time promise that is not backed by a filtration test on your material.
What happens if I undersize or oversize the filter press?
Undersizing is the more expensive mistake. Options are all bad: run extra shifts, thin the cake, or buy a second press — and retrofitting more chambers is only possible if the frame was ordered with spare length.
- Undersized: cake backs up, operators shorten filtration time, cake leaves wetter, disposal cost per tonne rises. Wet cake at 25% dry solids costs about 40% more to truck away than cake at 35%.
- Oversized: higher capital cost, more filter cloths to replace, and chambers that never fill produce thin, poorly formed cake that sticks to the cloth.
The practical fix is to order the frame with 20–30% spare length so chambers can be added later, and confirm this in writing before the contract. Our filter press cost guide covers how much that spare capacity typically adds to the price.
How much floor space does a filter press need?
Allow roughly twice the machine length and 2.5–3 m of headroom above the discharge point. A 1000 mm, 60-chamber press is typically about 5.5–6.5 m long, 1.8 m wide and 1.7 m high, and needs 1.5–2 m of clear space at the closing end for plate shifting plus room to withdraw plates for cloth changes.
Below the press you need clearance for a cake bin or conveyor. Presses are usually installed on a raised steel platform or concrete plinth for this reason. Add the feed pump, air compressor and filtrate tank to your layout — they are commonly forgotten and typically take another 6–10 m².
Sizing checklist before you request a quote
Send a supplier these six items and you will get an accurate quotation instead of a generic one:
- Slurry volume per day and per batch (m³)
- Solids concentration by weight (%) and particle size distribution
- Material name, pH and temperature
- Target cake dry solids (%)
- Operating hours per day and days per week
- Available floor area, headroom and power supply (voltage/frequency)
For material compatibility and weave selection, which affects both cycle time and cake release, see our filter press cloth guide. For a broader overview of press types, start with the filter press guide or the comparison of plate and frame vs chamber vs membrane presses.
Frequently asked questions
How do I convert m³/day of slurry into filter press size?
Multiply slurry volume by density and solids percentage to get dry solids per day, divide by cake dry-solids fraction to get wet cake mass, divide by cake bulk density (1,100–1,600 kg/m³) to get cake volume, then divide by cycles per day. Add 20–30% margin. Slurry flow rate alone cannot size a press.
What is a typical filter press cycle time?
A standard chamber filter press takes 1.5 to 4 hours per cycle. A membrane filter press with air squeeze usually completes a cycle in 45 to 120 minutes. Actual time depends on slurry filterability, feed pressure and cake thickness, and should be confirmed by a filtration test on your material.
How many chambers do I need in a filter press?
Divide your required chamber volume per cycle by the volume of one chamber. At 30 mm cake thickness, a 1000 × 1000 mm chamber holds about 21 L, so 410 L needs about 20 chambers. Order the frame with 20–30% spare length so chambers can be added later.
Does a membrane filter press let me buy a smaller machine?
Often, yes. Membrane squeezing typically raises cake dry solids by 5–10 percentage points versus a standard recessed chamber. Drier cake means less wet cake volume per kilogram of dry solids, so the required chamber volume falls. It also shortens cycle time, which raises cycles per day.
What cake thickness should I design for?
Most industrial presses use 25–32 mm chambers, with 30 mm as the default. Thicker cake means more volume per chamber but longer filtration time and wetter cake centres. Thin chambers (20–25 mm) are used for slow-filtering, highly compressible material such as biological sludge or fine clay.
What information does a manufacturer need to size a press correctly?
Slurry volume per day, solids concentration by weight, particle size, material name, pH and temperature, target cake dryness, operating hours per day, and available floor space and power supply. A slurry sample for a filtration test is the single most useful thing you can provide.
About Senjie
Senjie is a China-based manufacturer of filter presses and filter cloth, supplying chamber, membrane and plate-and-frame presses for mining, wastewater, chemical and food processing. We build presses from 630 mm to 2000 mm plate sizes and manufacture the filter cloth in-house. Send us your slurry data using the checklist above and we will return a sizing calculation and a general-arrangement drawing.
Further reading: Filter press (Wikipedia) and Dewatering (Wikipedia).
By Senjie Engineering Team — Last updated: July 14, 2026
Note: chamber volumes, filtration areas and dimensions in this article are typical industry values at 30 mm cake thickness and are given for sizing estimates only. Confirm exact figures against the manufacturer's drawing for your specific model.
Browse our full filter press product range or contact our engineers for a configuration recommendation.
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