Vacuum Belt Dewatering Filter Cloth
Vacuum belt dewatering filter cloth is replacement filter cloth, supplied as an endless belt, for the dewatering duty on rubber-belt vacuum filters — the last vacuum zone, where residual moisture is pulled out of a cake that has already been formed and washed.
The duty is the distinction — the product line is a question we have not answered
On a rubber-belt vacuum filter the cloth is not the belt that carries the load. It rides on a grooved rubber transporter, which carries vacuum through its drainage grooves; the cloth holds the cake and lets filtrate through. Slurry is fed at one end, the cake forms under vacuum, wash stages displace the liquor it was formed in, a final dry zone pulls air through the cake, and the cake releases at the discharge roller while the cloth is washed on its return run. That is one machine doing four jobs in series, and one endless belt passing through all of them.
So when the market says dewatering cloth rather than filtration cloth, it is not naming a different machine. It is naming which of those four jobs the specification is being tuned towards. A filtration and washing duty is judged on filtrate clarity and on how evenly wash water displaces liquor through the cake. A dewatering duty is judged on how much moisture is left in a cake that has already been washed. Those two questions do not always want the same weave, the same surface finish or the same open area — which is why the two phrases exist at all.
What we are not going to do on this page is tell you whether that makes them one product or two in our range. That is a fact about our mill, and it belongs to the factory specification package we have not received in writing. Claiming it either way would be a guess dressed as a catalogue entry.
This site also has a page for horizontal vacuum belt filter cloth. The two pages describe the same machine family and different duty emphases. We are deliberately not asserting that they are the same product, and deliberately not asserting that they are different ones. Send the duty and the machine; the answer is confirmed during the engineering review.
Ask which one your circuit needs →Rubber-belt vacuum filters, the OEM families observed in this service
These 5 families are the ones our equipment map records in flue-gas desulphurisation service. Evidence level is printed as we found it and is not upgraded to make the table look better.
| OEM family | Published size | Duty observed | Evidence level |
|---|---|---|---|
| FLSmidth EIMCO Extractor | Up to ~257 m² heritage | FGD, minerals | OBSERVED trade |
| Compositech T-REX / Chemifilter | ~4 m FGD class | FGD, chemicals US | OBSERVED |
| EKCP EIMCO-KCP | 5–200 m² | IN FGD + phosphate | OBSERVED |
| Toncin DU | DU tables 10–88 m² class | CN FGD, mining, Li | Company-reported |
| WesTech HBF | UNKNOWN public mix | Minerals, FGD directories | PARTIAL |
All OEM names are used for compatibility reference only. Cloth form in this family is: Endless belt, clipper / PAD, edge seal. What we need from you to start: Brand + model + width + seam photo.
Indexing and tray vacuum filters carry the cloth differently and are not covered by this page. Two further Metso names appear in the note below: Larox RB is a rubber-belt filter in the family this page does cover — it is absent from the table above only because that table is filtered to flue-gas desulphurisation duty — and Larox PF is a vertical pressure filter, a different machine again.
- BHS BF — Different cloth mechanics — not mapped to our belt range
- Metso Larox RT / Pannevis — Indexing vacuum — do not mix with Larox PF or RB
If that is what you run, say so and we will tell you honestly whether we can help.
Three gypsum duties, kept apart on purpose
Gypsum is where this dewatering emphasis comes up. That is one word covering several different plants, and treating them as interchangeable is how a belt gets specified against the wrong liquor.
FGD gypsum, wet-lime power scrubber
The classic dewatering duty. Scrubber bleed is filtered and washed, and what leaves the belt is a gypsum cake whose handling moisture decides whether it can be stacked, trucked or sold.
Evidence: OBSERVED
Start here → Process detail for this duty →By-product gypsum sold on, wallboard grade
Same operation as above, different buyer: the gypsum company, not the power station. The cake is a saleable product, so residual moisture and residual chloride are contract terms rather than housekeeping.
Evidence: OBSERVED (buyer-side quality discussion)
Start here → Process detail for this duty →Steel-sinter FGD gypsum
Flue-gas desulphurisation on a sinter plant produces its own by-product gypsum. It is a third duty, not the power-station one under another name, and we ask which one you run rather than assume.
Evidence: PARTIAL — public evidence is thinner here than on the utility side, and we say so
Start here → Process detail for this duty →It comes out of a wet-process phosphoric acid plant, not a scrubber, and the literature describes it as fluoride-bearing where the scrubber side is chloride-bearing. It has its own duty page and its own comparison page — phosphogypsum filtration and how the two gypsums differ.
