{"id":1920,"date":"2024-12-23T11:03:36","date_gmt":"2024-12-23T11:03:36","guid":{"rendered":"https:\/\/ecomacchine.it\/?post_type=production&p=1920"},"modified":"2026-10-09T12:22:32","modified_gmt":"2026-10-09T12:22:32","slug":"chiarificatori-rettangolari","status":"publish","type":"production","link":"https:\/\/ecomacchine.it\/en\/production\/chiarificatori-rettangolari\/","title":{"rendered":"Rectangular clarifiers"},"content":{"rendered":"

They are devices used in wastewater and industrial water treatment to remove suspended solids<\/strong> and other particles from the liquid.<\/p>\n","protected":false},"featured_media":1931,"template":"","class_list":["post-1920","production","type-production","status-publish","has-post-thumbnail","hentry"],"translation":{"provider":"WPGlobus","version":"2.10.10","language":"en","enabled_languages":["it","en"],"languages":{"it":{"title":true,"content":false,"excerpt":false},"en":{"title":true,"content":true,"excerpt":false}}},"acf":{"applications_and_models":{"items":[{"title":"Application","select":"Acordion","acordion":"\r\n

Municipal water and wastewater sedimentation<\/p>\r\n

Industrial water and wastewater sedimentation<\/p>\r\n

Steel rolling mill cooling water recycling<\/p>\r\n","complex":null},{"title":"Scraping or suction type rectangular clarifiers","select":"Complex","acordion":"","complex":[{"dimensions":null,"models":[{"image":1930,"label":"Hydraulic or mechanical scraping blade lifting clarifier","value":"EM50BB1","models_popup":"\r\n\r\n

\r\n
\r\n

EM50 - SCRAPER WITH TRAVELLING BRIDGE FOR RECTANGULAR TANK<\/h2>\r\n<\/div>\r\n
\r\n
\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
Application<\/td>\r\nClarifying of primary and secondary waste water<\/td>\r\n<\/tr>\r\n
Machine types<\/td>\r\nConcrete runways Rails<\/td>\r\n<\/tr>\r\n
Characteristics<\/td>\r\nThe equipment consists of a rotating bridge with bottom and surface scrapers.<\/td>\r\n<\/tr>\r\n
Operation<\/td>\r\nThe waste water is clarified in a rectangular tank, the sedimentable solids settle on the tank bottom and are conveyed to a hopper by the bottom scrapers, while the floating material is conveyed into an oil removal pipe.<\/td>\r\n<\/tr>\r\n
Materials<\/td>\r\nHot dip galvanized carbon steel or Stainless steel<\/td>\r\n<\/tr>\r\n
Installation<\/td>\r\nIn a concrete tank<\/td>\r\n<\/tr>\r\n
Tank diametre<\/td>\r\nFrom 4 to 25 m.<\/td>\r\n<\/tr>\r\n
Tank length<\/td>\r\nFrom 2 to 100 m.<\/td>\r\n<\/tr>\r\n
Optionals<\/td>\r\nScum removal system<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/div>\r\n<\/div>\r\n
\r\n
\r\n

<\/h3>\r\n

PRINCIPLES OF SIZING<\/h6>\r\nHydraulic sizing (process)<\/strong> The sizing of the feeding zone is based on the following parametres: \u2022 influent flow rate \u2022 dimensions of the pipings The water flowing to the sedimentation zone must have a very low kinetic energy in order to guarantee a good separation and settling of the solids. \r\n\r\n \r\n\r\nMechanical Sizing<\/strong> The sizing of the bottom scraper is based on the type of sludge to be evacuated from the tank bottom. Normally the trolleys and the scrapers are designed to bear a stress of 20 Kg. per linear metre.\r\n\r\n \r\n\r\nChecks<\/strong> The following checks regarding the movement of the machine components are very important for this kind of machine: \u2022 bridge: forward-backward movement \u2022 bottom scraper: lifting-lowering \u2022 surface scraper: lifting-lowering \u2022 electrical supply Our travelling bridges are always equipped with two limit switches for each movement (1 for operation and 1 for emergency) Buffer groups are also installed to limit the run of the moving units in case of failure the electrical limit switches and they are sized to bear the maximum stress.\r\n\r\n \r\n\r\nMotorization<\/strong> We use a double motorization for bridges exceeding 6 m. of width and moving over a runway of more than 12 m. This solution allows to achieve a good alignment of the bridge, even if the two motorized wheels diametres are not exactly equal. In this case, a simple motorization through a central shaft may cause the side-slip of one of the two motorized wheels.\r\n\r\n \r\n\r\nCharacteristics<\/strong> Both the motorized hweels and the idle wheels must be perfectly parallel and at the same distance; for this purpose, after the installation of the bridge, the diagonals between the wheels must be carefully measured.\r\n\r\n \r\n\r\nContrast wheels and buffers<\/strong> The contrast wheels and the buffers must be designed and sized so that the bridge cannot skid laterally out of the runways, under no circumstances.\r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n\r\n"},{"image":1929,"label":"Suction system with air-lift or pump or siphon clarifier","value":"EM51","models_popup":"\r\n\r\n
\r\n

