A mud pump and a method for configuring mud pump flushing parameters.

Abstract

This invention provides a mud pump and a method for configuring its flushing parameters. The mud pump includes two inlet guide pipes arranged symmetrically around the center line of the impeller. One end of each inlet guide pipe is connected to the suction flushing chamber and forms an inlet on the front cover; the other end is connected to an external water source. The length direction of the inlet guide pipe is aligned with the tangential direction of the suction flushing chamber. The water flow direction from the inlet guide pipe to the inlet is aligned with the rotation direction of the impeller, which reduces the impact of the flushing water flow on the rotating water flow in the suction flushing chamber and reduces wear on the mud pump's flow-through components. The mud pump flushing parameter configuration method is based on the impeller diameter D. 叶 The values ​​of mud pump speed n and mud pump head H are calculated using empirical formulas to obtain appropriate flushing flow rate and flushing pressure, preventing mud from flowing back into the gap between the impeller and the wear-resistant liner, improving the stability of mud pump operation, and contributing to the smooth progress of construction.

Description

Technical Field

[0001] This invention relates to the field of dredging technology, specifically to a mud pump and a method for configuring mud pump flushing parameters. Background Technology

[0002] The mud pump is a key piece of equipment on a hydraulic dredging vessel. It primarily utilizes water movement to achieve dredging. It loosens underwater soil layers through mechanical or high-pressure water cutting, mixing the mud and water to form a mud-water mixture (slurry). This slurry is then drawn into the mud pump through a vacuum suction port installed on the vessel and discharged into the dredging tank, directly onto a mud barge alongside the ship, or transported to the reclamation area via slurry pipelines, thus achieving the purpose of dredging and reclamation. Therefore, the mud pump is a crucial piece of equipment on a dredging vessel, and its hydraulic performance and wear resistance directly affect the dredging efficiency.

[0003] Because mud pumps transport high-concentration mud, their flow-through components are prone to wear. In existing technology, to reduce wear, a water inlet is typically installed on the front pump cover to introduce clean water from the outside; this is essentially a flushing system between the impeller and the liner to reduce wear from the mud on the impeller and liner. Figure 3 As shown, the hollow thick arrow indicates the direction of mud flow, and the unidirectional thin arrow indicates the direction of flushing water flow at the suction end. However, in the structure of a dredging mud pump, the flushing water at the suction end is usually a normal inlet, with the flushing water outlet direction perpendicular to the inner wall of the flushing chamber at the suction end, and the water flow direction passing through the center of the pump. The flushing water flow impacts the rotating water flow in the flushing chamber at the suction end, causing disturbance, which is not conducive to the discharge of mud and sand particles. At the same time, it is easy to induce local vortex backflow. Some mud and sand particles in the flushing chamber are aggravated by the vortex backflow, which intensifies the wear on the walls of the flow-through components, affecting the service life and reliability of the mud pump during operation, and is not conducive to construction. In addition, in actual engineering applications, the flushing parameters of the mud pump are usually set by the operator based on experience or habit, lacking a unified parameter setting rule, making the mud pump prone to failure, unstable working state, and affecting the continuity of construction. Summary of the Invention

[0004] This invention is made to solve the above-mentioned problems, and its purpose is to provide a mud pump and a method for configuring the flushing parameters of the mud pump.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A mud pump includes a housing consisting of a front cover, a pump casing, and a rear cover. An impeller is disposed inside the housing, and wear-resistant liners are provided between the impeller and both the front and rear covers. The impeller's suction end is provided with an impeller suction port anti-wear ring and a suction end water seal assembly, forming an annular suction end flushing chamber between the impeller, the front cover, and the wear-resistant liners. The pump also includes two inlet guide pipes, arranged symmetrically around the center line of the impeller. One end of each inlet guide pipe communicates with the suction end flushing chamber and forms an inlet on the front cover; the other end communicates with an external water source. The length direction of the inlet guide pipe is consistent with the tangential direction of the suction end flushing chamber, and the water flow direction from the inlet guide pipe to the inlet is consistent with the rotation direction of the impeller.

