WO1989007715A1

WO1989007715A1 - Centrifugal pump

Info

Publication number: WO1989007715A1
Application number: PCT/DK1989/000035
Authority: WO
Inventors: Kaj Arne SØRENSEN; Frede Holmbo Petersen (Deceased)
Original assignee: Soerensen Kaj Arne
Priority date: 1988-02-17
Filing date: 1989-02-16
Publication date: 1989-08-24
Also published as: DK158799C; DK80688A; DK158799B; AU3198789A; DK80688D0

Abstract

A centrifugal pump of the one-channel type where the rotor (11) is of the enclosed type with a transverse wall (20), which functions as a blade, has an opening (33) to counteract low pressure on the side of the wall (20) which is opposite the inlet opening (23). A partial flow of the pumping medium or another liquid is conducted from an outside source through an annular chamber (19) in the housing (1). It can hereby be avoided that solid matter in the pumping medium congregates in the rotor (11).

Description

CENTRIFUGAL PUMP

The invention concerns a centrifugal pump of the one- channel type consisting of a housing with at least one inlet and an outlet and in which an enclosed rotor is suspended ro, which rotor has an inlet opening placed co- axially with the rotational axis and an outlet passage on one side of a structure which functions as a rotor blade and which integrally connects two diametrically opposed points in the vicinity of the periphery of the rotor and between those two points has two in a plane normal to the axis oppositely curved parts of which one part continues in a half circular part encircling the rotational axis and connecting approximately tangentially with the other curved part in such a way that a blind chamber is formed at the opposite side to the inlet opening and without passage to the inlet opening.

Such pumps are used for pumping liquids containing solid parts, f. inst. waste water, because the wide free passage of this type of pump prevents clogging of the rotor by the solid material. This type of pump is also suitable where damage to the solid parts during the pumping has to be avoided, f. inst. when foodstuffs such as vegetables and sea food are being transported in a processing plant. Moreover this type of one-channel pump has a rotor with a better distribution of mass and a greater rigidity than another known one-channel type where the blade forms a spiral from the periphery to a point near the axis of ro¬ tation.

The first mentioned type of pump has the disadvantage that a low pressure is formed on the blind side of the rotor, which causes some of the solid material to be collected or deposited here. In the case of foodstuffs like sea food this represents a hygienic problem. In such cases the plant has to be stopped fairly often and the pump taken apart and cleaned.

The purpose of the invention is to provide a pump of the above mentioned type where the low pressure on the blind side can be eliminated and the disadvantages of this type of pump be avoided.

This is acchieved according to the invention in a centri¬ fugal pump of the type mentioned in the preliminary of claim 1, where the housing beside a central inlet opposite the inlet opening has a secondary inlet, which leads to an annular chamber, coaxial with the rotational axis, one side of which is confined by the rotor, which has an opening on the side towards the annular chamber, which opening cor¬ responds with the annular chamber and is connected with the blind chamber.

A pump according to the invention can be connected to a water supply whereby the pressure will be equalized during the running of the pump because the pump will take in li¬ quid into the chamber on the blind side. Solids carried through the central inlet can therefore not be sucked in and collected on the blind side of the rotor.

An embodiment of the invention will bee further described in the following with refernce to the drawings, in which

fig. 1 shows a section of a centrifugal pump according to the invention,

fig. 2 shows a front view and part section of the pump in fig. 1,

fig. 3 shows a top view of a rotor for the pump in fig. 1, and ^'

fig. 4 shows a section of the rotor on the line IV - IV in fig. 3.

The pump according to the invention contains a housing 1 with a main inlet 3, a secondary inlet 5, an outlet 7 and a bottom cover 9. The housing 1 supports a rotor 11 which may be driven by a shaft 13.

From the secondary inlet 5 a channel 15 leads to an annular chamber 17 which on three sides is confined by the housing and on the fourth side is confined by the upper flat side 19 of the rotor 11.

The rotor 1 is partitioned into an inlet side 21 with a direct connection to the inlet opening and a blind side 25 by a wall 20. The wall 20 has parts 27 and 29 closest to the periphery of the rotor, which parts 27, 29 are connected to a part 31 around the periphery of the inlet opening. On the blind side and starting at the part 27 is formed an opening 33 which has a width and distance from the axis 35 corresponding with the annular chamber's 17.

To make the production cheap most of the surfaces of the parts 27, 29 and 31 are formed cylindrical and the rotor 1 is made of plastic, preferably polyoxymethylene.

The pump according to the invention will be used especially for pumping of shrimps in production plants and wherever it has to be avoided that the shrimps are damaged during transport in the tubing. The pump according to the invention can also be used in plants where vegetables such as carrots, cauliflower, peas and the like are being transported in liquid.

Claims

CLAIM.

Centrifugal pump, of the one-channel type consisting of a housing (1) with at least one inlet (3) and an outlet (7) and in which an enclosed rotor (11) is suspended rotatably, which rotor (11) has an inlet opening (23) placed coaxially with the rotational axis (35) and an outlet passage on one side of a continuous structure (20) which functions as a pump vane and which integrally connects two diametrically opposed points in the vicinity of the periphery of the ro¬ tor, and between those two points has two in a plane normal to the axis oppositely curved parts (27, 29) of which one part (29) continues in a semicircular part (31) encircling the rotational axis (35) and connecting approximately tangentially with the other curved part (27) in such a way that a blind chamber is formed at the opposite side (25) to the inlet opening (23) and without passage to the inlet opening, c_h_a_r_a_c_t_e_r_i_s_e_d in that the housing

(1) besides a central inlet (3) opposite the inlet opening (23) has a secondary inlet (5) which leads to an annular chamber (17) coaxial with the rotational axis (35), one side of which chamber (17) is confined by the rotor (11) which has an opening (33) on the side facing the annular chamber, which opening (33) is placed correspondingly to the annular chamber (17) and is connected with the blind chamber.