CN217080810U - Molten salt pump - Google Patents

Abstract

The utility model discloses a molten salt pump belongs to non-positive displacement pump technical field, which comprises a motor, the motor mounting panel, the shaft coupling, bearing body subassembly, the bottom plate, the axle, the impeller, impeller lock nut, the pump cover, the pump case, play water pipe subassembly and connecting pipe, the motor is fixed in motor mounting panel top, the motor passes through the shaft coupling and is connected with the axle, install bearing body subassembly in the upper end of axle, bearing body subassembly passes through the bolt and fixes on the bottom plate, the interlude of axle is equipped with first guide bearing, first guide bearing outside is equipped with first guide bearing overcoat, first guide bearing overcoat passes through the bolt fastening with the connecting pipe, the bottom of axle passes through the key-type connection with the impeller and fixes through impeller lock nut, the outside of impeller is equipped with the pump case, the top of pump case has the pump case through the bolt fastening. The utility model discloses can improve the work efficiency of pump to improve the stability and the equilibrium of pump, prolonged the life of pump.

Description

Molten salt pump

Technical Field

The utility model relates to a non-positive displacement pump technical field, in particular to molten salt pump.

Background

The GY type molten salt pump is an advanced mature vertical long shaft pump developed for meeting the domestic market demand. The pump can be used for conveying clear water below 55 ℃, rainwater, ferric oxide scale water, sewage, corrosive industrial wastewater, seawater and other liquids, and can convey 90 ℃ liquid after special design. The GY type molten salt pump is applied to and carries high temperature fused salt (nitrate), belongs to vertical long-axis pump, belongs to one kind of centrifugal pump, and from the perspective of centrifugal pump, it is exactly that the improvement comes on the performance of submerged pump, makes its performance be higher than submerged pump greatly, and the stationarity when the operation is stronger. The method is widely applied to industrial and mining enterprises such as tap water companies, sewage treatment plants, power plants, iron and steel plants, mines and the like, and projects such as municipal water supply and drainage, flood control and waterlogging drainage. The existing GY type molten salt pump structure has the problems that the service life and the running stability of the pump are influenced due to abrasion among all parts caused by vibration of the pump in the running process, and the hydraulic efficiency is low due to large energy loss.

Disclosure of Invention

In order to solve the technical problem, an object of the present invention is to provide a molten salt pump.

The above object of the utility model is realized through following technical scheme: a molten salt pump comprises a motor, a motor mounting plate, a coupler, a bearing body assembly, a bottom plate, a shaft, an impeller locking nut, a pump cover, a pump shell, a water outlet pipe assembly and a connecting pipe, wherein the motor is fixed above the motor mounting plate and is connected with the shaft through the coupler, the bearing body assembly is installed at the upper end of the shaft and is fixed on the bottom plate through a bolt, a first guide bearing is arranged at the middle section of the shaft, a first guide bearing outer sleeve is arranged outside the first guide bearing and is fixed with the connecting pipe through the bolt, the bottom end of the shaft is connected with the impeller through a key and is fixed through the impeller locking nut, the pump shell is arranged outside the impeller, the pump cover is fixed above the pump shell through the bolt, the upper end of the connecting pipe is fixed with the bottom plate through the bolt, the lower end of the connecting pipe is fixed with the pump cover through the bolt, the shaft is connected with the pump cover through a second guide bearing and a second guide bearing outer sleeve, the second is led the bearing overcoat and is located the second and is led the bearing outside, be equipped with the limiting plate on the second and lead the bearing overcoat, the limiting plate passes through the bolt fastening with the pump cover, the connecting pipe is located the outside of axle, the medium entry has been seted up to the bottom of pump case, the side of pump case is equipped with the medium export, the outlet pipe subassembly includes flange, connecting elbow and outlet pipe, the medium export of pump case is connected with the one end of connecting elbow through flange, the other end of connecting elbow is connected with the outlet pipe, the outlet pipe end upwards wears out the bottom plate and is fixed with the bottom plate.

Further, the bearing body assembly comprises a bearing body, a rolling bearing, a shaft sleeve locking ring, a gland, an upper bearing body support and a lower bearing body support, wherein the rolling bearing is connected with the shaft through the shaft sleeve, the shaft sleeve locking ring is fixed above the shaft sleeve through a bolt, the gland is fixed above the bearing body through a bolt, the upper bearing body support and the lower bearing body support are arranged outside the bearing body, the upper bearing body support and the lower bearing body support are fixed through a bolt, the lower bearing body is fixed above the bottom plate through a bolt, and the upper part of the upper bearing body support is fixed with the motor mounting plate.

