{"id":14230,"date":"2026-05-29T00:33:41","date_gmt":"2026-05-29T07:33:41","guid":{"rendered":"https:\/\/www.recyclemachine.net\/"},"modified":"2026-05-29T00:33:42","modified_gmt":"2026-05-29T07:33:42","slug":"cum-sa-determinam-dimensiunea-unui-rezervor-de-separare-prin-flotare","status":"publish","type":"post","link":"https:\/\/www.recyclemachine.net\/ro\/cum-sa-determinam-dimensiunea-unui-rezervor-de-separare-prin-flotare\/","title":{"rendered":"Cum s\u0103 dimensionezi un rezervor de separare prin scufundare-plutire pentru linia ta de reciclare"},"content":{"rendered":"<p>Most sink-float separation tanks are bought on a single number \u2014 a target throughput in kg\/h \u2014 and that is exactly why so many of them underperform once real post-consumer material starts flowing. A tank that looks correctly sized on paper can still hand you contaminated flake, runaway water bills, or a sludge problem nobody planned for. Sizing a sink-float tank well means matching it to your <em>feedstock behavior<\/em>, your <em>purity target<\/em>, and the <em>machines on either side of it<\/em> \u2014 not just to a capacity figure. This guide walks through how to do that before you issue an RFQ.<\/p>\n<h2>What a sink-float tank actually does (and what it can\u2019t)<\/h2>\n<p>A sink-float separation tank \u2014 also called a float-sink tank, float washing tank, or floating washer \u2014 separates plastics purely by density relative to water (1.0 g\/cm\u00b3). Lighter-than-water polymers float and are skimmed off the surface; denser polymers and heavy contaminants sink and are dragged out at the bottom. There are no screens or sensors deciding the split \u2014 gravity and buoyancy do the work, which is why the tank is so reliable and cheap to run, and also why it has a hard limit.<\/p>\n<figure class=\"wp-block-table\">\n<table>\n<thead>\n<tr>\n<th>Material<\/th>\n<th>Densitate (g\/cm\u00b3)<\/th>\n<th>Behavior in water<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>PP<\/td>\n<td>0,90\u20130,92<\/td>\n<td>Floats<\/td>\n<\/tr>\n<tr>\n<td>PE (HDPE \/ LDPE)<\/td>\n<td>0.91\u20130.96<\/td>\n<td>Floats<\/td>\n<\/tr>\n<tr>\n<td>PS<\/td>\n<td>1.04\u20131.07<\/td>\n<td>Sinks<\/td>\n<\/tr>\n<tr>\n<td>ABS<\/td>\n<td>1.04\u20131.07<\/td>\n<td>Sinks<\/td>\n<\/tr>\n<tr>\n<td>PET<\/td>\n<td>1,38\u20131,40<\/td>\n<td>Sinks<\/td>\n<\/tr>\n<tr>\n<td>PVC (rigid)<\/td>\n<td>1.35\u20131.45<\/td>\n<td>Sinks<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n<p>The takeaway for sizing: a water tank cleanly splits floaters (PP\/PE) from sinkers (PET\/PVC\/PS\/ABS), but it <strong>cannot<\/strong> separate two materials that both sink. PET and PVC have overlapping densities, so both go to the bottom together. If your spec calls for sub-50-ppm PVC in rPET, you will need an electrostatic or NIR polishing step <em>after<\/em> the tank \u2014 size for that now, not later.<\/p>\n<h2>Step 1: Profile your feedstock before anything else<\/h2>\n<p>The single most useful thing you can do before sizing is characterize what is actually entering the tank. Three variables matter most:<\/p>\n<ul>\n<li><strong>Polymer mix.<\/strong> A clean PP\/PE float stream behaves completely differently from a mixed rigid post-consumer stream. The wider the density spread you need to capture, the more separation passes you want.<\/li>\n<li><strong>Bulk density and form.<\/strong> Light film and fluff sit on the surface and need strong, well-placed paddles to submerge and convey; heavy rigid flake sinks fast and loads the bottom screw harder.<\/li>\n<li><strong>Contamination load.<\/strong> Paper labels, glue, sand, fines, and organic residue all end up in the water and the sludge. Heavy contamination is the main reason a tank that is \u201cbig enough\u201d on throughput still fails on purity.