Hulpapparatuur
Een zink-drijf-scheidingstank scheidt gemengde kunststofvlokken op basis van soortelijk gewicht in een gecontroleerd waterbad. Rumtoo ontwerpt de tank rond uw werkelijke voeding (PET-flessen, PEHD-kannen, PP-doppen, folie, PVC), de gewenste zuiverheid en het waterhergebruik.
Scroll
Tank volume alone never predicts real-world purity. The machine must be matched to the feed density spread, flake size, contamination load and water-reuse target — here is the selection path that actually works.
Lijst elke polymeer: PE 0,91-0,94, PP 0,85-0,91, PET 1,38-1,40. Bij een verschil <0,02 g/cm³ voegt Rumtoo hydrocycloon of elektrostatische trappen toe.
Verblijftijd van 60–120 seconden is optimaal. Rumtoo dimensioneert de tank zodat vlokken met 0,05–0,10 m/s reizen.
Rumtoo specificeert een bezinktank en DAF-lus zodat 70–85% van het water wordt hergebruikt en slib als droge koek wordt afgevoerd.
De tank werkt stabiel dankzij integratie met de rest van de lijn, waardoor papiervervuiling stroomafwaarts tot een minimum wordt beperkt.
The business reason to install a sink float tank is not the technology — it is a measurable jump in PE/PP and PET purity, a lower reject rate at the extruder, and a closed water loop that avoids wastewater permits and 30–50 m³/day of fresh water consumption.
Typische zuiverheid van 98–99% per passage. Twin-tank ontwerpen met pekel-aanpassing halen 99,5%+ voor food-grade rPET.
Aanvullend watergebruik daalt naar 3–5 m³ per ton, wat tienduizenden euro per jaar bespaart aan waterkosten en lozingsrechten.
Dit is de cruciale stap die PVC en papier verwijdert vóór de extruder. Filterwissel-intervallen van de extruder verdrievoudigen doorgaans.
Rumtoo schaalt tanklengte en skimmersnelheid. Een 5000 kg/u lijn past in ongeveer 18 meter met een laag slibvolume.
Most poor-separation reports trace back to five production conditions — not the tank itself. This table shows what actually goes wrong in running lines and how Rumtoo corrects it during commissioning.
PET pellets float instead of sink — extruder rejects rPET for PVC contamination.
Rumtoo adds a short de-foaming baffle and lowers paddle speed; most "PET floating" cases are actually entrained air in thin bottle-wall flakes. Persistent cases get a brine dosing line that lifts water density to 1.05 g/cm³ for a guaranteed PET-PS separation.
Water turns gray, filters clog within two shifts and discharge fails limits.
Rumtoo sizes the sedimentation tank, bag filter and DAF loop so fine label, paper and glue particles are removed continuously. Sludge is de-watered to 60–70% solids in a screw press instead of being pumped out as liquid.
Paddle agitators foul with film and rope — tank shuts down twice a week for cleanout.
Rumtoo specifies an upstream trommel and film-rope separator so ribbons and long strands never reach the tank. Paddle geometry is adapted (cut-blade vs flat paddle) to the dominant flake shape in your feed.
Winter start-up produces black sludge and foul odor from caustic carry-over.
Rumtoo isolates the hot-wash caustic loop from the sink float bath with a rinse buffer tank and specifies a weekly tank drain/scrub SOP. A pH and turbidity sensor warns before biological growth crosses odor thresholds.
Gemengde vlokken komen in een waterbad waar peddel-agitators en een dwarsstroom fracties met lage dichtheid (PE/PP, 0,90–0,94 g/cm³) naar een skimmer leiden, terwijl zware vlokken (PET, PVC, metalen) zinken en via een bodemvijzel worden afgevoerd.
De tank is gebouwd van RVS 304 of 316L om bestand te zijn tegen loogresten. Peddels houden het bad in beweging tegen klonteren; een oppervlakeskimmer voert de drijvende fractie af; een bodemvijzel voert zware vlokken af met minimaal waterverlies.
In een PET-lijn staat de tank na de labelverwijderaar. Doppen (PEHD/PP) drijven; PET en PVC zinken. In een PEHD/PP-lijn is het omgekeerde het geval. De tank verwijdert de verkeerde polymeren vóór de warmwas om de extruder en warmtewisselaars te beschermen.
Watch how the paddle agitator, weir skimmer and sinking screw conveyor separate mixed plastic flakes into pure PE/PP floating fraction and PET/PVC sinking fraction in a controlled water bath.
A sink float tank earns its place in any plastic washing line where the target and contaminant polymers differ by at least 0.05 g/cm³ and the feed is already wet from pre-wash.
Removes HDPE caps, PP rings, paper label fragments and PLA sleeves from PET flakes before hot wash. Critical stage for lines targeting food-grade rPET approval from EFSA, FDA or similar regulators.
