Centrifugal pump for liquids containing solid material

• US 4,594,052 A
• Filed: 09/20/1983
• Issued: 06/10/1986
• Est. Priority Date: 02/08/1982
• Status: Expired due to Fees

• Current Assignee: A. Ahlstrom Osakeyhtio
• Original Assignee: A. Ahlstrom Osakeyhtio
• Inventors: Niskanen, Toivo
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/541,331
• Time in Patent Office: 994 Days
• Field of Search: 415/121 B, 415/213 A, 415/206, 415/215, 415/208, 415/219 C, 416/185, 416/228, 416/188
• US Class Current: 415/121.1
• CPC Class Codes: F04D 7/045 with means for comminuting, mixing stirring or otherwise treating

Abstract

A centrifugal pump for liquids containing solid material, the impeller of which has two or several vanes. In a bottom projection the leading edge (3) of the impeller (1) vane (2) is curved backwards in relation to the rotating direction of the impeller. The angle between the leading edge (3) and the outer edge (5) is obtuse in a meridian and a bottom projection. The outer end (10) of the leading edge of the vane is positioned behind a shoulder (9) provided with grooves (11), which cooperates with the vanes of the impeller. The form of the leading edge causes the fibres and the sticks to be conveyed towards the point of the vane where they are crushed by the combined effect of the groove and the vanes.

Claims

1. A centrifugal pump for liquids containing solid material comprising a housing (7), a multi-vane impeller (1), each of the vanes (2) having an outer edge (5), an inner edge (4), and a leading edge (3), said leading edge being curved backwardly in a bottom projection, with respect to the direction of rotation of the impeller, whereby the inner edge (4) runs ahead of the outer edge during rotation, said leading edge and outer edge forming angles (β

, ρ

) which are obtuse in a meridian and a bottom projection respectively;

said leading edge and inner edge forming an acute angle in the bottom projection, said leading edge having an outer end (10), said housing having an inner wall (8), said inner wall being provided with a shoulder (9) which forms a recess, said outer end (10) of the leading edge being positioned behind said shoulder (9) and within said recess, at least one of said shoulder and the inner wall of the housing being provided with at least one groove (11) having a cutting edge (13) which cooperates with the outer end of the leading edge of the vane for cutting said solid material.

2. A centrifugal pump according to claim 1, wherein a plurality of grooves is provided, the number of the grooves and the number of the vanes are not divisible by the same number.