Where the two emphases actually pull apart
The statements below are industry-level filtration engineering — how vacuum belt filters behave, not measurements of our cloth. They are here so you can judge whether we understand your circuit before you spend time on an enquiry.
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Air flow at the dry zone against particle retention
Once the cake has broken through, residual moisture on a vacuum filter is governed largely by air drawn through the cake during the dry zone — cake permeability, dry time and vacuum level set what you get. A fabric chosen to retain fines and give a clear filtrate restricts that air. A fabric chosen to pass air freely lets more solids through, at least until the cake itself starts doing the filtering.
Cloth implication: open area is not a quality grade with a better and a worse end. It is a trade-off, and which side you want depends on which stage you are being judged on.
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Cake release and back-wetting at the discharge roller
On a dewatering duty the cake leaving the belt is the thing you were trying to produce. Carry-over and cake picking moisture back up at discharge cost more here than they do on a duty whose product is the filtrate.
Cloth implication: surface finish and calendering are the levers on release behaviour, and they interact with discharge geometry — it is rarely one or the other alone.
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Even cake formation, because wash cannot fix a cracked cake
Wash water follows the path of least resistance. If the cake cracks or forms unevenly across the belt, wash channels through the cracks instead of displacing liquor, and the chloride or soluble load stays in the cake regardless of how many wash stages the machine has.
Cloth implication: on a duty where the washed cake is sold under a specification, cake formation behaviour — a weave and finish question — is upstream of the wash result.
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Blinding, which closes the dry zone first
Free area closes progressively as fines and precipitated scale lodge in the fabric. On a dewatering duty the first thing you notice is not a clear failure but cake coming off the belt wetter than it used to, while the machine looks fine.
Cloth implication: weave geometry and finish set how fast a fabric closes, and how much of it the cloth wash recovers on the return run.
Candidate polymers across this machine family, at industry level, are PET monofilament, PET monofilament/multifilament combinations, polypropylene, multi-layer weave constructions, and hydrolysis- or alkali-resistant specialities. Which of those is right for your liquor is decided from your chemistry, and which of them we can supply is confirmed during the engineering review — it is not published yet. Put your duty in front of an engineer →
Parameters
Our factory specification package has not been confirmed in writing, so every own-mill parameter reads UNKNOWN. Each one is fixed against your machine and your liquor during the engineering review and stated in the quotation. An empty cell here is the honest answer; a plausible-looking number would not be.
Confirmed against your duty — not published in advance
| Parameter | Value | Unit | How it is fixed |
|---|---|---|---|
| Polymer | UNKNOWN | — | Confirmed against the liquor your cake is washed with |
| Weave / construction | UNKNOWN | — | Confirmed against cake formation and the dry-zone duty |
| Open area / air flow at the dry zone | UNKNOWN | — | Confirmed against your dewatering requirement, not chosen from a table |
| Air permeability | UNKNOWN | L/dm²/min | Test method and test pressure will be stated with the value, once the mill confirms them in writing |
| Fabric weight | UNKNOWN | g/m² | Reported with the value, once confirmed in writing |
| Surface finish / calendering | UNKNOWN | — | Confirmed against cake release at the discharge roller |
| Seam type | UNKNOWN | — | Confirmed against the machine and a close-up photo of your joint |
| Edge treatment | UNKNOWN | — | Confirmed against the machine edge seal |
| Max fabricated width | UNKNOWN | mm | Confirmed against machine width and the fabrication limit |
| Continuous temperature limit | UNKNOWN | °C | Confirmed per polymer and finish |
| Chemical limit (chloride-bearing liquor) | UNKNOWN | — | Confirmed per polymer and finish |
Air permeability and tensile figures mean nothing without the test method and test pressure printed next to them. We will publish the method name with the value, and not before.
Industry reference — a statement about machines, not about us
| Parameter | Industry reference | Unit | Note |
|---|---|---|---|
| Belt width seen across this machine family | 4.5–4.8 m | — | Upper end observed on OEM machines in the rubber-belt family. A statement about the machine population, not about what our mill can make. |
There is exactly one row here because there is exactly one parameter in the published record we hold that is backed well enough to print. The table is short on purpose.
Filter Cloth Specification Guide
Every parameter reading UNKNOWN above is explained in the guide: what it governs, how it is measured, and what has to be known about a dewatering duty before it can be fixed.
Fifteen pages on how a filter cloth specification is built and read: the polymer envelope, yarn form, weave and finish, the four seam constructions drawn out, edge treatments, how to read an air permeability figure, and the full parameter set. It is the methodology edition: every value in it is industry reference — published polymer properties, limits the machines impose, and public test methods. None of it is our mill's own confirmed data, and a parameter edition carrying our values follows when the mill confirms them in writing.
