A filter to make things clearSelf-cleaning filter reduces maintenance costs and increases efficiency in wastewater treatmentLocation:Bocholt, GermanyChallenge:Filter out coarse particles in the wastewater flow in the mechanical cleaning stage to ensure trouble-free operation of hydro-cyclones and to enable automated operation of the entire system.Solution:Pre-filtration of the wastewater by mechanical self-cleaning MCS-500 filter with magnetically coupled pneumatic actuation.Result:The self-cleaning filter reduces maintenance, enables automatic pre-filtration of the wastewater, ensures smooth operation of the hydro-cyclone unit and in this way, increases the efficiency and operational safety of the entire sewage treatment plant.“After extensive testsand long periods of usein regular operation, ourexperience has beenconsistently positive.With the installation ofthe filter, we no longerhave any failures in thehydro-cyclone system.“Andreas Wehren,Operations Manager at theESB sewage treatment plantBackgroundReducing the energy consump-tion of sewage treatmentplants is a major challengein achieving climate goals.To contribute to this, thewaste disposal and servicecompany Bocholt (ESB) — theoperator of the central sewagetreatment plant in the Mussumdistrict — decided to optimizethe system’s energy efficiency,in which the wastewater frommore than 70,000 homes andseveral commercial operationsis treated. The measures notonly include reducing energyconsumption through highlyefficient pumps and low-con-sumption motors, but also aninnovative process to improvethe existing activated sludgeprocess: After mechanicalpre-cleaning with a rake andsand trap, the new processaccelerates the sedimentationof the sludge through the useof hydro-cyclones and reducesthe load on the secondaryclarification.ChallengeHydro-cyclones are centrifugalseparators for liquid mixturesthat separate solid particlesfrom suspensions in a processbased on centrifugal force.Thanks to this process, thesewage treatment in Bocholt ismore stable and efficient. How-ever, the innovative processhas one challenge: Largercontaminants such as plasticmaterial or leaves that happento pass through the rakes inthe mechanical pre-treatmentcan clog the hydro-cyclones. Ifseveral cyclones breakdown atthe same time, it can lead to ashutdown of the entire plant.To prevent unplanned down-times as much as possiblefrom the outset, the ESBpreviously used a manual bas-ket strainer that was installedbetween the mechani c al pre-rake and hydro-cyclones. Thefilter reliably removed contami-nants with sizes of over0.4 inch (9 millimeters). Thedisadvantage: The filter elementhad to be cleaned three timesa day. The sewage treatmentplant employees had to planone to two hours every day forthis process.Customer Success Story:ESB Bocholt (Waste disposal and service company in Bocholt)Market segment: Water and wastewaterThis manual clean i ng reinforced the need for a higher degree of automation at ESB. In addition, the employees came into con-tact with the just pre-cleaned waste w ater every time. For reasons of hygiene andem p loyee protection, ESB was therefore looking at alternatives.SolutionThe company found whatit was looking for at Eaton. The Filtration Division of the energy management company has decades of expertise in filtration with a wide rangeof products and solutions.“In many applications, basket strainers are ideally suited for coarse filtration of the process media,” says Ulrich Latz, Technical Sales Engineer in Eaton’s Filtration Division, who has already installed severalof his company’s self-cleaning filters in customers’ systems. “In our opinion, the operation in a sewage treatment plant with a very heterogeneous, debris loaded medium required a different solution,” explains Latz, “especially since the filtration step should not bea bottleneck with the desired degree of automation of the entire system”.After the first few discussions with the customer, we struck upon the idea to use a filter from the MCS series from Eaton. MCS filters work on a simple but effective principle: A cylindrical stainless steel housing contains a filter element. The liquid to be filtered enters the housing, flows through the filter element from the inside to the outside and leaves the housing through the outlet. During this process, the solids are deposited onthe inner surface of the filter element. Slotted wedge wire elements are used as filters in typical areas of application.“So far, the MCS series has mainly been used in in d us t rial processes, for example in treat m ent of process water and cooling water, or in the pro-duction of paper and cellulose or food and beverages,” says Latz, describing the areas of application. “For use in a municipal sewagetreatment plant, it was clearfrom the start that we wouldhave to replace the usual filterunit with a perforated filterelement to avoid sudden filtersclogging,” Latz continues. Inkeeping with the size of thesystem in Bocholt and thespecifications of the hydro-cyclones, he and his teamdecided on an MCS-500,which enables through p utsof up to 500 gallons perminute (114 cubic meters perhour), and a filter elementwith a perforation of 1/4 inch(6.35 millimeters).