CN103925234A - Wear-resistant axial flow pump impeller designing method - Google Patents

Abstract

The invention provides a wear-resistant axial flow pump impeller designing method. An axial flow pump is used for the field of petrifaction, mining, smelting and the like. A designing formula of main symmetric size parameters, like impeller inlet diameter Dj, impeller maximum diameter D, hub diameter Dh, blade axial length L and blade wrap angle phi, of an impeller is provided. By using a wear-resistant axial flow pump impeller designed by the method, wear-resistant performance of the pump can be improved, the problem of impeller wear when the axial flow pump is in media containing solid particles can be improved, and hydraulic efficiency and reliability of the impeller can be improved.

Description

A kind of wear-resistant axial-flow pump impeller design method

Technical field

Patent of the present invention relates to a kind of design method of axial-flow pump impeller, specifically, relates to a kind of wear-resistant axial-flow pump impeller design method being applicable under solid-liquid two-phase flow ambient condition.

Background technique

Axial-flow pump is the centrifugal pump pattern that a kind of flow is large, efficiency is high, lift is low, is widely used in the large flow circulatory system of petrochemical industry, mine and power domain.At present, hydraulic model of axial-flow pump generally designs according to water medium condition, in the time carrying water medium, has good hydraulic efficiency and medium passing capacity.But at numerous industrial fields, axial-flow pump is used to carry the two phase flow medium that contains a large amount of slags, tailings and coal slime, in the time carrying these containing the more solid-liquid two-phase flow medium of solid particle, conventional axial-flow pump impeller is easy to produce wear phenomenon, impeller blade and wheel hub change because of abrasion of particles, the medium transport ability of impeller reduces, and working life, flow and lift parameter all significantly decline, and easily causes the circulatory system to lose efficacy and fault.

Impeller is the core component that affects axial-flow pump wearing character and life-span, for carrying containing solid grain amount compared with for large medium, there is the working life that the impeller of abrasion resistance properties can improve axial-flow pump, improve solid-liquid two-phase flow in Internal Flow in Axial Pump situation, improve operational reliability and the hydraulic performance of axial-flow pump.

Summary of the invention

For solving axial-flow pump impeller at the wear problem containing in solid granule medium, the invention provides a kind of axial-flow pump impeller design method with wear-resistant property.Utilize following relation to determine the main geometric parameters of impeller, mainly comprise: impeller inlet diameter D _j, impeller maximum dimension D, hub diameter D _hwith blade axial length L.By impeller physical dimension Parameters design provided by the invention, reduce the wearing and tearing of impeller in solid-liquid two-phase flow, improve working life, hydraulic efficiency and the operational reliability of axial-flow pump.Realize the technological scheme that above-mentioned purpose adopts:

1, the inlet diameter of impeller

Its formula: $D_j=k_{j}3\sqrt{{\mathrm{Qn}}^2+D_h^3}$

In formula: D _j---impeller inlet diameter, rice;

Q---Impeller Design operating point flow, cube meter per second;

N---wheel speed, rev/min;

D _h---hub diameter, rice;

K _j---correction factor, k _j=1.1～1.3.

2, the maximum diameter of impeller

Its formula: $D=k_0\sqrt{\frac{1}{(1-k_1^{2.2})}}3\sqrt{{\mathrm{Qn}}^2}$

$k_1=9.14\frac{1}{0.44\sqrt{n_s}}$

In formula: D---impeller maximum diameter, rice;

Q---Impeller Design operating point flow, cube meter per second;

N---wheel speed, rev/min;

K ₀---correction factor, k ₀=1.15～1.4;

K ₁---correction factor;

N _s---impeller specific speed.

3, impeller hub diameter

Its formula: D _h=0.36+0.14In (n _s)

In formula: D _h---impeller hub diameter, rice.

N _s---impeller specific speed.

4, blade axial length

Its formula: L=k ₂d

L---blade axial length, rice;

D---impeller maximum diameter, rice;

K ₂---correction factor, k ₂=0.8～1.05.