Fit is earned by data
No verified fit record yet for this machine family on our cloth. Send your dimensions to start one.
There are no verification records on this duty to show, so none are shown. Status moves up on evidence only — your confirmed dimensions first, then a recorded trial result, then repeat production use. The full ladder and what each rung means →
The list that turns an enquiry into a quotation
Every belt is built to your machine dimensions — width, circumference, seam and edge treatment, and any perforation or drainage pattern your old belt carries. We quote per RFQ; there is no online checkout, because there is no stock size to sell you.
| What to confirm | How to get it |
|---|---|
| Machine brand and model | Off the nameplate. “Unknown” is a real answer and does not stop a quotation. |
| Belt width and length | Measured off the old cloth, not off the rubber transporter. |
| Seam type you run now | A close-up photo of the joint answers this faster than a word does. |
| Photos of the old cloth, face and back | Plus wherever it failed. This is the single most useful thing you can send. |
| Which gypsum this is | Power-station FGD, by-product gypsum sold on, or steel-sinter FGD. These are three duties. |
| What the cake has to reach | The moisture figure the cake is judged against downstream, and who judges it. |
| Where the cake goes next | Stack, landfill, or sold to a gypsum buyer under a specification. |
| What failed last time | Wet cake, blinding, tracking, seam leak, or short life — they lead to different fixes. |
Not sure how to take the dimensions off a belt that is still on the machine? The measuring guide walks through width, circumference and identifying your seam: how to measure your old belt.
Why a dewatering belt comes off
A belt that comes off early is rarely a pure cloth problem. Root cause splits between the cloth, the machine and the process, and a replacement belt will not fix a machine fault — we will say so when that is what we think it is.
Seam and joint leakage
A clipper or PAD joint opens and vacuum drops as it crosses each box. On this duty it shows up in the cake: wetter at discharge, on a cycle that matches the belt.
Tracking and wrinkling
The belt wanders on the grooved transporter, contacts the edge guides and the vacuum seal starts leaking. Fabricated length and seam squareness feed into it as much as roller alignment does.
Cloth life on this machine family is duty-specific; published third-party figures range from weeks to months depending on slurry and machine condition. We do not put a life figure on a quotation before seeing your duty, and a supplier who gives you one without asking what you filter is selling rather than engineering.
Photographs of the failed belt, face and back, are worth more than a description. Send them with your measurements →
Before you enquire
Is vacuum belt dewatering filter cloth the same thing as horizontal vacuum belt filter cloth?
They name the same machine family — a rubber-belt vacuum filter. What the two phrases separate is the job the cloth is being asked to do: one emphasises filtrate clarity and wash displacement, the other emphasises getting residual moisture out of a cake that has already been washed. Whether our own range treats those as one belt or two is part of the factory specification package we have not confirmed in writing, so we are not going to claim either answer here. Tell us the duty and the machine and the engineering review answers it for your case.
What do you need to quote a replacement dewatering belt?
Machine brand and model (or “unknown”), belt width and length, a photo of the old cloth and its seam, which gypsum duty this is, and what went wrong last time. Useful but not blocking: slurry temperature, pH, chloride level, particle size distribution, and the cake moisture the plant is held to.
Can one belt cover both the filtration stage and the dewatering stage?
On a single machine the same endless belt does pass through every zone — feed, filtration, wash and dry — so in that sense it already does both. The question that matters is which end of that range the specification is tuned towards, because open area that helps the dry zone is open area that can cost you filtrate clarity. That trade-off is settled against your numbers, not on a product page.
This list grows from enquiries as they arrive. It is not padded out in the meantime, and it is not marked up as structured data until the answers have a source we can point at. More questions across the whole site: the FAQ hub.
Get an engineering quote for a dewatering duty
Three steps after you submit: an engineer checks what you sent against the machine, we come back for anything missing, and you get a quotation or a sample plan.
The form defaults to the power-station FGD duty because that is where our evidence is thickest. If you are on by-product gypsum sold to a wallboard buyer, or on steel-sinter FGD, change the duty in the form — the buyer's own selection always wins over our default.
Samples available — freight terms confirmed per request.
Quality control and the production sequence for this cloth family are described on the factory and quality control page, including which steps are still awaiting written confirmation.
Where to go next
HVBF Filter Cloth
The same machine family described from the filtration and washing side. Weave, polymer, seam, edge and width.
FGD Gypsum Vacuum Belt Cloth
The cloth page written specifically around flue-gas desulphurisation gypsum.
FGD Gypsum Dewatering
The process side: what happens across the belt, stage by stage, and what makes the duty hard.
Machine Compatibility
Every OEM family we have recorded, with the evidence level held on each one.