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Next generation of tough submersible pumps KSB Aktiengeselischaft (Frankenthal, Germany) will launch a new generation of its Ama®-Drainer submersible motor pumps early this month. The new pump model comes with a corrosionresistant stainless steel casing as standard. The pumps are suitable for automatic drainage of excavation pits, collection sumps, tanks and cellars, and for pumping up water from rivers or reservoirs. The new pumps are supplied with one of two hydraulic systems: one is suitable for handling dirt particles measuring up to 10 mm, the other for foreign matter up to 35 mm in
stationary installation, the pumps are supplied with a float switch; portable units come with a 10 m long power supply cable. The maximum immersion depth is approximately 10 m. Fitted with a cooling jacket, which is available for retrofitting, the pump is suitable for extended periods of operation with the motor non-submerged. The bimetal switches integrated in the motor winding protect the pump against excessive heat generation. For short periods, it can, therefore, handle hot waste water of 90°C, as, for example, produced by the hot cycle of a household washing machine.
size. The pumps are driven by either three-phase or singlephase A.C. motors rated between 0.55 and 2.2 W. For
CONTACT KSB Aktiengesellschaft, D-67225 Frankenthal, Germany. Tel: +49 6233 863702; Fax: +49 6233 863456; E-mail: [email protected]
Submersible waste water pump provides reliable alternative The new K-83 submersible wastewater pump, manufactured by Pumpex, offers the reliability and durability of a higher powered pump in a 6 hp alternative specifically designed for cost-efficient operation in a low flow, high pressure system. The Pumpex K-83 provides non-clogging performance and needs only routine, scheduled maintenance during its life cycle, making it less costly to own than the grinder pumps it can replace. Unique design features on the Pumpex K-83 easily meet the specs of a low flow system, up to 230 gpm at 110 ft of pressure. Discharge sizes measuring 2.5 to 4 inch easily accommodate a small diameter piping system. A special vortex impeller assures nonclogging operating efficiency, and reduces cavitation and shutdown. A cartridge mechanical seal can , be replaced on-site in minutes. CONTACT Pumpex, 103A Molasses Hill Rd, Lebanon, NJ 08833, USA. Tel: +1 908 730 7004; Fax:+1 908 730 7580.
No need for drain-down
New design for stop-start cryogenic pumping range Girdlestone Pumps, now part of the Weir Group, has released details of its innovative 950 cryogenic pump range. The pump has been known about for the last four years and during this time Girdlestone has been perfecting its design and performance whilst establishing an experienced worldwide reference database. Working with the co-operation of one of the world's leading air separation specialists, the new pump has almost eliminated unscheduled downtime while making a significant contribution to increasing productivity. The pump is revolutionary because is does not use any conventional sealing technology or require the injection of an expensive inert gas; instead, it uses the cryogenic fluid's own unique properties to seal itself. Particularly successful on continuous operations, the concept was
developed for those difficult stopstart applications where conventional pumps need to be drained during stopped periods and conventional sealing methods tended to fail due to freezing of seal faces prior to restarting the pumps. Original estimates put the MTBF (mean-time between failure) for such applications as three months maximum, with repair and loss costs at about £1600 each time. This means that the 950 would pay for itself within 12 months. The pump can be kept cold indefinitely, does not need draining down and So the need for a standby unit is eliminated. This means that capital costs for new installations are significantly reduced. A simple design uses the unique properties of liquid nitrogen and liquid argon to pressurise the space between the pump and
motor, as well as the motor flame itself The pressure builds until it equalises the suction pressure; the product is then fully contained within this environment, with zero leakage. Fluid passes from the pump casing via a special lowtemperature, non-contacting throttle bush, which ensures the liquid is converted to a gas by lowering the pressure. As more and more gas enters the space, the pressure within the pump builds until it equals the pressure of the liquid contained in the pump casing. A heater mounted on the motor's front bearing and a RTD (resistance temperature device) are fitted to allow monitoring of the temperature in the pump. Various methods of control are available, depending on customer requirements, from a fully selfcontained unit to an arrangement which provides feedback to the client's own system. Using an
auxiliary motor cooling fan running at a constant speed makes the pump ideal for use with variable speed controllers for difficult low N P S H start-up applications. Using Girdlestone's proven 910 pump liquid end, with its high efficiency low NPSH design, the 950 draws on parts from stock and is available on short lead times. Each pump is mounted on a robust steel baseplate, complete with the controls as required, and is engineered to suit theclient's own particular application. Currently rated for 13 barg operating pressures, and pressure tested to 20 barg, special designs are available for higher pressures. CONTACT Girdlestone Pumps, Station Road, Melton, Woodbridge, Suffolk 1P12 1ER, UK. Tel: +44 1394 383777; Fax: +44 1394 386733; E-mail [email protected]
April 2000 ~9