<\/li>\n<\/ul>\n<p>If you can, run a float-sink test on a representative sample in a bucket of water. It tells you your real float:sink ratio, which directly drives skimmer and bottom-discharge sizing.<\/p>\n<h2>Step 2: Fix your real throughput band \u2014 not your peak<\/h2>\n<p>Throughput should be expressed as a band tied to a specific material, not a single headline number. A tank rated \u201c2000 kg\/h\u201d on clean PP regrind will not hold that rate on wet, contaminated post-consumer PET, because residence time \u2014 how long each flake stays in the water \u2014 is what determines separation quality. Push material through too fast and floaters get dragged down before they surface.<\/p>\n<p>Ca referin\u021b\u0103 pentru planificare, benzile tipice ale ma\u0219inilor cu un singur rezervor se \u00eencadreaz\u0103 aproximativ \u00een:<\/p>\n<ul>\n<li><strong>300\u20131,500 kg\/h<\/strong> \u2014 majoritatea liniilor de sp\u0103lare a filmului \u0219i a sticlelor, curate p\u00e2n\u0103 la moderat contaminat.<\/li>\n<li><strong>1,500\u20133,000 kg\/h<\/strong> \u2014 liniile cu capacitate mai mare \u0219i fluxuri post-consumator foarte contaminat (de obicei un rezervor cu trei r\u00e2nduri, vezi mai jos).<\/li>\n<li><strong>3,500\u20135,000 kg\/h<\/strong> \u2014 fabrici industriale de sticl\u0103 la sticl\u0103, de obicei cu multiple sau rezervori de lungime extins\u0103.<\/li>\n<\/ul>\n<p>Capacitatea real\u0103 depinde \u00eentotdeauna de geometria aliment\u0103rii, densitatea specific\u0103, contaminarea \u0219i c\u00e2t de strict este \u021binta de puritate \u2014 astfel c\u0103 acestea trebuie tratate ca puncte de plecare pentru o conversa\u021bie de inginerie, nu ca garan\u021bii.<\/p>\n<h2>Pa\u0219ul 3: Un r\u00e2nd vs. trei r\u00e2nduri \u2014 decizia care determin\u0103 dimensiunea ocupat\u0103<\/h2>\n<p>Aceasta este de obicei decizia de dimensiune real\u0103. Un rezervor cu un r\u00e2nd permite fiec\u0103rui fragment s\u0103 treac\u0103 o dat\u0103 prin ap\u0103. Un <a href=\"https:\/\/www.recyclemachine.net\/ro\/tehnologia-avansata-a-rezervorului-cu-trei-randuri-de-separare-cu-plutitor-pentru-chiuveta\/\">rezervor de scurgere \u0219i flotare cu trei r\u00e2nduri<\/a> face ca materialul s\u0103 parcurg\u0103 de trei ori distan\u021ba \u0219i s\u0103 se \u00eenmoaie de trei ori mai mult \u00eentr-un singur caroserie, ceea ce \u00eei permite s\u0103 ating\u0103 o puritate mai mare pe alimentare murdar\u0103 f\u0103r\u0103 a alinia trei rezervori separate \u00een serie.<\/p>\n<figure class=\"wp-block-table\">\n<table>\n<thead>\n<tr>\n<th>Criterii<\/th>\n<th>Rezervor cu un r\u00e2nd<\/th>\n<th>Rezervor cu trei r\u00e2nduri<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Banda de randament<\/td>\n<td>300\u20131,500 kg\/h<\/td>\n<td>1,000\u20133,000 kg\/h (o unitate \u00eenlocuie\u0219te ~3 rezervori cu un r\u00e2nd \u00een serie)<\/td>\n<\/tr>\n<tr>\n<td>Pasi de separare<\/td>\n<td>1 pas<\/td>\n<td>3 pasi \u2014 3\u00d7 mai mult\u0103 distan\u021b\u0103 \u0219i timp de \u00eenmuiere<\/td>\n<\/tr>\n<tr>\n<td>Puritate tipic\u0103<\/td>\n<td>98\u201399% \u00eentr-o etap\u0103<\/td>\n<td>99.5%+ chiar \u0219i pe contaminarea post-consumator grea<\/td>\n<\/tr>\n<tr>\n<td>Materie prim\u0103 tipic\u0103<\/td>\n<td>Regrind post-industrial curat; fl\u0103c\u0103ri PET\/HDPE pre-sortate<\/td>\n<td>PET post-consumator foarte contaminat, rigizi amestecate, WEEE, ASR auto<\/td>\n<\/tr>\n<tr>\n<td>Putere instalat\u0103<\/td>\n<td>5.5\u201315 kW<\/td>\n<td>15\u201322 kW<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n<p>Regula de baz\u0103: dac\u0103 \u021binta liniei tale este mai mare de 1,500 kg\/h, sau alimentarea ta provine din balote de curte sau DRS, configura\u021bia cu trei r\u00e2nduri de obicei \u00ee\u0219i recupereaz\u0103 premiumul \u00een primul an prin \u00eembun\u0103t\u0103\u021birea purit\u0103\u021bii \u0219i prin mai pu\u021bine schimb\u0103ri ale ecranelor de filtrare a extruderului \u00een aval.