KM Series
- Overview
- Features & Benefits
- Specifications
- Other Info
Overview
Dickow’s KM Series are a range of sealless, single-stage, volute casing pumps with a maximum flow rate of 70 m³/hr and maximum differential head to 65 m. The maximum operating temperature is 200°C. KML/KMB/KMR variants have closed impellers, back-pull-out design, with end suction and top discharge flange. The capacity and casing dimensions comply with EN 22858 / ISO 2858. The KMV version is a space saving, vertical inline-design. KMB and KMV designs are close-coupled.
A static containment shell forms a closed system replacing double acting mechanical seals, along with external fluid reservoirs and the necessary control equipment. KM pumps are designed to handle toxic, explosive or other dangerous liquids which react on contact with the atmosphere.
The single elements of the multipolar magnet coupling are manufactured of Cobalt-Samarium with unlimited lifetime. The magnets in the driven rotor are completely encapsulated and not in contact with liquid. Power is transmitted to the hermetically sealed liquid end by a bank of external magnets. Inner and outer magnet rings are locked together by magnet forces and work as a synchronous coupling.
The inner magnet ring transmits the required torque direct to the impeller. Overload of the magnet coupling and slipping will not cause demagnetization if temperature monitoring is available. Should an increase of motor power be required, i.e. when installing a larger impeller, the nominal power of coupling can be increased with additional magnets. The maximum drive power of KM pumps is approx. 17 kW at 2900 rpm.
The internal clearance between rotor and containment shell is approximately 1.0 mm for standard containment shells. This allows – together with wear-resistant SiC sleeve bearings – handling of solid containing fluids.
The drive shaft is carried by oil lubricated antifriction bearings, rated for 25,000 operating hours. The oil bath is protected against the atmosphere by a labyrinth seal. Oil level is controlled by a constant level oiler and an additional sight glass. The oil chamber is sealed against the magnetic coupling also by a labyrinth seal.
KML pumps have a one-piece drive shaft and drive rotor supported by generously dimensioned antifriction bearings, grease filled for life and protected against the environment by a radial seal ring. KMB/KMV versions have the drive magnet fixed on the motor shaft in overhung position. No additional antifriction bearings and no flexible couplings are required.
The pump shaft is carried by wetted sleeve bearings of pure Silicon Carbide with a diamond layer, providing limited dry-run capability.
Due to the internal circulation from discharge to discharge, there is no temperature elevation in the impeller eye. Handling of boiling liquids is therefore possible and no increase of NPSH is required.
When fitted with suitable Ex-drive motors, the pumps can be applied in hazardous area Group II, Category 2. The pumps meet the basic safety and health requirements of Explosion-proof Directive 94/9 EC and are suitable for plants with increased safety requirements.
