Dredge pump and dredge pump flushing parameter configuration method

Abstract

A dredge pump and a dredge pump flushing parameter configuration method. The dredge pump comprises two water inlet guide pipes (14), and the two water inlet guide pipes (14) are centrosymmetrically arranged around the center line of an impeller (20). One end of each water inlet guide pipe (14) is communicated with a suction end flushing cavity (25) and a water inlet (111) is formed on a front cover (11), and the other end of the water inlet guide pipe is communicated with an external water source. The length direction of the water inlet guide pipe (14) is consistent with the tangential direction of the suction end flushing cavity (25), and a direction of water flow flowing to the water inlet (111) by means of the water inlet guide pipe (14) is consistent with the rotation direction of the impeller (20), so that the impact of flushing water flow on the water flow rotating in the suction end flushing cavity (25) can be reduced, and the wear of a flow passage component of the dredge pump is reduced. According to the dredge pump flushing parameter configuration method, an appropriate flushing water flow and a proper flushing pressure are calculated by means of an empirical formula on the basis of the values of the diameter Dimpeller of the impeller (20), the rotating speed n of the dredge pump, and a dredge pump head H, preventing slurry from flowing back to gaps between the impeller (20) and wear-resistant linings (21), improving the operating stability of the dredge pump, and facilitating smooth construction.

Description

Mud pump and mud pump flushing parameter configuration method Technical Field

[0001] The present invention relates to the technical field of dredging, and in particular to a mud pump and a mud pump flushing parameter configuration method. Background Art

[0002] Dredgers are the primary equipment on hydraulic dredging vessels, utilizing the movement of water to accomplish dredging. Dredgers loosen the underwater soil layer through mechanical or high-pressure water cutting, mixing the sediment with water to form a mud-water mixture (i.e., slurry) of a certain concentration. The slurry is then drawn into the dredger through its vacuum suction port and discharged into the dredger's mud tank, directly to a side barge, or via a mud discharge pipeline to a filling area, achieving the purpose of dredging and filling. Therefore, dredgers are critical equipment, and their hydraulic performance and wear resistance directly impact the dredging efficiency of the dredger.

[0003] Since the mud pump transports a high concentration of mud, the flow-through components of the mud pump are prone to wear. In the prior art, in order to reduce wear, a water inlet is usually set on the front pump cover to introduce clean water from the outside, that is, flushing water is arranged between the impeller and the liner to reduce the wear of the mud on the impeller and the liner. As shown in Figure 3, the hollow thick arrow indicates the direction of mud flow, and the one-way thin arrow indicates the direction of flushing water flow at the suction end. In the existing dredging mud pump structure, the flushing water at the suction end is usually a normal inlet, the flushing water outlet direction is perpendicular to the inner wall of the flushing water chamber at the suction end, and the water flow direction passes through the center of the pump. The flushing water flow impacts the rotating water flow in the flushing water 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 cause local vortex backflow. Some of the mud and sand particles in the flushing water chamber are driven by the vortex backflow to aggravate the wear on the wall of the flow-through components, affecting the service life of the mud pump and the reliability during operation, and is not conducive to the progress of 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. There is a lack of unified parameter setting rules, which makes the mud pump prone to failure and unstable working state, affecting the continuity of construction.

[0004] Summary of the Invention

[0005] The present invention is made to solve the above-mentioned problem, and its purpose is to provide a mud pump and a mud pump flushing parameter configuration method.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] A mud pump comprises a shell consisting of a front cover, a pump casing and a rear cover, an impeller is provided inside the shell and wear-resistant liners are provided between the impeller and the front cover and the rear cover, an impeller suction port anti-wear ring and a suction end water seal assembly are provided at the suction end of the impeller, and an annular suction end flushing chamber is formed between the front cover and the wear-resistant liner, and also comprises: two water inlet guide pipes, the two water inlet guide pipes are arranged in a centrally symmetrical manner around the center line of the impeller, wherein one end of each of the water inlet guide pipes is connected to the suction end flushing chamber and forms a water inlet on the front cover, and the other end is connected to an external water source, the length direction of the water inlet guide pipe is consistent with the tangent direction of the suction end flushing chamber, and the direction of water flowing through the water inlet guide pipe to the water inlet is consistent with the rotation direction of the impeller.

[0008] Furthermore, the inner diameter d of the water inlet guide pipe is 管 The value range of d is: 管 =(0.013~0.018)D 叶 ·L -0.5

[0009] Where, L is the vertical distance from the water inlet guide pipe to the center line of the impeller, D 叶 is the diameter of the impeller, L, D 叶 d 管 The unit is m.

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

[0011] Furthermore, a flange is provided at one end of the water inlet guide pipe away from the front cover, and the flange is used to be connected to a water pipe of an external water source.