Furthermore, the upper end and the lower end of the impeller are respectively provided with a first impeller opening ring and a second impeller opening ring, the pump cover opening ring is arranged between the inner wall surface of the pump cover and the first impeller opening ring, the pump cover opening ring is arranged between the inner wall of the pump shell and the second impeller opening ring, and opening ring gaps between the first impeller opening ring and the pump cover opening ring and between the second impeller opening ring and the pump cover opening ring are both 0.45 mm.

Further, the distance L between the lower end face of the impeller and the pump shell is 7 mm.

Furthermore, a filter screen is arranged below the medium inlet of the pump shell.

Further, the impeller is a closed impeller, the number of blades of the impeller is 5, the outlet thickness b1 of the impeller is 35mm, the outlet width b2 of the impeller is 5mm-6mm, the outlet diameter D2 of the impeller is 259mm, the outlet angle beta of the blades is 20 degrees-30 degrees, the wrap angle theta of the blades is 115 degrees-130 degrees, the inlet diameter D3 of the impeller is 139.6mm, and the inlet diameter D1 of the blades is 113 mm.

Furthermore, the first guide bearing and the second guide bearing are respectively communicated with a lubricating liquid conveying pipeline through a first conveying pipe and a second conveying pipe, and the lubricating liquid conveying pipeline is used for conveying lubricating liquid to the first guide bearing and the second guide bearing.

The pump shell is a volute type pump shell and comprises a volute body, a first partition tongue, a partition plate and a second partition tongue, a water flow channel is arranged in the volute body, the first partition tongue is arranged on the volute body, the partition plate is arranged in the water flow channel, the second partition tongue is formed on the partition plate, the water flow channel is divided into an inner flow channel and an outer flow channel through the partition plate, the distance from the first partition tongue or the second partition tongue to the center of a medium inlet of the volute body is taken as a radius, the center of the medium inlet is taken as a circle center O, a connecting line between the first partition tongue and the circle center O is taken as a 0-degree position, and the central angle is formed by taking the connecting line between the first partition tongue and the circle center O as a circle center angle

The curvature tangential angle alpha 1 of the volute is 4.07 degrees at the central angle

The curvature tangential angle alpha 2 of the volute is 3.4 degrees at the central angle

The curvature tangential angle alpha 3 of the volute is 3.23 degrees at the central angle

The tangential angle alpha 4 of the volute is 3.11 degrees at the central angle

The tangential angle alpha 5 of the volute is 2.98 degrees at the central angle

The tangential angle alpha 6 of the volute is 2.79 DEG at the central angle

The tangential angle alpha 7 of the volute is 2.99 degrees at the central angle

The tangential angle alpha 8 of the volute is 2.76 DEG at the central angle

The tangential angle alpha 9 of the volute is 2.42 DEG at the central angle

The volute curvature tangential angle alpha 10 is 2.17 deg..

The beneficial effects of the utility model reside in that:

the utility model discloses an upper bearing body support and lower bearing body support provide the axial holding power for the pump body simultaneously, antifriction bearing also provides the axial holding power for the body simultaneously, antifriction bearing passes through the axle sleeve and connects with the hub connection, the axle sleeve locking ring passes through the bolt fastening in the top of axle sleeve, the top of the bearing body has the gland through the bolt fastening, the axial brace that makes the pump body is better for the pump vibrations reduce, and then reduce the wearing and tearing of each part, improve the stability and the equilibrium of pump, the life of extension pump.

The utility model discloses a many places spiral case camber corner cut to the hydraulic model of impeller and pump case improves, makes the utility model discloses at the during operation, the motion law more of water reduces the backward flow, lets useful work account for than higher, reduces energy loss to reach raises the efficiency, realize energy-concerving and environment-protective purpose.

