CN213298373U - Efficient cavitation-resistant impeller of mud pump of trailing suction dredger - Google Patents

Abstract

The utility model provides a high-efficient resistant cavitation impeller of drag suction ship dredge pump, includes: the impeller comprises an impeller body, an impeller cover plate and blades, wherein the impeller cover plate is welded with the upper part of the impeller body, and the blades are connected with the impeller body and the impeller cover plate in the middle. Wherein, impeller body includes: the rotary table comprises a wheel disc, a central column, a leaf wall and a groove. The utility model discloses compare with the conventional art, through addding the little dredge pump impeller of external diameter, widen the leaf wall width, the rotational speed is high, spherical area is wide mouthful design, dredge pump impeller material adopts novel material, more accord with the orbit of fluid material point when doing radial and rotary motion in the impeller, under same rotational speed, same clear water flow lift all has the improvement, the blade of curve impeller has been reduced, accord with the motion orbit of fluid material point more, cause the suction resistance to descend and improved positive water head characteristic, improve and get sand efficiency, and reduce the damage to the impeller as far as possible, improve impeller availability factor to the utmost, curve impeller's through-flow has increased to some extent, efficiency and suction performance have been improved.

Description

Efficient cavitation-resistant impeller of mud pump of trailing suction dredger

Technical Field

The utility model relates to a dredge engineering field, concretely relates to high-efficient resistant cavitation impeller of trailing suction dredger dredge pump.

Background

The drag suction ship is respectively constructed in engineering projects such as a deep water channel treatment three-phase dredging project at a Yangtze river mouth, a deep water channel first-phase project below 12.5 meters of Nanjing at the Yangtze river, a Hainan engineering project and the like, and the working conditions are dredging and hydraulic filling, so that the drag suction ship plays a due role in the production and operation of a company. However, as the daily wear of ship dredging equipment and the construction environment change over time and the dredging equipment is developed in recent years, particularly when the soil such as coral sand is excavated, the original mud pump of the trailing suction ship is not satisfactory, and the mud pump is poor in adaptability and low in construction efficiency. When the drag suction ship excavates the viscous blocky soil of coral sand, compared with other ships of a company and similar ships of brothers, the drag suction ship has low loading density and poor construction efficiency, and the construction efficiency of the drag suction ship is only 32% of that of the ships of the same level through statistical analysis of the construction efficiency of the ships participating in the same project.

In order to solve the above problems, we have made a series of improvements.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a high-efficient resistant cavitation impeller of trailing suction dredger dredge pump to overcome the above-mentioned shortcoming and not enough that prior art exists.

The utility model provides a high-efficient resistant cavitation impeller of drag suction ship dredge pump, includes: the impeller comprises an impeller body, an impeller cover plate and blades, wherein the impeller cover plate is welded with the upper part of the impeller body, and the blades are connected with the impeller body and the middle of the impeller cover plate;

wherein the impeller body includes: the novel rotary vane comprises a wheel disc, a central column, a leaf wall and a groove, wherein the central column is connected with the center of the wheel disc, the leaf wall is connected with the outer side of the wheel disc, the groove is formed in the wheel disc and is connected with vanes, and the spherical area of the central column is of a wide-mouth structure.

Further, the inclination angles of the blades relative to the impeller body are sequentially increased and decreased from inside to outside.

The utility model has the advantages that:

the utility model discloses compare with the conventional art, add the little dredge pump impeller of external diameter, widen the leaf wall width, the rotational speed is high, spherical area is wide mouthful design, dredge pump impeller material adopts novel material, more accord with the orbit of fluid material point when doing radial and rotary motion in the impeller, under same rotational speed, same clear water flow lift all has the improvement, the blade of curve impeller has been reduced, accord with the motion orbit of fluid material point more, cause the suction resistance to descend and improved positive water head characteristic, improve and get sand efficiency, and reduce the damage to the impeller as far as possible, improve impeller availability factor to the utmost, curve impeller's through-flow increases to some extent, efficiency and suction performance are improved.

Description of the drawings:

fig. 1 is a side view of the present invention.

Fig. 2 is a top view of the present invention.

Reference numerals:

impeller body 100, disk 110, center post 120, vane wall 130, and groove 140.

A shroud 200 and a blade 300.

Detailed Description

The present invention will be further described with reference to the following examples. It should be understood that the following examples are illustrative only and are not intended to limit the scope of the present invention.

Example 1

Fig. 1 is a side view of the present invention. Fig. 2 is a top view of the present invention.

As shown in fig. 1 and 2, a high-efficiency cavitation-resistant impeller of a drag suction dredge pump comprises: the impeller comprises an impeller body 100, an impeller cover plate 200 and blades 300, wherein the impeller cover plate 200 is welded with the upper part of the impeller body 100, and the blades 300 are connected with the impeller body 100 and the impeller cover plate 200 in the middle;

wherein, impeller body 100 includes: the impeller comprises an impeller disc 110, a center column 120, a leaf wall 130 and a groove 140, wherein the center column 120 is connected with the center of the impeller disc 110, the leaf wall 130 is connected with the outer side of the impeller disc 110, the groove 140 is arranged on the impeller disc 110, the groove 140 is connected with blades 300, and the spherical area of the center column 120 is of a wide-mouth structure.

