VACUUM News Important notice to readers

For further information on any matter mentioned in Vacuum News, tear out and post one of the reader enquiry cards

Manufacturers and others

Manufacturers and others are invited to submit information for inclusion in this feature addressed to The Vacuum News Editor Vacuum Pergamon Press Ltd Headington Hill Hall Oxford OX3 OBW

New products and developments

Quiet running vacuum pump

A low cost, general purpose vacuum pump which is almost as quiet as an electric motor and is virtually vibration-free, has been introduced by Edwards High Vacuum (part of BOC Ltd).

The pump, the New Speedivac 2, is a single stage, direct drive, oil sealed, rotary model, in the medium vacuum range. It will produce an ultimate vacuum of better than 0.1 torr and has a displacement of 45 I/min (2.7 ms/h).

A new design approach has isolated all noise producing parts, and the pump’s noise level is actually lower than 50 dB (B weighting) at1 m.

Edwards claim the pump is ideal for all uses where quiet running is of particular importance, for example in the school, laboratory and medical fields. Additionally, its performance makes it a suitable pump for many industrial applications such as refrigerator dehydration, vacuum handling, vacuum forming, lamp and valve evacuation and backing of diffusion pumps.

The pump has a gas ballast facility and is available with a choice of motor; a drip-proof ventilated type for general use, or a totally enclosed fan-cooled motor (TEFC) for medical or similar applications.

The pumps are of fully metric construction, and weigh approximately 12 kg. A carrying handle is supplied with models using ventilated motors, and is available as an optional extra with the TEFC motor version.

Edwards High Vacuum Circle number 30 on Reader Enquiry Service card

New faster and cheaper vacuum pumping system

Edwards High Vacuum are also introducing what they describe as a new concept in vacuum pumping systems. Called Diffstak@, it combines in one unit a three-stage diffusion pump, an optically opaque water-cooled baffle, a quarter swing valve and a roughing line. When combined with the new and ‘specially-designed-for Diffstak’ backing/roughing valve and an Edwards high performance rotary pump, the result is a system that increases pumping speed by up to 100% over a comparable combination of pumps, baffles and valves. Greatly reduced sealing requirements within the system, stainless steel construction and the use of polyphenyl ether pumping fluid significantly increase cleanliness of the system over other approaches. Reduced overall height is a byproduct of the new design that makes for easier, simpler installation (see illustration). The overall result is a much more economical, much more effective pumping system.

Edwards High Vacuum Circle number 31 on Reader Enquiry Service card

The Diffstake system

The Diffstak Vacuum Pumping System (Edwards High Vacuum)

Low-cost freeze-dryer

A new, low-cost freeze dryer named Modulyo, which is ideal for laboratory work or pilot runs, is the third new product introduced by Edwards High Vacuum.

Modulyo can be bought as a basic unit, comprising simply a cabinet containing an air-cooled refrigerator compressor and a condenser chamber together with appropriate connections and switching, or it is available complete with a whole range of accessories: vacuum pump, gauge, process attachments, coupling kits, and so on.

This gives customers the option of making use of any equipment they may already have, such as pumps or gauges, but if a complete unit is required the total specification can be tailored exactly to the requirement.

In either case initial expenditure can be kept to a minimum, while the capability of the unit can be expanded at any time by the purchase of further accessories.

The basic Modulyo, which measures 535 mm wide by 622 mm deep, can be bench or trolley mounted. Any suitable vacuum pump can be fitted to a standard 16 mm pipeline from the condenser chamber: the Edwards ED50 two-stage rotary pump, with ultimate vacuum of 1 O-2 to 2 x 1 O-2 torr and a

383