Systems running through flood conditions

Since long before the indus­tri­al rev­o­lu­tion, man­u­fac­tur­ers have extract­ed water from local rivers and streams. The process is still wide­ly used today, in appli­ca­tions from ener­gy gen­er­a­tion to paper mak­ing. Unlike their fore­bears, how­ev­er, mod­ern sys­tems inevitably include var­i­ous treat­ment process­es to ensure the extract­ed water meets appro­pri­ate qual­i­ty, safe­ty and process con­trol standards.
nrw Anla­gen­tech­nik GmbH, based in Hück­el­hoven, Ger­many, spe­cialis­es in the pro­duc­tion of stain­less steel prod­ucts for water and waste­water treat­ment in a wide vari­ety of munic­i­pal and indus­tri­al appli­ca­tions. The com­pa­ny has devel­oped a range of ver­ti­cal screens that are used to address one of the key chal­lenges inher­ent in riv­er water extrac­tion: solids.
Nat­ur­al riv­er water car­ries a wide range of mate­ri­als, from algae and plant debris to aquat­ic fau­na. All this mate­r­i­al can be removed by fil­tra­tion, but doing that puts addi­tion­al load on treat­ment equip­ment, con­sumes ener­gy and cre­ates a waste stream that must then be han­dled by the oper­a­tor. Far bet­ter to ensure that such mate­r­i­al is pre­vent­ed from enter­ing the treat­ment sys­tem in the first place.
nrw Anla­gen­tech­nik ver­ti­cal screens achieve that objec­tive using per­fo­rat­ed stain­less steel ele­ments immersed in the water at the extrac­tion point to pre­vent solids above a cer­tain size from enter­ing the water sup­ply.  Depend­ing on the appli­ca­tion, the screens use per­fo­ra­tions of between 1 mm and 20 mm diam­e­ter. To ensure the screens do not become blocked over time, a sys­tem of rotat­ing polypropy­lene brush­es keeps the out­er sur­face of the screens clear, return­ing debris safe­ly and con­tin­u­al­ly back into the water flow.
For many years, nrw Anla­gen­tech­nik, has spec­i­fied Bauer gear motors to oper­ate its ver­ti­cal brush sys­tems. The Bauer gear motors pro­vide com­pact, robust, and reli­able oper­a­tion, deliv­er­ing the required low rota­tion speed – typ­i­cal­ly less than 2 rev­o­lu­tions per minute – with­out the need for sec­ondary pow­er­train components.
In riv­er water extrac­tion appli­ca­tions, the abil­i­ty of the motor sys­tem to cope with demand­ing envi­ron­men­tal con­di­tions is of para­mount impor­tance. Not only are the gear motors mount­ed in a posi­tion exposed to the ele­ments and just a small dis­tance above the water sur­face, but in some instal­la­tions sea­son­al fluc­tu­a­tions in the water lev­el can mean the entire instal­la­tion is peri­od­i­cal­ly sub­merged, usu­al­ly dur­ing sea­son­al floods.
For these appli­ca­tions, Bauer, part of the Altra Indus­tri­al Motion Cor­po­ra­tion, sup­plies spe­cial IP68-rat­ed ver­sions of its motors, which are ful­ly sub­mersible and imper­vi­ous to water and dust ingress. In an instal­la­tion in South Ger­many, for exam­ple, the cus­tomer spec­i­fied Bauer Gear Motors, with a pow­er rat­ing of 0.12kW. The motors were sup­plied in the IP68 con­fig­u­ra­tion, with a spe­cial paint fin­ish, ful­ly com­pli­ant with nation­al Water Indus­try Mechan­i­cal and Elec­tri­cal Spec­i­fi­ca­tions (WIMES).