A centrifugal pump (1) for lifting clean water or water with suspended solids, comprising:
- a hollow body (2) defining a center axis (L), said hollow body (2) having a front opening (3) defined in a radial wall (6) and a volute (4) with a radial delivery port (5);
- an impeller (8) accommodated in said hollow body (2), said impeller (8) having blades (9) whose tips (10) are substantially coplanar at an annular peripheral area (11);
- a cover (12) for closing said front opening (3), said cover (12) comprising a flange (13) disposed to overlay said radial wall (6), said flange having a disc shaped central portion (14) facing an outer environment, and a peripheral portion (16) extending radially from said disc shaped central portion (14);
- a substantially annular wear plate (19), directly affixed to a rear of said disc shaped central portion (14) of said flange (13);
- wherein said disc shaped central portion (14) of said flange (13) has a central hole (20) providing a substantially axial suction port (15);
- wherein said substantially annular wear plate (19) is located at an axial distance (d1) from the tips (10) of the blades (9), the axial distance (d1) being maintained at a predetermined value to prevent sudden changes and leakage of the clean water or of the water with suspended solids;
- and
- an adjustment system (24) for controlled adjustment of said axial distance (d1) of said wear plate (19);
- wherein said adjustment system (24) is mounted onto said flange (13) and is accessible from outside, said adjustment system (24) being configured to both calibrate said axial distance (d1) of said wear plate (19) and to lock said wear plate (19) at said axial distance (d1);
- wherein said adjustment system (24) comprises a plurality of studs (25) with first threaded ends (26) tightened into a first ring of matingly threaded holes (27) formed in said hollow body (2) at a periphery of said front opening (3),
- wherein said studs (25) have intermediate smooth portions (28), which are adapted to pass through a second ring of corresponding smooth through holes (29) formed in the peripheral portion (16) of said flange (13);
- wherein said adjustment system further comprises second threaded ends (30) with a predetermined pitch (p), which are configured to project out of said peripheral portion (16) of said flange (13) and on which corresponding calibration stop nuts (32) are tightened;
- wherein said adjustment system causes a movement of said flange (13), with said substantially annular wear plate (19) affixed thereto, in relation to said radial wall (6) after the closing of said cover;
- wherein said cover (12) is connected to said hollow body (2) by a hinge (18) having a hinge axis (Y) that is substantially vertical and perpendicular to the center axis (L) of said hollow body (2);
- and
- wherein said hinge (18) consists of a first end member (18′) affixed to said hollow body (2), a second end member (18″) directly affixed to the cover (12), and an intermediate member (18′″) slidingly mounted to said first end member (18′) so as to slide along a respective longitudinal direction, said second end member (18″) being disposed to be pivoted thereupon about said hinge axis (Y), to allow said cover (12) to be opened by a longitudinal sliding motion and a pivoting motion, for easy inspection and maintenance of said hollow body (2).