RU239301U1 - SLURRY CENTRIFUGAL PUMP - Google Patents

Abstract

The utility model relates to centrifugal pumps for pumping special fluid media, such as viscous and heterogeneous fluid media, and can be used as a slurry pump in the mining industry, metallurgy, in the construction industry, and in wastewater treatment. A slurry centrifugal pump comprising a housing that contains a first section and a second section connected by side inlets, wherein the first section and the second section contain pump stages secured on a shaft supported by bearings, which, in turn, are secured in the housing, wherein the first section contains a pressure chamber of the first section, and the second section contains a pressure chamber of the second section, while the pressure chamber of the first section is separated from the pressure chamber of the second section by a gap seal located between the shaft and the elements of the housing, in addition, an impeller is installed on the reverse side of the driving disk of the centrifugal wheel of the outermost stage of the second section of the pump. The technical result of the utility model consists in increasing the service life and improving the reliability of the pump. 3 fig.

Description

The utility model relates to centrifugal pumps for pumping special fluid media, such as viscous and non-uniform fluid media, and can be used as a slurry pump in the mining industry, metallurgy, in the construction industry and in wastewater treatment.

A MULTISTAGE CENTRIFUGAL PUMP OF A SEGMENT TYPE is known from the prior art [CN 105351206 A, published 02/24/2016], comprising a suction section, a first stage impeller, impeller guide vanes, a middle section, a second stage impeller, an outlet section, a pump shaft, a shaft sleeve, an impeller spacer ring, a friction bearing connected to the outer side of the shaft sleeve, a rolling bearing, an elastic connector connected to the pump shaft, and an external prime mover driving the pump shaft through the elastic connector. A plurality of spiral grooves are formed in the inner wall of the friction bearing; the impellers are assembled on the pump shaft in a keyed connection mode; the impeller guide vanes are assembled in the middle section. The fluid is forced through the impellers and collected through the impeller guide vanes. The flow velocity decreases, and the fluid is discharged through the outlet section and fed into the piping system. Spiral grooves in the inner wall of the plain bearing increase the fluid circulation volume and ensure good lubrication of the plain bearing. A disadvantage of this pump is the increased content of solid mechanical impurities in the circulating fluid, which leads to accelerated wear of the moving parts of the pump, as well as the plain bearings, as the fluid circulates in the spiral grooves. This reduces the pump's reliability and shortens its service life.

The closest in technical essence is the EFFICIENT THROTELLING AND SEALING SELF-BALANCING MULTISTAGE CENTRIFUGAL PUMP [CN 215672848 U, publ. 28.01.2022], comprising a bearing assembly, a water inlet section, an impeller, a guide vane, a middle section and an end stage, an end mouth ring, a water outlet, a spiral groove of the annular sleeve of the shaft A, the last stage of the reverse impeller, the last stage of the reverse guide vane, the last stage of the reverse port ring, a reverse middle section, a reverse guide vane, a reverse impeller, a reverse water inlet section, a spiral groove of the annular sleeve B, a semi-open impeller, a seal assembly, a bearing assembly B and which is characterized in that the inner circumference of the front opening ring of the last stage is matched with the structure of the circular protrusion of the rear cover of the front impeller of the last stage to form an annular gap seal, and the inner circumference of the reverse opening ring of the last stage is matched with the structure of the circular protrusion of the rear cover of the reverse impeller of the last stage to form an annular gap seal, wherein the annular sleeve with a spiral The A-groove bushing is mounted on the pump shaft using a standard flat keyway, while the B-groove bushing is firmly mounted in the return water inlet section using screws. The main technical challenge of the prototype is the use of multi-stage elements with complex geometry and high mating precision, which increases the risk of misalignment, accelerated wear, contamination, and seizure of moving parts when the pumped liquid contains mechanical impurities. This reduces the pump's reliability and service life.

The purpose of a utility model is to eliminate the shortcomings of the prototype.

The technical result of the utility model is to increase the service life and improve the reliability of the pump.

