A fluid filtration unit comprising: a housing accommodating a cylindrical filter element, wherein the cylindrical filter element being stationary, wherein the cylindrical filter element defining a raw fluid chamber extending between an inlet of the housing and raw fluid face of the cylindrical filter element, and a filtered fluid chamber extending between a filtered fluid face of the cylindrical filter element and an outlet from said housing; a flushing and backspraying assembly comprising: a flushing pipe coupled to a lower pressure source and extending within the raw fluid chamber, and configured with a plurality of flushing nozzles _disposed in close proximity with the raw fluid face of the cylindrical filter element; a backspraying pipe; at least one backspraying arm in fluid communication with the backspraying pipe and coupled to a pressurized fluid source and extending within the filtered fluid chamber and configured with an array of backspraying nozzles disposed in close proximity with the filtered fluid face of the cylindrical filter element; and a driving mechanism for selectively imparting said flushing and backspraying assembly with rotary and linear motion; characterized in that the backspraying pipe is in pipe-in-pipe configuration with, and sits concentrically within the flushing pipe, providing a gap between the backspraying pipe and the flushing pipe such that there is created in said gap a tubular hollow space between an outer surface of the backspraying pipe and an inner surface of the flushing pipe. a housing accommodating a cylindrical filter element, wherein the cylindrical filter element being stationary, wherein the cylindrical filter element defining a raw fluid chamber extending between an inlet of the housing and raw fluid face of the cylindrical filter element, and a filtered fluid chamber extending between a filtered fluid face of the cylindrical filter element and an outlet from said housing; a flushing and backspraying assembly comprising: a flushing pipe coupled to a lower pressure source and extending within the raw fluid chamber, and configured with a plurality of flushing nozzles _disposed in close proximity with the raw fluid face of the cylindrical filter element; a backspraying pipe; at least one backspraying arm in fluid communication with the backspraying pipe and coupled to a pressurized fluid source and extending within the filtered fluid chamber and configured with an array of backspraying nozzles disposed in close proximity with the filtered fluid face of the cylindrical filter element; and a driving mechanism for selectively imparting said flushing and backspraying assembly with rotary and linear motion; characterized in that the backspraying pipe is in pipe-in-pipe configuration with, and sits concentrically within the flushing pipe, providing a gap between the backspraying pipe and the flushing pipe such that there is created in said gap a tubular hollow space between an outer surface of the backspraying pipe and an inner surface of the flushing pipe. a flushing pipe coupled to a lower pressure source and extending within the raw fluid chamber, and configured with a plurality of flushing nozzles _disposed in close proximity with the raw fluid face of the cylindrical filter element; a backspraying pipe; at least one backspraying arm in fluid communication with the backspraying pipe and coupled to a pressurized fluid source and extending within the filtered fluid chamber and configured with an array of backspraying nozzles disposed in close proximity with the filtered fluid face of the cylindrical filter element; and a driving mechanism for selectively imparting said flushing and backspraying assembly with rotary and linear motion;