“The highlight of the MCSseries is the automaticme c hani c al cleaning,”Latzemphasizes. The process iscontinuous: The differentialpressure before and after thefilter is measured continuously— once a certain pressureis reached, cleaning startsautomatically. A cleaning discsweeps the entire surfaceof the filter element andremoves any accumulated dirtparticles. In the same step, theaccumulated dirt is directed toa collection area. When this hasreached its maximum capacity,a dirt drain valve is opened andthe dirt is discharged in a highlyconcentrated manner.“The total travel time of thecleaning disc is only aboutfive seconds per stroke,”explains Latz. Only one to twoautomated cleaning processesper hour are necessary inthe sewage treatment plantin Bocholt, which amountsto a few minutes every day.“Compared to the previoustechnology, this is alreadyan enormous saving,” Latzemphasizes. “If you alsoconsider that the previousmanual cleaning is beingreplaced by a fully automaticsolution, the result is of coursesignificantly better.”To use the filtration unit withautomatic cleaning in thisapplication, a considerableupgrade was necessary: Theactuation for the cleaningsystem is a special Eatonsolution. “Employing amagnetically coupled linearactuator in fluids had not yetbeen attempted,” recalls Latz.“We then worked with anactuation expert vendor todevelop a solution that hadpassed extensive tests and wasreliable in operation.”ResultThe system displays itsstrengths especially whenused in the sewage treatmentplant in Bocholt: Withoutdynamic seals, the filter unitis completely leakproof andenables continuous operationwithout interruptions. Themaintenance-friendly designalso saves operating costsand simplifies routine work.“The MCS-500 is easilyserviced without any specialtools,” explains Latz. “Thefiltration unit can be completelydisassembled and reassembledin five minutes,” he adds.During the design phase,Eaton engineers also keptergonomics in mind: Thanksto the 45-degree incline, thefilter can be dismantled withouta crane. In-line filtration alsoenables the inlet and outlet tobe at the same level, whichmeans that there is no need foradditional, cumbersome pipework during installation.The MCS-500 has been in usesuccessfully in Bocholt since itsinstallation and ensures stableprocess conditions, significantlylower maintenance costs andreduced contact betweenemployees and wastewater.“After extensive tests andlong periods of use in regularoperation, our experience hasbeen consistently positive,”confirms Andreas Wehren,Operations Manager at the ESBsewage treatment plant. “Withthe installation of the filter, weno longer have any failures inthe hydro-cyclone system”— a decisive prerequisite forthe trouble-free and efficientoperation of the entire sewagetreatment process. Since thefilter unit can be operated fullyautomatically, it was integratedinto the process control systemof the sewage treatment plantso that all parameters can beretrieved centrally at any time.Wehren is particularly pleasedabout the seam l ess collabo r a-tion with the filtration expertsfrom Eaton.“We were very pleased withthe communication betweenthe partners, especially duringthe test phase,” recalls Wehren,and adds: “During the transitionfrom testing to purchasing thesystem, the entire process tookplace just as easily.”The keys to achieving theclimate goals are everywhere— in industry, with consumersand in municipalities. Withthe energy saving upgradeof its sewage treatmentplant, the city of Bocholt hastaken a huge step towardsassuming responsibility as amunicipality and significantlyreducing the ecologicalfootprint of its service groups.The Eaton solution providesan indispensable contributionto this, with its reliable andefficient filtration solutionfor the pre-filtration of thewastewater.For more information, pleaseemail us at ********************or visit /filtration© 2021 Eaton. All rights reserved. All trademarks and registeredtrademarks are the property of their respective owners. Allinformation and recommendations appearing in this brochureconcerning the use of products described herein are basedon tests believed to be reliable. However, it is the user’sresponsibility to determine the suitability for his own use of suchproducts. Since the actual use by others is beyond our control,no guarantee, expressed or implied, is made by Eaton as to theeffects of such use or the results to be obtained. Eaton assumesno liability arising out of the use by others of such products. Noris the information herein to be construed as absolutely complete,since additional information may be necessary or desirable whenparticular or exceptional conditions or circumstances exist orbecause of applicable laws or government regulations.North America44 Apple StreetTinton Falls, NJ 07724Toll Free: 800 656-3344(North America only)Tel: +1 732 212-4700Europe/Africa/Middle EastAuf der Heide 253947 Nettersheim, GermanyTel: +49 2486 809-0Friedensstraße 4168804 Altlußheim, GermanyTel: +49 6205 2094-0An den Nahewiesen 2455450 Langenlonsheim, GermanyTel: +49 6704 204-0Greater ChinaNo. 7, Lane 280,Linhong RoadChangning District, 200335Shanghai, P.R. ChinaTel: +86 21 5200-0099Asia-Pacific100G Pasir Panjang Road#07-08 Interlocal CentreSingapore 118523Tel: +65 6825-1668EN11-2021With a quick-cleaning actuation, theMCS-500 strainer basket filtermodel reduces costly maintenancework and downtime.In the sewage treatment plant, thefully automatic MCS-500 strainerbasket filter replaces a manualsolution that cost the operatingstaff several hours of work everyday.。