[0007] Furthermore, the inner diameter d of the water inlet guide pipe 管 The range of values ​​for is:

[0008] d 管 = (0.013~0.018)D 叶 ·L -0.5

[0009] In the formula, L is the vertical distance from the centerline of the inlet guide pipe to the impeller, and D... 叶 Where L and D are the diameters of the impeller. 叶 d 管 The unit for all values ​​is m.

[0010] Preferably, the inner diameter d of the water inlet guide pipe 管 The value is d 管 =0.0159D 叶 ·L -0.5 .

[0011] Furthermore, a flange is provided at the end of the water inlet guide pipe away from the front cover, which is used to connect to a water supply pipe from an external water source.

[0012] A method for configuring flushing parameters for a mud pump, using the aforementioned mud pump, includes:

[0013] Step S1: Determine the rotational speed n of the mud pump in rpm, and determine the head H of the mud pump and the diameter D of the impeller in the mud pump in meters. 叶 ;

[0014] Step S2, based on the pump speed n and the impeller diameter D mentioned in step S1. 叶 The value of the tangential flushing flow rate q is calculated using an empirical formula, which is q = (0.05~0.1)n·D. 叶 2 The unit is m 3 / h;

[0015] Step S3: Take the flushing pressure p as 1.3 times the mud pump head H, in mH2O.

[0016] Preferably, the tangential flushing flow rate q is taken as q = 0.075n·D 叶 2 .

[0017] The present invention has the following beneficial effects:

[0018] 1. In this invention, the mud pump introduces external water into the suction end flushing chamber through an inlet guide pipe, carrying away the mud and sand between the flushing chamber, impeller, and wear-resistant liner. The length direction of the inlet guide pipe is consistent with the tangential direction of the suction end flushing chamber, and the two inlet guide pipes are centrally symmetrically arranged, so that the incoming flushing water forms a ring-shaped water flow consistent with the impeller rotation direction. This reduces the impact of the flushing water flow on the rotating water flow in the suction side flushing chamber, avoids disturbance and local vortex backflow, reduces the wear of the mud pump's flow-through components, increases the service life of the mud pump's suction end sealing assembly, impeller, wear-resistant liner, and other flow-through components, reduces the need for repair and replacement of vulnerable parts, saves maintenance costs, and improves the continuity and efficiency of dredging operations.

[0019] 2. The mud pump flushing parameter configuration method provided by this invention is based on the impeller diameter D. 叶 The values ​​of mud pump speed n and mud pump head H are calculated using empirical formulas to obtain appropriate flushing flow rate and flushing pressure. This prevents mud from flowing back into the gap between the impeller and the wear-resistant liner, ensures the flushing effect on the flushing chamber and the mud and sand between the impeller and the wear-resistant liner, improves the stability of mud pump operation, reduces the possibility of failure, and helps the construction proceed smoothly. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the mud pump structure in an embodiment of the present invention;

[0021] Figure 2 This is a cross-sectional view of the mud pump in an embodiment of the present invention;

[0022] Figure 3 This is a cross-sectional view of the flushing chamber at the suction end in an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the front cover structure in an embodiment of the present invention;

[0024] Figure 5 This is a front view of the front cover in an embodiment of the present invention;

[0025] Figure 6 yes Figure 5 A sectional view of section AA; and

[0026] Figure 7 This is a flowchart of the mud pump flushing parameter configuration in an embodiment of the present invention.

[0027] Icon labels:

[0028] 10 Housing, 11 Front cover, 12 Pump housing, 13 Rear cover, 14 Inlet guide pipe, Flange 141;

[0029] 20 Impeller, 21 Wear-resistant liner, 22 Impeller suction port anti-wear ring, 23 Suction end water seal assembly, 24 Water seal chamber, 25 Suction end flushing chamber;

[0030] 30 Transmission mechanism, 31 Bearing housing, 32 Bearing cylinder assembly, 33 Pump shaft. Detailed Implementation

[0031] To make the technical means, creative features, objectives and effects of the present invention easy to understand, the following embodiments, in conjunction with the accompanying drawings, will specifically illustrate the mud pump of the present invention.

