FLOWSERVE CORPORATION Guardian Pumps. Centrifugal ANSI Pumps Product Training Program

Transcription

1 FLOWSERVE CORPORATION Guardian Pumps Centrifugal ANSI Pumps Product Training Program April 2017

2 Sealless Pumps Definition A pump that is designed with no externally actuated shaft penetrating the pump housing. Centrifugal Designs Magnetic Drive Canned Motor Applications -Emissions Reduction -Flammable -Ultrapure -Corrosive -Toxic -Expensive Liquids -Difficult Sealing Page 2

3 Magnetic Drive Pump Pump Shaft Outer Magnet Assembly Drive Shaft Bushings Impeller Thrust Journals Rotating Elements outlined in green Inner Magnet Assembly Casing Bearing Holder Page 3

4 Guardian ANSI Compliant Sealless Long and Closed Coupled Magnetically drive Page 4

5 Applications Corrosive Toxic Flammable Emissions Reduction Expensive Liquids Ultra-pure Difficult Sealing Page 5

6 Magnetic Drive Inner and Outer Magnet Set Containment shell Bearings Jacking bolts Tolerance ring Rub pads Permanent rare earth magnets Synchronous drive eliminates slippage Page 6

7 Containment Shell Hastelloy C276 Corrosion resistant Low permeability and eddy current loss Heavy wall and domed for added strength and corrosion allowance Meets Mark III pressure and temperature ratings Meets Section VIII ASME Pressure Vessel Code Page 7

8 Bearings Silicon Carbide radial and thrust bearings inside containment shell Long life under load Abrasion and chemical resistant Double spiral groove to improve circulation Non-clogging for better solids handling Page 8

9 Magnet Material Comparison Magnet Material Ferrites Alnico Samarium Cobalt (Sm Co) BH Max (M G O ) Reversible Tem p Coefficient (%/º C) Neodynium Iron (NdFe) Max. Operating Temp. º C (º F) (480) (1000) (550) (250) Cost Index / kg Cost Index / kw Curie Temp. º C Curie Tem p. (º F) 450 (840) 840 (1545) 700 (1290) 310 (590) BH Max: Coefficient maximum energy product Reversible Temp. Coeff: Percent per degree of magnetism lost above 20 C Max Operating Temp: Maximum temperature magnetic material may be exposed to without experiencing irreversible losses Curie Temp: Temperature at which complete loss of magnetism occurs Page 9

10 Temperature Stability All magnet materials are weakened at elevated temperatures. Some weakening is reversible. This is characterized by the reversible temperature coefficient, measured from 20 C. Magnet weakening is irreversible when the material is exposed to temperatures greater than the maximum rated operating temperature. A permanent, complete loss of magnetism occurs at the Curie temperature. Power strength Max. operating temperature Reversible area Irreversible area Temperature T (F)(º F) Curie temperature NdFe SmCo Page 10

11 Standard Circulation To silicon carbide bushings and journals (spiral and radial grooved to promote lubrication) To gap between magnet and containment shell to dissipate heat. Page 11

12 External Flush Inject clean compatible liquid OR, inject filtered bypass product Page 12

13 Synchronous Torque Ring Coupling Rare earth magnets utilized to transmit torque in a compact design Design is synchronous - no slip between motor and driven pump Advantage - efficient design with lower viscous & eddy current losses Disadvantage - lower temperature limit than asynchronous designs Page 13

14 Synchronous Magnetic Torque Coupling Page 14

15 Forces Between Magnets FA = force applied by driver FT = force transmitted by magnets L = distance between magnets Variables - Magnet material - Volume of magnets - Magnetic circuit design - Distance between center of magnet pairs Page 15

16 Torque & Power Transmission F = Force R = Radius T = Torque Power = (torque x rpm) / constant Therefore power depends on rpm Page 16

17 Maximum Torque and Decoupling If more than T is applied to coupling, the coupling will slip or dephase, referred to as decoupling Pump must be stopped in order to recouple the magnetic coupling Inner magnet assembly rotates very slowly or not at all Excessive noise & vibration Containment shell and magnets are heated by eddy currents Page 17