The inclination angle of the blade 300 with respect to the impeller body 100 increases to decrease from inside to outside in this order.

When the flow rate is about 5.5m3/s, cavitation already begins to occur when the vacuum degree reaches-0.75 bar, and the higher the vacuum degree is, the more bubbles are separated out from the water, and the more serious the cavitation phenomenon is. Meanwhile, the dug soil is coarse sand, certain abrasion is generated on a mud pump, and the movement speed, the movement fluctuation and the sedimentation angle of particles have certain influence on the abrasion. However, according to the results of the past mud pump disassembly and inspection, the damage of the impeller mainly comes from cavitation, the blade root at the front cover plate and the blade root at the position close to the impeller outlet are most seriously corroded, and finally 4 through holes are formed at the blade root of the left mud pump impeller and the blade root of the right mud pump impeller.

It can be known from the working principle of centrifugal pump that when the centrifugal pump is running, a certain low pressure Ps must be produced at the inlet to suck liquid continuously, but when Ps is lower than the vaporization pressure Pv of the liquid to be conveyed at a certain temperature, the liquid is vaporized, and when the vaporized bubbles enter a region with higher pressure, the bubbles are pressurized and broken, and strong impact is produced after the bubbles are broken and hit the impeller or the pump shell, so that the continuous local impact load gradually causes fatigue of the metal surface to degrade, even penetrate, and the bubbles produced by the cavitation block the flow channel, thus destroying the continuous flow of the liquid in the pump, and obviously reducing the flow rate, lift and efficiency of the pump. Because the installation position of the dredge pump is high relative to the suction port due to the extreme digging depth, and the suction vacuum degree is large, people need to pay close attention to the cavitation of the dredge pump during the extreme sand taking operation.

The utility model discloses a creativity appears, adopts the mud pump impeller external diameter little, the leaf wall width is wide, the rotational speed is high, and spherical area is wide mouthful of design, and the mud pump impeller material adopts novel material, more accords with the orbit of fluid mass point when doing radial and rotary motion in the impeller. Under the same rotating speed, the same clear water flow lift is improved, and the blades of the curved impeller are reduced to better conform to the motion track of fluid mass points, so that the suction resistance is reduced, the positive water head characteristic is improved, and the suction capacity is increased by 40-50%; the efficiency is improved by 5-7%, and the through flow of the curve impeller is increased to some extent. To improve efficiency and suction performance.

We do preliminary analysis for the high-efficiency cavitation-resistant impeller adopted this time, and can determine the difference between the high-efficiency cavitation-resistant impeller and the common straight-blade impeller by two basic parameters:

1) lift: the head H is the difference between the head of the liquid before it leaves the impeller and the head of the liquid as it enters the impeller.

H-u 22/g-u2v2rcot beta/g (where u2 is the peripheral speed of the liquid at the impeller outlet, v2r is the radial partial speed of the liquid at the impeller outlet, and beta is the vane outlet angle) is obtained by a series of conversions, and the pump lift depends on the vane outlet angle beta under the conditions of the same impeller diameter and the same pump rotating speed. In a centrifugal pump with the same size and rotating speed, the larger the blade outlet angle beta is, the higher the lift can be. The high-efficiency cavitation-resistant impeller changes the curvature of the blade on the basis of a straight blade impeller, so that the angle is increased. Under the same working condition, the curve impeller has higher lift than a non-curve impeller, and is beneficial to quickly taking sand. Under the same working condition, the impeller has higher lift than a common straight blade impeller, and is beneficial to remote sand blowing.

2) The cavitation margin NPSH is the difference between the total head of the liquid at the pump inlet and its saturated vapor pressure head. The required cavitation margin is a cavitation margin required for the pump to avoid cavitation, and the flow rate of the impeller is larger than that of the impeller under the condition of the same required cavitation margin NPSHr. In other words, under the condition of the same flow, the impeller has small necessary cavitation allowance, namely the impeller has the cavitation resistance compared with the common straight blade impeller, and the dredge pump can work under a slightly high vacuum degree without cavitation, thereby improving the pumping capacity of the dredge pump, shortening the sand extracting time and being beneficial to the deep sea sand extraction.

The above description has been made of the embodiments of the present invention, but the present invention is not limited thereto, and various changes may be made without departing from the spirit of the present invention.

Claims (2)

1. The utility model provides a high-efficient resistant cavitation impeller of drag suction ship dredge pump which characterized in that includes: the impeller comprises an impeller body (100), an impeller cover plate (200) and blades (300), wherein the impeller cover plate (200) is welded with the upper part of the impeller body (100), and the blades (300) are connected with the middle of the impeller body (100) and the impeller cover plate (200);

wherein the impeller body (100) comprises: the novel blade wheel comprises a wheel disc (110), a central column (120), a leaf wall (130) and a groove (140), wherein the central column (120) is connected with the center of the wheel disc (110), the leaf wall (130) is connected with the outer side of the wheel disc (110), the groove (140) is formed in the wheel disc (110), the groove (140) is connected with blades (300), and the spherical area of the central column (120) is of a wide-mouth structure.

2. The efficient cavitation-resistant impeller of the drag suction dredger dredge pump according to claim 1, characterized in that: the inclination angle of the blade (300) relative to the impeller body (100) is increased to be reduced from inside to outside in sequence.

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