<\/p>\n<h2>Pa\u0219ul 4: Dimensiunea circuitului de ap\u0103 \u0219i a gestion\u0103rii reziduurilor, nu doar a rezervorului<\/h2>\n<p>Rezervorul este partea ieftin\u0103. Sistemul de ap\u0103 \u0219i reziduuri din jurul acestuia este unde se c\u00e2\u0219tig\u0103 sau se pierde costul de operare, \u0219i este adesea subdimensionat.<\/p>\n<ul>\n<li><strong>Water consumption.<\/strong> Without a treatment loop, a tank typically draws 20\u201330 m\u00b3 of fresh water per ton of throughput. Adding a DAF (dissolved air flotation) and sedimentation loop typically cuts that to 3\u20135 m\u00b3 per ton \u2014 up to ~85% reuse. Over a year that difference dwarfs the price gap between tank models.<\/li>\n<li><strong>Sludge.<\/strong> Paper fiber, label glue, fines, and grit have to go somewhere. A dedicated screw press de-waters the sludge into a 60\u201370% solid cake that is cheap to haul away, instead of leaving you with a liquid-waste headache.<\/li>\n<\/ul>\n<p>Specify the water loop and sludge press <em>in the same RFQ<\/em> as the tank. Bolting them on afterward almost always costs more and fits worse.<\/p>\n<h2>Step 5: Place the tank correctly in the wash line<\/h2>\n<p>A sink-float tank is a separation stage, not a standalone machine. It needs the right feed condition coming in and the right handoff going out:<\/p>\n<ul>\n<li><strong>Upstream:<\/strong> material should already be size-reduced and pre-washed. A <a href=\"https:\/\/www.recyclemachine.net\/ro\/masina-de-spalat-cu-surub-de-frictiune\/\">\u0219aib\u0103 de fric\u021biune<\/a> sau <a href=\"https:\/\/www.recyclemachine.net\/ro\/sistem-de-spalare-la-cald-continua-pentru-animale-de-companie-si-fulgi-hdpe\/\">hot wash system<\/a> ahead of the tank removes the bulk of glue and surface dirt so the float-sink split is clean.<\/li>\n<li><strong>Downstream:<\/strong> separated flake still carries water. Plan for dewatering and drying before pelletizing, and \u2014 if you are chasing food-grade rPET \u2014 the electrostatic or optical PVC-removal step mentioned earlier.<\/li>\n<\/ul>\n<p>If you are scoping a full line rather than a single machine, start from the <a href=\"https:\/\/www.recyclemachine.net\/ro\/sisteme-de-spalare-prin-reciclare\/\">washing system<\/a> level and let the tank size fall out of the line target.<\/p>\n<h2>Quick-reference sizing checklist<\/h2>\n<p>Before you send an RFQ, have answers to these:<\/p>\n<ol>\n<li>What polymers are in the feed, and what is the approximate float:sink ratio?<\/li>\n<li>What is the realistic throughput band for <em>that<\/em> material \u2014 not your best-case peak?<\/li>\n<li>What purity does your buyer or extruder actually require?<\/li>\n<li>Is the feed clean post-industrial, or contaminated post-consumer? (This usually decides single- vs triple-row.)<\/li>\n<li>Are water reuse (DAF) and a sludge press included in the scope?<\/li>\n<li>What machine feeds the tank, and what machine receives the separated streams?<\/li>\n<\/ol>\n<h2>Five sizing mistakes that cost you later<\/h2>\n<ul>\n<li><strong>Sizing on peak kg\/h.<\/strong> Residence time, not nameplate capacity, sets purity. Size for sustained rate on your dirtiest realistic feed.<\/li>\n<li><strong>Expecting water alone to remove PVC from PET.<\/strong> It can\u2019t \u2014 both sink. Plan the polishing step up front.<\/li>\n<li><strong>Ignoring the water loop.<\/strong> A tank with no DAF can quietly cost more in fresh water and discharge fees than the tank itself.<\/li>\n<li><strong>Forgetting sludge.