[0012] A method for configuring mud pump flushing parameters, using the above-mentioned mud pump, comprises:

[0013] Step S1, determine the speed n of the mud pump in rpm, determine the mud pump head H and the diameter D of the impeller in the mud pump in m 叶 ;

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

[0015] Step S3, take the value of the flushing pressure p as 1.3 times the mud pump head H, the unit is mH2O.

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

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

[0018] 1. In the dredge pump of the present invention, an external water source is introduced into the flushing chamber at the suction end through a water inlet guide pipe, removing the silt in the flushing chamber and between the impeller and the wear-resistant liner. The length direction of the water inlet guide pipe is consistent with the tangential direction of the flushing chamber at the suction end, and the two water inlet guide pipes are arranged symmetrically around the center, so that the incoming flushing water forms an annular water flow consistent with the direction of rotation of the impeller. This reduces the impact of the flushing water flow on the rotating water flow in the flushing chamber on the suction side, avoids causing disturbances and triggering local vortex backflow, can reduce wear of the dredge pump's flow components, and increase the service life of the dredge pump's flow components such as the suction end water sealing assembly, impeller, and wear-resistant liner. This reduces the need for repair and replacement of wearing parts, saves maintenance costs, and improves the construction continuity and efficiency of the dredger.

[0019] 2. The mud pump flushing parameter configuration method provided by the present invention is based on the impeller diameter D 叶 The values ​​of mud pump speed n and mud pump head H are calculated through empirical formulas to obtain appropriate flushing water flow and flushing water pressure, which prevents mud from flowing back into the gap between the impeller and the wear-resistant lining, ensures the flushing effect of the flushing water cavity and the mud and sand between the impeller and the wear-resistant lining, improves the stability of the mud pump operation, reduces the possibility of failure, and helps the smooth progress of construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 is a schematic structural diagram of a mud pump according to an embodiment of the present invention;

[0021] FIG2 is a cross-sectional view of a mud pump according to an embodiment of the present invention;

[0022] FIG3 is a cross-sectional view of the flushing chamber at the suction end in an embodiment of the present invention;

[0023] FIG4 is a schematic structural diagram of the front cover in an embodiment of the present invention;

[0024] FIG5 is a front view of the front cover in an embodiment of the present invention;

[0025] FIG6 is a cross-sectional view taken along line AA in FIG5; and

[0026] FIG7 is a flow chart of mud pump flushing parameter configuration in an embodiment of the present invention.

[0027] Figure numbers: 10-housing, 11-front cover, 12-pump casing, 13-rear cover, 14-water inlet guide pipe, 141-flange; 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; 30-transmission mechanism, 31-bearing seat, 32-bearing cylinder assembly, 33-pump shaft. DETAILED DESCRIPTION

[0028] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the following embodiments and accompanying drawings are used to specifically illustrate the mud pump of the present invention.

[0029] As shown in Figures 1 to 3, 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 a wear-resistant liner 21 is 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. An annular suction end flushing chamber 25 is formed between 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.

[0030] A transmission mechanism 30 is also mounted on one side of the rear cover 13 of the dredger. This transmission mechanism 30 includes a bearing seat 31, a bearing cartridge assembly 32, and a pump shaft 33. The bearing seat 31 is mounted on the deck of the dredger to support the bearing cartridge assembly 32. The pump shaft 33 is mounted within the bearing cartridge assembly 32. The front end of the pump shaft 33 is fixedly connected to the impeller 20, for example, via a threaded connection, to drive the impeller 20 to rotate.

[0031] The rear cover 13 is mounted on the bearing seat 31 by bolts, the pump casing 12 is connected to the rear cover 13 by bolts, and the front cover 11 is connected to the pump casing 12 by bolts, so that the casing 10 as a whole is fixed to the deck through the bearing seat 31. The wear-resistant liners 21 on the front and rear sides of the impeller 20 are respectively fixed to the inner walls of the front cover 11 and the rear cover 13 to reduce wear on the casing. In this embodiment, the wear-resistant liners 21 are connected to the front cover 11 and the rear cover 13 by bolts. The impeller suction port anti-wear ring 22 is fastened to the impeller 20 by bolts, and the suction end water seal assembly 23 is fastened to the front cover 11 by bolts. A water seal chamber 24 is provided on the outside of the rear cover 13 to prevent mud and sand from entering the transmission mechanism 30 at the rear and wearing the pump shaft 33. The water seal chamber 24 is connected to the rear cover 13 by bolts.

[0032] As shown in Figures 4 to 6, in this embodiment, the mud pump also includes two water inlet guide pipes 14 connected to the outside of the front cover 11, and the two water inlet guide pipes 14 are arranged in a central symmetrical manner around the center line of the impeller 20, wherein one end of each water inlet guide pipe 14 is connected to the suction end flushing chamber 25 and forms a water inlet 111 on the front cover 11, and the other end is connected to an external water source, and the length direction of the water inlet guide pipe 14 is consistent with the tangential direction of the suction end flushing chamber 25, and the direction of water flow through the water inlet guide pipe 14 to the water inlet 111 is consistent with the rotation direction of the impeller 20 (for example, the tangential water flow direction and the impeller rotation direction in Figure 4 are both clockwise).