Drawings

Fig. 1 is a schematic structural diagram of the present invention;

FIG. 2 is an enlarged partial schematic view at A of FIG. 1;

FIG. 3 is a cut-away view of the impeller blades;

FIG. 4 is an axial view of a model impeller;

FIG. 5 is a cross-sectional schematic view of the pump casing;

in the figure: 1. motor, 2, motor mounting plate, 3, coupling, 4, bearing body assembly, 41, bearing body, 42, rolling bearing, 43, shaft sleeve, 44, shaft sleeve locking ring, 45, gland, 46, upper bearing body support, 47, lower bearing body support, 5, base plate, 6, shaft, 7, impeller, 8, impeller locking nut, 9, pump cover, 10, pump housing, 101, media inlet, 102, media outlet, 103, pump housing body, 104, first tongue, 105, partition, 1051, second tongue, 11, connecting tube, 12, connecting flange, 13, connecting elbow, 14, water outlet tube, 15, first impeller mouth ring, 16, second impeller mouth ring, 17, pump cover mouth ring, 18, pump housing mouth ring, 19, filter screen, 20, first guide bearing, 21, first guide bearing outer sleeve, 22, second guide bearing, 23, second guide bearing outer sleeve, 24, limiting plate, 25, bearing outer sleeve, 4, bearing body assembly, 44, bearing body locking ring, 45, gland, upper bearing body support, 47, lower bearing body support, 5, base plate, 6, shaft, 7, impeller, 8, impeller locking nut, 9, connecting tube, connecting flange, connecting tube, and connecting tube, A first delivery pipe 26, a second delivery pipe 27 and a lubricating liquid delivery pipeline.

Detailed Description

The detailed contents and specific embodiments of the present invention are further described below with reference to the accompanying drawings and specific embodiments.

As shown in the attached drawings 1-5, a molten salt pump comprises a motor 1, a motor mounting plate 2, a coupler 3, a bearing body assembly 4, a bottom plate 5, a shaft 6, an impeller 7, an impeller locking nut 8, a pump cover 9, a pump shell 10, a water outlet pipe assembly and a connecting pipe 11, wherein the motor 1 is fixed above the motor mounting plate 2, the motor 1 is connected with the shaft 6 through the coupler 3, the bearing body assembly 4 is installed at the upper end of the shaft 6, the bearing body assembly 4 is fixed on the bottom plate 5 through a bolt, a first guide bearing 20 is arranged at the middle section of the shaft 6, a first guide bearing outer sleeve 21 is arranged outside the first guide bearing 20, the first guide bearing outer sleeve 21 is fixed with the connecting pipe 11 through a bolt, the bottom end of the shaft 6 is in key connection with the impeller 7 and is fixed through the impeller locking nut 8, the pump shell 10 is arranged outside the impeller 7, the pump cover 9 is fixed above the pump shell 10 through a bolt, the upper end of the connecting pipe 11 is fixed with the bottom plate 5 through a bolt, the lower end of the connecting pipe 11 is fixed with the pump cover 9 through a bolt, the connecting pipe 11 is used for protecting the shaft 6 and the first guide bearing 20, when clear water is conveyed, the connecting pipe 11 is not required to be installed, and lubricating liquid is not required to be introduced into the first guide bearing 20; when sewage is conveyed, the connecting pipe 11 must be installed, and lubricating liquid must be introduced into the first guide bearing 20; shaft 6 and pump cover 9 are connected through second guide bearing 22 and second guide bearing overcoat 23 between, second guide bearing overcoat 23 is located second guide bearing 22 outside, be equipped with limiting plate 24 on the second guide bearing overcoat 23, limiting plate 24 passes through the bolt fastening with pump cover 9, connecting pipe 11 is located the outside of shaft 6, medium entry 101 has been seted up to the bottom of pump case 10, the side of pump case 10 is equipped with medium export 102, the outlet pipe subassembly includes flange 12, connecting elbow 13 and outlet pipe 14, the medium export 102 of pump case 10 is connected with the one end of connecting elbow 13 through flange 12, the other end of connecting elbow 13 is connected with outlet pipe 14, the end of outlet pipe 14 upwards wears out bottom plate 5 and is fixed with bottom plate 5.