EM51 - SUCTION TYPE SCRAPER WITH TRAVELLING BRIDGE FOR RECTANGULAR TANK<\/h2>\r\n<\/div>\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
Application<\/td>\r\nClarifying of secondary waste water.<\/td>\r\n<\/tr>\r\n
Type of sludge suction<\/td>\r\nSiphon Submersible pump Vertical pump Air lift<\/td>\r\n<\/tr>\r\n
Characteristics<\/td>\r\nThe equipment consists of a travelling bridge with bottom suction pipes and surface scrapers<\/td>\r\n<\/tr>\r\n
Operation<\/td>\r\nThe water is treated in a rectangular tank, the sedimentable solids settle on the tank bottom, are sucked by the suction pipes and conveyed to a channel while the floating material in conveyed into an oil removal pipe.<\/td>\r\n<\/tr>\r\n
Materials<\/td>\r\nHot dip galvanized carbon steel or Stainless steel<\/td>\r\n<\/tr>\r\n
Installation<\/td>\r\nIn a concrete tank<\/td>\r\n<\/tr>\r\n
Tank diametre<\/td>\r\nFrom 4 to 25 m.<\/td>\r\n<\/tr>\r\n
Tank length<\/td>\r\nFrom 20 to 100 m.<\/td>\r\n<\/tr>\r\n
Optionals<\/td>\r\nScum removal system<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n

<\/h3>\r\n

PRINCIPLES OF SIZING<\/h6>\r\nSludge suction unit sizing For the project of the sludge suction unit we have to make sure that the sludge is quickly removed from the tank bottom because if it tends to settle or get too thick for staying in the tank for a too long time, it may happen that: \u2022 a part of the recycled sludge returns to the oxidation tank when it is no more fresh and this will affect the treatment efficiency \u2022 a shortage of dissolved oxygen may cause a leakage of sludge in the effluent\r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\nMechanical Sizing Same principles as described for the Scraper with travelling bridge for rectangular tank mod. EM50.\r\n

<\/h3>\r\n

OPERATION DESCRIPTION<\/h6>\r\nThe bottom of the suction scraper bridge tank is flat and the suction pipes, sized according to sludge recycle flow rate, are placed at a distance which does not exceed 3 m. The sludge is conveyed towards the suction pipe by V-shaped scrapers which make the flowing of the sludge towards the piping much easier. Each suction pipe is equipped with a telescopic valve to regulate the flow into the hopper. The quality and quantity of sludge sucked by each pipe can be checked from the bridge. The sludge flows into the hopper according to the principle of the communicating vessels. The sludge flow rate depends on the difference of level between the water surface and the sludge level in the hopper. The sludge sucked by all of the suction pipes is conveyed out of the tank by means of a self-regulating siphon. The triggering of the siphon can be made during the commissioning phase by means of a pump or ejector.\r\n

<\/h3>\r\n

TECHNICAL AND DIMENSIONAL DATA NECESSARY TO MAKE A TECHNICAL PROPOSAL AND QUOTATION<\/h6>\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
1.1<\/td>\r\nFlow rate to the sedimentation tank (total)<\/td>\r\n: m3\/h<\/td>\r\n<\/tr>\r\n
1.2<\/td>\r\nFlow rate coming from the sedimentation tank (at the overflow weir)<\/td>\r\n: m3\/h<\/td>\r\n<\/tr>\r\n
1.3<\/td>\r\nFlow rate of sludge coming from the sedimentation tank<\/td>\r\n: m3\/h<\/td>\r\n<\/tr>\r\n
1.4<\/td>\r\nTank width<\/td>\r\n: m.<\/td>\r\n<\/tr>\r\n
1.5<\/td>\r\nTank length<\/td>\r\n: m.<\/td>\r\n<\/tr>\r\n
1.6<\/td>\r\nSludge level in the drain well<\/td>\r\n: +m.<\/td>\r\n<\/tr>\r\n
1.7<\/td>\r\nWater level in the sedimentation tank<\/td>\r\n: +m.<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n\r\n"}]}]},{"title":"Dredging chains clarifiers","select":"Complex","acordion":"","complex":[{"dimensions":null,"models":[{"image":"","label":"Bottom and or surface scraping clarifier","value":"EM53","models_popup":"\r\n
\r\n
\r\n

