SINGLE-STAGE CENTRIFUGAL PUMPING UNIT

Abstract

The invention relates to mechanical engineering, namely to pumping installations designed for pumping water, water solutions, as well as oil, oil products and the like through the main, process and auxiliary pipelines, and is directed toward providing a single-stage centrifugal pumping unit which demonstrates peak efficiency in non-nominal modes while having a simplified design and being universal in nature. To this end, a single-stage centrifugal pumping unit comprises a centrifugal single-stage double entry pump, an electric drive motor, a coupling, connecting their shafts, a support frame for mounting the pump housing and the electric motor thereon, a housing, which consists of a base and a cover, inlet and outlet manifolds, a rotor with an impeller mounted thereon, the rotor being installed in support bearings, and a volute configured according to the invention in the form of a separate, independent component, and parts of the outside surface thereof, which are intended to be accommodated in cradles provided for this purpose in the cover and the housing, correspond to the shape of the surfaces of said cradles. The impeller and the volute are replaceable as a pair, the parameters of the impeller and the volute in each pair are calculated to provide maximum efficiency while ensuring the requisite feed and pressure. The replaceable volutes are made as an integrated cast component and comprise a baffle separating the fluid flow during the movement.

Claims

1. A single-stage centrifugal pumping unit comprising a centrifugal single-stage double entry pump, an electric drive motor, a coupling, connecting their shafts, the said pump comprising a housing, which consists of a base and a cover, manifolds, a rotor with an impeller mounted thereon, the rotor being installed in support bearings, a volute, a support frame for mounting the pump housing and the electric motor thereon, wherein the volute is configured in the form of a separate, independent component, and parts of the outside surface thereof, which are intended to be accommodated in cradles provided for this purpose in the cover and the housing of the pump, correspond to the shape of the surfaces of said cradles, the impeller and the volute are replaceable as a pair, the parameters of the impeller and the volute in each pair are calculated to provide maximum efficiency while ensuring the requisite feed and pressure.

2. A single-stage centrifugal pumping unit according to claim 1, wherein the replaceable volutes are made as an integrated cast component and comprise a baffle separating the fluid flow during the movement.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The invention is illustrated by the following drawings.

[0008] FIG. 1 is a general view illustrating a single-stage centrifugal pumping unit;

[0009] FIG. 2 is a vertical plane cross-sectional view of the pump along the pipeline axis;

[0010] FIG. 3 is a vertical plane cross-sectional view illustrating schematic arrangement of a cover, a replaceable flow part and a pump housing along the pipeline axis;

[0011] FIG. 4 illustrates embodiments of replaceable volutes with constant outer connecting profile and various internal hydrodynamic profile designed for optimal operation and maximum efficiency.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0012] To ensure comprehensive understanding of the essence of the present invention, its numerous specific characteristics will be described hereinafter.

[0013] According to the present invention, a single-stage centrifugal pumping unit comprises an electric drive motor 2, a centrifugal single-stage double entry pump 1 (hereinafter, the pump), a coupling 3, connecting their shafts, a pump housing 17, which consists of a base 6 and a cover 7, an inlet manifold 8 and an outlet manifold 9, a rotor 10 with an impeller 11, the rotor being installed in support bearings 12, a volute 13, and a support frame 5 for mounting the pump housing 17 and the electric motor 2 thereon. As shown in FIG. 3, the volute 13 is configured in the form of a separate, independent component, and parts of the outside surface thereof, which are intended to be accommodated in cradles 14 and 15 provided for this purpose in the housing 6 and the cover 7, correspond to the shape of the surfaces of said cradles 14 and 15. The impeller 11 and the volute 13 are replaceable as a pair, the parameters of the impeller 11 and the volute 13 in each pair are calculated to provide maximum efficiency while ensuring the requisite feed and pressure. Preferably, the replaceable volutes 13 are made casted, and they may comprise a baffle 15 for separation of the fluid flow during the movement.

[0014] The pump works in the same way as other known centrifugal single-stage double entry pumps. Upon rotation of the shaft 4 of the pump, pump medium through the inlet manifold 8 is supplied to the impeller 11, interaction of blades of which with the flow of the pumped medium causes conversion of the drive energy to the energy of flow. From the impeller 11, the pumped medium enters the volute, where the flow is smoothed out, and further through the outlet manifold it passes to the pipeline.

[0015] Possibility of using a pair of impeller and volute implemented in the pump design, which is designed and manufactured to be operated in optimal mode, minimizes the radial forces acting on the rotor, which accordingly contributes to operation of the pump with low vibrations and increases its reliability.

[0016] The advantage of the filed invention relating to the possibility of using the same housing for pumps with different characteristics is achieved by that a pump being a base member is a complicated casting of carbon steel, or stainless steel, actually consisting of a housing and a cover. Therefore, in the event of change of the pump operating conditions (reducing pressure on already existing line, or changing the flow through the already existing line) it is not necessary to use the already operating pump in ineffective way, or dismantle it and install a new one designed for new conditions. Just install a new pair of impeller and volute designed for new operating environment in already existing housing, and you will get a pump with new relative calculated characteristics. Thus, there is a significant saving of money due to no need to dismantle the old pump and manufacture a new pump in a new housing. Of particular importance is solution of providing a pump with new characteristics on the basis of the old one, as there is no need to dismantle the pipeline, on which the old pump has been installed and operated.

[0017] In addition, possibility of replacing impellers in a pump to use them in optimal mode will extend the service life of the pump itself, as impellers are rapidly wearing parts and can be manufactured from costly high wear resistant materials, such as steel 20X13, 12X18H12MZTL or similar steel and materials.

[0018] The pump housing is horizontally split, which provides for possibility to dissect, inspect, repair, and replace the parts of the pump and the entire rotor without dismantling the pipes, since the pump inlet and suction manifolds are connected to the bottom of the pump housing.

INDUSTRIAL APPLICABILITY

[0019] The present invention in proposed combination of features can be used to provide a single-stage centrifugal pumping unit which demonstrates peak efficiency in non-nominal modes while having a simplified design, and being universal in nature, durable and easy to operate.