The bearing body assembly 4 comprises a bearing body 41, a rolling bearing 42, a shaft sleeve 43, a shaft sleeve locking ring 44, a gland 45, an upper bearing body support 46 and a lower bearing body support 47, wherein the rolling bearing 42 is connected with the shaft 6 through the shaft sleeve 43, the shaft sleeve locking ring 44 is fixed above the shaft sleeve 43 through a bolt, the gland 45 is fixed above the bearing body 41 through a bolt, the upper bearing body support 46 and the lower bearing body support 47 are arranged outside the bearing body 41, the upper bearing body support 46 and the lower shaft body support are fixed through a bolt, the lower bearing body 41 is fixed above the bottom plate 5 through a bolt, and the upper part of the upper bearing body support 46 is fixed with the motor mounting plate 2.

The upper end and the lower end of the impeller 7 are respectively provided with a first impeller opening ring 15 and a second impeller opening ring 16, a pump opening ring 17 is arranged between the inner wall surface of the pump cover 9 and the first impeller opening ring 15, a pump casing opening ring 18 is arranged between the inner wall of the pump casing 10 and the second impeller opening ring 16, and opening ring gaps between the first impeller opening ring 15 and the pump opening ring 17 and between the second impeller opening ring 16 and the pump casing opening ring 18 are both 0.45 mm.

The distance L between the lower end surface of the impeller 7 and the pump shell 10 is 7 mm.

A filter screen is provided below the medium inlet 101 of the pump housing 10. Not only effectively prevent large granule impurity to get into and damage the water pump in the pump, furthest has reduced the import loss again simultaneously, has improved the efficiency of pump.

The utility model discloses an improvement to impeller 7 has improved impeller 7 hydraulic efficiency, and then has promoted the efficiency of molten salt pump in the use pump, also makes the pump operation more stable and then promote work efficiency through the design to the structure simultaneously. The impeller 7 is a closed impeller, the number of blades of the impeller 7 is 5, the outlet thickness b1 of the impeller 7 is 35mm, the outlet width b2 of the impeller 7 is 5mm-6mm, the outlet diameter D2 of the impeller 7 is 259mm, the outlet angle beta of the blade is 20 degrees-30 degrees, the wrap angle theta of the blade is 115 degrees-130 degrees, the inlet diameter D3 of the impeller 7 is 139.6mm, and the inlet diameter D1 of the blade is 113 mm.

The first guide bearing 20 and the second guide bearing 22 are respectively communicated with a lubricating fluid delivery pipeline 27 through a first delivery pipe 25 and a second delivery pipe 26, and the lubricating fluid delivery pipeline 27 is used for delivering lubricating fluid to the first guide bearing 20 and the second guide bearing 22. The first guide bearing 20 and the second guide bearing 22 are made of polytetrafluoroethylene, sialon or nitrile rubber.

The pump casing 10 is a volute type pump casing, the pump casing 10 comprises a volute body 103, a first partition tongue 104, a partition plate 105 and a second partition tongue 1051, a water flow channel is arranged in the volute body 103, the first partition tongue 104 is arranged on the volute body 103, the partition plate 105 is arranged in the water flow channel, the second partition tongue 1051 is formed on the partition plate 105, the water flow channel is divided into an inner flow channel and an outer flow channel through the partition plate 105, the distance from the first partition tongue 104 or the second partition tongue 1051 to the center of a medium inlet 101 of the volute body 103 is taken as a radius (the distance from the first partition tongue 104 or the second partition tongue 1051 to the center of the medium inlet 101 of the volute body 103 is equal), a circle is made by taking the center of the medium inlet 101 as a circle center O, a connecting line between the first partition tongue 104 and the circle center O is taken as a 0-degree position, and the circle center is formed at a central angle

The tangential angle alpha 1 of the volute is 4.07 degrees (increased by 1.17 degrees compared with the tangential angle of the prior volute), and the central angle is

The tangential angle alpha 2 of the volute is 3.4 degrees (increased by 1.57 degrees compared with the tangential angle of the prior volute), and the tangential angle is at the central angle

The tangential angle alpha 3 of the volute is 3.23 degrees (increased by 1.5 degrees compared with the tangential angle of the prior volute curvature), and the tangential angle is at the central angle

The tangential angle alpha 4 of the volute is 3.11 degrees (increased by 1.33 degrees compared with the tangential angle of the prior volute curvature), and the tangential angle is at the central angle

The tangential angle alpha 5 of the volute is 2.98 degrees (which is reduced by 0.75 degrees compared with the tangential angle of the prior volute) and is at the central angle

The tangential angle alpha 6 of the volute is 2.79 degrees (2.12 degrees is increased compared with the tangential angle of the prior volute), and the tangential angle is at the central angle

