CN106640667A - Flow diversion shell type double-stage double-suction centrifugal pump - Google Patents

Abstract

The invention relates to a flow diversion shell type double-stage double-suction centrifugal pump. The flow diversion shell type double-stage double-suction centrifugal pump comprises a pump body and a transmission shaft penetrating through the pump body and rotationally connected with the pump body. Two first-stage impellers are arranged on the part, located in the pump body, of the transmission shaft front and back in a spaced mode. A second-stage impeller is arranged on the part, located between the two first-stage impellers, of the transmission shaft. An interstage flow diversion shell is fixedly arranged in the pump body and is an impeller. A runner of the interstage flow diversion shell is in an S shape. The interstage flow diversion shell is located among the first-stage impellers and the second-stage impeller. The inlet end of the interstage flow diversion shell is connected with the outlet ends of the first-stage impellers. The outlet end of the interstage flow diversion shell is connected with the inlet end of the second-stage impeller.

Description

A kind of twin-stage double suction centrifugal pump of water conservancy diversion shell-type

Technical field

The present invention relates to a kind of double-impeller pump, more particularly to a kind of twin-stage double suction centrifugal pump of water conservancy diversion shell-type.

Background technology

Double feed inlet two-stage double suction centrifugal pump has the features such as flow is big, lift is high, has in high-lift water lift engineering wide Wealthy application prospect.At present double feed inlet two-stage double entry pump mainly has two kinds of transition runner formula and radial vane formula.Transition runner formula Two-stage double suction centrifugal pump is added liquid by the way of gap bridge by first stage impeller introducing second level impeller using double feed inlet spiral case, and radially Current are introduced second level impeller by guide-vane two-stage double suction centrifugal pump by radial vane by first stage impeller.However, for transition Flow channel type two-stage double suction centrifugal pump, because gap bridge bulky dimensions, runner are turned anxious, complex structure, be difficult to pump containing compared with The liquid of bulky grain thing or flexible long fibre medium.For radial vane formula two-stage double suction centrifugal pump, the axial direction of its radial vane Small-sized, throat opening area is little, and fluid is quickly adjusted between guide vane and return guide vane, is pumping containing larger particles or soft During the liquid of property long fibre medium, it is easy to produce runner clogging.

Additionally, the lift of the both stage impellers of transition runner formula and radial vane formula twin-stage double suction centrifugal pump is all equal, The half of water pump total (pumping) head is, this causes the specific speed of both stage impellers identical, although this simplifies to a certain extent waterpower Design causes the leaf production of both stage impellers to use identical form drawing, but causes first stage impeller cavitation erosion performance and inlet capacity Difference.

The content of the invention

For problem present in background technology, it is an object of the invention to provide a kind of cavitation erosion ability is strong and inlet capacity is strong Water conservancy diversion shell-type twin-stage double suction centrifugal pump.

For achieving the above object, the present invention is employed the following technical solutions：A kind of twin-stage double suction centrifugal pump of water conservancy diversion shell-type, its It is characterised by：Its power transmission shaft for including the pump housing and being connected through the pump housing and with pump housing rotation, positioned at the pump housing Two first stage impellers are arranged at intervals with before and after on the interior power transmission shaft, the biography between positioned at two first stage impellers Second level impeller is provided with moving axis, blower inlet casing between level is fixedly installed in the pump housing, blower inlet casing is impeller between the level, its Runner is S-shaped, and it is located between the first stage impeller and the second level impeller, between the level entrance point of blower inlet casing with it is described The first stage impeller port of export connects, and its port of export is connected with the entrance point of the second level impeller.

The first stage impeller and the second level impeller are connected by key with the power transmission shaft.

The second level impeller is double-sided impeller.

The first stage impeller is single-suction impeller, and the back shroud of impeller of the first stage impeller is BI, itself and the biography The angle of moving axis axis is 75 °.

