Filter apparatus

A filter apparatus, comprising:

• a filter housing having a filter inlet for fluid to be filtered and a filter outlet for filtered fluid;
• a plurality of filter elements in the filter housing traversable for fluid in one direction for filtration and in an opposite direction for backwashing, each of the filter elements having an upper element opening and a lower element opening on opposite ends of each of the filter elements, the filter elements being arranged in the filter housing such that at least one of the filter elements filters fluid from the filter inlet while at least one other of the filter elements is simultaneously backwashed to clean a dirty filter surface thereof;
• a backwash device in the filter housing backwashing the filter elements;
• a pressure control device interacting with the backwash device and having a pressure control element controlling fluid flow along the filter elements during backwashing thereof;
• a housing connection chamber in the filter housing connected in fluid communication to filter cavities forming an unfiltrate side of the filter elements via the upper element openings providing a fluid path via which unfiltrate flows into the housing connection chamber during filtration and flows from the housing connection chamber through a respective upper element opening into a respective filter cavity during backwashing with unfiltrate flow through the respective upper element opening being controlled by the pressure control element;
• a discharge opening of the backwash device in fluid communication with the respective filter cavity via a respective lower element opening during backwashing;
• a control plate of the pressure control device being arranged inside the housing connection chamber, being laterally movable to pass over the upper element openings individually of filter elements being backwashed in a predeterminable sequence, covering the upper element openings to an increasing degree and then exposing the upper element openings again, the discharge opening being at least partially in fluid communication to the lower element opening of a respective filter element being backwashed as the pressure control element moves toward the respective upper element opening of the respective filter element being backwashed;
• a reniform recess in a reniform cover plate of the backwash device forming a backwash collection chamber of the backwash device, the reniform cover plate being guided for movement by a backwash arm extending from the discharge opening, the discharge opening being connectable in fluid communication to a valve via the backwash arm;
• and
• a cylindrical attachment piece on the reniform cover plate with the reniform recess and the cylindrical attachment piece being arranged in different planes in the reniform cover plate and with the cylindrical attachment piece attaching the reniform cover plate to the backwash arm.