The tangential angle alpha 7 of the volute is 2.99 degrees (reduced by 1.58 degrees compared with the tangential angle of the prior volute curvature), and the central angle is

The tangential angle alpha 8 of the volute is 2.76 degrees (0.35 degree is increased compared with the tangential angle of the prior volute curvature), and the central angle is

At a central angle of 2.42 DEG (reduced by 0.59 DEG from the original volute curvature chamfer angle) of volute curvature chamfer angle alpha 9

The volute curvature tangential angle alpha 10 is 2.17 degrees (0.25 degree increased compared with the original volute curvature tangential angle).

The utility model improves the volute curvature corner cut of the pump shell on the basis of the original ZA/ZE80-200 pump shell, so that the medium (the medium of the utility model is water) flows back and becomes small in the process of moving in the pump shell 10, the energy loss is reduced, the working efficiency is improved,

the utility model discloses a molten salt pump is brought power by motor 1, links to each other and transmits power with axle 6 through shaft coupling 3 to provide the support to the pump motion through bearing body subassembly 4, wherein bearing body 41 is connected with axle 6, and axle 6 passes through the key and gives impeller 7 with power transmission, and pump case 10 passes through bolted connection with pump cover 9, and impeller 7 passes through impeller lock nut 8 and axle 6 locking. The impeller 7 is matched with the pump cover opening ring 17 by the first impeller opening ring 15 on the impeller 7, and the second impeller opening ring 16 and the pump shell opening ring 18 are respectively matched and positioned with the pump cover 9 and the pump shell 10. The medium is filtered by the filter screen 19 from the suction inlet and then enters the medium inlet 101 of the pump shell 10, and after being pressurized by the impeller 7, the medium finally reaches the water outlet 141 through the water outlet pipe 14 from the medium outlet 102 of the pump shell 10.

The utility model discloses an upper bearing body support 46 reaches bearing body support 47 simultaneously for the pump body provides axial holding power, and antifriction bearing 42 also provides axial holding power for the pump body simultaneously, and antifriction bearing 42 passes through axle sleeve 43 and is connected with axle 6, and axle sleeve locking ring 44 passes through the bolt fastening in the top of axle sleeve 43, and there is gland 45 bearing body 41's top through the bolt fastening, the utility model discloses redesign to the bearing frame makes the axial holding nature of the pump body better for the pump vibrations reduce, and then reduces the wearing and tearing of each part, improves the stability and the equilibrium of pump, prolongs the life of pump.

Additionally, the utility model discloses a many places spiral case camber corner cut to impeller 7's hydraulic model and pump case 10 improves, makes the utility model discloses the molten salt pump is at the during operation, and the motion law of water reduces the backward flow more, lets useful work account for than higher, reduces energy loss to reach raises the efficiency, realize energy-concerving and environment-protective purpose. The utility model discloses an oral siphon clearance between first impeller oral siphon 15 and pump cover oral siphon 17 and between second impeller oral siphon 16 and the pump case oral siphon 18 is 0.45mm, and the lower terminal surface of impeller 7 is 7mm with the interval L of pump case 10, can make the pump operation more stable, and then the work efficiency of elevator pump.

The above, only be the concrete implementation of the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art is in the technical scope of the present invention, according to the technical solution of the present invention and the utility model, the concept of which is equivalent to replace or change, should be covered within the protection scope of the present invention.

Claims (8)

1. A molten salt pump is characterized by comprising a motor, a motor mounting plate, a coupler, a bearing body assembly, a bottom plate, a shaft, an impeller locking nut, a pump cover, a pump shell, a water outlet pipe assembly and a connecting pipe, wherein the motor is fixed above the motor mounting plate and connected with the shaft through the coupler, the bearing body assembly is installed at the upper end of the shaft and fixed on the bottom plate through bolts, a first guide bearing is arranged at the middle section of the shaft, a first guide bearing outer sleeve is arranged outside the first guide bearing and fixed with the connecting pipe through bolts, the bottom end of the shaft is in key connection with the impeller and fixed through the impeller locking nut, the pump shell is arranged outside the impeller, the pump cover is fixed above the pump shell through bolts, the upper end of the connecting pipe is fixed with the bottom plate through bolts, the lower end of the connecting pipe is fixed with the pump cover through bolts, and the shaft is connected with the pump cover through a second guide bearing and a second guide bearing outer sleeve, the second is led the bearing overcoat and is located the second and is led the bearing outside, be equipped with the limiting plate on the second and lead the bearing overcoat, the limiting plate passes through the bolt fastening with the pump cover, the connecting pipe is located the outside of axle, the medium entry has been seted up to the bottom of pump case, the side of pump case is equipped with the medium export, the outlet pipe subassembly includes flange, connecting elbow and outlet pipe, the medium export of pump case is connected with the one end of connecting elbow through flange, the other end of connecting elbow is connected with the outlet pipe, the outlet pipe end upwards wears out the bottom plate and is fixed with the bottom plate.