Suction chamber and pumping chamber are provided with the pump housing, the suction chamber is in half-spiral, and it is located at the pump housing Two ends and communicate with the entrance point of the first stage impeller, the pumping chamber be located at the middle part of the pump housing and with the second level leaf The port of export of wheel is communicated.

Chopped-off head sealing ring is provided between the import of the pump housing and the first stage impeller, blower inlet casing is outer between the level Front standstill seal is provided between pipe and the inner casing of the pump housing, it is common O-ring seals, the rear edge of blower inlet casing between the level Rear standstill seal is provided between the pump housing inner casing, it is common O-ring seals.

The number of blade of blower inlet casing is that the number of blade of the first stage impeller subtracts 1 between the level.

The import discharge section area of blower inlet casing and the outlet discharge section area of the first stage impeller are equal between the level, The outlet discharge section area of blower inlet casing is equal with the import discharge section area of the second level impeller between the level, the level Between blower inlet casing from import to outlet discharge section area F as the following formula (1) is gradually reduced：

F=(F₂-F₁)L²+F₁ (1)

Wherein, F₁It is the discharge section area in the first stage impeller exit, F₂It is the entrance mistake of the second level impeller 2 Water cross-sectional area.

The acquisition process of discharge section area F is as follows：

During centrifugal pump impeller discharge section area is calculated, cut in blower inlet casing impeller front and rear cover plate sectional view between the level Circle, obtains two point of contact A, B, and two point of contacts and the center of circle form triangle, and barycenter oftriangle is point C, and inscribed circle radius is ρ, string AB A length of s, R_cFor the distance of distance of center circle drive shaft axis, discharge section area F between level in blower inlet casing is calculated using such as following formula (2)

L is that blower inlet casing is with respect to streamline length between the level, and its satisfaction 0≤L≤1, its determination process is as follows：

The starting point for thinking blower inlet casing between the level is 0, and terminal is physical length n of blower inlet casing between the level, certain point away from It is w with a distance from the starting point of blower inlet casing between the level, formula such as following formula (3)：

The vane inlet laying angle of blower inlet casing and the blade exit laying angle of the first stage impeller are identical between the level；It is described The blade exit laying angle α of blower inlet casing between level₄For 90 °, blower inlet casing blade any position in addition to inlet and outlet between the level Laying angle α is determined by following formula (4)：

Wherein, α₃For the import laying angle of blower inlet casing blade between the level, φ is the cornerite of blower inlet casing blade between the level, X is the helix angle of circumference started at from the entrance of blower inlet casing blade between the level, and it meets 0≤x≤φ.

Due to taking above technical scheme, it has advantages below to the present invention：1st, the present invention is in first stage impeller and the second level Blower inlet casing is S-type between the level arranged between impeller, and its runner is broad, smooth-going of turning, therefore, it is possible to reduce energy loss as far as possible In the case of the complex fluid that first stage impeller flows out is introduced into into the stream that provides irrotationality fluidised form for second level impeller in the impeller of the second level Body, reduces energy loss, and the lift of first stage impeller is little, and back shroud is BI and pump axis angle is 75 °, therefore this Bright intake performance is good, and anti-cavitation ability is strong, is particularly suitable for pumping the liquid containing bulky grain or elongated flexible medium.2nd, this Second level impeller in bright is common double-sided impeller, and it passes through stream of the blower inlet casing reception from two first stage impellers between two levels Body, and continue to do work fluid, therefore the lift of this water pump is high.3rd, the pump housing in the present invention is used for high pressure chest and low pressure chamber Fluid isolation, therefore this water pump can for complete energy conversion necessary auxiliary space be provided.4th, the suction chamber in the present invention is Half-spiral, therefore, it is possible to create horizontal homogeneous inflow condition for first stage impeller.5th, the pumping chamber in the present invention is scroll casing shape, because This is few from the circular rector loss that second level impeller flows out fluid.6th, the import discharge section area of blower inlet casing and head between present invention middle rank The outlet discharge section area of level impeller is equal, and the outlet discharge section area of blower inlet casing is broken with the water that enters to make a slip of the tongue of second level impeller Face area equation, thus reduce fluid between first stage impeller and level between blower inlet casing and between level blower inlet casing and second level impeller it Between energy loss in transmittance process.