[0032] <Example>

[0033] like Figures 1-3 As shown, the mud pump of this embodiment includes a housing 10 consisting of a front cover 11, a pump casing 12, and a rear cover 13. An impeller 20 is provided inside the housing 10, and wear-resistant liners 21 are provided between the impeller 20 and the front cover 11 and the rear cover 13. The suction end of the impeller 20 is provided with an impeller suction port anti-wear ring 22 and a suction end water seal assembly 23. The impeller suction port anti-wear ring 22, the suction end water seal assembly 23, the front cover 11, and the wear-resistant liner 21 form an annular suction end flushing chamber 25.

[0034] A transmission mechanism 30 is also provided on one side of the rear cover 13 of the mud pump. The transmission mechanism 30 includes a bearing housing 31, a bearing sleeve assembly 32, and a pump shaft 33. The bearing housing 31 is installed on the hull deck to support the bearing sleeve assembly 32. The pump shaft 33 is disposed in the bearing sleeve assembly 32, and its front end is fixedly connected to the impeller 20, for example, by a threaded connection, to drive the impeller 20 to rotate.

[0035] The rear cover 13 is bolted to the bearing housing 31, the pump casing 12 is bolted to the rear cover 13, and the front cover 11 is bolted to the pump casing 12. Wear-resistant liners 21 on both sides of the impeller 20 are fixed to the inner walls of the front cover 11 and the rear cover 13, respectively, to reduce wear on the casing. The impeller suction inlet anti-wear ring 22 is bolted to the impeller 20, the suction end water seal assembly 23 is bolted to the front cover 11, and a water seal chamber 24 is provided on the outer side of the rear cover 13 to prevent mud and sand from abrading the pump shaft 33. The water seal chamber 24 is bolted to the rear cover 13.

[0036] like Figures 4-6As shown, in this embodiment, the mud pump further includes two inlet guide pipes 14, which are arranged symmetrically around the center line of the impeller 20. One end of each inlet guide pipe 14 is connected to the suction end flushing chamber and forms an inlet 111 on the front cover 11; the other end is connected to an external water source. The length direction of the inlet guide pipe 14 is consistent with the tangential direction of the suction end flushing chamber, and the water flow direction from the inlet guide pipe 14 to the inlet 111 is consistent with the rotation direction of the impeller 20. Figure 4 The tangential water flow direction and the impeller rotation direction are both clockwise.

[0037] Furthermore, the end of the water inlet guide pipe 14 away from the front cover 11 is provided with a flange 141, which is used to connect to the water supply pipe of an external water source.

[0038] In use, the flange 141 at the port of the inlet guide pipe 14 is connected to the outlet of the water pump. The water pump delivers clean water into the inlet guide pipe 14. The water flows tangentially into the suction end flushing chamber along the inlet guide pipe 14, then rotates along the inner wall of the flushing chamber to form an annular flow. The rotation direction is the same as the impeller 20's rotation direction, which reduces flow impact. Simultaneously, the flushing water flows from near the center of the impeller 20 to the outer edge along the gap between the impeller 20 and the wear-resistant liner 21 at the front cover, carrying away sediment and reducing wear on the suction end flushing chamber, the impeller suction port anti-wear ring 22, the impeller 20, and the wear-resistant liner 21. Therefore, the mud pump of this embodiment can avoid the flushing water impacting the rotating water flow in the suction end flushing chamber, causing disturbance and triggering local vortex backflow. This further prevents some sediment particles in the flushing chamber from increasing wear on the walls of the flow-through components due to the vortex backflow.