2. The molten salt pump according to claim 1, wherein the bearing assembly comprises a bearing body, a rolling bearing, a shaft sleeve locking ring, a gland, an upper bearing body support and a lower bearing body support, the rolling bearing is connected with the shaft through the shaft sleeve, the shaft sleeve locking ring is fixed above the shaft sleeve through a bolt, the gland is fixed above the bearing body through a bolt, the upper bearing body support and the lower bearing body support are arranged outside the bearing body, the upper bearing body support and the lower shaft body support are fixed through a bolt, the lower bearing body is fixed above the bottom plate through a bolt, and the upper bearing body support is fixed above the motor mounting plate.

3. The molten salt pump of claim 1, wherein a first impeller opening ring and a second impeller opening ring are respectively provided at upper and lower ends of the impeller, a pump cover opening ring is provided between an inner wall surface of the pump cover and the first impeller opening ring, a pump cover opening ring is provided between an inner wall of the pump cover and the second impeller opening ring, and opening ring gaps between the first impeller opening ring and the pump cover opening ring and between the second impeller opening ring and the pump cover opening ring are both 0.45 mm.

4. A molten salt pump according to claim 1, wherein the distance L between the lower end face of the impeller and the pump casing is 7 mm.

5. A molten salt pump as claimed in claim 1, wherein a filter screen is provided below the medium inlet of the pump housing.

6. A molten salt pump according to claim 1, wherein the impeller is a closed impeller having 5 blades, an impeller outlet thickness b1 of 35mm, an impeller outlet width b2 of 5mm to 6mm, an impeller outlet diameter D2 of 259mm, a blade outlet angle β of 20 ° to 30 °, a blade wrap angle θ of 115 ° to 130 °, an impeller inlet diameter D3 of 139.6mm, and a blade inlet diameter D1 of 113 mm.

7. A molten salt pump according to claim 1, wherein the first guide bearing and the second guide bearing are communicated with a lubricant delivery line through a first delivery pipe and a second delivery pipe, respectively, the lubricant delivery line being adapted to deliver lubricant to the first guide bearing and the second guide bearing.

8. The molten salt pump according to claim 1, wherein the pump casing is a volute casing type pump casing, the pump casing includes a volute casing body, a first partition tongue, a partition plate, and a second partition tongue, a water flow passage is provided in the volute casing body, the first partition tongue is provided on the volute casing body, the partition plate is provided in the water flow passage, the second partition tongue is formed on the partition plate, the water flow passage is divided into an inner flow passage and an outer flow passage by the partition plate, a radius is given by a distance from the first partition tongue or the second partition tongue to a center of a medium inlet of the volute casing body, a circle is given by a center of the medium inlet as a center O, a line connecting the first partition tongue and the center O is taken as a 0 ° position, and at a central angle, the center O is a center of the circle

The curvature tangential angle alpha 1 of the volute is 4.07 degrees at the central angle

The curvature tangential angle alpha 2 of the volute is 3.4 degrees at the central angle

The curvature tangential angle alpha 3 of the volute is 3.23 degrees at the central angle

The tangential angle alpha 4 of the volute is 3.11 degrees at the central angle

The tangential angle alpha 5 of the volute is 2.98 degrees at the central angle

The tangential angle alpha 6 of the volute is 2.79 DEG at the central angle

The tangential angle alpha 7 of the volute is 2.99 degrees at the central angle

The tangential angle alpha 8 of the volute is 2.76 DEG at the central angle

The tangential angle alpha 9 of the volute is 2.42 DEG at the central angle

The volute curvature tangential angle alpha 10 is 2.17 deg..

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