Description of the drawings

Fig. 1 is integrally-built half-section diagram of the invention；

Fig. 2 is the semi-section schematic diagram of first stage impeller of the present invention；

Fig. 3 is blower inlet casing and front standstill seal and the structural representation of rear standstill seal between level of the present invention；

Fig. 4 is blower inlet casing impeller cross-section of river schematic diagram between level of the present invention；

Fig. 5 is blower inlet casing Leaf laying angle schematic diagram between level of the present invention.

Specific embodiment

The present invention is described in detail with reference to the accompanying drawings and examples.

As shown in Figures 1 to 3, the present invention proposes a kind of twin-stage double suction centrifugal pump of water conservancy diversion shell-type, and it includes the pump housing 1 and passes through The power transmission shaft 2 worn the pump housing 1 and be connected with the rotation of the pump housing 1, before and after on the power transmission shaft 2 in the pump housing 1 two are being arranged at intervals with First stage impeller 3, is provided with second level impeller 4, the pump housing 1 on the power transmission shaft 2 between positioned at two first stage impellers 3 and is fixedly installed There are blower inlet casing 5 between level, blower inlet casing 5 is impeller between level, its runner is S-shaped, runner is broad, smooth-going of turning, and it is located at first stage impeller 3 Between second level impeller 4, the entrance point of blower inlet casing 5 is connected with the port of export of first stage impeller 3 between level, its port of export and second level leaf The entrance point connection of wheel 4, the fluid flowed out from first stage impeller 3 is introduced second level impeller 4 by blower inlet casing 5 between level, and for the second level Impeller 4 provides the fluid of irrotationality fluidised form.

In above-described embodiment, first stage impeller 3 and second level impeller 4 are connected by key with power transmission shaft 2.

In above-described embodiment, second level impeller 4 is double-sided impeller, and its diameter is big, and it is absorbed from two first stage impellers 3 Fluid, therefore lift be more than first stage impeller, improve the lift of water pump, this water pump intake performance is good, and anti-cavitation ability is strong.

In above-described embodiment, first stage impeller 3 is single-suction impeller, and the back shroud of impeller 31 of first stage impeller 3 is BI, its It is 75 ° with the angle of drive shaft axis, its lift is little, is easy to suck the fluid containing bulky grain or elongated flexible medium, strengthens The cavitation performance and intake performance of pump.

In above-described embodiment, suction chamber 6 and pumping chamber 10 are provided with the pump housing 1, suction chamber 6 is in half-spiral, and it is located at The two ends of the pump housing 1 and communicate with the entrance point of first stage impeller 3, pumping chamber 10 be located at the middle part of the pump housing 1 and with second level impeller 4 The port of export is communicated, and suction chamber 6 is used to create horizontal homogeneous inflow condition for first stage impeller 3, and pumping chamber 10 is used to collect the second level The fluid that impeller 4 flows out, eliminates circular rector.

In above-described embodiment, chopped-off head sealing ring 7 is provided between the import of the pump housing 1 and first stage impeller 3, it avoids current The low-pressure area 12 of impeller inlet is redirected back into from gap of the higher-pressure region 11 of the outlet of first stage impeller 3 between sound part；Between level Front standstill seal 8 is provided between the outer tube of blower inlet casing 5 and the inner casing of the pump housing 1, it is common O-ring seals, for preventing water Flow from the outlet of first stage impeller 3 and enter the perimeter of blower inlet casing 5 between level；Between level between the rear edge of blower inlet casing 5 and pump housing inner casing Rear standstill seal 9 is provided with, it is common O-ring seals, for preventing current from leading between level from the outlet of second level impeller 4 The perimeter of stream shell 5.