[0033] Furthermore, a flange 141 is provided at one end of the water inlet guide pipe 14 away from the front cover 11 , and the flange 141 is used to be connected to a water pipe of an external water source.

[0034] During use, the flange 141 at the end of the water inlet guide pipe 14 is connected to the water outlet of the water pump, and clean water is pumped into the water inlet guide pipe 14 through the water pump. The water flows tangentially along the water inlet guide pipe 14 into the suction end flushing chamber 25, and then rotates along the inner wall of the flushing chamber to form an annular water flow. The rotation direction is the same as that of the impeller 20, which can reduce flow impact. At the same time, the flushing water flows from a position near the center of the impeller 20 to the outer edge along the gap between the impeller 20 and the wear-resistant lining 21 at the front cover, carrying away silt and reducing wear of the suction end flushing chamber 25, the impeller suction port anti-wear ring 22, the impeller 20, and the wear-resistant lining 21. Therefore, the mud pump of this embodiment can prevent the flushing water from impacting the rotating water flow in the suction end flushing chamber 25, causing disturbances and inducing local vortex backflow, and further prevent some silt particles in the flushing chamber from increasing wear on the wall of the flow-through components due to the vortex backflow.

[0035] As shown in FIG7 , this embodiment further provides a method for configuring mud pump flushing parameters, which is performed using the above-mentioned mud pump and includes:

[0036] Step S1, determine the speed n of the mud pump in rpm, determine the mud pump head H and the diameter D of the impeller in the mud pump in m 叶 ;

[0037] Step S2, according to the speed n of the mud pump and the diameter D of the impeller in step S1 叶 The value of the tangential flushing flow rate q is calculated by the empirical formula, and the empirical formula is q = (0.05 ~ 0.1) n·D 叶 2 , unit is m 3 / h;

[0038] Step S3, take the value of the flushing pressure p as 1.3 times the mud pump head H, the unit is mH2O.

[0039] Specifically, as shown in Figures 2 and 3, based on the mud pump structure in this embodiment, the flushing water flows tangentially along the water inlet guide pipe 14 into the suction end flushing chamber 25, and then flows into the gap between the impeller 20 and the wear-resistant lining 21, and flows out to the outer edge of the impeller 20 (as shown by the one-way thin arrow in Figure 3). Under the premise of preventing the mud slurry at the outlet of the impeller 20 from flowing back into the gap between the impeller 20 and the wear-resistant lining 21, the flushing water flow rate needs to reach at least a specific value. Due to the rotation of the impeller 20, the liquid in the gap has a circumferential velocity, and the liquid has a tendency to move outward due to the centrifugal effect. The circumferential velocity at the outer edge of the impeller 20 and the mud pump speed n and the impeller diameter D 叶 Therefore, the flushing flow q, mud pump speed n, and impeller diameter D required to meet the prerequisites are 叶 related.

[0040] Through computer simulation, the required flushing flow rate of mud pumps with different speeds and impeller diameters is obtained, and the flushing flow rate q and mud pump speed n, impeller diameter D are established. 叶 Functional relationship:

[0041] First, a fixed mud pump (i.e. control the impeller diameter D 叶 The flushing flow rate is adjusted multiple times at the same speed to obtain the minimum flushing flow rate that meets the prerequisite (i.e., flushing water flows along the gap between the impeller and the liner toward the outer edge of the impeller without backflow), which is recorded as the required flushing flow rate q at this speed. Several commonly used mud pump speed values ​​are selected to obtain the required flushing flow rate q corresponding to each speed. In this embodiment, the impeller diameter D 叶 =2m as an example, the simulation results are shown in the following table:

[0042] From this we can see that for the same mud pump, the required flushing flow rate q is directly proportional to the mud pump speed n. Assuming the flushing flow rate q = k1n, when the impeller diameter is 2m, the coefficient k1 is 0.2.

[0043] Then, a simulation experiment was conducted on several mud pumps with different impeller diameters running at the same speed to obtain the required flushing flow rate q for each mud pump when the prerequisites were met. In this embodiment, the mud pump speed n = 300 rpm is used as an example, and the simulation results are shown in the following table:

[0044] Since the flushing flow rate q is proportional to the mud pump speed n, the functional relationship is established: q / n=f(D 叶 ), and by least squares fitting, we get q / n=kD 叶 2 , that is, f(D 叶 ) and impeller diameter D 叶The square of is linear, and the average value of coefficient k is about 0.05, so: q=0.05n·D 叶 2 .