18 Magnetic Coupling Startup Reserve Magnetic couplings must be able to transmit the maximum torque delivered by the motor through the coupling At startup, torque from the motor is required to accelerate Motor rotor Outer magnet assembly Provide Power to the Liquid Inner Magnet Assembly Impeller & liquid Magnetic coupling must be sized to transmit added torque at startup Page 18

19 Effects of a Barrier Non-magnetic barrier does not affect the magnetic field Magnetic barrier will short circuit the magnetic field Eddy currents will be induced in electrically conductive barriers when magnetic field moves Must use low conductivity material (e.g. C-276) to reduce eddy currents Page 19

20 Coupling Power Losses WINDAGE - Viscous drag of fluid between containment shell and inner magnet assembly EDDY CURRENT - Induced in containment shell (conductive) with rotating magnetic field - Results in power loss which is converted to heat Page 20

21 Jacking Bolts Reduce risk of injury Ease magnetic coupling assembly and disassembly Reduce potential for pump damage during assembly Page 21

22 Tolerance Ring Compensates for thermal expansion Used on High Temperature H series applications Positively locates journal bearings Protected by gaskets and o- rings to prevent corrosion and solids packing Page 22

23 Rub Pads Prevent outer magnet contact with containment shell if bearings should fail Non-sparking Replaceable Page 23

24 Additional Features No wetted fasteners Eliminates corrosion Eliminates potential for leaks Metal-to-metal fits assures precise alignment Page 24

25 Reverse Vane Impeller Provides consistent flow and pressure in containment shell No wear rings or close clearances needed to maintain hydraulic balance or recirculation flow Page 25

26 Additional Features ANSI B73.1 dimensions Wet end interchangeable with Mark 3 Power end pullout without breaking sealed containment Closed Coupled Version uses standard C-face NEMA motors Page 26

27 Full Back Pullout Design Page 27

28 Power End Pullout Page 28

29 Limitations Solids 300 micron (0.012 ) Less than 3% by weight No ferrous particles 2 Moh maximum hardness Talc = 1 Moh Diamond = 10 Moh Viscosity 0.3 to 300 cp others by review Page 29

30 Limitations Temperature (process temperature PLUS rise in containment shell) G series: Minus 100F to plus 250F H series Group 1: -100F to 550F H series Group 2: - 100F to 450F *Magnetism decreases with temperature rise Page 30

31 Limitations Process liquid can boil from heat added in containment shell! Consider Three values of vapor press. vs. temperature Critical pressure and temperature Normal boiling point at standard temperature and pressure. Page 31

32 Limitations Working pressure Same as Mark 3 Suction pressure Same as Mark 3 Page 32

33 Protection Options Pump Power Monitor Temperature probe Fiberoptic leak protection Vibration probe Page 33

34 Motor Selection Motor power determined by impeller power and magnetic coupling power Generally, power required by impeller at end of curve plus coupling losses is used to size motor Page 34

35 Power Protection Monitor For overload protection Excessive wear or rubbing Bearing failure Decoupled magnets Motor overload Page 35

36 Power Protection Monitor For under-load protection Dry run Blocked suction Decoupled magnets Failed spacer element Air entrainment Minimum flow Loss of prime Page 36

37 Temperature Probe Shell Probe Probe in constant contact with exterior surface of the shell Detects temperature increases that indicate Pump running dry Recirculation path blocked Page 37

38 Temperature Probe Process Probe Probe in a thermowell located in the bearing holder Thermocouple contacts the fluid as it leaves the shell Detects unusual temperature increase Responds quicker than shell probe but does not detect dry run Practical for monitoring temperature sensitive liquids High vapor pressure Polymer that polymerizes at elevated temperature Page 38

39 Fiberoptic Leak Detection Located on bearing housing Sensor can be located in hazardous area with electrical relays in safe area Page 39

40 Questions? Page 40