In above-described embodiment, the number of blade of blower inlet casing 5 subtracts 1 for the number of blade of first stage impeller 3 between level.

In above-described embodiment, the outlet cross-section of river face of the import discharge section area of blower inlet casing 5 and first stage impeller 3 between level Product is equal, and the outlet discharge section area of blower inlet casing and the import discharge section area of second level impeller 4 are equal between level, lead between level From import to discharge section area F of outlet, as the following formula (1) is gradually reduced stream shell 5：

F=(F₂-F₁)L²+F₁ (1)

Wherein, F₁It is the discharge section area in the exit of first stage impeller 3, F₂It is the entrance cross-section of river face of second level impeller 2 Product, the acquisition process of F is as follows：

As shown in figure 4, during centrifugal pump impeller discharge section area is calculated, to the impeller front and rear cover plate section view of blower inlet casing between level 5 The circle of contact is done in figure, two point of contact A, B are obtained, two point of contacts and the center of circle form triangle, barycenter oftriangle is point C, inscribed circle radius For ρ, a length of s of string AB, R_cFor the distance of the axis of distance of center circle power transmission shaft 2, the mistake between level in blower inlet casing 5 is calculated using such as following formula (2) Water cross-sectional area F

L is blower inlet casing with respect to streamline length (0≤L≤1).Its determination process is as follows：

Think blower inlet casing 5 between level starting point be 0, terminal for blower inlet casing physical length n, certain point blower inlet casing apart between level 5 starting point distance be w, formula such as following formula (3)：

In above-described embodiment, as shown in figure 5, the vane inlet laying angle of blower inlet casing 5 goes out with the blade of first stage impeller 3 between level Mouth laying angle is identical；The blade exit laying angle α of blower inlet casing 5 between level₄For 90 °, the blade of blower inlet casing 5 is in addition to inlet and outlet between level The laying angle α of any position is determined by following formula (4)：

Wherein, α₃For the import laying angle of blower inlet casing blade between level, φ is the cornerite of blower inlet casing blade 5 between level, and x is from level Between blower inlet casing blade 5 the helix angle of circumference (0≤x≤φ) started at of entrance.

The present invention is only illustrated with above-described embodiment, and the structure of each part, set location and its connection all can be have Changed, on the basis of technical solution of the present invention, all individual part is carried out improvement according to the principle of the invention and equivalent Conversion, should not exclude outside protection scope of the present invention.

Claims (10)

1. a kind of twin-stage double suction centrifugal pump of water conservancy diversion shell-type, it is characterised in that：It include the pump housing and through the pump housing and with institute The power transmission shaft that the pump housing rotates connection is stated, before and after on the power transmission shaft in the pump housing two chopped-off head leaves are arranged at intervals with Wheel, on the power transmission shaft between positioned at two first stage impellers second level impeller is provided with, and fixation in the pump housing sets Blower inlet casing between level is equipped with, blower inlet casing is impeller between the level, its runner is S-shaped, and it is located at the first stage impeller with described second Between level impeller, the entrance point of blower inlet casing is connected with the first stage impeller port of export between the level, its port of export and described second The entrance point connection of level impeller.

2. a kind of twin-stage double suction centrifugal pump of water conservancy diversion shell-type as claimed in claim 1, it is characterised in that：The first stage impeller and The second level impeller is connected by key with the power transmission shaft.

3. a kind of twin-stage double suction centrifugal pump of water conservancy diversion shell-type as claimed in claim 1, it is characterised in that：The second level impeller For double-sided impeller.

4. a kind of twin-stage double suction centrifugal pump of water conservancy diversion shell-type as claimed in claim 1, it is characterised in that：The first stage impeller is Single-suction impeller, the back shroud of impeller of the first stage impeller is BI, and it is 75 ° with the angle of the drive shaft axis.

