Sealless Magnetic CoupledCentrifugal Pumps acc. to EN 22858

Type NMR(Design with heavy duty oil lubricated bearing bracket)

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protection

The containment shell is bolted to the bearinghousing in a manner that allows removal of thebearing bracket together with the drive rotorwithout draining the pump.

Magnetic coupling

The single elements of the multipolar magneticcoupling are manufactured of permanent magnetmaterial "Cobalt Samarium" with unlimited lifetime.The magnets in the driven rotor are completelyencapsulated, not in contact with liquid. Power istransmitted to the hermetically sealed liquid endby a bank of external magnets. Inner and outermagnet rings are locked together by magnetic forces and work as a synchronous coupling.The inner magnet ring transmits the requiredtorque direct to the impeller. Overload of themagnetic coupling and slipping will not causedemagnetization if temperature monitoring isavailable. The magnetic couplings are designedfor electric motors, direct on line starting.Should a subsequent increase of motor powerbe required, i.e. when installing a larger impeller,the nominal power of coupling can be increasedwith additional magnets.

The maximum drive power of NMR-pumps isapproximately 161 kW @ 50 Hz (260 HP@ 60 Hz).

Internal clearances

The internal clearance between rotor andcontainment shell is appr. 1,0 mm for standardcontainment shells. This allows - together with thewear resistant SiC sleeve bearings - handling ofsolid containing fluids.

For application with solids internal circulationwith auxiliary impeller is recommended(frame I, II, III, IV).

Containment shell protection

The clearances between drive rotor and bearingbracket respectively between bearing bracket andcontainment shell are arranged such that rubbingof the magnets on the containment shell will beavoided, even in the case of worn out ballbearings.

Casing drain

Complete drainage of casing and magnet end ispossible through casing drain. No additional drainrequired.

General

Magnetic coupled DICKOW-pumps of the seriesNMR are sealless pumps. The static containmentshell forms a closed system with hermeticallysealed liquid end.

Applications

Magnetic coupled NMR-pumps are designedto improve plant and personnel safety, especiallywhen handling toxic, explosive or other dangerousliquids which react on contact with the atmos-phere. For all these services the containment shellreplaces the double acting mechanical seal withexternal fluid reservoirs and the necessary controlequipment. NMR-pumps therefore offer excep-tional benefits to the chemical, petrochemical andallied industries, and protect the environment.

Max. capacity and differential head:50 Hz - appr. 900 m3/h and appr. 150 m60 Hz - appr. 1000 m3/h and appr. 220 m

(appr. 4400 gpm and 720 ft)

The maximum operating temperature is 270°C.Higher operating temperatures are available onrequest.

Hazardous area

Together with the required Ex-drive motors, theNMR-pumps can be applied in hazardous areaGroup II, Category 2. The pumps meet the basicsafety and health requirements of Explosion-proofDirective 94/9 EC and are suitable for plants withincreased safety requirement.

Design / Casing

NMR-pumps are single stage volute casing pumpswith closed impellers, back-pull-out design, withend suction and top discharge flange. Sturdy feetare provided as standard for mounting on thebase plate. Centerline mounted design is availableon request.

Capacity and outer casing dimensions complywith DIN EN 22858.

Containment shell

The containment shell is designed as a pressu-rized vessel to separate the handled liquid fromthe atmosphere.

The containment shell is not used as an additionalbearing holder. No dynamic stress occurs.

Internal circulation frame 0:

Frame 0 circulation is not recommended forapplications with solids.

Internal circulation frame I / II / III / IVwith auxiliary impeller:

Outer ball bearings

The drive shaft is carried by generously dimen-sioned oil lubricated antifriction bearings, ratedfor 25000 operating hours. The oil bath is protec-ted against the atmosphere by a labyrinth seal.Oil level is controlled by a constant level oilerand an additional sight glass. The oil chamber issealed against the magnetic coupling also by alabyrinth seal.

Double sleeve bearings

The pump shaft is carried by wetted sleevebearings. Standard material is pure SiliconCarbide with diamond layer, providing limited dry-run capability. SiC is highly resistant to corrosionand wear and can be used for all kind of liquids,also for solid containing products. The SiC-com-ponents are shrinkfitted or elastically beared bytolerance rings and therefore protected againstshock and thermal stress. Both sleeve bearingsare bolted in one common bearing housing togrant a correct alignment.

NPSH-conditions

Due to the internal circulation from discharge todischarge, there is no temperature elevation inthe impeller eye. Handling of boiling liquids istherefore possible and there is no increase ofNPSH-required.

Balanced thrust loads

The thrust loads of the closed impellers arehydraulically balanced by wear rings, balanceholes, back vanes and / or auxiliary impeller. Thepump shaft connected to the impeller is floating.

Monitoring

Connection for temperature detection element forcontainment shell surface temperature is availa-ble as standard. Dry running protection andmonitoring of ball bearings and containment shelltemperature with the patented "mag-safe" systemis highly recommended.

Internal circulation, pressurized magnet end

When pump is in operation it generates eddycurrents which heat up the containment shell andthe pumpage in the magnet area. This heat isdissipated by internal circulation. There are twodifferent internal circulation systems available fordifferent frame sizes.

pressureincreasebyauxiliaryimpeller

NMR-Design

double containmentsleeve bearing shell protection

internal circulation

volute casing,foot mounted

casingwear ring

closed impeller

drain plug confined gaskets internal magnets

externalmagnets

containmentshell

heavy dutybearing bracket,oil lubricated

Type NMR b - with heating jacket

Optional designs, secondary seal

If desired, a mechanical stand-by seal can be supplied in lieu of the inboard labyrinth seal. This mecha-nical seal separates the magnet area from the oilbath respectively the atmosphere and forms, togetherwith the closed bearing bracket, a secondary containment behind the containment shell. The slide ringsof the secondary seal operate without contact and wear free. The seal will be activated only if the con-tainment shell leakage leads to a pressure increase in the bearing bracket.

volute casing with heating jacket magnetic coupling

drive coupling

containment shell

clamping ringrotating seal ring

O-ring

stationary seal ring

seal ring support

O-ring

gasket

sleeve bearings containment shell with heating jacket

Type NHMR - hot water design

Type NMR o - with open impeller and edge type filter

edge type filter open impeller

magnetic coupling

vent magnetic coupling

air cooler

Issu

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Technical changes reserved. Printed in Germany. 080-11.11 S&W

DICKOW PUMPEN KGPostfach 125484465 Waldkraiburg · GermanyTel. ++ 49 86 38 6 02 0Fax ++ 49 86 38 6 02 200 + 6 02 201info@dickow.de / export@dickow.dewww.dickow.de

Performance range

Performance curves for the differentpump sizes are available on request,also for 1750 min-1 und 3500 min-1.