[0039] like Figure 7 As shown, this embodiment also provides a method for configuring mud pump flushing parameters, using the aforementioned mud pump, including:

[0040] Step S1: Determine the rotational speed n of the mud pump in rpm, and determine the head H of the mud pump and the diameter D of the impeller in the mud pump in meters. 叶 ;

[0041] Step S2, based on the pump speed n and the impeller diameter D mentioned in step S1. 叶 The value of the tangential flushing flow rate q is calculated using an empirical formula, which is q = (0.05~0.1)n·D. 叶 2 The unit is m 3 / h;

[0042] Step S3: Take the flushing pressure p as 1.3 times the mud pump head H, in mH2O.

[0043] Specifically, based on the mud pump structure in this embodiment, the flushing water flows tangentially into the suction end flushing chamber along the inlet guide pipe 14, then flows into the gap between the impeller 20 and the wear-resistant liner 21, and flows out towards the outer edge of the impeller 20 diameter (e.g., Figure 3 (As indicated by the thin, unidirectional arrow). To prevent the slurry from the impeller 20 outlet from flowing back into the gap between the impeller 20 and the wear-resistant liner 21, the flushing flow rate needs to reach at least a specific value. Due to the rotational action of the impeller 20, the liquid within the gap acquires a circumferential velocity, and the liquid tends to move outward due to centrifugal force. The circumferential velocity at the outer diameter of the impeller 20, the slurry pump speed n, and the impeller diameter D... 叶 Therefore, the required flushing flow rate q, mud pump speed n, and impeller diameter D to meet the preconditions are related. 叶 related.

[0044] Through computer simulation, the required flushing flow rate for mud pumps with different rotational speeds and impeller diameters was obtained, and a relationship was established between the flushing flow rate q and the mud pump rotational speed n and impeller diameter D. 叶 Functional relationship:

[0045] First, for a fixed mud pump (i.e., controlling the impeller diameter D) 叶 (Unchanged), the minimum flushing flow rate is obtained by repeatedly adjusting the flushing flow rate at the same rotational speed to meet the prerequisite (i.e., flushing water flows along the gap between the impeller and the liner towards the outer diameter of the impeller without backflow), and is denoted as the required flushing flow rate q at that rotational speed. Several commonly used mud pump rotational speed values ​​are selected to obtain the required flushing flow rate q corresponding to the rotational speed. In this embodiment, the impeller diameter D is used as the reference value. 叶 Taking 2m as an example, the simulation results are shown in the table below:

[0046] Mud pump speed n (rpm) <![CDATA[Impeller diameter D 叶 (m)]]> <![CDATA[Required flushing flow rate q (m 3 / h)]]> 200 2 40 250 2 50 300 2 60 350 2 70 400 2 80 450 2 90

[0047] Therefore, for the same mud pump, the required flushing flow rate q is directly proportional to the pump speed n. Let the flushing flow rate q = k1n, then when the impeller diameter is 2m, the coefficient k1 is 0.2.

[0048] Then, simulation experiments were conducted on several mud pumps with different impeller diameters operating at the same speed to obtain the required flushing flow rate q for each mud pump under the given conditions. In this embodiment, the mud pump speed n = 300 rpm is taken as an example. The simulation results are shown in the table below:

[0049]

[0050] Since it is known that the flushing flow rate q is directly proportional to the mud pump speed n, the functional relationship can be established as: q / n=f(D 叶 After fitting using the least squares method, we obtain q / n = kD. 叶 2That is, f(D) 叶 ) and impeller diameter D 叶 The squares of the terms show a linear relationship, and the average value of the coefficient k is approximately 0.05, which yields:

[0051] q = 0.05n·D 叶 2 .

[0052] Finally, considering the changes in mortar concentration during pumping in practical applications and the increasing gap between the impeller 20 and the wear-resistant liner 21 due to wear and aging, it is necessary to appropriately increase the flushing flow rate q. Therefore, the range of the coefficient k is expanded to 0.05–0.1, resulting in the empirical formula for the flushing flow rate:

[0053] q=(0.05~0.1)n·D 叶 2 .