The said technical result is achieved due to the fact that the slurry centrifugal pump contains a housing which contains a first section and a second section connected by side inlets, wherein the first section and the second section contain pump stages secured on a shaft supported by bearings which, in turn, are secured in the housing, wherein the first section contains a pressure chamber of the first section, and the second section contains a pressure chamber of the second section, at the same time the pressure chamber of the first section is separated from the pressure chamber of the second section by a gap seal located between the shaft and the elements of the housing, in addition, an impeller is installed on the reverse side of the driving disk of the centrifugal wheel of the outer stage of the second section of the pump.

Brief description of the drawings:

Fig. 1 shows the general appearance of a slurry centrifugal pump.

Fig. 2 shows a longitudinal section of a slurry centrifugal pump.

Fig. 3 shows a local view of a longitudinal section of a slurry centrifugal pump.

The following are indicated on the figures: 1 - housing, 2 - first section, 3 - second section, 4 - suction chamber of the first section, 5 - suction chamber of the second section, 6 - pressure chamber of the first section, 7 - pressure chamber of the second section, 8 - centrifugal wheel of the outer stage of the second section, 9 - shaft, 10 - bearing, 11 - gap seal, 12 - side inlets.

Implementation of a utility model

The slurry centrifugal pump contains a housing 1, which contains a first section 2 and a second section 3, connected by side connections 12 (Fig. 1) and containing pump stages, wherein the pump stages are secured on a shaft 9, supported by bearings 10 secured in the housing 1, and between the shaft 9 and the elements of the housing 1 a gap seal 11 is provided (Fig. 2). The first section 2 contains a suction chamber of the first section 4, which is located on the side adjacent to the pump drive, and the second section 3 contains a suction chamber of the second section 5, which is located on the side opposite to the pump drive, wherein the first section 2 also contains a pressure chamber of the first section 6, and the second section 3 contains a pressure chamber of the second section 7. The pressure chamber of the first section 6 and the pressure chamber of the second section 7 are separated by a gap seal 11, located between the shaft 9 and the housing 1. In addition, the centrifugal wheel of the outer (i.e. closest to the pressure chamber of the second section 7) stage 8 of the second section 3 is equipped with an impeller configured to create, during rotation, a centrifugal force that accelerates the settling of large particles of sludge, while the settling speed of large particles under the action of centrifugal force is higher than the radial velocity of the liquid at the outer diameter of the impeller, which prevents them Entry into the gap of the gap seal 11. This significantly reduces seal wear and, consequently, increases the pump's reliability and service life. The impeller can be either a separate device adjacent to the eighth-stage centrifugal wheel 8, or it can be made as blades mounted on the reverse side of the drive disk of the outermost-stage centrifugal wheel 8 of the second section 3.

Examples of implementation of the utility model.

In accordance with this utility model, the following examples of the device implementation were implemented.

Example 1

The slurry centrifugal pump featured a horizontal casing, comprising a first section and a second section, connected via side inlets through which the pumped slurry circulated. Each section contained two pump stages, mounted on a common shaft supported by radial-thrust ball bearings. The bearings were housed in bearing seats in the casing and secured with pressure caps. A gap seal was located between the shaft and the pump casing, and an impeller, keyed to the shaft, was mounted on the reverse side of the drive disc of the outer impeller of the second section. This design solution created centrifugal force in the flow of the pumped liquid as the impeller blades rotated. This force facilitated the separation of large slurry particles and prevented them from entering the gap seal, significantly reducing wear. Based on the results of comparative tests, the pump, in accordance with this utility model, demonstrated a reduction in wear of the gap seal and shaft surface during the period between repairs by 1.64 times.

Example 2

The slurry centrifugal pump featured a horizontal casing comprising a first section and a second section, interconnected via side inlets through which the pumped slurry circulated. Each section contained four pump stages, mounted on a common shaft supported by radial-thrust ball bearings. The bearings were housed in bearing seats in the casing and secured with pressure caps. A gap seal was located between the shaft and the pump casing, and an impeller, secured to the shaft via a keyed connection, was mounted on the reverse side of the drive disc of the outer impeller of the second section. Comparative tests conducted on the pump, in accordance with this utility model, demonstrated a 1.52-fold reduction in wear on the gap seal and shaft surface during the period between overhauls.

