The KSB submersible motor pumps in the Amarex type series are employed in applications like waste water and sludge treatment as well as stormwater transport. They can handle waste water with long fibres and solid substances, fluids containing gas or sludges, service water and grey water and are equipped with either free-flow impellers (F-max) or open, two-vane impellers (D-max). Customers can thus choose the right impeller type depending on their requirements: low waste water flow rates at high heads or high flow rates at lower heads. Pump variants featuring D-max impellers are optionally available with a D-flector, which significantly increases resistance to clogging. A multitude of material and mechanical seal variants ensure that users can transport a wide range of corrosive and abrasive fluids.
The impellers’ non-clogging feature markedly reduces maintenance requirements compared with conventional designs while the pumps’ high levels of hydraulic efficiency combined with high-efficiency IE3 motors make for low energy consumption during operation. The type series has a maximum head of 42 m and a maximum flow rate of 320 m3/h. When designing Amarex, the engineers attached great importance to the pumps achieving a long service life. This is ensured by a generously dimensioned motor, robust rolling element bearings and a corrosion-resistant stainless steel shaft.
An environmentally friendly, non-toxic oil fill provides continuous lubrication of the mechanical seal. As is common practice with this type of pump, installation in the pump sump is effected via a duckfoot bend. A large range of adapter claws also allows the use of such bends from other manufacturers, so that a change of make is possible without requiring any major installation effort. Sealing between the duckfoot bend and the pump discharge flange is by a newly developed, absolutely water-tight and durable U-profile ring. Users also have several options when choosing the arrangement for placing the pump on the duckfoot bend: they can opt for a guide hoop, guide wire, single guide rail or twin guide rail arrangement.
For high ambient temperatures
One highlight of the Amarex type series is the KRT range of submersible motor pumps featuring jacket-cooled drives. They are designed to transport untreated waste water for municipal and industrial waste water management. The new pump sets are available with drive ratings from 10 to 30 kW and are suitable for vertical or horizontal dry installation. Since the pump motors remain fully operational when not submerged, the pump sets can also be used in pump sumps when water levels have dropped. Thanks to the IP 68 enclosures, these pumps additionally offer trouble-free continuous operation when flooded. The pump sets meet all explosion protection requirements set out in the Atex, FM and CSA standards.
The motor is cooled via a closed circuit to avoid contact between the circulating water-glycol mixture and the fluid handled. This simultaneously rules out any risk of contaminants in the fluid impairing cooling of the motor. The cooling liquid is circulated by a special impeller, which the pump’s design engineers have integrated into the cartridge seal.
This double mechanical seal is a proprietary development of the pump manufacturer, which has been producing its own mechanical seals in-house for several years. This cartridge can be replaced as a complete unit, facilitating and substantially accelerating servicing work.
The pumps are able to transport fluids with a temperature of up to 40 °C and operate in environments with a temperature of up to 55 °C. This enables them to be used in hot countries where they are often dry-installed in air-conditioned rooms. Convection cooling via the surface of the pump casing would place an enormous thermal load on the air-conditioning system and have a negative effect on power consumption.
Monitoring as standard
The sensor package installed as standard includes monitoring of the motor temperature via a PTC chain, a leakage sensor inside the motor and monitoring of mechanical seal leakage via a float switch. Users can also optionally order up to three Pt100 sensors for bearing and motor temperature monitoring as well as a vibration sensor. The signals from these sensors can be analysed by the Amacontrol III protection module, which can send the data collected to either a data recording system or a cloud.
Only one person needed
Another optional feature is the Amaslide maintenance aid for horizontal pump installation. With its help, only one person is needed to open an Amarex KRT and perform work such as impeller inspections. Cranes or lifting equipment are not required. Service engineers only have to remove the bolts between the pump casing and the discharge cover. They can then remove the back pull-out unit comprising the impeller, shaft, bearing, seals and motor from the casing. The latter remains in place, attached to its suction and discharge lines. Once the back pull-out unit has been removed, the impeller is freely accessible. Maintenance work can then be carried out without any problems. After completion, the service engineer simply pushes the back pull-out unit back into position.
KSB SE & Co. KGaA, Frankenthal, Germany
Dr. Bernd Rademacher