Dry vacuum pump technology reduces maintenance

Edited by the Engineeringtalk editorial team Jun 11, 2003

Cambustion has selected the XDS range of oil-free vacuum scroll pumps for its fast response exhaust analysers.

Leading developer of exhaust gas analysis equipment for motor manufacturers, Cambustion, has selected the XDS range of oil-free vacuum scroll pumps from BOC Edwards for its fast response exhaust analysers.

As a result, the company's customers which include leading names such as Ford, General Motors and Volkswagen will benefit from significantly reduced pump maintenance and much longer service intervals.

Cambustion's range includes specialist analysers for measuring nitrogen and carbon compounds (NOx, CO and CO2), hydrocarbons and other chemicals in engine exhaust gases.

Such measurements are useful in engine design and characterisation, applications include transient fuelling calibration, NOx trap purging and cold start combustion analysis.

Cambustion offers custom-built and standard systems, all of which feature a fast response time, allowing users to carry out very close analysis of changes in exhaust gases with every engine stroke.

This fast response is achieved by the location of the detector close to the sampling point in the engine, and use of a vacuum pump to create a low pressure (about 0.5bar(a)).

Exhaust gases are corrosive; they create a lot of wear and tear on the vacuum pump.

Previously Cambustion's customers found they needed to change the oil in their traditional oil-sealed pumps every 500 or 1000h, depending on the application.

"We had feedback from our customers that they were not happy with the maintenance requirement of the oil-sealed pumps.

They wanted a longer service interval", explains Dr Mark Peckham, Director of Products, Cambustion.

"We researched a number of vacuum suppliers and their products and chose the XDS range from BOC Edwards because we found it to be more robust and therefore more reliable than competitive products".

Cambustion now uses BOC Edward's largest pump in the range, XDS35i, in its top of the range custom analysis systems, and the smaller XDS10 on its standard 500-series equipment.

These pumps are all truly user serviceable; with no oil to change or dispose of, typically annual maintenance can be completed in about 20min without special tools.

The XDS35i pumping system has no bearings or lubrication products in the vacuum environment.

Inverter driven from a single phase supply, with a very quiet "pancake" motor, it is a good choice for large instrument applications, giving constant pumping performance anywhere in the world.

One simple switch changes voltage selection from high to low, 100 to 120V 50/60Hz and 200 to 230V 50/60Hz, giving easy access to a worldwide dry pumping solution.

Says Dr Peckham: "The technical support provided by BOC Edwards is very good.

For example, they provide user manuals - hard and soft copies - in other languages including Japanese.

We found this useful with our international customer base".