5. a kind of twin-stage double suction centrifugal pump of water conservancy diversion shell-type as claimed in claim 1, it is characterised in that：Arrange in the pump housing Have suction chamber and a pumping chamber, the suction chamber is in half-spiral, its be located at the two ends of the pump housing and with the first stage impeller Entrance point is communicated, and the pumping chamber is located at the middle part of the pump housing and communicates with the port of export of the second level impeller.

6. a kind of twin-stage double suction centrifugal pump of water conservancy diversion shell-type as claimed in claim 1, it is characterised in that：In the pump housing and institute Chopped-off head sealing ring is provided between the import for stating first stage impeller, between the level between the inner casing of the outer tube of blower inlet casing and the pump housing Front standstill seal is provided with, it is common O-ring seals, is arranged between the rear edge of blower inlet casing and the pump housing inner casing between the level There is rear standstill seal, it is common O-ring seals.

7. a kind of twin-stage double suction centrifugal pump of water conservancy diversion shell-type as claimed in claim 1, it is characterised in that：Blower inlet casing between the level The number of blade be that the number of blade of the first stage impeller subtracts 1.

8. a kind of twin-stage double suction centrifugal pump of water conservancy diversion shell-type as claimed in claim 1, it is characterised in that：Blower inlet casing between the level Import discharge section area it is equal with the outlet discharge section area of the first stage impeller, blower inlet casing goes out to make a slip of the tongue between the level Water cross-sectional area is equal with the import discharge section area of the second level impeller, and blower inlet casing is from import to outlet between the level As the following formula (1) is gradually reduced discharge section area F：

F=(F₂-F₁)L²+F₁ (1)

Wherein, F₁It is the discharge section area in the first stage impeller exit, F₂Be the entrance of second level impeller 2 cross water break Face area.

9. a kind of twin-stage double suction centrifugal pump of water conservancy diversion shell-type as claimed in claim 8, it is characterised in that：The cross-section of river face The acquisition process of product F is as follows：

During centrifugal pump impeller discharge section area is calculated, the circle of contact is done in blower inlet casing impeller front and rear cover plate sectional view between the level, Two point of contact A, B are obtained, two point of contacts and the center of circle form triangle, and barycenter oftriangle is point C, and inscribed circle radius is ρ, and string AB is a length of S, R_cFor the distance of distance of center circle drive shaft axis, discharge section area F between level in blower inlet casing is calculated using such as following formula (2)

$F=\frac{4}{3}{\mathrm{\πR}}_c(s+\mathrm{\ρ})---\left(2\right)$

L is that blower inlet casing is with respect to streamline length between the level, and its satisfaction 0≤L≤1, its determination process is as follows：

The starting point for thinking blower inlet casing between the level is 0, and terminal is physical length n of blower inlet casing between the level, and certain point is apart from institute The starting point distance of blower inlet casing between level is stated for w, formula such as following formula (3)：

$L=\frac{w}{n}.---\left(3\right)$

10. a kind of twin-stage double suction centrifugal pump of water conservancy diversion shell-type as claimed in claim 1, it is characterised in that：Water conservancy diversion between the level The vane inlet laying angle of shell is identical with the blade exit laying angle of the first stage impeller；The blade exit of blower inlet casing between the level Laying angle α₄For 90 °, the laying angle α of blower inlet casing blade any position in addition to inlet and outlet is determined by following formula (4) between the level：

$\mathrm{\α}=\frac{90-{\mathrm{\α}}_3}{\mathrm{\φ}}x+{\mathrm{\α}}_3---\left(4\right)$

Wherein, α₃For the import laying angle of blower inlet casing blade between the level, φ is the cornerite of blower inlet casing blade between the level, x be from The helix angle of circumference that the entrance of blower inlet casing blade is started between the level, it meets 0≤x≤φ.