Example 3

The slurry centrifugal pump featured a horizontal casing comprising a first section and a second section, interconnected via side inlets through which the pumped slurry circulated. Each section contained six pump stages, mounted on a common shaft supported by radial-thrust ball bearings. The bearings were housed in bearing seats in the casing and secured with pressure caps. A gap seal was located between the shaft and the pump casing, and an impeller, secured to the shaft via a keyed connection, was mounted on the reverse side of the drive disc of the outer impeller of the second section. Comparative tests conducted on the pump, in accordance with this utility model, demonstrated a 1.52-fold reduction in wear on the gap seal and shaft surface during the period between overhauls.

The technical result of the utility model is to increase the service life and improve the reliability of the pump.

This technical result is achieved by the pump's two sections, connected by side inlets. This ensures continued pump operation in the event of a failure of one section's pump stages, thereby increasing the pump's reliability. Furthermore, the two-section design of the slurry centrifugal pump, with the pump stages located on a common shaft and the pressure chambers of the first and second sections separated by a gap seal, helps contain liquid and solids flows within the respective sections, thereby ensuring increased pump reliability and a longer service life.

The technical result is also achieved by the inclusion of an impeller in the slurry centrifugal pump design, mounted on the reverse side of the drive disk of the centrifugal wheel of the outermost stage of the second section. This element, when rotating, generates a centrifugal force directed from the axis of rotation to the periphery, accelerating the settling of large solid particles of slurry. Because the settling velocity of these particles is higher than the radial velocity of the fluid at the impeller's outer diameter, a separation effect is created, preventing abrasive particles from entering the gap seal. This, in turn, significantly reduces seal wear, improving its efficiency and the reliability of the entire structure. Mounting the impeller on the reverse side of the drive disc of the centrifugal impeller of the outermost stage of the second section is crucial to achieving the stated technical result, as the outermost stage of the second section directly adjoins the pressure chamber of this section. Consequently, this zone experiences the highest pressures and is the most likely to attract solid particles of sludge into the gap seal. Mounting the impeller in this position effectively influences the fluid flow at the most critical point—at the outlet of the last stage, before the gap seal, where abrasive particles are most likely to enter the gap between the shaft and the housing elements. Furthermore, positioning the impeller behind the drive disc of the impeller promotes the formation of a localized vortex flow with a pronounced centrifugal component, which throws large solid particles of sludge away from the axial zone and toward the periphery. This creates an additional protective barrier for the gap seal, preventing solid particles from entering the gap and reducing their abrasive impact on the seal components.

Compared to the prototype and similar products, the claimed utility model offers an extended service life and improved reliability. Comparative tests using examples 1-3 showed that wear on the gap seal and shaft surface during the overhaul period was reduced by more than 50% compared to the prototype.

Thus, the claimed slurry centrifugal pump ensures high wear resistance of the gap seal and an extended service life. Only the presence of all of these features ensures high reliability of the pump's operating components and the ability to perform their functions for extended periods without failure or replacement, which together guarantees the achievement of the stated technical result—an extended service life and improved pump reliability. The omission or non-compliance with even one of these features leads to a reduction in the reliability of the utility model and its service life, and, consequently, to the failure to achieve the stated technical result.

Claims (1)

A slurry centrifugal pump comprising a housing which comprises a first section and a second section connected by side inlets, wherein the first section and the second section comprise pump stages secured on a shaft supported by bearings which, in turn, are secured in the housing, wherein the first section comprises a pressure chamber of the first section, and the second section comprises a pressure chamber of the second section, while the pressure chamber of the first section is separated from the pressure chamber of the second section by a gap seal located between the shaft and the elements of the housing, in addition, an impeller is installed on the reverse side of the driving disk of the centrifugal wheel of the outermost stage of the second section of the pump closest to the pressure chamber.