EM53 - SCRAPER WITH DREDGING CHAIN FOR RECTANGULAR TANK<\/h2>\r\n<\/div>\r\n<\/div>\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
Application<\/td>\r\nClarifying of primary and secondary waste water<\/td>\r\n<\/tr>\r\n
Characteristics<\/td>\r\nThe equipment consists of a dredging chain with bottom and surface scrapers.<\/td>\r\n<\/tr>\r\n
Operation<\/td>\r\nThe waste water is clarified in a rectangular tank, the sedimentable solids settle on the tank bottom and are conveyed to a hopper by the bottom scrapers, while the floating material is conveyed into an oil removal pipe.<\/td>\r\n<\/tr>\r\n
Materials<\/td>\r\nHot dip galvanized carbon steel or Stainless steel<\/td>\r\n<\/tr>\r\n
Installation<\/td>\r\nIn a concrete tank<\/td>\r\n<\/tr>\r\n
Tank diametre<\/td>\r\nFrom 2 to 16 m.<\/td>\r\n<\/tr>\r\n
Tank length<\/td>\r\nFrom 20 to 100 m.<\/td>\r\n<\/tr>\r\n
Optionals<\/td>\r\nScum removal system<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n

<\/h3>\r\n

PRINCIPLES OF SIZING<\/h6>\r\nHydraulic sizing (process)<\/strong> The sizing of the feeding zone is based on the following parametres: \u2022 influent flow rate \u2022 dimensions of the pipings The water flowing to the sedimentation zone must have a very low kinetic energy in order to guarantee a good separation and settling of the solids.\r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\nMechanical Sizing<\/strong> The sizing of the scrapers is based on the type of sludge to be evacuated from the tank bottom. Normally the scrapers, shafts and chains are designed to bear a stress of 20 Kg. per linear metre.\r\n\r\n \r\n\r\nTorque limiting device (dynamometric cell)\u00a0<\/strong> The dynamometric cell measures the torque transmitted by the drive unit. This value is evident directly on the instrument and allows to evaluate the stresses on the moving members during the rotation. The device is equipped with limit switches set at two different torque values, one for alarm and one for the machine shutdown.\r\n\r\n \r\n\r\nChecks<\/strong> The movement of the chains must be carefully checked because it is very important for this type of machine. For this purpose, we use to apply some sensors to check the idle shafts rotation.\r\n\r\n"}]}]},{"title":"Accessories","select":"Acordion","acordion":"\r\n

Oil and grease collecting system with scraping blade<\/p>\r\n

Oil collecting system with manual or automatic rotating pipe<\/span><\/p>\r\n

Telescopic valve<\/p>\r\n

Electronic alignment system<\/p>\r\n

Ice protection on running path<\/p>\r\n

Slipping alarm<\/p>\r\n","complex":null}]},"technical_information":{"text":"\r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n