[0054] In actual dredging projects, the specific gravity of the mud pumped is typically 1.3 g / cm³. 3 That is, the density of mud is equivalent to 1.3 times that of water. The head of the mud pump, H, is the lifting height of the mud pump. Therefore, 1.3 times the mud pump head H (clear water head) is equivalent to the mud pump head. Based on experience, the corresponding flushing pressure is determined to be 1.3 times the head H.

[0055] Furthermore, to reduce water flow impact disturbance, the velocity of the incoming flushing water is made the same as the velocity of the rotating water flow in the original flushing chamber, i.e. Let q = (0.05~0.1)n·D 叶 2 After substituting the values, we obtain the range of possible values ​​for the inner diameter of the water inlet guide pipe 14:

[0056] d 管 = (0.013~0.018)D 叶 ·L -0.5 ,

[0057] In the formula, L is the distance from the water inlet of the water inlet guide pipe on the front cover to the center line of the impeller. Figure 3 ), L, D 叶 d 管 The unit for all values ​​is m.

[0058] Preferably, the inner diameter of the water inlet guide pipe is d. 管 =0.0159D 叶 ·L -0.5 .

[0059] In this embodiment, the distance L from the inlet to the center line of the impeller 20 is 0.57m, and the impeller diameter D is... 叶 If the diameter is 2m, then the inner diameter of the inlet guide pipe 14 is taken as:

[0060] d 管 =0.0159D 叶 ·L -0.5 =0.0159×2×0.57 -0.5 =0.042m.

[0061] Preferably, the tangential flushing flow rate q is taken as q = 0.075n·D 叶 2 .

[0062] In this embodiment, taking a mud pump speed of 300 rpm, a mud pump head of 80 m, and an impeller diameter of 2 m as an example, the calculation is as follows:

[0063] Tangential flushing flow rate q = 0.075n·D 叶 2 =0.075×300×2 2 =90m 3 / h;

[0064] The flushing pressure p = 1.3H = 1.3 x 80 = 104 mH2O.

[0065] The above embodiments are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A mud pump, comprising a housing consisting of a front cover, a pump casing, and a rear cover, wherein an impeller is disposed inside the housing, and wear-resistant liners are provided between the impeller and both the front and rear covers; the suction end of the impeller is provided with an impeller suction port anti-wear ring and a suction end water seal assembly, forming an annular suction end flushing chamber between the impeller, the front cover, and the wear-resistant liners; characterized in that, Also includes: Two water inlet guide pipes are arranged symmetrically around the center line of the impeller. One end of each water inlet guide pipe is connected to the suction end flushing chamber and forms a water inlet on the front cover. The other end is connected to an external water source. The length direction of the water inlet guide pipe is consistent with the tangential direction of the suction end flushing chamber. The water flow direction from the water inlet guide pipe to the water inlet is consistent with the rotation direction of the impeller. Among them, the inner diameter of the water inlet guide pipe The range of values ​​for is: ； In the formula, L is the vertical distance from the water inlet guide pipe to the center line of the impeller. L is the diameter of the impeller. , The unit for all values ​​is m.

2. The mud pump according to claim 1, characterized in that: in, Inner diameter of the water inlet guide pipe Values .

3. The mud pump according to claim 1, characterized in that: in, The end of the water inlet guide pipe away from the front cover is provided with a flange, which is used to connect to the water supply pipe of an external water source.

4. A method for configuring flushing parameters for a mud pump, using the mud pump described in any one of claims 1 to 3, characterized in that, include: Step S1: Determine the rotational speed n of the mud pump in rpm, and determine the head H of the mud pump and the diameter of the impeller in the mud pump in meters. ; Step S2, based on the pump speed n and the impeller diameter mentioned in step S1. The value of the tangential flushing flow rate q is calculated using an empirical formula, which is: The unit is ; Step S3: Take the flushing pressure p as 1.3 times the mud pump head H, in meters. .

5. The method for configuring mud pump flushing parameters according to claim 4, characterized in that: in, The tangential flushing flow rate q is taken as: .

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