an apparatus for the separation and removal of solid waste material from a flowing liquid , for instance , wastewater , includes two endless , circulating chains , which are partially immersed in the liquid . the chains exhibit links which , by means of pivotal joints are bound together . between the two chains are placed sieve elements which , respectively , are rigidly affixed to each link . successive sieve elements overlap each other in the running direction of the chain in the area of the pivotal joint of the links .