5, subtended angle of blade

Subtended angle of blade φ=78 °～92 °.

The invention has the beneficial effects as follows: adopt the axial-flow pump impeller of the method design to there is good abrasion resistance properties, extended axial-flow pump in the working life containing in solid granule medium, and effectively improved operational reliability and the hydraulic performance of axial-flow pump.

The present invention is on probation through user, and product using effect is good, can effectively extend the axial-flow pump life-span, reduces parts replacement frequency and number of times, has saved the expense of plant maintenance and replacing.

Brief description of the drawings

Fig. 1 is the impeller axial plane figure of one embodiment of the invention;

Fig. 2 is same embodiment's impeller blade planimetric map.

In figure: 1-impeller inlet diameter D _j, 2-impeller maximum dimension D, 3-blade, 4-impeller hub diameter D _h, 5-impeller hub, 6-blade axial length L, 7-subtended angle of blade φ.

Embodiment

Fig. 1 and Fig. 2 have determined this embodiment's impeller shape and physical dimension jointly.It is a kind of higher specific speed impeller, blade (3) is evenly fixed on impeller hub (5), the outer rim of blade axial plane is circular arc, be conducive to improve impeller inside and pass through area, the solid particle of alleviating in solid-liquid two-phase flow weares and teares to the overcurrent of axial-flow pump, impeller inlet diameter (1) is less than impeller maximum diameter (2), can reduce Pressure Drop and the wearing and tearing at impeller inlet outer rim place, improves anti-cavitation and the abrasion resistance properties of impeller.In order to improve wear-resistant ability and the hydraulic performance of axial-flow pump, the present invention determines impeller inlet diameter (1) D by following relation _j, impeller maximum diameter (2) D, hub diameter (4) D _h, blade axial length (6) L and subtended angle of blade (7) φ.

$D_j=k_{j}3\sqrt{{\mathrm{Qn}}^2+D_h^3}$

$D=k_0\sqrt{\frac{1}{(1-k_1^{2.2})}}3\sqrt{{\mathrm{Qn}}^2}$

$k_1=9.14\frac{1}{0.44\sqrt{n_s}}$

D _h=0.36+0.14In(n _s)

L=k ₂D

φ=78°～92°

In figure, correction factor k _j, k ₀, k ₂and the selection of subtended angle of blade (7) and specific speed n _ssize relevant, specific speed is larger, correction factor k _j, k ₀and k ₂select higher value, it selects interval to be respectively between 1.1～1.3,1.15～1.4 and 0.8～1.05, and subtended angle of blade (7) is selected smaller value, and it selects interval between 78 °～92 °.

Claims (1)

1. a wear-resistant axial-flow pump impeller design method, provides impeller member and main geometric parameter impeller inlet diameter D _j, impeller maximum dimension D, hub diameter D _h, blade axial length L and subtended angle of blade φ design formula; It is characterized in that: between the physical dimension parameter of impeller and the performance parameter of pump operating point for design, be applicable to following relation:

$D_j=k_{j}3\sqrt{{\mathrm{Qn}}^2+D_h^3};$

$D=k_0\sqrt{\frac{1}{(1-k_1^{2.2})}}3\sqrt{{\mathrm{Qn}}^2};$

$k_1=9.14\frac{1}{0.44\sqrt{n_s}};$

D _h=0.36+0.14In(n _s)；

L=k ₂D；

φ=78°～92°；

In formula: Q is Impeller Design operating point flow, cube meter per second;

N is wheel speed, rev/min;

D _jimpeller inlet diameter, rice;

D is impeller maximum diameter, rice;

D _hhub diameter, rice;

L is blade axial length, rice;

φ is subtended angle of blade, degree;

N _sit is impeller specific speed;

K _jcorrection factor, k _j=1.1～1.3;

K ₀correction factor, k ₀=1.15～1.4;

K ₂correction factor, k ₂=0.8～1.05.