Separates PP caps, PET tamper bands, metal fines and dirt from HDPE flakes produced from milk, detergent and motor-oil bottles. Prepares HDPE flakes for pipe, crate and packaging compounders.
Splits PP from residual PET, PVC tamper bands and PS labels coming off food tubs, buckets and cap regrind so compounders receive a single-polymer feedstock.
Acts as the first bulk density stage for mixed post-consumer curbside input, routing a clean PE/PP float fraction to pelletizing while high-density material is sent to NIR, electrostatic or manual picking.
Paired with a pre-wash, the tank floats LDPE film fragments while soil fines, stones and metal wear particles sink — reducing extruder melt filter changes by 2–3×.
Used as a rough density splitter ahead of electrostatic separation to remove metals, glass fragments and rubber from ABS/PS/HIPS-dominant WEEE and automotive shredder residue feeds.
These are sizing references. Actual purity, water reuse and sludge volume depend on feed composition, contamination level and the filtration loop selected — Rumtoo confirms the final specification after reviewing your material data.
| Model | Throughput | Tank Volume | Power | Key Features |
|---|---|---|---|---|
| RT-SF500 | 300–500 kg/h | 2.5 m³ | 3 kW | Compact single-stage tank, 304 stainless, for small PET or HDPE lines |
| RT-SF1000 | 800–1200 kg/h | 5 m³ | 5.5 kW | Paddle agitator + weir skimmer, bag filter loop, suits standard PET bottle washing lines |
| RT-SF2000 | 1500–2500 kg/h | 9 m³ | 7.5 kW | Twin-tank with brine adjustment, DAF loop, 70–80% water reuse |
| RT-SF5000 | 3500–5000 kg/h | 18 m³ | 15 kW | Bottle-to-bottle grade twin-tank, 316L, DAF + screw press, 80–85% water reuse |
Typical water make-up with a full reuse loop is 3–5 m³ per ton of clean flake. Energy consumption is 20–35 kWh per ton including agitators, pumps and filtration. Rumtoo sizes the unit after reviewing your feed analysis, contamination level and local water and discharge cost.
Bring these data points to the RFQ and Rumtoo can size the tank, water-reuse loop and commissioning protocol in the first reply — avoiding weeks of back-and-forth.
List every polymer in the feed with its approximate share — PET, HDPE, PP, PVC, PS, PA, metals — so Rumtoo can confirm the cut-point target and decide whether plain water, salt brine, or a two-stage tank is required.
Share the flake size distribution (typical working range is 6–30 mm), shape (flake vs film vs granule) and fines content below 4 mm. Particle size controls paddle speed and retention time.
Specify the expected contamination per ton — paper label, PE/PP film, paper pulp, sand and metal fines. This determines filtration, sludge press sizing and tank cleaning frequency.
Provide target kg/h, planned shift hours and scheduled cleaning windows. Rumtoo builds around a realistic effective uptime, not name-plate capacity.
Share local water cost, discharge cost and effluent limits (COD, TSS, pH). The water-reuse loop is sized for the economic break-even between make-up water cost and capex.
Describe the full line — what comes before and after the tank. Rumtoo adjusts the cut-point, skimmer angle and discharge method so the tank integrates with existing hot-wash, friction and polishing stages.
A sink float tank is the right answer when the density gap is clear and the feed is already wet. This table shows where it wins and where a hydrocyclone, electrostatic separator or NIR sorter fits better.
| Decision Criteria | Hydrocyclone | NIR Optical Sorter | Electrostatic Separator | Rumtoo Sink Float Tank |
|---|---|---|---|---|
| PE/PP vs PET bulk separation | Good, but high capex | Works if colors differ | Needs pre-drying | Proven at 98–99% in one pass |
| Food-grade bottle-to-bottle rPET | Works as polishing stage | Works upstream of wash | Final PVC-ppm stage | Essential bulk stage, add electrostatic for <50 ppm |
| Handles paper, label and film fines | Poor | Not designed for this | Blocks the field | Removes them continuously |
| Water consumption | Very high, high pressure | None | None | 3–5 m³/ton with reuse loop |
| Energy per ton | 40–60 kWh + pump pressure | 10–15 kWh | 30–50 kWh | 20–35 kWh including filtration |
| Capex vs operating cost | High capex, high opex | Very high capex, low opex | Medium capex, low opex | Low-medium capex, low opex |
Niet alleen, omdat hun dichtheden overlappen (1,35–1,45 g/cm³). De tank verwijdert PE/PP, maar voor food-grade <50 ppm PVC voegt Rumtoo elektrostatiek of optiek toe.
Scheiding vindt plaats bij 25–40 °C. Rumtoo gebruikt vaak restwarmte van de warmwas via een warmtewisselaar om energie te besparen.
Stuur Rumtoo een voedinganalyse. We sturen binnen 24 uur een ROI-model en inbedrijfstellingsplan.
Offerte Zink-Drijf-Tank Aanvragen