[0045] Finally, considering the change in the concentration of the slurry transported by the mud pump in actual applications and the increase in the 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 value range of the coefficient k is expanded to 0.05-0.1, and the empirical formula for the flushing flow rate is finally obtained: q = (0.05-0.1)n·D 叶 2 .

[0046] The dredge pump head H is the pumping height of the dredge pump, that is, the clear water head of the dredge pump. The flushing pressure p is the mud head of the dredge pump, and the unit is mH2O, which represents the pressure of the corresponding clear water column with a height of several meters. The mud head of the dredge pump is related to the density of the transported mud, that is, mud head = clear water head × (mud density / clear water density). Since the mud density of the mud pumped in actual dredging projects is generally 1.3g / cm 3 , and the density of clean water is 1g / cm 3 The mud density is equivalent to 1.3 times that of water. Therefore, 1.3 times the mud pump head H (clean water head) is equivalent to the mud pump's mud head, and the corresponding flushing pressure is determined to be 1.3 times the mud pump head H.

[0047] Furthermore, in order to reduce the impact disturbance of water flow, the water flow velocity of the flushing water is made the same as the rotating water flow velocity in the original flushing chamber, that is, q=(0.05~0.1)n·D 叶 2 After substituting, we get the range of the inner diameter of the water inlet guide pipe 14: d 管 =(0.013~0.018)D 叶 ·L -0.5 ,

[0048] Where, 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 is m.

[0049] Preferably, the inner diameter of the water inlet guide pipe is d 管 =0.0159D 叶 ·L -0.5 .

[0050] In this embodiment, the distance L from the water inlet to the center line of the impeller 20 is 0.57m, and the impeller diameter D 叶 If the inner diameter of the water inlet guide pipe 14 is 2m, then take the inner diameter of the water inlet guide pipe 14 as: 管=0.0159D 叶 ·L -0.5 =0.0159×2×0.57 -0.5 =0.042m.

[0051] Preferably, the tangential flushing flow rate q is q = 0.075n·D 叶 2 .

[0052] In this embodiment, taking the mud pump speed of 300 rpm, the mud pump head of 80 m, and the impeller diameter of 2 m as an example, the calculation results are:

[0053] Tangential flushing flow q=0.075n·D 叶 2 =0.075×300×2 2 =90m 3 / h;

[0054] Flushing water pressure p = 1.3H = 1.3x80 = 104mH2O.

[0055] The above embodiments are preferred examples 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 composed of a front cover, a pump shell and a rear cover, an impeller is arranged inside the housing and wear-resistant linings are arranged between the impeller and the front cover and the rear cover, an impeller suction port anti-wear ring and a suction end water seal assembly are arranged at the suction end of the impeller, and an annular suction end flushing cavity is formed between the front cover and the wear-resistant lining, characterized in that: Also includes: Two water inlet guide pipes, the two water inlet guide pipes are arranged symmetrically around the center line of the impeller, One end of each of the water inlet guide pipes is connected to the suction end flushing cavity and forms a water inlet on the front cover, and the other end is connected to an external water source. The length direction of the water inlet guide pipe is consistent with the tangent direction of the flushing chamber at the suction end, and the direction of water flow through the water inlet guide pipe to the water inlet is consistent with the rotation direction of the impeller.

2. The mud pump according to claim 1, characterized in that: in, The inner diameter d of the water inlet guide pipe 管 The value range of is: d 管 =(0.013~0.018)D 叶 ·L -0.5 Where, L is the vertical distance from the water inlet guide pipe to the center line of the impeller, D 叶 is the diameter of the impeller, L, D 叶 ,d 管 The unit is m.

3. The mud pump according to claim 1, characterized in that: in, The inner diameter d of the water inlet guide pipe 管 The value is d 管 =0.0159D 叶 ·L -0.5 .

4. The mud pump according to claim 1, characterized in that: in, A flange is provided at one end of the water inlet guide pipe away from the front cover, and the flange is used to be connected to a water delivery pipe of an external water source.

5. A method for configuring mud pump flushing parameters, using the mud pump according to any one of claims 1 to 4, characterized in that: include: Step S1, determining the rotation speed n of the mud pump in rpm, determining the mud pump head H and the diameter D of the impeller in the mud pump in m 叶 ; Step S2, according to the rotation speed n of the mud pump and the diameter D of the impeller in step S1 叶 The value of the tangential flushing flow rate q is calculated by an empirical formula, and the empirical formula is q = (0.05-0.1) n·D 叶 2 , unit is m 3 / h; Step S3, taking the value of the flushing water pressure p as 1.3 times the mud pump head H, the unit is mH2O.

6. The method for configuring mud pump flushing parameters according to claim 5, characterized in that: in, The value of the tangential flushing flow q is q = 0.075n·D 叶 2 .

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