Filtration Testing and Trials
Quick answer: Send us a sample of your slurry and we will run a filtration test on it before anyone quotes a machine. The test tells you the cake moisture you can actually reach, how long a cycle takes, which cloth suits your material and what size press that implies — instead of a number taken from a catalogue.
Why test instead of quote from a description
Filter press sizing depends on how fast your specific material releases water. That depends on particle size distribution, solids concentration, chemistry and conditioning — none of which can be read off a product name. Two plants with identical tonnage routinely need different machines.
A supplier who quotes a model number from a one-line description is guessing. Sometimes the guess is close. When it is not, you find out after the machine is installed, which is the expensive moment to discover it.
What the test tells you
- Achievable cake moisture — measured on your material, with and without membrane squeeze where relevant.
- Cycle time — filtration rate, and how it changes as the chamber fills.
- Cloth recommendation — polymer, weave type and air permeability that suit your solids, with cake release behaviour observed rather than assumed.
- Whether conditioning helps — and roughly how much, if flocculant or coagulant is part of the answer.
- Implied machine size — chamber volume and plate count needed to meet your daily throughput at the observed cycle time.
- Whether a filter press is the right choice at all — sometimes a screw press or better upstream thickening is the honest recommendation.
What to send
A representative sample matters more than a large one. A sample skimmed off the top of a settled tank tells us about the top of the tank, not about your process.
- Volume: a few litres of slurry is usually enough. Tell us what you can supply and we will confirm.
- Condition: as it arrives at the dewatering stage — not dried, not decanted, not pre-treated unless that is what your plant does.
- Sealed and labelled, with a safety data sheet where the material requires one.
Information to send with it
The sample answers how it filters. These answer what it has to achieve:
- What the material is and which process produces it
- Daily volume or tonnage, and whether it is batch or continuous
- Feed solids concentration, if you measure it
- pH and temperature at the dewatering stage
- Any conditioning chemicals already dosed, and the dose rate
- The cake dryness you need to reach, and why — landfill acceptance, transport cost, sale specification or downstream process
Before you ship anything
Contact us first with the material description. Some materials are restricted for international shipment, and for hazardous or regulated waste there may be a better route than posting a sample — in some cases test data you already hold, or a test run locally, answers the question without a shipment. We will tell you which applies to your case, along with timing and any cost, before you send anything.
If you cannot send a sample
Selection is still possible from data, just with wider margins. Existing filtration or settling test results, historic cake moisture figures from equipment you already run, or a detailed process description let us give a reasoned recommendation — we will simply be explicit about which parts are measured and which are estimated.
Frequently asked questions
What will the test report contain?
The measured filtration behaviour of your sample, the cake moisture achieved, the cloth we recommend and why, and the machine size that follows from those numbers at your stated throughput.
How much sample do you need?
A few litres is normally sufficient for a filtration test. Send us the material details and we will confirm the volume before you ship.
How long does it take?
It depends on the material and how much conditioning work is needed — a straightforward mineral slurry is quick, a biological sludge needing conditioning trials takes longer. We will give you a timeframe when you describe the material.
Is the test free?
Tell us what you are dewatering and we will confirm the terms up front. We would rather be clear about this before you ship a sample than surprise you afterwards.
What if the test says a filter press is the wrong machine?
Then we will tell you that. A press sold into an application it does not suit generates complaints, not repeat business.
Start here
Describe what you are dewatering — material, volume, and the cake dryness you need — and we will tell you whether a test is worth doing and how to send the sample. Contact us.
Not sure which application you fall under? See filter press applications by industry.