<\/strong> No dewatering means a recurring liquid-waste cost and downtime.<\/li>\n<li><strong>Buying the tank in isolation.<\/strong> The wrong upstream wash or downstream dryer makes a perfectly sized tank look like it failed.<\/li>\n<\/ul>\n<h2>Frequently asked questions<\/h2>\n<h3>Can a sink-float tank fully separate PET from PVC?<\/h3>\n<p>No. PET (1.38\u20131.40 g\/cm\u00b3) and PVC (1.35\u20131.45 g\/cm\u00b3) both sink with overlapping densities, so a water tank sends them to the bottom together. For sub-50-ppm PVC in rPET, add an electrostatic separator or NIR optical sorter as a polishing stage after the tank.<\/p>\n<h3>How much water does a sink-float tank consume?<\/h3>\n<p>Typically 20\u201330 m\u00b3 of fresh water per ton without filtration. With a DAF and sedimentation loop, that usually drops to 3\u20135 m\u00b3 per ton (up to ~85% reuse), which is where most of the operating-cost savings come from.<\/p>\n<h3>When is a triple-row tank worth the extra cost?<\/h3>\n<p>Generally when your line runs above ~1,500 kg\/h or your feed is heavily contaminated post-consumer material (curbside, DRS bales, mixed rigids). The extra two passes lift purity and reduce downstream filter changes, usually paying back within the first year.<\/p>\n<h3>Where does the tank sit in the line?<\/h3>\n<p>After size reduction and pre-washing\/friction or hot washing, and before dewatering, drying, and pelletizing. Clean feed in means a clean float-sink split out.<\/p>\n<p>Need help matching a tank to your specific feed and line target? Share your polymer mix, contamination level, and throughput goal, and our engineers can recommend a <a href=\"https:\/\/www.recyclemachine.net\/ro\/rezervor-de-separare-cu-plutitor-chiuveta\/\">sink-float separation tank<\/a> configuration \u2014 single- or triple-row, with the right water loop and sludge handling \u2014 sized around your actual process rather than a headline number.<\/p>\n\n\n<p class=\"wp-block-paragraph\"><\/p>","protected":false},"excerpt":{"rendered":"<p>A practical sizing guide for sink-float separation tanks: match throughput, feedstock density, single- vs triple-row configuration, and water and sludge handling before you issue an RFQ.<\/p>","protected":false},"author":1,"featured_media":14234,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1997],"tags":[],"class_list":["post-14230","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-buying-guides"],"tsf_seo":{"title":"","description":"","robots":"index, follow","canonical":"","og_title":"","og_description":"","og_image":"","no_blogname":false},"_links":{"self":[{"href":"https:\/\/www.recyclemachine.net\/ro\/wp-json\/wp\/v2\/posts\/14230","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.recyclemachine.net\/ro\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.recyclemachine.net\/ro\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.recyclemachine.net\/ro\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.recyclemachine.net\/ro\/wp-json\/wp\/v2\/comments?post=14230"}],"version-history":[{"count":2,"href":"https:\/\/www.recyclemachine.net\/ro\/wp-json\/wp\/v2\/posts\/14230\/revisions"}],"predecessor-version":[{"id":14233,"href":"https:\/\/www.recyclemachine.net\/ro\/wp-json\/wp\/v2\/posts\/14230\/revisions\/14233"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.recyclemachine.net\/ro\/wp-json\/wp\/v2\/media\/14234"}],"wp:attachment":[{"href":"https:\/\/www.recyclemachine.net\/ro\/wp-json\/wp\/v2\/media?parent=14230"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.recyclemachine.net\/ro\/wp-json\/wp\/v2\/categories?post=14230"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.recyclemachine.net\/ro\/wp-json\/wp\/v2\/tags?post=14230"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}