\r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n
OUTLINES OF THE SEDIMENTATION PROCESS<\/h6>\r\nA good efficiency of the sedimentation process gives as a result a considerable reduction of BOD, COD, heavy metals, azote, phosphorus, etc. in the treated water. As the suspended substances in the waste water become larger, their sedimentation becomes easier.\r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\nStokes\u2019 law emphasizes the importance of the floc size for the speed of sedimentation.\r\n\r\n\"\"\r\n\r\nV = speed of sedimentation in m\/s \u03c1 = density of solids in kg\/m\u00b3 \u03c10\u00a0= densit\u00e0 dell\u2019acqua kg\/m\u00b3 g = 9,81 m\/s2 \u03bc = viscosity of water in in Pa x s (at 15\u00b0 C the viscosity of water is 1,06 x 10-3\u00a0Pa x s) D = diametre of the particle in m.\r\n\r\nA good way to obtain large flocs in the clarifier feeding is the installation of baffles using the kinetic energy of water to agglomerate the flocs to each other\r\n\r\n\"\"\r\n
\r\n
<\/div>\r\n<\/div>\r\nIn the secondary clarifiers, the type of scraping blades and the sizing of the central drain well are very important.\r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\n \r\n\r\nActually, given the enormous volume of \u201csludge\u201d compared to the feed flow rate (50%), we can hypothize that the sludge characteristics are just a little different from the ones of the clarified water (under static conditions the clarified water and the sludge stratify with a horizontal separation surface) and that, consequently, due to the slight bottom slope (\u223c 4%), it flows naturally towards the central well. However, we should not forget that the particles which touch the bottom, and the ones which stratify, adhere and loose the properties of \u201cfluid\u201d: so they must be actively moved and \u201cpushed\u201d towards the drain well before the layer becomes too thick and, above all, before the anoxic condition causes a strong de-nitrification with the production of floating plates. Therefore all of the sedimented sludge particles conveyed by the bottom scrapers to the central well from the tank periphery, must reach it quickly. This is achieved by giving a continuous profile with logarythmic shape to the blade; the relevant equation in polar coordinates is:\r\n
r=r0<\/sub>\u00b7em\u03b1<\/sup><\/div>\r\n
<\/div>\r\nwhere\u00a0r\u00a0and \u03b1 are the polar coordinates having the tank centre as a pole and ro\u00a0is the radius of the drain well. Under these conditions, the scraper moves the sludge, makes it more \u201cfluid\u201d (by eliminating the adhesion) and conveys it by a perpendicular force to its surface (Pascal); this force has a radial centripetal component, not null and constant. The angle \u03b3 is determined by:\r\n
r=r0<\/sub>\u00b7em\u03b1<\/sup><\/div>\r\n
<\/div>\r\nwhere r and \u03b1 are the polar coordinates with the centre of the tank as the pole, and ro<\/sub>\u00a0is the radius of the sump. Under these conditions the blade moves the sludge, restoring its \u201cfluid\u201d character (cancelling adhesion), and pushes it with a force perpendicular to its surface (Pascal) that has a non-zero, constant centripetal radial component. The angle \u03b3 is defined by:\r\n\r\n\"\"\r\n\r\n"},"gallery":{"items":[{"name":"ATLATEC2","image":1932},{"name":"EM50BB1 C04832","image":1931},{"name":"EM50BB1 VYKSA-C05025-(2)","image":1930},{"name":"EM51 BERNARDINELLO-C04996-2","image":1929},{"name":"EM51D Aguaprieta-C05028","image":1924},{"name":"EM51D C04837","image":1928},{"name":"EM51D C5028-000","image":1927},{"name":"EM51D C5028-001b","image":1926},{"name":"EM51D RomaEst-1612-19","image":1925}]},"download_the_brochure":{"file":1922},"description":{"text":"These are devices used in wastewater and industrial water treatment to\u00a0remove suspended solids and other particles from the liquid.\u00a0<\/strong>"},"subitems":{"items":[{"subtitle":"Circular clarifiers","subtext":"\r\n\r\nPrimarily used as primary clarifiers to remove coarse solids, or as secondary clarifiers to remove biological flocs after biological treatment.\r\n\r\n"},{"subtitle":"Rectangular clarifiers","subtext":"\r\n\r\nThey typically use scraper or conveyor belt systems to collect the settled solids. They are suitable for large-scale plants, where available space needs to be optimized.\r\n\r\n"},{"subtitle":"Lamella plate clarifiers","subtext":"\r\n\r\nThanks to inclined lamella plate packs that increase the available surface area for sedimentation, they are ideal for plants with limited space and where high treatment capacity is required with reduced settling times.\r\n\r\n"}]},"single_product":{"tab_text":"","tab_order":"3"}},"_links":{"self":[{"href":"https:\/\/ecomacchine.it\/en\/wp-json\/wp\/v2\/production\/1920","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ecomacchine.it\/en\/wp-json\/wp\/v2\/production"}],"about":[{"href":"https:\/\/ecomacchine.it\/en\/wp-json\/wp\/v2\/types\/production"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ecomacchine.it\/en\/wp-json\/wp\/v2\/media\/1931"}],"wp:attachment":[{"href":"https:\/\/ecomacchine.it\/en\/wp-json\/wp\/v2\/media?parent=1920"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}